FeC particle electrodes derived from copper slag boost peroxymonosulfate activation for efficient antibiotic...

Effective regulation of non-radical pathways plays a pivotal role in addressing the complex aquatic environments encountered in sulfate-based advanced oxidation processes. In this study, magnetic particle electrode (MPEs) was prepared by co-pyrolysis of modified corn stalk (BC derived from corn stalks) and copper slag. We found that calcining at 800 °C with a CS:BC ratio of 1:3 gave the best conditions for transforming the silicon ferrite crystal phase. In the three-dimensional electrocatalytic oxidation (3DECO) system, more than 98 % of LFX (30 mg/L) was removed by CS@BC₃-800 particle electrode within 15 min, and the apparent rate constant (k) of LFX was 0.323 min^-1, which was 7.8 times higher than that of 2DECO. The extensive conjugated graphitic structure of the biochar facilitated the rearrangement of Fe 3d orbital electrons, promoting the formation of empty orbitals and thereby enhancing direct persulfate activation via surface-mediated electron transfer. This mechanism underpinned the dominance of non-radical regulated pathways. Ion leaching tests, cycling experiments, and multi-pollutant removal assessments demonstrated the long-term stability and practical applicability of CS@BC₃-800 MPEs. This work supports the "waste-to-waste" strategy and highlights the potential of 3DECO for treating high-salinity organic wastewater.