Phytoremediation potential of some abundantly growing indigenous herbs of crude oil contaminated sites

Abstract

Aim: To study the total oil and grease (TOGs) removal potential of three abundant herb species of crude oil contaminated sites, namely Xanthium strumarium (L.), Ageratum conyzoides (L.) and Polygonum hydropiper (L.) from oil contaminated soils. Methodology: The pot experiment was carried out by taking soil samples of crude oil contaminated agricultural field. For each experimental plant, three replicas were maintained and a similar control setup was maintained without plants for comparing the results. Another control set up was maintained in non-contaminated soils to compare the plant growth parameters. Total oil and grease (TOG) contents, physico-chemical profiles of contaminated soil, plant growth/productivity parameters and functional groups were analyzed following the standard methods. Results: The results showed that total oil and grease (TOG) contents decreased significantly after treatments by plants against the initial level and control. Plant height, number of leaves, chlorophyll contents and biomass were found to be lower in all the three plant species that were grown in contaminated soil as against the control treatment. The improved physico-chemical profiles of contaminated soil samples after treatment indicated the positive effect of plants in treated soil samples. FTIR data revealed difference in peak intensities and the presence of petroleum hydrocarbons in plants that were grown in oil-contaminated soils. Interpretation: The herb species Xanthium strumarium, Ageratum conyzoides and Polygonum hydropiper showed the potential for removal of hydrocarbons from crude oil contaminated soil. Key words: Crude oil, Hydrocarbons, Indigenous herbs, Phytoremediation