| Supercritical water oxidation (SCWO) was a promising technology for treatment organic-containing wastewater. When exceeding critical point of water (Tc = 374℃; Pc = 22.1MPa), the values of density, dielectric constant, hydrogenous bond and ionic product of water drop down, so supercritical water acts as a non-polar solvent of high diffusivity and excellent transport properties. Consequently, even non-polar organic compounds and gases like oxygen become completely miscible with the supercritical fluid. The SCWO process that is based on the special physical properties of supercritical water has a great many of advantages. The oxidation reactions to occur rapidly without any interphase mass transport limitations. The organic compounds in wastewater were completely oxidized in several seconds to several minutes.The non-catalytic SCWO, homogeneous and inhomogeneous catalyzed SCWO of unsymmetrical dimethyl-hydrazine (UDMH) and para-aminophenol were performed in a continuous flow reactor. The oxidation efficiency and influence factor of this two kinds of organic compound contain nitrogen in supercritical water were investigated.The results indicate that UDMH and para-aminophenol were easily oxidized in supercritical water. 99% COD removal was obtained in several seconds at 430~550℃, 24~38MPa with H2O2 in excess. Gas products were analyzed with Gas Chromatogram (GC). The results indicate that gas products were CO2 N2 and excess O2. The COD elimination efficiency was significantly improved as reaction temperature, pressure, residence time or oxidant dosage was increased. The main influential factors of COD elimination efficiency were temperature, pressure and residence time. Oxidant dosage had little influence on SCWO under conditions of oxidant excess.Conventional SCWO processes, which usually operate around 25MPa and up to 550℃, rely on homogeneous, free-radical reactions to convert organic carbon to CO2, The catalytic supercritical water oxidation (CSCWO) was performed to reduce the severity of the processing conditions and possibly toreduce the processing cost. The results indicate that reaction temperature, pressure and residence time caught be reduced by using appropriate catalysts. The higher COD elimination efficiency was obtained by using CSCWO than conventional SCWO in the same experiment condition. The Cu2+ was a better catalyst in homogeneous catalyzed oxidation. CuO/ γ-Al2O3 catalysts exhibited higher activity than MnO2/γ-Al2O3 catalysts in heterogeneous catalyzed oxidation. The structure and composition of the fresh and used CuO/ γ - A12O3 and MnO2/ γ -Al2O3 catalysts were identified by X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) . The XRD and XPS results suggest that the γ-Al2O3 support in the fresh catalyst was largely transformed to Al2O3 during SCWO processes. The BET surface areas for two catalysts decreased after some day of continuous use. The supported CuO and MnO2 catalysts and Al2O3 support were dissolved during SCWO processes of UDMH and para-aminophenol, so activity of catalyst reduced. The CuO/ γ-Al2O3 catalyst exhibited higher activity than MnO2/ γ-Al2O3 catalyst in supercritical water, but CuO/ γ-Al2O3 catalyst offered lower stability than MnO2/ γ-Al2O3 catalyst under SCWO conditions.The liquid products and gas products of SCWO of UDMH and para-aminophenol were analyzed and identified systematically by GC-MS and GC, respective. The reaction path and mechanism of this two organic compounds contained nitrogen in SCWO processes were obtained. Free radical reactions were the same characters of SCWO for the two substances above. Free radicals -OH began the reactions. The final products were N2, CO2 and H2O after a series of complicated reactions.The kinetics of oxidative degradation of UDMH and para-aminophenol in SCW were investigated systematically. The global power-law rate equation and parameters as follows:UDMH: Ea is 44.65 kJmol-1 (without catalyst), 35.75 kJ-mol-1 CuO catalyst), 37.79 kJ mol-1 MnO2 catalyst). The reaction order of o...
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