bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soil Sorption of Volatile and Semivolatile Organic Compounds in a Mixture
Authors: Walton Barbara T. , Hendricks Marilyn S. , Anderson Todd A. , Griest W.H. , Merriweather R. , Beauchamp J.J. , Francis C.W. 
Published: July 2010

AbstractStudies were conducted to evaluate lipophilicity as a predictor sorption for a mixture of organic compounds with high vapor pressures commonly present at hazardous waste sites. Sorption partition coefficients (Kp) for the mixture of 16 volatile and semivolatile organic compounds were measured on a Captina silt loam (Typic Fragiudult) and a McLaurin sandy loam (Typic Paleudults) using a zero headspace extractor. The experimental Kp was determined for acrylonitrile, furan, methyl ethyl ketone, tetrahydrofuran, benzene, toluene, p‐xylene, chlorobenzene, chloroform, nitrobenzene, 1,2‐dichlorobenzene, 1,2,3‐trichloropropane, carbon tetrachloride, ethylene dibromide, 1,2,4,5‐tetrachlorobenzene, and hexachlorobenzene on each of the two soils. The Kp values were generally lower in the McLaurin sandy loam, which had a lower organic C content (0.66 ± 0.04%) than the Captina silt loam (organic C content = 1.49 ± 0.06%). Sorption was normalized to soil organic C content of the soil by converting Kp for each compound and soil to Koc. Weighted regression analyses of Koc observed for the compounds in the mixture on Koc predicted from the n‐octanol/water partition coefficient (Kow) for individual compounds yielded a pooled, weighted regression of Koc observed = 1.084 + 0.457 Koc predicted, n = 29, r = 0.88. Statistical analysis indicated that the slope of 0.457 ± 0.046 (estimated standard error) was significantly less than 1.00, indicating that soil sorption of nonionic organic compounds differed from that predicted for the same individual compounds based on Kow. The results indicate that predictive equations for sorption of individual organic compounds can be applied to mixtures of volatile and semivolatile organic compounds in soils when log Kow are in a range from approximately 1 to 3; however, outside this range a correction factor may be needed.
Indicator Bacterial Survival in Stream Sediments
Authors: Sherer Brett M. , Miner J. Ronald , Moore James A. , Buckhouse John C. 
Published: July 2010

AbstractThe impact of grazing cattle (Bostauras) on water quality has been the subject of considerable interest as water quality standards become more restrictive. Benthic sediments have been found to harbor significantly higher concentrations of enteric bacteria than the overlying water. In this study, the survival of fecal coliform and fecal streptococci organisms was demonstrated to be significantly longer in sediment laden waters than in those without sediment and further the survival was longer in the sediment‐laden waters than in a supernatant from that same sediment suspended in water. Fecal coliform and fecal streptococci bacteria revealed half‐lives from 11 to 30 d and 9 to 17 d, respectively when incubated with sediment. This is longer than when they are similarly incubated without sediment.
Nitrate Levels in Shallow Groundwater under Pastures Receiving Ammonium Nitrate or Slow‐Release Nitrogen Fertilizer
Authors: Owens L.B. , Edwards W.M. , Van Keuren R.W. 
Published: July 2010

AbstractThis study examined the impact on groundwater quality of conventional and slow‐release N fertilizer to small, grazed watersheds in eastern Ohio. Three small watersheds (each less than 1 ha) received 56 kg N/ha annually as NH4NO3 for 5 yr. For the next 10 yr, one watershed received 168 kg N/ha annually as NH4NO3 and two others received the same amount of N as methylene urea, a slow‐release fertilizer. Shallow groundwater samples were collected from springs and analyzed. After the 5‐yr prestudy period, NO3‐N levels in the groundwater from the three watersheds were in a 3 to 5 mg/L range. Groundwater NO3‐N concentrations increased slightly during the first 3 yr at the higher N fertilizer rate, though they remained in the 3 to 5 mg/L range. Nitrate‐N levels increased more sharply during the rest of the study. Although these NO3‐N levels varied more between the growing and dormant seasons than when lower rates of fertilizer were applied, they eventually reached a slower rate of increase. During the 9th and 10th yr of the high application, seasonal NO3‐N levels in groundwater ranged from 10 to 16 and 7 to 14 mg/L from the watersheds receiving NH4NO3 and methylene urea, respectively. This study showed that 168 kg N/ha was too much for this system, regardless of whether conventional or slow‐release N was used.
Fractionation of Phosphorus in the Sediment of a Wetland after a Decade of Receiving Sewage Effluent
Authors: Cooke James G. , Stub Laila , Mora Neil 
Published: July 2010

