Efficiency Comparison of PolyDADMAC Coagulant with Ferric Chloride in the Treatment of Ahvaz Drinking Water

PolyDADMAC is used in water and waste water treatment as a primary organic coagulant which can neutralize colloidal material with negative charge and reduces sludge volume compared with Mineral coagulants. The aim of this study was to evaluate and compare of PolyDADMAC with ferric chloride as a coagulant on the removal of turbidity, Coliform and Organic matter from Ahvaz drinking water.
This study was carried out in a lab scale and using a jartest device in Ahwaz water treatment. In this research, the coagulation of raw water was studied using PolyDADMAC alone, and mixed coagulant of PolyDADMAC and ferric chloride at various dose and ferric chloride alone were compared. The study range was selected for turbidity (NTU3850, 80), pH (9-5) and different concentrations of coagulant material .Data analysis was performed using Excel, SPSS software and one way ANOVA (p The optimal efficiency conditions of PolyDADMAC in turbidity 3850 NTU, pH=8, Flash Mix =120rpm and resulted in an optimum dose of 0.5 mg/L which the highest turbidity removal percentage was to be 99.84% in optimal dose of 0.5ppm of coagulant. The optimum doses of ferric chloride with PolyDADMAC were obtained at 15mg/L and 0/4mg/L, respectively. Under higher doses of PolyDADMAC, flocs showed stabilized in solution .In addition, PolyDADMAC also produced larger floc with higher settling velocity that need less time to settle.
The results from the comparison of the effect of coagulants mentioned in the high turbidity removal (NTU 3850) indicate the good performance of PolyDADMAC as coagulant to ferric chloride Also, the results showed that the removal efficiency was affected by the initial turbidity so that the higher the initial turbidity, would be the more efficient the turbidity removal.