Reaction mode between Si and Fe and evaluation of optimal species in poly-silicic-ferric coagulant

• 作 者: FU Ying YU Shui-li YU Yan-zhen
• 机 构: School of Municipal and Environmental Engineering,School of Civil and Architectural Engineering,Extr
• 出 处: 环境科学学报（英文版）
• 发表日期: 2004年期
• 关键词: poly-silicic-ferric coagulant reaction mode optimal species
• 基金项目: 国家重点基础研究发展计划(973计划)

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 and PSF3 denotes Si/Fe molar ratio of 0.5, 1 and 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 changing pH 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 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.