Chemical Speciation and Fractionation Study of Heavy Metals in Top Sediment Deposit of Owena River, Nigeria

This study investigates the chemical speciation and fractionation of heavy metals (Cd, Cr, Cu, Ni and Pb) in relation to their levels of pollution from six different locations along the course of Owena River during the dry and wet season of 2015. The top sediment deposit was subjected to sequential extraction and the heavy metals were identified and quantified using atomic absorption spectrophotometer. The concentration of the analyzed heavy metals in the top sediment deposit were found to occur below the maximum permissible limit of the Dutch reference standard for soil/sediment, thereby the sediment collected from Owena river is not contaminated with the analyzed heavy metals. The overall results of this research suggest that the mobility and bioavailability of heavy metals in sediment collected from Owena River decreases in the following order: Cu > Pb > Cr > Cd > Ni.