聚硅氯化铝(PASiC)混凝剂的特性及絮凝动态过程

Specific properties of polyaluminum silicate chloride (PASiC) coagulant and its dynamic process of flocculation.

采用共聚与复合两种制备工艺,分别制备出具有不同碱化度(B)和不同Al/Si摩尔比系列的商用聚硅氯化铝(PASiC)混凝剂,并分别采用颗粒粒径测定方法和流动电流(SC)测定技术研究比较了PASiC和聚合氯化铝(PAC)混凝剂的颗粒大小、电动特性和凝聚絮凝动态过程.结果表明,Al/Si摩尔比、B值和制备工艺影响PASiC的聚合和带电特性.Al/Si摩尔比越小和B值越大,PASiC的颗粒就越大;在相同的B值下,PASiC较PAC具有更大的颗粒粒径.PASiC的电中和能力较PAC有所下降,且Al/Si摩尔比越小,PASiC的电中和能力下降越多;与PAC相比,PASiC具有更快的凝聚絮凝速度和形成更大的絮体;且Al/Si摩尔比越小,PASiC形成的絮体就越大.

A series of commercial coagulants (PASiC) with different basicities (B) and Al/Si molar ratio was prepared by copolymerization technique and composite technique respectively. The particle size the electrokinetic characteristics of PASiC and polyaluminum chloride (PAC), and the dynamic process of flocculation with PASiC and PAC were investigated and compared by particle size determination and streaming current (SC) technique. The results show that the polymerization and the electrokinetic characteristics of PASiC are affected by Al/Si molar ratio, B value and preparation technique. The smaller the Al/Si molar ratio and the larger the B value, the larger the particle size of PASiC. PASiC has bigger particle size and lower charge-neutralizing ability in comparison with PAC at the same B value; and also the smaller the Al/Si molar ratio, the lower the charge-neutralizing ability of PASiC. Compared with PAC, PASiC has quicker coagulation rate and forms larger floc; and the smaller the Al/Si molar ratio, the larger the floc size.