BIOREMEDIATION OF SOIL CONTAMINATED WITH ESCRAVOS AND URALS CRUDE OILS USING OIL-FREE MORINGA OLEIFERA AND SOYA-BEAN CAKES

A study was carried out on the comparison of biodegradation potentials of a typical soil artificially contaminated with Escravos and Urals crude oils using natural stimulants from plant sources namely oil-free Moringaoleifera and Soya-bean cakes. The study was carried out in microcosms (i.e. improvised wooden boxes) employing land farming bioremediation technology. The total petroleum hydrocarbon (TPH) and the total heterotrophic bacteria count (THBC) were used as indicators of bioremediation. Results of the TPH removal revealed that both natural bio-stimulants i.e. oil-free Moringaoleifera cake and oil-free Soya bean cake were better bio-stimulants (89-98% degradation of the initial TPH achieved in 12 weeks) than NPK, 20:10:10 (maximum of 86% degradation of the initial TPH achieved in 12 weeks) in this study. In addition, from the biodegradation efficiencies obtained, it can be inferred that Escravos crude oil was more amenable to bioremediation than Urals crude oil.