bluuebunny/crossref_metadata_2025_split huggingface dataset:
Behavior of Sequential Extraction of Lead from Thermally Treated Lead(II)‐Doped Alumina
Authors: Wei Yu‐Ling , Huang Yu‐Ling 
Published: July 2010

AbstractThere are environmental concerns about emission of heavy metals in flue gases during incineration of hazardous wastes. Low temperature injection of sorbents has been suggested as a way to reduce the heavy metal content of the emitted gases. We investigated the extractive behavior of Pb in thermally treated Pb2+‐doped alumina using the USEPA toxicity characteristics leachability procedure (TCLP) and a sequential extraction method to obtain information on the Pb‐alumina reaction. Thermal treatment of Pb2+‐doped alumina was in the 100 to 900°C range for 10 to 60 min. Results indicated that the Pb2+‐doped alumina treated at higher temperature for longer duration was resistant to the TCLP and to the sequential extraction for the first four fractions, but not for the residual fraction (Fraction 5). The relationship between total extracted Pb of the first four fractions and the TCLP concentration was strong (r = 0.993 for the 100°C and r = 0.996 for the 500°C treatments). Almost all of the doped Pb was distributed between conceptual fractions that were either bound to carbonates or were residual that was extracted with 10% HF and H2O2. The shift in distribution of Pb that was carbonate‐bound to that bound in the residual fraction as treatment temperature increased from 100 to 500°C was more than that which shifted from 500 to 900°C. After treatment at 900°C most of the Pb was associated with the residual fraction (indicating a strong sorption between Pb and alumina) and the TCLP concentration dropped to nondetectable levels.
Fractionation and Distribution of Arsenic in Soils Contaminated by Cattle Dip
Authors: McLaren R. G. , Naidu R. , Smith J. , Tiller K. G. 
Published: July 2010

AbstractSoils surrounding cattle dips in Australia are known to be highly contaminated with As and are potentially of major concern to the environment and human health. A study of 11 dip sites in northern New South Wales (NSW) has revealed considerable surface soil (0–10 cm) contamination with As (37–3542 mg As kg−1 soil). In addition it was shown that considerable movement of As down through the soils had occurred with concentrations at 20 to 40 cm ranging from 57 to 2282 mg As kg−1 soil. At one particular site, an As concentration of above 14 000 mg As kg−1 soil was determined at a depth of 40 to 45 cm. A sequential fractionation scheme, based on a soil P fractionation, was developed to assess the chemical nature, and thus the potential bioavailability and mobility of As, at the sites. Soil As is separated into six fractions with (i) anion exchange resin, (ii) NaHCO3, (iii) NaOH, (iv) NaOH following sonication, (v) HCl, and (vi) HCl/HNO3. Although substantial differences between sites and soil depths were present, some general trends were apparent. Most sites contained substantial concentrations of As in the two most labile fractions, indicating high potential for phytotoxicity and leaching. The bulk of the contaminant As at the sites seemed to be associated with soil amorphous Fe and Al minerals.
Fate of Pig Sludge Liquid Fraction in Calcareous Soil: Agricultural and Environmental Implications
Authors: Giusquiani P. L. , Concezzi L. , Businelli M. , Macchioni A. 
Published: July 2010

AbstractThe characterization of pig sludge liquid fraction (PSLF) was conducted to achieve a better understanding of its chemical and physical chemical characteristics. Total dissolved organic carbon (TDOC) from pig sludge was separated into two fractions: acid insoluble dissolved organic carbon (AIDOC) and acid soluble dissolved organic carbon (ASDOC). Elemental analysis, acidic functional group determination, E4/E6 ratio, Gel‐Filtration Cromatography and FTIR Spectroscopy of ASDOC and AIDOC showed a similarity with humic and fulvic acids, isolated from soils and organic wastes. Phosphorus‐31 Nuclear Magnetic Resonance spectra demonstrated that the organic P in PSLF was present as P‐monoester. The complexing capacity of DOC vs. trace metals was demonstrated by Gel Filtration Chromatography and FTIR Spectroscopy. The interactions of DOC, Cu, and Zn, present in PSLF, with a calcareous soil were evaluated by adsorption isotherms that indicated that Zn was completely adsorbed by the soil, while Cu followed the same behavior as DOC, with only partial adsorption. Therefore, both Cu and DOC should be taken into consideration as a possible groundwater pollution hazard after pig sludge application to calcareous soil.
Relation between Irrigation Method, Sediment Yields, and Losses of Pesticides and Nitrogen
Authors: Ebbert James C. , Kim Moon H. 
Published: July 2010

