DOI QR코드

DOI QR Code

Filter- and Denuder-Based Organic Carbon Correction for Positive Sampling Artifacts

  • Hwang, InJo (Department of Environmental Engineering, Daegu University) ;
  • Na, Kwangsam (Mobile Source Control Division, California Air Resources Board)
  • Received : 2016.12.08
  • Accepted : 2017.03.31
  • Published : 2017.06.30

Abstract

This study describes (1) the impact of positive sampling artifacts caused by not only a filter-based sampling, but also a denuder-based sampling in the determination of particle-phase organic carbon (POC), (2) the effect of sample flow rate on positive artifacts, and (3) an optimum flow rate that provides a minimized negative sampling artifact for the denuder-based sampling method. To achieve the goals of this study, four different sampling media combinations were employed: (1) Quartz filter-alone (Q-alone), (2) quartz filter behind quartz-fiber filter (QBQ), (3) quartz filter and quartz filter behind Teflon filter (Q-QBT), and (4) quartz filter behind carbon-based denuder (Denuder-Q). The measurement of ambient POC was carried out in an urban area. In addition, to determine gas-phase OC (GOC) removal efficiency of the denuder, a Teflon filter and a quartz filter were deployed upstream and downstream of the denuder, respectively with varying sample flow rates: 5, 10, 20, and 30 LPM. It was found that Q-alone sampling configuration showed a higher POC than QBQ, Q-QBT, and Denuder-Q by 12%, 28%, and 23%, respectively at a sample flow rate of 20 LPM due to no correction for positive artifact caused by adsorption of GOC onto the filter. A lower quantity of GOC was collected from the backup quartz filter on QBQ than that from Q-QBT. This was because GOC was not in equilibrium with that adsorbed on the front quartz filter of QBQ during the sampling period. It is observed that the loss of particle number and mass across the denuder increases with decreasing sample flow rate. The contribution o f positive arti facts to POC decreased with increasing sample flow rate, showing 29%, 25%, and 22% for 10, 20, and 30 LPM, respectively. The 20 LPM turns out to be the optimum sample flow rate for both filter and denuder-based POC sampling.

