Preparation Of Iron-copper Bimetallic Materials And Study On Its Activation Oxone For The Degradation Performance For Levofloxacin

Levofloxacin（LVF）as a broad-spectrum antibiotic,it is toxic and difficult to biodegrade.The above characteristics lead to its long-term existence in natural water bodies and serious threat to human health.At present,such pollutants are mainly degraded by activating Oxone to generate active free radicals with strong oxidizing properties.Oxone activation methods mainly include two types of heterogeneous catalysis and homogeneous catalysis.Among them,the heterogeneous catalysis of multiple composite metals has the advantages of high catalytic efficiency,low cost,and good stability.Therefore,it has become a hot topic of recent research.Based on the above characteristics,two kinds of magnetic catalysts,Fe₃O₄-Cu_xO and CuFe₂O₄were prepared by ball milling and calcining.Fe₃O₄-Cu_xO and CuFe₂O₄were used to activate Oxone to degrade LVF in water.Explored the reaction mechanism of these catalysts with Oxone.Explored the degradation pathway of LVF in CuFe₂O₄/Oxone system.The main contents and conclusions of this study are as follows:（1）Synthesis of Fe₃O₄-Cu_xO and study of the degradation of LVF by Fe₃O₄-Cu_xO/Oxone system.Fe₃O₄-Cu_xO catalyst was synthesized by ball milling and calcination.The composition,micro-morphology,and magnetic properties of Fe₃O₄-Cu_xO were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,and Magnetic test（VSM）.Through X-ray photoelectron spectroscopy（XPS）analyzed of valence states of metal elements on catalyst surface.Evaluation of the catalytic performance of the catalyst by activating Oxone to degrade LVF.The effects of mass ratio of Fe and Cu O during ball milling and subsequent calcination temperature on the catalytic performance of synthetic materials were investigated.The result shows:Fe and Cu O are ball milled at a mass ratio of 1:1and calcined at 300℃for 90 min,then synthetic materials have the best catalytic performance.Under the conditions of Fe₃O₄-Cu_xO dosage of 1.4 g/L,Oxone of 0.6 mmol/L,and p H of 7.0,the 10 mg/L LVF was degradation 96.5%in 60 min at room temperature.When the dosage of Fe₃O₄-Cu_xO is less than 1.4 g/L and the initial concentration of Oxone is less than 0.6 mmol/L,the degradation rate of LVF increased rapidly with the increase of Fe₃O₄-Cu_xO dosage and the initial concentration of Oxone.Within the initial p H range of 3～11,the higher the initial p H,the higher the degradation rate of LVF.After 5 repeated experiments,the degradation rate of LVF by Fe₃O₄-Cu_xO/Oxone system is still above 85%.Dissolution metal ion detection and other experiments confirm that the above reactions are mainly heterogeneous catalytic reactions.The quenching experiment and ESR analysis demonstrated that the degradation of LVF was mainly caused by SO₄^-·.（2）Synthesis of CuFe₂O₄and study of the degradation of LVF by CuFe₂O₄/Oxone system.CuFe₂O₄was synthesized by ball milling and calcination method for the first time.The composition,micro-morphology,and magnetic properties of CuFe₂O₄were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,and Magnetic test（VSM）.Through X-ray photoelectron spectroscopy（XPS）analyzed of valence states of metal elements on catalyst surface.Evaluation of the catalytic performance of the catalyst by activating Oxone to degrade LVF.The effect of calcining temperature on CuFe₂O₄synthesis was investigated.The result shows:after Fe/Cu powder was ball milling in a molar ratio of 2:1 and calcined at 400℃for 120 min,the crystal shape of CuFe₂O₄was the best and the catalytic efficiency was the highest.Under the conditions of CuFe₂O₄dosage of 1.0 g/L,Oxone of 0.6mmol/L,and p H of 7.0,the 10 mg/L LVF was degradation 97.5%in 60 min at room temperature,and the removal rate of TOC at this time is 35.5%.Within the initial p H range of 3～11,the CuFe₂O₄synthesized in this study has high catalytic activity.After 5 repeated experiments,CuFe₂O₄still has high catalytic activity.Comparison of XRD characterization results of CuFe₂O₄before and after cycling shows that the crystal structure of CuFe₂O₄is stable.It shows that the CuFe₂O₄synthesized in this study has good stability.The quenching experiment and ESR analysis demonstrated that the LVF degradation was determined by the synergistic effect of SO₄^-·and·OH reactive species.According to the results of HPLC-MS,the degradation intermediates were identified and the possible transformation pathways were proposed.