Brief Summary of Minutes of Annual Meeting

Shad Nelson served as Chair of the committee and Joe Pignatello served as Secretary. The Administrative Advisor, Lee Sommers, summarized the vision and roles of NIFA and discussed the AFRI grants program. Each participant provided a research update, with discussion following each presentation. Thank you to all who were able to participate! Thomas Borch, from Colorado State University will serve as our Secretary the next two years, while Joe Pignatello will serve as the Chair. Based on discussion of the participants and emails sent prior to the meeting, we decided to schedule the meeting next year on January 23 and 24 in Fort Collins, CO. Thank you to our Administrative Advisor, Dr. Lee Sommers, for being willing to host us! There is always a weather risk in traveling to Ft. Collins during that time of year, but on the other hand, if we get snowed in we can probably find some winter sports nearby to keep us entertained! (and it will be more pleasant than St. Paul! :)!). It is likely we will have accommodations within easy walking distance from campus and a shuttle from the Denver airport is about $30 or so. This timing hopefully helps those of us who find it difficult to get away during the first weeks of spring semester / winter quarter due to classes.

Objective 1: To identify and quantify fundamental chemical, physical, and biological processes relevant to pesticides and contaminants in agricultural ecosystems I. University of Hawaii, at Manoa (J-P Bingham) A. Development and environment testing of novel peptide molluscicdes Accomplishment/output: The objective is to identify new biodegradable pesticide agents against invasive snails and determine their application and residual contribution in agricultural ecosystems. Cone Shells (genus Conus) represent an untapped library of peptides that specifically target conserved physiological mechanisms within snails. These mechanisms represent novel targets for agricultural molluscicide development. These species represent a novel source of molluscicides. Isolation of three bioactive peptides have been undertaken, the synthesis of these native-like peptides has then demonstrated a level of peptide degradation in solid. These are now being compared to a newly bioengineered versions of these toxin, namely the C- to N- cyclized versions that possess a higher orally activity in mice and demonstrate a higher rate of absorption in snails upon topical application. B. Evaluating the Risk of Diphacinone Rodenticide Pellets to Hawaiian Trigger Fish Accomplishment/output: Polynesian rats introduced on the island of Lehua in 1931 are highly detrimental to native vegetation and the eggs of seabirds. To exterminate the invasive rats, the anticoagulant rodenticide Diphacinone applied in pellets was used between December 2008 and February 2009, leaving a buffer zone around the shorelines, but nevertheless causing a fish die-off. Fish are exposed to Diphacinone by direct ingestion, indirect ingestion, and through absorption of dissolved rodenticide in the water. Our objective was to determine the effects for Diphacinone on Trigger fish using a closed model system, focusing on behavior, food consumption rates, palatability of pellets containing Diphacinone, and Diphacinone toxicity and accumulation in Trigger Fish. We are present developing both HPLC and LC/MS methods to quantify Diphacinone. II. Colorado State University, Fort Collins (Thomas Borch) A. Prediction and Analysis of Contaminant Persistence. Accomplishment/output: We investigated a quantum chemical approach to evaluate the fate of contaminants of emerging concern, applied here to hexamethylphosphoramide (HMPA), a widely used solvent and potential groundwater contaminant. Oxidation of HMPA is estimated to require at least iron-reducing conditions at low-to-neutral pH and nitrate-reducing conditions at high pH. Furthermore, the transformation of HMPA by permanganate is predicted to proceed through sequential N-demethylation. Experimental validation based on LC/TOF-MS analysis confirms the predicted pathways of HMPA oxidation by permanganate. The calculations also predict PN bond hydrolysis to be the only thermodynamically favorable reaction that may lead to its degradation under reducing conditions. It is predicted that HMPA hydrolyzes via an acid-catalyzed mechanism at pH < 8.2, and an uncatalyzed mechanism at pH 8.2-8.5. The estimated half-lives of thousands to hundreds of thousands of years over the groundwater-typical pH range of 6.0 to 8.5 indicate that HMPA will be persistent in the absence of suitable oxidants. We also we developed a new RPLC/ESI-TOF-MS method and further investigated the chromatographic performances of two columns. B. Artificial Sweeteners as Indicators for Anthropogenically Influenced