화학공학소재연구정보센터
홈 로그인 로그아웃 연락처 사이트맵
HWAHAK KONGHAK, Vol.38, No.5, 753-759, October, 2000
Export Citation
일라이트와 몬모릴로나이트에 대한 수용액상에서의 유로퓸과 토륨의 흡착특성
Adsorption Characteristics of Eu and Th on Illite and Montmorillonite in Aqueous Solution
이덕권, 김희택, 강문자1, †, 한필수1, 전관식1
  • 한양대학교 화학공학과
  • 1한국원자력연구소
Duck Kueon Lee, Hee Taik Kim, Mun Ja Kang1, †, Pil Soo Hahn1, and Kwan Sik Chun1
  • Department of Chemical Engineering, Hanyang University, Korea
  • 1Korea Atomic Energy Research Institute, Korea
E-mail:
초록
점토광물인 일라이트와 몬모릴로나이트에 대한 수용액상에서의 유로퓸과 토륨의 흡착특성을 회분식 실험을 통해서 살펴보았다. 유로퓸의 흡착특성은 pH 6이하에서는 pH변화에 무관하며 Ca2+의 영향을 많이 받아 이온교환 과정으로 해석할 수 있다. 그리고 pH 6과 8사이에서는 흡착량이 급격히 증가하는 pH모서리가 관찰되며 pH 8이상에서는 흡착량이 95%이상이었다. 이는 Eu3+나 유로퓸 탄산착물과 광물과의 표면착물 반응에 의한 것으로 생각된다. 토륨의 흡착특성은 pH 3과 5사이에서 흡착량이 급격히 증가하여 pH 5이상에서는 99%이상의 흡착량을 보였다. 이는 주로 Th4+나 토륨 수산화물의 표면착물 반응에 기인한다. 두 광물에 대한 유로퓸과 토륨의 흡착은 Langmuir 흡착등온선으로 나타낼 수 있었으며 흡착등온선으로부터 구한 최대흡착량은 일라이트의 경우 유로퓸과 토륨이 각각 32와 109 meq/100 g이었고 몬모릴로나이트의 경우 각각 95와 128 meq/100 g이었다. 그리고 MINTEQA2코드로 계산한 수용액상에서의 유로퓸 화학종은 Eu3+, EuOH2+, EuCO3+, Eu(CO3)2-이었고 토륨의 화학종은 Th4+, Th(OH)22+, Th(OH)3+, Th(OH)4이었다.
The adsorption characteristics of europium and thorium on clay minerals such as illite and montmorillonite were investiated by batch experiments. The adsorbed amount of Eu was constant as a function of pH and much affected by a Ca2+ ion at pH below 6. This means the Eu adsorption at low pH is described by ion-exchange reaction. The adsorbed amount was increased rapidly in the range of pH 6-8, which corresponds to pH edge. The adsorbed Eu was more than 95% of total Eu at pH above 8. The Eu adsorption at high pH is caused by the surface complexation reaction between Eu3+ or europium carbonates and minerals. The adsorbed amount of Th was sharply increased in the range of pH 3-5. Th adsorbed Th was more than 99% of total Th at pH above 5. The Th adsorption is mainly due to the surface complexation of Th4+ or thorium hydroxides. The adsorption characteristics of Eu and Th on illite and montmorillonite is represented by Langmuir adsorption isotherm. The maximum adsorbed amount of Eu and Th on illite, resulted from adsorption isotherm, is 32 and 109 meq/100 g, respectively. The maximum amount of Eu and Th on montmorillonite is 95 and 128 meq/100 g, respectively. The Eu-species calculated by MINTEQA2 are Eu3+, EuOH2+, EuCO3+ and Eu(CO3)2-. The Th exists in the species of Th4+, Th(OH)22+, Th(OH)3+ and Th(OH)4 in the aqueous phase.
Keywords:Europium;Thorium;Illite;Montmorillonite;Adsorption
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