Journal of Environmental Quality 30:1113-1117 (2001)
© 2001 American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America
EXECUTIVE SUMMARIES
This Issue in Journal of Environmental Quality
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Gobs of Fly Ash Neutralize Gob Piles
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Appalachian coal processing waste materials (gob piles) are generally high in iron pyrite (FeS2), which oxidizes to form metalliferous acid mine drainage. Alkaline fly ash from coal combustion could offer a low-cost liming alternative for these materials, which presumably would improve water quality over time. Stewart et al. report that blending 20 to 33% coal fly ash with acid-forming coal waste controlled long-term acid mine drainage emissions. At lower blending rates, however, the ashes actually contributed additional heavy metal loadings. Therefore, if ash is to be beneficially reused in the reclamation of acid-producing coal refuse, the alkalinity and potential acidity of the materials must be balanced through the appropriate addition of lime or other alkaline materials to the blended zone.
W.L. Daniels (wdaniels@vt.edu)
Evaluation of Leachates from Coal Refuse Blended with Fly Ash at Different Rates. J. Environ. Qual. 30:1382–1391.
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"Non-Discharge" Swine Farms Discharge Nitrate
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Intensive swine farms in North Carolina are classified as non-discharge systems, and swine waste is purportedly land-applied at agronomic rates for N. Minimum allowable riparian buffers about 8 to 10 m wide are intended to prevent offsite nitrate migration. However, natural-abundance 
15N measurements of swine waste lagoons, wells in sprayfields, and nearby streams showed otherwise in a report by Karr et al. The isotopic signal of swine waste N was conserved during ground water transport, discharge to streams, and during offsite stream transport >1 km. Denitrification in narrow buffers was limited to the upper few feet of the shallow aquifer, allowing discharge of ground water with very high nitrate levels. Median 15N values of lagoons, wells, and affected streams were identical over the course of about 18 months.
J. Karr (karr@duke.edu)
Tracing Nitrate Transport and Environmental Impact from Intensive Swine Farming using Delta Nitrogen-15. J. Environ. Qual. 30:1163–1175.
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Novel Extraction Procedure for Metal Fractionation
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Batch procedures are usually used to separate metals from solid materials. Sequential extraction is used to separate metals from into fractions of varying mobility in the environment and bioavailability to living organisms. Shiowatana et al. now describe a continuous-flow extraction system that is convenient, rapid, and less vulnerable to changing extraction conditions than previous methods. The new procedure also provides other useful information such as elemental association in different solid phases within the sample tested.
J. Shiowatana (scysw@mahidol.ac.th)
A Novel Continuous-Flow Sequential Extraction Procedure for Metal Speciation in Solids. J. Environ. Qual. 30:1195–1205.
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Sustainability Issues in Irrigation
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Water movement and storage in the soil are important aspects of environmental impact studies of irrigation projects. Manoliadis now describes an analysis of irrigation management using sustainability-related criteria such as water conservation and satisfactory production and income for farmers. The study indicates a trade-off between conservation of water and system sustainability in terms of yield and income distribution. Environmental indices were computed from data on soil moisture content at the root zone and irrigation water delivered to crops. The variation of the corresponding indices in time and space was high—up to 13% of water delivered to crops, 82% of yield loss, and 84% of economic return.
O. Manoliadis (omano@tee.gr)
Analysis of Irrigation Systems Using Sustainability-Related Criteria. J. Environ. Qual. 30:1150–1153.
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Immobilization of Cesium and Uranium in Contaminated Sediments
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The use of in situ chemical stabilizing agents to reduce contaminant migration and bioavailability is an attractive alternative to conventional excavation and long-term storage of soils and sediments. Seaman et al. evaluated hydroxyapatite, illitic clays, and zeolites as in situ immobilizing agents for 137Cs and U in highly weathered soils and sediments from the southeastern USA. Hydroxyapatite reduced U solubility, presumably due to the formation of secondary phosphate precipitates. Illite and zeolite were only moderately effective in reducing Cs mobility because much of the Cs was already strongly bound to the native illitic clays.
