Anchored highly stable Fe–Mn bimetallic catalyst in Al2O3 ceramic membranes for boosting Oxone activation and efficient degradation of emerging micropollutants

Abstract

Catalytic membrane integrating membrane filtration and advanced oxidation in one single-step is promising in addressing emerging micropollutants issue in water, the challenges in catalytic activity and stability still limit their practical application. This study successfully anchored highly stable Fe–Mn bimetallic catalyst (FMBC) in Al₂O₃-based microfiltration and ultrafiltration ceramic membranes channel (named as FMBC@Al₂O₃-MF or UF) via a novel in situ fabrication strategy. Characterization results revealed that FMBC was anchored on the membrane channel wall of Al₂O₃-MF/UF, which enabled boosting Oxone activation to generate sulfate radical and hydroxyl radical at circumneutral pH (e.g., 7.0–9.0) and with great stability. Notably, FMBC@Al₂O₃-UF exhibited a remarkable activity and anti-interference capability in actual water matrices, which resulted in efficient degradation of emerging micropollutants such as carbamazepine, crotamiton, diethyltoluamide, gemfibrozil and ibuprofen in lake water and municipal wastewater treatment plant secondary effluent at environmentally relevant concentrations. Moreover, FMBC@Al₂O₃-MF/UF also displayed high cleaning efficiency toward natural organic matter (NOM) and effluent organic matter (EfOM) fouling via Oxone activation. Besides, the intermediates of carbamazepine degradation were identified, and most of them had decreased aquatic toxicity based on Ecological Structure Activity Relationship (ECOSAR) prediction. The high activity, stability and environmentally friendly property of the as-prepared FMBC@Al₂O₃-MF/UF make them promising application for advanced treatment of emerging micropollutants in water.