Removal of pentachlorophenol from wastewater by combined anaerobic-aerobic treatment

In this research, the feasibility of combined anaerobic-aerobic biotreatment of pentachlorophenol (PCP) was studied. PCP at 15 mg l(-1) caused inhibition to both batch and continuous anaerobic systems. However, the recovery time was reduced significantly with higher biomass. With proper acclimation, an acetate-fed anaerobic column could degrade 93% of PCP with influent concentration of 15 mg l(-1). With an aerobic process (a conventional activated sludge system) alone, only 74% of 7.5 mg l(-1) of PCP was removed. Using an activated sludge system as a polishing unit following the upflow anaerobic column up to 97% of 15 mg l(-1) of PCP was removed.