EVALUATION OF THE BIOAUGMENTATION OF CONTAMINATED SOILS WITH PETROLEUM PRODUCTS BY ISOLATED BACTERIA FROM ACTIVATED SLUDGE OBTAINED FROM MUNICIPAL WASTEWATER TREATMENT IN ASALOUYEH REGION IN IRAN

Diesel oil, gasoline and kerosene are the most common petroleum pollutants. Increasing growth of industrial activities resulted in the entrance of these compounds into the environment. They are considered as environmental threatening agents because of their toxicity and carcinogenicity properties. Bioremediation is an effective method for petroleum pollution reduction among all purification method. The object of the present study was to isolate petroleum degrading bacteria from activated sludge and to use them for bioagumentation experiments and survey the reduction of total petroleum hydrocarbons (TPHs) in polluted soils. Samples were collected from two activated sludge treatment plants in Asalouyeh region, Busher, Iran. Isolation of degrading bacteria was performed by culturing the samples on mineral base medium. For bioremediation rate measurements, isolated bacteria were inoculated to oil polluted soils. Degradation rate was measured by IR spectroscopy device. In this study, some degrading bacteria were isolated and identified such as Acintobacter lowffi, Alcaligenes faecalls, Bacillus sp., Corynebacterium sp. and Pseudomonas sp. Highest TPHs reduction (85.28%) in the inoculated soils was observed by a consortium of five bacteria during 45 days. Bacillus sp. and Pseudomonas sp. were introduced as the strongest bacteria respectively. The findings of the present study indicated that exogenous isolated bacteria from activated sludge have high capability for bioagumentation and bioremediation of petroleum hydrocarbons polluted soils.