纳米级Pd/Fe-MWCNTs-Fe_3O_4体系对2,3-DCB的降解研究  

Degradation of 2,3-dichlorobiphenyl by Pd/Fe-MWCNTs-Fe_3O_4 nanocomposites

作　　者：吴杰 张佩[1] 吴纯鑫[1] 赵德明[1] WU Jie;ZHANG Pei;WU Chunxin;ZHAO Deming(College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014)

机构地区：[1]浙江工业大学化学工程学院,杭州310014

出　　处：《环境科学学报》2019年第5期1509-1518,共10页Acta Scientiae Circumstantiae

基　　金：浙江省自然科学基金(No.LY19B070006)

摘　　要：为有效抑制纳米级Pd/Fe颗粒的团聚和钝化及改善磁分离效果,以多壁碳纳米管(MWCNTs)和磁性纳米级Fe_3O_4颗粒为载体,在超声波辐照下利用液相还原法制备纳米级Pd/Fe-MWCNTs-Fe_3O_4颗粒,并采用XRD、TEM、SEM、EDX及BET表征其物性,最后以2,3-二氯联苯(2,3-DCB)为目标污染物,探究其对2,3-DCB还原脱氯的影响因素、降解机理和动力学.结果表明:制备的纳米级颗粒粒径均匀、分散性好、比表面积大;体系中纳米级Pd/Fe投加量、钯化率、纳米级Fe_3O_4投加量、MWCNTs投加量、反应温度、溶液初始pH及共存阴离子均会对2,3-DCB的降解效果产生明显影响;本研究推测出纳米级Pd/Fe-MWCNTs-Fe_3O_4体系对2,3-DCB的降解机理,发现其降解符合拟一级动力学关系.To inhibit the agglomeration and passivation of Pd/Fe nanoparticles and enable magnetic separation, multi-walled carbon nanotubes/magnetic Fe3O4 nanoparticles(MWCNTs-Fe3O4) composite was employed as platform to support them. Pd/Fe-MWCNTs-Fe3O4 nanocomposites were prepared via a facile liquid phase reductive method with the aid of ultrasound irradiation, and were full characterized by XRD, TEM, SEM, EDX, and BET. Thereafter, the catalytic performance of Pd/Fe-MWCNTs-Fe3O4 was checked using the model reaction of 2,3-dichlorobiphenyl(2,3-DCB) dechlorination, wherein the influential factors, degradation kinetics, and reaction mechanism were investigated. It can be found that:①the degradation of 2,3-DCB followed pseudo-first-order kinetics;②the highly dispersed Pd/Fe nanoparticles with uniform size as well as large surface area of Pd/Fe-MWCNTs-Fe3O4 catalyst could be accounted for the superior activity of 2,3-DCB dechlorination;③several factors such as Pd/Fe nanoparticles dosage, palladium content, Fe3O4 nanoparticles dosage, MWCNTs dosage, reaction temperature, initial pH and coexisting anions in the solution significantly affect the degradation of 2,3-DCB.

关 键 词：超声波 纳米级Pd/Fe-MWCNTs-Fe3O4颗粒 2 3-二氯联苯 还原脱氯 动力学 

分 类 号：X78[环境科学与工程—环境工程] TQ209[化学工程—有机化工]