bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sources and Evolution of Anthropogenic Lead in Dated Sediments from Lake Clair, Québec, Canada
Authors: Ndzangou Sabary Omer , Richer‐Laflèche Marc , Houle Daniel 
Published: May 2005

ABSTRACTTwo sediments cores were collected from the deepest part of Lake Clair (Québec, Canada) to assess the historical sources of Pb additions to the lake. The cores were collected by divers by carefully inserting a Plexiglas tube into the sediments. To determine the stratigraphic ages of the sediments, 210Pb and 137Cs activities were counted by γ‐ray spectroscopy. Lead concentrations and isotopic ratios were performed by inductively coupled plasma–mass spectrometry (ICP–MS), following digestion of the samples with a mixture of HF, HNO3, and HClO4 acids and Pb separation by anion‐exchange chromatography. Starting at the middle of the 19th century, Pb content of the sediments increased until 1975. The maximum Pb enrichment factor of 35 times (relative to the natural background) was found in sediments deposited in 1975. At this time, excess Pb flux was estimated to be about 0.03 g m−2 yr−1 Before 1872, the Pb isotopic ratios were relatively stable (mean 206Pb/207Pb = 1.20 ± 0.01), reflecting the natural Pb background. Between 1872 and 1894, the source of anthropogenic Pb was highly radiogenic as shown by the Pb isotopic signatures of the sediments (mean 206Pb/207Pb = 1.22 ± 0.01), possibly reflecting deforestation and agricultural developments in the St.‐Lawrence Valley. Between 1894 and 1937, widespread use of industrial and domestic charcoals may explain the isotopic composition of Pb accumulated in the sediments (mean 206Pb/207Pb = 1.19 ± 0.01). From 1937 to 1975, Pb isotopic compositions became less radiogenic (206Pb/207Pb from 1.18 to 1.17) even though elemental Pb abundance reached extremely high values (623 mg kg−1). This isotopic shift reflects increased use of alkyl‐lead in gasoline. For sediments accumulated between 1967 and 1996, the U.S. contribution to anthropogenic Pb accumulated in Lake Clair sediments amounted to between 30 and 63%.
Identification of the Source of Nitrate Contamination in Ground Water below an Agricultural Site, Jeungpyeong, Korea
Authors: Jun Seong‐Chun , Bae Gwang‐Ok , Lee Kang‐Kun , Chung Hyung‐Jae 
Published: May 2005

ABSTRACTThis study applied hydrogeological characterization and isotope investigation to identify source locations and to trace a plume of ground water contaminated by nitrate. Most of the study site is agricultural fields with the remainder being residential. A poultry farm is also within the study area, so that potential point and nonpoint sources were present. Estimates of seasonal ground water recharge from irrigation and precipitation, leakage of sewage, and the regional ground water flow were linked to the seasonal changes in isotopic values. Ground water recharge largely occurred in spring and summer following precipitation or irrigation, depending on the locations. Natural and fertilized soils were identified as nonpoint sources of nitrate contamination in this area, while septic and animal wastes were identified as small point sources. The seasonal changes in the relative impact of these sources on ground water contamination were related to such factors as source distribution, the aquifer confining condition, precipitation rate, infiltration capacity, recharge rate, and the land use pattern.
Colloidal and Dissolved Phosphorus in Sandy Soils as Affected by Phosphorus Saturation
Authors: Ilg Katrin , Siemens Jan , Kaupenjohann Martin 
Published: May 2005

