Journal of Korean Society for Atmospheric Environment (한국대기환경학회지)

Korean Society for Atmospheric Environment (한국대기환경학회)
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UV Photodegradation of Chlorinated VOCs: Removal Efficiency and Products

염소계 VOCs의 UV 광분해 연구: 제거율 및 부산물

  • Kang, InSun (School of Environment, Tsinghua University) ;
  • Xi, Jinying (School of Environment, Tsinghua University) ;
  • Wang, Can (School of Environmental Science and Engineering, Tianjin University) ;
  • Hu, Hong-Ying (School of Environment, Tsinghua University)
  • 강인선 (칭화대학교 환경학원) ;
  • ;
  • ;
  • Received : 2016.12.13
  • Accepted : 2017.02.22
  • Published : 2017.04.30
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Abstract

In this study, 4 gases containing typical chlorinated volatile organic compounds (VOCs) were treated by ultraviolet (UV) irradiation. The typical chlorinated VOCs are dichloromethane (DCM), trichloromethane (TCM), carbon tetrachloride (CTC) and trichloroethylene (TCE). The removal efficiency (RE) and the products of chlorinated VOCs by UV irradiation are investigated. At this time, 2 types of background gas (air and nitrogen) were used to figure out the RE by photooxidation and photolysis. The specification of UV-lamp used in this study was low-pressure mercury lamp emitting wavelength of 185~254 nm. The experimental conditions were set as initial VOC concentration of $180{\pm}10ppm$, empty bed retention time (EBRT) of 53 s, temperature of $23{\pm}2^{\circ}C$ and relative humidity of $65{\pm}5%$. In the photolysis condition with nitrogen ($N_2$) as background gas, the averaged RE of the 4 types of chlorinated VOCs was about 24% higher than that with photooxidation; and the REs of VOCs except CTC were confirmed as >99%. The composition of off-gases after UV photooxidation in air was investigated and several intermediates from DCM, TCM and TCE were detected by GC/MS. Among them, phosgene which is a toxics was detected as an intermediate of TCM. In addition, the concentration of carbon dioxide ($CO_2$) in the off-gases was measured to calculate the mineralization rate (MR). With the photooxidation, TCE showed the highest RE (>99%) while MR was the lowest (17%); and the MR of DCM was the highest (86%). In addition, particulate matters (PM) in the off-gases was also detected and high concentrated $PM_{10}$ ($21,580{\mu}g{\cdot}m^{-3}$) and $PM_{2.5}$ ($6,346{\mu}g{\cdot}m^{-3}$) were detected in TCE off-gas. More than 99% of the chlorinated VOCs could be removed using UV254-185 nm lamp, while it is necessary to conduct further studies on the production and treatment of secondary pollutants.

