Heavy Metal Concentrations (Cu, Cd and Pb) in Sediments in the Juru River, Penang, Malaysia

The purpose of this study were to determine the concentration of heavy metals namely copper (Cu), cadmium (Cd) and lead (Pb) in sediment and to investigate the effect of sediment pH and sediment organic matter on concentration of copper, cadmium and lead in sediment at oxidation fraction from Juru River, Penang, Malaysia. The sequential extraction procedure used in this study was based on defined fractions: exchangeable, acid reduction, oxidation and residual. The concentration of Cu, Pb and Cd in residual fraction were higher than the other fractions. Among the non-residual fractions, the concentration of heavy metals in organic matter fraction was much higher than other fractions collected from all sampling sites except for Cd. The pH of the sediment in all sites was acidic. The mean of total concentrations of Cu, Cd and Pb for the two sampling times were 667, 4.135 and Pb 927 μg g-1 dry weight, respectively. Results of organic matter analysis showed that the percentage of organic matter present in sediment samples varied throughout the river and all sites of sediments were ranged from 7.10 to 16.20%. Comparison between sampling sites using one-way analysis of variance showed that there were significant differences at exchangeable fraction for cadmium and lead while there was no significant differences for copper. At acid reduction fraction and oxidation fraction there were significant differences for the three metals while there was no significant difference at residual fraction.