Bioremediation of Crude Oil Contaminated Soil Using Cow Dung

Crude oil contaminated soils were obtained from an oil pit in Burutu L.G.A. of Delta State and the Cow dung was collected from Garki slaughterhouse along Benin-Sapele-Warri road Delta, Nigeria. The samples were sundried for a period of one week and kept in the laboratory. 500g of crude oil contaminated soil was weighed into four different containers labeled A, B, C and D. The soil was amended with the application of cow dung at various weights of 100g, 150g and 200g/kg respectively leaving sample D without amendment which served as the control for a period of 10 weeks. The microbiological and physiological analysis of crude oil contaminated soil amended with cow dung was investigated using standard cultural techniques. The Total Heterotrophic Bacterial count for the samples A, B, C and D treatment options increased from (8.1 x106–9.2x106cfu/g), (8.1x106–9.5x106cfu/g), (8.1x106–9.6x 106cfu/g) and (8.1 x 106–8.9x106cfu/g) respectively. The Total Hydrocarbon Utilizing Bacterial Count for the A, B, C, and D treatment options increased from (4.2 x106 –7.6x106cfu/g), (4.2x106–8.0x106cfu/g), (4.2 x 106–8.5 x 106cfu/g) respectively and sample D control increased slightly (4.2x106–4.9x106). The Nitrate concentration increased from (0.04mg/kg to 0.11mg /kg). Phosphate concentration also increased from (1.72mg/kg to 5.72mg/kg). Percentage loss of total hydrocarbon for the three treatment options A, B and C at the end of 10 weeks were 29.3%, 44.13% and 68% respectively. From the results obtained it can be concluded that cow dung has demonstrated high potential in enhancing bioremediation of crude oil contaminated soil.