Comparative study on bioaccumulation and translocation of metals in Bermuda grass (Cynodon Dactylon) naturally growing on fly ash lagoon and topsoil

Abstract

Cynodon dactylon (Bermuda grass) is one of the most common naturally colonized creeper grass found on fly ash lagoons and soils in India. Bioavailable metal concentrations in fly ash and topsoil were analyzed by using DTPA as extractant. Bioaccumulation of metals in the root and their translocation to the shoot were estimated for fly ash and compared with topsoil. Bioaccumulation of Zn, Mn, Ni and Cu were found similar for the plants growing on fly ash and topsoil. Different bioaccumulation trends were observed for Pb, Co and Cd, in fly ash and topsoil. In fly ash translocation factors were found >1 for Cd, Mn, Zn and Cu, indicating a higher translocation of these metals in aerial parts, which can easily transfer to the food chain. In topsoil, translocation factor for all the metals (except Cd) was found <1, indicating immobilization of metals in root. The study concluded that Bermuda grass growing on fly ash lagoons can act as a transferring link of heavy metals in the food chain.