高分子重金属絮凝剂PEX捕集Ni2+及除浊性能研究

以聚乙烯亚胺、NaOH、CS2为原料,在一定条件下合成了一种新型两性高分子重金属絮凝剂--聚乙烯亚胺基黄原酸钠(PEX),研究了其捕集Ni2 及除浊性能,并对几个影响因素作了考察.实验结果表明:(1)该絮凝剂对Ni2 有很好的捕集功能,Ni2 的最高去除率可达99%以上;(2)pH值对PEX投加量有一定的影响,但对Ni2 的最高去除率影响不大;(3)水中存在碱金属或碱土金属离子时在一定程度上会促进Ni2 的去除;(4)当有Fe3 存在时,在较低pH值下会明显降低Ni2 的去除,但当pH值升高时对Ni2 的去除有促进作用;(5)Cl-与NO3-的存在可促进PEX对Ni2 的去除,而SO42-的存在对Ni2 的去除有抑制作用,需增加投药量才能得到较好的去除;(6)Ni2 和致浊物质共存时,会互相影响彼此的去除.

Study on the trapping Ni2+ ions and the removing turbidity behavior of macromolecule heavy metal flocculant PEX

A novel water-soluble amphoteric macromolecule heavy metal flocculant polyethyleneimine-sodium xanthogente (PEX) has been synthesized by reacting polyethyleneimine with CS2 in alkaline medium. In jar tests, the flocculation performance of PEX was evaluated by using wastewater which contains Ni2 or/and turbidity. Some factors which affect the removal of Ni2 and turbidity were also studied. The experimental results showed that: (1) PEX had strong binding capabilities with Ni2 . The highest removal rate of Ni2 reached above 99%. (2) The pH value had some effect on the dosage of PEX, but little effect on the highest removal rate of Ni2 . (3) The existence of alkali metal or alkaline-earth metal ions in wastewater could promote the removal of Ni2 to some extent. (4) When there were Fe3 ions in wastewater, the removal rate of Ni2 would decrease evidently at lower pH value, and the existence of Fe3 ions would promote the removal of Ni2 with pH value increasing. (5) The existence of Cl- or NO-3 ions in wastewater could promote the removal of Ni2 , but SO2-4 ions would depress the removal of Ni2 . (6) Ni2 and turbidity-causing substance effected the removal of each other in the co-existing system of heavy metal ions and turbidity.