Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
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Chemical hydrogeology in natural and contaminated environments
Chemical hydrogeology, including organic and inorganic aspects, has contributed to an increased understanding of groundwater flow systems, geologic processes, and stressed environments. Most of the basic principles of inorganic-chemical hydrogeology were first established by investigations of organic-free, regional-scale systems for which simplifying assumptions could be made. The problems of grou
Authors
W. Back, M.J. Baedecker
Preliminary evaluations of regional ground-water quality in relation to land use
Preliminary results from New York, New Jersey, Connecticut, Florida, Nebraska, and Colorado indicate that regional ground-water quality has been affected by human activities. The frequencies of detection of volatile organic compounds and some trace elements were larger in ground water underlying urban or industrial areas in comparison to undeveloped areas. Ground water in agricultural areas genera
Authors
D. Cain, D.R. Helsel, S.E. Ragone
Calorimetry of heterogeneous systems: H+ binding to TiO2 in NaCl
A simultaneous calorimetric and potentiometric technique has been developed for measuring the thermodynamics of proton binding to mineral oxides in the presence of a supporting electrolyte. Modifications made to a commercial titration calorimeter to add a combination pH electrode and maintain an inert atmosphere in the calorimeter reaction vessel are described. A procedure to calibrate potentiomet
Authors
S.R. Mehr, D.J. Eatough, L.D. Hansen, E.A. Lewis, J.A. Davis
Transport of microspheres and indigenous bacteria through a sandy aquifer: Results of natural- and forced-gradient tracer experiments
Transport of indigenous bacteria through sandy aquifer sediments was investigated in forced- and natural-gradient tracer teste. A diverse population of bacteria was collected and concentrated from groundwater at the site, stained with a DNA-specific fluorochrome, and injected back into the aquifer. Included with the injectate were a conservative tracer (Br- or Cl-) and bacteria-sized (0.2-1.3-??m)
Authors
R.W. Harvey, L.H. George, R. L. Smith, D.R. LeBlanc
Organic markers as source discriminants and sediment transport indicators in south San Francisco Bay, California
Sediment samples from nearshore sites in south San Francisco Bay and from streams flowing into that section of the Bay have been characterized in terms of their content of biogenic and anthropogenic molecular marker compounds. The distributions, input sources, and applicability of these compounds in determining sediment movement are discussed. By means of inspection and multivariate analysis, the
Authors
F. D. Hostettler, J. B. Rapp, K. A. Kvenvolden, N L. Samuel
Can we determine the biological availability of sediment-bound trace elements?
It is clear from available data that the susceptibility of biological communities to trace element contamination differs among aquatic environments. One important reason is that the bioavailability of metals in sediments appears to be altered by variations in sediment geochemistry. However, methods for explaining or predicting the effect of sediment geochemistry upon metal bioavailability are poor
Authors
Samuel N. Luoma
Discussion of "Influence of temperature on oxygen transfer" by Allen C. Chao, David S. Chang, Charles Smallwood, Jr., and William S. Galler (August, 1987, Vol. 113, No. 4)
No abstract available.
Authors
R.E. Rathburn
Mineral saturation states in natural waters and their sensitivity to thermodynamic and analytical errors
Saturation indices computed with WATEQ4F chemical analyses from a groundwater in crystalline bedrock and a surface water receiving acid mine drainage are frequently at or above saturation with respect to calcite, fluorite, barite, gibbsite and ferrihydrite. Deep granitic groundwaters from Stripa, Sweden, are supersaturated with respect to calcite and fluorite. Acid mine waters from the Leviathan M
Authors
D. Kirk Nordstrom, James W. Ball
Solubility of jarosite solid solutions precipitated from acid mine waters, Iron Mountain, California
Because of the common occurrence of 15 to 25 mole percent hydronium substitution on the alkali site in jarosites, it is necessary to consider the hydronium content of jarosites in any attempt at rigorous evaluation of jarosite solubility or of the saturation state of natural waters with respect to jarosite. A Gibbs free energy of 3293.5±2.1 kJ mol-1 is recommended for a jarosite solid solution of
Authors
Charles N. Alpers, D. Kirk Nordstrom, J. W. Ball
Spectroscopic evidence for organic diacid complexation with dissolved silica in aqueous systems—I. Oxalic acid
Increased solubility of quartz and mobilization in contaminated groundwater due to the complexation with dissolved organic acids has been recently proposed [Bennett and Siegel, Nature326, 684–686 (1987)]. Using laser Raman and Fourier transform infrared spectroscopies, we have examined mixed solutions of oxalic and silicic acids at near neutral pH in the tenth molar concentration ranges in an atte
Authors
N.A. Marley, P. Bennett, D.R. Janecky, J.S. Gaffney
Use of on-site high performance liquid chromatography to evaluate the magnitude and extent of organic contaminants in aquifers
Appraisal of ground water contaminated by organic substances raises problems of difficult sample collection and timely chemical analysis. High-performance liquid chromatography was evaluated for on-site determination of specific organic contaminants in ground water samples and was used at three study sites. Organic solutes were determined directly in water samples, with little or no preparation, a
Authors
D.F. Goerlitz, B.J. Franks
Book review--"Coupled processes associated with nuclear waste repositories"
No abstract available.
Authors
D. Kirk Nordstrom