化学学报 ›› 2017, Vol. 75 ›› Issue (6): 602-607.DOI: 10.6023/A17010004 上一篇    下一篇

所属专题: 铁环境化学

研究论文

铜离子促进Fe@Fe2O3纳米线活化分子氧降解阿特拉津的研究

贾法龙, 刘娟, 张礼知   

  1. 农药与化学生物学教育部重点实验室 华中师范大学化学学院 武汉 430079
  • 收稿日期:2017-01-04 出版日期:2017-06-15 发布日期:2017-04-01
  • 通讯作者: 张礼知 E-mail:zhanglz@mail.ccnu.edu.cn
  • 基金资助:

    国家杰出青年基金(No.21425728)资助项目.

Copper Ions Promoted Aerobic Atrazine Degradation by Fe@Fe2O3 Nanowires

Jia Falong, Liu Juan, Zhang Lizhi   

  1. Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079
  • Received:2017-01-04 Online:2017-06-15 Published:2017-04-01
  • Contact: 10.6023/A17010004 E-mail:zhanglz@mail.ccnu.edu.cn
  • Supported by:

    Project supported by Natural Science Funds for Distinguished Young Scholars (No. 21425728).

阿特拉津是一种持久性含氯有机污染物,难以生物降解,因此有必要开发高效技术清除环境中残留的阿特拉津.近来纳米铁材料的发展为降解阿特拉津提供了一种可供选择的新方法,但降解过程中纳米铁活性逐渐减弱的问题仍需改进.本论文研究了铜离子(Cu2+)存在条件下Fe@Fe2O3纳米线活化分子氧降解阿特拉津的过程,并探讨了Cu2+的作用机理.研究结果表明,少量Cu2+的存在就可以显著促使Fe@Fe2O3生成溶解态Fe(Ⅱ),从而有助于分子氧活化并产生更多·OH等活性氧物种.在降解过程中,阿特拉津首先被氧化,进而发生脱氯上羟基反应、侧链氧化以及脱侧链反应.

关键词: 阿特拉津, 降解, Fe@Fe2O3纳米线, 分子氧活化, 铜离子

As a persistent chlorinated organic pollutant, Atrazine (2-chloro-4-(ethylamino)-6-isopropylamino-s-triazine) in the environment brings harm to natural environment as well as the human health. Since Atrazine is difficult to be degraded biologically, various strategies have been developed to realize efficient and environmentally-friendly removal of Atrazine. Recently, nanoscaled iron has been extensively applied for the remediation/treatment of wastewater contaminated with various organic and inorganic pollutants and exhibits superior activity than that of bulk iron. But its removal efficiency would decrease along with reaction time. In this study, we report that copper ions could efficiently promote atrazine degradation with Fe@Fe2O3 nanowires via the molecular oxygen activation processes. As indicated by the electron spin resonance analysis (ESR) and X-ray photoelectron spectroscopic analysis (XPS) results, the addition of Cu2+ ions could promote the release of dissolved Fe(Ⅱ) from Fe@Fe2O3. During the degradation process, the concentration of Fe(Ⅱ) in the solution with Cu2+ions is maintained at a much higher level than that without Cu2+ ions. At the same time, Cu2+ions were reduced to low valence states (Cu0), which further promoted the release of Fe2+. The generated Fe2+ would then activate the molecular oxygen via the single-electron or double-electron transfer route. As a result, more reactive oxygen species such as ·OH were generated to degrade atrazine. Under room temperature and aerobic condition, the Atrazine removal rate constant in Fe@Fe2O3/Cu2+ system was 0.694 h-1, which was almost 23 times that in Fe@Fe2O3 system. Moreover, the Fe@Fe2O3/Cu2+catalytic system also remains superior activity in the pH range of 2~5. The intermediates of atrazine degradation were detected and the atrazine degradation in the Fe@Fe2O3/Cu2+ catalytic system was accompanied with alkylic oxidation, dealkylation and dechlorination. This study provides a new way to enhance molecular oxygen activation by core-shell Fe@Fe2O3 nanowires, and also deepens our understanding of the molecular oxygen activation processes by Fe@Fe2O3 for the aerobic pollutant degradation.

Key words: atrazine, degradation, Fe@Fe2O3 nanowires, molecular oxygen activation, copper ions