Investigation into the Synergistic Effect of the Zinc Peroxide/Peroxymonosulfate Double-Oxidation System for the Efficient Degradation of Tetracycline

oleh: Shefeng Li, Yong Zhang, Siyu Ding, Xuli Li, Wei Wang, Ningning Dong, Miaomiao Nie, Pei Chen

Format: Article
Diterbitkan: MDPI AG 2024-08-01

Deskripsi

The increasingly severe antibiotic pollution has become one of the most critical issues. In this study, a zinc peroxide/peroxymonosulfate (ZnO<sub>2</sub>/PMS) double-oxidation system was developed for tetracycline (TC) degradation. A small amount of ZnO<sub>2</sub> (10 mg) and PMS (30 mg) could effectively degrade 82.8% of TC (100 mL, 50 mg/L), and the degradation process could be well described by the pseudo-second-order kinetic model. Meanwhile, the ZnO<sub>2</sub>/PMS double-oxidation system showed high adaptability in terms of reaction temperature (2–40 °C), initial pH value (4–12), common inorganic anions (Cl<sup>−</sup>, NO<sub>3</sub><sup>−</sup>, SO<sub>4</sub><sup>2−</sup> and HCO<sub>3</sub><sup>−</sup>), natural water source and organic pollutant type. The quenching experiment and electron paramagnetic resonance (EPR) characterization results confirmed that the main reactive oxygen species (ROS) was singlet oxygen (<sup>1</sup>O<sub>2</sub>). Moreover, three possible pathways of TC degradation were deduced according to the analyses of intermediates. On the basis of comparative characterization and experiment results, a synergistic activation mechanism was further proposed for the ZnO<sub>2</sub>/PMS double-oxidation system, accounting for the superior degradation performance. The released OH<sup>−</sup> and H<sub>2</sub>O<sub>2</sub> from ZnO<sub>2</sub> could activate PMS to produce major <sup>1</sup>O<sub>2</sub> and minor superoxide radicals (•O<sub>2</sub><sup>−</sup>), respectively.