Water. Accomplishment/output: Artificial sweeteners can be used as indicator compounds for wastewater influence on other water types. The objective of this work was to quantify sucralose in select U.S. drinking water systems. Water samples from 19 United States (U.S.) drinking water treatment plants (DWTPs) serving more than 28 million people were analyzed for sucralose using liquid chromatography tandem mass spectrometry (LC-MS/MS). Sucralose was found to be present in source water of 15 out of 19 DWTPs (472900 ng/L), finished water of 13 out of 17 DWTPs (492400 ng/L) and distribution system water of 8 out of the 12 DWTPs (482400 ng/L) tested. Sucralose displayed low removal (12% average) in the DWTPs. It was found persist regardless of the presence of residual chlorine or chloramines. In order to understand intra-DWTP consistency, sucralose was monitored at one drinking water treatment plant over an 11 month period from March 2010 through January 2011, and averaged 440 ng/L in the source water and 350 ng/L in the finished water. III. South Dakota State University, Brookings, SD A. Sorption and bioavailability of potentially toxic compounds produced from selected pesticides and pharmaceuticals in soil-water matrices and biological systems. Accomplishments/output: The studies focused on the effect of chlortetracycline on anaerobic manure decomposition, the impacts of tylosin- and chlortetracycline-containing manure on soil nutrients and soil microbial community structure, and sorption of herbicides to soils amended with biochars produced by microwave pyrolysis. High doses of chlortetracycline inhibited sequence batch reactors efficiencies, although total gas production was greater. Aged manure containing tylosin inhibited CO2 production the most in batch reactors. Sorption of atrazine, dicamba and 2,4-D to biochar alone was always greater than to soil alone. However, addition of 1 or 10% biochar to soil increased sorption only modestly, if at all. IV. University of Hawaii, Honolulu, HI (C. Ray) A. Transport of Cryptosporidum parvum oocysts in variable charge soils. Accomplishments/output: We studied the effect of dissolved organic carbon on the transport and attachment behavior of Cryptosporidium parvum oocysts and 1.8 micrometer polystyrene microspheres in a red, Fe-, Al-, and clay-rich volcanic soil from Oahu (called Poamoho soil), and an organic- and quartz-rich soil from Illinois (Drummer soil). Experiments were conducted using flow-through columns with or without 100 mg/L sodium dodecyl benzene sulfonate (SDBS) or Suwanee River Humic Acid (SRHA) in the influent. SDBS increased transport but SRHA reduced of microspheres through the soils. SDBS increased oocysts transport through Drummer, but no enhanced oocyst transport was detected in the Poamoho soil. SRHA slightly increased oocysts transport in Poahomo soil, but caused a 6-fold increase in transport through the Drummer soil. V. North Dakota State University, Fargo ND (Tom M. DeSutter) A. Manure management effects on 17²-estradiol Accomplishments/output: We investigated the association of the estrogen hormone 17²-estradiol with the soil solid phase when liquid manure was introduced. 17²-estradiol persisted in the solution phase longer when liquid swine manure was present compared to calcium chloride. The log Koc values were greater in the absence than the presence of swine manure. VI. University of California, Riverside (Jay Gan) A. Bioavailability and phase partition of hydrophobic contaminants: Accomplishments/output: Sorption isotherms were constructed for, polybrominated diphenyl ether (PBDE) flame retardants, BDE-47 and BDE-99, in sediments by different methods to measure the aqueous phase concentration Cw. The Cw measured by automated solid phase microextraction (Cw-SPME) was consistently smaller than by liquid-liquid extraction (Cw-LLE), suggesting substantial association of PBDEs with DOC. We evaluated biodegradation of pyrene by Mycobacterium vanbaalenii PYR-1 as a function of sediment particle sizes, and investigated the relationship between the rate of degradation on sand, silt and clay particles with their individual desorption kinetics measured with the Tenax extraction method. The fractions mineralized after 336-h incubation greatly surpassed the rapidly desorbing fraction (Frapid) values, suggesting utilization of pyrene in the slow desorption pool (Fslow). Model analysis showed that pyrene sorbed on silt and clay aggregates was directly utilized by the degrading bacteria. Like black carbon (BC) particles, single-wall carbon nanotubes (SWCNT) have a high affinity for hydrophobic organic contaminants (HOCs) and therefore the presence of SWCNT in sediment may lead to altered bioavailability of HOCs. We compared SWCNT with biochar and charcoal for their effect on the microbial degradability of 0.05 