bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sorption of Organic Chemicals by Microfilters
Authors: Xing Baoshan , Jin Zhaowei 
Published: July 2010

AbstractInline syringe microfilters are often used for separating solid particles from the solution phase in environmental research and sample preparation for high performance liquid chromatography (HPLC) analysis; but only limited information is available for retention of organic compounds by these microfilters. We here report on the results of naphthalene and toluene sorption by five polymer microfilters. The five filters had different polymers makeup for their membrane and housing and were: (i) nylon‐polypropylene (NY‐PP); (ii) borosilicate glass‐acrylic (BA‐AC); (iii) polyethersulfonc‐acrylic (PS‐AC); (iv) polyvinylidene difluoride‐polypropylene (PV‐PP); and (v) PTFE‐polypropylene (PT‐PP). Six aqueous concentrations over three orders of magnitude were used. All filters received five or six passages with each concentration solution. All of the five filters sorbed both naphthalene and toluene and sorption was largest at the first passage and declined with increasing number of passages. The sorption order of naphthalene (average of six concentrations at the first passage) was: BA‐AC (98%) > PV‐PP (93%) > NY‐PP (64%) > PS‐AC (49%) > PT‐PP (13%) and toluene was: BA‐AC (56%) > PV‐PP (25%) > PT‐PP (22%) ≥ PS‐AC (20%) = NY‐PP (20%). The magnitude sorption was generally independent of concentrations. These results suggest that suitability of polymer filters must be determined before actual use in environmental sampling and research involving organic chemicals, particularly ones with low solubility and polarity.
Advanced Information Technologies for Assessing Nonpoint Source Pollution in the Vadose Zone: Conference Overview
Authors: Corwin D. L. , Loague K. , Ellsworth T. R. 
Published: July 2010

AbstractThe information age has ushered in an awareness of and concern for global environmental problems such as climatic change, ozone depletion, deforestation, desertification, and nonpoint source (NPS) pollution. Nonpoint source pollution is the single greatest threat to surface and subsurface drinking water resources. Nonpoint source pollutants also pose a threat to sustainable agriculture, which is viewed as the most viable means of meeting the food demands of a world population that is expected to reach 9.4 billion by the middle of the next century. The ability to accurately assess present and future NPS pollution impacts on ecosystems ranging from local to global scales would provide a powerful tool for environmental stewardship and guiding future human activities. Assessing NPS pollutant is a multidisciplinary problem. To address the problem, advanced information technologies and methodologies are needed that draw from all areas of science and are applied in a spatial context. It was from this setting that the 1997 Joint AGU Chapman/SSSA Outreach Conference Application of GIS, Remote Sensing, Geostatistics, and Solute Transport Modeling for Assessing Nonpoint Source Pollutants in the Vadose Zone (19–24 Oct. 1997, Riverside, CA) materialized. The objective of the conference was to examine current multidisciplinary technologies and methodologies for assessing NPS pollutants in the vadose zone, and to explore new conceptual approaches. It was the conference's goal to provide a forum to stimulate multidisciplinary interaction to enhance the development of techniques for the real‐time measurement and modeling of NPS pollution in the vadose zone and subsurface waters.
DBCP Contaminated Groundwater: Hot Spots and Nonpoint Sources
Authors: Loague Keith , Abrams Robert H. 
Published: July 2010

AbstractThe regional‐scale nonpoint source (NPS) solute transport simulations reported by Loague et al. (1998a,b), for DBCP (1,2‐dibromo‐3‐chloropropane) for east‐central Fresno County (California), are the foundation of the work reported in this paper. This effort is divided into two phases. In the first phase we revisit our coupled 3‐D deterministic‐conceptual simulations of groundwater vulnerability for the Fresno study area (Loague et al., 1998a,b) and quantitatively evaluate the model performance by rigorously comparing the simulated DBCP concentrations, in both space and time, with field observations. The regional‐scale simulation results presented here indicate tremendous spatial and temporal variability in the estimates of DBCP loading at the water table based on NPS applications and illustrate a potential long‐term evolution scenario for the DBCP plume in the study area. The simulations presented here suggest that NPS applications of DBCP may not be totally responsible for all the observed hot spots in the Fresno County study area. Reverse flow path and forward solute transport simulations, with MODPATH and MT3D, respectively, were used in the second phase of this effort to determine if the isolated, high DBCP concentrations were likely to be the result of NPS applications. Unreasonably high simulated application rates were needed to generate a targeted observed DBCP hot spot if the sole source of the high concentrations was due to NPS agricultural applications. Potential sources for the DBCP contaminated groundwater, other than NPS label‐recommended application rates, are discussed.
Solubility and Ion Activity Products of Calcium Phosphate Minerals
Authors: Jaynes W. F. , Moore P. A. , Miller D. M. 
Published: July 2010