AbstractSediment deposited in traps positioned along a pollution gradient in a wetland receiving sewage effluent was fractionated with respect to phosphorus (P) to understand the processes of P removal. Significant differences in P fractions were found between sites. Close to the point of effluent discharge, virtually all of the P deposited was in organic form; whereas downstream of a confluence with a wetland not impacted by the sewage, inorganic P constituted 50 to 80% of the total P. More than 80% of the inorganic P occurred in forms extractable by 0.1 M NaOH. This form of P was highly correlated (r2 ≃0.5–0.8) with oxalate‐extractable Fe. Natural wetlands unimpacted by sewage effluent were shown to be the main source of the Fe. Hydrologic conditions regulating the delivery of Fe to the sewage‐impacted wetland were implicated as the main factors determining the relative concentrations of inorganic P within the impacted wetland system. While it is not clear whether adsorption or precipitation reactions were responsible for the P deposition, we conclude that the present rate of P removal is sustainable. Our results may explain why, in some cases, the P removal achieved in wastewater wetland systems is much greater than can be predicted solely from soil adsorption maxima.
Redistribution of Sludge‐Borne Cadmium, Copper, and Zinc in a Cultivated Plot
Authors: Yingming Liang , Corey R.B. 
Published: July 2010

AbstractThe vertical and horizontal redistribution of sludge‐borne Cd, Cu, and Zn was studied in and around a 6.1 by 7.3 m plot on Plano silt loam (Typic Argiudoll) that had received 112 Mg−1 of sewage sludge in the fall of 1978. This plot had been moldboard‐plowed and disked each year thereafter. Calculated loadings of trace metals to the cropped plot from the sludge application were: Cd, 25.6 kg ha−1; Cu, 149 kg ha−1; and Zn, 538 kg ha−1. Two hundred surface soil samples (0–20 cm) were taken from areas within the plot and up to 3 m on each side of the plot and 39 subsoil samples (20–30, 30–40, and 40–60 cm) were taken within the plot in the spring of 1989. Estimates of total trace‐metal concentrations in the soil samples were obtained by determining metal concentrations in a 4 M HNO3 extract (70°C) by atomic absorption spectrometry. The determined distributions of sludge‐borne Cd, Cu, and Zn, respectively, were: 66.7, 67.5, and 68.0% in the 0‐ to 20‐cm plow layer within the original pot area; 15.5, 18.1, and 21.0% dragged outside the plot area; and 15.2, 12.4, and 11.6% moved into the 20 to 30‐cm layer within the plot area. No significant enrichment with trace metals from the sludge application was found below 30 cm. Of the metals found outside the boundaries of the original plot, about 56% moved into adjacent areas in the direction of tillage and about 44% into areas perpendicular to the direction of tillage. A mass balance calculation using an assumed soil bulk density of 1.3 Mg m−3 showed an average recovery of 98.7% of the added metals.
Laboratory Observation of Funnel Flow Mechanism and its Influence on Solute Transport
Authors: Kung K.‐J. S. 
Published: July 2010

AbstractRecent field experiments have strongly indicated that contaminants could move preferentially and rapidly in unsaturated soils. Without knowing a priori what the preferential flow mechanisms are, it is impossible to predict solute movement based on numerical modeling with limited measured soil properties. The objective of this study was to characterize the mechanism of funnel flow (i.e., how an inclined soil layer with abrupt textural discontinuity will trigger preferential flow) in laboratory experiments and to determine the influence of funnel flow on solute transport. To simulate soil heterogeneity encountered in the field, a coarser sand lens with 15° inclination was packed in finer sand in a sand tank; three combinations of the coarser lens embedded in finer particles were tested. Water was applied at seven different rates in each combination to determine how the textural discontinuity between the two media would initiate the funnel flow, and to identify the critical water application rate at which water would enter the coarse sand lens. The water flow pattern, the influence of funnel flow on solute transport, and the effect of hysteresis on the funneling phenomenon were also examined. Results showed that funnel flow could occur along an inclined boundary between two soils if the following two conditions are both satisfied: (i) there is a macroscopic Haines' jump across the boundary, and (ii) water application rates are smaller than a certain critical rate. Under this condition, contaminants could be greatly congregated and accelerated by funnel flow.
The Effects of Establishment Methods and Fertilization Practices on Nitrate Leaching from Turfgrass
Authors: Geron C. A. , Danneberger T. K. , Traina S. J. , Logan T. J. , Street J. R. 
Published: July 2010

