Investigation on Solid-Liquid Poly-Silicic-Ferric Coagulant PSFN

A new type of inorganic polymer, poly-silicic-ferric coagulant with oxidization and with solid and liquid phase coexisting (PSFN) was prepared by adding KMnO₄ to the poly-silicic-ferric (PSF) coagulant. The characteristics and the removal efficiency of dissolved organic matters (DOMs) in water by PSFN were explored by both analytical methods and a coagulation test, in comparison with those by PSF and polyferric sulfate (PFS). The solid and liquid components in PSFN were analyzed. The effect of storage time on the stability of coagulation performance of PSFN was investigated. The results show that KMnO₄ added to PSF may be a participate in the complexation with Si and Fe, resulting in the difference of the characteristics between PSFN and PSF or PFS, which makes PSFN better in removing DOMs than PSF or PFS. The solid component in PSFN acts as a primary nucleus favoring the formation of flocs, which leads to the formation of larger flocs with sufficient ability of bridging or sweeping. PSFN has better removal efficiency of organic matters (OMs) than the filtrate of PSFN (PSFN-F). The species of PSFN has good stability of coagulation performance.