Solvent extraction is widely applied, while extraction wastewater treatment remains a huge challenge because of the stability of extractants. Heterogeneous Fenton-like catalysis is a promising method, but the short half-life of hydroxyl radicals (•OH) generated by hydrogen peroxide (H2O2) activation results in unsatisfactory •OH utilization and organics removal. Herein, an efficient strategy for treating extraction wastewater based on comediating adsorption and electron transfer by fluorine and nitrogen co-doped carbon (FNC) catalyst with dual-active site was developed. Specially, N sites adsorb organics and F sites activate H2O2, shortening the migration distance of •OH. Theoretical calculation and di(2-ethylhexyl) phosphoric acid (D2EHPA) extraction wastewater degradation experiment showed that F site with electron acquisition can transfer electrons provided by electron-rich D2EHPA enriched at N sites to H2O2, facilitating the continuous generation of •OH through lowering the energy barrier for H2O2 activation. As a result, 96.49% D2EHPA in simulated wastewater and 90.26% total organic carbon in real extraction wastewater were removed. Moreover, FNC catalyst exhibited excellent reusability and ionic adaptability, and can be extended to the removal of various extractants. The proposed dual-active site catalyst provides an effective strategy for Fenton-like reaction to treat refractory extraction wastewater, promoting sustainable development of solvent extraction industry.
Keywords: Extraction wastewater; Fenton-like reaction; H2O2 activation; adsorption; fluorine and nitrogen co-doped carbon.
© 2024 Wiley‐VCH GmbH.