bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Revegetation Techniques of a Saline Flue Gas Desulfurization Sludge Pond
Authors: Salo L. F. , Artiola J. F. , Goodrich‐Mahoney J. W.
Published: July 2010

Codisposal of flue gas desulfurization (FGD) sludge with low‐volume generating station waste simplifies disposal but creates a saline, high‐boron (B) waste that may be difficult to revegetate after site closure. Studies on a delta of waste material in a codisposal pond in eastern Arizona evaluated management techniques, amendments, and plants for revegetating this material. One study investigated leaching and ridging techniques and a second evaluated amendment with manure, wood shavings, and fly ash. Four salt‐tolerant grass species and four saltbushes (Atriplex spp.) were evaluated in the two studies. Criteria for success were high survival rates and growth, as measured by grass height and shrub height × width. Leaching salts and B from the waste was not necessary for establishment and growth of transplanted shrubs and grasses. Ridging was not a successful technique, due to limited moisture and high levels of salinity and B on these structures. Gardner saltbush [A. gardneri (Moq.) D. Dietr.] and a fourwing saltbush [A. canescens (Pursh) Nutt.] accession from the site were the most successful shrubs and alkali sacaton [Sporobolus airoides (Torr.) Torr. ‘Saltalk‘] was the most successful grass at this disposal pond. Amendment with manure, wood shavings, or fly ash did not increase plant survival. Growth of grasses was improved with all amendments and was greatest with manure, but growth of shrubs was not improved with any amendment.
Growth of Woolgrass in Acid Mine Drainage
Authors: Demchik Michael , Garbutt Keith
Published: July 2010

Acid mine drainage (AMD) has impacted more than 3200 km (2000 miles) of streams in West Virginia. Constructed wetlands have been used for passive AMD treatment since the early 1980s, and plant growth studies in constructed wetlands are scarce. Two populations of woolgrass [Scirpus cyperinus (L.) Kunth], a bulrush species common in naturally present AMD wetlands, were investigated to determine population level differences in aboveground and belowground growth response to AMD. Differences at the level of population were found in aboveground parameters. One population had significantly greater aboveground growth than the other population during portions of the growing season when growing in AMD, suggesting greater ability to grow in AMD wetlands. Differences at the level of population were also found for root growth; however, the root growth response to AMD was not different between populations. Treatment with AMD slightly increased aboveground growth but reduced belowground growth. This suggests a potential for differential allocation to different growth components under AMD treatment. These results suggest there is a potential for selecting genotypes of woolgrass for increased performance in the presence of AMD.
Gas Exchanges in Soybean as Affected by Landfill Biogas Atmosphere
Authors: Marchiol L. , Mori A. , Leita L. , Zerbi G.
Published: July 2010

A problem in the ecologicai restoration of closed landfills is the production of potentially toxic gases by decomposition of refuse that affects the root system and physiology of plants growing on these sites. The aim of the present study was to assess the effects induced by landfill biogas contamination on gas‐exchanges of soybean [Glycine max (L.) Merr.]. Simulated landfill and control gases were supplied to soybean plants under laboratory conditions for 10 d. The composition of the simulated landfill gas used was: 16% O2, 8% CO2, 3% CH4, and 73% N2; a control gas was also tested (21% O2, 0.035% CO2, and 78% N2). Photosynthesis and stomatal conductance were significantly affected by the gas treatment after 3 d; in the course of the experiment, biogas treatment progressively reduced Amax, in light‐saturation curves. The fresh and dry weight, leaf area and leaf chlorophyll content were not affected by the treatment. A metabolic adaptation to the biogas in the roots of treated plants was related to the disappearance of a fraction of the protein pool.
Tree‐Ring Cation Response to Experimental Watershed Acidification in West Virginia and Maine
Authors: DeWalle David R. , Tepp Jeffrey S. , Swistock Bryan R. , Sharpe William E. , Edwards Pamela J.
Published: July 2010

