# SRC TR 99-002



# FINAL REPORT


# Aerobic Biodegradation of Organic Chemicals

in Environmental Media: A Summary of Field and Laboratory Studies

Prepared by: Dallas Aronson Mario Citra Kirsten Shuler Heather Printup Philip H. Howard Environmental Science Center Syracuse Research Corporation 6225 Running Ridge Road North Syracuse, NY 13212-2509

Prepared for: U.S. Environmental Protection Agency, Athens, GA

January 27, 1999

# ii TABLE OF CONTENTS
1. PURPOSE
.................................................................1 2. TECHNICAL APPROACH
....................................................1 2.1. Literature Search
.....................................................1 2.2. Definition and Use of Biodegradation Rate Constants
..........................3 2.2.1.Zero-Order Rate Constants
.....................................3 2.2.2.First-Order Rate Constants
.....................................5 2.2.3. Mineralization Rate Constants Versus Primary Biodegradation Rate Constants5 2.3. Calculation of First-Order Rate Constants
..................................6 2.3.1.Laboratory Studies
............................................6 2.3.2.Field andin situ

Microcosm Studies
...............................8 3. RESULTS
................................................................10 3.1. BTEX Compounds
..................................................11 3.1.1. Benzene
...................................................12 3.1.2. Toluene
....................................................27 3.1.3. Ethylbenzene
................................................48 3.1.4. o-Xylene
...................................................52 3.1.5. m-Xylene
..................................................61 3.1.6. p-Xylene
...................................................66 3.2. PAH (Polycyclic Aromatic Hydrocarbon) Compounds
........................71 3.2.1. Naphthalene
................................................72 3.2.2. Fluorene
...................................................83 3.2.3. Benzo(a)anthracene
...........................................87 3.2.4. Chrysene
..................................................94 3.2.5. Fluoranthene
...............................................100 3.2.6. Pyrene
...................................................103 3.2.7. Benzo(a)pyrene
.............................................109 3.3. Chlorinated Aliphatic Compounds
......................................115 3.3.1. Tetrachloroethylene
..........................................115 3.3.2. Dichloromethane
............................................120 3.4. Phenol and Substituted Phenols
........................................122 3.4.1. Phenol
...................................................122 3.4.2. o-Cresol
..................................................133 3.4.3. m-Cresol
.................................................136 3.4.4. p-Cresol
..................................................140 3.5. Ketones
..........................................................145 3.5.1. Acetone
..................................................145

# iii 3.5.2. Methyl ethyl ketone
..........................................149 3.6. Miscellaneous
.....................................................151 3.6.1. Bis(2-ethylhexyl)phthalate
.....................................151 3.5.2. Methanol
.................................................158 4. SUMMARY
..............................................................161 5. REFERENCES
...........................................................164

# iv LIST OF TABLES Table 1. Final list of compounds
...................................................2 Table 2. Aerobic biodegradation rate constant values for benzene
.........................15 Table 3. Aerobic biodegradation rate constant values for toluene
..........................30 Table 4. Aerobic biodegradation rate constant values for ethylbenzene
......................49 Table 5. Aerobic biodegradation rate constant values for o-xylene
.........................54 Table 6. Aerobic biodegradation rate constant values for m-xylene
.........................63 Table 7. Aerobic biodegradation rate constant values for p-xylene
.........................68 Table 8. Aerobic biodegradation rate constant values for naphthalene
.......................74 Table 9. Aerobic biodegradation rate constant values for fluorene
..........................84 Table 10. Aerobic biodegradation rate constant values for benzo(a)anthracene
................89 Table 11. Aerobic biodegradation rate constant values for chrysene
........................96 Table 12. Aerobic biodegradation rate constant values for fluoranthene
....................101 Table 13. Aerobic biodegradation rate constant values for pyrene
........................105 Table 14. Aerobic biodegradation rate constant values for benzo(a)pyrene
..................111 Table 15. Aerobic biodegradation rate constant values for tetrachloroethylene
...............117 Table 16. Aerobic biodegradation rate constant values for dichloromethane
.................121 Table 17. Aerobic biodegradation rate constant values for phenol
.........................124 Table 18. Aerobic biodegradation rate constant values for o-cresol
.......................134 Table 19. Aerobic biodegradation rate constant values for m-cresol
.......................137 Table 20. Aerobic biodegradation rate constant values for p-cresol
.......................141 Table 21. Aerobic biodegradation rate constant values for acetone
........................147 Table 22. Aerobic biodegradation rate constant values for methyl ethyl ketone
...............150 Table 23. Aerobic biodegradation rate constant values for bis(2-ethylhexyl)phthalate
..........153 Table 24. Aerobic biodegradation rate constant values for methanol
.......................159 Table 25. Summary of median and range of aerobic biodegradation rate constant values for compounds listed in document
.............................................163

# v LIST OF FIGURES Figure 1a. Frequency histogram for the published primary biodegradation rate constant values for benzene.
..............................................................13 Figure 1b. Frequency histogram for the published mineralization rate constant values for benzene.
. .14 Figure 2a. Frequency histogram for the published primary biodegradation rate constant values for toluene.
...............................................................28 Figure 2b. Frequency histogram for the published mineralization rate constant values for toluene.
...29 Figure 3. Frequency histogram for the published primary biodegradation rate constant values of ethylbenzene.
...........................................................48Figure 4. Frequency histogram for the published primary biodegradation rate constant values for oxylene.
................................................................53Figure 5. Frequency histogram for the published primary biodegradation rate constant values of mxylene.
................................................................62Figure 6. Frequency histogram for the published primary biodegradation rate constant values of pxylene.
................................................................67 Figure 7a. Frequency distribution histogram for the published primary biodegradation rate constant values of naphthalene.
.....................................................73 Figure 7b. Frequency distribution histogram for the published mineralization rate constant values of naphthalene.
............................................................73 Figure 8a. Frequency distribution histogram for the published primary biodegradation rate constant values of fluorene.
.......................................................83 Figure 8b. Frequency distribution histogram for the published mineralization rate constant values of fluorene
...............................................................83 Figure 9a. Frequency distribution histogram for the published primary biodegradation rate constant values of benzo(a)anthracene.
...............................................87 Figure 9b. Frequency distribution histogram for the published mineralization rate constant values of benzo(a)anthracene.
......................................................88 Figure 10a. Frequency distribution histogram for the published primary biodegradation rate constant values of chrysene.
.......................................................94 Figure 10b. Frequency distribution histogram for the published mineralization rate constant values of chrysene.
..............................................................95 Figure 11. Frequency histogram for the published primary biodegradation rate constant values of fluoranthene.
..........................................................100 Figure 12a. Frequency distribution histogram for the published primary biodegradation rate constant values of pyrene.
.......................................................103 Figure 12b. Frequency distribution histogram for the published mineralization rate constant values of pyrene...............................................................104 Figure 13a. Frequency histogram for the published primary biodegradation rate constant values of benzo(a)pyrene.
........................................................109

# vi

Figure 13b. Frequency histogram for the published mineralization rate constant values of benzo(a)pyrene.
........................................................110 Figure 14. Frequency histogram for the published primary biodegradation rate constant values of dichloromethane.
.......................................................120 Figure 15a. The frequency histogram for the published primary biodegradation rate constant values of phenol.
...............................................................123 Figure 15b. The frequency histogram for the published mineralization rate constant values of phenol.123Figure 16. Frequency histogram for the published primary biodegradation rate constant values of ocresol.
...............................................................133Figure 17. Frequency histogram for the published primary biodegradation rate constant values of mcresol.
...............................................................136Figure 18. Frequency histogram for the published primary biodegradation rate constant values of pcresol.
...............................................................140 Figure 19. Rate constant versus initial concentration of acetone in a shallow stream.
...........145 Figure 20a. The frequency histogram for the published primary biodegradation rate constant values of acetone...............................................................146 Figure 20b. The frequency histogram for the published primary biodegradation rate constant values of acetone...............................................................146 Figure 21a. Frequency histogram for the published primary biodegradation rate constant values of bis(2-ethylhexyl)phthalate.
................................................152 Figure 21b. Frequency histogram for the published mineralization rate constant values of bis(2- ethylhexyl)phthalate.
.....................................................152 Figure 22. Frequency histogram for the published primary biodegradation rate constant values of methanol.
.............................................................158

# 1

1. PURPOSE In the following document, Syracuse Research Corporation (SRC) has reviewed the available aerobic biodegradation literature for several common organic chemicals and identified biodegradation rate constants from these studies. Unlike the anaerobic biodegradation rate constant database previously compiled (Aronson and Howard, 1997), the aerobic biodegradation rate constant database includes rate constant information from soil, surface water, and sediment as well as aquifer environments. This project has been completed to demonstrate that in many cases, a large amount of data is available from a variety of studies showing either the ability or inability of a particular compound of interest to degrade in the environment.
2. TECHNICAL APPROACH 2.1. Literature Search A list of 25 compounds was initially received from the U.S. EPA. A rapid search of the BIOLOG file of the Environmental Fate Data Base (EFDB) (Howard et. al., 1986) for compounds with aerobic studies revealed that four of the listed compounds did not have appropriate data available for input into the database (cyanide, vinyl acetate, methyl isobutyl ketone and cyanide). These compounds were dropped from the list. However, the compound “xylene” was separated into its three isomers and data were collected for each isomer individually. These changes resulted in a final list of 23 compounds (Table 1) for which biodegradation rate information was then summarized. The literature compilation began with an electronic search of two files in SRC’s EFDB, DATALOG and BIOLOG, as sources of extensive biodegradation information. Currently, there are over 315,000 catalogued records for 15,965 compounds in DATALOG and nearly 62,000 records for 7,820 compounds in BIOLOG. BIOLOG search terms were used to identify aerobic studies with a mixed population of microbes from soil, sediment, or water. DATALOG was searched for useful field, ecosystem, and biodegradation studies. Relevant papers were retrieved and summarized in the database. In addition to the literature searches, the reference section of every retrieved paper was scanned in order to identify additional relevant articles. To be included in this database, the study was required: 1) to use soil, aquifer material, groundwater, aerobic sediment, or surface water and 2) to be incubated under aerobic conditions. Studies where the environmental material was seeded with microorganisms from other sources(e.g.sewage, anaerobic sediment, and enrichment culture experiments) were not included. The database was constructed in PARADOX with fields for information about the site including location and type of site (e.g.spill site, industrial location, pristine site, landfill), the sampling protocol and method of analysis, the type of study (e.g.field, laboratory microcosm,in situ microcosm), whether the compound was present alone or found in the presence of others, pH, temperature, dissolved oxygen concentrations, redox conditions, initial and final concentrations of the compound, a

# 2

published or calculated rate constant, length of the study, lag period, control results, identification of reaction products, general comments (to accommodate other important information) and an abbreviated reference from which the information was retrieved. Table 1.Final list of compounds Chemical Name CAS Number Acetone 000067-64-1 Benzene 000071-43-2 Benzo(a)anthracene 000056-55-3 Benzo(a)pyrene 000050-32-8 Bis(2-ethylhexyl)phthalate 000117-81-7 Chrysene 000218-01-9 m-Cresol 000108-39-4 o-Cresol 000095-48-7 p-Cresol 000106-44-5 Dichloromethane (methylene chloride) 000075-09-2 Ethylbenzene 000100-41-4 Fluoranthene 000206-44-0 Fluorene 000086-73-7 Methanol 000067-56-1 Methyl ethyl ketone 000078-93-3 Naphthalene 000091-20-3 Phenol 000108-95-2 Pyrene 000129-00-0 Tetrachloroethylene 000127-18-4 Toluene 000108-88-3 m-Xylene 000108-38-3 o-Xylene 000095-47-6 p-Xylene 000106-42-3

# 3 (1)

(2)

(3) 2.2. Definition and Use of Biodegradation Rate Constants Over time, a compound will biodegrade at a particular rate and the biodegradation kinetics will be dependent on the environmental conditions and the availability and concentration of the substrate. The Monod equation was developed to describe the growth of a population of microbes in the presence of a carbon source. At low concentrations of substrate, the microbial population is small. With increasing substrate concentrations, the microbial population grows until a maximum growth rate is reached. This is mathematically described by:

where μ=growth rate of the microbe, S=substrate concentration, μ max

# =maximum growth rate of the microbe, and Ks

# =a constant defined as the value of S at which μ=0.5μ max

# . The Monod equation is best used when the microbial population is growing in size in relation to the substrate concentration (Alexander, 1994). Both first and zero-order rate constants are calculated when little to no increase in microbial cell numbers is seen (Schmidt et. al., 1985). This will occur where the cell density is high compared to the substrate concentration. In this case, biodegradation kinetics are better represented by the classic Michaelis-Menton equation for enzyme kinetics. This equation assumes that the reaction rate of the individual cells and not the microbial population is increasing in relation to increasing substrate concentrations:

wherev=reaction rate (μ in the Monod equation), V max

# =maximum reaction rate (μ max

# in the Monod equation), and K m

# is the Michaelis constant (Ks

# in the Monod equation) (Alexander, 1994). 2.2.1.Zero-Order Rate Constants A zero-order rate constant is calculated when the substrate concentration is much greater than K m

# so that as the substrate is biodegraded, the rate of biodegradation is not affected,i.e.loss is independent of substrate concentration. The rate of a zero-order reaction is linear (a constant amount of the substrate is lost per unit of time) and is represented by the differential:

# 4 (4)

and the integral:

where S0

# =initial substrate concentration, S=substrate concentration at time=t, and k 0

# =the zero-order rate constant (expressed as concentration/time,e.g. μg/L/day). In the aerobic biodegradation database, zero-order rate constants are reported where the author has determined this value. If the author did not specify that the zero-order rate constant was a better measurement of the kinetics, this value was placed in the rate constant comments field and a SRCcalculated first-order rate constant was placed in the rate constant field. If it was specified that zeroorder rate kinetics were superior in describing the loss of a compound in the measured system, the zero-order rate constant was placed in the rate constant field and a first-order rate constant calculated by SRC was reported in the rate constant comment field. When sufficient information was not present in the paper to convert the reported values to a first-order rate constant, then the zero-order rate constant was placed in the rate constant field. If a rate constant was not reported by the study authors and a value could be determined from the presented experimental data, SRC assumed first-order rate kinetics. A more accurate but time consuming approach would have been to plot the substrate concentration versus time. A straight line would signify zero-order kinetics and an exponential curve (or a straight line on a log linear paper) would indicate first-order kinetics. Priority was given to the determination of a first-order rate constant as many environmental models require the input of a first-order rate constant. This may not be strictly correct in all situations, such as when the substrate is present at high concentrations (above K m

# ), when substrate concentrations are toxic to the microbial population, when another substrate(s) is limiting the biodegradation rate or when the microbial population is significantly increasing or decreasing in size (Chapelle et. al., 1996). Recently, the common use of first-order rate constant values to describe the kinetics of biodegradationloss in natural systems has been criticized. Bekins et. al. (1998) suggest that the automatic use of firstorder kinetics without first determining whether the substrate concentration is less than the halfsaturation constant, K m

# , is incorrect and can lead to substantial miscalculations of the biodegradation rate of a studied compound. Using first-order kinetics where the substrate concentration is higher than Km

# will lead to an overprediction of the biodegradation rate, whereas in circumstances where the substrate concentration is much lower, the biodegradation rate is expected to be underestimated. Buscheck et. al. (1993) state that first-order rate constants are generally appropriate for soluble plumes where a contaminant concentration of less than 1 mg/L is present. However, a database of LUFT sites in California (Rice et. al., 1995) reports that benzene concentrations are greater than 2 mg/L at 625 of 1092 sites (Bekins et. al., 1998). This suggests that concentrations at spill sites may often exceed the

# 5 (5)

(6) Km

# value and that first-order kinetics may not adequately represent the biodegradation of the studied compound. First-order rate constants are, however, commonly used to describe kinetics in natural systems often because of the lack of sufficient data points and the ease with which these values can be calculated. Salanitro (1993) reports that several studies where BTEX concentrations range from <1 to 5000 ppb are adequately described by first-order kinetics. 2.2.2.First-Order Rate Constants First-order rate constants are used as a convenient approximation of the kinetics of degradation of test substrates where there is no growth of the microbial population and a low concentration of the test substrate is present. Under these circumstances, the substrate concentration is lower than K m

# and, over time, both the concentration of substrate and rate of degradation drop in proportion with each other. Thus, unlike zero-order kinetics, the rate of biodegradation in a first-order reaction is dependent on the substrate concentration and is represented by the differential:

and the integral:

where S0

# =initial substrate concentration, S=substrate concentration at time=t, and k1

# =the first-order rate constant. During first-order rate reactions, the loss of substrate is exponential and follows a logarithmic curve. The rate constant is used to correlate the rate of the reaction with time. In a first-order reaction, a constant percent of the substrate is lost with time and the rate is described by either percent per time or the half-life. The half-life is easily visualized and is more commonly used. In contrast, a zero-order rate constant by definition equals the rate and is given in units of concentration/time. This is because the rate is linear and loss is constant with time. 2.2.3. Mineralization Rate Constants Versus Primary Biodegradation Rate Constants Many experiments summarized in the aerobic biodegradation database measured mineralization, defined as the complete biodegradation of a compound to carbon dioxide (CO2

# ) and water, in contrast to experiments which measure primary biodegradation, defined as the loss of the parent compound. These values are labeled as such in the rate constant comment field. Mineralization rate constants, in general, represent a minimum estimate of the total degradation of the compound; some of the CO2

# 6

produced during the degradation of the original compound can be assimilated into natural, often high molecular weight compounds and is then generally not measured. In addition, once produced, CO2

# can be bound as carbonate within the study system. Thus, it is expected that unless degradation proceeds rapidly and completely to CO2

# and water, that mineralization rate constant values will be less than those measured for primary biodegradation. 2.3. Calculation of First-Order Rate Constants Rate constants were collected from eight types of studies: laboratory column, field, groundwater grab sample, groundwater inoculum,in situ microcosm, lysimeter, reactor systems, and laboratory microcosm studies. The majority of studies summarized in the aerobic biodegradation database were laboratory microcosm studies. Laboratory microcosm studies can be further subdivided by the type of grab sample used: soil, sediment, surface water (including freshwater, estuarine, and seawater), and aquifer sediment and groundwater mixtures. The information obtained from each of these studies ranged from published first-order rate constants to simply an indication or contraindication of biodegradation. In some cases, insufficient data were available to assess whether biodegradation had occurred; for these studies, the rate constant field was left blank. When published first-order rate constants were not available, but sufficient information was presented to calculate a value, the rate constant was calculated by SRC. To ensure that loss of a contaminant was due to biodegradation and not just to abiotic or transport processes, an appropriate control was necessary to correct the data set. This can be a problem in laboratory studies that are incubated for a long period of time. Mercuric chloride is known to adsorb to the clay component of soil or aquifer sediment reducing its efficacy whereas sodium azide only inhibits bacteria containing cytochromes (Wiedemeier et. al., 1996). In addition, autoclaving may not be totally suitable, probably due to incomplete sterilization (Dobbins et. al., 1992). Information on the control used in the study, if available in the paper, is found in the database field “control results”. This field was used mainly to state the method of sterilization, or, in the case of field studies, whether a conservative tracer was used. If a control was used by the author(s) but the method not specified then “yes” was placed in the “control results” field (e.g.Davis and Madsen, 1996). If the paper does not state whether a control was used then this field was left blank. In some instances, a value is also included in the control field. When reported, this represents the loss of compound in the control over the study period. Studies often did not specify the loss found in the control, or the half-life or rate constant was directly reported by the author(s) and it was assumed, unless stated otherwise, that these values had been corrected for abiotic loss. 2.3.1.Laboratory Studies A control was used in laboratory studies to correct for non-biodegradation processes such as sorption to sediment or the glass jar, headspace volatilization,etc. Data from laboratory studies (column, groundwater grab sample, groundwater inoculum, reactor systems, and laboratory microcosm studies) were obtained from graphs or tables giving concentrations of the compound of interest at specific

# 7 (7)

(8) timepoints. Lag periods were observed at times which is usually attributed to the need for acclimation (Alexander, 1994). The initial microbial species present, their relative numbers, metabolic state and ability to acclimate once exposed to a chemical are likely to vary considerably depending upon environmental parameters such as temperature, conductivity, pH, oxygen concentration, redox potential, concentration, the presence/absence of electron acceptors and donors, and effects, both synergistic and antagonistic, of associated microflora (Howard and Banerjee, 1984). Lag periods were established either from the discussion in the paper or from looking at the data, and an appropriate initial and final concentration was chosen. The value used for the initial concentration was the concentration present following the lag period; therefore, all rate calculations for this project are independent of the associated lag period. Where a value of “0? 

# g/L” was reached as a final timepoint, an earlier time was chosen for the kinetics calculation, if possible; the use of zero as a denominator in the first-order rate equation would result in an “infinite” value. If the concentration reached a value other than zero but leveled off at that point for the remainder of the experiment, the final concentration and time were chosen at the point where the concentration leveled off. In column studies, the time field in the database contains the retention time for the column, which is the value (? 

# t) used to calculate the rate constant; column experiments were usually run for long periods of time, which would allow for the development of an acclimated microbial population. The initial and final concentrations of the control within the chosen time period were obtained and the experimental data corrected for the loss shown by the control using the following equation:

where:Cf,corr

# =corrected final concentration of the contaminant (corrected for nonbiodegradation loss Cf 

# =final contaminant concentration, uncorrected Z i

# =initial control concentration Z f 

# =final control concentration. A first-order rate constant was then calculated for laboratory data using the corrected final contaminant concentration as follows:

# 8

where: Ci

# =initial contaminant concentration Cf,corr

# =corrected final concentration of the contaminant (corrected for non-biodegradation loss) ? 

# t=time interval k1

# =first-order rate constant.
2.3.2.Field andin situMicrocosm Studies In situ microcosms were designed to isolate a portion of the aquifer in order to make measurements directly in the field. This device is essentially a pipe divided into a test chamber and an equipment chamber, with two screens that permit water to be pumped both into and out of the interior of the pipe. More detailed information can be found in Gillham et. al. (1990). Groundwater is pumped to the surface, spiked with the compounds of interest plus other nutrients and/or electron acceptors if wanted, and then reinjected. Because the test zone is isolated from the main aquifer, advective and dispersive processes are not important to the study results. Often, this method is used to give very specific results for a particular redox regime within an aquifer (Nielsen et. al., 1995). The data obtained from this type of study was similar to that for a laboratory microcosm where loss of substrate is monitored with time; rate constants were calculated using the same method as for the laboratory studies. In general, the field studies reported in this database are for aquifer environments. Only a limited number of aerobic aquifer studies were located, mainly because the oxygen initially present in groundwater will be rapidly used during oxidative degradation. This results in anaerobic conditions close to the source and within the contaminant plume. However, biodegradation data were reported for a few aerobic aquifer environments. Data from field studies were generally reported for 1) plume studies where monitoring wells were placed along the centerline of a contaminant plume or for 2) continuous injection experiments where monitoring wells were placed in fences along the flow path fairly close to the injection point (often 2 and 5 meters away). Loss of a contaminant over distance does not necessarily indicate that the compound has undergone biodegradation. Significant loss in concentration along a flow path is often reported for compounds simply due to non-biological processes such as advection, dispersion, sorption, and dilution. However, degradation is the only mechanism which leads to an actual loss of the contaminant. The most convenient way to correct for non-biodegradation processes in both plume and injection studies is to use compounds present in the contaminant plume or injection mixture that are 1) biologically recalcitrant and 2) have similar properties, such as Henry’s Law constant and soil sorption coefficient, as the contaminant of interest (Wiedemeier et. al., 1995). Most studies summarized in the aerobic biodegradation database used either chloride or bromide ion as a tracer satisfying the first condition of biological recalcitrance. The procedure for obtaining a normalized data set from an aquifer field study was taken from Wiedemeier et. al. (1996) and is again outlined in the report accompanying the anaerobic biodegradation database (Aronson and Howard, 1997). This method requires measurements of tracer and contaminant concentrations from a minimum of two points along a flow

# 9

path in order to correct for the loss of the compound of interest due to transport processes. A mass balance approach has also been used by some researchers (Barker et. al., 1987) to determine the rate of biodegradation of specific contaminants in groundwater during a field study. Mass flux of the studied contaminant through a line/cluster of wells (a transect) is recorded instead of monitoring loss of the contaminant at specific points down the middle of a plume, as is typical for a plume centerline study. Wiedemeier et. al. (1996), suggests that the calculations involved are approximate and that often many of the required parameters necessary for the modeling are not available.

# 10

3. RESULTS Biodegradation of organic compounds under aerobic conditions most often occurs when bacteria catalyze the breakdown of these molecules and then recover some of this chemical energy as ATP (adenosine triphosphate) which is absolutely necessary for maintenance of the bacterial cell. ATP is generated through a series of oxidation-reduction reactions (the electron transport chain) where electrons are sequentially transferred from one compound, the electron donor, to an electron acceptor. The final or terminal electron acceptor in aerobic respiration is oxygen. Dissolved oxygen concentrations of 1 mg/L or greater are considered to define aerobic conditions. During aerobic respiration, the oxygen present in the environment is converted to water and thus the dissolved oxygen content can decrease. This is particularly significant in closed systems, as in a confined aquifer, where conditions can quickly become anaerobic with the metabolism of high concentrations of organic chemicals. Thermodynamically, the reduction of molecular oxygen to water is very favorable for the participating microorganisms. Because hydrocarbons are generally chemically reduced (chlorinated aliphatics are an exception within the group of compounds in this paper) and stable, this is a preferred pathway over other redox pathways such as anaerobic chemical reduction. Aerobic biodegradation results in the oxidation of the original compound. Metabolism of aliphatic compounds generally proceeds initially byproduction of the alcohol and then oxidation to the carboxylic acid which is susceptible to betaoxidation. In pure culture studies, aromatic hydrocarbons have been shown to biodegrade generallywith the addition of one molecule of oxygen giving the dihydrodiol intermediate, usually with a cisstereochemistry. This intermediate is then oxidized forming the catechol which then allows forortho

ormeta- cleavage of the aromatic ring structure (Gibson, 1977). The data collected during this project were mainly from laboratory microcosm studies, a classification including grab sample studies (except for groundwater grab samples) for the purposes of this database. Groundwater grab samples were considered separately as it has been shown that a large majority of microorganisms responsible for biodegradation in the subsurface environment are associated with the aquifer sediment surface (Thomas et. al., 1987). Therefore, rates collected during groundwater grab studies may not be as rapid as those where aquifer sediment is included. Laboratory microcosm studies are believed to give very good evidence of biodegradation at a specific location and can provide an “absolute mass balance” on a particular contaminant. In addition, the formation and measurement of metabolites can definitively show the biodegradation of the contaminant of interest. However, results from a laboratory microcosm can be greatly influenced by many factors such as the source, collection, and condition of the grab sample (e.g.what is a representative source of material for that site?), the ratio of soil/sediment/aquifer sediment to water used in the microcosm, the type of sampling (repetitive or sacrificed), incubation conditions (e.g.substrate concentration, temperature), and the length of the study period (and its effect particularly on the initial microbial population during a long study period) (Wiedemeier et. al., 1996). If a sufficient supply of oxygen is not available to completely biodegrade the added organic compound/s then anaerobic conditions may prevail. The mixing of a natural sample

# 11

during its collection or the construction of a microcosm may also result in a “disturbance artifact” which is seen as an increase in the microbial activity of the sample (Davis and Olsen, 1990). However, the influence of transport processes such as volatilization and adsorption cannot be measured in a microcosm experiment. If consideration of these processes is important, then field studies can be used to provide environmentally relevant data for a specific site, essentially showing whether the compound of interest can or cannot be biodegraded at that location. The results for each compound are presented in the following sections. Separation of the data into mineralization and primary degradation studies was initially completed and each category was considered separately. A range was given to represent the dispersion of the data within the group as well as a median value, representing the central tendency of the data. In addition, frequency distribution histograms for the two types of studies are given for each compound with sufficient data. Within the subcategories of mineralization and primary degradation, each study was given equal weighting despite differences in how the study was carried out. Rate constants which were given as zero-order and could not be converted to first-order rate constants were not included in the statistical analysis. 3.1. BTEX Compounds The BTEX group is composed of the water-soluble and monoaromatic compounds benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene. In both laboratory and field studies, the biodegradation of all the BTEX compounds has been shown under aerobic conditions (Tables 2 to 7). There is a stoichometric requirement of 3 ppm O2

# to 1 ppm BTEX for the aerobic degradation of fuel hydrocarbons with rates of biodegradation appearing to slow for dissolved oxygen concentrations below 1 to 2 ppm in microcosm and field studies and below 1 ppm for soil column studies (Salanitro, 1993; Chiang et. al., 1989).Laboratory studies where 8 mg/L dissolved oxygen is initially present have been shown to rapidly biodegrade 2 mg/L or less of a BTEX mixture or a particular BTEX compound (Salanitro, 1993). The majority of studies located for the BTEX compounds were for aquifer environments.As reported earlier, many aquifers become anaerobic during contaminant biodegradation due to the use of oxygen in aerobic respiration. Replacement of this oxygen from upgradient of the source, plume edges, infiltration of precipitation, or from vadose or saturated zone recharge is slower than its use during aerobic metabolism. Thus, the concentration of oxygen often becomes the rate-limiting factor in the biodegradation of the BTEX compounds in aquifer environments. During laboratory studies this can be controlled by the addition of oxygen or hydrogen peroxide. Extrapolation of laboratory rate constants to field environments which are confined or semi-confined systems, however, should be made with caution both because oxygen conditions cannot be controlled as readily and because laboratory rates are often higher (up to an order of magnitude) than those reported from field experiments.

# 12

3.1.1. Benzene While benzene is considered recalcitrant under anaerobic conditions, most evidence currently available shows that this compound is moderately degradable in the presence of oxygen (Table 2). Degradation is thought to proceed via catechol to CO2

# (Ribbons and Eaton, 1992). 3.08 mg of oxygen are necessary to biodegrade 1 mg of benzene to CO2

# and water (Wiedemeier et. al., 1995). This calculation does not include the energy requirement for cell maintenance and thus is not a conservative value. However, the value of 3.1 mg oxygen to degrade 1 mg benzene is suggested as a conservative estimate (Wiedemeier et. al., 1995). Most of the located data for benzene under aerobic conditions were for aquifer environments. Field studies at six different locations consistently reported the biodegradation of benzene, giving half-life values ranging from 58 to 693 days. The longer half-life was associated with an uncontaminated aquifer study (American Petroleum Institute, 1994). Initial concentrations of up to 25 mg/L were biodegraded under field conditions (Davis et. al., 1994). Biodegradation of benzene was observed as well duringin situ microcosm studies at two locations. Half-lives ranged from 1.4 (Nielsen et. al., 1996) to 103 (Holm et. al., 1992) days with an average half-life of 4 days. The high half-life value represents biodegradation in the groundwater only section of thein situ microcosm; half-life values obtained in the aquifer sediment + groundwater section were significantly lower. By far the most common type of study used to observe the biodegradation of benzene under aerobic conditions is the laboratory microcosm. Mineralization half-lives for benzene in lab microcosm studies ranged from 7 (Kemblowski et. al., 1987) to 1195 days (Thomas et. al., 1990) with the high value representing a study from an uncontaminated site. Microcosms established with sediment from a contaminated and a biostimulated region in the aquifer, measured during the same study, showed more rapid mineralization rates. The average half-life for mineralization was 53 days. In comparison, microcosm studies measuring primary biodegradation reported half-lives ranging from 0.2 (Kjeldsen et. al., 1997) to 679 (Pugh et. al., 1996) days with an average value of 1.5 days. Initial concentrations of up to 50 mg/L (Kemblowski et. al., 1987) were reported in these experiments without obvious deleterious effect. In general, however, initial concentrations of 5 mg/L or less were utilized. No biodegradation was reported for four lab microcosm studies. A study by the American Petroleum Institute, 1994A, reports that benzene was not biodegraded in the presence of 85% methanol over 278 days. This result was not unexpected as sufficient oxygen was available to degrade only 5% of the initially added methanol. This suggests that anaerobic conditions may have occurred rapidly within this microcosm.Hunt and Alvarez, 1997 also report that benzene in the presence of 300 mg/L ethanol was not biodegraded over a period of 3 days. However, aquifer material collected from the same site and incubated without ethanol and either with or without nutrients was able to rapidly degrade benzene. Pristine aquifer sediment was unable to biodegrade benzene over a 7-day period; however, when creosote-contaminated aquifer sediment was used, greater than 31% of the initially added benzene was biodegraded over 7 days (Wilson et. al., 1986). While benzene was degraded in groundwater alone and in river water during a study by Vaishnav and Babeu (1987), it was not biodegraded in the

# 13 0 20 40 60 80

00.40.81.21.622.42.83.23.6

Rate constant (days-1

# )Frequency 

# presence of harbor water collected in Lake Superior. The addition of both nutrients and an enriched microbial culture isolated from sewage resulted in the biodegradation of this compound indicating that bacteria capable of biodegrading benzene were either not present or not present in sufficient numbers to significantly remove benzene in the natural harbor water over a 20-day period. Laboratory column experiments by Anid et. al. (1991) and Alvarez et. al. (1998) report that benzene was not biodegraded under certain circumstances. Anid et. al. (1991) reported that columns supplemented with hydrogenperoxide but not columns supplemented with nitrate were able to degrade benzene. The nitrateamended columns may have exhibited nitrate-reducing conditions as over 60 mg/L BTEX mixture was initially added. However, no attempt was made by the authors to distinguish through end product measurements whether conditions remained aerobic or became nitrate-reducing. Alvarez et. al. (1998) showed biodegradation of benzene in laboratory columns fed with acetate and benzoate as cosubstrates. However, preacclimated sediment exposed to acetate and sediment columns which received no preacclimation period were unable to biodegrade benzene while a column which had been preacclimated to benzoate readily biodegraded this column. The median for the primary biodegradation rate constant of benzene, considering all studies, is 0.096/day (N = 118); a range of not biodegraded to 3.3/day is reported. The median for the mineralization rate constant of benzene is 0.0013/day (N = 30); a range of not biodegraded to 0.087/day is reported. The frequency distribution histograms for this data are shown in figures 1a and 1b. Benzene is expected to biodegrade fairly readily under most aerobic environmental conditions.

Figure 1a.Frequency histogram for the published primary biodegradation rate constant values for benzene.

# 14 0 5 10 15 20

00.020.040.060.081

Rate constant (days-1

# )Frequency



# Figure 1b.Frequency histogram for the published mineralization rate constant values for benzene.

# 15

Table 2.Aerobic biodegradation rate constant values for benzene Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference

Benzene Canada Forces Base, Borden,

Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.001/day American Petroleum Institute (1994) Benzene Canada Forces Base, Borden,

Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.003/day American Petroleum Institute (1994) Benzene Canada Forces Base, Borden,

Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.004/day American Petroleum Institute (1994) Benzene Columbus Air Force Base,

Columbus, Miss. Aquifer sediment + groundwater Field 224 0.0066/day Stauffer,TB et. al. (1994)

Benzene Michigan Gas plant facility Aquifer sediment + groundwater Field 0.0088- 0.0095/day Chiang,CY et. al. (1986)

Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Field 1.25 mg/L 0.012/day Kemblowski,MW et. al. (1987) Benzene Canada Forces Base, Borden,

Ontario Uncontaminated Aquifer sediment + groundwater Field 2.36 mg/L 374-434 30 mg/day Barker,JF et. al. (1987)

Benzene Amsterdam, The

Netherlands Dune infiltration site Sediment Field <0.05 ug/L 7-49 Biodegrades Bosma,TNP et. al. (1996)

Benzene Eastern seaboard Contaminated Aquifer sediment + groundwater Field 25 mg/L Biodegrades Davis,JW et. al. (1994)

Benzene Vejen City, Jutland,

Denmark Landfill site Groundwater Groundwater grab sample 120 ug/L 90 0.0017/day Holm,PE et. al. (1992)

Benzene Traverse City, Michigan Jet fuel contamination Groundwater Groundwater grab sample 800 ug/L 28 0.003/day Thomas,JM et. al. (1987)

Benzene Contaminated Groundwater Groundwater grab sample 100 mg/L 24 0.0082/day 3 Chang,BV et. al. (1997)

Benzene Contaminated Groundwater Groundwater grab sample 100 mg/L 33 0.0084/day 5 Chang,BV et. al. (1997)

Benzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 17.5 mg/L 0.016/day Morgan,P et. al. (1993)

Benzene 12 km north of Lake

Superior, Minnesota Groundwater Groundwater grab sample 20 0.025/day Vaishnav,DD & Babeu,L (1987)

# Table 2.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 16 Benzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 17.5 mg/L 0.027/day Morgan,P et. al. (1993)

Benzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 0.478 mg/L 0.032/day Morgan,P et. al. (1993)

Benzene Vejen City, Jutland,

Denmark Landfill site Groundwater Groundwater grab sample 120 ug/L 90 0.033/day Holm,PE et. al. (1992)

Benzene Traverse City, Michigan Jet fuel contamination Groundwater Groundwater grab sample 800 ug/L 28 0.035/day Thomas,JM et. al. (1987)

Benzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 17.5 mg/L 0.037/day Morgan,P et. al. (1993)

Benzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 17.5 mg/L 0.038/day Morgan,P et. al. (1993)

Benzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 17.5 mg/L 0.039/day Morgan,P et. al. (1993)

Benzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 17.5 mg/L 0.043/day Morgan,P et. al. (1993)

Benzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 17.5 mg/L 0.045/day Morgan,P et. al. (1993)

Benzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 17.5 mg/L 0.05/day Morgan,P et. al. (1993)

Benzene NW Gainesville, Florida Groundwater Groundwater grab sample 1 mg/L 16 0.107/day 8 Delfino,JJ & Miles,CJ (1985)

# Table 2.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 17 Benzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 0.478 mg/L 0.11/day Morgan,P et. al. (1993)

Benzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 0.478 mg/L 0.13/day Morgan,P et. al. (1993)

Benzene Vejen City, Jutland,

Denmark Uncontaminated landfill site Groundwater Groundwater grab sample 100 ug/L 23 0.13/day Albrechtsen,HJ et. al. (1996)

Benzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 0.478 mg/L 0.16/day Morgan,P et. al. (1993)

Benzene Vejen City, Jutland,

Denmark Uncontaminated landfill site Groundwater + sterile quartz Groundwater grab sample 100 ug/L 12 0.268/day Albrechtsen,HJ et. al. (1996)

Benzene Vejen City, Jutland,

Denmark Uncontaminated landfill site Groundwater + sterile rock wool Groundwater grab sample 100 ug/L 30 0.297/day 23 Albrechtsen,HJ et. al. (1996)

Benzene Grindsted, Denmark Uncontaminated landfill site Groundwater + sterile quartz Groundwater grab sample 100 ug/L 7 0.329/day Albrechtsen,HJ et. al. (1996)

Benzene Grindsted, Denmark Uncontaminated landfill site Groundwater Groundwater grab sample 100 ug/L 32 0.338/day 25 Albrechtsen,HJ et. al. (1996)

Benzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 0.478 mg/L 0.35/day Morgan,P et. al. (1993)

Benzene Los Angeles, California Gasoline contamination Groundwater Groundwater grab sample 477 ug/L 2 0.38/day Karlson,U & Frankenberger,WTJr (1989) Benzene Industrial site Groundwater Groundwater grab sample 32 mg/L 16.25 0.467/day 10.4 Williams,RA et. al. (1997)

Benzene Grindsted, Denmark Uncontaminated landfill site Groundwater + sterile rock wool Groundwater grab sample 100 ug/L 23 0.70/day 19 Albrechtsen,HJ et. al. (1996)

Benzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 0.478 mg/L 1.1/day Morgan,P et. al. (1993)

# Table 2.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 18 Benzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 0.478 mg/L 180 ug/L/day Morgan,P et. al. (1993)

Benzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 0.478 mg/L 200 ug/L/day Morgan,P et. al. (1993)

Benzene Los Angeles, California Gasoline contamination Groundwater Groundwater grab sample 477 ug/L 1 3.3/day Karlson,U & Frankenberger,WTJr (1989) Benzene Forlev landfill, Korsoer,

Zealand Sanitary landfill Leachate Groundwater inoculum 100 ug/L 100 0.047/day 3 Lyngkilde,J et. al. (1988)

Benzene Forlev landfill, Korsoer,

Zealand Sanitary landfill Leachate Groundwater inoculum 100 ug/L 13 0.419/day 2 Lyngkilde,J et. al. (1988)

Benzene Forlev landfill, Korsoer,

Zealand Sanitary landfill Leachate Groundwater inoculum 100 ug/L 8 0.658/day 1 Lyngkilde,J et. al. (1988)

Benzene Forlev landfill, Korsoer,

Zealand Sanitary landfill Leachate Groundwater inoculum 100 ug/L 8 0.658/day 1 Lyngkilde,J et. al. (1988)

Benzene Vejen City, Jutland,

Denmark Landfill site Groundwater In situ microcosm 120 ug/L 0.0067/day Holm,PE et. al. (1992)

Benzene Vejen City, Jutland,

Denmark Landfill site Groundwater In situ microcosm 120 ug/L 0.0067/day Holm,PE et. al. (1992)

Benzene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 120 ug/L 0.033/day Holm,PE et. al. (1992)

Benzene Canadian Forces Base,

Borden, Ontario Aquifer sediment + groundwater In situ microcosm 345 ug/L 8 0.046/day Gillham,RW et. al. (1990)

Benzene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 120 ug/L 0.058/day Holm,PE et. al. (1992)

Benzene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 0.2/day 5 Nielsen,PH et. al. (1996)

Benzene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 0.3/day 1 Nielsen,PH et. al. (1996)

Benzene Vejen City, Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 48 0.5/day 6 Bjerg,PL et. al. (1996)

# Table 2.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 19 Benzene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 0.5/day 6 Nielsen,PH et. al. (1996)

Benzene Northern Michigan Gas plant facility Aquifer sediment Lab column 20 mg/L 4.6 0.501/day Anid,PJ et. al. (1993) Benzene Uncontaminated Aquifer sediment Lab column 193 ug/L >8 1-5 ug/day 3 Alvarez,PJJ et. al. (1998) Benzene Uncontaminated Aquifer sediment Lab column 193 ug/L 2 2-9 ug/day Alvarez,PJJ et. al. (1998) Benzene Uncontaminated Aquifer sediment Lab column 193 ug/L >8 3-7 ug/day 3 Alvarez,PJJ et. al. (1998) Benzene Swan Coastal Plain,

Australia Uncontaminated Aquifer sediment + groundwater Lab column 1060 ug/L 9.5/day Patterson,BM et. al. (1993)

Benzene Swan Coastal Plain,

Australia Uncontaminated Aquifer sediment + groundwater Lab column 1060 ug/L 9.5/day Patterson,BM et. al. (1993)

Benzene Uncontaminated Aquifer sediment Lab column 150 ug/L 2.5 Biodegrades Alvarez,PJJ et. al. (1998) Benzene Amsterdam, The

Netherlands Dune infiltration site Sediment Lab column 0.5 ug/L Biodegrades Bosma,TNP et. al. (1996)

Benzene Amsterdam, The

Netherlands Dune infiltration site Sediment Lab column 10-20 ug/L Biodegrades Bosma,TNP et. al. (1996)

Benzene Skaelskor, Denmark Uncontaminated Fractured clay Lab column 3.2 Biodegrades Broholm,K et. al. (1995) Benzene Wageningen, The

Netherlands Sediment Lab column 10-20 ug/L Biodegrades Bosma,TNP et. al. (1996)

Benzene Uncontaminated Aquifer sediment Lab column 150 ug/L 3 No biodegradation Alvarez,PJJ et. al. (1998)

Benzene Uncontaminated Aquifer sediment Lab column 150 ug/L 3 No biodegradation Alvarez,PJJ et. al. (1998)

Benzene Northern Michigan Gas plant facility Aquifer sediment Lab column 20 mg/L 4.6 No biodegradation Anid,PJ et. al. (1993)

Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.00058/day Thomas,JM et. al. (1990)

Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.00065- 0.00087/day Thomas,JM et. al. (1990)

Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.00072/day Thomas,JM et. al. (1990)

# Table 2.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 20 Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm0.002 ug/L 42 0.00077/day Thomas,JM et. al. (1990)

Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0008/day Thomas,JM et. al. (1990)

Benzene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.00102/day Pugh,LB et. al. (1996)

Benzene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.00102/day Pugh,LB et. al. (1996)

Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0012/day Thomas,JM et. al. (1990)

Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0012/day Thomas,JM et. al. (1990)

Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0012/day Thomas,JM et. al. (1990)

Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0013/day Thomas,JM et. al. (1990)

Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0013/day Thomas,JM et. al. (1990)

Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0016/day Thomas,JM et. al. (1990)

Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0017/day Thomas,JM et. al. (1990)

Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0019/day Thomas,JM et. al. (1990)

# Table 2.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 21 Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.002/day Thomas,JM et. al. (1990)

Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0021/day Thomas,JM et. al. (1990)

Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm0.002 ug/L 42 0.00315/day Thomas,JM et. al. (1990)

Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Lab microcosm 50 mg/L 70 0.0035/day Kemblowski,MW et. al. (1987) Benzene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.0039/day Pugh,LB et. al. (1996)

Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Lab microcosm 50 mg/L 70 0.0044/day Kemblowski,MW et. al. (1987) Benzene Canada Forces Base, Borden,

Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm2538 ug/L 114 0.006/day 21 American Petroleum Institute (1994A) Benzene Canada Forces Base, Borden,

Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 5.5 mg/L 80 0.006/day 13 Barker,JF et. al. (1987)

Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Lab microcosm 500 ug/L 14 0.016/day Kemblowski,MW et. al. (1987) Benzene Canada Forces Base, Borden,

Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm2491 ug/L 232 0.021/day <7 American Petroleum Institute (1994A) Benzene Canada Forces Base, Borden,

Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 1903 ug/L 232 0.024/day <7 American Petroleum Institute (1994A) Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Lab microcosm 5 mg/L 0.025- 0.0866/day Kemblowski,MW et. al. (1987) Benzene East Texas Woodcreosoting plant Aquifer sediment Lab microcosm 84 0.030/day Wilson,JT et. al. (1983B)

Benzene East Texas Woodcreosoting plant Aquifer sediment Lab microcosm 84 0.030/day Wilson,JT et. al. (1983B)

Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Lab microcosm 50 ug/L 14 0.031/day Kemblowski,MW et. al. (1987)

# Table 2.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 22 Benzene Canada Forces Base, Borden,

Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm2.6 mg/L 80 0.032/day Barker,JF et. al. (1987)

Benzene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 120 ug/L 90 0.033/day Holm,PE et. al. (1992)

Benzene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 120 ug/L 90 0.033/day Holm,PE et. al. (1992)

Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Lab microcosm 5 mg/L 14 0.036-0.043/day Kemblowski,MW et. al. (1987) Benzene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 120 ug/L 90 0.042/day Holm,PE et. al. (1992)

Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Lab microcosm 5 mg/L 0.043-0.139/day Kemblowski,MW et. al. (1987) Benzene Traverse City, Michigan Jet fuel contamination Aquifer sediment Lab microcosm 800 ug/L 28 0.043/day Thomas,JM et. al. (1987)

Benzene Lester River, St. Louis

County, MN River water Lab microcosm 20 0.044/day Vaishnav,DD & Babeu,L (1987) Benzene Conroe, Texas Creosote waste site Aquifer sediment Lab microcosm 7 0.046/day Wilson,JT et. al. (1986)

Benzene Eastern seaboard Contaminated Aquifer sediment + groundwater Lab microcosm 10 mg/L 35 0.0495/day 10 Davis,JW et. al. (1994)

Benzene Michigan Gas plant facility Aquifer sediment Lab microcosm 5000 ug/L 35 0.05/day Chiang,CY et. al. (1986) Benzene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 45 0.0535/day Pugh,LB et. al. (1996)

Benzene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 120 ug/L 90 0.058/day Holm,PE et. al. (1992)

Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Lab microcosm 50 ug/L 14 0.065-0.075/day Kemblowski,MW et. al. (1987) Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Lab microcosm 500 ug/L 14 0.065-0.075/day Kemblowski,MW et. al. (1987) Benzene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 150 ug/L 0.07/day Nielsen,PH et. al. (1996)

# Table 2.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 23 Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Lab microcosm 5 mg/L 14 0.075-0.099/day Kemblowski,MW et. al. (1987) Benzene Michigan Gas plant facility Aquifer sediment Lab microcosm 325 ug/L 14 0.085/day Chiang,CY et. al. (1986) Benzene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 24 0.096/day Pugh,LB et. al. (1996)

Benzene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 140 ug/L 31.5 0.121/day 2-7 Nielsen,PH & Christensen,TH (1994B) Benzene Canada Forces Base, Borden,

Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 1.7 mg/L 43 0.122/day Barker,JF et. al. (1987)

Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Lab microcosm 10 ug/L 0.154/day Kemblowski,MW et. al. (1987) Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Lab microcosm 50 ug/L 0.154/day Kemblowski,MW et. al. (1987) Benzene Gloucester landfill, Ottawa,

Canada Landfill site Aquifer sediment + groundwater Lab microcosm 580 ug/L 21 0.16/day Berwanger,DJ & Barker,JF (1988) Benzene Eastern seaboard Contaminated Aquifer sediment + groundwater Lab microcosm 1 mg/L 8 0.173/day Davis,JW et. al. (1994)

Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Lab microcosm 10 ug/L 0.198/day Kemblowski,MW et. al. (1987) Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Lab microcosm 50 ug/L 0.198/day Kemblowski,MW et. al. (1987) Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Lab microcosm 500 ug/L 0.198/day Kemblowski,MW et. al. (1987) Benzene Skidaway River, Georgia River water Lab microcosm 6 ug/L 1 0.2 ug/L/day Lee,RF (1977) Benzene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 150 ug/L 0.2/day 5 Nielsen,PH et. al. (1996)

Benzene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 150 ug/L 0.2/day 5 Nielsen,PH et. al. (1996)

Benzene Skidaway River, Georgia River water Lab microcosm 12 ug/L 1 0.26 ug/L/day Lee,RF (1977) Benzene Indian River County,

Florida Gasoline spill Aquifer sediment + groundwater Lab microcosm 500 ug/L 0.277/day Kemblowski,MW et. al. (1987)

# Table 2.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 24 Benzene Soil Lab microcosm 132 mg VOC/kg soil 9 0.292 mg/day 5 English,CW & Loehr,RC (1991) Benzene Traverse City, MI JP-4 jet fuel spill Aquifer sediment Lab microcosm420 ug/L 14 0.326/day Wilson,BH et. al. (1990) Benzene Skidaway River, Georgia River water Lab microcosm24 ug/L 1 0.33 ug/L/day Lee,RF (1977) Benzene Sampson County, North

Carolina Gasoline contaminated site Aquifer sediment Lab microcosm2 mg/L 16 0.33/day Borden,RC et. al. (1997)

Benzene Traverse City, MI JP-4 jet fuel spill Aquifer sediment Lab microcosm450 ug/L 14 0.38/day Wilson,BH et. al. (1990) Benzene Santa Catarina Island, Brazil Uncontaminated Aquifer sediment Lab microcosm20 mg/L 9 0.46/day Hunt,CS & Alvarez,PJJ (1997) Benzene Sampson County, North

Carolina Gasoline contaminated site Aquifer sediment Lab microcosm2 mg/L 10 0.53/day Borden,RC et. al. (1997)

Benzene Michigan Gas plant facility Aquifer sediment Lab microcosm 340 ug/L 7 0.56/day Chiang,CY et. al. (1986) Benzene Grindsted, Denmark Uncontaminated landfill site Aquifer sediment + groundwater Lab microcosm 100 ug/L 5 0.576/day Albrechtsen,HJ et. al. (1996)

Benzene Santa Catarina Island, Brazil Uncontaminated Aquifer sediment Lab microcosm20 mg/L 11 0.65/day 4.5 Hunt,CS & Alvarez,PJJ (1997) Benzene Grindsted, Jutland,

Denmark Grindsted landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 5 0.701/day Albrechtsen,HJ et. al. (1997)

Benzene Michigan Gas plant facility Aquifer sediment Lab microcosm 50 ug/L 35 0.8/day Chiang,CY et. al. (1986) Benzene Traverse City, MI JP-4 jet fuel spill Aquifer sediment Lab microcosm 3.7 mg/L 7 0.84/day Hutchins,SR (1991) Benzene Grindsted, Jutland,

Denmark Grindsted landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 4 0.877/day Albrechtsen,HJ et. al. (1997)

Benzene Vejen City, Jutland,

Denmark Vejen landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 4 0.877/day Albrechtsen,HJ et. al. (1997)

Benzene Vejen City, Jutland,

Denmark Vejen landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 4 0.877/day Albrechtsen,HJ et. al. (1997)

Benzene Jurere Beach, Florianopolis,

Brazil Uncontaminated Aquifer sediment Lab microcosm20 mg/L 5 0.922/day Corseuil,HX et. al. (1997)

Benzene Michigan Gas plant facility Aquifer sediment Lab microcosm 1000 ug/L 35 0.95/day Chiang,CY et. al. (1986) Benzene Michigan Gas plant facility Aquifer sediment Lab microcosm 500 ug/L 35 0.95/day Chiang,CY et. al. (1986)

# Table 2.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 25 Benzene Vejen City, Jutland,

Denmark Uncontaminated landfill site Aquifer sediment + groundwater Lab microcosm 100 ug/L 3 1.0/day Albrechtsen,HJ et. al. (1996)

Benzene Northen Michigan Gas plant facility Aquifer sediment Lab microcosm 10-110 mg/L 1.09/day Alvarez,PJJ et. al. (1991) Benzene Santa Catarina Island, Brazil Uncontaminated Aquifer sediment Lab microcosm20 mg/L 2.6 1.5/day Hunt,CS & Alvarez,PJJ (1997) Benzene Vejen City, Jutland,

Denmark Vejen landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 2 1.75/day Albrechtsen,HJ et. al. (1997)

Benzene Holbaek,Western Sealand,

Denmark Skellingsted landfill Soil Lab microcosm 800-900 ug/L 2.5 1.9/day 0.63 Kjeldsen,P et. al. (1997)

Benzene Santa Catarina Island, Brazil Uncontaminated Aquifer sediment Lab microcosm20 mg/L 2.25 1.9/day 1 Hunt,CS & Alvarez,PJJ (1997) Benzene Holbaek,Western Sealand,

Denmark Skellingsted landfill Soil Lab microcosm 600 ug/L 0.83 3.3/day Kjeldsen,P et. al. (1997)

Benzene Holbaek,Western Sealand,

Denmark Skellingsted landfill Soil Lab microcosm 800-900 ug/L 2.8 3.3/day 1.67 Kjeldsen,P et. al. (1997)

Benzene North Charleston, South

Carolina JP-4 jet fuel contamination site Aquifer sediment Lab microcosm 30 ng/g 105 Limited Aelion,CM & Bradley,PM (1991)

Benzene Canada Forces Base, Borden,

Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm4528 ug/L 278 No biodegradation American Petroleum Institute (1994A) Benzene Conroe, Texas Uncontaminated Aquifer sediment Lab microcosm 7 No biodegradation Wilson,JT et. al. (1986)

Benzene NE of Barker's Island,

Superior Bay, WI Lake water Lab microcosm 20 No biodegradation Vaishnav,DD & Babeu,L (1987) Benzene Santa Catarina Island, Brazil Uncontaminated Aquifer sediment Lab microcosm20 mg/L 3 No biodegradation Hunt,CS & Alvarez,PJJ (1997) Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm 1 ug/L 35 No mineralization Thomas,JM et. al. (1990)

Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm 10 ug/L 35 No mineralization Thomas,JM et. al. (1990)

# Table 2.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 26 Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm 100 ug/L 35 No mineralization Thomas,JM et. al. (1990)

Benzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm 1000 ug/L 35 No mineralization Thomas,JM et. al. (1990)

Benzene North Charleston, South

Carolina JP-4 jet fuel contamination site Aquifer sediment Lab microcosm7 ng/g 120 No mineralization Aelion,CM & Bradley,PM (1991)

Benzene North Charleston, South

Carolina JP-4 jet fuel contamination site Aquifer sediment Lab microcosm7 ng/g 120 No mineralization Aelion,CM & Bradley,PM (1991)

Benzene Denmark Municipal landfill Leachate Reactor system 50 mg COD/L Biodegrades Lyngkilde,J et. al. (1992)

# 27

3.1.2. Toluene Biodegradation of toluene is expected to occur readily in aerobic environments (Table 3). Degradation is believed to proceed via 3-methylcatechol to CO2

# (Ribbons and Eaton, 1992). 3.13 mg of oxygen are necessary to biodegrade 1 mg of toluene to CO2

# and water (Wiedemeier et. al., 1995). This calculation does not include the energy requirement for cell maintenance and thus is not a conservative value. Most of the located data for toluene under aerobic conditions were for aquifer or soil environments. Aquifer field studies at two different locations reported the biodegradation of toluene giving half-life values ranging from 1.3 (McCarty et. al., 1998) to 77 (American Petroleum Institute, 1994) days. The longer half-life was associated with an uncontaminated aquifer study. Rate constants measured during a stream field study were very high giving half-lives less than 1 day in every case (Kim et. al., 1995). Biodegradation of toluene was observed as well during severalin situ microcosm studies at Vejen City, Denmark. Half-lives ranged from 1.7 (Nielsen et. al., 1996) to 103 (Holm et. al., 1992) days with an average half-life of 4.5 days. The high half-life value represents biodegradation in the groundwater only section of thein situ

microcosm; half-life values reached in the aquifer sediment + groundwater section were significantly lower. By far the most common type of study used to observe the biodegradation of toluene under aerobic conditions is the laboratory microcosm. Mineralization half-lives for toluene in lab microcosm studies ranged from 5 (Fan and Scow, 1993) to 693 days (Aelion et. al., 1989). The average half-life for mineralization was 36 days. In comparison, microcosm studies measuring primary biodegradation reported half-lives ranging from <1 (numerous studies, see Table 3) to 495 (Wilson et. al., 1984) days with an average value of 0.5 days. No biodegradation was reported for nine lab microcosm studies. A study by the American Petroleum Institute, 1994A, reports that toluene was not biodegraded in the presence of 85% methanol over 278 days. This result was not unexpected as sufficient oxygen was available to degrade only 5% of the initially added methanol. This suggests that anaerobic conditions may have occurred rapidly within this microcosm.In addition, the bacteria may have preferentially degraded the structurally simpler methanol or the concentration of methanol added may have been toxic to the indigenous bacterial population. Davis and Madsen, 1996, reported the biodegradation of toluene in three different soils under varying moisture and concentration levels. No biodegradation of toluene was reported in air-dried soils over 30 days; however, toluene added to the same soil, when 100% moisture was present, was biodegraded with a half-life of less than 1 day. Fan and Scow (1993) reported that toluene was not biodegraded in soil which had been incubated at a moisture level of 2.5%; however, half-lives of 2 and 71 days were measured for moisture levels of >16 and 5%, respectively. Initial concentrations of up to 50 mg/L (Davis and Madsen, 1996) were reported in these experiments without obvious deleterious effect. In general, however, initial concentrations of 5 mg/L or less were utilized. Concentrations of 500 mg/kg soil were shown to be inhibitory to the biodegradation of toluene

# 28 0 50 100 150 200

051015202530354045

Rate constant (days-1

# )Frequency 

# (Davis and Madsen, 1996) while at concentrations of 50 mg/kg soil or less, half-lives of less than 1 day were again measured. Similarly, Mu and Scow, 1994 reported that this compound was not degraded in soil samples exposed to 1000 mg/L toluene. Half-lives reported for the same soil but with toluene concentrations at 250 and 625 mg/L were 3 and 4 days, respectively. Inhibition of toluene degradation (present at 20 mg/L) in soil was shown when trichloroethylene was also present at concentrations of 20, 30, 50, and 60 mg/L giving half-lives of 2 days, 5 days, 60 days, and no biodegradation over the study period (42 days), respectively (Mu and Scow, 1994). Degradation of toluene may also be limited by concentrations of inorganic nutrients in its immediate environment. Allen-King et. al. (1994) reports that nitrogen limitation caused the degradation rate of toluene to be almost immeasurably slow in uncontaminated soil grab samples without added nutrients. However, when nitrogen was added, a half-life of 4.5 days was obtained for this compound in the same soil. Pristine aquifer sediment was unable to biodegrade benzene over a 7 day period; however, when creosote-contaminated aquifer sediment was used, greater than 18-22% of the initially added toluene was biodegraded over 7 days (Wilson et. al., 1986). Laboratory column experiments by Alvarez et. al. (1998) report that toluene was not biodegraded under certain circumstances. Biodegradation of toluene was observed in laboratory columns fed with acetate and benzoate as cosubstrates. However, preacclimated sediment exposed to acetate and columns which received no preacclimation were unable to biodegrade toluene while a column which had been preacclimated to benzoate readily biodegraded this compound. The median for the primary biodegradation rate constant of toluene is 0.2/day (N = 182); a range of not biodegraded to 42.5/day is reported. The median for the mineralization rate constant of toluene is 0.00895/day (N = 31); a range of not biodegraded to 0.149/day is reported. The frequency distribution histograms for this data are shown in figures 2a and 2b. Toluene is expected to biodegrade readily under most aerobic environmental conditions.

Figure 2a.Frequency histogram for the published primary biodegradation rate constant values for toluene.

# 29 0 5 10 15 20

00.020.040.060.080.10.120.140.16

Rate constant (days-1

# )Frequency



# Figure 2b.Frequency histogram for the published mineralization rate constant values for toluene.

# 30

Table 3.Aerobic biodegradation rate constant values for toluene Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference

Toluene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.009/day American Petroleum Institute (1994) Toluene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.009/day American Petroleum Institute (1994) Toluene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.013/day American Petroleum Institute (1994) Toluene Edwards AFB, California TCE-contaminated GW plume Aquifer sediment + groundwater Field 1.8-2.7 mg/L 10 0.52-0.56/day McCarty,PL et. al. (1998)

Toluene East Drainage Ditch,

Massachusetts Tanning and chemical manufacture Stream water Field 172-381 mg/m3 13.7/day Kim,H et. al. (1995)

Toluene East Drainage Ditch,

Massachusetts Tanning and chemical manufacture Stream water Field 59-214 mg/m3 19.44/day Kim,H et. al. (1995)

Toluene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 1.75 mg/L 270 37 mg/day Barker,JF et. al. (1987)

Toluene East Drainage Ditch,

Massachusetts Tanning and chemical manufacture Stream water Field 127-332 mg/m3 4.8/day Kim,H et. al. (1995)

Toluene East Drainage Ditch,

Massachusetts Tanning and chemical manufacture Stream water Field 149-325 mg/m3 41.52/day Kim,H et. al. (1995)

Toluene Contaminated Groundwater Groundwater grab sample 100 mg/L 24 0.0018/day Chang,BV et. al. (1997)

Toluene Contaminated Groundwater Groundwater grab sample 100 mg/L 24 0.00214/day Chang,BV et. al. (1997)

Toluene Vejen City, Jutland,

Denmark Landfill site Groundwater Groundwater grab sample 120 ug/L 90 0.0025/day Holm,PE et. al. (1992)

Toluene Clarke County, Georgia University of Georgia landfill Groundwater Groundwater grab sample 24.4 ug/L 3 0.031/day Armstrong,AQ et. al. (1991)

Toluene Clarke County, Georgia University of Georgia landfill Groundwater Groundwater grab sample 26.4 ug/L 3 0.031/day Armstrong,AQ et. al. (1991)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 31 Toluene Clarke County, Georgia University of Georgia landfill Groundwater Groundwater grab sample 37.2 ug/L 3 0.032/day Armstrong,AQ et. al. (1991)

Toluene Clarke County, Georgia University of Georgia landfill Groundwater Groundwater grab sample 24.9 ug/L 3 0.037/day 0.5-1 Armstrong,AQ et. al. (1991)

Toluene Clarke County, Georgia University of Georgia landfill Groundwater Groundwater grab sample 31.4 ug/L 3 0.037/day Armstrong,AQ et. al. (1991)

Toluene Clarke County, Georgia University of Georgia landfill Groundwater Groundwater grab sample 30.6 ug/L 3 0.040/day 0.5-1 Armstrong,AQ et. al. (1991)

Toluene Clarke County, Georgia University of Georgia landfill Groundwater Groundwater grab sample 21.4 ug/L 3 0.043/day Armstrong,AQ et. al. (1991)

Toluene Clarke County, Georgia University of Georgia landfill Groundwater Groundwater grab sample 29.7 ug/L 3 0.044/day Armstrong,AQ et. al. (1991)

Toluene Clarke County, Georgia University of Georgia landfill Groundwater Groundwater grab sample 27.4 ug/L 3 0.046/day Armstrong,AQ et. al. (1991)

Toluene Vejen City, Jutland,

Denmark Landfill site Groundwater Groundwater grab sample 120 ug/L 90 0.05/day Holm,PE et. al. (1992)

Toluene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 1.7 mg/L 0.087/day Morgan,P et. al. (1993)

Toluene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 1.7 mg/L 0.093/day Morgan,P et. al. (1993)

Toluene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 1.7 mg/L 0.10/day Morgan,P et. al. (1993)

Toluene Ottawa, Canada South Gloucester landfill Groundwater Groundwater grab sample 1000 ug/L 18 0.105/day Harrison,EM & Barker,JF (1987)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 32 Toluene Vejen City, Jutland,

Denmark Uncontaminated landfill site Groundwater + sterile rock wool Groundwater grab sample 100 ug/L 30 0.11/day Albrechtsen,HJ et. al. (1996)

Toluene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 1.7 mg/L 0.12/day Morgan,P et. al. (1993)

Toluene Vejen City, Jutland,

Denmark Uncontaminated landfill site Groundwater Groundwater grab sample 100 ug/L 23 0.126/day Albrechtsen,HJ et. al. (1996)

Toluene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 1.7 mg/L 0.13/day Morgan,P et. al. (1993)

Toluene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 1.7 mg/L 0.14/day Morgan,P et. al. (1993)

Toluene Grindsted, Denmark Uncontaminated landfill site Groundwater + sterile rock wool Groundwater grab sample 100 ug/L 23 0.172/day 10 Albrechtsen,HJ et. al. (1996)

Toluene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 1.7 mg/L 0.19/day Morgan,P et. al. (1993)

Toluene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 1.7 mg/L 0.19/day Morgan,P et. al. (1993)

Toluene Grindsted, Denmark Uncontaminated landfill site Groundwater Groundwater grab sample 100 ug/L 33 0.254/day 24 Albrechtsen,HJ et. al. (1996)

Toluene Vejen City, Jutland,

Denmark Uncontaminated landfill site Groundwater + sterile quartz Groundwater grab sample 100 ug/L 12 0.276/day Albrechtsen,HJ et. al. (1996)

Toluene Grindsted, Denmark Uncontaminated landfill site Groundwater + sterile quartz Groundwater grab sample 100 ug/L 9 0.303/day Albrechtsen,HJ et. al. (1996)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 33 Toluene Industrial site Groundwater Groundwater grab sample 32 mg/L 16.25 0.327/day 12.5 Williams,RA et. al. (1997)

Toluene Gassehaven, Denmark Fuel oil contamination Groundwater Groundwater grab sample 110 ug/L 38 0.39/day 14 Aamand,J et. al. (1989)

Toluene Gassehaven, Denmark Fuel oil contamination Groundwater Groundwater grab sample 110 ug/L 78 0.42/day 56 Aamand,J et. al. (1989)

Toluene Gassehaven, Denmark Fuel oil contamination Groundwater Groundwater grab sample 110 ug/L 18 0.65/day 3.7 Aamand,J et. al. (1989)

Toluene Gassehaven, Denmark Fuel oil contamination Groundwater Groundwater grab sample 110 ug/L 18 0.65/day 3.7 Aamand,J et. al. (1989)

Toluene Ottawa, Canada South Gloucester landfill Groundwater Groundwater grab sample 1100 ug/L 6 0.898/day Harrison,EM & Barker,JF (1987)

Toluene Grindsted, Denmark Heavy oil contamination Groundwater Groundwater grab sample 500-1000 ug/L 6.2 1.0-1.11/day Arvin,E et. al. (1988)

Toluene Sandbjerg and

Gassehaven, Denmark Fuel oil + gasoline contamination Groundwater Groundwater grab sample 110 ug/L 10 1.0/day 0.7 Aamand,J et. al. (1989)

Toluene Gassehaven, Denmark Fuel oil contamination Groundwater Groundwater grab sample 110 ug/L 9 1.03/day Aamand,J et. al. (1989)

Toluene Gassehaven, Denmark Fuel oil contamination Groundwater Groundwater grab sample 110 ug/L 11 1.26/day 3.6 Aamand,J et. al. (1989)

Toluene Ottawa, Canada South Gloucester landfill Groundwater Groundwater grab sample 1500 ug/L 4 1.38/day Harrison,EM & Barker,JF (1987)

Toluene Denmark Groundwater Groundwater grab sample 200-1000 ug/L 5 2.65-3.45/day 3 Arvin,E et. al. (1988)

Toluene Gassehaven, Denmark Fuel oil contamination Groundwater Groundwater grab sample 500-1000 ug/L 2.3 2.67-2.96/day Arvin,E et. al. (1988)

Toluene Los Angeles, California Gasoline contamination Groundwater Groundwater grab sample 561 ug/L 0.96 3.8/day Karlson,U & Frankenberger,WTJr (1989)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 34 Toluene Los Angeles, California Gasoline contamination Groundwater Groundwater grab sample 561 ug/L 0.71 5.7/day Karlson,U & Frankenberger,WTJr (1989) Toluene Ganlose, Denmark Fuel oil contamination Groundwater Groundwater grab sample 500-1000 ug/L 6 No biodegradation Arvin,E et. al. (1988)

Toluene Horsholm, Denmark Gasoline contamination Groundwater Groundwater grab sample 500-1000 ug/L 6 No biodegradation Arvin,E et. al. (1988)

Toluene Forlev landfill, Korsoer,

Zealand Sanitary landfill Leachate Groundwater inoculum 100 ug/L 14 0.354/day 1 Lyngkilde,J et. al. (1988)

Toluene Forlev landfill, Korsoer,

Zealand Sanitary landfill Leachate Groundwater inoculum 100 ug/L 14 0.354/day 1 Lyngkilde,J et. al. (1988)

Toluene Forlev landfill, Korsoer,

Zealand Sanitary landfill Leachate Groundwater inoculum 100 ug/L 14 0.354/day 1 Lyngkilde,J et. al. (1988)

Toluene Vejen City, Jutland,

Denmark Landfill site Groundwater In situ microcosm 120 ug/L 0.0067/day Holm,PE et. al. (1992)

Toluene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 120 ug/L 0.033/day Holm,PE et. al. (1992)

Toluene Vejen City, Jutland,

Denmark Landfill site Groundwater In situ microcosm 120 ug/L 0.039/day Holm,PE et. al. (1992)

Toluene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 120 ug/L 0.042/day Holm,PE et. al. (1992)

Toluene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 0.1/day 7 Nielsen,PH et. al. (1996)

Toluene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 0.2/day 1 Nielsen,PH et. al. (1996)

Toluene Vejen City, Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 0.4/day 5 Bjerg,PL et. al. (1996)

Toluene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 0.4/day 5 Nielsen,PH et. al. (1996)

Toluene Northern Michigan Gas plant facility Aquifer sediment Lab column 20 mg/L 4.6 0.651/day Anid,PJ et. al. (1993)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 35 Toluene Northern Michigan Gas plant facility Aquifer sediment Lab column 20 mg/L 4.6 0.651/day Anid,PJ et. al. (1993) Toluene Uncontaminated Aquifer sediment Lab column 183 ug/L 2 1-8 ug/day Alvarez,PJJ et. al. (1998) Toluene Uncontaminated Aquifer sediment Lab column 183 ug/L 9 3-6 ug/day 3 Alvarez,PJJ et. al. (1998) Toluene Uncontaminated Aquifer sediment Lab column 183 ug/L 8 4-6 ug/day 3 Alvarez,PJJ et. al. (1998) Toluene Uncontaminated Aquifer sediment Lab column 150 ug/L 2.5 Biodegrades Alvarez,PJJ et. al. (1998) Toluene Ada, Oklahoma Soil Lab column 0.20 mg/L Biodegrades Wilson,JT et. al. (1981) Toluene Ada, Oklahoma Soil Lab column 0.90 mg/L Biodegrades Wilson,JT et. al. (1981) Toluene Eastern Pennsylvania Gasoline contaminated site Soil Lab column 3 Biodegrades Venkatraman,SN et. al. (1998)

Toluene Eastern Pennsylvania Gasoline contaminated site Soil Lab column 3 Biodegrades Venkatraman,SN et. al. (1998)

Toluene Skaelskor, Denmark Uncontaminated Fractured clay Lab column 3.2 Biodegrades Broholm,K et. al. (1995) Toluene Uncontaminated Aquifer sediment Lab column 150 ug/L 3 No biodegradation Alvarez,PJJ et. al. (1998)

Toluene Uncontaminated Aquifer sediment Lab column 150 ug/L 3 No biodegradation Alvarez,PJJ et. al. (1998)

Toluene Traverse City, Michigan Uncontaminated landfill site Aquifer sediment Lab microcosm0.1-100 ng/g 68 0.001/day 10 Aelion,CM et. al. (1989)

Toluene Pickett, Oklahoma Uncontaminated Aquifer sediment Lab microcosm 7 0.0014/day Wilson,JT et. al. (1984) Toluene Fort Polk, Louisiana Uncontaminated Aquifer sediment Lab microcosm 7 0.0019/day Wilson,JT et. al. (1984) Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0019/day Thomas,JM et. al. (1990)

Toluene Fort Polk, Louisiana Uncontaminated Aquifer sediment Lab microcosm 7 0.003/day Wilson,JT et. al. (1984) Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0032/day Thomas,JM et. al. (1990)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 36 Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm 1000 ug/L 42 0.0033/day Thomas,JM et. al. (1990)

Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0033/day Thomas,JM et. al. (1990)

Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0035/day Thomas,JM et. al. (1990)

Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm 10 ug/L 42 0.00362/day Thomas,JM et. al. (1990)

Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm267 ug/L 42 0.0037/day Thomas,JM et. al. (1990)

Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm 100 ug/L 28 0.0040/day Thomas,JM et. al. (1990)

Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm 1 ug/L 42 0.0043/day Thomas,JM et. al. (1990)

Toluene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.00503/day Pugh,LB et. al. (1996)

Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm 35 ug/L 42 0.0054/day Thomas,JM et. al. (1990)

Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0061/day Thomas,JM et. al. (1990)

Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0061/day Thomas,JM et. al. (1990)

Toluene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.00786/day Pugh,LB et. al. (1996)

Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0083/day Thomas,JM et. al. (1990)

Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0096/day Thomas,JM et. al. (1990)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 37 Toluene Yolo County, California Agricultural soil Soil Lab microcosm20 mg/L 35 0.0097/day 16.7 Fan,S & Scow,KM (1993) Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.011- 0.017/day Thomas,JM et. al. (1990)

Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0115/day Thomas,JM et. al. (1990)

Toluene Yolo County, California Agricultural soil Soil Lab microcosm20 mg/L 27.7 0.0115/day 10 Mu,DY & Scow,KM (1994) Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0117/day Thomas,JM et. al. (1990)

Toluene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.013/day Pugh,LB et. al. (1996)

Toluene Uncontaminated Soil Lab microcosm0.5 ug/g 30 0.013/day Davis,JW & Madsen,S (1996) Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0135/day Thomas,JM et. al. (1990)

Toluene Traverse City, Michigan Contaminated with aviation fuel Aquifer sediment Lab microcosm0.1-100 ng/g 68 0.014/day Aelion,CM et. al. (1989)

Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0162/day Thomas,JM et. al. (1990)

Toluene Lula, Oklahoma Uncontaminated Aquifer sediment Lab microcosm 104 ug/kg 11 0.0169/day Swindoll,CM et. al. (1988) Toluene East Drainage Ditch,

Massachusetts Tanning and chemical manufacture Stream water Lab microcosm250 ug/L 0.017 mg/kg sed/hr Cohen,BA et. al. (1995)

Toluene Uncontaminated Soil Lab microcosm 50 ug/g 30 0.017/day Davis,JW & Madsen,S (1996) Toluene Port Valdez, Alaska Oil contamination Seawater Lab microcosm0.33-0.42 ug/L 0.02 ng/L/day Button,DK et. al. (1981A) Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm2 ng/L 28 0.0218/day Thomas,JM et. al. (1990)

Toluene Uncontaminated Soil Lab microcosm 5 ug/g 30 0.022/day 1.9 Davis,JW & Madsen,S (1996)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 38 Toluene Hanahan, South Carolina Uncontaminated Aquifer sediment Lab microcosm 10 umol/kg 0.022/day Bradley,PM & Chapelle,FH (1995) Toluene Conroe, Texas Creosote waste site Aquifer sediment Lab microcosm 7 0.023- 0.029/day Wilson,JT et. al. (1986)

Toluene East Drainage Ditch,

Massachusetts Tanning and chemical manufacture Stream water Lab microcosm230 ug/L 0.33 0.025 mg/kg sed/hr Cohen,BA et. al. (1995)

Toluene Uncontaminated Soil Lab microcosm 5 ug/g 30 0.025/day Davis,JW & Madsen,S (1996) Toluene East Drainage Ditch,

Massachusetts Tanning and chemical manufacture Stream water Lab microcosm250 ug/L 0.026 mg/kg sed/hr Cohen,BA et. al. (1995)

Toluene Livermore, California Uncontaminated Soil Lab microcosm20 mg/L 7.4 0.026/day 2.5 Fuller,ME et. al. (1995) Toluene Uncontaminated Soil Lab microcosm 5 ug/g 30 0.027/day 5.7 Davis,JW & Madsen,S (1996) Toluene Uncontaminated Soil Lab microcosm 5 ug/g 30 0.027/day Davis,JW & Madsen,S (1996) Toluene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm2.5 mg/L 74 0.029/day Barker,JF et. al. (1987)

Toluene East Texas Wood-creosoting plant Aquifer sediment Lab microcosm 84 0.03-0.035/day Wilson,JT et. al. (1983B)

Toluene East Texas Wood-creosoting plant Aquifer sediment Lab microcosm 84 0.03-0.035/day Wilson,JT et. al. (1983B)

Toluene Livermore, California Uncontaminated Soil Lab microcosm20 mg/L 91 0.0312/day Fuller,ME et. al. (1995) Toluene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 3.8 mg/L 80 0.032/day 13 Barker,JF et. al. (1987)

Toluene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 839 ug/L 120 0.037/day <7 American Petroleum Institute (1994A) Toluene East Drainage Ditch,

Massachusetts Tanning and chemical manufacture Stream water Lab microcosm 100 ug/L 0.038 mg/kg sed/hr Cohen,BA et. al. (1995)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 39 Toluene Cooper River, South

Carolina Oil contamination River water Lab microcosm 6 ug/L 1 0.041 ug/L/day Lee,RF (1977)

Toluene Lula, Texas Uncontaminated Aquifer sediment Lab microcosm 7 0.041/day Wilson,JT et. al. (1986) Toluene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 1261 ug/L 120 0.047/day <7 American Petroleum Institute (1994A) Toluene Cooper River, South

Carolina Oil contamination River water Lab microcosm 6 ug/L 1 0.048 ug/L/day Lee,RF (1977)

Toluene Georgia coast Seawater Lab microcosm20 ug/L 1 0.05 ug/L/day Lee,RF & Ryan,C (1976) Toluene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 120 ug/L 90 0.05/day Holm,PE et. al. (1992)

Toluene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 120 ug/L 90 0.05/day Holm,PE et. al. (1992)

Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm48.5 mg/L 7.5 0.052/day 2 Allen-King,RM et. al. (1994)

Toluene Livermore, California Uncontaminated Soil Lab microcosm20 mg/L 91 0.0576/day Fuller,ME et. al. (1995) Toluene Cooper River, South

Carolina Oil contamination River water Lab microcosm 6 ug/L 1 0.058 ug/L/day Lee,RF (1977)

Toluene Port Valdez, Alaska Oil contamination Seawater Lab microcosm0.33-0.42 ug/L 0.06 ng/L/day Button,DK et. al. (1981A) Toluene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 32 mg/L 45 0.0625/day Pugh,LB et. al. (1996)

Toluene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 120 ug/L 90 0.067/day Holm,PE et. al. (1992)

Toluene East Drainage Ditch,

Massachusetts Tanning and chemical manufacture Stream water Lab microcosm250 ug/L 0.068 mg/kg rock/hr Cohen,BA et. al. (1995)

Toluene Hanahan, South Carolina Petroleum contaminated site Aquifer sediment Lab microcosm 10 umol/kg 0.071/day Bradley,PM & Chapelle,FH (1995)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 40 Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm48.5 mg/L 7.5 0.080/day Allen-King,RM et. al. (1994)

Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm 350 ug/L 21 0.083/day Thomas,JM et. al. (1990)

Toluene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 120 ug/L 90 0.083/day Holm,PE et. al. (1992)

Toluene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 1242 ug/L 50 0.088/day 7 American Petroleum Institute (1994A) Toluene Livermore, California Uncontaminated Soil Lab microcosm20 mg/L 7.4 0.088/day 2.5 Fuller,ME et. al. (1995) Toluene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 150 ug/L 0.09/day Nielsen,PH et. al. (1996)

Toluene Uncontaminated Soil Lab microcosm200 ug/g 0.098/day 4.8 Davis,JW & Madsen,S (1996) Toluene East Drainage Ditch,

Massachusetts Tanning and chemical manufacture Stream water Lab microcosm230 ug/L 0.1 mg/kg sed/hr Cohen,BA et. al. (1995)

Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm200 ug/L 21 0.107/day Thomas,JM et. al. (1990)

Toluene Port Valdez, Alaska Oil contamination Seawater Lab microcosm0.33-0.42 ug/L 0.11 ng/L/day Button,DK et. al. (1981A) Toluene Skidaway River, Georgia River water Lab microcosm20 ug/L 0.5 0.12 ug/L/day Lee,RF & Ryan,C (1976) Toluene Skidaway River, Georgia River water Lab microcosm20 ug/L 0.75 0.12 ug/L/day Lee,RF & Ryan,C (1976) Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm48.5 mg/L 12.5 0.123/day 9 Allen-King,RM et. al. (1994)

Toluene Yolo County, California Agricultural soil Soil Lab microcosm20 mg/L 27.7 0.136/day 10.8 Mu,DY & Scow,KM (1994) Toluene Yolo County, California Agricultural soil Soil Lab microcosm20 mg/L 10 0.137/day 3.3 Fan,S & Scow,KM (1993) Toluene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm240 ug/L 14 0.140/day Thomas,JM et. al. (1990)

Toluene Yolo County, California Agricultural soil Soil Lab microcosm 5 mg/L 10 0.149/day 3.3 Fan,S & Scow,KM (1993)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 41 Toluene East Drainage Ditch,

Massachusetts Tanning and chemical manufacture Stream water Lab microcosm250 ug/L 0.15 mg/kg rock/hr Cohen,BA et. al. (1995)

Toluene Skidaway River, Georgia River water Lab microcosm20 ug/L 1 0.150 ug/L/day Lee,RF (1977) Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm48.5 mg/L 8 0.150/day Allen-King,RM et. al. (1994)

Toluene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 1.25 mg/L 32 0.156/day Barker,JF et. al. (1987)

Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm25 mg/L 24 0.156/day 12.5 Allen-King,RM et. al. (1994)

Toluene East Drainage Ditch,

Massachusetts Tanning and chemical manufacture Stream water Lab microcosm250 ug/L 0.16 mg/kg rock/hr Cohen,BA et. al. (1995)

Toluene Gloucester landfill,

Ottawa, Canada Landfill site Aquifer sediment + groundwater Lab microcosm 0.16/day Berwanger,DJ & Barker,JF (1988) Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm48.5 mg/L 12.5 0.161/day Allen-King,RM et. al. (1994)

Toluene Yolo County, California Agricultural soil Soil Lab microcosm 625 mg/L 42 0.169/day 13.3 Mu,DY & Scow,KM (1994) Toluene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 24 0.192/day Pugh,LB et. al. (1996)

Toluene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 150 ug/L 0.2/day 3 Nielsen,PH et. al. (1996)

Toluene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 150 ug/L 0.2/day 5 Nielsen,PH et. al. (1996)

Toluene Port Valdez, Alaska Oil contamination Seawater Lab microcosm0.33-0.42 ug/L 0.22 ng/L/day Button,DK et. al. (1981A) Toluene Yolo County, California Agricultural soil Soil Lab microcosm20 mg/L 36.5 0.224/day 13.3 Fan,S & Scow,KM (1993) Toluene Livermore, California Gasoline spill site Soil Lab microcosm20 mg/L 9.2 0.229/day Fuller,ME et. al. (1995)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 42 Toluene East Drainage Ditch,

Massachusetts Tanning and chemical manufacture Stream water Lab microcosm250 ug/L 0.23 mg/kg rock/hr Cohen,BA et. al. (1995)

Toluene Naval Air Station, Adak,

Alaska JP-5 Jet fuel contamination Aquifer sediment Lab microcosm 10 umol/kg 0.23/day Bradley,PM & Chapelle,FH (1995) Toluene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 143 ug/L 26.6 0.233/day 2-7 Nielsen,PH & Christensen,TH (1994B) Toluene Yolo County, California Agricultural soil Soil Lab microcosm250 mg/L 25 0.236/day 8.3 Mu,DY & Scow,KM (1994) Toluene Port Valdez, Alaska Oil contamination Seawater Lab microcosm0.38 ug/L 0.24 ng/L/day Button,DK et. al. (1981A) Toluene Naval Air Station, Adak,

Alaska Uncontaminated Aquifer sediment Lab microcosm 10 umol/kg 0.24/day Bradley,PM & Chapelle,FH (1995) Toluene Contaminated Soil Lab microcosm 5 ug/g 0.26/day Davis,JW & Madsen,S (1996) Toluene Michigan Gas plant facility Aquifer sediment Lab microcosm 310 ug/L 14 0.28/day Chiang,CY et. al. (1986) Toluene Santa Catarina Island,

Brazil Uncontaminated Aquifer sediment Lab microcosm20 mg/L 13 0.31/day 5 Hunt,CS & Alvarez,PJJ (1997)

Toluene Grindsted, Denmark Uncontaminated landfill site Aquifer sediment + groundwater Lab microcosm 100 ug/L 7 0.322/day Albrechtsen,HJ et. al. (1996)

Toluene Livermore, California Uncontaminated Soil Lab microcosm20 mg/L 7.4 0.325/day Fuller,ME et. al. (1995) Toluene Traverse City, MI JP-4 jet fuel spill Aquifer sediment Lab microcosm 380 ug/L 14 0.327/day Wilson,BH et. al. (1990) Toluene Uncontaminated Soil Lab microcosm0.2-0.4 mg/L 7 0.329/day McNabb,JF et. al. (1981) Toluene Sampson County, North

Carolina Gasoline contaminated site Aquifer sediment Lab microcosm2 mg/L 16 0.33/day Borden,RC et. al. (1997)

Toluene Lula, Texas Uncontaminated Aquifer sediment Lab microcosm 7 0.344/day Wilson,JT et. al. (1986) Toluene Yolo County, California Agricultural soil Soil Lab microcosm20 mg/L 25.6 0.354/day 9.4 Mu,DY & Scow,KM (1994) Toluene Lula, Texas Uncontaminated Aquifer sediment Lab microcosm 7 0.36/day Wilson,JT et. al. (1986) Toluene Traverse City, MI JP-4 jet fuel spill Aquifer sediment Lab microcosm420 ug/L 14 0.363/day Wilson,BH et. al. (1990)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 43 Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm25 mg/L 5 0.380/day Allen-King,RM et. al. (1994)

Toluene Yolo County, California Agricultural soil Soil Lab microcosm20 mg/L 5 0.383/day Fan,S & Scow,KM (1993) Toluene Yolo County, California Agricultural soil Soil Lab microcosm20 mg/L 5 0.383/day Fan,S & Scow,KM (1993) Toluene Yolo County, California Agricultural soil Soil Lab microcosm20 mg/L 5 0.436/day Fan,S & Scow,KM (1993) Toluene Uncontaminated Soil Lab microcosm0.5 ug/g 0.46/day 5.7 Davis,JW & Madsen,S (1996) Toluene Port Valdez, Alaska Oil contamination Seawater Lab microcosm0.33-0.42 ug/L 0.48 ng/L/day Button,DK et. al. (1981A) Toluene Uncontaminated Soil Lab microcosm200 ug/g 0.49/day 7.8 Davis,JW & Madsen,S (1996) Toluene Uncontaminated Soil Lab microcosm0.5 ug/g 0.53/day Davis,JW & Madsen,S (1996) Toluene Uncontaminated Soil Lab microcosm 5 ug/g 0.53/day 0.71 Davis,JW & Madsen,S (1996) Toluene Sampson County, North

Carolina Gasoline contaminated site Aquifer sediment Lab microcosm2 mg/L 10 0.53/day Borden,RC et. al. (1997)

Toluene Uncontaminated Soil Lab microcosm 50 ug/g 0.57/day 2.8 Davis,JW & Madsen,S (1996) Toluene Michigan Gas plant facility Aquifer sediment Lab microcosm 325 ug/L 7 0.60/day Chiang,CY et. al. (1986) Toluene Yolo County, California Agricultural soil Soil Lab microcosm20 mg/L 16.7 0.60/day 12.5 Fan,S & Scow,KM (1993) Toluene Port Valdez, Alaska Oil contamination Seawater Lab microcosm0.33-0.42 ug/L 0.62 ng/L/day Button,DK et. al. (1981A) Toluene Grindsted, Jutland,

Denmark Grindsted landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 4 0.63/day Albrechtsen,HJ et. al. (1997)

Toluene Vejen City, Jutland,

Denmark Vejen landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 4 0.63/day Albrechtsen,HJ et. al. (1997)

Toluene Vejen City, Jutland,

Denmark Vejen landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 4 0.63/day Albrechtsen,HJ et. al. (1997)

Toluene Port Valdez, Alaska Oil contamination Seawater Lab microcosm0.33-0.42 ug/L 0.65 ng/L/day Button,DK et. al. (1981A) Toluene Port Valdez, Alaska Oil contamination Seawater Lab microcosm0.33-0.42 ug/L 0.65 ng/L/day Button,DK et. al. (1981A)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 44 Toluene Canadian Forces Base,

