Bioremediation of in-situ crude oil contaminated soil using selected organic dung

Abstract

THE potential of cow, pig and poultry dung for the bioremediation of in-situ crude oil contaminated soil for a period of 3-15 days at different soil and dung ratios were the objectives of this investigation. Using simulated soil, 200 g were measured into polyethylene bags labelled A,B,C,D,E, F and G. Soil physicochemical parameters such as particle size distribution, pH, organic carbon, organic matter, nitrogen and phosphorus were analysed using standard methods. Total Petroleum Hydrocarbon (TPH) concentrations were analyzed using spectrophotometry method at 420 nm. The concentrations of TPH decreased progressively with an increase in dung and time in the order cow dung > pig dung > poultry dung except the control soil that showed slight TPH reduction. Results also show that biostimulant efficiency (BE) increases with increase in dung and reduces with time. Results also reveal that dung with high bioremediation constant recorded a corresponding short half-life. Results show that there is a significant difference (P < 0.05) between dung type and stimulation time. Similarly, there is no significant difference (P > 0.05) in amended soil and time for poultry dung except for cow and pig dung. This study has shown that cow dung is more effective in bioremediation of TPH in crude oil contaminated soil.