mg kg-1 14C-phenanthrene (PHE) by Mycobacterium vanbaalenii PYR-1 in two sediments. When the amendment rate of adsorbent was 1 mg g-1, PHE mineralization was inhibited much more significantly by SWCNT than by either biochar or charcoal, apparently due to its much larger specific surface area and pore volume. However, pre-interaction of SWCNT with dissolved organic matter led to attachment of polar molecules and reduced surface area on SWCNT, resulting in decreased PHE sorption and an alleviated effect on PHE biodegradation, in the order of peptone > tannic acid > humic acid. B. Characterizing pesticide sorption and washoff on concrete: Accomplishments/output: Use of pesticides around residential homes is linked to contamination of urban waterways, where impervious surfaces like concrete are considered as sources or facilitators of the contamination. Sorption of 14C-permethrin to concrete was rapid, but both the parent compound and total 14C showed an initial rapid desorption followed by prolonged slow desorption. Permethrin became more resistant to desorption as the pesticide contact time on the concrete increased. The decreased desorption was partially attributed to decomposition. Runoff from concrete 1 d after pesticide treatment contained high levels of bifenthrin and permethrin. Although runoff levels decreased over time, detectable residues were still found in runoff water after 3 months. ANOVA analysis showed that precipitation intensities and concrete surface conditions (i.e., acid wash, silicone seal, stamping, and addition of microsilica) did not significantly affect the pesticide transferability to runoff. C. Characterizing sorption and transformations of emerging contaminants. Accomplishments/output: Soil sorption and degradation are important processes affecting the leaching potential of trace contaminants in irrigated soil. We examined the sorption and attenuation of six psychoactive and antilipidemic drugs, carbamazepine, diazepam, dilantin, meprobamate, primidone, and gemfibrozil, in a loam (LVL) and a loamy sand (ALS) representaitve of golf course soils in the southwestern United States. For the same soil, the sorption affinity generally followed a decreasing order diazepam > carbamazepine > gemfibrozil > dilantin H meprobamate H primidone. While dilantin, gemfibrozil and meprobamate showed moderate persistence under aerobic conditions, , the test compounds were recalcitrant to degradation in the other treatments. We evaluated sorption and degradation in two soils collected from arid regions of five antibiotic and anti-inflammatory drugs, naproxen, trimethoprim, diclofenac, ibuprofen and sulfamethoxazole. Degradation was influenced by microbial activities, oxygen status in the soil, soil type and compound characteristics. Bisphenol F (BPF) is widely used in polycarbonate plastics and epoxy resins. This study considered oxidation of BPF by MnO2, a commonly occurring metal oxide in soil. MnO2 efficiently oxidized BPF. The reaction was pH dependent and influenced by cosolutes including humic acids, metal ions and anions. Five reaction intermediates were identified. VII. USDA-ARS, St. Paul, MN (William Koskinen) A. Sorption and sorption reversibility of herbicides Indaziflam, Aminocyclopyrachlor Accomplishments/output: Sorption and desorption of indaziflam and aminocyclopyrachlor in soils from Brazil and the USA, with different physical chemical properties, were investigated. The Freundlich parameters suggest low to moderate mobility for indaziflam and high mobility for aminocyclopyrachlor. However, sorption was hysteretic for both compounds on all soils. B. Metolachlor and Mesotrione degradation Accomplishments/output: Metolachlor (2-chloro-6-ethyl-N-(2-methoxy-1-methylethyl) aceto-o-toluidide) is a pre-emergent chloroacetanilide herbicide used to control broadleaf and annual grassy weeds in a variety of crops. In this study we examined respectively, for microorganisms that had the ability to degrade this herbicide. We report here on the isolation and characterization of pure cultures of Candida xestobii and Bacillus simplex, from a silty-clay soil (a Luvisol) from Spain with 10 and 2 year histories of metolachlor and S-metolachlor applications, that have the ability to use metolachlor as a sole source of carbon for growth. Moreover, the yeast degraded other acetanilide compounds; acetochlor and alachlor. Mesotrione is a benzoylcyclohexane-1,3-dione herbicide that inhibits 4-hydroxyphenyl pyruvate dioxygenase (HPPD) in target plants. Mesotrione-degrading bacteria were selected among strains isolated from Brazilian aquatic environments, located near corn fields treated with this herbicide. Pantoea ananatis was found to rapidly and completely degrade mesotrione, although mesotrione did not serve as a sole C, N, or S source for growth of