bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Drilling Fluids on Soils and Plants: I. Individual Fluid Components
Authors: Miller Raymond W. , Honarvar Shahnaz , Hunsaker Barbara
Published: July 2010

The effects of 31 drilling fluid (drilling mud) components on the growth of green beans (Phaseolus vulgaris L., ‘Tendergreen’) and sweet corn [Zea may var. saccharata (Sturtev.) ‘Bailey,’ Northrup King 199] were evaluated in greenhouse studies. Plants grew well in fertile Dagor silt loam soil (Cumulic Haploxeroli) when the soil was mixed with most soil‐component mixtures at disposal proportions normally expected. Vinyl acetate and maleic acid polymer (VAMA) addition caused significantly increased growth at the 95% confidence level. No statistically significant depression of plant growth occurred at normal rates with asbestos, asphalt, barite, bentonite, calcium lignosulfonate, sodium polyacrylate, a modified tannin, ethoxylated nonylphenol, a filming amine, gilsonite, a Xanthan gum, paraformaldehyde, a pipe dope, hydrolized polyacrylamide, sodium acid pyrophosphate, sodium carboxymethyl cellulose, sodium hydroxide added as pellets, and a sulfonated tall oil.

Statistically significant reductions in plant yields (at the 95% confidence level) occurred at normal disposal rates with a long‐chained aliphatic alcohol, sodium dichromate, diesel oil, guar gum, an iron chromelignosulfonate, lignite, a modified asphalt, a plant fibersynthetic fiber mixture, lignite, a nonfermenting starch, potassium chloride, pregelatinized starch, and sulfated triglyceride.

Thirteen drilling fluid components added individually to a fluid base (water, bentonite, and barite) and then to soil, were also tested for their effect on plant growth. Only the sulfated triglyceride (Torq‐Trim®) and the long‐chain (high molecular weight) alcohol (Drillaid 405®) caused no plant growth reductions at either rate added. The modified tannin (Desco®) caused minimal reduction in bean growth only when added to soil in “excess” levels. The pregelatinized starch, sodium dichromate, nonfermenting starch (Dextrid®), plant and synthetic fiber mix (Kwik‐Seal®), iron chromelignosulfonate (Q‐Broxin®), and guar gum (Gendril Thik®) did not depress plant growth at normal disposal rates used, but they did depress plant growth with the abnormally high (excess) rates of addition to soil. No plants grew either normal or excessive addition rates when potassium chloride was used. Also, no plants grew when abnormally high rates of sodium dichromate, lignite + sodium hydroxide, or calcium lignosulfonate + sodium hydroxide were added.
Movement of Chloride in a Soil with Variable Charge Properties: I. Chloride Systems
Authors: Chan K. Y. , Geering H. R. , Davey B. G.
Published: July 2010

The movement of synthetic chloride solutions, simulating a treated sanitary landfill leachate, through columns filled with the subsoil of a xanthic ferralsol were studied in the laboratory. The chloride movement did not follow the miscible displacement equation or more sophisticated models, because the amount of positive charge carried by the soil depended on both pH and the ionic strength of the solution moving through it. During movement of the alkaline synthetic leachate into the column, the amount of positive charge increased due to the higher ionic strength of the leachate relative to the soil solution. A further temporary increase in positive charge also took place due to the decrease in pH induced by cation exchange caused by the leachate front. Later, the desorption of Cl took place as the alkaline leachate titrated the soil to pH > 9.0 and the positive charge was neutralized by OH adsorption. These results show that variation in the positive charge of the soil, induced by the solution moving through it, causes the Cl outflow curve to deviate from theory. Before more advanced theories of miscible displacement can be applied to this type of situation, it will be necessary to develop adequate kinetic theories to describe the changes in the soil's charge properties induced by the solution moving through it.
Effect of Nitrification on Movement of Trace Metals in Soil Columns
Authors: Chang Fu‐Hsian , Broadbent F. E.
Published: July 2010

Soil column experiments were conducted with sludge‐treated and untreated samples of two soils, Omni silty clay and Delhi loamy sand, to determine whether protons generate during the nitrification process would affect the mobility of the trace metals Cd, Cr, Cu, Mn, Ph, and Zn. Columns 5 cm × 100 cm were leached bi‐ or tri‐weekly with 7.5‐cm applications of solutions of CaCl2, NH4Cl, or KCl. Trace metals in effluents from the columns were analyzed after each application of leaching solution. After 11 applications over a period of several months the columns were sectioned and the vertical distribution of 2N HCl‐extractable metals determined.

Average concentrations of metals in column effluents were well below 1 ppm in all cases except Zn eluted from untreated Delhi loamy sand where 20 mM NH4Cl or KCl leaching solutions produced effluent concentrations slightly above 1 ppm. There was evidence of nitrification affecting movement of several of the metals, particularly in the cases of Mn, Zn, Cu, and Cd in the untreated Delhi soil. The presence of sludge had a pronounced stabilizing influence of Cd and Zn, and to a lesser degree on other metals, probably as a result of organo‐metal complexes.

