Heavy metals bioavailability and phyto-accumulation potentials of selected plants on burrow-pit dumpsites in Aba and Ntigha Dumpsite in Isiala Ngwa of Abia State, Nigeria

Abstract

In this study, dumpsite soil physicochemical parameters, eight heavy metals speciation and soil-plant transfer of five plants species were investigated. The soil and plants parts (roots, stem and leaves) obtained from burrow-pit dumpsite in Aba and Ntigha dumpsite in Isiala Ngwa as well as a nearby farm land (control site) were subjected to standard methods of chemical analysis. Results obtained showed that mean pH, electrical conductivity, moisture, cation exchange capacity, total organic carbon, total organic matter, phosphate, sulphate, carbon:nitrogen ratio and total extractable metal for Cd, Cu, Mn, Pb, Zn, Fe, Ni, and Cr were significantly higher (P < 0.05) in the dumpsites compared to control site. Sequential extraction showed higher percentages of the non-residual fraction for all the metals studied except Cu. The order of mobility and bioavailability of these metals were: Cd > Fe > Pb > Mn > Zn > Cr > Ni > Cu. Total mean concentration of metals in different parts of Amaranthus hybridus, Talinum triangulare, Carica papaya, Ipomea batatas and Luffa aegyptica were significantly higher (P < 0.05) in the dumpsites compared to control site. The translocation factor, biological concentration factor and biological accumulation coefficient values of the plant species varied for all the metals. These results imply that pollution of an environment by dumpsites has health and ecological risks and that the plants studied could be used for environmental friendly phytoremediation technologies.