Ecology, Environment and Conservation Paper

SPECIATION OF TRACE METALS IN THE SURFACE SEDIMENTS OF CHITRAPUZHA, A TROPICAL TIDAL RIVER ON THE SOUTHWEST COAST OF INDIA

P.V. Joseph and Jacob Chacko

Abstract

The observed order of abundance was Zn > Ni > Cu > Pb.The speciation studies indicated selective accumulation of various metals in different phases of the sediments with spatial variability. Residual phase was found to be the prominent metal host for all metals. In the case of Pb, the residual phase accounted for 64% of the total Pb. Oxidizable phase was the second most important host for all the metals. Cu behaved in a different manner. Oxidizable phase was as significant as residual in the case of Cu. For Zn, all the geochemical phases were of comparable significance as metal host. 63% of total Zn was found to be in the environmentally labile fractions leaving only 37% in the residual fraction. Metal fractions of all the metals recorded comparatively higher concentrations in the industrial zone (zone 3) indicating anthropogenic inputs in this region. Metals generally showed lower concentrations for metal fractions at bar-mouth (station I).