bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rainfall Simulator‐Grid Lysimeter System for Solute Transport Studies Using Large, Intact Soil Blocks
Authors: Bowman B. T. , Brunke R. R. , Reynolds W. D. , Wall G. J. 
Published: July 2010

AbstractA grid lysimeter system and sample collection, containment, and storage techniques were developed for detailed laboratory studies of water and solute movement through intact soil blocks. This was done because existing designs and techniques had important deficiencies and were limited in their range of capabilities. Intact 46‐cm soil cubes were isolated, then contained within a polyurethane foam shell, which formed a stable, intimate soil bond, was impermeable to water and strong enough to support a large soil block, while sufficiently elastic to accommodate soil shrink‐swell with changing water content without rupturing. The soil blocks were instrumented with solution delivery, collection, and monitoring systems. A dripper‐based simulator delivered steady rainfall ranging from 4.8 to 30.0 mm h−1. The solution collection system was a 10 by 10 grid of cells (3.8 by 3.8 by 1.3 cm deep) milled into an aluminum block, which individually drained into collection tubes housed within a vacuum chamber. The collection grid permitted characterization of spatial and temporal water and solute movement through the block. The solution monitoring system consisted of side‐by‐side tensiometer pairs and time domain reflectometry (TDR) probes inserted horizontally through the foam shell at four depths in the block. As a partial test of the system, a bromide (Br−) tracer breakthough curve (saturated flow) was generated at a simulated rainfall rate of 19.2 mm h−1. Flow data indicated that 85% of the water in the block was bypassed by the Br−, and that >99% of the water flow passed through only 26% of the basal area of the block. The water flow pattern in the solution collector exhibited no evidence of preferential flow along the interface between the soil and the outer polyurethane shell. It was concluded that the rainfall simulator‐grid lysimeter system was operating effectively.
Herbaceous Layer and Soil Response to Experimental Acidification in a Central Appalachian Hardwood Forest
Authors: Gilliam Frank S. , Turrill Nicole L. , Aulick Staci D. , Evans Dan K. , Adams Mary Beth 
Published: July 2010

AbstractThe herbaceous layer (vascular plants ≤1 in in height) is an important component of forest ecosystems and a potentially sensitive vegetation stratum in response to acid deposition. This study tested several hypotheses concerning soil and herbaceous layer response to experimental acidification at the Fernow Experimental Forest in north‐central West Virginia. Fifteen circular sample plots (0.04 ha) were established in each of three watersheds: WS3 (an ≈ 20‐yr‐old watershed receiving acidification treatment with (NH4)2SO4), WS4 (>80‐yr‐old control), and WS7 (≈ 20‐yr‐old control). The herb layer was sampled intensively in 10 1‐m2 subplots within each sample plot, including determination of species composition, cover, and random biomass harvests. Harvested plant material was separated by species and analyzed for macronutrients, micronutrients, and Al. Soft was sampled from harvest subplots and analyzed for texture, pH, organic matter, and macro‐ and micronutrients. Few differences among watersheds for virtually all measured soil variables indicated minimal response of soil fertility to the acidification treatment. The herbaceous layer was also quite similar among watersheds with respect to cover‐biomass and species diversity; WS7, however, had ≈ 70% higher herb layer cover that both Ws3 and WS4, a result of the predominance of a few high‐cover fern species and attributable to the north‐facing aspect of WS7 vs. south‐facing aspects of WS3/WS4. There was a high degree of species similarity among watersheds, suggesting no shift in species composition in response to acidification. There was also minimal response of element concentrations to acidification, although Fe and Al exhibited evidence of increased uptake in WS3. We conclude that, contrary to our expectations, there has been little substantive response of the soil and herb layer to acidification, but hypothesize that herbaceous layer species may experience toxicity problems with increased mobility of Al and micronutrients in the future.
Using Gas Chromatography/Mass Spectroscopy Fingerprint Analyses to Document Process and Progress of Oil Degradation
Authors: Roques D. E. , Overton E. B. , Henry C. B. 
Published: July 2010

