New insights into natural organic matter transformation on enhanced membrane performance through peroxymonosulfate activation by Fe-based amorphous alloys

While Fe-based amorphous alloys exhibit remarkable pollutant degradation capabilities, their synergistic application with peroxymonosulfate (PMS) in ultrafiltration (UF) systems remains underexplored. This study investigated the novel Fe 92 B 6 Si 2 /PMS pretreatment system that significantly enhanced UF performance, with normalized flux (J/J₀) increasing from 0.28 to 0.93 LMH. The formation of a loose and porous cake layer led to significant reductions in reversible and irreversible resistances by 80.26% and 65.89%, respectively. It achieved significant NOM removal, with DOC and UV₂₅₄ reductions of 78.32% and 50.37%, respectively. Parallel factor analysis combined with self-organizing maps confirmed the effective removal of both humic-like and protein-like substances. Size exclusion chromatography and Fourier transform ion cyclotron resonance mass spectrometry further revealed the breakdown of high molecular weight organics into smaller fragments, with an 11.79% increase in low MW compounds (< 0.85 kDa). The oxidation process preferentially removed low-oxygen molecules (O/C < 0.6), generating high-oxygen compounds enriched with nitrogen and sulfur, such as tannins and condensed hydrocarbons. The high reactivity and self-renewing surface of Fe₉₂B₆Si₂, coupled with the Fe 2+ /Fe 3+ redox cycle, ensured continuous generation of SO₄• − and •OH radicals, effectively promoting pollutant degradation and membrane fouling mitigation. Moreover, the system maintained high degradation efficiency, stability, and safety over five cycles. These findings demonstrate the potential of Fe₉₂B₆Si₂/PMS as a promising UF pretreatment strategy to enhance water treatment efficiency.