DETERMINATION OF COAGULANT TYPE AND DOSAGE IN FERTILIZER INDUSTRY WASTEWATER TREATMENTIpung Fitri Purwanti, Harmin Sulistiyaning Titah, Irwan Bagyo Santoso, Rodhika Rachmawati, and Anindya Gayatri Puspitasari
Fertilizer Industry produces wastewater which mostly contains fluoride. The wastewater has potential to be reused as raw water for the scrubbing process, even though it has not been utilized yet. The reduction of fluoride can be done by adding aluminum sulfate, quick lime, and PAC. The aim of this study was to determine the optimum dose of the aluminum sulfate as the main coagulant and quick lime or PAC as a coagulant aid to produce water for the scrubbing process. The optimum dosage was determined by the 2- stages of jar test method with the addition of variation in the concentration of coagulant and stirring at constant speed. The addition of aluminum sulfate as main coagulant and quick lime as coagulant aid at concentration of 50 â 60 mg/l gave the highest fluoride reduction efficiency.