bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phytoremediation of Aged Petroleum Sludge: Effect of Inorganic Fertilizer
Authors: Hutchinson S.L. , Banks M.K. , Schwab A.P. 
Published: June 2010

ABSTRACTPhytoremediation is a promising new technology that uses higher plants to enhance biodegradation. Nutrient availability is an important factor governing the success of phytoremediation and can be regulated through the addition of fertilizer. A greenhouse study was conducted to assess the importance of nitrogen and phosphorus for the phytoremediation of petroleum sludge. Degradation of total petroleum hydrocarbons (TPH) was quantified for six fertilization rates and three vegetation treatments: bermuda grass [Cynodon dactylon(L.) Pers.], tall fescue (Festuca arundinaceaSchreb.), and an unvegetated control. During the first 6 mo of the experiment, TPH declined by an average of 49% with no significant differences between treatments. After 1 yr, TPH degradation was significantly greater in both vegetated treatments with a mean TPH reduction of 68% for bermuda, 62% for fescue, and 57% for the unvegetated control. Degradation of TPH in the fescue and bermuda treatments was significantly lower in the treatments in which no fertilizer was added or N and P were added simply to maintain plant growth compared with the higher rates of fertilization. For this short‐term, greenhouse experiment, optimal remediation was obtained by fertilization that produced a C to N to P ratio of 100:2:0.2.
Metalaxyl Toxicity, Uptake, and Distribution in Several Ornamental Plant Species
Authors: Wilson P.Chris , Whitwell Ted , Klaine Stephen J. 
Published: June 2010

ABSTRACTPhytoremediation depends on the ability of plants to tolerate and assimilate contaminants. This research characterized the interaction between several ornamental plant species and the fungicidal active ingredient, metalaxyl [N‐(2,6‐dimethylphenyl)‐N‐(methoxyacetyl)alanine methyl ester]. Species evaluated included sweetflag (Acorus gramineus Sol. ex Aiton), canna (Canna hybrida L. ‘Yellow King Humbert’), parrotfeather [Myriophyllum aquaticum (Vell.) Verdc.], and pickerelweed (Pontederia cordata L.). Metalaxyl tolerance levels for each species were determined by exposing plants for 7 d to solutions containing 0, 5, 10, 25, 50, 75, or 100 mg metalaxyl L−1 aqueous nutrient media. Response endpoints included fresh mass production after 7 d exposure and 7 d post‐exposure and quantum efficiency using dark‐adapted (Fv/Fm) and light‐adapted (fluorescence yields) plants. Metalaxyl uptake and distribution within the plant was determined by growing plants in aqueous nutrient media containing 1.18 × 106 Bq L−1 [14C]metalaxyl (0.909 mg L−1) for 1, 3, 5, or 7 d. Plant tissues were combusted and analyzed by liquid scintillation counting. Metalaxyl had no effects on the endpoints measured, except for fresh mass production of sweetflag at the 75 and 100 mg L−1 treatment levels. However, leaf necrosis was apparent in most species after 5 d exposure to concentrations greater than 25 mg L−1 Metalaxyl removal from the spiked nutrient media ranged from 15 to 60% during the 7‐d exposure period. The majority of metalaxyl removed from the solution was detected within individual plants. In nearly all cases, activity from the radiolabeled pesticide accumulated in the leaves. Uptake of metalaxyl was correlated with water uptake throughout the 7 d. These results suggest that all species examined may be good candidates for incorporation into a phytoremediation scheme for metalaxyl.
Summary of Well Water Sampling in California to Detect Pesticide Residues Resulting from Nonpoint‐Source Applications
Authors: Troiano John , Weaver Don , Marade Joe , Spurlock Frank , Pepple Mark , Nordmark Craig , Bartkowiak Donna 
Published: June 2010

