Removal of ^<137>Cs from ecosystems using phytoremediation in former Soviet Union

黏土矿物的同源分布模式和准土壤溶液组成的热力学分析揭示了湿润亚洲地区2:1矿物的风化序列：在中等至高度风化的土壤中，继承母质的二面体云母是土壤粘土中2:1矿物的主要来源。在泰国，在年降水量小于1500毫米的中酸性条件下，云母被认为是直接风化为高岭土矿物，即使有，也很少形成可膨胀的2:1矿物。而在强酸性条件下，在降水较多的印度尼西亚和/或日本，云母倾向于先风化为可膨胀的2:1矿物，再风化为高岭石，这种在酸性条件下形成的可膨胀2:1矿物可以广泛地固定Cs^+。此外，风化云母的FES可以固定Cs^+离子。在泰国和乌克兰，土壤的Cs固定能力相对较小，并且随着风化云母中FFS的出现而变化。根据不同离子强度下Cs吸附和解吸行为的结果判断，FES固定Cs不依赖于土壤溶液的I，而坍塌的层间位点也固定Cs，但在一定程度上受1的影响，即周围溶液离子浓度的增加可能会增强固定后Cs^+的脱附。粘土矿物对Cs吸附的这种性质可能通过土壤的形成而改变，即羟基层间和/或云母矿物的广泛风化作用。通常2:1可膨胀的矿物，具有模型到高电荷层，可以最强烈地固定Cs^+。在目前的研究中，日本和/或印度尼西亚的土壤就是这种情况，幸运的是，日本的土壤大多被羟基层间修饰，这可以减少不可逆的碳固定的机会。此外，Cs +离子一旦固定在可膨胀的2:1矿物坍塌层中，当溶液I增加时可以解吸。从这个意义上说，这是在日本和/或印度尼西亚土壤中尝试植物修复的空间，尽管如果提取Cs^+的主要目标是塌陷2:1层，则可能需要高剂量的可溶性盐。另一方面，风化云母的FES可以独立于溶液L固定Cs^+离子。在rum中，Cs^+离子一旦被云母矿物保留，不会因周围溶液1的变化而释放。在乌克兰和泰国的土壤中，这类云母矿物被认为是Cs固定的主要原因。因此，如果这些土壤中含有相当多的云母矿物，则很难从土壤中去除铯离子

The in sib distribution patterns of clay minerals and thermodynamic analysis of quasi-soil solution composition reveal the weathering, sequence of 2:1 minerals in humid Asia as follows : In moderately to highly weathered soils, dioctahedral mica inherited from parent materials is a major source of 2:1 minerals in soil clays. In Thailand, under moderately acidic conditions with annual precipitation of less than 1500 mm, mica is considered to be directly weathered to kaolin minerals with forming few expandable 2:1 minerals, if any. In contrast, under strongly acidic conditions in Indonesia and/or Japan with higher precipitation, mica tends to firstly weathered to expandable 2:1 minerals and then to kaoliniteSuch expandable 2:1 minerals formed under acidic conditions can immobilize Cs^+ extensively. In addition, FES of weathered mica can immobilize Cs^+ ion In Thailand and Ukraine, Cs immobilizing capacities of the soils are relatively small and vary depending on the occwYence of FFS in m … More ica minerals. Judging firm the results obtained for Cs-adsorption and desorption behaviors under different ionic strengths, FES immobilize Cs independently of I of a soil solution while collapsed interlayer sites also immobilize Cs but are, to some degree, affected by 1, i.e., increased ionic concentration of surrounding solution may enhance desarption of Cs^+ once immobilized. Such properties of clay minerals on Cs adsorption are possibly modified through soil formation, i.e., hydroxy-interlayering and/or extensive weathering of mica mineralsGenerally expandable 2:1 minerals with modeltely-to highly-charged layers can immobilize Cs^+ most strongly. This is the case that occurs in Japan and/or Indonesia among the present study Fortunately such soils in Japan are mostly modified by hydroxy interlayering, which can decrease the chance of irreversible Cs immobilization. Moreover, the Cs^+ ion once immobilized in the collapsed layers of expandable 2:1 minerals can be desorbed if solution I increases. In this sense, these is a room for trying phytoremediacion in Japanese and/or Indonesian soils,although high dose of soluble salts may be required if the main target for extraction of Cs^+ is collapsed 2:1 layers. On the other hand, FES of weathered mica can fix Cs^+ ion independently of solution L In rum, Cs^+ ion once retained by mica minerals would not be released by the change of 1 of surrounding solution In the soils of Ukraine and Thailand, such mica minerals are considered to be mainly responsible for Cs immobilization. It is, therefore, quite difficult to remove Cs^+ ion firm these soils if a fairly large amount of mica minerals is present Less