The Coagulation Performance and Floc Characteristics of Yellow River Reservoir Water Coagulated by Composite Coagulant Prepared by Polymeric Aluminum Ferric Chloride and Polydimethyl Diallylammonium Chloride

Abstract

In this paper, inorganic polymeric ferric aluminum chloride (PFAC) and composite polymeric aluminum ferric chloride polydimethyl diallylammonium chloride (PFAC-PDADMAC) were applied for the coagulation treatment of Yellow River reservoir water. The coagulation efficiency of PFAC-PDADMAC for reservoir water treatment was investigated at different weight ratios (Ferric and Aluminum to PDADMAC, Wr=2, 4 and 8). During coagulation, the size distribution, breakage factor (Bf) and recovery factor (Rf) of flocs was investigated to systemically estimate the floc characteristics of PFAC-PDADMAC coagulation system. It was confirmed that coagulation performance of PFAC-PDADMAC was better than that of PFAC when Wr and dosage were 4 and 8 mg/L, respectively for Yellow River reservoir water coagulation. Although they were more sensitive to external interference, the flocs formed by PFAC-PDADMAC coagulation system had bigger size, faster growth rate and stronger re-growth capability than that by PFAC coagulation system. At Wr=4, the floc size and growth rate of flocs by PFAC-PDMDAAC coagulation were 409μm and 54 μm/min, respectively.