Much of the input labeled NH4‐N was denitrified, as shown by recoveries of N ranging from 14 to 20% in the Omni soil and 40 to 78% in the Delhi soil. Proton generation during nitrification was, thus, partially offset by neutralization during denitrification. It was concluded that nitrification had relatively little effect on metal mobility under the conditions of the experiment.
A Comparison of the Distribution of Industrially Released 238Pu and Fallout 239,240Pu in Temperate, Northern United States Soils
Authors: Alberts James J. , Bobula Charles M. , Farrar David T.
Published: July 2010

Studies of 238Pu dispersed from the stack of a nuclear fabrication facility in southwestern Ohio indicate that the predominant deposition occurs within 8 km of the site. Plutonium‐238 from this source exhibits the same relative solubility as 239,240Pu from fallout. Both 238Pu from the facility and 239,240Pu from fallout move downward through the soil column, but 238Pu appears to have moved more slowly. Reasons for this apparent differential behavior are explored.
Extraction, Speciation, and Analysis of Arsenic and Arsenical Herbicides in Runoff: Evaluation of Simple Methods at the ppb Level
Authors: Wauchope R. D. , Yamamoto M.
Published: July 2010

The use of a column chromatographic technique for separation of inorganic arsenic (As) from methyl‐ and dimethyl‐derivatives, and flameless atomic absorption technique for quantitating the separated As species at the ppb level, have been evaluated for use in studies of the behavior of arsenate and methanearsonate (CH3AsO32‐) ions in runoff (water and suspended sediment). The former ion is a natural component of soils. The latter ion is extensively used as an herbicide in the sodium and disodium salt forms, commonly called MSMA and DSMA, respectively. Runoff from two watersheds was spiked with 200 ppb As as arsenate or 189 ppb As as methanearsonate, or both. The partitioning of the As between sediment and water phases was measured and the As species in both phases were identified and quantitated. Recoveries ranged from 80 to 100%, and relative precision between samples averaged 10% for As concentrations between 10 and 200 ppb. In the partitioning of the added As between sediment and water phases of the runoff, arsenate appears to be much more strongly adsorbed by sediments than in methanearsonate. Although both speciation and quantitation techniques are relatively simple, they will be adequate for exploratory studies on arsenate and methanearsonate behavior in runoff and impoundments.
The Effect of a Marsh on Runoff: I. A Water‐Budget Model
Authors: Huff D. D. , Young H. L.
Published: July 2010

A water‐budget model was developed to aid the study of transport of nutrients in surface and subsurface flows across a marsh. The model is based on field studies of Wingra marsh adjacent to Lake Wingra in Madison, Wis., and was used to calculate monthly totals of actual evapotranspiration, surface runoff, and subsurface drainage from April 1970 through August 1976. About 90% of the water entering the marsh comes from urban storm runoff. The remainder is precipitation (8%) and deep ground‐water inflow (2%). Water leaves the marsh through evapotranspiration (7%), shallow ground‐water discharge (8%), and surface outflow (85%). The model was used to estimate the water‐table elevation at an observation well where direct measurements were taken (November 1975 through October 1976). The observed depth to the water table ranged from 0 to 150 cm below the surface and the simulated value usually was within ± 10 cm. This suggests that the model adequately computes the water budget for the marsh and provides a sound basis for calculating dissolved and suspended material loads transported through the marsh into Lake Wingra.
Transport of Resistance‐labeled Escherichia Coli Strains Through a Transition Between Two Soils in a Topographic Sequence
Authors: Mc Coy E. L. , Hagedorn C.
Published: July 2010

Field experiments were conducted to determine the pathways and characteristics of bacterial transport through a saturated soil profile which represented a transition between the Steiwer (Ultic Haploxeroll) and Hazelair (Aquultic Haploxeroll) soil series and was located in a concave footslope position. Three separately distinguishable Escherichia coli strains were injected into three perforated horizontal lines installed upslope from the transition, and positioned in the A, B, and C horizons of the soil profile. Migration of the labeled strains was evaluated by collecting water samples from piezometers, sampling various depth zones in the soil, and placed in rows at various distances downslope. In addition, surface runoff samples were collected at the furthest upslope location of observed overland flow. Bacterial translocation patterns varied with depth of injection at the first sampling row downslope; however, as the bacteria penetrated into the transition zone, flow pathways converged and injection depth differences disappeared. Also, a transition from predominately matrix flow to predominately “pipe” flow was observed as the downslope flow of water was directed upward in the soil profile by hydraulic gradients and a restrictive clay layer. Translatory channel flow (“pipe” flow) demonstrated widespread influence through this transition and apparently large volumes of the water passing downslope were intercepted and conducted by these channels. This study provides the link joining results from previous reports and more completely describes septic‐system effluent migration on saturated hillslopes while additionally stressing the influence of pipe flow on hillslope hydrologic processes.
A Survey of Sorption Relationships for Reactive Solutes in Soil
Authors: Travis C. C. , Etnier Elizabeth L.
Published: July 2010

The present study provides a survey of relationships in current use to quantify sorption of reactive solutes by soil. Its purpose is to examine present concepts and to indicate active research directions. Both equilibrium and first‐order kinetic sorption models are reviewed. Equilibrium models discussed include the linear, Freundlich, Langmuir, two‐surface Langmuir, and competitive Langmuir isotherms. Kinetic sorption models reviewed are the reversible linear, reversible nonlinear, kinetic product, bilinear, mass transfer, Elovich, Fava and Eyring, and two‐site kinetic model.

