Simultaneous Treatment of Carbon Dioxide and Ammonia by Microalgal Culture

조류배양을 통한 이산화탄소 및 암모니아의 동시처리

  • 윤영상 (포항공과대학 환경공학부 화학공학과) ;
  • 박종문 (포항공과대학 환경공학부 화학공학과) ;
  • Published : 1999.06.01

Abstract

A green microalga, Chlorella vulgaris UTX 259, was cultivated in a bench-scale raceway pond. During the culture, 15%(v/v) $CO_2$ was supplied and industrial wastewater discharged from a steel-making plant was used as a culture medium. In a small scale culture bottle, the microalga grew up to 1.8 g $dm^{-3}$ of cell concentration and ammonia was completely removed from the wastewater with an yield coefficient of 25.7 g dry cell weight $g^{-1}\;NH_3-N$. During the bottle-culture, microalga was dominant over heterotrophic microorganisms in the culture medium. Therefore, the amount of carbon dioxide fixation could be estimated from the change of dry cell weight. In a semi-continuous operation of raceway pond with intermittent lighting (12 h light and 12 h dark), increase of dilution rate resulted in increase of the ammonia removal rate as well as the $CO_2$ fixation rate but the ammonia removal efficiency decreased. Ammonia was not completely removed from the medium (wastewater) of raceway pond which was operated in a batch mode under a light intensity up to 20 klux. The incomplete removal of ammonia was believed due to insufficient light supply. A mathematical model, capable of predicting experimental data, was developed in order to simulate the performance of the raceway pond under the light intensity of sun during a bright daytime. Simulation results showed that the rates of $CO_2$ fixation and ammonia removal could be enhanced by increasing light intensity. According to the simulation, 80 mg $dm^{-3}$ of ammonia in the medium could be completely removed if the light intensity was over 60 klux with a continuous lighting. Under the optimal operating condition determined by the simulation, the rates of carbon dioxide fixation and ammonia removal in the outdoor operation of raceway pond were estimated as high as $24.7 g m^{-2} day^{-1}$ and $0.52 g NH_3-N m^{-2} day^{-1}$, respectively.

본 연구에서는 제철소에서 배출되는 산업폐수를 이용하여 미세조류를 성공적으로 배양하였으며 이에 대한 모델링 연구를 통해 이산화탄소의 고정화 및 암모니아의 제거효율에 미치는 환경인자에 대하여 살펴보고 실제 옥외배양에서의 성능을 평가하고자 하였다. Bottle에서의 배양을 통해 산업폐수에서 미세조류가 성장하면서 암모니아를 완전히 제거할 수 있음을 확인하였다. 또한 이때 타양미생물의 성장은 미세조류의 성장에 비해 미미하였으므로 건조중량으로부터 고정화된 이산화탄소를 계산할 수 있었다. Raceway pond의 회분식운전 결과로부터 조류성장에 대한 모델을 구축하고 관계되는 parameter를 결정할 수 있었으며 이로부터 실제 옥외에서의 빛의 세기에서 고정화된 이산화탄소의 누적량 및 암모니아의 제거를 계산할 수 있었다. 그 결과 60 klux이상의 빛에서는 암모니아가 완전히 제거될 수 있다는 결과를 얻었으며 빛의 세기가 증가할 수록 성능이 향상되지만 빛에너지에 대한 효율은 감소하는 경향을 발견하였다. Raceway pond의 실제 옥외운전을 모사하기 위한 반연속식 배양실험에서는 dilution rate이 증가할 때 이산화탄소의 고정화율 및 암모니아의 제거율이 증가하나 암모니의 제거효율은 감소하는 경향을 얻었다. 또한 raceway pond의 옥외배양시 빛의 세기 및 폐수의 깊이, dilution rate에 따른 성능변화를 모델로 이용하여 계산하였는데 결과적으로 하루에 12시간동안 100klux의 태양빛이 공급되는 조건에서 raceway pond를 운전할 때 최적의 dilution rate은 0.425$day^{-1}$이며 이러한 조건에서 24.7 g$m^{2}day^{-1}$의 속도로 이산화탄소를 고정할 수 있는 것으로 평가되었다. 또한 이러한 조건에서 암모니아는 0.52 g $NH_3-Nm^{-2}day^{-1}$의 속도로 제거될 수 있으며 배출수증의 암모니아농도는 폐수의 깊이에 따라 크게 변화하는 것으로 나타났다.

