The use of indigenous hydrocarbon utilizing bacteria in bioreactor-based bioremediation of hydrocarbon-polluted soil of Awoye, Ondo State, Nigeria

Abstract

Petroleum exploration in riverine areas of Ondo State have caused numerous problems by generating hazardous waste pollution that endangers plants, animals, and human lives. The aim of this study was to isolate indigenous hydrocarbon utilizing bacteria from oil polluted soil and use them in bioreactor-based bioremediation of hydrocarbon-polluted soil of Awoye, Ondo State, Nigeria. Soil samples were collected from Awoye community using standard techniques. The bacteria from the soil were identified using cultural and molecular methods. Proteus mirabilis, Escherichia fergusonii, Klebsiella pneumoniae and Clostridium sporogenes were identified. The four bacterial isolates were then tested in three bioremediation treatments of oil polluted soils inside 5 litres stirred tank bioreactors labeled Awoye soil on Natural attenuation (AWNA), Awoye soil on Bioaugmentation (AWBA) and Awoye soil whose contents have been heat killed (AWHK) over a 56 - day period. In the AWNA treatment, the Total Petroleum Hydrocarbon (TPH) decreased by 59.04 % while it was 78.33 % in the AWBA treatment and 3 % reduction in TPH content of the AWHK treatment. It was concluded that the oil polluted soils have inherent bacteria group that can utilize hydrocarbon as carbon source and can be used for bioremediation of oil polluted soil.