AbstractYields of suspended sediment from watersheds in the Quincy and Pasco Basins of Washington State have been reduced by the use of sprinkler irrigation on cropland previously in furrow irrigation. Mean daily yields of suspended sediment from nine watersheds sampled during April and May 1994 ranged from 0.4 kg/ha of irrigated cropland in a watershed with no furrow irrigation to 19 kg/ha in a watershed where 58% of irrigated cropland was in furrow irrigation. About 67% of the variation in the yields can be attributed to irrigation method. Temporal trends also indicated that use of sprinkler irrigation reduced sediment yields. Mean daily yields of suspended solids from one of the watersheds decreased from 0.3 kg/ha in 1975 to <0.2 kg/ha in 1988, corresponding with a decrease from about 65% to <50% in the use of furrow irrigation. Sampling in two watersheds suggests that the use of sprinkler irrigation reduces runoff losses of pesticides and N. For 10 of 13 pesticides and N, runoff losses from a watershed with mostly furrow irrigation exceeded runoff losses from a watershed with mostly sprinkler irrigation.
Evaluation of NCSWAP Model Using Nitrate‐Leaching Data from Soil Core Lysimeters
Authors: Jabro J. D. , Stout W. L. , Fales S. L. , Fox R. H. 
Published: July 2010

AbstractThe accuracy of the Ṉitrogen and C̱arbon cycling in S̱oil, W̱ater A̱nd P̱lant (NCSWAP) model to simulate (nitrate‐nitrogen) NO3‐N leaching from orchardgrass (Dactylis glomerata L.) pasture was evaluated using data collected from a 3‐yr leaching experiment conducted in central Pennsylvania on Hagerstown silt loam soil (fine, mixed, mesic, Typic Hapludalf). Nitrate leaching losses below the 1‐m depth from N‐fertilized orchardgrass sod were measured with intact soil core lysimeters (0.6‐m diam. by 1‐m long). Five N‐fertilizer treatments consisted of a control, urine application in the spring, urine application in the summer, urine application in the fall, and feces application in the summer were used to test the model. The model was calibrated using the data from 1993 to 1994 and then was validated using 1994 to 1995 and 1995 to 1996 water flow and NO3‐N leaching data. Statistical analysis indicated a good fit between field measured and predicted NO3‐N leaching for most treatments in each year. The model simulations of water flow and NO3‐N leaching losses below the 1‐m depth were compared with the meau of measured field data for these 3 yr. The results of this study showed that the NCSWAP model performed well and accurately simulated water flow and total annual NO3‐N loss through leaching below the 1‐m depth under orchardgrass pasture. However, the model failed to produce accurate simulations for the feces treatment in 1994 to 1995. The simulation error in the feces treatment seemed to be related to N mineralization process in the model. Generally, the results of this study suggest that the NCSWAP model can be used for predicting NO3‐N leached annually from pastured orchardgrass.
Decomposition of Land Applied Oily Food Waste and Associated Changes in Soil Aggregate Stability
Authors: Plante Alain F. , Voroney R. Paul 
Published: July 2010

AbstractSince traditional methods of disposing of oily food wastes have recently lost favor, there is a current search for alternatives. Field‐and laboratory‐scale experiments examined the decomposition of oily food wastes applied to agricultural lands to examine this disposal option and potential agronomic benefits. Treatment rates of oily food waste equivalent to 3 to 11.3 g of C kg−1 increased soil microbial biomass C in the field by up to five times control levels. Wet aggregate stability also increased with waste addition and was maintained over the course of the growing season. Laboratory incubation studies examining the biodegradation of canola oil and oily food waste showed that the oily fraction of the waste was not rate limiting, and that both substrates degraded rapidly with initial decomposition half‐lives of 40 to 45 h and 70 to 94 h for canola oil and waste treatments, respectively. The extents of mineralization over 4 wk were up to 84 and 40% for canola oil and oily food waste, respectively. Similar to the field, increases in aggregate stability were measured in the canola oil incubation. Examination of the biodegradation data indicates two substrate pools are being sequentially decomposed, and that the added substrate is not directly responsible for improved structural properties. The longer lasting binding abilities of microbial products and bodies are the major contributing factors for the increased soil aggregation. It is concluded that the land application of oily food waste is agronomically beneficial by increasing soil microbial activity, and in turn improving soil structure through increased aggregate stability.
Effect of Soil Solution Chloride on Cadmium Availability to Swiss Chard
Authors: Smolders E. , Lambregts R. M. , McLaughlin M. J. , Tiller K. G. 
Published: July 2010