P. ananatis, and mesotrione catabolism required glucose supplementation to minimal media. Intermediates were identified other than 2-amino-4-methylsulfonyl benzoic acid (AMBA) or 4-methylsulfonyl-2-nitrobenzoic acid (MNBA), two metabolites previously identified in a mesotrione-degrading Bacillus strain. VIII. University of California, Davis Davis, CA (Sanjai J. Parikh) A. Examining the potential for rapid transport of veterinary antibiotics to groundwater. Accomplishments/output: Groundwater samples were obtained from two monitoring wells concurrent with fertigation of an agricultural field at a dairy facility in the Central Valley of California. Eight common veterinary antibiotics (oxytetracycline, chlortetracycline, sulfamethazine, sulfamerazine, sulfadiazine, sulfamethoxazole, sulfadimethoxine, and monensin) used in the dairy industry were targeted for analysis. Analytical method development was carried out and established limits of quantification (LOQ). Sulfadimethoxine and monensin were detected in the lagoon water ranging from 16.4 ng L-1 to 116 ng L-1 and 159 ng L-1 to 4772 ng L-1, respectively. In groundwater, sulfadimethoxine, sulfamethazine, and monensin were commonly measured with reliable reporting levels above the LOQ between 1.33 ng L-1 to 20.6 ng L-1. Analysis of general water chemistry indicate that the lagoon water and hence, antibiotics did not reach the groundwater. Instead, the results suggest that antibiotics were present before the irrigation season and indicate persistence in the groundwater. B. Role of soil minerals on sorption and facilitated transport of veterinary antibiotics. Accomplishments/output: Preliminary sorption data reveals no sorption of sulfamethazine to the mineral phases studied except birnessite and therefore suggest facile transport through soil. For monensin, only goethite was shown to bind monensin. Goethite is positively charged and monensin is negatively charged within the pH range. The decreased sorption of monensin to goethite with increasing ionic strength suggests an outer-sphere mechanism. In the current study, increased functionalization of sulfamethazine observed upon reaction with ´-MnO2 indicates cleaving of aromatic rings, and that abiotic degradation is occurring. C. Impact of biochar soil amendments on pesticide and pharmaceutical transport in soil. Accomplishments/output: Addition of a highly sorbing material at the time of biosolid application would serve to reduce the bioavailability of the wide range of hydrophobic compounds found in biosolids, and support beneficial reuse of organic wastes, such as biosolids and agricultural materials (e.g., walnut shells). We examined sorption of the fluoroquinolone antibiotic ciprofloxacin used in human medicine and of the phenylurea pesticides, linuron, diuron, and monuron, Yolo silt loam, kaolinite, biochar (wood feedstock and walnut shell), activated carbon, biosolids and a soil/biochar and biosolid mixture. Our results demonstrate that ciprofloxacin has high sorption affinity to walnut shell biochar and activated carbon, moderate sorption to kaolinite and low sorption to woodstock biochar. The results suggest that walnut shell biochar used as a co-amendment with biosolids could limit the bioavailability of the antibiotic ciprofloxacin when applied to soil. IX. University of Nebraska-Lincoln (Patrick J. Shea) A. Production of N-nitrosoatrazine and Adsorption-desorption of atrazine and N-nitrosoatrazine in soil. Accomplishments/output: In the companion project (NEB-38-069), NNAT formed readily from atrazine (pKa = 1.7) and nitrite in solution at pH 2-4 and in soil at pH d5. Simazine (pKa = 1.62) also formed nitrososimazine. NNAT degrades to atrazine and hydroxyatrazine. NNAT formation is catalyzed by acetate acid and fulvic acid in water at pH 5 to 7, but not by humic acid. NNAT half-life in Aksarben soil was about 9 d, with degradation to atrazine and other compounds. We studied the soil adsorption-desorption behavior of atrazine and N-nitrosoatrazine (NNAT), formed from reaction of atrazine with nitrite under acidic conditions. The pH was adjusted to 3-8. Adsorption and desorption Kd and Koc values indicated greater adsorption of NNAT than atrazine, and greater hysteresis of NNAT than atrazine. Soil texture was important. The Kd for NNAT and atrazine increased when bentonite clay was treated with dodecyltrimethylammonium bromide (DDTMA) or tannic acid (TAC) DDTMA or TAC, indicating that adsorption was further increased by coating the clay with organic material. X. Connecticut Agricultural Experiment Station, New Haven (J. Pignatello) A. Adsorption of Ionizable Compounds to Black Carbon Accomplishments/output: Black carbon is a natural constituent of soils and amendment of soil with manufactured black carbon (biochar) has attracted interest as a way to improve