title: Reaction mode between Si and Fe and evaluation of optimal species in poly-silicic-ferric coagulant.
abstract: A kind of Fe-polysilicate polymer, poly-silicic-ferric (PSF) coagulant was prepared by co-polymerization (hydroxylation of mixture of Fe3+ and fresh polysilicic acid (PS)), in which PSF0.5, PSF1 or PSF3 denotes Si/Fe molar ratio of 0.5, 1 or 3, respectively. The effects of Si/Fe ratio and reaction time (co-polymerization time or aging time) on the reaction mode between Si and Fe were studies, and the optimal species of PSF was evaluated by pH change during the preparation of PSF and coagulation tests. The results showed that the characteristics of PSF are largely affected by both reaction time and Si/Fe ratio. PSF is found to be a essential complex of Si, Fe, and many other ions. The reaction mode between Si and Fe differs with various Si/Fe ratios. The pH of PSF0.5, PSF1 or PSF3 tended to be stable when reaction time is 10, 25 or 55 min, respectively, which is almost consistent with the time reaching the relative stable morphology that is just the optimal species of higher coagulation efficiency. The optimal reaction time reaching optimal species can be evaluated by measuring the pH change during the polymerization process.
authors.affiliation: School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China. hit.fuying@126.com
authors.forename: Ying
authors.initials: Y
authors.lastname: Fu
authors.forename: Shui-li
authors.initials: SL
authors.lastname: Yu
authors.forename: Yan-zhen
authors.initials: YZ
authors.lastname: Yy
authors.forename: Li-ping
authors.initials: LP
authors.lastname: Qiu
authors.forename: Ban
authors.initials: B
authors.lastname: Hui
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry; D005427:Flocculation; D006812:Humic Substances; D007501:Iron / Q000737:chemistry*; D007616:Kaolin / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D013464:Sulfuric Acids / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D005290:Ferric Compounds; D006812:Humic Substances; D011108:Polymers; D013464:Sulfuric Acids; D014874:Water Pollutants, Chemical; D007616:Kaolin; C024823:ferric sulfate; D012822:Silicon Dioxide; D007501:Iron; C033158:sulfuric acid; D012825:Silicon