Journal of Korean Society on Water Environment (한국물환경학회지)

Korean Society on Water Environment (한국물환경학회)
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Investigation on the Adsorption Features of Humic Acid on Carbon Nanotubes

탄소나노튜브의 휴믹산 흡착특성에 관한 기초연구

  • Lee, Sun-Hwa (Dept. of Environmental Science and Engineering Ewha Womans University) ;
  • Kim, Dong-Su (Dept. of Environmental Science and Engineering Ewha Womans University)
  • 이선화 (이화여자대학교 환경학과) ;
  • 김동수 (이화여자대학교 환경학과)
  • Received : 2004.07.14
  • Accepted : 2004.09.02
  • Published : 2004.09.30
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Abstract

As a feasibility study for the application of carbon nanotubes to the treatment of environmental pollutants, the adsorption characteristics of humic acid on carbon nanotubes has been investigated. The dispersion features of carbon nanotubes in aquatic environment were investigated by measuring the variation of their electrokinetic potentials with pH, and the effects of some dispersants on their dispersion features were also examined. Under the experimental conditions, humic acid was observed to mostly adsorb on nanotubes within a few minutes and reach the equilibrium state within about one hour. The adsorption features of humic acid on nanotubes were found to follow the Freundlich model better than the Langmuir Model. Humic acid adsorbed on carbon nanotubes endothermically and the change of enthalpy in adsorption reaction was estimated to be ca. 18.37kJ/mol at standard state. The entropic change in adsorption reaction for humic acid was ca. 0.0503kJ/mol at standard state and the activation energy for adsorption was also estimated based on the change of rate constants with temperature. FT-IR investigations showed that the functional groups such as alcohol, ester, and aromatics existing in the chemical structure of humic acid might work as the bridge in its adsorption on nanotubes.

Keywords

References

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