MnO2/UIO-66 improves the catalysed degradation of oxytetracycline under UV/H2O2/PMS system

In this study, novel MnO2/UIO-66 composite material was constructed via oil bath heating. MnO2 was prepared from KMnO4 and UIO-66 was prepared from C8H6O4 and ZrCl4. The MnO2/UIO-66 activated peroxymonosulfate (PMS) with high efficiency for oxytetracycline (OTC) decomposition under UV-light which was much more effective than adding MnO2/UIO-66 without PMS. Characterization analysis was carried out by means of XRD, SEM, TEM and XPS, etc. The effects of reaction system and catalyst addition on the degradation of OTC were also studied. Degradation of OTC with MnO2, UIO-66 and MnO2/UIO-66 was inhibited in the H2O2 system and promoted in the PMS and H2O2/PMS system. The MnO2/UIO-66 also displayed prominent stability and recyclability. The effect of initial pH on OTC degradation was studied. The effects of inorganic anions such as CO32−, HCO3−, SO42−, Cl− and NO3− on the degradation of OTC was also being studied. This study showed that MnO2/UIO-66 composite had great potential in antibiotic-contaminated wastewater treatment. Most importantly, reliable free radical attack sites were proposed based on density functional theory (DFT) calculation.