壳聚糖改性絮凝剂对含铅废水的强化絮凝处理  

Enhanced Flocculation Treatment of Lead-Containing Wastewater by ChitosanModified Flocculant

作　　者：刘丽秀[1] 何爱江[1] 曾碧涛[1] Liu Lixiu;He Aijiang;Zeng Bitao(Yibin Vocational Technical College,Yibin 644003,China)

机构地区：[1]宜宾职业技术学院,四川宜宾644003

出　　处：《山东化工》2023年第15期30-33,36,共5页Shandong Chemical Industry

基　　金：化工与环保科技创新团队(No.ybzy20cxtd03)。

摘　　要：选用壳聚糖(CS)、丙烯酰胺(AM)和衣康酸(IA)作为接枝共聚单体,通过超声波-自由基引发聚合制备出富含羧酸基团的新型重金属絮凝剂CS-g-P(AM-IA),该絮凝剂兼具螯合配位与絮凝作用,用以高效去除重金属Pb^(2+)。FTIR和SEM的分析结果表明AM与IA成功接枝CS。絮凝实验结果表明:在pH值=5.0,絮凝时间为25 min,CS-g-P(AM-IA)和CS投加量为3.0 mg/L时,对Pb^(2+)的去除率分别达到了84.5%与64.3%。CS-g-P(AM-IA)对Pb^(2+)的去除效果明显优于CS。离子强度和共存阳离子对CS-g-P(AM-IA)和CS吸附絮凝性能有一定的影响,其中Ca^(2+)的影响最为明显。CS-g-P(AM-IA)主要通过其IA上的羧基基团螯合配位Pb^(2+)离子并将其固定住,然后在吸附架桥和网捕卷扫絮凝作用下,生成大而密实的重金属絮体结构(d_(50)=275.9μm,D_(f)=1.91),强化了Pb^(2+)的分离去除。In this study,chitosan(CS),acrylamide(AM)and itaconic acid(IA)were selected as raw monomers to prepare the new heavy metal flocculant CS-g-P(AM-IA)with rich carboxylic acid ionic groups through ultrasonic-free radical initiated polymerization.The CS-g-P(AM-IA)has both chelation coordination and flocculation effect and used to remove heavy metal Pb^(2+)efficiently.The results of FTIR and SEM indicated that CS was successfully grafted by AM and IA.In addition,the chelating-flocculation experimental results showed that the removal rate of Pb^(2+)reached 84.5%and 64.3%by CS-g-P(AM-IA)and CS at pH value=5.0,flocculation time of 25 min,flocculant dosage of 3.0 mg/L,respectively.The Pb^(2+)removal effect by CS-g-P(AM-IA)was obviously superior than that of CS.The ionic strength and coexisting positive ion had an adverse effect on the adsorption performance for the flocculants,and the effect of Ca^(2+)was the most obvious.Pb^(2+)ions were mainly immobilized by CS-g-P(AM-IA)through chelation and flocculation by its IA carboxyl group.And then it was generated large and dense heavy metal flocs(d_(50)=275.9μm,D_(f)=1.91)by adsorption bridge and net trapping and scavenging,which enhanced the separation and removal of Pb^(2+)ions.

关 键 词：壳聚糖 衣康酸 Pb 2+ 重金属废水 絮凝剂 接枝聚合 

分 类 号：TQ314.253[化学工程—高聚物工业] X703.5[环境科学与工程—环境工程]