bluuebunny/crossref_metadata_2025 huggingface dataset:
Toxicity, Uptake, and Elimination of the Herbicides Alachlor and Dinoseb in Freshwater Fish
Authors: Call D. J. , Brooke L. T. , Kent R. J. , Poirier S. H. , Knuth M. L. , Shubat P. J. , Slick E. J.
Published: July 2010

Fathead minnows (Pimephales promelas) 30 d of age were exposed to technical grade alachlor [2‐chloro‐2′ ,6′‐diethyl‐N‐(methoxymethyl)acetanilide] and dinoseb (2‐sec‐butyl‐4,6‐dinitrophenol) in flow‐through tests to determine acute toxicity. Median lethal concentrations (LC50 values) for alachlor were 9.9, 6.6, 5.0, and 3.0 mg L−1 at 24, 48, 96, and 192 h, respectively; and for dinoseb were 0.8, 0.7, 0.7, and 0.5 mg L−1, respectively. Early life‐stages of the fathead minnow (embryos, fry, and juveniles) were exposed to lower concentrations of each compound for a total of 64 d. The “no effect” concentration was estimated to lie between 0.52 and 1.10 mg L−1 for alachlor and between 14.5 and 48.5 µg L−1 for dinoseb. Neither herbicide was appreciably accumulated in fish tissue. Whole body bioconcentration factors for parent 14C‐alachlor and 14C‐dinoseb were 6.0 and 1.4, respectively. Rainbow trout (Salmo gairdneri) injected with radiolabeled herbicides eliminated ≥ 83% of the radioactivity within 24 h as a combination of parent compound and metabolites.

These laboratory studies suggest that the accumulation of alachlor and dinoseb residues and the toxicity of alachlor do not present great environmental risks to fish. However, the toxicity of dinoseb may pose some risk.
Denitrification Associated with Stream Periphyton: Chamber Estimates from Undisrupted Communities
Authors: Duff J. H. , Triska F. J. , Oremland R. S.
Published: July 2010

Undisrupted periphyton communities from a N‐rich (NO3− = 63 µmol L−1) and pristine (NO3− = 2.9 µmol L−1) stream were assayed for denitrifying activity (acetylene‐blockage technique) in 40‐L chambers incubated at in situ temperature and nutrient concentrations. Nitrous oxide formation associated with periphyton from the N‐rich stream was immediate and linear (52.1 µmol N2O m−2 h−1) in the dark, anaerobic chamber (50 kPa C2H2). In the corresponding light, aerobic chamber (50 kPa C2H2), N2O production was inhibited by 82% (9.3 µmol N2O m−2 h−1). Nitrous oxide formation was not associated with periphyton from the pristine stream incubated in situ, either with or without NO3− amendment.

Denitrification estimates made with undisrupted periphyton communities at in situ temperature and nutrient concentrations (40‐L chambers) were less variable than estimates made with periphyton “scrapings” in small flasks (room temperature). The calculated diel periphyton‐associated denitrification rate based on a 14‐h light‐10‐h dark day was 651 µmol N2O m−2 d−1. The data suggest denitrification within periphyton mats may contribute toward removal of NO3− from N‐rich fluvial environments.
Use of Peat for On‐Site Wastewater Treatment: II. Field Studies
Authors: Brooks J. L. , Rock C. A. , Struchtemeyer R. A.
Published: July 2010

Three full‐size sphagnum (Sphagnum spp.) peat filter fields were monitored to determine the treatment levels after application of septic tank effluent (STE). Systems I and II were designed with a liner and had overboard discharges, whereas system III was constructed with a subsurface discharge. Gravity‐feed, dosed‐feed, and pressure distribution systems all provided excellent organic and 99% fecal coliform removal without additional disinfection.

The 5‐day biochemical oxygen demand (BOD5) reduction exceeded 90% and chemical oxygen demand (COD) reduction exceeded 80% in all three systems. Total suspended solids (TSS) measured 16 and 9 mg/L in the effluent from systems I and II, respectively. Systems I and II showed 58 and 62% total P reduction, respectively, while a total P reduction of 96% was obtained in system III. Nitrate‐N in the effluent from all three systems was < 4.5 mg/L, well below the recommended limit of 10 mg/L. The pH of the effluents ranged from 5.3 to 6.5 and color averaged 330 standard units. In Maine, or other areas where the natural waters tend to be both colored and slightly acidic, neither parameter would be problematic when using an overboard discharge. Effluent from the well‐aerated fields contained dissolved O2 averages of 4.6 and 6.7 mg/L for systems I and II.

Annual variation in weather conditions, including prolonged cold, with and without snow cover, and extreme short‐term precipitation, had no adverse effects on the performance of the peat filter fields. The use of sphagnum peat for on‐site wastewater treatment seems to be an acceptable alternative for areas where conventional systems cannot be installed.
Weathering Processes in Relation to Leachate Properties of Alkaline Fly Ash
Authors: Warren C. J. , Dudas M. J.
Published: July 2010

