• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.223-227
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• 2005

본 연구에서는 과거 주요소로 사용되었던 유류오염 현장에서 BTEX의 오염 현황과 자연저감기법을 통해 저감되는 BTEX 양을 계산하였다. 일정 시간 간격으로 시료를 채취, 분석한 결과, 2곳에서 NAPL이 존재하고 있다는 것을 알 수 있었다. 조사 지역은 지하수 흐름방향에 따라 3개의 단면으로 나눈 후 각각의 단면을 통과하는 mass flux를 계산하였다. 약 40일정도 지난 후 BTEX 양은 각각 20.2%, 33.5%, 그리고 25.4% 감소되는 것으로 나타났다.

• Journal of Soil and Groundwater Environment
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• v.12 no.2
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• pp.47-54
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• 2007

The partitioning tracer method has been studied as an alternative method for detecting and characterizing the distribution of nonaqueous phase liquids (NAPLs) contaminants in subsurface. The reliability of the partitioning tracer method depends on accurate measurements of partition coefficients of the partitioning tracers between water and NAPLs. In this study, partition coefficients of several alcohol tracers between water and benzene, toluene, ethylbenzene, xylene, and BTEX mixtures are estimated using the modified approach of equivalent alkane carbon number (EACN). Agreements between the measured and estimated partition coefficients were generally observed in experiments. Based on these results, it is confirmed that the partition coefficients of tracers are readily obtained without experiments if the EACN values for the tracers and LNAPLs are known.

• Analytical Science and Technology
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• v.25 no.1
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• pp.14-18
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• 2012

Rn-222 was used as a natural radioactive isotope tracer to evaluate non-aqueous phase liquid(NAPL) contaminated soil and aquifer. In the case of soil sample, Rn-222 concentration was inversely decreased with diesel concentration in the granite soil sample and it was decreased about 30% at the 13% diesel contaminated soil. For evaluating trichloroethylene (TCE) contaminated aquifer, the natural radioisotope Rn-222 was used as naturally occurring partitioning tracer for the approximate localization and semiquantitative assessment of the TCE source zone. Rn-222 was analyzed for the estimation of TCE contamination ranges of the acquifer in the contaminated site at Wonju in Korea.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.1
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• pp.46-52
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• 2008

Oils and chlorinated solvents leaking to the subsurface are entrapped in the soil pore and these are called as nonaqueous phase liquids (NAPL). NAPL entrapped in porous media acts as a continuous source for surface and ground water contamination. This study visualized dissolution of trichloroethylene (TCE) entrapped in porous media and quantified the velocity of TCE dissolution using an image analysis technique. As the water velocity increased, the level of dissolution increased. The results imply that a TCE contaminated region having a high infiltration rate and groundwater velocity may result in severe groundwater contamination. Microscopic images of TCE entrapped in porous media showed that TCE present in the preferential flow paths was easily dissoluted into the water phase. However, TCE present in the stagnant flow region was visualized for long time. The results imply that TCE would be still present in the soil if TCE is detected in goundwater.

• Economic and Environmental Geology
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• v.34 no.3
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• pp.301-306
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• 2001

Column tests were conducted to investigate the optimal condition of surfactant solution pH that can affect the removal efficiency in surfactant-assisted remediation. Toluene and 1,2,4-trichlorobenzene were chosen as the model hydrophobic substances. Two Iowa soils, Fruitfield sand and Webster clay loam, were leached with solutions of 4%(v/v) sodium diphenyl oxide disulfonate (DOSL, trade name Dowfax 8390), or 4%(v/v) trideceth-19-carboxylic acid (TDCA, trade name Sandopan JA36), or 4% (v/v) octylphenoxypoly ethoxyethanol (OPEE, trade name Triton X100). The test results revealed that a maximum removal of toluene and 1,2,4-trichlorobenzene was obtained at pH 10 of surfactant solution, and maximum recoveries of added toluene (94%) or 1 ,2,4- trichlorobenzene (97 %) were obtained for DOSL surfactant solution in Fruitfield sandy soil column. Increased removal efficiency by pH control of both toluene and 1,2,4trichlorobenzene was 16% and 20% for DOSL with Fruitfild sandy soil, respectively. In addition, the maximum recoveries of added toluene or I ,2,4-trichlorobenzene were 89% and 93% for DOSL surfactant solution in Webster clay loam soil column. The maximum increase of toluene and 1,2,4-trichlorobenzene removal was 26% and 19% for DOSL with Webster clay loam soil, respectively. These experimental results indicate that maintaining a high pH surfactant solution in surfactant-assisted remediation is desirable for efficient removal of NAPLs from contminated soils.