Publication Date:
2015-08-25
Description:
A framework was developed to estimate dry deposition of polycyclic aromatic compounds (PACs), including 17 polycyclic aromatic hydrocarbons (PAHs), 21 alkylated PAHs, and 5 parent and alkylated dibenzothiophenes (DBTs), to various land covers surrounding three monitoring sites in the Athabasca oil sands region. Modelled dry deposition velocities for various gaseous PACs and over various land covers were mostly in the range of 0.01-0.5 cm s −1 with median and annual mean values between 0.08 and 0.24 cm s −1 , comparable with literature values obtained from field studies. Annual dry deposition of the sum of PAHs was estimated to range from 330 to 560 µg m −2 over forested canopies surrounding the three sites and from 270 to 490 µg m −2 over grass and shrubs. The corresponding values are 3920 to 5380 µg m −2 and 2850 to 4920 µg m −2 for the sum of 21 alkylated PAHs, and are 230 to 1120 µg m −2 and 450 to 930 µg m −2 for the sum of 5 DBTs. The three monitoring sites are situated nearby the Athabasca River, and the direct annual atmospheric dry deposition to water surface was estimated to range from 350 to 500, 3170 to 4530, and 170 to 840 µg m −2 for PAHs, alkylated PAHs, and DBTs, respectively. Alkylated PAHs contributed 80% of the total dry and 60% of the total wet deposition budget, suggesting the importance of including this group of PAHs in the atmospheric deposition budget estimation for subsequent ecosystem impact studies. This article is protected by copyright. All rights reserved.
Electronic ISSN:
1942-2466
Topics:
Geography
,
Geosciences
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