Journal of Soil and Groundwater Environment (한국지하수토양환경학회지:지하수토양환경)

Korean Society of Soil and Groundwater Environment (한국지하수토양환경학회)
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Measurement of Gas-Accessible PCE Saturation in Unsaturated Soil using Gas Tracers during the Removal of PCE

토양 내 PCE 제거과정에서 가스 분배추적자기법을 이용한 공기노출 PCE의 잔류량 검출

  • Kim, Heon-Ki (Dept. of Environmental Science and Biotechnology, Hallym University, Institute of Energy and Environment, Hallym University) ;
  • Kwon, Han-Joon (Dept. of Environmental Science and Biotechnology, Hallym University, Institute of Energy and Environment, Hallym University) ;
  • Song, Young-Soo (Dept. of Environmental Science and Biotechnology, Hallym University, Institute of Energy and Environment, Hallym University)
  • 김헌기 (한림대학교 환경생명공학과, 한림대학교 에너지.환경 연구소) ;
  • 권한준 (한림대학교 환경생명공학과, 한림대학교 에너지.환경 연구소) ;
  • 송영수 (한림대학교 환경생명공학과, 한림대학교 에너지.환경 연구소)
  • Received : 2011.08.08
  • Accepted : 2011.10.27
  • Published : 2011.10.31
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Abstract

In this laboratory study, the changes in gas-exposed perchloroethene (PCE) saturation in sand during a PCE removal process were measured using gaseous tracers. The flux of fresh air through a glass column packed with PCEcontaminated, partially water-saturated sand drove the removal of PCE from the column. During the removal of PCE, methane, n-pentane, difluoromethane and chloroform were used as the non-reactive, PCE-partitioning, water-partitioning, and PCE and water-partitioning tracers, respectively. N-pentane was used to detect the PCE fraction exposed to the mobile gas. At water saturation of 0.11, only 65% of the PCE was found to be exposed to the mobile gas prior to the removal of PCE, as calculated from the n-pentane retardation factor. More PCE than that detected by n-pentane was depleted from the column due to volatilization through the aqueous phase. However, the ratio of gas-exposed to total PCE decreased on the removal of PCE, implying gas-exposed PCE was preferentially removed by vaporization. These results suggest that the water-insoluble, PCE-partitioning tracer (n-pentane in this study), along with other tracers, can be used to investigate the changes in fluid (including nonaqueous phase liquid) saturation and the removal mechanism during the remediation process.

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References

  1. Annable, M.D., Jawitz, J.W., Rao, P.S.C., Dai, D.P., Kim, H., and Wood, A.L., 1998(a), Field evaluation of interfacial and partitioning tracers for characterization of effective NAPL-water contact areas, Ground Water, 36, 495-502. https://doi.org/10.1111/j.1745-6584.1998.tb02821.x
  2. Annable, M.D., Rao, P.S.C., Hatfield, K., Graham, W.D., Wood, A. L., and Enfield, C.G., 1998(b), Partitioning tracers for measuring residual NAPL: Field-scale test results, J. Environ. Eng., 124, 498-503. https://doi.org/10.1061/(ASCE)0733-9372(1998)124:6(498)
  3. Deeds, N.E., Pope, G.A., and McKinney, D.C., 1999, Vadose zone characterization at a contaminated field site using partitioning interwell tracer technology, Environ. Sci. Technol., 33, 2745-2751. https://doi.org/10.1021/es9900252
  4. Hunkeler, D., Hoehn, E., Hohener, P., and Zeyer, J., 1997, $^{222}Rn$ as a partitioning tracer to detest diesel fuel contamination in aquifers: Laboratory study and field observations, Environ. Sci. Technol., 31, 3180-3187. https://doi.org/10.1021/es970163w
  5. Jin, M., Delshad, M., Dwarakanath, V., McKinney, D.C., Pope, G.A., Sepehrnoori, K., and Tilburg, C.E., 1995, Partitioning tracer test for detection, estimation, and remediation performance assessment of subsurface nonaqueous phase liquids, Water Resour. Res., 31, 1201-1211. https://doi.org/10.1029/95WR00174
  6. Keller, J.M. and Brusseau, M.L., 2003, In-situ characterization of soil-water content using gas-phase partitioning tracer tests: Field-scale evaluation, Environ. Sci. Technol., 37, 3141-3144. https://doi.org/10.1021/es0340329
  7. Kim, H., Choi, K.-M., Rao, and P. Suresh. C., 2007, Measurement of gas-accessible NAPL saturation in soil using gaseous tracers, Environ. Sci. Technol., 41, 235-241. https://doi.org/10.1021/es060992u
  8. Kim, H., Rao, P.S.C., and Annable, M.D., 1999, Gaseous tracer technique for estimating air-water interfacial areas and interface mobility, Soil Sci. Soc. Am. J., 63, 1554-1560. https://doi.org/10.2136/sssaj1999.6361554x
  9. Mackay, D. and Shiu, W.Y., 1981, A critical-review of Henrys's law constants for chemicals of environmental interest, J. Phys. Chem. Ref. Data, 10, 1175-1199. https://doi.org/10.1063/1.555654
  10. Mariner, P.E., Jin, M., Studer, J.E., and Pope, G.A., 1999, The first vadose zone partitioning interwell tracer test for nonaqueous phase liquid and water residual, Environ. Sci. Technol., 33, 2825-2828. https://doi.org/10.1021/es9901720
  11. Nelson, N.T. and Brusseau, M.L., 1996, Field study of the partitioning tracer method for detection of dense nonaqueous phase liquid in a trichloroethene-contaminated aquifer, Environ. Sci. Technol., 30, 2859-2863. https://doi.org/10.1021/es960148b
  12. Nelson, N.T., Brusseau, M.L., Carlson, T.D., Costanza, M.S., Young, M.H., Johnson, G.R., and Wierenga, P.J., 1999, A gas-phase partitioning tracer method for the in situ measurement of soil-water content, Water Resour. Res., 35, 3699-3707. https://doi.org/10.1029/1999WR900250
  13. Nelson, N.T., Oostrom, M., Wietsma, T.W., and Brusseau, M.L., 1999, Partitioning tracer method for the in situ measurement of DNAPL saturation: Influence of heterogeneity and sampling method, Environ. Sci. Technol., 33, 4046-4053. https://doi.org/10.1021/es990022p
  14. Valocchi, A.J., 1985, Validity of the local equilibrium assumption for modeling sorbing solute transport through homogeneous soils, Water Resour. Res., 21, 808-820. https://doi.org/10.1029/WR021i006p00808
  15. Whitley Jr., G.A., McKinney, D.C., Pope, G.A., Rouse, B.A., and Deeds, N.E., 1999, Contaminated vadose zone characterization using partitioning gas tracers, J. Environ. Eng., 125, 574-582. https://doi.org/10.1061/(ASCE)0733-9372(1999)125:6(574)
  16. Young, C.M., Jackson, R.E., Jin, M., Londergan, J.T., Mariner, P.E., .Pope, G.A., Anderson, F.J., and Houk, T., 1999, Characterization of a TCE DNAPL zone in alluvium by partitioning tracers, Ground Water Monit. Rem., 19, 84-94. https://doi.org/10.1111/j.1745-6592.1999.tb00190.x