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Relationship between Interfacial Tension and Solubility of Diesel Fuel in Surfactant Solutions

계면활성제용액-경유 간 계면장력과 용해도 상관관계 연구

  • Jeong, Seung-Woo (Department of Environmental Engineering, Kunsan National University) ;
  • Hur, Jeong-Hyun (Department of Environmental Engineering, Kunsan National University)
  • Received : 2012.12.12
  • Accepted : 2013.01.18
  • Published : 2013.01.30

Abstract

Solubility of oil contaminants in surfactant solutions plays an important role in selecting a suitable surfactant type for soil remediation. Solubility measurement procedures consist of making an equilibrium between surfactant solution and oil, solvent extraction using dichloromethane, and condensation for gas chromatography analysis. Solubility measurement requires time consumption and lots of materials. Interfacial tension is the contracting force between two immiscible liquids, surfactant solution and oil, and also closely related to solubility of oil. This study established a relationship between the interfacial tension and solubility of diesel fuel in surfactant solution and suggested a quick method to estimate solubility of oil in a surfactant solution by measuring its interfacial tension. The results of this study showed that the solubility of diesel fuel in surfactant solution was exponentially increased by decreasing the interfacial tension between two immiscible liquids. The solubility of diesel fuel was significantly increased under the interfacial tension conditions below 1 dyne/cm, while the solubility change was not apparent under the interfacial tension conditions beyond 5 dyne/cm. Interfacial tension measurements may allow us to quickly select an efficient surfactant and its concentration for soil remediation.

토양정화를 위한 토양 세정 및 세척 공정에서 계면활성제 선택 기준과 가장 중요한 설계인자는 오염물질의 용해도이다. 계면활성제의 오염물질 용해도는 오염물질과 평형상태를 만든 후 Dichrolomethane을 이용한 추출, 증발, 농축 등의 전처리과정을 거쳐야 한다. 따라서 계면활성제 용액 내 유류 오염 물질의 용해도 분석은 많은 시간과 재료를 필요로 한다. 계면장력은 계면활성제용액과 유류오염물질 사이에 유지되는 힘을 지칭하는 것으로 용해도와 밀접한 관계를 가진다. 본 연구는 계면활성제용액과 경유 간 계면장력과 용해도를 측정하여 계면장력과 용해도간 상관관계를 정립하므로 신속한 계면 장력 측정을 통한 용해도를 가늠할 수 있는 방안을 제시하였다. 계면장력과 유류용해도간 상관관계를 평가한 결과 두 특성은 기하급수적인 반비례관계를 보였다. 즉, 계면장력이 5 dyne/cm 이상조건에서 경유의 용해도는 크게 차이를 보이지 않다가 1 dyne/cm 이하에서 경유의 용해도는 급격하게 증가하였다. 앞으로 계면활성제용액 간 계면장력을 우선적으로 측정해 본다면 토양정화에 적합한 계면활성제 종류 및 농도를 매우 신속하고 효율적으로 선택할 수 있을 것으로 판단된다.

Keywords

References

  1. Jeong, S. W. and An, Y. J., Soil Remediation Engineering, Second Edition, Dongwha Publishing Co., Korea, pp. 229- 230(2012).
  2. Ko, J. S., Kwak, Y. J, Gil, M. S., Kim, Y. D., Kim, J. H., Kim, H. D., Ryu, D. I., Shin, Y. S., Oh, T. W., Lee, W. J. and Jung, H. K, Theory and Practices of Interfacial Science, Chonnam Univ. Press, pp. 384-387(2008).
  3. Sabatini, D. A., Knox, R. C. and Harwell, J. H., "Environmental Research Brief: Surfactant-enhanced DNAPL remediation: surfactant selection, hydraulic efficiency, and economic factors," USEPA, Ada, USA, pp. 2-5(1996).
  4. West, C. C. and Hawell, J. H., "Surfactants and subsurface remediation," Environ. Sci. Technol., 26(12), 2324-2330(1992). https://doi.org/10.1021/es00036a002
  5. Campanelli, J. R. and Wang, X., "Effect of neck formation on the measurement of dynamic interfacial tension in a drop volume tensiometer, J. Colloid. Interface Sci., 190(2), 491- 496(1997). https://doi.org/10.1006/jcis.1997.4891
  6. Korean Agency for Technology and Standards, Energy, Environment, and KS Standards: Interfacial Tension Measurement using Drop Volume Methods (2008).
  7. Ministry of Environment, Standard Methods for Water Analysis: Total Petroleum Hydrocarbon(2007).
  8. Pennell, K. D., Abriola, L. M. and Pope, G. A., "Influence of viscous and buoyancy forces on the mobilization of residual tetrachloroethylene during surfactant flushing." Environ. Sci. Technol., 30(4), 1328-1335(1996). https://doi.org/10.1021/es9505311
  9. Jawitz, J. W., Annable, M. D., Rao, P. S. C. and Rhue, R. D., "Field implementation of a Winsor Type I surfactant/Alcohol mixture for in situ solubilization of a complex LNAPL as a single-phase microemulsion," Environ. Sci. Technol., 32 (4), 523-530(1998). https://doi.org/10.1021/es970507i