化学学报 ›› 2017, Vol. 75 ›› Issue (6): 538-543.DOI: 10.6023/A17020047 上一篇    下一篇

所属专题: 铁环境化学

研究评论

纳米零价铁活化分子氧原理及降解有机污染物性能增强策略

穆毅, 贾法龙, 艾智慧, 张礼知   

  1. 农药与化学生物学教育部重点实验室 环境与应用化学研究所 华中师范大学 武汉 430079
  • 收稿日期:2017-02-10 出版日期:2017-06-15 发布日期:2017-04-01
  • 通讯作者: 艾智慧, 张礼知 E-mail:jennifer.ai@mail.ccnu.edu.cn;zhanglz@mail.ccnu.edu.cn
  • 基金资助:

    项目受国家重点研发计划纳米科技专项(2016YFA0203000),国家自然科学基金(Nos.21425728,21177048,21173093,21477044,51472100),中央高校基本科研业务费专项资金(Nos.CCNU16A02029,CCNU16A04005),华中师范大学优秀博士学位论文培育计划(2015YBZD024&2016YBZZ031)资助.

Molecular Oxygen Activation with Nano Zero-valent Iron for Aerobic Degradation of Organic Contaminants and the Performance Enhancement

Mu Yi, Jia Falong, Ai Zhihui, Zhang Lizhi   

  1. Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Applied & Environmental Chemistry, Central China Normal University, Wuhan 430079
  • Received:2017-02-10 Online:2017-06-15 Published:2017-04-01
  • Contact: 10.6023/A17020047 E-mail:jennifer.ai@mail.ccnu.edu.cn;zhanglz@mail.ccnu.edu.cn
  • Supported by:

    Project supported by the National Key Research and Development Program of China (2016YFA0203000), National Natural Science Foundation of China (Nos. 21425728, 21177048, 21173093, 21477044, 51472100), Self-Determined Research Funds of CCNU from the Colleges' Basic Research and Operation of MOE (Nos. CCNU16A02029, CCNU16A04005), Excellent Doctorial Dissertation Cultivation Grant from Central China Normal University (2015YBZD024 and 2016YBZZ031).

纳米零价铁直接还原降解有机污染物运行长效性差,且不能矿化有机污染物.利用纳米零价铁还原活化分子氧生成活性氧物种可以氧化甚至矿化有机污染物.在最近的研究中,作者提出了纳米零价铁活化分子氧的双途径机理,即铁核电子转移到氧化铁壳表面的双电子还原活化分子氧途径和氧化铁表面结合态亚铁离子的单电子还原活化分子氧途径,阐释了纳米零价铁核壳结构依赖的分子氧活化降解有机污染物性能机制及性能增强策略.证实在纳米零价铁活化分子氧体系添加少量亚铁离子能在零价铁表面形成更多的结合态亚铁,显著增强纳米铁表界面活性氧物种生成量;同时,在纳米零价铁活化分子氧体系中引入少量有机或无机配体亦可提高活性氧物种产生效率,从而增强有机污染物降解性能.最后讨论了典型环境因素如pH值、共存离子、天然有机物等影响纳米零价铁活化分子氧降解有机污染物性能的规律.

关键词: 纳米零价铁, 分子氧活化, 活性氧物种, 高级氧化技术

Nano zero-valent iron (nZVI) is a special kind of iron with large specific surface area, strong reduction activity, and the environmental friendliness. nZVI was usually used to reductively degrade organic pollutants, but its long-term performance was poor and the organic pollutants could not be mineralized. Nano zero-valent iron can reductively activate molecular oxygen to generate reactive oxygen species for oxidation or even mineralization of organic pollutants. Recently, we found the core-shell structure dependent aerobic degradation of organic pollutants by nZVI and proposed a new physical insight into the molecular oxygen activation mechanism of the aerobic nZVI process, where the outward electrons transfer from the iron core initiate the two-electron molecular oxygen activation and surface bound ferrous ions on iron oxide shell favor the single-electron molecular oxygen activation. Several strategies have also been proposed to enhance the production of reactive oxidants by nZVI-induced oxygen activation. We confirmed that addition of extra ferrous ions into the nZVI/O2 system could generate more surface bound ferrous ions for significantly enhancing the generation of reactive oxygen species. Meanwhile, the introduction of some inorganic or organic ligands in the aerobic nZVI system could also improve the active oxygen species generation efficiency. Finally main typical environmental factors including of the pH value, coexisting ions, natural organic matter on the organic pollutants degradation with the aerobic nZVI were discussed. By the way, we also investigated the anoxic Cr(VI) removal with nZVI. It was found the Cr(VI) removal rate constant was mainly attributed to the reduction of Cr(VI) by the surface bound Fe(Ⅱ) besides the reduction of Cr(VI) adsorbed on the iron oxide shell via the electrons transferred from the iron core. We also demonstrated that the presence of oxygen molecule can inhibit Cr(VI) removal with nZVI, which was attributed to that the oxygen molecular activation could compete with Cr(VI) for the consumption of surface bond Fe(Ⅱ) and donor electrons transferred from Fe0 core.

Key words: nano zero-valent iron, molecular oxygen activation, reactive oxygen species, advanced oxidation technology