bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enzyme‐Linked Immunosorbent Assay for Ultratrace Determination of Antibiotics in Aqueous Samples
Authors: Kumar Kuldip , Thompson Anita , Singh Ashok K. , Chander Yogesh , Gupta Satish C. 
Published: July 2013

ABSTRACTTwo commercially available enzyme‐linked immunosorbent assay (ELISA) kits that are commonly used for tylosin or tetracycline residues in meat and milk were adapted for ultratrace analysis of these antibiotics in surface and ground waters. These two antibiotics are commonly fed to swine, turkeys, and cattle at subtherapeutic doses for growth promotion purposes. Both ELISA techniques were found to be highly sensitive and selective for the respective antibiotics with detection limits of 0.10 and 0.05 μg L−1 for tylosin and tetracycline, respectively. The recovery of both tylosin and tetracycline from spiked samples of lake waters, runoff samples, soil saturation extracts, and nanopure water was close to 100%. Tetracycline ELISA was highly specific for tetracycline and chlortetracycline but not for other forms of tetracycline (oxytetracycline, demeclocycline, and doxycycline). Analysis of a few liquid swine manure samples by liquid chromatography–mass spectrometry (LC–MS) showed lower concentrations for chlortetracycline as compared with concentrations obtained using ELISA. However, the concentrations of tylosin from ELISA were comparable with that of LC–MS. The lower concentrations of chlortetracycline obtained by LC–MS in manure samples indicate the presence of other similar or transformed compounds that were detected by ELISA but not determined by LC–MS. These results indicate that both ELISA kits can be useful tools for low‐cost screening of tylosin, tetracycline, and chlortetracycline in environmental waters. Furthermore, both ELISA procedures are rapid, portable, and easily adaptable for testing of multiple samples simultaneously.
Nutrient Retention Efficiency in Streams Receiving Inputs from Wastewater Treatment Plants
Authors: Marti Eugènia , Aumatell Jordi , Godé Lluís , Poch Manel , Sabater Francesc 
Published: July 2013

ABSTRACTWe tested the effect of nutrient inputs from wastewater treatment plants (WWTPs) on stream nutrient retention efficiency by examining the longitudinal patterns of ammonium, nitrate, and phosphate concentrations downstream of WWTP effluents in 15 streams throughout Catalonia (Spain). We hypothesized that large nutrient loadings would saturate stream communities, lowering nutrient retention efficiency (i.e., nutrient retention relative to nutrient flux) relative to less polluted streams. Longitudinal variation in ambient nutrient concentration reflected the net result of physical, chemical, or biological uptake and release processes. Therefore, gradual increases in nutrient concentration indicate that the stream acts as a net source of nutrients to downstream environments, whereas gradual declines indicate that the stream acts as a net sink. In those streams where gradual declines in nutrient concentration were observed, we calculated the nutrient uptake length as an indicator of the stream nutrient retention efficiency. No significant decline was found in dilution‐corrected concentrations of dissolved inorganic nitrogen (DIN) and phosphate in 40 and 45% of streams, respectively. In the remaining streams, uptake length (estimated based on the decline of nutrient concentrations at ambient levels) ranged from 0.14 to 29 km (DIN), and from 0.14 to 14 km (phosphate). Overall, these values are longer (lower retention efficiency) than those from nonpolluted streams of similar size, supporting our hypothesis, and suggest that high nutrient loads affect fluvial ecosystem function. This study demonstrates that the efficiency of stream ecosystems to remove nutrients has limitations because it can be significantly altered by the quantity and quality of the receiving water.
Bromide and Nitrate Movement through Undisturbed Soil Columns
Authors: Clay D. E. , Zheng Z. , Liu Z. , Clay S. A. , Trooien T. P. 
Published: July 2013

