Kinetic study of the anaerobic degradation of toluene by a mixed culture

Abstract

Toluene was anaerobically degraded by an enriched mixed culture under methanogenic conditions. The mixed culture was originally developed from cow-dung and sludge from a laboratory reactor, in which benzene was anaerobically degraded by sulphate-reducing bacteria. First the mixed culture was enriched on toluene over a year with and without the use of sulphate in the medium. For the evaluation of growth-kinetic and maintenance parameters, namely μ max , K S , k d and Y o X/S , the anaerobic degradation of toluene was carried out in batch as well as in continuous reactor systems. The gas volume and the methane content in the produced gas was somewhat lower than the theoretical value expected, indicating an incomplete degradation of some of the complex intermediates of the toluene degradation pathway. However, the mixed culture was able to transform 41.3% of the toluene carbon into methane.