The models reviewed appear to provide a reasonably good basis for extrapolation and interpolation of data. There is a continuing need, however, to upgrade these methodologies as demand for accuracy and realism increases. It is expected that the state‐of‐the‐art review provided by this survey will assist in this process.
Ammonia Volatilization from Liquid Swine Manure Applied to Cropland
Authors: Hoff J. D. , Nelson D. W. , Sutton A. L.
Published: July 2010

Randomized complete block design field experiments were conducted to determine the effects of rates and methods of liquid swine manure application on volatile NH3‐N losses from cropland. In addition, a greenhouse study was conducted to determine the effect of wind on the rate of NH3‐N volatilization from soil and the accuracy of NH3‐N loss measurements under field conditions. A partially closed system was utilized to directly collect volatilized NH3‐N from microplots.

The NH3‐N collection system did not accurately estimate volatile N losses when windy conditions existed as often encountered in the field. Using direct measurement of NH4+‐N in waste before and after exposure to the atmosphere to correct for the low estimates of NH3‐N loss under field conditions, an average of 48.1% of the volatilized N was collected under greenhouse conditions with relatively constant temperature and wind.

The rate of NH3‐N loss from manure increased with increasing temperature and air movement. The proportions of the applied NH4+‐N lost as NH3‐N during a 3.5‐day sampling period in the spring from swine manure (pH 6.4) applied to soil (pH 6.4) and corrected for the effect of wind were: 14.0%, 12.2%, and 11.2% for the 90, 135 and 180 metric ton/ha, respectively, of surface applied liquid swine manure; 2.5% for both the 90 and 180 metric ton rates, respectively, of injected liquid swine manure; 14.7% for surface applied urea fertilizer (168 kg N/ha); and 65.8% of the applied NH4+‐N from swine manure surface applied (90 metric tons/ha) on a plastic liner. Fresh swine manure (pH 7.8) surface applied at the rate of 135 metric tons/ha on greenhouse loam soil (pH 7.0) lost 82.5% of the applied NH4+‐N in an 8‐day sampling period.
Effect of Cadmium on Soil Bacteria and Actinomycetes
Authors: Williams S. E. , Wollum A. G.
Published: July 2010

Soil procaryotic populations were evaluated from a soybean field (Glycine max L.) that had been amended 3 years previously with Cd (as CdCl2·2½H2O) at rates corresponding to 0, 6, 22, and 40 kg Cd/ha. Replicate aliquots of soil suspensions from the treated plots were plated on media containing increasing concentrations of Cd. This was done to determine if soil bacteria and actinomycetes (procaryotes) that were tolerant of Cd had developed in Cd‐treated soils. It was found that the level of DTPA‐TEA extractable soil Cd had no influence on the development of Cd‐tolerant soil populations on media amended with Cd. Rather, it was found that low levels of media Cd retarded procaryote growth, whereas high levels did not. This also occurred regardless of the level of soil extractable Cd. Soil moisture at the time of sampling was found to be inversely related to procaryote numbers on media containing 0 ppm Cd and directly related on media containing 10, 20, and 40 ppm Cd. On media containing 5 ppm Cd, numbers of soil organisms were low with respect to the control and other Cd media levels and had no relationship to soil moisture. Growth rate constants of 58 pure cultured bacteria were determined at Cd concentrations of 0, 5, 10, 20, and 40 ppm in liquid media. The organisms exhibited tolerant, intolerant, and stimulated responses of Cd; however, 50% were intolerant to 5 ppm Cd but tolerant at concentrations > 5 ppm.
Behavior of Chromium in Soils: IV. Toxicity to Microorganisms
Authors: Ross D. S. , Sjogren R. E. , Bartlett R. J.
Published: July 2010

The toxicity of Cr to soil bacterial isolates was studied by measuring turbidity of liquid cultures supplemented with Cr(VI) or Cr(III). Ten to 12 ppm Cr(VI) was found inhibitory to most isolates growing in either a soil‐extract medium and or in a semisynthetic medium. Gram negative bacteria were more affected than gram positive bacteria by Cr(VI) both at this level and at 1 ppm. Toxicity due to Cr(III) was not observed at similar levels.

Nellis loam (Typic Eutrochrept) and Hinesburg fine sandy loam (Entic Haplorthod) samples were treated with 10 and 100 ppm Cr(VI) and 100 ppm Cr(III). All three treatments significantly decreased CO2 evolution from that of controls for the 3‐week duration of the experiment. Extractable Cr(VI) in these soils decreased rapidly during this time, indicating that reduction of the added Cr(VI) was occurring.

The toxicity of low levels of Cr(VI) to gram negative bacteria in aqueous culture indicates that soil microbial transformations, such as nitrification, may be affected. The fact that both Cr(III) and Cr(VI) inhibited microbial activity in soil shows that more caution may be needed in handling Cr‐containing wastes, regardless of the form of Cr.
The Contribution of Phosphorus Leached from Crop Canopy to Losses in Surface Runoff
Authors: Sharpley A. N.
Published: July 2010

