This study was conducted to determine the baseline water quality characteristics of a contaminated NAHRIM lake undergoing remediation by the constructed wetlands, based on the physico-chemical and biological parameters. The sampling was conducted for six months (May-October) in 2016 from 5 stations of the lake and analysed using APHA standard methods for water and wastewater analysis, while Malaysian water quality index (WQI) was used to calculate quality of the lake. The results showed that, the Conductivity, Dissolved Oxygen, NO3-N, NO2-N, PO4, Temperature, Turbidity, TDS, TSS, and Zn were under class I, while pH, B and COD were categorized under class II. NH3-N, BOD, Fe, Escherichia coli, Total coliform and Mn were categorized as class III. Moreover, Al was not given any classification under NWQS but their concentration did not exceed EPA guidelines. Furthermore, as compared to the water samples from the constructed wetlands that reported a class III WQI, the lake was observed to show an overall class II WQI. This is suggestive of the retaining and remedial role of the constructed wetlands being the first point of contact for the contaminants going to the lake. Thus the lake is suitable for recreational activities.
The present study aims to determine the level of heavy metals in surface soils and street dust from selected urban and peri-urban locations in the metropolitan city of Kuala Lumpur. Samples were collected from 15 different locations, where Kuala Lumpur City Centre (KLCC) served as the centre point while other locations were located at specific distances from the centre. Surface soils and street dust were collected to detect the level of contamination based on five elements (Zn, Cu, Pb, Cd and Fe). Results indicated that the metal distribution displayed a descending trend as follows: [Fe] > [Zn] > [Pb] > [Cu] > [Cd] and [Fe] > [Zn] > [Cu] > [Pb] > [Cd] in the surface soil and street dust samples, respectively. Geoaccumulation index (Igeo), contamination factor (CF) and pollution load index (PLI) were calculated. Based on the Igeo index, Fe in both samples was found to cause no pollution in all study sites. In surface soils, CF showed all sites were contaminated with Cd in both soil and street dust. In conclusion, the soil sample was polluted with metals while no pollution was found in the street dust in all sites sampled. Further intensive studies are recommended in order to determine other factors which may cause contamination.