关键词: Catalytic ozonation, Two-dimensional ceramic membranes, Fe/Mn bimetallic MOF, Micropollutants

Abstract: Two-dimensional (2D) catalytic ozonation membranes are promising for the treatment of micropollutants in wastewater due to simultaneous ozone-catalyzed degradation and membrane filtration processes. However, it remains challenging for 2D catalytic ozonation membranes to efficiently degrade micropollutants due to low mass-transfer efficiency and poor catalytic activity. Herein, Fe/Mn bimetallic metal-organic framework (MOF) intercalated lamellar MnO₂ membranes with fast and robust ozone-catalyzed mass-transfer channels were developed on the surface of the hollow fiber ceramic membrane (HFCM) to obtain 2D Fe/Mn-MOF@MnO₂-HFCM for efficiently degrading micropollutants in wastewater. The intercalation of Fe/Mn-MOF expanded the interlayer spacing of the MnO₂ membrane, thereby providing abundant transport channels for rapid passage of water. More notably, the Fe/Mn-MOF provided enriched reactive sites as well as high electron transfer efficiency based on the redox cycling between Mn³⁺/Mn⁴⁺ and Fe²⁺/Fe³⁺, ensuring the effective catalytic oxidative degradation of micropollutants including tetracycline hydrochloride (TCH), methylene blue, and methyl blue. Moreover, the carboxyl groups on the MOF formed covalent bonds (-COO-) with the hydroxyl groups in MnO₂ between layers, which increased the interaction between MnO₂ nanosheets to form stable interlayer channels. Specifically, the optimal composite membrane achieved a high removal rate of TCH micropollutant (93.4%), high water treatment capacity (282 L·m^-2·h^-1·MPa^-1), and excellent long-term stability (1200 min). This study provides a simple and easily scalable strategy to construct fast, efficient, and stable 2D catalytic mass-transfer channels for the efficient treatment of micropollutants in wastewater.

Key words: Catalytic ozonation, Two-dimensional ceramic membranes, Fe/Mn bimetallic MOF, Micropollutants