ABSTRACTThis report summarizes well sampling protocols, data collection procedures, and analytical results for the presence of pesticides in ground water developed by the California Department of Pesticide Regulation (DPR). Specific well sampling protocols were developed to meet regulatory mandates of the Pesticide Contamination Prevention Act (PCPA) of 1986 and to provide further understanding of the agronomic, chemical, and geographic factors that contribute to movement of residues to ground water. The well sampling data have formed the basis for the DPR's regulatory decisions. For example, a sampling protocol, the Four‐Section Survey, was developed to determine if reported detections were caused by nonpoint‐source agricultural applications, a determination that can initiate formal review and subsequent regulation of a pesticide. Selection of sampling sites, which are primarily rural domestic wells, was initially based on pesticide use and cropping patterns. Recently, soil and depth‐to‐ground water data have been added to identify areas where a higher frequency of detection is expected. In accordance with the PCPA, the DPR maintains a database for all pesticide well sampling in California with submission required by all state agencies and with invitations for submission extended to all local and federal agencies or other entities. To date, residues for 16 active ingredients and breakdown products have been detected in California ground water as a result of legal agricultural use. Regulations have been adopted for all detected parent active ingredients, and they have been developed regardless of the level of detection.
Immobilization of Nickel and Other Metals in Contaminated Sediments by Hydroxyapatite Addition
Authors: Seaman John C. , Arey J.Samuel , Bertsch Paul M. 
Published: June 2010

ABSTRACTBatch experiments were conducted to evaluate the ability of hydroxyapatite (HA) to reduce the solubility of metals, including the primary contaminants of concern, Ni and U, from contaminated sediments located on the Department of Energy's Savannah River Site, near Aiken, SC. Hydroxyapatite was added to the sediments at application rates of 0, 5, 15.8, and 50 g kg−1After equilibrating in either 0.02MKCl or 0.01MCaCl2, the samples were centrifuged and the supernatants filtered prior to metal, dissolved organic C, and PO4analyses. The treated soils were then air‐dried and changes in solid‐phase metal distribution were evaluated using sequential extractions and electron‐based microanalysis techniques. Hydroxyapatite was effective at reducing the solubility of U and, to a lesser degree, Ni. Hydroxyapatite was also effective in reducing the solubility of Al, Ba, Cd, Co, Mn, and Pb. Sequential extractions indicate that HA transfers such metals from more chemically labile forms, such as the water‐soluble and exchangeable fractions, by altering solid‐phase speciation in favor of secondary phosphate precipitates. Hydroxyapatite effectiveness was somewhat reduced in the presence of soluble organics that likely increased contaminant metal solubility through complexation. Arsenic and Cr solubility increased with HA addition, suggesting that the increase in pH and competition from PO4reduced sorption of oxyanion contaminants. Energy dispersive x‐ray (EDXA) analysis conducted in the transmission electron microscope (TEM) confirmed that HA amendment sequesters U, Ni, Pb, and possibly other contaminant metals in association with secondary Al‐phosphates.
Removal of Uranium(VI) from Contaminated Sediments by Surfactants
Authors: Gadelle Frederic , Wan Jiamin , Tokunaga Tetsu K. 
Published: June 2010

ABSTRACTUranium(VI) sorption onto a soil collected at the Melton Branch Watershed (Oak Ridge National Laboratory, TN) is strongly influenced by the pH of the soil solution and, to a lesser extent, by the presence of calcium, suggesting specific chemical interactions between U(VI) and the soil matrix. Batch experiments designed to evaluate factors controlling desorption indicate that two anionic surfactants, AOK and T77, at concentrations ranging from 60 to 200 mM, are most suitable for U(VI) removal from acidic soils such as the Oak Ridge sediment. These surfactants are very efficient solubilizing agents at low uranium concentrations: ca. 100% U(VI) removal for [U(VI)]o,sorbed = 10−6 mol kg−1 At greater uranium concentrations (e.g., [U(VI)]o,sorbed = ca. 10−5 mol kg−1), the desorption efficiency of the surfactant solutions increases with an increase in surfactant concentration and reaches a plateau of 75 to 80% of the U(VI) initially sorbed. The most probable mechanisms responsible for U(VI) desorption include cation exchange in the electric double layer surrounding the micelles and, to a lesser extent, dissolution of the soil matrix. Limitations associated with the surfactant treatment include loss of surfactants onto the soil (sorption) and greater affinity between U(VI) and the soil matrix at large soil to liquid ratios. Parallel experiments with H2SO4 and carbonate–bicarbonate (CB) solutions indicate that these more conventional methods suffer from strong matrix dissolution with the acid and reduced desorption efficiency with CB due to the buffering capacity of the acidic soil.
Approximating Phosphorus Release from Soils to Surface Runoff and Subsurface Drainage
Authors: McDowell R.W. , Sharpley A.N. 
Published: June 2010

