Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 3787
Measurement of in situ rates of selenate removal by dissimilatory bacterial reduction in sediments
A radioisotope method for measurement of bacteria respiratory reduction of selenate to elemental selenium in aquatic sediments was devised. Sediments were labeled with [75Se]selenate, incubated, and washed, and 75Se0(s) was determined as counts remaining in the sediments. Core profiles of selenate reduction, sulfate reduction, and denitrification were made simultaneously in the sediments of an agr
Authors
Ronald S. Oremland, Nisan A. Steinberg, Ann S. Maest, Laurence G. Miller, James T. Hollibaugh
Application of the Stefan-Maxwell Equations to determine limitations of Fick's law when modeling organic vapor transport in sand columns
The organic component of the vapor phase of a porous medium contaminated by an immiscible organic liquid can be significant enough to violate the condition of a dilute species diffusing in a bulk phase assumed by Fick's law. The Stefan-Maxwell equations provide a more comprehensive model for quantifying steady state transport for a vapor phase composed of arbitrary proportions of its constituents.
Authors
Arthur L. Baehr, Clifford J. Bruell
A method for testing whether model predictions fall within a prescribed factor of true values, with an application to pesticide leaching
A quantitative method is described for testing whether model predictions fall within a specified factor of true values. The technique is based on classical theory for confidence regions on unknown population parameters and can be related to hypothesis testing in both univariate and multivariate situations. A capability index is defined that can be used as a measure of predictive capability of a mo
Authors
Rudolph S. Parrish, Charles N. Smith
Effects of benthic flora on arsenic transport
Chemical and biological interactions involving arsenic (As) and phosphorus (P) appear to affect significantly As transport and distribution in Whitewood Creek, South Dakota. Data (first‐order uptake rate constants, standing crop, and accumulation factors) that can be used to predict As transport have been determined using algae collected in the creek along a transect from upstream of mine discharg
Authors
James S. Kuwabara, Cecily C.Y. Chang, Sofie P. Pasilis
Effect of some petroleum sulfonate surfactants on the apparent water solubility of organic compounds
No abstract available.
Authors
Daniel E. Kile, Cary T. Chiou, Robin S. Helburn
Problems and methods involved in relating land use to ground-water quality
Efforts to relate shallow ground-water quality to the land use near a well lead to several statistical difficulties. These include potential uncertainty in land-use categorical data due to misclassification, data closure, distributional skewing, and spatial autocorrelation. Methods of addressing these problems are, respectively, the establishment of limits on minimum buffer radius, the estimation
Authors
Thomas Barringer, Dennis Dunn, William Battaglin, Eric Vowinkel
Hydrogeochemistry of rivers and lakes
This chapter has three principal objectives: (1) to summarize the present chemical composition of North American surface waters and point out any discernible trends with time; (2) to review chemical and biochemical principles and processes that control natural water composition, and the ways in which these may be involved in attaining the particular chemical compositions and trends that we can obs
Authors
John David Hem, Adrian Demayo, Richard A. Smith
Roles of organic matter, minerals, and moisture in sorption of nonionic compounds and pesticides by soil
No abstract available.
Authors
C. T. Chiou
The production and variability of acid mine drainage at Iron Mountain, California: A superfund site undergoing rehabilitation
No abstract available.
Authors
D. Kirk Nordstrom, J.M. Burchard, Charles N. Alpers
Origin of solutes in saline lakes and springs on the Southern High Plains of Texas and New Mexico
Analysis of hydraulic heads, calculation of pore volume flushing, and analysis of solute and isotopic chemistry strongly suggest that the solutes originate from the concentration by evaporation of runoff and potable shallow ground water that discharges from the High Plains aquifer. Chloride/bromide solute ratios, which are thought to be unaffected by mineral precipitation or sorption, average 160
Authors
W. Wood, B.F. Jones
Influence of seasonal growth, age, and environmental exposure on Cu and Ag in a bivalve indicator, Macoma balthica, in San Francisco Bay
Temporal and spatial variations in Cu and Ag in the deposit-feeding clam Macoma balthica and in surficial sediments were analysed at 8 stations in San Francisco Bay at near-monthly intervals for periods ranging from 3 to 10 yr during 1977 to 1986. Strong seasonal variations in metal concentrations of M. balthica were associated with seasonal variations in soft tissue weight. Aperiodic fluctuations
Authors
Daniel J. Cain, Samuel N. Luoma
Enzyme-linked immunosorbent assay compared with gas chromatography/mass spectrometry for the determination of triazine herbicides in water
No abstract available.
Authors
E. Michael Thurman, Michael Meyer, Michael Pomes, Charles A. Perry, A. Paul Schwab