J. Seaman (seaman@srel.edu)
Immobilization of Cesium-137 and Uranium in Contaminated Sediments Using Soil Amendments. J. Environ. Qual. 30:1206–1213.
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The Dope on Soap in Soil
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Linear alkylbenzene sulfonates (LAS) are the major surfactants in soap. Consequently, relatively high concentrations of LAS occur in sewage sludge used in agriculture as a fertilizer and an organic amendment to improve physical and chemical soil properties. Mortensen et al. grew barley, rape, and carrot on a sandy soil amended with different rates of sewage sludge and found no plant uptake of LAS above the detection limit. Plant growth stimulated the degradation of LAS in the soil. Over a 30-day growth period LAS concentrations in soil dropped from 27 to 1.4 mg/kg (dry wt.) where rape was grown, but decreased to only 2.4 mg/kg in plant-free pots.
G.K. Mortensen
(gerda.krog.mortensen@risoe.dk)
Influence of Plant Growth on Degradation of Linear Alkylbenzene Sulfonate in Sludge-Amended Soil. J. Environ. Qual. 1266–1270.
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Herbicides Degrade in Anaerobic Sediment
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Atrazine and metolachlor are widely used herbicides that can move and end up in anaerobic wetland sediment. Seybold et al. report that both herbicides are degraded in highly reducing conditions. Hydroxyatrazine was the major atrazine metabolite detected. The two commonly found metolachlor metabolites, ethanesulfonic acid and oxanilic acid, were insignificant under anaerobic conditions. However, if present, hydroxyatrazine, ethanesulfonic acid, and oxanilic acid can persist in anaerobic and highly reducing conditions.
W. Mersie (wmersie@vsu.edu)
Anaerobic Degradation of Atrazine and Metolachlor and Metabolite Formation in Wetland Soil and Water Microcosms. J. Environ. Qual. 30:1271–1277.
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Turn Trash into Cash
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Large quantities of construction and demolition wastes (CDW) have accumulated in Taiwan from damaged buildings near the epicenter of the catastrophic 1999 earthquake. Chang et al. studied the use of incineration facilities for burning the combustible portion of CDW (CCDW) to recover part of the heat sources and combustion ash for economic uses. Kinetic parameters for oxidation of CCDW were calculated using thermal gravimetric analysis at different temperatures and heating rates. Fourier transform infrared spectroscopy was employed to monitor the flue gas during the oxidation of CCDW. This information is being used to design a resources recovery program.
Ni-Bin Chang
(A1211@mail.ncku.edu.tw)
Oxidation Kinetics of the Combustible Fraction of Construction and Demolition Wastes. J. Environ. Qual. 30:1392–1401.
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Overburden Properties Predict Minesoil Properties
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Surface-mined lands must be returned to a condition that is equal or more productive than the original soil. Selected chemical and physical properties of the overburden column are commonly evaluated before mining and used to predict postmine soil properties and to plan reclamation. Textural analysis and cation exchange properties of overburden materials that may be used to reclaim the site are critical in the preliminary evaluation of potential minesoil properties. Stewart and Hossner now report that methods commonly used by soil scientists to determine texture and cation exchange properties may have to be altered to provide an accurate evaluation of geologic samples.
L.R. Hossner (l-hossner@tamu.edu)
Factors Affecting the Ratio of Cation Exchange Capacity to Clay Content in Lignite Overburden. J. Environ. Qual. 30:1143–1149.
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Phosphorus Limits Bioavailable Lead
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Phosphorus (P) amendment has been proposed as a remediation option for communities with lead (Pb)-contaminated soils. Hettiarachchi et al. now report that the addition of P provides up to 37% reduction in bioavailable Pb based on a physiologically based extraction test compared with unamended controls. Results suggest that P addition reduces bioavailable Pb and has potential for in situ remediation of Pb-contaminated soils. They used a bioaccessibility test that mimics the human digestive system to examine Pb availability in five metal-contaminated soils–mine wastes to which different sources of P were added.