Results are presented for a column leaching experiment designed to evaluate the relationship among leachate properties, weathering processes, and solid phase characteristics of an alkaline fly ash. Fly ash was weathered with 0.005 mol/L H2SO4 in a series of five leaching columns. Acidification of the ash leachates occurred in a stepwise fashion involving three buffer stages. Chemical dissolution and mobilization of elements was greatest in the first column and decreased to minimal dissolution and maximum accumulation of weathered products in ash of the fifth column. Results indicated that unreacted fly ash consists of spherical micron‐sized particles composed of mullite enclosed in a two‐phase glassy matrix. The external glass was enriched in Ca, Mg, Fe, and Al. The interior glass matrix was composed primarily of Si and a major portion of the total Na and K. The ash also contained a highly reactive inorganic phase composed largely of submicron‐sized CaO fragments on the surfaces of ash particles. Initial dissolution characteristics were dictated by the reactions of the CaO fragments and surface‐associated soluble salts. Leachate characteristics were largely controlled by dissolution of the external glassy matrix after the rapid dissolution of surface salts. Solid state migration and removal of Na from the interior glassy matrix was active under acidic leaching conditions.
Irrigation of Monterey Pine with Wastewater: Effect on Soil Chemistry and Groundwater Composition
Authors: Cromer R. N. , Tompkins D. , Barr N. J. , Hopmans P.
Published: July 2010

Fifteen‐year old Monterey pine (Pinus radiata) was irrigated for 3 yr with wastewater derived from industrial and municipal sources. The wastewater contained high concentrations of Na2+ and HCO3− and was quite alkaline. Irrigation thus caused substantial increases in exchangeable Na2+, extractable P, exchangeable K+, pH, and the electrical conductivity of the soil solution. Highly colored organic compounds derived from pulp‐mill effluent apparently combined with inorganic N from municipal effluent to form organic N compounds. Nitrogen remained largely in the organic form and became concentrated in the groundwater with colored humic compounds. The greatest environmental hazard in the use of such blended wastewater for irrigation is the contamination of drainage water with colored, saline water containing high concentrations of organic N. The organic compounds appeared to inhibit nitrification in the groundwater.
Behavior Assessment Model for Trace Organics in Soil: II. Chemical Classification and Parameter Sensitivity
Authors: Jury W. A. , Farmer W. J. , Spencer W. F.
Published: July 2010

In this paper, the organic chemical transport screening model developed in Jury et al. (1983) is simplified by dividing chemicals into volatilization and mobility categories. The volatilization classification is based on whether or not the predominant resistance to volatilization loss lies in the soil or in the boundary layer above the soil surface. This categorization reduces to a condition on the Henry's constant (KH) and organic C partition coefficient (Koc) when standard values are used to represent soil and chemical parameters. The mobility categories are based on the calculated time to convect or diffuse a given distance through the soil.

Simulations are conducted for chemicals falling into one or another of these volatilization or mobility categories to examine the sensitivity of these processes to variations in water evaporation, water content, organic C fraction, and boundary layer thickness. The dependence of both volatilization flux and leaching flux on these parameters is summarized.
Interlaboratory Comparison of a Standardized Phosphorus Adsorption Procedure
Authors: Nair P. S. , Logan T. J. , Sharpley A. N. , Sommers L. E. , Tabatabai M. A. , Yuan T. L.
Published: July 2010

A standard P adsorption procedure was proposed and the ability of four laboratories to produce consistent results over a wide range of soils was determined. For this procedure, 0.5 to 1.0 g of soil were shaken in 0.01 mol L−1 CaCl2 at a soil/solution ratio of 1:25 in containers allowing a 50% head space for 24 h at 24 to 26°C on an end‐over‐end shaker. Initial dissolved inorganic P concentrations of 0 to 323 µmol P L−1 (as KH2PO4 or NaH2PO4) were used and microbial activity inhibited by 20 g L−1 chloroform. Excellent agreement between the four laboratories was obtained for the amount of P adsorbed by the 12 soils studied, with a mean coefficient of variation (CV) over all P levels and soils of 0.91%. The laboratories also exhibited a high degree of replication of individual treatments with no laboratory showing a strong consistent bias across all soils and P levels in terms of P adsorption. Langmuir, Freundlich, and Tempkin adsorption models were highly correlated with the adsorption data. Respective mean correlations for the 12 soils were 0.98, 0.97, and 0.95. The proposed method, therefore, has the potential to produce consistent results that can be used to predict partitioning of dissolved inorganic P between solid and solution phases in the environment.
The Role of Leaf Litter Nitrogen Immobilization in the Nitrogen Budget of a Swamp Stream
Authors: Qualls Robert G.
Published: July 2010

The interactions of water level, dissolved nutrients, litter decomposition, and N immobilization were investigated in two blackwater stream swamps in North Carolina: Creeping Swamp (CR) and Chicod Creek (CH). Leaf litterbags were sampled along hydroperiod‐elevation gradients in CR during the winter‐spring high water period. Litterbags were also sampled at two elevations at two sites in CH with contrasting levels of dissolved nutrients. With the low levels of dissolved nutrients in CR, there was little difference in litter decomposition rate along elevation gradients. Decomposition was faster at the inundated sites in CH and the faster decomposition was associated with nutrient enrichment. Exogenous N immobilized in litter reached higher levels in the enriched swamp (CH). Despite faster decomposition in CH, no substantial mineralization of litter N had occurred prior to June. A budget of litter N and dissolved inorganic N inflow showed that immobilization by flooded litter over 1 linear km of Creeping Swamp during the sampling period was 87 kg, equivalent to about 25% of the inorganic N inflow. This proportion shows that litter can play a significant role in controlling N concentrations in stream water in small swamp streams.
Metal Concentrations in Earthworms From Sewage Sludge‐Amended Soils at a Strip Mine Reclamation Site
Authors: Pietz R. I. , Peterson J. R. , Prater J. E. , Zenz D. R.
Published: July 2010

A 3‐yr study of earthworms was initiated in selected minesoil and nonmined fields at a Fulton County, IL land reclamation site. The purpose of this research was to determine the effect of the land application of anaerobically digested sewage sludge, used to reclaim the site, on heavy metal accumulations in earthworms.