AbstractA lysimeter study was conducted at the Ohio State University Turfgrass Research Center, Columbus, to investigate NO3‐N leaching losses from fertilized turfgrass. Nitrogen fertilizer treatments were applied to ‘Baron’ Kentucky bluegrass (Poa pratensis L.) seeded and sodded turf established on a Miamian silt loam (fine, mixed, mesic Typic Hapludalf). Treatments included two N sources, urea and resin‐coated urea (RCU); and Two fertilization programs, one that emphasize spring and summer applications (SSF) and the second program that included a late season application (LSF). Both the SSF‐ and LSF‐fertilization programs received 218.2 kg N ha−1 yr−1. The NO3‐N leachate concentrations from seeded turfgrass exceeded those from sodded turf for the first 3 mon. As the turf matured, NO3‐N losses from sod exceeded NO3‐N from the seeded plots. Leachate concentrations were 1.1 and 3.5 mg NO3‐N L−1 for seed and sod turf, respectively, from April 1990 through March 1991. Less rooting in the sodded plots resulted in greater N loss. Annual NO3‐N losses were not affected by N source. During the winter of 1991, significantly (P = 0.05) higher percolate NO3‐N concentrations were recorded from urea‐treated plots (3.66 mg NO3‐N L−1) vs. RCU (2.10 mg NO3‐N L−1), however. Similarly, N programs did not result in annual differences in percolate concentration, but differed during the winter of 1991. Concentrations were 3.37 and 2.39 mg NO3‐N L−1 for LSF and SSF, respectively. The NO3‐N leaching losses from all treatments exceeded the maximum concentration limit (MCL) early in the study. These high concentrations were caused by soil disturbance during establishment. During the 2nd yr, NO3‐N leaching results were more representative of typical turfgrass situations with mean annual flow‐weighted NO3‐N concentrations well below the MCL. Different N sources and fertilizer programs did not result in greater NO3‐N percolate losses compared to unfertilized turfgrass plots.
Biodegradation of Synthetic Chelates in Subsurface Sediments from the Southeast Coastal Plain
Authors: Bolton H. , Li S. W. , Workman D. J. , Girvin D. C. 
Published: July 2010

AbstractThe codisposal of synthetic chelating agents [e.g., ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and nitrilotriacetic acid (NTA)] and radionuclides has been implicated in increased radionuclide transport in the subsurface environment. Microbial transformations of chelates in the subsurface are currently unknown, but could influence chelate persistence and thus alter the transport of radionuclides. Surface soil and subsurface sediments from five formations (36‐ to 376‐m depth) were collected near Allendale, SC. Aerobic mineralization of 14C‐labeled EDTA, DTPA, and NTA occurred in select sediments indicating that subsurface microorganisms can degrade chelates, whereas chelates may be relatively stable in strata where limited mineralization occurred. The chelates were not mineralized more rapidly or to a greater extent in the surface soil than in the subsurface sediments. The relative order of chelate persistence was EDTA > DTPA > NTA, with the maximum amount mineralized during 115 d at 15, 26, and 43%, respectively. Maximum mineralization of all three chelates did not occur in the same sediment, indicating that different microbial populations were responsible for the degradation of each chelate. Mineralization of chelates was minimal under denitrifying conditions and was reduced when additional soluble C was added. There was no relationship between chelate mineralization and the adsorption of chelates to sediments or the aqueous speciation of the chelates.
Soil Nitrate Concentrations under Corn as Affected by Tillage, Manure, and Fertilizer Applications
Authors: Angle J. S. , Gross C. M. , Hill R. L. , McIntosh M. S. 
Published: July 2010