G.M. Hettiarachchi
(hettiarachchi.ganga@epa.gov)
In Situ Stabilization of Soil Lead Using Phosphorus. J. Environ. Qual. 30:1214–1221.
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Of Rock, Heavy Metal, and Exposure
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Transmission of Cd through the food chain via plant uptake, and exposure to Pb through ingestion of contaminated soil, are important human exposure pathways. Basta et al. describe an inexpensive and very effective alternate remediation technology that uses municipal biosolids or rock phosphate to treat heavy metal–contaminated soil. Alkaline organic treatments decrease Cd transmission through the food chain pathway, whereas rock phosphate decreases exposure to Pb via the soil ingestion pathway. Alkaline organic treatments can reduce human exposure to Cd and Pb from eroded soil by reducing Zn phytotoxicity and by revegetating contaminated sites.
N. Basta (ntb@mail.pss.okstate.edu)
Chemical Immobilization of Lead, Zinc, and Cadmium in Smelter-Contaminated Soils Using Biosolids and Rock Phosphate. J. Environ. Qual. 30:1222–1230.
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Fly Ash and Limestone Neutralize Mine Spoil
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Seoane and Leiros have used fly ash and agricultural limestone to neutralize acidity produced by the abundant overburden material produced during open-cast mining of lignite. They report that the principal acidification processes were oxidation of sulfide and formation of hydroxysulfate (FeOHSO4), whereas the main neutralization processes were weathering of aluminosilicates in fly ash–treated samples and dissolution of calcium carbonate in limestone-treated samples. The experiment was carried out with soil moisture maintained at field capacity or alternate cycles of wetting–drying.
S. Seoane (seoane@lugo.usc.es)
Acidification–Neutralization Processes in a Lignite Mine Spoil Amended with Fly Ash or Limestone. J. Environ. Qual. 30:1420–1431.
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Vegetation Alters Soil Particle Retention Efficiency
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Small constructed wetlands are like the jars of Zarephath (1 Kings 17:16) concerning topsoil from arable land—they will never be empty. According to a report by Braskerud, vegetation increases sediment retention in constructed wetlands by decreasing the resuspension of captured sediment even though the hydraulic loads may be very high. As vegetation cover increases, hydraulic load and sediment load have a greater impact on retention performance than does the vegetation. Vegetation increases the hydraulic efficiency; hence, the retention of soil particles is stimulated.
B.C. Braskerud
(bent.braskerud@jordforsk.no)
The Influence of Vegetation on Sedimentation and Resuspension of Soil Particles in Small Constructed Wetlands. J. Environ. Qual. 30:1447–1457.
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Tracking the Flow of Turf Herbicides
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Dicamba herbicide is commonly used to kill weeds in lawns. Roy et al. now report dicamba concentrations >1 mg/L in soil water. They used field lysimeters, a laboratory degradation study, and the pesticide-leaching model EXPRES to study the fate of dicamba applied to turfgrass. Although drying of the soil during the summer prevented deep transport, increased infiltration in late autumn resulted in greater leaching. The degradation rate for dicamba in thatch was 5.9 to 8.4 times greater than for soil, with a calculated half-life as brief as 5.5 days. In general, EXPRES predictions were similar to observed concentration profiles, with differences probably due to minor inaccuracies in the water-flow simulation and the model's inability to modify dicamba degradation rates with changing climatic conditions.
G. Parkin (gparkin@lrs.uoguelph.ca)
Seasonal Leaching and Biodegradation of Dicamba in Turfgrass. J. Environ. Qual. 30:1360–1370.
