Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 4094
Effects of copper on composition species of periphyton in a Sierra Nevada, California, stream
An oligotrophic stream was continuously dosed for 1 yr at 2.5, 5 and 10 mu g l-1 CuT; c12, 25 and 50 ng l-1 Cu2+. The numerically most abundant taxa were Bacillariophyceae (Achnanthes minutissima, Cocconeis placentula, Cymbella microcephala, C. sinuata, Fragilaria construens, F. crotonensis, Navicula spp., Synedra acus and S. rumpens), and the Cyanophyta Lyngbya spp., a co-dominant during spring a
Authors
H.V. Leland, J.L. Carter
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 were used fo
Authors
T.R. Steinheimer, M.G. Brooks
Comparison of sediments and organisms in identifying sources of biologically available trace metal contamination
Sediments and an indicator organism (Macoma balthica, a deposit-feeding bivalve) were used to assess the relative importance of secondary sewage, urban runoff, a landfill containing metal-enriched ash wastes and a yacht harbor in contributing to Ag, Cu and Zn enrichment in South San Francisco Bay. Spatial gradients in sediments and organisms showed Cu and Ag enrichment originated from sewage disch
Authors
E.A. Thomson, Samuel N. Luoma, C.E. Johansson, D.J. Cain
Subsurface injection of treated sewage into a saline-water aquifer at St. Petersburg, Florida - Water-quality changes and potential for recovery of injected sewage
The city of St. Petersburg is testing subsurface injection of treated sewage into the Floridan aquifer as a means of eliminating discharge of sewage to surface waters and as a means of storing treated sewage for future nonpotable reuse. The injection zone at the test site at the start of injection contained saline water with chloride concentrations ranging from 14,000 to 20,000 milligrams per lite
Authors
J.J. Hickey, G. G. Ehrlich
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 the aqueous
Authors
J.A. Davis
Bonded-phase extraction column isolation of organic compounds in groundwater at a hazardous waste site
A procedure for isolation of hazardous organic compounds from water for gas chromatography/mass spectrometry analysis Is presented and applied to creosote- and pentachlorophenol-contaminated groundwater resulting from wood-treatment processes. This simple procedure involved passing a 50-100-mL sample through a bonded-phase extraction column, eluting the trapped organic compounds from the column wi
Authors
C.E. Rostad, W. E. Pereira, S.M. Ratcliff
Origin and distribution of carbon dioxide in the unsaturated zone of the southern High Plains of Texas
Partial pressures of CO2, O2, N2, and Ar were monitored at two locations in the Ogallala aquifer system on the Southern High Plains of Texas. Samples were collected monthly during parts of 1980–1981 from nine depths ranging from 0.6 to 36 meters below land surface. PCO2 was observed to be greater at depth than in the active soil zone and thus appears to contradict the normal process in which CO2 i
Authors
Warren W. Wood, Michael J. Petraitis
Heating rates in furnace atomic absorption using the L'vov platform
Heating rate profiles for the furnace tube wall, the furnace atmosphere, and a L'vov platform were established for a range of conditions in a cyclically heated graphite atomizer. The tube wall profile was made by direct observation with a recording optical pyrometer. The sodium line reversal method was used to establish the heating rate of the furnace atmosphere, and appearance temperatures for a
Authors
S.R. Koirtyohann, R.C. Giddings, Howard E. Taylor
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 of chloride
Authors
Kenneth E. Bencala, Vance C. Kennedy, Gary W. Zellweger, Alan P. Jackman, Ronald J. Avanzino
Adsorption of goethite onto quartz and kaolinite
The adsorption of colloidal goethite onto quartz and kaolinite substrates has been studied as a function of pH and NaCl concentration. Goethite adsorption was measured quantitatively by Fourier-transform infrared spectroscopy. The results indicate that adsorption onto both substrates is due primarily to coulombic forces; however, the pH dependence of adsorption is very different for the two substr
Authors
M. C. Goldberg, Eugene R. Weiner, P.M. Boymel
Pore volume determination in activated carbon and coal
No abstract available.
Authors
P.J. Reucroft, K.B. Patel, C. T. Chiou
Volatilization of ketones
Volatilization fluxes of seven ketones were measured over a range of temperatures. Gas-film coefficients were calculated from these volatilization fluxes and related to the gas-film coefficient for the evaporation of water. These relations, when combined with an equation for estimating the gas-film coefficient for evaporation of water from a canal, permit estimating gas-film coefficients for the v
Authors
R. E. Rathbun, D. Y. Tai