Keywords

References

  1. Science v.243 The greenhouse effect: science and policy Schneider, S. H.
  2. Adv. Biochem. Eng./Biotechnol. v.46 biotechnological reduction of CO₂emissions Karube, T.;T. Takeuchi;D. J. Barnes
  3. Energy Convers. Manag. v.34 Reducing atmospheric CO₂using biomass energy and photobiology Hall, D. O.;J. I. House
  4. J. Biotechnol. v.25 Carbon dioxide fixation by an unicellular green alga Oocystis sp. Takeuchi, T.;K. Utsunomia;K. Kobayashi;M. Owada;I. Karube
  5. Phytochemistry v.31 Tolerance of microalgae to high CO₂and high temperature Hanagata, N.;T. Takeuchi;Y. Fukuju;D. J. Barnes;I. Karube
  6. J. Mar. Biotechnol. v.1 A new species of highly CO₂-tolerant fast-growing marine microalga for high density culture Kodama, M.;H. Ikemoto;S. Miyachi
  7. J. Ferment. Bioeng. v.82 Biological elimination of nitric oxide and carbon dioxide from flue gas by marine microalga NOA-113 cultivated in a long tubular photobioreactor Yoshilhara, K.-I.;H. Nagase;K. Eguchi;K. Hirata;K. Miyachi
  8. Biotechnol. Tech. v.10 Enhancement of CO₂tolerance of Chlorella vulgaris by gradual increase of CO₂concentration Yun, Y.-S.;J. M. Park;J.-W. Yang
  9. Appl. Biochem. Biotechnol. v.39/40 Carbon dioxide fixation by microalgae photosynthesis using actual flue gas discharged from al bioler Negoro, M.;A. Hamasaki;Y. Ikuta;T. Makita;K. Hirayama;S. Suzuki
  10. Appl. Biochem. Biotechnol. v.45/46 Carbon dioxide fixation by microalgal protosynthesis using actual flue gas Hamasaki, A.;N. Shioji;Y. Ikuta;Y. Hukuta;T. Makita;K. Hirayama;H. Matutaki;T. Tukamoto;S. Sasaki
  11. Appl. Biochem. Biotechnol. v.28/29 Glutamate production form CO₂by marine cyanobacterium Synechococcus sp. using a novel biosolar reactor employing light-diffusing optical fibers Matunaga, T.;H. Takeyama;H. Sudo;N. Oyama;S. Ariura;H. Takano;M. Hirano;J. G. Burgess;K. Sode;N. Nakamura
  12. Appl. Biochem. Biotechnol. v.34/35 CO₂removal by high-density culture of a marine cyanobacterium Synechococcus using an improved photobioreactor employing light-diffusing optical fibers Takano, H.;H. Takeyama;N. Nakamura;K. Sode;J. G. Burgess;E. Manabe;M. Hirano;T. matunaga
  13. Kor. J. Chem. Eng. v.14 Development of gas recycling photobioreactor system for microalgal carbon dioxide fixation Yun, Y.-S.;J. M. Park
  14. J. Chem. Tech. Biotechnol. v.70 Carbon dioxide fixation by algal cultivation using wastewater untrients Yun, Y.-S.;S. B. Lee;J. M. Park;C.-I. Lee;J.-W. Yang
  15. Renweable Energy v.16 Isolation of a new highly CO₂tolerant freshwater microalga Chlorella sp. KR-1 Sung, K. D.;J. S. Lee;C. S. Shin;S. C. Park
  16. Division of Fuel Chemisitry of the American Chemical Society v.41 Current aspects of carbon dioxide fixation by microalgae in Korea Lee, J. S.;K. D. Sung;M. S. Kim;S. C. Park;K. W. Lee
  17. 화학공업과 기술 v.13 생물학적 이산화탄소 고정화 공정의 개발 이선복;박찬범;서인수
  18. Advances in Chemical Conversions for Mitigating Carbon Dioxide Cultivation of cyanobacterium in various types of photo-biorectors for biological CO₂fixation Suh, I. S.;C. B. Park;J. K. Han;S. B. Lee;T. Inui(ed.);M. Anpo(ed.);K. Izui(ed.);S. Yanagida(ed.);T. Yamaguchi(ed.)
  19. J. Phycol. v.29 no.Suppl. UTEX: the Culture Collection of Algae at the University of Texas at Ustin Starr, R. C.;J. A. Zeikus
  20. Hanbook of Microalgal Mass Culture Laboratory techniques for the cultivation of microalgae Vonshak, A.;A. Richmond(ed.)
  21. Photosynthetic Energy Transduction Hipkins, M. F.;N. R. Baker
  22. Microbiological Appliations(6th ed.) Benson, H. L.
  23. Standard Methods for the Examination of Water and Wastewater(19th ed.) Eaton, A. D.;L. S. Clesceri;A. E. Greenberg
  24. Biotechnol. Lett. v.19 Variations of photosynthetic activity and growth of frestwater algae according to ozone contact time in ozone treatment Yun, Y.-S.;S. R. Lim;K.-K. Cho;J. M. Park
  25. Plant Physiol. v.48 Regulation of nitrate reductase in Chlorella vulgaris Smith, F. W.;J. F. Thompson
  26. Annual. Rev. Plant Physiol. v.32 the assimilatory nitrate-reducing system and its regulation Guerrero, M. G.;J. M. Vega;M. Losada
  27. PhD Thesis, The University of Michigan Photobioreactor Engineering: High Density Algal Culture Using Light-emitting Diodes Lee, C.-G.
  28. HWAHAK KONGHAK Modeling of microalgal photosynthetic activity depending on light intensity, cell density and light pathlength Yun, Y.-S.;J. M. Park;B. Volesky
  29. Algal Photosynthesis Geider, R. J.;B. A. Osborne