Treatment of Cu(II)-EDTA using Solar/$TiO_2$ Photocatalysis

태양광/$TiO_2$ 광산화를 이용한 Cu(II)-EDTA의 제거

  • Shin, In-Soo (Division of Civil & Environmental Engineering, Kwandong University) ;
  • Lee, Seung-Mok (Division of Civil & Environmental Engineering, Kwandong University) ;
  • Yang, Jae-Kyu (LG Environmental Strategy Institute) ;
  • Shin, Won-Tae (Ministry of Maritime Affairs & Fisheries)
  • Published : 2005.02.28

Abstract

Photocatalytic oxidation of Cu(II)-EDTA has been studied using solar/$TiO_2$ photocatalysis as an energy source. Photocatalysis efficiency on the treatment of Cu(II)-EDTA was investigated using different types of solar collectors as well as by variation of the angles of solar collector solar light intensities, flow rates, and areas of solar collector. effect of $H_2O_2$ and types of $TiO_2$ catalyst on the treatment of Cu(II)-EDTA was also investigated. Removal of Cu(II) and DOC was favorable with a hemispherical collector than with a flat collector Removal of Cu(II) and DOC increased with increasing angles of solar collector up to $38^{\circ}$. Slurry type $TiO_2$ showed four-times higher removal efficiency than immobilized type $TiO_2$. Removal of both Cu(II) and DOC at a clear sky of solar light intensity ranging from 0.372 to $2.265\;mW/cm^2$ was greater than removal at a cloudy day of solar light intensity ranging from 0.038 to $1.129\;mW/cm^2$. From the result of this research that the removal efficiency of Cu(II) and DOC increased as the solar light intensity increased, it can be inferred that quantum yield in the destruction of Cu(II)-EDTA may directly related with the solar light intensity. Removal of Cu(II) increased as increasing the area of solar collector and was similar at lower flow rates white removal of Cu(II) was interfered at higher flow rates. When immobilized $TiO_2$ was used, removal efficiency of Cu(II) increased in the presence of $H_2O_2$ while negligible effect was found in the use of $TiO_2$ slurry.

본 연구에서는 인공 UV lamp의 대체에너지로 무한한 청정에너지인 태양광을 광원으로 이용하여 Cu(II)-EDTA 제거를 위한 광촉매 산화반응을 실시하였다. Cu(II)-EDTA의 광촉매 산화반응의 효율에 관한 연구를 위해 집광반사판의 형태, 집광반사판의 입사각, 광세기, 유량, 반응면적, $H_2O_2$의 효율, 그리고 광촉매 형태의 변화에 따라 실시하였다. Cu(II)와 DOC 제거율은 평판형의 집광반사판보다 반구형의 집광반사판 사용시 높게 나타났으며, 반사판의 각도를 $38^{\circ}$까지 증가시킬수록 제거속도 및 제거율이 각각 증가였다. $TiO_2$ 분말시스템은 $TiO_2$ 코팅 시스템보다 Cu(II)와 DOC 제거율에 있어서 약 4배 이상의 큰 제거율을 나타내어서 제거효율에 있어서는 우수한 것으로 조사되었다. Cu(II)와 DOC 모두 자외선 세기가 높은 맑은 날($0.372{\sim}2.265\;mW/cm^2$)에 제거효율이 가장 좋은 것으로 나타났는데, Cu(II)의 경우 흐린날($0.038{\sim}1.129\;mW/cm^2$에 비하여 약 3배, DOC의 경우 약 2배의 높은 제거율이 나타나서 광세기가 양자수율에 직접적으로 영향을 미침을 알 수 있었다. Cu(II)가 제거되는 경향은 반응기의 면적이 클수록 증가하였으며, 유량변동에는 비슷한 경향을 보였지만 일정유량 이상에서는 방해요인이 되는 것으로 나타났다. 코팅된 $TiO_2$를 광촉매로 사용하였을 때 $H_2O_2$ 농도증가에 따라 Cu(II)의 제거효율은 크게 증가하였지만 분말형 $TiO_2$ 사용시에는 이에 비해 $H_2O_2$ 주입효과가 크게 나타나지 않았다.