AbstractMost phosphate mineral solubility data in use were measured more than 20 yr ago when instrumentation and methods were generally less sophisticated. The objective of this study was to measure calcium phosphate mineral solubilities using modern analytical equipment and techniques. Natural and synthetic Ca phosphate minerals (<50 µm) were equilibrated in water and dilute HCl for 6 mo with continuous agitation. X‐ray diffraction (XRD) was used to identify compositions before and after equilibration. Filtered (<0.2 µm) solution aliquots were analyzed for pH and chemistry. Chemical compositions were determined using inductively‐coupled plasma spectroscopy (ICP). Aqueous carbonates were determined from alkalinity titrations after phosphate alkalinity corrections. The chemical speciation model “Soilchem” was used to calculate free ion concentrations and ionic strengths. Ion activity products (IAPs) were determined from free ion concentrations and single ion activity coefficients. Experimental log IAPs of monetite (CaHPO4) were consistent (−6.60) with published values for brushite (CaHPO4·2H2O) suggesting that the IAPs of these minerals are identical. No change in mineralogy during equilibration was revealed by XRD. Experimental log IAPs of synthetic whitlockite (−30.74, β‐Ca3(PO4)2) indicated somewhat lower solubility than published values. Log IAPs of synthetic hydroxyapatite (−56.02, Ca5(PO4)3OH) were within the range of published values. Natural samples of whitlockite and fluorapatite did not attain equilibrium due to extraneous siderite (FeCO3) and silica phases within the samples. A long equilibration time, modern analytical equipment, and a chemical speciation program can yield more reliable solubility data for phosphates and other minerals.
Bioavailablility of Heavy Metals in Strongly Acidic Soils Treated with Exceptional Quality Biosolids
Authors: Basta N. T. , Sloan J. J. 
Published: July 2010

AbstractNew federal regulations may increase application of exceptional quality (EQ) biosolids to acidic soils, and information on the effect of this practice on bioavailability of heavy metal is limited. The objective of this study was to compare bioavailability of heavy metal in soil treated with nonalkaline or alkaline EQ biosolids with limestone‐treated soils. Three acidic soils (pH 3.7–4.3) were treated with three amounts of lime‐stabilized biosolids (LS), anaerobic‐digested biosolids (AN), or agricultural limestone (L), and incubated 25°C. Soil solution Cd, Zn, and other chemical constituents were measured at 1, 30, 90, and 180 d incubation. Chemical fractionation of heavy metal was performed after 180 d incubation. Soil solution Cd and Zn were AN > LS ≥ L, C. Soil solution Cd and Zn increased with AN applied but decreased with LS applied. The high application of LS had soil solution Zn equal to that obtained using limestone. Soil solution Cd and Zn dramatically decreased at soil pH >5.5 and >5.1, respectively. Soil solution Cd and Zn increases were AN > LS with incubation time. Biosolids treatments increased heavy metal in Ca(NO3)2 and NaOAc fractions. Except for Cd, most metal from biosolids were in EDTA and HNO3 fractions. Heavy metal bioavailability, measured using lettuce (Lactuca sativa L.), was AN > LS ≥ L, C. Although state regulations prohibiting application of nonalkaline EQ biosolids to acidic soil is a prudent practice, application of EQ alkaline biosolids that achieves soil pH >5 minimizes risk from soil solution Cd and Zn and plant uptake of heavy metal.
Trace Element Solubility from Land Application of Fly Ash/Organic Waste Mixtures
Authors: Jackson B. P. , Miller W. P. , Schumann A. W. , Sumner M. E. 
Published: July 2010