soil fertility and store carbon. While adsorption of nonionic compounds to black carbon has been extensively studied, far less attention has been paid to ionic and ionizable compounds. The intensity of adsorption of ionic compounds, even negatively charged compounds, is surprisingly strong. We have identified some unique reactions of ionizable compounds on charcoals. Adsorption of organoanions, such as aromatic acid anions (cinnamic acid, coumaric acid) and the sulfonamide anion of the veterinary antimicrobial, sulfamethazine, release hydroxide ion upon adsorption. The resulting neutral molecule engages in an especially strong hydrogen bond with a carboxyl or phenoxyl group on the surface known as a negative charge-assisted H-bond. Sulfamethazine acquires a positive charge as pH decreases due to protonation of the amino group on the p-aminosulfonamide ring. In addition to charge pairing with surface negatively charged sites, this charged ring system was shown to engage in a pi-pi electron donor-acceptor interaction with the polyaromatic surface of graphitic microcrystallites of which black carbon is composed. This interaction is a result of the electron-deficient p-aminosulfonamide ring due to the withdrawing properties of the sulfonamide and positively charged amino groups ring, interacting with the electron-rich and polarizable polyaromatic surface. B. Predicting Sulfamethazine Adsorption in Biochar-Amended Soil. Accomplishments/output: Biochar has been shown to be a beneficial soil amendment in some agricultural applications. Since charcoal can be a potent sorbent, we sought to determine whether four commercial prototype biochars could predictably reduce pore water concentrations of the veterinary antimicrobial, sulfamethazine (SMT) in St. Joan loam soil (Spain). The adsorbed-to-dissolved concentration ratio log Kd,BC of SMT increased exponentially with properties that reflect degree of carbonization and micropore development in the biochar. Except for the biochar produced by fast pyrolysis, Kd,BC was between 10^1 and 10^5 times greater than the soil organic carbon-normalized distribution ratio (KOC) of SMT, depending on the biochar and SMT concentration. The pH dependence of Kd,BC between 5 and 8 was consistent with strong H-bonding of the anion of SMT with a surface oxyl group that we proposed earlier. While as expected addition of biochar to soil (1% or 2%) increased the Kd of the mixture in relation to soil alone in proportion to the Kd,BC of the biochar, the increase was overestimated by the sum of sorption to the two components by as much as 10^2 due to weathering effects. Weathering is most likely due to fouling of the biochar by humic substances. Most of the weathering took place already after the shorter of the two weathering regimes tested (20 oC, 48 h biochar-soil pre-wetting, followed by 48 h sorption). C. Preparation and Characterization of Humic Acid Cross-linked with Organic Bridging Groups. Accomplishments/output: Cross-linking of humic substances with organic bridging groups is thought to contribute to soil organic matter humification and according to polymer theory is expected to alter its sorbent properties. Model cross-linked humic substances were prepared by cross-linking Amherst soil humic acid by a diepoxide and a polycarboxylic acid in the solid state, applying procedures established for cross-linking of polymers and textile fabrics. Physicochemical properties of the products were determined by solubility experiments and thermal analysis. The incorporation of the cross-linker into the matrix of the humic acid by covalent linkages was confirmed by both the disappearance of bands of the reactive functional groups of the cross-linker in the FTIR spectrum and the increase of signals related to the incorporation of the cross-linker into the matrix of the humic acid in the FTIR and 13C-CPMAS-NMR spectra. The formation of covalent ester and ether linkages by the cross-linking reaction was indicated. Water solubilities at pH 6.2 of the cross-linked samples as determined by UV/Vis spectrometry were reduced compared to controls. Fewer water molecule bridges were formed in the cross-linked samples, which was attributed to a lower number of available functional groups and increased distances between humic acid strands caused by the cross-linking molecules. Reduced reactivities of humic acid strands in the cross-linked samples further indicated successful cross-linking. Objective 2: Integrate chemical and biological process information for use in models applicable across different spatial and temporal scales. I. University of Hawaii, Honolulu (C. Ray) A. Transport of selected endocrine disrupting chemicals from wastewater through a Hawaiian Oxisol. Accomplishments/output: We continued experiments on the leachability of two estrogen hormones (17-beta estradiol [E2] and estrone [E1]) introduced simultaneously through an intact soil core (15 to 45 cm) of an Oxisol from Oahu. The soil columns were eluted with municipal wastewater that has gone through treatment, filtration, and UV disinfection (TOC content 7.7 mg/L). Both compounds started to breakthrough around 12 pore volumes; however, the rate of breakthrough of E1 was much faster than that of E2. After 66 pore volumes, the column was flushed with deionized water 1 mM CaCl2. Bromide was fully flushed out of the column within 5 more pore volumes. The flushing continued for 18 more pore volumes and during that time 75% of E1 and 40 of E2 were removed. B. Sewage biomarkers to assess infiltration of rainwater into municipal sewer systems. Accomplishments/output: The infiltration of heavy rainfall to sewer systems increases treatment costs and the chance of overflow of untreated sewage to receiving waters. Selected chemical and biological markers of sewage (caffeine, total N, suspended solids, E. coli, and enterococci) were monitored during wet and dry weather conditions. Rainfall derived infiltration was determined independently by measuring flow in sewers or by marker concentrations. II. University of Nebraska-Lincoln (Patrick J. Shea) A. Adaption of a watershed vulnerability model to atrazine. Accomplishments/output: The components of a watershed-scale vulnerability model (developed in a USDA-NIWQP project) were analyzed, converted to a GIS, and adapted to the field scale using SSURGO and field data, with a goal of finding the best resolution for raster maps. Model output was generated for the acid-sensitive herbicide, atrazine, on the day of application and 7 days after application for a 35-ha field in north-central Missouri, an intensely row-cropped agricultural field with claypan soils located in Major Land Resource Area 113. The initial model showed how acid-catalyzed hydrolysis of atrazine would reduce vulnerability to solution runoff in the north part of a Missouri test field. Vulnerability to leaching in the test field was comparatively lower than to solution runoff. An early version of the watershed model had overpredicted leaching vulnerability due to the presence of claypans in the Missouri study area. Because a claypan is not a diagnostic horizon, identification criteria for a surface restrictive layer were developed based upon the Nebraska Rainwater Basins and Missouri claypans. A runoff penalty (which increases vulnerability) was created based on the large pore volume (saturated  0.33 bar moisture) above the clay restrictive layer or depth to free water, whichever is shallower. Using these criteria, a clay restrictive layer was identified in the southern Blue River Basin, an area with atrazine runoff problems. Objective 3. Provide stakeholders with tools for developing strategies to ensure sustainable agriculture and to protect natural resource systems. I. University of Hawaii, Honolulu (C. Ray) A. Registration of New Chemicals in Hawaii Accomplishments/output: Hawaii is one of the few states in the union that does not automatically accept the registration of a given chemical issued by USEPA. If the compound is going to be used over a large area and has the potential to leach to ground water, the state conducts in-house evaluation of its environmental impact. If the impact exceeds a pre-judged score, the University of Hawaii is asked to complete a detailed assessment of its potential to leach to ground water. For this purpose, the registrant provides copies of all fate and transport studies used in EPAs registration process. We used data from these studies to evaluate leaching, potential loss to runoff water, and ecotoxicological impacts. In the current year, we are re-evaluating our pesticide registration decisions based on new data provided by selected registrants. II. University of Nebraska-Lincoln (Patrick J. Shea) A. Identification of variables affecting atrazine runoff from subwatersheds. Accomplishments/output: The impacts of corn and sorghum planting progress (indicating atrazine application), rainfall, antecedent soil water content, and the presence of a soil surface restrictive layer on stream-measured weekly atrazine load for 1997-2004, were determined for independent subwatersheds of the NE-KS Blue River Basin. Analysis of atrazine monitoring data showed maximum atrazine runoff after most of the corn had been planted but during sorghum planting from mid-May to early June, immediately following multiple rainfall events that saturated the soil profile and caused runoff from fields. Analysis of covariance showed rainfall was the most significant factor associated with atrazine loading, but soil water content, corn and sorghum planting progress, and the presence of a soil surface restrictive layer were also important.

