bluuebunny/crossref_metadata_2025 huggingface dataset:
Solubility and Leachability of Fishwaste Compost Phosphorus in Soilless Growing Media
Authors: Kuo S. , Hummel R. L. , Jellum E. J. , Winters D.
Published: July 2010

Knowledge of solubility and leachability of fishwaste compost P is needed to effectively use fishwaste compost as a P source in soilless growing media. The fishwaste compost contained 3.6 g P kg−1 compost on a dry weight basis and had high P solubility, with 64.4% of the total P in the compost extractable by six successive extractions with 0.01 M NaCl. In the dilute salt solution, the Ca release from the compost paralleled that of P. The sequential extraction did not substantiate that Ca‐P was the predominant P form in the compost, because substantial amounts of P solubilized in 0.01 M NaCl were from the labile P (NH4Cl‐P) and potentially labile P (Fe‐ and Al‐P) pools. High solubility of the compost P resulted in elevation of P concentrations in leachates and cumulative amounts of P leached over 10 wk when the growing media containing 25% or more compost was irrigated with overhead sprinkler irrigation. Young rhododendron (Rhododendron fortunei ‘Scintillation’) did not significantly (P > 0.05) reduce P leaching from the 50% or higher compost treatments because the amount of P accumulated in the plant leaves represented 3 ± 0.9 (SD)% of P in the compost and P fertilizer combined. To reduce P leaching and minimize nonpoint P pollution, additions of P fertilizer to the soilless growing media containing the fishwaste compost should be restricted. Otherwise, the proportion of the compost in the media should be limited to 25% or less, unless it is used in conjunction with controlled drip irrigation.
Occurrence and Mass Balance of Polycyclic Aromatic Hydrocarbons in the Thessaloniki Sewage Treatment Plant
Authors: Manoli E. , Samara C.
Published: July 2010

The occurrence and the mass balance of the 16 EPA polycyclic aromatic hydrocarbons (PAHs) were investigated in a conventional activated sludge treatment plant. Polycyclic aromatic hydrocarbon concentrations were determined in wastewater and sludge samples from different treatment stages. The concentrations of PAHs in raw sewage were statistically analyzed to examine whether temporal factors (sampling period, day and hour of sampling) had a significant effect on the observed variance. Sampling period was the only factor that showed a significant impact. Principal component analysis (PCA) was used to assess similarities of the wastewater PAH pattern with possible source matrices (domestic effluents, urban runoff, and atmospheric particulates). The composition of wastewaters was found to be particularly similar to that of domestic effluents. Mass balances of PAHs were calculated for individual stages of wastewater treatment (primary treatment, secondary treatment, and chlorination), as well as for the whole treatment process. Relatively good mass balances were calculated in the primary clarifier for most PAHs. Lower molecular weight PAHs (Np, Ace, Ph, An, and Fl) showed substantial losses (>40%), in the secondary treatment probably due to biodegradation and volatilization. Good closures for all PAHs were found in the chlorination stage. Total mass balances indicated that only the lower PAHs are effectively removed, whereas the heavier compounds are rather resistant to the treatment process. Sorption was found to be the dominating removal process of PAHs—especially of the heavier ones—during primary treatment, while their removal during the secondary treatment is also governed by other processes, such as biodegradation and/or volatilization.
Ammonia Volatilization from Liquid Hog Manure Amended with Paper Products in the Laboratory
Authors: Subair S. , Fyles J. W. , O'Halloran I. P.
Published: July 2010

Losses of N from livestock operations due to ammonia (NH3) volatilization from animal wastes is a major source of pollution in Europe and North America, and represents a significant economic loss. Paper products have potential as amendments to reduce NH3 loss because their high carbon (C) and low nitrogen (N) contents would be expected to cause N immobilization. Reduction in NH3 volatilization from liquid hog manure (LHM) by paper bag (PB), filter paper (FP), newsprint (NP), and pulp sludge (PS) added at 2.5 and 5% (fresh LHM weight) was evaluated in a 56 d incubation study. Cumulative NH3 volatilization ranged between 28 and 53% of initial manure N. When the rate increased from 2.5 to 5%, NH3 volatilization was reduced by 47, 40, 37, and 29%, respectively, compared to the control. Increasing the rate increased the amount of C lost from the LHM and reduced the net mineralization of organic N. Hence, the addition of organic amendments appeared to have decreased NH3 volatilization by increasing microbial activity and N immobilization. Liquid hog manure pH was negatively correlated with C loss, indicating that microbial decomposition of paper amendments lowered manure pH but this effect did not appear to be important in controlling NH3 volatilization. Paper lignin content was not correlated with the loss of C, manure pH, or NH3 volatilization, suggesting that the effectiveness of paper products in reducing NH3 volatilization is not controlled by lignin content but rather by other more labile components.
Irrigation of Native Rangeland Using Treated Wastewater from In Situ Uranium Processing
Authors: Levy D. B. , Kearney W. F.
Published: July 2010