Two species of earthworms, Lumbricus terrestris and Aporrectodea tuberculata, were identified in the sludge‐amended and nonamended, nonmined fields sampled. Only A. tuberculata was found in the sludge‐amended and nonamended minesoil fields sampled.

Earthworm metal concentrations generally increased with time in all the sampled fields. The decreasing order of metal accumulation by earthworms in all sludge‐amended fields sampled was Cu > Cd > Ni > Cr > Pb > Zn. Sewage sludge applications to fields on both land types resulted in significant accumulations of Cd, Cu, and Zn. Land type (minesoil vs. nonmined) significantly affected earthworm Zn concentrations, with levels being higher in all nonmined fields sampled. Earthworm Cd and Cu accumulations in all fields sampled were significantly related to the current amounts of sludge‐applied metals, the amount applied since the previous sampling. Concentrations of Ni, Cr, and Pb in earthworms were not significantly related to sewage sludge applications during the 1975 to 1977 sampling period. The higher Cd and Cu concentrations in earthworms from sludge‐amended fields may pose a potential hazard to predators.
Swine Lagoon Effluent Applied to ‘Coastal’ Bermudagrass: I. Forage Yield, Quality, and Element Removal
Authors: Burns J. C. , Westerman P. W. , King L. D. , Cummings G. A. , Overcash M. R. , Goode L.
Published: July 2010

Swine (Sus scrofa domesticus) production in confinement requires economical and environmentally safe waste management systems. Anaerobic lagoons require periodic removal of effluent for land application to avoid lagoon overflow in humid regions. The objective of this experiment was to determine the utilization potential and the environmental effects of applying swine lagoon effluent to ‘Coastal’ bermudagrass [Cynodon dactylon (L.) Pers.]. Effluent loading rates to apply approximately 335, 670, and 1340 kg of N ha−1 yr−1 were evaluated. The experiment was a randomized complete block with three replications and was conducted for 6 yr on a loamy, siliceous, thermic Arenic Paleudult (two replications) or a fine‐loamy, siliceous thermic Typic Paleudult (one replication). The highest application rate resulted in additions of N, P, and K at about 4, 10, and 8 times, respectively, the normally recommended fertilizer applications for high yields of bermudagrass hay.

Effluent loading rates altered dry matter yields with the high and medium rates being similar (15 800 and 14 200 kg ha−1) but greater than the low rate (10 800 kg ha−1). Severe winters injured stands most on the medium and high loading rates and were associated with soil characteristics. Concentrations of P, K, Ca, Mg, Mn, and Zn were increased in forage by increased effluent loading rates, while Cl−, Cu, Fe, and Na varied. Effluent loading rates significantly increased in vitro dry matter disappearance 3 of the 6 yr and N concentrations all years, especially from the low to medium loading rates (quadratic effect). High applications of effluent greatly increased the concentration of nitrates in the forage to levels that approached, but did not exceed, concentrations unsafe for ruminants. The medium and high rates resulted in large additions of elements not recovered in the forage and could have environmental implications as to effects on the soil, groundwater, and surface runoff.
Swine Lagoon Effluent Applied to ‘Coastal’ Bermudagrass: II. Effects on Soil
Authors: King Larry D. , Westerman P. W. , Cummings G. A. , Overcash M. R. , Burns J. C.
Published: July 2010

Effluent from animal waste lagoons can degrade water quality if allowed to discharge into surface waters. To determine the feasibility of using swine (Sus scrofa domesticus) lagoon effluent as a source of water and nutrients for crop production, effluent was applied via sprinkler irrigation to ‘Coastal’ bermudagrass [Cynodon dactylon (L.) Pers.] on Norfolk and Wagram soils (Paleudults) at rates to supply 335, 670, and 1340 kg N ha−1 yr−1 for 6 yr. Soil nitrate concentrations to a depth of 300 cm showed significant differences in the order high > medium = low rate. At the high rate, 56% of the applied N could not be accounted for by crop removal or increased N content of the soil to a depth of 210 cm. Evidence of P movement to a depth of 60 cm was obtained. Calcium and Mg concentrations in the topsoil were reduced due to relatively high rates of application of Na+, K+, and NH4+. Soil pH was correspondingly reduced. Soil nitrate data suggest that groundwater pollution by nitrate would result from the high rate and possibly from the medium rate.
Fate of Nitrogen‐15‐Labeled Fertilizer Nitrogen in Revegetated Cretaceous Coal Spoils
Authors: Reeder J. D.
Published: July 2010

