Degradation of Tetrachloroethene and Trichloroethene by Immobilized Anaerobic and Aerobic Microorganisms

摘要

Degradation of tetrachloroethene (PCE) and trichloroethene (TCE) by combining an anaer- obic consortium with an aerobic bacterium was investigated. The anaerobic enrichment culture that dechlorinated high concentration of PCE to cis-1, 2-dichloroethene (cDCE) without methane production and sulfate reduction, was obtained from TCE contaminated soil. The aerobic phenol-oxidizing bacterium that degraded TCE and cDCE was isolated from leachate of a waste landfill site. Each culture retained chloroethene degrading activities after immobili- zation in k-carrageenan gel beads. In a batch bioreactor containing the immobilized cells, PCE and TCE were converted to cDCE and chloride ion under anaerobic condition. After addition of phenol and oxygen (or hydrogen peroxide) to the reactor, cDCE was degraded. PCE and TCE (40-50mg· l~(-1)) were degraded in 3 days with the bioreactor. The immobilized cells retained the degrading activities in repeated use.