Performance of phenol-acclimated activated sludge in the presence of various phenolic compounds

Abstract

The objective of this study was to evaluate the performance of phenol-acclimated activated sludge in the presence of various phenolic compounds in the separated batch reactors. The phenol-acclimated activated sludge was observed to be capable of completely removing phenol, o-cresol, m-cresol, and 4-chlorophenol. Nevertheless, in the presence of 2-chlorophenol and 3-chlorophenol merely at 50 mg/L, incomplete removal of these phenolic compounds were noticed. The specific oxygen uptake rate patterns obtained for phenol, o-cresol, m-cresol, and 4-chlorophenol could be used to approximate the end point of these phenolic compounds removal as well as to monitor the growth of biomass. As the 2-chlorophenol and 3-chlorophenol were only partially removed in the mixed liquor, the patterns of specific oxygen uptake rate attained for these phenolic compounds were not feasible for the similar estimation. The calculated toxicity percentages show the toxicity effects of phenolic compounds on the phenol-acclimated activated sludge followed the order of 2-chlorophenol ≈ 3-chlorophenol > 4-chlorophenol > o-cresol ≈ m-cresol > phenol. © 2013 The Author(s).