Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 3787
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
Chlorofluorocarbons as tracers of groundwater transport processes in a shallow, silty sand aquifer
Detailed depth profiles of Chlorofluorocarbons CFC-11(CFCl3(, CFC-12 (CF2Cl2) and CFC-113 (C2F3Cl3) have been obtained from a well-characterized field site in central Ontario. Aquifer materials comprise predominantly silty sands, with a mean organic carbon content of 0.03%. Nearly one-dimensional flow exists at this site, and the vertical migration of a well-defined 3H peak has been tracked throug
Authors
P.G. Cook, D. K. Solomon, Niel Plummer, E. Busenberg, S.L. Schiff
Modeling the effects of variable groundwater chemistry on adsorption of molybdate
Laboratory experiments were used to identify and quantify processes having a significant effect on molybdate (MoO42−) adsorption in a shallow alluvial aquifer on Cape Cod, assachusetts. Aqueous chemistry in the aquifer changes as a result of treated sewage effluent mixing with groundwater. Molybdate adsorption decreased as pH, ionic strength, and the concentration of competing anions increased. A
Authors
Kenneth G. Stollenwerk
Sorption and coprecipitation of trace concentrations of thorium with various minerals under conditions simulating an acid uranium mill effluent environment
Sorption of thorium by pre-existing crystals of anglesite (PbSO4), apatite (Ca5(PO4)3(HO)), barite (BaSO4), bentonite (Na0.7Al3.3Mg0.7Si8O20(OH)4), celestite (SrSO4), fluorite (CaF2), galena (PbS), gypsum (CaSO4·2H2O), hematite (Fe2O3), jarosite (KFe3(SO4)2(OH)6), kaolinite (Al2O3·2SiO2·2H2O), quartz (SiO2) and sodium feldspar (NaAlSi3O8) was studied under conditions that simulate an acidic uraniu
Authors
Edward R. Landa, Anh H. Le, Rudy L. Luck, Philip J. Yeich
Deducing the distribution of terminal electron-accepting processes in hydrologically diverse groundwater systems
The distribution of microbially mediated terminal electron-accepting processes (TEAPs( was investigated in four hydrologically diverse groundwater systems by considering patterns of electron acceptor (nitrate, sulfate) consumption, intermediate product (hydrogen (H2)) concentrations, and final product (ferrous iron, sulfide, and methane) production. In each hydrologic system a determination of pre
Authors
Francis H. Chapelle, Peter B. McMahon, Neil M. Dubrovsky, Roger F. Fujii, Edward T. Oaksford, Don A. Vroblesky
An updated model of induced airflow in the unsaturated zone
Simulation of induced movement of air in the unsaturated zone provides a method to determine permeability and to design vapor extraction remediation systems. A previously published solution to the airflow equation for the case in which the unsaturated zone is separated from the atmosphere by a layer of lower permeability (such as a clay layer) has been superseded. The new solution simulates airflo
Authors
Arthur L. Baehr, Craig J. Joss
Applications of the transient tracers tritium/helium-3, and chlorofluorocarbons for tracing and age-dating yound ground water: Field examples from the USA and Germany
The transient tracers tritium/helium-3 (3H/3He) and chlorofluorocarbons (CFC-11, CFC-12, CFC-113) are well suited for tracing and age-dating young ground water. Their detection in ground water indicates waters recharged within the past 30 (3H/3He, CFC-113) to 50 (CFC-11, CFC-12) years, or ground water mixtures that contain at least a portion of young water. The ground water age can be determined i
Authors
S. Drenkard, Niel Plummer, Eurybiades Busenberg, P. Schlosser, M. Stute, H. Dorr
Interpreting spatial profiles of concentration in acid mine drainage streams
No abstract available.
Authors
R. E. Broshears, Briant A. Kimball, Robert L. Runkel