Atmospheric Dry Deposition of Polychlorinated Dibenzo-p-Dioxins/Dibenzofurans (PCDD/Fs) and Polychlorinated Biphenyls (PCBs) in Southern Taiwan

Received: July 5, 2012
Revised: August 28, 2012
Accepted: August 28, 2012
Download Citation: RIS|BibTeX|https://doi.org/10.4209/aaqr.2012.07.0172  

Cite this article:
Mi, H.H., Wu, Z.S., Lin, L.F., Lai, Y.C., Lee, Y.Y., Wang, L.C. and Chang-Chien, G.P. (2012). Atmospheric Dry Deposition of Polychlorinated Dibenzo-p-Dioxins/Dibenzofurans (PCDD/Fs) and Polychlorinated Biphenyls (PCBs) in Southern Taiwan. Aerosol Air Qual. Res. 12: 1016-1029. https://doi.org/10.4209/aaqr.2012.07.0172

ABSTRACT

Dry deposition is one of the major routes by which air pollutants enter the ecosystem, and thus this study investigated the dry deposition characteristics of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and biphenyls (PCBs) in the ambient air of industrial, urban, and rural areas in southern Taiwan from November 2010 to May 2011. Average dry deposition fluxes of total PCDD/Fs and PCBs in the ambient air of four sites were 157–544 pg/m²-day (8.30–27.5 pg I-TEQ/m²-day) and 289–1010 pg/m²-day (0.540–1.94 pg WHO-TEQ/m²-day), respectively. The results showed that particle phase depositions dominated the dry deposition processes for the removal of PCDD/Fs and PCBs from the atmosphere, and the atmospheric deposition flux in the cold season tended to be higher than that during the warm season. The dry deposition velocity of individual PCDD/Fs (0.031–0.546 cm/s) increased as the number of chlorinated substitutes increased, which were similar to those measured or predicted in other Asian countries. Similar patterns of dry deposition velocities were observed for individual PCBs (0.069–3.38 cm/s), due to the fact that low chlorinated PCBs are predominant in gas phase and have lower deposition velocities.

Keywords: Polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs); Polychlorinated biphenyls (PCBs); Gas-Particle partitioning; Dry deposition flux; Dry deposition velocity