聚硅酸铁(PSF)混凝剂搅拌动力学的特性及理论分析

以水玻璃、硫酸亚铁及氯酸钠为原料，制备聚硅酸铁（PSF）混凝剂；用透射电镜观察PSF的微观形态，针对模拟水及松花江水，采用正交实验从GT值来研究搅拌条件对PSF混凝效果的影响。结果表明，PSF是由许多链节样物种连接而成的分维数很大的敞开式枝状结构，并且形态大小不均，覆盖范围很宽。对于不同的水质，PSF的最佳搅拌动力学条件基本一致，快搅200r／min，2min，慢搅梯度为：60r／min，3min，40r／min，5min，20r／min，2min；快搅和慢搅要密切配合，才能达到最佳的混凝效果；快搅GT值是决定混凝平衡、絮体破碎的关键因素，同时要求适度的快搅速度、稍长的快搅时间，并且要求初始速度较快的慢搅时间较长。

DYNAMIC CHARACTERISTICS OF POLY SILICON FERRIC SULFATE(PSF)COAGULANT STIRRING AND THEORETICAL ANALYSIS

A new coagulant,poly silicon ferric sulfate(PSF),was prepared with water glass,ferrous sulfate and sodium chlorate,and the microstructure of PSF was explored with Transmission Electron Microscope(TEM).The effect of stirring conditions on coagulation performance by PSF was investigated by orthogonal design in treating Songhuajiang and simulating water in terms of GT values.The results showed that a kind of multi-branched structure with larger fractal dimension connected by many short chain-like matters was observed,having wider molecular weight fractions.The optimum stirring condition is basically similar to each other for the two waters: rapid agitation 200r/min for 2min,followed by slow agitation step of 60r/min for 3min,40r/min for 5min and 20r/min for 2min.The optimum coagulation effect could be obtained by close coordination of rapid agitation and slow agitation.Rapid agitation GT value is a key factor affecting the coagulation equilibrium and floc breakage,and it is required to have moderate rapid agitation speed,slightly long rapid agitation time and longer slow agitation time with more rapid initial speed.