Enhanced tetracycline degradation by manganic iron‑manganese compounds with peroxymonosulfate(PMS): Experimental optimization and environmental fate estimation

Abstract

Antibiotics have earned wide attention because of its direct and indirect health and environment risks. As a result, numerous techniques have been explored for deep degradation of antibiotics. Among them, advanced oxidation technologies with Fe-Mn-based catalysts have a great potential on efficient wastewater purification mainly due to low expense, abundant reserves, chemical stabilities and strong oxidation. Herein, we propose a novel wastewater degradation system (Fe₃O₄-FeMn₂O₄/(peroxymonosulfate)PMS degradation system) as an efficient method for TC decontamination via sulfate radicals based-advanced oxidation processes (SR-AOPs). The results showed that nearly 100 % TC was eliminated in 70 min with the condition of [FM1:3] = 0.50 g/L, [PMS] = 0.25 g/L, pH = 6 and reaction temperature in 25 °C. Based on morphological structure and operating mechanism analysis, the as-prepared Fe₃O₄-FeMn₂O₄ displays obvious porous structures and rich surface functional groups, which positively promotes the oxidative ability of degradation system. Otherwise, dominant active species and possible intermediates are revealed with the results of EPR, HPLC-MS and scavenging experiments, illustrating that nine transformation pathways are ascribed to sulfate radical (SO₄·⁻) and singlet oxygen (¹O₂). This study provides a new method for the development of SR-AOPs towards higher sustainability and more environmental suitability.