Efficient and easy-to-recover immobilized heterogeneous catalyst CuSF/ZIF-67 activates peroxymonosulfate to remove refractory antibiotics

Abstract

Aiming at the challenge of catalyst recovery and reuse from aqueous solution, in this study, a novel immobilized heterogeneous catalyst, CuSF/ZIF-67, was innovatively designed and prepared, and PMS was activated by the synergistic effect of Cu, Co and low-valent sulfur species. The catalyst can degrade 98.01 % OTC (20 mg/L) within 20 minutes. Its high efficiency is mainly attributed to the promotion of Co²⁺ regeneration by low-valent sulfur species (S^2-/S₂^2-) and Cu⁺. In addition, the catalyst showed strong oxidation ability, and through the synergistic effect of free radicals (SO₄^•-, •OH, •O₂^-) and non-free radicals (¹O₂), it realized the efficient removal of various antibiotics and dyes. Additionally, after 10 cycles, its degradation efficiency only decreased by 5.12 %, which proved its good reusability. The intermediate was characterized in detail through LC-MS technology. The biological toxicity of the degradation intermediate was assessed both theoretically and experimentally, relying on the QSAR model and toxicology experiment. Ultimately, we designed and fabricated a catalytic reactor to validate the performance of the catalyst in the actual wastewater remediation process. The experimental results show that the solid catalyst shows great potential in practical application. This study not only offers a novel concept for the design of efficient and recyclable catalysts, but also furnishes robust technical support for the actual wastewater remediation.