Bioremediation of oil contaminated soil

Contamination of soil and ground water by Petroleum hydrocarbons is a serious and wide spread environmental problem. The United State Environmental Protection Agency (U.S EPA) has proposed various technological approaches for treating soil contaminated by petroleum hydrocarbons. Among them, bioremediation is a promising technology used to remediate oil contaminated soil that involves indigenous oil degrading microorganisms, especially Pseudomonas. In this study oil contaminated soil from a motor workshop site was taken to evaluate the effect of nutrients and bulking agent in the remediation of oil contaminated soil. The above said experiments were carried out in two reactors one with amendments and the other as a control plot. Vegetable waste and saw dust were added to the contaminated soil as the nutrient and bulking agent respectively in the ratio of 0.6:1 and 0.5:1. Neutral pH and 50% moisture content were maintained in both the reactors throughout the experiment. Oil content of the bioremediated soil was measured every 2 days during the period of study. Results indicated that the supplement of amendments significantly increased the indigenous microbial populations in soils, and thus enhanced the oil degradation. Maximum remediation occurred in the reactor with the amendments, where the oil removal efficiency was found to be 74%.