The impact of experimental watershed acidfication on xylem cation chemistry was evaluated in eight tree species at two sites in West Virginia (Clover Run and Fernow) and one site in Maine (Bear Brook). All sites had received regular additions of (NH4)2SO4 equivalent to twice the ambient annual wet plus dry atmospheric deposition of N and S. Multiple wood cores were extracted from tree boles in five trees of each species on treatment and control areas at each site with increment borers. Cores were divided into several age segments and composited for each tree. Ground wood samples were destructively analyzed for Ca, Mg, Mn, and Al concentrations using inductively coupled plasma emission (ICP) methods. All tree species sampled at the two West Virginia sites exhibited significant Ca and/or Mg concentration decreases and Mn concentration increases in sapwood on the treated relative to control areas after 8 yr of treatment. At Bear Brook, tree‐ring concentrations in three species showed similar trends after 5 yr of treatment, but differences were generally not significant. Sapwood molar ratios of Ca/Mn and Mg/Mn were better indices to soil acidification than Ca/Al, due to low Al concentrations and insensitivity of sapwood Al concentrations to treatments. Overall, sapwood chemistry appeared to be a reliable indicator of the current nutrient status of trees; but, except for Japanese larch (Larix leptolepis Sieb. and Zucc.), sapwood chemistry did not preserve a record of the chronology of past changes due to treatments.
Sorption of Organic Chemicals by Microfilters
Authors: Xing Baoshan , Jin Zhaowei
Published: July 2010

Inline syringe microfilters are often used for separating solid particles from the solution phase in environmental research and sample preparation for high performance liquid chromatography (HPLC) analysis; but only limited information is available for retention of organic compounds by these microfilters. We here report on the results of naphthalene and toluene sorption by five polymer microfilters. The five filters had different polymers makeup for their membrane and housing and were: (i) nylon‐polypropylene (NY‐PP); (ii) borosilicate glass‐acrylic (BA‐AC); (iii) polyethersulfonc‐acrylic (PS‐AC); (iv) polyvinylidene difluoride‐polypropylene (PV‐PP); and (v) PTFE‐polypropylene (PT‐PP). Six aqueous concentrations over three orders of magnitude were used. All filters received five or six passages with each concentration solution. All of the five filters sorbed both naphthalene and toluene and sorption was largest at the first passage and declined with increasing number of passages. The sorption order of naphthalene (average of six concentrations at the first passage) was: BA‐AC (98%) > PV‐PP (93%) > NY‐PP (64%) > PS‐AC (49%) > PT‐PP (13%) and toluene was: BA‐AC (56%) > PV‐PP (25%) > PT‐PP (22%) ≥ PS‐AC (20%) = NY‐PP (20%). The magnitude sorption was generally independent of concentrations. These results suggest that suitability of polymer filters must be determined before actual use in environmental sampling and research involving organic chemicals, particularly ones with low solubility and polarity.
Advanced Information Technologies for Assessing Nonpoint Source Pollution in the Vadose Zone: Conference Overview
Authors: Corwin D. L. , Loague K. , Ellsworth T. R.
Published: July 2010

The information age has ushered in an awareness of and concern for global environmental problems such as climatic change, ozone depletion, deforestation, desertification, and nonpoint source (NPS) pollution. Nonpoint source pollution is the single greatest threat to surface and subsurface drinking water resources. Nonpoint source pollutants also pose a threat to sustainable agriculture, which is viewed as the most viable means of meeting the food demands of a world population that is expected to reach 9.4 billion by the middle of the next century. The ability to accurately assess present and future NPS pollution impacts on ecosystems ranging from local to global scales would provide a powerful tool for environmental stewardship and guiding future human activities. Assessing NPS pollutant is a multidisciplinary problem. To address the problem, advanced information technologies and methodologies are needed that draw from all areas of science and are applied in a spatial context. It was from this setting that the 1997 Joint AGU Chapman/SSSA Outreach Conference Application of GIS, Remote Sensing, Geostatistics, and Solute Transport Modeling for Assessing Nonpoint Source Pollutants in the Vadose Zone (19–24 Oct. 1997, Riverside, CA) materialized. The objective of the conference was to examine current multidisciplinary technologies and methodologies for assessing NPS pollutants in the vadose zone, and to explore new conceptual approaches. It was the conference's goal to provide a forum to stimulate multidisciplinary interaction to enhance the development of techniques for the real‐time measurement and modeling of NPS pollution in the vadose zone and subsurface waters.
DBCP Contaminated Groundwater: Hot Spots and Nonpoint Sources
Authors: Loague Keith , Abrams Robert H.
Published: July 2010

