Comparative study of Poly Aluminum Ferric and Poly Aluminum Chloride Performance for Turbidity Removal from River Water

Due to urbanization and industrial development, pollution of water bodies has become a serious concern. Coagulation and flocculation system is the conventional method of removal of the contaminants from raw water. In this study, the effectiveness of PAF and PAC was evaluated at different turbidity levels in order to find optimal operational conditions for low to high turbidity river waters. A set of jar test experiments was conducted to find the optimal coagulant dosage for turbidity removal in Babolrood River samples, Results demonstrated that coagulation process can assure turbidity removal from low to high turbidity waters (i.e., 18.3, 39.2, 72.5, and 136 NTU) effectively using relatively low levels of PAF and PAC (2.5 to 16 ppm). Results showed that turbidity removal is dependent on coagulant dosage, as well as initial turbidity of water for both used coagulants. The highest turbidity removal efficiency was within 96.6-98.3% for PAF and PAC over the applied range of turbidity. Both applied coagulants demonstrated promising performance in turbidity removal from water; however, PAC showed better performance compared to PAF as the optimal dosage of PAC for maximum turbidity removal was 6.5 ppm, which is lesser than 12.5 ppm of PAF. The results of the current study can be used as a baseline data for river water treatment facilities which uses these two types of coagulants.