Study On Advanced Treatment Of Dying Wastewater By Ozone Heterogeneous Catalytic Oxidation Processes

With the strong oxidizability,lou treatment cost and without secondly pollution,ozone heterogeneous catalytic oxidation technology show promising potentials.ozone heterogeneous catalytic oxidation technology,which was applied to the adwanced treatment of methyl orange dye wastewater,is studied in this paper.The main content includes the preparation of loading manganese oxide ceramic catalysts.Then the catalytic performance on the advanced treatment and various factors on the degradationg of methyl orange wastewater,degradation mechanism of heterogeneous catalytic oxidation were investigated.Finally,we also considered the practical engineering application of loading manganese oxide ceramic catalysts.The loading manganese oxide ceramic catalysts,which were prepared through the disc granulator process,can improve the efficiency on the oxidation and degradation of methyl orange wastewater.When the influent pH value was 3,the flow rate was 15 L/min,the temperature is 20 ? and the ozone dosage was 15 mg/min,the COD removal rate and decolorization ratio of ozone catalytic oxidation system reached 37.6 % and 90 % respectively.The adsorption had little effect.o on the COD removal rate and decolorization ratio.The main component of loading manganese oxide ceramic catalysts was Mn₂O₃ and Mn₃O₄.The catalysts,which were strongly adhered by active components,had good stability and could be used repeatly for many times.The preparation process of loading manganese oxide ceramic catalysts was optimized.With saturated solution of potassium permanganate and manganese sulfate as the binder,when calcination temperature was 900 ?,calcining time was 20 min,the ceramic catalysts achieved the high catalytic activity.The main component of loading manganese oxide ceramic catalysts was Mn₂O₃,Mn₃O₄ and MnO₂.The actual loading content of manganese was 1.61 %.After three levels of leaching experiment,the manganese leaching rate was less than 1mg/L and the ceramic catalysts showed the excellent stability.The acidity was favorable for degradation of methyl orange.The decolorization was achieved by direct ozone oxidation.When it came to the later stage of intermediate degradation,the hydroxyl radicals indirect oxidation played an enssential role.At the same time,enhance the initial wastewater temperature and ozone dosage and reduce the initial concentration of methyl orange can improve the decolorization ratio and COD removal rate in the reaction system.Na₂CO₃ in the solution,which inhibit the generation of hydroxyl radicals,can weaken the removal effect of pollutants in the reaction system.In the ozone oxidation column,the higher height of the column,the better methyl orange removal efficiency was obtained.The results of GC/MS,FTIR infrared spectroscopy and UV-Vis showed that methyl orange molecular is oxidized and transformed into benzene,aldehyde,ketone,lipid and some small molecular oganic compounds.Instead of physical and chemical treatment process,ozone catalytic oxidation was applied as process in an actual textile treatment.When the influent flow was 60000 m³/d,COD was less than 250 mg/L,color degree was less than 100 times,ozone dosages was 40⁴5 mg/L,catalysts were 1200 t,COD and color was further reduced.Water quality was effectively improved.When ozone consumption was about 1 mg/L,the COD consumption was zbout 1 mg/L.The perating costs of the system is 0.712 yuan per tun for water.