Anaerobic Bioremediation Performance and Indigenous Microbial Communities in Treatment of Trichloroethylene/Nitrate-Contaminated Groundwater

Abstract To meet recommended drinking water standards, developing effective methods for eliminating mixed contamination of trichloroethylene (TCE) and nitrate, the two most common groundwater contaminants, is critical. However, many previous studies examined bioremediation performance only for single contaminants. In this study, the performance of indigenous microbial communities on anaerobic removal of TCE/nitrate mixed contamination in groundwater was investigated. Central composite design (CCD) and response surface methodology (RSM) predicted that for bioremoval of 3.87 mg/L TCE combined with 50 mg/L nitrate-N, the optimal conditions were: pH 8.01, 20.18°C, and a powder activated carbon (PAC) dosage of 4.04% (w/v). Under these conditions, 100% of both TCE and nitrate could be removed with no by-product accumulation after 14 days. Presence of TCE and nitrate did not inhibit bioremoval performance for mixed contaminations, although pH and temperature had a more significant influence on mixed compared to ...