Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 4094
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
Retardation of ammonium and potassium transport through a contaminated sand and gravel aquifer: The Role of cation exchange
The role of cation exchange in the retardation of ammonium (NH4+) and potassium (K+) transport in a shallow sand and gravel aquifer was evaluated by use of observed distributions of NH4+ and K+ within a plume of sewage-contaminated groundwater, small-scale tracer injection tests, and batch sorption experiments on aquifer material. Both NH4+ and K+ were transported ???2 km in the 4-km-long contamin
Authors
M.L. Ceazan, E.M. Thurman, R. L. Smith
Book review--"Coupled processes associated with nuclear waste repositories"
No abstract available.
Authors
D. Kirk Nordstrom
The dissolution of quartz in dilute aqueous solutions of organic acids at 25°C
The dissolution of quartz in dilute aqueous solutions of organic acids at 25° and standard pressure was investigated by the batch dissolution method. The bulk dissolution rate of quartz in 20 mmole/Kg citrate solutions at pH 7 was 8 to 10 times faster than that in pure water. After 1750 hours the concentration of dissolved silica in the citrate solution was 167 μmole/Kg compared to 50 μmole/Kg in
Authors
P.C. Bennett, M.E. Melcer, D. I. Siegel, J.P. Hassett