Simulated rainfall (6 cm/hour) was used to leach P from growing cotton (Gossypium hirsutum), sorghum (Sorghum sudanense), and soybean (Glycine max.) plants as a function of soil type and time interval between rainfall events. The relative contribution of plant material and surface soil to the transport of soluble P in surface runoff was estimated. The amount of soluble P in plant leachate, collected before contacting the soil surface, was found to increase with plant age and soil‐water stress when changes in leaf area index were accounted for. A period of at least 1 day between rainfall events was needed for P to reaccumulate on the leaf surface. The contribution of soluble P in plant leachate to that transported in surface runoff was estimated as the difference in runoff concentration between planted and bare soil. When plants were subject to a soil P stress, canopy leachate contributed the major proportion (90%) of that transported in surface runoff. With an increase in plant age from 42 to 82 days, the contribution of plant leachate to surface runoff increased from approximately 20–60%. The possible sorption of leached P is discussed along with estimating leaching losses in improving the predictive ability of nutrient models.
The Establishment of Cheatgrass (Bromus Tectorum L.) on Spent Oil Shale from the Paraho Process
Authors: George Melvin R. , Mc Kell C. M. , Richardson Steven G.
Published: July 2010

Experiments were conducted in a greenhouse with the following objectives: (i) to study the emergence and seedling growth of cheatgrass (Bromus tectorum L.) in soil and in Paraho spent oil shale that was either leached, treated with sulfuric acid, covered with soil, or mixed with soil, and (ii) to study emergence and seedling growth of cheatgrass on spent shale that was fertilized with ammonium nitrate and triple superphosphate. The ECe of the spent shale was 14 mmhos/cm, the pH was 9 and the shale was low in plant available N and P. The soil from Federal oil shale lease tract U‐a near Bonanza, Utah was a coarse textured alluvium with low moisture retention. Cheatgrass planted on soil alone and shale covered with soil had the highest emergence rates (75–86%) and produced the greatest total biomass (8.55–13.4 g). Seedling emergence rates on leached and unleached spent shale were 44% and 36%, respectively, and total biomass was <1 g on either treatment. Seedlings failed to emerge on sulfuric acid‐treated spent shale. The addition of sulfuric acid to spent shale increased the ECe of the shale to over 21 mmhos/cm. Leached and unleached spent shale was fertilized with N at rates of 0, 28, and 56 kg/ha and P at rates of 0, 24.4, and 48.8 kg/ha. The total biomass for any fertilizer treatment was <1 g. We conclude that covering shale disposal piles with topsoil may improve the site for successful invasion by a colonizing species such as cheatgrass.
Nitrous Oxide Emissions From Cropped Fields
Authors: Mosier A. R. , Hutchinson G. L.
Published: July 2010

From mid‐May to mid‐September 1978, nitrous oxide (N2O) emissions from an irrigated corn (Zea mays L.) field in northern Colorado totaled only 2.5 kg N ha−1, and even smaller losses were measured from a nearby sugarbeet (Beta vulgaris L.) field. Fluxes measured by a simple soil cover method compared favorably with micrometeorological estimates of vertical N2O flux density. About 30% of the N2O lost from the corn field was emitted during the 2 weeks following fertilization while NH3 was being rapidly nitrified, and 59% was evolved during the week following the field's first irrigation, when restricted oxygen diffusion favored denitrification. Other occurrences of irrigation or precipitation exceeding 0.7 cm were also followed by rapid, though much smaller, increases in N2O emissions. The flux of N2O was not significantly correlated with soil nitrate concentration but was strongly correlated with soil water content and N2O concentration in the soil atmosphere, which always exceeded the ambient atmospheric concentration. We found no evidence that either site ever behaved as a sink for tropospheric N2O. Total N2O emissions from the corn field amounted to only 1.3% of the 200 kg NH3‐N ha−1 applied to the crop, a much smaller fraction than has been used in models predicting the effect of agricultural fertilizers upon stratospheric ozone depletion.
Decomposition of Water Hyacinth in Agricultural Drainage Water
Authors: Reddy K. R. , Sacco P. D.
Published: July 2010

The present study was designed to evaluate the nutrient release from decomposing water hyacinths [Eichhornia crassipes (Mart.) Solms.] in agricultural drainage water. In a laboratory incubation study, nutrient release from the decomposing water hyacinths was measured under aerobic and anaerobic conditions at varying levels of water hyacinth additions. In a field study, impact of water hyacinth die‐off on drainage canal water quality was evaluated after a herbicide application.

In the laboratory study, under both aerobic and anaerobic systems about 21–45% of the added N was lost resulting in low accumulation of inorganic N. At all levels of water hyacinth additions, soluble P release into the water was higher under anaerobic conditions than aerobic conditions. At the end of the 100‐day decomposition, chemical oxygen demand (COD) of the water hyacinth treated water was reduced by 42–73% under aerobic conditions, and by 16 to 57% under anaerobic conditions and biological oxygen demand (BOD) of the water was reduced by about 67–85% under aerobic conditions and 20–53% under anaerobic conditions. Electrical conductivity (EC) and K, Mg, and Ca concentration of the water were not influenced by the oxygen status (aerobic or anaerobic conditions) of the water for any level of water hyacinth addition.

Under field conditions, water hyacinth die off as a result of a herbicide application resulted in an increased concentration of soluble N and P in the drainage canal water.
Formation of N‐Nitrosodiethanolamine from Diethanolamine in Lake Water and Sewage
Authors: Yordy Jerry R. , Alexander Martin
Published: July 2010

A thin‐layer chromatographic method using a 14C‐labeled secondary amine was used to measure the possible formation of nitrosamines in samples of natural waters and sewage. The lower limit of sensitivity was 1 ng of nitrosamine/ml.

