Study On Catalytic Wet Oxidation Of High Concentration Imidacloprid Pesticide Wastewater

The significance of dealing with the high concentration imidacloprid pesticide waste water was analyzed in this paper. The composite metal oxide catalyst was prepared through co-precipitating method. The technological conditions of dealing with the high concentration imidacloprid pesticide waste water with wet oxidation were confirmed. The conditions are: 190℃, 8.0Mpa, 1.6Mpa partial pressure of oxygen, and PH 8.28. The loss of active components in the catalyst, chiefly copper and others, is studied under these conditions.During the study, composite hydroxides, such as Cu/Mn Cu/Ce Ce/Mn and Ce/Ag, were prepared through co-precipitating method. The catalyst was obtained after calcinations. Under the above technological conditions, three composite metal oxides, Cu/Mn Cu/Ce and Ce/M, were screened out as the optimal catalyst according to three kinds of compounds, such as transition metal-salts, composite metal oxides and ra re-earth series, and using COD removal rate, specific surface and dissolving out degree of metal ions as index. The optimal use levels of the three compounds were studied. They are 3.0g/L 3.0g/L and 2.0g/L, and the highest removal rates are 92% 98% and 93% accordingly.The catalyst structure was analyzed with XRD. It was found that Cu/Mn Cu/Ce and Ce/Mn formed sosoloid structures under high temperature. These kinds of sosoloid catalysts have not only high catalyst activities, but also stable structures. Reasons why the active components of the three catalysts could not lose easily were explained theoretically. About how to control the loss of catalyst active components, the paper suggest to improve catalysts and improve their stabilities through the method of changing their structures at the first time. The introductory theoretical analysis and computation were presented. The loss reason of the active component—copper was also studied. It was found that the loss of the active component was related not only to the catalyst structure, but also to reaction conditions, such as temperature and PH, etc.The corresponding settle project was brought forward: (1) A kind of stable catalyst should be synthesized. (2) Technological conditions should be improved according to the loss reason of copper.