Degradation Of Cation Iic Blue X-BL By CWAO Coupled With Catalytic Ozonation At Room Temperature And Atmospheric Pressure

With the development of dye industry,dyes are widely used in various fields.In the process of dye production,a large number of printing and dyeing wastewater is produced,which has the characteristics of high concentration,high chroma,poor biodegradability,and difficult to degrade.CWAO and ozone catalytic oxidation technology are the most widely used methods to degrade dye wastewater because of their high efficiency,fast reaction and small two pollution.While in the actual dye wastewater treatment,the use of a treatment technology to degrade the wastewater,may not achieve the desired treatment effect.It needs for two or more technology coupling treatment.It is a hotspot in the field of environmental chemical engineering to achieve the strengthening of wastewater treatment by coupling technology.So in this paper,Mo-Zn-Al-O was chosen as catalyst,and the degradation of dye wastewater by CWAO coupled with ozone catalytic oxidation was studied:?1?In the single CWAO process at room temperature and atmospheric,when the air flow rate was 1.6 L/min,the Mo-Zn-Al-O catalyst dosage was 0.5 g/L,the temperature is 25 ? and initial dye p H was 3,cationic blue X-BL dye wastewater decolorization rate was 83.0%,the removal rate of TOC was 50.3%;if do not adjust the initial dye p H,the rate of decolorization was 68.8%.In the wet catalytic oxidation,the decolorization rate of the cationic blue X-BL was 61.8%,only decreased by 7% after the catalyst was reused for more than 5 times.?2?In the single ozone oxidation process,when the initial dye p H was 3,ozone flow rate was 200 m L/min and the Mo-Zn-Al-O catalyst dosage was 0.5 g/L,the decolorization rate of cationic blue X-BL dye wastewater was 99.9%,the removal rate of TOC was 64.8%.In the catalytic oxidation of ozone,the degradation rate of cationic blue X-BL was still 89.8%,and the stability of the catalyst was highly after the repeated use of the catalyst for more than 5 times.?3?In the coupled systems,the catalytic activity of cationic blue X-BL was better than that in single systems.In the ozone flow rate was 60 m L/min and the air flow rate was 1.6 L/min,the Mo-Zn-Al-O catalyst dosage of 0.5 g/L cases?without adjusting the initial dye p H?,ozone oxidation system,single single wet oxidation system,single adsorption system,single wet catalytic oxidation system,single ozone catalytic oxidation system,the atmospheric wet catalytic oxidation coupling ozone catalytic oxidation system on decolorization rate of cationic blue X-BL degradation rate were 2.2%,2.1%,39.8%,68.8%,54.2% and 91.8%.?4?The optimum experimental conditions of degrading cationic blue X-BL by CWAO coupled with catalytic ozonation was that the initial dye p H was 3,the Mo-Zn-Al-O catalyst dosage was 0.5 g/L,ozone flow rate was 60 m L/min and the air flow rate was 1.6 L/min,the decolorization rate was 98.4%.Free radicals produced during the reaction was mainly singlet oxygen and hydroxyl radical reaction mechanism for oxygen and ozone adsorption on the surface of the catalyst,and the catalyst surface in the presence of active reaction of singlet oxygen and hydroxyl radicals,and the oxidation degradation of cationic blue X-BL,the oxidation decomposition were two methyl formamide and N N-two-1,4-two methyl benzene amine,then oxidative degraded into small molecules or CO₂ and H₂O.