| Antibiotic wastewater pollution and dye wastewater pollution have received more and more attention.However,these two types of pollutants are difficult to biodegrade.Heterogeneous Fenton,as an efficient wastewater treatment technology,has received great attention in recent years.However,heterogeneous Fenton still has practical problems such as narrow pH range,large amount of metal ion leaching,low catalytic performance,and poor catalyst reusability.Therefore,it is necessary to develop more efficient and stable heterogeneous Fenton catalysts.In this study,CuOx/Al2O3-EPC catalyst and Cu2Fe/Al2O3 catalyst were prepared by electroless plating and calcination method(EPC)and sol-gel method,respectively.Tetracycline(TC)and reactive Red 2(RR2)were selected as the target pollutants,respectively.The catalytic effect of the homogeneous Fenton catalytic system,and the stability of the catalyst and the catalytic degradation mechanism of the Cu2Fe/Al2O3 catalyst were studied.First,the CuOx/Al2O3-EPC catalyst was prepared by electroless plating and the preparation conditions were optimized.The catalyst plating under the condition of pH=9 at 80℃ and calcinated at 700℃ has the best catalytic effect.Secondly,the iron-copper alumina catalyst was prepared by the sol-gel method,and it was found that the iron-copper metal mass ratio was 1:2,the metal loading amount was 25%(w%),and the calcination temperature was 400℃.The Cu2Fe/Al2O3 material had the best catalytic effect.The results of scanning electron microscopy(SEM),X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR)show that the CuOx/Al2O3-EPC catalyst has good crystallinity,and its main components are Al2O3,Fe2O3 and CuO;while the Cu2Fe/Al2O3 catalyst has poor crystallinity,and its main components areγ-Al2O3,iron-aluminum spinel and copper-aluminum spinel.In the study of CuOx/Al2O3-EPC heterogeneous Fenton catalyst to degrade TC,it is found that the catalytic efficiency of the catalyst is at a reaction temperature of 20℃,a catalyst dosage of 0.25 g/L,and a H2O2 concentration of 0.04 mol/L.The highest,it can almost completely degrade the target pollutant TC within 1.5 h.CuOx/Al2O3-EPC can effectively degrade pollutants when the pH of the solution is in the range of 3-10,and the removal rate of organic pollutants TC can reach more than 86%.The catalyst was reused 8 times,and the removal rate of TC remained above 85%,which shows that the catalyst has good reusability.Secondly,in the study of Cu2Fe/Al2O3 heterogeneous Fenton catalyst degradation of reactive Red 2,the catalyst has the highest catalytic efficiency and can almost completely decolorize reactive Red 2 within 2 h when the temperature was 25℃,the catalyst dosage was 0.50 g/L,and the H2O2 concentration was 0.04 mol/L.When the pH of the solution is in the range of 5-9,the catalyst can quickly and efficiently degrade pollutants.At the same time,the Cu2Fe/Al2O3 catalyst also shows excellent stability and reusability.Finally,we explored the catalytic mechanism of the Cu2Fe/Al2O3 heterogeneous Fenton system.First,Fe and Cu,as the active sites of the catalyst,combined with H2O2 to produce ·OH and ·HO2 Such as strong oxidizing free radicals,oxidize and decompose organic pollutants in water.At the same time,Cu+ promotes the regeneration of Fe2+by reducing Fe3+to Fe2+,and accelerates the redox cycle of Fe3+/Fe2+and Cu2+/Cu+. |
