Bioremediation of Crude Oil Contaminated Soil Using Pleurotuspulmonarius, a White-rot Fungus

This study was conducted to investigate the extent of degradation of crude oil in contaminated soil by harnessing the remedial potential of Pleurotuspulmonarius when grown in soil with saw dust and rice bran as amendment additives. Physico-chemical parameters such as pH, total organic carbon (%TOC), total organic matter (%TOM), total nitrogen (TN), available phosphorus (P), available potassium (K) and total petroleum hydrocarbon (TPH) of the contaminated soil and soil amended with saw dust and rice bran were monitored during the study period. Homogenized sterilized soil (700g) each was amended with 150 g of saw dust, rice bran and inoculated with P.pulmonariusspawn,to establish A (soil + saw dust + rice bran + P.pulmonarius), B (soil + rice bran + P.pulmonarius), C (soil + saw dust + P.pulmonarius) and D (soil + saw dust + rice bran) experimental set-up. The experiment was allowed to run for 60 days with periodic sampling every 15 days intervals for analysis. The results revealed a sharp decrease in TPH concentration after 15 days, which progressively decreased further over the subsequent sampling intervals; with a corresponding increase in the removal rate of nitrogen, phosphorus and potassium. Set-up A and D emerged as the maximum and minimum for the removal of TPH components at the end of the bioremediation process as illustrated in the order: A (90.12%) > B (77.42%) > C (72.20%) > D (9.98%). It was observed that the saw dust and rice bran blend had sufficient amounts of nitrogen, phosphorus and potassium (NPK) to sustain biodegradation of crude oil components in the contaminated soil. Biodegradation of the hydrocarbon components of the crude oil was confirmed using gas chromatography and reduction of crude fractions with carbon atoms ranging from C10-C40 was observed. This study showed that P.pulmonarius is effective at decontaminating crude oil polluted soil.