The regional‐scale nonpoint source (NPS) solute transport simulations reported by Loague et al. (1998a,b), for DBCP (1,2‐dibromo‐3‐chloropropane) for east‐central Fresno County (California), are the foundation of the work reported in this paper. This effort is divided into two phases. In the first phase we revisit our coupled 3‐D deterministic‐conceptual simulations of groundwater vulnerability for the Fresno study area (Loague et al., 1998a,b) and quantitatively evaluate the model performance by rigorously comparing the simulated DBCP concentrations, in both space and time, with field observations. The regional‐scale simulation results presented here indicate tremendous spatial and temporal variability in the estimates of DBCP loading at the water table based on NPS applications and illustrate a potential long‐term evolution scenario for the DBCP plume in the study area. The simulations presented here suggest that NPS applications of DBCP may not be totally responsible for all the observed hot spots in the Fresno County study area. Reverse flow path and forward solute transport simulations, with MODPATH and MT3D, respectively, were used in the second phase of this effort to determine if the isolated, high DBCP concentrations were likely to be the result of NPS applications. Unreasonably high simulated application rates were needed to generate a targeted observed DBCP hot spot if the sole source of the high concentrations was due to NPS agricultural applications. Potential sources for the DBCP contaminated groundwater, other than NPS label‐recommended application rates, are discussed.
Solubility and Ion Activity Products of Calcium Phosphate Minerals
Authors: Jaynes W. F. , Moore P. A. , Miller D. M.
Published: July 2010

Most phosphate mineral solubility data in use were measured more than 20 yr ago when instrumentation and methods were generally less sophisticated. The objective of this study was to measure calcium phosphate mineral solubilities using modern analytical equipment and techniques. Natural and synthetic Ca phosphate minerals (<50 µm) were equilibrated in water and dilute HCl for 6 mo with continuous agitation. X‐ray diffraction (XRD) was used to identify compositions before and after equilibration. Filtered (<0.2 µm) solution aliquots were analyzed for pH and chemistry. Chemical compositions were determined using inductively‐coupled plasma spectroscopy (ICP). Aqueous carbonates were determined from alkalinity titrations after phosphate alkalinity corrections. The chemical speciation model “Soilchem” was used to calculate free ion concentrations and ionic strengths. Ion activity products (IAPs) were determined from free ion concentrations and single ion activity coefficients. Experimental log IAPs of monetite (CaHPO4) were consistent (−6.60) with published values for brushite (CaHPO4·2H2O) suggesting that the IAPs of these minerals are identical. No change in mineralogy during equilibration was revealed by XRD. Experimental log IAPs of synthetic whitlockite (−30.74, β‐Ca3(PO4)2) indicated somewhat lower solubility than published values. Log IAPs of synthetic hydroxyapatite (−56.02, Ca5(PO4)3OH) were within the range of published values. Natural samples of whitlockite and fluorapatite did not attain equilibrium due to extraneous siderite (FeCO3) and silica phases within the samples. A long equilibration time, modern analytical equipment, and a chemical speciation program can yield more reliable solubility data for phosphates and other minerals.
Bioavailablility of Heavy Metals in Strongly Acidic Soils Treated with Exceptional Quality Biosolids
Authors: Basta N. T. , Sloan J. J.
Published: July 2010