Keywords

References

  1. Cao, L.X., Z. Gao, S.L. Suib, T.N. Obee, S.O. Hay, and J.D. Freihaut (2000) Photocatalytic oxidation of toluene on nanoscale $TiO_2$ catalysts: Studies of deactivation and regeneration. Journal of Catalysis, 196(2), 253-261. https://doi.org/10.1006/jcat.2000.3050
  2. Chen, F.Y., S.O. Pehkonen, and M.B. Ray (2002) Kinetics and mechanisms of UV-photodegradation of chlorinated organics in the gas phase, Water Research, 36(17), 4203-4214. https://doi.org/10.1016/S0043-1354(02)00140-9
  3. Cheng, Z.W., P.F. Sun, Y.F. Jiang, J.M. Yu, and J.M. Chen (2013) Ozone-assisted UV254nm photodegradation of gaseous ethylbenzene and chlorobenzene: Effects of process parameters, degradation pathways, and kinetic analysis. Chemical Engineering Journal, 228, 1003-1010. https://doi.org/10.1016/j.cej.2013.05.076
  4. Cho, I.C., J.H. Byun, E.S. Byun, D.G. Lee, and S.W. Kim (2001) Gas phase photocatalytic oxidation of PCE with $TiO_2$. Journal of Korean Society for Atmospheric Environment, 17(1), 57-66. (in Korean with English abstract)
  5. Gong, S.Y., S.P. Hong, and G.S. An (2014) Impacts of facilities with strengthened emission limit value on environmental technology development and emission reduction, Research Report 2014-09, Korea Environment Institute, Korea, 51-57 pp.
  6. Kam, S.K., J.W. Jeon, and M.G. Lee (2014) Effect of methyl ethyl ketone and ethyl acetate vapor on photocatalytic decomposition of n-pentane vapor. Journal of Environmental Science International, 23(6), 1151-1156. (in Korean with English abstract) https://doi.org/10.5322/JESI.2014.23.6.1151
  7. Keshmiri, M., T. Troczynski, and M. Mohseni (2006) Oxidation of gas phase trichloroethylene and toluene using composite sol-gel $TiO_2$ photocatalytic coatings. Journal of Hazardous Materials, 128(2), 130-137. https://doi.org/10.1016/j.jhazmat.2005.07.060
  8. Kim, K.J. and O.H. Park (2008) A comparative study on degradation of BTEX vapor by $O_3$/UV, $TiO_2$/UV, and $O_3/TiO_2$/UV system with operating conditions. Journal of Korean Society for Atmospheric Environment, 24(1), 91-99. (in Korean with English abstract) https://doi.org/10.5572/KOSAE.2008.24.1.091
  9. Larson, S.A. and J.L. Falconer (1994) Characterization of $TiO_2$ photocatalysts used in trichloroethene oxidation. Applied Catalysis B: Environmental, 4(4), 325-342. https://doi.org/10.1016/0926-3373(94)00030-1
  10. Lee, E.J. and K.H. Lim (2010) Treatment of malodorous waste air using hybrid system. Korean Chemical Engineering Research, 48(3), 382-390. (in Korean with English abstract)
  11. Lee, S.Y., S.M. Lee, Y.J. Kim, I.K. Kim, and D.H. Choi (2015) Transboundary air pollution management strategies among China, Japan, and Korea, Research Report 2015-02, Korea Environment Institute, Korea, 1 pp.
  12. Mohseni M. (2005) Gas phase trichloroethylene (TCE) photooxidation and byproduct formation: photolysis vs. titania/silica based photocatalysis. Chemosphere, 59(3), 335-342. https://doi.org/10.1016/j.chemosphere.2004.10.054
  13. Moussavi, G. and M. Mohseni (2007) Using UV pretreatment to enhance biofiltration of mixtures of aromatic VOCs. Journal of Hazardous Materials, 144(1), 59-66. https://doi.org/10.1016/j.jhazmat.2006.09.086
  14. Rafael, M.R. and C.M. Nelson (1998) Relationship between the formation of surface species and catalyst deactivation during the gas-phase photocatalytic oxidation of toluene, Catalysis Today, 40(4), 353-365. https://doi.org/10.1016/S0920-5861(98)00064-9
  15. Rosenlund, M., F. Forastiere, D. Porta, M.D. Sario, C. Badaloni, and C.A. Perucci (2009) Traffic-related air pollution in relation to respiratory symptoms, allergic sensitisation and lung function in schoolchildren. Thorax, 64(7), 573-580. https://doi.org/10.1136/thx.2007.094953
  16. Rundell, K.W., J.B. Slee, R. Caviston, and A.M. Hollenbach (2008) Decreased lung function after inhalation of ultrafine and fine particulate matter during exercise is related to decreased total nitrate in exhaled breath condensate. Inhalation Toxicology, 20(1), 1-9. https://doi.org/10.1080/08958370701758593
  17. Wang, C., J.Y. Xi, and H.Y. Hu (2008) A novel integrated UVbiofilter system to treat high concentration of gaseous chlorobenzene. Chinese Science Bulletin, 53(17), 2712-2716.
  18. Wang, C., J.Y. Xi, and H.Y. Hu (2009) Reduction of toxic products and bioaerosol emission of a combined ultraviolet-biofilter process for chlorobenzene treatment. Journal of the Air & Waste Management Association, 59(4), 405-410. https://doi.org/10.3155/1047-3289.59.4.405
  19. Wei, Z.S., J.L. Sun, Z.R. Xie, M.Y. Liang, and S.Z. Chen (2010) Removal of gaseous toluene by the combination of photocatalytic oxidation under complex light irradiation of UV and visible light and biological process. Journal of Hazardous Materials, 177(1), 814-821. https://doi.org/10.1016/j.jhazmat.2009.12.106
  20. Yu, J.M., W.J. Cai, J.M. Chen, L. Feng, Y.F. Jiang, and Z.W. Cheng (2012) Conversion characteristics and mechanism analysis of gaseous dichloromethane degraded by a VUV light in different reaction media. Journal of Environmental Sciences, 24(10), 1777-1784. https://doi.org/10.1016/S1001-0742(11)61021-8

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