AbstractOne of the challenges in testing the effectiveness of bioremediation products is the lack of a standardized testing protocol. One requirement of any such evaluation is baseline and benchmark analyses of the oil and its degradation processes. The method described uses high resolution gas chromatography mass spectroscopy (GC/MS). This method has been adapted from oil fingerprinting techniques used by our group for oil spill response to major spills such as T/V Exxon Valdez and T/V Megaborg. It results in a high degree of chemical and spectral resolution from a single analysis that allows quantification of saturated hydrocarbons, polynuclear aromatic hydrocarbons (PAHs), sulfur heterocycles, and selected biomarkers such as hopanes and steranes. We demonstrate that high resolution GC/MS and compound specific analyses are a viable and efficient method of analyzing the extent and progress of oil bioremediation and that it should be possible to standardize the method for monitoring the biodegradation of oil. We also present data that show increased useful information obtained from this method and suggest possible future uses for this expanded database.
Biodegradation of Chromate‐Contaminated Groundwater by Reduction and Precipitation in Surface Soils
Authors: Losi M. E. , Amrhein C. , Frankenberger W. T. 
Published: July 2010

AbstractA cost‐effective method is needed for removing chromate from cooling water blowdown, wastewater effluent, and contaminated groundwater. Experiments were conducted to determine the effectiveness of treating Cr‐contaminated water by using the water for irrigation, and that reduction of Cr(VI) to Cr(III) would occur in a soil amended with organic matter and irrigated to promote low oxidation/reduction status. The Cr(III) would then precipitate as oxides and hydroxides, and be immobilized and rendered plant unavailable. Samples of a field soil (mixed, thermic Typic Torripsamments) overlying a contaminated groundwater site were placed in pots and irrigated for 20 wk with water containing 1000 µg L−1 Cr(VI). Treatments included plants (alfalfa; Medicago sativa L.) vs. no plants, each at three organic matter Ioadings ‐ 0, 12, and 50 Mg ha−1 dried cattle manure (0, 5.5, and 21.8 g manure kg−1 soil). The drainage waters were collected weekly and analyzed for total Cr, Cr(VI), pH, dissolved O2, dissolved organic C, and electrical conductivity. The removal percentages of Cr(VI) from the enriched water ranged from 51 to 98% and increased with increasing organic matter loading. Chromium concentrations in the drainage water were consistently <50 µg L−1 in the organic‐amended soil. Daily irrigation yielded lower drainage water Cr concentrations than weekly irrigation (at a constant weekly volume) due to increased residence time of the water in the bioactive zone. Chromate adsorption accounted for <1% of the total immobilized Cr and the amount taken up by the alfalfa shoots was <0.5% of the total added. This method shows promise as a cost‐effective treatment for Cr‐contaminated groundwater.
Phytoremediation Potential of Thlaspi caerulescens and Bladder Campion for Zinc‐ and Cadmium‐Contaminated Soil
Authors: Brown S. L. , Chaney R. L. , Angle J. S. , Baker A. J. M. 
Published: July 2010

AbstractMetal‐tolerant hyperaccumulator plants may be useful to phytoremediate contaminated soils. To evaluate agronomic management practices to maximize phytoremediation, two metallophytes, Thlaspi caerulescens J. and C. Presl (Zn hyperaccumulator) and bladder campion [Silene vulgaris (Moench) Garcke L.] (an indicator) were compared to ‘Rutgers’ tomato (Lycopersicon esculentum L.) in a pot study to assess Zn and Cd uptake patterns in relation to soil pH. Soils used for the study were gathered at three different sites in the vicinity of an old Zn smelter in Palmerton, PA, and contained 48 000, 4100, and 2100 mg kg−1 Zn and 1020, 37.4, and 35.2 mg kg−1 Cd, respectively. Each soil was adjusted to three pH levels ranging from 5.06 to 7.04. Thlaspi caerulescens showed much greater tolerance to the metals than the other plants (up to 18 455 mg kg−1 Zn and 1020 mg kg−1 Cd dry shoots without yield reduction) with metal stress apparent only in the low pH treatments of the two most contaminated soils. In all treatments except for the farm Soil (least contaminated) at pH 5.06, T. caerulescens had higher concentrations of both Zn and Cd than bladder campion and tomato. Thlaspi caerulescens was also more effective at translocating both Zn and Cd from soil to plant shoots. A variety of soil extractions were used to evaluate the correlation of shoot metal concentrations with quantitative measures of “available” soil metals. Concentrations of Cd measured in several common extractants (DTPA, water, 0.01 M Ca(NO3)2, and 1.0 M NH4NO3) were significantly correlated with Cd concentrations in tissue of each plant. Shoot Zn concentrations of bladder campion and tomato were significantly correlated with Zn extracted by the neutral salt extractants for all soils. For T. caerulescens, the neutral salt extractable Zn was significantly correlated with shoot Zn only in the two more contaminated soils. No extractant predicted shoot Zn concentration for T. caerulescens in the least contaminated soil.
Nitrogen and Carbon Mineralization Rates of Composted Manures Incubated in Soil
Authors: Hadas Aviva , Portnoy Rita 
Published: July 2010

