Biodegradation of Benzene by an Indigenous Microorganism in a Batch Reactor

Abstract

Biodegradation of benzene by an indigenous culture isolated from municipal waste water treatment plant was investigated in a batch shake flasks. Benzene with lower concentration of 25 mg l-1 and higher concentration of 600 mg l-1 were acclimatized in the enrichment medium before the biodegradation in batch reactor. The degradation rate (D) and specific growth rate (μ) were maximum, i.e. 15.857 mg l-1 h-1 and 0.02696 h-1, respectively at 300 mg l-1. At higher concentration, D and μ decreased due to substrate inhibition and at lower concentration they were observed to be less due to lack of carbon source i.e benzene for growth of the culture. The experimental specific growth rates were fitted to Haldane and Edward models, from which Haldane model was found to be a better fit with root mean square error 0.0026. The biokinetics constants determined by these two models showed good potential of isolated culture of genera Aeromonas for biodegradation of benzene from waste streams.