Phytotreatment of water contaminated with waste lubricating oil using Pistia stratiotes

ABSTRACT Auto-mechanic service workshops in Nigeria tend to spill waste lubricating oil into the soil. The waste lubricating oil is washed into nearby streams by runoff leading to water pollution. The current study is aimed at assessing the performance and response of P. stratiotes in the remediation of water contaminated with waste lubricating oil. The contaminated water used for this study is a product of an artificial spillage of surface water and different volumes (30, 60, 90, 120 and 150 mL) of waste lubricating oil. The reduction efficiency, biotranslocation, bioconcentration factor, relative growth rate and the enzymatic and non-enzymatic response of P. stratiotes were determined. The results show that the efficiency of P. stratiotes in improving the quality of the contaminated water increases with an increase in the retention time of P. stratiotes but decreases with an increase in the volume of used lubricating oil. The result also shows an increase in the growth rate of P. stratiotes with increasing retention time but a decrease with an increased volume of used engine oil. The study also shows that P. stratiotes can counteract any effect induced by the pollutants in the contaminated water through antioxidant and non-antioxidant responses.