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Constructed Wetlands Remove Wastewater Metals
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Cattail-dominated wetlands can remove >95% of iron (Fe), manganese (Mn), and cobalt (Co) from coal combustion by-product leachate. In a 2-year field study, Ye et al. tested the effectiveness of a constructed wetland at Springdale, PA, for the treatment of metal-contaminated wastewater. The results showed that the metal removal efficiency remained consistent throughout the year. Most of the metal removed by the wetland was immobilized in sediment, with a small proportion of the metals accumulating in cattail shoots and litter, as well as in submerged macroalgae.
N. Terry
(nterry@nature.berkeley.edu)
Removal and Distribution of Iron, Manganese, Cobalt, and Nickel within a Pennsylvania Constructed Wetland Treating Coal Combustion By-Product Leachate. J. Environ. Qual. 30:1464–1473.
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Ag Phosphorus in the Everglades
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The Florida Everglades have experienced significant ecological changes resulting from human manipulation of hydrology, nutrient loading, and fire. DeBusk et al. now report that a "front" of soil phosphorus (P) enrichment has advanced from the highly P-enriched northern fringe of Water Conservation Area 2A into the relatively undisturbed interior marsh. This conservation area in the northern Everglades has been a focal point for the study of ecological effects of nutrient loading, primarily due to P transport in runoff from the nearby Everglades Agricultural Area. The authors evaluated changes in the spatial extent and patterns of elevated soil P concentration during the period 1990–1998 to demonstrate that the extent of soil P enrichment increased significantly during the 1990s.
W.F. DeBusk (wfd@mail.ifas.ufl.edu)
Spatio–Temporal Patterns of Soil Phosphorus Enrichment in Everglades Water Conservation Area 2A. J. Environ. Qual. 30:1438–1446.
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A Pivotal Study on Nitrate Leaching
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Nitrate leaching is very difficult to control from well-drained soils cropped to irrigated corn. Spalding et al. now report that careful and uniform applications of water and nitrogen fertilizer through center-pivot systems can dramatically reduce nitrate transport to the shallow ground water, compared with furrow irrigation systems. They used extensive ground water instrumentation and a sophisticated water-dating technique to evaluate the effectiveness of off-the-shelf irrigation technologies in reducing leaching.
R.F. Spalding (rspalding1@unl.edu)
Controlling Nitrate Leaching in Irrigated Agriculture. J. Environ. Qual. 30:1184–1194.
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Coal Combustion Products as Constructed Wetland Liners
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Various products have been used as liners for constructed wetlands, including clays and synthetic materials. Ahn and Mitsch now describe studies using a recycled coal combustion product as a liner. Arsenic, Ca, and pH were higher in the surface soil of flue gas desulfurization–lined mesocosms relative to unlined mesocosms. Higher pH, conductivity, and concentrations of Al, B, Ca, K, and S (SO4–S) were observed in the leachate from lined mesocosms compared with unlined controls. Initially high pH and soluble salt concentrations measured in the leachate from the lined mesocosms may indicate the reason for relatively lower growth of wetland vegetation.
W.J. Mitsch (mitsch.1@osu.edu)
Chemical Analysis of Soil and Leachate from Experimental Wetland Mesocosms Lined with Coal Combustion Products. J. Environ. Qual. 30:1457–1463.
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Pesticide Movement with Effluent Is a Complex Matter
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The potential of enhanced transport of pesticides complexed with mobile effluent-borne organic matter has not been given much consideration in decisions regarding the use of lagoon effluents for agricultural irrigation. Huang and Lee report that dissolved organic matter (DOM) from poultry, swine, and cow waste–derived lagoon effluent has a strong affinity to associate with chlorpyrifos and some affinity to sorb to soils. In the field, where soil mass/solution volume ratios are large, sorption of effluent dissolved organic matter to soils reduces the amount of chlorpyrifos associated with waterborne DOM, thus greatly reducing the potential for DOM-enhanced transport.
L. Lee (lslee@purdue.edu)
Effects of Dissolved Organic Matter from Animal Waste Effluent on Chlorpyrifos Sorption by Soils. J. Environ. Qual. 30:1258–1265.