ABSTRACTPhosphorus application in excess of crop needs has increased the concentration of P in surface soil and runoff and led many states to develop P‐based nutrient management strategies. However, insufficient data are available relating P in surface soil, surface runoff, and subsurface drainage to develop sound guidelines. Thus, we investigated P release from the surface (0–5 cm depth) of a Denbigh silt loam from Devon, U.K. (30–160 mg kg−1 Olsen P) and Alvin, Berks, Calvin, and Watson soils from Pennsylvania (10–763 mg kg−1 Mehlich‐3 P) in relation to the concentration of P in surface runoff and subsurface drainage. A change point, where the slopes of two linear relationships between water‐ or CaCl2–extractable soil P and soil test phosphorus (STP) (Olsen or Mehlich‐3) meet, was evident for the Denbigh at 33 to 36 mg kg−1 Olsen P, and the Alvin and Berks soils at 185 to 190 mg Mehlich‐3 P kg−1 Similar change points were also observed when STP was related to the P concentration of surface runoff (185 mg kg−1) and subsurface drainage (193 mg kg−1). The use of water and CaCl2 extraction of surface soil is suggested to estimate surface runoff P (r2 of 0.92 for UK and 0.86 for PA soils) and subsurface drainage P (r2 of 0.82 for UK and 0.88 for PA soils), and to determine a change point in STP, which may be used in support of agricultural and environmental P management.
Tillage, Intercrop, and Controlled Drainage–Subirrigation Influence Atrazine, Metribuzin, and Metolachlor Loss
Authors: Gaynor J.D. , Tan C.S. , Drury C.F. , Ng H.Y.F. , Welacky T.W. , van Wesenbeeck I.J. 
Published: June 2010

ABSTRACTAtrazine (6‐chloro‐N2‐ethyl‐N4‐isopropyl‐1,3,5‐triazine‐2,4‐diamine) and metolachlor [2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐N‐(2‐methoxy‐1‐methylethyl)acetamide] have been found with increasing occurrence in rivers and streams. Their continued use will require changes in agricultural practices. We compared water quality from four crop‐tillage treatments: (i) conventional moldboard plow (MB), (ii) MB with ryegrass (Lolium multiflorum Lam.) intercrop (IC), (iii) soil saver (SS), and (iv) SS + IC; and two drainage control treatments, drained (D) and controlled drainage–subirrigation (CDS). Atrazine (1.1 kg a.i. ha−1), metribuzin [4‐amino‐6‐(1,1‐dimethylethyl)‐3‐(methylthio)‐1,2,4‐triazine‐5(4H)‐one] (0.5 kg a.i. ha−1), and metolachlor (1.68 kg a.i. ha−1) were applied preemergence in a band over seeded corn (Zea mays L.) rows. Herbicide concentration and losses were monitored from 1992 to spring 1995. Annual herbicide losses ranged from <0.3 to 2.7% of application. Crop‐tillage treatment influenced herbicide loss in 1992 but not in 1993 or 1994, whereas CDS affected partitioning of losses in most years. In 1992, SS + IC reduced herbicide loss in tile drains and surface runoff by 46 to 49% compared with MB. The intercrop reduced surface runoff, which reduced herbicide transport. Controlled drainage–subirrigation increased herbicide loss in surface runoff but decreased loss through tile drainage so that total herbicide loss did not differ between drainage treatments. Des‐ethyl atrazine [6‐chloro‐N‐(1‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine] comprised 7 to 39% of the total triazine loss.
Correlation of Human Olfactory Responses to Airborne Concentrations of Malodorous Volatile Organic Compounds Emitted from Swine Effluent
Authors: Zahn J.A. , DiSpirito A.A. , Do Y.S. , Brooks B.E. , Cooper E.E. , Hatfield J.L. 
Published: June 2010

