Impact of Nutrients, Aeration and Agitation on the Bioremediation of Crude Oil Polluted Water Using Mixed Microbial Culture

Crude oil polluted water was treated using a bioremediation strategy encompassing natural attenuation and biostimulation using a mixed microbial culture of Aspergillus niger and Pseudomonas aeruginosa. Four (4) samples of petroleum hydrocarbon polluted water; Control (no nutrient), A (nutrient from NPK 15:15:15), B (nutrient plus aeration), and C (nutrient, aeration and agitation) were monitored for 8 weeks for bioremediation indicating parameters such as Biological Oxygen Demand (BOD), Dissolved Oxygen (DO), Total Hydrocarbon Content (THC) and pH. The results obtained showed an increase in DO levels of 86.4, 87.0 and 87.5 % for samples A, B, and C respectively. The BOD of the samples was observed to decrease in the course of bioremediation with reduction levels of 98.6, 98.7 and 98.8% recorded for samples A, B, and C respectively. Reductions in THC corresponded to 92.3, 93.6, and 94.4% respectively for samples A, B and C. The pH of all samples fell within the acceptable limit of 6-9 as stipulated by regulatory agencies such as the Federal Environmental Protection Agency (FEPA) and the department of petroleum resources (DPR). The final values of BOD and THC fell within the values of 30 and 10 mg/l respectively stipulated by FEPA and DPR with the exception of sample A which had a final THC value of 14 mg/l.