• Measurement of Gas-Accessible PCE Saturation in Unsaturated Soil using Gas Tracers during the Removal of PCE
  • Kim, Heon-Ki;Kwon, Han-Joon;Song, Young-Soo;
  • Dept. of Environmental Science and Biotechnology, Hallym University, Institute of Energy and Environment, Hallym University;Dept. of Environmental Science and Biotechnology, Hallym University, Institute of Energy and Environment, Hallym University;Dept. of Environmental Science and Biotechnology, Hallym University, Institute of Energy and Environment, Hallym University;
  • 토양 내 PCE 제거과정에서 가스 분배추적자기법을 이용한 공기노출 PCE의 잔류량 검출
  • 김헌기;권한준;송영수;
  • 한림대학교 환경생명공학과, 한림대학교 에너지.환경 연구소;한림대학교 환경생명공학과, 한림대학교 에너지.환경 연구소;한림대학교 환경생명공학과, 한림대학교 에너지.환경 연구소;
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.

Keywords: Soil;Unsaturated zone;Remediation;Contamination;PCE;NAPL;Partitioning tracer;

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