Catalytic degradation of ciprofloxacin via peroxymonosulfate activation using a UiO66 and amino functionalized silica coated magnetite composite

In the present study, Fe 3 O 4 @SiO 2 -NH 2 (FSN) nanoparticles combined with UiO-66 (FSNUiO-66) were synthesized as a novel catalyst for activating peroxymonosulfate (PMS) in the degradation of ciprofloxacin (CIP). Optimization using response surface methodology coupled with Box–Behnken design (RSM-BBD) identified a quadratic model (p < 0.0001, adjusted R 2 = 0.913) as the best fit for the experimental data, predicting a maximum CIP removal efficiency of 96.44% under operational conditions of pH 3.22, catalyst dose of 0.51 g/L, PMS concentration of 3.22 mM, reaction time of 57.99 min, and initial CIP concentration of 12.20 mg/L. The FSNUiO-66 catalyst exhibited 1.14–4.80 times higher performance than other catalysts in both adsorption and catalytic roles. A 6% decrease in efficiency over six reaction cycles highlighted the excellent stability of FSNUiO-66 for continuous CIP degradation. Effluent toxicity was assessed using LC 50 and toxicity unit (TU) analyses, revealing an average increase of 71.93 mg/L in LC 50 and a reduction of 4.71 TU. The BOD 5 /COD ratio of 0.82 and 90.09% COD removal confirmed the effective mineralization of CIP and its conversion into biodegradable molecules. The results demonstrated that the developed model was highly significant (F = 65.84, p < 0.0001) with a strong goodness of fit (R 2 = 0.942). The analysis indicated that reaction time and initial pH were the most influential parameters affecting the process efficiency, while the model showed good predictive capability and reliability. Quenching experiments identified SO 4 •- , • OH, and O 2 •- radicals, and a possible degradation mechanism based on these results and previous studies was proposed. Treatment of hospital wastewater using FSNUiO-66/PMS achieved 74.15% COD removal, demonstrating the catalyst’s high capacity for both synthetic wastewater treatment and aqueous matrix treatment.