Western wheatgrass (Agropyron smithii L.) was grown in a greenhouse study on two Cretaceous coal spoils and a topsoil to describe the short‐term behavior of several levels of added 15N‐labeled (NH4)2SO4 (0, 60, 120, and 240 mg N kg−1 soil). Recovery and distribution of fertilizer N was measured at harvest in the soil materials and in the harvested tops, roots, crowns, and rhizomes of the western wheatgrass. Fertilizer N uptake by plants grown in the topsoil increased significantly with increasing fertilizer rate, but a significant increase in aboveground biomass did not occur with the 240 mg N kg−1 treatment. In contrast, aboveground biomass on the two spoils increased significantly with the addition of 60 mg N kg−1, but additional increases in plant biomass with higher fertilizer rates did not occur, and a significant decrease in plant biomass occurred with the 240 mg N kg−1 treatment. Significantly lower water holding capacities and cation exchange capacities resulted in significantly higher NH4+ concentrations in solution in the spoil materials as compared with the topsoil. Thus, suppressed seedling emergence and establishment in the spoil materials was attributed to NH3 toxicity and/or phytotoxicity due to NO2− accumulation in the spoil. Substantial fractions of added fertilizer N (65–72%) were immobilized by the plants and into soil organic matter in the topsoil, and only at the highest fertilizer rate did fertilizer N accumulate in mineral form. Under field conditions, this immobilized N should be available for recycling and plant uptake in subsequent years and thus help reestablish a functional N‐cycling ecosystem. In comparison, percent recovery of added N decreased in plant biomass and increased in NO3− form in the two spoils as the rate of fertilizer application increased. Thus, 40 to 50% of added fertilizer N could be susceptible to leaching losses under field conditions.
Hexazinone Adsorption‐Desorption Studies with Soil and Organic Adsorbents
Authors: Bouchard D. C. , Lavy T. L.
Published: July 2010

Hexazinone [13‐cyclohexyl‐6‐(dimethylamino)‐1‐methyl‐1,3,5‐triazine‐ 2,4(1H,3H)‐dione] adsorption‐desorption was studied using soil from different horizons and using organic adsorbents. Hexazinone was adsorbed less than atrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine] by soil. The Oi horizon (leaf litter) of a forest soil showed the greatest adsorptivity for hexazinone (K = 15.09). Hexazinone was desorbable from all soil horizons with 0.01M CaCl2. Normalizing for the organic C content of the soil horizons with Koc removed differences in the adsorptivity between soils. The octanol‐water partition coefficient (Kow) estimated the Koc for the hexazinone‐soil horizon systems within a factor of 2 to 3.

Hexazinone was not adsorbed from 0.01M CaCl2 by purified cellulose, or by anionic (pH = 5.8) or neutral (pH = 2.8) carboxymethyl cellulose. Nonpolar surfaces seem to be important in hexazinone adsorption as polystyrene adsorbed all of the hexazinone from 0.01M CaC2. The hexazinone adsorbed by polystyrene was not desorbable with 0.01M CaCl2, but was desorbable with a 3:2 methanol/water (vol/vol) solution. In the absence of competing water molecules, hexazinone was adsorbed from hexane solution on cellulose.
A Modified Langmuir Equation for Predicting Sorption of Methylacridinium Ion in Soils and Sediments
Authors: Brown David S. , Combs George
Published: July 2010

An empirical model for predicting sorption isotherms of organic cations was tested using a set of 10 soils and sediments. The model is based on a competitive Langmuir equation with modifications for grouping the various competing ion species and for normalizing over a broad range of sediment properties. Normalization is accomplished by substituting cation exchange capacities (CECs) determined with NH4+ for the Langmuir capacity term. Natural exchange ions are grouped and treated as a single competing species for simplicity. A single calibration enables estimation of sorption isotherms for other sediments for which estimates of CECs and competing electrolyte concentrations are known.
Salt Accumulation in the Rivers of North Dakota
Authors: Maianu A.
Published: July 2010

Chemical determinations on over 9000 water samples collected from 83 rivers and analyzed by the U.S. Geological Survey between 1949 and 1982 were used to establish the patterns of salt accumulation in North Dakota rivers. The concentrations of the principal anions, cations, and sodium adsorption ratio (SAR) were related with the total salinity (electrical conductivity, EC) of each water sample. Some patterns of salt accumulation were observed: first, according to the anions that accumulate as a continuum with increases in total salinity; and secondly, by the rate of anion accumulation. Taking into consideration these two factors, eight groups of river waters were established. Thirdly, the change of the ratios between the anions with increases in total salinity creates a succession of stages of salt accumulation. Each stage corresponds to the change of the river water chemical composition between particular total salinity limits. These changes are specific for each group of rivers depending on the topographic and geologic conditions that prevail in the drainage basin of the rivers. Based on these three factors, a genetic classification of river waters was derived, which consists in ranking the waters in three categories: classes, groups, and stages of salt accumulation.
Aflatoxin Movement in Soil
Authors: Goldberg B. S. , Angle J. S.
Published: July 2010

Crops contaminated with > 20 µg kg−1 aflatoxin cannot be transported across state lines. Contaminated preharvest crops are often disposed of by plowing the crop into the soil, thereby creating the potential for aflatoxin contamination of groundwater. The objective of this study was thus to determine the leaching and adsorption potential of aflatoxin in soils.

Leaching and adsorption studies were conducted with a silt loam, clay loam, sandy loam, and silty clay loam soil. Soil columns were utilized in the leaching experiment. The length of the column and the volume of soil used were 30.54 cm and 1234 cm3, respectively. A total of 2.5 mg aflatoxin B1 was applied to the soil surface and the column was leached with 1 L of water under saturated conditions for 24 h. The results demonstrate that aflatoxin B1 or its derivatives, aflatoxin B2 and G2, were retained within the upper 20 cm of all soil types. Between 80 and 92% of the total amount of aflatoxin applied was retained in the upper 2.5 cm of the soil columns. No aflatoxin was found in the leachate from any of the soils.

