Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 4094
Copper transport along a Sierra Nevada stream
No abstract available.
Authors
James S. Kuwabara, H.V. Leland, Kenneth E. Bencala
Effect of organic contamination upon microbial distributions and heterotrophic uptake in a Cape Cod, Massachusetts, aquifer
No abstract available.
Authors
R.W. Harvey, R. L. Smith, L. George
Isotope composition of sulphate in acid mine drainage as measure of bacterial oxidation
The formation of acid waters by oxidation of pyrite-bearing ore deposits, mine tailing piles, and coal measures is a complex biogeochemical process and is a serious environmental problem. We have studied the oxygen and sulphur isotope geochemistry of sulphides, sulphur, sulphate and water in the field and in experiments to identify sources of oxygen and reaction mechanisms of sulphate formation. H
Authors
B.E. Taylor, M.C. Wheeler, D. Kirk Nordstrom
Field testing the hypothesis of Darcian flow through a carbonate aquifer
The acceptability of the hypothesis of Darcian flow through a semiconfined carbonate aquifer was tested prior to running a multiple-day aquifer test in Pinellas County, Florida. The approach used to test the hypothesis was to run a number of hour-long aquifer tests at different discharges with drawdown measured at the same time during each test in two observation wells, one at 35 feet and the othe
Authors
J.J. Hickey
Denitrification associated with stream periphyton: Chamber estimates from undisrupted communities
Undisrupted periphyton communities from a N‐rich (NO3− = 63 µmol L−1) and pristine (NO3− = 2.9 µmol L−1) stream were assayed for denitrifying activity (acetylene‐blockage technique) in 40‐L chambers incubated at in situ temperature and nutrient concentrations. Nitrous oxide formation associated with periphyton from the N‐rich stream was immediate and linear (52.1 µmol N2O m−2 h−1) in the dark, ana
Authors
J.H. Duff, F.J. Triska, R.S. Oremland
Aquifer reclamation design: The use of contaminant transport simulation combined with nonlinear programing
A simulation-management methodology is demonstrated for the rehabilitation of aquifers that have been subjected to chemical contamination. Finite element groundwater flow and contaminant transport simulation are combined with nonlinear optimization. The model is capable of determining well locations plus pumping and injection rates for groundwater quality control. Examples demonstrate linear or no
Authors
Steven M. Gorelick, Clifford I. Voss, Philip E. Gill, Walter Murray, Michael A. Saunders, Margaret H. Wright
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 varied from +4.
Authors
B.E. Taylor, M.C. Wheeler, D. Kirk Nordstrom
Comment on "environmental fate and effects of ethylene oxide"
No abstract available.
Authors
R. E. Rathbun, D. Y. Tai, R.L. Berglund, R.A. Conway, G.T. Waggy, M.H. Spiegel
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 parameter
Authors
Kenneth E. Bencala
Effect of anisotropy and groundwater system geometry on seepage through lakebeds. 1. Analog and dimensional analysis
Distribution of seepage through lakebeds is controlled partly by geometric configuration of the lake and of the groundwater system interacting with the lake. To evaluate the effect of these factors, conductive-paper electric-analog models were used to analyze a number of lake and groundwater settings having different geometric configurations. Most settings analyzed are of lakes that do not penetra
Authors
H.O. Pfannkuch, T. C. Winter
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 hydrous met
Authors
Diane M. McKnight, G. L. Feder
Effect of anisotropy and groundwater system geometry on seepage through lakebeds. 2. Numerical simulation analysis
The interaction of lakes and groundwater is controlled partly by the geologic framework through which the water flows. Two interrelated geometric factors of the groundwater system that affect flow are overall geometry of the system, and anisotropy of the porous media within the system. Numerical simulation analysis was made for variations in the coefficient of anisotropy for each of several lake a
Authors
T. C. Winter, H.O. Pfannkuch