ABSTRACTFertilization exceeding crop requirements causes an accumulation of phosphorus (P) in soils, which might increase concentrations of dissolved and colloidal P in drainage. We sampled soils classified as Typic Haplorthods from four fertilization experiments to test (i) whether increasing degrees of phosphorus saturation (DPS) increase concentrations of dissolved and colloidal P, and (ii) if critical DPS levels can be defined for P release from these soils. Oxalate‐extractable concentrations of P, iron (Fe), and aluminum (Al) were quantified to characterize DPS. Turbidity, zeta potential, dissolved P, and colloidal P, Fe, Al, and carbon (C) concentrations were determined in water and KCl extracts. While concentrations of dissolved P decreased with increasing depth, concentrations of water‐extractable colloidal P remained constant. In topsoils 28 ± 17% and in subsoils 94 ± 8% of water‐extractable P was bound to colloids. Concentrations of dissolved P increased sharply for DPS > 0.1. Colloidal P concentrations increased with increasing DPS because of an additional mobilization of colloids and due to an increase of the colloids P contents. In addition to DPS, ionic strength and Ca2+ affected the release of colloidal P. Hence, using KCl for extraction improved the relationship between DPS and colloidal P compared with water extraction. Accumulation of P in soils increases not only concentrations of dissolved P but also the risk of colloidal P mobilization. Leaching of colloidal P is potentially important for inputs of P into water bodies because colloidal P as the dominant water‐extractable P fraction in subsoils was released from soils with relatively low DPS.
Understanding Long‐Term Baseflow Water Quality Trends Using a Synoptic Survey of the Ground Water–Surface Water Interface, Central Wisconsin
Authors: Browne Bryant A. , Guldan Nathan M. 
Published: May 2005

ABSTRACTThe relationship between stream water quality and landscape activities is difficult to evaluate where the principal source of stream flow is ground water seepage because the average travel time from ground water recharge areas to stream discharge positions can be on the order of decades. We tested the idea that past and future baseflow water quality can be predicted based on a synoptic survey of ground water recharge age‐dates (based on chlorofluorocarbon [CFC] measurements) and water quality measurements obtained at the ground water–surface water interface. In this study we (i) characterize the discharge‐weighted age distribution and water quality of ground water seepage into the Little Plover River (LPR); (ii) use this information to backcast and forecast baseflow NO3− concentrations; and (iii) evaluate NO3− backcasts against historical baseflow data (1960 to 2000). The discharge‐weighted apparent CFC age of ground water seepage into the LPR was 23.7 (±7) yr. Baseflow backcasts matched the four decade rise of baseflow NO3− from 2 to 8 mg L−1 Baseflow forecasts included three scenarios. Scenario A projects the historical rise of NO3− in the LPR basin's ground water recharge through 2050. Scenario B projects a leveling off of NO3− in ground water recharge in the year 2000. Scenario C projects a leveling off in the year 1985. Under Scenario A, LPR baseflow NO3− will increase steadily from 8 to 19 mg L−1 between 2000 and 2050. Under scenarios B and C baseflow NO3− will plateau at 13 mg L−1 in 2030 and at 10 mg L−1 in 2010, respectively. The approach developed in this study can be used to (i) reconstruct historical baseflow water quality patterns in the absence of long‐term monitoring data and (ii) project the effects of potential management decision on future water quality.
The Influence of Lipids on the Energetics of Uptake of Polycyclic Aromatic Hydrocarbons by Natural Organic Matter
Authors: Chilom Gabriela , Kohl Scott D. , Rice James A. 
Published: May 2005

ABSTRACTAlthough most of the organic carbon in soils and sediments may be composed of humic substances, their interaction with other compounds, especially their sorption interactions, may be significantly affected by the presence of small amounts of the other components of natural organic matter (NOM). In this investigation, the influence of the lipid fraction of NOM on the sorption thermodynamics of fluorene, phenanthrene, and pyrene to several geosorbent samples was examined before and after extraction of lipids. Batch experiments were performed at the same concentration for all polycyclic aromatic hydrocarbons (PAHs) (0.025 × their solubility in water) at different temperatures (10, 20, 30, and 40°C), and the thermodynamic parameters were calculated. Removal of the lipids increases the sorption capacity of the samples as well as the exothermicity of the process. The free energy change was negative for all the samples and no significant differences were noticed on lipid removal. The entropy changes were small and positive for the whole geosorbent samples, but even smaller or more negative when the lipids were removed. This indicates that the interaction of PAHs with soils and sediments in the absence of extractable lipids is stronger and the mechanisms involved may be different, changing from a partitioning‐like mechanism to specific adsorption. Because of the competition between lipids and PAHs for the same sorption sites, the lipids can be viewed as an “implicit sorbate.”
Multivariate Analysis of Paired Watershed Data to Evaluate Agricultural Best Management Practice Effects on Stream Water Phosphorus
Authors: Bishop Patricia L. , Hively W. Dean , Stedinger Jery R. , Rafferty Michael R. , Lojpersberger Jeffrey L. , Bloomfield Jay A. 
Published: May 2005

