Study On Adsorption And Catalytic Purify The Organic Contaminant Formaldehyde And Toluene Indoor

TiO₂is the most developed catalyst on the moment, but its rate of utilization to visiblelight is low. This study is by doping TiO₂with others to improve the rate of the utilization ofvisible light and the degradation of the formaldehyde, on the other hand, the load of thecatalyst solves the problem of catalyst easily taken away and difficult to recycle. Using Butyltitanate as precursor, acetic acid as hydrolysis inhibitors, and ethanol as solvent, catalystwhich is doping TiO₂with Iron and zinc is prepared by the Sol-gel method. This studyexplores the affect of process to the effect and performance of indoor pollution gas,formaldehyde, and makes the dynamic analysis. The results show that it has the theoreticalsupport for0.005Zn,0.01Fe-TiO₂.1. Catalyst which is doping TiO₂with Iron and zinc is prepared by the Sol-gel methodwith zeolite as the carrier. According to experiment and analysis the different loading,calcinations temperature and Zn, Fe-doped amount, we find that the degradation of theformaldehyde is the top92%as the loading is1:20, the calcinations temperature500℃andthe Molar ratio of Zn, Fe-doped amount0.005、0.1.2. In order to further study the impact of operating variables on the catalytic degradationeffect, dealing with low concentrations of indoor formaldehyde gas by using0.005Zn,0.01Fe-TiO₂, we explore the effect of the initial formaldehyde concentration, relativehumidity and the number of reuse a amount of catalyst to the degradation of formaldehydegas. The results show that the more the amount of catalyst is, the greater the rate ofdegradation of formaldehyde as doing comparative experiments with2,5,8g catalyst. As theweight of catalyst is5g during the later experiment. When the gas path relative humidity isaround50%and the initial concentration of formaldehyde is0.1mg/m3, the catalyticefficiency is up to81%.The loading of formaldehyde gas with the increase of initial concentration of formaldehyde increases per gram of catalyst, and it show the synergy ofadsorption and photo catalytic.3. Dealing with low concentrations of indoor formaldehyde gas with the dynamic gasand the static gas system, we explore the affect of the load amount of the catalyst, the dopingamount of heavy metals, the initial concentration, relative humidity a nd the number of reuse aamount of catalyst to the degradation of formaldehyde gas with the dynamic gas system.Catalyst doping zeolite with0.005Zn-0.01Fe-TiO₂makes the degradation rate offormaldehyde gas up to81%during one hour, but the undoped or only doped Zn Respectively54%and67%. The rate of degradation of formaldehyde Increases with decreasing initialconcentration of formaldehyde. Increase of indoor humidity conduces to the dissemination offormaldehyde, and addition of humidity increases the indoor concentration of formaldehyde.4. We have SEM scanning and XRD tests and kinetic analysis on the catalyst with theoptimum amount of loading and doping in the experiments. The results showed that thezeolite loaded TiO₂which is prepared by sol-gel method has better dispersion, Conducing toadsorption and degradation of Organic matter with a porous structure because there is enoughlight penetrating the pore-forming three-dimensional photodegradation environment, forminga certain gap. Analysis by XRD patterns shows that the surface defects bit of TiO₂nanotubeswhich is nuclear sites in rutile phase increases due to the doping of Zn and Fe, so the phasetransformation of catalyst improves. We calculated its average particle diameter is24.5nm5. The analysis of reaction kinetics of the affect of degradation of formaldehyde with thedifferent initial formaldehyde concentration and load doping shows that formaldehydeadsorption and catalytic reaction synergies order kinetics model.