Investigation on speciation and pollution index of heavy metals in River Ala sediment, Akure, Nigeria

Abstract

This study investigated the chemical speciation of Cd, Cr, Cu, Ni and Pb and their contamination/pollution indices in the sediment of River Ala in Akure, Nigeria. Sediment samples taken along the course of the river were subjected to Sequential Extraction Technique and the heavy metals were quantified using atomic absorption spectrophotometer. Varied distribution of metals among the chemical fractions was recorded, with contribution from both anthropogenic and geogenic sources to the total heavy metals concentration in the sediment. Pollution/contamination index evaluation showed that the sediment fall within the “very slight and “moderate contamination” range with respect to Cr, Cu, Ni and Pb and in the moderate pollution range with
Cd.