SELECTION OF VARIOUS COAGULANTS FOR SUGAR INDUSTRY WASTEWATER TREATMENT

Abstract

Sugar industry is one of the industries that produce a high amount of pollutant which if it is discharged without a proper treatment into the watercourse, it can cause problem to aquatic life and environment. For the primary treatment process, sugar wastewater can be treated by using chemical precipitation method which involves coagulation process. Currently, ferric chloride has been used as the coagulant however it consumes more alkalinity and corrosive. In this study, the suitable coagulant to be used to treat the wastewater from sugar industry and the optimum conditions to achieve high percentage removal of COD was determined. Before any treatment of the wastewater, the characteristic of the wastewater was determined. By using aluminium sulphate, ferric chloride and polyaluminium chloride as coagulant, the most suitable coagulant to be used for the treatment was studied by determining their efficiency to reduce COD and TSS in the wastewater at different dosage. The optimum condition of the coagulant (pH, coagulant dosage, fast mixing speed) was determined by using Design Expert software. The result shown that alum can be used to effectively remove 42.9% of COD and 100% of TSS at high dosage (50mg/l). The optimum condition of alum was at pH 5.2, 10mg/l of alum and 250rpm fast mixing speed. This shows that at optimum condition, alum can be used to treat wastewater from sugar industry.