Abstract

Mixed microbial culture collected from effluent treatment plant of a coke oven industry has been studied for its phenol biodegrading potential under aerobic condition in a batch reactor. The result showed that, after acclimatization, the culture could biodegrade up to 700 mg/l of phenol. The results showed that specific growth rate of microorganisms and specific substrate degradation rate increased up to 300 mg/l of initial phenol concentration and then started decreasing. The biodegradation kinetics is fitted to different substrate inhibition models by MATLAB 7.1^©. Among all models, Haldane model was best fitted (Root Mean Square Error = 0.0067) for phenol degradation. The different biodegradation constants (K_s, K_i, S_m, m_max, Y_X/S, k_d) estimated using these models showed good potential of the mixed microbial culture in phenol biodegradation.

Key words: Mixed culture, phenol biodegradation, kinetics, inhibition model.