The Research Of Purification No-containing Gas By Aqueous Oxidation With UV/H₂O₂

As main resources of21century in my country,coal resources influence thesustainable development of social economy greatly,it is more and more seriousenvironment pollution situation which caused by the coal.The acid rain andphotochemical smog are caused by NOxand SO₂,which has threaten human health.TheSCR method which is now commercially implemented world-wide is proved the bestmaturely technology of flue gas denitrification,and has higher efficiency.But thefollowing points cannot be ignored before putting it into operation：H₂O and SO₂resistance of catalystï¼›wear and jam of catalyst caused by fly ashï¼›ammonia escapeï¼›exhaust gas must be reheated when the SCR reactor is installed in the sternï¼›thecatalyst is expensive,et al.Furthermore,mostly SCR method dependent on theabroad,all of these are restricts factors while spreading and applying the SCR methodin China.Consequently,based on the characteristic of wet desulphurization and vastpotential for future development, it is the mainstream trend of market for Denox that akind of economic feasibility, simple, practicable, efficient, steady and combining withwet desulphurization is studied,which has very important meaning to reduce thedischarge value of NOxand SO₂.Wet denitration method centered on NO oxidation is important studied. Theinfluence of some experimental factors on removal efficiency of nitric oxide （NO）under the condition of liquid-phase oxidation with UV/H₂O₂, such as H₂O₂concentration, solution temperature, initial pH, NO concentration, illuminationcondition, O₂content and gas flow rate, were investigated by employing orthogonalexperiments and single factor experiments. The results showed that NO could beefficiently removed by the aqueous oxidation technology with UV/H₂O₂system, thehighest NO removal rate was about80%,and the SO₂removal rate maintain in90%above.Moreover, H₂O₂concentration, temperature and initial pH had varying degreeeffects on purifying NO-containing gas, whereas NO removal rate were more affectedby H₂O₂concentration and temperature. The single factor experimental results showedthat high NO removal rate could be obtained when H₂O₂concentration was0.2mol/Land the initial pH was6～7. H₂O₂concentration and initial pH should be maintainedat an appropriate level or the production of·OH could be restricted, which wouldresult in lower NO removal rate. The optimum operation temperature was40℃, which is lower than common operating temperature—50℃for the wet scrubber. Enlargingthe illumination strength and O₂content could improve the NO removal rate.Furthermore, the NO removal rate was also controlled by the area and coefficient ofgas-liquid mass transfer. Finally,the kinetics of gas denitrification by UV/H₂O₂system is primary discussed access to lots of documents.NOxis removed by theoxidation of OH, and the final product is NO3-. SO₂can be innocuous or stimulatoryto the NO removal rate.There are many advantages of purifying waste gas by UV/H₂O₂system.If we canoptimize technological conditions further, ameliorate photocatalysis reactor, and seeksimilar Advanced Oxidation Processes, UV/H₂O₂system will have a bright future fordecarbolize, denitration and mercury removal.