Anaerobic Degradation of PCP and Phenol in Fixed-Film Reactors: The Influence of an Additional Substrate

The anaerobic degradation of pentachlorophenol (PCP) and phenol was examined in two lab-scale fixed-film reactors. Anaerobic digested sewage sludge from a municipal treatment plant was used as inoculum. The reactors were fed a mineral medium containing PCP (1-2 mg/l) and phenol (4-6 mg/l). In addition one of the reactors received 1 g/l glucose as an easily degradable carbon source. After 6 months of continuous operation, the removal of PCP in the reactor with no glucose added was approximately 60%, whereas the removal in the reactor with glucose reached 98%. Tetrachlorophenol (TeCP) and trichloro-phenol (TCP) were found as degradation products and the removal of these compounds was also significantly enhanced by the presence of glucose. Phenol degradation was approximately 70% with glucose added and 95% without glucose.