Molybdenum-modified iron oxides mediated enhanced degradation of meropenem by peroxydisulfate

초록

Meropenem, a last-resort antibiotic, is frequently detected in wastewater, but research on its removal remains limited. This study introduces molybdenum-modified iron oxides (MFx), synthesized via a simple solution combustion method, to activate peroxydisulfate (PDS), for enhanced oxidation of meropenem in heterogeneous advanced oxidation processes. The physicochemical and magnetic properties of MFx were systematically analyzed, revealing that sodium molybdate and polyvinyl alcohol (PVA) play key roles in forming Mo-incorporated maghemite. Mössbauer spectroscopy and magnetic characterization further validated the successful incorporation of molybdenum into maghemite. Among the synthesized MFx at different iron to molybdenum molar ratios (x), MF 1.0 demonstrated superior catalytic performance due to its higher molybdenum content and larger surface area, achieving >99 % meropenem removal under optimal conditions (0.25 g L−1 catalyst dosage, 1.0 mM PDS, pH 4.0). Mechanistic investigations identified sulfate radical (SO<inf>4</inf>•−) and hydroxyl radical (HO•) as primary reactive species, with EPR and XPS measurements confirming the role of Fe2+/Fe3+ and Mo5+/Mo6+ redox transitions in the activation of PDS. The MF 1.0/PDS system exhibited promising recyclability, maintaining over 90 % meropenem removal efficiency even after five consecutive cycles, highlighting its potential applicability in practical water treatment systems. This study highlights the potential of molybdenum-modified iron oxides for achieving pharmaceutical remediation, contributing to improved environmental and public health outcomes. © 2025 Elsevier B.V.

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