Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 4094
Wide angle X-ray scattering (WAXS) study of "two-line" ferrihydrite structure: Effect of arsenate sorption and counterion variation and comparison with EXAFS results
Wide angle X-ray scattering (WAXS) measurements have been made on a suite of “two-line” ferrihydrite (FHY2) samples containing varying amounts of coprecipitated arsenate. Samples prepared at pH 8 with counter ions chloride, nitrate, and a mixture of both also were examined. The raw WAXS scattering functions show that “two-line” ferrihydrite actually has a large number of non-Bragg (i.e., diffuse s
Authors
G.A. Waychunas, C. C. Fuller, B.A. Rea, J.A. Davis
Reactive transport modeling of acidic metal-contaminated ground water at a site with sparse spatial information
No abstract available.
Authors
P. Glynn, J. Brown
Infiltration and solute transport experiments in unsaturated sand and gravel, Cape Cod, Massachusetts: Experimental design and overview of results
A series of infiltration and tracer experiments was conducted in unsaturated sand and gravel deposits on Cape Cod, Massachusetts. A network of 112 porous cup lysimeters and 168 time domain reflectometry (TDR) probes was deployed at depths from 0.25 to 2.0 m below ground surface along the centerline of a 2-m by 10-m test plot. The test plot was irrigated at rates ranging from 7.9 to 37.0 cm h−1 thr
Authors
David L. Rudolph, R. Gary Kachanoski, Michael A. Celia, Denis R. LeBlanc, Jonathon H. Stevens
Reactive solute transport in acidic streams
Spatial and temporal profiles of Ph and concentrations of toxic metals in streams affected by acid mine drainage are the result of the interplay of physical and biogeochemical processes. This paper describes a reactive solute transport model that provides a physically and thermodynamically quantitative interpretation of these profiles. The model combines a transport module that includes advection-
Authors
R. E. Broshears
Occurrence and accumulation of pesticides and organic contaminants in river sediment, water and clam tissues from the San Joaquin River and tributaries, California
A study was conducted in 1992 to assess the effects of anthropogenic activities and land use on the water quality of the San Joaquin River and its major tributaries. This study focused on pesticides and organic contaminants, looking at distributions of contaminants in water, bed and suspended sediment, and the bivalve Corbicula fluminea. Results indicated that this river system is affected by agri
Authors
W. E. Pereira, Joseph L. Domagalski, F. D. Hostettler, L. R. Brown, J. B. Rapp
Analysis of fractures intersecting Kahi Puka Well 1 and its relation to the growth of the island of Hawaii
As part of the Hawaii Scientific Drilling Project, Kahi Puka Well 1 penetrated about 275 m of Mauna Loa basalts overlying a sequence of Mauna Kea flow units as it was drilled and cored to a total depth of 1053 m below land surface. A borehole televiewer (BHTV) was run in most of the well in successive stages prior to casing in order to obtain magnetically oriented acoustic images of the borehole w
Authors
Roger H. Morin, Frederick L. Paillet
Flow to a well in a water-table aquifer: An improved laplace transform solution
An alternative Laplace transform solution for the problem, originally solved by Neuman, of constant discharge from a partially penetrating well in a water-table aquifer was obtained. The solution differs from existing solutions in that it is simpler in form and can be numerically inverted without the need for time-consuming numerical integration. The derivation invloves the use of the Laplace tran
Authors
A.F. Moench
Movement of nitrate fertilizer to glacial till and runoff from a claypan soil
Although water from 20 to 25% of shallow farmstead wells in northern Missouri has concentrations of nitrate (NO3/-) exceeding 10 mg L-1 as nitrogen (N), many potential sources for this NO3/- are usually present. A field experiment was designed to trace and isolate the amount of a single application of N fertilizer lost to a glacial-till aquifer and runoff from a 400 m2 corn (Zea mays L.) plot with
Authors
D. W. Blevins, D.H. Wilkison, B. P. Kelly, S. R. Silva
Hydrogeology of the Hawaii Scientific Drilling Project borehole KP-1 1. Hydraulic conditions adjacent to the well bore
Temperature and formation resistivity logs obtained in borehole KP-1 of the Hawaii Scientific Drilling Project indicate that the adjacent formation is characterized by several zones of distinctly different average temperature and water salinity. A series of hydraulic analyses and water sampling programs were conducted to rule out the possibility of local hydraulic effects associated with the prese
Authors
Frederick L. Paillet, D. M. Thomas
Characterization of metal adsorption variability in a sand and gravel aquifer, Cape Cod, Massachusetts, U.S.A
Several geochemical properties of an aquifer sediment that control metal-ion adsorption were investigated to determine their potential use as indicators of the spatial variability of metal adsorption. Over the length of a 4.5-m-long core from a sand and gravel aquifer, lead (Pb2+) and zinc (Zn2+) adsorption at constant chemical conditions (pH 5.3) varied by a factor of 2 and 4, respectively. Pb2+
Authors
C. C. Fuller, J.A. Davis, J.A. Coston, E. Dixon
Estimation of rates of aerobic hydrocarbon biodegradation by simulation of gas transport in the unsaturated zone
The distribution of oxygen and carbon dioxide gases in the unsaturated zone provides a geochemical signature of aerobic hydrocarbon degradation at petroleum product spill sites. The fluxes of these gases are proportional to the rate of aerobic biodegradation and are quantified by calibrating a mathematical transport model to the oxygen and carbon dioxide gas concentration data. Reaction stoichiome
Authors
Matthew A. Lahvis, Arthur L. Baehr
Choosing optimum station configurations for summarizing water quality characteristics, in 1994 Annual Report, San Francisco Estuary Regional Monitoring Program for Trace Substances: San Francisco Estuary Institute
One of the central problems in regional monitoring is choosing a station array that accurately reflects the distribution of values for the entire region of interest. For time-consuming or expensive measurements, an additional goal is to make the number of sampling locations and times as small as possible. These problems are probably most difficult in estuaries because of the relatively large varia
Authors
James E. Cloern, Brian E. Cole, J.M. Caffrey, A.D. Jassby