多孔α-Mn_(2)O_(3)的制备及其催化过一硫酸盐降解亚甲基蓝溶液的性能  

Synthesis of porousα-Mn_(2)O_(3) and its catalytic performance for activating peroxymonosulfate to degrade methylene blue solution

作　　者：向小倩 夏强 廖小刚 郑林 李纲 胡学步[1] XIANG Xiaoqian;XIA Qiang;LIAO Xiaogang;ZHENG Lin;LI Gang;HU Xuebu(College of Chemistry and Chemical Engineering,Chongqing University of Technology,Chongqing 400054,China)

机构地区：[1]重庆理工大学化学化工学院,重庆400054

出　　处：《材料工程》2022年第2期164-172,共9页Journal of Materials Engineering

基　　金：重庆市教委科学技术研究重点项目(KJZD-K201801103);重庆市科技局技术创新与应用发展专项面上项目(cstc2019jscx-msxmX0358);重庆理工大学项目(clgycx20203085,KLA20031)。

摘　　要：采用草酸盐热分解法制得由微米板堆垛而成的呈无规则颗粒状形貌的多孔α-Mn_(2)O_(3),探索其作为催化剂活化过一硫酸盐(PMS)降解模拟染料废水亚甲基蓝(MB)溶液的性能。系统考察催化剂的煅烧温度、催化剂投加量、PMS用量和阴离子种类等工艺参数对锰氧化物催化PMS降解MB溶液的影响。结果表明:450℃煅烧温度下所获产物表现出最为优异的活化PMS的能力,α-Mn_(2)O_(3)/PMS体系对MB的降解率达75.88%,而单一PMS或α-Mn_(2)O_(3)对MB的降解率仅为22.19%和5.72%。该催化体系降解500 mL浓度为10 mg/L的MB溶液的优化实验参数为:PMS(0.1 mol/L)用量为3 mL,催化剂投加量为0.05 g,反应50 min后MB的降解率可达83.55%。反应体系中引入C_(2)O^(2-)_(4)或PO^(3-)_(4)后会对MB溶液的降解产生抑制作用,抑制率分别为49.11%和10.27%,但Cl^(-)的存在对MB降解无影响。此外,借助淬灭实验和电子顺磁共振技术(EPR)对反应体系中存在的活性物种进行鉴定,α-Mn_(2)O_(3)催化PMS可产生·OH,SO^(-)_(4)·,·O^(-)_(2)和单线态氧(^(1)O_(2)),且1O 2是参与直接氧化降解MB的最主要活性中间体。动力学分析表明,α-Mn_(2)O_(3)催化活化PMS对MB溶液的降解为二级反应,反应速率常数为3.53 L·mmol^(-1)·min^(-1)。Porousα-Mn_(2)O_(3) with irregular granular morphology stacked from microplates was synthesized through thermal decomposition of oxalate,and its performance as a catalyst to activate peroxymonosulfate(PMS)for degradation of simulated dyestuff wastewater with methylene blue(MB)as main component was explored.Influences of calcination temperature,catalyst addition,PMS dosage and anion species on MB degradation efficiency were investigated.The results show that the product obtained at 450℃exhibits the most excellent catalytic ability.The degradation ratio of MB is 75.88%in the system ofα-Mn_(2)O_(3)/PMS,while its counterpart is only 22.19%and 5.72%for PMS orα-Mn_(2)O_(3) alone,respectively.The optimization reaction additions for degradation of MB of 500 mL with a concentration of 10 mg/L are:3 mL of PMS(0.1 mol/L),0.05 g ofα-Mn_(2)O_(3).At this condition,a MB degradation ratio of 83.55%can be achieved in 50 min.In addition,it is found that introduction of C_(2)O^(2-)_(4) or PO^(3-)_(4) has a negative effect on MB degradation,whose inhibition rate is 49.11%and 10.27%,respectively.However,Cl^(-) has no inhibitory effect for MB degradation.Furthermore,the active species in the reaction system are identified by the quenching experiments and electron paramagnetic resonance(EPR)tests.The results confirm that there are·OH,SO^(-)_(4)·,·O^(-)_(2)and^(1)O_(2)in the reaction system,and 1O 2 is the most important active intermediate involved in the direct oxidation degradation of MB.Kinetic analysis demonstrates that the degradation of MB solution with PMS catalyzed byα-Mn_(2)O_(3)is a secondary reaction,and the kinetic reaction rate constant is 3.53 L·mmol^(-1)·min^(-1).

关 键 词：草酸盐法 α-Mn_(2)O_(3) 过一硫酸盐 亚甲基蓝 单线态氧 

分 类 号：X131.2[环境科学与工程—环境科学]