| With the development of city construction and the improvement of people's life, it is an urgent problem to treat the domestic refuse of the city. Because of the low cost, advanced technologies, and convenience in management and transportation, the landfill was now one of the most recommendable technologies for the garbage treatment home and abroad. Landfill leachates is a kind of harmful wastewater containing high concentration organic compounds. Because of its serious pollution to the circumjacent environment and substrate of the landfill, the long-term maintenance of pollution, and the secondary pollution, it is an urgent problem to collect and treat the landfill leachates effectively in city environments.There are not only a lot of organic pollutants, but also highly concentrated ammonia and many kinds of heavy metals in landfill leachates. Ammonia, which has a large range of variation from 100 mg/L to over 1000 mg/L, was produced in the bio-degradation of nitrogenous compounds like protein. Highly concentrated ammonia could aggravate the pollution of receiving water. And the high ration of N/C could bring the maladjustment of nutrition and restrain the biodegradability, which could affect the stabilization and efficiency of the biological treatment system and could aggravate the load of the following treatment. So, treatment of high concentrated ammonia in the landfill leachates effectively causes worldwide attention in the field of environmental protection. In the past twenty years, many investigations were carried out about the wastewater treatment of ammonia domestic and abroad. Traditional techniques for the treatment include biochemical methods and physicochemistry method, such as biological nitrification, active carbon adsorption, ozone oxidation and ion exchange. But only transformation of form was achieved, and the potential sources of activated sludge and sorbents were still remained. So all of them have their own limitation. Catalytic wet air oxidation was very effective physicochemistry method for treatment of industrial wastewater. In this research paper, catalytic wet air oxidation (CWAO) over Co/Bi catalyst was employed to remove high ammonia nitrogen (NH3-N) with oxygen as the oxidant and to build the technical condition of disposal landfill leachates using CWAO. Catalytic wet air oxidation (CWAO) was a method of oxidizing dissolvable or suspended organic compounds as well as reducible inorganic compounds with oxygen or air under the circumstances of high temperature and high pressure in liquid phase. CWAO is an available technology for treating wastewaters that are too concentrated or toxic to biologically degrade. The process needs short operating period and high removal rate without producing NOX, SO2, HCl, dioxins, furans and fly ash.Common catalysts include homogeneous catalysts and heterogeneous catalysts. While the reactants and the catalysts are the same phase, the reaction is called homogeneous catalytic reaction, or the reaction is called heterogeneous catalytic reaction. Copper ion, such as Cu(NO3)2,CuSO4, is the most effective homogeneous catalysts. But the homogeneous catalysts were in the same phase with the reactants, which need to be recovered by an additional separation process. Otherwise, it will cause potential pollution and the loss of catalysts. Compared with soluble catalysts, heterogeneous catalysts that can be easily separated form the reaction medium are better suited for continuous processes. Supported noble metals catalysts such as ruthenium platinum and rhodium is effective heterogeneous catalysts in many fields. Most of the heterogeneous catalysts suitable to CWAO are transition metals, oxide and composite oxides catalysts. Lots of transition metals were considered to have the catalytic activation through investigation. Noble metals have high catalytic activity, long life-span and good adaptability, but because of high cost, which severely affects the economy of noble catalysts. Now more and more attention is paid to n...
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