Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 4094
Distribution, variability, and impacts of trace elements in San Francisco Bay
No abstract available.
Authors
Samuel N. Luoma, D.J.H. Phillips
Mechanistic characterization of chloride interferences in electrothermal atomization systems
A computer-controlled spectrometer with a photodiode array detector has been used for wavelength and temperature resolved characterization of the vapor produced by an electrothermal atomizer. The system has been used to study the chloride matrix interference on the atomic absorption spectrometric determination of manganese and copper. The suppression of manganese and copper atom populations by mat
Authors
J.M. Shekiro, R.K. Skogerboe, Howard E. Taylor
Partition of nonionic organic compounds in aquatic systems
In aqueous systems, the distribution of many nonionic organic solutes in soil-sediment, aquatic organisms, and dissolved organic matter can be explained in terms of a partition model. The nonionic organic solute is distributed between water and different organic phases that behave as bulk solvents. Factors such as polarity, composition, and molecular size of the solute and organic phase determine
Authors
James A. Smith, Patrick J. Witkowski, Cary T. Chiou
Sorption characteristics of organic compounds on hexadecyltrimethylammonium-smectite
When hexadedyltrimethylammonium (HDTMA) ion is exchanged for metal cations like calcium in smectite, the sorptive properties of the clay are greatly modified. The resultant HDTMA-smectite complex behaves as a dual sorbent, in the sorption of organic compounds, in which the mineral fraction functions as a solid adsorbent and the organic (HDTMA) phase as a partition medium. Capacities of mineral ads
Authors
Stephen A. Boyd, Max M. Mortland, Cary T. Chiou
Hydraulic conductivity of a sandy soil at low water content after compaction by various methods
To investigate the degree to which compaction of a sandy soil influences its unsaturated hydraulic conductivity K, samples of Oakley sand (now in the Delhi series; mixed, thermic, Typic Xeropsamments) were packed to various densities and K was measured by the steady-state centrifuge method. The air-dry, machine packing was followed by centrifugal compression with the soil wet to about one-third sa
Authors
John R. Nimmo, Katherine C. Akstin
Determining the distribution of hydraulic conductivity in a fractured limestone aquifer by simultaneous injection and geophysical logging
A field technique for assessing the vertical distribution of hydraulic conductivity in an aquifer was applied to a fractured carbonate formation in southeastern Nevada. The technique combines the simultaneous use of fluid injection and geophysical logging to measure in situ vertical distributions of fluid velocity and hydraulic head down the borehole; these data subsequently are analyzed to arrive
Authors
Roger H. Morin, A.E. Hess, Frederick L. Paillet
Sorption of vapors of some organic liquids on soil humic acid and its relation to partitioning of organic compounds in soil organic matter
Vapor sorption of water, ethanol, benzene, hexane, carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, and 1,2-dibromoethane on (Sanhedron) soil humic acid has been determined at room temperature. Isotherms for all organic liquids are highly linear over a wide range of relative pressure, characteristic of the partitioning (dissolution) of the organic compounds in s
Authors
G.T. Chlou, D. E. Kile, R. L. Malcolm
A statistical evaluation of formation disturbance produced by well- casing installation methods
Water-resources investigations concerned with contaminant transport through aquifers comprised of very loose, unconsolidated sediments have shown that small-scale variations in aquifer characteristics can significantly affect solute transport and dispersion. Commonly, measurement accuracy and resolution have been limited by a borehole environment consisting of an annulus of disturbed sediments pro
Authors
R. H. Morin, Denis R. LeBlanc, W.E. Teasdale
Hausmannite (Mn3O4) conversion to manganite (γ-MnOOH) in dilute oxalate solution
Oxalic acid retards the alteration of Mn3O4 to γ-MnOOH during aging at pH 7.4 ?? 0.2 in well-aerated, abiotic suspensions that contain 4.4 ?? 10-3 M total Mn. In solutions of 1.25 ?? 10-3 M oxalate and greater, about 15% of the initial Mn3O4 altered to ??-MnOOH by day 10, and in solutions of 6.7 ?? 10-4 M oxalate, about 45% altered to ??-MnOOH by day 67. Although precipitation continued through da
Authors
Carol J. Lind
Contamination of estuarine water, biota, and sediment by halogenated organic compounds: A field study
Studies conducted in the vicinity of an industrial outfall in the Calcasieu River estuary, Louisiana, have shown that water, bottom and suspended sediment, and four different species of biota are contaminated with halogenated organic compounds (HOC) including haloarenes. A "salting-out" effect in the estuary moderately enhanced the partitioning tendency of the contaminants into biota and sediments
Authors
W. E. Pereira, C.E. Rostad, C. T. Chiou, T.I. Brinton, L.B. Barber, D.K. Demcheck, C. R. Demas
Long-term fate of organic micropollutants in sewage-contaminated groundwater
No abstract available.
Authors
Larry B. Barber, M.P. Schroeder, E. Michael Thurman, Denis R. LeBlanc
Hydrogen concentrations as an indicator of the predominant terminal electron-accepting reactions in aquatic sediments
Factors controlling the concentration of dissolved hydrogen gas in anaerobic sedimentary environments were investigated. Results, presented here or previously, demonstrated that, in sediments, only microorganisms catalyze the oxidation of H2 coupled to the reduction of nitrate, Mn(IV), Fe(III), sulfate, or carbon dioxide. Theoretical considerations suggested that, at steady-state conditions, H2 co
Authors
D. R. Lovley, S. Goodwin