DOI QR코드

DOI QR Code

자외선 LED와 백금으로 박막된 TiO2 광촉매를 이용한 중금속과 결합한 시안화합물의 광촉매 산화

Photo-catalytic Oxidation of Cyanide Complexes Associated with Heavy Metals Using UV LED and Pt-dopped TiO2

  • 설정우 (경상대학교 자연과학대학 지구환경과학과 및 기초과학연구소) ;
  • 김성희 (경상대학교 자연과학대학 지구환경과학과 및 기초과학연구소) ;
  • 이우춘 (경상대학교 자연과학대학 지구환경과학과 및 기초과학연구소) ;
  • 조현구 (경상대학교 자연과학대학 지구환경과학과 및 기초과학연구소) ;
  • 김순오 (경상대학교 자연과학대학 지구환경과학과 및 기초과학연구소)
  • Seol, Jeong Woo (Department of Earth and Environmental Sciences and Research Institute of Natural Science, Gyeongsang National University) ;
  • Kim, Seong Hee (Department of Earth and Environmental Sciences and Research Institute of Natural Science, Gyeongsang National University) ;
  • Lee, Woo Chun (Department of Earth and Environmental Sciences and Research Institute of Natural Science, Gyeongsang National University) ;
  • Cho, Hyen Goo (Department of Earth and Environmental Sciences and Research Institute of Natural Science, Gyeongsang National University) ;
  • Kim, Soon-Oh (Department of Earth and Environmental Sciences and Research Institute of Natural Science, Gyeongsang National University)
  • 투고 : 2015.02.13
  • 심사 : 2015.03.25
  • 발행 : 2015.03.31

초록

광석에서 순도 높은 금은을 추출하기 위해 사용된 청화법으로부터 시안이 유출되어 광석 내 존재하는 중금속들과 결합하여 다양한 형태의 시안화합물이 생성된다. 이러한 시안화합물은 난분해성 오염물질로서 인간을 포함한 생태계에 악영향을 끼친다. 결합력에 따라서 중금속과 결합한 시안화합물은 공유결합성 화합물(weak acid dissociable, WAD)과 착화합물(strong acid dissociable, SAD) 등으로 분류할 수 있다. 본 연구에서는 시안화합물의 존재 형태별 광촉매 산화 효율을 비교 평가하였다. 특히 자외선 LED 광원의 파장과 광촉매 표면 개질이 시안화합물의 분해에 미치는 영향을 살펴보았다. 실험 결과, 동일한 광촉매 산화 조건에서 자유 시안보다는 중금속과 결합한 시안화합물의 광산화 분해 효율이 떨어짐을 알 수 있었다. 그리고 자유 시안의 경우에는 짧은 파장에서 광촉매 산화가 효과적이었지만 중금속과 결합한 시안화합물의 경우에는 긴 파장에서 광산화 분해능이 더 높게 나타났다. 그리고 광촉매 표면 개질에 의하여 광촉매 산화 공정의 성능을 향상시킬 수 있음을 확인하였다.

Cyanide can be leached out from the cyanidation method which has been used to extract high-purity gold and silver from ores, and it becomes a variety of cyanide complexes associated with heavy metals contained in ores. Such cyanide complexes are considered as persistent and non-degradable pollutants which cause adverse effects on humans and surrounding environments. Based on binding force between heavy metals and cyanide, cyanide complexes can be categorized weak acid dissociable (WAD) and strong acid dissociable (SAD). This study comparatively evaluated the performance of photo-catalytic process with regard to forms of cyanide complexes. In particular, both effects of UV LED wavelength and surface modification of photo-catalyst on the removal efficiency of cyanide complexes were investigated in detail. The results indicate that the performance of photo-catalytic oxidation is significantly affected by the form of cyanide complexes. In addition, the effect of UV LED wavelength on the removal efficiency was quite different between free cyanide and cyanide complexes associated with heavy metals. The results support that the surface modification of photo-catalyst, such as doping can improve overall performance of photo-catalytic oxidation of cyanide complexes.

