Physicochemical and microbial alterations in crude oil-contaminated soil samples

Abstract

Environmental pollution is becoming an issue of concern due to its negative impact on the living and non-living components of the environment. Crude oil and its products are the major sources of environmental pollution that renders negative impact on the soil mineral components and microorganism. This study was thus carried out to determine the effect of crude oil on soil physicochemical properties, bacterial and fungal population. The experiment lasted for 42 days and the analysis were carried out at days 0, 14, 28 and 42 using standard protocols. Results obtained show significant changes (P ≤ 0.05) in hydrocarbons and other physicochemical parameters such as pH, nitrate, electrical conductivity, sodium ion, calcium ion, phosphate and magnesium ion, when the control was compared with crude oil contaminated soil. Also, soil bacterial and fungal count decreased significantly (P ≤ 0.05) with increasing concentrations of crude oil indicating its toxicity to soil microbial consortium. However, results also showed that hydrocarbon-degrading microorganisms strived at higher concentrations but insignificantly (P ≤ 0.05) in comparison with the control. Owing to the result obtained in this study, crude oil exploration should be properly managed to prevent spillages that negatively impact on the environment.