ABSTRACTField experiments often assume that Br−, 14NO−3–N, and 15NO−3–N have similar leaching kinetics. This study tested this assumption. Twenty‐four undisturbed soil columns (15‐cm diameter) were collected from summit–shoulder, backslope, and footslope positions of a no‐tillage field with a corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] rotation. Each of the landscape positions had a different soil series. After conditioning the columns with 4 L of 0.01 M CaCl2 (2 pore volumes), 15N‐labeled Ca(NO3)2 and KBr were applied to the soil surface and leached with 4 L of 0.01 M CaCl2 Leachate was collected, weighed, and analyzed for NO−3–N, NH4+–N, 15N, 14N, and Br− The total amount of 15NO−3–N and 14NO−3–N collected in 1000, 2000, and 3000 mL of leachate was similar. These data suggest that 15N discrimination during leaching did not occur. Bromide leached faster through the columns than NO−3–N. The more rapid transport of Br− than NO−3–Nwas attributed to lower Br− (0.002 ± 0.036 mg kg−1) than NO−3–N (0.17 ± 0.03 mg kg−1) sorption. Results from this study suggest that (i) if Br− is used to estimate NO−3–N leaching loss, then NO−3–N leaching losses may be overestimated by 25%; (ii) the potential exists for landscape position to influence anion retention and movement in soil; and (iii) 15N discrimination was not detected during the leaching process.
Fly Ash as a Liming Material for Cotton
Authors: Stevens Gene , Dunn David 
Published: July 2013

ABSTRACTA field experiment was conducted to determine the effect of fly ash from a coal combustion electric power facility on soil acidity in a cotton (Gossypium hirsutumL.) field. Fresh fly ash was applied to a Bosket fine sandy loam (fine‐loamy, mixed, thermic Mollic Hapludalf) soil with an initial soil pHsaltof 4.8. The fly ash was equivalent to 42 g kg−1calcium carbonate with 97% passing through a 60 mesh (U.S. standard) sieve. Fly ash was applied one day before cotton planting in 1999 at 0, 3.4, 6.7, and 10.1 Mg ha−1No fly ash was applied in 2000. Within 60 d of fly ash application in 1999, all rates of fly ash significantly increased soil pH above 6.0. Manganese levels in cotton petioles were reduced significantly by 6.7 and 10.1 Mg ha−1of fly ash. Soil boron (B) and sodium (Na) concentrations were significantly increased with fly ash. In 1999, B in cotton leaves ranged from 72 to 84 mg kg−1in plots with fly ash applications. However, no visual symptoms of B toxicity in plants were observed. In 1999, cotton lint yield decreased on average 12 kg ha−1for each Mg of fly ash applied. In 2000, cotton yields were significantly greater for the residual 3.4 and 6.7 Mg fly ash ha−1plots than the untreated check. Due to the adverse yield effects measured in the first year following application, fly ash would not be a suitable soil amendment for cotton on this soil at this time.
Carbon, Nitrogen Balances and Greenhouse Gas Emission during Cattle Feedlot Manure Composting
Authors: Hao Xiying , Chang Chi , Larney Francis J. 
Published: July 2013

