Innovative Technology of Landfill Stabilization Combining Leachate Recirculation with Shortcut Biological Nitrogen Removal Technology

침출수 재순환과 생물학적 단축질소제거공정을 병합한 매립지 조기안정화 기술 연구

  • Published : 2007.09.30

Abstract

A leachate containing an elevated concentration of organic and inorganic compounds has the potential to contaminate adjacent soils and groundwater as well as downgradient areas of the watershed. Moreover high-strength ammonium concentrations in leachate can be toxic to aquatic ecological systems as well as consuming dissolved oxygen, due to ammonium oxidation, and thereby causing eutrophication of the watershed. In response to these concerns landfill stabilization and leachate treatment are required to reduce contaminant loading sand minimize effects on the environment. Compared with other treatment technologies, leachate recirculation technology is most effective for the pre-treatment of leachate and the acceleration of waste stabilization processes in a landfill. However, leachate recirculation that accelerates the decomposition of readily degradable organic matter might also be generating high-strength ammonium in the leachate. Since most landfill leachate having high concentrations of nitrogen also contain insufficient quantities of the organic carbon required for complete denitrification, we combined a shortcut biological nitrogen removal (SBNR) technology in order to solve the problem associated with the inability to denitrify the oxidized ammonium due to the lack of carbon sources. The accumulation of nitrite was successfully achieved at a 0.8 ratio of $NO_2^{-}-N/NO_x-N$ in an on-site reactor of the sequencing batch reactor (SBR) type that had operated for six hours in an aeration phase. The $NO_x$-N ratio in leachate produced following SBR treatment was reduced in the landfill and the denitrification mechanism is implied sulfur-based autotrophic denitrification and/or heterotrophic denitrification. The combined leachate recirculation with SBNR proved an effective technology for landfill stabilization and nitrogen removal in leachate.

본 연구는 침출수 재순환 공법과 산소요구량과 탄소요구량의 절감이 가능한 단축질소제거공법(shortcut biological nitrogen removal: SBNR)을 병합하여 침출수중의 암모니아와 유기물을 효과적으로 제거하는 방안에 대해 부피 약 200 $m^3$의 pilot 규모 매립지를 만들어 연구하였다. 매립지에서 발생한 침출수는 연속회분식반응기(sequencing batch reactor: SBR)형태의 on-site reactor에서 암모니아성 질소를 아질산으로 부분질산화 시킨 후 매립지로 재유입 시켜 지중탈질(in-situ denitrification)을 유도하였다. 침출수는 매립면적에 따른 년평균 강우량을 기준으로 약 221 L/cycle을 주당 3회 재순환 하였다. 그 결과 반응시간은 약 6시간으로 운전하였을 때 $NO_2^{-}-N/NO_x-N$의 비는 약 0.8에 이르러 효과적인 아질산 축적을 이룰 수 있었으며 온도저하로 인해 질산화의 저해가 일어나기 이전의 질산화 효율은 약 80%에 달하여 단축질소제거공정을 위한 아질산 축적이 가능함을 보여주었다. 이와 같이 SBR을 통해 질산화하여 재순환한 침출수의 $NO_x$-N는 모형 매립지 내에서 모두 제거할 수 있었으며, 침출수에 비교적 높은 농도의 황산염이 존재하여 황산염환원 및 황을 이용한 독립영양탈질반응이 매우 중요한 반응기전이 되는 것으로 나타났다. 따라서 침출수 재순환 공법과 단축질소제거공법을 병합한 조기안정화 기술은 매립지의 조기안정화와 침출수의 질소제거에 효과적인 공법으로 사용할 수 있을 것이라 사료된다.

