A novel heterogeneous system for sulfate radical generation through sulfite activation on a CoFe 2 O 4 nanocatalyst surface

• Published in: Journal of hazardous materials Vol. 324; no. Pt B; p. 583
• Main Authors: Liu, Zizheng, Yang, Shaojie, Yuan, Yanan, Xu, Jing, Zhu, Yifan, Li, Jinjun, Wu, Feng
• Format: Journal Article
• Language: English
• Published: Netherlands 15.02.2017
• Subjects: Alkaline pH; Oxysulfur radical; Sulfite; Metoprolol; CoFeO nanocatalyst
• ISSN: 1873-3336

Heterogeneous catalytic activation is important for potential application of new sulfate-radical-based advanced oxidation process using sulfite as source of sulfate radical. We report herein a heterogeneous system for sulfite activation by CoFe O nanocatalyst for metoprolol removal. Factors that influence metoprolol removal were investigated, including pH and initial concentrations of components. The CoFe O nanocatalyst was characterized by X-ray diffractometry (XRD) and transmission electron microscopy (TEM), and the catalytic stability was tested by consecutive runs. Radicals generated in the CoFe O S(IV)O system were identified through radical quenching experiments and by electron spin resonance (ESR). The catalytic mechanism was elucidated further by X-ray photoelectron spectroscopy (XPS). The catalytic process was dependent on initial pH, and more than 80% of the metoprolol can be removed at pH 10.0 following the Langmubir-Hinshelwood equation. The generation of Co-OH complexes on the CoFe O surface was crucial for sulfite activation. SO was verified to be the main oxidative species responsible for metoprolol degradation. Other organic pollutants, such as sulfanilamide, sulfasalazine, 2-nitroaniline, sulfapyridine, aniline, azo dye X-3B and 4-chloroaniline, could also be removed in this CoFe O S(IV)O system. The results suggest that the CoFe O S(IV)O system has good application prospects in alkaline organic wastewater treatment.