An investigation into the ex-situ bioremediation of crude oil polluted soil using algal species was carried out. The bioremediation was initiated by spilling crude oil on both sterilized soil (SS) and unsterilized soil (UNS) and inoculating with crude oil degrading micro-algal species of Aphanocapsa elachista. The total heterotrophic count was carried out in both the SS and UNS by viable count. Aliphatic hydrocarbon in the remediated soil was determined by gas chromatography Hewlett-Packard HP 6890 model equipped with FID at initial temperature of 650C and final temperature of 3000C. The heterotrophic count in the SS was initially 1.90 x 104 cfu/ml and biweekly measurement for six weeks gave 3.51 x 104, 4.26 x 104 and 3.01 x 104 cfu/ml respectively. The UNS sample gave initial count of 1.92 x 104 cfu/ml and the biweekly measurement for 6 weeks gave 2.69 x 104, 2.83 x 104 and 2.24 x 104 cfu/ml respectively. The gas chromatographic analysis showed a decrease in total hydrocarbon from 863.68402 mg/ml on zero day to 596.76653 mg/ml in the week six sample. Analysis of the sterilized soil showed a decrease of physicochemical parameters after bioremediation.The research concludes that Aphanocapsa elachista algal species had the potentials for ex-situ bioremediation of crude oil polluted soils.
