[Coagulation characteristics of polyferric chloride-poly (epichlorohydrin-dimethylamine) composite flocculant for simulated water treatment].

Polyferric chloride (PFC) and poly (epichlorohydrin-dimethylamine) [P(EPI-DMA)] were applied as raw materials to prepare a novel inorganic-organic flocculant [PFC-P(EPI-DMA)] with various intrinsic viscosities (eta), basicity (B, OH/Fe molar ratio), and organic component fractions [omega(E)]. The PFC-P(EPI-DMA) prepared was then evaluated for the coagulation treatment of synthetic active dying wastewater and simulated ground water. Effects of B, and omega (E) on the Fe speciation distribution and coagulation performance of PFC-P(EPI-DMA) were comparatively examined as a function of coagulant dosage. The coagulation mechanism of PFC-P(EPI-DMA) was also discussed in this paper. Experimental results indicated the interaction effect of PFC and P (EPI-DMA) component in composite PFC-P (EPI-DMA). The effective Fe speciation content of PFC-EPI-DMA decreased with increasing omega(E), while it was maximized when eta = 850 mPa x As B value increased gradually, the Fe(b) concentration initially increased and then decreased, but the Fe(c) concentration kept continuously increasing. To some extent, higher eta and lower B value was favorable for the improvement of coagulation performance for coagulation treatment of both synthetic dyeing wastewater and simulated ground water. The omega (E) influence on the coagulation performance of PFC-P(EPI-DMA) was related to the treatment target. Both charge neutralization and adsorption bridging effect played roles in the coagulation process of the composite PFC-P(EPI-DMA).