assessment bioremediation of contaminated soils to petroleum compounds and role of chemical fertilizers in the decomposition process

today oil removal from contaminated soil by new methods such as bioremediation is necessary.  in this paper, the effect of chemical fertilizers and aeration on bioremediation of oil-contaminated soil has been investigated. also the control group, (bioremediation of petroleum hydrocarbons in contaminated soil without treatment by chemical fertilizers and aeration treatment was examined. the condition of experiment is as following: those were treated 70 days in glass columns (30×30×30cm dimensions), ambient temperature (25-30 0 c), relative humidity 70%, aeration operation with flow 0.7 lit/min.  the total number of heterotrophic bacteria of break down oil and the total of petroleum hydrocarbons were analyzed using gas chromatography analysis. all experiments were replicated three times. the microbial population results for control soil, treated soil by aeration and treated soil by aeration and chemical fertilizers columns are 2.3×10 5 , 1.04×10 10 , and 1.14×10 11 cfu/gr, respectively. the concentrations of total petroleum hydrocarbons of remaining are 46965, 38124, and 22187 mg kg -1 respectively. the obtained results show that the aeration operation and chemical fertilizers have effective role on degradation of petroleum hydrocarbon by oil degrading bacteria from soil.