Microbial reductive dechlorination of the persistent polychlorinated biphenyls (PCBs) is attracting much attention in cleanup of the contaminated environment. Nevertheless, most PCB dechlorinating cultures require presence of sediment or sediment substitutes to maintain their dechlorination activities which hinders subsequent bacterial enrichment and isolation processes. The information on enri...

Advancement of Nucleic Acid-Based Tools for Monitoring In Situ Reductive Dechlorination Vangelas, K., E. Edwards, F. Loeffler, B.B. Looney. Paper No: WSRC-STI-2006-00332, 23 pp, Nov 2006 Regulatory protocols generally recognize that destructive processes are the most effective mechanisms that support natural attenuation of chlorinated solvents. In many cases, these destructive processes will be...

Degradation of tetrachloromethane was examined in the three strictly anaerobic bacteria, Acetobacterium woodii. Desulfobacterium autotrophicum and Methanobacterium thermoauwtrophicum. When incubated under anaerobic conditions in reduced buffer, suspensions of each organism degraded CCI4 by both reductive and substitutive mechanisms. The products formed included less-highly chlorinated methanes ...

Anaerobic bioreactors containing Dehalococcoides spp. can be effective for the treatment of trichloroethene (TCE) contamination. However, reductive dehalogenation of TCE often results in partial conversion to harmless ethene, and significant production of undesired cis-1,2-dichloroethene (cis-DCE) and vinyl chloride (VC) is frequently observed. Here, a detailed modeling study was conducted focu...

The concern about synthetic chemical compounds such as polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) as a threat to living organisms (21) has fostered research on innovative treatment technologies for their destruction. Because of their hydrophobic properties, these compounds accumulate in fatty tissues of all organisms (21). In the environment, they often partition into aquatic ...

Trichlorofluoroethene (TCFE) was used as a reactive tracer to determine the in situ rate of reductive dechlorination in treatment zones impacted by three large-diameter permeable columns (LDPCs) that were installed at a trichloroethene (TCE)–contaminated site. The LDPCs were part of a pilot study to evaluate the effectiveness of hydrogen, lactate, and zerovalent iron for remediating TCE-contami...

Dehalococcoides ethenogenes strain 195 reductively dechlorinates tetrachloroethene (PCE) and trichloroethene (TCE) to vinyl chloride and ethene using H2 as an electron donor. PCE- and TCE-reductive dehalogenase (RD) activities were mainly membrane associated, whereas only about 20% of the hydrogenase activity was membrane associated. Experiments with methyl viologen (MV) were consistent with a ...

Recently, Cong et al. (2010) published a comprehensive study on the characterization of reductive properties of hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethane (DDTs) using powdered metallic iron (Fe). Quantum chemical descriptors characterizing different molecular structures and physicochemical properties of the seven tested organochlorine pesticides (4 HCHs and 3 DDTs) were ...

A bacterial mixed culture reductively dechlorinating trichlorobenzenes was established in a defined, synthetic mineral medium without any complex additions and with pyruvate as the carbon and energy source. The culture was maintained over 39 consecutive transfers of small inocula into fresh media, enriching the dechlorinating activity. In situ probing with fluorescence-labeled rRNA-targeted oli...