Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 3787
Determination of alachlor and its sulfonic acid metabolite in water by solid-phase extraction and enzyme-linked immunosorbent assay
No abstract available.
Authors
D.S. Aga, E.M. Thurman, M.L. Pomes
Reduction of nonpoint source contamination of surface water and groundwater by starch encapsulation of herbicides
The loss of the preemergent herbicide atrazine in surface runoff from experimental field plots growing corn (Zea mays L.) was significantly reduced using a starchencapsulated formulation versus a conventional powdered formulation. Field edge losses of starch-encapsulated atrazine were described as following a Rayleigh distribution totaling 1.8% of applied herbicide compared to exponential powdered
Authors
M. S. Mills, E.M. Thurman
Formation and transport of deethylatrazine and deisopropylatrazine in surface water
No abstract available.
Authors
E.M. Thurman, M. T. Meyer, M. S. Mills, L.R. Zimmerman, C. A. Perry, D. A. Goolsby
Batch experiments characterizing the reduction of chromium(VI) using suboxic material from a mildly reducing sand and gravel aquifer
Batch experiments were conducted with sand collected from a shallow sand and gravel aquifer to identify the principal chemical reactions influencing the reduction of Cr(VI), so that field-observed Cr(V1) reduction could be described. The reduction appeared to be heterogeneous and occurred primarily on Fe(I1)-bearing minerals. At only 1 wt % , the fine fraction (<64 μm diameter) of the sediments do
Authors
Linda Davis Anderson, Douglas B. Kent, James A. Davis
Chlorofluorocarbons (CCl3F and CCl2F2) as dating tools and hydrologic tracers in shallow groundwater of the Delmarva Peninsula, Atlantic Coastal Plain, United States
Concentrations of the Chlorofluorocarbons (CFCs) CFC-11 and CFC-12 were determined in groundwater from coastal plain sediments of the Delmarva Peninsula. CFC-modeled ages were calculated independently for CFC-11 and CFC-12, and agreed to within 2–3 years in the majority of the waters. Recharge temperatures, determined from dissolved nitrogen and argon concentrations, varied from 9±2°C over most of
Authors
S.A. Dunkle, Niel Plummer, E. Busenberg, P. J. Phillips, J. M. Denver, P. A. Hamilton, R. L. Michel, T. B. Coplen
Adaptive estimation of the log fluctuating conductivity from tracer data at the Cape Cod Site
An adaptive estimation scheme is used to obtain the integral scale and variance of the log-fluctuating conductivity at the Cape Cod site based on the fast Fourier transform/stochastic model of Deng et al. (1993) and a Kalmanlike filter. The filter incorporates prior estimates of the unknown parameters with tracer moment data to adaptively obtain improved estimates as the tracer evolves. The result
Authors
F.W. Deng, J.H. Cushman, J.W. Delleur
Modeling steady-state methanogenic degradation of phenols in groundwater
Field and microcosm observations of methanogenic phenolic compound degradation indicate that Monod kinetics governs the substrate disappearance but overestimates the observed biomass. In this paper we present modeling results from an ongoing multidisciplinary study of methanogenic biodegradation of phenolic compounds in a sand and gravel aquifer contaminated by chemicals and wastes used in wood tr
Authors
Barbara A. Bekins, E. Michael Godsy, Donald F. Goerlitz
Methods of characterizing fluid movement and chemical transport in fractured rock
No abstract available.
Authors
Paul A. Hsieh, Allen M. Shapiro, C.C. Barton, F. P. Haeni, C. D. Johnson, C. Martin, F.L. Paillet, T. C. Winter, D.L. Wright
Simulating the volatilization of solvents in unsaturated soils during laboratory and field infiltration experiments
This paper describes laboratory and field experiments which were conducted to study the dynamics of trichloroethylene (TCE) as it volatilized from contaminated groundwater and diffused in the presence of infiltrating water through the unsaturated soil zone to the land surface. The field experiments were conducted at the Picatinny Arsenal, which is part of the United States Geological Survey Toxic
Authors
H. Jean Cho, Peter R. Jaffe, James A. Smith
Influence of Pb on microbial activity in Pb-contaminated soils
Investigations of the influence of Pb on soil microbial communities have focused on Pb concentrations of 1 g kg-’ or less (Barkay et al., 1985; Capone et al., 1983; Chang and Broadbent, 1981; Doelman and Haanstra, 1979; Trevors et al., 1985). However, a number of environments exist in which Pb concentrations exceed 1 g kg-’ dry soil (Davenport and Peryea, 1991; Davis et al., 1992; Bisessar, 1982).
Authors
J. E. Landmeyer, P. M. Bradley, F. H. Chapelle
Arsenate inhibition of denitrification in nitrate contaminated sediments
Short-term and chronic exposure effects of arsenic on sediment denitrification were evaluated. N2O production rates were determined for As-contaminated (chronic treatment) and uncontaminated (short-term treatment) sediments exposed to a range of As concentrations. The As-containing sediments, collected from an herbicide-contaminated shallow aquifer, exhibited significantly lower rates of denitrifi
Authors
P. M. Bradley, F. H. Chapelle
Long-term frozen storage of stream water samples for dissolved orthophosphate, nitrate plus nitrite, and ammonia analysis
Many researchers have used freezing as an effective, short-term, water sample preservation method for subsequent nutrient analysis. In this study, filtered samples held at −16±2°C for 4–8 years were reanalyzed for orthophosphate, nitrate plus nitrite, and ammonia. Orthophosphate and ammonia concentrations decreased by 0.2 μg P/L and 5 μg N/L, respectively, at mean concentrations of 69.4 μg P/L and
Authors
Ronald J. Avanzino, Vance C. Kennedy