Modified Fly Ash Were Used As Adsorbents To Study The Synergetic Removal Mechanism Of SO₂/NO Pollutants

In this paper,According to physicochemical properties of the fly ash,CeO₂-CuO/fly ash prepared by liquid phase impregnation at room temperature and orthogonal and single factor experimental design was prepared as adsorbents to remove SO₂ and NO gas.A series of physical characterization,conditions of desulfurization and denitrification optimization and reaction mechanism were studied.The main conclusions are as follows:1.The optimal preparation conditions of CeO₂-CuO/fly ash were as follows:fly ash（g）:cerium nitrate solution（ml）=1:3,concentration of cerium nitrate=0.05mol/L,calcination temperature=600°C,calcination time=4h,copper nitrate（m）:fly ash（m）=10%.2.CeO₂-CuO/fly ash has the best adsorption effect on SO₂ when the sample weight is 0.3g,the temperature is 50℃,the flow rate of SO₂ is8ml/min,and flow rate of O₂ is 4ml/min.When the sample weight is 0.4g,the temperature is 70℃,the flow rate of NO is 6ml/min,and the flow rate of O₂ is 4ml/min,the adsorption effect of NO is best.Coadsorption decreases the respective adsorption efficiency.3.Under oxygen rich conditions,The results show that SO₂ can produce sulfate and sulfite species on the adsorbent surface,The main species are nitrate and nitrite for NO.Under anaerobic conditions,The amount of species generated on the surface from SO₂ and NO decreases to varying degrees.The main species on the adsorbent surface are weakly adsorbed NO;Infrared spectra of adsorption of pyridine showed that strong lewis acid sites are formed on the surface of the adsorbent after modification.After participating in the co-adsorption reaction,the amount of corresponding acid decreases.However,the introduction of SO₄^2-results in weak bronsted acid sites on the surface.