| With the development of our national economy, printing and dyeing industry have been expanding, in the enormous economic benefits, but also had a very serious pollution problems. Printing and dyeing wastewater containing high concentrations of organic matter, color depth, poor biodegradability, direct emissions would lead to severe environmental pollution. Currently, wet air oxidation (WAO) process is used in industry to treat it. Wet air oxidation can decomposite most of the organic matter to inorganic or organic small molecules, but the harsh reaction conditions and equipment into a large, high treatment costs. Since inception of Wet air oxidation, people continue to improve it, to introduce hydrogen peroxide as the oxidant instead of air to eliminate the process of oxygen transfer, to resist the catalyst into reaction, to alleviate reaction conditions. In this paper, Fe/TiO2-CeO2 catalysts series were prepared in different methods, and to treat H-acid wastewater by catalytic wet hydrogen peroxide oxidation (CWPO) process.The COD removal rate and the Fe ion release rate were considered as in the main index to evaluate the performance of different catalysts. XRD, BET, TG and other characterization methods, were studied to explore the structure of the catalyst, and reaction kinetics were studied Preliminary.To prepare the TiO2-CeO2 catalysts with coprecipitation methed,the affection of Ti-Ce molar ratio, aging pH, calcination temperature on the TiO-CeO2 Catalyst were studied. Experiments show that, Ti:Ce= 9:1, the catalyst has the best structural characteristics; at a higher aging temperature, the crystal structure developed more completely, and better catalytic activity were achieved; with the calcination temperature increased, the catalyst crystal structure improved.When the calcination temperature is 550℃, catalyst performance over the best, COD removal rate was 69.7%.To load Fe element on the TiO2-CeO2 catalysts by excessive impregnation method investigated the affections of calcination temperature and the Fe% on the catalyst performance, the results show that after the loading of Fe, the catalytic activity significantly increased,550℃calcination, loading of Fe is 2%, the water samples COD removal rate reached 75.2%. Calcination temperature increase can inhibit the dissolution of Fe ions, when calcinated in 550℃,Fe ion dissolution rate was of the lowest. To preare Fe/TiO2-CeO2 catalyst by coprecipitation of three-components.Founding that three-component co-precipitation method is more conducive to the active component in the catalyst dispersion, when loading of Fe is 1%, the catalytic activity was of the best, COD removal rate up to 81.1%; Fe ion release of the catalyst prepared by three-component coprecipitation are more serious, calcinated in 550℃, Fe ion dissolution rate was of 55.2%. To prepare Fe/TiO2-CeO2 catalysts by sol-gel methods. Affections of Fe%, calcination temperature, temperature water bath, on the catalyst performance were studied. The results showed that:dispersion of active components in catalysts prepared by sol-gel method is better than the ones prepared by three components co-precipitation, when loading of Fe is 0.5% COD removal rate reached 69.2%; Fe ion release in catalysts were serious, and as the calcination temperature increased, the release phenomenon is inhibited, but the catalyst for change in crystal structure, activity; lower The water bath temperature is beneficial to the catalyst stability of the crystal structure in the calcinating process and is conducive to improve the catalytic activity.H-acid on the CWPO wastewater treatment process was studied, the best response was identified in the initial pH= 5, the reaction temperature is 100℃, the reaction process kinetics were studied and found the it is a second order reaction on[COD], and the kinetic model is-dC/dt= 2.87·exp (-37270/RT) [H2O2] 0.956 [COD]2... |
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