Although land disposal of municipal and industrial wastewater is a common practice, there is a potential for adverse environmental effects resulting from the application of some wastewaters. This study was conducted to assess the effects of rangeland irrigation using treated process waters from in situ leaching (ISL) operations at the Highland Uranium Project in Wyoming. Irrigation water quality was evaluated based on guidelines developed by the U.S. Salinity Laboratory, and concentrations of Se, B, U, and 226Ra were monitored in soil and vegetation for 6 yr. The effects of Se and B to forage grasses and wildlife were evaluated based on known toxicity thresholds obtained from the literature. Although the water is moderately saline (EC = 2.8 dS m−1), the site maintains adequate leaching to control salt accumulation in the root zone. Selenium, B, U, and 226Ra concentrations in grasses were within the natural ranges that have been documented in the literature, and were also below phytotoxic levels. Boron concentrations in both the irrigation waters and forage grasses were sufficiently low that they appear to pose no threat to livestock or waterfowl. Plant tissue Se concentrations were at or below the lowest reported tolerance level for livestock during most years, and also below the threshold for Se toxicity in pronghorn antelope. Therefore, sprinkler irrigation on rangeland appears to be a safe and practical wastewater disposal option at the Highland Uranium Project, and may be a practical method of wastewater disposal for other ISL operations as well.
Metal Solubility in Phosphogypsum‐Amended Sediment under Controlled pH and Redox Conditions
Authors: Carbonell A. A. , Porthouse J. D. , Mulbah C. K. , DeLaune R. D. , Patrick W. H.
Published: July 2010

The storage of phosphogypsum (PG, CaSO4 xH2O) has occupied vast areas of land that remain abandoned and subject to leaching and erosion by wind and water. The major constraints for PG use in the environment are the presence of several heavy metals and its radioactivity. Mississippi River alluvial sediment amended with PG (1%) was equilibrated under controlled redox (−250, −100, 0, 150, 300, and 500 mV) and pH (5.0 and 7.0) conditions to evaluate the feasibility of using PG to reduce aqueous concentrations of potentially toxic heavy metals and as a nutrients source. Phosphogypsum is an effective nutrient source since it increased water soluble Ca, Mg, K, and P concentrations (essential plant nutrients). At the same time, PG significantly reduced soluble Al at pH 7.0 (normal pH value of anaerobic wetland sediments), thereby reducing Al toxicity to plants growing in the sediment. Phosphogypsum addition resulted in a large increase in sulfide levels in reduced sediment suspensions. As a result, at low redox potential values, the solubility of spiked heavy metals (Cd and Ni at rates of 1000 mg kg−1) and natural trace elements was substantially reduced by precipitation as insoluble sulfides. Low sediment pH (pH 5.0) resulted in the highest release of all the studied metals [Ca, Mg, P, K, Fe, Mn, Cd, and Ni] into the sediment solution, likely due to H+, Fe2+, Mn2+, and Al3+ displacing these metals from the exchange complex. This study, therefore, indicates that PG application to Louisiana Mississippi River alluvial sediments is useful for alleviating Al toxicity (neutral pH), increasing nutrient availability under watterlogged conditions, and reducing aqueous concentrations of toxic heavy metals to trace levels under anoxic conditions by precipitating these toxic elements as insoluble sulfides. If PG or PG‐products are placed in neutral to alkaline sediments/soils and/or reducing environments, metals release at toxic levels should be of little concern to the wetland environment.
In‐Stream Wetland Mitigation of Nitrogen Contamination in a USA Coastal Plain Stream
Authors: Hunt P. G. , Stone K. C. , Humenik F. J. , Matheny T. A. , Johnson M. H.
Published: July 2010

Nonpoint source N from riverine origin is a major water quality problem throughout the world. Nitrogen removal from a contaminated (6.6 mg L−1, NO3‐N) stream was evaluated in this study using an instream wetland (ISW). The ISW was established at the exit of a 425‐ha USDA Water Quality Demonstration watershed in the Coastal Plain of North Carolina. It ranged in depth from about 0.2 to 2 m, and it was <1% (3.3 ha) the size of the watershed. The ISW dramatically lowered mean stream NO3‐N from 6.6 to 2.0 mg L−1. Nitrate‐N mass removal was highly correlated to inflow NO3‐N (r = 0.93) in the warmer months when biological processes were more active. Ammonia‐N mass removal was opposite that of NO3‐N. It was highly correlated to inflow NH3‐N (r = 0.81) during the cooler months. Removal of both NO3‐N and total‐N (NO3‐N + TKN) were positively correlated to temperature with r values of 0.77 and 0.62, respectively. Total annual N removal for the ISW was approximately 3 kg ha−1 d−1, which was about 37% of the inflow N. The ISWs appear to be very good landscape features for mitigating excess nonpoint source N in the southeastern Coastal Plain of the USA. As such, they are a good complement to other best management practices for improved water quality.
In Situ Measurements of Denitrification in Constructed Wetlands
Authors: Xue Yuan , Kovacic David A. , David Mark B. , Gentry Lowell E. , Mulvaney Richard L. , Lindau Charles W.
Published: July 2010

