S. K. Sahu , G. G. Pandit, V. D. Puranik
Received:
November 30, 2008
Revised:
November 30, 2008
Accepted:
November 30, 2008
Download Citation:
||https://doi.org/10.4209/aaqr.2008.06.0021
Cite this article:
Sahu, S.K., Pandit, G.G. and Puranik, V.D. (2008). Dry Deposition of Polycyclic Aromatic Hydrocarbons Associated with Atmospheric Particulate Matters in an Urban Site, Mumbai, India.
Aerosol Air Qual. Res.
8: 437-446. https://doi.org/10.4209/aaqr.2008.06.0021
The rate of dry deposition of polycyclic aromatic hydrocarbons (PAHs) depends on the size of the particulate matter on which they are adsorbed. The distribution of PAHs on size-fractionated aerosol samples has been studied during winter and in the absence of precipitation to estimate the dry deposition flux of individual PAHs. Size-fractionated ambient particulate matter samples were collected during a 72-hour period, using an eight-stage cascade impactor. Filter paper samples were then extracted ultrasonically, and PAH characterization and quantification performed with a high-performance liquid chromatograph (HPLC) system with UV-visible detector. Total PAH concentrations associated with the size-segregated ambient particulate matters collected on different impactor stages were in the range of 18.3 to 66.6 ng/m3. The size distribution of atmospheric total PAHs was found to be bimodal. The modeled deposition velocity (Vd,i) at the sampling site for the particle size range of < 0.4 µm, 0.4-1.1 µm, 1.1-3.3 µm and 3.3-9.0 µm were found to be 0.004 cm/sec, 0.037 cm/sec, 0.283 cm/sec and 2.72 cm/sec, respectively. The dry deposition flux for individual PAHs at the sampling site was found to be in the range of 0.17 μg/m2/day-2.69 μg/m2/day. The results indicate that the dry deposition of PAHs is mainly due to gravitational settling of coarse particulates.
ABSTRACT
Keywords:
PAHs; Size distribution; HPLC; Cascade impactor; Deposition velocity; Dry deposition flux
