Preparation And Application Of Ozone Catalysts For Oxidation Of Dying And Printing Wastewater

The printing and dyeing wastewater has deep chromaticity and large emissions.There are many organic matters in this kind of wastewater which are difficult to be further biodegraded,therefore,the printing and dyeing wastewater is a major problem in industrial wastewater treatment. It is suggested that catalytic ozonation processes was applied to treat Orange G wastewater. In the study, new catalyst for ozonation process prepared by mixing method was used for the treatment of Orange G wastewater and the reaction mechanism was studied. Finally, the homemade catalyst was applied to real wastewater treatment.In catalyst preparation process,the adhesive,carrier and active component types and quality of the percentage were screened in detail,and the best conditions of preparation of catalyst was explored.The properties of the catalyst were characterized by scanning electron microscopy (SEM),X- ray diffraction (XRD) analysis and thermogravimetric(TG).The influences of initial pH,ozone release rate and the dose of catalyst on the removal efficiency of orange G were investigated.Furthermore,the reaction kinetics of catalytic ozonation decomposition orange G were studied. Adding tert-butyl alcohol to the reaction system,using ultraviolet-visible absorption spectrometry and liquid chromatography (HPLC) to discussed the reaction mechanism of catalytic ozonation decomposition orange G.The performance of the homemade catalyst and the commercially available were compared.Finally,the homemade catalyst was applied to real wastewater treatment.The optimum mixing conditions:carrier D as the carrier,the activity order of active component for A,Al2O3 and CuO is:A > Al2O3 > CuO,adhesive and active component (A)percentage of 60% and 10% respectively,the quality of the best roasting temperature is 800?,he best roasting time is 2h.The optimum technological conditions in catalytic ozonation degradation of orange G: initial wastewater pH is 6.5,catalyst dosing quantity is 300g/L and ozone release rate is 1.60mg/(L min).Under the best condition,the removal rate of COD and orange G reached 93.46% and 99% respectively after 30 min.It is showed that the catalyst has good catalytic activity and the catalytic ozone oxidation degradation process of orange G met pseudo-first-order-kinetics.ozone catalytic oxidation reaction were depressed obviously by the addition of hydroxyl capture tert-butyl alcohol,so catalytic reaction system follows the principle of hydroxyl radical.Compered with the commercially,the catalyst showed a better activity.Finally,the application of the catalyst to the real printing and dyeing waste water was studied.There is remarkable effect that catalytic ozonation degradation the real wastewater,the effluent COD was 72.9 mg/L,already meet the national discharge standards (GB4287-2012) after 30 min.