AbstractPotted soil experiments were conducted to analyze how higher Cl concentrations in soil enhance Cd uptake by plants. Two soils (W,L) were moistened with complete nutrient solution containing either NaCl or NaNO3 at concentrations ranging from 0 to 120 mmol L−1. Swiss chard (Beta vulgaris L., cv. Fordhook Giant) was grown in the soils until the 4th leaf appeared (15 d on soil W, 20 d on soil L). Plant dry weights generally decreased with increasing salt concentration, but were not significantly affected by the type of Na salt. For both soils, shoot Cd concentrations in the 120 mmol L−1 NaCl treatment almost doubled those in the zero salt treatments. In contrast, increasing NaNO3 concentrations either reduced shoot Cd concentration (soil L) or had no effect (soil W). Increasing concentrations of NaCl in the soil solution significantly increased the Cd concentration in solution from 65 to 400 nmol L−1 (soil W) and from 64 to 300 nmol L−1 (soil L). Increasing concentrations of NaNO3 in solution had no effect on Cd concentrations in solution. Speciation calculations predicted that the solution concentration of the free metal ion Cd2+ was not significantly affected by the NaCl (both soils) or NaNO3 (soil L) treatments. In soil W, the predicted Cd2+ concentrations in soil solution slightly decreased with increasing NaNO3 rate. It is concluded that the enhancing effect of NaCl on Cd uptake is due to chloride complexation of Cd.
Relationships between Loading Rates and Pollutant Removal during Maturation of Gravel‐Bed Constructed Wetlands
Authors: Tanner Chris C. , Sukias James P. S. , Upsdell Martin P. 
Published: July 2010

AbstractRelationships between pollutant mass loading and removal are reported for a series of five pilot‐scale constructed wetlands in their 4th and 5th years of operation. The wetlands received different hydraulic loadings ranging between ∼15 and 70 mm d−1 (9.5‐2 d theoretical retention, respectively). Effluent concentrations of 5‐d carbonaceous biochemical oxygen demand (CBOD), total nitrogen (TN), ammonium N (NH4‐N), and fecal coliforms (FC) broadly followed seasonal patterns in influent wastewater strength. Mean annual mass removals of 58 to 78% suspended solids (SS), 73 to 91% CBOD, 48 to 65% TN, 34 to 60% NH4‐N, 15 to 38% total phosphorus (TP), and 93 to 99.6% of FC were recorded, with removal efficiencies inversely related to loadings. Mass removal rates were monotonically related to loading rates, and could be modeled using a simple plug‐flow, first‐order approach accounting for removal down to nonzero background concentrations. Comparisons with treatment performance recorded for the wetlands soon after commissioning showed relatively constant relationships between mass loading and removal of CBOD, TN, and FC. In contrast, SS and TP removal declined significantly over the same period. Reduced SS removal efficiency appeared to result from clogging of the gravel substratum by refractory organic solids, and reduced TP removal from saturation of substratum sorption capacity and filling of plant storage pools. To improve N removal predictions for wetlands treating ammonium‐rich wastewaters, the use of a combined carbonaceous and nitrogenous BOD term is proposed, which addresses the oxygen dependence of microbial nitrification, the principal rate‐controlling process.
Dairy Manure Influences on Phosphorus Retention Capacity of Spodosols
Authors: Nair V. D. , Graetz D. A. , Reddy K. R. 
Published: July 2010

AbstractLand areas used for dairy farming can result in accumulation of manure on soils that could produce nutrient‐rich surface and subsurface runoff and cause accelerated lake eutrophication. This research was conducted on Spodosols that were differentially impacted by manure; the study included sites with different levels of total P (TP), from 2300 mg kg−1 in the soil highly impacted by intensive dairy farming to 18 mg kg−1 in an unimpacted area. The P retention characteristics of these soils were determined by using both single‐point (1000 mg P kg−1 or 100 mg P L1) and traditional Langmuir isotherms. Phosphorus sorption values using a single high P solution had approximately a 1:1 relationship with values obtained for the maximum retention capacity, Smax, obtained from Langmuir isotherms (r2 = 0.98). The surface A and E horizons of manure‐impacted soils had essentially no sorbing capacity while the Bh (spodic) and Bw horizons had mean Smax values 430 and 385 mg kg−1, respectively. The P sorbing capacity of the Bh and Bw horizons were attributed to high Al concentrations in these horizons. Higher P concentrations in the surface A horizon resulted in greater P concentrations in solutions equilibrated with the Bh‐ and Bw‐ horizon materials, which suggests a potential for vertical P movement through the soil profile. The spodic horizon of the less‐impacted soils may not have been exposed to sufficiently high solution P concentrations to accumulate significant P in the soluble fraction.
Leaching Potentials of Four Pesticides Used for Bananas in the Canary Islands
Authors: Diaz‐Diaz Ricardo , Garcia‐Hernandez Jose Enrique , Loague Keith 
Published: July 2010