New federal regulations may increase application of exceptional quality (EQ) biosolids to acidic soils, and information on the effect of this practice on bioavailability of heavy metal is limited. The objective of this study was to compare bioavailability of heavy metal in soil treated with nonalkaline or alkaline EQ biosolids with limestone‐treated soils. Three acidic soils (pH 3.7–4.3) were treated with three amounts of lime‐stabilized biosolids (LS), anaerobic‐digested biosolids (AN), or agricultural limestone (L), and incubated 25°C. Soil solution Cd, Zn, and other chemical constituents were measured at 1, 30, 90, and 180 d incubation. Chemical fractionation of heavy metal was performed after 180 d incubation. Soil solution Cd and Zn were AN > LS ≥ L, C. Soil solution Cd and Zn increased with AN applied but decreased with LS applied. The high application of LS had soil solution Zn equal to that obtained using limestone. Soil solution Cd and Zn dramatically decreased at soil pH >5.5 and >5.1, respectively. Soil solution Cd and Zn increases were AN > LS with incubation time. Biosolids treatments increased heavy metal in Ca(NO3)2 and NaOAc fractions. Except for Cd, most metal from biosolids were in EDTA and HNO3 fractions. Heavy metal bioavailability, measured using lettuce (Lactuca sativa L.), was AN > LS ≥ L, C. Although state regulations prohibiting application of nonalkaline EQ biosolids to acidic soil is a prudent practice, application of EQ alkaline biosolids that achieves soil pH >5 minimizes risk from soil solution Cd and Zn and plant uptake of heavy metal.
Trace Element Solubility from Land Application of Fly Ash/Organic Waste Mixtures
Authors: Jackson B. P. , Miller W. P. , Schumann A. W. , Sumner M. E.
Published: July 2010

Use of fly ash (FA) as a soil amendment is hindered by a lack macronutrients in the ash and concerns about trace element availability. Mixing FA with an organic waste can increase macronutrients while reducing odor and improving material handling, but the trace element solubility requires investigation. This study examined the trace element solubility and availability resulting from land application of such mixed wastes. Two FAs were applied as mixtures with either poultry litter (PL) or sewage sludge (SS) to field plots at rates 100 and 120 Mg ha−1 for FA/PL and FA/SS, respectively. Suction cup lysimeters were used to collect soil solution, and trace element uptake was monitored in maize (Zea mays L.) leaf tissue and grain. Soluble B was initially >25 mg L−1 for one high B FA/PL mixture and led to initial toxicity in seedlings. Soil solution concentrations of dissolved C, P, As, Se, Mo, Cu, and Cr were increased in FA/PL field plots. For P, C, As, and Cu, increased solubility was due to increased load in the FA/PL mixtures, while for Mo, Se, and Cr, mixing fly ash with poultry litter appeared to increase solubilization from the ash when compared with an equivalent mass of FA mixed with sewage. Leaf tissue data confirmed an increase in available As from the FA/PL mixtures, while leaf tissue Se was more dependent on the total Se concentrations of the ash.
The Effects of Pocket Gopher Burrowing on Water Balance and Erosion from Landfill Covers
Authors: Hakonson T. E.
Published: July 2010

A 2‐yr field study was conducted to evaluate the impact of burrowing and soil casting by pocket gophers (Thomomys bottae) on runoff, soil loss (mass and size distribution), soil moisture status, and transport of stable cesium (133Cs) that was applied to the soil surface. A rotating boom rainfall simulator was used on 3.1 by 10.9 m landfill cover plots with and without vegetation and with and without pocket gopher burrowing. Gopher burrowing in the presence of vegetation resulted in large decreases in runoff, erosion, and cesium loss via erosion but increased migration of cesium to the subsurface soil due to increased infiltration. Vegetation slightly decreased runoff but greatly decreased erosion and cesium loss by erosion. As with gophers, vegetation enhanced movement of cesium into the soil. Under the conditions of this study, the effects of pocket gopher burrowing in degrading a landfill cover were minimal when vegetation was a component of the cover.
Impact of Land Use on Microbial Transformations of Atrazine
Authors: Aelion C. Marjorie , Cresci Dana C.
Published: July 2010

