Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 4094
Well-purging criteria for sampling purgeable organic compounds
The results indicate that 1) purgeable organic compound concentrations stabilized when three casing volume were purged in only 55% of the cases evaluated in this study, 2) purgeable organic compounds concentrations did not consistently follow the temporal variation of, nor stabilize at the same time as, the measure field characteristics, and 3) purging to achieve hydraulic equilibrium between casi
Authors
J. Gibs, T.E. Imbrigiotta
Anaerobic oxidation of toluene, phenol, and p-cresol by the dissimilatory iron-reducing organism, GS-15
The dissimilatory Fe(III) reducer, GS-15, is the first microorganism known to couple the oxidation of aromatic compounds to the reduction of Fe(III) and the first example of a pure culture of any kind known to anaerobically oxidize an aromatic hydrocarbon, toluene. In this study, the metabolism of toluene, phenol, and p-cresol by GS-15 was investigated in more detail. GS-15 grew in an anaerobic me
Authors
D. R. Lovley, D.J. Lonergan
Rates of microbial metabolism in deep coastal plain aquifers
Rates of microbial metabolism in deep anaerobic aquifers of the Atlantic coastal plain of South Carolina were investigated by both microbiological and geochemical techniques. Rates of [2-14C]acetate and [U-14C]glucose oxidation as well as geochemical evidence indicated that metabolic rates were faster in the sandy sediments composing the aquifers than in the clayey sediments of the confining layer
Authors
F. H. Chapelle, D. R. Lovley
Nitrogen fixation dynamics of two diazotrophic communities in Mono Lake, California
Two types of diazotrophic microbial communities were found in the littoral zone of alkaline hypersaline Mono Lake, California. One consisted of anaerobic bacteria inhabiting the flocculent surface layers of sediments. Nitrogen fixation (acetylene reduction) by flocculent surface layers occurred under anaerobic conditions, was not stimulated by light or by additions of organic substrates, and was i
Authors
R.S. Oremland
Determination of trace levels of herbicides and their degradation products in surface and ground waters by gas chromatography/ion-trap mass spectrometry
A rapid, specific and highly sensitive method is described for the determination of several commonly used herbicides and their degradation products in surface and ground waters by using gas chromatography/ion-trap mass spectrometry. The compounds included atrazine, and its degradation products desethylatrazine and desisopropylatrazine; Simazine; Cyanazine; Metolachlor; and alachlor and its degrada
Authors
W. E. Pereira, C.E. Rostad, T.J. Leiker
Prediction of stream volatilization coefficients
Equations are developed for predicting the liquid-film and gas-film reference-substance parameters for quantifying volatilization of organic solutes from streams. Molecular weight and molecular-diffusion coefficients of the solute are used as correlating parameters. Equations for predicting molecular-diffusion coefficients of organic solutes in water and air are developed, with molecular weight an
Authors
Ronald E. Rathbun
Reaction paths and equilibrium end-points in solid-solution aqueous-solution systems
Equations are presented describing equilibrium in binary solid-solution aqueous-solution (SSAS) systems after a dissolution, precipitation, or recrystallization process, as a function of the composition and relative proportion of the initial phases. Equilibrium phase diagrams incorporating the concept of stoichiometric saturation are used to interpret possible reaction paths and to demonstrate rel
Authors
P. D. Glynn, E.J. Reardon, Niel Plummer, E. Busenberg
Kinetically influenced terms for solute transport affected by heterogeneous and homogeneous classical reactions
Simulation of transport affected by heterogeneous or homogeneous reversible reactions requires a choice between local equilibrium-based and kinetics-based models. The error associated with the use of equilibrium-based models is equivalent to the error of neglecting certain mathematical terms in the governing kinetics-based transport equations. Identification and evaluation of these kinetically inf
Authors
Jean M. Bahr
Fe(III)-reducing bacteria in deeply buried sediments of the Atlantic Coastal Plain
The possibility that microorganisms are catalyzing the ongoing reduction of Fe(III) in the sediments of deep (20-250 m) aquifers was investigated. Acetate-oxidizing, Fe(III)-reducing bacteria were recovered from deep subsurface sediments, but only from sediments in which it appeared that Fe(III) reduction was the terminal electron-accepting process for oxidation of organic matter. The Fe(III)-redu
Authors
D. R. Lovley, F. H. Chapelle, E. J. P. Phillips
Application of a hollow-fiber, tangential-flow device for sampling suspended bacteria and particles from natural waters
The design and application of a hollow-fiber tangential-flow filtration device has been used to concentrate bacteria and suspended particles from large volume surface water and groundwater samples (i.e., hundreds of liters). Filtrate tlux rates (4–8 L min−1) are equal to or faster than those of other devices that are based on continuous flow centrifugation and plate and frame filtration. Particle
Authors
J.S. Kuwabara, R.W. Harvey
Transformation of Monoaromatic hydrocarbons to organic acids in anoxic groundwater environment
The transformation of benzene and a series of alkylbenzenes was studied in anoxic groundwater of a shallow glacial-outwash aquifer near Bemidji, Minnesota, U.S.A. Monoaromatic hydrocarbons, the most water-soluble components of crude oil, were transported downgradient of an oil spill, forming a plume of contaminated groundwater. Organic acids that were not original components of the oil were identi
Authors
I.M. Cozzarelli, R.P. Eganhouse, M.J. Baedecker
The surface area of soil organic matter
The previously reported surface area for soil organic matter (SOM) of 560-800 m2/g as determined by the ethylene glycol (EG) retention method was reexamined by the standard BET method based on nitrogen adsorption at liquid nitrogen temperature. Test samples consisted of two high organic content soils, a freeze-dried soil humic acid, and an oven-dried soil humic acid. The measured BET areas for the
Authors
C. T. Chiou, J.-F. Lee, S.A. Boyd