Quantitative estimates of denitrification are needed in designing artificial wetlands to optimize nitrate (NO−3) removal. Acetylene blockage and 15N‐tracer methods were employed to quantify denitrification in constructed wetlands receiving agricultural tile drainage, using plastic tubes to enclose in situ mesocosms. Estimates were also made through NO−3 disappearance from mesocosm water columns. The 15N and C2H2 methods yielded comparable rates. At 4 to 25°C, and with 9 to 20 mg NO−3‐N L−1 initially in the mesocosm water columns, denitrification rates by the C2H2 technique ranged from 2.0 to 11.8 mg N m−2 h−1. In the June–August 15N experiment, when wetland NO−3 was below detection, a time series of denitrification rates followed a bell‐shaped curve after a pulse input of NO−3 (∼15 mg N L−1, 70 atom% 15N). The maximal denitrification rate (9.3 mg N m−1 h−1) was observed 5.4 d after the pulse. After 33 d, 58% of the 15NO−3 had been evolved as N2, only ∼0.1% as N2O; 6 to 10% was recovered in plant shoots and as organic N in the upper 5 cm of sediment. From 32 to 36% of the 15NO−3 spike was not recovered, and presumably seeped into the sediments. The NO3 disappearance rates in the water column ranged from 12 to 63 mg N m−2 h−1 at 11 to 27°C. Because water infiltration carries NO−3 through the anaerobic sediment/water interface for denitrification, a subsurface‐flow wetland may denitrify more NO−3 than a surface‐flow wetland.
Soluble Barium in Barite and Phosphogypsum Amended Mississippi River Alluvial Sediment
Authors: Carbonell A. A. , Pulido R. , DeLaune R. D. , Patrick W. H.
Published: July 2010

Barite (BaSO4), a density control material used in petroleum drilling fluids, can enter coastal and wetland environments. Because of its low solubility, it has been generally concluded that barium (Ba) will not leach into groundwater supplies, nor will it be taken up in significant quantities by plants and aquatic organisms. Such conclusions were mainly based on experiments conducted at neutral pH values and under oxidized conditions. The influence of pH and redox potential (Eh) on solubility of Ba from barite and phosphogypsum (PG) in Louisiana Mississippi River alluvial sediment was examined. Sediment suspensions containing barite or PG were incubated under oxidized and reduced conditions at pH 8, 7, 6, 5, and 4. The amount of Ba in solution at each combination (Eh‐pH) was measured. Results demonstrated that a combination of low pH and highly anaerobic conditions resulted in a release of Ba to the sediment solution. If low pH and anaerobic environment happen simultaneously, barite can account for significant levels of dissolved Ba entering the environment. In this study, approximately 4.4% of the total native Ba present in Louisiana Mississippi River alluvial sediment was converted to a soluble form under acidic and anaerobic conditions, compared to approximately 0.3% under alkaline and either anaerobic or aerobic conditions. Phosphogypsum application to the sediment significantly reduced the level of soluble Ba compared to control sediments, this was attributed to Ba precipitation as insoluble sulfates or sulfides under oxidized and reduced conditions.
Effects of Soil on Trace Metal Leachability from Papermill Ashes and Sludge
Authors: Xiao Chengqing , Ma Lena Q. , Sarigumba Terry
Published: July 2010

Understanding trace metal leachability is important for successful land application of papermill residues. Trace metal leachability from papermill ashes (Ash 1 and Ash 2) and papermill sludge (Sludge), and the effects of a soil on their leachability were determined by leaching the three papermill residues packed on top of a soil in a column. The leachates were analyzed for pH, electrical conductivity (EC), dissolved organic carbon (DOC), and concentrations of six metals (Cd, Cr, Cu, Pb, Se, and Zn). Ash 1 behaved significantly differently from Ash 2 during the leaching experiment, primarily due to its high pH and Na contents. Application of papermill residues significantly increased the pH, EC, and DOC concentrations in leachates, with Ash 1 having significantly greater impacts than Ash 2 and sludge. Soil columns under alkaline leaching of Ash 1 appeared bleached due to the dissolution of solid‐phase organic matter. Significant amounts of Zn were leached from all papermill residues, whereas significant amounts of Cr, Se, and Cu were leached only in the Ash 1 treatments. The presence of a soil (especially a Bh horizon) generally enhanced metal leachability in the Ash 1 treatments due to the extremely high pH of Ash 1, whereas it decreased metal leachability in the Ash 2 and sludge treatments. Thus, organic matter enhances metal sorption when present as a solid phase, but it increases metal leachability when present in dissolved form under alkaline conditions.
Sorption and Desorption of Copper on Soil Clay Components
Authors: Wu J. , Laird D. A. , Thompson M. L.
Published: July 2010

Toxic effects have been reported due to the accumulation of Cu in soils receiving long‐term applications of swine (Sus scrofa) manure, sewage, municipal composts, and mining waste. The objective of this study was to quantify sorption and desorption of Cu on various clay and clay‐organic matter fractions separated from a Zook soil (fine, smectitic, mesic Cumulic Vertic Endoaquolls) located in central Iowa. The clay was separated into four particle‐size fractions and portions of each fraction were treated with H2O2 and/or dithionite‐citrate‐bicarbonate (DCB) for removal of organic matter and free‐iron compounds, respectively. A batch‐equilibration technique was employed to evaluate sorption of Cu at pH 6.0 in the presence of 0.01 M CaCl2. The sorption isotherms show that Cu was preferentially sorbed on organic matter associated with the coarse clay fraction of the soil. After removal of organic matter, the fine clay (<0.02 µm) exhibited higher Cu retention than did the coarse (0.2–2.0 µm) and medium clay (0.02–0.2 µm). The DCB treatment created or exposed high‐affinity sites for Cu on the fine clay, but had little effect on Cu sorption for the coarse day. Copper appears to be specifically sorbed on the surfaces of silicate clays in excess of that which can be accounted for by variable charge sites. The results also suggest that Fe oxides may coat lateral surfaces of layer silicates, blocking access of Cu to potential sorption sites. Substantial sorption‐desorption hysteresis was observed for all samples, suggesting that Cu forms high‐energy bonds with both organic matter and layer‐silicate surfaces.
A Type Transfer Function Approach for Regional‐Scale Pesticide Leaching Assessments
Authors: Stewart Iris T. , Loague Keith
Published: July 2010

