The Study Of Photocatalytic Oxidation Of Low Concentration Of Cyanide Wastewater

Based on the experiment of irradiated cyanide wastewater, the photocatalytic oxidationmechanism was indicated. Effect of pH, stirring speed, intensity of irradiation,temperature,H₂O₂dosage,ZnO, TiO₂and the modified TiO₂on removal of CN-were investigated.Photochemical oxidational experiment results show that the pH, stirring, intensity ofradiation,temperature and H₂O₂all take the effect on the degradation of cyanide.The totalremoval of CN-increases with the enhancement of intensity of radiation, stirring speed andthe H₂O₂dosage. CN-had a high degradation rate at acidic pH, with pH ascending, theremoval rate of CN-photodecomposition dereased. The photocatalytic oxidation is positiverelation with the addition of TiO₂,especially under the increscent irradiation intensity. Whenthe TiO₂amount is0.3g/L, the maximal removal rate can be reached.The efficient degradationcould be obtained with the use of ZnO and modificated TiO₂,the optimal amount of ZnO was0.5g/L.Photocatalytic efficiency of composite particles was greatly enhanced by addingH₂O₂,and the optimam content of H₂O₂was10mmol/L.At present there was less study on the photocatalytic degradation of low concentration,inview of the above,the research of this article will play an actual appliance value. The resultsalso showed that the rection of degradation of which followed the mechanism ofphotochemical oxidation and photocatalytic oxidation,was an advanced oxygenation process.Modification experiment were provided with innovation; the removal rate can be enhancedunder the optimized conditions, possessing potential development and applied vaule.