Study on optimization of adsorbents for uranium recovery from desalination plants of seawater

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04946
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 31010:Nuclear engineering-related
• Research Institution: Kindai University
• Principal Investigator: Nogami Masanobu 近畿大学, 理工学部, 教授 (50415866)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 海水ウラン / 回収 / 吸着 / トリホスフィントリオキシド

Outline of Final Research Achievements

Novel barium alginate gel (BaALG) encapsulating PPTPT, one of organophosphorus compounds with unusual high selectivity for uranium(VI) in HNO3 of very low concentrations, was investigated for recovery of uranium from seawater and, in particular, highly saline solutions generated in desalination plants. The advantage of microcapsules (MCs) such as BaALG is that MCs may fix extractants inclusively in the gel polymer support and suppress gradual leaching of extractants from the support during operation which is generally inevitable for impregnated-type adsorbents. As the result of experiments using aqueous NaCl solutions of various concentrations at pH8, it was found that co-encapsulation of another compound which works as a “wall material”, e.g., dodecylbenzenesulfonic acid is necessary for preventing the leaching of PPTPT. This leads to the increase in the adsorption property for U(VI).

Free Research Field

放射性核種分離

Academic Significance and Societal Importance of the Research Achievements

本研究は、非解離性の鎖状化合物であるPPTPTが中性領域でU(VI)と選択的かつ強力に結合する作用を利用するという、アクチノイドの溶液化学の知見を活用した非常に独創性の高い研究であると言える。また、金属イオン回収システムを海水の淡水化プラントに併設することで、高塩分濃度水溶液および吸着剤性能の有効活用を目指す点が従来の研究にない特色である。今回の結果から得られたマイクロカプセルのNaCl水溶液での安定性および金属イオン吸着特性は、海水ウラン回収という我が国にとり非常に重要な研究課題の今後の進展において、非常に大きな意義があるといえる。