環境（2）

[PY-34] Cs⁺とSr²⁺ の安定化を目的とした石炭フライアッシュ由来ゼオライトAの合成と特性化

○Tian Quanzhi¹、笹木 圭子¹ (1. 九州大学)

キーワード：石炭灰、ゼオライトA、セシウムイオンとストロンチウムイオン、構造、不動化

Zeolite A was synthesized from coal fly ash as a cation exchanger for removal of Cs⁺ and Sr²⁺ which were surrogates of radionuclides from aqueous solutions in batch operation. A series of adsorption experiments of Cs⁺ and Sr²⁺ were conducted as a function of pH, contact time and initial ion concentration. Kinetic and thermodynamic models were applied to the rate and isotherm sorption data, resulting in the relevant kinetic and thermodynamic parameters. Importantly, the structures of Cs-loaded and Sr-loaded zeolites were revealed by XRD structural refinement. Meanwhile, the properties of them were determined through Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TG-DTA) and analysis of nitrogen adsorption-desorption isotherm with a comparison of original zeolite. On the other hand, the solidifications of Cs-loaded and Sr-loaded zeolites by thermal treatment and geopolymerization were evaluated. The results showed that fly ash-based zeolite can be an alternative material for immobilization of Cs⁺ and Sr²⁺. The zeolite structure changed after loading Cs⁺ or Sr²⁺. Both techniques including thermal treatment and geopolymerization can be applied for solidification of Cs⁺ and Sr²⁺.