摘要
采用间歇式超临界水氧化设备,对粉碎后的阳离子交换树脂水悬浮液进行处理。研究了反应温度、压力、停留时间、过氧系数对COD(化学需氧量)去除率的影响,考察了浆料在处理过程中模拟核素的转移,研究了进料pH对反应釜腐蚀的影响。结果表明:主要因素对处理效果的影响排序为:温度>过氧系数>停留时间>压力。最佳处理条件反应温度520℃、压力23MPa、停留时间30min、氧化系数3和进水pH=7下,COD去除率为99.5%,高于99.8%锶离子和钴离子沉积于排盐口。调节进水pH为7,COD的去除率提高了50.6%;树脂的质量减量率达到99.6%。为核废料有效减容提供了新途径。
Batch supercritical water oxidation(SCWO)equipment was used to study the treatment of discarded cation resin water suspension under supercritical conditions.The effects of reaction temperature,reaction pressure,residence time,and coefficient of peroxide on the removal rate of COD(chemical oxygen demand)were investigated experimentally.At the same time,the transfer of simulated nuclides under supercritical conditions was studied.Through orthogonal test,the most significant factors influencing the reaction system are ranked as follows:reaction temperature>residence time>peroxide coefficient>reaction pressure.The experiment shows that the degradation rate of COD of cationic resin is 99.5% under the conditions of reaction temperature 520 ℃,reaction pressure 23 MPa,residence time 30 min,pH=7,and oxidation coefficient 3.The cesium and cobalt ions were used to simulate the nuclear radioactive material in the discarded resin slurry.Under the optimal conditions,the cesium and cobalt ions were separated from the treated solution by 99.8%.
引文
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