Formation of N‐nitrosodiethanolamine from diethanolamine in lake water and sewage was demonstrated, with the identity of the product verified by combined gas chromatography‐mass spectrometry. The greatest amount of the carcinogenic nitrosamine was generated in sewage, considerably less was produced in Caynga Lake water, and the least amount was formed in water from an acid lake. The amount of nitrosamine formed was related to the amount of diethanolamine added and the nitrite level in samples of the environments. Autoclaved samples of sewage and Cayuga Lake water either did not produce N‐nitrosodiethanolamine or formed it at rates much lower than in nonsterile samples, suggesting a role for microorganisms or some other heat‐labile factor in the formation of the nitroso compound. The nitrosamine could be metabolized in all three environments, but it persisted in lake water samples taken in the winter.
Characteristics of Coal Mine Overburden Important to Plant Growth
Authors: Mc Fee W. W. , Byrnes W. R. , Stockton J. G.
Published: July 2010

This investigation was conducted to determine physical and chemical properties of mineland overburden, to evaluate plant growth in these materials, and to identify properties of overburden materials before mining that may serve as predictors of potential plant growth.

Eighteen overburden materials from five surface coal mines in the Illinois coal basin of southwestern Indiana were sampled and analyzed for 20 physical and chemical properties. Twelve were unconsolidated materials, including A and B horizons, lacustrine sediments, and glacial tills, and six were rock strata that break and weather easily. Growth potential for overburden materials, with and without sewage sludge and fertilizer amendments, was evaluated in greenhouse pot culture using alfalfa, wheat, and white pine. Oats yield, and survival and growth of Virginia pine and yellow‐poplar were evaluated for 10 materials in outdoor containers.

Regression analysis of plant growth against chemical and physical properties of the overburden materials did not reveal properties that could be consistently used in a formula approach to predicting plant growth potential of the materials. Electrical conductivity of the material extract and water storage capacity were most frequently significantly related to growth. High plant tissue levels of B, Fe, Mn, and Al suggested toxicity problems on some materials. The general ranking of overburden materials evaluated for plant growth potential was lacustrine sedment ≥ A horizons > B horizons = glacial tills ≥ brown shale > sandstone > gray shale > black fissile shales; however, physical properties unfavorable to extraction and replacement of lacustrine material may limit its use under field conditions. Addition of sewage sludge resulted in vastly improved growth of wheat, and to a lesser extent, alfalfa, on most materials in the greenhouse. Fertilization with N‐P‐K was less effective than sludge but usually produced increased plant growth.
Sand‐Filter Trenches for Purification of Septic Tank Effluent: I. The Clogging Mechanism and Soil Physical Environment
Authors: Kristiansen Rolv
Published: July 2010

Investigations were conducted for 17 months in three pilot plant sand filters to elucidate the relationship between clogging and soil physical and chemical environment in sand filters. Two trenches (A and C) were loaded with septic tank effluent at a rate of 4–6 cm/day, and one (B) at 12–18 cm/day. The temperature in A was 12–15°C, and in B and C was ambient (4–16°C).

The septic tank effluent concentrated in one end of the filters. Here the sand surface clogged and ponding occurred. Ponding rates of 0.33, 0.27, and 0.16 m2/month and crust resistances of 35, 5.5, and 4 days were found in units A, B, and C, respectively. The C/N ratio in the crust zone was 5.9 ± 0.2, and in the rest of the sandfill was 5.8 ± 0.3. Bacterial cells occupied 0.74% of the pore volume in the clogged layer of A. Production of extracellular slimy material, which probably filled a larger proportion of the pore volume than the cells, was probably temperature dependent.

Increased clogging intensity induced reduced soil water content below the crust zone. Because the filters were aerated from below, the increased clogging led to improved aeration that was shown by gas and redox measurements. While low Eh values (<0 mV) and O2 contents (<2%) regularly were found down to 30 cm in the clogged end of the least clogged unit (C), such values were predominantly detected in the crusted zone of A. Here, up to 15.5% CH4 was measured. In zones of sand containing <1% O2, up to 93% N2 was found. N2O contents above the detection limit (200 ppm) were never measured.
Sand‐Filter Trenches for Purification of Septic Tank Effluent: III. The Microflora
Authors: Kristiansen Rolv
Published: July 2010

The microbial flora of sand filters play an important role in purification and clogging processes in sand. The organisms were studied by plate counts, microscopic counts, and biomass calculations. Fecal coliforms were estimated by MPN techniques.

In sand‐filter trenches A, B, and C, operated at different temperatures and loading rates for further treatment of septic tank effluent, the number of viable bacteria in the infiltrative surface generally increased from 106 to 107–108/g sand, and was about 107 in the sandfill below. The total number of bacteria was a 100–1,000 times the viable count, and decreased with depth. This was most profound in a heavily clogged filter (A) which was kept at the highest temperature (12–15°C). Fecal coliform numbers followed the same pattern with depth.

Rods (ca. 0.3 µm3) and cocci (ca. 0.06 and 0.5 µm3) dominated the bacterial flora of the sand‐filter trenches. Cocci (ca. 0.5 µm3) and small rods penetrated the whole profile in the least clogged unit, but were retained to a certain degree in unit A.

In the crust layer of a heavily clogged sand filter, 44 mg C and 13 mg N/100 g sand were bound in bacteria. The bottom sand layers contained about 0.2 mg C and 0.006 mg N/100 g sand bound in the biomass. In a slightly clogged filter these values were about 40–50 times as high. In the most clogged unit the biomass was strongly correlated with the amount of total C. This was not the case in a slightly clogged unit.

