Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 3785
Groundwater contamination and aquifer reclamation at the Rocky Mountain Arsenal, Colorado Groundwater contamination and aquifer reclamation at the Rocky Mountain Arsenal, Colorado
No abstract available.
Authors
Leonard F. Konikow, D. Thompson
Volatilization of chlorinated hydrocarbons from water Volatilization of chlorinated hydrocarbons from water
Coefficients for the volatilization from water of 1,1,1-trichloroethane and 1,2-dichloroethane were measured in a stirred tank. Experiments at constant mixing conditions over a wide range of concentrations showed that the volatilization coefficient was independent of concentration, confirming the assumption that volatilization is a first order process. Simultaneous measurements of the
Authors
R. E. Rathbun, D. Y. Tai
Complexation of trace metals by adsorbed natural organic matter Complexation of trace metals by adsorbed natural organic matter
The adsorption behavior and solution speciation of Cu(II) and Cd(II) were studied in model systems containing colloidal alumina particles and dissolved natural organic matter. At equilibrium a significant fraction of the alumina surface was covered by adsorbed organic matter. Cu(II) was partitioned primarily between the surface-bound organic matter and dissolved Cu-organic complexes in...
Authors
J.A. Davis
Development and evaluation of a gas chromatographic method for the determination of triazine herbicides in natural water samples Development and evaluation of a gas chromatographic method for the determination of triazine herbicides in natural water samples
A multi-residue method is described for the determination o triazine herbicides in natural water samples. The technique uses solvent extraction followed by gas chromatographic separation and detection employing nitrogen-selective devices. Seven compounds can be determined simultaneously at a nominal detection limit of 0.1 μg/L in a 1-litre sample. Three different natural water samples...
Authors
T.R. Steinheimer, M.G. Brooks
The role of bacterial exopolymer and suspended bacteria in the nutrition of the deposit-feeding clam, Macoma balthica The role of bacterial exopolymer and suspended bacteria in the nutrition of the deposit-feeding clam, Macoma balthica
Significant removal and assimilation of suspended bacteria by M. balthica was observed within two days, although the low clearance rates suggested planktonic bacteria may not be among its major food sources.
Authors
R.W. Harvey, Samuel N. Luoma
Stable isotope geochemistry of acid mine drainage: Experimental oxidation of pyrite Stable isotope geochemistry of acid mine drainage: Experimental oxidation of pyrite
Sulfate and water from experiments in which pyrite was oxidized at a pH of 2.0 were analyzed for sulfur and oxygen stable isotopes. Experiments were conducted under both aerobic and anaerobic sterile conditions, as well as under aerobic conditions in the presence of Thiobacillus ferrooxidans, to elucidate the pathways of oxidation. Oxygen isotope fractionation between SO2-4 and H2O...
Authors
B.E. Taylor, M.C. Wheeler, D. Kirk Nordstrom
The ecological effect of acid conditions and precipitation of hydrous metal oxides in a Rocky Mountain stream The ecological effect of acid conditions and precipitation of hydrous metal oxides in a Rocky Mountain stream
Periphyton and benthic invertebrates assemblages were studied at the confluence of two Rocky Mountain streams, Deer Creek and the Snake River near Montezuma, Colorado. Upstream from the confluence the Snake River is acidic and enriched in dissolved trace metals, while Deer Creek is a typical Rocky Mountain stream. In the Snake River, downstream from the confluence, the pH increases and...
Authors
Diane M. McKnight, G. L. Feder
Interactions of solutes and streambed sediment: 1. An experimental analysis of cation and anion transport in a mountain stream Interactions of solutes and streambed sediment: 1. An experimental analysis of cation and anion transport in a mountain stream
An experimental injection was performed to study the transport of stream water solutes under conditions of significant interaction with streambed sediments in a mountain pool-and-riffle stream. Experiments were conducted in Little Lost Man Creek, Humboldt County, California, in a period of low flow duringwhich only a part of the bank-full channel held active surface flow. The injection...
Authors
Kenneth E. Bencala, Vance C. Kennedy, Gary W. Zellweger, Alan P. Jackman, Ronald J. Avanzino
Interactions of solutes and streambed sediment: 2. A dynamic analysis of coupled hydrologic and chemical processes that determine solute transport Interactions of solutes and streambed sediment: 2. A dynamic analysis of coupled hydrologic and chemical processes that determine solute transport
Solute transport in streams is determined by the interaction of physical and chemical processes. Data from an injection experiment for chloride and several cations indicate significant influence of solutestreambed processes on transport in a mountain stream. These data are interpreted in terms of transient storage processes for all tracers and sorption processes for the cations. Process...
Authors
Kenneth E. Bencala
Copper transport along a Sierra Nevada stream Copper transport along a Sierra Nevada stream
No abstract available.
Authors
James S. Kuwabara, H.V. Leland, Kenneth E. Bencala
Denitrification in San Francisco Bay intertidal sediments Denitrification in San Francisco Bay intertidal sediments
The acetylene block technique was employed to study denitrification in intertidal estuarine sediments. Addition of nitrate to sediment slurries stimulated denitrification. During the dry season, sediment-slurry denitrification rates displayed Michaelis-Menten kinetics, and ambient NO3− + NO2− concentrations (≤26 μM) were below the apparent Km (50 μM) for nitrate. During the rainy season...
Authors
Ronald S. Oremland, Cindy Umberger, Charles W. Culbertson, Richard L. Smith