Bioremediation of Soils Contaminated with Hydro Carbon (Oil Spillage) in Nigeria

Abstract

The aim of the study was to determine the rate at which bioremediation of hydrocarbon occurs in a polluted soil medium and also to examined the effects of organic substrate such as cow dung on the bioremediation processes. A pot experiment (CRD) was conducted for four weeks on two group bases, group1 contained the polluted soil and group 2 contained polluted soil amended with organic substrate (cow dung). In the group 1 experiment, the nitrate concentration of 8.4 mg/g at zero day of the experiment to 6.24mg/g at week 4, phosphate concentration decreased from 5.2mg/g to 4.4mg/g, TOC reduced from 3.9% to 2.28%, pH reduced from 7.8 to 7.5 and the total petroleum hydrocarbon reduced from 0% to 18% to 22% to 29% and 29% at week zero, week 1, week 2, week 3 and week 4 respectively. Group 2 experiment, the pH increased from 6.8 to a neutral range of 7.1 at week 4, the nitrate concentration, phosphate concentration and TOC reduced drastically from week zero to week four at 14.72mg/g to 4.2mg/g, 10.81mg/g to 2.42mg/g, and 6.44% to 1.28% respectively. The TPH in the group 2 experiment shows a lost in TPH of 32%, 68%, 89% and 98% at week 1, week 2, week 3 and week 4 respectively. The study showed that a natural bioremediation process occurs in the soil and that the bioremediation process could be further enhanced by amending the polluted soil with organic substrates such as cow dung.