Borden, Ontario Contaminated Soil + groundwater Lab microcosm2.5 mg/L 1.4 0.654/day Allen-King,RM et. al. (1994)

Toluene Grindsted, Jutland,

Denmark Grindsted landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 7 0.701/day Albrechtsen,HJ et. al. (1997)

Toluene Uncontaminated Soil Lab microcosm 5 ug/g 0.72/day 5.9 Davis,JW & Madsen,S (1996) Toluene Yolo County, California Agricultural soil Soil Lab microcosm20 mg/L 7.5 0.737/day Mu,DY & Scow,KM (1994) Toluene Yolo County, California Agricultural soil Soil Lab microcosm 100 mg/L 8.75 0.746/day Mu,DY & Scow,KM (1994) Toluene Traverse City, MI JP-4 jet fuel spill Aquifer sediment Lab microcosm2.8 mg/L 7 0.80/day Hutchins,SR (1991) Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm48.5 mg/L 12 0.853/day 8.3 Allen-King,RM et. al. (1994)

Toluene Northen Michigan Gas plant facility Aquifer sediment Lab microcosm 10-100 mg/L 0.91/day Alvarez,PJJ et. al. (1991) Toluene Uncontaminated Soil Lab microcosm 5 ug/g 1.04/day 2.5 Davis,JW & Madsen,S (1996) Toluene Holbaek,Western

Sealand, Denmark Skellingsted landfill Soil Lab microcosm450-600 ug/L 2.5 1.15/day Kjeldsen,P et. al. (1997)

Toluene Port Valdez, Alaska Oil contamination Seawater Lab microcosm 3.9 ug/L 1.2 ng/L/day Button,DK et. al. (1981A) Toluene Canadian Forces Base,

Borden, Ontario Contaminated Soil + groundwater Lab microcosm2.5 mg/L 32 hours 1.29/day Allen-King,RM et. al. (1994)

Toluene Canadian Forces Base,

Borden, Ontario Contaminated Soil + groundwater Lab microcosm2.5 mg/L 1.4 1.29/day Allen-King,RM et. al. (1994)

Toluene East Drainage Ditch,

Massachusetts Tanning and chemical manufacture Stream water Lab microcosm250 ug/L 1.5 mg/kg sed/hr Cohen,BA et. al. (1995)

Toluene Uncontaminated Soil Lab microcosm 5 ug/g 1.5/day 1.9 Davis,JW & Madsen,S (1996) Toluene East Drainage Ditch,

Massachusetts Tanning and chemical manufacture Stream water Lab microcosm250 ug/L 1.6 mg/kg sed/hr Cohen,BA et. al. (1995)

Toluene Livermore, California Uncontaminated Soil Lab microcosm20 mg/L 2.5 1.66/day Fuller,ME et. al. (1995)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 45 Toluene Sandbjerg and

Gassehaven, Denmark Fuel oil + gasoline contamination Aquifer sediment + groundwater Lab microcosm 110 ug/L 6 1.76/day 0.7 Aamand,J et. al. (1989)

Toluene Jurere Beach,

Florianopolis, Brazil Uncontaminated Aquifer sediment Lab microcosm20 mg/L 2 1.90/day Corseuil,HX et. al. (1997)

Toluene Vejen City, Jutland,

Denmark Uncontaminated landfill site Aquifer sediment + groundwater Lab microcosm 100 ug/L 3 1.96/day Albrechtsen,HJ et. al. (1996)

Toluene Canadian Forces Base,

Borden, Ontario Contaminated Soil + groundwater Lab microcosm25 mg/L 7.5 hours 11.4/day Allen-King,RM et. al. (1994)

Toluene Port Valdez, Alaska Oil contamination Seawater Lab microcosm0.33-0.42 ug/L 14.4 ng/L/day Button,DK et. al. (1981A) Toluene Holbaek,Western

Sealand, Denmark Skellingsted landfill Soil Lab microcosm450-600 ug/L 3.5 2.0/day 2.5 Kjeldsen,P et. al. (1997)

Toluene Yolo County, California Agricultural soil Soil Lab microcosm20 mg/L 6.25 2.07/day 3.75 Mu,DY & Scow,KM (1994) Toluene Canadian Forces Base,

Borden, Ontario Contaminated Soil + groundwater Lab microcosm25 mg/L 8 hours 2.08/day Allen-King,RM et. al. (1994)

Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm45.8 mg/L 21.7 mg/kg/day Allen-King,RM et. al. (1996)

Toluene Riverside, California Uncontaminated Soil Lab microcosm 140 mg/L 34.2/day Jin,Y et. al. (1994) Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm 18.2 mg/L 35.3 mg/kg/day Allen-King,RM et. al. (1996)

Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm 8.32 mg/L 35.6 mg/kg/day Allen-King,RM et. al. (1996)

Toluene Vejen City, Jutland,

Denmark Vejen landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 2. 4.61/day Albrechtsen,HJ et. al. (1997)

Toluene Holbaek,Western

Sealand, Denmark Skellingsted landfill Soil Lab microcosm400-500 ug/L 0.83 4.7/day Kjeldsen,P et. al. (1997)

Toluene Livermore, California Uncontaminated Soil Lab microcosm20 mg/L 1 4.71/day Fuller,ME et. al. (1995) Toluene Canadian Forces Base,

Borden, Ontario Contaminated Soil + groundwater Lab microcosm2.5 mg/L 10 hours 4.73/day Allen-King,RM et. al. (1994)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 46 Toluene Riverside, California Uncontaminated Soil Lab microcosm 140 mg/L 42.5/day Jin,Y et. al. (1994) Toluene Port Valdez, Alaska Oil contamination Seawater Lab microcosm0.33-0.42 ug/L 58 ng/L/day Button,DK et. al. (1981A) Toluene Canadian Forces Base,

Borden, Ontario Contaminated Soil + groundwater Lab microcosm2.5 mg/L 5 hours 7.22/day Allen-King,RM et. al. (1994)

Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm 10.57 mg/L 8.67 mg/kg/day Allen-King,RM et. al. (1996)

Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm24 mg/L 9.07 mg/kg/day Allen-King,RM et. al. (1996)

Toluene Canadian Forces Base,

Borden, Ontario Contaminated Soil + groundwater Lab microcosm2.5 mg/L 10 hours 9.39/day Allen-King,RM et. al. (1994)

Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm23.7 mg/L 9.61 mg/kg/day Allen-King,RM et. al. (1996)

Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm4.24 mg/L 9.85 mg/kg/day Allen-King,RM et. al. (1996)

Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm9 mg/L 9.86 mg/kg/day Allen-King,RM et. al. (1996)

Toluene Port Valdez, Alaska Oil contamination Seawater Lab microcosm0.33-0.42 ug/L >170-210 ng/L/day Button,DK et. al. (1981A)

Toluene Riverside, California Uncontaminated Soil Lab microcosm 11.1 mg/L 6 Biodegrades Jin,Y et. al. (1994) Toluene Riverside, California Uncontaminated Soil Lab microcosm25.1 mg/L 12 Biodegrades Jin,Y et. al. (1994) Toluene Riverside, California Uncontaminated Soil Lab microcosm27.6 mg/L 2.5 Biodegrades Jin,Y et. al. (1994) Toluene North Charleston, South

Carolina JP-4 jet fuel contamination site Aquifer sediment Lab microcosm43 ng/g 105 Limited Aelion,CM & Bradley,PM (1991)

Toluene Uncontaminated Soil Lab microcosm 5 ug/g No biodegradation Davis,JW & Madsen,S (1996)

Toluene Uncontaminated Soil Lab microcosm 500 ug/g No biodegradation Davis,JW & Madsen,S (1996)

# Table 3.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 47 Toluene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm2846 ug/L 278 No biodegradation American Petroleum Institute (1994A) Toluene Canadian Forces Base,

Borden, Ontario Uncontaminated Soil + groundwater Lab microcosm25 mg/L 33 No biodegradation Allen-King,RM et. al. (1994)

Toluene Conroe, Texas Uncontaminated Aquifer sediment Lab microcosm 7 No biodegradation Wilson,JT et. al. (1986)

Toluene Pickett, Oklahoma Uncontaminated Aquifer sediment Lab microcosm 7 No biodegradation Wilson,JT et. al. (1984)

Toluene Yolo County, California Agricultural soil Soil Lab microcosm20 mg/L 32 No biodegradation Fan,S & Scow,KM (1993)

Toluene Yolo County, California Agricultural soil Soil Lab microcosm 1000 mg/L 42 No biodegradation Mu,DY & Scow,KM (1994)

Toluene Yolo County, California Agricultural soil Soil Lab microcosm20 mg/L 27.7 No biodegradation Mu,DY & Scow,KM (1994)

Toluene North Charleston, South

Carolina JP-4 jet fuel contamination site Aquifer sediment Lab microcosm 17 ng/g 120 No mineralization Aelion,CM & Bradley,PM (1991)

Toluene Denmark Municipal landfill Leachate Reactor system 50 mg COD/L Biodegrades Lyngkilde,J et. al. (1992)

# 48 

# 0 10 20

012345

Rate constant (days-1

# )Frequency 

# 3.1.3. Ethylbenzene Ethylbenzene is moderately degradable in the presence of oxygen (Table 4). Degradation is thought to proceed via 3-ethylcatechol to CO2

# (Ribbons and Eaton, 1992). 3.17 mg of oxygen are necessary to biodegrade 1 mg of ethylbenzene to CO2

# and water (Wiedemeier et. al., 1995). As for the other BTEX compounds, most of the located data for ethylbenzene under aerobic conditions were from aquifer environments. Field studies at two different locations reported the biodegradation of ethylbenzene. Half-life values ranged from 87 to 231 days for an uncontaminated aquifer study (American Petroleum Institute, 1994). Noin situ microcosm studies were found for this compound. Only one study was found which measured the rate of mineralization for ethylbenzene. A mineralization half-life of 19 days was calculated in river water (Ludzack and Ettinger, 1963). By far the most common type of study used to observe the biodegradation of ethylbenzene under aerobic conditions is the laboratory microcosm. Half-lives ranging from 1 (Hutchins, 1991) to 231 (American Petroleum Institute, 1994A) days with an average value of 4.4 days were measured. The high half-life reported by the American Petroleum Institute represents a microcosm study where 85% methanol was present. When methanol was not present, a half-life of 22 days was obtained. Initial concentrations of up to 20.6 mg/L (Ludzack and Ettinger, 1963) were reported in these experiments without obvious deleterious effect. In general, however, initial concentrations of less than 2 mg/L were utilized. No biodegradation was reported for one lab column study. Anid et. al. (1991) reports thatcolumns supplemented with nitrate were unable to degrade ethylbenzene as well as meta- and paraxylenes and benzene. The nitrate-amended columns may have exhibited nitrate-reducing conditions as over 60 mg/L total BTEX mixture was added. However, no attempt was made by the authors todistinguish through end product measurements whether conditions remained aerobic or became nitratereducing. The median for the primary biodegradation rate constant of ethylbenzene, considering all studies, is 0.113/day (N = 21).A range of 0.003 to 4.8/day is reported. The frequency distribution histogram for this data is shown in figure 3. Ethylbenzene is expected to biodegrade fairly readily under most aerobic environmental conditions.

Figure 3.Frequency histogram for the published primary biodegradation rate constant values of ethylbenzene.

# 49

Table 4.Aerobic biodegradation rate constant values for ethylbenzene Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference
Ethylbenzene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.003/day American Petroleum Institute (1994) Ethylbenzene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.007/day American Petroleum Institute (1994) Ethylbenzene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.008/day American Petroleum Institute (1994) Ethylbenzene Amsterdam, The

Netherlands Dune infiltration site Sediment Field <0.05 ug/L 7-49 Biodegrades Bosma,TNP et. al. (1996)
Ethylbenzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 169 ug/L 0.14/day Morgan,P et. al. (1993)

Ethylbenzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 169 ug/L 0.17/day Morgan,P et. al. (1993)

Ethylbenzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 169 ug/L 25 ug/L/day Morgan,P et. al. (1993)

Ethylbenzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 169 ug/L 32 ug/L/day Morgan,P et. al. (1993)

Ethylbenzene Industrial facility,

New Jersey Vinyl wall covering facility Groundwater Groundwater grab sample 50 mg/L 1.67 4.8/day Graves,DA et. al. (1994)
Ethylbenzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 169 ug/L 40 ug/L/day Morgan,P et. al. (1993)

Ethylbenzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 169 ug/L 41 ug/L/day Morgan,P et. al. (1993)

# Table 4.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 50 Ethylbenzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 169 ug/L 46 ug/L/day Morgan,P et. al. (1993)

Ethylbenzene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 169 ug/L 59 ug/L/day Morgan,P et. al. (1993)

Ethylbenzene Amsterdam, The

Netherlands Dune infiltration site Sediment Lab column 0.5 ug/L Biodegrades Bosma,TNP et. al. (1996)
Ethylbenzene Amsterdam, The

Netherlands Dune infiltration site Sediment Lab column 10-20 ug/L Biodegrades Bosma,TNP et. al. (1996)
Ethylbenzene Wageningen, The

Netherlands Sediment Lab column 10-20 ug/L Biodegrades Bosma,TNP et. al. (1996)
Ethylbenzene Northern Michigan Gas plant facility Aquifer sediment Lab column 3 mg/L 4.6 No biodegradation Anid,PJ et. al. (1993)
Ethylbenzene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 359 ug/L 278 0.003/day American Petroleum Institute (1994A) Ethylbenzene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.018/day Pugh,LB et. al. (1996)

Ethylbenzene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.022/day Pugh,LB et. al. (1996)

Ethylbenzene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.025/day Pugh,LB et. al. (1996)

Ethylbenzene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm92 ug/L 120 0.031/day 7 American Petroleum Institute (1994A) Ethylbenzene Ohio River River water Lab microcosm20.6 mg/L 15 0.036/day Ludzack,FJ & Ettinger,MB (1963)

# Table 4.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 51 Ethylbenzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm225 ug/L 21 0.074/day Thomas,JM et. al. (1990)
Ethylbenzene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 134 ug/L 25 0.077/day <7 American Petroleum Institute (1994A) Ethylbenzene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 139 ug/L 50 0.088/day <7 American Petroleum Institute (1994A) Ethylbenzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm205 ug/L 21 0.0915/day Thomas,JM et. al. (1990)
Ethylbenzene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 24 0.111/day Pugh,LB et. al. (1996)

Ethylbenzene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm2 mg/L 16 0.115/day Pugh,LB et. al. (1996)

Ethylbenzene Gloucester landfill,

Ottawa, Canada Landfill site Aquifer sediment + groundwater Lab microcosm 0.16/day Berwanger,DJ & Barker,JF (1988) Ethylbenzene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm240 ug/L 7 0.202/day Thomas,JM et. al. (1990)
Ethylbenzene Sampson County,

North Carolina Gasoline contaminated site Aquifer sediment Lab microcosm2 mg/L 16 0.33/day Borden,RC et. al. (1997)
Ethylbenzene Sampson County,

North Carolina Gasoline contaminated site Aquifer sediment Lab microcosm2 mg/L 10 0.53/day Borden,RC et. al. (1997)
Ethylbenzene Traverse City, MI JP-4 jet fuel spill Aquifer sediment Lab microcosm 1.85 mg/L 7 0.75/day Hutchins,SR (1991)

# 52

3.1.4. o-Xylene o-Xylene is moderately degradable in the presence of oxygen (Table 5). Degradation is thought to proceed via 3,4-dimethylcatechol to CO2

# (Gibson and Subramanian, 1984). 3.17 mg of oxygen are necessary to biodegrade 1 mg of o-xylene to CO2

# and water (Wiedemeier et. al., 1995). As for the other BTEX compounds, most of the located data for o-xylene under aerobic conditions were for aquifer environments. Two different field studies from the same location reported the biodegradation of o-xylene giving half-life values ranging from 116 to 173 days (American Petroleum Institute, 1994). Biodegradation of o-xylene was observed as well duringin situ microcosm studies at Vejen City, Denmark. Half-lives ranged from 7 (Nielsen et. al., 1996) to 408 days (Holm et. al., 1992) days with an average half-life of 18 days. The high half-life value represents biodegradation in the groundwater only section of thein situ microcosm; half-life values obtained in the aquifer sediment + groundwater section were significantly lower. By far the most common type of study used to observe the biodegradation of o-xylene under aerobic conditions is the laboratory microcosm. Half-lives ranging from 1 (Hutchins, 1991) to 41 (Holm et. al., 1992) days with an average value of 4.3 days (rate constant of 2.42/day reported by Aamand et. al., 1989 was not used in this calculation) were measured. Initial concentrations of up to 20 mg/L were reported in these experiments without obvious deleterious effect. In general, however, initial concentrations of less than 2 mg/L were utilized. No biodegradation was reported for several microcosm studies. A study by the American Petroleum Institute (1994A) reports that o-xylene, as well as benzene, toluene and bothmeta- andpara-xylene, were not biodegraded in the presence of 85% methanol over 278 days. This result was not unexpected as sufficient oxygen was available to degrade only 5% of the initially added methanol (over 7 grams were initially added). This suggests that anaerobic conditions may have occurred rapidly within this microcosm. In addition, the bacteria may have preferentially degraded the structurally simpler methanol or the concentration of methanol added may have been toxic to the indigenous bacterial population. Pristine aquifer sediment was unable to biodegrade o-xylene over a 7 day period; however, when creosote-contaminated aquifer sediment was used, greater than 19-21% of the initially added o-xylene was biodegraded over 7 days. Thomas et. al. (1990) reported that o-xylene was readily biodegraded in uncontaminated aquifer material with a half-life of 7 days but when either contaminated or biostimulated aquifer material was used instead, no biodegradation was reported over 21 days. Laboratory microcosms which contained double concentrations of nitrogen and phosphorus nutrients were able to significantly biodegrade a xylene mixture; however, unamended and single nutrient amendments to the microcosm were insufficient to encourage biodegradation of this mixture (Pugh et. al., 1996).Laboratory column experiments by Broholm et. al. (1995) and Alvarez et. al. (1998) report that oxylene was not biodegraded under certain circumstances. Alvarez et. al. (1998) showed biodegradation of o-xylene in laboratory columns fed with acetate and benzoate as cosubstrates. However, preacclimated sediment exposed to acetate and columns which received no preacclimation period were unable to biodegrade o-xylene while a column which had been preacclimated to benzoate

# 53 0 20 40 60 80

012345678



# Rate constant (days-1

# )Frequency 

# readily biodegraded o-xylene. Broholm et. al. (1995) were not able to explain their results showing no to slight biodegradation of o-xylene over an experimental period of 3.5 days. It may be that this time period was not sufficient for acclimation of the bacterial population within the clay column. The median for the primary biodegradation rate constant of o-xylene, considering all studies, is 0.054/day (N = 92); a range of not biodegraded to 7.625 is reported.The frequency distribution histogram for this data is shown in figure 4. o-Xylene is expected to biodegrade readily under most aerobic environmental conditions.

Figure 4.Frequency histogram for the published primary biodegradation rate constant values for oxylene.

# 54

Table 5.Aerobic biodegradation rate constant values for o-xylene Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference
o-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.004/day American Petroleum Institute (1994) o-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.005/day American Petroleum Institute (1994) o-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.006/day American Petroleum Institute (1994) o-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 1.29 mg/L 270 47 mg/day Barker,JF et. al. (1987)
o-Xylene Vejen City, Jutland,

Denmark Landfill site Groundwater Groundwater grab sample 120 ug/L 90 0.0017/day Holm,PE et. al. (1992)
o-Xylene Grindsted, Denmark Uncontaminated landfill site Groundwater + sterile rock wool Groundwater grab sample 100 ug/L 48 0.0067/day 8 Albrechtsen,HJ et. al. (1996)
o-Xylene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 295 ug/L 0.0073/day Morgan,P et. al. (1993)

o-Xylene Vejen City, Jutland,

Denmark Landfill site Groundwater Groundwater grab sample 120 ug/L 90 0.0083/day Holm,PE et. al. (1992)
o-Xylene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 295 ug/L 0.014/day Morgan,P et. al. (1993)

o-Xylene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 295 ug/L 0.020/day Morgan,P et. al. (1993)

o-Xylene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 295 ug/L 0.021/day Morgan,P et. al. (1993)

o-Xylene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 295 ug/L 0.023/day Morgan,P et. al. (1993)

# Table 5.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 55 o-Xylene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 295 ug/L 0.031/day Morgan,P et. al. (1993)

o-Xylene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 295 ug/L 0.038/day Morgan,P et. al. (1993)

o-Xylene Vejen City, Jutland,

Denmark Uncontaminated landfill site Groundwater Groundwater grab sample 100 ug/L 48 0.040/day 8 Albrechtsen,HJ et. al. (1996)
o-Xylene Grindsted, Denmark Uncontaminated landfill site Groundwater Groundwater grab sample 100 ug/L 48 0.0444/day 23 Albrechtsen,HJ et. al. (1996)
o-Xylene Vejen City, Jutland,

Denmark Uncontaminated landfill site Groundwater + sterile quartz Groundwater grab sample 100 ug/L 28 0.125/day Albrechtsen,HJ et. al. (1996)
o-Xylene Grindsted, Denmark Uncontaminated landfill site Groundwater + sterile quartz Groundwater grab sample 100 ug/L 23 0.132/day 5 Albrechtsen,HJ et. al. (1996)
o-Xylene Gassehaven, Denmark Fuel oil contamination Groundwater Groundwater grab sample 160 ug/L 65 0.16-0.54/day 14 Aamand,J et. al. (1989)
o-Xylene Vejen City, Jutland,

Denmark Uncontaminated landfill site Groundwater + sterile rock wool Groundwater grab sample 100 ug/L 12 0.201/day Albrechtsen,HJ et. al. (1996)
o-Xylene Gassehaven, Denmark Fuel oil contamination Groundwater Groundwater grab sample 160 ug/L 18 0.62/day 2.4 Aamand,J et. al. (1989)
o-Xylene Gassehaven, Denmark Fuel oil contamination Groundwater Groundwater grab sample 160 ug/L 38 0.69/day 24 Aamand,J et. al. (1989)
o-Xylene Industrial facility, New

Jersey Vinyl wall covering facility Groundwater Groundwater grab sample 50 mg/L 7.5 0.70/day Graves,DA et. al. (1994)
o-Xylene Grindsted, Denmark Heavy oil contamination Groundwater Groundwater grab sample 500-1000 ug/L 5.2 1.2-1.33/day Arvin,E et. al. (1988)
o-Xylene Sandbjerg and

Gassehaven, Denmark Fuel oil + gasoline contamination Groundwater Groundwater grab sample 160 ug/L 10 1.21/day 2 Aamand,J et. al. (1989)
o-Xylene Gassehaven, Denmark Fuel oil contamination Groundwater Groundwater grab sample 160 ug/L 10 1.27/day 2.4 Aamand,J et. al. (1989)

# Table 5.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 56 o-Xylene Gassehaven, Denmark Fuel oil contamination Groundwater Groundwater grab sample 160 ug/L 11 1.42/day 4.2 Aamand,J et. al. (1989)
o-Xylene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 295 ug/L 180 ug/L/day Morgan,P et. al. (1993)

o-Xylene Horsholm, Denmark Gasoline contamination Groundwater Groundwater grab sample 500-1000 ug/L 2.4 2.6-2.88/day Arvin,E et. al. (1988)
o-Xylene Gassehaven, Denmark Fuel oil contamination Groundwater Groundwater grab sample 160 ug/L 6 2.69/day 2.4 Aamand,J et. al. (1989)
o-Xylene Ganlose, Denmark Fuel oil contamination Groundwater Groundwater grab sample 500-1000 ug/L 2.1 2.96-3.29/day Arvin,E et. al. (1988)
o-Xylene Gassehaven, Denmark Fuel oil contamination Groundwater Groundwater grab sample 500-1000 ug/L 2.1 2.96-3.29/day Arvin,E et. al. (1988)
o-Xylene Denmark Groundwater Groundwater grab sample 200-1000 ug/L 4.3 6.62-8.63/day 3.5 Arvin,E et. al. (1988)
o-Xylene Forlev landfill, Korsoer,

Zealand Sanitary landfill Leachate Groundwater inoculum 100 ug/L 60 0.0808/day 3 Lyngkilde,J et. al. (1988)
o-Xylene Forlev landfill, Korsoer,

Zealand Sanitary landfill Leachate Groundwater inoculum 100 ug/L 60 0.089/day 8 Lyngkilde,J et. al. (1988)
o-Xylene Forlev landfill, Korsoer,

Zealand Sanitary landfill Leachate Groundwater inoculum 100 ug/L 75 0.0903/day 24 Lyngkilde,J et. al. (1988)
o-Xylene Forlev landfill, Korsoer,

Zealand Sanitary landfill Leachate Groundwater inoculum 100 ug/L 50 0.154/day 20 Lyngkilde,J et. al. (1988)
o-Xylene Vejen City, Jutland,

Denmark Landfill site Groundwater In situ microcosm 120 ug/L 0.0017/day Holm,PE et. al. (1992)
o-Xylene Vejen City, Jutland,

Denmark Landfill site Groundwater In situ microcosm 120 ug/L 0.0033/day Holm,PE et. al. (1992)
o-Xylene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 120 ug/L 0.0083/day Holm,PE et. al. (1992)
o-Xylene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 120 ug/L 0.011/day Holm,PE et. al. (1992)

# Table 5.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 57 o-Xylene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 0.04/day Nielsen,PH et. al. (1996)
o-Xylene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 0.04/day 3 Nielsen,PH et. al. (1996)
o-Xylene Vejen City, Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 100 0.1/day 7 Bjerg,PL et. al. (1996)
o-Xylene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 0.1/day 7 Nielsen,PH et. al. (1996)
o-Xylene Northern Michigan Gas plant facility Aquifer sediment Lab column 4 mg/L 4.6 0.0625/day 30 Anid,PJ et. al. (1993) o-Xylene Northern Michigan Gas plant facility Aquifer sediment Lab column 4 mg/L 4.6 0.262/day Anid,PJ et. al. (1993) o-Xylene Uncontaminated Aquifer sediment Lab column 192 ug/L 9 1-3 ug/day 3 Alvarez,PJJ et. al. (1998) o-Xylene Uncontaminated Aquifer sediment Lab column 192 ug/L 2 1-8 ug/day Alvarez,PJJ et. al. (1998) o-Xylene Uncontaminated Aquifer sediment Lab column 192 ug/L 9 2-4 ug/day 3 Alvarez,PJJ et. al. (1998) o-Xylene Aquifer sediment Lab column 0.5 uM 17 Biodegrades Kuhn,EP et. al. (1985) o-Xylene Uncontaminated Aquifer sediment Lab column 150 ug/L 3 Biodegrades Alvarez,PJJ et. al. (1998) o-Xylene Uncontaminated Aquifer sediment Lab column 150 ug/L 3 No biodegradation Alvarez,PJJ et. al. (1998)
o-Xylene Uncontaminated Aquifer sediment Lab column 150 ug/L 3 No biodegradation Alvarez,PJJ et. al. (1998)
o-Xylene Skaelskor, Denmark Uncontaminated Fractured clay Lab column 3.2 No biodegradation Broholm,K et. al. (1995)
Xylene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.00136/day Pugh,LB et. al. (1996)

Xylene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 24 0.00677/day Pugh,LB et. al. (1996)

o-Xylene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 120 ug/L 90 0.017/day Holm,PE et. al. (1992)
o-Xylene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 120 ug/L 90 0.017/day Holm,PE et. al. (1992)

# Table 5.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 58 o-Xylene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 120 ug/L 90 0.017/day Holm,PE et. al. (1992)
o-Xylene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 150 ug/L 0.02/day Nielsen,PH et. al. (1996)
o-Xylene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 141 ug/L 82 0.0248/day 2-7 Nielsen,PH & Christensen,TH (1994B) o-Xylene Conroe, Texas Creosote waste site Aquifer sediment Lab microcosm 7 0.025- 0.028/day Wilson,JT et. al. (1986)
o-Xylene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 120 ug/L 90 0.025/day Holm,PE et. al. (1992)
o-Xylene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 150 ug/L 0.03/day Nielsen,PH et. al. (1996)
o-Xylene Vejen City, Jutland,

Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 150 ug/L 0.03/day Nielsen,PH et. al. (1996)
o-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 168 ug/L 120 0.030/day <7 American Petroleum Institute (1994A) o-Xylene East Texas Wood-creosoting plant Aquifer sediment Lab microcosm 84 0.030/day Wilson,JT et. al. (1983B)
o-Xylene East Texas Wood-creosoting plant Aquifer sediment Lab microcosm 84 0.030/day Wilson,JT et. al. (1983B)
Xylene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.033/day Pugh,LB et. al. (1996)

Xylene Michigan Gas plant facility Aquifer sediment Lab microcosm285 ug/L 14 0.035/day Chiang,CY et. al. (1986) o-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm248 ug/L 50 0.047/day <7 American Petroleum Institute (1994A) o-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm228 ug/L 25 0.048/day <7 American Petroleum Institute (1994A) o-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm20 mg/L 58 0.054/day Barker,JF et. al. (1987)
o-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm2 mg/L 54 0.056/day 13 Barker,JF et. al. (1987)

# Table 5.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 59 o-Xylene Gloucester landfill,

Ottawa, Canada Landfill site Aquifer sediment + groundwater Lab microcosm 0.057/day Berwanger,DJ & Barker,JF (1988) Xylene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 16 0.077/day Pugh,LB et. al. (1996)

o-Xylene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm250 ug/L 14 0.099/day Thomas,JM et. al. (1990)
o-Xylene Grindsted, Jutland,

Denmark Grindsted landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 23 0.10/day Albrechtsen,HJ et. al. (1997)
o-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm900 ug/L 25 0.14/day 10 Barker,JF et. al. (1987)
o-Xylene Vejen City, Jutland,

Denmark Vejen landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 19 0.158/day Albrechtsen,HJ et. al. (1997)
o-Xylene Vejen City, Jutland,

Denmark Vejen landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 19 0.158/day Albrechtsen,HJ et. al. (1997)
o-Xylene Grindsted, Denmark Uncontaminated landfill site Aquifer sediment + groundwater Lab microcosm 100 ug/L 23 0.163/day 5 Albrechtsen,HJ et. al. (1996)
o-Xylene Soil Lab microcosm 123 mg VOC/kg soil 0.227 mg/day 10 English,CW & Loehr,RC (1991)
Xylene Santa Catarina Island,

Brazil Uncontaminated Aquifer sediment Lab microcosm20 mg/L 0.25/day 5 Hunt,CS & Alvarez,PJJ (1997)
o-Xylene Traverse City, MI JP-4 jet fuel spill Aquifer sediment Lab microcosm 370 ug/L 14 0.296/day Wilson,BH et. al. (1990) o-Xylene Sampson County, North

Carolina Gasoline contaminated site Aquifer sediment Lab microcosm2 mg/L 16 0.33/day Borden,RC et. al. (1997)
o-Xylene Traverse City, MI JP-4 jet fuel spill Aquifer sediment Lab microcosm 390 ug/L 14 0.33/day Wilson,BH et. al. (1990) o-Xylene Grindsted, Jutland,

Denmark Grindsted landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 13 0.333/day Albrechtsen,HJ et. al. (1997)
o-Xylene Sampson County, North

Carolina Gasoline contaminated site Aquifer sediment Lab microcosm2 mg/L 10 0.53/day Borden,RC et. al. (1997)
Xylene Michigan Gas plant facility Aquifer sediment Lab microcosm 300 ug/L 7 0.56/day Chiang,CY et. al. (1986) o-Xylene Vejen City, Jutland,

Denmark Uncontaminated landfill site Aquifer sediment + groundwater Lab microcosm 100 ug/L 5 0.60/day Albrechtsen,HJ et. al. (1996)

# Table 5.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 60 o-Xylene Vejen City, Jutland,

Denmark Vejen landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 4 0.75/day Albrechtsen,HJ et. al. (1997)
o-Xylene Jurere Beach,

Florianopolis, Brazil Uncontaminated Aquifer sediment Lab microcosm20 mg/L 8 0.750/day 3 Corseuil,HX et. al. (1997)
o-Xylene Traverse City, MI JP-4 jet fuel spill Aquifer sediment Lab microcosm2.3 mg/L 15 0.78/day Hutchins,SR (1991) o-Xylene Sandbjerg and

Gassehaven, Denmark Fuel oil + gasoline contamination Aquifer sediment + groundwater Lab microcosm 160 ug/L 6 2.42/day 2 Aamand,J et. al. (1989)
Xylene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 No biodegradation Pugh,LB et. al. (1996)

o-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 544 ug/L 278 No biodegradation American Petroleum Institute (1994A) o-Xylene Conroe, Texas Uncontaminated Aquifer sediment Lab microcosm 7 No biodegradation Wilson,JT et. al. (1986)
o-Xylene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm260 ug/L 21 No biodegradation Thomas,JM et. al. (1990)
o-Xylene Granger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm270 ug/L 21 No biodegradation Thomas,JM et. al. (1990)
o-Xylene Denmark Municipal landfill Leachate Reactor system 50 mg COD/L Biodegrades Lyngkilde,J et. al. (1992)

# 61

3.1.5. m-Xylene m-Xylene is moderately degradable in the presence of oxygen (Table 6). Degradation is thought to proceed via 2,4-dimethylcatechol to CO2

# (Gibson and Subramanian, 1984). 3.13 mg of oxygen are necessary to biodegrade 1 mg of m-xylene to CO2

# and water (Wiedemeier et. al., 1995). As for the other BTEX compounds, most of the located data for m-xylene under aerobic conditions were for aquifer environments. Two different field studies from the same location reported the biodegradation of m-xylene giving half-life values ranging from 50 to 77 days (American Petroleum Institute, 1994). Noin situ microcosm studies were found for this compound. By far the most common type of study used to observe the biodegradation of m-xylene under aerobic conditions is the laboratory microcosm. Half-lives ranging from 1 (Hutchins, 1991) to 27 (Wilson et. al., 1986) days with an average value of 4.3 days were measured. Initial concentrations of up to 20 mg/L (Hunt and Alvarez, 1997) were reported in these experiments without obvious deleterious effect. In general, however, initial concentrations of less than 2 mg/L were utilized. No biodegradation was reported for several microcosm studies. A study by the American Petroleum Institute, 1994A, reports that m-xylene was not biodegraded in the presence of 85% methanol over 278 days. This result was not unexpected as sufficient oxygen was available to degrade only 5% of the initially added methanol. In addition, the bacteria may have preferentially degraded the structurally simpler methanol or the concentration of methanol added may have been toxic to the indigenous bacterial population. Laboratory microcosms which contained double concentrations of nitrogen and phosphorus nutrients were able to significantly biodegrade a xylene mixture; however, unamended and single nutrient amendments to the microcosm were insufficient to encourage biodegradation of this mixture (Pugh et. al., 1996). Pristine aquifer sediment was unable to biodegrade m-xylene over a 7- day period; however, when creosote-contaminated aquifer sediment was used, greater than 19-22% of the initially added m-xylene was biodegraded over 7 days. Anid et. al. (1991) report that columns supplemented with hydrogen peroxide but not columns supplemented with nitrate were able to degrade m-xylene. The nitrate-amended columns may have exhibited nitrate-reducing conditions as over 60 mg/L BTEX mixture was added. However, no attempt was made by the authors to distinguish through end product measurements whether conditions remained aerobic or became nitrate-reducing. The median for the primary biodegradation rate constant of m-xylene is 0.057/day (N = 32); a range from not biodegraded to 0.76/day is reported.The frequency distribution histogram for this data is shown in figure 5. m-Xylene is expected to biodegrade fairly readily under most aerobic environmental conditions.

# 62 0 5 10 15 20 25

00.10.20.30.40.50.60.70.8

Rate constant (days-1

# )Frequency



# Figure 5.Frequency histogram for the published primary biodegradation rate constant values of mxylene.

# 63

Table 6.Aerobic biodegradation rate constant values for m-xylene Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference
m-XyleneCanada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.009/day American Petroleum Institute (1994) m-XyleneCanada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.010/day American Petroleum Institute (1994) m-XyleneCanada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.014/day American Petroleum Institute (1994) m-XyleneCanada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 1.09 mg/L 270 33 mg/day Barker,JF et. al. (1987)
m-XyleneUiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 310 ug/L 0.056/day Morgan,P et. al. (1993)

m-XyleneUiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 310 ug/L 0.06/day Morgan,P et. al. (1993)

m-XyleneUiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 310 ug/L 0.065/day Morgan,P et. al. (1993)

m-XyleneUiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 310 ug/L 0.088/day Morgan,P et. al. (1993)

m-XyleneUiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 310 ug/L 0.1/day Morgan,P et. al. (1993)

m-XyleneUiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 310 ug/L 37 ug/L/day Morgan,P et. al. (1993)

m-XyleneUiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 310 ug/L 79 ug/L/day Morgan,P et. al. (1993)

# Table 6.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 64 m-XyleneUiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 310 ug/L 91 ug/L/day Morgan,P et. al. (1993)

m-XyleneNorthern Michigan Gas plant facility Aquifer sediment Lab column 13 mg/L 4.6 0.350/day Anid,PJ et. al. (1993) m-Xylene Aquifer sediment Lab column 0.5 uM 17 Biodegrades Kuhn,EP et. al. (1985) m-XyleneNorthern Michigan Gas plant facility Aquifer sediment Lab column 13 mg/L 4.6 No biodegradation Anid,PJ et. al. (1993)
Xylene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.00136/day Pugh,LB et. al. (1996)

Xylene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 24 0.00677/day Pugh,LB et. al. (1996)

m-XyleneConroe, Texas Creosote waste site Aquifer sediment Lab microcosm 7 0.025- 0.029/day Wilson,JT et. al. (1986)
m-XyleneEast Texas Wood-creosoting plant Aquifer sediment Lab microcosm 84 0.030/day Wilson,JT et. al. (1983B)
m-XyleneEast Texas Wood-creosoting plant Aquifer sediment Lab microcosm 84 0.030/day Wilson,JT et. al. (1983B)
Xylene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.033/day Pugh,LB et. al. (1996)

Xylene Michigan Gas plant facility Aquifer sediment Lab microcosm285 ug/L 14 0.035/day Chiang,CY et. al. (1986) m-XyleneCanada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm216 ug/L 120 0.038/day <7 American Petroleum Institute (1994A) m-XyleneCanada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 1.1 mg/L 63 0.048/day Barker,JF et. al. (1987)
m-XyleneGloucester landfill,

Ottawa, Canada Landfill site Aquifer sediment + groundwater Lab microcosm 0.057/day Berwanger,DJ & Barker,JF (1988)

# Table 6.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 65 m-XyleneCanada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 361 ug/L 50 0.058/day <7 American Petroleum Institute (1994A) m-XyleneGranger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm200 ug/L 21 0.061/day Thomas,JM et. al. (1990)
m-XyleneCanada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm290 ug/L 25 0.076/day <7 American Petroleum Institute (1994A) Xylene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 16 0.077/day Pugh,LB et. al. (1996)

m-XyleneGranger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm210 ug/L 7 0.213/day Thomas,JM et. al. (1990)
Xylene Santa Catarina Island,

Brazil Uncontaminated Aquifer sediment Lab microcosm20 mg/L 0.25/day 5 Hunt,CS & Alvarez,PJJ (1997)
m-XyleneSampson County, North

Carolina Gasoline contaminated site Aquifer sediment Lab microcosm2 mg/L 16 0.33/day Borden,RC et. al. (1997)
m-XyleneSampson County, North

Carolina Gasoline contaminated site Aquifer sediment Lab microcosm2 mg/L 10 0.53/day Borden,RC et. al. (1997)
Xylene Michigan Gas plant facility Aquifer sediment Lab microcosm 300 ug/L 7 0.56/day Chiang,CY et. al. (1986) m-XyleneGranger, Indiana Unleaded gasoline spill site Aquifer sediment Lab microcosm250 ug/L 7 0.687/day Thomas,JM et. al. (1990)
m-XyleneTraverse City, MI JP-4 jet fuel spill Aquifer sediment Lab microcosm2 mg/L 7 0.76/day Hutchins,SR (1991) m-XyleneCanada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 872 ug/L 278 No biodegradation American Petroleum Institute (1994A) m-XyleneConroe, Texas Uncontaminated Aquifer sediment Lab microcosm 7 No biodegradation Wilson,JT et. al. (1986)
Xylene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 No biodegradation Pugh,LB et. al. (1996)

# 66

3.1.6. p-Xylene p-Xylene is moderately degradable in the presence of oxygen (Table 7). Degradation is thought to proceed via 3,6-dimethylcatechol to CO2

# (Gibson and Subramanian, 1984). 3.13 mg of oxygen are necessary to biodegrade 1 mg of p-xylene to CO2

# and water (Wiedemeier et. al., 1995). As for the other BTEX compounds, most of the located data for p-xylene under aerobic conditions were for aquifer environments. Three field studies from two different locations reported the biodegradation of p-xylene giving half-life values ranging from 49 (Staffer et. al., 1994) to 231 days (American Petroleum Institute, 1994). Noin situ microcosm studies were found for this compound. By far the most common type of study used to observe the biodegradation of p-xylene under aerobic conditions is the laboratory microcosm. Half-lives ranging from 1 (Chiang et. al., 1986) to 28 (American Petroleum Institute, 1994A) days with an average value of 4.4 days were reported. Initial concentrations of up to 20 mg/L were reported in these experiments without obvious deleterious effect. In general, however, initial concentrations of less than 2 mg/L were utilized. No biodegradation was reported for two microcosm studies. A study by the American Petroleum Institute, 1994A, reports that p-xylene was not biodegraded in the presence of 85% methanol over 278 days. This result was not unexpected as sufficient oxygen was available to degrade only 5% of the initially added methanol. In addition, the bacteria may have preferentially degraded the structurally simpler methanol or the concentration of methanol added may have been toxic to the indigenous bacterial population. Laboratory microcosms which contained double concentrations of nitrogen and phosphorus nutrients were able to significantly biodegrade a xylene mixture; however, unamended and single nutrient amendments to the microcosm were insufficient to encourage biodegradation of this mixture (Pugh et. al., 1996). Anid et. al. (1991) reports that columns supplemented with hydrogenperoxide but not columns supplemented with nitrate were able to degrade p-xylene. The nitrateamended columns may have exhibited nitrate-reducing conditions as over 60 mg/L BTEX mixture was added. However, no attempt was made by the authors to distinguish through end product measurements whether conditions remained aerobic or became nitrate-reducing. The median for the primary biodegradation rate constant of p-xylene, considering all studies, is 0.052/day (N = 27); a range of not biodegraded to 0.56/day is reported.The frequency distribution histogram for this data is shown in figure 6. p-Xylene is expected to biodegrade fairly readily under most aerobic environmental conditions.

