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

Abstract

Biodegradation of methylene chloride by a mixed microbial culture, isolated from a common sewage treatment plant, was investigated in a batch system. Batch experiments were performed at room temperature (27 °C) and pH value of 7. The methylene chloride concentration in growth media varied from 25 mgl⁻¹ to 250mgl⁻¹. A maximum observed degradation was 1 mgl⁻¹h⁻¹ at 100 mgl⁻¹ of methylene chloride. The culture followed substrate inhibition kinetics and specific growth rate were fitted to different substrate inhibition models (Haldane, Aiba and Edwards models) by MATLAB 7.1@. Among all models, Haldane was found to better fit with root mean square of 0.947. The biokinetic constants estimated using these models show good potential of the mixed microbial culture in methylene Chloride degradation. Escherichia coli and Staphylococcus aureus are predominant microbes present in the mixed culture.