Parajuli Durga, Tanaka Hisashi, Sakurai Koji, Hakuta Yukiya, Kawamoto Tohru
Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8565, Japan.
Materials (Basel). 2021 Mar 1;14(5):1151. doi: 10.3390/ma14051151.
Prussian blue analogs (PBA) are widely studied for radioactive cesium decontamination. However, there are fewer works related to their post use storage. Considering the oxidative stabilization of the material after the selective uptake of Cs, the thermogravimetric properties in powder and bead form, with various Cs and other alkali metal ions adsorbed, and various heating rates were studied. TG-DTA taken in dry air condition shows an exothermic decomposition at ~270 °C. This temperature varied with the heating rate, mass, and the proportion of adsorbed ions. The best condition for complete oxidation of Prussian blue (PB) is found to be a gradual oxidative decomposition by heating in the temperature range of 200-220 °C until the total mass is decreased by >35%. After this, the temperature could be safely increased to >300 °C for the complete oxidative decomposition of PB that formed iron oxide and salt of the adsorbed Cs. A pilot scale test conducted using the radioactive Cs adsorbed Prussian blue microbeads (PB-b) confirmed that no Cs was released in the effluent air during the process.
普鲁士蓝类似物（PBA）在放射性铯去污方面得到了广泛研究。然而，关于其使用后储存的相关研究较少。考虑到材料在选择性摄取铯后的氧化稳定性，研究了吸附有各种铯和其他碱金属离子的粉末和珠状形式在不同加热速率下的热重性质。在干燥空气条件下进行的热重-差示热分析（TG-DTA）显示在约270°C有放热分解。该温度随加热速率、质量和吸附离子的比例而变化。发现普鲁士蓝（PB）完全氧化的最佳条件是在200-220°C温度范围内加热进行逐步氧化分解，直到总质量减少>35%。在此之后，温度可以安全地升高到>300°C，以使形成氧化铁和吸附铯盐的PB完全氧化分解。使用吸附放射性铯的普鲁士蓝微珠（PB-b）进行的中试规模试验证实，在此过程中废气中没有释放出铯。
