Distribution of heavy metals in sediments of Setiu Wetland, Terengganu during monsoon and non monsoon seasons

Abstract

Surface sediment samples from 10 stations along the Setiu River were analyzed to investigate and analyzed the differences on the distribution and sources of heavy metals during monsoon and non monsoon seasons. Sediment particle size was studied and the value of the sediment mean size was found to be higher during the monsoon season. The mean size ranged between 0.700 to 5.290 and 0.500 to 2.380 during both the non monsoon and monsoon seasons respectively. The organic carbon content also was studied and was higher during the monsoon season and ranged between 1.73% to 4.89% during the non monsoon season and 2.75% to 4.94% during the monsoon season. Correlation between organic carbon and particle mean size was high on the non monsoon season and was moderate on the monsoon season. Heavy metal was found to be lower on the monsoon season. The ranged of the heavy metals concentrations for both non monsoon and monsoon season are 2.58μglg-8.83μglg and l .09μglg-2.5 l μgig for Cu, 54.65μglg- 272.90μglg and 76.91 μglg-199.29 μgig for Mn, 0.04μglg-0.25μglg and 0.01 μglg-0.12 μgig for Cd, 9.23μglg-l 7.31 μg/g and 5.34μg/g-10.67μg/g for Pb, 10.14μg/g-58.74μg/g and 5.90μg/g-2 l.09μglg for Zn, and 6.04%-13.18% and 2.41%-5.04% for Al. The selected heavy metals had a weak correlation with both particle size and organic carbon content. Enrichment Factor showed a non significant correlation relationship with Al (p>0.05), and the source of heavy metal was of natural origin except for Pb which indicates the pollution is at the initial stage.