ABSTRACTCarbon and N losses reduce the agronomic value of compost and contribute to greenhouse gas (GHG) emissions. This study investigated GHG emissions during composting of straw‐bedded manure (SBM) and wood chip‐bedded manure (WBM). For SBM, dry matter (DM) loss was 301 kg Mg−1, total carbon (TC) loss was 174 kg Mg−1, and total nitrogen (TN) loss was 8.3 kg Mg−1 These correspond to 30.1% of initial DM, 52.8% of initial TC, and 41.6% of initial TN. For WBM, DM loss was 268 kg Mg−1, TC loss was 154 kg Mg−1, and TN loss was 1.40 kg Mg−1, corresponding to 26.5, 34.5, and 11.8% of initial amounts. Most C was lost as CO2 with CH4 accounting for <6%. However, the net contribution to greenhouse gas emissions was greater for CH4 since it is 21 times more effective at trapping heat than CO2 Nitrous oxide (N2O) emissions were 0.077 kg N Mg−1 for SBM and 0.084 kg N Mg−1 for WBM, accounting for 1 to 6% of total N loss. Total GHG emissions as CO2–C equivalent were not significantly different between SBM (368.4 ± 18.5 kg Mg−1) and WBM (349.2 ± 24.3 kg Mg−1). However, emission of 368.4 kg C Mg−1 (CO2–C equivalent) was greater than the initial TC content (330.5 kg Mg−1) of SBM, raising the question of the net benefits of composting on C sequestration. Further study is needed to evaluate the impact of composting on overall GHG emissions and C sequestration and to fully investigate livestock manure management options.
Dredged Illinois River Sediments
Authors: Darmody R. G. , Marlin J. C. , Talbott J. , Green R. A. , Brewer E. F. , Stohr C. 
Published: July 2013

ABSTRACTSedimentation of the Illinois River in central Illinois has greatly diminished the utility and ecological value of the Peoria Lakes reach of the river. Consequently, a large dredging project has been proposed to improve its wildlife habitat and recreation potential, but disposal of the dredged sediment presents a challenge. Land placement is an attractive option. Previous work in Illinois has demonstrated that sediments are potentially capable of supporting agronomic crops due to their high natural fertility and water holding capacity. However, Illinois River sediments have elevated levels of heavy metals, which may be important if they are used as garden or agricultural soil. A greenhouse experiment was conducted to determine if these sediments could serve as a plant growth medium. A secondary objective was to determine if plants grown on sediments accumulated significant heavy metal concentrations. Our results indicated that lettuce (Lactuca sativaL.), barley (Hordeum vulgareL.), radish (Raphanus sativusL.), tomato (Lycopersicon lycopersicumL.), and snap bean (Phaseolus vulagarisL. var.humillis) grown in sediment and a reference topsoil did not show significant or consistent differences in germination or yields. In addition, there was not a consistent statistically significant difference in metal content among tomatoes grown in sediments, topsoil, or grown locally in gardens. In the other plants grown on sediments, while Cd and Cu in all cases and As in lettuce and snap bean were elevated, levels were below those considered excessive. Results indicate that properly managed, these relatively uncontaminated calcareous sediments can make productive soils and that metal uptake of plants grown in these sediments is generally not a concern.
Validation of the In Vitro Gastrointestinal (IVG) Method to Estimate Relative Bioavailable Lead in Contaminated Soils
Authors: Schroder J. L. , Basta N. T. , Casteel S. W. , Evans T. J. , Payton M. E. , Si J. 
Published: July 2013

ABSTRACTThe effect of the dosing vehicle (e.g., dough) on the ability of an in vitro gastrointestinal (IVG) method to predict relative bioavailable Pb associated with soil ingestion was evaluated. Bioaccessible Pb determined by the IVG method was compared with relative bioavailable Pb measured from dosing trials using juvenile swine for 18 contaminated soils ranging from 1270 to 14200 mg Pb kg−1 Bioaccessible Pb was measured in the IVG gastric extraction (GE) and intestinal extraction (IE) solutions. Mean bioaccessible Pb values were 32.2% for GE without dough, 23.0% for GE with dough, 1.06% for IE without dough, and 0.56% for IE with dough. It is possible that phytic acid associated with the dough addition decreased bioaccessible Pb. In vivo relative bioavailable Pb ranges for different swine tissues were 1 to 87% for blood, 0 to 110% for liver, 1 to 124% for kidney, and 0.04 to 94% for bone. Strong linear relationships between IVG GE Pb with dough (r > 0.76, P < 0.0002), IVG IE Pb with dough (r > 0.56, P < 0.015), and IVG GE Pb without dough (r > 0.81, P < 0.0001) and in vivo bioavailable Pb as estimated with blood, kidney, liver, and bone were found. Inexpensive in vitro methods may be useful in providing an estimate of the variability in relative bioavailable Pb at a single study site. The IVG method can be used to estimate relative bioavailable Pb, As, and Cd in contaminated soil.
Predicting Cadmium Concentrations in Wheat and Barley Grain Using Soil Properties
Authors: Adams M. L. , Zhao F. J. , McGrath S. P. , Nicholson F. A. , Chambers B. J. 
Published: July 2013