# 67 0 5 10 15 20 25

0.000.200.400.60

Rate constant (days-1

# )Frequency



# Figure 6.Frequency histogram for the published primary biodegradation rate constant values of pxylene.

# 68

Table 7.Aerobic biodegradation rate constant values for p-xylene Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference
p-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.003/day American Petroleum Institute (1994) p-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.006/day American Petroleum Institute (1994) p-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 476 0.007/day American Petroleum Institute (1994) p-Xylene Columbus Air Force

Base, Columbus, Miss. Aquifer sediment + groundwater Field 224 0.0141/day Stauffer,TB et. al. (1994)
p-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 1.08 mg/L 270 55 mg/day Barker,JF et. al. (1987)
p-Xylene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 310 ug/L 0.056/day Morgan,P et. al. (1993)

p-Xylene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 310 ug/L 0.060/day Morgan,P et. al. (1993)

p-Xylene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 310 ug/L 0.065/day Morgan,P et. al. (1993)

p-Xylene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 310 ug/L 0.088/day Morgan,P et. al. (1993)

p-Xylene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 310 ug/L 0.10/day Morgan,P et. al. (1993)

# Table 7.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 69 p-Xylene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 310 ug/L 37 ug/L/day Morgan,P et. al. (1993)

p-Xylene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 310 ug/L 79 ug/L/day Morgan,P et. al. (1993)

p-Xylene Uiterburen, The

Netherlands Natural gasproduction siteBTEX contamination Groundwater Groundwater grab sample 310 ug/L 91 ug/L/day Morgan,P et. al. (1993)

p-Xylene Northern Michigan Gas plant facility Aquifer sediment Lab column 13 mg/L 4.6 0.350/day Anid,PJ et. al. (1993) p-Xylene Aquifer sediment Lab column 0.5 uM 17 Biodegrades Kuhn,EP et. al. (1985) p-Xylene Northern Michigan Gas plant facility Aquifer sediment Lab column 13 mg/L 4.6 No biodegradation Anid,PJ et. al. (1993)
Xylene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.00136/day Pugh,LB et. al. (1996)

Xylene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 24 0.00677/day Pugh,LB et. al. (1996)

p-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 85 ug/L 120 0.025/day <7 American Petroleum Institute (1994A) Xylene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.033/day Pugh,LB et. al. (1996)

Xylene Michigan Gas plant facility Aquifer sediment Lab microcosm285 ug/L 14 0.035/day Chiang,CY et. al. (1986) p-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 133 ug/L 50 0.044/day <7 American Petroleum Institute (1994A)

# Table 7.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 70 p-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 143 ug/L 25 0.048/day <7 American Petroleum Institute (1994A) p-Xylene Gloucester landfill,

Ottawa, Canada Landfill site Aquifer sediment + groundwater Lab microcosm 300 ug/L 21 0.057/day 5 Berwanger,DJ & Barker,JF (1988) Xylene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 16 0.077/day Pugh,LB et. al. (1996)

Xylene Santa Catarina Island,

Brazil Uncontaminated Aquifer sediment Lab microcosm20 mg/L 0.25/day 5 Hunt,CS & Alvarez,PJJ (1997)
p-Xylene Traverse City, MI JP-4 jet fuel spill Aquifer sediment Lab microcosm 370 ug/L 14 0.30/day Wilson,BH et. al. (1990) p-Xylene Sampson County, North

Carolina Gasoline contaminated site Aquifer sediment Lab microcosm2 mg/L 16 0.33/day Borden,RC et. al. (1997)
p-Xylene Traverse City, MI JP-4 jet fuel spill Aquifer sediment Lab microcosm 390 ug/L 14 0.382/day Wilson,BH et. al. (1990) p-Xylene Sampson County, North

Carolina Gasoline contaminated site Aquifer sediment Lab microcosm2 mg/L 10 0.53/day Borden,RC et. al. (1997)
Xylene Michigan Gas plant facility Aquifer sediment Lab microcosm 300 ug/L 7 0.56/day Chiang,CY et. al. (1986) p-Xylene Canada Forces Base,

Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 319 ug/L 278 No biodegradation American Petroleum Institute (1994A) Xylene Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 No biodegradation Pugh,LB et. al. (1996)

# 71

3.2. PAH (Polycyclic Aromatic Hydrocarbon) Compounds PAH compounds are ubiquitous compounds in the environment due to their production during incomplete combustion and pyrolytic processes. In addition, effluents from wood-preserving (creosoting sites), refinery and oil waste, waste incineration, coal gasification and liquification, and coal tar distillation sites often provide high concentrations of PAH compounds (Cerniglia, 1992). Structurally, PAHs are considered to have two or more fused benzene ring structures in various arrangements. This database includes several PAHs including naphthalene (2 rings), fluorene (3 rings), benzo(a)anthracene, chrysene, fluoranthene, and pyrene (4 rings), and benzo(a)pyrene (5 rings). Based on pure culture studies, bacterial biodegradation of PAHs is believed to proceed via oxidation of the ring structure using dioxygenase enzymes in the presence of molecular oxygen. The cis-dihydrodiol is then dehydrogenated forming the catechol which leaves the aromatic ring open to enzymatic cleavage by another dioxygenase activity (Cerniglia, 1992). The two hydroxyl groups must be located either orthoorparato each other for ring cleavage to occur. The lower molecular weight PAH compounds are generally more rapidly degraded than the higher molecular weight PAH compounds. This was shown by Park et. al. (1990), in a study investigating the biodegradation of 14 PAH compounds in two different soils. Compounds with two or three rings were extensively degraded while, in general, compounds with four or five rings were resistant to biodegradation. Sorption of the PAH compound to the soil or sediment appears to strongly affect its ability to be biodegraded. Maliszewska-Kordybach (1998) examined the physical properties and their correlation to the biodegradation rate reported for four PAH compounds in ten different soils varying in pH and organic matter content. The length of time the PAH was in contact with the soil had a strong effect on the importance of the physical property/properties relationship to persistence. Initially, volatilization, reflected by Henry’s Law constant was correlated to loss of the PAH in soil. However, over time, other properties such as water solubility and sorption became more important in determining the resistance of a particular PAH to degradation. Lower water solubilities were correlated to lower biodegradation rates. Sorption properties, however, showed the strongest influence in determining PAH persistence in soil. Loehr and Webster (1996) reviewed the current literature examining the effect exposure time had on the biodegradation in soil of compounds ranging from chlorinated aliphatics to PAHs. They proposed that studies using soil freshly amended with a compound cannot fairly reflect the biodegradative ability of a compound which has been in contact with soil for a long period of time and has thus undergone weathering processes. Sorption of compounds mainly by soil organic matter has been indicated, with increasing organic matter generally resulting in increasing sorption (Manilal and Alexander, 1991; Maliszewska-Kordybach, 1998). It is believed that a compound in contact with soil for a long time will be more strongly sorbed, have a lesser ability to desorb and will be generally less bioavailable that a compound that was recently spiked into the same soil environment. This is reflected experimentally by an initial period of relatively rapid biodegradation followed by a phase of little to no further loss.

# 72

Keck et. al. (1989) looked at PAH disappearance as the single compound, in a defined mixture of PAH compounds, in oil refinery waste, and in a creosote wood-preserving waste. The degradation of 3-ring PAH compounds was similar in all four systems; however, PAH compounds with 4 or more rings were more rapidly degraded in the oil-refinery and the wood-preserving waste. This suggested to the authors that co-oxidation of these larger PAH compounds was occurring. Rates of biodegradation also appear to be higher in environments where the medium is contaminated when compared to sites which are initially pristine (Herbes and Schwall, 1978; Cerniglia, 1992). 3.2.1. Naphthalene Naphthalene is a PAH with a 2-ring structure. In general, PAHs that contain three or fewer rings tend to be biodegraded more rapidly than compounds containing four or five benzene rings. First-order rate constants for naphthalene ranged from 0.0064/day to 5.0/day, with the majority of the values occurring between 0.1 to 1.0/day. These values correspond to half-lives of <1 to 108 days. The highest rate constant (5.0/day) resulted from polluted groundwater obtained downgradient from a landfill (Albrechtsen et. al., 1996) while the lowest rate constant was calculated from a field experiment in which naphthalene was injected into a series of wells and its concentration was measured over time (MacIntyre et. al., 1993). The primary biodegradation of naphthalene resulted in the following products: cis-1,2-dihydroxy-1,2-dihydronaphthalene, 1-naphthol, salicylic acid and catechol (Heitkamp & Cerniglia, 1987). Naphthalene will be degraded rapidly by indigenous microorganisms in soils and groundwater that have previously been exposed to PAHs. The rate constant determined from sediment in an oil polluted stream was 3.36/day while the rate constant determined from sediment in a non-polluted stream was less than 0.0096/day (Herbes and Schwall, 1978) . The median for the primary biodegradation rate constant of naphthalene is 0.308/day (N = 49); a range of 0 to 5.0/day is reported. The median for the mineralization rate constant of naphthalene is 0.023/day (N = 47); a range of 0 to 3.34/day is reported. The frequency distribution histograms for this data are shown in figures 7a and 7b.

# 73 

# 0 5 10 15 20

00.71.52.233.74.55.2

Half-Life (days-1

# )Frequency



# 0 10 20 30 40

00.40.81.21.622.42.83.2

Half-Life (days-1

# )Frequency 

# Figure 7a.Frequency distribution histogram for the published primary biodegradation rate constant values of naphthalene.

Figure 7b.Frequency distribution histogram for the published mineralization rate constant values of naphthalene.

# 74

Table 8.Aerobic biodegradation rate constant values for naphthalene Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference
NaphthaleneColumbus AFB,

Mississippi Aquifer Aquifer sediment + groundwater Field 7.23 mg/L 440 0.0064/day MacIntyre,WG et. al. (1993)
NaphthaleneGrindsted,

Denmark Landfill Groundwater Groundwater grab sample 100 ug/L 50 0.028/day Albrechtsen,HJ et. al. (1996)
NaphthaleneVejen, Denmark Landfill Groundwater Groundwater grab sample 100 ug/L 10 0.56/day Albrechtsen,HJ et. al. (1996)
NaphthaleneGainesville,

Florida Groundwater Groundwater Groundwater grab sample 1.5 mg/L 8 0.77/day 5 Delfino,JJ & Miles,CJ (1985)
NaphthaleneDenmark Groundwater Groundwater grab sample 200-1000 ug/L 4.1 1.29-1.68/day Arvin,E et. al. (1988)
NaphthaleneGrindsted,

Denmark Heavy oil contamination Groundwater Groundwater grab sample 500-1000 ug/L 4.4 1.44-1.57/day Arvin,E et. al. (1988)
NaphthaleneVejen, Denmark Landfill Groundwater + sterile quartz Groundwater grab sample 100 ug/L 10 2.5/day Albrechtsen,HJ et. al. (1996)
NaphthaleneHorsholm,

Denmark Gasoline contamination Groundwater Groundwater grab sample 500-1000 ug/L 2.1 2.96-3.29/day Arvin,E et. al. (1988)
NaphthaleneGanlose, DenmarkFuel oil contamination Groundwater Groundwater grab sample 500-1000 ug/L 1.5 4.14-4.61/day Arvin,E et. al. (1988)
NaphthaleneGrindsted,

Denmark Heavy oil contamination Groundwater Groundwater grab sample 4/day Arvin,E et. al. (1988)
NaphthaleneVejen, Denmark Landfill Groundwater + sterile rock wool Groundwater grab sample 100 ug/L 10 5.0/day Albrechtsen,HJ et. al. (1996)
NaphthaleneGassehaven,

Denmark Fuel oil contamination Groundwater Groundwater grab sample 500-1000 ug/L 1.2 5.18-5.76/day Arvin,E et. al. (1988)
NaphthaleneVejen, Denmark Landfill Groundwater Groundwater grab sample 160 ug/L 90 7-13 ug/L/day 15 Holm,PE et. al. (1992)
NaphthaleneVejen, Denmark Landfill Aquifer sediment + groundwater In situ microcosm 150 ug/L 15 0.069/day Nielsen,PH & Christensen,TH (1994)
NaphthaleneVejen, Denmark Landfill Aquifer sediment + groundwater In situ microcosm 150 ug/L 150 0.2/day and 0.9/day 6-12 Nielsen,PH et. al. (1996)

NaphthaleneVejen, Denmark Landfill Groundwater In situ microcosm 120 ug/L 90 0.5-0.8 ug/L/day Holm,PE et. al. (1992)

# Table 8.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 75 NaphthaleneVejen City,

Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 0.8/day 6 Bjerg,PL et. al. (1996)

NaphthaleneVejen, Denmark Landfill Aquifer sediment + groundwater In situ microcosm 150 ug/L 150 0.8/day 6 Nielsen,PH et. al. (1996)

NaphthaleneVejen, Denmark Landfill Aquifer sediment + groundwater In situ microcosm 120 ug/L 90 1.5-2.0 ug/L/day Holm,PE et. al. (1992)

NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.00048- 0.0022/day Durant,ND et. al. (1995)

NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.00073- 0.010/day Durant,ND et. al. (1995)

NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.001/day Durant,ND et. al. (1995)

NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.0015/day 6 Durant,ND et. al. (1995)

NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.002- 0.0068/day Durant,ND et. al. (1995)

NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.0022/day 12 Durant,ND et. al. (1995)

NaphthaleneNarragansett Bay,

Rhode Island Uncontaminated Seawater Lab microcosm 50 ug/L 0.0022/day Lee,RF & Ryan,C (1983)
NaphthaleneNarragansett Bay,

Rhode Island Uncontaminated Seawater Lab microcosm 25 ug/L 0.0023/day Lee,RF & Ryan,C (1983)
NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.0032/day 6 Durant,ND et. al. (1995)

# Table 8.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 76 NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.0039- 0.0085/day Durant,ND et. al. (1995)

NaphthaleneSkidaway River,

Savannah, Georgia Oilcontamination River water Lab microcosm 2.5 ug/L 0.0039/day Lee,RF & Ryan,C (1983)
Naphthalene Manufactured gas plant Soil Lab microcosm 0.36 ug/g 3 0.00432 ug/g/day Fleming,JT et. al. (1993)
NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.0051/day 6 Durant,ND et. al. (1995)

NaphthaleneNarragansett Bay,

Rhode Island Uncontaminated Seawater Lab microcosm 10 ug/L 0.0055/day Lee,RF & Ryan,C (1983)
NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.0065/day Durant,ND et. al. (1995)

NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.0065/day Durant,ND et. al. (1995)

NaphthaleneAmerican

Creosote Works, Pensacola, FL Wood preserving site Soil Lab microcosm 1 mg/kg 77 0.007/day 7 Mueller,JG et. al. (1991A)

NaphthaleneConroe, Texas Landfill Aquifer sediment + groundwater Lab microcosm 56 0.0073/day Wilson,JT et. al. (1985)

NaphthaleneAmerican

Creosote Works, Pensacola, FL Wood preserving site Soil Lab microcosm 1 mg/kg 84 0.011/day Mueller,JG et. al. (1991A)

NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.011/day Durant,ND et. al. (1995)

NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.011/day Durant,ND et. al. (1995)

Naphthalene Uncontaminated Soil Lab microcosm 12 mg/kg soil 130 0.016/day 75 Pott,BM & Henrysson,T (1995)

# Table 8.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 77 NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.021/day Durant,ND et. al. (1995)

NaphthaleneAmerican

Creosote Works, Pensacola, FL Wood preserving site Sediment Lab microcosm 3924.5 mg/kg 84 0.022/day Mueller,JG et. al. (1991A)

NaphthaleneBlekholmstorget,

Stockholm, Sweden Creosote production facility Soil Lab microcosm 300 mg/kg 28 0.022/day Ellis,B et. al. (1991)

NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.023/day Durant,ND et. al. (1995)

NaphthaleneDegray Resevoir,

Arkansas Unpolluted freshwater reservoir Lake water + sediment Lab microcosm 500 ng/g 56 0.023/day Heitkamp,MA & Cerniglia,CE (1987)
NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.026/day 6 Durant,ND et. al. (1995)

NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 0.030/day Durant,ND et. al. (1995)

NaphthaleneLake Chicot,

Arkansas Freshwater lake Lake water + sediment Lab microcosm 500 ng/g 56 0.030/day Heitkamp,MA & Cerniglia,CE (1987) Naphthalene Plasticizer manufacturing site Soil Lab microcosm 340 mg/kg 42 0.035/day Fogel,S et. al. (1995)

NaphthaleneMarquette,

Michigan Aquifer near a charcoal manufacturing plant Aquifer sediment + groundwater Lab microcosm 500 ug/L 24 0.038/day Klecka,GM et. al. (1990)

NaphthaleneGeorgia coast Seawater Seawater Lab microcosm 130 ppb 1 0.04 ug/L/day Lee,RF & Ryan,C (1979) NaphthaleneRedfish Bay,

Texas Estuary Estuarine water + sediment Lab microcosm 500 ng/g 56 0.040/day Heitkamp,MA & Cerniglia,CE (1987)

# Table 8.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 78 NaphthaleneAmerican

Creosote Works, Pensacola, FL Wood preserving site Sediment Lab microcosm 0.041/day Mueller,JG et. al. (1991A)

NaphthaleneTamar Estuary,

England Estuary Estuarine water + sediment Lab microcosm 3 ug/L 1 0.041/day Readman,JW et. al. (1982)
NaphthaleneTamar Estuary,

England Estuary Estuarine water + sediment Lab microcosm 3 ug/L 1 0.041/day Readman,JW et. al. (1982)
NaphthaleneBlekholmstorget,

Stockholm, Sweden Creosote production facility Soil Lab microcosm 300 mg/kg 63 0.043/day Ellis,B et. al. (1991)

NaphthaleneMarquette,

Michigan Aquifer near a charcoal manufacturing plant Aquifer sediment + groundwater Lab microcosm 500 ug/L 24 0.043/day Klecka,GM et. al. (1990)

NaphthaleneLula, Oklahoma Aquifer Soil Lab microcosm 0.01-622 ug/g 0.044/day Swindoll,CM et. al. (1988) Naphthalene Uncontaminated Soil Lab microcosm 12 mg/kg soil 80 0.046/day Pott,BM & Henrysson,T (1995) Naphthalene Plasticizer manufacturing site Soil Lab microcosm 3800 mg/kg 98 0.049/day Fogel,S et. al. (1995)

NaphthaleneSkidaway River,

Georgia Estuary Estuarine water Lab microcosm 40 ppb 2 0.05 ug/L/day Lee,RF & Ryan,C (1979)
NaphthaleneCooper River,

Charleston, South Carolina Oilcontamination River water Lab microcosm 2.5 ug/L 0.05/day Lee,RF & Ryan,C (1983)

NaphthaleneTamar Estuary,

England Estuary Estuarine water + sediment Lab microcosm 3 ug/L 1 0.055/day Readman,JW et. al. (1982)
NaphthaleneMarquette,

Michigan Aquifer near a charcoal manufacturing plant Aquifer sediment + groundwater Lab microcosm 500 ug/L 24 0.063/day Klecka,GM et. al. (1990)

NaphthaleneSaucon Creek,

Bethlehem, Pennsylvania Polluted stream Stream water Lab microcosm 4 0.077/day Herbes,SE (1981)

# Table 8.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 79 NaphthaleneSkidaway River,

Georgia Estuary Estuarine water Lab microcosm 30 ug/L 1 0.07ug/L/day Lee,RF (1977)
NaphthaleneGrindsted,

Denmark Landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 20 0.089/day Albrechtsen,HJ et. al. (1996)

NaphthaleneNarragansett Bay,

Rhode Island Oilcontamination Seawater Lab microcosm 50 ug/L 0.099/day Lee,RF & Ryan,C (1983)
NaphthaleneSkidaway River,

Savannah, Georgia Oilcontamination River water Lab microcosm 2.5 ug/L 0.099/day Lee,RF & Ryan,C (1983)
Naphthalene Coal-tar contaminated Soil Lab microcosm 186 mg/kg soil 105 0.10/day Wischmann,H & Steinhart,H (1997) Naphthalene Plasticizer manufacturing site Soil Lab microcosm 1018 mg/kg 49 0.12/day Fogel,S et. al. (1995)

NaphthaleneNarragansett Bay,

Rhode Island Oilcontamination Seawater Lab microcosm 25 ug/L 0.14/day Lee,RF & Ryan,C (1983)
NaphthaleneNarragansett Bay,

Rhode Island Oilcontamination Seawater Lab microcosm 10 ug/L 0.17/day Lee,RF & Ryan,C (1983)
NaphthaleneLincolnshire, UK Unpolluted soil Soil Lab microcosm 0.5 mg/g 0.20/day Smith,MJ et. al. (1997) NaphthaleneSufflok, UK Unpolluted sand Soil Lab microcosm 0.5 mg/g 0.20/day Smith,MJ et. al. (1997) NaphthaleneUttar Pradesh,

India Soil receiving effluent from an oil refinery Soil Lab microcosm 20 mg/kg 60 0.23/day Ashok,BT et. al. (1995)

NaphthaleneHudson River

Estuary, New York Estuary Estuarine water Lab microcosm 1 ug/L 2 0.26/day Hudak,JP et. al. (1988)

NaphthaleneMississippi Uncontaminated Soil Lab microcosm 101 mg/kg 105 0.308/day Park,KS et. al. (1990) NaphthalenePaleudult,

Mississippi Pristine soil Soil Lab microcosm 101 mg/kg 105 0.308/day Park,KS et. al. (1990)
NaphthaleneCalciaquoll, Utah Pristine soil Soil Lab microcosm 101 mg/kg 196 0.337/day Park,KS et. al. (1990) NaphthaleneUtah Uncontaminated Soil Lab microcosm 101 mg/kg 196 0.3370/day Park,KS et. al. (1990)

# Table 8.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 80 NaphthaleneSkidaway River,

Savannah, Georgia Oilcontamination River water Lab microcosm 2.5 ug/L 0.35/day Lee,RF & Ryan,C (1983)
NaphthaleneCass County,

North Dakota Agricultural soil Soil Lab microcosm 7 mg/L 10 0.39/day Mihelcic,JR & Luthy,RG (1988) NaphthaleneVejen, Denmark Landfill Aquifer sediment + groundwater Lab microcosm 150 ug/L 150 0.4/day 10 Nielsen,PH et. al. (1996)

NaphthaleneSkidaway River,

Georgia Estuary Estuarine water Lab microcosm 15 ug/L 1 0.42 ug/L/day Lee,RF (1977)
NaphthaleneSkidaway River,

Georgia Estuary Estuarine water Lab microcosm 40 ppb 0.33 0.56 ug/L/day Lee,RF & Ryan,C (1975)
NaphthaleneSkidaway River,

Georgia Estuary Estuarine water Lab microcosm 30 ug/L 1 0.68 ug/L/day Lee,RF (1977)
NaphthaleneTamar Estuary,

England Estuary Estuarine water + sediment Lab microcosm 3 ug/L 1 0.693/day Readman,JW et. al. (1982)
NaphthaleneUnspecified site Polluted pond Pond water + sediment Lab microcosm 10 mg/L 2 0.77/day Meyer,JS et. al. (1984)
NaphthaleneUnspecified site Polluted pond Pond water + sediment Lab microcosm 10 mg/L 10 0.77/day 8 Meyer,JS et. al. (1984)
NaphthaleneTamar Estuary,

England Estuary Estuarine water + sediment Lab microcosm 3 ug/L 1 0.80/day Readman,JW et. al. (1982)
NaphthaleneSkidaway River,

Georgia Estuary Estuarine water Lab microcosm 30 ug/L 1 0.82 ug/L/day Lee,RF (1977)
NaphthaleneVejen, Denmark Landfill Aquifer sediment + groundwater Lab microcosm 150 ug/l 150 0.9/day 8-9 Nielsen,PH et. al. (1996)

NaphthaleneSkidaway River,

Georgia Estuary Estuarine water Lab microcosm 40 ppb 1 0.90 ug/L/day Lee,RF & Ryan,C (1975)
NaphthaleneSkidaway River,

Georgia Estuary Estuarine water Lab microcosm 60 ug/L 1 1.2 ug/L/day Lee,RF (1977)
Naphthalene Manufactured gas plant Soil Lab microcosm 0.36 ug/g 3 1.22 ug/g/day Fleming,JT et. al. (1993)

# Table 8.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 81 NaphthaleneLong Island

Sound, New York Estuary Estuarine water Lab microcosm 1 ug/L 2 1.63/day Hudak,JP et. al. (1988)
NaphthaleneAmerican

Creosote Works, Pensacola, FL Wood preserving site Aquifer sediment + soil Lab microcosm 28.7 ug/L 14 1.85/day Mueller,JG et. al. (1991)

NaphthaleneSaucon Creek,

Bethlehem, Pennsylvania Polluted stream Sediment Lab microcosm 1 ug/g 24 1.87/day Herbes,SE (1981)

NaphthaleneTamar Estuary,

England Estuary Estuarine water + sediment Lab microcosm 3 ug/L 1 1/day Readman,JW et. al. (1982)
NaphthaleneVejen, Denmark Landfill Aquifer sediment + groundwater Lab microcosm 160 ug/L 90 12-13 ug/L/day 15 Holm,PE et. al. (1992)

Naphthalene Creosote contaminated soil Soil Lab microcosm 0.36 ug/g 3 18.7 ug/g/day Fleming,JT et. al. (1993)

NaphthaleneHudson River

Estuary, New York Estuary Estuarine water Lab microcosm 1 ug/L 2 2.4/day Hudak,JP et. al. (1988)

NaphthaleneCooper River,

South Carolina Estuary Estuarine water Lab microcosm 30 ug/L 1 2.8 ug/L/day Lee,RF (1977)
NaphthaleneFort Point

Channel, Boston Harbor Estuary Sediment Lab microcosm 20 ng/g 2.5 2277.6 ng/g/day Shiaris,MP (1989)

NaphthaleneWeymouth Back

River, Boston Harbor Estuary Sediment Lab microcosm 20 ng/g 2.5 27.84 ng/g/day Shiaris,MP (1989)

NaphthaleneVejen, Denmark Landfill Aquifer sediment + groundwater Lab microcosm 100 ug/L 10 3.3/day Albrechtsen,HJ et. al. (1996)

NaphthaleneKnoxville,

Tennessee Oilcontaminated stream Sediment Lab microcosm 2 3.36/day Herbes,SE & Schwall,LR (1978)
NaphthaleneSkidaway River,

Georgia Estuary Estuarine water Lab microcosm 130 ppb 1 4.4 ug/L/day Lee,RF & Ryan,C (1975)

# Table 8.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 82 NaphthaleneCooper River,

South Carolina Estuary Estuarine water Lab microcosm 60 ug/L 1 4.7 ug/L/day Lee,RF (1977)
NaphthaleneLower Neck

Quincy Bay, Boston Harbor Estuary Sediment Lab microcosm 20 ng/g 2.5 41.28 ng/g/day Shiaris,MP (1989)

NaphthaleneConroe, Texas Landfill Aquifer sediment + groundwater Lab microcosm 200 ug/L 8 67.2 ug/L/day Thomas,JM et. al. (1986)

Naphthalene Manufactured gas plant Soil Lab microcosm 0.36 ug/g 3 7.7X10-4 ug/g/day Fleming,JT et. al. (1993)
NaphthaleneVejen, Denmark Landfill Aquifer sediment + groundwater Lab microcosm 160 ug/L 90 9-10 ug/L/day 15 Holm,PE et. al. (1992)

NaphthaleneWalker Branch,

Oakridge, Tennessee Non-polluted stream Sediment Lab microcosm 5 < 0.0096/day Herbes,SE & Schwall,LR (1978)
NaphthaleneConroe, Texas Landfill Aquifer sediment + groundwater Lab microcosm 56 > 0.32/day Wilson,JT et. al. (1985)

NaphthaleneConroe, Texas Landfill Aquifer sediment + groundwater Lab microcosm 56 > 0.51/day Wilson,JT et. al. (1985)

Naphthalene Plasticizer manufacturing site Soil Lab microcosm 34-35 mg/kg 63 No biodegradation Fogel,S et. al. (1995)

NaphthaleneBaltimore Gas &

Electric Spring Gardens Former manufactured gas plant facility Aquifer sediment Lab microcosm 4 mg/L 42 No mineralization Durant,ND et. al. (1995)

# 83 

# 0 10 20 30

00.050.10.150.20.250.30.35

Rate constant (days-1

# )Frequency



# 0 1 2 3 4

00.010.020.030.040.050.06

Rate constant (days-1

# )Frequency 

# 3.2.2. Fluorene Fluorene is a PAH with a 3-ring structure, that is virtually insoluble in water. In general, PAHs that contain three or fewer rings tend to be biodegraded more rapidly than compounds containing four or five benzene rings. First-order rate constants were in the range of 0.0018/day to 0.33/day, corresponding to half-lives of about 2 to 385 days. The smallest rate constant was observed in a pristine soil with no history of pollution (Park et. al., 1990), while the largest rate constant was observed in creosote-contaminated aquifer material obtained from a wood preserving site (Mueller et. al., 1991). One study reported 9-fluorenone as a primary biodegradation product of fluorene (Wischmann and Steinhart, 1997). The median for the primary biodegradation rate constant of fluorene is 0.015/day (N = 28); a range of 0.0018 to 0.33/day is reported. The median for the mineralization rate constant of fluorene is 0.019/day (N = 7); a range of 0.00385 to 0.05/day is reported.The frequency distribution histograms for this data are shown in figures 8a and 8b. For the most part, fluorene is expected to biodegrade slowly under aerobic conditions in the environment.

Figure 8a.Frequency distribution histogram for the published primary biodegradation rate constant values of fluorene.

Figure 8b.Frequency distribution histogram for the published mineralization rate constant values of fluorene

# 84

Table 9.Aerobic biodegradation rate constant values for fluorene Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference

Fluorene Brookhaven, Mississippi Wood-preserving site Soil Field 225 ug/g 56 0.025/day Lamar,RT & Glaser,JA (1994) Fluorene Calciaquoll, Utah Pristine soil Soil Lab microcosm 883 mg/kg 196 0.0018/day Park,KS et. al. (1990) Fluorene Paleudult, Mississippi Pristine soil Soil Lab microcosm 913 mg/kg 105 0.0026/day Park,KS et. al. (1990) Fluorene American Creosote Works,

Pensacola, FL Wood preserving site Sediment Lab microcosm 1792.1 mg/kg 84 0.003/day Mueller,JG et. al. (1991A) Fluorene Skidaway River,

Savannah, Georgia Oil-contamination Sediment Lab microcosm 2.5 ug/g sediment 0.00385/day Lee,RF & Ryan,C (1983)

Fluorene American Creosote Works,

Pensacola, FL Wood preserving site Sediment Lab microcosm 1792.1 mg/kg 84 0.004/day Mueller,JG et. al. (1991A) Fluorene American Creosote Works,

Pensacola, FL Wood preserving site Soil Lab microcosm 3.1 mg/kg 84 0.004/day Mueller,JG et. al. (1991A) Fluorene Musi River, India Hazardous waste site Soil Lab microcosm 1000 ppm 450 0.0041/day Mahmood,SK & Rao,PR (1993) Fluorene Skidaway Institute of

Oceanography, GA Uncontaminated Sediment Lab microcosm 2.5 ug/g sediment 3 0.006/day Lee,RF & Silva,M (1994)

Fluorene Montreal, Quebec Uncontaminated Soil Lab microcosm 100 mg/L 120 0.0069/day Leduc,R et. al. (1992) Fluorene Utah State University,

Kaysville, Utah Uncontaminated soil Soil Lab microcosm 29 ug/g 0.007/day Keck,J et. al. (1989)

Fluorene Blekholmstorget,

Stockholm, Sweden Creosote production facility Soil Lab microcosm 124 mg/kg 28 0.0071/day Ellis,B et. al. (1991)

Fluorene Blekholmstorget,

Stockholm, Sweden Creosote production facility Soil Lab microcosm 124 mg/kg 63 0.0073/day Ellis,B et. al. (1991)

Fluorene Skidaway River,

Savannah, Georgia Oil-contamination Sediment Lab microcosm 2.5 ug/g sediment 0.00845/day Lee,RF & Ryan,C (1983)

Fluorene Coal-tar contaminated Soil Lab microcosm 198 mg/kg soil 175 0.0085/day Wischmann,H & Steinhart,H (1997) Fluorene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.0099/day MaliszewskaKordybach,B (1993)

# Table 9.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 85 Fluorene Conroe, Texas Landfill Aquifer sediment + groundwater Lab microcosm 56 0.012/day Wilson,JT et. al. (1985)

Fluorene Kaysville, Utah Uncontaminated Soil Lab microcosm 100 ug/g 240 0.012/day Coover,MP & Sims,RC (1987) Fluorene Kaysville, Utah Uncontaminated Soil Lab microcosm 100 ug/g 240 0.015/day Coover,MP & Sims,RC (1987) Fluorene Utah State University,

Kaysville, Utah Uncontaminated soil Soil Lab microcosm 100 ug/g 0.015/day Keck,J et. al. (1989)

Fluorene American Creosote Works,

Pensacola, FL Wood preserving site Soil Lab microcosm 3.1 mg/kg 84 0.019/day Mueller,JG et. al. (1991A) Fluorene Narragansett Bay, Rhode

Island Uncontaminated Sediment Lab microcosm 1 ug/g sediment 0.019/day Lee,RF & Ryan,C (1983)

Fluorene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.022/day MaliszewskaKordybach,B (1993) Fluorene Kaysville, Utah Uncontaminated Soil Lab microcosm 100 ug/g 240 0.022/day Coover,MP & Sims,RC (1987) Fluorene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.025/day MaliszewskaKordybach,B (1993) Fluorene Narragansett Bay, Rhode

Island Oil-contamination Sediment Lab microcosm 5 ug/g sediment 0.025/day Lee,RF & Ryan,C (1983)

Fluorene Utah State University,

Kaysville, Utah Uncontaminated soil Soil Lab microcosm 180 ug/g 0.027/day Keck,J et. al. (1989)

Fluorene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.0277/day MaliszewskaKordybach,B (1993) Fluorene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.029/day MaliszewskaKordybach,B (1993) Fluorene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.0335/day MaliszewskaKordybach,B (1993) Fluorene Narragansett Bay, Rhode

Island Oil-contamination Sediment Lab microcosm 2.5 ug/g sediment 0.035/day Lee,RF & Ryan,C (1983)

# Table 9.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 86 Fluorene Skidaway Institute of

Oceanography, GA Uncontaminated Sediment Lab microcosm 2.5 ug/g sediment 3 0.05/day Lee,RF & Silva,M (1994)

Fluorene Delson, Quebec, Canada Wood-preserving industrial site Soil Lab microcosm 181 mg/kg soil 77 0.061/day Deschenes,L et. al. (1996) Fluorene Narragansett Bay, Rhode

Island Oil-contamination Sediment Lab microcosm 1 ug/g sediment 0.063/day Lee,RF & Ryan,C (1983)

Fluorene Delson, Quebec, Canada Wood-preserving industrial site Soil Lab microcosm 240 mg/kg soil 14 0.11/day Deschenes,L et. al. (1995) Fluorene Conroe, Texas Landfill Aquifer sediment + groundwater Lab microcosm 56 0.18/day Wilson,JT et. al. (1985)

Fluorene American Creosote Works,

Pensacola, FL Wood preserving site Aquifer sediment + soil Lab microcosm 11.6 ug/mL 14 0.33/day Mueller,JG et. al. (1991)

# 87 

# 0 10 20 30

00.010.020.030.040.050.060.070.08

Rate constant (days-1

# )Frequency 

# 3.2.3. Benzo(a)anthracene Benzo(a)anthracene is a PAH with a 4-ring structure, that is virtually insoluble in water. In general,PAHs that contain more than 3 rings tend to be biodegraded rather slowly in the environment. Firstorder rate constants were in the range of 0.000033/day to 0.116/day, corresponding to half-lives of about 6 to 21,000 days. The majority of the rate constants were less than 0.01/day. There were also several studies for which no rate constant was reported or could be calculated since the compound was not observed to biodegrade during the course of the study. This included an experiment where no measurable biodegradation was observed in a coal-tar polluted soil over a 80 day incubation period (Grosser et. al., 1995). Similar results were obtained from other studies with shorter incubation periods (Carmichael and Pfaender, 1997; Lee et. al., 1978; Herbes, 1981). Biodegradation reaction products were reported as benzo(a)anthracene-7,12-dione (Wischmann and Steinhart, 1997) and unspecified phenol and quinone metabolites (Hinga et. al., 1980). The median for the primary biodegradation rate constant of benzo(a)anthracene, considering all studies, is 0.0035/day (N = 27); a range of 0.000096 to 0.072/day is reported. The median for the mineralization rate constant of benzo(a)anthracene is 0.0029/day (N = 32); a range of not biodegraded to 0.116/day is reported.The frequency distribution histograms for the data are shown in figures 9a and 9b. For the most part, benzo(a)anthracene is expected to biodegrade slowly under aerobic conditions or be recalcitrant in the environment.

Figure 9a.Frequency distribution histogram for the published primary biodegradation rate constant values of benzo(a)anthracene.

# 88 

# 0 5 10 15 20

00.020.040.060.080.10.12

Rate constant (days-1

# )Frequency



# Figure 9b.Frequency distribution histogram for the published mineralization rate constant values of benzo(a)anthracene.

# 89

Table 10.Aerobic biodegradation rate constant values for benzo(a)anthracene Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference
Benzo(a)anthraceneBrookhaven, Mississippi Wood-preserving site Soil Field 74 ug/g 56 0.0021/day Lamar,RT & Glaser,JA (1994) Benzo(a)anthraceneWiroa Island, Auckland, New Zealand Uncontaminated Sediment Field 256 <0.00693/day Wilcock,RJ et. al. (1996)
Benzo(a)anthraceneNarragansett Bay, Rhode Island Uncontaminated Sediment Lab microcosm2.5 ug/g sediment 0.000033/day Lee,RF & Ryan,C (1983)
Benzo(a)anthraceneWalker Branch, Oak Ridge, Tennessee Uncontaminated Sediment Lab microcosm 26 0.000096/day Herbes,SE & Schwall,LR (1978) Benzo(a)anthraceneNarragansett Bay, Rhode Island Uncontaminated Sediment Lab microcosm2.5 ug/g sediment 0.00029/day Lee,RF & Ryan,C (1983)
Benzo(a)anthracene Uncontaminated Soil Lab microcosm 480 0.0005/day 120 Bossert,ID & Bartha,R (1986) Benzo(a)anthraceneDover, Ohio Coal tar refining plant Soil Lab microcosm 1.2 ng/g 80 0.0006/day Grosser,RJ et. al. (1995)
Benzo(a)anthraceneDover, Ohio Coal tar refining plant Soil Lab microcosm 1.2 ng/g 80 0.0006/day Grosser,RJ et. al. (1995)
Benzo(a)anthraceneNarragansett Bay, Rhode Island Uncontaminated Sediment Lab microcosm2.5 ug/g sediment 0.00063/day Lee,RF & Ryan,C (1983)
Benzo(a)anthraceneAmerican Creosote Works, Pensacola, FL Wood preserving site Soil Lab microcosm 11.9 mg/kg 84 0.001/day Mueller,JG et. al. (1991A)
Benzo(a)anthraceneKaysville, Utah Uncontaminated Soil Lab microcosm 30.1 ug/g 240 0.001/day Coover,MP & Sims,RC (1987) Benzo(a)anthraceneDover, Ohio Coal tar refining plant Soil Lab microcosm 1.2 ng/g 80 0.0015- 0.0058/day Grosser,RJ et. al. (1995)
Benzo(a)anthraceneSkidaway River, Savannah, Georgia Oil-contamination Sediment Lab microcosm2.5 ug/g sediment 0.0015/day Lee,RF & Ryan,C (1983)
Benzo(a)anthraceneKaysville, Utah Uncontaminated Soil Lab microcosm 30.1 ug/g 240 0.0016/day Coover,MP & Sims,RC (1987)

# Table 10.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 90 Benzo(a)anthraceneReilly Tar & Chemical,St. Louis Park, MN Industrial location Soil Lab microcosm214 ng/g 56 0.0019/day Carmichael,LM & Pfaender,FK (1997) Benzo(a)anthraceneSkidaway River, Savannah, Georgia Oil-contamination Sediment Lab microcosm2.5 ug/g sediment 0.002/day Lee,RF & Ryan,C (1983)
Benzo(a)anthraceneUtah State University, Kaysville, Utah Uncontaminated soil Soil Lab microcosm 30.1 ug/g 0.002/day Keck,J et. al. (1989)
Benzo(a)anthraceneCalciaquoll, Utah Pristine soil Soil Lab microcosm 33 mg/kg 196 0.0022/day Park,KS et. al. (1990) Benzo(a)anthracene Uncontaminated Soil Lab microcosm21.5 mg/kg soil 175 0.0023/day 80 Pott,BM & Henrysson,T (1995) Benzo(a)anthraceneKnoxville, Tennessee Oil contaminated Sediment Lab microcosm 26 0.0024/day Herbes,SE & Schwall,LR (1978) Benzo(a)anthraceneCalciaquoll, Utah Pristine soil Soil Lab microcosm 107 mg/kg 196 0.0026/day Park,KS et. al. (1990) Benzo(a)anthraceneUtah Uncontaminated Soil Lab microcosm 107 mg/kg 196 0.0026/day Park,KS et. al. (1990) Benzo(a)anthraceneKaysville, Utah Uncontaminated Soil Lab microcosm 30.1 ug/g 240 0.0029/day Coover,MP & Sims,RC (1987) Benzo(a)anthraceneSkidaway Institute of Oceanography, GA Uncontaminated Sediment Lab microcosm2.5 ug/g sediment 3 0.0029/day Lee,RF & Silva,M (1994)
Benzo(a)anthraceneAmerican Creosote Works, Pensacola, FL Wood preserving site Sediment Lab microcosm22.6 mg/kg 84 0.003/day Mueller,JG et. al. (1991A)
Benzo(a)anthraceneUtah State University, Kaysville, Utah Uncontaminated soil Soil Lab microcosm 107 ug/g 0.003/day Keck,J et. al. (1989)
Benzo(a)anthracenePaleudult, Mississippi Pristine soil Soil Lab microcosm 33 mg/kg 105 0.0030/day Park,KS et. al. (1990) Benzo(a)anthraceneCentral Narragansett Bay Uncontaminated Seawater + sediment Lab microcosm 230 0.0035/day Hinga,KR et. al. (1980)
Benzo(a)anthraceneAmerican Creosote Works, Pensacola, FL Wood preserving site Sediment Lab microcosm22.6 mg/kg 84 0.004/day Mueller,JG et. al. (1991A)

# Table 10.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 91 Benzo(a)anthraceneAmerican Creosote Works, Pensacola, FL Wood preserving site Soil Lab microcosm 11.9 mg/kg 84 0.004/day Mueller,JG et. al. (1991A)
Benzo(a)anthraceneMississippi Uncontaminated Soil Lab microcosm99 mg/kg 105 0.0043/day Park,KS et. al. (1990) Benzo(a)anthracenePaleudult, Mississippi Pristine soil Soil Lab microcosm99 mg/kg 105 0.0043/day Park,KS et. al. (1990) Benzo(a)anthraceneDover, Ohio Coal tar refining plant Soil Lab microcosm 1.2 ng/g 80 0.0045- 0.012/day Grosser,RJ et. al. (1995)
Benzo(a)anthraceneSkidaway River, Savannah, Georgia Oil-contamination Sediment Lab microcosm2.5 ug/g sediment 0.0058/day Lee,RF & Ryan,C (1983)
Benzo(a)anthraceneDelson, Quebec, Canada Wood-preserving industrial site Soil Lab microcosm 128 mg/kg soil 315 0.0073/day Deschenes,L et. al. (1996)
Benzo(a)anthraceneDelson, Quebec, Canada Wood-preserving industrial site Soil Lab microcosm 180 mg/kg soil 315 0.0076/day Deschenes,L et. al. (1995)
Benzo(a)anthraceneUtah State University, Kaysville, Utah Uncontaminated soil Soil Lab microcosm 53 ug/g 0.008/day Keck,J et. al. (1989)
Benzo(a)anthraceneDubose Oil Recycling, Cantonment, FL Industrial location Soil Lab microcosm214 ng/g 56 0.009/day Carmichael,LM & Pfaender,FK (1997) Benzo(a)anthraceneReilly Tar & Chemical,St. Louis Park, MN Industrial location Soil Lab microcosm214 ng/g 56 0.009/day Carmichael,LM & Pfaender,FK (1997) Benzo(a)anthraceneUtah State University, Kaysville, Utah Uncontaminated soil Soil Lab microcosm 130.1 ug/g 0.009/day Keck,J et. al. (1989)
Benzo(a)anthraceneReilly Tar & Chemical,St. Louis Park, MN Contaminated Soil Lab microcosm214 ng/g 56 0.0091/day Carmichael,LM & Pfaender,FK (1997) Benzo(a)anthraceneDubose Oil Recycling, Cantonment, FL Industrial location Soil Lab microcosm214 ng/g 56 0.012/day Carmichael,LM & Pfaender,FK (1997) Benzo(a)anthraceneDubose Oil Recycling, Cantonment, FL Contaminated Soil Lab microcosm214 ng/g 56 0.014/day Carmichael,LM & Pfaender,FK (1997) Benzo(a)anthracene Uncontaminated Soil Lab microcosm24 mg/kg soil 130 0.016/day Pott,BM & Henrysson,T (1995)

# Table 10.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 92 Benzo(a)anthraceneSkidaway Institute of Oceanography, GA Uncontaminated Sediment Lab microcosm2.5 ug/g sediment 3 0.019/day Lee,RF & Silva,M (1994)
Benzo(a)anthraceneReilly Tar & Chemical,St. Louis Park, MN Contaminated Soil Lab microcosm214 ng/g 56 0.022/day Carmichael,LM & Pfaender,FK (1997) Benzo(a)anthraceneCentral Narragansett Bay Uncontaminated Seawater + sediment Lab microcosm270 ng/L 202 0.024/day Hinga,KR & Pilson,MEQ (1987) Benzo(a)anthracene Uncontaminated Soil Lab microcosm23 mg/kg soil 130 0.027/day 20 Pott,BM & Henrysson,T (1995) Benzo(a)anthraceneCooper River, Charleston, South Carolina Oil-contamination Sediment Lab microcosm2.5 ug/g sediment 0.043/day Lee,RF & Ryan,C (1983)
Benzo(a)anthraceneDubose Oil Recycling, Cantonment, FL Contaminated Soil Lab microcosm214 ng/g 56 0.05/day Carmichael,LM & Pfaender,FK (1997) Benzo(a)anthraceneAmerican Creosote Works, Pensacola, FL Wood preserving site Aquifer sediment + soil Lab microcosm2.9 ug/mL 14 0.052/day Mueller,JG et. al. (1991)

Benzo(a)anthraceneSaucon Creek, Bethlehem, PA Contaminated Sediment Lab microcosm 1 ug/g sediment 4 0.072/day Herbes,SE (1981)
Benzo(a)anthraceneSaucon Creek, Bethlehem, PA Uncontaminated Sediment Lab microcosm 1 ug/g sediment 4 0.072/day Herbes,SE (1981)
Benzo(a)anthraceneNarragansett Bay, Rhode Island Oil-contamination Sediment Lab microcosm 5 ug/g sediment 0.087/day Lee,RF & Ryan,C (1983)
Benzo(a)anthraceneNarragansett Bay, Rhode Island Oil-contamination Sediment Lab microcosm 1 ug/g sediment 0.116/day Lee,RF & Ryan,C (1983)
Benzo(a)anthraceneNarragansett Bay, Rhode Island Oil-contamination Sediment Lab microcosm2.5 ug/g sediment 0.116/day Lee,RF & Ryan,C (1983)
Benzo(a)anthracene Coal-tar contaminated Soil Lab microcosm<0.2 mg/kg soil 175 Biodegrades Wischmann,H & Steinhart,H (1997)

# Table 10.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 93 Benzo(a)anthraceneAlaskan continental shelf Uncontaminated Seawater + sediment Lab microcosm 42 No mineralizatio n Roubal,G & Atlas,RM (1978)
Benzo(a)anthraceneBozeman, MT Pristine soil Soil Lab microcosm214 ng/g 56 No mineralizatio n Carmichael,LM & Pfaender,FK (1997)
Benzo(a)anthraceneBozeman, Montana Uncontaminated Soil Lab microcosm214 ng/g 56 No mineralizatio n Carmichael,LM & Pfaender,FK (1997)
Benzo(a)anthraceneDover, Ohio Coal tar refining plant Soil Lab microcosm 1.2 ng/g 80 No mineralizatio n Grosser,RJ et. al. (1995)

Benzo(a)anthraceneSaanich Inlet, western Canada Uncontaminated Seawater + sediment Lab microcosm 3 No mineralizatio n Lee,RF et. al. (1978)

Benzo(a)anthraceneSaanich Inlet, western Canada Uncontaminated Seawater + sediment Lab microcosm 3 No mineralizatio n Lee,RF et. al. (1978)

Benzo(a)anthraceneSaucon Creek, Bethlehem, PA Contaminated Creek water Lab microcosm 4 No mineralizatio n Herbes,SE (1981)

# 94 

# 0 10 20 30

00.010.020.030.04

Rate constant (days-1

# )Frequency 

# 3.2.4. Chrysene Chrysene is a PAH with a 4-ring structure, that is virtually insoluble in water. In general, PAHs that contain more than 3 rings tend to be biodegraded rather slowly in the environment. First-order rate constants were in the range of 0.0005/day to 0.037/day, corresponding to half-lives of about 19 to 1,400 days. The majority of the rate constants were smaller than 0.01/day. There were also several studies for which no rate constant was reported or could be calculated since the compound was not observed to biodegrade during the course of the study. This included an experiment where no measurable biodegradation was observed in an uncontaminated soil over a 56-day incubation period (Carmichael and Pfaender, 1997). Similar results were obtained from other studies with shorter incubation periods (Ellis et. al., 1991; Hungspreugs et. al., 1984). No reaction products were reported for the degradation of chrysene. The median for the primary biodegradation rate constant of chrysene is 0.003/day (N = 31); a range of not biodegraded to 0.037/day is reported. The median for the mineralization rate constant of chrysene is 0.0037/day (N = 20); a range from not biodegraded to 0.035/day is reported. The frequency distribution histograms for this data are shown in figures 10a and 10b. Chrysene is expected to biodegrade slowly under aerobic conditions or to be recalcitrant in the environment.

