Vertical distribution of heavy metals in core sediments from Kelantan River off Tanah Merah, Kelantan, Malaysia

Abstract

Core sediments from two sampling points namely TM 2 and TM3 which are located at the Kelantan Rive near to Tanah Merah district had been collected to determine the vertical profile of heavy metals contents. TM 2 and TM3 were located near to gold mining area and agriculture area, respectively. The heavy metals in Tanah Merah were analysed using Atomic Absorption Spectrophotometer (AAS) PinA Acle 900F model. The degree of pollution has been investigated using Geo-accumulation (Igeo) index. For the result, the average value of heavy metals in Tanah Merah are Cu (12.67 ± 5.38 mg/kg), Pb (44.57 ± 8.75 mg/kg), Cr (56.69. ± 10.38 mg/kg), Zn (157.89 ± 88.56 mg/kg), Fe (4.08 ± 0.82 %) and Al (7.84 ± 1.53 %). The vertical profile of Cu and Zn at the bottom layer showed the decreasing trend toward the bottom of sediment suggesting the additional anthropogenic input of both metals to the sediment. In addition, most of the concentration value of Zn at TM2 near to gold mining set were exceed the permissible limit set by WHO. Furthermore, the result from the Igeo index also supported sediments at TM 2 which is located near to mining area are extremely contaminated with Cu and Zn. As conclusion, the authorities should closely monitor the level of pollution at the Kelantan River especially near to mining area.