ABSTRACTThe entry of Cd into the food chain is of concern as it can cause chronic health problems. To investigate the relationship between soil properties and the concentration of Cd in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) grain, we analyzed 162 wheat and 215 barley grain samples collected from paired soil and crop surveys in Britain, and wheat and barley samples from two long‐term sewage sludge experiments. Cadmium concentrations were much lower in barley grain than in wheat grain under comparable soil conditions. Multiple regression analysis showed that soil total Cd and pH were the significant factors influencing grain Cd concentrations. Significant cultivar differences in Cd uptake were observed for both wheat and barley. Wheat grain Cd concentrations could be predicted reasonably well from soil total Cd and pH using the following model: log(grain Cd) = a + b log(soil Cd) − c(soil pH), with 53% of the variance being accounted for. The coefficients obtained from the data sets of the paired soil and crop surveys and from long‐term sewage sludge experiments were similar, suggesting similar controlling factors of Cd bioavailability in sludge‐amended or unamended soils. For barley, the model was less satisfactory for predicting grain Cd concentration (22% of variance accounted for). The model can be used to predict the likelihood of wheat grain Cd exceeding the new European Union (EU) foodstuff regulations on the maximum permissible concentration of Cd under different soil conditions, particularly in relation to the existing Directive and the proposed new Directive on land applications of sewage sludge.
Incubation Time Effects on Imazaquin Desorption as Determined by Nonequilibrium Thin‐Soil Disc Flow
Authors: Smith M. Cade , Shaw David R. , Massey Joseph H. , Boyette Michele , Kingery William 
Published: July 2013

ABSTRACTBecause organic sorption in soil may never reach equilibrium, a thin‐disc flow nonequilibrium method may be helpful in understanding herbicide–soil interactions. This research was conducted to (i) determine the influence of incubation time on imazaquin [2‐(4,5‐dihydro‐4‐methyl‐4‐(1‐methylethyl)‐5‐oxo‐1H‐imidazol‐2‐yl)‐3‐quinolinecarboxylic acid] desorption from soil, (ii) examine the influence of solution flow velocities on desorption, and (iii) elucidate the most appropriate kinetic model to describe imazaquin leaching. Soil at 7.5% moisture w/w was treated with imazaquin and incubated for 24, 72, and 168 h. Treated soil was sealed in an in‐line filter apparatus and rinsed with 5.0 mM CaCl2 at 0.33, 0.67, or 1.0 mL min−1 Effluent was collected as 1.0‐mL fractions for a total of 50 mL. Flow was stopped for 24 h. When flow resumed, fractions were collected for an additional 15 mL. After the initial desorption, 79% of the imazaquin incubated for 24 h was leached. Increasing incubation time beyond 24 h reduced imazaquin leaching. After both desorption events, 13% of the initially applied imazaquin remained in the soil incubated for 168 h, compared with 7% with soil incubated for 24 h. Elovich and Freundlich kinetics accounted for 98% of the variance observed in the imazaquin desorption curves. First‐order and diffusion kinetics accounted for 91% of the variance. Incubating soil for 72 h before desorption reduced the rate of imazaquin desorption by approximately 12%, compared with the 24‐h incubation treatment. Imazaquin desorption was not affected by wash solution flow rate. These data suggest that the kinetics of desorption in prolonged desorption events are limited by transport phenomena (i.e., particle and film diffusion).
Attenuation of Methane and Volatile Organic Compounds in Landfill Soil Covers
Authors: Scheutz Charlotte , Mosbæk Hans , Kjeldsen Peter 
Published: July 2013

