Performance of prototype bioreactors for biodegradation of trichloroethylene by Methylocystis sp. M

Two prototype bioreactors were tested for continuous biodegradation of trichloroethylene (TCE) by Methylocystis sp. M, a methane-utilizing bacterium. One bioreactor was a fluidized-bed bioreactor (FBB) containing alginate-immobilized cells and the other a membrane bioreactor (MB) in which hollow fiber membrane modules were employed for recovering free cells from treated water. TCE degradation efficiency was 80% to 90% with FBB, which was operated at an influent TCE concentration of about 1 mg/L and a hydraulic retention time (HRT) of 2.6 hours. MB, which was operated at an influent TCE concentration of about 0.25 mg/L and HRT of 3.3 hours, yielded a TCE degradation efficiency of 90 to 99%. In this study, MB was found to be more practical than FBB.