Influence of Amino Acids on the Mobility of Iodide in Hydrocalumite
In the cement system, hydrocalumite is a candidate adsorbent for low-level <sup>129</sup>I anionic species. However, the stability of hydrocalumite after immobilizing I<sup>−</sup> is unclear when they are exposed to pedosphere characterized by organic substances derived from...
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MDPI AG
2021-08-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/11/8/836 |
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| author | Mengmeng Wang Hirofumi Akamatsu Keiko Sasaki |
| author_facet | Mengmeng Wang Hirofumi Akamatsu Keiko Sasaki |
| author_sort | Mengmeng Wang |
| collection | DOAJ |
| description | In the cement system, hydrocalumite is a candidate adsorbent for low-level <sup>129</sup>I anionic species. However, the stability of hydrocalumite after immobilizing I<sup>−</sup> is unclear when they are exposed to pedosphere characterized by organic substances derived from living organisms. In the present work, five amino acids were selected as simplified models of natural organic substances under alkaline conditions. L-cysteine (H<sub>2</sub>Cys) and L-aspartic acid (H<sub>2</sub>Asp) accelerated the release of I<sup>−</sup> from I-hydrocalumite through ion-exchange. Ion-exchange of Cys<sup>2−</sup> with I<sup>−</sup> in I-hydrocalumite was faster than Asp<sup>2−</sup>, and the interlayer spacing (<i>d</i><sub>003</sub>) of Cys-hydrocalumite was smaller than that of Asp-hydrocalumite. DFT simulations not only supported the above results but also predicted that there was a positive correlation between the formation energies and interlayer spacings of amino acids intercalated hydrocalumite, depending on the configurations. Moreover, in the DFT predictions, the interaction between amino acids and metallic hydroxide layers was responsible for the formation of hydrogen bonds and Ca-O chemical bonds between the -COO<sup>−</sup> groups and [Ca<sub>2</sub>Al(OH)<sub>6</sub>]<sup>+</sup>. The other three amino acids did not show intercalation through ion-exchange. The stability of I-hydrocalumite is influenced differently by coexisting amino acids, depending on the ionic sizes, charge numbers, and hydrophilicity, which cause the second contamination. |
| first_indexed | 2024-03-10T08:34:18Z |
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| series | Minerals |
| spelling | doaj.art-848d15a1a0e941d9803e114ad8d3bb132023-11-22T08:49:39ZengMDPI AGMinerals2075-163X2021-08-0111883610.3390/min11080836Influence of Amino Acids on the Mobility of Iodide in HydrocalumiteMengmeng Wang0Hirofumi Akamatsu1Keiko Sasaki2Department of Earth Resources Engineering, Kyushu University, Fukuoka 819-0395, JapanDepartment of Applied Chemistry, Kyushu University, Fukuoka 819-0395, JapanDepartment of Earth Resources Engineering, Kyushu University, Fukuoka 819-0395, JapanIn the cement system, hydrocalumite is a candidate adsorbent for low-level <sup>129</sup>I anionic species. However, the stability of hydrocalumite after immobilizing I<sup>−</sup> is unclear when they are exposed to pedosphere characterized by organic substances derived from living organisms. In the present work, five amino acids were selected as simplified models of natural organic substances under alkaline conditions. L-cysteine (H<sub>2</sub>Cys) and L-aspartic acid (H<sub>2</sub>Asp) accelerated the release of I<sup>−</sup> from I-hydrocalumite through ion-exchange. Ion-exchange of Cys<sup>2−</sup> with I<sup>−</sup> in I-hydrocalumite was faster than Asp<sup>2−</sup>, and the interlayer spacing (<i>d</i><sub>003</sub>) of Cys-hydrocalumite was smaller than that of Asp-hydrocalumite. DFT simulations not only supported the above results but also predicted that there was a positive correlation between the formation energies and interlayer spacings of amino acids intercalated hydrocalumite, depending on the configurations. Moreover, in the DFT predictions, the interaction between amino acids and metallic hydroxide layers was responsible for the formation of hydrogen bonds and Ca-O chemical bonds between the -COO<sup>−</sup> groups and [Ca<sub>2</sub>Al(OH)<sub>6</sub>]<sup>+</sup>. The other three amino acids did not show intercalation through ion-exchange. The stability of I-hydrocalumite is influenced differently by coexisting amino acids, depending on the ionic sizes, charge numbers, and hydrophilicity, which cause the second contamination.https://www.mdpi.com/2075-163X/11/8/836iodidehydrocalumiteamino acidsDFT simulationsimple dissolutionion-exchange |
| spellingShingle | Mengmeng Wang Hirofumi Akamatsu Keiko Sasaki Influence of Amino Acids on the Mobility of Iodide in Hydrocalumite Minerals iodide hydrocalumite amino acids DFT simulation simple dissolution ion-exchange |
| title | Influence of Amino Acids on the Mobility of Iodide in Hydrocalumite |
| title_full | Influence of Amino Acids on the Mobility of Iodide in Hydrocalumite |
| title_fullStr | Influence of Amino Acids on the Mobility of Iodide in Hydrocalumite |
| title_full_unstemmed | Influence of Amino Acids on the Mobility of Iodide in Hydrocalumite |
| title_short | Influence of Amino Acids on the Mobility of Iodide in Hydrocalumite |
| title_sort | influence of amino acids on the mobility of iodide in hydrocalumite |
| topic | iodide hydrocalumite amino acids DFT simulation simple dissolution ion-exchange |
| url | https://www.mdpi.com/2075-163X/11/8/836 |
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