Cobalt-Based MOF Material Activates Persulfate to Degrade Residual Ciprofloxacin

Abstract

Antibiotic residues in water environments have garnered widespread attention. Metal-organic frameworks (MOFs) have found extensive applications in water purification. This study investigates the use of a cobalt-based MOF material, zeolitic imidazolate framework-67(ZIF-67)(Co), for activating persulfate (PMS) to remove residual antibiotic ciprofloxacin (CIP) from aqueous environments. The main findings are as follows: ZIF-67(Co) exhibits insignificant adsorption capacity for CIP, and PMS alone does not degrade CIP effectively. However, ZIF-67(Co)-activated PMS demonstrates the efficient degradation of CIP, following pseudo-second-order reaction kinetics. Under optimal conditions of the catalyst dosage (15 mg) and PMS concentration (1.0 mM), the removal efficiency reaches 88% after 60 min. Comparative analysis of CIP degradation at different initial pH levels shows that the highest efficiency is reached under mildly acidic conditions, with an 86% removal rate achieved within 60 min under these conditions. Investigation into the impact of various inorganic anions on the ZIF-67(Co)-catalyzed PMS degradation of CIP reveals significant inhibition by chloride ions (Cl−), whereas nitrate (NO3-) and sulfate (SO42-) ions have minor effects on the degradation efficiency. The system demonstrates a consistent performance across different water matrices, highlighting ZIF-67(Co)/PMS as effective for ciprofloxacin removal in environmental waters. This study provides technical support for the efficient removal of antibiotic residues.