ABSTRACTThe potential for natural attenuation of volatile organic compounds (VOCs) in landfill covers was investigated in soil microcosms incubated with methane and air, simulating the gas composition in landfill soil covers. Soil was sampled at Skellingsted Landfill at a location emitting methane. In total, 26 VOCs were investigated, including chlorinated methanes, ethanes, ethenes, fluorinated hydrocarbons, and aromatic hydrocarbons. The soil showed a high capacity for methane oxidation resulting in very high oxidation rates of between 24 and 112 μg CH4 g−1 h−1 All lower chlorinated compounds were shown degradable, and the degradation occurred in parallel with the oxidation of methane. In general, the degradation rates of the chlorinated aliphatics were inversely related to the chlorine to carbon ratios. For example, in batch experiments with chlorinated ethylenes, the highest rates were observed for vinyl chloride (VC) and lowest rates for trichloroethylene (TCE), while tetrachloroethylene (PCE) was not degraded. Maximal oxidation rates for the halogenated aliphatic compounds varied between 0.03 and 1.7 μg g−1 h−1 Fully halogenated hydrocarbons (PCE, tetrachloromethane [TeCM], chlorofluorocarbon [CFC]‐11, CFC‐12, and CFC‐113) were not degraded in the presence of methane and oxygen. Aromatic hydrocarbons were rapidly degraded giving high maximal oxidation rates (0.17–1.4 μg g−1 h−1). The capacity for methane oxidation was related to the depth of oxygen penetration. The methane oxidizers were very active in oxidizing methane and the selected trace components down to a depth of 50 cm below the surface. Maximal oxidation activity occurred in a zone between 15 and 20 cm below the surface, as this depth allowed sufficient supply of both methane and oxygen. Mass balance calculations using the maximal oxidation rates obtained demonstrated that landfill soil covers have a significant potential for not only methane oxidation but also cometabolic degradation of selected volatile organics, thereby reducing emissions to the atmosphere.
Degradation and Sorption of Metribuzin and Primary Metabolites in a Sandy Soil
Authors: Henriksen Trine , Svensmark Bo , Juhler René K. 
Published: July 2013

ABSTRACTLeaching to the ground water of metabolites from the herbicide metribuzin [4‐amino‐6‐(1,1‐dimethylethyl)‐3‐(methylthio)‐1,2,4‐triazin‐5‐one] has been measured in a Danish field experiment in concentrations exceeding the European Union threshold limit for pesticides at 0.1 μg/L. In the present work, degradation and sorption of metribuzin and the metabolites desamino‐metribuzin (DA), diketo‐metribuzin (DK), and desamino‐diketo‐metribuzin (DADK) were studied in a Danish sandy loam topsoil and subsoil from the field in question, using accelerated solvent extraction and liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis. Fast dissipation of metribuzin and the metabolites was observed in the topsoil, with 50% disappearance within 30 to 40 d. A two‐compartment model described degradation of metribuzin and DA, whereas that of DADK could be described using first‐order kinetics. Part of the dissipation was probably due to incorporation into soil organic matter. Degradation in subsoil occurred very slowly, with extrapolated half‐lives of more than one year. Sorption in the topsoil followed the order DA > metribuzin > DK > DADK. Subsoil sorption was considerably lower, and was hardly measurable for metribuzin and DK. Abiotic degradation was considerably higher in the topsoil than the subsoil, especially concerning the de‐amination step, indicating that organic matter may be related to the degradation process. The present results confirm observations of metribuzin and transformation product leaching made in the field experiment and demonstrate the need for knowledge on primary metabolites when assessing the risk for pesticide leaching.
Chemical Composition of Organic Matter in Extremely Acid, Lignite‐Containing Lake Sediments Impacted by Fly Ash Contamination
Authors: Chabbi A. , Rumpel C. 
Published: July 2013

