Search / Korean Journal of Chemical Engineering
HWAHAK KONGHAK,
Vol.28, No.3, 303-312, 1990
함수 산화티탄(IV)에 의한 우라늄의 흡착
Adsorption of Uranium by Hydrous Titanium(IV) Oxides
해수 증에 용존하고 있는 우라늄 채취용 흡착제 개발과 공정의 기초자료를 얻기 위하여 출발물질인 titanium(IV) alkoxides을 가수분해 온도별로 제조하여 얻을 함수 산화티탄(IV)을 그의 물성과 우라늄의 흡착량, 흡착평형과 흡착과정의 율속단계, 유효 세공용적 확산계수 등을 측정하였다. 흡착제의 물성은 가수분해 온도, 출발물질에 따라 영향이 있었으며, titanium(IV) alcoxides중에서 높은 가수분해 온도를 TTPO에 의해 조제된 함수 산화티탄(IV)이 TTIPO와 TTBO로 조제한 것보다 우라늄 흡착제로서 가장 우수한 흡착능을 보였으며, 조제시의 가수분해 온도와 흡착온도가 증가할수록 흡착량이 증가하였다. 우라늄에 대한 흡착 평형관계는 Freundlich 등온식을 따르며, 흡착열을 흡열반응이었고, 이 때 Fre-undlich constant(1/n), 흡착열 및 활성화에너지는 각각 0.11-0.28, 1.11-7.54kcal/mol, 0.96-1.97kcal/mol 범위이었다. 함수 산화티탄(IV)에 대한 우라늄의 흡착과정은 세공용적 확산율적이며, 유효 세공용적 확산계수는 7.5×10-7-2.24×10-5cm2/sec 범위이었다.
In order to develop an effective adsorbent for the recovery of dissolved uranium in sea water, hydrous titanium(IV) oxides were prepared by the hydrolysis of titanium(IV) alkoxides under aqueous alkaline solution. Effects of hydrolysis temperature on the adsorptive characteristics of adsorbents were investigated in terms of the physical properties of adsorbents and the mechanism of adsorption. The physical properties of hydrous titanium(IV) oxides are dependent on starting material and hydrolysis tem-peratures. Hydrous titanium(IV) oxide prepared by TTPO at high hydrolysis temperature was more effective for the adsorption of uranium than that prepared by either TTIPO or TTBO. The amount of uranium adsorbed on hydrous titanium(IV) oxides increased with rising hydrolysis and adsorption temperature. Adsorption equilibrium relation and heat of adsorption for uranium were correlated with Freundlich equation and endothermic process respectively. Freundlich constant(1/n), heats of adsorption and activation energy values were ranged 0.11-0.28, 1.11-7.54kcl/mol and 0.97-1.97kcal/mol respectively. The mechanism of adsorption of uranium on hydrous titanium(IV) oxides were elucidated as intraparticle diffusion controlling, an effective pore volume diffusivities were ranged of 7.5×10-7-2.24×10-5cm2/sec.
[References]
  1. Miyasaki H, J. Mech. Soc. Jpn., 81, 475, 1978
  2. Keen NJ, J. Br. Nucl. Energy Soc., 7, 178, 1968
  3. Davies RV, Nature, 203, 110, 1964
  4. Ogata N, Kakikana H, J. Atm. Energy Soc. Jpn., 11, 82, 1969
  5. Egawa H, Harada H, Nonaka T, J. Chem. Soc. Jpn., 1767, 1980
  6. Omichi H, Katakai A, Sugo T, Okamoto J, Sep. Sci. Technol., 20, 163, 1985
  7. Hirotsu T, Fujii A, Sakane K, Katoh S, Sugasaka K, Miyazaki H, Bull. Soc. Water Sci. Jpn., 35, 16, 1981
  8. Ozawa Y, Murata T, J. Nucl. Sci. Technol., 16, 671, 1979
  9. Bonsack JP, J. Colloid Interface Sci., 44, 430, 1973
  10. Maki T, J. Chem. Soc. Jpn., 945, 1978
  11. Ooi K, Kitamura T, Kath S, Sugasaka K, J. Chem. Soc. Jpn., 534, 1984
  12. Yamashita H, Ozawa Y, Nakajima F, Murata T, Bull. Chem. Soc. Jpn., 53, 3050, 1980
  13. Kanno M, Bull. Chem. Soc. Jpn., 31, 155, 1977
  14. Kawazoe K, Fujimoto M, Kag. Kog. Ronbunshu, 9, 159, 1983
  15. Liu SL, Chem. Eng. Sci., 22, 871, 1967
  16. Dollimore D, Heal GR, J. Appl. Chem., 14, 109, 1964
  17. Willard HH, Winter OB, Ind. Eng. Chem. Anal. Ed., 5, 7, 1933
  18. Ogata N, Bull. Soc. Sea Water Sci. Jpn., 24, 127, 1971
  19. Yamashita H, Ozawa Y, Nakajima F, Murata T, J. Chem. Soc. Jpn., 1057, 1978
  20. Takemaka Y, Nakatani M, Sugimori S, Uchida H, J. Chem. Soc.-Jpn., 1650, 1985
  21. Mikhail R, Brunauer S, Rodor EF, J. Colloid Interface Sci., 26, 54, 1968