The assessment of the concentrations of contaminated heavy metals in the stream sediments of the Akashi River system

Abstract

Concentrations of contaminated heavy metals (Cu, Pb, Zn, Cd, Cr, Mn, Ni, Co) in the stream sediments at 21 points of the Akashi River system (Akashi River and Ikawa River) are determined for the assessment of the environmental pollution. These stream sediments were sieved into the three fractions: <63 μm, 63∼125 μm, and 125∼250 μm sized grains. Then the analyses of the heavy metal concentrations were performed after the standard procedure for the environmental analyses. The finest portions of all the analyzed sites show the higher concentrations of the heavy metals than the other two divisions. The loss on ignition (LOI) at 600°C is positively correlated with the metal concentrations. Among the analyzed elements, the correlation for Cd is stronger than the correlations for the other elements. Correlation coefficients for all the analyzed elements are higher than those between LOI values at 1200°C and heavy metal concentrations.