Membrane Journal (멤브레인)

The Membrane Society of Korea (한국막학회)
권호 표지

Scale Formation in the Concentrate Compartment of an Electrodialysis Stack During Desalination of Brackish Water

염수의 탈염을 위한 전기투석 농축실에서의 스케일 형성

  • Moon Seung-Hyeon (Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST)) ;
  • Yang Jung-Hoon (Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST)) ;
  • Yeon Kyeong-Ho (Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST))
  • 문승현 (광주과학기술원 환경공학과) ;
  • 양정훈 (광주과학기술원 환경공학과) ;
  • 연경호 (광주과학기술원 환경공학과)
  • Published : 2005.06.01
Download PDF
⟨ Previous Next ⟩

Abstract

An electrodialysis process was operated for a long period to investigate the scale formation on the membrane surface. During the desalination process, concentration of $Ca^{2+}$ and $SO_4^{2-}$ ions increased continuously in the concentrate compartment and eventually caused precipitation on the cation exchange membrane (Neosepta CMX) surface. During the initial scale formation, the performance of the process and membrane characteristics did not show significant changes, except the decrease in limiting current density of the CMX membrane occurring due to increase in the salt concentration in the concentrate compartment. Eventually, the limiting current density of the fouled CMX membrane dropped significantly to $300\;A/m^2$ as water dissociation occurred in the CMX membrane. It was concluded that the fouling was caused mainly by the scale formation on the cation exchange membrane surface in the concentrate and consequent water dissociation. Also the scale formation was reasonably predicted by the solubility of $CaSO_4$.

전기투석 공정에서 이온교환막 표면에 형성되는 스케일 영향을 조사하기 위해 장기간 동안 운전되었다. 탈염공정 동안, $Ca^{2+}$과 $SO_4^{2-}$ 이온의 농도는 농축실에서 연속적으로 증가하였으며 양이온교환막(Neosepta CMX)표면에 침전이 발생하였다. 초기 스케일 형성동안, 공정성능과 막 특성의 변화는 농축실 염농도 증가에 기인하여 일어나는 양이온교환막의 하계전류밀도가 감소하는 것을 제외하곤 미미하였다. 공정운전이 진행됨에 따라 양이온교환막의 한계전류밀도는 물의 해리 현상이 진행되어 $300\;A/m^2$까지 감소하였다. 막 오염은 농축실에서 양이온교환막 표면에 형성된 스케일과 물의 해리현상에 의해 유발된다는 결론을 얻었으며, 이러한 스케일 형성은 $CaSO_4$의 용해도에 의해 예측 가능한 것을 알 수 있었다.

Keywords

References

  1. W. S. Winston, H. Kamalesh, and K. Sirkar, 'Membrane Handbook,' Van Nostrand Reinhold Publ., New York (1992)
  2. K. H. Yeon and S. H. Moon, 'Principle and Application of Continuous Electrodeionization,' Membrane Journal, 11, 61 (2001)
  3. B. K. Park, B. P. Hong, K. S. Yeo, M. H. Yun, H. S. Byun, and H. J. Kang, 'Preparation and Application of Pore-filled PVDF Ion Exchange Membrane,' Membrane Journal, 14, 108 (2004)
  4. J. P. van der Hoek and J. A. M. H. Hofman, 'Electrodialysis as an alternative for reverse osmosis in an integrated membrane system,' Desalination, 117, 159 (1998)
  5. Y. Tanaka, 'Water dissociation in ion-exchange membrane electrodialysis,' J. Membr. Sci., 203, 227 (2002)
  6. M. Turek, 'Cost effective electrodialytic seawater desalination,' Desalination, 153, 371 (2002)
  7. J. M. Ortiz, J. A. Sotoca, E. Exposito, F. Gallud, V. Garcia-Garcia, V. Montiel, and A. Aldaz, 'Brackish water desalination by electrodialysis: batch recirculation operation modeling,' J. Membr. Sci., 252, 65 (2005)
  8. P. Tsiakis and L. G. Papageorgiou, 'Optimal design of an electrodialysis brackish water desalination plant,' Desalination, 173, 173 (2005)
  9. E. Komgold, L. Aronov, N. Belayev, and K. Kock, 'Electrodialysis with brine solutions oversaturated with caleium sulfate,' Desalination, 172, 63 (2005)
  10. N. Kahraman, Y. A. Cengel, B. Wood, and Y. Cerci, 'Energy analysis of a combined RO, NF, and EDR desalination plant,' Desalination, 171, 217 (2005)
  11. H. J. Lee and S. H. Moon, 'Fouling of Ion Exchange Membranes and Their Fouling Mitigation,' Membrane Journal, 12, 55 (2002)
  12. J. H. Choi and S. H. Moon, 'Concentration Polarization Phenomena in Ion-Exchange Membranes,' Membrane Journal, 12, 143 (2002)
  13. J. S. Park, J. H. Choi, and S. H. Moon, 'Operation of Electrodialysis at Over Limiting Current Density,' Membrane Journal, 12, 171 (2002)
  14. M. S. Kang, Y. J. Choi, and S. H. Moon, 'Effects of Immobilized Bipolar Interface Formed by Multivalent and Large Molecular Ions on Electrodialytic Water Splitting at Cation-Exchange Membrane Surface,' Membrane Journal, 13, 143 (2003)
  15. V. I. Zabolotsky, V. V. Nikonenko, and N. D. Pismenskaya, and A. G. Istoshin, 'Electrodialysis technology for deep demineralization of surface and ground water,' Desalination, 108, 179 (1996)
  16. E. James Watkins and Peter H. Pfromm, 'Capacitance spectroscopy to characterize organic fouling of electrodialysis membranes,' J. Membr. Sci., 162, 213 (1999)
  17. Y. Tanaka, 'Mass transport and energy consumption in ion-exchange membrane electrodialysis of seawater,' J. Membr. Sci., 215, 265 (2003)
  18. I. Atamanenko, A. Kryvoruchko, L. Yurlova, and E. Tsapiuk, 'Study of the $CaSO_4$ deposits in the presence of scale inhibitors,' Desalination, 147, 257 (2002)
  19. Tokuyama Soda Inc., 'Neosepta ion exchange mem branes,' Product brochure, Japan, (1995)
  20. M. Mulder, 'Basic Principles of Membrane Tech nology,' Kluwer Academic Publishers, Dordrecht Boston, London (1996)
  21. H. G. Heitmann, 'Saline water processing,' pp. 45 VCH Press, New York (1990)