SUMMARY
In this study, a physico-chemical analysis of untreated and treated phenol-containing waste water samples from a Nigerian Refinery was carried out and the biodegradation of the constituent phenol using two Pseudomonas species were investigated in batch processes. The results of the physico-chemical analysis of the raw water and the treated water showed the phenolic content, BOD at 20oC, sulphide content, Total suspended solids. Total dissolved solid Phosphate content and Ammonia content for the raw water to be 28.4ppm, 94mg/L, 5.15ppm, 248ppm, 1196ppm, 10.36ppm, 2.16ppm and for the treated water to be 7.26ppm, 82mg/L, 2.84ppm, 116ppm, 1148ppm, 3.77ppm, 0.52ppm respectively. This results indicate that even though the installed treatment plant was very efficient for phenol removal by removing 74.44% of initial phenol concentration of the untreated waste water, the resultant treated water phenol concentration failed to comply with the Federal Environmental Protection Agency (FEPA) limit. Subsequent the aerobic chemoheterotropic growth of both pseudomonas aeruginosa and pseudomonas fluorescens on a formulated basal medium using the wastewater samples was investigated. During the batch growth processes, the wastewater samples were supplemented with nutrients, the culture of organisms were added and the progress followed for 48hrs. samples were withdrawn at regular intervals of 6hrs and analyzed for biomass and phenol concentrations. The data obtained were used to estimate the