ABSTRACTDirect multicomponent analysis of malodorous volatile organic compounds (VOCs) present in ambient air samples from 29 swine (Sus scrofa) production facilities was used to develop a 19‐component artificial swine odor solution that simulated olfactory properties of swine effluent. Analyses employing either a human panel consisting of 14 subjects or gas chromatography were performed on the air stream from an emission chamber to assess human olfactory responses or odorant concentration, respectively. Analysis of the olfactory responses using Fisher's LSD statistics showed that the subjects were sensitive to changes in air concentration of the VOC standard across dilutions differing by approximately 16%. The effect of chemical synergisms and antagonisms on human olfactory response magnitudes was assessed by altering the individual concentration of nine compounds in artificial swine odor over a twofold concentration range while maintaining the other 18 components at a constant concentration. A synergistic olfactory response was observed when the air concentration of acetic acid was increased relative to the concentration of other VOC odorants in the standard. An antagonistic olfactory response was observed when the air concentration of 4‐ethyl phenol was increased relative to the other VOC odorants in the standard. The collective odorant responses for nine major VOCs associated with swine odor were used to develop an olfactory prediction model to estimate human odor response magnitudes to swine manure odorants through measured air concentrations of indicator VOCs. The results of this study show that direct multicomponent analysis of VOCs emitted from swine effluent can be applied toward estimating perceived odor intensity.
Functional Classification of Swine Manure Management Systems Based on Effluent and Gas Emission Characteristics
Authors: Zahn J.A. , Hatfield J.L. , Laird D.A. , Hart T.T. , Do Y.S. , DiSpirito A.A. 
Published: June 2010

ABSTRACTGaseous emissions from swine (Sus scrofa) manure storage systems represent a concern to air quality due to the potential effects of hydrogen sulfide, ammonia, methane, and volatile organic compounds on environmental quality and human health. The lack of knowledge concerning functional aspects of swine manure management systems has been a major obstacle in the development and optimization of emission abatement technologies for these point sources. In this study, a classification system based on gas emission characteristics and effluent concentrations of total phosphorus (P) and total sulfur (S) was devised and tested on 29 swine manure management systems in Iowa, Oklahoma, and North Carolina in an effort to elucidate functional characteristics of these systems. Four swine manure management system classes were identified that differed in effluent concentrations of P and S, methane (CH4) emission rate, odor intensity, and air concentration of volatile organic compounds (VOCs). Odor intensity and the concentration of VOCs in air emitted from swine manure management systems were strongly correlated r2=0.88 The concentration of VOC in air samples was highest with outdoor swine manure management systems that received a high input of volatile solids (Type 2). These systems were also shown to have the highest odor intensity levels. The emission rate for VOCs and the odor intensity associated with swine manure management systems were inversely correlated with CH4 and ammonia (NH3) emission rates. The emission rates of CH4, NH3, and VOCs were found to be dependent upon manure loading rate and were indirectly influenced by animal numbers.
Denitrification Losses from Outdoor Piglet Production: Spatial and Temporal Variability
Authors: Petersen S.O. , Kristensen K. , Eriksen J. 
Published: June 2010

ABSTRACTAnimal welfare considerations have stimulated the development of outdoor piglet (Sus scrofa) production systems, but the high levels of nutrients excreted suggest that nutrient losses from this system may be high. This study first described the spatial distribution of denitrification activity in a 5‐ × 5‐m grid within and outside a paddock immediately after the sows (32 sows ha−1 for 6 mo) were removed in October 1997, and again the following March. Denitrification rates averaged 0.01 kg N ha−1 d−1 outside, and 0.5 kg N ha−1 d−1 inside the paddock in October, while the corresponding figures in March were 0.01 and 0.1 kg N ha−1 d−1 The highest denitrification rates were observed around the feeder, and this was also the case for concentrations of dissolved organic C and inorganic N in the soil. A statistical model that included both soil parameters and distance to feeder and huts gave the best description of the variability, but there was no significant autocorrelation between sampling points. In a second phase, seasonal variation of denitrification activity within a paddock (12 sows ha−1 yr−1) was quantified; 10 soil cores were sampled along a transect 11 times between March 1998 and February 1999. There was a significant positive effect of dissolved organic carbon (DOC) on denitrification at <25% gravimetric soil moisture (i.e., to November in this study). Both climate and management (position of huts and feeder) appeared to influence denitrification, which was estimated to be 69 kg N ha−1 yr−1, or 11% of the N surplus of this production system.
Selenium Distribution and Fluxes in Intertidal Wetlands, San Francisco Bay, California
Authors: Zawislanski P.T. , Mountford H.S. , Gabet E.J. , McGrath A.E. , Wong H.C. 
Published: June 2010