Figure 10a.Frequency distribution histogram for the published primary biodegradation rate constant values of chrysene.

# 95 

# 0 5 10

00.010.020.030.04

Rate constant (days-1

# )Frequency



# Figure 10b.Frequency distribution histogram for the published mineralization rate constant values of chrysene.

# 96

Table 11.Aerobic biodegradation rate constant values for chrysene Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference
Chrysene Brookhaven, Mississippi Wood-preserving site Soil Field 90 ug/g 56 0.0011/day Lamar,RT & Glaser,JA (1994) Chrysene Wiroa Island, Auckland,

New Zealand Uncontaminated Sediment Field 256 <0.00693/day Wilcock,RJ et. al. (1996) Chrysene Skidaway River, Savannah,

Georgia Oil-contamination Sediment Lab microcosm 2.5 ug/g sediment 0.0005/day Lee,RF & Ryan,C (1983) Chrysene Uttar Pradesh, India Soil receiving effluent from an oil refinery Soil Lab microcosm 20 mg/kg 90 0.00068/day Ashok,BT et. al. (1995)

Chrysene Utah State University,

Kaysville, Utah Uncontaminated soil Soil Lab microcosm 200 ug/g 0.000693/day Keck,J et. al. (1989)
Chrysene Uncontaminated Soil Lab microcosm 480 0.0007/day 120 Bossert,ID & Bartha,R (1986) Chrysene Kaysville, Utah Uncontaminated Soil Lab microcosm 200 ug/g 240 0.0007/day Coover,MP & Sims,RC (1987) Chrysene Kaysville, Utah Uncontaminated Soil Lab microcosm 200 ug/g 240 0.00071/day Coover,MP & Sims,RC (1987) Chrysene Musi River, India Hazardous waste site Soil Lab microcosm 1000 ppm 459 0.00072/day Mahmood,SK & Rao,PR (1993) Chrysene Kaysville, Utah Uncontaminated Soil Lab microcosm 200 ug/g 240 0.00095/day Coover,MP & Sims,RC (1987) Chrysene Narragansett Bay, Rhode

Island Uncontaminated Sediment Lab microcosm 2.5 ug/g sediment 0.0014/day Lee,RF & Ryan,C (1983) Chrysene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.0017/day MaliszewskaKordybach,B (1993) Chrysene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.0017/day MaliszewskaKordybach,B (1993) Chrysene Mississippi Uncontaminated Soil Lab microcosm 105 mg/kg 105 0.0018/day Park,KS et. al. (1990) Chrysene Paleudult, Mississippi Pristine soil Soil Lab microcosm 105 mg/kg 105 0.0018/day Park,KS et. al. (1990)

# Table 11.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 97 Chrysene Calciaquoll, Utah Pristine soil Soil Lab microcosm 100 mg/kg 196 0.0019/day Park,KS et. al. (1990) Chrysene Reilly Tar & Chemical,St.

Louis Park, MN Industrial location Soil Lab microcosm 237 ng/g 56 0.0019/day Carmichael,LM & Pfaender,FK (1997) Chrysene Utah Uncontaminated Soil Lab microcosm 100 mg/kg 196 0.0019/day Park,KS et. al. (1990) Chrysene Utah State University,

Kaysville, Utah Uncontaminated soil Soil Lab microcosm 100 ug/g 0.0019/day Keck,J et. al. (1989)
Chrysene Reilly Tar & Chemical Co.,

St. Louis, MN Contaminated Soil Lab microcosm 1.6-2.8 ug/L 0.002 ug/L/hr Carmichael,LM et. al. (1997) Chrysene Skidaway River, Savannah,

Georgia Oil-contamination Sediment Lab microcosm 2.5 ug/g sediment 0.0028/day Lee,RF & Ryan,C (1983) Chrysene American Creosote Works,

Pensacola, FL Wood preserving site Sediment Lab microcosm 481.2 mg/kg 84 0.003/day Mueller,JG et. al. (1991A) Chrysene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.0030/day MaliszewskaKordybach,B (1993) Chrysene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.0035/day MaliszewskaKordybach,B (1993) Chrysene Narragansett Bay, Rhode

Island Oil-contamination Sediment Lab microcosm 2.5 ug/g sediment 0.0036/day Lee,RF & Ryan,C (1983) Chrysene Upper Gulf of Thailand Seawater + sediment Lab microcosm 3 0.0037/day Hungspreugs,M et. al. (1984) Chrysene American Creosote Works,

Pensacola, FL Wood preserving site Sediment Lab microcosm 481.2 mg/kg 84 0.004/day Mueller,JG et. al. (1991A) Chrysene Dubose Oil Recycling,

Cantonment, FL Industrial location Soil Lab microcosm 237 ng/g 56 0.004/day Carmichael,LM & Pfaender,FK (1997) Chrysene Reilly Tar & Chemical,St.

Louis Park, MN Contaminated Soil Lab microcosm 237 ng/g 56 0.0044/day Carmichael,LM & Pfaender,FK (1997) Chrysene Chao Phraya River Seawater + sediment Lab microcosm 3 0.0045/day Hungspreugs,M et. al. (1984)

# Table 11.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 98 Chrysene Utah State University,

Kaysville, Utah Uncontaminated soil Soil Lab microcosm 51 ug/g 0.0047/day Keck,J et. al. (1989)
Chrysene Blekholmstorget,

Stockholm, Sweden Creosote production facility Soil Lab microcosm 81 mg/kg 63 0.0048/day Ellis,B et. al. (1991)
Chrysene Delson, Quebec, Canada Wood-preserving industrial site Soil Lab microcosm 165 mg/kg soil 315 0.0052/day Deschenes,L et. al. (1995) Chrysene Delson, Quebec, Canada Wood-preserving industrial site Soil Lab microcosm 127 mg/kg soil 315 0.0053/day 14 Deschenes,L et. al. (1996) Chrysene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.0054/day MaliszewskaKordybach,B (1993) Chrysene Reilly Tar & Chemical,St.

Louis Park, MN Industrial location Soil Lab microcosm 237 ng/g 56 0.006/day Carmichael,LM & Pfaender,FK (1997) Chrysene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.0062/day MaliszewskaKordybach,B (1993) Chrysene Cooper River, Charleston,

South Carolina Oil-contamination Sediment Lab microcosm 2.5 ug/g sediment 0.0088/day Lee,RF & Ryan,C (1983) Chrysene American Creosote Works,

Pensacola, FL Wood preserving site Soil Lab microcosm 38 mg/kg 84 0.009/day Mueller,JG et. al. (1991A) Chrysene Dubose Oil Recycling,

Cantonment, FL Industrial location Soil Lab microcosm 237 ng/g 56 0.009/day Carmichael,LM & Pfaender,FK (1997) Chrysene Utah State University,

Kaysville, Utah Uncontaminated soil Soil Lab microcosm 140 ug/g 0.009/day Keck,J et. al. (1989)
Chrysene American Creosote Works,

Pensacola, FL Wood preserving site Soil Lab microcosm 38 mg/kg 84 0.011/day Mueller,JG et. al. (1991A) Chrysene Reilly Tar & Chemical,St.

Louis Park, MN Contaminated Soil Lab microcosm 237 ng/g 56 0.016/day Carmichael,LM & Pfaender,FK (1997) Chrysene Dubose Oil Recycling,

Cantonment, FL Contaminated Soil Lab microcosm 237 ng/g 56 0.019/day Carmichael,LM & Pfaender,FK (1997)

# Table 11.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 99 Chrysene Dubose Oil Recycling,

Cantonment, FL Contaminated Soil Lab microcosm 237 ng/g 56 0.035/day Carmichael,LM & Pfaender,FK (1997) Chrysene American Creosote Works,

Pensacola, FL Wood preserving site Aquifer sediment + soil Lab microcosm 2.7 ug/mL 14 0.037/day Mueller,JG et. al. (1991) Chrysene Dubose Oil Recycling site,

Cantonment,FL Contaminated Soil Lab microcosm 1.6-2.8 ug/L 0.04 ug/L/hr Carmichael,LM et. al. (1997) Chrysene Blekholmstorget,

Stockholm, Sweden Creosote production facility Soil Lab microcosm 81 mg/kg 28 No biodegradation Ellis,B et. al. (1991)
Chrysene Bozeman, MT Pristine soil Soil Lab microcosm 237 ng/g 56 No mineralization Carmichael,LM & Pfaender,FK (1997) Chrysene Bozeman, Montana Uncontaminated Soil Lab microcosm 237 ng/g 56 No mineralization Carmichael,LM & Pfaender,FK (1997) Chrysene Chao Phraya River River water Lab microcosm 3 No mineralization Hungspreugs,M et. al. (1984) Chrysene Upper Gulf of Thailand Seawater Lab microcosm 3 No mineralization Hungspreugs,M et. al. (1984)

# 100 

# 0 5 10

00.010.020.030.040.05

Rate constant (days-1

# )Frequency 

# 3.2.5. Fluoranthene Fluoranthene is a PAH with a 4-ring structure. In general, PAHs that contain more than 3 rings tend to be biodegraded rather slowly in the environment. The primary biodegradation rate constant for fluoranthene ranges from 0.0015/day to 0.045/day, corresponding to half-lives of about 15 to 462 days. The lowest rate constant is derived from an unpolluted pristine soil (Keck et. al., 1989), while the largest rate constant was observed in aquifer material from a heavily-polluted wood-preserving facility (Mueller et. al., 1991). The half-life of fluoranthene in pristine sediment obtained from New Zealand was reported as greater than 100 days (Wilcock et. al., 1996), further illustrating that biodegradation will be extremely slow in non-acclimated environments. No reaction products have been reported from the primary biodegradation of fluoranthene. The median for the primary biodegradation rate constant of fluoranthene is 0.0048/day (N = 20); a range of not biodegraded to 0.045/day is reported.No mineralization data are available. The frequency distribution histogram for this data is shown in figure 11. Fluoranthene is expected to biodegrade slowly or be recalcitrant under most environmental conditions.

Figure 11.Frequency histogram for the published primary biodegradation rate constant values of fluoranthene.

# 101

Table 12.Aerobic biodegradation rate constant values for fluoranthene Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference

Fluoranthene Brookhaven, Mississippi Wood-preserving site Soil Field 972 ug/g 56 0.0047/day Lamar,RT & Glaser,JA (1994) Fluoranthene Wiroa Island, Auckland,

New Zealand Uncontaminated Sediment Field 256 <0.00693/day Wilcock,RJ et. al. (1996)

Fluoranthene Southern Uintah County,

Utah Uncontaminated Soil Lab column 1.61 ug/g soil 90 0.004/day Grenney,WJ et. al. (1987) Fluoranthene Utah State University,

Kaysville, Utah Uncontaminated soil Soil Lab microcosm 400 ug/g 0.0015/day Keck,J et. al. (1989)

Fluoranthene Kaysville, Utah Uncontaminated Soil Lab microcosm 400 ug/g 240 0.0016/day Coover,MP & Sims,RC (1987) Fluoranthene Utah Uncontaminated Soil Lab microcosm 883 mg/kg 196 0.0018/day Park,KS et. al. (1990) Fluoranthene Utah State University,

Kaysville, Utah Uncontaminated soil Soil Lab microcosm 883 ug/g 0.0018/day Keck,J et. al. (1989)

Fluoranthene Mississippi Uncontaminated Soil Lab microcosm 913 mg/kg 105 0.0026/day Park,KS et. al. (1990) Fluoranthene Coal-tar contaminated Soil Lab microcosm 53 mg/kg soil 175 0.0029/day Wischmann,H & Steinhart,H (1997) Fluoranthene American Creosote Works,

Pensacola, FL Wood preserving site Sediment Lab microcosm 1628.7 mg/kg 84 0.003/day Mueller,JG et. al. (1991A) Fluoranthene Blekholmstorget,

Stockholm, Sweden Creosote production facility Soil Lab microcosm 286 mg/kg 28 0.004/day Ellis,B et. al. (1991)

Fluoranthene Blekholmstorget,

Stockholm, Sweden Creosote production facility Soil Lab microcosm 286 mg/kg 63 0.0048/day Ellis,B et. al. (1991)

Fluoranthene American Creosote Works,

Pensacola, FL Wood preserving site Sediment Lab microcosm 1628.7 mg/kg 84 0.005/day Mueller,JG et. al. (1991A) Fluoranthene Kaysville, Utah Uncontaminated Soil Lab microcosm 400 ug/g 240 0.005/day Coover,MP & Sims,RC (1987) Fluoranthene American Creosote Works,

Pensacola, FL Wood preserving site Soil Lab microcosm 34.7 mg/kg 84 0.006/day Mueller,JG et. al. (1991A)

# Table 12.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 102 Fluoranthene Delson, Quebec, Canada Wood-preserving industrial site Soil Lab microcosm 705 mg/kg soil 315 0.0095/day Deschenes,L et. al. (1996) Fluoranthene American Creosote Works,

Pensacola, FL Wood preserving site Soil Lab microcosm 34.7 mg/kg 84 0.010/day Mueller,JG et. al. (1991A) Fluoranthene Delson, Quebec, Canada Wood-preserving industrial site Soil Lab microcosm 810 mg/kg soil 315 0.010/day Deschenes,L et. al. (1995) Fluoranthene Utah State University,

Kaysville, Utah Uncontaminated soil Soil Lab microcosm 570 ug/g 0.012/day Keck,J et. al. (1989)

Fluoranthene Utah State University,

Kaysville, Utah Uncontaminated soil Soil Lab microcosm 787 ug/g 0.027/day Keck,J et. al. (1989)

Fluoranthene Lancaster, UK Agricultural soil Soil Lab microcosm 205 0.043/day Wild,SR & Jones,KC (1993) Fluoranthene American Creosote Works,

Pensacola, FL Wood preserving site Aquifer sediment + soil Lab microcosm 16.2 ug/mL 14 0.045/day Mueller,JG et. al. (1991)

Fluoranthene Hamburg, Germany Tar oil contaminated site Soil Lab microcosm 1480 mg/kg soil 70 No biodegradation Mahro,B et. al. (1994)

Fluoranthene Kaysville, Utah Uncontaminated Soil Lab microcosm 400 ug/g 240 No biodegradation Coover,MP & Sims,RC (1987)

# 103 

# 0 10 20 30 40

00.020.040.060.080.10.120.140.16

Rate constant (days-1

# )Frequency 

# 3.2.6. Pyrene Pyrene is a PAH with a 4-ring structure. In general, PAHs that contain more than 3 rings tend to be biodegraded rather slowly in the environment. First-order rate constants were in the range of 0.00036/day to 0.143/day, with the majority of the rate constant values less than 0.01/day. These values correspond to half-lives of 5 to 1,925 days. The smallest rate constant was observed in an unpolluted sandy loam that had a mixture of 16 other PAHs. This rate constant was derived from the reported half-life of 1,900 days (Coover and Sims, 1987). The largest rate constants (0.136/day and 0.143/day) were observed in unpolluted soil with roughly 80% moisture content (Schwab et. al., 1995). These two rate constants are much larger than those of any other study including those obtained from material at industrial locations with acclimated microbes. There were also several studies for which no rate constant was reported or could be calculated since the compound was not observed to biodegrade over the course of the study. This included one experiment where no measurable biodegradation was observed in an unpolluted sandy loam during a 240-day incubation period (Coover and Sims, 1987). Similar results were obtained from other studies with shorter incubation periods (Carmichael and Pfander, 1997; Mahro et. al., 1994; Heitkamp and Cerniglia, 1987; Heitkamp and Cerniglia, 1989). No reaction products were reported for the biodegradation of pyrene. The median for the primary biodegradation rate constant of pyrene, considering all studies, is 0.00345/day (N = 40); a range of not biodegraded to 0.052day is reported. The median for the mineralization rate constant of pyrene is 0.006/day (N = 18); a range of not biodegraded to 0.143/day is reported. The frequency distribution histograms for this data are shown in figures 12a and 12b. Pyrene is expected to biodegrade slowly under aerobic conditions or to be recalcitrant in the environment.

Figure 12a.Frequency distribution histogram for the published primary biodegradation rate constant values of pyrene.

# 104 

# 0 2 4 6

00.010.020.030.040.05

Rate constant (days-1

# )Frequency



# Figure 12b.Frequency distribution histogram for the published mineralization rate constant values of pyrene.

# 105

Table 13.Aerobic biodegradation rate constant values for pyrene Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference
Pyrene Brookhaven, Mississippi Wood-preserving site Soil Field 572 ug/g 56 0.0019/day Lamar,RT & Glaser,JA (1994) Pyrene Champion Intnt'l site,

Libby, Montana Contaminated industrial site Soil Field 84.9-90.5 mg/kg 54-60 0.0125- 0.0155/day Huling,SG et. al. (1995) Pyrene Wiroa Island, Auckland,

New Zealand Uncontaminated Sediment Field 256 <0.00693/day Wilcock,RJ et. al. (1996) Pyrene Kaysville, Utah Uncontaminated Soil Lab microcosm 400 ug/g 240 0.00036/day Coover,MP & Sims,RC (1987) Pyrene Blekholmstorget,

Stockholm, Sweden Creosote production facility Soil Lab microcosm 323 mg/kg 63 0.0004/day Ellis,B et. al. (1991)
Pyrene Lake Chicot, Arkansas Freshwater lake Lake water + sediment Lab microcosm 500 ng/g 56 0.001/day Heitkamp,MA & Cerniglia,CE (1987) Pyrene Southern Illinois Unpolluted soil Soil Lab microcosm 8.5 65 0.002/day Grosser,RJ et. al. (1991) Pyrene Southern Illinois Unpolluted soil Soil Lab microcosm 8.5 ng/g 65 0.002/day Grosser,RJ et. al. (1991) Pyrene Coal-tar contaminated Soil Lab microcosm 17 mg/kg soil 175 0.0025/day Wischmann,H & Steinhart,H (1997) Pyrene Calciaquoll, Utah Pristine soil Soil Lab microcosm 686 mg/kg 196 0.0027/day Park,KS et. al. (1990) Pyrene Utah Uncontaminated Soil Lab microcosm 686 mg/kg 196 0.0027/day Park,KS et. al. (1990) Pyrene American Creosote Works,

Pensacola, FL Wood preserving site Sediment Lab microcosm 1015.9 mg/kg 84 0.003/day Mueller,JG et. al. (1991A) Pyrene American Creosote Works,

Pensacola, FL Wood preserving site Sediment Lab microcosm 1015.9 mg/kg 84 0.003/day Mueller,JG et. al. (1991A) Pyrene Dover, Ohio Polluted soil Soil Lab microcosm 8.5 ng/g 85 0.003/day Grosser,RJ et. al. (1995) Pyrene Dover, Ohio Unpolluted soil Soil Lab microcosm 8.5 ng/g 85 0.003/day Grosser,RJ et. al. (1995) Pyrene Redfish Bay, Texas Estuary Estuarine water + sediment Lab microcosm 500 ng/g 56 0.003/day Heitkamp,MA & Cerniglia,CE (1987)

# Table 13.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 106 Pyrene Utah State University,

Kaysville, Utah Uncontaminated soil Soil Lab microcosm 686 ug/g 0.003/day Keck,J et. al. (1989)
Pyrene Uttar Pradesh, India Soil receiving effluent from an oil refinery Soil Lab microcosm 20 mg/kg 90 0.0031/day Ashok,BT et. al. (1995)

Pyrene Lincolnshire, UK Uncontaminated soil Soil Lab microcosm 0.5 mg/g 0.0032/day Smith,MJ et. al. (1997) Pyrene Kaysville, Utah Uncontaminated Soil Lab microcosm 400 ug/g 240 0.0033/day Coover,MP & Sims,RC (1987) Pyrene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.0034/day MaliszewskaKordybach,B (1993) Pyrene Uncontaminated Soil Lab microcosm 480 0.0034/day Bossert,ID & Bartha,R (1986) Pyrene Mississippi Uncontaminated Soil Lab microcosm 697 mg/kg 105 0.0035/day Park,KS et. al. (1990) Pyrene Paleudult, Mississippi Pristine soil Soil Lab microcosm 697 mg/kg 105 0.0035/day Park,KS et. al. (1990) Pyrene Reilly Tar & Chemical,St.

Louis Park, MN Industrial location Soil Lab microcosm 100 ng/g 56 0.004/day Carmichael,LM & Pfaender,FK (1997) Pyrene Southern Illinois Polluted soil Soil Lab microcosm 8.5 ng/g 65 0.004/day Grosser,RJ et. al. (1991) Pyrene Suffolk, UK Uncontaminated sand Soil Lab microcosm 0.5 mg/g 0.0045/day Smith,MJ et. al. (1997) Pyrene Uncontaminated Soil Lab microcosm 95-100 mg/kg soil 97 0.0047/day Mahro,B et. al. (1994)
Pyrene Dover, Ohio Polluted soil Soil Lab microcosm 8.5 ng/g 85 0.005/day Grosser,RJ et. al. (1995) Pyrene Dubose Oil Recycling,

Cantonment, FL Industrial location Soil Lab microcosm 100 ng/g 56 0.005/day Carmichael,LM & Pfaender,FK (1997) Pyrene Dubose Oil Recycling,

Cantonment, FL Industrial location Soil Lab microcosm 100 ng/g 56 0.006/day Carmichael,LM & Pfaender,FK (1997) Pyrene Southern Illinois Unpolluted soil Soil Lab microcosm 8.5 ng/g 65 0.006/day Grosser,RJ et. al. (1991)

# Table 13.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 107 Pyrene Musi River, India Hazardous waste site Soil Lab microcosm 1000 ppm 450 0.0062/day Mahmood,SK & Rao,PR (1993) Pyrene Southern Illinois Polluted soil Soil Lab microcosm 8.5 ng/g 65 0.008/day Grosser,RJ et. al. (1991) Pyrene American Creosote Works,

Pensacola, FL Wood preserving site Soil Lab microcosm 49.4 mg/kg 84 0.009/day Mueller,JG et. al. (1991A) Pyrene Dover, Ohio Polluted soil Soil Lab microcosm 8.5 ng/g 85 0.009/day Grosser,RJ et. al. (1995) Pyrene Delson, Quebec, Canada Wood-preserving industrial site Soil Lab microcosm 550 mg/kg sol 315 0.0092/day Deschenes,L et. al. (1995) Pyrene Delson, Quebec, Canada Wood-preserving industrial site Soil Lab microcosm 485 mg/kg soil 315 0.0095/day Deschenes,L et. al. (1996) Pyrene Southern Illinois Polluted soil Soil Lab microcosm 8.5 ng/g 65 0.011/day Grosser,RJ et. al. (1991) Pyrene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.0114/day MaliszewskaKordybach,B (1993) Pyrene American Creosote Works,

Pensacola, FL Wood preserving site Soil Lab microcosm 49.4 mg/kg 84 0.012/day Mueller,JG et. al. (1991A) Pyrene Utah State University,

Kaysville, Utah Uncontaminated soil Soil Lab microcosm 570 ug/g 0.013/day Keck,J et. al. (1989)
Pyrene DeGray Reservoir,

Arkadelphia, Arkansas Uncontaminated Sediment + waterLab microcosm 28 0.014/day Heitkamp,MA & Cerniglia,CE (1989) Pyrene Lancaster, UK Agricultural soil Soil Lab microcosm 205 0.014/day Wild,SR & Jones,KC (1993) Pyrene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.0143/day MaliszewskaKordybach,B (1993) Pyrene Dover, Ohio Polluted soil Soil Lab microcosm 8.5 ng/g 85 0.015/day Grosser,RJ et. al. (1995) Pyrene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.0152/day MaliszewskaKordybach,B (1993)

# Table 13.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 108 Pyrene Utah State University,

Kaysville, Utah Uncontaminated soil Soil Lab microcosm 640 ug/g 0.016/day Keck,J et. al. (1989)
Pyrene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.0198/day MaliszewskaKordybach,B (1993) Pyrene Agricultural soil Soil Lab microcosm 20 ug/g 180 0.0202/day MaliszewskaKordybach,B (1993) Pyrene Reilly Tar & Chemical,St.

Louis Park, MN Industrial location Soil Lab microcosm 100 ng/g 56 0.049/day Carmichael,LM & Pfaender,FK (1997) Pyrene American Creosote Works,

Pensacola, FL Wood preserving site Aquifer sediment + soil Lab microcosm 10.4 ug/mL 14 0.052/day Mueller,JG et. al. (1991) Pyrene Uncontaminated Soil Lab microcosm 10 mg/kg 100 0.136/day Schwab,AP et. al. (1995) Pyrene Uncontaminated Soil Lab microcosm 10 mg/kg 100 0.143/day Schwab,AP et. al. (1995) Pyrene Utah State University,

Kaysville, Utah Uncontaminated soil Soil Lab microcosm 400 ug/g 3.6X10-4/day Keck,J et. al. (1989)
Pyrene Blekholmstorget,

Stockholm, Sweden Creosote production facility Soil Lab microcosm 323 mg//kg 28 No biodegradation Ellis,B et. al. (1991)
Pyrene Bozeman, MT Pristine soil Soil Lab microcosm 100 ng/g 56 No mineralization Carmichael,LM & Pfaender,FK (1997) Pyrene Degray Resevoir,

Arkansas Unpolluted freshwater reservoir Lake water + sediment Lab microcosm 500 ng/g 56 No biodegradation Heitkamp,MA & Cerniglia,CE (1987) Pyrene Hamburg, Germany Tar oil contaminated site Soil Lab microcosm 1250 mg/kg soil 70 No biodegradation Mahro,B et. al. (1994)
Pyrene Kaysville, Utah Uncontaminated Soil Lab microcosm 400 ug/g 240 No biodegradation Coover,MP & Sims,RC (1987) Pyrene DeGray Reservoir,

Arkadelphia, Arkansas Uncontaminated Sediment + waterLab microcosm 28 No mineralization Heitkamp,MA & Cerniglia,CE (1989)

# 109 

# 0 5 10 15 20

00.010.020.030.040.050.06

Rate constant (days-1

# )Frequency 

# 3.2.7. Benzo(a)pyrene Benzo(a)pyrene is a PAH with a 5-ring structure that is virtually insoluble in water. In general, PAHs that contain more than 3 rings tend to be biodegraded rather slowly in the environment. Biodegradation of benzo(a)pyrene appears to occur at an extremely slow rate when compared to other PAHs. First-order rate constants ranged from 0.00006/day to 0.057/day. These values correspond to half-lives of 12 to 11,552 days. The smallest rate constant was observed in soil that contained 8 other PAHs (Grosser et. al., 1995). The biodegradation rate of benzo(a)pyrene was slower than the other compounds, indicating microbes may selectively degrade PAH compounds. The largest rate constant was observed in creosote-contaminated groundwater obtained from a wood-preserving facility (Mueller et. al., 1991). There were also several studies for which no rate constant was reported or could be calculated since the compound was not observed to biodegrade over the course of the study. This included an experiment where no measurable biodegradation was observed in a polluted sandy loam over a 315-day incubation period (Deschenes et. al., 1996). Similar results were obtained from other studies with shorter incubation periods (Carmichael and Pfaender, 1997; Lee et. al., 1978; Heitkamp and Cerniglia, 1987A; Grosser et. al., 1995). No reaction products were reported for the degradation of benzo(a)pyrene. The median for the primary biodegradation rate constant of benzo(a)pyrene is 0.0027/day (N = 23); a range of not biodegraded to 0.057/day is reported. The median for the mineralization rate constant of benzo(a)pyrene is 0.00015/day (N = 25); a range of not biodegraded to 0.0037/day is reported.The frequency distribution histograms for this data are shown in figures 13a and 13b. For the most part, benzo(a)pyrene is expected to be recalcitrant under most environmental conditions.

Figure 13a.Frequency histogram for the published primary biodegradation rate constant values of benzo(a)pyrene.

# 110 

# 0 5 10 15 20 25

0.0000.0010.0020.0030.004

Rate constant (days-1

# )Frequency



# Figure 13b.Frequency histogram for the published mineralization rate constant values of benzo(a)pyrene.

# 111

Table 14.Aerobic biodegradation rate constant values for benzo(a)pyrene Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference
Benzo(a)pyrene Wiroa Island, Auckland, New Zealand Uncontaminated Sediment Field 256 <0.00693/day Wilcock,RJ et. al. (1996)

Benzo(a)pyrene Uncontaminated Soil Lab microcosm 10 ug/g soil 28 Lu,PY et. al. (1977) Benzo(a)pyrene Dover, Ohio Coal tar refining plant Soil Lab microcosm 105 ng/g 80 0.00006/day Grosser,RJ et. al. (1995)
Benzo(a)pyrene Southern Illinois Uncontaminated coal gasification plant site Soil Lab microcosm 84.4 ng/g 225 0.00024/day Grosser,RJ et. al. (1991)

Benzo(a)pyrene Dover, Ohio Coal tar refining plant Soil Lab microcosm 105 ng/g 80 0.0003/day Grosser,RJ et. al. (1995)
Benzo(a)pyrene Southern Illinois Contaminated coal gasification plant site Soil Lab microcosm 84.4 ng/g 225 0.00032/day Grosser,RJ et. al. (1991)

Benzo(a)pyrene Southern Illinois Contaminated coal gasification plant site Soil Lab microcosm 84.4 ng/g 225 0.00032/day Grosser,RJ et. al. (1991)

Benzo(a)pyrene Uncontaminated Soil Lab microcosm 480 0.0005/day 120 Bossert,ID & Bartha,R (1986) Benzo(a)pyrene Dover, Ohio Coal tar refining plant Soil Lab microcosm 105 ng/g 160 0.0006/day Grosser,RJ et. al. (1995)
Benzo(a)pyrene Southern Illinois Uncontaminated coal gasification plant site Soil Lab microcosm 84.4 ng/g 225 0.00065/day Grosser,RJ et. al. (1991)

Benzo(a)pyrene Southern Illinois Uncontaminated coal gasification plant site Soil Lab microcosm 84.4 ng/g 225 0.0009/day Grosser,RJ et. al. (1991)

Benzo(a)pyrene Reilly Tar & Chemical,St. Louis Park, MN Contaminated Soil Lab microcosm 136 ng/g 56 0.0011/day Carmichael,LM & Pfaender,FK (1997)
Benzo(a)pyrene Reilly Tar & Chemical,St. Louis Park, MN Contaminated Soil Lab microcosm 136 ng/g 56 0.0012/day Carmichael,LM & Pfaender,FK (1997)
Benzo(a)pyrene Kaysville, Utah Uncontaminated Soil Lab microcosm 10.76 ug/g 240 0.0013/day Coover,MP & Sims,RC (1987)

# Table 14.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 112 Benzo(a)pyrene Southern Illinois Contaminated coal gasification plant site Soil Lab microcosm 84.4 ng/g 225 0.0013/day 25 Grosser,RJ et. al. (1991)

Benzo(a)pyrene DeGray Reservoir, Arkadelphia, Arkansas Uncontaminated Sediment + water Lab microcosm 28 0.0015/day Heitkamp,MA & Cerniglia,CE (1989)
Benzo(a)pyrene Utah Uncontaminated Soil Lab microcosm 33 mg/kg 196 0.0022/day Park,KS et. al. (1990) Benzo(a)pyrene Utah State University, Kaysville, Utah Uncontaminated soil Soil Lab microcosm 33 ug/g 0.0022/day Keck,J et. al. (1989)

Benzo(a)pyrene Kaysville, Utah Uncontaminated Soil Lab microcosm 10.76 ug/g 240 0.0024/day Coover,MP & Sims,RC (1987) Benzo(a)pyrene Utah State University, Kaysville, Utah Uncontaminated soil Soil Lab microcosm 10.8 ug/g 0.0024/day Keck,J et. al. (1989)

Benzo(a)pyrene Mississippi Uncontaminated Soil Lab microcosm 33 mg/kg 105 0.0030/day Park,KS et. al. (1990) Benzo(a)pyrene Kaysville, Utah Uncontaminated Soil Lab microcosm 10.76 ug/g 240 0.0032/day Coover,MP & Sims,RC (1987) Benzo(a)pyrene American Creosote Works, Pensacola, FL Wood preserving site Soil Lab microcosm28.1 mg/kg 84 0.0034/day Mueller,JG et. al. (1991A)

Benzo(a)pyrene Dubose Oil Recycling, Cantonment, FL Contaminated Soil Lab microcosm 136 ng/g 56 0.0034/day Carmichael,LM & Pfaender,FK (1997)
Benzo(a)pyrene American Creosote Works, Pensacola, FL Wood preserving site Sediment Lab microcosm 82.2 mg/kg 84 0.0035/day Mueller,JG et. al. (1991A)

Benzo(a)pyrene Dubose Oil Recycling, Cantonment, FL Contaminated Soil Lab microcosm 136 ng/g 56 0.0037/day 28 Carmichael,LM & Pfaender,FK (1997)
Benzo(a)pyrene American Creosote Works, Pensacola, FL Wood preserving site Sediment Lab microcosm 82.2 mg/kg 84 0.0038/day Mueller,JG et. al. (1991A)

Benzo(a)pyrene Utah State University, Kaysville, Utah Uncontaminated soil Soil Lab microcosm 13 ug/g 0.0046/day Keck,J et. al. (1989)

# Table 14.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 113 Benzo(a)pyrene Lancaster, UK Agricultural soil Soil Lab microcosm 205 0.0062/day Wild,SR & Jones,KC (1993) Benzo(a)pyrene American Creosote Works, Pensacola, FL Wood preserving site Soil Lab microcosm28.1 mg/kg 84 0.0068/day Mueller,JG et. al. (1991A)

Benzo(a)pyrene Uttar Pradesh, India Soil receiving effluent from an oil refinery Soil Lab microcosm20 mg/kg 90 0.0068/day Ashok,BT et. al. (1995)

Benzo(a)pyrene Saucon Creek, Bethlehem, PA Contaminated Sediment Lab microcosm 1 ug/g sediment 4 0.00816/day Herbes,SE (1981)
Benzo(a)pyrene Saucon Creek, Bethlehem, PA Uncontaminated Sediment Lab microcosm 1 ug/g sediment 4 0.00816/day Herbes,SE (1981)
Benzo(a)pyrene American Creosote Works, Pensacola, FL Wood preserving site Aquifer sediment + soil Lab microcosm2.1 ug/mL 14 0.057/day. Mueller,JG et. al. (1991)

Benzo(a)pyrene Fort Point Channel, Boston Harbor Estuary Sediment Lab microcosm20 ng/g 5 1188 ng/g/day Shiaris,MP (1989)

Benzo(a)pyrene Weymouth Back River, Boston Harbor Estuary Sediment Lab microcosm20 ng/g 5 3.6 ng/g/day Shiaris,MP (1989)

Benzo(a)pyrene Lower Neck Quincy Bay, Boston Harbor Estuary Sediment Lab microcosm20 ng/g 5 41.28 ng/g/day Shiaris,MP (1989)

Benzo(a)pyrene Lake Chicot, Arkansas Sediment + water Lab microcosm 500 ng/g 56 <0.00033/day Heitkamp,MA & Cerniglia,CE (1987A) Benzo(a)pyrene Redfish Bay, Texas Sediment + water Lab microcosm 500 ng/g 56 <0.0005/day Heitkamp,MA & Cerniglia,CE (1987A) Benzo(a)pyrene Knoxville, Tennessee Oil contaminated Sediment Lab microcosm 26 <0.00072/day Herbes,SE & Schwall,LR (1978)
Benzo(a)pyrene Walker Branch, Oak Ridge, Tennessee Uncontaminated Sediment Lab microcosm 26 <0.00072/day Herbes,SE & Schwall,LR (1978)

Benzo(a)pyrene Delson, Quebec, Canada Wood-preserving industrial site Soil Lab microcosm46 mg/kg soil 315 No biodegradation Deschenes,L et. al. (1996)

# Table 14.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 114 Benzo(a)pyrene Delson, Quebec, Canada Wood-preserving industrial site Soil Lab microcosm90 mg/kg soil 315 No biodegradation Deschenes,L et. al. (1995)
Benzo(a)pyrene Bozeman, MT Pristine soil Soil Lab microcosm 136 ng/g 56 No mineralization Carmichael,LM & Pfaender,FK (1997) Benzo(a)pyrene Bozeman, MontanaUncontaminated Soil Lab microcosm 136 ng/g 56 No mineralization Carmichael,LM & Pfaender,FK (1997) Benzo(a)pyrene DeGray Reservoir, Arkadelphia, Arkansas Uncontaminated Sediment + water Lab microcosm 500 ng/g 56 No mineralization Heitkamp,MA & Cerniglia,CE (1987A)
Benzo(a)pyrene Dover, Ohio Coal tar refining plant Soil Lab microcosm 105 ng/g 80 No mineralization Grosser,RJ et. al. (1995)
Benzo(a)pyrene Dover, Ohio Coal tar refining plant Soil Lab microcosm 105 ng/g 80 No mineralization Grosser,RJ et. al. (1995)
Benzo(a)pyrene Dubose Oil Recycling, Cantonment, FL Industrial location Soil Lab microcosm 136 ng/g 56 No mineralization Carmichael,LM & Pfaender,FK (1997)
Benzo(a)pyrene Reilly Tar & Chemical,St. Louis Park, MN Industrial location Soil Lab microcosm 136 ng/g 56 No mineralization Carmichael,LM & Pfaender,FK (1997)
Benzo(a)pyrene Reilly Tar & Chemical,St. Louis Park, MN Industrial location Soil Lab microcosm 136 ng/g 56 No mineralization Carmichael,LM & Pfaender,FK (1997)
Benzo(a)pyrene Saanich Inlet, western Canada Uncontaminated Seawater + sediment Lab microcosm 3 No mineralization Lee,RF et. al. (1978)
Benzo(a)pyrene Saanich Inlet, western Canada Uncontaminated Seawater + sediment Lab microcosm 3 No mineralization Lee,RF et. al. (1978)
Benzo(a)pyrene Saucon Creek, Bethlehem, PA Contaminated Creek water Lab microcosm 4 No mineralization Herbes,SE (1981)

# 115

3.3. Chlorinated Aliphatic Compounds While anaerobic biodegradation of highly chlorinated aliphatic compounds generally proceeds readily in strong reducing, anaerobic environments, aerobic degradation of these compounds is less likely. The degree of chlorination of the aliphatic compound will determine its ability to be aerobically biodegraded. Compounds such as tetrachloroethylene and carbon tetrachloride, which are highly oxidized and highly chlorinated, will not be readily biodegraded under aerobic conditions while less oxidized and less highly chlorinated compounds such as dichloromethane and vinyl chloride will. The major route of degradation for these less chlorinated compounds is via a cometabolic pathway using broad specificity bacterial oxygenases. In this case, the chlorinated aliphatic is not used as a growth substrate but is fortuitously degraded during the biodegradation of other non-chlorinated compounds (or methane) present in the bacterial environment. Methanotrophs (methane-oxidizing bacteria) are able to metabolize some chlorinated aliphatics during a cometabolic process due to the methane monooxygenase enzyme complex. However, the rate of aerobic degradation by methanotrophs also appears to lessen with an increasing number of chlorine atoms on the molecule (Broholm et. al., 1991; Henson et. al., 1988). Tetrachloroethylene is apparently not susceptible to degradation by methanotrophs (Broholm et. al., 1991; Henson et. al., 1988; Lige et. al., 1995). In aerobic environments, as found in unsaturated soil orsurface water, processes such as leaching or volatilization may be more important in the loss of highlychlorinated aliphatic compounds than biodegradation. 3.3.1. Tetrachloroethylene This compound, while readily biodegraded under anaerobic conditions through reductive dechlorination processes, is resistant to biodegradation under aerobic conditions (Table 15). Reductive dechlorination does not occur at oxygen concentrations greater than 0.5 mg/L (Wiedemeier et. al., 1996). Enzien et. al. (1994) studied the degradation of tetrachloroethylene in laboratory columns where the measured dissolved oxygen concentration did not drop below 1.6 mg/L. Significant degradation of this compound occurred and the authors postulated that anaerobic microsites were responsible although the column was kept under bulk aerobic conditions. MPN counts of both aerobic and anaerobic bacteria showed that abundant populations of each existed in the aquifer sediment. Methane was measured in the column indicating that methanogens were present and providing more evidence that anaerobic conditions, as microsites, may have been present. Finally, cis-dichloroethylene was reported as the major metabolite of tetrachloroethylene degradation, again suggesting that anaerobic biodegradation was responsible for the breakdown of this compound during the experiment. A groundwater recharge field study by Roberts et. al. (1982) reporting the biodegradation of tetrachloroethylene, injected water with dissolved oxygen concentrations of 1.86 mg/L which may not have been sufficient to prevent anaerobic conditions from developing in the aquifer. In both oxygen-saturated and methanotrophic lab microcosm conditions, tetrachloroethylene was minimally degraded from 0 to 6% over a 56-day period (Lige et. al., 1995). No measurable oxygen consumption or carbon dioxide production was seen in these microcosms relative to the control microcosms; however, some loss of methane in the methanotrophic microcosms, in excess of that found

# 116

in the controls, was reported suggesting possible unmeasurable transformation by a methanotrophic population. The remainder of the studies summarized in the database show that aerobic biodegradation of tetrachloroethylene does not occur even given time frames of over 700 days (Roberts et. al., 1986). Studies incorporating methane and oxygen in the microcosm atmosphere also reported that tetrachloroethylene was not biodegraded, again showing that this compound is not susceptible to methanotrophic cometabolism.