AbstractRates of decomposition and inorganic N release from composted manures should be known and predictable on the basis of their composition for their proper use as a source of available N. Four composted cattle manures were analyzed for their inorganic N, soluble organic C and N, and total N and organic matter contents. The composts were incubated in soil for 32 wk at 30°C and 60% water‐holding capacity. Inorganic N and CO2 evolution were determined periodically. Inorganic N released from the composts after 32 wk ranged from 11 to 29% of their total N content, 2 to 12% of total N were initially inorganic, and 1 to 5% were soluble organic N. The rates of decomposition of the composts were computed by the simulation model NCSOIL by minimizing the deviation of the model output from the periodically measured CO2 and inorganic N release and by using the soluble and insoluble organic C and N contents of the composts as input. The soluble components decomposed before the end of the first week. The decomposition rate constant obtained for the insoluble components of three composts was 4 to 5 × 10−4 d−1, whereas for one compost it was 1 × 10−8 d−1, indicating that this compost was much more stable. To obtain universal rate constants that will fit any compost, components of the insoluble material must be better defined.
Kinetics of Ion Removal from an Iron‐Rich Industrial Coproduct: I. Chloride
Authors: Salingar Yigal , Sparks Donald L. , Ghodrati Masoud , Hendricks Gerald J. 
Published: July 2010

AbstractAn industrial TiO2 extraction process results in a Fe‐rich material (IRM) that contains substantial chlorides. Recent investigations showed that washed IRM may serve as a soil amendment for agricultural use. Yet, washing processes at the industrial production facility are currently problematic and costly, and it is essential to devise effective procedures for Cl removal. This study was conducted to determine the mechanism of Cl retention, and to ascertain whether the rate of Cl removal was governed by time‐dependent surface‐chemical kinetics or diffusion (transport)‐controlled kinetics. The IRM samples we used throughout the study were homogenous. It was physicochemically characterized and concentrations of heavy metals were determined. The IRM batch studies revealed negative Cl adsorption, even though its point of zero charge was 8.3. Column studies showed that 92% of the Cl was removed with the first pore volume. Additionally, the salt removal decreased the electrolyte concentration, caused dispersion, and, ultimately, lowered the hydraulic conductivity. Stirred‐flow kinetic studies established that Cl leaching was a function only of the total volume that flowed through the chamber, and that no chemical kinetics were involved.
Kinetics of Ion Removal from an Iron‐Rich Industrial Coproduct: II. Sulfate
Authors: Salingar Yigal , Sparks Donald L. , Pesek John D. 
Published: July 2010

AbstractAn iron‐rich material (IRM) contained copious quantities of salts, including Cl and SO4. A previous study on Cl removal hypothesized that SO4 played a major role in the chemistry of the IRM. Therefore, this study investigated the kinetics of SO4 removal from the IRM, which had a point of zero charge similar to those of some tropical soils. Stirred‐flow (SF) and column studies showed that SO4 removal was a time‐dependent chemical reaction(s). The SF technique facilitated modeling of the chemical kinetics of SO4 removal by providing a uniformly mixed system. The SO4 removal mechanism from the IRM to the ambient solution, in the SF system, was a zero‐order oxidation‐dissolution reaction of the Fe‐sulfide present as a minor constituent in the IRM. The computed value of the rate‐constant was 0.043 µmol min−1. In the column studies, the newly dissolved SO4 was present in the effluent, and was adsorbed on the IRM through a ligand (OH−) exchange mechanism. Calcium hydroxide dissolution, together with the SO4 adsorption, resulted in a pH increase with pore‐volume.
Kinetics of Ion Removal from an Iron‐Rich Industrial Coproduct: III. Manganese and Chromium
Authors: Salingar Yigal , Sparks Donald L. , Pesek John D. 
Published: July 2010

