Studies of the Effects of Co-substrates on Biodegradation Kinetics of 4-Chlorophenol Using Response Surface Methodology (RSM)

Abstract

This study aimed to investigate the effect of glucose or sucrose as cosubstrate on the kinetics of 4-chlorophenol (4-CP) biodegradation by 4-CP-acclimated activated sludge. The performance of 4-CP biodegradation was enhanced in the presence of co-substrate with greater values of zero-order rate constant observed for sucrose compared to glucose at higher 4-CP concentration. The interaction effects of two factors, namely initial 4-CP and co-substrate concentrations ranging from 100-500 mg l -1 and 0-1000 mg l -1 , respectively, on the biodegradation kinetics were examined by using response surface methodology (RSM). For glucose, the kinetics was found dependent on the 4-CP initial concentration. The optimised condition for 4-CP biodegradation in the presence of glucose was: 200 mg l -1 4-CP and 750 mg l -1 glucose with rate constant of 7.630 mg l -1 h -1 .