# 117

Table 15.Aerobic biodegradation rate constant values for tetrachloroethylene

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference
Tetrachloroethylene Palo Alto Baylands, California Injection site of municipal wastewater Aquifer sediment + groundwater Field 2.5 ug/L 350 0.0021/day Roberts,PV et. al. (1982)
Tetrachloroethylene Canadian Forces Base, Borden, Ontario Aquifer sediment + groundwater Field 30.2 ug/L 709 No biodegradation Roberts,PV et. al. (1986)

Tetrachloroethylene Lower Glatt River Valley, Switzerland River infiltration site Aquifer sediment + groundwater Field 0.60 ug/L No biodegradation Schwarzenbach,RP et. al. (1983) Tetrachloroethylene Victoria, Texas DuPont Plant West Landfill Aquifer sediment + groundwater Field 10 uM 203 No biodegradation Beeman,RE et. al. (1994)
Tetrachloroethylene Vejen City, Jutland, Denmark Contaminated landfill site Aquifer sediment + groundwater In situ microcosm 120 ug/L 90 No biodegradation Nielsen,PH et. al. (1992)
Tetrachloroethylene Vejen City, Jutland, Denmark Contaminated landfill site Aquifer sediment + groundwater In situ microcosm 120 ug/L 90 No biodegradation Nielsen,PH et. al. (1992)
Tetrachloroethylene Vejen City, Jutland, Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 70 No biodegradation Nielsen,PH et. al. (1996)
Tetrachloroethylene Vejen City, Jutland, Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 70 No biodegradation Nielsen,PH et. al. (1996)
Tetrachloroethylene Vejen City, Jutland, Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 70 No biodegradation Nielsen,PH et. al. (1996)
Tetrachloroethylene Vejen City, Jutland, Denmark Uncontaminated landfill site Aquifer sediment + groundwater In situ microcosm 120 ug/L 90 No biodegradation Nielsen,PH et. al. (1992)
Tetrachloroethylene Savannah River Site, South Carolina Soil + groundwater Lab column 500 ug/L 1.25 0.139/day Enzien,MV et. al. (1994)
Tetrachloroethylene Ada, Oklahoma Soil Lab column 0.15 mg/L No biodegradation Wilson,JT et. al. (1981)
Tetrachloroethylene Ada, Oklahoma Rapid infiltration site Soil Lab column 2.6 umol/L 196 No biodegradation Piwoni,MD et. al. (1986)
Tetrachloroethylene Glatt River, Switzerland River/Groundwater infiltration zone Aquifer sediment Lab column 30 mg/L 270 No biodegradation Kuhn,EP et. al. (1985)

# Table 15.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 118 Tetrachloroethylene Rhine River sediment River infiltration site Sediment Lab column 0.5-60 ug/L No biodegradation Bosma,TNP et. al. (1990)
Tetrachloroethylene Skrydstrup, Denmark Uncontaminated Soil Lab column 1.1 mg/kg wet soil 289 No biodegradation Broholm,K et. al. (1991)
Tetrachloroethylene Swan Coastal Plain, Australia Uncontaminated Aquifer sediment + groundwater Lab column 490 ug/L No biodegradation Patterson,BM et. al. (1993) Tetrachloroethylene Swan Coastal Plain, Australia Uncontaminated Aquifer sediment + groundwater Lab column 490 ug/L No biodegradation Patterson,BM et. al. (1993) Tetrachloroethylene Swan Coastal Plain, Australia Uncontaminated Aquifer sediment + groundwater Lab column 540 ug/L No biodegradation Patterson,BM et. al. (1993) Tetrachloroethylene Swan Coastal Plain, Australia Uncontaminated Aquifer sediment + groundwater Lab column 580 ug/L No biodegradation Patterson,BM et. al. (1993) Tetrachloroethylene The Netherlands Infiltration area Sediment Lab column 40-60 ug/L No biodegradation van der Meer,JR et. al. (1992) Tetrachloroethylene Dover AFB, Dover, Delaware Contaminated Aquifer sediment + groundwater Lab microcosm 1 mg/L 56 0.000361/day Lige,JE et. al. (1995)
Tetrachloroethylene Dover AFB, Dover, Delaware Contaminated Aquifer sediment + groundwater Lab microcosm 1 mg/L 56 0.000916/day Lige,JE et. al. (1995)
Tetrachloroethylene Dover AFB, Dover, Delaware Contaminated Aquifer sediment + groundwater Lab microcosm 1 mg/L 56 0.0011/day Lige,JE et. al. (1995)
Tetrachloroethylene Dover AFB, Dover, Delaware Contaminated Aquifer sediment + groundwater Lab microcosm 1 mg/L 56 No biodegradation Lige,JE et. al. (1995)
Tetrachloroethylene Fort Polk, Louisiana Aquifer sediment Lab microcosm 600-800 ug/L 63 No biodegradation Wilson,JT et. al. (1983)
Tetrachloroethylene Fort Polk, Louisiana Aquifer sediment Lab microcosm 600-800 ug/L 63 No biodegradation Wilson,JT et. al. (1983)
Tetrachloroethylene Iowa River, Iowa Freshwater River water Lab microcosm 20.1 mg/L 4.5 No biodegradation Mudder,TI (1981)

# Table 15.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 119 Tetrachloroethylene Lula, Oklahoma Aquifer sediment Lab microcosm 600-800 ug/L 63 No biodegradation Wilson,JT et. al. (1984)
Tetrachloroethylene Lula, Oklahoma Aquifer sediment Lab microcosm 600-800 ug/L 63 No biodegradation Wilson,JT et. al. (1984)
Tetrachloroethylene Pickett, Oklahoma Aquifer sediment Lab microcosm 600-800 ug/L 189 No biodegradation Wilson,JT et. al. (1983)
Tetrachloroethylene Pickett, Oklahoma Aquifer sediment Lab microcosm 600-800 ug/L 189 No biodegradation Wilson,JT et. al. (1983)
Tetrachloroethylene Vejen City, Jutland, Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 150 ug/L 150 No biodegradation Nielsen,PH et. al. (1996)
Tetrachloroethylene Vejen City, Jutland, Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 150 ug/L 150 No biodegradation Nielsen,PH et. al. (1996)
Tetrachloroethylene Vejen City, Jutland, Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 150 ug/L 150 No biodegradation Nielsen,PH et. al. (1996)
Tetrachloroethylene Denmark Municipal landfill Leachate Reactor system 50 mg COD/L No biodegradation Lyngkilde,J et. al. (1992)

# 120 

# 0 1 2 3 4 5

00.10.20.30.40.50.6 Rate constant (days-1

# )Frequency 

# 3.3.2. Dichloromethane Several studies using pure cultures or mixed defined bacterial cultures show that dichloromethane, unlike the more highly chlorinated aliphatic compounds can be utilized by bacteria as a carbon and energy source for growth (Davis and Madsen, 1991). Biodegradation of this compound is believed to be catalyzed initially by a dehalogenase resulting in the formation of formaldehyde and hydrochloric acid (Davis and Madsen, 1991). Only three papers were located reporting the biodegradation of dichloromethane in environmental media (Table 16). Based on this data, dichloromethane is expected to be moderately degradable under aerobic conditions. Davis and Madsen (1991) investigated the aerobic degradation of dichloromethane in several soils without the addition of methane. The rate of degradation was dependent on the soil type, substrate concentration, organic carbon availability and redox condition of the particular soil studied. Rates were significantly higher for concentrations between 0.5 mg/L (T1/2

# of 1.3 days) and 5 mg/L (T1/2

# of 191 days) for the same soil although degradation was shown at concentrations up to 50 mg/L. Henson et. al. (1988) reported the biodegradation of dichloromethane following the addition of methane to stimulate the naturally occurring population of methanotrophs. Without the prior addition of methane only 43% of the initially added dichloromethane was degraded in 6 days whereas the enrichment procedure, with methane added over the 6 weeks before the addition of dichloromethane, showed 98% loss over 6 days. The median for the primary biodegradation rate constant of dichloromethane, considering all studies, is 0.0546/day (N = 8); a range of 0.00362 to 0.533/day is reported. The frequency distribution histogram for this data is shown in figure 14. Dichloromethane is expected to be fairly readily biodegraded under most aerobic environmental conditions.

Figure 14.Frequency histogram for the published primary biodegradation rate constant values of dichloromethane.

# 121

Table 16.Aerobic biodegradation rate constant values for dichloromethane Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period

(days) Rate Constant Lag Time (days) Reference

Dichloromethane Rhine River, The Netherlands Uncontaminated River water Field 5 ug/L 80 0.0182/day Zoeteman,BCJ et. al. (1980)

Dichloromethane Rhine River, The Netherlands Uncontaminated River water Field 5 ug/L 132 0.021/day Zoeteman,BCJ et. al. (1980)

DichloromethaneMidland County, Michigan Uncontaminated Soil Lab microcosm 5 mg/L 220 0.00362/day Davis,JW & Madsen,SS (1991)

DichloromethaneMidland County, Michigan Uncontaminated Soil Lab microcosm 5 mg/L 196 0.00645/day Davis,JW & Madsen,SS (1991)

Dichloromethane Bay County, Michigan Uncontaminated Soil Lab microcosm 0.5 mg/L 140 0.0126/day Davis,JW & Madsen,SS (1991)

DichloromethaneMidland County, Michigan Uncontaminated Soil Lab microcosm 5 mg/L 31 0.043/day Davis,JW & Madsen,SS (1991)

DichloromethaneMidland County, Michigan Uncontaminated Soil Lab microcosm 0.5 mg/L 36 0.0546/day Davis,JW & Madsen,SS (1991)

Dichloromethane Bay County, Michigan Uncontaminated Soil Lab microcosm 0.5 mg/L 21 0.0737/day Davis,JW & Madsen,SS (1991)

DichloromethaneMidland County, Michigan Uncontaminated Soil Lab microcosm 0.5 mg/L 68 0.096/day 50 Davis,JW & Madsen,SS (1991)

Dichloromethane Ada, Oklahoma Uncontaminated Soil Lab microcosm 275 ug/L 6 0.101/day Henson,JM et. al. (1988) DichloromethaneMidland County, Michigan Uncontaminated Soil Lab microcosm 0.16 mg/L 5.25 0.533/day Davis,JW & Madsen,SS (1991)

# 122

3.4. Phenol and Substituted Phenols Both phenol and the cresol isomers are readily degraded under aerobic conditions in environmental media (see Tables 17, 18, 19, and 20). The cresols are monosubstituted phenols commonly used in disinfectants and fumigants, in photographic developers, as a manufacturing intermediate in the production of synthetic resins and in explosives. Because of their common usage, these compounds are often found in the environment and are listed as priority pollutants by the U.S. EPA. Phenol is expected to biodegrade more rapidly than the cresol isomers. Phenols withortho- orpara- substituents were shown to be preferentially degraded over those withmeta- substitution (Medvedev and Davidov, 1981). m-Cresol is thought to exhibit a greater stability of the benzene ring making it more difficult to biodegrade than the other two isomers. 3.4.1. Phenol Phenol is rapidly biodegraded in the environment under aerobic conditions, usually without any apparent lag time. First-order biodegradation rate constants were in the range of 0.006/day T1/2

# =116 days) to 11/day (T1/2

# <1 day), with the majority of the values greater than 1/day. The lowest rate constant was derived from unpolluted aquifer material 12-12.6 m below the soil surface and had a lag period of 16 days. Substantially larger rate constants were calculated for aquifer material collected at different depths in this study (Konopka and Turco, 1991). A field study in Terrebonne Bay and Barataria Bay, LA was conducted in which the half-lives of phenol in sediment cores were reported as 1.9 and 4.1 days. These half-lives were in good agreement with half-lives determined in laboratory experiments using continuous flow reactor systems (Portier, 1985). Biodegradation of phenol in soils under aerobic conditions was also rapid. First-order rate constants of 4.5/day to 7.3/day were determined in unpolluted Captina and Palouse soils at initial concentrations of 1X10-6

# M to 1X10-9

# M (Scott et. al., 1983). The median for the primary biodegradation rate constant of phenol, considering all studies, is 0.21/day (N = 38). The median for the mineralization rate constant of phenol, considering all studies, is 1.56/day (N = 26). The frequency histograms for this data are shown in figures 15a and 15b.

# 123 

# 0 5 10 15 20 25 30

0246810 Rate constant (days-1

# )Frequency



## 0 2 4 6 8 10 12 14

023.556.589.511



# Rate constant (days-1

# )Frequency 

# Figure 15a.The frequency histogram for the published primary biodegradation rate constant values of phenol.

Figure 15b.The frequency histogram for the published mineralization rate constant values of phenol.

# 124

Table 17.Aerobic biodegradation rate constant values for phenol Compound Site Name Site Type Inoculum Study Type Initial Concn. Time

Period (days) Rate Constant Lag Time (days) Reference

Phenol Terrebonne Bay and

Barataria Bay, LA Estuary Bay water + sediment Field 5 mg/L 0.17/day Portier,RJ (1985)

Phenol Terrebonne Bay and

Barataria Bay, LA Estuary Bay water + sediment Field 5 mg/L 0.36/day Portier,RJ (1985)

Phenol Lake Superior, WI Groundwater Groundwater Groundwater grab sample 0-3.2 mg/L 20 0.035/day Vaishnav,DD & Babeu,L (1987) Phenol Purdue University, W.

Lafayette, Indiana Aquifer Aquifer sediment Lab microcosm 10 uM 32 0.006/day 16 Konopka,A & Turco,R (1991)

Phenol Memorial Park pond,

Athens, Georgia Pristine pond Pond water Lab microcosm 1 mg/L 0.024-0.14/day Paris,DF & Rogers,JE (1986)

Phenol Wiggins, Mississippi Acidic soil Soil Lab microcosm 350 mg/kg 30 0.030/day Loehr,RC & Matthews,JE (1992) Phenol Lula, Oklahoma Aquifer Aquifer sediment Lab microcosm 9 ng/g 250 0.035/day Aelion,CM et. al. (1987) Phenol Lula, Oklahoma Aquifer Aquifer sediment Lab microcosm 461 ng/g 250 0.036/day Aelion,CM et. al. (1987) Phenol Purdue University, W.

Lafayette, Indiana Aquifer Aquifer sediment Lab microcosm 10 uM 32 0.047/day 2 Konopka,A & Turco,R (1991)

Phenol Hickory Hills pond,

Athens, Georgia Pristine pond Pond water Lab microcosm 1 mg/L 0.048-0.072/day Paris,DF & Rogers,JE (1986)

Phenol Water Works pond,

Athens, Georgia Pristine pond Pond water Lab microcosm 1 mg/L 0.048-0.096/day Paris,DF & Rogers,JE (1986)

Phenol Hickory Hills pond,

Athens, Georgia Pristine pond Pond water Lab microcosm 1 mg/L 0.048-4.8/day Paris,DF et. al. (1983)

Phenol Park pond, Athens,

Georgia Pristine pond Pond water Lab microcosm 1 mg/L 0.058-5.8/day Paris,DF et. al. (1983)

Phenol Chernozen, Ukraine Industrial location Soil Lab microcosm 1000 mg/kg 16 0.058/day Medvedev,VA & Davidov,VD (1981A) Phenol Lester River, MN River water River water Lab microcosm 0-3.2 mg/L 20 0.065/day Vaishnav,DD & Babeu,L (1987)

# Table 17.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time

Period (days) Rate Constant Lag Time (days) Reference



# 125 Phenol Williams pond, Athens,

Georgia Pristine pond Pond water Lab microcosm 1 mg/L 0.072-7.2/day Paris,DF et. al. (1983)

Phenol Skidaway River, Georgia Estuary Estuarine water Lab microcosm 25 ug/L 2 0.079/day Lee,RF & Ryan,C (1979) Phenol Oconee River, Athens,

Georgia Pristine river River water Lab microcosm 1 mg/L 0.10-10/day Paris,DF et. al. (1983)

Phenol Overlook pond, Athens,

Georgia Pristine pond Pond water Lab microcosm 1 mg/L 0.11-11/day Paris,DF et. al. (1983)

Phenol Oconee River, Athens,

Georgia Pristine river River water Lab microcosm 1 mg/L 0.14-0.21/day Paris,DF & Rogers,JE (1986)

Phenol Purdue University, W.

Lafayette, Indiana Aquifer Aquifer sediment Lab microcosm 10 uM 32 0.15/day Konopka,A & Turco,R (1991)

Phenol Austin, Texas Basic soil Soil Lab microcosm 700 mg/kg 12 0.17/day Loehr,RC & Matthews,JE (1992) Phenol Samber River, Belgium Polluted river River water Lab microcosm 20 ppm 7 0.17/day Borighem,G & Vereecken,J (1978) Phenol Purdue University, W.

Lafayette, Indiana Aquifer Aquifer sediment Lab microcosm 10 uM 32 0.2/day Konopka,A & Turco,R (1991)

Phenol Samber River, Belgium Polluted river River water Lab microcosm 20 ppm 6.7 0.21/day Borighem,G & Vereecken,J (1978) Phenol Samber River, Belgium Polluted river River water Lab microcosm 20 ppm 5 0.22/day Borighem,G & Vereecken,J (1978) Phenol Lake Superior Harbor,

WI Lake water Lake water Lab microcosm 0-3.2 mg/L 12 0.247/day Vaishnav,DD & Babeu,L (1986) Phenol Purdue University, W.

Lafayette, Indiana Aquifer Aquifer sediment Lab microcosm 10 uM 32 0.25/day 1 Konopka,A & Turco,R (1991)

Phenol Samber River, Belgium Polluted river River water Lab microcosm 10 ppm 4 0.32/day Borighem,G & Vereecken,J (1978)

# Table 17.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time

Period (days) Rate Constant Lag Time (days) Reference



# 126 Phenol Samber River, Belgium Polluted river River water Lab microcosm 10 ppm 4 0.34/day Borighem,G & Vereecken,J (1978) Phenol Samber River, Belgium Polluted river River water Lab microcosm 10 ppm 4 0.42/day Borighem,G & Vereecken,J (1978) Phenol Samber River, Belgium Polluted river River water Lab microcosm 5 ppm 2.9 0.59/day Borighem,G & Vereecken,J (1978) Phenol Purdue University, W.

Lafayette, Indiana Aquifer Aquifer sediment Lab microcosm 10 uM 32 0.72/day Konopka,A & Turco,R (1991)

Phenol Samber River, Belgium Polluted river River water Lab microcosm 5 ppm 2.6 0.76/day Borighem,G & Vereecken,J (1978) Phenol Samber River, Belgium Polluted river River water Lab microcosm 5 ppm 2 0.92/day Borighem,G & Vereecken,J (1978) Phenol Lake Superior Harbor,

WI Lake water Lake water Lab microcosm 0-3.2 mg/L 12 1.03/day Vaishnav,DD & Babeu,L (1986) Phenol New River, Virginia Pristine river River water + sediment Lab microcosm 1 ug/L 1.0X10-5 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Jefferson National

Forest, Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 1.0X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Stoney Creek, Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 1.1X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Stoney Creek, Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 1.1X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol White Rocks Branch,

Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 1.2X10-5 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol White Rocks Branch,

Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 1.2X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol White Rocks Branch,

Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 1.2X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

# Table 17.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time

Period (days) Rate Constant Lag Time (days) Reference



# 127 Phenol New River, Virginia Pristine river River water + seston Lab microcosm 1 ug/L 1.3X10-5 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Jefferson National

Forest, Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 1.5X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Jefferson National

Forest, Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 1.5X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol New River, Virginia Pristine river River water + sediment Lab microcosm 1 ug/L 1.5X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Jefferson National

Forest, Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 1.6X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol White Rocks Branch,

Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 1.6X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Jefferson National

Forest, Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 1.9X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Jefferson National

Forest, Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 1.9X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol White Rocks Branch,

Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 1.9X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol New River, Virginia Pristine river River water + seston Lab microcosm 1 ug/L 2.0X10-5 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Stoney Creek, Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 2.0X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Stoney Creek, Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 2.0X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol White Rocks Branch,

Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 2.0X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol White Rocks Branch,

Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 2.1X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

# Table 17.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time

Period (days) Rate Constant Lag Time (days) Reference



# 128 Phenol White Rocks Branch,

Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 2.1X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol New River, Virginia Pristine river River water + seston Lab microcosm 1 ug/L 2.2X10-5 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Jefferson National

Forest, Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 2.2X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Samber River, Belgium Polluted river River water Lab microcosm 0.5 ppm 0.5 2.4/day Borighem,G & Vereecken,J (1978) Phenol Unspecified site Soil Soil Lab microcosm 1X10-7 mols/g 1 2.4/day Dao,TH & Lavy,TL (1987)

Phenol New River, Virginia Pristine river River water + sediment Lab microcosm 1 ug/L 2.4X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol New River, Virginia Pristine river River water + seston Lab microcosm 1 ug/L 2.4X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Stoney Creek, Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 2.4X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Stoney Creek, Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 2.4X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol White Rocks Branch,

Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 2.4X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol White Rocks Branch,

Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 2.4X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Jefferson National

Forest, Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 2.4X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol New River, Virginia Pristine river River water + seston Lab microcosm 1 ug/L 2.4X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Stoney Creek, Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 2.4X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

# Table 17.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time

Period (days) Rate Constant Lag Time (days) Reference



# 129 Phenol Stoney Creek, Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 2.4X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Stoney Creek, Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 2.4X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Stoney Creek, Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 2.4X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Stoney Creek, Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 2.4X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol White Rocks Branch,

Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 2.4X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol White Rocks Branch,

Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 2.4X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol White Rocks Branch,

Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 2.5X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol New River, Virginia Pristine river River water + seston Lab microcosm 1 ug/L 2.6X10-5 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol White Rocks Branch,

Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 2.6X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Jefferson National

Forest, Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 2.9X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Jefferson National

Forest, Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 2.9X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Jefferson National

Forest, Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 3.0X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Brians Pond, Summit,

New Jersey Pond water Pond water Lab microcosm 1000 ng/mL1 3.2/day Chesney,RH et. al. (1985)

Phenol Samber River, Belgium Polluted river River water Lab microcosm 0.5 ppm 0.5 3.3/day Borighem,G & Vereecken,J (1978)

# Table 17.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time

Period (days) Rate Constant Lag Time (days) Reference



# 130 Phenol Jefferson National

Forest, Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 3.3X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Samber River, Belgium Polluted river River water Lab microcosm 0.5 ppm 0.5 3.4/day Borighem,G & Vereecken,J (1978) Phenol Stoney Creek, Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 3.6X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Stoney Creek, Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 4.3X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol White Rocks Branch,

Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 4.3X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Brians Pond, Summit,

New Jersey Pond water Pond water Lab microcosm 10 ng/mL 1 4.4/day Chesney,RH et. al. (1985)

Phenol Whitman County,

Washington Unpolluted Palouse soil Soil Lab microcosm 1X10-9 M 4.5/day Scott,HD et. al. (1983)

Phenol Whitman County,

Washington Unpolluted Palouse soil Soil Lab microcosm 1X10-6 M 4.6/day Scott,HD et. al. (1983)

Phenol Whitman County,

Washington Unpolluted Palouse soil Soil Lab microcosm 1X10-7 M 4.8/day Scott,HD et. al. (1983)

Phenol New River, Virginia Pristine river River water + sediment Lab microcosm 1 ug/L 4.8X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol New River, Virginia Pristine river River water + seston Lab microcosm 1 ug/L 4.8X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Jefferson National

Forest, Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 4.8X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Stoney Creek, Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 4.8X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol White Rocks Branch,

Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 4.8X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

# Table 17.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time

Period (days) Rate Constant Lag Time (days) Reference



# 131 Phenol Jefferson National

Forest, Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 4.9X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Jefferson National

Forest, Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 4.9X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Whitman County,

Washington Unpolluted Palouse soil Soil Lab microcosm 1X10-8 M 5.0/day Scott,HD et. al. (1983)

Phenol New River, Virginia Pristine river River water + sediment Lab microcosm 1 ug/L 5.0X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Jefferson National

Forest, Virginia Pristine stream Stream water + seston Lab microcosm 1 ug/L 5.0X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Brians Pond, Summit,

New Jersey Pond water Pond water Lab microcosm 100 ng/mL 1 5.4/day Chesney,RH et. al. (1985)

Phenol Washington County,

Arkansas Unpolluted Captina soil Soil Lab microcosm 1X10-9 M 5.4/day Scott,HD et. al. (1983)

Phenol Brians Pond, Summit,

New Jersey Pond water Pond water Lab microcosm 1 ng/mL 1 5.5/day Chesney,RH et. al. (1985)

Phenol New River, Virginia Pristine river River water + sediment Lab microcosm 1 ug/L 6.0X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Washington County,

Arkansas Unpolluted Captina soil Soil Lab microcosm 1X10-8 M 6.1/day Scott,HD et. al. (1983)

Phenol Washington County,

Arkansas Unpolluted Captina soil Soil Lab microcosm 1X10-7 M 6.2/day Scott,HD et. al. (1983)

Phenol New River, Virginia Pristine river River water + sediment Lab microcosm 1 ug/L 7.2X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Washington County,

Arkansas Unpolluted Captina soil Soil Lab microcosm 1X10-6 M 7.3/day Scott,HD et. al. (1983)

Phenol New River, Virginia Pristine river River water + sediment Lab microcosm 1 ug/L 7.5X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

# Table 17.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time

Period (days) Rate Constant Lag Time (days) Reference



# 132 Phenol St. Lawrence River,

Canada River water River water Lab microcosm 125 ppb 0.2 7.99/day Visser,SA et. al. (1977)

Phenol Stoney Creek, Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 8.0X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Stoney Creek, Virginia Pristine stream Stream water + sediment Lab microcosm 1 ug/L 9.0X10-7 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol New River, Virginia Pristine river River water + seston Lab microcosm 1 ug/L 9.6X10-6 mg/mg/day Peters,GT & Colwell,FS (1989)

Phenol Chernozen, Ukraine Industrial location Soil Lab microcosm 100 mg/kg 5 Biodegrades Medvedev,VA & Davidov,VD (1981A) Phenol Chernozen, Ukraine Industrial location Soil Lab microcosm 100 mg/kg 3 Biodegrades Medvedev,VA & Davidov,VD (1981A) Phenol Chernozen, Ukraine Industrial location Soil Lab microcosm 500 mg/kg 6 Biodegrades Medvedev,VA & Davidov,VD (1981B) Phenol Chernozen, Ukraine Industrial location Soil Lab microcosm 500 mg/kg 16 Biodegrades Medvedev,VA & Davidov,VD (1981B) Phenol Waterloo, Ontario Uncultivated soil Soil Lab microcosm 100 ug/g 5 Biodegrades Baker,MD & Mayfield,CI (1980) Phenol Chernozen, Ukraine Industrial location Soil Lab microcosm 1000 mg/kg 44 No biodegradation Medvedev,VA & Davidov,VD (1981A) Phenol Terrebonne Bay and

Barataria Bay, LA Estuary Sediment Reactor system 5 mg/L 0.18/day Portier,RJ (1985)

Phenol Terrebonne Bay and

Barataria Bay, LA Estuary Sediment Reactor system 5 mg/L 0.31/day Portier,RJ (1985)

# 133 

# 0 5 10 15

0.001.002.003.004.005.00

Rate constant (days-1

# )Frequency 

# 3.4.2. o-Cresol o-Cresol is readily degraded under aerobic conditions (Table 18). Biodegradation of this compound is believed to proceed via hydroxylation to 2-methylcatechol followed by ring cleavage (Paris et. al., 1983). While no field studies were located for this compound,in situ microcosm studies conducted at Vejen City, Denmark showed that o-cresol was readily degraded in an aquifer environment with an average half-life of 2.6 days (Nielsen et. al., 1996). Rate constants were mainly collected for laboratory microcosm studies with calculated half-lives ranging from less than 1 day (several studies, see Table 18) to 10 days (Mueller et. al., 1991A). The average half-life for these data was less than 1 day. Rate constants reported for a study using groundwater as an inoculum for the degradation of o-cresol were considerably higher than those reported in other study types. The median for the primary biodegradation rate constant of o-cresol, considering all studies, is 0.4/day (N = 22); a range of 0.069 to 4.61/day is reported. The frequency distribution histogram for the data is shown in figure 16. The mean for the lab microcosm studies alone is 0.49/day. o-Cresol is expected to be readily biodegraded under most aerobic environmental conditions.

Figure 16.Frequency histogram for the published primary biodegradation rate constant values of ocresol.

# 134

Table 18.Aerobic biodegradation rate constant values for o-cresol Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference

o-Cresol Denmark Groundwater Groundwater grab sample 200-1000 ug/L 20 0.33-0.43/day 4 Arvin,E et. al. (1988)

o-Cresol Forlev landfill,

Korsoer, Zealand Sanitary landfill Leachate Groundwater inoculum 100 ug/L 1 4.61/day Lyngkilde,J et. al. (1988)

o-Cresol Forlev landfill,

Korsoer, Zealand Sanitary landfill Leachate Groundwater inoculum 100 ug/L 1 4.61/day Lyngkilde,J et. al. (1988)

o-Cresol Forlev landfill,

Korsoer, Zealand Sanitary landfill Leachate Groundwater inoculum 100 ug/L 1 4.61/day Lyngkilde,J et. al. (1988)

o-Cresol Forlev landfill,

Korsoer, Zealand Sanitary landfill Leachate Groundwater inoculum 100 ug/L 1 4.61/day Lyngkilde,J et. al. (1988)

o-Cresol Vejen City,

Jutland, Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 0.2/day Nielsen,PH et. al. (1996)

o-Cresol Vejen City,

Jutland, Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 0.2/day Nielsen,PH et. al. (1996)

o-Cresol Vejen City,

Jutland, Denmark Landfill site Aquifer sediment + groundwater In situ microcosm 150 ug/L 0.4/day Nielsen,PH et. al. (1996)

o-Cresol Skaelskor,

Denmark Uncontaminated Fractured clay Lab column 3.2 Biodegrades 0.5 Broholm,K et. al. (1995)

o-Cresol American Creosote

Works, Pensacola, FL Wood preserving site Sediment Lab microcosm 9.7 mg/kg 56 0.069/day Mueller,JG et. al. (1991A)

o-Cresol American Creosote

Works, Pensacola, FL Wood preserving site Sediment Lab microcosm 9.7 mg/kg 56 0.087/day 7 Mueller,JG et. al. (1991A)

o-Cresol Wiggins,

Mississippi Soil Lab microcosm 250 mg/kg soil 0.136/day Loehr,RC & Matthews,JE (1992) o-Cresol River water Lab microcosm 0.160/day 2 Kaplin,VT et. al. (1968) o-Cresol Cliffs-Dow

Chemical Co., Marquette, MI Charcoal manufacturing plant Aquifer sediment Lab microcosm 500 ug/L 21 0.19/day Klecka,GM et. al. (1990)

# Table 18.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 135 o-Cresol Cliffs-Dow

Chemical Co., Marquette, MI Charcoal manufacturing plant Aquifer sediment Lab microcosm 500 ug/L 21 0.33/day Klecka,GM et. al. (1990)

o-Cresol Vejen City,

Jutland, Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 150 ug/L 0.4/day Nielsen,PH et. al. (1996)

o-Cresol Vejen City,

Jutland, Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 150 ug/L 0.4/day 1 Nielsen,PH et. al. (1996)

o-Cresol Vejen City,

Jutland, Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 150 ug/L 0.4/day 2 Nielsen,PH et. al. (1996)

o-Cresol Austin, Texas Soil Lab microcosm 500 mg/kg soil 0.433/day Loehr,RC & Matthews,JE (1992) o-Cresol Soil Lab microcosm 1000 mg/kg soil 16 0.72-0.82/day Medvedev,VA & Davidov,VD (1981) o-Cresol Cliffs-Dow

Chemical Co., Marquette, MI Charcoal manufacturing plant Aquifer sediment Lab microcosm 500 ug/L 0.77/day Klecka,GM et. al. (1990)

o-Cresol Vejen City,

Jutland, Denmark Landfill site Aquifer sediment + groundwater Lab microcosm 150 ug/L 10 0.877/day Nielsen,PH & Christensen,TH (1994A) o-Cresol American Creosote

Works, Pensacola, FL Wood preserving site Aquifer sediment + groundwater Lab microcosm 4.2 mg/L 3 0.88/day Mueller,JG et. al. (1991)

o-Cresol Soil Lab microcosm 500 mg/kg soil 8 1.35-1.55/day Medvedev,VA & Davidov,VD (1981B) o-Cresol Denmark Municipal landfill Leachate Reactor system 50 mg COD/L Biodegrades Lyngkilde,J et. al. (1992)

# 136 0 5 10 15

0.00.20.40.60.81.01.2

Rate constant (days-1

# )Frequency 

# 3.4.3. m-Cresol m-Cresol is rapidly degraded under aerobic conditions (Table 19). Biodegradation is believed to proceed via hydroxylation to 3-methylcatechol followed by ring cleavage (Paris et. al., 1983). No field orin situ

microcosm studies were located for this compound. Rate constants were exclusively collected for laboratory microcosm studies with calculated half-lives ranging from less than 1 day (several studies, see Table 19) to 198 days (Dobbins and Pfaender, 1988). The average half-life for this data was approximately 1.5 days. The high half-life was taken from a study measuring the biodegradation of m-cresol at different horizons in a sediment core from a pristine aquifer site. The half-lives measured for this core varied from 28 to 198 days depending on the location of the sediment used in the laboratory microcosm. A single mineralization study was reported giving a half-life of 714 days for m-cresol in uncontaminated aquifer sediment (Aelion et. al., 1987). Loehr and Matthews (1992) reported that biodegradation of m-cresol was considerably slower in an acid soil (pH 4.8) when compared to degradation in a basic soil (pH 7.8) giving half-lives of 0.6 and 11.3 days, respectively. This difference was not seen in the same magnitude for the other cresol isomers although degradation of the cresols in the acidic soil was slower in all cases. Work by Palumbo et. al. (1988) showed that maximum uptake rates of m-cresol in environmental water samples were seasonal, with rates significantly slower in the winter months and then increasing through the summer months as water temperatures and microbial activity increased before declining again during the fall. The median for the primary biodegradation rate constant of m-cresol, considering all studies, is 0.133/day (N = 19); a range of 0.0035 to 1.16/day is reported. The frequency distribution histogram for this data is shown in figure 17. m-Cresol is expected to be readily biodegraded under most aerobic environmental conditions.

Figure 17.Frequency histogram for the published primary biodegradation rate constant values of mcresol.

# 137

Table 19.Aerobic biodegradation rate constant values for m-cresol Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference

m-Cresol Lula, Oklahoma Uncontaminated Aquifer sediment Lab microcosm 0.00024- 0.0024/day Dobbins,DC & Pfaender,FK (1987) m-Cresol Lula, Oklahoma Uncontaminated aquifer site Aquifer sediment Lab microcosm 39 ng/g 150 0.00097/day Aelion,CM et. al. (1987)

m-Cresol Lula, Oklahoma Uncontaminated Aquifer sediment Lab microcosm 0.0035/day Dobbins,DC & Pfaender,FK (1988) m-Cresol Lula, Oklahoma Uncontaminated Aquifer sediment Lab microcosm 0.0073/day Dobbins,DC & Pfaender,FK (1988) m-Cresol Lula, Oklahoma Uncontaminated Aquifer sediment Lab microcosm 0.012/day Dobbins,DC & Pfaender,FK (1988) m-Cresol Lula, Oklahoma Uncontaminated Aquifer sediment Lab microcosm 0.012/day Dobbins,DC & Pfaender,FK (1988) m-Cresol Lula, Oklahoma Uncontaminated Aquifer sediment Lab microcosm 0.025/day Dobbins,DC & Pfaender,FK (1988) m-Cresol Coastal water

adjacent to the Newport R. Uncontaminated Seawater Lab microcosm 1-35 ug/L 0.21-0.5 0.032/day Palumbo,AV et. al. (1988)

m-Cresol American

Creosote Works, Pensacola, FL Wood preserving site Sediment Lab microcosm 21.1 mg/kg 84 0.057/day Mueller,JG et. al. (1991A)

m-Cresol Wiggins,

Mississippi Soil Lab microcosm 130 mg/kg soil 0.061/day Loehr,RC & Matthews,JE (1992) m-Cresol American

Creosote Works, Pensacola, FL Wood preserving site Sediment Lab microcosm 21.1 mg/kg 56 0.078/day 7 Mueller,JG et. al. (1991A)

m-Cresol River water Lab microcosm 0.188/day 2 Kaplin,VT et. al. (1968) m-Cresol Soil Lab microcosm 1000 mg/kg soil 27 0.43-0.49/day Medvedev,VA & Davidov,VD (1981)

# Table 19.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 138 m-Cresol Lake Michie,

Durham, North Carolina Uncontaminated Lake water Lab microcosm 0-500 ug/L 0.576/day Shimp,RJ & Pfaender,FK (1985)

m-Cresol Lake Michie,

Durham, North Carolina Uncontaminated Lake water Lab microcosm 0-500 ug/L 0.624/day Shimp,RJ & Pfaender,FK (1985)

m-Cresol Newport River

estuary, NC Uncontaminated Estuarine water Lab microcosm 1-35 ug/L 0.21-0.5 0.70/day Palumbo,AV et. al. (1988)

m-Cresol Lake Michie,

Durham, North Carolina Uncontaminated Lake water Lab microcosm 0-500 ug/L 0.792/day Shimp,RJ & Pfaender,FK (1985)

m-Cresol Newport River,

NC Uncontaminated River water Lab microcosm 1-35 ug/L 0.21-0.5 0.82/day Palumbo,AV et. al. (1988)

m-Cresol Soil Lab microcosm 500 mg/kg soil 11 0.98-1.13/day Medvedev,VA & Davidov,VD (1981B) m-Cresol Lake Michie,

Durham, North Carolina Uncontaminated Lake water Lab microcosm 0-500 ug/L 1.01/day Shimp,RJ & Pfaender,FK (1985)

m-Cresol American

Creosote Works, Pensacola, FL Wood preserving site Aquifer sediment + groundwater Lab microcosm 2.5 mg/L 3 1.07/day Mueller,JG et. al. (1991)

m-Cresol Austin, Texas Soil Lab microcosm 120 mg/kg soil 1.16/day Loehr,RC & Matthews,JE (1992) m-Cresol Newport River

estuary, North Carolina Uncontaminated Estuarine water Lab microcosm Biodegrades Pfaender,FK & Bartholomew,GW (1982)

m-Cresol Newport River

estuary, North Carolina Uncontaminated Estuarine water Lab microcosm Biodegrades Pfaender,FK & Bartholomew,GW (1982)

# Table 19.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 139 m-Cresol Newport River

estuary, North Carolina Uncontaminated Estuarine water Lab microcosm Biodegrades Pfaender,FK & Bartholomew,GW (1982)

m-Cresol Newport River

estuary, North Carolina Uncontaminated Estuarine water Lab microcosm Biodegrades Pfaender,FK & Bartholomew,GW (1982)

m-Cresol Newport River

estuary, North Carolina Uncontaminated Estuarine water Lab microcosm Biodegrades Pfaender,FK & Bartholomew,GW (1982)

m-Cresol Newport River

estuary, North Carolina Uncontaminated Estuarine water Lab microcosm Biodegrades Pfaender,FK & Bartholomew,GW (1982)

m-Cresol Newport River,

North Carolina Uncontaminated River water Lab microcosm Biodegrades Pfaender,FK & Bartholomew,GW (1982) m-Cresol Offshore, North

Carolina Uncontaminated Seawater Lab microcosm Biodegrades slightly Pfaender,FK & Bartholomew,GW (1982)

# 140 0 2 4 6 8 10 12

02468101214

Rate constants (days-1

# )Frequency 

# 3.4.4. p-Cresol p-Cresol is readily degraded under aerobic conditions (Table 20). Biodegradation is believed to proceed via hydroxylation to 4-methylcatechol followed by ring cleavage (Paris et. al., 1983). No field orin situ

microcosm studies were located for this compound. Rate constants were exclusively collected for laboratory microcosm studies aside from one groundwater grab study (Delfino and Miles, 1985) with calculated half-lives ranging from less than 1 day (several studies, see Table 20) to 27 days (Paris et. al., 1983). The average half-life for this data was less than 1 day. A single mineralization study was reported giving an approximate half-life of 10 days for p-cresol in aquifer sediment (Millette et. al., 1995). In a factorial experiment, it was found that the mineralization of p-cresol was unaffected by the presence of other compounds commonly found in creosote (Millette et. al., 1995). The median for the primary biodegradation rate constant of p-cresol is 1.75/day (N = 28); a range of 0.079 to 13.15/day is reported. The frequency distribution histogram for this data is shown in figure 18. p-Cresol is expected to be readily biodegraded under most aerobic environmental conditions.

Figure 18.Frequency histogram for the published primary biodegradation rate constant values of pcresol.

# 141

Table 20.Aerobic biodegradation rate constant values for p-cresol Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference
p-Cresol NW Gainesville,

Florida Groundwater Groundwater grab sample 2.2 mg/L 8 1.26/day 2 Delfino,JJ & Miles,CJ (1985)
p-Cresol Lago Lake,

Georgia Uncontaminated Lake water Lab microcosm 1 ug/L 0.003 ug/L/day Hwang,HM et. al. (1989)
p-Cresol Okefenokee

Swamp, Mizell Prairie Uncontaminated Freshwater Lab microcosm 1 ug/L 0.01 ug/L/day Hwang,HM et. al. (1989)

p-Cresol Williams pond,

Georgia Pond water Lab microcosm 1 mg/L 0.026-2.6/day Paris,DF et. al. (1983)
p-Cresol Mamma Rhoda

Channel, Bahamas Uncontaminated Seawater Lab microcosm 1 ug/L 0.027 ug/L/day Hwang,HM et. al. (1989)
p-Cresol Park pond,

Georgia Pond water Lab microcosm 1 mg/L 0.058-5.8/day Paris,DF et. al. (1983)
p-Cresol Hickory Hills,

Georgia Freshwater Lab microcosm 1 mg/L 0.062-6.3/day Paris,DF et. al. (1983)
p-Cresol Oconee River,

Georgia River water Lab microcosm 1 mg/L 0.072-7.2/day Paris,DF et. al. (1983)
p-Cresol Canadian Forces

Base, Borden, Canada Aquifer sediment Lab microcosm 101.4 mg/L 15 0.0723/day 3 Millette,D et. al. (1995)

p-Cresol American Creosote

Works, Pensacola, FL Wood preserving site Sediment Lab microcosm 21.7 mg/kg 56 0.079/day Mueller,JG et. al. (1991A)

p-Cresol American Creosote

Works, Pensacola, FL Wood preserving site Sediment Lab microcosm 21.7 mg/kg 56 0.084/day Mueller,JG et. al. (1991A)

p-Cresol Overlook pond,

Georgia Pond water Lab microcosm 1 mg/L 0.11-11/day Paris,DF et. al. (1983)
p-Cresol River water Lab microcosm 0.188/day 2 Kaplin,VT et. al. (1968)

# Table 20.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 142 p-Cresol Mamma Rhoda

Channel, Bahamas Uncontaminated Seawater Lab microcosm 500 ug/L 0.22 ug/L/day Hwang,HM et. al. (1989)
p-Cresol Lago Lake,

Georgia Uncontaminated Lake water Lab microcosm 1 ug/L 0.24 ug/L/day Hwang,HM et. al. (1989)
p-Cresol Bay Bridge,

Pensacola, Florida Estuarine water Lab microcosm 200 ug/L 4.1 0.384/day 2.5 Vanveld,PA & Spain,JC (1983)
p-Cresol Lago Lake,

Georgia Uncontaminated Lake water Lab microcosm 1 ug/L 0.5 ug/L/day Hwang,HM et. al. (1989)
p-Cresol James River,

Virginia River water Lab microcosm 4.2 0.842/day Bourquin,AW (1984)
p-Cresol Yakima River,

Washington River water Lab microcosm 100 ug/L 0.75 0.98-1.22/day Rogers,JE et. al. (1984)
p-Cresol Sabine Island,

Florida Estuarine water + sediment Lab microcosm 200 ug/L 2.5 1.06/day 0.42 Vanveld,PA & Spain,JC (1983)
p-Cresol Sabine Island,

Florida Estuarine water Lab microcosm 200 ug/L 1.5 1.08/day 1 Vanveld,PA & Spain,JC (1983)
p-Cresol Soil Lab microcosm 1000 mg/kg soil 9 1.28-1.46/day Medvedev,VA & Davidov,VD (1981) p-Cresol Wiggins,

Mississippi Soil Lab microcosm 45 mg/kg soil 1.39/day Loehr,RC & Matthews,JE (1992) p-Cresol Bay Bridge,

Pensacola, Florida Estuarine sediment Lab microcosm 200 ug/L 1.25 1.46/day 0.42 Vanveld,PA & Spain,JC (1983)
p-Cresol Soil Lab microcosm 500 mg/kg soil 7 1.55-1.78/day Medvedev,VA & Davidov,VD (1981B) p-Cresol Yakima River,

Washington River water Lab microcosm 1000 ug/L 2.25 1.7-2.64/day 1.6 Rogers,JE et. al. (1984)
p-Cresol Bayou Chico,

Florida Estuarine water Lab microcosm 200 ug/L 1.25 1.75/day Vanveld,PA & Spain,JC (1983)

# Table 20.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 143 p-Cresol 331 Bldg Fish

Pond, Richmond, WA Pond water Lab microcosm 1000 ug/L 3.5 1.94-1.99/day 2.75 Rogers,JE et. al. (1984)

p-Cresol Walla Walla River,

Washington River water Lab microcosm 1000 ug/L 2.5 1.97-2.57/day Rogers,JE et. al. (1984)
p-Cresol Yakima River,

Washington River water Lab microcosm 100 ug/L 1.97-2.57/day Rogers,JE et. al. (1984)
p-Cresol Lago Lake,

Georgia Uncontaminated Lake water Lab microcosm 10000 ug/L 10.95 ug/L/day Hwang,HM et. al. (1989)
p-Cresol Lago Lake,

Georgia Uncontaminated Lake water Lab microcosm 10000 ug/L 14.67 ug/L/day Hwang,HM et. al. (1989)
p-Cresol Bayou Chico,

Florida Estuarine sediment Lab microcosm 200 ug/L 1 2.02/day Vanveld,PA & Spain,JC (1983)
p-Cresol Bay Bridge,

Pensacola, Florida Estuarine water + sediment Lab microcosm 200 ug/L 1.25 2.28/day Vanveld,PA & Spain,JC (1983)
p-Cresol 331 Bldg Fish

Pond, Richmond, WA Pond water Lab microcosm 100 ug/L 2.5 2.45-3.7/day 1.25-1.9 Rogers,JE et. al. (1984)

p-Cresol Sabine Island,

Florida Estuarine sediment Lab microcosm 200 ug/L 1 2.88/day Vanveld,PA & Spain,JC (1983)
p-Cresol 331 Bldg Fish

Pond, Richmond, WA Pond water Lab microcosm 1000 ug/L 2.9 2.98-10.4/day 2.3 Rogers,JE et. al. (1984)

p-Cresol American Creosote

Works, Pensacola, FL Wood preserving site Aquifer sediment + groundwater Lab microcosm 2.0 mg/L 1 3.0/day Mueller,JG et. al. (1991)

p-Cresol Lago Lake,

Georgia Uncontaminated Lake water Lab microcosm 100000 ug/L 32.1 ug/L/day Hwang,HM et. al. (1989)

# Table 20.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 144 p-Cresol Okefenokee

Swamp, Mizell Prairie Uncontaminated Freshwater Lab microcosm 100000 ug/L 38 ug/L/day Hwang,HM et. al. (1989)

p-Cresol Bayou Chico,

Florida Estuarine water + sediment Lab microcosm 200 ug/L 0.79 5.52/day Vanveld,PA & Spain,JC (1983)
p-Cresol Columbia River,

Washington River water Lab microcosm 1000 ug/L 2.67 7.3-19.0/day 0-2.4 Rogers,JE et. al. (1984)
p-Cresol 331 Bldg Fish

Pond, Richmond, WA Pond water Lab microcosm 100 ug/L 1.8 7.7-8.2/day 1.5 Rogers,JE et. al. (1984)

p-Cresol Austin, Texas Soil Lab microcosm 100 mg/kg soil >100 mg/kg/day Loehr,RC & Matthews,JE (1992) p-Cresol 331 Bldg Fish

Pond, Richmond, WA Pond water Lab microcosm 100 ug/L Biodegrades Rogers,JE et. al. (1984)

p-Cresol Athens, Georgia Freshwater Lab microcosm 130 ug/L 0.38 Biodegrades Hwang,HM & Maloney,SW (1996) p-Cresol Athens, Georgia Freshwater Lab microcosm 300 ug/L 0.38 Biodegrades Hwang,HM & Maloney,SW (1996) p-Cresol Athens, Georgia Freshwater Lab microcosm 500 ug/L 0.38 Biodegrades Hwang,HM & Maloney,SW (1996) p-Cresol Athens, Georgia Freshwater Lab microcosm 60 ug/L 0.38 Biodegrades Hwang,HM & Maloney,SW (1996) p-Cresol Columbia River,

Washington River water Lab microcosm 1000 ug/L Biodegrades Rogers,JE et. al. (1984)
p-Cresol Yakima River,

Washington River water Lab microcosm 1000 ug/L Biodegrades Rogers,JE et. al. (1984)

# 145 Rate Constant vs. Concentration

0 100 200 300 400 500 600

0.250.270.320.780.330.62.47.3

Rate constant (days-1

# )Concentration(ug/L) 

# 3.5. Ketones Data were located for two of the three original members of this group, acetone, methyl ethyl ketone and methyl isobutyl ketone. No data were found for methyl isobutyl ketone and this compound was not included in this discussion. The ketones, in general, are readily biodegraded in soil and water and thus are expected to naturally attenuate in the environment. 3.5.1. Acetone Acetone is expected to biodegrade rapidly under aerobic conditions (Table 21). Only three papers were located, however, reporting the degradation of this compound in environmental media. Hwang et. al. (1989) reported that mineralization of acetone in freshwater samples, varying time ofcollection and concentration, followed multiphasic kinetics which was best described by the MichaelisMenton model. First-order biodegradation rate constants of 0.025/day to 7.3/day were calculated from these data. The largest values were observed for low initial concentrations of acetone (0.5 μg/L), while the smallest values were observed for high initial concentrations (500 μg/L). The plot of the calculated first-order rate constant versus the initial concentration of acetone used in this study is shown in figure 19.

