Publications

A series of single-solute and binary-solute sorption data have been obtained on representative samples of polar compounds (substituted ureas and phenolic compounds) and of nonpolar compounds (e.g., EDB and TCE) on a peat soil and a mineral (Woodburn) soil; the data extend to low relative solute concentrations (C(e)/S(w)). At relatively low C(e)/S(w), both the nonpolar and the polar...

Transport and biodegradation of linear alkylbenzenesulfonate (LAS) in sewage-contaminated groundwater were investigated for a range of dissolved oxygen concentrations. Both laboratory column and an 80-day continuous injection tracer test field experiments were conducted. The rates of LAS biodegradation increased with increasing dissolved oxygen concentrations and indicated the...

Adsorption/thermal desorption with multisorbent air-sampling cartridges was developed for the determination of 87 method analytes including halogenated alkanes, halogenated alkenes, ethers, alcohols, nitriles, esters, ketones, aromatics, a disulfide, and a furan. The volatilities of the compounds ranged from that of dichlorofluoromethane (CFC12) to that of 1,2,3- trichlorobenzene. The...

The work reported here is the first part of a larger effort focused on efficient numerical simulation of redox zone development in contaminated aquifers. The sequential use of various electron acceptors, which is governed by the energy yield of each reaction, gives rise to redox zones. The large difference in energy yields between the various redox reactions leads to systems of equations...

Ground-water contamination by crude oil, and other petroleum-based liquids, is a widespread problem. An average of 83 crude-oil spills occurred per year during 1994-96 in the United States, each spilling about 50,000 barrels of crude oil (U.S. Office of Pipeline Safety, electronic commun., 1997). An understanding of the fate of organic contaminants (such as oil and gasoline) in the...

As part of a regional monitoring program, water samples were collected in the San Francisco Bay estuary during 20 cruises from January through November 1997. Conductivity, temperature, light attenuation, turbidity, oxygen, and in-vivo chlorophyll fluorescence were measured longitudinally and vertically in the main channel of the estuary from south of the Dumbarton Bridge in the southern...

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No abstract available.

Remediation goals for the source areas of a chlorinated ethene‐contaminated groundwater plume were identified by assessing the natural attenuation capacity of the aquifer system. The redox chemistry of the site indicates that sulfate‐reducing (H2 ∼ 2 nanomoles [nM]) per liter conditions near the contaminant source grade to Fe(III)‐reducing conditions (H2 ∼ 0.5 nM) downgradient of the...

This article summarizes recent experiences in arsenic (As) quantification, preservation, and speciation developed during AWWA Research Foundation (AWWARF) and Water Industry Technical Action Fund (WITAF) projects. The goal of this article is to alert analysts and decision-makers to potential problems in As analysis and speciation, because there appear to be several unresolved problems...

As the result of a pipeline burst, a body of light aliphatic crude oil floats atop the groundwater in a shallow sand and gravel aquifer in a remote area outside Bemidji, Minnesota. Biodegradation has resulted in the formation of a plume of DOC downgradient from the oil body. Groundwater has also been contaminated in an area known as the spray zone, from vertical infiltration of DOC...

The potential for humic substances to serve as a terminal electron acceptor in microbial respiration and to function as an electron shuttle between Fe(III)‐reducing microorganisms and insoluble Fe(III) oxides was investigated. The Fe(III)‐reducing microorganism Geobacter metallireducens conserved energy to support growth from electron transport to humics as evidenced by continued...