Using X-ray absorption near edge structure to evaluate adsorption properties of rare earths and nitrogen by difference of their interactions

Minowa, Kazuki*; Watanabe, So  ; Nakase, Masahiko*; Takahatake, Yoko  ; Miyazaki, Yasunori  ; Ban, Yasutoshi  ; Matsuura, Haruaki*

In this study, X-ray absorption near edge structure (XANES) spectral analysis and column experiments were used to verify the selectivity of rare earth (RE) ions by alkyl diamide amine (ADAAM) adsorbent. In addition, the interactions between the N atoms of ADAAM and RE ions were evaluated to determine whether any of the RE ions are a valid simulant for developing a mutual separation process for minor actinides (MAs) in highly radioactive liquid waste. It was confirmed that La and Ce interacted with the amine N atom of ADAAM and they showed a peak shift of the N-K edge XANES spectrum; this finding suggested that a soft interaction is an essential factor influencing ion selectivity. Therefore, the selection factor of RE ions by ADAAM adsorbent was similar to that of MAs. It was concluded that RE ions are reasonable species to simulate MAs.