Freundlichs isotherm was used to establish adsorption coefficients for the soils by the slurry technique. The concentrations of aflatoxin used to establish the constants were 0.1, 1.0, 5.0, and 10 mg L−1. The resulting adsorption coefficients were 238, 76, 46, and 17 mg kg−1 for the silty clay loam, silt loam, clay loam, and sandy loam, respectively. As a result of the two experiments, aflatoxin contamination of groundwater would not be expected to occur unless the soils were extremely sandy or shallow.
Partitioning Behavior of Insecticides in Soil‐Water Systems: I. Adsorbent Concentration Effects
Authors: Bowman B. T. , Sans W. W.
Published: July 2010

Adsorption studies were conducted to determine whether adsorbent concentration (soil‐solution ratio) affected insecticide adsorption by soils and clays. Adsorption isotherms were obtained for several insecticides in Bondhead sandy loam and Ca‐saturated illite suspensions using adsorbent concentrations that were varied over several orders of magnitude. There was no evidence that altering adsorbent concentration exerted any influence on partitioning of insecticides between the adsorbent and solution phases. The centrifugation process, which in effect greatly increased adsorbent concentration at the bottom of the centrifugation tube, did not change the partitioning of the insecticides between the two phases. Dieldrin (1,2,3,4,10,10‐hexachloro‐exo‐6,7‐epoxyl, 4,4a,5,6,7,8,8a‐octahydro‐1,4‐endo,exo‐5,8‐dimethanophthalene), unlike the other insecticides, exhibited strong concentration‐dependent adsorption by glass surfaces, which invalidated the use of the normal “blank” (no adsorbent) sample for determining the initial solute concentration. Since glass adsorption appeared quite irreversible in aqueous solution, a sequential blank/sample adsorption technique was adopted whereby the stock solution was initially equilibrated in the glass bottle, then a small aliquot was removed for analysis before adding the adsorbent for its equilibration period. This technique produced consistent adsorption data that showed no evidence of being influenced by adsorbent concentration.
Partitioning Behavior of Insecticides in Soil‐Water Systems: II. Desorption Hysteresis Effects
Authors: Bowman B. T. , Sans W. W.
Published: July 2010

This investigation was undertaken to determine whether desorption hysteresis effects were dependent upon methods used in obtaining desorption data. Adsorption‐desorption isotherms were obtained for two organophosphorus insecticides in aqueous suspensions of a clay, a sandy loam, and an organic soil. Desorption isotherms were obtained using both the consecutive desorption method and the dilution method. In the consecutive method, the same sample (after adsorption step) was put through a series of equilibration‐centrifugation steps in which, following equilibration, the adsorbent was thrown down by centrifugation, and part of the supernatant pesticide solution was replaced by distilled water before reequilibration. In the dilution method a series of replicate samples (same adsorbent weight), after the adsorption step, were diluted to different volumes with distilled water, reequilibrated, then centrifuged to separate the phases. With the exception of one insecticide‐soil system (where both methods produced minimal hysteresis), hysteresis effects were considerably reduced by using the dilution method. Repeated centrifugation appeared to be associated with the appearance of hysteresis effects observed using the consecutive desorption method. A short discussion is included on the improper use of desorption data to construct “single point desorption isotherms,” which has created confusion in the literature.
Dissipation of Carbaryl and the 1‐Naphthol Metabolite in Flooded Rice Fields
Authors: Deuel L. E. , Brown K. W. , Price J. D. , Turner F. T.
Published: July 2010

Field and laboratory experiments were conducted under flooded rice (Oryza sativa L.) culture to evaluate persistence of carbaryl (1‐naphthyl‐N‐methyl carbamate) and the 1‐naphthol metabolite. Treatments consisted of two rates of carbaryl (1.12 and 5.60 kg ha−1) super‐imposed on two irrigation management schemes (i.e., intermittent and continuous flow) to determine their potential for environmental contamination. Results showed that foliarly applied carbaryl was washed from the rice canopy into plot water and subsequently degraded via chemical and biological mechanisms. Time of sample collection and application rate had a highly significant influence on the residual levels of carbaryl in the flood water for each of the 3 yr tested. The effect of irrigation management was statistically significant in two of the three seasons studied, with greater levels of carbaryl residues observed for the intermittent irrigation scheme. Carbaryl residues in plot water were greatest in those years when a rainfall event occurred within 24 h following the foliar spray application. A significant first order interaction between time and application rate was observed in 1973 and 1975, when measurable rainfall was recorded prior to the 24‐h sampling period. The 1‐Naphthol recovered in the plot water was proportional to the contamination level of the carbaryl spray formulation and did not reflect the quantities of dissipated carbaryl. Field results and laboratory experiments suggested that 1‐naphthol was degraded more rapidly under flooded soil conditions than carbaryl.
Description and Application of an Animal Waste Phosphorus Loading Model
Authors: Moore I. C. , Madison F. W.
Published: July 2010

An animal waste loading model was developed to estimate total phosphorus (P) loadings from winter‐spread manure, barnyards and feedlots, and aboveground manure storage facilities. Literature studies were used to establish the percentage of manure P which could potentially be carried in runoff from a specific manure source. Likewise, a critical distance over which manure polluted runoff must travel as overland flow in order for P to be reduced to background levels was established. The model was tested on a 328‐ha watershed in Shawano County, WI, which is devoted to dairy agriculture and where surface water was monitored and intensive land use inventories were completed. For the years 1974 to 1976, the model predicted total P loadings from animal wastes of 96.0 kg yr−1, of which 24.6 kg yr−1 or 26% was attributed to winter spreading, and the balance of 71.4 kg yr−1 or 74% to runoff from barnyards and above‐ground storage facilities. The animal waste model was linked to a model estimating cropland losses of total P to develop a prediction of total P losses from the watershed. Comparison between predicted and monitored values suggested that the animal waste model was a useful tool for estimating total P losses from various waste handling practices on a long‐term basis. As such, it will serve as a valuable planning tool for nonpoint source abatement programs.
Sample Design and Analysis for Regional Geochemical Studies
Authors: Klusman R. W.
Published: July 2010