AbstractA 3‐yr study was conducted to examine combination effects of tillage (no‐till, conventional‐till), manure, and inorganic fertilizer (ammonium nitrate) on leaching of nitrates from the root zone of corn (Zea mays L.). Soil cores were collected every spring to a depth of 210 cm and analyzed for NO3‐N. Leaching of NO3‐N significantly increased as fertilizer N rates increased, especially when rates exceeded the crop's potential to assimilate N. The concentration of soil nitrate (averaged over depth and tillage) in Year 3 of the study under the unfertilized control plots was 2.5 mg NO3‐N kg−1, whereas the concentration under plots fertilized with 260 kg N ha−1 was 8.7 mg NO3‐N kg−1. Soil nitrate concentrations were consistently lower under no‐tillage when compared with conventional‐tillage. Tillage differences were greatest when high rates of N were added to soil. These results indicate that the use of no‐tillage cultivation may reduce the leaching of nitrates beyond the crop root zone.
The Origin and Identification of Macropores in an Earthen‐Lined Dairy Manure Storage Basin
Authors: McCurdy M. , McSweeney K. 
Published: July 2010

AbstractEarthen‐lined basins have been used to store dairy manure in Wisconsin since the early 1970s. Monitoring data indicate that many of these basins are leaking, but little effort has been directed toward explaining the mechanisms responsible for leakage. Morphological and micromorphological techniques were used to identify macropores in the sidewall of an earthen‐lined manure storage basin. Laboratory and field dye studies provided evidence of contaminant movement via macropores. Results indicate that physicochemical and biological mechanisms were responsible for creating macropores capable of providing pathways for preferential flow. These mechanisms, and the resulting macropores, can significantly affect the long‐term viability of earthen‐lined manure storage basins.
Changes in Mine Soil Properties Resulting from Overburden Weathering
Authors: Haering Kathryn C. , Daniels W. Lee , Roberts Jesse A. 
Published: July 2010

AbstractHard rock overburden is often used as a topsoil substitute for reclamation in the southern Appalachian surface mining region because of the limited availability of natural topsoil. In relatively unweathered overburden materials, soil‐forming processes are accelerated and the resulting mine soils form rapidly. Morphological, physical, and chemical properties related to overburden weathering in mine soils formed from siltstone and sandstone overburden were observed for 6 to 8 yr. Distinct surface soil horizons, enriched with organic matter, occurred within two growing seasons after mine soil construction, and discernible subsurface horizonation developed within four growing seasons. The degree of development of surface and subsurface soil horizons became more pronounced after 8 yr. Coarse fragment content of sandstone‐derived mine soils decreased, and silt content of siltstone‐containing mine soils increased during six growing seasons. Although pH and extractable Ca and Mg levels decreased during the first three growing seasons, apparently due to rapid leaching of exposed carbonates, these properties rebounded to near initial levels after six growing seasons due to release of Ca and Mg from continued carbonate weathering and phytocycling. Levels of extractable Fe tripled between the first and second growing seasons and then remained relatively constant for the rest of the study. The changes in soil properties in these mine soils indicated that geochemical weathering and oxidation was occurring rapidly. This study demonstrated the complexity of mine soil weathering and development processes and the difficulties involved in predicting all eventual mine soil properties from premining overburden analysis.
Compacted Soil Barriers at Abandoned Landfill Sites are Likely to Fail in the Long Term
Authors: Suter Glenn W. , Luxmoore Robert J. , Smith Ellen D. 
Published: July 2010

AbstractAt innumerable sites in the USA and around the world, buried waste has been isolated from the environment by barriers constructed entirely or in part of compacted soil. The chief concern in barrier design has been to isolate the waste in the short term by preventing movement of water into and through the waste. However, in the long term a variety of mechanisms can act to compromise this isolation. The mechanisms of long‐term failure include initial flaws in barrier construction, shrink‐swell cycles, freeze‐thaw cycles, erosion, subsidence, root intrusion, and animal intrusion. Evidence for action of all of these mechanisms is summarized. The likelihood of long‐term failure suggests that either perpetual care must be provided for buried hazardous wastes, or the waste sites must be designed to withstand long‐term threats to barrier integrity.
Environmental Impacts of Coal Combustion Residues
Authors: Carlson Claire L. , Adriano Domy C. 
Published: July 2010

