Determination of total organic carbon concentration in surficial sediments of Sungai Pinang, Penang, Malaysia

The concentration of total organic carbon (TOC) and mean size sediment in a total of 24 samples of surficial sediment were determined. From the results of study, the concentration of TOC (5.33%) was found high nearby the housing area at Sungai Pinang. At the downstream of the river tend to have higher concentration of TOC (1.05% - 5.33 %) while at the upstream tend to have low degree of TOC in surficial sediments (0.36% - 0.78%). The major contribution in TOC contamination at the bottom part of the river maybe due to anthropogenic activities such as waste effluent from urban runoff, industrial activities and boat activities. Apart from that, the mean grain size was probably an important factor that influences the TOC content in surficial sediment at Sungai Pinang. This is because the distribution of the mean grain size that had similar trend to TOC. In addition, the high correlation relationship between TOC and mean grain size were observed and it had accounted for r = 0.67 owing to fine particles of sediment which had provided a large binding capacity for the sorption of organic carbon. Moreover, fine sediment probably indicates slow hydrodynamic energy at the downstream. It might affect the chemical sorption process and allow the particulate organic carbon to accumulate at the bottom of the water column. Thus, fine sediment maybe playing dominant role in the content of TOC in surficial sediment at Sungai Pinang