Metal speciation in Jhanji River sediments

The chemical forms of Lead, Zinc, Chromium, Cobalt, Nickel and Copper have been determined using the fractionation scheme of Tessier et al. (1979) and Chao (1972) in the bed sediments of Jhanji River, Assam, India. Almost a similar trend throughout the stretch with no significant spatial variation has been observed in the present study. Significant association with the residual fraction (F5) and a scavenging action by the Fe-Mn oxide fraction (F3b) of the sediments were observed. Except copper, no significant association of other metals with the organic fraction (F4) was observed. Thus, they cannot be easily leached out and may pose less environmental risk. The sediment characteristics played a significant role in defining the chemical forms of the metals present in the sediments.