bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transport of Cryptosporidium parvum Oocysts through Saturated Columns
Authors: Brush Charles F. , Ghiorse William C. , Anguish Lynne J. , Parlange Jean‐Yves , Grimes Hilary G. 
Published: July 2010

AbstractTransport of Cryptosporidium parvum oocysts through three substrates was used to determine dispersion, retardation, and first‐order decay parameters for the convective dispersion equation (CDE). Pulses of diluted Holstein calf feces containing oocysts were passed through saturated columns packed with either glass beads, coarse sand, or shale aggregate. Effluent chloride breakthrough curves (BTCs) were used to fit pore water velocities and dispersions for each column to the CDE. These pore water velocities were then used to fit dispersion, retardation and first‐order decay factors to the CDE for C. parvum oocyst BTCs for each column. Dispersion coefficients for oocysts averaged 0.8 cm2 s−1 in glass beads, 1.7 cm2 s−1 in sand, and 1.3 cm2 s−1 in shale aggregate. The ratio of oocyst dispersion to chloride dispersion was <1 for all substrates, suggesting oocysts experienced less shear and turbulence than the pore water. Diffusivities of 0.07 cm for glass beads, 0.15 cm for sand, and 0.09 cm for shale aggregate show that facilitated transport in sand was greater than in the other two substrates. Retardation coefficients for oocysts averaged 1.0 in glass beads and sand and 0.9 in shale aggregate, indicating oocysts did not adhere to these substrates. First‐order decay coefficients of 0.5 s−1 for glass beads, 0.8 s−1 for sand, and 0.6 s−1 for shale aggregate indicate significantly higher removal rates in the sand columns. These data suggest oocysts may travel significant distances in both subsurface and overland flow.
Agricultural‐Nitrogen Contributions to Hypoxia in the Gulf of Mexico
Authors: Burkart Michael R. , James David E. 
Published: July 2010

AbstractNitrate (NO3) is the principal nutrient transported through the Mississippi River basin that is related to hypoxia in the Gulf of Mexico. Agriculture is a major contributor to the N load. Knowledge of the geographic distribution of NO3 sources and losses within the basin is critical to understanding the problem and identifying potential solutions. This paper defines the geographic distribution, by hydrologic unit, of major agricultural sources and dominant losses of N in the basin. Sources include imported N such as inorganic fertilizer, manure, and atmospheric deposition, and in situ sources such as mineralized N from soil organic matter, N2 fixed by legumes, and redeposition of locally derived ammonia (NH3). The dominant N losses include crop harvests, losses to the atmosphere through volatilization of manure and inorganic fertilizer, plant senescence, and denitrification of soil NO3. National data bases used in the analysis include the State Soils Geographic Database, 1992 Census of Agriculture, and the National Atmospheric Deposition Program/National Trends Network. The hydrologic units with the largest residual N contributions available to streams are located in the Upper Mississippi River and the Ohio River basins. Mineralizable soil N, inorganic N fertilizer, legume fixation, and redeposition of locally derived NH3 constitute the major sources in this part of the basin, although manure is a minor source. However, these northern hydrologic regions use a greater fraction of the sources to produce crop N than do the southern hydrologic regions. Residual contributions to the Tennessee, Arkansas/Red, and Lower Mississippi hydrologic regions are greatest when analyzed as a percentage of the total sources.
Poultry Litter and Grazing Animal Waste Effects on Runoff Water Quality
Authors: Sauer T. J. , Daniel T. C. , Moore P. A. , Coffey K. P. , Nichols D. J. , West C. P. 
Published: July 2010