ABSTRACTQuantification of the effects of management programs on water quality is critical to agencies responsible for water resource protection. This research documents reductions in stream water phosphorus (P) loads resulting from agricultural best management practices (BMPs) implemented as part of an effort to control eutrophication of Cannonsville Reservoir, a drinking water supply for New York City. Dairy farms in the upstate New York reservoir basin were the target of BMPs designed to reduce P losses. A paired watershed study was established on one of these farms in 1993 to evaluate changes in P loading attributable to implementation of BMPs that included manure management, rotational grazing, and improved infrastructure. Intensive stream water monitoring provided data to calculate P loads from the 160‐ha farm watershed for all runoff events during a two‐year pre‐treatment period and a four‐year post‐treatment period. Statistical control for inter‐annual climatic variability was provided by matched P loads from a nearby 86‐ha forested watershed, and by several event flow variables measured at the farm. A sophisticated multivariate analysis of covariance (ANCOVA) provided estimates of both seasonal and overall load reductions. Statistical power and the minimum detectable treatment effect (MDTE) were also calculated. The results demonstrated overall event load reductions of 43% for total dissolved phosphorus (TDP) and 29% for particulate phosphorus (PP). Changes in farm management practices and physical infrastructure clearly produced decreases in event P losses measurable at the small watershed scale.
Tillage and Nutrient Source Effects on Water Quality and Corn Grain Yield from a Flat Landscape
Authors: Thoma David P. , Gupta Satish C. , Strock Jeffrey S. , Moncrief John F. 
Published: May 2005

ABSTRACTBeneficial effects of leaving residue at the soil surface are well documented for steep lands, but not for flat lands that are drained with surface inlets and tile lines. This study quantified the effects of tillage and nutrient source on tile line and surface inlet water quality under continuous corn (Zea maysL.) from relatively flat lands (<3%). Tillage treatments were either fall chisel or moldboard plow. Nutrient sources were either fall injected liquid hog manure or spring incorporated urea. The experiment was on a Webster–Canisteo clay loam (Typic Endoaquolls) at Lamberton, MN. Surface inlet runoff was analyzed for flow, total solids, NO3–N, NH4–N, dissolved P, and total P. Tile line effluent was analyzed for flow, NO3–N, and NH4–N. In four years of rainstorm and snowmelt events there were few significant differences (p< 0.10) in water quality of surface inlet or tile drainage between treatments. Residue cover minimally reduced soil erosion during both snowmelt and rainfall runoff events. There was a slight reduction in mineral N losses via surface inlets from manure treatments. There was also a slight decrease (p= 0.025) in corn grain yield from chisel‐plow plots (9.7 Mg ha−1) compared with moldboard‐plow plots (10.1 Mg ha−1). Chisel plowing (approximately 30% residue cover) alone is not sufficient to reduce nonpoint source sediment pollution from these poorly drained flat lands to the extent (40% reduction) desired by regulatory agencies.
A Method for Determining the Phosphorus Sorption Capacity and Amorphous Aluminum of Aluminum‐Based Drinking Water Treatment Residuals
Authors: Dayton E. A. , Basta N. T. 
Published: May 2005

