高分子重金属絮凝剂MAPEI的制备及性能研究

Study on preparation of the macromolecular heavy metal flocculant MAPEI and its performance

通过酰胺化反应将重金属络合剂巯基乙酸(TGA)接入高分子絮凝剂聚乙烯亚胺(PEI)的分子链中,合成了新型高分子重金属絮凝剂巯基乙酰聚乙烯亚胺(MAPEI),以达到用同一种絮凝剂既能除重金属又能除浊的目的.实验结果表明:①该絮凝剂对Cu2+有很好的捕集功能,Cu2+的最高去除率可达95%以上;②pH值对MAPEI除Cu2+、去浊的效果有一定的影响但影响不大,pH值低时除浊效果较好,pH值较高时除Cu2+效果较好;③当Cu2+和致浊物质共存时,会互相促进彼此的去除;④废水中Ca2+的存在会促进Cu2+的去除,Fe3+的存在会抑制Cu2+的去除.

In order to remove both soluble heavy metal species and insoluble substances efficiently by flocculation,a novel water-soluble macromolecule heavy metal flocculant, mercaptoacetyl polyethyleneimine （MAPEI） was synthesized by reacting polyethyleneimine with mercaptoacetic acid. Its performance was tested using wastewater containing turbidity and Cu^2＋ as targets. The mechanism of removing Cu^2＋ and turbidity,and factors which affect the removal rates of Cu^2＋ and turbidity were studied, for example, pH, flocculant dosage, and settling time. The experimental results showed that： ① MAPEI has a strong affinity for Cu^2＋ and the removal rate of Cu^2＋ exceeded 95% ;②The pH value has little effect on the removal of Cu^2 ＋ or turbidity in the pH range 2-5. Lower pH wastewater is more suitable for the removal of turbidity, but a higher pH is more suitahle for the removal of Cu^2＋ ;③ When Cu^2＋ and turbidity-causing substances coexist in a water sample, Cu^2 ＋ and turbidity-causing substances synergistically promote their mutual removal,and the residual concentration of Cu^2＋ and turbidity decrease further ; ④ The existence of Ca^2＋ in wastewater can promote the removal of Cu^2＋, and widens the optimum dosage range of MAPEL When Fe^3 ＋ ions coexist in the wastewater,the removal rate of Cu^2 ＋ will decrease if the MAPEI dosage is too low.