AbstractIn complex landscapes with multiple land uses, it is often difficult to identify the source of contaminant loadings. The objective of this study was to compare nutrient runoff as affected by grazing animal depositions vs. poultry litter application. Simulated rainfall was applied twice to 1.5 by 6.0 m runoff plots of tall fescue (Festuca arundinacea Schreb.) with treatments of no waste (CT), dairy calf feces and urine (DFU), poultry litter (PL), and dairy calf feces and urine with poultry litter (DFU + PL). Chemical properties of the runoff samples including pH, electrical conductivity (EC), C, soluble reactive phosphorus (SRP), total nitrogen (TN), NH4‐N, NO3‐N, K, Mg, S, B, Cu, Fe, Mn, Mo, Na, and Zn were determined. Plots receiving poultry litter had significantly greater losses of most nutrient parameters for both rainfall simulations. For the nutrient parameters of primary interest with regard to water quality, 5.0, 29.5, and 21.9% of the TN, NH4‐N, and SRP applied in the PL treatment were transported in runoff during the first rainfall simulation as compared to 3.9, 5.0, and 15.3%, respectively, for the DFU treatment. Comparable percentages of the applied nutrients were lost from the PL and DFU treatments even though the PL treatment, with the exception of NH4‐N, provided at least six times the amount of each nutrient. A severe rainfall event shortly after poultry litter application produces significantly greater nutrient losses as compared to similar application of grazing animal depositions at the rates used in the experiment.
Site‐Specific Sorption Values for Mixtures of Volatile and Semivolatile Organic Compounds in Sandy Soils
Authors: Carmichael Lisa M. , Smith Tom G. , Pardieck Daniel L. 
Published: July 2010

AbstractThe purpose of this work was to determine site‐specific partition coefficients, Kd values, for the sorption and desorption of a mixture of 11 volatile and semivolatile organic compounds (VOC and SVOC) in subsurface, low organic soils (average site ƒOC = 0.00019) and ground water from the Toms River superfund site in southern New Jersey. Although literature Kd values are available for some of these compounds, many of the previously published values were measured with single compounds instead of a mixture of compounds. Kd values were determined via column desorption studies using soils with preexisting contamination and uncontaminated site ground water via retardation factors and via batch sorption studies with contaminated ground water and uncontaminated soils. Partition coefficients estimated from the batch and column studies were usually not different across VOC/SVOC and were usually not related to solubility characteristics of the target compounds. Kd values derived from the column experiments were usually an order of magnitude smaller than those estimated from the batch studies. Estimates of Kd values through log KOW or water solubility relationships were usually greater than the experimentally derived Kd values, especially for those compounds with log KOW values greater than 3. Predicted Kd values from the partition models were similar to calculated values for the less hydrophobic compounds (Log KOW < 3). In addition, Kd values determined from batch and column studies were usually smaller than literature values. These comparisons suggest that determining site‐specific partition coefficients is necessary for hydrophobic compounds in soils or sediments that have low organic carbon contents.
Influence of Land Use and Hydrology on Exports of Carbon and Nitrogen in a Maine River Basin
Authors: Cronan C. S. , Piampiano J. T. , Patterson H. H. 
Published: July 2010

AbstractThe influences of land use patterns and hydrology on element transport were examined in the Aroostook River Basin of northern Maine. The drainage area contains 80% forest, 13% agriculture, 5% wetland cover, 2% surface water, and <0.5% urban development. Surface water chemistry in the Aroostook River and 18 tributary streams varied with geologic conditions, land use, and seasonal hydrology. Concentrations of Ca2+, Mg2+, NO−3, Cl−, SOl2−4, and suspended solids were up to an order of magnitude higher in streams draining agricultural watersheds, compared to tributaries with forest and wetland cover. Mean concentrations of dissolved organic carbon (DOC) were 50% higher in tributaries dominated by forest and wetland cover, as compared to those with extensive agriculture. Dissolved organic carbon in streams influenced by agriculture was proportionately enriched in lower molecular weight solutes (<1000 Da) and depleted in higher molecular weight fractions (>10 000 Da). Daily export of DOC by the Aroostook River varied over nearly three orders of magnitude from maximum values of 890 000 kg C d−1 in November to minimum values of 1600 kg C d−1 in September. Peak fluvial exports of suspended solids in the Aroostook River amounted to 870 000 kg d−1. Annual runoff exports of inorganic N ranged 10‐fold from 0.7 kg N ha−1 yr−1 in forested watersheds to 7.2 kg N ha−1 yr−1 in agricultural watersheds, and amounted to approximately 1 × 106 kg N yr−1 for the entire river basin.
Pesticide and Nitrate Transport into Subsurface Tile Drains of Different Spacings
Authors: Kladivko E. J. , Grochulska J. , Turco R. F. , Van Scoyoc G. E. , Eigel J. D. 
Published: July 2010

