Study On The Treatment Of Dye Wastewater By Catalytic Wet Air Oxidation

The purpose of this experiment is to prepare several kinds of catalysts.The catalytic wet air oxidation method is used to degrade the simulated solution of dyeing wastewater methyl orange,find out the best catalyst,and find out the best preparation conditions and reaction conditions of the catalyst.Four metal supported catalysts,Fe,Zn,Co and Ni,were prepared by impregnation,drying and calcination.The best metal supported catalyst,Fe/Al₂O₃,was found,and the Fe/Al₂O₃ catalyst was tested by XRD.It is found that the best preparation condition of Fe/Al₂O₃ catalyst is that the concentration of immersion solution is 0.1mol/l and the calcination temperature is350?.The optimum reaction conditions were 27?,pH 7,catalyst dosage 300mg,oxidant 30%hydrogen peroxide solution 5ml,reaction time 90min,and the maximum degradation rate of methyl orange was 91.01%.The catalysts supported by rare earth elements La and y were prepared by impregnation,drying and calcination.The better catalyst Y/Al₂O₃ was selected by comparing the ability of them to treat methyl orange,and the Y/Al₂O₃ catalyst was tested by XRD.It is found that the best preparation condition of Y/Al₂O₃ is that the concentration of impregnating solution is 0.1mol/l and the calcination temperature is350?.The optimum reaction conditions were 27?,pH 7,catalyst dosage 300mg,oxidant 30%hydrogen peroxide solution 5ml,reaction time 90min,and the maximum degradation rate of methyl orange was 83.49%.At last,the metal elements were modified by rare earth elements.The Y-Fe/Al₂O₃modified catalyst was prepared by impregnating yttrium and iron on the support of?-Al₂O₃ by step impregnation method.The results showed that the catalyst with 0.1mol/l yttrium nitrate solution and 0.3mol/l iron nitrate impregnation at 350?had the best catalytic effect,and the degradation rate of methyl orange was 87.90%.