Sequential Transformation of Carbon Tetrachloride, Perchloroethylene, and 1,1,1-Trichloroethane Using Methanogenic and Methanotrophic Conditions

摘要

A methanogenic-methanotrophic system has been established to assess thecapability of sequential treatment to transform the chlorinated aliphatics perchloroethylene (PCE), carbon tetrachloride (CT), and 1,1,1-trichloroethane (1,1,1-TCA). Experiments compared the transformation of PCE alone and in a mixture of the target compounds. A comparison of acetate and iron as electron donors was also made. Data from the anaerobic systems have shown that PCE transformation is inhibited when in a mixture with CT and 1,1,1-TCA compared to when it is fed alone. When iron is the electron donor, PCE and 1,1,1-TCA are transformed without an acclimation period. CT was completely transformed regardless of the electron donor used. The acetate-fed system required approximately 60 days to acclimate to 1,1,1-TCA and 70 days for acclimation to PCE.