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Salinity from Coal Mining Waste
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Mining of low-sulfur coal in western North America produces surface deposits of waste rock that act as point sources of salinity and some metals. Present salinization of nearby surface water and alkaline soils can be assessed in a reconnaissance-sampling mode, but in arid lands of mixed use other sources of salinity such as irrigated agriculture must also be considered. Zielinski et al. demonstrate how S isotopic measurements of sulfate in surface water and in leachates of soil and mine waste can distinguish sulfate derived from low-S coal mine waste and quantify its mixing with sulfate from irrigation runoff. Spatial–chemical sampling indicated that the mine waste was also a source of nitrate but that high concentrations of Se, U, Li, Mn, and B downstream from the waste pile were contributed by irrigation drainage.
R. Zielinski (rzielinski@usgs.gov)
Sources of Salinity Near a Coal Mine Spoil Pile, North-Central Colorado. J. Environ. Qual. 30:1237–1248.
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Most Nitrogen Applied to Irrigated Vegetables Leaches to Groundwater
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Substantial groundwater pollution has resulted from placing agricultural systems demanding large inputs of fertilizers, pesticides, and irrigation water in Wisconsin's central sand plains where soils are coarse and groundwater is shallow. Stites and Kraft report annual nitrate N leaching of 165 kg ha-1 when sweet corn was grown and 228 kg ha-1 when potato was grown. They used a new method of measurement based on detailed monitoring of groundwater in the upper saturated zone. The measured leaching losses represented 66 to 70% of the fertilizer N applied. Limiting fertilizer to university-recommended application rates would not greatly reduce leaching, and each irrigated vegetable field would need to be offset by five to seven times as much land supplying no nitrate if the average groundwater recharge is to meet the U.S. drinking water standard.
W. Stites (wstites@coredcs.com)
Nitrate and Chloride Loading to Groundwater from an Irrigated North-Central U.S. Sand-Plain Vegetable Field. J. Environ. Qual. 30:1176–1184.
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Unraveling Phosphorus Export Patterns
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Sediment and P export vary through space and time as a result of many controlling factors. Steegen et al. report that some of these factors are related to the physical catchment characteristics such as the morphology and landscape structure of the catchment, while others are more variable, such as the occurrence of extreme events, vegetation cover, and land use. Results are based on a study of sediment and total P export from two agricultural catchments.
A. Steegen
(an.steegen@geo.kuleuven.ac.be)
Factors Controlling Sediment and Phosphorus Export from Two Belgian Agricultural Catchments. J. Environ. Qual. 30:1249–1258.
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Desulfurization By-Product Alters Acid Mine Drainage
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The removal of sulfur oxides during combustion of high sulfur coal results in the production of >20 million tonnes of flue gas desulfurization by-product (FGD) every year. Because coal-fired power plants are typically located close to coal mines, there is increasing interest in the placement of FGD in deep mine environments for the purpose of FGD disposal and acid mine drainage reduction. Lamminen et al. now report that the injection of FGD in an abandoned coal mine results in an initial increase in acidity, Fe, Al, Ca, and S in mine drainage waters. The long-term concentrations of these constituents, however, approach levels observed before FGD injection. These results suggest that placement of FGD in deep mines does not have deleterious, long-term effects on water quality.
H. Walker (walker.455@osu.edu)
Effect of Flue Gas Desulfurization (FDG) By-Product on Water Quality at an Underground Coal Mine. J. Environ. Qual. 30:1371–1381.
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Sampling Manure for Accurate Nutrient Analysis
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Accurate and reliable nutrient analysis is needed for appropriate management of animal manure. Given manure's heterogeneity and the considerable cost of standard laboratory testing, a sensible choice is to perform analysis based on a composite of multiple samples per manure system. Dou et al. report that accurate and reliable nutrient testing is achievable by analyzing composites of three to five samples collected during storage unloading with concurrent agitation. Sampling from nonagitated systems offers limited chance for satisfactory results unless extensive sampling (40 samples) is conducted. Results highlight the importance of agitating stored manure to reduce sample variability and aid in obtaining representative samples for meaningful nutrient analysis.
