Tertiary treatment of industrial organic wastewater: development of heterogeneous Fenton catalysts

Compared to other treatment methods, Fenton technology is an effective method for the degradation of non-biodegradable organic pollutants in water due to the generated highly oxidative hydroxyl radicals(•OH). However, the application of traditional homogeneous Fenton reaction is limited by its narrow pH response range, difficult recovery and separation of the active components of the catalyst, and easily generated iron sludge that will cause secondary pollution. In recent years, the heterogeneous reaction, which can effectively overcome the above drawbacks and has good industrial application prospects, has attracted extensive attention and research. This article mainly summarizes the development of Fenton technology, especially for the heterogeneous ones from the aspects of reaction mechanism, influence of reaction parameters, and materials. The emphasis is given on the advances in heterogeneous catalysts particularly for the Fe-based ones, Fe-free metal ones, carbon-based ones with introduction of their synthesis method, structure-performance analysis, plausible reaction pathways and catalytic performance for organic degradation. Finally, the influence of catalysts stability, utilization of hydrogen peroxide and rate-limit step in the heterogeneous Fenton catalyst system are summarized, which provides ideas for further improving the rational design and fabrication method of heterogeneous Fenton catalysts. © 2021, Chemical Industry Press Co., Ltd. All right reserved.