Heavy metal contamination in the water of a semi-urban lake – Bolgoda lake, Sri Lanka

Abstract

Urbanisation and industrialisation have intensified the heavy metal contamination in inland water bodies. Therefore, this study investigates the recent status of heavy metal pollution in the water of the Bolgoda Lake in Sri Lanka, a semi-urban inland water body that receives both treated and untreated municipal and industrial discharge from the surrounding area. A total of 11 lake water samples were analysed by Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) to determine the concentrations of As, Cd, Cr, Co, Cu, Ni, Pb, and V. Their mean concentrations in the Bolgoda Lake water were 0.661 ± 0.264 ppm, 0.010 ± 0.004 ppm, 0.090± 0.018 ppm, 0.007± 0.002 ppm, 0.043± 0.039 ppm, 0.002± 0.001 ppm, 0.662± 0.264 ppm, and 0.091 ± 0.018 ppm, respectively. However, the derived contamination factors of the analysed heavy metals revealed that Bolgoda Lake is highly polluted with Cd (22.0) and V (13.2), whereas moderately polluted with Pb (1.8). Compared to previous studies, heavy metal contents in Bolgoda Lake water have increased significantly, especially Cd and Pb. Therefore, Cd, V, and Pb can pose the greatest threat to the ecological environment of Bolgoda Lake, thus effective strategies such as treatment or recycling of wastewater and industrial discharges are needed to protect this lake from further contamination.