계면활성제를 이용한 오염대수층의 선택적 폭기기술

Air-sparging Technology for Remediation of Specific Aquifer Layer Using Surfactant

  • 김헌기 (한림대학교 환경생명공학과) ;
  • 송영수 (한림대학교 환경생명공학과) ;
  • 권한준 (한림대학교 환경생명공학과)
  • Kim, Heon-Ki (Dept. of Environmental Sciences and Biotechnology, Hallym University) ;
  • Song, Young-Su (Dept. of Environmental Sciences and Biotechnology, Hallym University) ;
  • Kwon, Han-Joon (Dept. of Environmental Sciences and Biotechnology, Hallym University)
  • 발행 : 2008.12.31

초록

본 연구는 전통적인 지하 대수층 폭기기술을 시행하는 데 있어서 대수층의 특정층에 미리 수용액상 계면활성제를 수평방향으로 도입함으로써 오염물질이 실제로 존재하는 특정 지층으로 선택적으로 폭기되도록 하여 최소한의 공기량으로 오염물질 제거 효율을 극대화 하는 기술을 개발하는 것을 목적으로 한다. 본 연구에서는 균일질 모래로 충진된 2차원 상자 모델을 대수층 모사를 위하여 사용하였으며, 저농도(100 mg/L)의 음이온계 계면활성제(sodium dodecylbenzene sulfonate) 수용액을 대수층의 표면장력을 조절하는 데 사용되었다. 실험은 첫째, 계면활성제가 처방되지 않은 경우, 둘째, 공기도입부 근처에 계면활성제 용액이 도입된 경우, 그리고 셋째, 공기도입부와 토양표면의 중간부분에 계면활성제 용액이 도입된 경우의 세 부분으로 구성되어 실시되었다. 실험 결과, 계면활성제가 도입된 경우 계면활성제가 투입되지 않은 경우에 비하여 최고 5배에 해당하는 현저한 폭기영향권의 확대가 관찰되었다. 또한 계면활성제가 도입되지 않았을 때에는 폭기영향권의 범위가 도입유량에 거의 영향을 받지 않았으나 계면활성제가 도입된 경우 폭기영향권은 도입유량에 비례하는 것으로 나타났다. 특기할만한 것은 폭기영향권이 계면활성제가 도입된 수평층을 중심으로 형성되어 이 부분에 집중되어 존재하는 오염물질의 제거에 매우 유리할 수 있다는 점이다. 현재 까지 대수층 폭기기술이 도입공기의 수평확산을 유도하는 기술이 개발되어 있지 않으므로 본 연구는 기존의 대수층 폭기 복원기술의 효율을 획기적으로 개선할 수 있을 것으로 기대된다.

Air sparging technique has been used for remediation of VOC(volatile organic compound)-contaminated aquifer. The aim of this study was to develop an innovative air sparging technique that enhances the efficiency of air intrusion into a specific horizontal layer of aquifer where the contaminants exist with the help of water-soluble surfactant. A twodimensional physical box model, packed with homogeneous sand, was used for simulating the aquifer in this study. Aqueous solution of anionic surfactant (100 mg/L, sodium dodecylbenzene sulfonate) was used to suppress the surface tension of groundwater. Three sets of experiments were conducted: air sparging experiment without surfactant application, air sparging experiments for box model where the surfactant solution was applied right above the air injection point, and air sparging experiments with surfactant solution layer formed in the middle of the box. It was found that the sparging influence zone was expanded up to five times of that formed by sparging without surfactant application. The size of sparging influence zone was more sensitive to the air flow (injection) rate with surfactant application than that without surfactant. More importantly, injection of air into the target aquifer layer was successful with surfactant application. Findings in this study are expected to provide more options for designing remediation processes using air sparging.

키워드

참고문헌

  1. Adams, J.A. and Reddy, K.R., 2000, Removal of dissolved- and free-phase benzene pools from ground water using in situ air sparging, J. Envir. Engrg., 126, 697-707 https://doi.org/10.1061/(ASCE)0733-9372(2000)126:8(697)
  2. Braida, W.J. and Ong, S.K., 1998, Air sparging: Air-water mass transfer coefficients, Water Resour. Res., 34, 3245-3253 https://doi.org/10.1029/98WR02533
  3. Brooks, R.H. and Corey, A.T., 1966, Properties of porous media affecting fluid flow, J. Irrig. Drain., 92, 61-68
  4. Johnson, R.L., Johnson, P.C., McWhorter, D.B., Hinchee, R.E., and Goodman, I., 1993, An overview of in situ air sparging, Ground Water Monit. Rev., 13, 127-135
  5. Johnston, C.D., Rayner, J.L., and Briegel, D., 2002, Effectiveness of in situ air sparging for removing NAPL gasoline from a sandy aquifer near Perth, Western Australia, J. Contam. Hydrol., 59, 87-111 https://doi.org/10.1016/S0169-7722(02)00077-3
  6. Kim, H. and Annable, M.D., 2006a, Effect of surface reduction on VOC removal during surfactant-enhanced air sparging, J. Environ. Sci. Health Part A, 41, 2799-2811 https://doi.org/10.1080/10934520600966946
  7. Kim, H., Choi, K.-M., Moon, J.-W., and Annable, M.D., 2006b, Changes in air saturation and air-water interfacial area during surfacatant-enhanced air sparging in saturated sand, J. Conatam. Hydrol., 88, 23-35 https://doi.org/10.1016/j.jconhyd.2006.05.009
  8. Kim, H., Soh, H.-E., Annable, M.D., and Kim, D.-J., 2004, Surfactant-enhanced air sparging in saturated sand, Environ. Sci. Technol., 38, 1170-1175 https://doi.org/10.1021/es030547o
  9. Lundegard, P.D. and LaBrecque, D., 1995, Air sparging in a sandy aquifer (Florence, Oregon, USA): Actual and apparent radius of influence, J. Contam. Hydrol., 19, 1-27 https://doi.org/10.1016/0169-7722(95)00010-S
  10. Marley, M.C., Hazebrouck, D.J., and Walch, M.T., 1992, The application of in situ air sparging as an innovative soils and ground water remediation technology, Gound Water Monit. Rev. 12, 137-145 https://doi.org/10.1111/j.1745-6592.1992.tb00044.x
  11. Rabiduar, A.J., Blayden, J.M., and Ganguly, C., 1999, Field performance of air-sparging system for removing TCE from groundwater, Environ. Sci. Technol., 33, 157-162 https://doi.org/10.1021/es980538t
  12. Reddy, K.R. and Adams, J.A., 1998, System effect on benzene removal from saturated soils and groundwaterusing air sparging, J. Environ. Engrg., 124, 288-299 https://doi.org/10.1061/(ASCE)0733-9372(1998)124:3(288)
  13. Reddy, K.R., Kosgi, S., and Zhou, J., 1995, A review of in-situ air sparging for the remediation of VOC-contaminated saturated soils and groundwater, Haz. Waste and Haz. Mat., 12, 97-118 https://doi.org/10.1089/hwm.1995.12.97
  14. Unger, A.J.A., Sudicky, E.A., and Forsyth, P.A., 1995, Mechanisms controlling vacuum extraction coupled with air sparging for remediation of heterogeneous formation contaminated by dense nonaquesous phase liquids, Water Resour. Res., 31, 1913-1925 https://doi.org/10.1029/95WR00172