[Effect of temperature on decomposition of leachates by WAO/CWAO]

Catalytic wet air oxidation (CWAO) is a very effective physical chemistry method to treat organic wastewater. In this experiment, CWAO is employed to reduce the organic compounds in the landfill leachates. Temperature is an important factor in treating leachates by CWAO, so the effect of temperature on the reduction efficiency and decomposition rate of organic pollutants is investigated emphatically and the quantificational relationship is established between the decomposition rates and temperatures used in this study. The function of Co/Bi catalyst for the reduction of landfill leachates is also discussed. The influence of temperature on the degradation of landfill leachates by CWAO is carried out in a sealed environment using catalyst. The resulted information shows that the reduction rate of total organic carbon (TOC) and chemical oxygen demand (COD) increases notably with increase in temperature with or without the catalyst, and that the Elovich equation can describe dynamics course of landfill leachates degradation well. Rate constant k also increases with increase in temperature and the quantificational relationship is established between the rate constant k and temperature; the main reason of pH value reducing rapidly at first and later rising slowly is that a large amount of organic acid is produced in the early period in the reaction and the organic acid is degraded gradually later. Degradation of landfill leachates by CWAO can reach better treatment efficiency in gentle condition with catalyst Co/Bi in this study. The temperature's relatively great impact on the reaction using CWAO is discussed only in the paper and the effects of the other reaction conditions such as oxidant and catalyst dosage and the concentration of wastewater on degrading efficiency by CWAO are to be focused on.