Z. Dou (dou@cahp2.nbc.upenn.edu)
Manure Sampling for Nutrient Analysis: Variability and Sampling Efficacy. J. Environ. Qual. 30:1432–1437.
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Phosphorus Sorption in Estuarine Sediments
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Estuarine sediments could function as sources or sinks for P to the overlying water, depending on their physico–chemical characteristics. Pant and Reddy report that sediments enriched with amorphous and poorly crystalline forms of Fe act as a reservoir for P by adsorbing excessive P in aerobic sediment zones and releasing upon burial in anaerobic zones. Results indicate that equilibrium P concentration of sediment or soil is a collective function of the individual equilibria of the sorbed P complexes.
K.R. Reddy (krr@ufl.edu)
Phosphorus Sorption Characteristics of Estuarine Sediments under Different Redox Conditions. J. Environ. Qual. 30:1474–1480.
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Organics in Remote Lakes
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If you are planning a vacation to a secluded mountain lake to escape the problems of the modern world, the findings of Vilanova et al. might give you pause. They measured hexachlorocyclohexanes (HCH), endosulfans, hexachlorobenzene (HCB), DDT, and polychlorobiphenyls (PCB) in waters from three European remote mountain lakes in the Alps, Pyrenees, and Caledonian mountains. High HCH concentrations were found in all lakes, those in the Alps and Pyrenees (990–2900 pg/L) being among the highest recorded in continental waters. In contrast, the concentrations of HCB, DDTs, and PCB (4–8, 0.6–16, and 26–110 pg/L, respectively) were low compared with other continental waters exhibiting a phase partitioning dependence on temperature and water-suspended particles. Comparison between different sampling seasons and water depths indicated a remarkable concentration uniformity within lake, but major interlake differences. Normalization to turnover rates showed higher interlake similarity.
J.O. Grimalt (jgoqam@cid.csic.es)
Organochlorine Pollutants in Remote Mountain Lake Waters. J. Environ. Qual. 30:1286–1295.
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Protein Index Predicts Nitrogen Mineralization
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To use biosolids as a fertilizer, it is important to be able to predict the amount and rate of mineralization of nutrients, particularly N, from them. Rowell et al. report that rates of net N mineralization were best predicted by a model incorporating the initial organic N concentration and the proportion of phenolic C determined from solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Among biosolids there was a strong correlation between organic N concentration and indices of protein determined from 13C NMR, suggesting that these protein indices may be useful for predicting N mineralization from biosolids. There was some evidence that the protein content and N mineralization in biosolids may be predictable from the sewage treatment process employed.
C. Prescott (cpres@interchg.ubc.ca)
Decomposition and Nitrogen Mineralization from Biosolids and Other Organic Materials: Relationship with Initial Chemistry. J. Environ. Qual. 30:1401–1410.
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Natural Systems Cut Nitrogen Loss
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Nitrogen losses from agricultural fields to surface waters have been an international concern for many years, since they are higher than those observed in undeveloped land and may have detrimental effects on natural ecosystems and human health. Borin et al. now report that controlled drainage reduced N losses 50%, and constructed wetlands 95%, compared with the usual water management. Results from discharge of agricultural drainage water into natural or constructed wetlands before being routed into water bodies were similar for all hydrophytes used (common reed, common cattail, tufted sedge). In a 3-year lysimeter study, they considered all these techniques as natural systems where alternative management of water table could ameliorate water quality, and compared them to the usual water management of crops in the open field.
M. Borin (Borin@agripolis.unipd.it)
Controlled Drainage and Wetlands to Reduce Agricultural Pollution: A Lysimetric Study. J. Environ. Qual. 30:1330–1340.
