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.
作者
吴杰
张佩
吴纯鑫
赵德明
WU Jie;ZHANG Pei;WU Chunxin;ZHAO Deming(College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014)
出处
《环境科学学报》
CAS
CSCD
北大核心
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)
