Catalytic Degradation of Tetracycline in Water by Activation of Peroxymonosulfate Using Epsilon-MnO₂/MnFe₂O₄ as Composite Catalyst

Exploring efficient and sustainable catalysts is the focus of the development of persulfate advanced oxidation process.Epsilon-MnO2/MnFe2O4 complex was synthesized with Fe-Mn spinel MnFe2O4 and ε-MnO2,the microstructure and morphology were characterized by XRD,SEM,FTIR and XPS.The catalytic degradation performance of ε-MnO2/MnFe2O4 was investigated by activating peroxymonosulfate（PMS）as a catalyst to degrade tetracycline（TC）.The results showed that the catalytic degradation of TC could reach 90.4% in 90 min when 0.1 g/L catalyst was added, PMS dosage was 0.05 g/L,pH was not adjusted and temperature was 25 ℃.After 5 cycles of experiments, the degradation efficiency of ε-MnO2/MnFe2O4 activated PMS for TC was still 76.3%,which indicated that the catalyst had good cycle stability.The free radical capture experiments showed that a variety of reactive oxygen species co-contributed to the degradation of TC,such as-OH on the catalyst surface, SO4·-,·OH,O2·- and 1O2,in which the -OH group on the catalyst surface played a leading role.The prepared catalyst activated PMS had good removal efficiency for antibiotics in water, and therefore had potential for application.