ABSTRACTIn the Lusatian lignite mining district of eastern Germany, extremely acid lakes developed during ground water rising after exploitation of lignite in open‐cast mines. The reasons of plant colonization (Juncus bulbosus L.) of some lakes exhibiting moderate pH values while others remain extremely acid and unvegetated are unknown. Alkalinity gain may be achieved by addition of alkaline materials and/or decomposition of organic matter. Our objective was to examine fly ash deposition and the resulting changes in organic matter composition in the uppermost 0 to 5 cm of the sediment sampled from vegetated and unvegetated lakes. Bulk soil and particle size fractions were analyzed for elemental composition, magnetic susceptibility, and chemical structure of the organic matter by 13C solid‐state nuclear magnetic resonance (NMR) spectroscopy. The lignite content of the samples was estimated by 14C activity measurements. The pH values decreased with increasing depth and the changes in pH were found to be correlated with changes in magnetic susceptibility. Carbon and nitrogen contents were found to decrease with increasing depth. The C to N ratios are consistent with the (i) the presence of decomposing plant residues and/or microbial material such as algae in the upper 0 to 5 cm of the sediment and (ii) the dominance of lignite in the layers below this depth as confirmed by 14C activity measurements. The structural analyses of the particle size separates from the 0‐ to 5‐cm depth were consistent with the presence of organic matter derived from plant material. This study confirms that fly ash is an important source of alkalinity in the upper 0 to 5 cm of the sediment that enhanced plant growth and led to enrichment of the sediment with organic matter derived from plant material.
Reducing Atrazine Losses
Authors: Harman Wyatte L. , Wang E. , Williams J. R. 
Published: July 2013

ABSTRACTWater quality is being affected by herbicides, some allegedly harmful to human health. Under scrutiny is atrazine (1‐chloro‐3‐ethylamino‐5‐isopropylamino‐2,4,6‐triazine), a commonly used herbicide in corn (Zea mays L.) and sorghum [Sorghum bicolor (L.) Moench] production. Concentrations of soluble and adsorbed atrazine losses sometimes exceed the safe drinking water standard of 3 μg L−1 established by the USEPA. This study assesses the protective implications of runoff control structures and alternative crop farming practices to minimize atrazine losses. Using a computerized simulation model, APEX, the following four practices were the most effective with respect to the average atrazine loss as a percent of the amount applied: (i) constructing sediment ponds, 0.09%; (ii) establishing grass filter strips, 0.14%; (iii) banding a 25% rate of atrazine, 0.40%; and (iv) constructing wetlands, 0.45%. Other atrazine runoff management options, including adoption of alternative tillage practices such as conservation and no‐till as well as splitting applications between fall and spring, were marginally effective.
Phytoavailability of Biosolids Phosphorus
Authors: O'Connor G. A. , Sarkar D. , Brinton S. R. , Elliott H. A. , Martin F. G. 
Published: July 2013

ABSTRACTEfficient utilization of biosolids P for agronomic purposes requires accounting for differences in the phytoavailability of P in various biosolids. Greenhouse studies were conducted with a common pasture grass grown in two P‐deficient soils amended with 12 biosolids and a commercial fertilizer (triple superphosphate, TSP) to quantify P uptake and to assess the relative phytoavailabilities of the P sources. Biosolids were grouped into three general categories of phytoavailability relative to TSP: high (>75% of TSP), moderate (25–75% of TSP), and low (<25% of TSP). Two biosolids, produced via biological phosphorus removal (BPR) processes, were in the high category, and mimicked fertilizer P with regard to P phytoavailability. Most biosolids produced by conventional wastewater and solids digestion and additional treatments like composting were in the moderate category. Also included in this category was a BPR that had been pelletized and another BPR supplemented with Al. The low category included biosolids containing greater than normal (>50 g kg−1) total Fe and Al concentrations and processed to high (>60%) solids content.