AbstractNonpoint source (NPS) groundwater contamination, that is related to the regional‐scale use of agrochemicals, is a major environmental problem. This paper reports preliminary assessments of groundwater vulnerability due to pesticide leaching for areas of banana (Musa balbisiana) silviculture for the Canary Island of Tenerife using simple indices. Estimates of contamination potential were made for the four most commonly used pesticides using the retardation factor (RF) and the attenuation factor (AF). Soil, crop, and recharge maps for Tenerife were overlaid using a geographic information system (GIS) approach. Soil depth, the type of irrigation, soil‐pH dependent chemical halflives, and the method of landcover characterization were each assessed relative to their individual and cumulative impacts on assessing regional‐scale NPS groundwater vulnerability. The order of leaching potential, in terms of greatest mobility, for the four chemicals was found to be: (i) carbofuran (2,3‐dihydro‐2,2‐dimethyl‐7‐benzofluranyl‐n‐methylcarbamate), (ii) ethoprophos (O‐ethyl‐S,S‐di‐n‐propylphosphorodithioate), (iii) fenamiphos (ethyl 3‐methyl‐4‐(methylthio)‐phenyl1‐methylethylphosphoramidate), and (iv) oxamyl (methyl 2‐(dimethylamino)‐N‐[[(methylamino)carbony]oxy]‐2‐oxoethanimidothioate). The worst‐case scenario for groundwater contamination in Tenerife, related to banana silviculture, was found to be carbofuran with furrow irrigation. The best pesticide and irrigation combination to minimize potential groundwater contamination, related to the cultivation of bananas in Tenerife, was oxamyl and drip irrigation. The regional‐scale NPS groundwater vulnerability assessments presented here for Tenerife are the first to be made for the island and will be useful for future chemical regulation decisions and for targeting critical areas that may require remediation.
Trace Metal Speciation in Three Unbuffered Salt Solutions Used to Assess their Bioavailability in Soil
Authors: Lebourg A. , Sterckeman T. , Ciesielski H. , Proix N. 
Published: July 2010

AbstractThree unbuffered salt solutions used to estimate soil trace metal bioavailability were compared. The objective was to evaluate chemical speciation of Cd, Cu, Pb, and Zn in 0.01 M CaCl2, 0.1 M NaNO3, and 1 M NH4NO3 extracts. The metal in each extract were speciated with a model that was optimized experimentally using an exchange resin. In NH4NO3, Cd, Cu, and Zn were completely complexed by NH3. In extracts of pH lower than 6.5, Pb was essentially present as free Pb2+ and metal‐organic complexes. In extracts of higher pH, PbCO3 and free Pb2+ were dominant. In CaCl2, Cu and Zn were mainly present as organic complexes and free Zn2+, respectively. In all extracts, 50% of Cd was free Cd2+ and 50% CdCl+. As pH increased, the proportions of free Pb2+ and organic complexes decreased while those of inorganic complexes increased. In NaNO3, Cd, Cu, and Zn were, respectively, mainly present as free Cd2+, organic complexes and free Zn2+. Speciation of Pb changed with pH as in NH4NO3. Similarities were expected between the qualitative composition of the extracts and the soil solution, justifying the use of unbuffered salt solutions, particularly NaNO3 and CaCl2, in the evaluation of soil trace metal availability.
Vegetative Growth and Trace Metal Accumulation on Metalliferous Wastes
Authors: Pichtel J. , Salt Carol A. 
Published: July 2010

