Engineering commercial activated carbon with carbonyl site for activation of peroxymonosulfate and degradation of tetracycline

Abstract

Reduction of antibiotics in water by active of peroxymonosulfate (PMS) using low-cost metal-free activated carbon (AC) is an effective route to a better future. Herein, we report a new activated carbon (AC-12) by incorporating carbonyl (CO) into commercial AC to efficiently activate PMS and degrade tetracycline (TC). The AC-12/PMS system degrades 97.6 % of TC within 10 min, superior to sole AC (39 %), PMS (11.5 %), and AC/PMS system (61.1 %), respectively. The pseudo-first-order kinetic constant of AC-12/PMS is 0.372 min−1, 4.27-fold higher than AC/PMS. Furthermore, AC-12/PMS exhibits outstanding performance in TC degradation across various environmental factors (e.g., water bodies, pH, ions, and organics). Capture tests and electron spin resonance (ESR) spectroscopy indicate that TC degradation over AC-12/PMS predominantly involves synergistic interactions between superoxide radicals (O2−) and singlet oxygen (1O2), contributing nearly 100 % to TC removal. Additionally, high-performance liquid chromatography-mass spectrometry (HPLC-MS) elucidates potential degradation pathways and by-products. This study underscores the utility of AC-12 with carbonyl sites as an exemplary metal-free catalyst for PMS activation, highlighting its advantages of cost-effectiveness, facile regeneration, environmental friendliness, and excellent stability.