Biodegradation of automobile service station wastewater

Abstract

Oil and greases are released from automobile service stations into terrestrial and aquatic environment and they severely damages the surrounding ecosystems. In this research, the initial characteristics of automobile wastewater were analyzed and Pseudomonas aeruginosa was isolated and inoculated into wastewater, whereas 50% of oil degradation was observed under the optimized growth conditions at pH 7 of 48 h. Addition of optimized dosage of 0.2 mL glycerol as a carbon source and 0.1 mL surfactant results in oil degradation of 72 and 61%, respectively. A combination of carbon source and surfactant was found to be the most effective treatment, leading to 93% of oil degradation. Further, treated wastewater was subjected to conventional sequential batch reactor, best effluent quality was obtained at 10 h of hydraulic retention and 10 days of solid retention resulting in COD = 100 mg/L and TSS = 85 mg/L, which meets the requirements of the discharge standard.