超临界水氧化法去除废水有机氮的工艺和动力学研究

PROCESS AND KINETICS OF SUPERCRITICAL WATER OXIDATION OF NITROGENOUS ORGANIC COMPOUNDS IN WASTE WATER

引言 超临界水氧化法(SCWO)是一种新型高效的废水和废物处理技术.水在超临界条件下具有独特的物理化学性质,它能与非极性物质如烃类和其他有机物完全互溶,而无机物特别是盐类在超临界水中的溶解度很低.另外,超临界水可以与气体(如空气、氧气、二氧化碳等)完全互溶.这些性质使得超临界水作为反应介质的超临界水氧化法具有独特的优势.

The efficiency and kinetics of the destruction of nitrogen - containing organic compounds in waste water by Supercritical Water Oxidation at 673. 2 K-823.2K and 24 MPa-30 MPa was investigated. The removal efficiencies are lower than 10% below 673.2K, and higher than 90% above 823.2 K. The increasing of the temperature, pressure or reaction time will result in the higher removal efficiency. Under the conditions of the experiments, the rate of removal of Kjeldahl's Nitrogen is first order,and independent of the concentration of oxygen. The effect of temperature on the rate constant can be expressed by Arrherrius equation. The rate constant depends on the pressure especially near the critical point of water.