Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 3787
Data on natural organic substances in dissolved, colloidal, suspended-silt and -clay, and bed-sediment phases in the Mississippi River and some of its tributaries, 1991-92
No abstract available.
Authors
J. A. Leenheer, L. B. Barber, C.E. Rostad, T.I. Noyes
A Lagrangian stochastic model for aerial spray transport above an oak forest
An aerial spray droplets' transport model has been developed by applying recent advances in Lagrangian stochastic simulation of heavy particles. A two-dimensional Lagrangian stochastic model was adopted to simulate the spray droplet dispersion in atmospheric turbulence by adjusting the Lagrangian integral time scale along the drop trajectory. The other major physical processes affecting the transp
Authors
Yansen Wang, David R. Miller, Dean E. Anderson, Michael L. McManus
Hydrologic and geochemical effects on oxygen uptake in bottom sediments of an effluent-dominated river
More than 95% of the water in the South Platte River downstream from the largest wastewater treatment plant serving the metropolitan Denver, Colorado, area consists of treated effluent during some periods of low flow. Fluctuations in effluent-discharge rates caused daily changes in river stage that promoted exchange of water between the river and bottom sediments. Groundwater discharge measurement
Authors
P. B. McMahon, J.A. Tindall, J.A. Collins, K.J. Lull, J.R. Nuttle
Gross-beta activity in ground water: natural sources and artifacts of sampling and laboratory analysis
Gross-beta activity has been used as an indicator of beta-emitting isotopes in water since at least the early 1950s. Originally designed for detection of radioactive releases from nuclear facilities and weapons tests, analysis of gross-beta activity is widely used in studies of naturally occurring radioactivity in ground water. Analyses of about 800 samples from 5 ground-water regions of the Unite
Authors
Alan H. Welch, Zoltan Szabo, David L. Parkhurst, Peter C. Van Metre, Ann H. Mullin
Geometry of sorbed arsenate on ferrihydrite and crystalline FeOOH: Re-evaluation of EXAFS results and topological factors in predicting sorbate geometry, and evidence for monodentate complexes
Manceau's (1995) reinterpretation of some of our EXAFS results (Waychunas et al., 1993) has been analyzed using both old and newly collected data in an attempt to clarify the nature of proposed monodentate and edge-sharing bidentate arsenate complexes on the ferrihydrite surface. It is shown that EXAFS analysis utilizing data with sufficient k-range does indicate the presence of relatively short A
Authors
Glenn A. Waychunas, James A. Davis, Christopher C. Fuller
State-dependent anisotrophy: Comparison of quasi-analytical solutions with stochastic results for steady gravity drainage
Anisotropy in large-scale unsaturated hydraulic conductivity of layered soils changes with the moisture state. Here, state-dependent anisotropy is computed under conditions of large-scale gravity drainage. Soils represented by Gardner's exponential function are perfectly stratified, periodic, and inclined. Analytical integration of Darcy’s law across each layer results in a system of nonlinear equ
Authors
Timothy R. Green, David L. Freyberg
Methane production and consumption monitored by stable H and C isotope ratios at a crude oil spill site, Bemidji, Minnesota
Stable isotopic ratios of C and H in dissolved CH4 and C in dissolved inorganic C in the ground water of a crude-oil spill near Bemidji, Minnesota, support the concept of CH4production by acetate fermentation with a contemporaneous increase in HCO3−concentration. Methane concentrations in the saturated zone decrease from 20.6 mg L−1 to less than 0.001 mg L−1 along the investigated flow path. Disso
Authors
Kinga Revesz, Tyler B. Coplen, Mary J. Baedecker, Pierre D. Glynn
Combined use of groundwater dating, chemical, and isotopic analyses to resolve the history and fate of nitrate contamination in two agricultural watersheds, Atlantic coastal plain, Maryland
The history and fate of groundwater nitrate (NO3−) contamination were compared in 2 small adjacent agricultural watersheds in the Atlantic coastal plain by combined use of chronologic (CCl2F2, 3H), chemical (dissolved solids, gases), and isotopic (δ15N,δ13C, δ34S) analyses of recharging groundwaters, discharging groundwaters, and surface waters. The results demonstrate the interactive effects of c
Authors
J.K. Böhlke, J. M. Denver
Estimating 14C groundwater ages in a methanogenic aquifer
This paper addresses the problem of 14C age dating of groundwaters in a confined regional aquifer affected by methanogenesis. Increasing CH4 concentrations along the groundwater flow system and 13C and 14C isotopic data for dissolved inorganic carbon, dissolved organic carbon, and CH4 clearly show the effect of methanogenesis on groundwater chemistry. Inverse reaction path modeling using NETPATH i
Authors
Ramon Aravena, Leonard I Wassenaar, Niel Plummer
Pesticide, nutrient, water-discharge and physical-property data for the Mississippi River and some of its tributaries, April 1991-September 1992
No abstract available.
Authors
Richard H. Coupe
Intercomparison experiments on dissolved trace-metal data from the Mississippi River and some of its tributaries, 1989-90
No abstract available.
Authors
Howard E. Taylor, A.M. Shiller, J.R. Garbarino, T.I. Brinton
Concentration and transport data for selected dissolved inorganic constituents and dissolved organic carbon in water collected from the Mississippi River and some of its tributaries, July 1991-May 1992
No abstract available.
Authors
John R. Garbarino, Ronald C. Antweiler, T.I. Brinton, D.A. Roth, Howard E. Taylor