Keywords

References

  1. Thomas, H. M., Abhaya, K. D., and Melissa, F., 'Oxidation of metal-EDTA complex by $TiO_2$ photocatalysis,' Environ. Sci. Technol., 31(12), 3457-3481(1997)
  2. Davis, A. P. and Green, D. L., 'Photocatalytic oxidation of Cadmium-EDTA with titanium dioxide,' Environ. Sci. Technol., 33(4), 609-617(1999) https://doi.org/10.1021/es9710619
  3. Yang, J. K. and Davis, A. P., 'Photocatalytic oxidation of Cu(II)-EDTA with illuminated Ti02: Kinetics,' Environ. Sci. Technol., 34(17), 3789-3795(2000) https://doi.org/10.1021/es990874p
  4. Yang, J. K. and Davis, A. P., 'Photocatalytic oxidation of Cu(II)-EDTA with illuminated TiO2: Mechanisms,' Environ. Sci. Technol., 34(17), 3796-3801(2000) https://doi.org/10.1021/es990875h
  5. 신인수, 최봉종, 이승목, 양재규, '$TiO_2$ 광촉매반응을 이용한 구리함유 폐수처리 연구,' 대한환경공학회지, 25(10), 1225-1232(2003)
  6. 오정무, '태양에너지 이용에 관한 현황 및 전망,' 화학공학, 18(14), 301-307(1980)
  7. Cho, I. H., Moon, I. Y., Chung, M. H., Lee, H. K., and Zoh, K. D. 'Disinfection effects on E. coli using $TiO_2$/UV and solar light system,' Water Sci. Technol.: Water Supply, 2(1), 181-190(2002a)
  8. Cho, I. H., Kim, H. Y., Zoh, K. D., and Lee, H. K. 'A study on the removal of toxic metal-EDTA complex using solar Iight/$TiO_2$ system,' Water Sci. Technol.: Water Supply, 2(1), 299-304(2002b)
  9. Cho, I. H., Kim, H. Y., and Zoh, K. D. 'Detoxification of trichlchloroethylene(TCE) using solar light/$TiO_2$, in a UV concentrating radiation system,' J. Water Environ. Technol., 1(1), 37-42(2003) https://doi.org/10.2965/jwet.2003.37
  10. Ahmed, S. and Ollis, D. F., 'Solar photoassisted catalytic decomposition of the chlorinated hydrocarbons trichloroethylene and trichloromethane,' Solar Energy, 32(5), 597-601(1984) https://doi.org/10.1016/0038-092X(84)90135-X
  11. Boston, J. R., 'The photochemical conversion and storage of solar energy: an historical perspective,' Solar Eng. Mat. Solar Cells, 38, 543-554(1995) https://doi.org/10.1016/0927-0248(94)00208-8
  12. Chang, W. and Lin, W. Y. 'Bactericidal activity of $TiO_2$ photocatalyst in aqueous media: Toward a solar-assisted water disinfection system,' Environ. Sci. Technol., 28(5), 934 - 938(1994) https://doi.org/10.1021/es00054a027
  13. Jean, M, H., Jean, D., Pierre, P., Sixto, M., and Blanco, J., '$TiO_2-based$ solar photocatalytic detoxification of water containing organic pollutants: Case studies of 2,4-dichlorophenoxyacetic acid(2,4-D) and of benzofuran,' Appl. Catal., B: Environmental, 17, 15-23(1988) https://doi.org/10.1016/S0926-3373(97)00098-2
  14. Alfanoa, O. M., Bahnemann, D., Cassano, A. E., Dillert, D., and Goslich, R., 'Photocatalysis in water environments using artificial and solar light,' Catal. Today, 58, 199-230(2000) https://doi.org/10.1016/S0920-5861(00)00252-2