阳离子淀粉絮凝剂合成及处理煤矿井废水性能研究

摘要

In view of the characteristics of high turbidity coal mine wastewater, a cationic starch flocculant which can be used for its treatment was synthesized through the following procedures: synthesizing starch (St)-acrylic amide (AM) graft copolymer flocculant with St and AM as the material, ammonium persulfate and sodium hydrogen sulfite as the initiator; and then, modifying the St-AM graft copolymer with GTA as the cationic etheri-fying agent. The optimal synthesis condition for the said flocculant was determined through orthogonal test: the reaction time of graft copolymerization was 4 h, the dosage of St, initiator, GTA and NaOH were 5, 1.4, 2.6 and 0.24 g respectively, the mass ratio of AM to St was 4:1, the reaction time of etherification was 2.5 h, the temperature was 70 ℃. A performance comparison between cationic starch flocculant compound PAC and present flocculation process was carried out, the influence of flocculant dosage, compound effect, temperature and pH value on flocculation effect were analyzed, and the application condition of cationic starch flocculant was finally determined.%针对高浊度煤矿井水的特点,以玉米淀粉(St)和丙烯酰胺(AM)为原料,过硫酸铵和亚硫酸氢钠为引发剂,通过共聚反应合成了淀粉/丙烯酰胺接枝共聚物絮凝剂,以2,3-环氧丙基三甲基氯化铵(GTA)为阳离子醚化剂,对淀粉接枝共聚物进行阳离子化.根据正交试验确定了最佳合成工艺条件:接枝共聚反应时间为4h,St用量为5 g,AM与St质量比为4∶1,引发剂用量为1.4 g,GTA用量为2.6 g,NaOH用量为0.24g,醚化反应时间为2.5h,反应温度为70℃.并将阳离子淀粉絮凝剂复配PAC与现有絮凝工艺进行了对比和性能评价,分别对投加量、复配效果以及适合的温度、pH值对絮凝性能参数进行了评价,从而得出阳离子淀粉絮凝剂优化的应用条件.