Journal of Korean Society of Environmental Engineers (대한환경공학회지)

Korean Society of Environmental Engineers (대한환경공학회)
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Physicochemical Adsorption Characteristics of MTBE and Cadmium on Clay Minerals

점토광물에 대한 MTBE와 카드뮴의 물리화학적 흡착 특성

  • Lim, Nam-Ho (Department of Environmental Engineering, Inha University) ;
  • Seo, Hyung-Joon (Department of Environmental Engineering, Inha University) ;
  • Kim, Chang-Gyun (Department of Environmental Engineering, Inha University)
  • 임남호 (인하대학교 환경공학과) ;
  • 서형준 (인하대학교 환경공학과) ;
  • 김창균 (인하대학교 환경공학과)
  • Published : 2005.03.31
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Abstract

This study was performed to investigate adsorption characteristics of MTBE and Cd depending upon types of clay minerals md their physicochemical properties. The adsorption characteristics were examined by batch adsorption test on various experimental parameters such as adsorption time, ratio of solution to soil, concentration of contaminants, content of organic matter, pH, and zeta potential. The adsorption efficiency of MTBE or Cd for three types of clays decreased in response to the increase of the ratio of solution to soil whereas their adsorbed amounts increased. MTBE was greatly adsorbed in the decreasing order of vermiculite, bentonite, and CTAB-bentonite while Cd was adsorbed in the decreasing order of bentonite, vermiculite, and CTA-bentonite. An equilibrium isotherm for MTBE was well fitted to Freundlich plotting whereas that for Cd was closely corresponded to Langmuir isotherm. The adsorbed amount of MTBE on bentonite and vermiculite showed the maximum at 1% and 5% of humic acid, thereafter diminished while the adsorbed amount of MTBE on CTAB-bentonite increased in proportion to humic acid. Conversely, the adsorbed amount of Cd on the addition of humic acid continued to increase regardless of types of adsorbents. For all types of adsorbents, adsorbed quantity and adsorption efficiency of Cd have been coincidently increased at pH 8 and they were further enhanced at pH 10 showing 90% adsorption efficiency. Upon pH rose, the zeta potential on each adsorbent began to decrease, while increasing Cd concentration led to decline of zeta potential, which in turn ascribed to lowering dispersion stability that could consequently enhance adsorption capability.

본 연구에서는 MTBE, 카드뮴의 점토광물 종류 및 물리화학적 특성에 따른 흡착 경향 및 계면동전위의 특성을 규명하고자 흡착시간, 혼합비(용매 대 흡착질 비), 오염물질의 농도, 휴믹산 및 pH 변화에 따른 회분식 흡착실험을 수행하였다. 혼합비가 증가할수록 초기농도에 상관없이 흡착량은 증가한 반면, 흡착 효율은 감소하였다. MTBE의 흡착량은 vermiculite> bentonite> CTAB-bentonite 순으로 높았으며, 카드뮴의 흡착량은 bentonite> vermiculite> CTAB-bentonite 순이었다. 이때 MTBE 흡착은 Freundlich 등온 흡착식에 가장 잘 부합되었으며, 카드뮴의 경우 Langmuir 등온 흡착식에 잘 적용되었다. 유기물 함량에 따른 MTBE의 흡착실험 결과 CTAB-bentonite는 유기물의 함량이 높을수록 흡착량이 증가하였으나 bentonite는 유기물 함량 1%, vermiculite는 5%에서 최대 흡착량을 보인 후 감소하였다. 반면 카드뮴은 유기물 함량이 증가할수록 모든 흡착제의 흡착량과 흡착율이 급격히 증가하였다. 카드뮴의 흡착량과 흡착율은 모든 흡착제에 대해 pH 8 이상부터 급격히 증가하였으며, pH 10 이상의 경우 흡착율이 90%까지 증가하였다. 또한 pH가 증가할수록 각 흡착제의 계면동전위는 감소하였고, 카드뮴의 농도가 증가할수록 계면동전위의 절대치가 감소하여 분산안정성이 낮아져 결과적으로 카드뮴의 흡착 효율이 증가하였다.

Keywords

References

  1. Jonson, R., Pankow, J., and Zorgorski, J., 'MTBE-To what extent will past releases contaminate community water supply wells?,' Environ. Sci. Technol., 34, 210A(2000)
  2. 한국환경정책 . 평가연구원, '연료첨가제 MTBE 의 위해성 및 관리 필요성에 관한 세미나'(2002)
  3. 정현정, 이민희, '토양 특성에 따른 TCE 홉착능 비교,' 한국지하수토양환경학회 추계학술발표회지, 362-365(2002)
  4. FitzPatrick, E. A., 'Soils: Their formation, classification and distribution,' Longman Science & Technical, London, pp. 353(1986)
  5. Ball, D. F., 'Loss-on-ignition as an estimate of organic matter and organic carbon in non-calcareous soil,' J. Soil Sci., 15, 84-92(1964) https://doi.org/10.1111/j.1365-2389.1964.tb00247.x
  6. Jung, M. C., Heavy Metal Contamination of Soils, Plants, Waters and Sediments in the Vicinity of Metalliferous Mines in Korea, Ph. D. thesis, Univ. of London, pp. 455(1995)
  7. Boyd, S. A., Mortland, M. M., and Chiou, C. T., 'Sorption characteristics of organic compounds on hexadecyltrimethyl ammonium smectite,' Soil Sci. Soc. Am. J., 52, 652-657(1988) https://doi.org/10.2136/sssaj1988.03615995005200030010x
  8. Xu, S., Sheng, G., and Boyd, S. A., 'Use of organo-clays in pollution abatement,' Adv. Agron., 59, 25-62(1997). https://doi.org/10.1016/S0065-2113(08)60052-8
  9. Xu, S. and Boyd, S. A., 'Cation exchange chemistry of hexadecyltrimethyl ammoniumin a subsoil containing vermiculite,' Soil Sci. Soc. Am. J., 58, 1382- 1391(1994) https://doi.org/10.2136/sssaj1994.03615995005800050015x
  10. AI-Asheh, S., Banat, F., and Abu-Aitah, L., 'Adsorption of phenol using different types of activated bentonites,' Sep. Purifi. Tech., 33(1), 1-10(2002)
  11. Yoo, J. Y., Choi, J. Y., and Park, J. W., 'Adsorption of cadmium and lead on organobentonite,' J. KoSSGE., 6(3), 21-29(2001)
  12. Brownawell, B. J., Chen, H., Collier, J. M., and Westall, J. C., 'Adsorption of organic cations to natural materials,' Environ. Sci. Technol., 24(8), 1234-1241(1990) https://doi.org/10.1021/es00078a011
  13. Weber, W. J., Physicochemical Processes for Water Quality Control, John Wiley, New York, pp. 204-273(1992)
  14. Kim, H. G. and Lee, S. B., 'Effects of organic matter on cadmium adsorption in soil,' J. KSEE., 20(1), 1-8(1998)
  15. Mohamed, A. M. O. and Antia, H. E., Geoenvironmental Engineering, Developments in Geotechnical Engineering 82, Elsevier, Amsterdam, pp. 520(1998)
  16. Inskeep, W. P. and Baham, J., 'Adsorption of Cd(II) and Cu(II) by Na-montmorillonite at low surface coverage,' Soil Sci. Soc. Am. J., 47, 660-665(1983) https://doi.org/10.2136/sssaj1983.03615995004700040011x