活性硅酸对铝盐的助凝作用

Improvement Coagulation of Polyaluminum Chloride by Active Silica

利用水玻璃制备了具有较佳形态的活性硅酸,研究了该活性硅酸对不同B值铝盐助凝时模拟体系的混凝行为.结果表明:该活性硅酸具有明显的助凝效果;当有活性硅酸助凝时,体系Zeta电位明显降低,而除浊效率得到明显提高;有活性硅酸参与下的混凝机理有别于单纯铝盐,活性硅酸的介入会削弱铝盐在混凝中的电中和作用,但同时强化了黏接架桥与网捕卷扫的作用机制.

Activated silicic acid is a common kind of coagulant aids. In this paper the activated silicic acid which has better speciation was prepared by water glass. The coagulation behavior that the effect of better speciation of silica on coagulation of kaolin by iron （III） chloride and PAC1 was investigated in detail. The results showed that the higher dosage of silica, the lower charge-neutralization capability is exhibited. However, the higher dosage of silica, the better turbidity removal is observed. When the active silica participates in the system, the mechanism differs from the coagulation only by iron （Ⅲ） chloride or PACl：the acid silicic can lower charge-neutralization effect, however, their aggregation function can be strengthened at the same time.