Measurement report: Ambient volatile organic compound (VOC) pollution in urban Beijing: characteristics, sources, and implications for pollution control
<p>The increasing ozone (O<span class="inline-formula"><sub>3</sub></span>) pollution and high fraction of secondary organic aerosols (SOA) in fine particle mass has highlighted the importance of volatile organic compounds (VOCs) in air pollution control. In t...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-09-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/22/11931/2022/acp-22-11931-2022.pdf |
| Summary: | <p>The increasing ozone (O<span class="inline-formula"><sub>3</sub></span>) pollution and high fraction of secondary
organic aerosols (SOA) in fine particle mass has highlighted the importance of
volatile organic compounds (VOCs) in air pollution control. In this work,
four intensive field measurements of VOCs during winter of 2018 (from 1 December 2018 to 17 January 2019), spring (15 April to 27 May), summer
(17 June to 13 July), and autumn (22 September to 27 November) of 2019 were
conducted at an urban site in Beijing to characterize VOC sources and their
contributions to air pollution. The total mixing ratio of the 95 quantified
VOCs (TVOC) observed in this study ranged from 5.5–118.7 ppbv with the mean
value of 34.9 ppbv. Alkanes, OVOCs, and halocarbons were the dominant
chemical groups, accounting for 75 %–81 % of the TVOC across the sampling
months. The molar ratios of VOCs to NO<span class="inline-formula"><sub><i>x</i></sub></span> indicated that O<span class="inline-formula"><sub>3</sub></span>
formation was limited by VOCs during the whole sampling period. Positive
matrix factorization (PMF) analysis showed that diesel vehicle exhaust,
gasoline vehicle exhaust, and industrial emissions were the main VOC sources
during both the O<span class="inline-formula"><sub>3</sub></span>-polluted and PM<span class="inline-formula"><sub>2.5</sub></span>-polluted months. On the basis
of O<span class="inline-formula"><sub>3</sub></span> formation impact, VOCs from fuel evaporation and diesel exhaust,
particularly toluene, xylenes, <i>trans</i>-2-butene, acrolein, methyl
methacrylate, vinyl acetate, 1-butene, and 1-hexene, were the main
contributors, illustrating the necessity of conducting emission controls on
these pollution sources and species to alleviate O<span class="inline-formula"><sub>3</sub></span> pollution.
Instead, VOCs from diesel exhaust as well as coal and biomass combustion were found to
be the dominant contributors to secondary organic aerosol formation
potential (SOAFP), particularly the VOC species of toluene, 1-hexene,
xylenes, ethylbenzene, and styrene, and top priority should be given to these
for the alleviation of haze pollution. This study provides insights for the
government to formulate effective VOC control measures for air pollution in
Beijing.</p> |
|---|---|
| ISSN: | 1680-7316 1680-7324 |