Phytoremediation of crude oil-contaminated soil with local plant species

Contamination of soil by crude oil is prevailing due to increasing petroleum-related activities. Soil contaminated by crude oil is often rendered unfit for habitation and agriculture due to health concerns. Phytoremediation has emerged as a cost-effective and uncomplicated method of remediating crude oil-contaminated soil. This study examines the potential of four local plant species in phytoremediation of crude oil-contaminated soil, i.e. Pteris vittata, Epipremnum aureum, Mucuna bracteata and Imperata cylindrica. Changes in the crude oil concentrations, pH and moisture of potted soil planted with the aforementioned species were tracked over six weeks. The results were compared against an un-vegetated pot of soil serving as control. The results showed that all vegetated pots had higher crude oil removal compared to the control. Epipremmum aureum demonstrated the highest ability of crude oil removal with 50.4% of crude oil removed, followed by Imperata cylindrica (39.5%), Pteris vittata (36%) and Mucuna bracteata (30.9%). The sequence of plant species in terms of increasing rate of crude oil removal is Pteris vittata, Imperata cylindrica, Mucuna bracteata and Epipremmum aureum. Soil moisture and pH fluctuated over small ranges. This study contributes to identification of local, readily-available plant species and their effectiveness for cost-effective phytoremediation of crude oil-contaminated soil.