Concentrations of fecal coliforms in sand and outlet water from filters with low clogging intensities operated at ambient temperature were considerably higher than concentrations from a filter operated at a higher temperature and thus a higher clogging intensity.
Empirical Prediction of Organic Pollutant Sorption in Natural Sediments
Authors: Brown D. S. , Flagg E. W.
Published: July 2010

An empirical relationship between the octanol/water partition coefficients (Kow) and sediment sorption coefficients (Koc) was determined for nine chloro‐s‐triazine and dinitroaniline compounds. Results were compared with earlier work that reported an excellent correlation between Kow and Koc for polynuclear aromatic and chlorinated hydrocarbons. The more polar character of the present compounds, however, reduced the precision of estimating sorption from octanol/water partition coefficients. A fit of the combined data sets for a total of 19 compounds of widely varied properties (five orders of magnitude variation in solubility) yielded a relationship that should be useful for predicting simple partition coefficients (Kp) in a number of modeling and assessment applications. Reasonable estimates of Kp or Koc can be obtained from a single determination of the octanol/water partition coefficient and knowledge of the organic carbon content of the sediment.
Nitrogen Leaching as Influenced by Nitrogen Management and Supplemental Irrigation Level
Authors: Timmons D. R. , Dylla A. S.
Published: July 2010

Corn (Zea mays L.) management systems involving two nitrogen (N) fertilization methods and two supplemental irrigation levels were evaluated for soil water percolation and N leaching losses in west central Minnesota. Nonweighing lysimeters were used to collect soil water and the accompanying nutrients that moved below the root zone of the droughty Estherville sandy loam soil studied. Nitrogen was applied either as granules broadcast and disked in before planting or in liquid form through the irrigation system four times during the growing season. Supplemental irrigation was applied as either a partial replenishment (2.5 cm) or full replenishment (5 cm) irrigation each time the available soil water decreased to about 5 cm (50% depletion).

Annual soil water percolation from spring thaw to fall freezeup averaged about 7.1, 11.2, and 18.0 cm for nonirrigated corn, 2.5‐cm irrigated corn, and 5‐cm irrigated corn, respectively, during the 5‐year period studied. Average annual NO3‐N leaching losses ranged from about 29 (for nonfertilized, nonirrigated corn) to 112 kg ha−1, and the combination of variable rainfall, soil NO3‐N content, and low soil water‐holding capacity caused great variation within and among years. Compared with values for fertilized nonirrigated corn, annual NO3‐N leaching losses increased an average of 17 and 53%, respectively, for the partial and full replenishment irrigations. The periodic application of liquid N through the irrigation system reduced average annual NO3‐N leaching loss by about 12 kg ha−1 at the 5‐cm irrigation level, but no difference resulting from N management was observed at the 2.5‐cm level.
Renovation of Septic Tank Effluent in Sand‐Clay Mixtures
Authors: Willman B. P. , Petersen G. W. , Fritton D. D.
Published: July 2010

Sand required by Pennsylvania code for use in elevated sand mounds is not specified by sand mineralogy but does require 5–15% clay by weight. Since this required sandy material is expensive and research elsewhere would suggest that a specific clay percentage is not required, the objective of this research was to test the validity of the clay content requirements and the effect of sand mineralogy on septic tank effluent renovation.

Limestone, sandstone, and shale sands were used with clay added to give 0, 3, 6, and 12% clay. Septic tank effluent was applied at the rate of 1.5 cm/day to the surface of each sand‐clay mixture for 23 weeks. The effluent was analyzed at regular intervals before and after flowing through 60 cm of the sand for the following 16 chemical and biological variables: pH, chemical oxygen demand (COD), fecal coliforms, fecal streptococci, total Kjeldahl N, NH4‐N, NO2‐N, NO3‐N, (NO3‐NO2)‐N, PO4‐P, total P, Cl, Ca, Na, K, and specific conductivity. All the sand‐clay combinations (including the 0% clay samples) removed over 99% of the fecal coliforms and streptococci. The removal of P and COD and the transformation of N were highly efficient in the limestone and shale sands regardless of clay content. Renovation in the sandstone sand, which is a relatively inert material, was increased by the addition of small amounts of clay. It was concluded that sand type influences the renovation of effluent and is more important than the amount of clay. The results of this study indicate that limestone is the most desirable sand type, although long‐term dissolution may be a problem, followed by sandstone with a small percentage of clay, and then by shale. Although shale was a relatively efficient renovator of effluent over the time period studied, it is anticipated that the susceptibility of shale to weathering would lead to early clogging.
Volatile Fatty Acids in a Redox‐Controlled Cattle Manure Slurry
Authors: Guenzi W. D. , Beard W. E.
Published: July 2010