키워드

참고문헌

  1. Chiang, K., Amal, R., and Tran, T. (2002) Photocatalytic degradation of cyanide using titanium dioxide modified with copper oxide. Journal of Advances in Environmental Research. 6, 471-485. https://doi.org/10.1016/S1093-0191(01)00074-0
  2. Chiang, K., Amal, R., and Tran, T. (2003) Photocatalytic oxidation of cyanide : kinetic and mechanistic studies. Journal of Molecular catalysis A : Chemical. 193, 285-297. https://doi.org/10.1016/S1381-1169(02)00512-5
  3. Choi, W. (2003) Studies on $TiO_2$ photocatalytic reactions. Journal of Korean Industrial and Engineering Chemistry, 14, 1011-1022 (Korean with English abstract).
  4. Eaton, A.D., Clesceri, L.S., Rice, E.W., and Greenberg, A.E. (2005) Standard methods the examination of water and wastewater (21st edition). APHA/AWWA/ WEF, Maryland, p.4/34-4/54.
  5. EPA (2010) Free cyanide in water, soils and solid wastes by microdiffusion, EPA method 9016.
  6. Gerakines, P.A., Moore, M.H., and Hudson, R.L. (2004) Ultraviolet photolysis and proton irradiation of astrophysical ice analogs containing hydrogen cyanide. ICARUS, 170, 202-213. https://doi.org/10.1016/j.icarus.2004.02.005
  7. Gonghu, L. and Gray, K.A. (2007) The solid-solid interface: Explaining the high and unique photocatalytic reactivity of $TiO_2$-based nanocomposite materials. Journal of Chemical Physics. 339, 173-187.
  8. Gurley, T.W. (1980) Determination of terephthalic acid at the low parts-per-billion level by reverse phase high performance liquid chromatography. Journal of Chromatographic Science, 18, 39-41. https://doi.org/10.1093/chromsci/18.1.39
  9. Hashimoto, K., Irie, H., and Fujishima, A. (2005) $TiO_2$ Photocatalysis : A historical Overview and Future Prospects. Journal of Applied Physics. 12, 8269-8285.
  10. Jung, M.C. (1999) Investigation of soil contamination and its remediation system in the vicinity of abandoned Au-Ag mine in Korea. Economic and Environmental Geology, 32, 73-82 (Korean with English abstract).
  11. Jung, M.C. and Jung, M.Y. (2006) Evaluation and management method of environmental contamination from abandoned metal mines in Korea. Korean Society of Mineral Energy and Resources Engineers, 43, 383-394 (Korean with English abstract).
  12. Jung, Y.H. and Lee, S.K. (2009) Treatment characteristics of plating wastewater containing freecyanide, cyanide complexes and heavy metals (I). Journal of Korean Society on Water Quality, 25, 979-983 (Korean with English abstract).
  13. Kim, M. and Shin, B.S. (1998) Electrolytic treatment of copper cyanide in wastewater from gold mines. Korean Society of Mineral Energy and Resources Engineers, 35, 280-286 (Korean with English abstract).
  14. Kim, S.T., Yoon, Y.H., Park, J.A., and Shim, U.S. (1999) Distribution of heavy metals and cyanide in tailings, soils, and stream sediments around Gubong disused mine. Journal of Korean Soil Environment Society, 4, 35-47 (Korean with English abstract).
  15. Lee, G.D. and Lee, H.I. (1992) Application of photocatalysis. Journal of Korean Industrial and Engineering Chemistry, 3, 35-45 (Korean with English abstract).
  16. Li, F.B. and Li, X.Z. (2002) The enhancement of photodegradation efficiency using Pt-$TiO_2$ catalyst. Journal of Chemosphere. 48, 1103-1111. https://doi.org/10.1016/S0045-6535(02)00201-1
  17. Johnson, C.A., Leinz, R.W. Grimes, D.J., and Rye, R.O. (2002) Photochemical changes in cyanide speciation in drainage from a precious metal ore heap. Journal of Environmental Science & Technology. 36, 840-845. https://doi.org/10.1021/es011064s
  18. Johnson, C.A., Leinz, R.W. Grimes, D.J., and Rye, R.O. (2008) Cyanide speciation at four gold leach operations undergoing remediation. Journal of Environmental Science & Technology. 42, 1038-1044. https://doi.org/10.1021/es702334n
  19. Malhotra, S., Pandit, M., Kapoor, J.C., and Tyagi, D.K. (2005) Photo-oxidation of cyanide in aqueous solution by the UV/H2O2 process. Journal of Chemical Technology and Biotechnology. 80, 13-19. https://doi.org/10.1002/jctb.1127
  20. Meehan, S.M.E., Weaver, T.R., and Lawrence, C.R. (1999) The biodegradation of cyanide in groundwater at gasworks sites, Austraila: implications for site management, Environ. Manag. Health, 10, 64-71. https://doi.org/10.1108/09566169910257112
  21. MOE (Ministry of Environment). (2009) Cyanide-Absorptiometric analysis, Standard method for soil contamination.
  22. Parga, J.R., Shukla, S.S., and Carrillo-Pedroza, F.R., (2003) Destruction of cyanide waste solutions using chlorine dioxide, ozone and titania sol. Journal of Waste Management. 23, 183-191. https://doi.org/10.1016/S0956-053X(02)00064-8
  23. Raybuck, S.A. (1992) Microbes and microbial enzymes for cyanide degradation, Biodegradation, 3, 3-18.
  24. Wada, H., Yanaga, K., Kuroda, Y., Hanela, S., and Hirayama, Y. (2005) Recycling of wastewater containing iron-complex cyanides using UV photodecomposition and UV ozone oxidation in combination with an ion-exchange resin method. Bulletin of the Chemical Society of Japan, 78, 512-518. https://doi.org/10.1246/bcsj.78.512
  25. Watanabe, A., Yano, K., Ikebukuro, K., and Karube, I. (1998) Cyanide hydrolysis in a cyanide-degrading bacterium, Pseudomonas stutzeri AK61, by cyanidase, Microbiology, 144, 1677-82. https://doi.org/10.1099/00221287-144-6-1677
  26. Zagury, G.J., Oudjehani, K., and Deschênes, L. (2004) Characterization and availability of cyanide in solid mine tailings from gold extraction plants, Science of the Total Environment. 320, 211-224. https://doi.org/10.1016/j.scitotenv.2003.08.012
  27. Zalesks, A. (2008) Doped-$TiO_2$: A review, Recent Patents on Engineering. 2, 157-164. https://doi.org/10.2174/187221208786306289