ABSTRACTA high amorphous aluminum or iron oxide content in drinking water treatment residuals (WTRs) can result in a high phosphorus (P) sorption capacity. Therefore, WTR may be used beneficially to adsorb P and reduce P loss to surface or ground water. The strong relationship between acid ammonium oxalate–extractable aluminum (Alox) and Langmuir phosphorus adsorption maximum (Pmax) in WTR could provide a useful tool for determining Pmaxwithout the onus of the multipoint batch equilibrations necessary for the Langmuir model. The objectives of this study were to evaluate and/or modify an acid ammonium oxalate extraction of Aloxand the experimental conditions used to generate P adsorption isotherms to strengthen the relationship between Aloxand PmaxThe oxalate extraction solution to WTR ratio varied from 40:1, 100:1, and 200:1. Batch equilibration conditions were also varied. The WTR particle size was reduced from <2 mm to <150 μm, and batch equilibration was extended from 17 h to 6 d. Increasing the solution to WTR ratio to 100:1 extracted significantly greater Aloxat levels of >50 mg Al kg−1No additional increase was found at 200:1. Reducing WTR particle size from <2 mm to <150 μm increased Pmax2.46‐fold. Extending the equilibration time from 17 h to 6 d increased Pmaxby a mean of 5.83‐fold. The resulting empirical regression equation between the optimized Aloxand Pmax(r2= 0.91, significant at the 0.001 probability level) may provide a tool to estimate the Pmaxof Al‐based WTR simply by measuring AloxThe accurate determination of WTR Pmaxand Aloxis essential in using WTR effectively to reduce P loss in runoff or to reduce the solubility of P in agricultural soils or organic waste materials (biosolids, manure).
Distribution and Persistence of Pyrethroids in Runoff Sediments
Authors: Gan J. , Lee S. J. , Liu W. P. , Haver D. L. , Kabashima J. N. 
Published: May 2005

ABSTRACTPyrethroids are commonly used insecticides in both agricultural and urban environments. Recent studies showed that surface runoff facilitated transport of pyrethroids to surface streams, probably by sediment movement. Sediment contamination by pyrethroids is of concern due to their wide‐spectrum aquatic toxicity. In this study, we characterized the spatial distribution and persistence of bifenthrin [BF; (2‐methyl(1,1′‐biphenyl)‐3‐yl)methyl 3‐(2‐chloro‐3,3,3‐trifluoro‐1‐propenyl)‐2,2‐dimethylcyclopropanecarboxylate] and permethrin [PM; 3‐(2,2‐dichloroethenyl)‐2,2‐dimethylcyclopropanecarboxylic acid (3‐phenoxyphenyl)methyl ester] in the sediment along a 260‐m runoff path. Residues of BF and PM were significantly enriched in the eroded sediment, and the magnitude of enrichment was proportional to the downstream distance. At 145 m from the sedimentation pond, BF was enriched by >25 times, while PM isomers were enriched by >3.5 times. Pesticide enrichment along the runoff path coincided with enrichment of organic carbon and clay fractions in the sediment, as well as increases in adsorption coefficient Kd, suggesting that the runoff flow caused selective transport of organic matter and chemical‐rich fine particles. Long persistence was observed for BF under both aerobic and anaerobic conditions, and the half‐life ranged from 8 to 17 mo at 20°C. The long persistence was probably caused by the strong pesticide adsorption to the solid phase. The significant enrichment, along with the prolonged persistence, suggests that movement of pyrethroids to the surface water may be caused predominantly by the chemically rich fine particles. It is therefore important to understand the fate of sediment‐borne pyrethroids and devise mitigation strategies to reduce offsite movement of fine sediment.
Advanced Thermal Characterization of Fractionated Natural Organic Matter
Authors: DeLapp Rossane C. , LeBoeuf Eugene J. , Chen Jie , Gu Baohua 
Published: May 2005

