铁锰双金属氧化物对过硫酸氢钾降解酸性橙7的催化效果  

Degradation of Acid Orange 7 by Peroxomonosulfate Activated with Fe-MnO_x

作　　者：张古承 张静[1] 万子谦[1] 陈云宇 丁超[1] 安晓倩[1] 

机构地区：[1]四川大学建筑与环境学院,四川成都610065 [2]大庆石油责任有限公司,黑龙江大庆163000

出　　处：《环境科学研究》2015年第12期1902-1907,共6页Research of Environmental Sciences

基　　金：国家自然科学基金项目(51008052);教育部新世纪优秀人才支持计划项目(NCET-11-0082)

摘　　要：为了发挥均相体系中过渡金属元素对PMS（过硫酸氢钾）的催化效果,同时解决存在的金属离子污染的问题,以AO7（酸性橙7）为目标污染物,研究了采用溶胶-凝胶法（sol-gel method）制备Fe-MnOx（铁锰双金属氧化物）催化剂催化PMS的效果及降解机理.结果表明：ρ（Fe-MnOx）由50 mg/L升至200 mg/L后,35 min时AO7降解率由53.74%升至96.65%;继续升高ρ（Fe-MnOx）,AO7降解率提升效果不明显.随着ρ（PMS）0（PMS初始质量浓度）的升高,AO7的降解率变化趋势与之相同;而随着ρ（AO7）0（AO7初始质量浓度）的升高,AO7降解率有所下降.分别投加EA（乙醇）、TBA（叔丁醇）这2种捕获剂来验证体系氧化物种时发现,55 min时AO7降解率分别为79.40%和91.33%,氧化体系的主要氧化物种为·SO4^-（硫酸根自由基）和少量·OH（羟基自由基）.XRD（X射线衍射）和XPS（X射线光电子能谱）结果显示,Fe-MnOx催化剂中的Fe、Mn主要以Fe^3＋、Mn^2＋、Mn^4＋3种形式存在,Fe、Mn、O 3种元素中,Fe^3＋、Mn^2＋、Mn^4＋、O^2-和表面羟基氧的摩尔比分别为20.49%、26.46%、5.60%、32.51%和14.91%.研究显示,Fe-MnOx催化剂具有金属离子溶出量低、催化性能良好等优良性能,能够有效催化PMS生成自由基,对水中的污染物具有良好的降解效果.Bimetallic Fe-Mn oxide（ Fe-MnOx） was prepared using the sol-gel method to take advantage of the ability of Fe and Mn ions to activate peroxymonosulfate（ PMS） in a homogeneous system and avoid pollution caused by metal ions. The degradation process and mechanism were investigated for the removal of Acid Orange 7（ AO7） by using Fe-MnOxas a catalyst to generate powerful radicals from PMS. The effects of ρ（ Fe-MnOx）,ρ（ PMS）0and ρ（ AO7）0on the degradation of AO7 were tested. The results showed that with theρ（ Fe-MnOx） from 50 mg/L to 200 mg/L,the degradation rate of AO7 increased from 53. 74% to 96. 65% at 35 min. However,no significant change in the degradation rate was observed with further increases of ρ（ Fe-MnOx）. In addition,the degradation rate of AO7 decreased when ρ（ AO7）0increased. The reaction of the Fe-MnOxcatalyst-activated PMS was conducted with the addition of one of two probe compounds to detect the generation of reactive oxygen species： ethylalcohol（ EA） and tertbutylalcohol（ TBA）. The degradation rate of AO7 at 55 min was 79. 40% by adding EA and 91. 33% by adding TBA. Therefore,the oxygen species in the system were identified as mostly sulfate radicals and a small amount of hydroxyl radicals. The results of XRD and XPS indicated that the Fe-MnOx catalyst consisted of Fe2O3,Mn3O4 and Mn5O8,in which the relative molar quantities of Fe^3 ＋,Mn^2 ＋,Mn^4 ＋,O^2 ＋and surface hydroxyl oxygen were 20. 49%,26. 46%,5. 60%,32. 51% and 14. 91%,respectively. The study indicated that Fe-MnOxcatalyst had a low metallic ion leaching, and good ability to activate PMS and degrade organic pollutants into radicals.

关 键 词：溶胶-凝胶法 Fe-MnOx催化剂 酸性橙7 硫酸根自由基(·SO4^-) 

分 类 号：X52[环境科学与工程—环境工程]