Study On Organic Pollutants Degradation Using Peroxymonosulfate Active By Co/Mn/Fe Heterogeneous Catalyst

Water sacristy and pollution have become more and more severe on a global scale,making water pollution control imminent.Among them,organic wastewater is the most difficult to be degraded owing to its complex components and high toxicity.Sulfate radical-based advanced oxidation process?SR-AOPs?with strong oxidizing ability,efficiency,easy operation,wide application and low energy consumption is a good choice for wastewater control.The key of SR-AOPs is to find new heterogeneous transition metal catalysts with high efficiency,stability and good reusability.Cobalt-manganese-iron transition metal element has been widely used as a raw material for metal catalyst synthesis,because their strong catalytic activity,large amount of crust and easy to obtain.Therefore,Co-Mn LDH and Co₃MnFeO₆ were synthesized and utilized as novel heterogeneous catalysts to active peroxymonosulfate?PMS?for the degradation of organic dyes and carbamazepines in our study.The specific researchs are as follows:?1?Co-Mn LDH catalyst was synthesized via a simple co-precipitation method.And the morphology,crystal form,structure and specific surface area of as-prepared Co-Mn LDH were characterized by XRD,FITR,TEM,HRTEM,EDS,BET.Then,Co-Mn LDH/PMS system was constructed for the degradation of organic dyes.A series of degradation experiments were carried out to investigate the catalytic property of the catalyst.Finally,the mechanism of Co-Mn LDH/PMS system was explored combining radical quenching studies and XPS characterization.The results suggest that Co-Mn LDH with high purity,large BET surface area and tidy morphology was successfully synthesized.The degradation tests showed that Co-Mn LDH/PMS system exhibited excellent performance for degradation of organic dyes and had a wide application range of pH?3-10?.Repeated experiments and characterization results show that the prepared Co-Mn LDH exhibits good stability and reusability due to the synergistic effect of Co and Mn elements.Radical quenching studies indicated that both HO^·and SO₄^·-were generated during the PMS activation,And SO₄^·-played more critical role in the degradation process than HO^·.?2?Magnetic Co₃MnFeO₆ catalyst was synthesized using a simple sol-gel method.And the morphology,structure,magnetism and so on of as-prepared Co₃MnFeO₆ were investigated by related characterization technologies.The prepared Co₃MnFeO₆ was utilized as a novel heterogeneous catalyst to active PMS for the degradation of carbamazepine.In the degradation experiments,Co₃MnFeO₆/PMS system showed excellent performance that CBZ could be quickly removed at a wider pH range from 2.5 to 11.Moreover,it was found that Co₃MnFeO₆ catalyst maintained high activity and stability during the degradation.Through the comparison of CBZ degradation tests using different Co/Mn/Fe-based catalysts and XPS characterization,it was found that the excellent performance of Co₃MnFeO₆ catalysts is mainly rely on the synergistic effect between the three metal ions,the roles of Co,Mn and Fe in synergistic effect were identified as:the redox cycles of Co and Mn mainly worked for the activation of PMS,and Fe mainly provided magnetism for Co₃MnFeO₆catalyst as well as the adsorption site for PMS and CBZ.