Department of Civil and Environmental Engineering, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Korea.
Department of Civil and Environmental Engineering, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Korea.
J Hazard Mater. 2021 Jun 15;412:125165. doi: 10.1016/j.jhazmat.2021.125165. Epub 2021 Jan 16.
Solutions of monovalent and divalent ions, including calcium, magnesium, ammonium, and potassium, were tested in the removal of Sr and Cs from soil near a nuclear power plant. The Ca and K solutions exhibited removal efficiencies of 68.2% and 81.3% for Sr and Cs, respectively. This high performance was probably due to the physicochemical similarities between 'Ca and Sr' and 'K and Cs'. Alternatively, the Mg and NH solutions performed much worse, despite having the same valences as Ca and K, respectively. Ca and K solutions could also simultaneously remove cationic toxic metals present with the nuclides, albeit much less efficiently (30-40%). For anionic metalloid As and anionic toxic metal Cr, the efficiency was even lower (< 20%). The five-step sequential extraction experiment confirmed that all chemical forms of Sr and Cs, except the residual form, were extensively removed by the Ca and K solutions respectively. For comparison, widely used washing agents exhibited removal efficiencies of 25-30%. Notably, Fe and Mn ions were hardly detected in the Ca solution, while their concentrations were much higher in the common washing agents, suggesting the involvement of an ion-exchange mechanism in Sr and Cs removal, rather than a Fe/Mn oxide dissolution mechanism.
一价和二价离子溶液，包括钙、镁、铵和钾，被测试用于去除核电站附近土壤中的 Sr 和 Cs。Ca 和 K 溶液对 Sr 和 Cs 的去除效率分别为 68.2%和 81.3%。这种高性能可能是由于“Ca 和 Sr”和“K 和 Cs”之间的物理化学相似性。相比之下，尽管 Mg 和 NH 溶液的价态分别与 Ca 和 K 相同，但性能却差得多。Ca 和 K 溶液还可以同时去除与核素共存的阳离子毒性金属，尽管效率要低得多（30-40%）。对于阴离子类金属 As 和阴离子毒性金属 Cr，效率甚至更低（<20%）。五步连续提取实验证实，除残余形式外，Ca 和 K 溶液分别可有效去除 Sr 和 Cs 的所有化学形态。相比之下，常用的洗涤剂的去除效率为 25-30%。值得注意的是，在 Ca 溶液中几乎检测不到 Fe 和 Mn 离子，而在常用的洗涤剂中它们的浓度要高得多，这表明 Sr 和 Cs 的去除涉及离子交换机制，而不是 Fe/Mn 氧化物溶解机制。
