Batch biodegradation of toluene by mixed microbial consortia and its kinetics

Biodegradation of toluene in a batch system by mixed microbial culture isolated from cow dung compost was investigated. Batch biodegradation of toluene was carried out at various initial concentrations ranging from 50 to 500 mg l(-1) at room temperature (28 degrees C) with initial a pH value of 6.85 maximum observed specific growth rate was 0.062 h(-1) and maximum removal efficiency of toluene was 84% at 100 mg l(-1). Biochemical characterizations were carried out by different sugar fermentation tests to identify the microorganisms responsible for biodegradation of toluene. Pseudomonas species, Bacillus species and Escherichia coli were found to be dominant strains among the mixed culture. The effect of pH and inoculum size on biodegradation of toluene at initial concentration of 100 mg l(-1) was also studied. Different substrate inhibition models (Haldane, Edwards and Levenspiel) were fitted with the experimental data. (C) 2016 Elsevier Ltd. All rights reserved.