Characteristics of atmospheric mercury in a suburban area of east China: sources, formation mechanisms, and regional transport
<p>Speciated atmospheric mercury including gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and particulate-bound mercury (PBM) were measured continuously for a 1-year period at a suburban site, representing a regional transport intersection zone, in east China. Annual mean con...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-05-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/19/5923/2019/acp-19-5923-2019.pdf |
| Summary: | <p>Speciated atmospheric mercury including gaseous elemental mercury (GEM),
gaseous oxidized mercury (GOM), and particulate-bound mercury (PBM) were
measured continuously for a 1-year period at a suburban site, representing a
regional transport intersection zone, in east China. Annual mean
concentrations of GEM, PBM, and GOM reached 2.77 ng m<span class="inline-formula"><sup>−3</sup></span>,
60.8 pg m<span class="inline-formula"><sup>−3</sup></span>, and 82.1 pg m<span class="inline-formula"><sup>−3</sup></span>, respectively. GEM concentrations were
elevated in all the seasons except autumn. High mercury concentrations were
related to winds from the south, southwest, and north of the measurement
site. Combining analysis results from using various source apportionment
methods, it was found that GEM concentration was higher when quasi-local
sources dominated over long-range transport. Six source factors belonging to
the anthropogenic sources of GEM were identified, including the common
sectors previously identified (industrial and biomass burning, coal
combustion, iron and steel production, cement production, and incineration),
as well as an additional factor of shipping emissions (accounting for
19.5 % of the total), which was found to be important in east China where
marine vessel shipping activities are intense. Emissions of GEM from natural
surfaces were also found to be as important as those from anthropogenic
sources for GEM observed at this site. Concurrences of high GOM
concentrations with elevated <span class="inline-formula">O<sub>3</sub></span> and temperature, along with the lagged
variations in GEM and GOM during daytime demonstrated that the very high GOM
concentrations were partially ascribed to intense in situ oxidation of GEM.
Strong gas–particle partitioning was also identified when PM<span class="inline-formula"><sub>2.5</sub></span> was
above a threshold value, in which case GOM decreased with increasing PM<span class="inline-formula"><sub>2.5</sub></span>.</p> |
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| ISSN: | 1680-7316 1680-7324 |