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Titel |
A temporally and spatially resolved validation of emission inventories by measurements of ambient volatile organic compounds in Beijing, China |
VerfasserIn |
M. Wang, M. Shao, W. Chen, B. Yuan, S. Lu, Q. Zhang, L. Zeng, Q. Wang |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 14, no. 12 ; Nr. 14, no. 12 (2014-06-16), S.5871-5891 |
Datensatznummer |
250118808
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Publikation (Nr.) |
copernicus.org/acp-14-5871-2014.pdf |
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Zusammenfassung |
Understanding the sources of volatile organic compounds (VOCs) is essential
for ground-level ozone and secondary organic aerosol (SOA) abatement
measures. We made VOC measurements at 27 sites and online observations at
an urban site in Beijing from July 2009 to January 2012. Based on these
measurement data, we determined the spatial and temporal distribution of
VOCs, estimated their annual emission strengths based on their emission
ratios relative to carbon monoxide (CO), and quantified the relative
contributions of various sources using the chemical mass balance (CMB)
model. These results from ambient measurements were compared with existing
emission inventories to evaluate the spatial distribution, species-specific
emissions, and source structure of VOCs in Beijing. The measured VOC
distributions revealed a hotspot in the southern suburban area of Beijing,
whereas current emission inventories suggested that VOC emissions were
concentrated in downtown areas. Compared with results derived from ambient
measurements, the annual inventoried emissions of oxygenated VOC (OVOC)
species and C2–C4 alkanes may be underestimated, while the emissions of
styrene and 1,3-butadiene may be overestimated by current inventories.
Source apportionment using the CMB model identified vehicular exhaust as the
most important VOC source, with the relative contribution of 49%, in
good agreement with the 40–51% estimated by emission inventories. The
relative contribution of paint and solvent utilization obtained from the CMB
model was 14%, significantly lower than the value of 32% reported by
one existing inventory. Meanwhile, the relative contribution of liquefied
petroleum gas (LPG) usage calculated using the CMB model was 6%, whereas
LPG usage contribution was not reported by current emission inventories.
These results suggested that VOC emission strengths in southern suburban
area of Beijing, annual emissions of C2–C4 alkanes, OVOCs and some alkenes,
and the contributions of solvent and paint utilization and LPG usage in
current inventories all require significant revisions. |
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