The objective of this study was the development of a transfer function protocol to obtain quantitative, regional‐scale estimates of groundwater contamination from agricultural chemicals. The Jury transfer function model was extended for the first time to regional scales through the development of ‘type’ transfer functions (TTFs). Type transfer functions are generalized impulse‐response functions, that define not only the response of a particular system that is characterized by a particular soil profile and surface‐water flux, but give a representative response for sufficiently similar systems. For this study TTFs were developed for the Fresno case study. The Fresno case study is a regional‐scale, simulated database of 1,2‐dibromo‐3‐chloropropane (DBCP) leaching for a 1172‐km2 study area in east‐central Fresno County, California. Simulated TTF concentration time series for each DBCP application in every 1‐km2 element of the study area were obtained by scaling the appropriate TTF by the mass of applied solute, the annual recharge, and a correction function accounting for sorption and decay. The results of the TTF simulations were compared with PRZM‐2 simulations for the same study area. The comparison showed that the TTF model (i) only required scaling of a known function once the set of TTFs was identified, (ii) yielded quantitative estimates of peak DBCP concentrations within one order of magnitude of the PRZM‐2 estimates, and (iii) overestimated DBCP concentrations because of a basic TFM formulation and a conservative modeling strategy. The TTF approach is capable of producing quantitative, regional‐scale groundwater vulnerability assessments that compare well to process‐based simulations.
Distributed Watershed Modeling of Design Storms to Identify Nonpoint Source Loading Areas
Authors: Endreny T. A. , Wood E. F.
Published: July 2010

Watershed areas that generate nonpoint source (NPS) polluted runoff need to be identified prior to the design of basin‐wide water quality projects. Current watershed‐scale NPS models lack a variable source area (VSA) hydrology routine, and are therefore unable identify spatially dynamic runoff zones. The TOPLATS model used a watertable‐driven VSA hydrology routine to identify runoff zones in a 17.5 km2 agricultural watershed in central Oklahoma. Runoff areas were identified in a static modeling framework as a function of prestorm watertable depth and also in a dynamic modeling framework by simulating basin response to 2, 10, and 25 yr return period 6 h design storms. Variable source area expansion occurred throughout the duration of each 6 h storm and total runoff area increased with design storm intensity. Basin‐average runoff rates of 1 mm h−1 provided little insight into runoff extremes while the spatially distributed analysis identified saturation excess zones with runoff rates equaling effective precipitation. The intersection of agricultural landcover areas with these saturation excess runoff zones targeted the priority potential NPS runoff zones that should be validated with field visits. These intersected areas, labeled as potential NPS runoff zones, were mapped within the watershed to demonstrate spatial analysis options available in TOPLATS for managing complex distributions of watershed runoff. TOPLATS concepts in spatial saturation excess runoff modeling should be incorporated into NPS management models.
Empirical Modeling of Spatial Vulnerability Applied to a Norflurazon Retrospective Well Study in California
Authors: Troiano J. , Marade J. , Spurlock F.
Published: July 2010

One goal of mandated well monitoring in California is to search for residues of active ingredients previously undetected in the state's groundwater. The realization that pesticide residues move into groundwater via several different pathways has led us to develop an empirical approach to delineate vulnerable areas; major climatic and edaphic features of areas where pesticides residues have been detected in well water have been identified on a geographic basis. The objective of this study was to evaluate the use of our empirical model in a retrospective well‐ sampling study for norflurazon, a preemergence herbicide with physical‐chemical properties that indicated potential to move offsite with water. In our modeling approach, sections of land, which are 2.59 km2 areas, were identified as having a greater potential for contamination based on soil and depth‐to‐groundwater (DGW) data. Wells were sampled from a subset of these sections where use of norflurazon was historically the greatest. Norflurazon residue was detected in 8 of 43 wells sampled in Fresno County, California, and in concentrations ranging from 0.07 to 0.69 µg L−1. This result was considered highly successful because residues had not been detected in 18 previous California groundwater studies for other active ingredients, some of which had been detected in other state and federal sampling programs. Location of sampling sites in these previous 18 California studies was based only on pesticide use data. The detections of norflurazon in this study indicated that, even though using an empirical modeling approach appeared to be unorthodox, it enabled us to effectively identify vulnerable areas.
Uncertainty in a Regional‐Scale Assessment of Cadmium Accumulation in the Netherlands
Authors: Tiktak Aaldrik , Leijnse Anton , Vissenberg Harald
Published: July 2010