AbstractLeaching of agrichemicals into subsurface tile drainage water is a concern for water quality. The objective of this 3‐yr study was to determine field‐scale pesticide and nitrate (NO3) losses to instrumented subsurface drains as affected by drain spacing (5, 10, and 20 m). Small amounts of carbofuran [2,3‐dihydro‐2,2‐dimethyl‐7‐benzofuranyl‐methylcarbamate]; atrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine]; cyanazine [2‐chloro‐4‐(1‐cyano‐1‐methyl‐ethyl‐amino)‐6‐ethylamino‐s‐triazine]; and alachlor [2‐chloro‐2′,6′‐diethyl‐N‐(methoxymethyl) acetanilide] were detected in subsurface drainflow in the first large rainstorm after chemical application, which occurred between 3 to 14 d after applications and produced 0.2 to 1.0 cm net drainflow. Annual carbofuran losses in subsurface drainflow ranged from 0.6 to 28.1 g ha−1, or 0.04 to 1.9% of the amount applied to the soil, depending on year and drain spacing. Losses of all other pesticides were ≤0.1% of the amount applied. Total mass of pesticides, NO3‐N, and water removed by subsurface drains on a per‐area basis was greatest for the 5‐m spacing and least for the 20‐m spacing. Annual NO3‐N losses to drainflow ranged from 14 to 105 kg ha−1 during the 1988 to 1991 period. The data indicate that preferential flow may be the primary mechanism of pesticide leaching to shallow ground water in silt loam soils, but that total amounts leached are often quite small. Conversely, NO3‐N leaching is most significant during the off‐season, when most of the drainflow occurs.
A Statistical Approach for Estimating the Radiocesium Interception Potential of Soils
Authors: Waegeneers N. , Smolders E. , Merckx R. 
Published: July 2010

AbstractThe solid‐liquid distribution of radiocesium (137Cs) varies extensively among soil types. A statistical approach was used to relate 137Cs sorption with soil properties. Eighty‐eight pasture soils were sampled in Belgium. All soil samples were characterized for texture, cation exchange capacity, exchangeable K, Ca, and Mg content, pH and organic C content. Soil samples were equilibrated in a 10−1 M CaCl2 — 5.10−4 M KCl solution. Adsorption of 137Cs was measured after 16 h in this medium. The solid‐liquid concentration ratio, KD, of 137Cs in this specific ionic scenario allows for the calculation of the Radiocesium Interception Potential (RIP), which in turn can be used for KD predictions for a wide range of different ionic scenarios. The RIP varied from 54 to 11 200 mmolc kg−1. Stepwise multiple regression between RIP and soil characteristics yielded statistically significant models (P < 0.001) for samples from each northern and southern Belgium. For northern Belgium the regression model only included texture fractions (R = 0.86, n = 62) whereas for southern Belgium the regressors were texture fractions and soil pH (R = 0.88, n = 26). The correlations between the RIP and soil characteristics depend strongly on the geological origin of the soil.
Selenium Volatilization and Accumulation by Twenty Aquatic Plant Species
Authors: Pilon‐Smits E. A. H. , de Souza M. P. , Hong G. , Amini A. , Bravo R. C. , Payabyab S. T. , Terry N. 
Published: July 2010

AbstractAquatic plants can remove selenium (Se) from agricultural or industrial wastewater through Se accumulation and volatilization, that is, the conversion of selenate or selenite to volatile forms of Se. To identify aquatic plant species that will be good at removing Se from contaminated water, 20 plant species were screened for their ability to accumulate and volatilize Se when supplied with 20 µM selenate or selenite under controlled conditions. There was at least a 50‐fold variation in Se accumulation and volatilization capacity among the plant species tested, regardless of the form of Se supplied. The best plant species for Se volatilization from selenate were also the best species for selenite volatilization. Selenium volatilization rates were twofold higher from selenite than from selenate but more selenate‐Se was translocated into harvestable plant tissues than selenite‐Se. Several aquatic plant species showed Se volatilization and accumulation rates (per unit surface area) that were comparable with Indian mustard [Brassica juncea (L.)], the best‐known terrestrial plant species for Se phytoremediation. Therefore, many wetland species identified in this study, for example, parrot's feather (Myriophyllum brasiliense Camb.), iris‐leaved rush (Juncus xiphioides), cattail (Typha latifolia L.), saltmarsh bulrush (Scirpus robustus), etc., have a great potential for Se phytoremediation in wetlands.
Assessing the Potential Long‐Term Behavior of the Landfill Fraction of Sorted Demolition Wastes
Authors: Johnson C. Annette , Moench Hermann , Brandenberger Sandro 
Published: July 2010