ABSTRACTSelenium (Se) concentrations exceeding ecological guidelines for sediments and suspended particulate matter (SPM) have been observed in the northern reach of the San Francisco Bay estuary. Long‐term availability of elevated Se in wetland sediments depends in part on the fluxes controlling Se distribution. The relative contribution of sedimentary vs. post‐depositional Se fluxes in two San Francisco Bay intertidal wetlands was estimated. Selenium concentrations on surface wetland sediments were compared with levels on SPM, and with previously established background levels in San Francisco Bay sediments. Sediment Se fluxes to the wetlands were measured directly using sediment traps. Although dissolved Se concentrations are higher than particulate Se concentrations in San Francisco Bay water, sediment input into the system provides the major flux of Se. Strong correlation between Se and C on SPM (r2 = 0.81) indicates the importance of organic particulate deposition. Dependence on sediment texture was qualitatively established by measuring Se on particle‐size separates. Normalization to Al showed that 65% of Se spatial variability is related to sediment texture. Selenium is further enriched in the marsh via post‐depositional inputs, probably due to in situ adsorption from overlying water and chemical reduction. According to sediment flux measurements, enrichment in the marsh is equivalent to 20 to 25% of the particulate Se flux, thereby defining the marsh as a Se sink. These findings highlight the need for more intensive monitoring of SPM as the major source of Se to intertidal wetlands.
Profenofos Residues in Wild Fish from Cotton‐Growing Areas of New South Wales, Australia
Authors: Kumar A. , Chapman John C. 
Published: June 2010

ABSTRACTThe organophosphorus (OP) pesticide profenofos (O‐4‐bromo‐2‐chlorophenyl O‐ethyl S‐propyl phosphorothioate) is used heavily in cotton‐growing areas of eastern Australia toward the end of the growing season. European carp (Cyprinus carpio), bony bream (Nematalosa erebi), and mosquitofish (Gambusia holbrooki) were collected from the cotton‐growing areas around Wee Waa, New South Wales, to determine the relationship between profenofos residues and acetylcholinesterase (AChE) activity in wild fish. Profenofos concentrations in water, sediment, and fish tissue reflected its general level of use; levels in March 1994 were significantly higher than in 1993 and generally decreased in May, 6 wk after cessation of spraying. Residues in carp and bony bream generally correlated with concentrations in water and sediment, although residues in fish tend to persist longer at some sites. Acetylcholinesterase inhibition was a useful indicator of profenofos exposure within a season, particularly if linked with residue measurements. Bony bream and gravid female mosquitofish recovered AChE levels more slowly than carp or nongravid mosquitofish. Recovery in creeks was generally more rapid than in lagoons.
Availability of Arsenic, Copper, Lead, Thallium, and Zinc to Various Vegetables Grown in Slag‐Contaminated Soils
Authors: Bunzl K. , Trautmannsheimer M. , Schramel P. , Reifenhäuser W. 
Published: June 2010

ABSTRACTTo anticipate a possible hazard resulting from the plant uptake of metals from slag‐contaminated soils, it is useful to study whether vegetables exist that are able to mobilize a given metal in the slag to a larger proportion than in an uncontaminated control soil. For this purpose, we studied the soil to plant transfer of arsenic, copper, lead, thallium, and zinc by the vegetables bean (Phaseolus vulgaris L. ‘dwarf bean Modus’), kohlrabi (Brassica oleracea var. gongylodes L.), mangold (Beta vulgaris var. macrorhiza), lettuce (Lactuca sativa L. ‘American gathering brown’), carrot (Daucus carota L. ‘Rotin’, ‘Sperlings’s'), and celery [Apium graveiolus var. dulce (Mill.) Pers.] from a control soil (Ap horizon of a Entisol) and from a contaminated soil (1:1 soil–slag mixtures). Two types of slags were used: an iron‐rich residue from pyrite (FeS2) roasting and a residue from coal firing. The metal concentrations in the slags, soils, and plants were used to calculate for each metal and soil–slag mixture the plant–soil fractional concentration ratio (CRfractional,slag), that is, the concentration ratio of the metal that results only from the slag in the soil. With the exception of Tl, the resulting values obtained for this quantity for As, Cu, Pb, and Zn and for all vegetables were significantly smaller than the corresponding plant–soil concentration ratios (CRcontrol soil) for the uncontaminated soil. The results demonstrate quantitatively that the ability of a plant to accumulate a given metal as observed for a control soil might not exist for a soil–slag mixture, and vice versa.