Atrazine has been one of the most heavily applied preemergent herbicides in the USA, and with alachlor, represents more than 45% (4.082 × 106 kg) of total herbicide application in coastal U.S. counties. Several studies using bacterial isolates or mixed cultures have demonstrated that mineralization of atrazine [6‐chloro‐N‐ethyl‐N′‐(1‐methyl‐ethyl)‐1,3,5‐triazine‐2,4‐diamine] is rapid, yet in soil microcosms mimicking in situ conditions, mineralization accounts for <1% of the applied compound. This study examined the impact of land use on atrazine biotransformation in sediments from three coastal sites, all in an historically agricultural area that has undergone extensive development in recent years. Production of 14CO2 was monitored in sediment incubated with [U‐14C]‐atrazine from a forested preserve, a suburban neighborhood and a golf course, all of which were previously impacted by agriculture. Solid phase extraction of both liquid and sediment fractions was carried out over time to determine whether metabolic transformation of atrazine occurred. Results indicated that mineralization represented <1% of the atrazine added, and ring carbons were not assimilated into cellular biomass. Production of 14C‐transformation products was a significant portion of the total 14C‐atrazine added at all sites, but was greatest in the golf course sediments. This may be attributed to several environmental conditions of land development such as the preexposure of the golf course bacteria to frequent pesticide applications, and 100% sand content of the golf course sediment vs. higher clay and organic C content at the other two sites, causing less sorption and more bioavailability of atrazine.
Dust and Endosulfan Deposition in a Cotton‐Growing Area of Northern New South Wales, Australia
Authors: Larney Francis J. , Leys John F. , Müller Jochen F. , McTainsh Grant H.
Published: July 2010

The pesticide endosulfan (6,7,8,9,10,10‐hexachloro‐1,5,5a,6,9,9a‐hexahydro‐6,9‐methano‐2,4,3‐benzodioxathiepin‐3‐oxide) has been detected in rivers in the cotton (Gossypium hirsutum L.)‐growing area of northern New South Wales at a 5 yr mean (1991–1995) concentration of 0.06 µg L−1. One pathway by which endosulfan reaches the riverine environment is transport on contaminated dust. Our objectives were to examine: (i) dust deposition from vehicular traffic on an unsealed road on a cotton farm, and around a cotton field in the 11 to 65 h period after endosulfan application; (ii) endosulfan deposition in the 11 to 65 h period after endosulfan application, and over a 3‐mo period at on‐farm and off‐farm (nontarget) locations. Dust deposition rates from vehicular traffic varied from 0.013 g m−2 vehicle−1 at 1 m distance, to 0.002 g m−2 vehicle−1 at 100 m distance from an unsealed road (soil surface, no gravel added). The maximum endosulfan deposition in the 11 to 65 h post‐spraying period was 95 µg m−2 at 5 m from the field. Over a 3‐mo monitoring period (December 1996–March 1997), the average daily deposition rate of endosulfan was 0.16 µg m−2 d−1 for the off‐farm sites compared with 0.35 µg m−2 d−1 for the on‐farm site. As the measurement period was one of the wettest on record and the number of endosulfan applications was less‐than‐normal, the dust and endosulfan deposition results may be interpreted as minima.
Nitrogen Mineralization in a Mature Boreal Forest, Isle Royale, Michigan
Authors: Stottlemyer Robert , Toczydlowski David
Published: July 2010

