Seasonal Variation of Grain Size and Heavy Metals Concentration in Sediment of Sungai Perlis

Heavy metals concentration (As, Co, Cu, Pb, Zn, Cr) and grain size analysis were determined in sediment collected from Sungai Perlis during Southwest and Northeast monsoon. Ten sampling areas of the Sungai Perlis were selected based upon anthropogenic activities which resulted in elevated metals load into the river. Heavy metals concentration in the sediments show average decreasing trend of Zn> Cr> Pb> Cu> As> Co during Southwest monsoon and Cr> Zn> Pb> As> Cu> Co on Northeast monsoon which can be related by the impact of the anthropogenic activities. Most of the sampling areas were dominated by silt sediments while sand and clay sediment were poorly present. Result of grain size showed that the average mean size, sorting and skewness are 7.32 ± 0.44 phi, 1.55 ± 0.14 phi and -0.16 ± 0.19 phi for Southwest monsoon and 7.14 ± 0.27 phi, 1.56 ± 0.12 phi and -0.08 ± 0.17 phi during Northeast monsoon. The analysis of heavy metals and grain size fractions of sediments indicated that the distributions of metals and grain size in upstream and downstream river sediments were affected by monsoon seasons. (author)