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Wood Ash Fertilizer Adds Organic Contaminants
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Wood ash used as a fertilizer in forests can contain organic contaminants as well as heavy metals. Bundt et al. report that wood ash application increased polycyclic aromatic hydrocarbon (PAH) concentrations in the organic horizons up to sixfold, whereas polychlorinated biphenyl (PCB) concentrations decreased due to mobilization. In the mineral soil, preferential flow paths contained higher concentrations of PCB and PAH than the rest of the soil matrix. They conclude that only wood ash with low concentrations of organic contaminants should be used to fertilize forests.
M. Bundt (Bundt.Maya@bcg.com)
Forest Fertilization with Wood Ash: Effect on the Distribution and Storage of Polycyclic Aromatic Hydrocarbons (PAHs) and Polychlorinated Biphenyls (PCBs). J. Environ. Qual. 30:1296–1304.
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Drain-Tile Nitrogen Threatens Sustainability
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Nitrogen fertilizer used in corn production is a leading source of nitrate contamination of surface waters in the Mississippi watershed. Jaynes et al. describe the yield, N budget, and nitrate loss in a producer's field where three different N fertilizer rates were used. The economically optimum rate was close to the 2/3 rate, but at this rate the nitrate concentration in tile drainage was above the maximum contaminant level (MCL) set by the USEPA for drinking water. Even at lower fertilizer rates, nitrate concentrations frequently exceeded the MCL. At all but the highest fertilizer rate, more N was removed from the field in grain and tile drainage than was replenished by fertilizer and other sources. This indicates that the lower fertilizer rates are not sustainable because they are mining N (and thus fertility) from these very productive soils.
D. Jaynes (Jaynes@nstl.gov)
Nitrate Loss in Subsurface Drainage as Affected by Nitrogen Fertilizer Rate. J. Environ. Qual. 30:1305–1314.
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Mulch Masks Metal Mess
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One way to remove heavy metals from polluted soils is to immobilize the metals by binding agents. Kiikkilä et al. added a compost and woodchip mulch to forest soil to study in situ bioremediation of soil polluted by a Cu–Ni smelter. They report that the exchangeable Cu concentration and the toxicity of the soil solution to bacteria decreased, microbial activity and bacterial growth rate increased, and the tolerance of bacteria to Cu decreased on the mulched plots.
O. Kiikkilä (oili.kiikkila@metla.fi)
In Situ Bioremediation through Mulching of Soil Polluted by a Copper–Nickel Smelter. J. Environ. Qual. 30:1134–1143.
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Water Source Related to Phosphorus Runoff
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Phosphorus from irrigation runoff or eroded soil can reach lakes and streams where it increases algal and other plant growth, which reduces dissolved oxygen. Irrigation water quality and antecedent soil surface conditions are thought to influence P in runoff. Aase et al. found that irrigation water similar to either the soil or rainwater quality had similar P runoff relationships. Soil surface conditions had little or no effect on amount of P in runoff. Their studies were conducted on a calcareous soil with a wide range of P concentrations.
D.T. Westermann
(dtw@kimberly.ars.pn.usbr.gov)
Phosphorus Runoff from Two Water Sources on a Calcareous Soil. J. Environ. Qual. 30:1315–1323.
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Solvent Transport and Transformation Modeled
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Industrial use of chlorinated hydrocarbons as solvents has lead to wide-spread ground water contamination problems. These solvents will degrade after some time but many of the products that are formed are equally or more dangerous. Casey and 
im
nek developed a new computer model method to better understand the degradation and transformation of chlorinated hydrocarbons by simultaneously modeling the transport of trichloroethylene as it transformed to ethylene. This method results in a better understanding of the fate and transport processes of industrial solvents and other pollutants that undergo transformation reactions, such as N fertilizers and radioactive isotopes.
F.X.M. Casey
(Francis_Casey@NDSU.NoDak.edu)
Inverse Analyses of Transport of Chlorinated Hydrocarbons Subject to Sequential Transformation Reactions. J. Environ. Qual. 30:1354–1360.
TOP
Gobs of Fly Ash...
"Non-Discharge" Swine Farms...