Preliminary Assessment of Selected Water Quality Parameters in the Lower Basin of Perak River Using GIS and QUAL2K

The issues concerning pollution concentration that significantly affects the water quality throughout a river network have led to the increase number of studies addressing this problem worldwide. Pollutants upon entering a water body immediately take course and disperse according to the flow and the magnitude of the water current. Depending on the concentration and volume, the receiving water body has a certain capacity to dilute and disperse it further downstream within a river basin. This research is conducted within the lower basin of Perak River to evaluate its water quality status and to map out the pollutant distribution. Three types of water quality parameter were carried out, i.e. total suspended solid (TSS), turbidity, and total Kjeldahl nitrogen (TKN). The results according to the parameters in sequence fall within a range of 30.67–742 mg/L, 21.55–87 NTU, and 0–4.928 mg/L, respectively. The concentration of heavy metals analysed using inductively coupled plasma-optical emission spectrometer (ICP-OES) yielded in the following descending order, Cu > Fe > Mn > As > Pb > Cr > Cd. The concentration of the analysed metals is Cu, 0.0465–26.1427; Fe, 0.5816–5.6658; Mn, 0.0461–0.3522; As, 0.0168–0.1816; Pb, 0.0456–0.0812; Cr, 0.0012–0.0685; and Cd, 0.001–0.0507 mg/L. A modelling software, Qual2K, was applied to model the dispersion of heavy metals throughout the lower basin of Perak River. The pollutant distribution is finally plotted out using geographic information system (GIS) mapping.