Microbial Population and Physicochemical Properties of Oil-polluted sites in selected areas of Niger Delta, Nigeria

Abstract

Oil spills are known to be the most important and widespread forms of pollution of agricultural lands and water bodies in the Niger Delta regions in Nigeria, due to the increasing demand for energy. This is an inevitable disaster which has to be attended to, in order to minimize its harmful effect on the ecosystem, thereby, conserving nature and sustaining livelihood. The aims of this study are to determine the growth of the indigenous bacteria and fungi from oil-polluted areas in Niger Delta, on kerosene, petrol and diesel and determine the physicochemical properties of the oil-polluted soils and waters bodies. Pour plate technique was employed for the enumeration of bacteria and fungi using Bushnell-Haas medium and Minimal Salt medium respectively. The culture media were supplemented with 2% oil (kerosene, diesel, and petrol) as sole source of carbon and energy. Physicochemical parameters of the environmental samples were analyzed on the environmental samples using standard chemical methods such as oven-drying method, EDTA titrimetric method and atomic absorption spectrophotometry. The growth of indigenous bacteria and fungi on the different oils confirms their degradative ability.  Hence, they are responsible for the degrading activity in the sites where the samples were collected. The physicochemical parameters obtained in this study revealed that the moisture contents and pH of the samples were optimum for oil degradation. The oil and grease found in the water samples show that the samples were polluted with oil and grease. The concentrations of phosphates and nitrates were low while the concentration of lead was high when compared with the recommended standard. In conclusion, the physicochemical analyses of the soil and water showed that the soils are not good for agriculture and the water, not good for consumption. This calls for immediate bioremediation of the affected areas using biostimulation.

Keywords: Microbial population, biostimulation, physicochemical parameters, degrading ability.