AbstractUse of fly ash (FA) as a soil amendment is hindered by a lack macronutrients in the ash and concerns about trace element availability. Mixing FA with an organic waste can increase macronutrients while reducing odor and improving material handling, but the trace element solubility requires investigation. This study examined the trace element solubility and availability resulting from land application of such mixed wastes. Two FAs were applied as mixtures with either poultry litter (PL) or sewage sludge (SS) to field plots at rates 100 and 120 Mg ha−1 for FA/PL and FA/SS, respectively. Suction cup lysimeters were used to collect soil solution, and trace element uptake was monitored in maize (Zea mays L.) leaf tissue and grain. Soluble B was initially >25 mg L−1 for one high B FA/PL mixture and led to initial toxicity in seedlings. Soil solution concentrations of dissolved C, P, As, Se, Mo, Cu, and Cr were increased in FA/PL field plots. For P, C, As, and Cu, increased solubility was due to increased load in the FA/PL mixtures, while for Mo, Se, and Cr, mixing fly ash with poultry litter appeared to increase solubilization from the ash when compared with an equivalent mass of FA mixed with sewage. Leaf tissue data confirmed an increase in available As from the FA/PL mixtures, while leaf tissue Se was more dependent on the total Se concentrations of the ash.
The Effects of Pocket Gopher Burrowing on Water Balance and Erosion from Landfill Covers
Authors: Hakonson T. E. 
Published: July 2010

AbstractA 2‐yr field study was conducted to evaluate the impact of burrowing and soil casting by pocket gophers (Thomomys bottae) on runoff, soil loss (mass and size distribution), soil moisture status, and transport of stable cesium (133Cs) that was applied to the soil surface. A rotating boom rainfall simulator was used on 3.1 by 10.9 m landfill cover plots with and without vegetation and with and without pocket gopher burrowing. Gopher burrowing in the presence of vegetation resulted in large decreases in runoff, erosion, and cesium loss via erosion but increased migration of cesium to the subsurface soil due to increased infiltration. Vegetation slightly decreased runoff but greatly decreased erosion and cesium loss by erosion. As with gophers, vegetation enhanced movement of cesium into the soil. Under the conditions of this study, the effects of pocket gopher burrowing in degrading a landfill cover were minimal when vegetation was a component of the cover.
Impact of Land Use on Microbial Transformations of Atrazine
Authors: Aelion C. Marjorie , Cresci Dana C. 
Published: July 2010

AbstractAtrazine has been one of the most heavily applied preemergent herbicides in the USA, and with alachlor, represents more than 45% (4.082 × 106 kg) of total herbicide application in coastal U.S. counties. Several studies using bacterial isolates or mixed cultures have demonstrated that mineralization of atrazine [6‐chloro‐N‐ethyl‐N′‐(1‐methyl‐ethyl)‐1,3,5‐triazine‐2,4‐diamine] is rapid, yet in soil microcosms mimicking in situ conditions, mineralization accounts for <1% of the applied compound. This study examined the impact of land use on atrazine biotransformation in sediments from three coastal sites, all in an historically agricultural area that has undergone extensive development in recent years. Production of 14CO2 was monitored in sediment incubated with [U‐14C]‐atrazine from a forested preserve, a suburban neighborhood and a golf course, all of which were previously impacted by agriculture. Solid phase extraction of both liquid and sediment fractions was carried out over time to determine whether metabolic transformation of atrazine occurred. Results indicated that mineralization represented <1% of the atrazine added, and ring carbons were not assimilated into cellular biomass. Production of 14C‐transformation products was a significant portion of the total 14C‐atrazine added at all sites, but was greatest in the golf course sediments. This may be attributed to several environmental conditions of land development such as the preexposure of the golf course bacteria to frequent pesticide applications, and 100% sand content of the golf course sediment vs. higher clay and organic C content at the other two sites, causing less sorption and more bioavailability of atrazine.
Dust and Endosulfan Deposition in a Cotton‐Growing Area of Northern New South Wales, Australia
Authors: Larney Francis J. , Leys John F. , Müller Jochen F. , McTainsh Grant H. 
Published: July 2010

