A case study of monitored natural attenuation at the petroleum hydrocarbon contaminated site: I. Site characterization

유류오염부지에서 자연저감기법 적용 사례연구: I. 부지특성 조사

  • Published : 2003.12.01

Abstract

The study site located in an industrial complex has a Precambrian age gneiss as a bedrock. The poorly-developed, disturbed soils in the study site have loamy-textured surface soil (1 to 2 m) and gravelly sand alluvium subsurface (2 to 6 m) on the top of weathered gneiss bedrock. The depth of the groundwater table was about 3.5 m below ground surface and increased toward down-gradient of the site. The hydraulic conductivity of transmitted zone (gravelly coarse sand) was in the range of 5.0${\times}$10$\^$-2/∼1.85${\times}$10$\^$-1/ cm/sec. The fine sand layer was in the range of 1.5${\times}$10$\^$-3/ to 7.6${\times}$10$\^$-3/ cm/sec. and the reclaimed upper soil layer was less than 10$\^$-4/ cm/sec. Toluene, ethylbenzene, and xylene (TEX) was the major contaminant in the soil and groundwater. The average depth of the soil contamination was about 1.5 m in the gravelly sand alluvium layer. At the depth interval 2.4∼4.8 m, the highest contamination in the soil is located approximately 50 to 70 m from the suspected source areas. The concentration of TEX in the groundwater was highest in the suspected source area and a lesser concentration in the center and southwest parts of the site. The TEX distribution in the groundwater is associated with their distribution in the soil. Microbial isolation showed that Pseudomonas flurescence, Burkholderia cepacia, and Acinetobactor lwoffi were the dominant aerobic bacteria in the contaminated soils. The analytical results of the groundwater indicated that the concentrations of dissolved oxygen (DO), nitrate, and sulfate in the contaminated area were significantly lower than their concentrations in the none-contaminated control area. The results also indicated that groundwater at the contaminated area is under anaerobic condition and sulfate reduction is the predominant terminal electron accepting process. The total attenuation rate was 0.0017 day$\^$-1/ and the estimated first-order degradation rate constant (λ) was 0.0008 day$\^$-1/.

연구대상부지는 주로 선캄브리아기의 변성암의 일종인 편마암으로 형성되어 있으며, 토양은 하천에 축적된 비교적 투수성이 높은 매질로 구성된 충적토를 모재로 형성되었다. 지하수위는 지표로부터 평균 3.5m 깊이에서 나타나며. 하류 방향으로 갈수록 깊어지는 경향을 나타내었다. 대상부지의 수리전도도는 자갈이 혼재된 조립질 모래층은 5.0${\times}$$10^{-2}$∼1.85${\times}$$10^{-1}$ cm/sec, 세립질 모래층은 $1.5{\times}$$10^{-3}$ to 7.6${\times}$$10^{-3}$ cm/sec, 복토층은 $10^{-4}$ cm/sec 이하로 나타났다. 연구대상부지의 주오염물질은 Toluene, Ethylbenzene, xylene(이하 TEX)이며, 오염토양층은 1.5 m내외로 깊이별 토양중 TEX의 농도는 추정오염원으로부터 70m떨어진 곳의 질이 2.4∼4.8m에서 가장 높았다. 지하수중 TEX의 농도는 추정오염원의 주변지역에서 가장 높았으며, 조사대상부지의 중앙지역과 남서쪽지역에서도 높게 나타났으며, 이러한 지하수중 TEX의 농도분포는 토양중의 TEX의 농도분포와 상당히 일치하는 경향을 보이고 있다. 연구대상부지에 서식하고 있는 톨루엔 분해 호기성세균의 주종은 Pseudomonas fluorescence, Burkholderia cepacia, Acinetobactor lwoffi로 확인되었다. 지하수 분석결과 전자수용체인 용존산소, 질산염, 황산염 등이 배경지역에 비해 오염지역에서 상당히 낮게 나타났다. 한편, 연구대상부지에서의 계산된 전체 자연저감속도는 0.0017da $y^{-1}$이며, 1차 생분해속도는 0.0008 da $y^{-1}$로 계산되었다.

Keywords

References

  1. National Research Council (NRC), Natural Attenuation for Groundwater Remediation. National Academy Press, Washington, D.C. (2001)
  2. U.S. EPA, Use of monitored natural attenuation at super-fund, RCRA corrective action, and underground storage tank sites, OSWER Directive 9200.4-17P, Office of Solid Waste and Emergency Response, Washington, D.C. (1999)
  3. Environment Agency, Guidance on the assessment and monitohng of natural attenuation of contaminants in groundwater, R&D Publication 95 (2000)
  4. Alexander, M., Biodegradation and bioremediation. Academic press, Inc., Califomia (1994)
  5. Wiedemeier, T.H., Wilson, J.T., Kampbell, D.H., Miller, R.N., and Hansen, J. Technical protocol for implementing intrinsic remediation with long-term monitoring for natural attenuation of fuel contamination dissolved in groundwater, Volume 1 & 2, Air Force Center for Environmental Excel-lence, Technology Transfer Division, Brooks AFB, San Antonio, Texas (1995)
  6. 국립환경연구원, 의왕시 소재 유류오염부지 등에 대한토양 정밀조사 보고서 (1998)
  7. 농업기술연구소, 토양화학분석법(1988)
  8. 삼정 토양학, 향문사(1986)
  9. 환경부, 토양오염공정시험방법 (1999)
  10. Cheon, J.Y, Field and numerical studies on groundwaterand soil environments of an LNAPL-contaminated site. MS thesis, Seoul National University, Seoul. Korea (2000)
  11. Borden, R.C., Gomez, C.A., Becker, M.T. 'Geochemical indicators of intrinsic bioremediation', Ground Water 33, pp. 180-189 (1995) https://doi.org/10.1111/j.1745-6584.1995.tb00272.x
  12. Lee, C.H., Lee, J.Y, Cheon, J.Y, and Lee, K.K. 'Attenua-tion of petroleum hydrocarbons in smear zones : case study'. J. Environ. Eng. 127(7), pp. 639-647 (2001) https://doi.org/10.1061/(ASCE)0733-9372(2001)127:7(639)
  13. ASTM Standard guide for remediation of groundwater by natural attenuation at petroleum release sites, ASTM E 1943-1998. Piladelphia, P.A. (1998)
  14. Newell, C.J., McLeod, R.K., and Gonzeles, J.R., Bioscreen: Natural attenuation decision support system, Version 1.4. prepared for the Air Force Center For Environmental Excel-lence, Brooks AFB, Texas (1997)
  15. Buscheck, T.E., and Alcantar, C.M., Regression techniques and analytical solutions to demonstrate intnnsic bioremedia-tion. In, Proceedings of the 1995 Battelle Intemational Con-ference on In-Situ and On Site Bioreclamation, April 1995
  16. Lee, Jin-Yong, Environmental site assessment and evaluation of attenuation characteristics for a petroleum contaminated site, Thesis for A Ph.D. degree, school of earth and environmental sciences, Seoul National University (2001)
  17. Chhstensen, T.H., Bjerg, P.L., Banart, S.A., Jakobsen, R.,Heron, G. and Albrechtsen, H. 'Characterization of redox conditions in groundwater contaminant plumes' J. Contam. Hydro. 45, PP. 165-241 (2000) https://doi.org/10.1016/S0169-7722(00)00109-1