Figure 19.Rate constant versus initial concentration of acetone in a shallow stream. A field study that measured the fate of acetone in a shallow stream reported a biodegradation rate constant of 1.2/day (Rathbun et. al., 1993). This rate constant was determined by subtracting the volatilization rate constant from the overall loss rate constant. A study by Pugh et. al. (1996) reports that acetone was not biodegraded over 30 days in a non-amended microcosm using soil and groundwater from an contaminated solvent storage site. When nitrogen and phosphorus were added, however, half-lives from 20 to 49.5 days were reported. A second study by the same authors using pre-acclimated soil (over 30 days), reported a half-life of 3.6 days for acetone. The median for the primary biodegradation rate constant of acetone is 0.035/day (N = 5); a range of not biodegraded to 1.2/day is reported. The median for the mineralization rate constant of acetone is

# 146 

# 0 1 2 3 4 5

00.20.40.60.811.21.4

Rate constant (days-1

# )Frequency



# 0 2 4 6 8 10 12 14

01234567

Rate constant (days-1

# )Frequency 

# 0.078/day (N = 13); a range of 0.025 to 7.3/day is reported.. The mineralization rate constants were all measured in the same paper for lake water grab samples (Hwang et. al., 1989). The frequency histograms for this data are shown in figure 20a and 20b.

Figure 20a.The frequency histogram for the published primary biodegradation rate constant values of acetone.

Figure 20b.The frequency histogram for the published mineralization rate constant values of acetone.

# 147

Table 21.Aerobic biodegradation rate constant values for acetone Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference

Acetone Stennis Space

Center, Mississippi Surface water Stream water Field 30 1.2/day Rathbun,RE et. al. (1993)

Acetone Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.014/day Pugh,LB et. al. (1996)

Acetone Lake Lago, Athens,

Georgia Surface water Lake water Lab microcosm 500 ug/L 0.025/day Hwang,HM et. al. (1989)

Acetone Lake Lago, Athens,

Georgia Surface water Lake water Lab microcosm 100 ug/L 0.028/day Hwang,HM et. al. (1989)

Acetone Lake Lago, Athens,

Georgia Surface water Lake water Lab microcosm 101 ug/L 0.028/day Hwang,HM et. al. (1989)

Acetone Lake Lago, Athens,

Georgia Surface water Lake water Lab microcosm 105 ug/L 0.028/day Hwang,HM et. al. (1989)

Acetone Lake Lago, Athens,

Georgia Surface water Lake water Lab microcosm 50 ug/L 0.032/day Hwang,HM et. al. (1989)

Acetone Lake Lago, Athens,

Georgia Surface water Lake water Lab microcosm 51 ug/L 0.032/day Hwang,HM et. al. (1989)

Acetone Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.035/day Pugh,LB et. al. (1996)

Acetone Lake Lago, Athens,

Georgia Surface water Lake water Lab microcosm 10 ug/L 0.078/day Hwang,HM et. al. (1989)

Acetone Lake Lago, Athens,

Georgia Surface water Lake water Lab microcosm 9 ug/L 0.086/day Hwang,HM et. al. (1989)

Acetone Lake Lago, Athens,

Georgia Surface water Lake water Lab microcosm 8 ug/L 0.097/day Hwang,HM et. al. (1989)

Acetone Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 24 0.19/day Pugh,LB et. al. (1996)

Acetone Lake Lago, Athens,

Georgia Surface water Lake water Lab microcosm 3 ug/L 0.33/day Hwang,HM et. al. (1989)

# Table 21.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference



# 148 Acetone Lake Lago, Athens,

Georgia Surface water Lake water Lab microcosm 2 ug/L 0.6/day Hwang,HM et. al. (1989)

Acetone Lake Lago, Athens,

Georgia Surface water Lake water Lab microcosm 1 ug/L 2.4/day Hwang,HM et. al. (1989)

Acetone Lake Lago, Athens,

Georgia Surface water Lake water Lab microcosm 0.5 ug/L 7.3/day Hwang,HM et. al. (1989)

Acetone Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 No biodegradation Pugh,LB et. al. (1996)

# 149

3.5.2. Methyl ethyl ketone Methyl ethyl ketone is expected to biodegrade rapidly under aerobic conditions (Table 22). Only two papers were located, however, reporting the degradation of this compound in environmental media. In pure culture experiments, methyl ethyl ketone was initially hydroxylated to acetoin, and then degraded to diacetyl and acetic acid (Lijmbach and Brinkhuis, 1973). Dojlido (1979) reports that concentrations up to 800 mg/L were not toxic to microbial activity during typical screening tests using municipal wastewater. In river die-away studies, methyl ethyl ketone initially present at 20 mg/L was degraded within one to two days. A second addition of 20 mg/L methyl ethyl ketone to the same river water, once degradation from the first addition was complete, resulted in 100% degradation in less than one day. Delfino and Miles (1985) reported that methyl ethyl ketone, at 1 mg/L, was completely biodegraded in an aerated, previously anaerobic groundwater within 12 days including a 4 to 5 day lag phase. A spill of methyl ethyl ketone, resulting in groundwater contamination, was remediated by air stripping and then by biological degradation. While there was insufficient information in the paper to report a rate constant, the authors stated that laboratory tests showed that the indigenous bacteria were capable of degrading this compound (Halvorsen and Ohneck, 1985). The median for the primary biodegradation rate constant of methyl ethyl ketone, based on limited data, is 0.69/day (N = 3); a range of 0.4 to 1.4/day is reported.

# 150

Table 22.Aerobic biodegradation rate constant values for methyl ethyl ketone Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period (days) Rate Constant Lag Time (days) Reference
Methyl ethyl ketone Gainesville, Florida GroundwaterGroundwate r Groundwater grab

sample 1 mg/L 12 0.40/day 4 days Delfino,JJ & Miles,CJ (1985) Methyl ethyl ketone Vistula River, Warsaw, Poland River water River water Lab microcosm 20 mg/L 2 19.2mg/L/day 0.8 Dojlido,JR (1979)
Methyl ethyl ketone Vistula River, Warsaw, Poland River water River water Lab microcosm 20 mg/L 1 28.8 mg/L/day Dojlido,JR (1979)

# 151

3.6. Miscellaneous This section contains the data for two compounds, bis(2-ethylhexyl)phthalate and methanol. 3.6.1. Bis(2-ethylhexyl)phthalate Bis(2-ethylhexyl)phthalate, a plasticizer widely used in PVC, is a ubiquitous environmental contaminant. The current literature shows that this compound is considered to be “moderately” degradable (Scheunert et. al., 1987) under aerobic condtions. Half-life values from 3 to 630 days were reported for bis(2-ethylhexyl)phthalate (Table 23). High CO2

# production measured during mineralization experiments as well as the inability to measure intermediates such as monoethylhexyl phthalate and phthalate indicate that this compound can be readily mineralized (Maag and Loekke, 1990; Ruedel et. al., 1993; Saeger and Tucker, 1973). Studies generally used a14

# C-radiolabeled carbonyl group; cleavage of the carbonyl group and release as CO2 

# thus by itself does not indicate complete mineralization of the compound. Labeling of the ring, however, and subsequent CO2

# production does indicate that mineralization is occurring. Only 3 studies looked at the biodegradation of bis(2-ethylhexyl)phthalate in the presence of other organic compounds (Hattori et. al., 1975; Graves et. al., 1994; Schouten et. al., 1979). The rate constants obtained from these studies were, in general, greater that values reported for other studies using bis(2-ethylhexyl)phthalate as a single compound. No biodegradation of bis(2-ethylhexyl)phthalate was reported in two studies. Ritsema et. al. (1989) reported no biodegradation of this compound at 4 °C over 10 days; however, at 20 °C, a half-life of 19 days was calculated. A second laboratory microcosm study by Rubin et. al. (1982) reported that water obtained from an oligotrophic lake was unable to mineralize bis(2-ethylhexyl)phthalate over 60 days. In the same study, water collected from a eutrophic lake readily biodegraded this compound at concentrations ranging from 40 ng/L to 200 μg/L without a lag phase. The median for the primary biodegradation rate constant of bis(2-ethylhexyl)phthalate, considering all studies, is 0.0205/day (N = 36); a range of not biodegraded to 0.23/day is reported. The median for the mineralization rate constant of bis(2-ethylhexyl)phthalate, considering all studies, is 0.014/day (N = 28); a range of 0.0022 to 0.045/day is reported.The frequency distribution histograms for this data are shown in figures 21a and 21b.

# 152 0 5 10 15 20

0.000.040.080.120.160.200.24

Rate constant (days-1

# )Frequency



# 0 5 10 15

00.020.040.060.080.1

Rate constant (days-1

# )Frequency 

# Figure 21a.Frequency histogram for the published primary biodegradation rate constant values of bis(2-ethylhexyl)phthalate.

Figure 21b.Frequency histogram for the published mineralization rate constant values of bis(2- ethylhexyl)phthalate.

# 153

Table 23.Aerobic biodegradation rate constant values for bis(2-ethylhexyl)phthalate

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period

(days) Rate Constant Lag Time (days) Reference
Bis(2-ethylhexyl)phthalate Industrial facility, New Jersey Contaminated Groundwater Groundwater grab sample 17 mg/L 21 0.00903/hr Graves,DA et. al. (1994)

Bis(2-ethylhexyl)phthalate White Lake, Old Forge, New YorkUncontaminated Lake water Lab microcosm 60 Subba-Rao,RV et. al. (1982)
Bis(2-ethylhexyl)phthalate Little Dixie Lake, Columbia, Missouri Uncontaminated Sediment Lab microcosm 28 0.0011/day Johnson,BT et. al. (1984)

Bis(2-ethylhexyl)phthalate Little Dixie Lake, Columbia, Missouri Uncontaminated Sediment Lab microcosm 28 0.0014/day 21 Johnson,BT et. al. (1984)

Bis(2-ethylhexyl)phthalate Contaminated industrial site Soil Lab microcosm 21940 mg/kg 70 0.002/day Maag,J & Loekke,H (1990)
Bis(2-ethylhexyl)phthalate Uncontaminated Soil Lab microcosm 15 ug 56 0.0022/day Scheunert,I et. al. (1987) Bis(2-ethylhexyl)phthalate Little Dixie Lake, Columbia, Missouri Uncontaminated Sediment Lab microcosm 28 0.0022/day Johnson,BT et. al. (1984)

Bis(2-ethylhexyl)phthalate Little Dixie Lake, Columbia, Missouri Uncontaminated Sediment Lab microcosm 1.82 mg/L 28 0.0032/day Johnson,BT et. al. (1984)

Bis(2-ethylhexyl)phthalate Little Dixie Lake, Columbia, Missouri Uncontaminated Sediment Lab microcosm 0.182 mg/L 28 0.0035/day Johnson,BT et. al. (1984)

Bis(2-ethylhexyl)phthalate Little Dixie Lake, Columbia, Missouri Uncontaminated Sediment Lab microcosm 0.0182 mg/L 28 0.0037/day Johnson,BT et. al. (1984)

Bis(2-ethylhexyl)phthalate Little Dixie Lake, Columbia, Missouri Uncontaminated Sediment Lab microcosm 28 0.004/day Johnson,BT et. al. (1984)

Bis(2-ethylhexyl)phthalate Lower Saxonia, Germany Uncontaminated Soil Lab microcosm 1 mg/L 100 0.004/day Ruedel,H et. al. (1993)
Bis(2-ethylhexyl)phthalate Missouri River, Easley, Missouri Uncontaminated River water Lab microcosm 0.10 mg/L 32 0.004/day 12 Wylie,GD et. al. (1982)
Bis(2-ethylhexyl)phthalate Missouri River, Easley, Missouri Uncontaminated River water Lab microcosm 0.10 mg/L 32 0.004/day 7 Wylie,GD et. al. (1982)

# Table 23.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period

(days) Rate Constant Lag Time (days) Reference



# 154 Bis(2-ethylhexyl)phthalate Little Dixie Lake, Columbia, Missouri Uncontaminated Sediment Lab microcosm 14.3 mg/L 28 0.005/day Johnson,BT et. al. (1984)

Bis(2-ethylhexyl)phthalate Contaminated industrial site Soil Lab microcosm 21940 mg/kg 70 0.006/day Maag,J & Loekke,H (1990)
Bis(2-ethylhexyl)phthalate Missouri River, Easley, Missouri Uncontaminated River water Lab microcosm 0.10 mg/L 32 0.006/day 3 Wylie,GD et. al. (1982)
Bis(2-ethylhexyl)phthalate Missouri River, Easley, Missouri Uncontaminated River water Lab microcosm 0.10 mg/L 32 0.006/day 7 Wylie,GD et. al. (1982)
Bis(2-ethylhexyl)phthalate Uncontaminated Soil Lab microcosm 33 0.0073/day Schmitzer,JL et. al. (1988) Bis(2-ethylhexyl)phthalate Little Dixie Lake, Columbia, Missouri Uncontaminated Sediment Lab microcosm 10.0 mg/L 28 0.0079/day Johnson,BT et. al. (1984)

Bis(2-ethylhexyl)phthalate Germany Uncontaminated Soil Lab microcosm 0.5 mg/kg 63 0.009- 0.0134/day Dorfler,U et. al. (1996)
Bis(2-ethylhexyl)phthalate New Mexico Uncontaminated Soil Lab microcosm 20 mg/kg146 0.0096/day Fairbanks, BC et. al. (1985) Bis(2-ethylhexyl)phthalate New Mexico Uncontaminated Soil Lab microcosm 20 mg/kg146 0.0097/day Fairbanks, BC et. al. (1985) Bis(2-ethylhexyl)phthalate Lower Saxonia, Germany Uncontaminated Soil Lab microcosm 1 mg/L 100 0.01/day Ruedel,H et. al. (1993)
Bis(2-ethylhexyl)phthalate Missouri River, Easley, Missouri Uncontaminated River water Lab microcosm 0.10 mg/L 32 0.012/day 7 Wylie,GD et. al. (1982)
Bis(2-ethylhexyl)phthalate New Mexico Uncontaminated Soil Lab microcosm 2 mg/kg 146 0.012/day Fairbanks, BC et. al. (1985) Bis(2-ethylhexyl)phthalate Beebe Lake, Ithaca, New YorkUncontaminated Lake water Lab microcosm 2 ng/mL33 0.013/day Subba-Rao,RV et. al. (1982)
Bis(2-ethylhexyl)phthalate Missouri River, Easley, Missouri Uncontaminated River water Lab microcosm 0.10 mg/L 32 0.013/day 4 Wylie,GD et. al. (1982)
Bis(2-ethylhexyl)phthalate Beebe Lake, Ithaca, New YorkUncontaminated Lake water Lab microcosm 200 pg/mL 40 0.0137/day Subba-Rao,RV et. al. (1982)
Bis(2-ethylhexyl)phthalate New Mexico Uncontaminated Soil Lab microcosm 2 mg/kg 146 0.014/day Fairbanks, BC et. al. (1985) Bis(2-ethylhexyl)phthalate New Mexico Uncontaminated Soil Lab microcosm 20 mg/kg146 0.0148/day Fairbanks, BC et. al. (1985)

# Table 23.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period

(days) Rate Constant Lag Time (days) Reference



# 155 Bis(2-ethylhexyl)phthalate Baierbrunn, Germany Uncontaminated Soil Lab microcosm 0.5 mg/kg 28-63 0.015- 0.019/day Dorfler,U et. al. (1996)
Bis(2-ethylhexyl)phthalate New Mexico Uncontaminated Soil Lab microcosm 2 mg/kg 146 0.015/day Fairbanks, BC et. al. (1985) Bis(2-ethylhexyl)phthalate New Mexico Uncontaminated Soil Lab microcosm 20 mg/kg146 0.015/day Fairbanks, BC et. al. (1985) Bis(2-ethylhexyl)phthalate New Mexico Uncontaminated Soil Lab microcosm 2 mg/kg 146 0.0156/day Fairbanks, BC et. al. (1985) Bis(2-ethylhexyl)phthalate New Mexico Uncontaminated Soil Lab microcosm 20 mg/kg146 0.0158/day Fairbanks, BC et. al. (1985) Bis(2-ethylhexyl)phthalate Germany Uncontaminated Soil Lab microcosm 10 mg/kg63 0.017- 0.024/day Dorfler,U et. al. (1996)
Bis(2-ethylhexyl)phthalate Missouri River, Easley, Missouri Uncontaminated River water Lab microcosm 0.10 mg/L 32 0.017/day 3 Wylie,GD et. al. (1982)
Bis(2-ethylhexyl)phthalate New Mexico Uncontaminated Soil Lab microcosm 2 mg/kg 146 0.017/day Fairbanks, BC et. al. (1985) Bis(2-ethylhexyl)phthalate Ebersberger Forst, Germany Uncontaminated Soil Lab microcosm 0.5 mg/kg 28-63 0.018- 0.028/day Dorfler,U et. al. (1996)
Bis(2-ethylhexyl)phthalate NorthrhineWestfalia, Germany Uncontaminated Soil Lab microcosm 1 mg/L 100 0.02/day Ruedel,H et. al. (1993)

Bis(2-ethylhexyl)phthalate Plasticizer manufacturing site Soil Lab microcosm 5200 mg/kg 98 0.024/day Fogel,S et. al. (1995)

Bis(2-ethylhexyl)phthalate Mississippi River Uncontaminated River water Lab microcosm 1 mg/L 35 0.029/day Saeger,VW & Tucker,ES (1976)
Bis(2-ethylhexyl)phthalate NorthrhineWestfalia, Germany Uncontaminated Soil Lab microcosm 1 mg/L 100 0.03/day Ruedel,H et. al. (1993)

Bis(2-ethylhexyl)phthalate Plasticizer manufacturing site Soil Lab microcosm 310 mg/kg 42 0.033/day Fogel,S et. al. (1995)

Bis(2-ethylhexyl)phthalate Beebe Lake, Ithaca, New YorkUncontaminated Lake water Lab microcosm 200 ng/mL 28 0.035/day Subba-Rao,RV et. al. (1982)
Bis(2-ethylhexyl)phthalate Neuherberg, Germany Uncontaminated Soil Lab microcosm 0.5 mg/kg 28-63 0.036- 0.057/day Dorfler,U et. al. (1996)

# Table 23.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period

(days) Rate Constant Lag Time (days) Reference



# 156 Bis(2-ethylhexyl)phthalate Mississippi River, Missouri Uncontaminated River water Lab microcosm 1 ppm 19 0.036/day Saeger,VW & Gledhill,WE (1978) Bis(2-ethylhexyl)phthalate Mt. Pleasant, New York Uncontaminated Soil Lab microcosm 1 ug/g dry soil 20 0.036/day Efroymson,RA & Alexander,M (1994) Bis(2-ethylhexyl)phthalate Rhine River, the Netherlands Uncontaminated River water Lab microcosm 3.3 ppb 10 0.036/day Ritsema,R et. al. (1989)
Bis(2-ethylhexyl)phthalate Missouri River, Easley, Missouri Uncontaminated River water Lab microcosm 0.10 mg/L 32 0.037/day 4 Wylie,GD et. al. (1982)
Bis(2-ethylhexyl)phthalate Mississippi River Uncontaminated River water Lab microcosm 1.0 mg/L 0.040/day Saeger,VW and Tucker,ES (1973a) Bis(2-ethylhexyl)phthalate Mississippi River Uncontaminated River water Lab microcosm 42 0.041/day Saeger,VW & Tucker,ES (1973b)
Bis(2-ethylhexyl)phthalate Beebe Lake, Ithaca, New YorkUncontaminated Lake water Lab microcosm 21 pg/mL 28 0.045/day Subba-Rao,RV et. al. (1982)
Bis(2-ethylhexyl)phthalate Fish-Pesticide Research Laboratory, MO Uncontaminated Freshwater hydrosoil Lab microcosm 1 m/L 30 0.045/day Johnson,BT & Lulves,W (1975)

Bis(2-ethylhexyl)phthalate Plasticizer manufacturing site Soil Lab microcosm 1120 mg/kg 49 0.051/day Fogel,S et. al. (1995)

Bis(2-ethylhexyl)phthalate Ogawa River, Japan Uncontaminated River water Lab microcosm 17 0.064/day 3 Hattori,Y et. al. (1975)
Bis(2-ethylhexyl)phthalate Osaka Bay, off Tomokeshima, Japan Uncontaminated Seawater Lab microcosm 19 0.065/day 3 Hattori,Y et. al. (1975)

Bis(2-ethylhexyl)phthalate Soil Lab microcosm 480 ug/g 30 0.082/day Shanker,R et. al. (1985) Bis(2-ethylhexyl)phthalate Ogawa River, Japan Uncontaminated River water Lab microcosm 17 0.085/day 3 Hattori,Y et. al. (1975)
Bis(2-ethylhexyl)phthalate the Netherlands Uncontaminated River water Lab microcosm 50 ug/L 14 0.13/day Schouten,MJ et. al. (1979) Bis(2-ethylhexyl)phthalate Osaka Bay, near costal factory, Japan Uncontaminated Seawater Lab microcosm 19 0.23/day 2 Hattori,Y et. al. (1975)

# Table 23.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period

(days) Rate Constant Lag Time (days) Reference



# 157 Bis(2-ethylhexyl)phthalate Beebe Lake, Ithaca, New YorkUncontaminated Lake water Lab microcosm 450 ng/L 100 pg/L/hr Rubin,HE et. al. (1982)
Bis(2-ethylhexyl)phthalate Beebe Lake, Ithaca, New YorkUncontaminated Lake water Lab microcosm 5 ug/L 2 ng/L/hr Rubin,HE et. al. (1982)
Bis(2-ethylhexyl)phthalate Beebe Lake, Ithaca, New YorkUncontaminated Lake water Lab microcosm 200 ug/L 450 ng/L/hr Rubin,HE et. al. (1982)
Bis(2-ethylhexyl)phthalate Beebe Lake, Ithaca, New YorkUncontaminated Lake water Lab microcosm 40 ng/L 50 pg/L/hr Rubin,HE et. al. (1982)
Bis(2-ethylhexyl)phthalate Rhine River, the Netherlands Uncontaminated River water Lab microcosm 3.3 ppb 10 No biodegradation Ritsema,R et. al. (1989)
Bis(2-ethylhexyl)phthalate White Lake, Old Forge, New YorkUncontaminated Lake water Lab microcosm 60 No biodegradation Rubin,HE et. al. (1982)
Bis(2-ethylhexyl)phthalate Lower Saxonia, Germany Uncontaminated Soil Lysimeter 100 0.003/day Ruedel,H et. al. (1993)
Bis(2-ethylhexyl)phthalate Lower Saxonia, Germany Uncontaminated Soil Lysimeter 100 0.013/day Ruedel,H et. al. (1993)
Bis(2-ethylhexyl)phthalate NorthrhineWestfalia, Germany Uncontaminated Soil Lysimeter 100 0.033/day Ruedel,H et. al. (1993)

Bis(2-ethylhexyl)phthalate NorthrhineWestfalia, Germany Uncontaminated Soil Lysimeter 100 0.05/day Ruedel,H et. al. (1993)

# 158 0 2 4 6 8 10

00.10.20.30.40.50.60.7

Rate constant (days-1

# )Frequency 

# 3.5.2. Methanol Methanol is readily biodegraded under aerobic conditions in most cases (Table 24). First-order rate constants for biodegradation were less than or equal to 0.693/day in laboratory studies. The sole field study reported a rate constant of 0.019/day (T1/2

# =36 days) (American Petroleum Institute, 1994). Several experiments in two studies reported no biodegradation of methanol over the time period measured. Work by Pugh et. al. (1996) at a former pharmaceutical tank farm, showed that methanol concentrations did not uniformly decrease in laboratory microcosms. However, the presence of other compounds including acetone and isopropanol, suggest that methanol is being produced by the degradation of these compounds. Thus, the degradation of methanol may be masked by its concurrent production. The American Petroleum Institute (1994) reported that methanol was readily degraded in a field experiment following a lag phase of 100 days; however, in laboratory microcosm studies where methanol concentrations ranged from 1000 to over 7000 mg/L, no biodegradation of methanol was seen over time periods of up to 200 days (American Petroleum Institute, 1994A). These concentrations may be too high to allow microbial populations to exist readily. In addition, incomplete oxidation of methanol leading to the production of formaldehyde could act to inhibit microbial populations. In a field environment where physical processes such as dilution and dispersion initially act to lower concentrations, biodegradation appears to be facilitated. The median for the primary biodegradation rate constant of methanol is 0.118/day (N = 20); a range of not biodegraded to 0.693/day is reported. The frequency distribution histogram for this data is shown in figure 22.

Figure 22.Frequency histogram for the published primary biodegradation rate constant values of methanol.

# 159

Table 24.Aerobic biodegradation rate constant values for methanol Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period

(days) Rate Constant Lag Time (days) Reference

Methanol Canada Forces

Base, Borden, Ontario Uncontaminated Aquifer sediment + groundwater Field 7034 mg/L 476 0.019/day 100 American Petroleum Institute (1994)

Methanol Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 127 Pugh,LB et. al. (1996)

Methanol Canada Forces

Base, Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm7318 mg/L 278 >103 American Petroleum Institute (1994A)

Methanol Mamma Rhoda

Channel, Bahamas Uncontaminated Seawater Lab microcosm 1 ug/L 0.00002 ug/L/day Hwang,HM et. al. (1989)

Methanol Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 0.007/day Pugh,LB et. al. (1996)

Methanol Pennsylvania Uncontaminated Aquifer sediment + groundwater Lab microcosm750 mg/L 185 0.0134/day Novak,JT et. al. (1985)

Methanol Pennsylvania Uncontaminated Aquifer sediment + groundwater Lab microcosm750 mg/L 185 0.0134/day Novak,JT et. al. (1985)

Methanol Pennsylvania Uncontaminated Aquifer sediment + groundwater Lab microcosm 820 mg/L 185 0.0159/day Novak,JT et. al. (1985)

Methanol Pennsylvania Uncontaminated Aquifer sediment + groundwater Lab microcosm700 mg/L 185 0.0179/day Novak,JT et. al. (1985)

Methanol Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 24 0.027/day Pugh,LB et. al. (1996)

Methanol Pennsylvania Uncontaminated Aquifer sediment + groundwater Lab microcosm93 mg/L 26 0.125/day Novak,JT et. al. (1985)

Methanol Pennsylvania Uncontaminated Aquifer sediment + groundwater Lab microcosm 100 mg/L 23 0.130/day Novak,JT et. al. (1985)

Methanol Pennsylvania Uncontaminated Aquifer sediment + groundwater Lab microcosm 106 mg/L 26 0.131/day Novak,JT et. al. (1985)

Methanol Pennsylvania Uncontaminated Aquifer sediment + groundwater Lab microcosm 107 mg/L 26 0.131/day Novak,JT et. al. (1985)

# Table 24.(Continued)

Compound Site Name Site Type Inoculum Study Type Initial Concn. Time Period

(days) Rate Constant Lag Time (days) Reference



# 160 Methanol Pennsylvania Uncontaminated Aquifer sediment + groundwater Lab microcosm 106 mg/L 26 0.131/day Novak,JT et. al. (1985)

Methanol Pennsylvania Uncontaminated Aquifer sediment + groundwater Lab microcosm 102 mg/L 23 0.131/day Novak,JT et. al. (1985)

Methanol Pennsylvania Uncontaminated Aquifer sediment + groundwater Lab microcosm 120 mg/L 23 0.138/day Novak,JT et. al. (1985)

Methanol Pennsylvania Uncontaminated Aquifer sediment + groundwater Lab microcosm 120 mg/L 23 0.138/day Novak,JT et. al. (1985)

Methanol Uncontaminated Soil Lab microcosm 5 0.153/day Scheunert,I et. al. (1987) Methanol Wiggins,

Mississippi Uncontaminated Soil Lab microcosm740 mg/kg soil 65 0.216/day Loehr,RC & Matthews, JE (1992)

Methanol Mamma Rhoda

Channel, Bahamas Uncontaminated Seawater Lab microcosm 500 ug/L 0.63 ug/L/day Hwang,HM et. al. (1989)

Methanol Austin Texas Uncontaminated Soil Lab microcosm740 mg/kg soil 65 0.693/day Loehr,RC & Matthews, JE (1992)

Methanol Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 No biodegradation Pugh,LB et. al. (1996)

Methanol Pharmaceutical plant underground tank farm Soil + groundwater Lab microcosm 30 No biodegradation Pugh,LB et. al. (1996)

Methanol Canada Forces

Base, Borden, Ontario Uncontaminated Aquifer sediment + groundwater Lab microcosm 1039 mg/L 232 No degradation >114 American Petroleum Institute (1994A)

Methanol Pharmaceutical plant underground tank farm Soil + groundwater Reactor system 23 mg/L 32 0.118/day Pugh,LB et. al. (1996)

# 161

4. SUMMARY Syracuse Research Corporation has compiled aerobic biodegradation rate constant information for 23 compounds in a single database. This database currently holds 1450 records from 194 different references. A summary of the aerobic biodegradation rate constant statistics for these compounds is presented in Table 25. If the compound had sufficient data, results were divided into primary biodegradation and mineralization studies, and values for median and range determined for each. No further division of the results was attempted although studies were completed under different conditions of temperature, substrate concentration, nutrients, environmental media, in the presence of other compounds,etc.Each of these conditions is expected to affect the outcome of the results, and in some cases will do so considerably. However, the results given in Table 25 are present to provide a data summary for this report as well as a comparison of rate constant values among compounds grouped together as shown. Mean values are not reported in this table as a number of very high rate constant values for some of the reported compounds had a strong weighting effect on the data. A comparison of median rate constant values between groups is not advised as: 1. some groups of compounds appear to be studied almost exclusively in one particular environment (e.g.BTEX compounds in groundwater environments, PAHs in soil environments), and 2. limited data were located for some compounds. Studies completed in the same environment but by different authors may produce very different degradation rates, depending on the location, study conditions, whether other compounds were present,etc.Thus, the statistical data reported here may be skewed based on the studies available for a compound (e.g.more studies with large rate constants were summarized than those with smaller rate constants), particularly if only a few studies were found. The same papers tended to be reviewed within a group of compounds and thus differences within a group of similar compounds (such as within the BTEX compounds or within the PAH compounds) may be minimized. Barker et. al. (1987) commented that the biodegradation rates of the BTEX compounds in a series of microcosm experiments were very similar to each other. The BTEX compounds, when arranged bymedian rate constant, show the order: toluene > ethylbenzene > benzene > m-xylene, o-xylene, pxylene. In general, however, the differences in rate constant values between the BTEX compounds are not very great. The PAH group, including compounds with two to five aromatic rings, had median values for primary degradation which were surprisingly similar once four rings were present in the structure. When arranged by median rate constant, the order: naphthalene > fluorene > fluoranthene > benzo(a)anthracene, pyrene, chrysene > benzo(a)pyrene is shown. This is predicted by the simple rule that compounds with fewer aromatic rings (lower molecular weight) have a more rapid biodegradation rate than those with more aromatic rings (higher molecular weight). Mineralization rate constants, when arranged by median values, followed the order: naphthalene > fluorene > pyrene > chrysene > benzo(a)anthracene >> benzo(a)pyrene. Insufficient mineralization data for fluoranthene were located to include this compound in this analysis. Individual compounds within this group had median values from

# 162

primary biodegradation and mineralization studies which were surprisingly similar; benzo(a)pyrene was the only compound in this group to report at least an order of magnitude difference between study types. This result may be due to the tendency to run mineralization studies in the presence of the studied PAH only, while primary biodegradation studies tended to use a mixture of PAH compounds. The phenol group had some of the highest median rate constant values within this report. These compounds are expected to biodegrade rapidly in the environment. The order of median primary biodegradation rate constant values follows: p-cresol > o-cresol > phenol > m-cresol. The median mineralization rate constant for phenol however, is much greater than that for primary degradation. If this value is used then the order is: p-cresol > phenol > o-cresol > m-cresol. The results from the cresol isomers follows the order predicted by Medvedev and Davidov (1981). Mean values for aerobic biodegradation rate constants for the cresol isomers were 2.49 day -1

# (std. deviation=2.74 day1

# ), 1.17 day

-1

# (std. deviation=1.64 day -1

# ), and 0.42 day -1

# (std. deviation=0.44 day -1

# ) for p-cresol, ocresol, and m-cresol, respectively. The extent of the difference in mean and median rate constant values seems high but may only be an artifact of the studies summarized in this database. The determination of median values as a method of comparison between compounds in a group mainly has context within this compiled data set. As new data from other types of environmental media and other locations are added, these results may change, especially if relatively little information is currently available for a particular compound. In general, however, it is evident from these data that most of the studied compounds are susceptible to aerobic biodegradation in most environments. Within this set of compounds, only the highly chlorinated aliphatic compounds and the high molecular weight PAHs currently appear to be resistant to degradation in an oxygenated environment.

# 163

Table 25.Summary of median and range of aerobic biodegradation rate constant values for compounds listed in document Group Compound Median(day-1

## )Range (day-1

## )N=

BTEX CompoundsBenzene (Mineralization) 0.0013 0-0.087 30

Benzene (Primary degradation) 0.096 0-3.3 118 Toluene (Mineralization) 0.00895 0-0.149 31 Toluene (Primary degradation) 0.20 0-42.5 182 Ethylbenzene (Primary degradation) 0.113 0.003-4.8 21 o-Xylene (Primary degradation) 0.054 0-7.625 92 m-Xylene (Primary degradation) 0.057 0-0.76 32 p-Xylene (Primary degradation) 0.052 0-0.56 27

PAH CompoundsNaphthalene (Mineralization) 0.023 0-3.34 44

Naphthalene (Primary degradation) 0.308 0-5.0 46 Fluorene (Mineralization) 0.019 0.00385-0.057 Fluorene (Primary degradation) 0.015 0.0018-0.33 28 Benzo(a)anthracene (Mineralization) 0.0029 0-0.116 32 Benzo(a)anthracene (Primary degradation) 0.0035 0.000096-0.07227 Chrysene (Mineralization) 0.0037 0-0.035 20 Chrysene (Primary degradation) 0.003 0-0.037 31 Fluoranthene (Primary degradation) 0.0048 0-0.045 20 Pyrene (Mineralization) 0.006 0-0.143 18 Pyrene (Primary degradation) 0.00345 0-0.052 40 Benzo(a)pyrene (Mineralization) 0.00015 0-0.0037 25 Benzo(a)pyrene (Primary degradation) 0.0027 0-0.057 23 Chlorinated AliphaticsTetrachloroethylene (Primary degradation) 0 0-0.139 36

Dichloromethane (Primary degradation) 0.0546 0.00362-0.5338 Phenol and Substituted Phenols Phenol (Mineralization) 1.56 0.006-7.3 26

Phenol (Primary degradation) 0.21 0.024-11.0 38 o-Cresol (Primary degradation) 0.40 0.069-4.61 22 m-Cresol (Primary degradation) 0.133 0.0035-1.16 19 p-Cresol (Primary degradation) 1.75 0.079-13.15 28
Ketones Acetone (Primary degradation) 0.035 0-1.2 5

Acetone (Mineralization)* 0.078 0.025-7.3 13 Methyl ethyl ketone (Primary degradation) 0.69 0.4-1.4 3

MiscellaneousBis(2-ethylhexyl)phthalate (Mineralization) 0.014 0.0022-0.04528

Bis(2-ethylhexyl)phthalate (Primary degradation) 0.0205 0-0.23 36 Methanol (Primary degradation) 0.118 0-0.693 20 

# *Results taken from one mineralization study only.

# 164

5. REFERENCES Aamand J., Jorgensen C., Arvin E. and Jensen B.K. Microbial adaptation to degradation of hydrocarbons in polluted and unpolluted groundwater. J. Contam. Hydrol. 4: 299-312. 1989. Aelion C.M., Swindoll C.M. and Pfaender F.K. Adaptation to and biodegradation of xenobiotic compounds by microbial communities from a pristine aquifer. Appl. Environ. Microbiol. 9: 2212-2217. 1987. Aelion C.M., Dobbins D.C. and Pfaender F.K. Adaptation of aquifer microbial communities to the biodegradation of xenobiotic compounds: influence of substrate concentration and preexposure. Environ. Toxicol. Chem. 8: 75-86. 1989. Aelion C.M. and Bradley P.M. Aerobic biodegradation potential of subsurface microorganisms from a jet fuel-contaminated aquifer. Appl. Environ. Microbiol. 57: 57-63. 1991. Albrechtsen H-J., Smith P.M., Nielsen P. and Christensen T.H. Significance of biomass support particles in laboratory studies on microbial degradation of organic chemicals in aquifers. Wat. Res. 30: 2977-2984. 1996. Albrechtsen H-J., Smith P.M., Nielsen P. and Christensen T.H. Importance of sediment fines in laboratory studies on the degradation of organic chemicals in aquifers. Wat. Res. 31: 2287-2299. 1997. Alexander M.Biodegradation and Bioremediation . Academic Press: New York, NY. 1994. Allen-King R.M., Barker J.F., Gillham R.W. and Jensen B.K. Substrate- and nutrient-limited toluene biotransformation in sandy soil. Environ. Toxicol. Chem. 13: 693-705. 1994. Allen-King R.M., Gillham R.W., Barker J.F. and Sudicky E.A. Fate of dissolved toluene during steady infiltration through unsaturated soil: II. Biotransformation under nutrient-limited conditions. J. Environ. Qual. 25: 287-295. 1996. Alvarez P.J.J., Anid P.J. and Vogel T.M. Kinetics of aerobic biodegradation of benzene and toluene in sandy aquifer material. Biodegradation. 2: 43-51. 1991. Alvarez P.J.J., Cronkhite L.A. and Hunt C.S. Use of benzoate to establish reactive buffer zones for enhanced attenuation of BTX migration: Aquifer column experiments. Environ. Sci. Technol. 32: 509- 515. 1998.

# 165

American Petroleum Institute. Transport and fate of dissolved methanol, methyl-tertiary-butyl-ether, and monoaromatic hydrocarbons in a shallow sand aquifer. American Petroleum Institute. Health Environ. Sci. Dept. API Publ. No. 4601. April 1994. American Petroleum Institute. Transport and fate of dissolved methanol, methyl-tertiary-butyl-ether, and monoaromatic hydrocarbons in a shallow sand aquifer. Appendix H: Laboratory Biotransformation Studies. American Petroleum Institute. Health Environ. Sci. Dept. API Publ. No. 4601. April 1994A. Anid P.J., Alvarez P.J.J. and Vogel T.M. Biodegradation of monoaromatic hydrocarbons in aquifer columns amended with hydrogen peroxide and nitrate. Wat. Res. 27: 685-691. 1993. Armstrong A.Q., Hodson R.E., Hwang H.M. and Lewis D.L. Environmental factors affecting toluene degradation in ground water at a hazardous waste site. Environ. Toxicol. Chem. 10: 147-158. 1991. Aronson D. and Howard P. Anaerobic biodegradation of organic chemicals in groundwater: a summary of field and laboratory studies. Final Report. Prepared by Syracuse Research Corporation for the American Petroleum Institute. November 12, 1997. Arvin E., Jensen B., Aamand J. and Jorgensen C. The potential of free-living ground water bacteria to degrade aromatic hydrocarbons and heterocyclic compounds. Wat. Sci. Tech. 20: 109-118. 1988. Ashok B.T., Saxena S., Singh K.P. and Musarrat J. Short communication: Biodegradation of polycyclic aromatic hydrocarbons in soil around Mathura oil refinery. World J. Microbiol. Biotechnol. 11: 691-692. 1995. Baker M.D. and Mayfield C.I. Microbial and non-biological decomposition of chlorophenols and phenols in soil. Water, Air and Soil Pollut. 13: 411. 1980. Barker J.F., Patrick G.C. and Major D. Natural attenuation of aromatic hydrocarbons in a shallow sand aquifer. Ground Water Monit. Rev. 7: 64-72. 1987. Bauer J.E. and Capone D.G. Degradation and mineralization of the polycyclic aromatic hydrocarbons anthracene and naphthalene in intertidal marine sediments. Appl. Environ. Microbiol. 50: 81-90. 1985. Beeman R.E, Howell J.E., Shoemaker S.H., Salazar E.A. and Buttram J.R. A field evaluation of in situ microbial reductive dehalogenation by the biotransformation of chlorinated ethenes. In: Bioremediation Chlorinated Polycyclic Aromatic Hydrocarbon Compounds. Hinchee R.E. (ed.). Lewis Publishers: Boca Raton, FL. pp. 14-27. 1994.

