(320y) Uptake Characteristics of Monovalent Metal Ion Species by Tannin-Gel

Tannin is included in much plant, and a tannin gel that made from it catches metal ion species. The authors already reported that uptake behavior about divalent, trivalent and hexavalent heavy metal ion species by it (made by Mitsubishi Nuclear Fuel Co. Ltd.). Following that, uptake behavior such as effect of terminal groups of the gel and of initial pH of solution was investigated for Cs+ among monovalent species. As a result, Cs+ was caught well in the case of gel terminal group with Na type, and was hardly caught with H type. The amount caught of Cs+ tended to increase with rise of the initial pH in the range of 7 or less, and both H and Na types caught few Cs+ when the initial pH was about 2. The amount caught of Cs+ in the case of Na type gel was able to be similar by the Langmuir equation. The pH of solution at equilibrium converged to about 7 regardless of the initial pH value and also when the initial pH was about 7 the amount caught of Cs+ became the maximum value. In the case of the initial pH 8 and 9, the amount caught of Cs+ at equilibrium was a more little than that in the range of the acidic initial pH. In present work, the authors consider the consequence mentioned above.