Cs desorption behavior during hydrothermal treatment of illite with oxalic acid
- PDF / 1,857,210 Bytes
- 11 Pages / 595.276 x 790.866 pts Page_size
- 82 Downloads / 148 Views
RESEARCH ARTICLE
Cs desorption behavior during hydrothermal treatment of illite with oxalic acid Sung-Man Kim 1,2 & In-Ho Yoon 1
&
Il-Gook Kim 1 & Chan Woo Park 1 & YoungHo Sihn 1 & June-Hyun Kim 1 & So-Jin Park 2
Received: 19 February 2020 / Accepted: 9 June 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract The desorption of radioactive cesium (Cs) in soil is influenced by the clay mineral type, adsorption site, and concentration of Cs. In this study, experiments to detect desorption of non-radioactive and radioactive Cs from illite using oxalic acid were performed for 2 days at 70 °C in hydrothermal conditions. The results showed that the 133Cs removal efficiency by oxalic acid and inorganic acid treatment was similar at high concentration (22.86 mmol/kg) of non-radioactive 133Cs. In the radioactive 137Cs experiment, the removal efficiency by oxalic acid was higher than that by inorganic acid at low concentration (0.79 × 10−6 mmol/kg) of radioactive 137Cs. Based on the illite hypothetical frayed edge site (FES) concentration of 0.612 mmol/kg, the results suggested that 137Cs was preferentially adsorbed to FES on illite. The 137Cs at low concentration was difficult to remove because it was irreversible adsorption to FES, while the non-radioactive Cs at high concentration was mainly adsorbed to planar sites, and so was easy to desorb by ion exchange. Based on the results of NMR, FTIR, and XPS analyses, we concluded that the higher efficiency of 137Cs removal at low concentration by oxalic acid treatment than by treatment with inorganic acid was because of chelation effects associated with the complexation of oxalic acid (ligands) and metal ions in irreversible site (FES). Keywords Illite . Oxalic acid . Cesium . Metal-ligand complex . Remediation
Introduction Cesium-137 (137Cs) is a hazardous source of environmental radiation exposure that can lead to malignant tumors and life-shortening. In nuclear accidents, large quantities of radionuclides can be released to the environment, leading to serious consequences for all associated ecosystems (Bálsamo et al. 2019; Ding et al. Responsible Editor: Tito Roberto Cadaval Jr. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11356-020-09675-3) contains supplementary material, which is available to authorized users. * In-Ho Yoon [email protected] * So-Jin Park [email protected] 1
Decommissioning Technology Research Division, Korea Atomic Energy Research Institute, 989-111, Daedeokdae-ro, Yuseong-gu, Daejeon 34057, Republic of Korea
2
Department of Chemical Engineering and Applied Chemistry, College of Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Republic of Korea
2016; Yamamoto 2012). When Cs enters soil, strong adsorption to silt or clay occurs compared with large-sized gravel or coarse sand, because of the relatively large specific surface areas and small particle sizes of these soil types (Lee et al. 2017). Illite has a 2:1 structure in which one octahedr
Data Loading...
