Establishment of foam separation method for removal of radioactive metals

• Project/Area Number: 16K00582
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Environmental engineering and reduction of environmental burden
• Research Institution: Saitama University
• Principal Investigator: MATSUOKA Keisuke 埼玉大学, 教育学部, 准教授 (90384635)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2018: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2017: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2016: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 泡 / 泡沫 / 気泡 / 界面活性剤 / 泡沫分離 / 放射性金属 / マイクロバブル / セシウム / 泡沫分離法 / 放射線 / 汚染質除去技術 / 界面科学

Outline of Final Research Achievements

Foam separation could be used to remove a series of alkali metals and alkali earth metals from aqueous solutions based on electrostatic interactions between the anionic surfactant and metals. The most suitable concentration of the surfactant for which the alkali ions were selectively adsorbed was less than the CMC. The microbubble generator apparatus used in this study was effective in removing the alkali metals. The order of removal rate of the alkali metal was almost Li < K < Rb < Cs for the sodium dodecylsulfate surfactant system. On the other hand, the order of removal rate of the alkali earth metal was almost Mg < Ca < Sr for the sodium decylsulfate surfactant system. The order is lined up atomic number. The first order of removal rate constants with crystal ion radius were showed linear relationships in respective series. This method may be applied in the purification of the contaminated water from nuclear power plants and in industrial drainage.

Academic Significance and Societal Importance of the Research Achievements

汚水や水溶液中に溶解している金属を、微小気泡を用いた泡沫分離を用いて効果的に除去することが可能であることを証明した。その方法は高価な除去剤（樹脂系、酸化チタン系吸着剤）を使用する必要がない。最終処理物が金属と界面活性剤の結晶だけであり、減容化が可能である。最終的に水溶液から界面活性剤は泡沫として除去されるため、水は純水に近づく。

Research Products

• [Journal Article] Removal of alkali metal ions from aqueous solution by foam separation method (2018)
  • Author(s): Keisuke Matsuoka, Hiroaki Miura, Shiho Karima, Chiharu Taketaka, Shota Ouno, Yoshikiyo Moroi
  • Journal Title: Journal of Molecular Liquids Volume: 印刷中
  • Peer Reviewed
• [Presentation] Removal of alkali metals by using foam separation (I) (2018)
  • Author(s): Keisuke Matsuoka
  • Organizer: Elsevier,8th International Colloids Conference
  • Int'l Joint Research
• [Presentation] 泡沫分離法によるアルカリ土類金属の除去 (2018)
  • Author(s): 松岡圭介
  • Organizer: 第57回日本油化学会年会
• [Presentation] Removal of Alkali Metals by Using Foam Separation I (2017)
  • Author(s): Keisuke Matusoka, Hiroaki Miura
  • Organizer: The Asian Conference on Oleo Science 2017
  • Int'l Joint Research
• [Presentation] 泡沫分離法によるドデシル硫酸ナトリウム水溶液からセシウムの除去 (2016)
  • Author(s): 松岡圭介, 刈間詩帆, 竹高千陽, 大野翔太, 師井義清
  • Organizer: 日本油化学会第55 回年会
  • Place of Presentation: 奈良女子大学（奈良県 . 奈良市）
  • Year and Date: 2016-09-07
• [Remarks] 埼玉大学 松岡研究室ホームページ
  • URL: http://park.saitama-u.ac.jp/~matsuokakem/index.html
• [Remarks] 埼玉大学教育学部自然科学講座 松岡研究室
  • URL: http://park.saitama-u.ac.jp/~matsuokakei/index.html