The compilation of baseline geochemical data prior to the development of large‐scale energy projects is necessary in order to assess possible impacts the development may have on the local environment. Most studies are site specific and difficult to integrate where several independent studies are being carried out on adjacent projects. Methods are presented, hierarchial analysis of variance complemented with kriging, to carry out preliminary geochemical baseline determinations over relatively large regions. These efficient, low‐cost methods provide data on natural compositional trends with a known degree of reliability. Soil molybdenum from the Piceance Basin of Colorado and Uinta Basin of Utah are used to illustrate the methods. Sample densities ranging from one per 62 km2 to one per 0.5 km2 are evaluated with respect to effectiveness in presenting the distribution of soil molybdenum of these areas. A sample density of one per 47 km2 was determined to be adequate by analysis of variance, for low resolution mapping of a portion of the eastern Uinta basin. Maps generated by geostatitical analysis followed by kriging provide a visual representation of soil molybdenum and the associated estimation variance. A density of one sample per 62 km2 was demonstrated not to be adequate for low resolution mapping of soil molybdenum in the Piceance basin. A higher sampling density of one per 0.66 km2 was utilized in mapping soil molybdeuum of oil shale Tract C‐a and vicinity. Analysis of variance demonstrates this is an adequate density for mapping at higher resolution. Geostatistical analysis and kriging were used to generate an estimate map and variance estimate for Tract C‐a and vicinity.
Sorption and Transport of Hydrophobic Organic Chemicals in Aqueous and Mixed Solvent Systems: Model Development and Preliminary Evaluation
Authors: Rao P. S. C. , Hornsby A. G. , Kilcrease D. P. , Nkedi‐Kizza P.
Published: July 2010

A theoretical approach, based upon the assumption of predominance of solvophobic interactions, was formulated to quantitatively describe the sorption and transport of hydrophohic organic chemicals (HOC) from aqueous and aqueous‐organic‐solvent mixtures. In the theoretical approach, solvent‐sorbate interactions (solubility) are specifically considered in order to predict sorbate‐sorbent interactions (sorption). For HOC sorption from a single solvent, the HOC sorption coefficient was shown to increase loglinearly with the hydrocarbonaceous surface area (HSA) of the sorbate. For HOC sorption from aqueous‐organic binary solvent mixtures, the sorption coefficient is predicted to decrease exponentially as the fraction of organic cosolvent increases. This is a direct consequence of increased HOC solubility in the binary solvent. Because sorption and mobility of HOC are inversely related, a decrease in sorption coefficient leads to an enhanced HOC mobility as the fraction of organic cosolvent is increased. A preliminary verification of the theory was performed by an analysis of published data for (i) HOC sorption by soils and sediments from water, (ii) HOC retention by reversed‐phase chromatographic sorbents during isocratic elution with methanol‐water binary solvent mixture, and (iii) HOC mobility on soil‐TLC plates eluted with ethanol‐water mixtures.
Redistribution of Bromide by Rainfall Infiltration into a Cecil Sandy Loam Landscape
Authors: Bruce R. R. , Leonard R. A. , Thomas A. W. , Jackson W. A.
Published: July 2010

The redistribution of bromide applied to the soil surface at selected positions in a sample Cecil sandy loam (clayey, kaolinitic, thermic Typic Hapludults) landscape was measured in relation to rainfall and pedon characteristics. Three bromide application sites were located in drainageway positions and three on slope positions exhibiting different degrees of erosion. Observations of nearly 4 yr measured 4.7 m of rainfall to show that rainfall was more effective in transporting Br through drainageway pedons than those on the slopes. After 1000 mm of rainfall, half of the applied Br was above 0.6 m on the slope sites and above 1.0 m on the drainageway sites. This difference seems to relate closely to the higher hydraulic conductivity in the Bt horizon above 1.2 m in the drainageway pedons than in the slope pedons. Also, the maximum clay zones in the Bt horizons of the drainageway sites were significantly lower than those on the slope sites and occurred about 0.5 m deeper. At the completion of this study, an elevated Br level was measured in a drainageway site between 1.5 and 2.4 m with no evidence of Br below 3.8 m. These data provide a basis for assigning solute transport characteristics to the identified variability in this and similar landscapes.
Determination of Potassium, Sodium, Calcium, and Magnesium in Natural Waters by Ion Chromatography
Authors: Basta N. T. , Tabatabai M. A.
Published: July 2010

