Growth kinetics of an indigenous mixed microbial consortium during phenol degradation in a batch reactor

Biodegradation of phenol by a mixed microbial culture, isolated from a sewage treatment plant, was investigated in batch shake flasks. A minimum concentration of 100 and a maximum of 800 mg 1−1 of phenol in the media were adapted in the degradation study. The phenol degradation rate varied largely and was less than 10 mg l−1 h−1 at both extremes of the initial concentrations in the media. The degradation rate was maximum 15.7 mg l−1 h−1 at 400 mg l−1 phenol. The culture followed substrate inhibition kinetics and the specific growth rate were fitted to Haldane and Han–Levenspiel models. Between the two models the Han–Levenspiel was found to be a better fit with a root mean square error of 0.0211. The biokinetics constants estimated using these models showed good potential of the mixed microbial culture in phenol degradation.