ABSTRACT

Mycoremediation ofspent engine oil polluted soil was investigated using Pleurotus ostreatus for a period of 42 days with a view to ascertaining its efficacy in reducing the toxicity of polluted soils. Pasteurised soil samples (1000g) contained in four difference transparent buckets were contaminated with spent engine oil at 5, 10, 15, 20 and 25% v/w concentrations, inoculated with 80g ofPleurotus ostreatus mycelium and incubated for 42 days. Soil samples from the polluted soil were taken every 21 days for duration of forty-two days for analysis before and after the inoculation for the total percentage of petroleum hydrocarbons lost, the effect of pH in the biodegradation and examine the level of pollutant absorbed by Pleurotus ostraetus during the mycoremediation process. The result shows that there was a considerable reduction in the total percentage of spent engine oil for all oil-contaminated soils. The most considerable reduction was at 5% spent engine oil contamination with 38.65% reduction and the lowest was at 20% Contamination with 19.84% reduction when compared with the control. The impact ofPleurotus ostreatuson the soil pH was least in soil sample treated with 15% spent engine oil 5.90b±0.00 and the highest was at 5% spent engine oil treatment 5.41d±0.01. The final pH result of the soil samples was lower than the initial pH ofthe samples and the result also shows that two rounds of mushroom harvests that was made across all the polluted soil samples absorbed a considerable amount of spent engine oil, the highest absorption of spent engine oil by mycelia pellets was at 10% with 0.0214 rate of TPH absorption, whereas absorption was the lower at 5% with 0.018 rate of TPH absorption. Statistical analysis revealed significant differences between the inoculated samples and the controls, indicating degradation ofthe spent engine polluting oil.