AbstractThe pesticide endosulfan (6,7,8,9,10,10‐hexachloro‐1,5,5a,6,9,9a‐hexahydro‐6,9‐methano‐2,4,3‐benzodioxathiepin‐3‐oxide) has been detected in rivers in the cotton (Gossypium hirsutum L.)‐growing area of northern New South Wales at a 5 yr mean (1991–1995) concentration of 0.06 µg L−1. One pathway by which endosulfan reaches the riverine environment is transport on contaminated dust. Our objectives were to examine: (i) dust deposition from vehicular traffic on an unsealed road on a cotton farm, and around a cotton field in the 11 to 65 h period after endosulfan application; (ii) endosulfan deposition in the 11 to 65 h period after endosulfan application, and over a 3‐mo period at on‐farm and off‐farm (nontarget) locations. Dust deposition rates from vehicular traffic varied from 0.013 g m−2 vehicle−1 at 1 m distance, to 0.002 g m−2 vehicle−1 at 100 m distance from an unsealed road (soil surface, no gravel added). The maximum endosulfan deposition in the 11 to 65 h post‐spraying period was 95 µg m−2 at 5 m from the field. Over a 3‐mo monitoring period (December 1996–March 1997), the average daily deposition rate of endosulfan was 0.16 µg m−2 d−1 for the off‐farm sites compared with 0.35 µg m−2 d−1 for the on‐farm site. As the measurement period was one of the wettest on record and the number of endosulfan applications was less‐than‐normal, the dust and endosulfan deposition results may be interpreted as minima.
Nitrogen Mineralization in a Mature Boreal Forest, Isle Royale, Michigan
Authors: Stottlemyer Robert , Toczydlowski David 
Published: July 2010

AbstractThe 115‐ha boreal Wallace Lake watershed, located on Isle Royale in the Lake Superior Basin, receives moderate anthropogenic atmospheric N inputs (3 kg ha−1 yr−1). Ecosystem response to atmospheric N inputs is, in part, determined by internal production and consumption of this limiting nutrient. The objectives of this 2‐yr study on plots dominated by birch, spruce, or alder were to quantify forest floor and surface soil net and gross N mineralization rates, and examine potential effects of changes in temperature and moisture on these processes. Gross N mineralization rates were 23 times net mineralization rates, and increased with forest floor/soil temperature and moisture. Substrate quality was a likely factor in higher gross mineralization rates beneath birch and spruce. Ammonium immobilization increased with forest floor/soil temperature and moisture. Higher net N mineralization rates beneath alder resulted from lower microbial immobilization rather than greater gross N mineralization. The greatest differences between gross N mineralization and immobilization occurred in early summer. Ammonium immobilization averaged 62% of gross N mineralization. Net and gross nitrification rates differed by vegetation type, were highest in spring and fall, and increased with moisture. Gross nitrification was 19 times net nitrification rates. Nitrate immobilization increased with soil moisture, and equalled or exceeded gross nitrification. Net and gross N mineralization or nitrification rates were not correlated. Seasonal variation in forest floor and surface soil N cycling coupled with high ecosystem retention of precipitation N inputs suggest streamwater N concentrations and output reflect trends in soil processes.
On‐Line Solid Phase Extraction for Polycyclic Aromatic Hydrocarbons in Soil Column Effluents
Authors: Weigand Harald , Totsche Kai U. , Kögel‐Knabner Ingrid 
Published: July 2010

AbstractOn‐line solid phase extraction with C‐18 cartridges provided a reliable method for the extraction of polycyclic aromatic hydrocarbons (PAHs) from soil column effluents. The on‐line extraction was compared to the common off‐line extraction of effluent fractions with respect to the mass recoveries of an internal standard. The effluent was obtained from a water unsaturated soil column under steady state water flow conditions. The column was packed with an artificially anthracene‐contaminated soil material. Our results showed superior and more reproducible PAH trapping when the on‐line extraction was used. The PAH mass recoveries were unaffected by the range of dissolved organic carbon (DOC) concentrations covered in the experiment. This held true over a range of pHs and water unsaturated conditions of the C‐18 material. By using the on‐line extraction procedure, losses of PAHs due to sorption to the surfaces of collection vessels were avoided. The combination with a fraction collector allowed for the extraction of very small sample volumes. Thus, the method is suitable for an unbiased evaluation of PAH mobility in soil column experiments.
Adsorption of Selected Pesticides on a Rigid PVC Lysimeter
Authors: Koskinen W. C. , Cecchi A. M. , Dowdy R. H. , Norberg K. A. 
Published: July 2010