Simultaneous determination of alkali and alkaline earth metals in water samples is needed. Studies to evaluate the Dionex Model 10 Ion Chromatograph (IC) for simultaneous determination of K and Na or Ca and Mg in diverse types of natural waters, including soil extracts, showed that the results by the IC method closely agreed with those obtained by flame photometry for K and Na and by atomic absorption spectrophotometry for K, Na, Ca, and Mg. The IC method is based on separation of the monovalent and divalent cations by a separator column containing a low‐capacity sulfonated divinylbenzene polystyrene copolymer, cation‐exchange resin in the H↓ form and on converting the various metal ions to their corresponding hydroxides by a suppressor column containing a high‐capacity, anion‐exchange resin in the OH− form. The eluent used for determination of alkali metals was 5 mM HCl, and a solution containing 2.5 mM HCl + 2.5 mMm‐phenylenediamine dihydrochloride was used for determination of alkaline earth metals. Electrical conductivity is used as the mode of detection. The method is precise, accurate, and can detect as little as 0.1 mg L−1 of K, Na, Ca, or Mg in water samples. The coefficient of variation values ranged from 1.3 to 5.0% for K, from 0.63 to 9.1% for Na, from 1.9 to 3.5% for Ca, and from 0 to 2.4% for Mg. With the IC method, K and Na or Ca and Mg can be determined simultaneously in 2 mL of water in approximately 7 min. A single operator can perform about 40 analyses of alkali or alkaline earth metals in a normal working day. Successive analyses of waters containing high concentrations of metals (e.g., Fe) may lead to loss of resolution of alkali metals, but this can be restored by washing the separator column with 3 M HCl saturated with EDTA.
Headwater Stream Losses of Nitrogen from Two Coastal Plain Watersheds
Authors: Jacobs T. C. , Gilliam J. W.
Published: July 2010

Nitrogen concentrations and water flow were measured for a 3‐yr period from two watersheds of the Atlantic Coastal Plain in North Carolina to assess sinks for NO3‐N4 Both of the areas are typical of the largest agricultural producing area in the region. From the Middle Coastal Plain watershed with 1299 ha of predominantly well‐ to moderately well‐drained soils, the losses of NO3‐N and total N in surface drainage water were 2.5 and 4.5 kg ha−1 yr−1, respectively. The Lower Coastal Plain watershed with 6998 ha of somewhat poorly‐ to poorly‐drained soils had NO3‐N and total N losses of 0.5 and 2.5 kg ha−1 yr−1, respectively. These values were much lower than expected based on agricultural production, fertilizer used, and crop efficiency. The soils included in the study were Typic Paleudults to Aquic Paleudults and Aquic Hapludults to Aeric Paleaquults. Denitrification between the field and stream was concluded to be the primary reason for these low values. However, the concentrations of NO3‐N in streams near the field outlets decreased significantly as N enriched water moved through the transport system. The lowest stream elevations sampled on the Middle and Lower Coastal Plain watersheds averaged 0.6 and < 0.1 mg L−1 NO3‐N with maximum values of 2.5 and 0.6 mg L−1, respectively. Comparing changes in nitrate and chloride concentrations and the reducing Eh in the stream and floodplain sediments suggest denitrification as the loss mechanism in the stream transport system. Ostensibly the stream is responsible for the loss rather than the riparian area; however, the area inundated by the stream is small compared to the flood plain. The Middle and Lower Coastal Plain watersheds have 2.5 and 94 ha inundated by the stream while confined to the channel, but while in a moderate flood these values increase to 20 and 250 ha, respectively. While instream losses of NO3‐N are important in this region to maintain water quality, they are not sufficient to completely counter heavy loading by nonpoint sources.
Residual Cadmium Forms in Acid‐extracted Anaerobically Digested Sewage Sludge
Authors: Feltz Robert E. , Logan Terry J.
Published: July 2010

The effects of phosphorus and lime additions after acid extraction on residual Cd solubility and chemical forms in an anaerobically digested sewage sludge were investigated. High Cd content (11 mmol Cd kg−1) anaerobically digested sewage sludge was aerated and then acidified to pH 2 to solubilize Cd. After 18 h of acidification, the sludge was dewatered and the supernatant and solids separated. Seventy or more percent of the Cd was removed from the solids. Similar amounts of Ni, Mn and Zn were also removed, but Cu removal was only 26% and that of Pb was < 5%. The acid extracted sludge was neutralized to pH 5.9 with Ca(OH)2. Before liming, the sludge was amended with rock phosphate (RP) or monocalcium phosphate (MCP). The RP was insoluble while MCP dissolved, providing a high level of phosphate ligand for Cd precipitation or coprecipitation. Solution Cd in the limed MCP sludge was 12% of that in the limed RP sludge or in the limed sludge without P addition. Estimated sludge solution solubility products for major Fe, Al and Ca phosphates showed that several of these minerals could have precipitated with P addition, especially with MCP, and Cd may have coprecipitated with these solid phases. Cadmium phosphate may also have been formed in the MCP sludge. Chemical fractionation indicated that 50% of the Cd in the aerated unextracted sludge existed as inorganic precipitates with another 40% Na4P2O7 extractable (organically bound). Acidification solubilized 98% of the inorganic Cd and 86% of the organically bound Cd. Seventy‐nine percent of the Cd remaining in the dewatered acidified sludge was in the KNO3 extractable (exchangeable) fraction. Liming redistributed the Cd with 13 to 19% as inorganic precipitates, 70 to 85% organically bound and < 3% in the exchangeable fraction. Phosphate addition had no significant effect on Cd fractionation.
Distribution of Plutonium and Americium Beneath a 33‐yr‐old Liquid Waste Disposal Site
Authors: Nyhan J. W. , Drennon B. J. , Abeele W. V. , Wheeler M. L. , Purtymun W. D. , Trujillo G. , Herrera W. J. , Booth J. W.
Published: July 2010

