两性高分子絮凝剂聚乙烯亚胺基黄原酸钠除浊性能

Removal performance for turbidity by amphoteric macromolecule flocculant with polyethyleneimine-sodium xanthogenate

以不同分子量的聚乙烯亚胺(PEI)为母体,通过化学反应将二硫代羧基引入到其分子链中,制备出3种新型高分子絮凝剂聚乙烯亚胺基黄原酸钠(PEX),采用2种性质不同的高岭土配制的含浊水样作为考察对象,通过絮凝实验法研究PEX对水样中浊度的去除性能.结果表明,3种PEX对不同性质含浊水样中浊度的去除性能具有一定的差异,浊度的最高去除率随着PEX分子量的增加而升高,随着原浊的增加而略有升高.PEX为两性聚电解质,PEX-1、PEX-6、PEX-60溶液的等电点pH_(iep)分别为3.8、5.0、8.7;当体系初始pH值位于3种PEX各自等电点处,浊度的去除率最高,可分别达到98.6%、96.6%、91.3%.含浊水样中共存Cu(Ⅱ)或Ni(Ⅱ)时,可明显提高浊度的去除效果.体系中余浊随着静置后Zeta电位绝对值的降低(升高)而减小(增大).

Three kinds of novel macromolecule flocculant,called polyethyleneimine-sodium xanthogenate(PEX),were prepared by chemical reaction to graft dithiocarboxylic groups onto three different molecular weights of polyethyleneimine.The removal performance of turbidity by PEX was studied with two different types of turbidity-containing water samples through using flocculation experiments.The results showed that the three kinds of PEX had different removal properties for turbidity with the different turbidity-containing water samples.The highest removal efficiency of turbidity increased with the increase of the molecular weights of PEX,and slightly increased with the increase of the original turbidity of water samples.When pH value of the water samples reached the isoelectric point(pHiep)of PEX,the removal rate of turbidity was highest,and reached98.6%,96.6%and91.3%at pHiep of3.8,5.0and8.7for PEX-1,PEX-6and PEX-60,respectively.The removal efficiency of turbidity was obviously improved with the coexistence of Cu(Ⅱ)or Ni(Ⅱ)in the water samples.The residual turbidity decreased or increased with the decrease or increase of the absolute value of zeta potential in the system.