Concentration of selected heavy metals in water adn surface sediment in Salut-Mengkabong Lagoon, Tuaran, Sabah

• Main Author: Han Peirong
• Format: Thesis
• Language: English; English
• Published: 2020
• Subjects: TD1-1066 Environmental technology. Sanitary engineering
• Online Access: https://eprints.ums.edu.my/id/eprint/42273/1/24%20PAGES.pdf; https://eprints.ums.edu.my/id/eprint/42273/2/FULLTEXT.pdf; https://eprints.ums.edu.my/id/eprint/42273/
• Institution: Universiti Malaysia Sabah

The accelerated development of human activities at lagoon area contributes to the increasing load of heavy metals into lagoon body which could cause adverse effects on organisms and environment. Most studies on heavy metals are not more than six months. Heavy metals have been studied mainly in sediment but not in water. It has been more than ten years since the last study related to heavy metal was reported at Salut Lagoon. Thus, the key objective of this study is to determine the concentrations and variations of five heavy metals (Cd, Cr, Cu, Pb and Zn) in both water and surface sediment in Salut-Mengkabong Lagoon for 9 months. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to determine the concentrations of heavy metals in digested samples. In this study, 1 ml water sample was digested with 65% HNO, at 100 ®C for 1 hour while 1 g sediment sample was digested with 40 ml aqua regia at 130 °C for 30 mins. By comparing with Interim Malaysian Marine Water Quality Standards (IMMWQS), Cu, Pb and Zn had relative high concentrations. As for Hong Kong Interim Sediment Quality Guidelines (ISQGs), only Cd and Zn were found to have higher concentrations than their standard values. Results of agglomerative hierarchical clustering (AHC) and discriminant analysis (DA) showed that heavy metals had minimal spatial variation in water. In surface sediment, concentration of Cu, Pb and Zn showed dissimilar (higher) value at 56 compared to other stations. However, Cd and Cr had minimal spatial variation in surface sediment. According to principle component analysis (PCA) result, no relationship was found between heavy metals in lagoon water. In surface sediment, Cu, Pb and Zn were found to have positive significant relationship between each other, thus they probably came from the same source. Cr, Cu and Pb in water were found to have higher concentration in periods of south-west monsoon (SWM) than in north-east monsoon (NEM) while Zn in sediment was found to have higher concentration value in SWM than that in NEM. For other parameters, no relationship was found (P>0.005) between SWM and NEM. Results of indexes assessments showed that surface sediment were unpolluted except at 56 due to the enrichment of Cd. Concentration of heavy metal showed no relationship between water and surface sediment. Overall, lagoon water was found to have abundance of Cu, Pb and Zn while lagoon sediment was only slightly polluted for Cd at S6.