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아임계수 분해를 이용한 난분해성 물질로 오염된 토양의 정화 연구

Remediation of Soil Contaminated with Persistent Organic Pollutants through Subcritical Water Degradation

  • Choi, Jae-Heon (Daeil Engineering and construction Co., Ltd.) ;
  • Lee, Hwan (Daeil Engineering and construction Co., Ltd.) ;
  • Lee, Cheol-Hyo (Daeil Engineering and construction Co., Ltd.) ;
  • Kim, Ju-Yup (Daeil Engineering and construction Co., Ltd.) ;
  • Oh, Seok-Young (Department of Civil and Environmental Engineering, University of Ulsan)
  • 투고 : 2014.10.31
  • 심사 : 2015.02.26
  • 발행 : 2015.02.28

초록

본 연구에서는 대표적 난분해성 유기화합물인 PCBs (Polychlorinated Biphenyls) 및 기타 난분해성 물질 오염토양을 정화하기 위하여 고온고압의 물을 이용하였다. 먼저, PCBs 오염토 적용시 반응온도에 따른 영향에서는 아임계수 조건에서 온도가 증가함에 따라 처리효율이 선형적으로 증가하였고 반응시간의 증가에 따라서도 처리효율은 증가함을 보였다. 처리입경별 실험에서는 미세토의 경우가 처리효율이 약간 낮았다. 아임계수와 영가철에 의한 PCBs 분해 기작을 예측하기 위해 Ion chromatography 및 GC-MS 분석을 한 결과 탈염화 반응산물이 생성되었으며 헤드스페이스 실험결과 PCBs분해기작은 대부분 산화이며, 일부만이 탈염화에 의한 것임을 확인하였다. TPH, BTEX, TCE/PCE, 클로르피리포스 등의 난분해성 물질 오염토처리를 위해 $300^{\circ}C$ 아임계수 조건을 적용한 결과 모두 90% 이상의 처리효율을 나타냈으며, 처리효율과 반응부산물 등의 검토를 통해 PCBs 오염토 외에 다른 난분해성 물질 오염토 처리분야에도 적용가능함을 확인하였다.

This study examined remediation of soil contaminated with polychlorinated biphenyls (PCBs) and other persistent organic pollutants by using subcritical water. Our results showed that removal efficiency of PCBs from soil and treatment temperature were linearly proportional under subcritical conditions. The removal efficiency as increased as reacting period increased. PCBs contaminating fine particles in soil were less effectively removed than those in entire contaminated soil. Reaction of the zero-valent iron and PCBs under subcritical condition produced dechlorinated product, where most of the PCBs were oxidised while little remained as dechlorinated. Other organic pollutants, such as TPH, BTEX, TCE/PCE, and chlorpyrifos, were removed by more than 90% at $300^{\circ}C$. Considering removal efficiency and identification of by-products, we suggest that subcritical water treatment may be effectively applied to soils contaminated with various persistent organic pollutants.

키워드

참고문헌

  1. U.S. Environmental Protection Agency Home page. http://www.epa.gov/epawaste/hazard/tsd/pcbs/pubs/effects.htm, June (2013).
  2. Yak, H. K., Wenclawiak, B. W., Cheng, I. F., Doyle, J. G. and Wai, C. M., "Reductive Dechlorination of Polychlorinated Biphenyls by Zerovalent Iron in Subcritical Water," Environ. Sci. Technol., 33(8), 1307-1310(1999). https://doi.org/10.1021/es981066l
  3. Yak, H. K., Lang, Q. and Wai, C. M., "Relative Resistance of Positional Isomers of Polychlorinated Biphenyls toward Reductive Dechlorination by Zerovalent Iron in Subcritical Water," Environ. Sci. Technol., 34, 2792-2798(2000). https://doi.org/10.1021/es990689b
  4. Weber, R., Yoshida, S. and Miwa, K., "PCBs destruction in subcritical and supercirical water-Evaluation of PCDF Formation and initial steps of degradation mechanisms," Environ. Sci. Technol., 36(8), 1839-1844(2002). https://doi.org/10.1021/es0113910
  5. Kluyev, N., Cheleptchikov, A., Brodsky, E., Soyfer, V. and Zhilnikov, V., "Reductive dechlorination of polychlorinated dibenzo-p-dioxins by zerovalent iron in subcritical water," Chemosphere, 46(9-10), 1293-1296(2002). https://doi.org/10.1016/S0045-6535(01)00276-4
  6. Hashimoto, S., Watanabe, K., Nose, K. and Morita, M., "Remediation of soil contaminated with dioxins by subcritical water extraction," Chemosphere, 54(1), 89-96(2004). https://doi.org/10.1016/S0045-6535(03)00673-8
  7. Erickson, M. D., Analytical Chemistry of PCBs, 2nd ed., Lewis Publishers, pp. 18-19(1992).
  8. National Institute of Environmental Research, Managements and Analysis of Polychlorinated Biphenyls (PCBs) containing Waste and soil (Educational Resources), Ministry of Environment, pp.14-15(2006).
  9. Cengel, Y. A. and Boles, M. A., Thermodynamics: an engineering approach, 4th ed., McGraw-Hill, New York, pp. 91-93(2002).
  10. Siskin, M. and Brons, G., "Aqueous Organic Chemistry. 1. Aquathermolysis: Comparison with Thermolysis in the Reactivity of Aliphatic Compounds," Energy & Fuels, 4(5), 475-482(1990). https://doi.org/10.1021/ef00023a012
  11. Anitescu, G. and Tavlarides, L. L., "Oxidation of Aroclor 1248 in supercritical water: A global kinetic study," Ind. Eng. Chem. Res., 39, 583-591(2000). https://doi.org/10.1021/ie990704l
  12. Taniguchi, S., Miyamura, A., Ebihara, A., Hosomi, M. and Murakami, A., "Treatment of PCB-contaminated soil in pilotscale continuous decomposition system," Chemosphere, 37(9-12), 2315-2326(1998). https://doi.org/10.1016/S0045-6535(98)00290-2