Keywords

References

  1. Bisht, D.S., Dumka, U.C., Kaskaoutis, D.G., Pipal, A.S., Srivastava, A.K., Soni, V.K., Attri, S.D., Sateesh, M., Tiwan, S. (2015) Carbonaceous aerosols and pollutants over Delhi urban environment: Temporal evolution, source apportionment and radiative forcing. Science of The Total Environment 521-522, 431-445. https://doi.org/10.1016/j.scitotenv.2015.03.083
  2. Biswas, P., Flagan, R.C. (1988) The particle trap impactor. Journal of Aerosol Science 19, 113-121. https://doi.org/10.1016/0021-8502(88)90260-1
  3. Casimiro, P., Mario, C., Roy, M.H., Teresa, N., Fatima, M., Celia, A., Cesae, O., Ana, S.C., Begona, A., Manuel, M. (2011) OC/EC ration observations in Europe: Re-thinking the approach for apportionment between primary and secondary organic carbon. Atmospheric Environment 45, 6121-6132. https://doi.org/10.1016/j.atmosenv.2011.08.045
  4. Cheng, Y., He, K.B., Duan, F.K., Zheng, M., Ma, Y.L., Tan, J.H. (2009) Positive sampling artifact of carbonaceous aerosols and its influence on the thermal-optical split of OC/EC. Atmospheric Chemistry and Physics 9, 7243-7256. https://doi.org/10.5194/acp-9-7243-2009
  5. Djacinto, A., Monteiro, D.S., Joel, F.B., Jose, M.G., Paulo, A. (2016) Ambient concentrations and insights on organic and elemental carbon dynamics in Sao Paulo, Brazil. Atmospheric Environment 144, 226-233. https://doi.org/10.1016/j.atmosenv.2016.08.081
  6. Intergovernmental Panel on Climate Change (IPCC) (2007) IPCC fourth assessment report 2007, Cambridge University Press, London.
  7. Kim, B.M., Teffera, S., Zeldin, M.D. (2000) Characterization of $PM_{2.5}$ and $PM_{10}$ in the South Coast Air Basin of Southern California: Part1-Spatial Variations. Journal of the Air & Waste Management Association 50, 2034-2044. https://doi.org/10.1080/10473289.2000.10464242
  8. Kim, D., Jung, J., Lee, H., Choi, S.H., Lee, S. (2016) Characterization of sampling artifacts in the measurement of carbonaceous particles using high- and lowvolume samplers in Daejeon, Korea. Atmospheric Environment 139, 157-166. https://doi.org/10.1016/j.atmosenv.2016.05.029
  9. Kirchstetter, T.W., Corrigan, C.E., Novakov, T. (2001) Laboratory and field investigation of the adsorption of gaseous organic compounds onto quartz filters. Atmospheric Environment 35, 1663-1671. https://doi.org/10.1016/S1352-2310(00)00448-9
  10. Liu, C.N., Lin, S.F., Awasthi, A., Tsai, C.J., Wu, Y.C. (2014) Sampling and conditioning artifacts of $PM_{2.5}$ in filter-based samplers. Atmospheric Environment 85, 48-53. https://doi.org/10.1016/j.atmosenv.2013.11.075
  11. McDow, S.R., Huntzicker, J.J. (1990) Vapor adsorption artifact in the sampling of organic aerosol: face velocity effects. Atmospheric Environment 24A, 2563-2571.
  12. Na, K., Sawant, A.A., Song, C., Cocker, D.R. (2004) Primary and secondary carbonaceous species in the atmosphere of Western Riverside County, California. Atmospheric Environment 38(9), 1345-1355. https://doi.org/10.1016/j.atmosenv.2003.11.023
  13. Olson, D.A., Norris, G.A. (2005) Sampling artifacts in measurement of elemental and organic carbon: Lowvolume sampling in indoor and outdoor environments. Atmospheric Environment 39, 5437-5445. https://doi.org/10.1016/j.atmosenv.2005.05.040
  14. Safai, P.D., Raju, M.P., Rao, P.S.P., Pandithurai, G. (2014) Characterization of carbonaceous aerosols over the urban tropical location and a new approach to evaluate their climatic importance. Atmospheric Environment 92, 493-500. https://doi.org/10.1016/j.atmosenv.2014.04.055
  15. Salako, G.O., Hopke, P.K., Cohen, D.D., Begum, B.A., Biswas, S.K., Pandit, G.G., Chung, Y.S., Rahman, S.A., Hamzah, M.S., Davy, P., Markwitz, A., Shagjjamba, D., Lodoysamba, S., Wanna, W., Bunprapob, S. (2012) Exploring the variation between EC and BC in a variety of locations. Aerosol and Air Quality Research 12, 1-7. https://doi.org/10.4209/aaqr.2011.09.0150
  16. Subramanian, R., Khlystov, A.Y., Cabada, J.C., Robinson, A.L. (2004) Positive and negative artifacts in particulate organic carbon measurement with denuded and undenuded sampler configurations. Aerosol Science and Technology 38, 27-48. https://doi.org/10.1080/02786820490247605
  17. Turpin, B.J., Saxena, P., Andrews, E. (2000) Measuring and simulating particulate organics in the atmosphere: problems and prospects. Atmospheric Environment 34, 2983-3013. https://doi.org/10.1016/S1352-2310(99)00501-4
  18. Zhu, C.S., Tsai, C.J., Chen, S.C., Cao, J.J., Roam, G.D. (2012) Positive sampling artifacts of organic carbon fractions for fine particles and nanoparticles in a tunnel environment. Atmospheric Environment 54, 225-230. https://doi.org/10.1016/j.atmosenv.2012.02.060