AbstractIn Switzerland, demolition wastes are sorted for recycling purposes and the finest fraction, the (landfill) fraction of sorted demolition waste (LFSDW, <50 mm) is mostly landfilled. The risks associated with landfilling have been assessed by analysis of potential inorganic contaminants and the factors controlling their mobility. Samples of LFSDW were sieved and analyzed for major and minor elemental components. X‐ray diffractograms were made to determine major mineral components. Titratlons were also carried out to determine the acid neutralizing capacity (ANC) and of trace metal cation solubility. Landfill sorted demolition waste is largely composed of quartz, silicates, gypsum, calcite, and organic C. The calcite content of samples analyzed in this study is approximately 30% of the total weight. Metal concentrations range from 0.03 to 0.04 g kg−1 Cr, 0.02 to 0.2 g kg−1 Cu, 0.03 to 1.36 g kg−1 Pb, 0.0001 to 0.0007 g kg−1 Cd, and 0.2 to 0.5 g kg−1 Zn. In comparison to a model of the earth's crust (50% basalt and 50% granite) or to average soil concentrations, only Pb and Zn are enhanced. Heavy metal concentrations appear to be undersaturated with respect to metal carbonates and hydroxides and may be controlled by sorption processes. The ANC is sufficiently large to control the solubility of Pb and Zn in the long‐term, that is, over thousands of years. The organic C content (approximately 45 g kg−1) is sufficiently high to affect landfill leachate composition in the short term.
Redistribution of Biosolids‐Derived Total Phosphorus Applied to a Mollisol
Authors: Sui Yaobing , Thompson Michael L. , Mize Carl W. 
Published: July 2010

AbstractThe amount of P applied to land with biosolids is generally more than plants need when the application rate is based on the potentially available N. The subsequent accumulation of P is of environmental rather than agronomic concern, because it could lead to eutrophication of water bodies if P is carried off‐site in surface runoff, subsurface drainage water, or eroded soil. In a large‐scale field study with three biosolids application rates (approximately 0, 7.4, and 13.0 Mg dry matter ha−1), we investigated the redistribution of P derived from surface‐applied biosolids in soil under poplars and switchgrass. Soil samples were collected from two depths (0–5 cm and 5–25 cm), and total P was determined by colorimetry after strong acid digestion. Total P in mobile soil water samples collected by zero‐tension lysimeters was determined by inductively coupled plasma spectrometry. After 6 yr of continuous biosolids application to poplar tree (Populus sp.) plots, total P in soil increased significantly (α = 0.05) at both the 0‐ to 5‐ and 5‐ to 25‐cm depths under poplars. Also at both depths, a linear relationship between total P in soil and the amount of P applied with biosolids (α = 0.05) was found. Under switchgrass (Panicum virgatum L.), total P increased significantly (α = 0.05) at only the 0‐ to 5‐cm depth. A linear relationship between total P in soil and the amount of P applied with biosolids (α = 0.05) was found at the 0‐ to 5‐cm depth under switchgrass but not at the 5‐ to 25‐cm depth. The amount of P taken up annually by switchgrass was estimated to be five times more than that taken up by poplars. The amount of P leached in mobile soil solution of switchgrass plots was estimated to be twice that leached in soil solution of poplar tree plots. Phosphorus that accumulated in the upper 5 cm of the soil accounted for ≥45% or more of the total P applied with biosolids, except for the low biosolids application rate to switchgrass plots where the value was 28%.
Plants' Use of Leachate Derived from Municipal Solid Waste
Authors: Revel J. C. , Morard P. , Bailly J. R. , Labbé H. , Berthout C. , Kaemmerer M. 
Published: July 2010