AbstractAn iron‐rich material (IRM) contained the potential soil and water pollutants Mn and Cr. Therefore, to assess the feasibility of using the IRM in agricultural and nonagricultural settings, this study was conducted to determine the processes and kinetics of Mn and Cr (total soluble metals) retention and removal from the IRM. This was accomplished by employing adsorption isotherms, column studies, and the stirred‐flow (SF) kinetic technique. Manganese adsorption conformed to the Langmuir equation and Cr adsorption was described by the Freundlich equation. The kinetic studies showed that indigenous Mn salts were depleted instantaneously via a volume‐dependent process. Both Mn and Cr in the IRM became solubilized while being processed at the industrial plant. But, unlike Mn, Cr was readsorbed by the IRM after the initial solubilization. This fraction of the Cr was desorbed rapidly, conforming to first‐order kinetics and yielding a rate‐constant of 0.56 min−1. After the rapid removal of some of the Mn and Cr, a steady‐state with wodginite may have governed Mn removal, and chromite may have controlled the Cr concentration, through zero‐order dissolution reactions. Both column and SF studies showed that the proportion of total soluble (dischargeable) Mn and Cr was small.
Natural Revegetation of 15 Abandoned Mine Land Sites in West Virginia
Authors: Skousen J. G. , Johnson C. D. , Garbutt K. 
Published: July 2010

AbstractFifteen AML sites ranging in age from 13 to 35 yr in northern West Virginia were selected from three surface‐mined coal beds (Pittsburgh, Freeport, and Kittanning) to evaluate plant invasion and establishment on disturbed sites. Three 10 m by 10 m plots were randomly located on each site, and cover, density, and stem diameter of all woody plant species were measured. Herbaceous and plant litter cover were also estimated in square‐meter quadrats within each 10‐m2 plot. Total tree cover was significantly different among sites on Pittsburgh and Kittanning coal mined sites, but not among Freeport sites. Among coal beds, Kittanning sites had the lowest tree cover (33% avg), Pittsburgh had an average of 67%, while Freeport sites had a multilayered tree cover averaging >100%. A total of 29 tree species were found on these sites. No tree species occurred on all 15 sites, but black cherry (Prunus serotina Ehrh.) and red maple (Acer rubrum L.) were found on 13 sites. Clustering produced three distinct plant communities including (i) an herbaceous community, (ii) a tree community dominated by red maple, and (iii) another tree community of primarily black birch (Betula lenta L.). Herbaceous communities were found on sites with soil pH > 5.0, while tree communities occurred on sites with pH < 5.0. On disturbed sites with high soil pH, herbaceous plants rapidly invaded and formed an almost complete cover. On low‐pH sites, the invasion of plant species from adjacent undisturbed sites was initiated in favorable microsites where minesoil or environmental conditions were ameliorated.
Modeling of Heavy Metal Transport in a Contaminated Soil
Authors: Černík Miroslav , Federer Peter , Borkovec Michal , Sticher Hans 
Published: July 2010

AbstractObserved depth profiles in soils polluted by Zn and Cu that originate from a metal smelter are quantitatively interpreted by combining the production history of the smelter with established transport models. Using independent laboratory and field data, we were able to calculate the present depth profiles semiquantitatively by applying the pure convection model without parameter fitting. The agreement of the calculated depth profiles with the experimental data can be improved by including dispersion effects in the convection‐dispersion model or the stochastic convection model. For the latter model, the depth profiles were calculated analytically. These models were used to calculate the expected depth profiles in the future and to judge possible remediation strategies.
Passive Treatment of Acid Mine Drainage with Limestone
Authors: Hedin Robert S. , Watzlaf George R. , Nairn Robert W. 
Published: July 2010

AbstractThe water treatment performances of two anoxic limestone drains (ALDs) were evaluated. Anoxic limestone drains are buried beds of limestone that are intended to add bicarbonate alkalinity to flow‐through acid mine drainage. Both ALDs received mine water contaminated with Fe2+ (216–279 mg L−1) and Mn (41–51 mg L−1). Flow through the Howe Bridge ALD increased alkalinity by an average 128 mg L−1 (CaCO3 equivalent) and Ca by 52 mg L−1, while concentrations of Fe, K, Mg, Mn, Na, and SO2−4 were unchanged. The Morrison ALD increased alkalinity by an average 248 mg L−1 and Ca by 111 mg L−1. Concentrations of K, Mg, Mn, and SO2−4 all decreased by an average 17%, an effect attributed to dilution with uncontaminated water. Iron, which decreased by 30%, was partially retained within the Morrison ALD. Calcite dissolution was enhanced at both sites by high PCO2. Untreated mine waters at the Howe Bridge and Morrison sites had average calculated PCO2 values of 6.39 kPa (10−1.20 atm) and 9.24 kPa (10−1.04 atm), respectively. At both sites, concentrations of bicarbonate alkalinity stabilized at undersaturated values (SICalcite = 10−1.2 at Howe Bridge and 10−0.8 at Morrison) after flowing through approximately half of the limestone beds. Flow through the second half of each ALD had little additional effect on mine water chemistry. At the current rates of calcite solubilization, 17.9 kg d−1 CaCO3 at Howe Bridge and 2.7 kg d−1 CaCO3 at Morrison, the ALDs have theoretical effective lifetimes in excess of 20 yr. By significantly increasing alkalinity concentrations in the mine waters, both ALDs increased metal removal in downstream constructed wetlands.
Nonpoint‐Source Groundwater Contamination by 1,2,2‐Trichloropropane, A Trace Impurity in Soil Fumigant Formulations
Authors: Szeto S. Y. , Grove G. , Liebscher H. , Hii B. , Zebarth B. J. 
Published: July 2010

