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

粘土矿物的同胞分布模式和准土壤溶液组成的热力学分析揭示了亚洲潮湿土壤中2：1矿物的风化序列如下：在中度至高度风化的土壤中，继承自母质的二八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 mm的中等酸性条件下，云母被认为直接风化成高岭土矿物，形成很少的可膨胀2：1矿物（如果有的话）。而在印度尼西亚和/或日本的强酸性条件下，云母倾向于先风化成可膨胀的2：1矿物，然后风化成高岭石。在泰国和乌克兰，风化云母的FFS对Cs^+的固定能力相对较小，且随风化云母中FFS的出现而变化。 关于我们 伊卡矿物。从不同离子强度下Cs吸附和解吸行为的结果来看，FES对Cs的吸附与土壤溶液的I无关，而塌陷的层间位点也对Cs有吸附作用，但在某种程度上受I的影响，即，当Cs^+被固定后，周围溶液中离子浓度的增加可能会促进Cs^+的解吸。粘土矿物对Cs吸附的这种性质可能通过土壤形成而改变，即，羟基夹层和/或云母矿物的广泛风化通常可膨胀的2：1矿物具有模型至高电荷层，可以最强烈地固定Cs^+。幸运的是，在日本这样的土壤大多是通过羟基夹层，这可以减少不可逆的Cs固定的机会。此外，Cs^+离子一旦被固定在可膨胀的2：1矿物的塌陷层中，如果溶液I增加，就可以解吸。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^+的主要目标是塌陷的2：1层，则可能需要高剂量的可溶性盐。风化云母的FES对Cs^+的固定作用不依赖于溶液L。反之，Cs^+一旦被云母矿物所固持，就不会因周围溶液L的变化而释放出来。因此，如果这些土壤中含有相当大量的云母矿物，则很难将Cs^+离子从土壤中去除。

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