北京大学学报自然科学版 ›› 2019, Vol. 55 ›› Issue (3): 482-488.DOI: 10.13209/j.0479-8023.2019.019

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水体中磺胺甲恶唑在BDD电极体系中的电化学氧化机理

蒋欢1,2, 王婷2, 郑彤2, 任艳粉3, 倪晋仁1,2,†   

  1. 1. 北京大学深圳研究生院环境与能源学院, 深圳 518055 2. 北京大学环境工程系, 北京市新型污水深度处理工程技术研究中心, 北京 100871 3. 黄河水利委员会黄河水利科学研究院, 郑州 450003
  • 收稿日期:2018-04-17 修回日期:2018-05-03 出版日期:2019-05-20 发布日期:2019-05-23
  • 通讯作者: 倪晋仁,E-mail:nijinren(at)iee.pku.edu.cn
  • 基金资助:
    黄河水利科学研究院基本科研业务费专项(HKY-JBYW-2016-05)资助

Electrochemical Oxidation Mechanism of Sulfamethoxazole in BDD Electrode System

JIANG Huan1,2, WANG Ting2, ZHENG Tong2, REN Yanfen3, Ni Jinren1,2,†   

  1. 1. School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055 2. Beijing New Advanced Treatment Technology Research Center, Department of Environmental Engineering, Peking University, Beijing 100871 3. Yellow River Institute of Hydraulic Research, Zhengzhou 450003
  • Received:2018-04-17 Revised:2018-05-03 Online:2019-05-20 Published:2019-05-23
  • Contact: NI Jinren,E-mail:nijinren(at)iee.pku.edu.cn

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摘要：

以磺胺甲恶唑(SMX)为研究对象, 采用掺硼金刚石薄膜(BDD)电极电化学氧化法, 研究电流密度和电解质溶液对其降解效果的影响; 用循环伏安扫描和GC-MS测定中间产物, 提出SMX降解的机理。结果表明, BDD电化学氧化SMX的最佳电流密度为20 mA/cm2, 最适电解质溶液为0.05 mol/L Na2SO4, 此外, 可在50分钟内实现100%的SMX去除, 且去除过程满足一级反应动力学方程。低电流密度下, SMX可发生直接电化学氧化, 通过苯胺基失去电子生成二聚物; 高电流密度下, SMX以间接?OH氧化为主, 可能的降解途径有两条, 分别为?OH攻击导致S-N键断裂和?OH攻击杂环使得苯环开裂, 生成小分子羧酸, 最终矿化成CO2, H2O以及无机离子。

关键词: 掺硼金刚石薄膜电极, 磺胺甲恶唑, 循环伏安法, ?OH氧化

Abstract:

By choosing sulfamethoxazole as the typical pollutant, this paper studied influences of current density and electrolyte solution on electrochemical oxidation by BDD electrode. The degradation mechanism was illustrated through cyclic voltammetry (CV) and intermediates detection using GC-MS. As results, the optimal conditions for SMX degradation were 20 mA/cm2 for current density and 0.05 mol/L Na2SO4 for electrolyte solution, at which the removal efficiency of SMX was 100% within 50 min, and the degradation kinetics followed pseudo-first order model. At lower current density, the SMX dimer was fabricated due to the electron losen of phenylamino group, which could be directly electrochemical oxidized. While at higher current density, the indirect oxidation by ?OH was the main process. Two possible pathways could occur, one way was conducted due to the break of S-N bond, and the other was the attack to the heterocyclic ring resulting in the breakage of benzene ring. Finally, SMX was mineralized to CO2, H2O and inorganic ions. 

Key words: boron doped diamand, sulfamethoxazole, cyclic voltammetry, ?OH oxidation

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