Atmospheric deposition and agricultural activities may cause the cadmium (Cd) content in the rural environment in the Netherlands to exceed legal environmental standards. A simple process‐oriented model, SOACAS, in combination with a Geographical Information System was used to assess the magnitude of the Cd accumulation on a regional scale. The objective of this study was to quantify the uncertainty in the Cd accumulation due to data uncertainty. Another objective was to study whether maps of simulated and observed Cd contents were statistically different when the uncertainty in both maps was considered. From a Monte Carlo analysis we derived that the model behaved virtually linear within the range of model inputs considered, and concluded that first‐order uncertainty analysis (FOUA) was appropriate for mapping prediction uncertainties. The maps created by FOUA indicated that the contribution of individual model parameters to the total uncertainty was soil dependent, and that the pedotransfer function for Cd sorption gave the largest contribution to the total uncertainty. In an earlier analysis we found that in 25% of the total area SOACAS underestimated the average levels of current Cd contents by >50%. The model predictions and the observations were statistically different at a much smaller area (10% of the total area), showing that ignoring uncertainty may result in misleading interpretations when the model is compared with field measurements.
Stochastic Simulation of Pesticide Transport in Heterogeneous Unsaturated Fields
Authors: Wu Q. J. , Workman S. R.
Published: July 2010

Commonly used vadose‐zone models typically lack the capability to account for the spatial variability of soil properties that can greatly affect water flow and solute transport. In this study, stochastic techniques were applied to Groundwater Loading Effects of Agricultural Management Systems (GLEAMS), a deterministic vadose‐zone model, to simulate pesticide transport within experimental plots in southern Ohio subject to three different agricultural treatments. A hydrologic environment was discretized vertically into three layers based on the characteristics of the soil horizons. Selected hydrologic parameters in GLEAMS were described within each discretized layer by a random multivariate normal (MVN) vector. Simulations of transport and fate of three commonly used pesticides in the top 1.22‐m root zone were carried out at two levels: (i) single‐value output was obtained by using the mean values of the MVN vector components; and (ii) an empirical probability density function (pdf) was obtained by using the generated MVN vector realizations for each discretized layer. Statistical analyses were conducted to compare the simulation results and field observations, and examine the treatment effect on pesticide transport. Conclusions include: (i) soil spatial heterogeneity significantly affected pesticide movement and caused spatial variation of their distribution, and (ii) the Level 2 stochastic approach resulted in a better prediction of pesticide transport and fate.
Improved Models for Estimating Soil Erosion Rates from Cesium‐137 Measurements
Authors: Walling D. E. , He Q.
Published: July 2010

Fallout cesium‐137 (137Cs) measurements have been used in investigations of water‐induced soil erosion in a wide range of environments and in many different areas of the world over the past 20 yr. However, the existing calibration procedures commonly used for deriving quantitative estimates of soil redistribution rates from 137Cs measurements involve several limitations and uncertainties. Existing approaches to calibration and their associated limitations and uncertainties are briefly reviewed and improved models for converting 137Cs measurements to estimates of rates of water‐ and tillage‐induced soil redistribution, applicable to both cultivated and undisturbed soils, are proposed. Results obtained from existing field investigations and laboratory experiments indicate that redistribution of fallout 137Cs within the soil profile and across the land surface is influenced by several factors. These include time‐dependent fallout input, initial distribution within the surface layer, post‐depositional redistribution resulting from mechanical, physical, chemical, and biological processes operating in the soil system and the grain size selectivity associated with soil erosion and sediment transport processes. It is important to consider these factors when deriving estimates of soil redistribution rates using the 137Cs technique, and they have been incorporated into the improved models. The use of these models is demonstrated using data from a case study undertaken in a small catchment in Devon, UK, involving both cultivated and undisturbed soils.
Soluble Organic Carbon in a Biosolids‐Amended Mollisol
Authors: Han Nizhou , Thompson Michael L.
Published: July 2010

Organic matter can be mobilized from many sources and transported in soil by precipitation, snowmelt, and water table fluctuations. Knowledge of the potential fluxes of soluble organic C in different kinds of soil is essential to improve global C budgets. We characterized the soluble and suspendable organic matter in a biosolids‐amended fine, smectitic, mesic Cumulic Vertic Endoaquoll under two vegetation treatments: switchgrass (Panicum virgatum L.) and cottonwood‐poplar hybrid (Populus × euramericana—clone NC‐5326). Soil organic C (OC) that was dispersed in 0.1 mM CaCl2 was fractionated according to molecular weight and polarity using dialysis membranes and XAD‐8 resin chromatography. Under both types of vegetation, addition of biosolids increased the amount of soluble OC (SOC) in the soil, particularly under switchgrass. Biosolids application shifted the molecular‐weight distribution of SOC to lower weights (<14 000 Da). The concentrations of hydrophilic OC fractions exceeded those of hydrophobic OC in all treatments, although biosolids application increased the levels of both fractions. As the rate of biosolids addition increased, the 0 to 5 cm zone yielded smaller concentrations of extractable colloidal organic compounds than the 5 to 25 cm zone, and we attributed this to the high amounts of soluble salts introduced by biosolids application. A sequential extraction experiment showed that large amounts of colloidal organic compounds could be mobilized from the soil only after removal of the soluble salts. Our results suggest that biosolids amendments could increase the mobilization of hydrophilic, low‐molecular‐weight compounds in a soil while at the same time limiting the mobility of organic colloids.
Nonylphenol and Estrogenic Activity in Aquatic Environmental Samples
Authors: Tanghe Tom , Devriese Greet , Verstraete Willy
Published: July 2010

