Phytoremediation Potential of Kenaf (Hibiscus Cannabinus) in Soil Contaminated with Used Lubricating Oil

Abstract

Soil and groundwater contamination incidences with petroleum and petrochemical based products are growing in frequency and quantity. One example is used lubricating oil from machineries. There is a growing demand to remediate the contaminated soil with in-situ phytoremediation. Therefore in this work, Hibiscus cannabinus was investigated for its potential to remove hydrocarbon and heavy metals from soil contaminated with 2.5% and 1% used lubricating oil and amended with organic wastes [banana skin (BS), brewery spent grain (BSG) and spent mushroom compost(SMC)] for a period of 90 days. Loss of 86.4% and 91.8% used lubricating oil was recorded in soil contaminated with 2.5% and 1% oil and amended with organic wastes respectively at the end of 90 days. However, 52.5% and 58.9% oil loss was recorded in unamended soil contaminated with 2.5% and 1% oil, respectively. The plant did not accumulate hydrocarbon from the soil but shows appreciable accumulation of Fe and Zn in the root and stem. 47.0 mg/kg and 2.37 mg/kg of Fe accumulated in the root and stem while 1.5 mg/kg and 1.64 mg/kg of Zn accumulated in roots and stems of H. cannabinus respectively at the end of the experiment. The results of this study suggest that H. cannabinus has high potential for remediation of hydrocarbon and heavy metal contaminated soil.