Fatty acids have been implicated as a part of the overall odor problem associated with the management of animal wastes. This study was conducted to determine the relationship between redox potential (Eh) and volatile fatty acid (VFA) transformations in a cattle manure slurry. The controlled redox system was sequentially lowered in 100‐mV increments from +300 to −200 mV, and acid concentrations of the suspension were determined by gas chromatography. Acids associated with the added dry manure disappeared at + 300 mV Eh, and only acetic acid was detected at very low concentrations at Eh levels of +200, +100, and 0 mV. Acetic, propionic, and isobutyric acids started to accumulate at −100 mV and butyric acid began to accumulate at −200 mV. The rate of acid formation was considerably higher at −200 mV than at −100 mV, except for isobutyric concentrations, which began forming at −100 to −200 mV but remained consistently low. Acid accumulations during the 7‐day period at −200 mV were 6.66, 0.86, and 0.05 mg/g manure for acetic, propionic, and butyric acids, respectively. Saturated manure samples incubated at constant temperatures ranging from 5 to 35°C reached an Eh of −100 mV after 2 hours at 5°C and after 1 hour at 15°C. A −200‐mV Eh was reached after 0.5 hour at 25 and 35°C. Therefore, the conditions required for acid formation and, perhaps, release as odor components, could occur within hours after a feedlot has received moisture that initiates and accelerates microbial activity.
Effects of Sewage Sludge on Phenoxy Herbicide Adsorption and Degradation in Soils
Authors: O'Connor G. A. , Fairbanks B. C. , Doyle E. A.
Published: July 2010

The adsorption and degradation of two herbicides, 2,4,dichlorophenoxyacetic acid (2,4‐D) and 2,4,5‐trichlorophenoxyacetic acid (2,4,5‐T), were examined in three soils either freshly amended or preconditioned for 2 months with sewage sludge. Sludge additions generally enhanced herbicide degradation, but had no effect on 2,4‐D degradation in a soil with a history of 2,4‐D applications. Fresh sludge additions had little effect on herbicide adsorption by soils, while preconditioning the sludge‐soil mixtures generally increased herbicide adsorption.
Chemical Availability of Cadmium in Mississippi River Sediment
Authors: Khalid Rashid A. , Gambrell Robert P. , Patrick William H.
Published: July 2010

There is concern that changes in the physicochemical conditions occurring during dredging and disposal of polluted sediments may increase chemical mobility and hence bioavailability of sediment‐bound toxicants such as Cd. The objectives of this research were to study the chemical transformations of Cd in freshwater sediment as affected by pH and redox potential under controlled laboratory conditions and predict Cd behavior during dredging and disposal of Cd‐contaminated sediments.

Mississippi River sediment suspensions were incubated at four redox potential levels (−150, +50, +250, and +500 mV) at each of three pH levels (5.0, 6.5, and 8.0) and spiked with 0.2 µCi carrier‐free 109Cd/g solids. Sediment suspensions were sequentially extracted for easily mobile and potentially available 109Cd fractions. Essentially all of 109Cd extracted from alkaline sediment suspensions was associated with potentially available chelated, insoluble organic‐bound and reducible fractions and was not affected by changes in oxidation‐reduction conditions. A change from alkaline to acidic pH under moderately oxidized to well‐oxidized conditions resulted in 109Cd transformations from potentially available organic forms to more mobile and readily available dissolved and exchangeable forms. This could create potential hazards of disposal of Cd‐contaminated dredged sediments due to enhanced availability and leaching of Cd as affected by altered physicochemical environments.
Spatial and Temporal Variation of Fecal Coliform Movement Surrounding Septic Tank‐Soil Absorption Systems in Two Atlantic Coastal Plain Soils
Authors: Stewart L. W. , Reneau R. B.
Published: July 2010

Field experiments involving residential, conventional septic tank‐soil absorption systems (ST‐SAS) were conducted to determine the extent, direction, and seasonal variation of fecal coliform movement away from drainfields placed in two poorly drained Coastal Plain soils with seasonally high fluctuating water tables. Monitoring wells at 152‐ and 305‐cm depths were placed in and around two ST‐SAS that had been in operation for about 2 years. Fecal coliform levels were measured one to two times per month from January 1977 to September 1979. One site had effective artificial drainage that created a water table gradient of 3.2% and resulted in lateral mass flow of bacteria, up to 10 m, in the direction of the gradient. At this site the predominate fecal coliform movement was horizontal, as indicated by an average concentration of <3 Most Probable Number (MPN)/100 ml in the deep wells within the drainfield. The lack of a discernible water table gradient at the second site, which employed only shallow surface drains, resulted in downward movement of fecal coliforms with the deep wells, averaging 10 MPN/100 ml compared with the 45 MPN/100 ml average in the shallow wells within the drainfield. Fecal coliform movement at both sites was almost entirely limited to periods when the water table was at or above the drainfield trench bottoms. Nonuniform distribution of septic tank effluent throughout the entire drainfield was apparent at both locations. The results indicate placement of conventional ST‐SAS in high‐water‐table soils may result in contamination of shallow ground waters (305 cm).
Accumulation of Heavy Metals in Arid‐Zone Soils Irrigated with Treated Sewage Effluents and Their Uptake by Rhodes Grass
Authors: Banin A. , Navrot J. , Noi Y. , Yoles D.
Published: July 2010

Prolonged commercial irrigation with treated sewage effluents from rural sources resulted in accumulation of heavy metals in the top 10‐ to 15‐cm layer of the soil in three commercial fields. Statistically significant differences were found for total content and extractable fraction of Cd in all three soils, and for Cu, Ni, and Pb in clay soils by comparing these fields and adjacent ones irrigated with normal water. Chromium concentration differences were not statistically significant. As a result, there was some increase in the concentration of these elements in Rhodes grass (Chloris gayana Kunth.) grown in the sewage‐effluent‐irrigated fields as compared with the grass grown in the fields irrigated with normal water. The increase, although statistically significant, was slight, even in the field that had been irrigated with sewage effluents for up to 28 years. The uptake of the various metals, as assessed by the enrichment factor (EF = µg element g−1 plant/µg element g−1 soil), tended to diminish with an increase in the specific surface area of the soil. This was particularly pronounced with the more labile of the elements studied—Cd, Cu, and Ni—and less so for Pb and Cr. The uptake of a given element appears to be largely determined by its solubility in the soil solution and can be generally predicted by its ionic potential. The relative magnitude of the enrichment factor established for Rhodes grass is in the following order: Cu > Cd > Pb > Ni ≫ Cr.
Effect of Simulated Acid Rain on Nitrification and Nitrogen Mineralization in Forest Soils
Authors: Strayer Richard F. , Lin Chyi‐Jiin , Alexander Martin
Published: July 2010

