Trichloroethylene bioremediation

Once all of the controllable factors are in place, it is critical to select the proper bacterial combination(s) that enables the appropriate rate of biomass growth and enzyme production. For instance, the primary step in trichloroethylene bioremediation is the production of oxygenases, such as toluene dioxygenase (tod). However, oxidation of trichloroethylene generates intermediates that inactivate the tod enzyme and can even be toxic to the cells themselves, i.e., catabolite repression. Thus, the biomass growth rate and... 

Hopkins GD, J Munakata, L Semprini, PL McCarty (1993a) Trichloroethylene concentration effects on pilot-scale in-situ groundwater bioremediation by phenol-oxidizing microorganisms. Environ Sci Technol 27 2542-2547. 

Kinsella, J. V. and Nelson, M. J. K., 1993, In Situ Bioremediation Site Characterization, System Design, and Full Scale Field Remediation of Petroleum Hydrocarbon and Trichloroethylene Contaminated Groundwater In Bioremediation Field Experience (edited by P. E. Flathman and D. E. Jerger), CRC Press, Boca Raton, FL. 

Significant activation occurs during the microbial metabolism of trichloroethylene (TCE). This compound was once widely used and now represents a major contaminant of many aquifers. Because TCE is metabolized by many bacteria, its elimination by bioremediation is being actively pursued. However, a major product frequently encountered is vinyl chloride, a potent carcinogen ... 

Bearehaven Reclamation, Inc. (Bearehaven), in situ bioremediation is a proprietary technology for the treatment of organic contaminants. According to the vendor, the process can readily remediate trichloroethylene (TCE), polychlorinated biphenyls (PCBs), diesel fuel, and other more complex organic compounds in soil, water, sludge, and landfills. 

TCE-degrading bacteria is a patented technology for the treatment of soil, groundwater and wastewater contaminated with trichloroethylene (TCE). The particular strain of bacteria used in this technology does not require the addition of a toxic co-substrate to activate the bacterial destruction of TCE. The technology can be used to remediate virtually any media type contaminated with one or more volatile organic compounds (VOCs), including TCE, and can be used for in situ or ex situ bioremediation. 

In situ bioremediation has also been proposed for the cleanup of aquifers contaminated by solvents such as trichloroethylene (TCE) and dichloroethylene (DCE). Compounds like TCE are usually not degraded as sole sources of carbon and... 

Interest in the bioremediation of chlorinated solvents is widespread. It is impractical to consider all the excellent efforts underway. An example will be given for both a chlorinated alkane and a chlorinated alkene. Both compounds, dichloromethane and trichloroethylene, are commonly used industrial solvents and degreasers that are important soil and water pollutants. 

Ornstein, R. L. (1991)- Why timely bioremediation of synthetics may require rational enzyme redesign preliminary report on redesigning cytochrome P450cam for trichloroethylene dehalogenation. In On-Site Bioreclamation. Processes for Kenobiotic and Hydrocarbon Treatment, ed. R. E. Hinchee and R. F. Olfenbuttel, pp. 509-14. Boston Butterworth-Heinemann. 

Bioremediation and thermal desorption are the most frequently selected innovative technologies for NPL sites with SVOCs, which are the second most common contaminants found at NPL sites. Also, SVE has been selected for some of the most volatile SVOCs (e.g., phenols and naphthalenes). Current research efforts are focused on biodegradation of chlorinated aliphatic hydrocarbons, such as trichloroethylene (TCE) and vinyl chloride, which occur at many sites. Thermal desorption most effectively treats PAHs and PCBs, and it may be particularly useful to pretreat organics prior to metal treatment. 

O Neill, W, Nzengung, V, Noakes, J., Bender, J., and Phillips, P., Biodegradation of tetrachloroehtylene and trichloroethylene using mixed-species microbial mats. In Wickramanayake, G.B., and Hinchee, R.E., editors. Bioremediation and Phytoremediation, Batelle, Columbus, WA, pp. 233-237, 1998. 

Bioremediation has been successfully demonstrated for a variety of contaminant classifications. The majority of the studies have focused on petroleum compounds (BTEX, gasoline, diesel, jet fuel, etc.) because of their widespread occurrence as a contaminant. The other major waste classifications where bioremediation has been successful are solvents (toluene, trichloroethylene, etc.), creosote, pulp and paper, pesticides, textiles, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs). Table 1 contains a partial list of the microbial genus successfully implemented for these contaminants. For aqueous petroleum contaminants, bacteria and yeasts are the most prevalent degraders. In contaminated soil systems, bacteria and fungi are the microorganisms responsible for degradation. ... 

Wilson, X T. Kampell, D. H. Weaver, X W Imbrigiotta, B. Ehlke, T. (1996) A review of intrinsic bioremediation of trichloroethylene in ground water at Picatinny arsenal. New Jersey and St. Jospehs, Michigan. In Proceedings of Symposium on Natural Attenuation of chlorinated Organics in Ground Water, Dallas, Texas, Sept. 1996, EPA/540/R-96/509, 11-14. 

The EMSP con lements the NABIR program by including research that addresses non-metal contamination that is a major concern at DOE sites, such as trichloroethylene and other DNAPLs. The EMSP also supports research into phytoremediation— the use of plants for bioremediation— while NABIR research is focused on bioremediation by microbes. 

Anderson TA, Walton BT. Comparative plant uptake and microbial degradation of trichloroethylene in the rhizospheres of five plant species Implications for bioremediation of contaminated surface soUs. ORNL/TM-12017. Oak Ridge, TN. 1992 pp.l86. 

---