Research On Catalytic Removal Of Dimethyl Sulfoxide From Wastewater Using H₂O₂

Dimethyl sulfoxide（DMSO）is a polar organic solvent used as a solvent in many industries,including pharmaceuticals,coatings,film and polymer manufacturing.With the development of the chemical industry,the CONTENT of DMSO discharged into the environment every year has gradually increased,and the environmental problems caused by it have become more and more serious.The biodegradation of DMSO is very slow,and volatile toxic compounds such as dimethyl sulfide,methyl mercaptan and hydrogen sulfide are often released during the degradation process.The development of efficient and environmentally friendly DMSO wastewater degradation technology is urgent.In recent years,with the development of advanced oxidation technology,advanced oxidation technology based on hydrogen peroxide has received general attention,and the green and efficient advantages of advanced oxidation technology are fully reflected in the treatment of refractory organic matter.A large number of scholars at home and abroad have reported on this and applied it to the treatment of various types of refractory organic pollutants.Based on the theory of Fenton-like reactions,and taking the catalytic activity and stability as the evaluation indexes,the preparation process and catalytic properties of niobium and molybdenum support catalytic materials were studied,and N2adsorption-desorption,X-ray diffraction（XRD）,Raman（Raman）,ultraviolet-visible diffuse reflection（DR UV-vis）,X-ray photoelectron spectroscopy（XPS）,scanning electron microscopy（SEM）and high-power transmission electron microscopy（HR-TEM）were used to characterize them.At the same time,the process of catalytic hydrogen peroxide degradation of DMSO was studied,and the kinetic process of catalytic hydrogen peroxide degradation of DMSO was discussed.The MoO₃/SiO₂ catalyst was prepared by a simple wet impregnation method,and its effect of degrading DMSO in the presence of hydrogen peroxide was preliminarily investigated.is an environmentally friendly compound that is biodegradable without releasing harmful sulfides.Further research found that the catalyst had the best performance when the calcination temperature was500°C and the loading was 30%,and 179 mmol/L DMSO could be completely removed after 2 h of reaction at 50°C.The Nb₂O₅/SiO₂ catalyst was prepared by a simple wet impregnation method,and it was used to activate hydrogen peroxide to degrade DMSO.It was found that the catalyst with Nb₂O₅ as the active component had stronger catalytic performance than the MoO₃ catalyst,and it could remove 179mmol/L at 25℃.DMSO,while 20%was found to be the optimal load.It was verified by EPR analysis that the degradation of DMSO followed a non-radical oxidation mechanism.Kinetic studies on 20%Nb₂O₅/SiO₂ catalyst confirmed that the catalytic oxidation of DMSO is a pseudo-first-order reaction at 25℃.The catalytic activity of Nb₂O₅/SiO₂ decreased significantly after each use,but its recyclability was significantly improved after calcination.The DMSO conversion rate was 82.2%after five runs,and the catalytic performance was stable.