TPH bioremediation by microbial consortium isolated from oil contaminated soil

A 36 L laboratory scale study was conducted in order to investigate the ability of indigenous microcosms to remediate oil pollutions. Hydrocarbon-degrading bacteria, adapted to grow and thrive in oil containing environments, have most important role in biological treatment of these kinds of pollutions. In this study bacillus and pseudomonas bacterial strains were isolated from oil contaminated soil sample during two steps; plate agar inoculation and aquatic inoculation. These bacterial strains could utilize crude petroleum hydrocarbons as sole source of carbon and energy. Biodegradation of Total Petroleum Hydrocarbons (TPH) was then followed in aerobic condition in a biological reactor contained bacterial strains isolated before. Effect of series parameters like pH, temperature, Hydraulic Residence Time (HRT), nutrients (nitrogen & phosphorus) on biodegradation process was investigated. Biodegradation of TPH with isolated bacteria showed a significant reduction of TPH level in treated samples. The tests revealed that it’s possible to degrade more than 99% of initial petroleum hydrocarbons (420 ppm) within 5 days with added nutrients. Least success was achieved without nutrients and very low or high pH. Also the results showed that isolated bacteria could be effective for bioremediation.

Keywords:

Total Petroleum Hydrocarbon (TPH) , bioremediation , microbial consortium , Hydraulic Residence Time M(HRT)