Study On Degradation Of Golden Orange G With Peroxymonosulfate Activated By Copper Ferrite Composite Catalyst

The printing and dyeing industry produced a large amount of organic wastewater which had the characteristics of high color and strong toxicity.Traditional methods were difficult to treat these wastewaters.Advanced oxidation processes(AOPs)has been considered as the effect technology in treatment of refractory organic matter,because of its excellent reaction rate and oxidation degradability.Among these AOPs,the advanced oxidation technology based on sulfate radical(SO₄^·-)has attracted wide attention due to its wide range of p H adaptability and strong redox potential.In this paper,the heterogeneous catalyst spinel copper ferrite(Cu Fe₂O₄)used in activated persulfate advanced oxidation technology was modified and Cu Fe₂O₄-GO and Cu Co_xFe_2-xO₄ was synthesized by adding GO support and doping transition metal Co.Study the catalytic oxidation performance of copper ferrite composite catalyst by degrading the azo dye Golden Orange G(OG).Using X-ray diffraction(XRD),scanning electron microscopy(SEM),and magnetic performance testing(VSM)to characterize the morphology,structure and magnetic properties of each catalyst.The effects of catalyst dosage,PMS dosage,initial p H value,Cl^-concentration and concentration of humic acid in the reaction system on the degradation rate of OG were studied through the experiments of each catalyst activated PMS to degrade OG.Total organic carbon(TOC)detection and ultraviolet full-wavelength scanning(UV-Vis)were used to study the mineralization ability of copper ferrite composite catalyst,and the repeated use performance of copper ferrite composite catalyst was studied.Combining the free radical quenching experiment and XPS analysis,explored the mechanism of Cu Fe₂O₄-GO and Cu Co_xFe_2-xO₄ activating PMS to degrade OG.The main research results of this article are as follows:(1)Structure control and magnetic properties of the catalyst:The synthesized Cu Fe₂O₄ was spinel crystal type spherical particles.GO sheets had a good dispersion effect on Cu Fe₂O₄.Co doping had no significant effect on the crystal structure and morphology of Cu Co_0.6Fe_1.4O₄ spherical particles.The saturation magnetization of Cu Fe₂O₄,Cu Fe₂O₄-GO and Cu Co_0.6Fe_1.4O₄ was 27.8 emug^-1,27.4 emug^-1 and 31.6emug^-1,respectively,all of which had good magnetic separation performance.(2)Catalytic oxidation performance:The catalytic activation performance of Cu Fe₂O₄ on persulfate(PMS)and persulfate(PDS)was studied respectively,and it was believed that Cu Fe₂O₄ has excellent activation performance on PMS.With the increase of Cu Fe₂O₄,Cu Fe₂O₄-GO and Cu Co_0.6Fe_1.4O₄ catalyst and PMS dosage,the degradation rate of OG also accelerated.Cu Fe₂O₄-GO had the best catalytic performance at 20%mass fraction of GO.The best doping amount of Co of Cu Co_xFe_2-xO₄ was x=0.6.Cu Fe₂O₄-GO and Cu Co_0.6Fe_1.4O₄had better degradation effects on OG under neutral and weak alkaline conditions.Cl^-had a certain promoting effect on the degradation of OG by Cu Fe₂O₄-GO,while had no obvious effect on the degradation of OG by Cu Co_0.6Fe_1.4O₄.Humic acid(HA)had a certain inhibitory effect on the degradation of OG by Cu Fe₂O₄-GO,but had no obvious effect on the degradation of OG by Cu Co_0.6Fe_1.4O₄(3)Catalytic oxidation mechanism:The active substances that played a major role in OG degradation in Cu Fe₂O₄/PMS and Cu Fe₂O₄-GO/PMS systems was SO₄^·-and SO₄^·-/¹O₂,respectively.This was because the Cu/Fe bimetallic active center on the surface of Cu Fe₂O₄-GO activated PMS to produce SO₄^·-,and the rich oxygen-containing groups on the surface of GO could directly activate PMS to produce ¹O₂.The catalytically active substances in the Cu Co_0.6Fe_1.4O₄/PMS system were SO₄^·-and¹O₂.This was due to the Co element doping that produced oxygen vacancies(OVs)in the catalyst,and OVs could react with PMS to produce ¹O₂This paper showed that the Cu Co_0.6Fe_1.4O₄/PMS system was better than the Cu Fe₂O₄-GO/PMS system in terms of initial p H adaptability and mineralization ability of the solution,and it had a stronger damage effect and faster damage to the benzene ring and naphthalene ring of OG,but the repeated use performance of Cu Fe₂O₄-GO was better than Cu Co_0.6Fe_1.4O₄.