# 166

Bekins B.A., Warren E. and Godsy E.M. A comparison of zero-order, first-order, and monod biotransformation models. Ground Water. 36: 261-268. 1998. Berwanger D.J. and Barker J.F. Aerobic biodegradation of aromatic and chlorinated hydrocarbons commonly detected in landfill leachates. Water Poll. Res. J. Canada. 23: 460-475. 1988. Bjerg P.L., Brun A., Nielsen P.H. and Christensen T.H. Application of a model accounting for kinetic sorption and degradation to in situ microcosm observations on the fate of aromatic hydrocarbons in an aerobic aquifer. Water Resources Res. 32: 1831-1841. 1996. Borden R.C., Daniel R.A., LeBrun IV L.E. and Davis C.W. Intrinsic biodegradation of MTBE and BTEX in a gasoline-contaminated aquifer. Wat. Resources Res. 33: 1105-1115. 1997. Borighem G. and Vereecken J. Study of the biodegradation of phenol in river water. Ecological Modeling 4: 51-59. 1978. Bosma T.N.P., te Welscher R.A.G., Schraa G., Smeenk J.G.M.M. and Zehnder A.J.B. Microbial aspects of the behaviour of chlorinated compounds during soil passage. Org. Micropollut. Aquat. Environ. Proc. Eur. Supp., 6th

# , pp. 184-192. 1990. Bosma T.N.P., Ballemans E.M.W., Hoekstra N.K., te Welscher R.A.G., Smeenk J.G.M.M., Schraa G. and Zehnder A.J.B. Biotransformation of organics in soil columns and an infiltration area. Ground Water. 34: 49-56. 1996. Bossert I.D. and Bartha R. Structure-biodegradability relationships of polycyclic aromatic hydrocarbons in soil. Bull. Environ. Contam. Toxicol. 37: 490-495. 1986. Bourquin A.W. Biodegradation in the estuarine-marine environments and the genetically altered microbe. EPA-600/D-84-051. (NTIS PB84-151315). Gulf Breeze, FL: USEPA Environ. Research Lab. pp. 35. 1984. Bradley P.M. and Chapelle F.H. Rapid toluene mineralization by aquifer microorganisms at Adak, Alaska: Implications for intrinsic bioremediation in cold environments. Environ. Sci. Technol. 29: 2778-2781. 1995. Broholm K., Christensen T.H. and Jensen B.K. Laboratory feasibility studies on biological in-situ treatment of a sandy soil contaminated with chlorinated aliphatics. Environ. Technol. 12: 279-289. 1991.

# 167

Broholm K., Arvin E., Hansen A., Hinsby K. and Jorgensen P. The fate of dissolved creosote compounds in an intact fractured clay column. Groundwater Quality: Remediation and Protection. In: Proceedings of the Prague Conference, May 1995. IAHS Publ. No. 225. 1995. Buscheck T.E., O’Reilly K.T. and Nelson S.N.Evaluation of intrinsic bioremediation at field sites. In: Proceedings of the 1993 Petroleum Hydrocarbon and Organic Chemicals in Ground Water: Prevention, Detection, and Restoration. Dublin, OH: Water Well J. Publ. pp. 367-381. 1993. Button D.K., Robertson B.R. and Craig K.S. Dissolved hydrocarbons and related microflora in a fjordal seaport: Sources, sinks, concentrations, and kinetics. Appl. Environ. Microbiol. 42: 708-719. 1981A. Carmichael L.M. and Pfaender F.K. Polynuclear aromatic hydrocarbon metabolism in soils: relationship to soil characteristics and preexposure. Environ. Toxicol. Chem. 16: 666-675. 1997. Carmichael L.M., Christman R.F. and Pfaender F.K. Desorption and mineralization kinetics of phenanthrene and chrysene in contaminated soils. Environ. Sci. Technol. 31: 126-132. 1997. Cerniglia C.E. Biodegradation of polycyclic aromatic hydrocarbons. Biodegradation. 3: 351-368. 1992. Chang B.V., Wu W.B. and Yuan S.Y. Biodegradation of benzene, toluene, and other aromatic compounds by Pseudomonas sp. D8. Chemosphere 35: 2807-2815. 1997. Chapelle F.H., Bradley P.M., Lovley D.R. and Vroblesky D.A. Measuring rates of biodegradation in a contaminated aquifer using field and laboratory methods. Ground Water. 34: 691-698. 1996. Chesney R.H., Sollitti P. and Rubin H.E. Incorporation of phenol carbon at trace concentrations by phenol-mineralizing microorganisms in fresh water. Appl. Environ. Microbiol. 49: 15-18. 1985. Chiang C.Y., Klein C.L., Salanitro J.P. and Wisniewski H.L. Data analyses and computer modelling of the benzene plume in an aquifer beneath a gas plant. In: Proceedings of NWWA/API Conference on Petroleum Hydrocarbons in Groundwater. pp. 157-176. 1986. Chiang C.Y., Salanitro J.P., Chai E.Y., Colthart J.D. and Klein C.L. Aerobic biodegradation of benzene, toluene, and xylene in a sandy aquifer--data analysis and computer modeling. Ground Water. 27: 823-834. 1989. Cohen B.A., Krumholz L.R., Kim H. and Hemond H.F. In-situ biodegradation of toluene in a contaminated stream. 2. Laboratory studies. Environ. Sci. Technol. 29: 117-125. 1995.

# 168

Coover M.P. and Sims R.C. The effect of temperature on polycyclic aromatic hydrocarbon persistence in an unacclimated agricultural soil. Hazard. Waste & Hazard. Mater. 4: 69-82. 1987. Corseuil H.X., dos Santos R.C.F. and Marins M.D.M. Gasoline spills in Brazil: effect of ethanol on groundwater contamination. Presented at: IAWQ Inter. Conf. Waste Control Environ. Manag. Large Metro. Areas. Sao Paolo, Brazil. May. 1997. Dao T.H. and Lavy T.L. A kinetic study of adsorption and degradation of aniline, benzoic acid, phenol and diuron in soil suspensions. Soil Sci. 143: 66-72. 1987. Davis A. & Olsen R.L. Predicting the fate and transport of organic compounds in groundwater. Haz. Mat. Control. V3: 18-37. 1990. Davis J.W. and Madsen S.S. The biodegradation of methylene chloride in soils. Environ. Toxicol. Chem. 10: 463-474. 1991. Davis J.W., Klier N.J. and Carpenter C.L. Natural biological attenuation of benzene in ground water beneath a manufacturing facility. Ground Water. 32: 215-226. 1994. Davis J.W. and Madsen S. Factors affecting the biodegradation of toluene in soil. Chemosphere. 33: 107-130. 1996. Delfino J.J. and Miles C.J. Aerobic and anaerobic degradation of organic contaminants in Florida groundwater. Soil Crop Science Society of Florida Proceedings. 44: 9-14. 1985. Deschenes L., Lafrance P., Villeneuve J.P. and Samson R. The effect of an anionic surfactant on the mobilization and biodegradation of PAHs in a creosote-contaminated soil. J. des Sciences Hydrologiques. 40: 471-484. 1995. Deschenes L., Lafrance P., Villeneuve J.P. and Samson R. Adding sodium dodecyl sulfate and Pseudomonas aeruginosa UG2 biosurfactants inhibits polycyclic aromatic hydrocarbon biodegradation in a weathered creosote-contaminated soil. Appl. Microbiol. Biotechnol. 46: 638-646. 1996. Dobbins D.C. and Pfaender F.K. Kinetics of amino acids and m-cresol biodegradation in an unpolluted aquifer soil profile. Amer. Soc. Microbiol. Abstract. 87th

# Annual Meeting. Atlanta, GA. pp. 298. 1987. Dobbins D.C. and Pfaender F.K. Methodology for assessing respiration and cellular incorporation of radiolabeled substrates by soil microbial communities. Microb. Ecol. 15: 257-273. 1988.

# 169

Dobbins D.C.,Aelion C.M. and Pfaender F. Subsurface, terrestrial microbial ecology and biodegradation of organic chemicals: a review. Crit. Rev. Environ. Control. 22: 67-136. 1992. Dojlido J.R. Testing of biodegradability and toxicity of organic compounds; Final repot 1975-79. EPA-600/2-79-163. Cincinnati, OH: Municipal Environ. Research Lab. pp. 118. 1979. Dorfler U., Haala R., Matthies M. and Scheunert I. Mineralization kinetics of chemicals in soils in relation to environmental conditions. Ecotoxicol. Environ. Safety. 34: 216-222. 1996. Durant N.D., Johkers C.A.A., Wilson L.P. and Bouwer E.J. Enhanced biodegradation of naphthalene in MGP aquifer microcosms. In: Intrinsic Biorem. [Pap. Int. In Situ On-Site Bioreclam. Symp.]. 3rd



# . Hinchee R.E. et. al. (Eds). Battelle Press: Columbus, OH. pp. 189-196. 1995. Efroymson R.A. and Alexander M. Biodegradation in soil of hydrophobic pollutants in nonaqueous-phase liquids (NAPLs). Environ. Toxicol. Chem. 13: 405-411. 1994. Ellis B., Harold P. and Kronberg H. Bioremediation of a creosote contaminated site. Environ. Technol. 12: 447-459. 1991. English C.W and Loehr R.C. Degradation of organic vapors in unsaturated soils. J. Hazard. Materials. 28: 55-63. 1991. Enzien M.V., Picardal F., Hazen T.C., Arnold R.G. and Fliermans C.B. Reductive dechlorination of trichloroethylene and tetrachloroethylene under aerobic conditions in a sediment column. Appl. Environ. Microbiol. 60: 2200-2204. 1994. Fairbanks B.C., O'Connor G.A. and Smith S.E. Fate of di-2-(ethylhexyl)phthalate in three sludge-amended New Mexico soils. J. Environ. Qual. 14: 479-483. 1985. Fan S. and Scow K.M. Biodegradation of trichloroethylene and toluene by indigenous microbial populations in soil. Appl. Environ. Microbiol. 59: 1911-1918. 1993. Flemming J.T., Sanseverino J. and Saylor G.S. Quantitative relationship between naphthalene catabolic gene frequency and expression in predicting PAH degradation in soils at town gas manufacturing sites. Environ. Sci. Technol. 27: 1068-1074. 1993. Fogel S., Findlay M., Scholl C. and Warminsky M. Biodegradation and bioavailability of bis(2- ethylhexyl)phthalate in soil. In: Intrinsic Biorem. [Pap. Int. In Situ On-Site Bioreclam. Symp.]. 3rd



# . Hinchee R.E. et. al. (Eds). Battelle Press: Columbus, OH. pp. 315-322. 1995.

# 170

Fuller M.E., Mu D.Y. and Scow K.M. Biodegradation of trichloroethylene and toluene by indigenous microbial populations in vadose sediments. Microb. Ecol. 29: 311-325. 1995. Gibson D.T. Biodegradation of aromatic petroleum hydrocarbons. In: Fate and Effects of Petroleum Hydrocarbons in Marine Organisms and Ecosystems. Chapter 4: 36-46. Wolfe D.A. (Ed.). Pergamon Press: New York, NY. 1977. Gibson D.T. and Subramanian V. Microbial degradation of aromatic hydrocarbons. In: Microbial Degradation of Organic Compounds. Chp. 7: 181-252. Gibson D.T. (Ed.). Marcel Dekker, Inc.: New York, NY. 1984. Gillham R.W., Starr R.C. and Miller D.J. A device for in situ determination of geochemical transport parameters. 2. Biochemical reactions. Ground Water. 28: 858-862. 1990. Graves D.A., Lang C.A. and Rightmyer J.N. Biodegradation of bis(2-ethylhexyl)phthalate, ethylbenzene, and xylenes in groundwater: treatability study supporting in situ aquifer bioremediation. In: Appl. Biotechnol. Site Remed. [Pap. Int. Symp., In Situ On-Site Bioreclam.] 2nd

# . Hinchee R.E.L. et. al. (Eds.). Lewis Publishers: Boca Raton, FL. pp. 167-185. 1994. Grenney W.J., Caupp C.L., Sims R.C. and Short T.E. A mathematical model for the fate of hazardous substances in soil: Model description and experimental results. Hazard. Waste & Hazard. Materials. 4: 223-239. 1987. Grosser R.J., Warshawsky D. and Vestal J.R. Indigenous and enhanced mineralization of pyrene, benzo(a)pyrene, and carbazole in soils. Appl. Environ. Microbiol. 57: 3462-3469. 1991. Grosser R.J., Warshawsky D. and Vestal J.R. Mineralization of polycyclic and N-heterocyclic aromatic compounds in hydrocarbon-contaminated soils. Environ. Toxicol. Chem. 14: 375-382. 1995. Halvorsen F. and Ohneck R. MEK groundwater decontamination. In: Hazardous Waste and Environ. Emergencies. Silver Springs, Maryland: Hazardous Material Control Research Institute. pp. 193-195. 1985. Harrison E.M. and Barker J.F. Sorption and enhanced biodegradation of trace organics in a groundwater reclamation scheme Gloucester site, Ottawa, Canada. J. Contam. Hydrol. 1: 349-373. 1987. Hattori Y., Kuge Y. and Nakagawa S. Microbial decomposition of phthalate esters in environmental water. Pollut. Control Cent. Osaka Prefect., Mizu Shori Gijutsu.16:951-954. 1975.

# 171

Hatzinger P.B. and Alexander M. Effect of aging of chemicals in soil on their biodegradability and extractability. Environ. Sci. Technol. 29: 537-545. 1995. Heitkamp M.A. and Cerniglia C.E. Effects of chemical structure and exposure on the microbial degradation of polycyclic aromatic hydrocarbons in freshwater and estuarine ecosystems. Environ. Toxicol. Chem. 6: 535-546. 1987A. Heitkamp M.A. and Cerniglia C.E. Polycyclic aromatic hydrocarbon degradation by a Mycobacterium sp. in microcosms containing sediment and water from a pristine ecosystem. Appl. Environ. Microbiol. 55: 1968-1973. 1989. Henson J.M., Yates M.V., Cochran J.W. and Shackleford D.L. Microbial removal of halogenated methanes, ethanes, and ethylenes in an aerobic soil exposed to methane. FEMS Microbiol. Ecol. 53: 193-201. 1988. Herbes S.E. and Schwall L.R. Microbial transformation of polycyclic aromatic hydrocarbons in pristine and petroleum-contaminated sediments. Appl. Environ. Microbiol. 35: 306-316. 1978. Herbes S.E. Rates of microbial transformation of polycyclic aromatic hydrocarbons in water and sediments in the vicinity of coal-coking wastewater discharge. Appl. Environ. Microbiol. 41: 20-28. 1981. Hinga K.R., Pilson M.E.Q., Lee R.F., Farrington J.W., Tjessem K. and Davis A.C. Biogeochemistry of benzanthracene in an enclosed marine ecosystem. Environ. Sci. Technol. 14: 1136-1143. 1980. Hinga K.R. and Pilson M.E.Q. Persistence of benz(a)anthracene degradation products in an enclosed marine ecosystem. Environ. Sci. Technol. 21: 648-653. 1987. Holm P.E., Nielsen P.H., Albrechtsen H-J. and Christensen T.H. Importance of unattached bacteria and bacteria attached to sediment in determining potentials for degradation of xenobiotic organic contaminants in an aerobic aquifer. Appl. Environ. Microbiol. 58: 3020-3026. 1992. Howard P.H. and Banerjee S. Interpreting results from biodegradability tests of chemicals in water and soil. Environ. Toxicol. Chem. 3: 551-562. 1984. Howard P.H. et. al. BIOLOG, BIODEG and FATE/EXPOS: New files on microbial degradation and toxicity as well as environmental fate/exposure of chemicals. Environ Toxic Chem. 5: 977-988. 1986. Hudak J.P., McDaniel J., Lee S. and Fuhrman J.A. Mineralization potentials of aromatic hydrocarbons by estuarine microorganisms; Variations with season, location and bacterioplankton production. Mar. Ecol.: Prog. Ser. 47: 97-102. 1988.

# 172

Huling S.G., Pope D.F., Matthews J.E., Sims J.L., Sims R.C. and Sorenson D.L. Wood preservingwaste-contaminated soil: treatment and toxicity response. In: Intrinsic Biorem. [Pap. Int. In Situ OnSite Bioreclam. Symp.]. 3rd

# . Hinchee R.E. et. al. (Eds). Battelle Press: Columbus, OH. pp. 101-109. 1995. Hungspreugs M., Silpipat S., Tonapong C., Lee R.F., Windom H.L. and Tenore K.R. Heavy metals and polycyclic hydrocarbon compounds in benthic organisms of the Upper Gulf of Thailand. Marine Pollut. Bull. 15: 213-218. 1984. Hunt C.S. and Alvarez P.J.J. Effect of ethanol on aerobic BTX degradation. In: In Situ and On-Site Bioremediation. Volume I. 4th

# International In situ and On-Site Bioremediation Symposium. Biorem. 4: 49-54. 1997. Hutchins S.R. Biodegradation of monoaromatic hydrocarbons by aquifer microorganisms using oxygen, nitrate, or nitrous oxide as the terminal electron acceptor. Appl. Environ. Microbiol. 57: 2403- 2407. 1991. Hwang H.M., Hodson R.E. and Lewis D.L. Microbial degradation kinetics of toxic organic chemicals over a wide range of concentrations in natural aquatic systems. Environ. Toxicol. Chem. 8: 65-74. 1989. Hwang H.M. and Maloney S.W. A study of microbial transformations of trichloroaniline and p-cresol using size-fractionation technique. Bull. Environ. Contam. Toxicol. 56: 343-350. 1996. Jin Y., Streck T. and Jury W.A. Transport and biodegradation of toluene in unsaturated soil. J. Contam. Hydrol. 17: 111-127. 1994. Johnson B.T. and Lulves W. Biodegradation of di-n-butyl phthalate and di-2-ethylhexyl phthalate in freshwater hydrosoil. J. Fish. Res. Board Can. 32:333-339. 1975. Johnson B.T., Heitkamp M.A. and Jones J.R. Environmental and chemical factors influencing the biodegradation of phthalic acid esters in freshwater sediments. Environ. Pollut. B. 8:101-118. 1984. Kaplin V.T., Semenchenko L.V. and Ivanov E.G. Decomposition of a phenol mixture in natural waters (miniature-scale operation). Gidrokhim. Mater. 46: 199-202. 1968. Karlson U. and Frankenberger W.T.Jr. Microbial degradation of benzene and toluene in groundwater. Bull. Environ. Contam. Toxicol. 43: 505-510. 1989. Keck J., Sims R.C., Coover M., Park K. and Symons B. Evidence for cooxidation of polynuclear aromatic hydrocarbons in soil. Wat. Res. 23: 1467-1476. 1989.

# 173

Kemblowski M.W., Salanitro J.P., Deeley G.M. and Stanley C.C. Fate and transport of residual hydrocarbon in groundwater-A case study. In: Proceedings of the Petroleum Hydrocarbons and Organic Chemicals in Ground Water Conference. National Water Well Association and American Petroleum Institute. pp. 207-231. Houston, TX. 1987. Kim H., Hemond H.F., Krumholz L.R. and Cohen B.A. In-situ biodegradation of toluene in a contaminated stream. 1. Field studies. Environ. Sci. Technol. 29: 108-116. 1995. Kjeldsen P., Dalager A. and Broholm K. Attenuation of methane and nonmethane organic compounds in landfill gas affected soils. J. Air & Waste Manage. Assoc. 47: 1268-1275. 1997. Klecka G.M., Davis J.W., Gray D.R. and Madsen S.S. Natural bioremediation of organic contaminants in groundwater: Cliffs-Dow superfund site. Ground Water 28: 534-543. 1990. Konopka A. and Turco R. Biodegradation of organic compounds in vadose zone and aquifer sediment. Appl. Environ. Microbiol. 57: 2260-2268. 1991. Kuhn E.P., Colberg P.J., Schnoor J.L., Wanner O., Zehnder A.J.B. and Schwarzenbach R.P. Microbial transformations of substituted benzenes during infiltration of river water to groundwater: Laboratory column studies. Environ. Sci. Technol. 19: 961-968. 1985.Lamar R.T. and Glaser J.A. Field evaluations of the remediation of soils contaminated with woodpreserving chemicals using lignin-degrading fungi. In: Bioremediation of Chlorinated Polycyclic Aromatic Hydrocarbon Compounds. Hinchee, RE (ed.). Boca Raton, FL: Lewis Publishers. pp. 239-247. 1994. Leduc R., Samson R., Al-Bashir B., Al-Hawari J. and Cseh T. Biotic and abiotic disappearance of four PAH compounds from flooded soil under various redox conditions. Wat. Sci. Tech. 26: 51-60. 1992. Lee R.F. and Ryan C. Biodegradation of petroleum hydrocarbons by marine microbes. In: Proceedings International Biodegradation Symposium, 3rd

# . pp. 119-125. 1975. Lee R.F. and Ryan C. Biodegradation of petroleum hydrocarbons by marine microbes. Proceedings International Biodegradation Symposium. 3rd

# . 1975. pp. 119-125. 1976. Lee R.F. Fate of petroleum components in estuarine waters of the southeastern United States. In: Proceedings of the 1977 Oil Spill Conference. New Orleans, LA: American Petroleum Institute. pp. 611-616. 1977.

# 174

Lee R.F., Gardner W.S., Anderson J.W., Blaylock J.W. and Barwell-Clarke J. Fate of polycyclic aromatic hydrocarbons in controlled ecosystem enclosures. Environ. Sci. Technol. 12: 832-838. 1978. Lee R.F. and Ryan C. Microbial degradation of organochlorine compounds in estuarine waters and sediments. In: EPA-600/9-79-012. Microbial Degradation of Pollutants in Marine Environments. Bourquin A.W. and Pritchard P.H. (eds.). Gulf Breeze, FL: U.S. EPA. pp. 443-450. 1979. Lee R.F. and Ryan C. Microbial and photochemical degradation of polycyclic aromatic hydrocarbons in estuarine waters and sediments. Can. J. Fish. Aquat. Sci. 40 (Suppl. 2): 86-94. 1983. Lee R.F. and Silva M. Polycyclic aromatic hydrocarbon removal rates in oiled sediments treated with urea, urea-fish protein, or ammonium nitrate. In: Appl. Biotechnol. Site Rem.. [Pap. Int. Symp., In Situ On-Site Bioreclam.] 2nd

# . Hinchee R.E.L. et. al. (Eds.). Lewis Publishers: Boca Raton, FL. pp. 320- 325. 1994. Lige J.E., MacFarlane I.D. and Hundt T.R. Treatability study to evaluate in situ chlorinated solvent and pesticide bioremediation. In: Bioremediation of Chlorinated Solvents. [Pap. Interntl. In Situ On-Site Bioreclam. Symp.] 3rd

# . Hinchee R.E. et. al. (eds.). Battelle Press: Columbus, OH. pp. 313-320. 1995. Lijmbach G.W.M. and Brinkhuis E. Microbial degradation of secondary n-alkyl sulfates and secondary alkanols. Antonie van Leeuwenhoek. 39: 415-423. 1973. Loehr R.C. and Matthews J.E. Loss of organic chemicals in soil: pure compound treatability studies. J. Soil Contam. 1: 339-360. 1992. Lu P.Y., Metcalf R.L., Plummer N. and Mandel D. The environmental fate of three carciogens: benzo(a)pyrene, benzidine and vinyl chloride evaluated in laboratory model ecosystems. Arch. Environm. Contam. Toxicol. 6: 129-142. 1977. Ludzack F.J. and Ettinger M.B. Biodegradability of organic chemicals isolated from rivers. Purdue University, Eng. Bull., Ext. Service. No. 115, pp. 278-282. 1963. Lyngkilde E.J., Tjell J.C. and Foverskov A. The degradation of specific organic compounds with landfill leachate as a primary substrate. In: Contaminated Soil ‘88. Wolf K. et. al. (eds.). Hingham, MA: Kluwer Acad. Publishers. pp. 91-100. 1988. Lyngkilde J., Christensen T.H., Gillham R., Larsen T., Kjeldsen P., Skov B., Foverskov A. and O’Hannesin S. Degradation of specific organic compounds in leachate-polluted groundwater. Landfilling Waste: Leachate. Christensen T.H. et. al. (eds.). Elsevier Publishers: London, U.K. pp. 485-495. 1992.

# 175

Maag J. and Loekke H. Landfarming of DEHP contaminated soil. In: Contaminated Soil ‘90. Arendt F. et. al. (Eds.). pp. 975-982. 1990. MacGillivray A.R. and Shiaris M.P. Microbial ecology of polycyclic aromatic hydrocarbon (PAH) degradation in coastal sediments. In: Biological Degradation and Bioremediation of Toxic Chemicals. Chapter 6: 125-147. Chaudhry G.R. (Ed.). Dioscorides Press: Portland, OR. 1994. MacIntyre W.G., Boggs M., Antworth C.P. and Stauffer T.B. Degradation kinetics of aromatic organic solutes introduced into a heterogeneous aquifer. Water Resources Res. 29: 4045-4051. 1993. Mahmood S.K. and Rao P.R. Microbial abundance and degradation of polycyclic aromatic hydrocarbons in soils. Bull. Environ. Contam. Toxicol. 50: 486-491. 1993. Mahro B., Schaefer G. and Kastner M. Pathways of microbial degradation of polycyclic aromatic hydrocarbons in soil. In: Bioremediation of Chlorinated Polycyclic Aromatic Hydrocarbon Compounds. Hinchee, RE (ed.). Boca Raton, FL: Lewis Publishers. pp. 203-217. 1994. Maliszewska-Kordybach B. The effect of temperature on the rate of disappearance of polycyclic aromatic hydrocarbons from soils. Environ. Pollut. 79: 15-20. 1993. Maliszewska-Kordybach B. The relationship between the properties of PAHs and the rate of their disappearance from soils. Toxicol. Environ. Chem. 66: 47-52. 1998. Manilal V.B. and Alexander M. Factors affecting the microbial degradation of phenanthrene in soil. Appl. Microbiol. Biotechnol. 35: 401-405. 1991. McCarty P.L., Goltz M.N., Hopkins G.D., Dolan M.E., Allan J.P., Kawakami B.T. and Carrothers T.J. Full-scale evaluation of in situ cometabolic degradation of trichloroethylene in groundwater through toluene injection. Environ. Sci. Technol. 32: 88-100. 1998. McNabb J.F., Smith B.H. and Wilson J.T. Biodegradation of toluene and chlorobenzene in soil and groundwater. 81st

# Annual Meeting of the Amer. Society for Microbiology. Dallas, TX. March 1-6. 213 pp. 1981. Medvedev V.A. and Davidov V.D. Decomposition of high doses of phenol and indole by a Chernozem soil. In: Decomposition of Toxic and Nontoxic Organic Compounds in Soil. Overcash M.R. (Ed.). Ann Arbor, MI: Ann Arbor Sci. Publ. pp.210-215. 1981.

# 176

Medvedev V.A. and Davidov V.D. Phenol and quinone degradation rates in Chernozem soil based on infrared spectroscopy data. In: Decomposition of toxic and nontoxic organic compounds in soil. Overcash M.R. (ed.). Ann Arbor, MI: Ann Arbor Sci. Publishers. pp. 193-199. 1981A. Medvedev V.A. and Davidov V.D. The transformation of various coke industry products in Chernozem soil. In: Decomposition of Toxic and Nontoxic Organic Compounds in Soil. Overcash, MR (ed.). Ann Arbor Sci. Publ. Ann Arbor, MI. pp. 245-254. 1981B. Meyer J.S., Marcus M.D. and Bergman H.L. Inhibitory interactions of aromatic organics during microbial degradation. Environ. Toxicol. Chem. 3: 583-587. 1984. Mihelcic J.R. and Luthy R.G. Microbial degradation of acenaphthalene and naphthalene under denitrification conditions in soil-water systems. Appl. Environ. Microbiol. 54: 1188-1198. 1988. Millette D., Barker J.F., Comeau Y., Butler B.J., Frind E.O., Clement B. and Samson R. Substrate interaction during aerobic biodegradation of creosote-related compounds: a factorial batch experiment. Environ. Sci. Technol. 29: 1944-1952. 1995. Morgan P., Lewis S.T. and Watkinson R.J. Biodegradation of benzene, toluene, ethylbenzene and xylenes in gas-condensate-contaminated ground-water. Environ. Pollut. 82: 181-190. 1993. Mu D.Y. and Scow K.M. Effect of trichloroethylene (TCE) and toluene concentrations on TCE and toluene biodegradation and the population density of TCE and toluene degraders in soil. Appl. Environ. Microbiol. 60: 2661-2665. 1994. Mudder T.I. Development of empirical structure-biodegradability relationships and testing protocol for slightly soluble and volatile priority pollutants. Ph.D. Dissertation, University of Iowa. 1981. Mueller J.G., Middaugh D.P., Lantz S.E. and Chapman P.J. Biodegradation of creosote and pentachlorophenol in contaminated groundwater: Chemical and biological assessment. Appl. Environ. Microbiol. 57: 1277-1285. 1991. Mueller J.G., Lantz S.E., Blattmann B.O. and Chapman P.J. Bench-scale evaluation of alternative biological treatment processes for the remediation of pentachlorophenol- and creosote-contaminated materials: Solid-phase bioremediation. Environ. Sci. Technol. 25: 1045-1055. 1991A. Nielsen P.H., Holm P.E. and Christensen T.H. A field method for determination of groundwater and groundwater-sediment associated potentials for degradation of xenobiotic organic compounds. Chemosphere. 25: 449-462. 1992.

# 177

Nielsen P.H. and Christensen T.H. In situ measurement of degradation of specific organic compounds under aerobic, denitrifying, iron(III)-reducing and methanogenic ground water conditions. In: Bioremediation of Chlorinated Polycyclic Aromatic Hydrocarbon Compounds. Hinchee R.E. (ed.). Boca Raton, FL: Lewis Publishers. pp. 416-422. 1994. Nielsen P.H. and Christensen T.H. Variability of biological degradation of phenolic hydrocarbons in an aerobic aquifer determined by laboratory batch experiments. J. Contam. Hydrol. 17: 55-67. 1994A. Nielsen P.H. and Christensen T.H. Variability of biological degradation of aromatic hydrocarbons in an aerobic aquifer determined by laboratory batch experiments. J. Contam. Hydrol. 15: 305-320. 1994B. Nielsen P.H., Albrechtsen H.J., Heron G. and Christensen T.H.In situ and laboratory studies on the fate of specific organic compounds in an anaerobic landfill leachate plume, 1. Experimental conditions and fate of phenolic compounds. J. Contam. Hydrol. 20: 27-50. 1995. Nielsen P.H., Bjerg P.L., Nielsen P., Smith P. and Christensen T.H. In situ and laboratory determined first-order degradation rate constants of specific organic compounds in an aerobic aquifer. Environ. Sci. Technol. 30: 31-37. 1996. Novak J.T., Goldsmith C.D., Benoit R.E. and O’Brien J.H. Biodegradation of methanol and tertiary butyl alcohol in subsurface systems. Wat. Sci. Tech. 17: 71-85. 1985. Palumbo A.V., Pfaender F.K. and Paerl H.W. Biodegradation of NTA and m-cresol in coastal environments. Environ. Toxicol. Chem. 7: 573-585. 1988. Paris D.F., Wolfe N.L., Steen W.C. and Baughman G.L. Effect of phenol molecular structure on bacterial transformation rate constants in pond and river samples. Appl. Environ. Microbiol. 45: 1153- 1155. 1983. Paris D.F. and Rogers J.E. Kinetic concepts for measuring microbial rate constants: Effects of nutrients on rate constants. Appl. Environ. Microbiol. 51: 221-225. 1986. Park K.S., Simms R.C., Dupont R.R., Doucette W.J. and Matthews J.E. Fate of PAH compounds in two soil types: Influence of volatilization, abiotic loss and biological activity. Environ. Toxicol. Chem. 9: 187-195. 1990. Patterson B.M., Pribac F., Barber C., Davis G.G. and Gibbs R. Biodegradation and retardation of PCE and BTEX compounds in aquifer material from Western Australia using large-scale columns. J. Contam. Hydrol. 14: 261-278. 1993.

# 178

Peters G.T. and Colwell F.S. Effects of stream order and season on mineralization of (carbon-14) phenol in streams. Hydrobiologia 174: 79-87. 1989. Pfaender F.K. and Bartholomew G.W. Measurement of aquatic biodegradation rates by determining heterotrophic uptake of radiolabeled pollutants. Appl. Environ. Microbiol. 44: 159-164. 1982. Piwoni M.D., Wilson J.T., Walters D.M., Wilson B.H. and Enfield C.G. Behavior of organic pollutants during rapid-infiltration of wastewater into soil: I. Processes, definition, and characterization using a microcosm. Hazard. Waste & Hazard. Materials. 3: 43-55. 1986. Portier R.J. Comparison of environmental effect and biotransformation of toxicants on laboratory microcosm and field microbial communities. In: ASTM Spec. Tech. Publ. 865 (Validation Predict Lab. Methods Assess. Fate Eff. Contam. Aquat. Ecosyst.): 14-30. 1985. Pott B.M. and Henrysson T. Ex situ bioremediation of polycyclic aromatic hydrocarbons in laboratory systems. In: Intrinsic Biorem. [Pap. Int. In Situ On-Site Bioreclam. Symp.]. 3rd

# . Hinchee R.E. et. al. (Eds). Battelle Press: Columbus, OH. pp. 39-44. 1995. Pugh L.B., Christian B.J. and Carey C.E. Bioremediation of contaminated soils and groundwater at a former solvent storage site. In: Biotechnol. Indus. Waste Treat. Biorem. International Symposium Implementation Biotechnol. Indus. Waste Treat. Biorem. Hickey R.F. and Smith G (Eds.). Chapter 12, pp. 195-211. 1996. Rathbun R.E., Stephans D.W. and Tai D.Y. Fate of acetone in water. Chemosphere 11: 1097-1114. 1993. Readman J.W., Mantoura R.F.C., Rhead M.M. and Brown L. Aquatic distribution and heterotrophic degradation of polycyclic aromatic hydrocarbons (PAH) in the Tamar estuary. Estuarine, Coastal. Shelf. Sci. 14: 369-389. 1982. Ribbons D.W. and Eaton R.W. Chemical transformations of aromatic hydrocarbons that support the growth of microorganisms. In: Environmental Microbiology. Mitchell R. (Ed.). Wiley-Liss Publishers: New York, NY. 1992. Rice D.W., Grose R.D., Michaelsen J.C., Dooher B.P., MacQueen D.H., Cullen S.J., Kastenberg W.E., Everett L.G. and Marino M.A. California leaking underground fuel tank (LUFT) historical case analyses. UCRL-AR-122207. Livermore, California: Lawrence Livermore National Laboratory. 1995.

# 179

Ritsema R., Cofino W.P., Frintrop P.C.M. and Brinkman U.A.T. Trace-level analysis of phthalate esters in surface water and suspended particulate matter by means of capillary gas chromatography with electron-capture and mass-selective detection. Chemosphere. 18:2161-2175. 1989. Roberts P.V., McCarty P.L., Reinhard M. and Schreiner J. Organic contaminant behavior during groundwater recharge. J Water Pollut Control Fed. 52: 161-72. 1980. Roberts P.V., Schreiner J. and Hopkins G.D. Field study of organic water quality changes during groundwater recharge in the Palo Alto Baylands. Water Res. 16: 1025-1035. 1982. Roberts P.V., Goltz M.N. and Mackay D.M. A natural gradient experiment on solute transport in a sand aquifer. 3. Retardation estimates and mass balances for organic solutes. Wat. Resources Res. 22: 2047-2058. 1986. Robinson K.G., Farmer W.S. and Novak J.T. Availability of sorbed toluene in soils for biodegradation by acclimated bacteria. Water Res. 24: 345-350. 1990. Rogers J.E., Li S.W. and Felice L.J. Microbiological transformation kinetics of xenobiotics in the aquatic environment. EPA-600/3-84-043. (NTIS PB84-162866). Richland, WA: Battelle Pacific Northwest Labs. pp. 105. 1984. Roubal G. and Atlas R.M. Distribution of hydrocarbon-utilizing microorganisms and hydrocarbon biodegradation potentials in Alaskan continental shelf areas. Appl. Environ. Microbiol. 35: 897-905. 1978. Rubin H.E., Subba-Rao R.V. and Alexander M. Rates of mineralization of trace concentrations of aromatic compounds in lake water and sewage samples. Appl. Environ. Microbiol. 43:1133-8. 1982. Ruedel H., Schmid T.S., Koerdel W. and Klein W. Degradation of pesticides in soil: Comparison of laboratory experiments in a biometer system and outdoor lysimeter experiments. Sci. Total Environ. 132:181-200. 1993. Saeger V.W. and Tucker E.S. Biodegradation of phthalate esters. Tech. Pap., Reg. Tech. Conf., Soc. Plast. Eng., Palisades Sect. pp. 105-113. 1973A. Saeger V.W. and Tucker E.S. Phthalate esters undergo ready biodegradation. Plast. Eng., Aug, 1973. pp. 46-49. 1973B. Saeger V.W. and Tucker E.S. Biodegradation of phthalic acid esters in river water and activated sludge. Appl. Environ. Microbiol. 31:29-34. 1976.

# 180

Saeger V.W. and Gledhill W.E. Biodegradability of plasticizers. ES-78-SS-7. St. Louis, MS: Monsanto Industrial Chemicals Company. 1978. Salanitro J.P. The role of bioattenuation in the management of aromatic hydrocarbon plumes in aquifers. Ground Water Monitoring Review. Fall. pp. 150-161. 1993. Scheunert I., Vockel D., Schmitzer J. and Korte F. Biomineralization rates of14

# C-labelled organic chemicals in aerobic and anaerobic suspended soil. Chemosphere. 16: 1031-1041. 1987. Schmidt S.K.,Simkins S. and Alexander M.Models for the kinetics of biodegradation of organic compounds not supporting growth. Appl. Environ. Microbiol.. 50: 323-331. 1985. Schmitzer J.L., Scheunert I. and Korte F. Fate of bis(2-ethylhexyl) [14

# C]phthalate in laboratory and outdoor soil-plant systems. J. Agric. Food Chem. 36: 210-215. 1988. Schouten M.J., Peereboom J.W.C. and Brinkman U.A.T. Liquid chromatographic analysis of phthalate esters in Dutch river water. Int. J. Environ. Anal. Chem. 7:13-23. 1979. Schwab A.P., Banks M.K. and Arunachalam M. Biodegradation of polycyclic aromatic hydrocarbons in rhizosphere soil. In: Intrinsic Biorem. [Pap. Int. In Situ On-Site Bioreclam. Symp.]. 3rd

# . Hinchee R.E. et. al. (Eds). Battelle Press: Columbus, OH. pp. 23-29. 1995. Schwarzenbach R.P., Giger W., Hoehn E. and Schneider J.K. Behavior of organic compounds during infiltration of river water to groundwater. Field studies. Environ. Sci. Technol. 17: 472-479. 1983. Scott H.D., Wolf D.C. and Lavy T.L. Adsorption and degradation of phenol at low concentrations in soil. J. Environ. Qual. 12: 91-95. 1983. Shanker R., Ramakrishna C. and Seth P.K. Degradation of some phthalic acid esters in soil. Environ. Pollut. 39: 1-7. 1985. Shiaris M.P. Seasonal biotransformation of naphthalene, phenanthrene and benzo[a]pyrene in surficial estuarine sediments. Appl. Environ. Microbiol. 55: 1391-1399. 1989. Shimp R.J. and Pfaender F.K. Influence of easily degradable naturally occurring carbon substrates on biodegradation of monosubstituted phenols by aquatic bacteria. Appl. Environ. Microbiol. 49: 394- 401. 1985. Smith M.J. Bioavailability and biodegradation of polycyclic aromatic hydrocarbons in soils. FEMS Microbiol. Lett. 152: 141-147. 1997.

# 181

Stauffer T.B., Antworth C.P., Boggs J.M. and Macintyre W.G. A natural gradient tracer experiment in a heterogeneous aquifer with measured in situ biodegradation rates: A case for natural attenuation. In: Proceedings EPA Symp. Intrinsic Bioremed. Groundwater. USEPA. EPA-540/R-94-515. 1994. Steinberg S.M., Pignatello J.J. and Sawhney B.L. Persistence of 1,2-dibromoethane in soils: entrapment in intraparticle micropores. Environ. Sci. Technol. 28: 1843-1852. 1987. Subba-Rao R.V., Rubin H.R. and Alexander M. Kinetics and extent of mineralization of organic chemicals at trace levels in freshwater and sewage. Appl. Environ. Microbiol. 43: 1139-1150. 1982. Swindoll C.M., Aelion C.M. and Pfaender F.K. Influence of inorganic and organic nutrients on aerobic biodegradation and on the adaptation response of subsurface microbial communities. Appl. Environ. Microbiol. 54: 212-217. 1988. Thomas J.M., Yordy J.R., Amador J.A. and Alexander M. Rates of dissolution and biodegradation of water-insoluble organic compounds. Appl. Environ. Microbiol. 52: 290-296. 1986. Thomas J.M., Lee M.D. and Ward C.H. Use of ground water in assessment of biodegradation potential in the subsurface. Environ. Toxicol. Chem. 6: 607-614. 1987. Thomas J.M., Gordy V.R., Fiorenza S. and Ward C.H. Biodegradation of BTEX in subsurface materials contaminated with gasoline: Granger, Indiana. Wat. Sci. Tech. 22: 53-62. 1990. Vaishnav D.D. and Babeu L. Occurrence and rates of chemical biodegradation in Superior harbor water. J. Great Lakes Res. 12: 184-192. 1986. Vaishnav D.D. and Babeu L. Comparison of occurrence and rates of chemical biodegradation in natural waters. Bull. Environ. Contam. Toxicol. 39: 237-244. 1987. van der Meer J.R., Bosma T.N.P., de Bruin W.P., Harms H., Holliger C., Rijnaarts H.H.M., Tros M.E., Schraa G. and Zehnder A.J.B. Versatility of soil column experiments to study biodegradation of halogenated compounds under environmental conditions. Biodegradation. 3: 265-284. 1992. Vanveld P.A. and Spain J.C. Degradation of selected xenobiotic compounds in three types of aquatic test systems. Chemosphere 12: 1291-1305. 1983.Venkatraman S.N., Kosson D.S. and Schuring J.R. Transport and biological fate of toluene in lowpermeability soils. GWMR. 18: 105-113. 1998. Visser S.A., Lamontagne G., Zoulalian V and Tessier A. Bacteria active in the degradation of phenols in polluted waters of the St. Lawrence river. Arch. Environ. Contam. Toxicol. 6: 455-470. 1977.

# 182

Weissenfels W.D., Klewer H. and Langhoff J. Adsorption of polycyclic aromatic hydrocarbons (PAHs) by soil particles: influence on biodegradability and biotoxicity. Appl. Microbiol. Biotechnol. 36: 689-696. 1992. Wiedemeier T., Wilson J.T., Kampbell D.H., Miller R.N. and Hansen J.E. Technical Protocol for Implementing Intrinsic Remediation with Long-Term Monitoring for Natural Attenuation of Fuel Contamination Dissolved in Groundwater. Volume 1. Air Force Center for Environmental Excellence, Technology Transfer Division Brooks AFB, San Antonio, TX. 1995. Wiedemeier,TH et. al. Technical Protocol for Evaluating Natural Attenuation of Chlorinated Solvents in Groundwater. Air Force Center for Environmental Excellence, Technology Transfer Division Brooks AFB, San Antonio, TX. 1996. Wilcock R.J., Corban G.A., Northcott G.L., Wilkins A.L. and Langdon A.G. Persistence of polycyclic aromatic compounds of different molecular size and water solubility in surficial sediment of an intertidal sandflat. Environ. Toxicol. Chem. 15: 670-676. 1996. Wild S.R. and Jones K.C. Biological and abiotic losses of polynuclear aromatic hydrocarbons (PAHs) from soils freshly amended with sewage sludge. Environ Toxicol. Chem. 12: 5-12. 1993. Williams R.A., Shuttle K.A., Kunkler J.L., Madsen E.L. and Hooper S.W. Intrinsic bioremediation in a solvent-contaminated alluvial groundwater. J. Indus. Microbiol. & Biotechnol. 18: 177-188. 1997. Wilson B.H., Wilson J.T., Kampbell D.H., Bledsoe B.E. and Armstrong J.M. Biotransformation of monoaromatic and chlorinated hydrocarbons at an aviation gasoline spill site. Geomicrobiol. J. 8: 225- 240. 1990. Wilson J.T., Enfield C.G., Dunlap W.J., Cosby R.L., Foster D.A. and Baskin L.B. Transport and fate of selected organic pollutants in a sandy soil. J. Environ. Qual. 10: 501-506. 1981. Wilson J.T., McNabb J.F., Wilson B.H. and Noonan M.J. Biotransformation of selected organic pollutants in ground water. Devel. Indust. Microbiol. 24: 225-233. 1983. Wilson J.T., Dunlap W.J., Cosby R.L. and Chang R.S. Adaption of ground-water microorganisms at a creosote waste disposal site. Symp. Amer. Chem. Soc., Div. Environ. Chem. 186th

# Natl. Mtg., Washington, DC. 23: 294-296. 1983B. Wilson J.T., Cosby R.L. and Smith G.B. Potential for biodegradation of organo-chlorine compounds in ground water. Pre-publication. Ada, OK: RS Kerr Environmental Res. Lab. 1984.

# 183

Wilson J.T., McNabb J.F., Cochran J.W., Wang T.H., Tomson M.B. and Bedient P.B. Influence of microbial adaptation on the fate of organic pollutants in groundwater. Environ. Toxicol. Chem. 4: 721- 726. 1985. Wilson J.T., Miller G.D., Ghiorse W.C. and Leach F.R. Relationship between the ATP content of subsurface material and the rate of biodegradaiton of alkylbenzenes and chlorobenzene. J. Contam. Hydrol. 1: 163-170. 1986. Wischmann H. and Steinhart H. The formation of PAH oxidation products in soils and soil/compost mixtures. Chemosphere. 35: 1681-1698. 1997. Wylie G.D., Jones J.R. and Johnson B.T. Evaluation of the river die-away biodegradation test. J. Water Pollut. Control Fed. 54:1231-1236. 1982. Zoeteman B.C.J., Harmsen K., Linders J.B.H.J., Morra C.F.H. and Slooff W. Persistent organic pollutants in river water and ground water of The Netherlands. Chemosphere. 9: 231-249. 1980.