Harnessing WMS-MnFe2O4 to drive photocatalytic peroxydisulfate activation for remediation of the refractory antibiotic ciprofloxacin

Resource recovery of waste molecular sieves was achieved through the synthesis of a WMS-MnFe 2 O 4 composite via combined co-precipitation and hydrothermal processes. • Under optimized parameters, approximately 95% degradation of 10 mg/L CIP was accomplished within 30 min by the WMS-MnFe 2 O 4 /UV/PDS system. • WMS-MnFe 2 O 4 /PDS/UV system has a wide range of pH applications. • Analysis of 13 intermediates led to the proposal of three primary degradation pathways: hydroxylation, ring cleavage, and defluorination. • Excellent catalytic stability and reusability were evidenced by a consistent degradation efficiency exceeding 80% over five cycles. To investigate the degradation of ciprofloxacin, a waste molecular sieve-supported manganese ferrite (WMS-MnFe 2 O 4 ) catalyst was fabricated via a combined co-precipitation and hydrothermal method and subsequently evaluated within a peroxydisulfate/UV activation system. The materials were examined by X-ray Diffraction, scanning electron microscope, energy-dispersive, UV-Vis diffuse reflectance spectroscopy, Brunauer-Emmett-Teller analysis via N 2 physisorption, and Vibrating Sample Magnetometer. Under the established optimal conditions (0.25 g/L WMS- MnFe 2 O 4 , 1.00 mM PDS, initial pH 6.3, and 28 W UV light), a degradation efficiency of approximately 95% was observed for 10.00 mg/L CIP, 300 mL solution after a 30-min reaction period. The radical quenching experiments show that ‐ O 2 · ‐ ${\mathrm{O}}_2^{·‐}$ , · OH, ‐ SO 4 · ‐ ${\text{SO}}_4^{·‐}$ , and h + generated in the WMS-MnFe 2 O 4 /PDS/UV system, and all played a major role. Liquid chromatography-mass spectrometry analysis identified 13 possible intermediates and suggested three degradation pathways, including hydroxylation, ring cleavage, and defluorination reaction. WMS- MnFe 2 O 4 exhibited excellent stability and recoverability, maintaining a degradation efficiency above 80% over five consecutive cycles. The minimal changes observed in the XRD patterns and SEM images of the spent catalyst further confirm its structural integrity and reusability. This work demonstrates a synergistic approach that enables both the resource recovery of waste molecular sieves and the remediation of organic wastewater. Download: Download high-res image (390KB) Download: Download full-size image