Application of Electron Microscopy to Understanding Colloid-Facilitated Transport of Radionuclides at the Mayak Production Association Facility, Near Lake Karachai, Russia
Application of Electron Microscopy to Understanding Colloid-Facilitated Transport of Radionuclides at the Mayak Production Association Facility, Near Lake Karachai, Russia
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应用电子显微镜了解俄罗斯卡拉柴湖附近 Mayak 生产协会设施中放射性核素的胶体促进传输
DOI：
10.1007/978-981-15-0679-6_7
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Ewing Rodney C.
中科院分区：
文献类型：
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作者：
Utsunomiya Satoshi;Yokoo Hiroki;Oki Takumi;Kawamoto Keisuke;Takeda Ayaka;Wang Honggui;Ewing Rodney C.
在俄罗斯Mayak生产协会的Karachai湖的地下水系统中，已证实了水铁矿与钚的结合和迁移（Novikov等人，2006年）。自这一初步描述以来，在理解控制马亚克地点钚浓度和分布的机制方面取得了实质性进展。本章是一个简明的工作回顾，在过去的10年中，利用最新进展的纳米级，分析技术。利用对分布函数分析确定了水铁矿（P63 mc）的结构。扫描透射电子显微镜的Mayak胶体解决了混合二氧化硅纳米胶体和水铁矿的发生。热力学性质的水PU物种已被更新。利用同步辐射X射线吸收光谱测定了吸附钚的内球表面络合作用。高分辨透射电子显微镜显示，吸附的钚可以转化为钚-二氧化物纳米粒子。Pu（OH）22+·6 H2O的立方Pu-二羟基结构单元的聚集也可以进行Pu（OH）22+·6 H2O的聚合。钚解吸发生与再吸附在中性pH值。建立全面的模型，钚运输在Mayak网站，上述详细的机制必须考虑。胶体的严格表征是必要的，这些结果必须与实验研究获得的结果进行比较。关于钚与铁氢氧化物的关联的最新知识现在已经足够好地理解，安全评估不再需要依赖于经典的Kd方法。
Plutonium association and transport by ferrihydrite has been confirmed in the groundwater system of Lake Karachai at the Mayak Production Association, Russia (Novikov et al. 2006). Since this initial description, there has been substantial progress in understanding the mechanisms that control the concentrations and distribution of Pu at the Mayak site. This chapter is a concise review of work during the past 10 years that utilizes to advantage recent advances in nanoscale, analytical techniques. The structure of ferrihydrite (P63mc) was determined using a pair-distribution function analysis. Scanning transmission electron microscopy of Mayak colloids resolved the occurrence of mixed silica nano-colloids and ferrihydrite. Thermodynamic properties for aqueous Pu-species have been updated. Inner-sphere surface complexation was determined for adsorbed Pu using synchrotron-based X-ray absorption spectroscopy. The adsorbed Pu can transform into Pu-dioxide nanoparticles as revealed by high-resolution transmission electron microscopy. Plutonium polymerization can also proceed by aggregation of cubic Pu-dihydroxy building blocks of Pu(OH)22+•6H2O. Plutonium desorption occurs associated with re-adsorption at neutral pH. To establish comprehensive model of Pu transport at the Mayak site, the detailed mechanisms described above must be considered. Rigorous characterization of colloids is necessary and these results must be compared with results obtained from experimental studies. The state-of-the-art knowledge on the Pu association with Fe hydroxides is now well enough understood that safety assessments no longer need to rely on the classicalKdapproach.