The 115‐ha boreal Wallace Lake watershed, located on Isle Royale in the Lake Superior Basin, receives moderate anthropogenic atmospheric N inputs (3 kg ha−1 yr−1). Ecosystem response to atmospheric N inputs is, in part, determined by internal production and consumption of this limiting nutrient. The objectives of this 2‐yr study on plots dominated by birch, spruce, or alder were to quantify forest floor and surface soil net and gross N mineralization rates, and examine potential effects of changes in temperature and moisture on these processes. Gross N mineralization rates were 23 times net mineralization rates, and increased with forest floor/soil temperature and moisture. Substrate quality was a likely factor in higher gross mineralization rates beneath birch and spruce. Ammonium immobilization increased with forest floor/soil temperature and moisture. Higher net N mineralization rates beneath alder resulted from lower microbial immobilization rather than greater gross N mineralization. The greatest differences between gross N mineralization and immobilization occurred in early summer. Ammonium immobilization averaged 62% of gross N mineralization. Net and gross nitrification rates differed by vegetation type, were highest in spring and fall, and increased with moisture. Gross nitrification was 19 times net nitrification rates. Nitrate immobilization increased with soil moisture, and equalled or exceeded gross nitrification. Net and gross N mineralization or nitrification rates were not correlated. Seasonal variation in forest floor and surface soil N cycling coupled with high ecosystem retention of precipitation N inputs suggest streamwater N concentrations and output reflect trends in soil processes.
On‐Line Solid Phase Extraction for Polycyclic Aromatic Hydrocarbons in Soil Column Effluents
Authors: Weigand Harald , Totsche Kai U. , Kögel‐Knabner Ingrid
Published: July 2010

On‐line solid phase extraction with C‐18 cartridges provided a reliable method for the extraction of polycyclic aromatic hydrocarbons (PAHs) from soil column effluents. The on‐line extraction was compared to the common off‐line extraction of effluent fractions with respect to the mass recoveries of an internal standard. The effluent was obtained from a water unsaturated soil column under steady state water flow conditions. The column was packed with an artificially anthracene‐contaminated soil material. Our results showed superior and more reproducible PAH trapping when the on‐line extraction was used. The PAH mass recoveries were unaffected by the range of dissolved organic carbon (DOC) concentrations covered in the experiment. This held true over a range of pHs and water unsaturated conditions of the C‐18 material. By using the on‐line extraction procedure, losses of PAHs due to sorption to the surfaces of collection vessels were avoided. The combination with a fraction collector allowed for the extraction of very small sample volumes. Thus, the method is suitable for an unbiased evaluation of PAH mobility in soil column experiments.
Adsorption of Selected Pesticides on a Rigid PVC Lysimeter
Authors: Koskinen W. C. , Cecchi A. M. , Dowdy R. H. , Norberg K. A.
Published: July 2010

Lysimeters have traditionally been made out of stainless steel and teflon to monitor soil solutions and groundwater. The possibility of adsorption of organic chemicals to polyvinyl chloride (PVC) lysimeters, a more economical alternative to stainless steel, has led to debate over their suitability for groundwater sampling. The adsorption of different pesticide chemistries, chloroacetanilide (alachlor (2‐chloro‐N‐(2,6‐diethylphenyl)‐N‐(methoxymethyl)acetamide)), s‐triazine (atrazine (6 ‐ chloro ‐ N ‐ ethyl ‐ N′‐1‐methylethyl)‐1‐3‐5‐triazine‐2,4‐diamine)), chloronicotinyl (intidacloprid (1‐[(6‐chloro‐3‐pyridinyl)‐methyl]‐N‐nitro‐2‐imidazolidinimine)), organophosphorus (isofenphos (1‐methylethyl 2‐[[ethoxy[(1‐methylethyl)amino]phosphinothioyl] oxy]benzoate)), sulfonylurea (nicosulfuron (2‐[[[[(4,6‐dimethoxy‐2‐pyr‐imidinyl) amino ] carbonyl]amino]sulfonyl]‐N,N‐dimethyl ‐3‐pyridine carboxamide)), and azole (triadimefon (1‐(4‐chlorophenoxy)‐3,3‐dimethyl‐1‐(1H‐1,2,4‐triazol‐1‐yl)‐2‐butanone)), on a lysimeter constructed from rigid PVC was determined to evaluate the suitability of PVC material for use in groundwater sampling. Among all pesticides tested, only isofenphos demonstrated slight adsorption (9% of applied) on the lysimeter; adsorption was rapid and isophenfos was not easily desorbed with methanol and water. None of the other pesticides adsorbed to the lysimeter. When selecting a lysimeter, potential adsorptive interactions between other pesticide chemistries and the materials used in the lysimeter construction should be evaluated.
Drilling Fluid Effects on Crop Growth and Iron and Zinc Availability
Authors: Bauder T. A. , Barbarick K. A. , Shanahan J. F. , Ayers P. D. , Chapman P. L.
Published: July 2010

