不同含量硫酸根和硝酸根作为反离子对聚二甲基二烯丙基铵盐絮凝性能的影响

The effect of different content of nitrate or sulfate ion as counterions on flocculation properties of Polydiallyldimethylammonium salts

在实验室烧杯实验中,通过利用光散射监控技术,以及测定絮凝后上清液的残余浊度和Zeta电位,研究了硫酸根和硝酸根聚二甲基二烯丙基铵盐聚电解质(PDADMAX)的絮凝性能.以不同浊度的高岭土悬浊液为目标物,详细地讨论了反离子中不同含量的SO42-或NO3-对絮凝效能的影响.为了进一步阐明PDADMAX的絮凝机理,用原子力显微镜(AFM)和比浓粘度表征了反离子对PDADMAX溶液性质和吸附形貌的影响.实验结果表明:反离子明显影响了PDADMAX的絮凝性能.含有NO3-的PDADMAX具有更强的“电中和作用”和更高的絮凝效率,而含有SO24-的PDADMAX具有更高的“吸附架桥作用”既更宽的最佳絮凝剂投量范围、更大的絮体.不同的SO42-或NO3-含量的PDADMAX絮凝剂的絮凝效率不同,其中都在含量20%时效果最好.而且在高浊度条件下,SO42-或NO3-对PDADMAX的絮凝效果有更明显地增强.

The effect of nitrate or sulfate as countefions on flocculation properties of polydiallyldimethylammonium salts （PDADMAX） was investigated by using an optical monitoring technique together with the conventional jar test procedure and zeta potential measurement. Effect of the different content of monovalent nitrate ion and divalent sulfate ion was discussed in detail by measuring turbidity of the stock kaohn suspension solution. Moreover, in order to indicate the flocculation mechanism of PDADMAX, the effect of counterions on the solution property and adsorption morphology was studied by reduced viscosity and atomic force microscopy （AFM）. The experiment results showed that counterion had a significantly different effect on PDADMAX flocculation as a result of the most commercially important polymer flocculant, where charge neutralization and bridging action played different parts in the flocculation process. PDADMAX having NO3^- had stronger flocculation efficiency, whereas having SO4^2- had the wider optimum dosage and larger floc size. The flocculation efficiency of PDADMAX having different content of SO4^2- or NO3^- was different, the optimum content of SO4^2- or NO3^- was 20%. In particular, for high turbidity kaolin suspension solution, the flocculation of PDADMAX having SO4^2- or NO3^- was obviously increased.