关键过程参数对超临界水氧化降解核工业废树脂的影响研究

Study on the Influence of Key Process Parameters on the Degradation of Waste Resin by Supercritical Water Oxidation

以核工业难以有效处理的废阴离子和阳离子交换树脂为研究对象,通过调控反应温度、氧化系数、停留时间、物料浓度等反应条件,探索超临界水氧化过程中不同关键过程参数对废树脂有机物降解的影响规律。研究得出关键过程参数反应温度、氧化系数、停留时间与两种树脂的降解效率呈正相关关系,而物料浓度与树脂降解效率的关系较为复杂;在480℃及以上温度,两种树脂COD去除率基本保持平稳;受反应初期树脂固体颗粒的传质影响,两种树脂的氧化系数需大于130%;阳离子交换树脂在反应过程中会生成强酸性物质抑制反应进行,添加NaOH后,阳离子交换树脂去除效率显著提高。

In this paper,anion and cation exchange resins as the typical radioactive waste in nuclear power plants are used as degradation substrates.By regulating reaction temperature,oxidation coefficient,residence time,material concentration and reaction alkalinity,the effects of different key process parameters on the degradation of organic matter in supercritical water oxidation process are explored.The results show that the key process parameters,such as reaction temperature,oxidation coefficient and residence time,are positively correlated with the degradation rate of the two resin organic compounds.With the increase of the key process parameters,the degradation rate of the resin organic compounds increases continuously.At the temperature of 480℃and above,the COD removal rate of the two resins can be basically stable.The oxidation coefficient of the two resins should be greater than 130%due to the mass transfer of resin solid particles in the early stage of reaction.The cation exchange resin will generate strong acidic substances during the reaction process,resulting in the overall reaction rate slowing down.After adding NaOH,the removal efficiency of cation exchange resin is significantly improved.