Waste drilling fluids are often land‐farmed following completion of an oil or gas well in Colorado. This material usually contains production water, bentonitic clays, formation cuttings, barite, Na compounds, and synthetic organic polymers. We investigated the effects of 5 to 60 dry g drilling fluid kg−1 soil on the growth and trace metal concentration of sorghum—sudangrass (Sorghum bicolor L. Moench ‘DeKalb ST‐6’—S. sudanense) in the greenhouse. A nonlinear regression exponential‐rise model fit the increased plant total dry matter yield response to increasing drilling fluid rates. Increased plant tissue Fe concentration and uptake (P < 0.05) indicated that increased plant‐available Fe was primarily responsible for the yield response, but increased Zn availability was also suspected. Results from a second greenhouse study confirmed that drilling fluid can also correct Zn deficiency in corn (Zea mays L.). Soil SAR (sodium adsorption ratio) was higher with increasing drilling fluid, but was still <1. Other trace‐element concentrations in sudangrass tissue and soil pH and ECsat were not significantly increased due to application of drilling fluid. This study showed that application of controlled rates of water‐based drilling fluid from operations in Weld County, Colorado, was beneficial to the growth of sorghum—sudangrass and provided evidence that land application is an acceptable method of disposal.
Phosphorus Storage on Effluent Irrigated Land
Authors: Menzies N. W. , Skilton J. A. , Guppy C. N.
Published: July 2010

Land disposal of secondary treated sewage effluent is being widely adopted in Australia as an alternative to tertiary treatment. At the Cleveland Waste Water Pollution Control Works, effluent has been applied to a Hapludalf at high rates (3000 mm yr−1) for more than 20 yr, adding an estimated 4.5 t P ha−1 to the soil. Thus, this site provides an opportunity to assess the retention of P under conditions typical of southeast Queensland. Laboratory chemical fractionation and P sorption studies of effluent irrigated and control sites were undertaken to determine the amount and forms of P retained within this soil and its capacity to retain further P. Organic material (peat) which had accumulated on the surface of effluent irrigated plots, was also sampled and its P content determined. Accumulation of P was limited to the sandy surface soil, increasing total soil P content by ≈ 700 kg ha−1, with this increase being approximately evenly distributed between inorganic and organic pools. The excessive irrigation rate used on this site, and the management adopted, has resulted in a marked podzolization of the surface horizon, apparent in reduced extractable Fe and Al concentrations. The removal of these P adsorbing materials would contribute, along with P saturation and organic ligand competition, to the much lower P sorption capacity of irrigated sites relative to the control. The largest P pool was found to be the peat layer, containing approximately 1500 kg P ha−1. On this site P has accumulated principally in organic forms, both within the soil and as peat on its surface. This finding throws into question the common practice of predicting disposal scheme life on the basis of P adsorption curves.
Transport of Cryptosporidium parvum Oocysts through Saturated Columns
Authors: Brush Charles F. , Ghiorse William C. , Anguish Lynne J. , Parlange Jean‐Yves , Grimes Hilary G.
Published: July 2010

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

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

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

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

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

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

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

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

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

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

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