Gan, J., S. Bondarenko, L. Oki, D. Haver, and J.X. Li. 2011. Occurrence of fipronil and its biologically active derivatives in urban residential runoff. Environmental Science & Technology (in press). Jiang, W.Y., D. Haver, M. Rust, and J. Gan. Runoff of pyrethroid insecticides from concrete surfaces following simulated and natural rainfalls. 2012. Water Research (in press). Lin, K.D., S. Bondarenko, and J. Gan. 2011. Sorption and persistence of wastewater-borne psychoactive and antilipidemic drugs in soils. Journal of Soils and Sediments 11:13631372. Haruta, S., W.T. Jiao, W.P. Chen, A.C. Chang, and J. Gan. 2011. Evaluating Henrys law constant of N-nitrosodimethylamine (NDMA). Water Science and Technology 64: 1636-1641. Delgado-Moreno, L., K.D. Lin, R. Veiga-Nascimento, and J. Gan. 2011. Occurrence and toxicity of three classes of insecticides in water and sediment in two Southern California Coastal watersheds. Journal of Agricultural and Food Chemistry 59: 9448-9456. Lao, W.J., and J. Gan. 2011. Enantioselective degradation of warfarin in soils. Chirality (in press) Lu, Z.J., K.D. Lin, and J. Gan. 2011. Oxidation of bisphenol F (BPF) by manganese dioxide. Environmental Pollution 159: 2546-2551. Cui, X.Y., F. Jia, Y.X. Chen, and J. Gan. 2011. Influence of single-walled carbon nanotube on microbial availability of phenanthrene in sediment. Ecotoxicology 20:1277-1285. Budd, R., A. OGeen, K. Goh, S. Bondarenko, and J. Gan. 2011. Removal mechanisms and fate of insecticides in constructed wetlands. Chemosphere 83: 1581-1587. Lin, K.D., and J. Gan. 2011. Sorption and degradation of wastewater-associated non-steroidal anti-inflammatory drugs and antibiotics in soils. Chemosphere 83: 240-246. Cui, X.Y., W. Hunter, Y. Yang, Y.X. Chen, and J. Gan. 2011. Biodegradation of pyrene in sand, silt and clay fractions of sediment. Biodegradation 22:297307 Liu, W.P., H.H. Zhang, B.P. Cao, K.D. Lin, and J. Gan. 2011. Oxidative removal of bisphenol A using zero valent aluminum-acid system. Water Research 45: 1872-1878. Wang, W., L. Moreno, Q.F. Ye, and J. Gan. 2011. Improved measurements of partition coefficients for polybrominated diphenyl ethers (PBDEs). Environmental Science & Technology 45: 1521-1527. Jiang, W., J. Gan, and D. Haver. 2011. Sorption and desorption of pyrethroid insecticide permethrin on concrete. Environmental Science & Technology 45: 602-607. Derby, N., H. Hakk, F. Casey, and T. DeSutter. 2011. Effects of composting swine manure on nutrients and estrogens. Soil Sci. 176:91-98. Schuh, M.C., F.X.M. Casey, H. Hakk, T.M. DeSutter, K.G. Richards, E. Khan, and P. Odour. 2011. An on-farm survey of spatial and temporal stratifications of 17²-estradiol concentrations. Chemosphere 82:1683-1689. Schuh, M.C., F. Casey, H. Hakk, T.M. DeSutter, K.G. Richards, and E. Khan. 2011. Effects of field-manure applications on stratified 17²-estradiol concentrations. J. Haz. Mat. 192:748-752. 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