Evaluation of biodegradation process: Comparative study between suspended and hybrid microorganism growth system in sequencing batch reactor (SBR) for removal of phenol

The treatment of toxic organic compound phenol through sequencing batch reactor (SBR) is known to be effective especially in aerobic conditions. The three major biological treatment processes under aerobic condition are suspended, attached and hybrid growth process. In this study, two different growth systems using laboratory scale aerobic sequencing batch reactors (SBR) were tested to evaluate the biodegradation efficiency of phenol. The objective of this study is to evaluate the performances of two SBR bioreactors with suspended (SG-SBR) and hybrid (HG-SBR) microorganism growth system for removal of phenol containing wastewater. The activated sludge containing microorganisms are maintained in suspension under the suspended system, while granular activated carbon (GAC) was added to promote the formation of biofilm in hybrid system. Both systems were operated with FILL:REACT:SETTLE:DRAW in the time ratio of 1:20:2:1 for a cycle time of 24 h. The average phenol removal were above 80% in the presence of 25 mg/L, 50 mg/L, 75 mg/L and 100 mg/L for both system. The kinetic studies conducted showed that HG-SBR minimized the inhibitory effect of phenol towards the biochemical activities of the microorganisms compared to SG-SBR. (C) 2016 Elsevier B.V. All rights reserved.