We surveyed a series of surface waters and sewage treatment plants in Flanders (north of Belgium) for the presence of estrogenic activity and a xeno‐estrogenic compound para‐nonylphenol (NP), respectively. The surface waters of rural origin, used for drinking water production, were free of significant levels of estrogenic activity and NP (<1 µg/L). Domestic sewage, after proper treatment, appeared to be no major source of this chemical. Yet, in some industrial effluents and surface waters of highly industrialized regions, NP and/or estrogenic activity was prominent, that is, <1 to 122 µg NP/L and 11 to 42 µg NP/L, respectively. This is because of the ongoing use of NP polyethoxylates in industry. The response of the recombinant yeast estrogen assay to the environmental samples tested was not consistent with the detected concentrations of NP. Standard addition of a natural estrogen, 17β‐estradiol, generated no or a reduced response compared to the standard curve concentration. Application of humic acids to standard series of NP and 17β‐estradiol resulted in a dose‐dependent decrease of the estrogenic response. It appears that this bioassay is subject to considerable interferences due to the complexity of environmental samples. Parallel implementation of extensive chemical screening for xenobiotics and use of the bioassay are needed for adequate assessment of the potential estrogenic hazard to avoid false negative evaluations.
Correlating Microbes to Major Odorous Compounds in Swine Manure
Authors: Zhu Jun , Jacobson Larry D.
Published: July 2010

Malodor generation from swine manure is complicated by the involvement of many bacterial species that produce an extensive array of volatile organic compounds (VOCs). A lack of understanding of the basic manure microbiology further complicates the problem. This review covers pertinent detailed information about the indigenous bacterial genera in swine manure and their potential for producing odorous volatile compounds. It addresses not only the odorous compounds in swine manure but also the relations between bacterial species and the related compounds. It appears that volatile fatty acids may be the major odorous compounds in swine manure, and two bacterial genera, Eubacterium and Clostridium, are most likely the major contributors to these odorous acids. More research is needed to identify the bacterial species within these two genera to better understand the kinetics of malodor production by the bacteria.
Effects of Acidification on Metal Mobility in a Papermill‐Ash Amended Soil
Authors: Chirenje Tait , Ma Lena Q.
Published: July 2010

Elevated soil pH due to papermill ash application has adverse effects on forest soils. Column leaching studies were conducted to determine the effects of acidification on trace metal mobility in a papermill‐ash amended soil. Two types of ash, aged and fresh, were used. The aged ash‐soil profile was collected from the field where the ash was mixed with the surface soil to a depth of 47 cm at rates of 896 and 1792 mt ha−1 and left to stand for 1.5 yr. The fresh ash‐soil profile was prepared by mixing fresh ash with the surface soil at the same rates as the aged ash‐soil profiles. The pHs of the ash‐soil profiles were adjusted from 9–10 to 7 and 6 using dilute HNO3. Leachate concentrations of As, Ca, Cd, Cr, Cu, Na, Ni, Se, and dissolved organic carbon (DOC), and pH were measured at the end of 7 and 35 d. Acidification of the aged ash‐soil profiles elevated concentrations of Se, As, Cd, and Ni in leachate possibly due to the dissolution of CaCO3 and release of metals adsorbed to CaCO3. Reduced Cu concentrations were possibly due to reduced DOC concentrations at reduced pH. On the other hand, acidification greatly reduced the amount of metals leached through the fresh ash‐soil profiles (except Ca and Cd), mainly due to significant reduction in the mobilization/solubilization of organic matter. The high metal mobility in the unacidified fresh ash‐soil profiles could have been due to DOC‐facilitated metal migration.
Soil Air Carbon Dioxide and Nitrous Oxide Concentrations in Profiles under Tallgrass Prairie and Cultivation
Authors: Sotomayor David , Rice Charles W.
Published: July 2010

Assessing the dynamics of gaseous production in soils is of interest because they are important sources and sinks of greenhouse gases. Changes in soil air carbon dioxide (CO2) and nitrous oxide (N2O) concentrations were studied in a Reading silt loam (fine‐silty, mixed, mesic Typic Argiudolls) under prairie and cultivation. Concentrations were measured in situ over a 17‐mo period to a depth of 3 m. Multilevel samplers permitted collection of gases with subsequent measurement by gas chromatography in the laboratory. Soil air N2O concentrations were near atmospheric levels for a majority of the study period in the prairie site (0.184–2.25 µL L−1) but were significantly higher in the cultivated site (0.257–7.56 µL L−1). Annual mean N2O concentrations were 0.403 and 1.09 µL L−1 in the prairie and cultivated sites, respectively. Soil air CO2 annual mean concentrations were 1.56 × 104 and 1.10 × 104 µL L−1 and ranged from 0.096 × 104 to 6.45 × 104 µL L−1 and 0.087 × 104 to 3.59 × 104 µL L−1 in the prairie and cultivated sites, respectively. Concentrations generally increased with depth, with maximum soil air N2O and CO2 concentrations at 1.0 m in the prairie site and 0.5 m in the cultivated site. Nitrous oxide in the cultivated site and CO2 at both sites did not change markedly over winter months, but CO2 and N2O concentrations reached maximums during the summer months and decreased as the year progressed. Although soil air concentrations peaked and decreased faster at shallower depths, deeper depths exhibited relative maximum concentrations for longer time periods.
Water Quality Impacts by Golf Courses
Authors: Cohen Stuart , Svrjcek Amelia , Durborow Tom , Barnes N. LaJan
Published: July 2010