AbstractLysimeters have traditionally been made out of stainless steel and teflon to monitor soil solutions and groundwater. The possibility of adsorption of organic chemicals to polyvinyl chloride (PVC) lysimeters, a more economical alternative to stainless steel, has led to debate over their suitability for groundwater sampling. The adsorption of different pesticide chemistries, chloroacetanilide (alachlor (2‐chloro‐N‐(2,6‐diethylphenyl)‐N‐(methoxymethyl)acetamide)), s‐triazine (atrazine (6 ‐ chloro ‐ N ‐ ethyl ‐ N′‐1‐methylethyl)‐1‐3‐5‐triazine‐2,4‐diamine)), chloronicotinyl (intidacloprid (1‐[(6‐chloro‐3‐pyridinyl)‐methyl]‐N‐nitro‐2‐imidazolidinimine)), organophosphorus (isofenphos (1‐methylethyl 2‐[[ethoxy[(1‐methylethyl)amino]phosphinothioyl] oxy]benzoate)), sulfonylurea (nicosulfuron (2‐[[[[(4,6‐dimethoxy‐2‐pyr‐imidinyl) amino ] carbonyl]amino]sulfonyl]‐N,N‐dimethyl ‐3‐pyridine carboxamide)), and azole (triadimefon (1‐(4‐chlorophenoxy)‐3,3‐dimethyl‐1‐(1H‐1,2,4‐triazol‐1‐yl)‐2‐butanone)), on a lysimeter constructed from rigid PVC was determined to evaluate the suitability of PVC material for use in groundwater sampling. Among all pesticides tested, only isofenphos demonstrated slight adsorption (9% of applied) on the lysimeter; adsorption was rapid and isophenfos was not easily desorbed with methanol and water. None of the other pesticides adsorbed to the lysimeter. When selecting a lysimeter, potential adsorptive interactions between other pesticide chemistries and the materials used in the lysimeter construction should be evaluated.
Drilling Fluid Effects on Crop Growth and Iron and Zinc Availability
Authors: Bauder T. A. , Barbarick K. A. , Shanahan J. F. , Ayers P. D. , Chapman P. L. 
Published: July 2010

AbstractWaste drilling fluids are often land‐farmed following completion of an oil or gas well in Colorado. This material usually contains production water, bentonitic clays, formation cuttings, barite, Na compounds, and synthetic organic polymers. We investigated the effects of 5 to 60 dry g drilling fluid kg−1 soil on the growth and trace metal concentration of sorghum—sudangrass (Sorghum bicolor L. Moench ‘DeKalb ST‐6’—S. sudanense) in the greenhouse. A nonlinear regression exponential‐rise model fit the increased plant total dry matter yield response to increasing drilling fluid rates. Increased plant tissue Fe concentration and uptake (P < 0.05) indicated that increased plant‐available Fe was primarily responsible for the yield response, but increased Zn availability was also suspected. Results from a second greenhouse study confirmed that drilling fluid can also correct Zn deficiency in corn (Zea mays L.). Soil SAR (sodium adsorption ratio) was higher with increasing drilling fluid, but was still <1. Other trace‐element concentrations in sudangrass tissue and soil pH and ECsat were not significantly increased due to application of drilling fluid. This study showed that application of controlled rates of water‐based drilling fluid from operations in Weld County, Colorado, was beneficial to the growth of sorghum—sudangrass and provided evidence that land application is an acceptable method of disposal.
Phosphorus Storage on Effluent Irrigated Land
Authors: Menzies N. W. , Skilton J. A. , Guppy C. N. 
Published: July 2010

AbstractLand disposal of secondary treated sewage effluent is being widely adopted in Australia as an alternative to tertiary treatment. At the Cleveland Waste Water Pollution Control Works, effluent has been applied to a Hapludalf at high rates (3000 mm yr−1) for more than 20 yr, adding an estimated 4.5 t P ha−1 to the soil. Thus, this site provides an opportunity to assess the retention of P under conditions typical of southeast Queensland. Laboratory chemical fractionation and P sorption studies of effluent irrigated and control sites were undertaken to determine the amount and forms of P retained within this soil and its capacity to retain further P. Organic material (peat) which had accumulated on the surface of effluent irrigated plots, was also sampled and its P content determined. Accumulation of P was limited to the sandy surface soil, increasing total soil P content by ≈ 700 kg ha−1, with this increase being approximately evenly distributed between inorganic and organic pools. The excessive irrigation rate used on this site, and the management adopted, has resulted in a marked podzolization of the surface horizon, apparent in reduced extractable Fe and Al concentrations. The removal of these P adsorbing materials would contribute, along with P saturation and organic ligand competition, to the much lower P sorption capacity of irrigated sites relative to the control. The largest P pool was found to be the peat layer, containing approximately 1500 kg P ha−1. On this site P has accumulated principally in organic forms, both within the soil and as peat on its surface. This finding throws into question the common practice of predicting disposal scheme life on the basis of P adsorption curves.