MEO/Ce^(4+)电催化体系的蒽醌染料(RB19)降解机理与效果研究  

The study on degradation mechanism and efficiency of MEO/Ce^(4+)electrocatalytic system on anthraquinone dye(RB19)

作　　者：李冬梅[1] 陈彦冰 蒋树贤[1] 陈璟恺 张文欣 张网 马圳锴 张刚毅 LI Dongmei;CHEN Yanbing;JIANG Shuxian;CHEN Jingkai;ZHANG Wenxin;ZHANG Wang;MA Zhenkai;ZHANG Gangyi(Faculty of Civil and Transportation Engineering,Guangdong University of Technology,Guangzhou 510006;School of Mechanical and Power Engineeing,Guangdong Ocean University,Yangjiang 529500;Morning Star Academy,Guangzhou 511430)

机构地区：[1]广东工业大学土木与交通工程学院,广州510006 [2]广东海洋大学机械与能源工程学院,阳江529500 [3]晨星学院,广州511430

出　　处：《环境科学学报》2024年第3期23-37,共15页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.51378129,51108094)。

摘　　要：以蒽醌染料活性蓝19(RB19)模拟染料废水,采用Ce^(4+)介体(MEO/Ce^(4+))电催化体系,对RB19进行电催化降解实验.对比了不同催化体系的降解性能,探讨了电流密度值、电解质种类及其浓度、初始Ce^(4+)浓度、初始pH等因素对MEO/Ce^(4+)体系降解RB19的效果,计算了不同降解驱动力的贡献率,并通过分析其氧化性中间物质种类及降解机理,探讨其可能的降解途径.结果表明:①MEO/Ce^(4+)电催化体系中产生的氧化活性物质主要有Ce^(4+)和羟基自由基,在降解RB19过程检测出9类中间态小分子有机物.②MEO/Ce^(4+)电催化体系氧化降解RB19的贡献率构成为:Ce^(4+)的催化氧化作用为主(占52.9%),直接电催化作用次之(占43.6%),羟基自由基的氧化作用最弱(占3.5%).③初始Ce^(4+)浓度对体系的氧化降解能力起决定性作用,电流密度值、电解质种类及其浓度、初始pH是影响体系氧化能力的关键因素.④新型MEO/Ce^(4+)电催化体系最佳反应条件为:电流密度值为228 A·m^(-2),电解质Na2SO4浓度为25 mmol·L^(-1),初始pH值为4和初始Ce^(4+)浓度为50μmol·L^(-1).在此条件下反应50 min,MEO/Ce^(4+)电催化体系对RB19的降解效果优于其他催化体系.其中,MEO/Ce^(4+)电催化体系去除率高达99.1%,是直接电催化(DET)体系去除率(43.2%)的2.3倍;而其降解速率为0.0804 min^(-1),是DET体系降解速率(0.01074 min^(-1))的7.49倍.(5)降解机理为:通过DET快速降解一部分RB19,另一部分R19则由强氧化活性物质Ce^(4+)完成.Ce^(4+)由溶液中的Ce^(3+)在阳极失去电子转化而成.Ce^(4+)快速将RB19氧化分解,最终产物为无机物(CO_(2)和H_(2))和小分子有机物.To take the anthraquinone dye Reactive Blue 19(RB19)as an example of dye wastewater,and Ce^(4+)as a mediator,electrocatalytic degradation experiments of the MEO/Ce^(4+)electrocatalytic system on RB19 were conducted.Compared with other electrocatalysis systems,the electrocatalysis degradation effect of MEO/Ce^(4+)was investigated under different conditions,such as current density,electrolyte types,electrolyte concentration,initial Ce^(4+)concentration and initial pH.By analyzing types of oxidizing intermediates and their degradation mechanisms,the contribution rate of different oxidizing active substances on R19 and the possible degradation pathways were explored.The results showed that:①The oxidizing active substances produced in MEO/Ce^(4+)electrocatalytic system mainly were Ce^(4+)and hydroxyl radicals.There were 9 types of intermediate small molecule organic compounds detected in the degradation process.②The contribution rate of oxidation active substances in MEO/Ce^(4+)electrocatalytic system on RB19 was that,Ce^(4+)was dominated in the catalytic oxidation efficiency(52.9%),followed by direct electrocatalysis(DET)(43.6%),and the oxidation of hydroxyl radicals was the weakest(3.5%).③The initial Ce^(4+)concentration played a decisive role in the oxidative degradation ablity of MEO/Ce^(4+)system,then followed the key factors,such as the current density,electrolyte type and its concentration,and initial pH.④We have calibrated the optimal preparation conditions for the new MEO/Ce^(4+)electrocatalytic system to be:current density as 228 A·m^(-2),electrolyte Na_(2)SO_(4)as 25 mmol·L-1,initial pH value as 4,and initial concentration of Ce^(4+)as 50μmol·L-1.Under these conditions,the removal efficiency of MEO/Ce^(4+)system on RB19 was better than other catalytic systems.Typically,its removal rate was as high as 99.1%,which was 2.3 times that of DET system(43.2%);its degradation rate was 0.0804 min-1,which was 7.49 times that of the DET system(0.01074 min^(-1)).⑤The degradation mechanism of MEO/Ce^(4+)was

关 键 词：MEO/Ce^(4+)电催化体系 蒽醌染料RB19 氧化性中间产物 降解贡献率 电催化机理与效果 

分 类 号：X703[环境科学与工程—环境工程]