Anaerobic Biotransformation of 1,1,1-Trichloroethane or Chloroform: Effects on Dechlorination of Tetrachloroethene

摘要

Many hazardous waste sites are contaminated with mixtures of chlorinated organic chemicals. 1,1,1-trichloroethane (TCA), chloroform (CF), tetrachloroethene, also known as perchloroethylene (PCE), and trichloroethylene (TCE) are frequent groundwater co-contaminants. Under anaerobic conditions, TCA, CF, and PCE are biologically reduced to lesser chlorinated daughter products. Such dechlorination has been demonstrated with TCA, CF, or PCE as sole contaminants. However, few investigations have explored anaerobic biotransformation of TCA or CFand PCE simultaneously. Studies involving biodegradation of mixtures of contaminants are important to ascertain potential impacts on bioremediation systems. Experiments were undertaken to examine if a methanogenic, PCE-dechlorinating culture could biotransform TCA or CF in the presence of PCE. The effect of TCA or CF on PCE dechlorination was also investigated.