Study Of Polyferric Chloride/Poly(Epichlorohydrin-dimethylamine) Composite Flocculants

In this paper, a series of composite inorganic-organic coagulant was prepared by polyferric chloride (PFC) and epichlorohydrin-dimethylamine (EPI-DMA) with different basicity (B) of PFC,different cross-linker and different mass fraction (w(E)). The composite PFC-EPI-DMA was characterized by means of chemical and instrumental analysis methods, so as to investigate the influence of synthesis process and raw materials proportion on product stability and its flocculation performance. The impact of the kinds of modifying agent on product stability and flocculation performance was also discussed in this study. In addition, flocculation dynamics and floc characteristics of composite PFC-EPI-DMA was carried out to proclaim the action mechanism, application range and affecting factors of the composite flocculant.The experimental results indicated that the B value, type of cross-linker and mass ratio of inorganic-organic component showed significant impact on speciation distribution, charge characteristics, structure and morphology of the composite PFC-EPI-DMA. For the coagulation treatment of simulated dyeing wastewater, composite PFC-EPI-DMA exhibited superior coagulation performance under conditions of mass ratio of inorganic-organic component=2:1, lower B value and triethylenetetramine as cross-linker. Their effects on floc characteristics were related to coagulant dosages. For the coagulation treatment of oil wastewater, composite PFC-EPI-DMA exhibited superior coagulation performance under conditions of mass ratio of inorganic-organic component=4:1, higher B value (1.0-1.5) and diethylenetriamine as modifying agent. Under these conditions, the formed flocs showed faster growth rate, larger size and lesser floc difference. The composite PFC-EPI-DMA could obtain good coagulation performance via charge neutralization and bridging adsorption mechanism. For the coagulation treatment of Yellow River reservoir water, PFC-EPI-DMA exhibited superior coagulation perofmrance under conditions of mass ratio of inorganic-organic component=2:1, lower B value and triethulenetetramine as modifying agent.