Keywords: acid sulphate soils, heavy metals, metal pollution, pyrite oxidation, QUAL2E modelling, Sembrong River, water pollution, environmental pollution, Malaysia, aluminium, iron, manganese, water quality
Study of metal pollution in Sembrong River, Johor, Malaysia
Sampling of the Sembrong River over a 9-month period revealed maximum total aluminium (Al), ferum (Fe) and manganese (Mn) concentrations of 61.0, 33.0 and 1.5 mg/L, respectively, and pH as low as 2.5, making it one of the most metal- and acid-contaminated rivers in Malaysia. The river serves as a fresh water source to water treatment plants located at the downstream reach of the river, which supplies potable water to more than 500,000 residents in the area. This paper outlines the water quality problems and demonstrates the application of the USEPA's QUAL2E model to the Sembrong River, Malaysia. The results showed that the main source of low pH and metals pollution to the Sembrong River is the acid sulphate soils. The water quality parameters included in the model were conservative minerals, namely Al, Fe and Mn. The model was calibrated and validated using the data collected in 2005.