Various radionuclides including fission products and heavy nuclides were released into the environment during the Fukushima Daiichi Nuclear Power Station (FDNPS) accident. The dissolution followed by migration of deposited radionuclides of Cs, Sr and U on soils could take place to the local environment. Therefore, it is necessary to determine sorption-desorption coefficients of U in soil-water system around the FDNPS from a migration viewpoint. The determination of sorption coefficient K_d(S) as well as desorption coefficient K_d(D) for U has been carried out in the present study using a laboratory batch method. Stable U was used for sorption from simulated ground water onto contaminated soil samples collected from Okuma Town, Fukushima. Different soil parameters were measured to understand their effects on sorption and desorption processes. The obtained K_d(S) and K_d(D) values of U were compared with values of K_d(S) and K_d(D) of Cs and Sr and K_d(S)–U in known Fukushima accident contaminated soils reported in the literature for better understanding. It was observed that K_d(S)–U varied from 160 to 5100 L/kg, whereas K_d(D)-U ranged from 200 to 11000 L/kg. K_d(D) was higher than K_d(S) for U in these soils implying irreversibility of the sorption process. Pearson's correlation of K_d(S) values suggested that U sorption is affected by various soil parameters. However, desorption is decided by the nature of U species formed in sorption process and soil parameters like pH, presence of carbonates, Ca ions, clay minerals etc. to some extent. The comparison between K_d(S) and K_d(D) values for Cs, Sr and U revealed that unsorbed Sr could migrate farther than unsorbed Cs or U under the present experimental conditions. Both sorption and desorption studies are of great importance to understand migration of metal ions from contaminated sites to local uncontaminated areas.

在福岛第一核电站事故中，包括裂变产物和重核素在内的各种放射性核素被释放到环境中。溶解后，沉积的Cs，Sr和U放射性核素可能会迁移到当地环境中。因此，有必要从迁移的角度确定FDNPS周围土壤-水系统中U的吸附-解吸系数。吸附系数K _d（S）以及解吸系数K _d的确定在本研究中，使用实验室批处理方法对U进行（D）。稳定的U被用于从模拟地下水吸附到从福岛县大沼町收集的受污染土壤样品上。测量了不同的土壤参数，以了解它们对吸附和解吸过程的影响。将获得的U的K _d（S）和K _d（D）值与已知福岛事故污染土壤中Cs和Sr和K _d（S）–U的K _d（S）和K _d（D）值进行比较在文献中进行了报道，以便更好地理解。据观察，K _d（S）-U的变化范围为160至5100 L / kg，而K _d（D）-U的变化范围为200至11000 L / kg。ķ _d在这些土壤中，U的（D）高于K _d（S），这表明吸附过程不可逆。皮尔逊的K _d（S）值的相关性表明，U的吸附受各种土壤参数的影响。但是，解吸取决于吸附过程中形成的U物种的性质以及土壤参数，例如pH，碳酸盐，Ca离子，粘土矿物的存在等。Cs，Sr和U的K _d（S）和K _d（D）值之间的比较表明，在当前的实验条件下，未吸附的Sr可能比未吸附的Cs或U迁移得更远。吸附和解吸研究对于了解金属离子从受污染场所向本地未受污染区域的迁移都非常重要。