Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
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Effects of colloids on metal transport in a river receiving acid mine drainage, upper Arkansas River, Colorado, U.S.A.
Inflows of metal-rich, acidic water that drain from mine dumps and tailings piles in the Leadville, Colorado, area enter the non-acidic water in the upper Arkansas River. Hydrous iron oxides precipitate as colloids and move downstream in suspension, particularly downstream from California Gulch, which has been the major source of metal loads. The colloids influence the concentrations of metals dis
Authors
Briant A. Kimball
Comment on "Thermodynamics of organic chemical partition in soils"
No abstract available.
Authors
Cary T. Chiou
Transport of chromium and selenium in a pristine sand and gravel aquifer: Role of adsorption processes
Field transport experiments were conducted in an oxic sand and gravel aquifer using Br (bromide ion), Cr (chromium, injected as Cr(VI)), Se (selenium, injected as Se(VI)), and other tracers. The aquifer has mildly acidic pH values and low concentrations of dissolved salts. Within analytical errors, all mobile Cr was present as Cr(VI). All mobile Se was probably present as Se(VI). Adsorption of Cr
Authors
D.B. Kent, J.A. Davis, L.C.D. Anderson, B.A. Rea
Effect of Triton X-100 on the rate of trichloroethene desorption from soil to water
No abstract available.
Authors
James J. Deitsch, James A. Smith
Mechanism of formation of humus coatings on mineral surfaces 1. Evidence for multidentate binding of organic acids from compost leachate on alumina
Measurements of the infrared linear dichroism of carboxylate groups of organic acids from compost leachate adsorbed to an alumina surface and the enthalpy of adsorption of this reaction have been made. The linear dichroism measurements indicated that the carboxylate groups are not free to rotate. This limited rotation probably results from bidentate binding of the carboxylate groups. The molar ent
Authors
R. L. Wershaw, J. A. Leenheer, R.P. Sperline, Yuan Song, L.A. Noll, R.L. Melvin, G.P. Rigatti
Large-scale atmospheric forcing of recent trends toward early snowmelt runoff in California
Since the late 1940s, snowmelt and runoff have come increasingly early in the water year in many basins in northern and central California. This subtle trend is most pronounced in moderate-altitude basins, which are sensitive to changes in mean winter temperatures. Such basins have broad areas in which winter temperatures are near enough to freezing that small increases result initially in the for
Authors
Michael D. Dettinger, Daniel R. Cayan
XAS study of AsO43− and SeO42− substituted schwertmannites
Synthetic schwertmannite samples with varying amounts of arsenate and selenate substituting for sulfate were examined by XAS methods in an attempt to characterize the location of the anion complexes. Selenate appears to both substitute directly for sulfate within tunnels in the structure, and sorb onto the outside of crystallites. No disruption of the basic structure appears with selenate substitu
Authors
G.A. Waychunas, Ning Xu, C. C. Fuller, J.A. Davis, J.M. Bigham
Screening tests for assessing the anaerobic biodegradation of pollutant chemicals in subsurface environments
Screening methods were developed to assess the susceptibility of ground water contaminants to anaerobic biodegradation. One method was an extrapolation of a procedure previously used to measure biodegradation activity in dilute sewage sludge. Aquifer solids and ground water with no additional nutritive media were incubated anaerobically in 160-ml serum bottles containing 250 mg·l−1 carbon of the s
Authors
Joseph M. Suflita, Frank Concannon
Groundwater transport of crater-lake brine at Poa´s Volcano, Costa Rica
Poa´s Volcano is an active stratovolcano in Costa Rica that has a lake in its active crater. The crater lake has high temperatures (50–90 °C), high acidity (pH ≈ 0.0), and a high dissolved-solids content (100 g/kg). The volcano has numerous freshwater springs on its flanks, but a few on the northwestern flank are highly acidic (pH = 1.6–2.5) and have high dissolved-solids concentrations (2–22 g/kg
Authors
Ward E. Sanford, Leonard F. Konikow, Gary L. Rowe, Susan L. Brantley
Remediation of uranium contaminated soils with bicarbonate extraction and microbial U(VI) reduction
A process for concentrating uranium from contaminated soils in which the uranium is first extracted with bicarbonate and then the extracted uranium is precipitated with U(VI)-reducing microorganisms was evaluated for a variety of uranuum-contaminated soils. Bicarbonate (100 mM) extracted 20–94% of the uranium that was extracted with nitric acid. The U(VI)-reducing microorganism,Desulfovibrio desul
Authors
Elizabeth J.P. Philips, Edward R. Landa, Derek R. Lovely
Using borehole flow logging to optimize hydraulic-test procedures in heterogeneous fractured aquifers
Hydraulic properties of heterogeneous fractured aquifers are difficult to characterize, and such characterization usually requires equipment-intensive and time-consuming applications of hydraulic testing in situ. Conventional coring and geophysical logging techniques provide useful and reliable information on the distribution of bedding planes, fractures and solution openings along boreholes, but
Authors
F.L. Paillet
Kinetics of oxidation of selenite to selenate in the presence of oxygen, titania and light
No abstract available.
Authors
Karen A. Gruebel, James A. Davis, James O. Leckie