Study On Preparation Of Metal Oxide@ZSM-5/SiO₂ Composite Nanofibrous Membrane And Its Catalytic Ozonation Degradation Of Phenol

Phenol,with strong toxicity,is one of the most difficult to remove toxic pollutants in wastewater,and is commonly found in wastewater such as dyeing wastewater.Phenol not only pollutes the environment,but also disease and damage people's health.At present,the methods for removing phenol solution mainly include the physical,biological,and advanced oxidation methods.The advanced oxidation process has become a hot spot due to its high degradation efficiency,stable reaction,and environmental protection.The Catalytic ozonation is a representative of the advanced oxidation methods.At present,the catalyst is difficult to recover to cause secondary pollution,poor stability,and the like.Therefore,this paper aims to prepare metal oxide@ZSM-5/SiO₂ composite nanofibrous membrane to solve these problems.The material firstly takes a flexible SiO₂ nanofiber membrane prepared by electrospinning as a carrier,and adopts an impregnation method to load ZSM-5 molecular sieve powder onto the fiber membrane,thereby realizing the conversion from the molecular sieve powder to the molecular sieve material;and the metal oxide@ZSM-5/SiO₂ composite nanofibrous membrane is prepared by an equal volume impregnation method.Finally,the structure of the composites was analyzed by some methods,and the catalytic performance of catalytic ozonation was evaluated.In this paper,the flexible silicon nanofiber membrane is firstly prepared via electrospinning.The mass ratio of tetraethyl orthosilicate,deionized water,and phosphoric acid is changed by the addition of phosphoric acid,and then the effect of phosphoric acid on the electrospinning solution is explored.After the analysis of conductivity,viscosity,surface tension,and SEM characterization,it is finally concluded that the prepared fiber membrane is smooth when the mass ratio of tetraethyl orthosilicate,deionized water,and phosphoric acid is1:1:0.01.A series of characterization and analysis of good nanofiber membranes are carried out,and the specific surface area of silicon dioxide is 7.5m~2g^-1 and there are basically no chemical structure change before and after the calcination of the silicon nanofiber membrane.The mechanical properties of the flexible silica nanofiber membranes are excellent,and the tensile strength is up to 2.1MPa.Then the prepared silica nanofiber membrane is used as a carrier,and the ZSM-5 molecular sieve is loaded on the silica nanofiber membrane through an impregnation method and high-temperature calcination to prepare the ZSM-5/SiO₂ material.It is observed by SEM that no fibers could be seen on the surface of the material,and the particles of the ZSM-5 molecular sieve are uniformly arranged.BET characterization shows that ZSM-5/SiO₂material has micropores,and the specific surface area reaches 197.21 m~2g^-1,which is conducive to the subsequent treatment of phenol solution.On the basis of ZSM-5/SiO₂,the metal oxide@ZSM-5/SiO₂ composite nanofibrous membrane is prepared by the equal volume impregnation method on the ZSM-5/SiO₂ material.By changing the concentration of ferric nitrate nonahydrate and manganese(?)nitrate tetrahydrate solutions,three composite nanofibrous membrane with the concentration of 0.5mol/L,0.7 mol/L,and 0.9 mol/L are prepared.It can be observed by SEM that the surface of the composite nanofibrous membrane consists of newly added coarse particles,and the more materials are with the increase of concentration.BET analysis shows that the composite nanofibrous membrane have micropores,and at 0.9 M,the specific surface area is 101.29 m~2g^-1.XRD,EDS,and other characterization have confirmed that iron and manganese oxides are successfully loaded.Finally,the catalytic effect of catalytic ozonation on the degradation of phenol is analyzed.The effects of the p H of phenol,metal salt concentration,and the addition of metal oxide@ZSM-5/SiO₂ composite nanofibrous membrane on the degradation are analyzed in sequence.The final results show that when the p H is 10.5,metal salt concentration is 0.9 mol/L and the addition amount of composite nanofibrous membrane material is 400mg,the degradation effect of phenol is optimal,and the degradation rate is 86%.The prepared metal oxide@ZSM-5/SiO₂ composite nanofibrous membrane has reusable properties.