Determination of Total Organic Carbon Concentration in Surficial Sediments of Sungai Pinang, Penang, Malaysia

Abstract

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.Keywords: total organic carbon, mean size sediment, surficial sediments, Sungai Pinang Abstrak Kandungan jumlah karbon organik (TOC) dan purata saiz sedimen di dalam 24 sampel sedimen permukaan telah ditentukan. Dari hasil kajian ini, kepekatan TOC (5.33%) didapati tinggi berhampiran dengan kawasan perumahan di Sungai Pinang. Di kawasan hilir sungai tersebut mempunyai kepekatan TOC yang lebih tinggi (1.05% -5.33%) manakala di kawasan hulu sungai mempunyai kepekatan yang rendah dalam permukaan sedimen (0.36% -0.78%). Kemungkinan punca utama untuk pencemaran TOC di bahagian hilir sungai adalah dari aktiviti antropogenik seperti sisa buangan daripada bandar, aktiviti perindustrian dan aktiviti bot. Selain itu, purata saiz partikel kemungkinan adalah faktor penting menpergaruhi kandungan TOC dalam sedimen permukaan di Sungai Pinang. Ini kerana taburan purata saiz partikel mempunyai corak yang sama dengan TOC. Tambahan pula, hubungan korelasi antara TOC dan purata saiz partikel didapati tinggi dalam sedimen permukaan, iaitu r = 0.67 disebabkan saiz partikel yang halus memperolehi kapasiti pengikatan yang luas untuk penyerapan karbon organik. Selain itu, sedimen yang halus berkemungkinan menunjukkan tenaga hidrodinamik yang perlahan di bahagian hiliran. Hal ini berkemungkinan mempengaruhi proses penyerapan dan pengumpulan zarah karbon organik di bahagian bawah turus air. Oleh itu, sedimen yang halus berkemungkinan besar memainkan peranan yang paling dominan kepada kandungan TOC yang dalam sedimen permukaan di Sungai Pinang.Kata kunci: jumlah karbon organik, purata saiz sedimen, sedimen permukaan, Sungai...