Experimental Study On Photocatalytic Oxidation Of Nitrobenzene Wastewater By Fe And N Doped TiO₂

Nitrobenzene wastewater has always been a difficult point in the industrial water treatment industry.Traditional physicochemical and biochemical methods are not ideal for treatment.Therefore,it is necessary to seek a green and energy-efficient treatment method.The photocatalytic oxidation method can completely decompose the refractory organic matter efficiently,and the modified TiO₂ photocatalyst has the characteristics of green energy saving.In this study,the preparation conditions of Fe,N co-doped TiO₂/GF photocatalyst and the processing conditions of nitrobenzene wastewater were studied,which provided a basis for accelerating the industrial use of photocatalytic oxidation technology.The test used nitrobenzene wastewater as a treated water sample and was tested in a self-made photocatalytic reactor.The research contents include:preparation of TiO₂/GF photocatalyst and treatment of nitrobenzene wastewater under ultraviolet light;preparation of Fe,N co-doped TiO₂/GF photocatalyst and treatment of nitrobenzene wastewater under ultraviolet light;simulation of sunlight Study on the treatment of nitrobenzene wastewater by Fe and N co-doped TiO₂/GF photocatalyst.TiO₂/GF photocatalysts were prepared by sol-gel/impregnation-lifting method.XRD and SEM showed that TiO₂ was mainly anatase and the surface of glass fiber was evenly loaded.The results show that the photocatalytic performance of the TiO₂/GF photocatalyst prepared by the test is good when the coating layer is 4 layers,the calcination temperature is 450?,and the calcination time is 120 min.The removal rate of p-nitrobenzene wastewater can reach 88.7%and TiO₂/The GF catalyst can be reused multiple times.Ion doping modification of TiO₂ was carried out by dividing iron nitrate and urea into water and nitrogen sources.XRD and SEM characterization showed that there were obvious anatase peaks in the TiO₂ after doping,and the surface of the glass fiber was dense and uniform.The orthogonal experimental results show that the optimum preparation conditions for Fe and N co-doped TiO₂/GF catalysts are:calcination time 2h,calcination temperature 4500 C,n?Fe?:n?Ti?=0.9%,n?N?:n?Ti?=0.2?molar fraction?.Under the irradiation of ultraviolet light,the concentration of wastewater,aeration amount and dosage of catalyst have certain influence on the photooxidation effect of the catalyst.For the concentration of 80 mg/L nitrobenzene wastewater,when the solution pH=3,H₂O₂?30%?concentration of lml/L,Fe,N co-doped TiO₂/GF catalyst 0.15g,aeration rate of 0.6m3/L,nitrobenzene removal rate of 97.6%,COD removal rate of 89.4%.Under the irradiation of simulated sunlight,the Fe and N co-doped TiO₂/GF catalyst prepared by the test also has a good removal effect on the nitrobenzene wastewater.The removal rate of nitrobenzene is 90.6%,and the COD removal rate is up to 85.5%,the removal effect is only about 5 to 7 percentage points lower than that under ultraviolet light.The Fe and N co-doped TiO₂/GF catalysts overcome the tendency of traditional powdered TiO₂ to agglomerate in solution.The TiO₂ crystal form is anatase.The doping reduces the recombination rate of electron-hole pairs and broadens the photoresponse of TiO₂.The range is effective to improve the photocatalytic performance of TiO₂,and the nitrobenzene-wastewater has a good removal effect.