Preparation Of Clay Bimetallic Heterogeneous Fenton Catalyst And Its Application In Water Treatment

Organic wastewater is the most common source of pollution in industrial production at present.It has the characteristics of high TOC and high COD,and the structure of organic matter is stable.It is discharged into the water body without treatment or incomplete treatment,which poses hidden dangers to aquatic animals and plants and human health.At present,wastewater treatment methods mainly include adsorption method,membrane filtration method,chemical precipitation method,biochemical method,etc.Compared with the above-mentioned treatment methods,Fenton catalytic method has significant advantages.It can not only realize the complete mineralization of organic matter,but also does not produce secondary pollution.Some shortcomings of homogeneous Fenton system,such as narrow reaction p H range,easy to produce iron sludge,difficulty in catalyst recovery,etc,limit its application in actual production.Heterogeneous Fenton catalysis can effectively overcome the above shortcomings,and the catalyst is relatively stable.Good reusability and good development prospects in the industrial production process.In this paper,using montmorillonite as the carrier,the Fe/Cu-MMT catalyst was prepared by loading iron and copper onto montmorillonite through a two-step method of impregnation and calcination.The microscopic morphology,structural composition and chemical composition of the catalyst were also characterized.Through the microscopic characterization,it is found that the heterogeneous Fe/Cu-MMT Fenton catalyst supported by iron and copper metal still basically maintains the morphological structure of the montmorillonite,and the oxide nanoparticles are uniformly dispersed on the surface of the montmorillonite.The FT-IR and XPS spectra show that iron and copper have been successfully introduced into the montmorillonite structure.The thermal analysis results show that the thermal stability of iron and copper is significantly improved after loading.According to the nitrogen adsorption-desorption results,the specific surface area is slightly reduced after the iron and copper are loaded.This is due to the iron-copper oxide nanoparticles entering the microporous structure and occupying the active sites on the surface of the montmorillonite,and due to the oxidation of iron and copper.The introduction of the pillaring agent enlarges the distance between layers of montmorillonite,thereby expanding the average pore size and improving the adsorption capacity to a certain extent.The catalytic activity of heterogeneous Fenton catalyst（Fe/Cu-MMT）was studied by removing rhodamine B（RhB）from the solution.The experimental results show that under the optimized conditions of 1.5 g·L^-1 Fe/Cu-MMT,5 mmol·L^-1 H₂O₂ and p H 7.0,the decolorization efficiency and TOC removal rate of RhB within 90 minutes reach 98.4%and 87.9%.It is worth noting that after 10 consecutive cycles,the decolorization efficiency and TOC removal rate of RhB can still reach 87.9%and 66.5%,indicating that the heterogeneous Fenton catalyst has excellent catalytic activity and reusability.In addition,active radical capture experiments and EPR spectroscopy studies show that hydroxyl radicals（·OH）and superoxide radicals（·O₂^-）play a major role in the mineralization of RhB.The heterogeneous Fenton catalyst prepared in this study has the advantages of high catalytic activity,good reusability,low cost,and environmental protection.It provides a new material for the efficient removal of organic pollutants and is a bimetallic clay-based heterogeneous Fenton.The research and application of the catalyst have laid the foundation.