Keywords

References

  1. 환경부, 환경백서2004, 환경부, 서울(2004)
  2. Carter, J. L., Curran, G., and Schafer, P. E., 'A new type of anaerobic design for energy recovery and treatment of leachate wastes,' in proceedings of 39th Purdue Industrial Waste Conference, Purdue University, USA, pp. 369-376(1984)
  3. Ragle, N., Kissel, J., Ongerth, J.E., and DeWalle, F.B., 'Composition and variability of leachate from recent and aged areas within a municipal landfill,' Water Environ. Res., 67(2), 238-243(1995) https://doi.org/10.2175/106143095X131411
  4. Christensen, T. H. and Kjeldsen, P., Basic Biochemical Processes in Landfills, Sanitary Landfilling: Process, Technology and Environmental Impact, Academic press, pp. 29-49(1989)
  5. Dedhar, S. and Mavinic, D. S., 'Ammonia removal from a landfill leachate by nitrification and denitrification,' Wateri Qual. Res. J. Can., 2(3), 126-137(1986)
  6. Mostafa, W., 'Bioreactor landfills: experimental and field results,' Waste Manage., 22(1), 7-17(2002) https://doi.org/10.1016/S0956-053X(01)00014-9
  7. Yuen, S. T. S., Styles, J. R., and Mcmahon, T. A., 'An active, landfill management by leachate recirculation: A review and an outline of a full-scale project,' in Proceedirigs of Sardinia 95, Fifth International Landfill Symposium, Italy, pp. 403-418(1995)
  8. Pacey, J. P., Yazdani, R., Reinheart, D., Morek, R., and Augenstein, D., The Bioreactor Landfill: An Innovation in Sdlid Waste Management, SWANA, Silver Springs, Maryland, USA(1998)
  9. Pohland, F. G., 'Leachate recycle as landfill management option,' J. Environ. Eng., 106(6), 1057-1069(1980)
  10. Onay, T. T. and Pohland, F. G., 'In-situ Nitrogen management in controlled bioreactor landfills,' Water Res., 32(5); 1383-1392(1998) https://doi.org/10.1016/S0043-1354(97)00392-8
  11. Pohland, F. G. and Harper, S. R., Chritical Review and Summary of Leachate and Gas Production from Landfills, U.S.EPA/600/2-86/073, EPA, Washington D.C., USA (1985)
  12. Keenan, J. D., Steiner, R. L., and Fungaroli, A. A., 'Landfill leachate treatment,' J. Water Pollut. Control Fed., 56(1), 27-33(1984)
  13. Spengel, D. B. and Dzombak, D. A., 'Treatment of landfill leachate with rotaing biological contactors : banch-scale experiments,' J. Water Pollut. Control Fed., 63(7), 971-980(1991)
  14. Robinson, H. D. and Grantham., G., 'The treatment of landfill leachates in on-site aerated lagoon plants: experience in Britain and Ireland,' Water Res., 22(6), 733-747(1988) https://doi.org/10.1016/0043-1354(88)90184-4
  15. Carley, B. N. and Mavinic D. S., 'The effects of external carbon loading on nitrification and denitrification of a high ammonia landfill leachate,' Water Qual. Res. J. Can., 63(1), 51-59(1991)
  16. Alleman, J. E. and Irvine, R. L., 'Nitrification in the sequencing batch biological reactor,' J. Water Pollut. Control Fed., 52(7), 2747-2754(1980)
  17. Abe1ing, U. and Seyfried, C. F., 'Anaerobic-aerobic treatment of high strength ammonium wastewater nitrogen removal via nitrite,' Water Sci. Technol., 26(5-6), 1007-1015(1992)
  18. Turk, O. and Mavinic, D.S. 'Preliminary assessment of a shortcut in nitrogen removal from wastewater,' Can. J. Civ. Engrg., Ottawa, 13(3), 600-605(1986) https://doi.org/10.1139/l86-094
  19. Turk, O. and Mavinic. D. S., 'Selective inhibition: A novel concept for removing nitrogen from highly nitrogenous wastes,' Environ. Trchnol. Lett., 8(3), 419-426(1987) https://doi.org/10.1080/09593338709384500
  20. Chung, J., Bae, W., Lee, Y. W., and Rittmann, B. E., 'Shortcut biological nitrogen removal in hybrid biofilm/ suspended growth reactors,' Process Biochemistry, 42(3), 320-328(2007)
  21. 강석태, 매립지 안정화에 대한 침출수 재순환율의 영향, 석사학위논문, KAIST(1996)
  22. San, I. and Onay, T. T., 'Impact of various leachate recirculation regimes on municipal solid waste degradation,' J Hazard. Mater., 87(1-3), 259-271(2001) https://doi.org/10.1016/S0304-3894(01)00229-1
  23. APHA, Standard Methods for the Examination of Water and Waste Water. 19th ed., American Public Health Association, USA(1995)
  24. Yuen, S. T. S., Wang, Q. J., Styles, J. R., and Mcmahon, T. A., 'Water balance comparison between a dry and a wet landfill-a full scale experiment,' J. Hydrol., 251(1-2), 29-48(2001) https://doi.org/10.1016/S0022-1694(01)00428-0
  25. Zeiss, C. and Major, W., 'Moisture flow throuhg municipal solid waste: pattern and characteristics,' J. Environ. Syst., 22(2), 211-231(1993)
  26. Metcalf and Eddy, Inc., Wastewater Engineering-Treatment, Disposal, McGraw-Hill, NY, USA(1991)
  27. Anthonisen, A. C., Loehr, R. C., Prakasam. T. B. S., and Srinath, E, G., 'Inhibition of nitrification by ammonia and nitrous acid,' J. Water Pollut. Control Fed., 48(5), 835-852(1976)
  28. Frumai, H., Tagui, H., and Fujita K., 'Effects of pH and alkalinity on sulfur-denitrification in a biological granular filter,' Water Sci. Technol., 34(1-2), 355-362 (1996)
  29. 김석구, 오염 건설부지의 환경친화적 복원기술 개발, 한국건설기술연구원(2000)