To determine the possible microbiological changes in soil resulting from acid rain, columns containing samples of forest soils were leached with either a continuous application of 100 cm of simulated acid rain (pH 3.2–4.1) at 5 cm/hour or an intermittent 1.5‐hour application of 1.2 cm of simulated acid rain twice weekly for 19 weeks. The upper 1.0‐ to 1.5‐cm portions of soil from treated columns were used to determine the changes in inorganic N levels in the soil. Nitrification of added ammonium (NH4+) was inhibited following continuous exposure of soil to simulated acid rain of pH 4.1−3.2. The extent of the inhibition was directly related to the acidity of the simulated rain solutions. The production of inorganic N in the absence of added NH4+ was either stimulated or unaffected following continuous treatment of soils with pH 3.2 simulated acid rain. The addition of nitrapyrin (2‐chloro‐6‐[trichloromethyl]pyridine), an inhibitor of autotrophic nitrification, caused a decrease in nitrification in water‐treated soil but had little effect on nitrification in soil treated with pH 3.2 simulated acid rain. Intermittent applications of simulated acid rain (pH 3.5–4.1) for 19 weeks partially inhibited nitrate (NO3−) production in soil amended with NH4+ following the exposure period, but NO3− production in unamended soil was either unaffected or stimulated.
Occurrence of Naturally High Cadmium Levels in Soils and Its Accumulation by Vegetation
Authors: Lund L. J. , Betty E. E. , Page A. L. , Elliott R. A.
Published: July 2010

A survey of soils in the Santa Monica Mountains of Los Angeles and Venture Counties, Calif., was conducted to determine the relationship between parent materials and soil Cd contents. Twenty‐four series were sampled and analyzed for Cd after digestion in 4N HNO3. Residual soils developed from shale parent materials had the greatest Cd concentrations, with a mean of 7.5 µg/g, whereas soils developed from sandstone and basalt had the lowest Cd concentrations, with a mean of 0.84 µg/g. Alluvial soils with parent materials from mixed sources had an intermediate mean Cd content of 1.5 µg/g. A more extensive survey of the dominant soil series of the area was carried out and the Millsholm series, mapped in 30% of the area, was found to have a mean Cd content of 7.3 µg/g. A greenhouse vegetable study conducted with seven soils from the area, representing a range of Cd concentrations, showed that the Cd present naturally in these soils was absorbed by the vegetables in amounts sufficient to be of public health concern.
Potential Polychlorinated Biphenyl Residues in Animal Products from Application of Contaminated Sewage Sludge to Land
Authors: Fries George F.
Published: July 2010

Laboratory studies and field observations involving polychlorinated biphenyls (PCB's) and related compounds were used in making an assessment of residues in animal products from the application of sewage sludge to agricultural land. Animals can become exposed to PCB's applied to land by three routes: direct ingestion of sewage sludge that adheres to plants during sludge application, ingestion of plants indirectly contaminated by uptake or volatilization from the soil, and ingestion of contaminated soil when grazing. The last route has the greatest realistic potential for producing residues in animal products from a given rate of long‐term application of PCB‐contaminated sludge to land. Feeding experiments with PCB's indicate that the steady‐state milk‐fat concentrations are about five times the diet concentrations (dry basis) in dairy cattle and that the steady‐state body‐fat concentration will be similar in non‐lactating animals. Soil consumption by grazing dairy cows can be as high as 14% of dry‐matter intake when the amount of available forage is low and no supplemental feed is used. This could cause milk‐fat residues of 0.7 ppm for each ppm of PCB in surface soil. There is little root absorption and translocation of PCB's to the aerial parts of plants. Plants can become contaminated by volatilization of PCB's from soil and redeposition on the plants if the residue occurs at the soil surface. Field experience with other halogenated hydrocarbons suggest that volatilization and redeposilion of PCB's will be less important in determining rates of PCB‐containing sludge that can be applied to land than direct animal ingestion of sludge or contaminated soil.
The Occurrence of Flow Channels in Soils
Authors: Simpson T. W. , Cunningham R. L.
Published: July 2010

Specialized flow features (channels) described in Typic Hapludalf, clayey, mixed, mesic soils that have been used for waste‐water irrigation are reported, to explain the mechanism for widely different water‐flow velocities through soil.

A field investigation of 15 soil‐pit transects revealed vertical zones of loose, porous, fine‐structured soil through which rapid saturated flow occurred. The texture of the soil in the channels was clay, as was the matrix between channels.

Rapid flow of effluent‐irrigation waters through channels in the soil may lessen the renovating capability of the soil because of the reduced surface area and reduced contact time. Because the channels were coincident in some cases with carbonate bedrock solution channels, possible ground‐water pollution may have occurred.