고준위 폐액의 열발생 핵종인 세슘 및 스트론튬 제거를 위하여 내산성이 강한 potassium titanate(K2Ti4O9)를 합성하여 Sr과 Cs 이온 혼합용액에 대한 흡착평형 특성을 평가하였다. 티탄산 칼륨 흡착제는 Sr 이온에 선택적이었고, pH2의 산성용액에서 Sr 이온 및 Cs 이온의 분배계수(Kd)는 각각 3,300 mL/g과 200mL/g을 나타내었다. K2Ti4O9의 Sr과 Cs 이온에 대한 흡착평형 등온식으로 Langmuir, Freundlich, Dubinin-Polanyi model을 평가하였다. 이성분의 경우 모든 모델들이 실험 데이터를 잘 표현하였으나, 특히 Freundlich 모델과 Dubinin-Polanyi 모델들이 실험데이터를 정확하게 모사하였다. 반면에 다성분계의 경우, 이성분계 표준 등온선을 확장한 다성분 모델로는 예측할 수 없었으며 새로운 실험적 경험식인 수정된 Dubinin-Polanyi식을 이용하여 실험치를 정확히 예측할 수 있었다.
Potassium titanate ion exchanger was synthesized to use for removing strontium and caesium ions, which are the heat generation radionuclides in HLLW(high level liquid waste). Adsorption equilibria for Sr and Cs ions were evaluated with the synthetic potassium titanate(K2Ti4O9) ion exchanger. The potassium titanate ion exchanger showed selective adsorption for Sr ion over Cs ion. The distribution coefficients for Sr and Cs ions at pH 2 were 3,300 mL/g and 200 mL/g, respectively. Standard isotherm equations such as Langmuir, Freundlich and Dubinin-Polanyi equations were used to model the experimental data. For the binary data modeling, even though all models fit the data, Freundlich model and Dubinin-Polanyi model fit the experimental data more correctly. For multicomponent system, however, the experimental data could not be predicted from binary data using standard isotherms. While, a modified version of Dubinin-Polanyi equation, which is a semi-empirical equation, fit the experimental data accurately.
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