Abstract
Groundwater contamination by tetrachloroethylene (PCE) is one of the most serious environmental problems. PCE is hard to be biodegraded and suspected as carcinogenic substance. In this study, anaerobic degradation of PCE by expanded-bed granular activated carbon (GAC) bioreactor was experimentally studied. This reactor has two treatment mechanisms with the adsorption by GAC and biodegradation by attached microorganism on GAC. Continuous treatment was performed with successful results. PCE was stably removed from 2.7∼17.2mg/L in influent to less than 0.5 μ g/L in effluent under the PCE loading condition of 2.7∼15.3mgPCE/(kgGAC · d). PCE was shown to be dehalogenated to TCE and VC by attached microorganism in batch experiment. Dehalococcoides which dehalogenates PCE was shown to exist in the reactor.
