The Distribution of Co, Pb and Zn in the Bottom Sediment Offshore Of Kemaman, Terengganu Malaysia during Pre- and Post-Monsoon Periods

This study focussed on heavy-metal concentrations in sediment off the coast of Kemaman. Sampling was conducted at 21 stations during the pre-monsoon and post-monsoon seasons. Sediment was analysed for total concentration of Co, Pb and Zn using ICP-MS after total acid digestion. The grain size of the sediment samples were measured by dry sieving and using a particle-size analyser. In addition, organic carbon content in the sediment was determined using the wet dichromate-oxidation method. The average concentration of Co, Pb and Zn during the pre-monsoon season was 11.40±3.84 μg/g dry weight, 44.08±33.40 μg/g dry weight and 254.90±141.02 μg/g dry weight, respectively. The average concentration of Co, Pb and Zn during the post-monsoon season was 10.60±12.66 μg/g dry weight, 17.54±30.79 μg/g dry weight and 110.71±58.14 μg/g dry weight, respectively. Cu, Pb and Zn show poor correlation or negligible relationship with sediment particle size and organic carbon content. This study also found that all the elements have a mainly crustal origin rather than anthropogenic input with Geoaccumulation Index (Igeo) value of less than 1.0 and Enrichment Factors (EF) of 0.69-2.91which suggests minimal-to-moderate enrichment of the metals.