Abstract

The role of Aspergillus niger (fungus) and the use of 0.2 M sodium nitrate and 0.2 M sodium nitrite as nutrients on the bioremediation of petroleum hydrocarbon polluted water was investigated in this study. 2 samples of petroleum hydrocarbon polluted water each had 0.2 M NaNO₃ (aq) and 0.2 M NaNO₂ (aq) and A. nigeradded and a control was monitored over a period of 49 days for physicochemical parameters such as Biological Oxygen Demand (BOD), Total Hydrocarbon Content (THC) and pH as indicators of the degree of bioremediation. The results obtained showed the sample amended with 0.2 M NaNO₃ (aq) gave a reduction in BOD of 98.4% (1760 - 28 mg/l) compared with that amended with 0.2 M NaNO₂(aq) which gave a BOD reduction of 97.4% (1760 - 46 mg/l). The sample remediated with 0.2 M sodium nitrate showed the greatest reduction in THC of 97.5% (282 - 7.0 mg/l) compared to 94% (282 - 17 mg/l) and 79.5% (282 - 58 mg/l) for the sample with 0.2 M sodium nitrite and control respectively. The pH of all samples fell within acceptable limit of 6 - 9 as stipulated by regulatory agencies such as FEPA and DPR. Over a period of 49 days of study only sample amended with 0.2 M sodium nitrate gave BOD and THC values that fell within stipulated values of 30 and 10 mg/l respectively by FEPA and DPR.

Key words: Bioremediation, efficiency of nutrients, Aspergillus niger, environment.