Acta Chimica Sinica ›› 2019, Vol. 77 ›› Issue (10): 1017-1023.DOI: 10.6023/A19060203 Previous Articles     Next Articles

Article

非均相芬顿体系协同去除复合双污染物: 化学转化, pH影响和机理分析

杨波, 张永丽*()   

  1. 四川大学建筑与环境学院 成都 610065
  • 收稿日期:2019-06-08 出版日期:2019-10-15 发布日期:2019-09-05
  • 通讯作者: 张永丽 E-mail:zxm581212@163.com
  • 基金资助:
    项目受国家自然科学基金(51878422)

Synergistic Removal of Co-contamination by Heterogeneous Fenton System: Chemical Conversion, pH Effect and Mechanism Analysis

Yang, Bo, Zhang, Yongli*()   

  1. College of Architecture & Environment, Sichuan University, Chengdu 610065, China
  • Received:2019-06-08 Online:2019-10-15 Published:2019-09-05
  • Contact: Zhang, Yongli E-mail:zxm581212@163.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China(51878422)

The chemical transformation of ZVI micro-surface and the degradation mechanism in the process of synergistic removal of copper ions and methylene blue pollutants by ZVI-Fenton system were studied systematically. The samples of ZVI, before and after reaction in the ZVI/H2O2 and ZVI/H2O2-Cu systems, were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS) and Fourier Transform infrared spectroscopy (FTIR) to research the changes of ZVI surface structure, Fe and Cu species’ chemical conversion. The results showed that the residual corrosion products on the surface of ZVI were more and the corrosion products were mainly Fe3O4 and Fe2O3 after reaction in the ZVI/H2O2 system. However, in the ZVI/H2O2-Cu system, the corrosion effect of ZVI was more significant, but the residual corrosion products of ZVI surface were less, and the proportion of Fe3O4 increased. In addition, the main reduction product of Cu 2+ was Cu 0, which was accompanied by the generation of CuO. Furthermore, the effects of pH on the removal of pollutants from the five systems (ZVI, ZVI-Cu, H2O2-Cu, ZVI/H2O2 and ZVI/H2O2-Cu) were compared and the changes in TCu and TFe concentrations under different pH conditions were monitored. The results indicated that the ZVI/H2O2-Cu system not only simultaneous effectively remove MB and TCu compared with other three systems, but also enlarged the effective pH range (pH=2.5~5.5) of ZVI-Fenton system. In addition, free radical capture experiments showed that hydroxyl radicals played an important role in the oxidative degradation of methylene blue, and 10 mmol/L tert-butanol could completely capture hydroxyl radicals in the system. Finally, the mechanism of synergistic removal of TCu and MB degradation by ZVI-Fenton system was revealed. The substitution reaction between ZVI and Cu 2+, the action of Cu 0 and ZVI galvanic cells, the acid corrosion effect, and the redox cycle of iron and copper together accelerate the degradation of MB by the system and promote the conversion of ZVI surface substances. This study provides a theoretical basis for collaborative treatment of industrial complex pollutants.

Key words: zero-valent iron powder, heterogeneous Fenton, cyclic catalysis, synergism, micro surface transformation