Bioremediation can be defined as any process that uses microorganisms or their enzymes to remove and or neutralize contaminants within the environment (i.e., within soil and water) to their original condition. Bioremediation can be employed to remediate specific types of contaminants such as; petroleum hydrocarbons, polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyl’s (PCB), chlor...

The dechlorination of chlorinated hydrocarbons has been examined in detail. The reaction is catalyzed by cytochrome P-450 and occurs optimally in the presence of oxygen although some dechlorination may occur under anaerobic conditions. Halothane has been shown to undergo an oxidative dechlorination and a reductive defluorination. Enzymatic attack of chlorinated olefins and hydrocarbons is not o...

Biogeochemical reductive dechlorination (BiRD) is a new remediation approach for chlorinated aliphatic hydrocarbons (CAHs). The approach stimulates common sulfate-reducing soil bacteria, facilitating the geochemical conversion of native iron minerals into iron sulfides. Iron sulfides have the ability to chemically reduce many common CAH compounds including PCE, TCE, DCE, similar to zero valent ...

We estimated the distribution of chlorinated aliphatic hydrocarbons (CAHs) from groundwater samples collected along three transects in a sand aquifer. Trichloroethylene (TCE) leaked and contaminated the aquifer probably more than a decade before we collected the measurements. The data show significant concentrations of TCE, cis-1,2dichloroethylene (c-DCE), vinyl chloride (VC), and ethene. We at...

Stable isotopic characterization of chlorine in chlorinated aliphatic pollution is potentially very valuable for risk assessment and monitoring remediation or natural attenuation. The approach has been underused because of the complexity of analysis and the time it takes. We have developed a new method that eliminates sample preparation. Gas chromatography produces individually eluted sample pe...

In situ anaerobic bioremediation of chlorinated solvents such as perchloroethene (PCE) frequently faces the problem of accumulating toxic, lower chlorinated compounds such as dichloroethene (cis-DCE) and vinyl chloride (VC). In the present study, the efficacy of the sequential application of electron donors, supporting reductive dechlorination, and of humic acids, acting as extracellular electr...

A number of commercial compounds having chlorinated aromatic hydrocarbon structures are used extensively for medical(3), industrial(4) and agricultural(5) purposes. Quantities of certain parent chlorinated aromatic hydrocarbons and metabolites have been repeatedly detected as residues in the food supply and tissues of birds, fish, and mammals(6-9) including man(10). Chlor-inated diphenyl-p-diox...