Monolithic ceramsite with interpenetrating-network MgMnO₃ shell for green catalytic ozonation of antibiotics in freshwater/marine aquaculture wastewater

Heterogeneous catalytic ozonation shows great promise for advanced wastewater treatment, yet powdered catalysts face practical limitations of poor recoverability and low matrices interference resistance. To address this, we developed a reusable monolithic MgMnO₃@CM catalyst by anchoring active MgMnO₃ components onto lightweight centimeter-scale ceramsite (CM) via impregnation-assisted sol-gel method. The morphology and electronic structure of MgMnO₃ shell was modulated by controlling the concentrations of Mg and Mn precursor, and an active interpenetrating-network configuration was achieved. This unique shell architecture and interfacial interactions endowed MgMnO₃@CM with exceptional mass transfer channels and redox properties, enabling superior catalytic ozonation of refractory sulfamethoxazole (SMZ). The catalyst achieved a high reaction rate constant (0.266 min^-1) and increased mineralization efficiency from 22.5±1.0% to 69.4±1.4%. Crucially, a MgMnO₃@CM-packed filter maintained an average SMZ rejection of 93.5% across diverse coexisting matrices (mg/L level) during continuous 12-hour operation, demonstrating sustainable potential for treating real freshwater and marine aquaculture wastewater. Mechanistic studies revealed MgMnO₃@CM modulated surface atomic oxygen (*O)-driven non-radical oxidation pathways. This work provides a green engineering strategy for designing efficient, waste-free catalytic systems to support sustainable aquaculture.