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In this study, we report the development of a novel magnetized coal fly ash-supported nano-silver composite (AgNPs/MCFA) for dual-functional applications in wastewater treatment: efficient degradation of methyl orange (MO) dye and broad-spectrum antibacterial activity. The composite was synthesized via a facile im-pregnation-reduction-sintering route, utilizing sodium citrate as both a reducing and stabilizing agent. The AgNPs/MCFA composite was systematically characterized through multiple analytical techniques, including Fourier transform infrared spectros-copy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), X-ray diffraction (XRD), and vibrating sample magnetometry (VSM). Results confirmed the uniform dispersion of AgNPs (average size: 13.97 nm) on the MCFA matrix, with chemical bonding (Ag-O-Si) enhancing stability. Under optimized condi-tions (0.5 g·L-1 AgNO3, 250 oC sintering temperature, and 2 h sintering time), AgNPs/MCFA exhibited exceptional catalytic performance, achieving 99.89% MO deg-radation within 15 min (pseudo-first-order rate constant ka=0.3133 min-1) in the presence of NaBH4. The composite also demonstrated potent antibacterial efficacy against Esche-richia coli (MIC=0.5 mg·mL-1) and Staphylococcus aureus (MIC=2 mg·mL-1), attributed to membrane disruption, intracellular content leakage, and reactive oxygen species gen-eration. Remarkably, AgNPs/MCFA retained >90% catalytic and antibacterial efficiency after five reuse cycles, enabled by its magnetic recoverability. By repurposing industrial waste (coal fly ash) as a low-cost carrier, this work provides a sustainable strategy to mitigate nanoparticle aggregation and environmental risks while enhancing multi-functional performance in water remediation.