Fe-Mn Bimetallic Oxide-Enabled Facile Cleaning of Microfiltration Ceramic Membranes for Effluent Organic Matter Fouling Mitigation via Activation of Oxone

Membrane fouling caused by effluent organic matters (EfOM) remains a major challenge in wastewater reclamation. Herein, we report a promising catalytic microfiltration ceramic membrane (CM) that features with ∼20 μm thickness of Fe-Mn bimetallic oxide (Mn1.5FeO6.35) active layer coating on the α-Al2O3 membrane base (α-Al2O3@Mn1.5FeO6.35 CM), which enables fantastic mitigation of irreversible EfOM fouling via in situ Oxone activation. Modeling results indicated that complete and standard pore blocking dominated an initial fouling mechanism on the α-Al2O3@Mn1.5FeO6.35 CM, followed by a cake mode as the fouling evolution. Critically, the cake fouling layer was effectively removed through a facile on-line cleaning with Oxone aqueous solutions, resulting in rapid flux restoration. The mechanism was dominated by radical cleaning pathways, and hydroxyl radicals (HO·) played a critical role in reducing EfOM fouling over other reactive species (e.g., sulfate radicals (SO4·–) and singlet oxygen (1O2)). A key feature of as-prepared α-Al2O3@Mn1.5FeO6.35 CM is the favorable slightly basic pH cleaning conditions (∼pH 10), restricting Fe and Mn leaching and maximizing the membrane-sustained activity and durability. Hence, this study highlights the robust cleaning capability of α-Al2O3@Mn1.5FeO6.35 CM toward EfOM fouling and proposes a new strategy in developing environmentally friendly catalytic CMs for wastewater reclamation.