AbstractA greenhouse study was conducted to investigate the growth of the grass cover crops Agrostis capillaris, Festuca ovina, F. rubra, Lolium perenne, and Phleum pratense and their accumulation of Cu, Pb, Zn, Ni, and Cr in three metal‐contaminated wastes arising from a steelworks, a lead mine, and a chemical works. Soil metals were extracted by five reagents (Mehlich 1, 0.1 M HCl, 0.005 M DTPA, 0.005 M EDTA, 0.005 M NTA) and values were correlated with plant tissue accumulation of metals. Agrostis capillaris accumulated the greatest concentration of metals from each waste material. Dry matter production for all grasses decreased on contaminated substrates compared to the control; however, overall ground cover was satisfactory except for A. capillaris on the chemical works waste. Lolium perenne and P. pratense consistently produced the highest dry matter yields. All grasses accumulated excessive amounts of Cr on the chemical waste and Pb on the mine waste, presumably from reservoirs in the readily extractable and soluble forms. The extractability of most metals was generally 0.1 M HCl > Mehlich 1 > DTPA = EDTA = NTA. Mehlich 1 did not appreciably extract Pb from two wastes. No extractant was able to represent metal uptake by a particular grass in a linear fashion.
Mechanical Advancing Handle that Simplifies Minirhizotron Camera Registration and Image Collection
Authors: Johnson M. G. , Meyer P. F. 
Published: July 2010

AbstractMinirhizotrons in conjunction with a minirhizotron video camera system are becoming widely used tools for investigating root production and survival in a variety of ecosystems. Image collection with a minirhizotron camera can be time consuming and tedious particularly when hundreds or thousands of images are collected routinely. To help us with image collection in our minirhizotron studies we developed a mechanical handle that simplifies minirhizotron camera registration and image collection. The handle is attached to the minirhizotron camera and fits inside 5 cm, internal diameter, minirhizotron tubes. The handle couples a ratchet advancing mechanism with another mechanism that locks the handle to the minirhizotron tube, ensuring proper camera and tube registration. The ratchet mechanism advances the camera one camera field of view (frame) at a time. While the handle can be used to rapidly advance the camera, it is best to pause 2 to 3 s after each advance, to allow sufficient time for the image to be recorded on video tape. At this rate, 20 to 30 frames can be recorded each minute. The camera, with handle attached, is easily moved from one minirhizotron tube to another. We conducted a simple study of handle performance and estimate that camera registration precision (a measure of relocating the camera in the same position) is >99%.
Forms and Concentration of Phosphorus in Drainage Water of Twenty‐Seven Tile‐Drained Soils
Authors: Beauchemin Suzanne , Simard R. R. , Cluis D. 
Published: July 2010

AbstractIn most mineral soils, P leaching is rarely viewed as an important environmental issue. However, P accumulation and decreased P sorption capacities in surface horizons of long‐term fertilized soils may increase downward P movement. The objective of this study was to measure the concentration and characterize the P forms in drainage waters from nine soil series widely differing in clay content. Twenty‐seven sites were sampled in 1994 and 1995 from an intensively cropped area of the province of Quebec, Canada. Drainage waters were characterized for their total P (TP), dissolved reactive P (DRP), dissolved organic P (DOP), and total particulate P (TPP) contents. The Quebec surface water quality standard of 0.03 mg TP L1 was exceeded in 14 out of 27 sites in 1994 but only in 6 out of 25 sites in 1995. Of the 14 sites exceeding 0.03 mg TP L−1 in 1994, 10 were clayey soils. Under these circumstances, more than 50% of the TP was as TPP whereas DOP forms represented <30%. In 1995, TPP forms accounted for, on average, <50% of TP and DOP accounted for more than 40% of the TP concentrations. This study suggests that flat clayey soils of medium to rich P status may be particularly at risk of exceeding water quality standards in subsurface runoff. Phosphorus losses in particulate form may be important in subsurface runoff from clayey soils when weather conditions favor rapid flow through cracks or macropores.
Unwanted Agricultural Pesticides: State Disposal Programs
Authors: Centner Terence J. 
Published: July 2010

AbstractMillions of pounds of unwanted pesticides have accumulated in storage barns throughout our country. The potential environmental and health risks posed by this situation have garnered public attention and governmental action. While the possession of unwanted pesticides generally is not illegal, agricultural producers need to follow requisite legal requirements and dispose of pesticides properly to avoid legal infractions. The federal government has published the Universal Waste Rule so that it is easier to dispose of unwanted pesticides through waste pesticide collection programs. Nearly every state has initiated efforts to collect and dispose of accumulated pesticides in a safe manner, but many programs only address a part of the problem. For many states, the lack of implementation of funding or a permanent mechanism for the collection of unwanted pesticides means that pesticides will continue to present risks to our society.