The distribution of Pu, 241Am, and water in Bandelier Tuff beneath a former liquid waste disposal site at Los Alamos was investigated. The waste use history of the site was described, as well as the previous field and laboratory studies of radionuclide migration performed at this site. One of the absorption beds studied had 20.5 m of water added to it in 1961 in an aggressive attempt to change the distribution of radionuclides in the tuff beneath the bed. Plutonium and 241Am were detected to sampling depths of 30 m in this bed, but only found to depths of 6.5 to 13.41 m in an adjacent absorption bed (bed 2) not receiving additional water in 1961. After 17 yr of migration of the slug of water added to bed 1, 0.3 to 5.1% of the Pu inventory and 3.0 to 49.6% of the 241Am inventory was mobilized within the 30‐m sampling depth, as less than one column volume of water moved through the tuff profile under the bed. The results of similar lab and field studies performed since 1953 were compared with our 1978 data and site hydrologic data was used as a time marker to estimate how fast radionuclide migration occurred in the tuff beneath absorption bed 1. Most of the radionuclide migration appeared to have occurred within 1 yr of the 20.5‐m water leaching in 1961. The implications of our research results to nuclear waste management were also discussed.
Two Agricultural Production Data Libraries for Risk Assessment Models
Authors: Baes C. F. , Shor R. W. , Sharp R. D. , Sjoreen A. L.
Published: July 2010

Two data libraries based on the 1974 United States Census of Agriculture are described. The data packages (AGDATC and AGDATG) are available from the Radiation Shielding Information Center (RSIC), Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (contact: B. L. McGill, 615‐574‐6176 or FTS 624‐6176). Agricultural production and land‐use information by county (AGDATC) or by 1/2 by 1/2 degree longitude‐latitude grid cell (AGDATG) provide geographical resolution of the data. The libraries were designed for use in risk assessment models that simulate the transport of radionuclides from sources of airborne release through food chains to man. However, they are also suitable for use in the assessment of other airborne pollutants that can affect man from a food ingestion pathway such as effluents from synfuels or coal‐fired power plants. The principal significance of the data libraries is that they provide default location‐specific food‐chain transport parameters when site‐specific information are unavailable. Plant food categories in the data libraries include leafy vegetables, vegetables and fruits exposed to direct deposition of airborne pollutants, vegetables and fruits protected from direct deposition, and grains. Livestock feeds are also tabulated in four categories: pasture, grain, hay, and silage. Pasture was estimated by a material balance of cattle and sheep inventories, forage feed requirements, and reported harvested forage. Cattle (Bos spp.), sheep (Ovis aries), goat (Capra hircus), hog (Sus scrofa), chicken (Gallus domesticus), and turkey (Meleagris gallopavo) inventories or sales are also tabulated in the data libraries and can be used to provide estimates of meat, eggs, and milk production. Honey production also is given. Population, irrigation, and meteorological information are also listed.
Mobility and Uptake by Plants of Elements Placed Near a Shallow Water Table Interface
Authors: Sheppard S. C. , Evenden W. G.
Published: July 2010

The water table interface is the transition between unsaturated, usually aerated, soil and water‐saturated, often anaerobic soil. Plant roots may approach this transition zone and absorb elements soluble in and below the transition zone. To examine this possibility, we studied elements that differ in solubility as a function of oxidation‐reduction potential. Barley (Hordeum vulgare cv. Conquest) was grown in field lysimeters, and treatments included various elements (iron, technetium and uranium plus phosphorus), element placement depths, and water table regimes. Measurements included plant uptake of each element, plant root distribution, and soil profiles of total and extractable amounts of each study element and related elements. The transition from aerobic to anaerobic conditions occurred −10 cm above the water table interface. The mobility of the elements decreased in the order Tc > U > P ≥ Fe. The redox gradient markedly modified the mobility of Tc and U. The Fe was more soluble in the reducing environment than in the oxidizing environment, but no migration of Fe was detected. The plant roots were almost entirely confined to the oxidized layers of soil. The plants absorbed no treatment Fe, very little treatment P and U (from the shallow placement only), but substantial amounts of Tc. A fluctuating water table further restricted plant uptake. The water table interface markedly changed the mobility of some of the study elements but the effect on rooting depth was more profound. Thus, the water table interface did not present a unique condition for plant roots to absorb elements as the elements diffused upward from the reducing environment.
Plant Uptake of Trace Elements from Coal Gasification Ashes
Authors: Francis C. W. , Davis E. C. , Goyert J. C.
Published: July 2010

Uptake of trace elements in annual ryegrass (L. multiflorum Lam.) grown in mixtures of three gasification ashes and two soils under greenhouse conditions is reported. The gasification ashes selected were those produced in fluidized‐, fixed‐, and entrained‐bed gasification processes. Soils consisted of a surface agricultural soil and a subsurface weathered shale. Plant uptake was evaluated under two management regimes, with and without lime and fertilizer amendments. Six harvests were made over 180 d. Ryegrass yields were highly dependent on application of lime and fertilizer regardless of quantity or type of ash in the soil‐ash mixtures. Yields from unlimed/unfertilized treatments were low because of the limited supply of N, P, and K and phytotoxic levels of Al, Cd, Ni, and Zn. The entrained‐bed ash contained a relative high S concentration (38 g/kg) that oxidized and made the soil‐ash mixtures very acid (pH < 4). Ryegrass grown in unlimed/unfertilized soil‐ash mixtures of this ash contained very high concentrations of Al, B, Cd, Co, Mo, Ni, and Zn (up to 2449, 97, 24, 38, 5, 532, and 1109 mg/kg, respectively). Many of these concentrations were considered to be phytotoxic and/or sufficiently high to be toxic to animals under continuous long‐term grazing conditions. However, applications of the same gasifier ash to soils that were limed and fertilized with N, P, and K produced ryegrass that did not contain phytotoxic levels of any of the trace elements examined or concentrations that would be of concern in the transport of these metals along foodchains to man. Risk was related to soil pH, a factor that can be managed with proper liming and fertilizing practices.