SORPTION BEHAVIOR OF ACTINOIDS ON WEATHERED MINERALS

锕系元素对风化矿物的吸附行为

基本信息

批准号：
07680521
负责人：
YAMAZAKI Hiromichi
金额：
$ 1.6万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

Understanding the sorption behavior of nuclides having long-term radiological toxicity onto geological materials is central to the safety assessment of underground disposal of radioactive waste. In order to see the effect of crystal structure, crystallinity and surface conditions of various oxides and hydrous oxides on the sorption of metal ions, the sorption of tracer concentrations of Np(V) on naturally occurring iron and alumiun minerals, synthetic oxide powders and laboratory-prepared hydrous oxides was studied as a function of pH.The orders of their abilities to sorb Np(V) were hydrous oxides including oxyhydroxides and hydroxides > synthetic oxide powders > minerals (hematite, magnetite and corundum). These results suggest that the sorption of tracer concentrations of actinoids is controlled primarily by their crystal structures and subsidiarily by their surface areas, indicating that the transformation of oxides and hydrous oxides of iron and aluminum occurring in natural enviro … More nments will give a serious influence on the migration of radionuclides. The effects of metal ion saturation on the sorption of Eu(III) and Co(II) on goethite, gibbsite and laboratory-prepared amorphous iron and aluminum oxides were studied as a function of pH over a wide range of metal ion concentrations. When the metal ion concentrations were low, a simple Langmuir equation, assuming a single binding constant, was capable of describing sorption on these hydrous oxides. At high metal ion concentrations, sorption on goethite and gibbsite exhibited clear saturation maxima, indicating that sorption on these minerals was controlled by a simple one-to-one interaction between the metal ion and a binding site. Conversely, sorption on laboratory-prepared hydrous oxides continued to increase even at high metal ion concentrations, indicating that sorption on amorphous hydrous oxides proceeds through a somewhat different pathway, such as the formation of a pricipitate or a solid solution at the binding surface. Less

了解具有长期放射学毒性对地质材料的核素的吸附行为对于放射性废物地下处置的安全性评估至关重要。为了查看晶体结构的影响，各种氧化物和含水氧化物对金属离子的吸附的结晶度和表面条件，NP（V）示踪剂浓度的吸附对天然存在的铁和铝矿物矿物质，连接氧化物粉末，以及实验室氧化物的自然氧化物的作用。氧化物和氢氧化物>合成氧化物粉末>矿物质（赤铁矿，磁铁矿和刚毛）。这些结果表明，圣素的示踪剂浓度的吸附主要由它们的晶体结构控制，并由其表面积进行辅助，这表明在天然Enviro中发生的氧化物和氧化物的转化和铝的含水氧化物……更多的NEMEMT将对Radiouclies的迁移产生严重的影响。金属离子饱和度对欧盟（III）和CO（II）焊接的影响，对乙石，吉布斯石和实验室准备的无定形铁和氧化铝氧化物的影响是pH值的函数。当金属离子浓度较低时，假设单个结合常数的简单Langmuir方程能够描述这些含水氧化物上的吸附。在高金属离子浓度下，对黄铁矿和吉布斯特岩的吸附暴露于透明的饱和度最大值，表明这些矿物质的吸附受到金属离子和结合位点之间的简单一对一相互作用来控制。相反，即使在高金属离子浓度下，对实验室准备的含水氧化物上的吸附也继续增加，这表明对无定形含水氧化物的吸附通过稍有不同的途径进行，例如在结合表面上形成降低或实心溶液。较少的