AbstractGroundwater samples were collected from 60 piezometers and 23 domestic wells from March 1991 to April 1992 as part of a study to quantify NO−3 and pesticide contamination of the Abbotsford Aquifer, located in the lower Fraser Valley, southwestern British Columbia, Canada. A new contaminant, 1,2,2‐trichloropropane (1,2,2‐TCP), was detected and confirmed in 296 of the 514 samples by purge and trap GC/MS, and its concentration was determined in 150 of the samples collected between January and April 1992. The contaminant was detected in 34 (57%) of the piezometers sampled, and 10 (44%) of the domestic wells sampled. Mean 1,2,2‐TCP concentration (±1 SD) was 0.12 ± 0.11 µg L−1 in 123 piezometer samples and 0.14 ± 0.09 µg L−1 in 27 domestic well samples. The highest 1,2,2‐TCP concentrations measured were 0.62 and 0.32 µg L−1 for piezometers and domestic wells, respectively. The probable nonpoint sources of the contaminant are the synthetic pesticides, Telone (mixture of 1,3‐dichloropropene and 1,2‐dichloropropane) and Telone II (1,3‐dichloropropene), used to control pathogenic nematodes in raspberry (Rubus idaeus L.) production. Analyses of Telone and Telone II confirmed the presence of 1,2,2‐TCP as impurities in both products. The study demonstrates that an impurity present in pesticide formulations in trace quantities, which is persistent in soil and water, has the potential to result in significant groundwater contamination under the appropriate soil and climatic conditions.
Biodegradation Rate Enhancement of Hydrocarbons by an Oleophilic Fertilizer and a Rhamnolipid Biosurfactant
Authors: Churchill S. A. , Griffin R. A. , Jones L. P. , Churchill P. F. 
Published: July 2010

AbstractThe oleophilic fertilizer Inipol EAP 22 and a microbial biosurfactant (rhamnolipid) were investigated for their ability to increase the rate of biodegradation of aliphatic and aromatic hydrocarbons by pure bacterial cultures. Both Inipol EAP 22 and rhamnolipid were found to lower the surface tension of a phosphate buffered solution to 32 mN m−1. Each surfactant dramatically increased the apparent aqueous solubility of solid 2‐methylnaphthalene, and were capable of emulsifying liquid hydrocarbons. Biodegradation experiments were carried out with the TOL plasmid‐containing strain, Pseudomonas putida (ATCC30015); the OCT plasmid‐containing strain, P. oleovorans (ATCC29347); and an unknown naphthalene‐degrading strain (ATCC15075). Cells were grown under conditions where biodegradative enzymes were induced before their utilization. Model studies were conducted to investigate the ability of Inipol EAP 22 and rhamnolipid to enhance the rate of transport and uptake of hydrocarbons into bacterial cells, and to assess the impact that increasing the apparent aqueous solubility of hydrocarbons has on their rate of biodegradation. The extent of rate enhancement of compound mineralization resulting from surfactant addition was significantly greater for the sparingly soluble alkanes, hexadecane and octadecane, than for the more soluble aromatics, toluene and 2‐methylnaphthalene. The results suggest that increasing the bioavailability of hydrocarbons to bacteria may be a useful method to accelerate the rate of biodegradation at contaminated sites. Lastly, the data supports the hypothesis that surface‐active components present in the oleophilic fertilizer formulation, Inipol EAP 22, may have significantly contributed to the positive results reported in tests of remedial agent impact on bioremediation, which was used as a supplemental cleanup technology on Exxon Valdez crude oil contaminated Alaskan beaches.