ABSTRACTThis work focuses on an experimental investigation of the thermodynamic properties of natural organic matter (NOM), and whether fractions of NOM possess the same thermodynamic characteristics as the whole NOM from which they are derived. Advanced thermal characterization techniques were employed to quantify thermal expansion coefficients (α), constant‐pressure specific heat capacities (Cp), and thermal transition temperatures (Tt) of several aquatic‐ and terrestrial‐derived NOM. For the first time, glass transition behavior is reported for a series of NOM fractions derived from the same whole aquatic or terrestrial source, including humic acid–, fulvic acid–, and carbohydrate‐based NOM, and a terrestrial humin. Thermal mechanical analysis (TMA), standard differential scanning calorimetry (DSC), and temperature‐modulated differential scanning calorimetry (TMDSC) measurements revealed Tt ranging from −87°C for a terrestrial carbohydrate fraction to 62°C for the humin fraction. The NOM generally followed a trend of increasing Tt from carbohydrate to fulvic acid to humic acid to humin, and greater Tt associated with terrestrial fractions relative to aquatic fractions, similar to that expected for macromolecules possessing greater rigidity and larger molecular weight. Many of the NOM samples also possessed evidence of multiple transitions, similar to β and α transitions of synthetic macromolecules. The presence of multiple transitions in fractionated NOM, however, is not necessarily reflected in whole NOM, suggesting other potential influences in the thermal behavior of the whole NOM relative to fractionated NOM. Temperature‐scanning X‐ray diffraction studies of each NOM fraction confirmed the amorphous character of each sample through Tt
Initial Tree Establishment on Blocky Quarry Waste Ameliorated with Hydrogel or Slate Processing Fines
Authors: Rowe E. C. , Williamson J. C. , Jones D. L. , Holliman P. , Healey J. R. 
Published: May 2005

ABSTRACTPocket planting reclamation techniques developed in the 1970s for revegetating blocky quarrying waste have met with very limited success, often because the low water‐holding capacity of the waste and limited root development within a small volume of planting pocket material result in severe drought mortality. We tested pocket planting approaches for waste tip reclamation at Europe's largest slate quarry, and compared materials for enhancing the continuity of water‐ and nutrient‐holding down into the interior of the waste tip. When small compost‐filled pocket planting bags were placed above slate processing fines (SPF) or water absorbent cross‐linked polyacrylamide gel (“hydrogel”), tree growth rates increased in comparison with pocket planting bags alone. The SPF significantly improved tree survival especially during severe drought, but survival was not enhanced by the use of hydrogel. The sorption characteristics of hydrogel indicated that its presence may help to reduce nutrient leaching, but that it may have a negative effect on nitrogen availability. A more likely explanation for the poor performance of pure hydrogel is that it did not maintain sufficient available water, because of discontinuities caused by shrinkage and movement of the hydrogel, and/or degradation of water‐holding capacity with environmental exposure. However, the root growth observed in the hydrogel treatments suggests that this technique, if adapted to reduce the effects of hydrogel shrinkage by using finer‐grade hydrogel, mixing it with other soil‐forming material, and reducing its exposure to extremes of temperature or sunlight, might have the potential to improve the growth and survival of trees planted on sites where delivery of heavy materials such as SPF is impractical. Fine mineral processing waste is freely available at active quarries and should be seen as a key resource for reclamation schemes.
Field‐Scale Application of Oily Food Waste and Nitrogen Fertilizer Requirements of Corn at Different Landscape Positions
Authors: Rashid M. T. , Voroney R. P. 
Published: May 2005

ABSTRACTOily food waste (FOG; fat + oil + greases) containing high concentrations of fat, oil and grease is produced by the food service, production, and processing industries. It has a high C to N ratio (90:1) and can recycle soil available N through immobilization and remineralization during its decomposition. Experiments were conducted at a farm (Hillsburg fine sandy loam; Typic Hapludalf) having rolling topography (5 and 9% slope) during 1995 and 1996. Objectives of this study were to (i) examine the variability of available N and corn (Zea maysL.) grain yield at different landscape positions of FOG‐amended fields and (ii) determine whether N fertilizer management could be improved by considering the spatial variability of soil NO3–N at different landscape positions in FOG‐amended fields. A spatial and temporal variability in soil NO3–N was observed during both years. Corn grain yields at all N fertilizer application rates were affected by slope position and followed the pattern: lower > upper ≥ middle. Nitrogen fertilizer requirements for corn production in conjunction with FOG management were also affected by slope position. Essentially no additional fertilizer N was required for corn production at the lower landscape position. It was estimated that site‐specific fertilizer N management on FOG‐amended fields could result in an average savings of 51 and 63 kg N ha−1(with a potential economical savings of US$42 and US$52 ha−1) during 1995 and 1996, respectively.