The Treatment Non-degradable Organic Wastewater By Wet Air Oxidation

The treatment of non-degradable organic wastewater is an important problem which isneeded to resolve in the domestic and international environmental protection realm at present.Presently wet air oxidation （WAO） technique has the bigger advantage to handle this organicwastewater. Recently, the noble catalyst has the better activity and stability in the WAO, butthe high cost of noble mental limits its large-scale industrial use. In this dissertation, we try tofind steady and efficient inexpensive system under mild conditions represent a significant stepfor the treatment of non-degradable organic wastewater.In this study, dyes were studied by wet air oxidation. The application of KBrO₃/O₂andNaNO₂/FeCl₃/O₂system for the treatment of azo dye Reactive Red2BF were evaluated.The optimal conditions of application of KBrO₃/O₂system for the treatment of azo dyeReactive Red2BF were:2BF concentration400mg/L, reaction temperature160℃, oxygenpartial pressure0.8Mpa, pH4, n（KBrO₃）:n（Reactive Red2BF）=0.5:1, and reaction time6h,the red color of2BF （400mg/L） was degraded to colorless and the TOC removal rate was52%.The optimal conditions of application of NaNO₂/FeCl₃/O₂system for the treatment of azodye Reactive Red2BF were:2BF concentration400mg/L, reaction temperature160℃,oxygen partial pressure0.8Mpa, pH3, Reactive Red2BF: NaNO₂: FeCl₃（mole ratio）=1:1:0.2,and reaction time6h, the TOC, COD and color were63%,70%and99%, respectively.The degradation process with the Ultraviolet-visible absorption spectrum was studied.Asthe reaction time prolonged, the maximum absorption band of Reactive Red2BF decreased,and then completely disappeared. It indicated that the labile azo bond （-N=N-） was broken,Reactive Red2BF is degraded.The reaction kinetics of the two systems for the treatment were investigated. It indicatesthat the two reactions were both consistant with a pseudo-first order kinetic model. The EaTOCof application of KBrO₃/O₂system for the treatment of azo dye Reactive Red2BF is46.9kJ/mol.The reaction rate as following: The EaTOCand EaCODof application of KBrO₃/O₂system for the treatment of azo dyeReactive Red2BF is93.4kJ/molå'Œ47.4kJ/mol.The reaction rate as following:...