Phytoremedial potentials of Ipomoea aquatica and Colocasia esculenta in soils contaminated with heavy metals through automobile painting, repairing and service centres

Abstract

Heavy metal pollution is one of the biggest environmental issues at present. The study was conducted with the objectives of evaluation of soil contamination of heavy metals with Cu, Zn, Pb, Mn, Cr and Fe by automobile repairing, painting and service centres in Kandy area, Sri Lanka, and the phytoremediation potential of using Ipomoea aquatica and Colocasia esculenta in such soils. Soil and plant samples from ten sites associated with these industries were analyzed for the Cu, Zn, Pb, Mn, Cr and Fe concentrations and Bioconcentration (BCF) and the translocation factors (TF) were determined.The soils associated with these nutrients were highly contaminated with all the heavy metals studied and both plant species accumulated these heavy metals in different concentrations. The automobile repairing centres caused highest pollution by Cu, Mn and Cr, automobile painting centres caused highest pollution by Pb and Zn, and automobile service stations caused highest pollution by Cr and Fe. Fe concentration was the highest in contaminated soils. Heavy metals were accumulated in all plant parts, roots containing the highest concentrations. Considering the TF and BCF, I. aquatica was identified to be suitable for phytoextraction of Cu and Mn, while C. esculenta was found to be suitable for phytostabilization of Cu, Pb, Mn, Fe and Zn. Uncontrolled release of waste containing heavy metal pollutants, and consequences of I. aquatica and C. esculenta growing in such contaminated sites may cause heavy health hazards.