AbstractLeachate was collected from a watertight pit at a landfill center dealing mainly with household refuse and plant waste. This effluent was characterized by a moderate organic matter content, a pH slightly higher than neutral and strong electrical conductivity. This latter was due to the presence of chlorides, Na, K, and ammonium. The organic content could be divided into two fractions: Fraction A consisting of large molecules (5000 Da and above) and Fraction B of smaller (between 300 to 1000 Da), more acidic molecules. The presence of phenols (sinapic acid, acetosyringone, and pyrogallol) could be identified in the leachate as a whole. A biological treatment of this leachate, involving methanization followed by aerated lagooning, was set up on the site: this led to a reduction of nearly 60% in the organic content and almost total elimination of the ammonium. This treatment was not however sufficient to allow direct evacuation of the resulting effluent into the surface ground water. As heavy metals were absent from this effluent, the leachates from this landfill site could possibly be envisaged in the fertilization of soil‐grown crops or for furrow irrigation‐fertilization of tree plantations. The effect of irrigating soil‐grown plants with a solution of leachate was examined using pots of ryegrass (Lolium sp.). Application of solutions containing dilutions of 1 to 400 mL L−1 of this effluent had a highly favorable effect on plant growth. Toxicity phenomena were apparent above this concentration. The optimum effect on ryegrass growth, under the conditions of this trial, was obtained by watering each pot with 30 mL of a solution containing 400 mL L−1 of leachate, every 2 d. This solution improved water and N nutrition in these plants.
Coamendments to Modify Phosphorus Extractability and Nitrogen/Phosphorus Ratio in Feedlot Manure and Composted Manure
Authors: Dao Thanh H. 
Published: July 2010

AbstractA narrow nitrogen to phosphorus ratio (N/P) exists in animal manure, resulting in P high loading and pollution risks when land applications are made to meet N demands of a crop. Nonhazardous mineral by‐products potentially widen the effective N/P ratio in manure. We determined the effects of alum, caliche, and Class C fly ash on extractable P concentrations in stockpiled and composted cattle (Bos taurus) manure at rates of 0, 0.10, 0.25, and 0.50 kg kg−1 manure. The mixtures were also added to Amarillo fine sandy loam (Aridic Paleustalf) and Pullman clay loam (Torrertic Paleustoll) at the rate of 22 Mg ha−1. Caliche, alum, and fly ash reduced water‐extractable P (WP) in stockpiled manure by 21, 60, and 85% and by 50, 83, and 93% in composted manure at the O.1kg kg−1 rate. Alum and fly ash also significantly reduced Bray‐I P (BP) concentrations by 75 and 90% in stockpiled and composted manure, respectively, and >90% at higher rates. Fly ash also decreased Mehlich III‐P (MP) concentrations, ranging from 50 to 98%. Mixing these amendments with feedlot manure widened the effective manure N/P ratio by a factor ranging from 1.5 to 18. Applying fly ash‐treated stockpiled or composted manure reduced all extractable P fractions from amended soils. Alum and caliche consistently reduced the WP fraction only. Coapplications of mineral and animal by‐products stabilized manure P where uncovered storage is unavoidable or widened its effective N/P ratio, allowing land application rates needed to fulfill plant N requirements without causing water quality impairments.
Predicting Plant Available Nitrogen in Land‐Applied Biosolids
Authors: Gilmour John T. , Skinner Vaughn 
Published: July 2010

AbstractThe rate at which biosolids (municipal sewage sludge) may be applied to land is dependent on factors including concentrations of metals, pathogens, toxic organic compounds, and nutrients. Where other properties are not limiting, land application rates are often based on matching crop N needs with the plant available N (PAN). The objectives of this study were to quantify biosolids PAN under field conditions and to propose methods including computer simulation to estimate biosolids PAN in a land application program. Six biosolids were evaluated over a 2‐yr period. Laboratory incubations were used to obtain decomposition kinetics. Field studies provided a relationship between inorganic fertilizer N rate and sorghum sudangrass [Sorghum bicolor (L.) Moench] tissue N concentration, which was used to determine biosolids PAN in a Captina silt loam soil (fine‐silty, siliceous, mesic Typic Fragiudult). Biosolids PAN released during the field experiment was linearly related to biosolids C/N ratio, organic N, or total N. Computer model predictions of PAN in the field were also linearly related to field estimates of biosolids PAN. Decay series (first and second year N mineralization percentages) obtained using the computer model, average biosolids decomposition kinetics, and average application site weather were very similar to decay series obtained using the computer model, actual weather, and kinetic data. Either decay series and routine analytical data for biosolids are proposed to estimate PAN for a given situation. Use of the computer model and weather data makes the approach site‐specific, while analytical data for a specific biosolids makes the approach biosolids‐specific.