Characterization of Leachate from Kuala Sepetang and Kulim Landfills: A Comparative Study

The general characteristics of Kuala Sepetang Landfill Site (KSLS) and Kulim Landfill Site (KLS) in the northern part of Malaysia were investigated. The average values of the parameters for leachate at KSLS and KLS, such as pH (8.05 and 7.59), EC (11.9 and 2.92 mS/cm), ORP (-33.02 and +17.8 mV), turbidity (88.9 and 26 NTU), colour (2200 and 326 Pt Co), SS (233 and 47 mg/L), BOD5 (158 and 29 mg/L), COD (855 and 117 mg/L), BOD5/COD (0.19 and 0.24), ammonia-N (857 and 210 mg/L), sulphate (91.48 and 141.71 mg/L), chloride (1800.46 and 243.18 mg/L), copper (0.08 and 0.03 mg/L), iron (2.18 and 0.38 mg/L), manganese (0.08 and 0.09 mg/L), nickel (0.16 and 0,07 mg/L), and zinc (0.26 and 0.09), were recorded, respectively. Results of this study indicate that KSLS and KLS had low refractory (BOD5/COD) organic compounds and high quantities of COD and ammonia-N. Furthermore, the amounts of colour, suspended solid (SS), BOD5,COD, ammonia-N, and sulphate exceeded the standard limits imposed by the Environmental Quality (Control of Pollution from Solid Waste Transfer Station and Landfill) Regulations 2009, Malaysian Environmental Quality Act 1974 (Act 127). On the other hand, parameters such as pH, copper, iron, manganese, nickel, and zinc remained within the allowable limits. The measured leachate would need an appropriate treatment strategy to reduce the pollutants to a satisfactory level prior to discharge into receiving system.