Volcanic rock-confined core-shell nanoreactors as a highly effective and recyclable peroxymonosulfate activator for levofloxacin degradation: Performance, mechanism, and ecotoxicity assessment.

Levofloxacin (LEV), a widely detected fluoroquinolone antibiotic, threatens aquatic ecosystems due to its environmental persistence and potential to induce antibiotic resistance. While conventional powdered catalysts can degrade LEV, their practical application is hindered by poor recyclability and metal leaching. This study develops a volcanic rock-supported core-shell nanoreactor (ZPS@Volcanics) through encapsulation of ZIF-67/PBA@SiO2 nanoreactors within a porous volcanic matrix. Material characterization reveals a spatially confined architecture with stable interfaces. The ZPS@Volcanics/PMS system achieves 90.85% LEV removal within 50 min while maintaining over 80% efficiency after six cycles, with metal leaching below 0.1 mg/L. Mechanistic studies demonstrate SO4•--dominated oxidation with contributions from •OH and 1O2. The system exhibits strong resistance to common water matrix interferents and pH fluctuations, with ECOSAR analysis confirming that the acute toxicity of the intermediate products of LEV degradation was significantly reduced, and eventually some of them were mineralized into CO2 and H2O. This work provides an effective solution for antibiotic wastewater treatment by simultaneously addressing the dual challenges of catalytic efficiency and nanocatalyst recovery, offering practical potential for engineering applications.