Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 4094
The determination and fate of unstable constituents of contaminated groundwater
No abstract available
Authors
M.J. Baedecker, M. Cozzarelli
Nitrate is a preferred electron acceptor for growth of freshwater selenate-respiring bacteria
An anaerobic, freshwater enrichment grew with either nitrate or selenate as an electron acceptor. With both ions present, nitrate reduction preceded selenate reduction. An isolate from the enrichment grew on either ion, but the presence of nitrate precluded the reduction of selenate. Stock cultures of denitrifiers grew anaerobically on nitrate but not on selenate.
Authors
Nisan A. Steinberg, Jodi Switzer Blum, Lawrence Hochstein, Ronald S. Oremland
Tensiometers: Theory, construction, and use
Standard tensiometers are used to measure matric potential as low as −870 cm of water in the unsaturated zone by creating a saturated hydraulic link between the soil water and a pressure sensor. The direction and, in some cases, quantity of water flux can be determined using multiple installations.A variety of commercial and fabricated tensiometers are commonly used. Saturated porous ceramic mater
Authors
D.I. Stannard
Synthetic organic agrochemicals in the lower Mississippi River and its major tributaries--Distribution, transport and fate
The Mississippi River and its major tributaries transport herbicides and their degradation products from agricultural areas in the mid-western U.S.A. These compounds include atrazine and its degradation products (desethyl- and desisopropylatrazine), simazine, cyanazine, metolachlor, and alachlor and its degradation products (2-chloro-2′,6′-diethylacetanilide 2-hydroxy-2′,6′-diethylacetanilide and
Authors
W. E. Pereira, C.E. Rostad, T.J. Leiker
Geochemical heterogeneity in a sand and gravel aquifer: Effect of sediment mineralogy and particle size on the sorption of chlorobenzenes
The effect of particle size, mineralogy and sediment organic carbon (SOC) on sorption of tetrachlorobenzene and pentachlorobenzene was evaluated using batch-isotherm experiments on sediment particle-size and mineralogical fractions from a sand and gravel aquifer, Cape Cod, Massachusetts. Concentration of SOC and sorption of chlorobenzenes increase with decreasing particle size. For a given particl
Authors
Larry B. Barber, E. Michael Thurman, Donald D. Runnells
Nitrogen-15 and carbon-13 NMR investigation of hydroxylamine-derivatized humic substances
No abstract available.
Authors
Kevin A. Thorn, Jeffrey B. Arterburn, Michael A. Mikita
Sampling vadose-zone water for a volatile organic compound at Picatinny Arsenal, New Jersey
A new method of collecting samples of unsaturated-zone water for quantitative analysis for a volatile organic compound, trichloroethene (TCE), was compared to three other, previously described sampling methodologies in the laboratory and in the field. In the laboratory, prepared water samples containing TCE in a known concentration (20 µg/L) were sampled repeatedly by using each of the four method
Authors
James A. Smith, H. Jean Cho, Peter R. Jaffe, Cecilia L. MacLeod, Susan A. Koehnlein
A critical review of inductively coupled plasma-mass spectrometry for geoanalysis, geochemistry and hydrology, Part 1. Analytical performance
Present-day inductively coupled plasma-mass spectrometry (ICP-MS) instrumentation is described briefly. Emphasis is placed on performance characteristics for geoanalysis, geochemistry, and hydrology. Applications where ICP-MS would be indispensable are indicated. Determination of geochemically diagnostic trace elements (such as the rare earth elements [REE], U and Th), of isotope ratios for finger
Authors
I.B. Brenner, Howard E. Taylor
Identification of persistent anionic surfactant-derived chemicals in sewage effluent and groundwater
Preparative isolation and fractionation procedures coupled with spectrometric analyses were used to identify surfactant-derived contaminants in sewage effluent and sewage-contaminated groundwater from a site located on Cape Cod, Massachusetts. Anionic surfactants and their biodegradation intermediates were isolated from field samples by ion exchange and fractionated by solvent extraction and adsor
Authors
Jennifer A. Field, Jerry A. Leenheer, Kevin A. Thorn, Larry B. Barber, Colleen Rostad, Donald L. Macalady, Stephen R. Daniel
Reply to comment by G. de Marsily, P. Combes, and P. Goblet on "Ground-water models cannot be validated"
No abstract available.
Authors
J. D. Bredehoeft, Leonard F. Konikow
Associations of free-living bacteria and dissolved organic compounds in a plume of contaminated groundwater
Associations of free-living bacteria (FLB) and dissolved organic contaminants in a 4-km-long plume of sewage-contaminated groundwater were investigated. Abundance of FLB in the core of the plume (as delineated by maximum specific conductance) steadily decreased in the direction of flow from a point 0.25 km downgradient from the source to the toe of the plume. At 0.25 km downgradient, FLB comprised
Authors
Ronald W. Harvey, Larry B. Barber
Bioaccumulation of hydrocarbons derived from terrestrial and anthropogenic sources in the Asian clam, Potamocorbula amurensis, in San Francisco Bay estuary
An assessment was made in Suisun Bay, California, of the distributions of hydrocarbons in estuarine bed and suspended sediments and in the recently introduced asian clam, Potamocorbula amurensis. Sediments and clams were contaminated with hydrocarbons derived from petrogenic and pyrogenic sources. Distributions of alkanes and of hopane and sterane biomarkers in sediments and clams were similar, in
Authors
Wilfred E. Pereira, Frances D. Hostettler, John B. Rapp