Characterisation of Water Treatment Sludge (WTS) at a Water Treatment Plant in Melaka

Abstract

Water treatment sludge (WTS) is a by-product produced in the process of water treatment plants (WTP). It is estimated that an ordinary WTP produces over 10,000 tonnes of WTS per day, which has become a major concern in the management of WTS. Numerous previous studies have been accomplished to determine a safe disposal method and the potential reuse of WTS. In most investigations, material characterisation was the adopted method. It is known that each WTP produces different chemical composition of WTS according to raw water intake and the treatment process. The aim of this paper is to examine the chemical composition of WTS in the WTP at Melaka. The WTS sample is collected from WTP after the pressing process, where large amounts of water have been removed. The sample is tested using the Scanning Electron Microscopy with energy dispersive X-ray (SEM-EDX) and X-ray Diffraction (XRD). The SEM-EDX results revealed that by weight percentage (%), WTS contains zirconium (Zr) (28 to 46%), oxygen (28 to 40%) and carbon (7 to 26%). Aluminium and silicon have weight percentages ranging from 7 to 8%. The outcomes are then confirmed by XRD, which showed the high intensity of Zr and α-Zr at approximately 35.3 and 36.1. of 2θ. Based on these findings, the suitable and potential reuse of WTS would be the extraction of Zr. However, further research is required to verify the consistency of Zr in WTS.