AbstractCoal combustion residues account for 90% of all fossil fuel combustion wastes produced in the USA. It is projected that by the year 2000 more than 150 million t of these materials will be produced in the USA each year. Presently, only about 20% of these wastes are utilized, with the remainder deposited in landfills or surface impoundments. This article reviews the information available concerning the environmental impacts associated with the disposal or utilization of coal combustion residues. The majority of the information available in the literature concerns the impacts of fly and bottom ashes; other coal combustion wastes have not received much attention. The major potential impacts of ash disposal on terrestrial ecosystems include: leaching of potentially toxic substances into soils and groundwater; reductions in plant establishment and growth due primarily to adverse chemical characteristics of the ash; changes in the elemental composition of vegetation growing on the ash; and increased mobility and accumulation of potentially toxic elements throughout the food chain. Ash disposal in landfills and settling ponds can influence adjacent aquatic ecosystems directly, through inputs of ash basin effluent and surface runoff, and indirectly, through seepage and groundwater contamination. Major impacts are generally associated with changes in water chemistry, including changes in pH and concentrations of potentially toxic elements. Using ash as a soil amendment can improve soil texture and water‐holding capacity, increase soil pH, and enhance soil fertility. However, it may also result in excessive soluble salt concentrations, excess B, and increased concentrations of other potentially toxic trace elements; reduction in the concentrations and/or availability of soil N and P; elemental imbalances due to excessively high pH; and cementation or compaction of soil. Scrubber sludge and fluidized bed combustion waste may be used as soil amendments as well, but also may create problems due to high alkalinity and high salinity.
Influence of Amount and Method of Irrigation Water Application on Leaching of Atrazine
Authors: Troiano J. , Garretson C. , Krauter C. , Brownell J. , Huston J. 
Published: July 2010

AbstractA study was conducted to relate leaching of a herbicide, atrazine [6‐chloro‐N‐ethyl‐N′‐(1‐methylethyl)‐1,3,5‐triazine‐2,4,‐diamine], and inorganic water tracers, Br− and Cl−, to the amount of deep‐percolating water produced from irrigation. Soil at the site was classified as a Dehli Loamy Sand (Mixed, Thermic, Tepic Xeropsamment) which was an unstructured sandy soil that was low in organic C content, conditions conducive to solute leaching. The relationship between depth of solute movement and amount of deep‐percolating water was measured in sprinkler, basin, and furrow irrigation methods. Soil distribution of inorganic tracers indicated that graded levels of added water treatments, which were based on reference evapotranspiration, produced corresponding increases in the depth of percolated water. Atrazine's soil distribution indicated greater downward movement in response to increases in amount of deep‐percolating water. Magnitude of leaching differed between irrigation methods and increased in the order: sprinkler < basin < furrow. Simulations using the LEACHM model provided a physically based explanation for the differences in water movement between sprinkler and basin methods. The total amount of applied water was similar at each level of percolation but sprinkler irrigations were more frequent, resulting in more evaporation and, consequently, less water available for deep percolation. Both amount and method of water application are important factors that determine pesticide movement and that, in irrigated agriculture, must be considered as integral components of pesticide management.
Laboratory Experiments Evaluating the Transport and Fate of DBCP in Hanford Sandy Loam
Authors: Litton Gary M. , Guymon Gary L. 
Published: July 2010

AbstractSoil column, batch adsorption, and batch biodegradatian experiments were conducted to determine the fate of DBCP applied in irrigation water at low concentrations (≈ 3 µg L−1) to unsaturated Hanford sandy loam soil (coarse‐loamy, mixed, nonacid, thermic Typic Xerorthents). The objective was to determine the extent that soil might treat DBCP‐contaminated groundwater proposed for irrigation of citrus in the Redlands California area. Water applications were performed cyclically to simulate citrus irrigation practices. Volatilization of DBCP to the atmosphere between irrigations was the dominant mechanism controlling its fate once applied to the soil. Soil adsorption was found to retard the transport of DBCP 3 to 5 times when compared with the wetting front movement. Batch biodegradation experiments suggested that DBCP may also be significantly metabolized by subsurface microorganisms. The half‐life was estimated to be approximately 7 d. Soil water characteristic curve hysteresis was observed with the soil column experiments and water content distributions calculated from soil water pore pressures required that scanning curves be developed to accurately simulate experimental data.