Optimization of Coagulation-Flocculation Process for Tello River Water Treatment Using Poly Aluminum Chloride and Aluminum Sulfate

Tello River Water was utilized by PT. PLN SULSERABAR as Boiler feed water. Total Suspended Solid (TSS) in river water can be removed by the coagulation-flocculation process. Improved performance of coagulation process can be done by optimizing coagulant concentration and pH on coagulation. This research focused on optimization of pH and percent (%) removal of TSS using Poly Aluminum Chloride (PAC) and Aluminum Sulfate (Alum). The concentration of coagulant was 25% of the initial TSS of the sample for PAC and 35% of the initial TSS of the sample for Alum. The sample used in this research is Tello River Water which has initial TSS concentration of 195 mg/L with rapid mixing (350 rpm) for 1 minute, slow mixing (50 rpm) for 20 minutes and 30 minutes of sedimentation. The coagulation-flocculation process was carried out in the pH range of 4-10 and the TSS concentration was analyzed using the Gravimetric method. The optimum pH on coagulation and percent (%) TSS removal obtained from this study were 7, 99.23% for PAC and 6, 89.48% for Alum. These results indicated that PAC was the perfect coagulant for the removal of TSS because it was able to eliminate TSS nearly 100%.