Microbial dechlorination of tetrachloroethene under anaerobic environment

Contamination of subsurface environments with chloroethenes [tetrachloroethene (PCE) trichloroethene (TCE), dichloroethenes (cis-DCE and trans-DCE) and vinyl chloride (VC)] is drawing more concerns to date than ever. The conventional remedial technique is pump-and-treat. However, due to the physical/chemical properties of this class of compounds, and the heterogenous nature of the subsurface, extraction approaches have limited success. Bioremediation represents an alternative for the dechlorination treatment. Aerobic oxidation of chloroethenes into CO{sub 2} has limited application due to the low oxygen concentration in the subsurface environment. Moreover, PCE is not subject to oxidative reaction. However, PCE has shown to undergo reductive transformation under anaerobic conditions. Therefore, the anaerobic process appears to hold the most promise for the development of a usable in-situ treatment technology. It has been shown that some of the carboxylic acids were linked to the microbial dechlorination of chloroethenes. In this work, study was focused on the anaerobic dechlorination of PCE stimulated by lactate.