Biodegradation of Spent Automobile Engine Oil in Soil Microcosms Amended with Cow Dung

The discharge of spent engine oil in terrestrial and aquatic environments constitutes public health socio-economic hazards. In this study, the potentials organic waste (cow dung) amendments as biostimulating agents indigenous microflora for hydrocarbon biodegradation soil microcosms deliberately contaminated with (5%v/w) was investigated a period 6 weeks. Physico-chemical microbiological analysis samples determined using standard methods. A microcosm constructed consists 8 trays containing 1kg soil, artificially 50ml treated 50g, 100g 150g cow dung. Spent degradation assessed gravimetrically at weekly interval chromatographically after weeks treatment. Results physico-chemical showed that pH 6.56 while nitrate, moisture content, phosphate total content were 0.82mg/kg, 9.28%, 0.73mg/kg 3.60mg/kg respectively. Microbiological sample heterotrophic bacteria 3.6x106cfu/g, fungal utilizing (HUB) 2.2x104cfu/g 7.9 x104cfu/g mean value viable counts (TVC) population hydrocarbon-utilizers higher biostimulated which ranged from (2.10x105-5.30x109cfu/g) compared control (1.20x105-3.10x108cfu/g). Residual concentration more remarkable decrease throughout incubation (0.400-0.259mg/g, 0.420-0.218mg/g 0.410-0.220mg/g treatments 1, 2 3 respectively) when to 0.400-0.304mg/g. At end studies, percentage degradations 23.81%, 35.29%, 45.45% 44.94% CON, T1, T2 T3 result obtained study dung can be effectively used biostimulant during bioremediation polluted site enhance ability microbial population.