Performance and mechanism of polyferric aluminum chloride-quaternary ammonium salt composite flocculants in treating surface water

摘要

A new composite coagulant, polymeric ferric aluminum chloride-polydimethyl diallylammonium chloride (PFAC-PD), was prepared by combing Polymeric ferric aluminum chloride (PFAC) with polydimethyl diallylammonium chloride (PDMDAAC). The turbidity, ultraviolet absorbance at 254 nm (UV_(254)) and specific ultraviolet absorbance (SUVA) removal and flocculating mechanisms of the new composite coagulant and the traditional coagulants (PFAC, adding PFAC before adding PDMDAAC and adding PFAC after adding PDMDAAC) were investigated in treating surface water. The results indicated that the new composite coagulants exhibited better flocculation efficiency than PFAC and successive addition of PFAC and PDMDAAC. The neutralization ability of the coagulants was in the following order: PFAC-PD > PD+PFAC > PFAC+PD > PFAC.