The efficiency assessment of Poly-Aluminium Chloride (PAC) in water treatment plant process: a case study at Sultan Iskandar Water Treatment Plant, Johor / Aina Asyura Azhar, Nuryazmeen Farhan Haron & Herda Balqis Ismail

The rate of population growth and river pollution are significant factors contributing to the increase in water demand in Johor. Generally, this may affect the quality of water treated at one of the biggest water treatment plants in Johor namely Sultan Iskandar Water Treatment Plant (SIWTP). The coverage of SIWTP water supply is wide and comprise almost all area of Pasir Gudang and half of the Johor Bahru district. This situation indirectly affects consumer demand when the treated water is insufficiently supplied by the potable water supply provider due to the use of conventional coagulants in the water treatment plant process. Therefore, this is an initial study as the Poly-Aluminium Chloride (PAC) coagulant is still in the early stages of implementation at SIWTP. It is important to determine the performance of PAC coagulant in the coagulation-flocculation process of the water treatment plant. The PAC performance is compared to Aluminium Sulphate which is a common type of coagulant used in the treatment plant, in order to establish efficiency. A pH adjustment test, turbidity test and the residual Aluminium test were conducted for both coagulants and six jar test readings were recorded to plot the comparison graph between PAC and Alum coagulants. The results showed that PAC is more efficient with 83.74% as compared with Alum which has an efficiency rate of 83.35%. Even though the difference is too small, it is concluded that PAC has better performance and is more efficient compared to Alum due to its better coagulation performance. In addition, PAC produces lesser residual Aluminium and required a lesser amount of dosage. This may reduce cost and therefore save overall operating costs.