Characterization of the Purified Ca-type Bentonil-WRK Montmorillonite and Its Sorption Thermodynamics With Cs(I) and Sr(II)

• 발행기관: 한국방사성폐기물학회
• 저자명: Seonggyu Choi Bong-Ju Kim Surin Seo Jae-Kwang Lee Jang-Soon Kwon
• 간행물 정보: 『Journal of Nuclear Fuel Cycle and Waste Technology (JNFCWT)』Vol.21 No.4, 427~438쪽, 전체 12쪽
• 주제분류: 공학 > 공학일반
• 파일형태: PDF
• 발행일자: 2023.12.30

국문 초록

Thermodynamic sorption modeling can enhance confidence in assessing and demonstrating the radionuclide sorption phenomena onto various mineral adsorbents. In this work, Ca-montmorillonite was successfully purified from Bentonil-WRK bentonite by performing the sequential physical and chemical treatments, and its geochemical properties were characterized using X-ray diffraction, Brunauer-Emmett-Teller analysis, cesium-saturation method, and controlled continuous acidbase titration. Further, batch experiments were conducted to evaluate the adsorption properties of Cs(I) and Sr(II) onto the homoionic Ca-montmorillonite under ambient conditions, and the diffuse double layer model-based inverse analysis of sorption data was performed to establish the relevant surface reaction models and obtain corresponding thermodynamic constants. Two types of surface reactions were identified as responsible for the sorption of Cs(I) and Sr(II) onto Ca-montmorillonite: cation exchange at interlayer site and complexation with edge silanol functionality. The thermodynamic sorption modeling provides acceptable representations of the experimental data, and the species distributions calculated using the resulting reaction constants accounts for the predominance of cation exchange mechanism of Cs(I) and Sr(II) under the ambient aqueous conditions. The surface complexation of cationic fission products with silanol group slightly facilitates their sorption at pH > 8.

키워드

Thermodynamic sorption modeling Bentonil-WRK montmorillonite Cesium Strontium Cation exchange Surface complexation