锰基催化剂催化臭氧氧化有机污染物研究  

Catalytic ozonation study of organic pollutants by manganese-based catalysts

作　　者：卢嘉心 陈硕[1] LU Jiaxin;CHEN Shuo(School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China)

机构地区：[1]大连理工大学环境学院,辽宁大连116024

出　　处：《大连理工大学学报》2021年第6期576-585,共10页Journal of Dalian University of Technology

基　　金：中央高校基本科研业务费专项资金资助项目(DUT20TD205).

摘　　要：为制备连续流条件下具有高活性和稳定性的臭氧氧化催化剂,采用氧化还原沉淀法制备了锰基负载型催化剂(Mn-CeOx/γ-Al_(2)O_(3)、Mn-FeOx/γ-Al_(2)O_(3)、Mn-CoOx/γ-Al_(2)O_(3)),对其进行表征分析,考察催化剂在苯酚降解过程中的催化活性和稳定性,探究催化臭氧氧化反应机理.结果表明:连续流中n(Mn)/n(Ce)为2∶1的Mn-CeOx/γ-Al_(2)O_(3)在催化臭氧氧化降解苯酚时催化活性最佳,TOC去除率达到80.2%,水力停留时间3.3 min、气相臭氧浓度10.3 mg·L^(-1)、溶液初始pH 9为最佳反应条件.经过6次重复实验后苯酚的TOC去除率仍高达79.6%,溶液中活性组分溶出量几乎可以忽略不计.Mn-CeOx/γ-Al_(2)O_(3)催化剂在催化臭氧氧化降解草酸、对硝基酚的过程中也表现出较高的矿化效率,TOC去除率在77%~83%,该催化剂具有广谱适用性.电子顺磁共振波谱证明催化臭氧氧化反应体系中产生的活性氧物种为OH,Ce的引入有利于提高Mn-CeOx/γ-Al_(2)O_(3)催化剂中Mn4+与晶格氧的含量.In order to develop ozonation catalysts with high catalytic activity and good stability under continuous flow conditions,manganese-based supported catalysts(Mn-CeOx/γ-Al_(2)O_(3),Mn-FeOx/γ-Al_(2)O_(3),Mn-CoOx/γ-Al_(2)O_(3))were prepared using redox precipitation method.The catalysts were characterized and analyzed,and the catalytic activity and stability of the catalysts in phenol degradation process were investigated.The catalytic ozonation reaction mechanism was explored.The results show that the Mn-CeOx/γ-Al_(2)O_(3)with n(Mn)/n(Ce)of 2∶1 has the best catalytic activity for the catalytic ozonation of phenol under continuous flow conditions,with the TOC removal rate being 80.2%.The optimized operation conditions are as follows:hydraulic retention time is 3.3 min,gas phase ozone concentration is 10.3 mg·L-1,and initial pH is 9.After 6 repeated experiments,TOC removal rate is still as high as 79.6%,and the dissolved amount of active components in the solution is almost negligible.The catalyst also shows high mineralization efficiency in the process of catalytic ozonation degradation of oxalic acid and p-nitrophenol with TOC removals ranging from 77%to 83%,which shows the universality for the organic pollutants treatment.The electron spin resonance spectroscopy characterization proves that the reactive oxygen specieOH is produced in the catalytic ozonation system,and the introduction of Ce can improve the content of Mn4+and lattice oxygen in Mn-CeOx/γ-Al_(2)O_(3)catalysts.

关 键 词：非均相催化臭氧氧化 氧化还原沉淀法 锰基催化剂 连续流 

分 类 号：X511[环境科学与工程—环境工程]