Fe^(3+)/H_(2)O_(2)氧化体系降解邻苯二酚的过程机制  

Process mechanism on catechol degradation by Fe^(3+)/H_(2)O_(2) oxidation system

作　　者：张悦茹 钱征 陈荣志 杨生炯[1] ZHANG Yueru;Qian Zheng;CHEN Rongzhi;YANG Shengjiong(School of Environmental and Municipal Engineering.Xi′an University of Architecture and Technology,Xi′an 710055,China;College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]西安建筑科技大学环境与市政工程学院,西安710055 [2]中国科学院大学资源与环境学院,北京100049

出　　处：《环境工程学报》2024年第7期1840-1848,共9页Chinese Journal of Environmental Engineering

基　　金：陕西省自然科学基础研究计划面上项目(2024JC-YBMS-270)。

摘　　要：本研究构建了Fe^(3+)/H_(2)O_(2)氧化体系,且对其降解水中邻苯二酚的效果进行了研究,考察了不同反应条件对体系降解性能的影响,借助顺磁共振、活性物种淬灭、量子化学等手段对降解过程机制进行了详细分析。结果表明,Fe^(3+)/H_(2)O_(2)氧化体系可以在弱酸条件下实现邻苯二酚的高效降解。顺磁共振分析与淬灭实验结果表明,降解过程除羟基自由基的生成外,体系中共存有大量烃基自由基。结合电子光谱分析结果发现,邻苯二酚在被降解的过程中与Fe^(3+)形成了弱场配合物,该配合物不仅可在较温和的pH条件下实现Fe^(3+)的水解抑制,还可通过配体到Fe^(3+)的电荷迁移促进Fe(Ⅱ)-Fe(Ⅲ)-Fe(Ⅱ)的循环,从而加速自身的降解。更重要的是,Fe^(3+)/H_(2)O_(2)/邻苯二酚氧化体系可对水中共存的其他有机污染物产生显著的降解效果。以上研究结果可为抑制芬顿氧化过程中铁离子易水解和价态循环效率低的难题提供新的思路。Fe^(3+)/H_(2)O_(2) oxidation system was developed in this study to explore catechol degradation effect in water.The oxidation performances of this system under different reaction conditions were examined,its mechanism was investigated through electron paramagnetic resonance(EPR),reactive oxidation species(ROS)scavenging experiment,and quantum chemistry theoretical calculation.The results showed that catechol could be degraded by Fe^(3+)/H_(2)O_(2) system efficiently under mild acidic conditions,EPR and scavenging tests results indicated that large amounts of alkyl radicals besides hydroxyl radicals were produced.Electron spectroscopy analysis revealed a weak-field coordination complex occurred between catechol and Fe^(3+)during degradation,which could inhibit Fe^(3+)hydrolysis under mild pH conditions and further promote Fe(Ⅱ)-Fe(Ⅲ)-Fe(Ⅱ)redox cycling through charge transfer from ligand to metal,and thereby accelerating its self-degradation.Fe^(3+)/H_(2)O_(2)oxidation system could significantly enhance the degradation efficiency of coexisting organic compounds.This work provides a novel approach to face facile hydrolysis of iron and low redox cycling in Fenton process.

关 键 词：邻苯二酚 芬顿体系 助催化剂 配位化学 活性物种 

分 类 号：X703[环境科学与工程—环境工程]