Effect of clay and biosurfactant on the biodegradation of toluene

In this study, non-aseptic biodegradation of toluene, a priority pollutant, was investigated in continuously stirred batch reactors. Activated sludge (mixed culture) from a wastewater treatment plant was first acclimated to used motor oil in several stages before using it for biodegrading toluene degradation. Since the biodegradation rates may be affected by the fine particles in water, the effect of a clay suspension on the biodegradation process was investigated. Also the role of a biosurfactant, which was produced under non-aseptic condition, in the degradation of toluene was investigated. The toluene concentrations were measured using a gas chromatography. During the biodegradation change in total organic carbon (TOC) in the reactors were also monitored. Toluene up to 100 mg/l was biodegraded and literature review indicates that this is one of the highest concentration of toluene biodegraded so far. The lag time for toluene degradation increased with initial toluene concentration. The presence of 2 g/l kaolinite clay suspension affects the biodegradation of toluene. But the biosurfactant did not inhibit the degradation of toluene at the concentrations used.