Interest in water quality impacts by golf courses has grown significantly since the late 1980s due mostly to the local permitting process. Results from permit‐driven studies are frequently not published. Seventeen studies (36 golf courses) passed our review criteria and were incorporated into a detailed data review. A total of 16 587 data points from pesticide, metabolite, solvent, and NO3 analyses of surface water and ground water were reviewed. There were approximately 90 organics analyzed in the surface water database and approximately 115 organics in the ground water database. Widespread and/or repeated water quality impacts by golf courses are not happening at the sites studied. None of the authors of the individual studies concluded that toxicologically significant impacts were observed, although HALs, MCLs, or MACs were occasionally exceeded. The individual pesticide database entries that exceeded HALs/MCLs for ground water and surface water were 0.07 and 0.29%, respectively. The percentages would be somewhat higher if they could be expressed in terms of samples collected rather than chemicals analyzed. The MCL (10 mg/L) for nitrate—nitrogen (NO3—N) in surface water was not exceeded, and only 31/849 (3.6%) of the samples exceeded the MCL in ground water; however, most of the NO3 MCL exceedances were apparently due to prior agricultural land use. There was a slight trend for detected pesticides to be more persistent and more mobile than pesticides that were not detected, but the trend was not statistically significant. There are major data gaps in this review, particularly in the midcontinent area.
Temporal and Spatial Trends in Streamwater Nitrate Concentrations in the San Bernardino Mountains, Southern California
Authors: Fenn Mark E. , Poth Mark A.
Published: July 2010

We report streamwater nitrate (NO−3) concentrations for December 1995 to September 1998 from 19 sampling sites across a N deposition gradient in the San Bernardino Mountains. Streamwater NO3 concentrations in Devil Canyon (DC), a high‐pollution area, and in previously reported data from the San Gabriel Mountains 40 km northeast of Los Angeles, are the highest values reported in North America for undisturbed forest or shrub land watersheds. Concentrations in the primary stream draining western DC peaked at 350 µmol L−1 in December 1997 and minimum base flow NO−3 concentrations were nearly always ≥80 µmol L−1. In the San Gorgonio Wilderness (SGW), average NO−3 concentrations in four streams along the southern transect (moderate N deposition), ranged from 10 to 37 µmol L−1, while average NO−3 concentrations were ≤0.7 µmol L−1 in seven streams along the northern transect (low N deposition). Peak NO−3 concentrations in DC and in the SGW occurred after large winter storms, and a large spike in NO−3 concentrations (10–370 µmol L−1) in SGW Streams 1 to 5 was observed after thundershower activity in July 1997. Streamwater export of NO3‐N from Devil Canyon ranged from 3.6 to 11.6 kg ha−1 yr−1 during water years 1995 to 1998. This study further indicates that N emissions from fossil fuels and agriculture impact not only air quality, but also water quality from watersheds that are recipients of atmospheric N deposition.
A Multi‐Year Study of Four Herbicides in Surface Water of a Small Prairie Watershed
Authors: Rawn Dorothea F. K. , Halldorson Thor H. J. , Turner William N. , Woychuk Robert N. , Zakrevsky Jean‐Guy , Muir Derek C. G.
Published: July 2010

Temporal trends of three phenoxy‐herbicides (2,4‐D, dichlorprop and MCPA) and bromoxynil were determined in the South Tobacco Creek, which drains a 70 km2 agricultural watershed near Miami, Manitoba, over a 4‐yr sampling program. The quantities of all pesticides used in the watershed and their application times were accurately recorded with the cooperation of landowners. Herbicide concentrations in South Tobacco Creek ranged from <0.01 ng/L to a maximum concentration of 680 ng/L (for 2,4‐D) and reflected local application times. Spring melt contributions were important when no significant runoff events occurred late in the previous growing season. Discharge of these herbicides in the South Tobacco Creek was calculated to be <0.01% of their quantities used within the watershed. No correlation was found between the water quality parameters: total organic C, total N, and total P and herbicide concentrations in South Tobacco Creek. Total N and P, however, were correlated to water flow, indicating runoff and ground water sources rather than atmospheric. We concluded that detailed temporal patterns of herbicides and nutrients could only be established if high sampling frequency was maintained during such critical periods such as application periods and during major runoff events. An unexpected finding was that herbicide concentrations were not related to runoff losses, but instead they did correspond to elevated levels in precipitation and air measured within the watershed.
Bacterial Reduction of Perchlorate and Nitrate in Water
Authors: Herman David C. , Frankenberger William T.
Published: July 2010

