Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 3785
Temporal fluctuations in grain size, organic materials and iron concentrations in intertidal surface sediment of San Francisco Bay Temporal fluctuations in grain size, organic materials and iron concentrations in intertidal surface sediment of San Francisco Bay
The physical and chemical characteristics of the oxidized surface sediment in an estuary fluctuate temporally in response to physical forces and apparently-fluctuating inputs. These characteristics, which include grain size and concentrations of organic materials and iron, will influence both trace-metal geochemistry and bioavailability. Temporal trends in the abundance of fine particles...
Authors
E. A. Thomson-Becker, Samuel N. Luoma
Statistical evaluation of an inductively coupled plasma atomic emission spectrometric method for routine water quality testing Statistical evaluation of an inductively coupled plasma atomic emission spectrometric method for routine water quality testing
In an interlaboratory test, inductively coupled plasma atomic emission spectrometry (ICP-AES) was compared with flame atomic absorption spectrometry and molecular absorption spectrophotometry for the determination of 17 major and trace elements in 100 filtered natural water samples. No unacceptable biases were detected. The analysis precision of ICP-AES was found to be equal to or better...
Authors
J.R. Garbarino, B. E. Jones, G.P. Stein
Field determination of the three-dimensional hydraulic conductivity tensor of anisotropic media: 2. Methodology and application to fractured rocks Field determination of the three-dimensional hydraulic conductivity tensor of anisotropic media: 2. Methodology and application to fractured rocks
The analytical solutions developed in the first paper can be used to interpret the results of cross-hole tests conducted in anisotropic porous or fractured media. In the particular case where the injection and monitoring intervals are short relative to the distance between them, the test results can be analyzed graphically. From the transient variation of hydraulic head in a given...
Authors
Paul A. Hsieh, Shlomo P. Neuman, Gary K. Stiles, Eugene S. Simpson
Geophysical techniques for reconnaissance investigations of soils and surficial deposits in mountainous terrain Geophysical techniques for reconnaissance investigations of soils and surficial deposits in mountainous terrain
Two techniques were assessed for their capabilities in reconnaissance studies of soil characteristics: depth to the water table and depth to bedrock beneath surficial deposits in mountainous terrain. Ground-penetrating radar had the best near-surface resolution in the upper 2 m of the profile and provided continuous interpretable imagery of soil profiles and bedrock surfaces. Where thick...
Authors
C.G. Olson, J.A. Doolittle
Isolation of anaerobic oxalate-degrading bacteria from freshwater lake sediments Isolation of anaerobic oxalate-degrading bacteria from freshwater lake sediments
Enrichment cultures that anaerobically degraded oxalate were obtained from lake sediment inocula. From these, 5 pure cultures of anaerobic oxalate-degrading bacteria were isolated and partially characterized. The isolates were Gram-negative, non-sporeforming, non-motile, obligate anaerobes. Oxalate was required for growth and was stoichiometrically converted to formate; 14CO2 was also...
Authors
R. L. Smith, F.E. Strohmaier, Ronald S. Oremland
Partition coefficients of organic compounds in lipid-water systems and correlations with fish bioconcentration factors Partition coefficients of organic compounds in lipid-water systems and correlations with fish bioconcentration factors
Triolein-water partition coefficients (KtW) have been determined for 38 slightly water-soluble organic compounds, and their magnitudes have been compared with the corresponding octanol-water partition coefficients (KOW). In the absence of major solvent-solute interaction effects in the organic solvent phase, the conventional treatment (based on Raoult's law) predicts sharply lower...
Authors
C. T. Chiou
Culturing Selenastrum capricornutum (Chlorophyta) in a synthetic algal nutrient medium with defined mineral particulates Culturing Selenastrum capricornutum (Chlorophyta) in a synthetic algal nutrient medium with defined mineral particulates
Algal nutrient studies in chemically-defined media typically employ a synthetic chelator to prevent iron hydroxide precipitation. Micronutrient-particulate interactions may, however, significantly affect chemical speciation and hence biovailability of these nutrients in natural waters. A technique is described by which Selenastrum capricornutum Printz (Chlorophyta) may be cultured in a...
Authors
James S. Kuwabara, J.A. Davis, Cecily C.Y. Chang
Unit hydrograph approximations assuming linear flow through topologically random channel networks Unit hydrograph approximations assuming linear flow through topologically random channel networks
The instantaneous unit Hydrograph (IUH) of a drainage basin is derived in terms of fundamental basin characteristics (Z, α, β), where α parameterizes the link (channel segment) length distribution, and β is a vector of hydraulic parameters, Z is one of three basin topological properties, N, (N, D), or (N, M), where N is magnitude (number of first-order streams), D is diameter (mainstream...
Authors
Brent M. Troutman, Michael R. Karlinger
Migration of wood-preserving chemicals in contaminated groundwater in a sand aquifer at Pensacola, Florida Migration of wood-preserving chemicals in contaminated groundwater in a sand aquifer at Pensacola, Florida
Operation of a wood-preserving facility for nearly 80 years at Pensacola, FL, contaminated the near-surface groundwater with creosote and pentachlorophenol. The major source of aquifer contamination was unlined surface impoundments that were in direct hydraulic contact with the groundwater. Episodes of overtopping the impoundments and overland flow of treatment liquor and waste were also
Authors
D.F. Goerlitz, D.E. Troutman, E.M. Godsy, B.J. Franks
Soil sorption of organic vapors and effects of humidity on sorptive mechanism and capacity Soil sorption of organic vapors and effects of humidity on sorptive mechanism and capacity
No abstract available.
Authors
C. T. Chiou, T.D. Shoup
Assessment of long-term salinity changes in an irrigated stream-aquifer system Assessment of long-term salinity changes in an irrigated stream-aquifer system
Changes in salinity in groundwater and surface water in the Arkansas River valley of southeastern Colorado are primarily related to irrigation practices. A solute transport model was applied to an 11-mile reach of the valley to compute salinity changes in response to spatially and temporally varying stresses. The model was calibrated in 1973 using detailed field measurements made during...
Authors
Leonard F. Konikow, Mark Person
Partitioning studies of coal-tar constituents in a two-phase contaminated ground-water system Partitioning studies of coal-tar constituents in a two-phase contaminated ground-water system
Organic compounds derived from coal-tar wastes in a contaminated aquifer in St. Louis Park, Minnesota, were identified, and their partition coefficients between the tar phase and aqueous phase were determined and compared with the corresponding n-octanol/water partition coefficients. Coal tar contains numerous polycyclic aromatic compounds, many of which are suspected carcinogens or...
Authors
Colleen E. Rostad, W. E. Pereira, M. F. Hult