新型螯合凝胶在废水除镉(Cd^(2+))中的应用  

Preparation of removing cadmium(Cd^(2+)) using a new chelating gel

作　　者：栾义峰[1] 李晨阳 常文娟 

机构地区：[1]长安大学环境科学与工程学院,陕西西安710054

出　　处：《应用化工》2018年第2期224-226,230,共4页Applied Chemical Industry

基　　金：国家自然科学基金(20877036);长安大学创新创业训练(201710710092)

摘　　要：聚丙烯酰胺(PAM)聚合链上的酰胺基团通过Mannich反应,获得接枝双硫腙或巯基乙胺,得到聚丙烯酰胺双硫腙接枝和巯基乙胺接枝凝胶,考察pH、振荡时间、反应温度、凝胶用量及干扰因子等对水中镉离子(Cd^(2+))去除效果的影响。结果表明,除镉的最佳条件为:含镉废水浓度5 mg/L,溶液pH为6.0,振荡时间2.0 h,温度20℃,双硫腙螯合凝胶2.5 g或巯基乙胺螯合凝胶0.5 g。在此条件下,其螯合除镉率高达99.98%,溶液中余镉残留量低于0.001 mg/L,达到国家排放标准。凝胶除镉的效果不受KCl、Na_2CO_3、Mg(NO_3)_2、Na_2SO_4干扰离子的影响。获得了一种新的从工业废水中除去镉离子(Cd^(2+))的方法。The amide groups on the polyacrylamide( PAM) polymer chains are grafted with dithizone or mercaptoethylamine by Mannich reaction. The removal of cadmium ions in water is achieved by the chalation of dithizone graft gel or mercaptoethylamine graft gel which are fixed on polyacrylamide chains and cadmium ions( Cd^(2+)) in water. The influence of p H,reaction time,gel content and interference factors on the removal rate of Cd^(2+) in water were investigated. The results indicated that the optimum conditions for removing cadmium are: the concentration of cadmium irons in waste water is 5 mg/L,the p H of solution is 6. 0,the reaction time is 2. 0 h and the temperature is 20 ℃. In this case should add dithiocarbide graft gel 2. 5 g or mercaptoethylamine graft gel 0. 5 g. Under these conditions,the removal rate of cadmium ions can be as high as 99. 98%,the concentration of residual cadmium irons in the water can be less than 0. 001 mg/L,which up to the national emission standards. The presence of KCl,Na_2CO_3,Mg(NO_3)_2 and Na_2SO_4 interferons has no effect on the adsorption of cadmium by gel. A new method for removing cadmium ions( Cd^(2+)) from industrial waste water is obtained.

关 键 词：工业废水 除镉 双硫腙接枝凝胶 巯基乙胺接枝凝胶 

分 类 号：TQ028.1[化学工程] O69[理学—化学]