A bacterial isolate, strain perclace, was shown to reduce the ground water contaminant perchlorate (ClO−4) to levels <0.005 mg L−1 when grown on acetate under anaerobic conditions. The ability of perclace to simultaneously reduce perchlorate and another ground water pollutant, nitrate (NO−3), was examined in batch studies and in a sand‐packed column under saturated flow conditions. Nitrate removal was monitored using ion chromatography, and perchlorate removal was monitored using a perchlorate specific electrode or ion chromatography, depending on the study. In batch studies, the reduction of 0.089, 0.92, 12.0, and 122 mg L−1 perchlorate was examined in the presence and absence of 62 mg L−1 NO3. Perchlorate was reduced more rapidly in the absence of NO−3 than in its presence. However, both perchlorate and NO−3 were reduced by more than 10‐fold within 48 h. A sand‐packed column (2.8 by 14 cm) inoculated with perclace simulated a flow‐through biotreatment system for water contaminated with a low level of perchlorate (0.130 mg L−1) and a much higher level of NO3 (125 and 20 mg L−1). Biotreatment could reduce perchlorate to <0.005 mg L in a 3 h residence time. The addition of NOr initially decreased the efficiency of perchlorate removal, however within 1 d the biotreatment system had adjusted such that there was complete removal of perchlorate and the reduction of NO−3 to <1 mg L−1.
Sizing Considerations for Gravel Beds Treating Acid Mine Drainage by Sulfate Reduction
Authors: Lyew Darwin , Sheppard John
Published: July 2010

An important consideration in the use of sulfate‐reducing bacteria (SRB) for treatment of acid mine drainage (AMD) is that SRB require a physicai support such as a gravel bed to become established. A quantitative method of describing the relationship between SRB activity and the physical parameters of the bed was investigated in a series of column reactors, as such information would be useful in the sizing of AMD treatment systems using SRB. This was accomplished by the use of ratios comprised of the amount of fresh AMD entering the system (Vc) and of physical parameters of the bed, namely the total surface area (tSA) of the gravel in the bed, the interfacial or superficial surface area (sSA) of the bed, and the void volume (Vv). Two numbers, D (= Vc/Vv, * sSA/tSA) and F (= Vv/Vc * sSA/tSA), were used in the analysis of the sulfate removal data obtained in column reactors. The sulfate removal data can be expressed either as the proportion of sulfate removed or the rate of sulfate removal. A relationship existed between the “proportion of sulfate removed” data and number D but not with F, while a relationship existed between the “rate of sulfate removed” data and number F, but not with D. This difference was due to the arrangement of the parameters in the numbers which reflected fundamental relationships between the physical environment and SRB activity. The relationships observed were that sulfate removal was optimal for D values between 0.0075 and 0.015, and that the rate of sulfate removal decreased as F‐values increased.
Seepage Losses and Nitrogen Export from Swine‐Waste Lagoons: A Water Balance Study
Authors: Ham Jay M. , DeSutter Tom M.
Published: July 2010

Seepage losses from animal‐waste lagoons could affect ground water quality. Water balance methods were used to study seepage and N export from three swine‐waste lagoons in southwestern Kansas. Lagoons ranged in size from 0.8 to 2.2 ha and had an average waste depth of 5.6 m. Compacted soil liners were 0.30 to 0.46 m thick and built with native soil or, in one case, a soil‐bentonite mixture. Seepage was calculated from measurements of evaporation and changes in depth when the addition or removal of waste was precluded or quantified. Seepage rates were 1.1, 1.1, and 0.8 mm d−1 from the three lagoons, with the lowest rate occurring at the site with a 0.46‐m liner augmented with bentonite. The in situ coefficient of permeability of the soil liners ranged from 7.8 × 10−8 and 1.5 × 10−7 cm s−1. In two lagoons built with silt loam liners (no bentonite), permeabilities on a whole‐lagoon basis were about five times less than those measured from soil cores collected before the addition of waste. Results imply that permeability was reduced by organic sludge on the bottom of the lagoons. The average ammonium‐N concentration in the lagoons was 665 mg L−1, accounting for almost all of the soluble N. Calculations indicate that the ammonium‐N export rates were between 2187 and 2726 kg ha−1 yr−1, but more information is needed regarding the fate of N deposited in the soil beneath lagoons.
Soil and Stream‐Water Impacts of Sewage Effluent Irrigation onto Steeply Sloping Land
Authors: Speir T. W. , van Schaik A. P. , Kettles H. A. , Vincent K. W. , Campbell D. J.
Published: July 2010

In a pilot study, we investigated how irrigation of secondary sewage effluent onto steeply sloping land affected soil physical, chemical, and biochemical properties, the composition of soil‐ and surface‐waters and the vegetation on the site. The 3.36‐ha site received up to 44 mm effluent/wk (over a 7–11 h period), for 65 wk. Irrigation significantly improved total‐ and Olsen‐P status of the soils and greatly enhanced nitrification potential. Respiration increased with increasing soil water content, but microbial biomass was not greatly affected by irrigation. Soil phosphatase activity decreased with increasing P fertility. Soil physical properties were not affected by effluent and hydraulic conductivities were sufficient to conduct water into and through the soil profiles. Soil‐ and surface‐water NO−3‐N concentrations increased markedly, especially in the second half of the trial when soil nitrification rates were also high. However, the streamwater NO3‐N concentrations remained well below the drinking water limit concentration of 11.3 g m−3. In contrast, streamwater NH+4‐N and PO3−4‐P concentrations remained low and results indicated that concentrations of PO3−4‐P in river water, resulting from a full‐scale irrigation scheme, would not exceed the target limit level of 0.0056 g m−3. Irrigation accelerated natural successional changes in the vegetation, with a decline in undesirable fire‐prone and shrnbby species and an increase in native trees and tree ferns. These results demonstrated that, in the short term at least, a carefully designed and implemented irrigation scheme on steepland could renovate secondary sewage effluent, without adversely affecting soil properties and surface water quality.