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| Titel |
Primary and secondary sources of formaldehyde in urban atmospheres: Houston Texas region |
| VerfasserIn |
D. D. Parrish, T. B. Ryerson, J. Mellqvist, J. Johansson, A. Fried, D. Richter, J. G. Walega, R. A. Washenfelder, J. A. Gouw, J. Peischl, K. C. Aikin, S. A. McKeen, G. J. Frost, F. C. Fehsenfeld, S. C. Herndon |
| 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 ; 12, no. 7 ; Nr. 12, no. 7 (2012-04-05), S.3273-3288 |
| Datensatznummer |
250011012
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| Publikation (Nr.) |
 copernicus.org/acp-12-3273-2012.pdf |
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| Zusammenfassung |
| We evaluate the rates of secondary production and primary emission of
formaldehyde (CH2O) from petrochemical industrial facilities and
on-road vehicles in the Houston Texas region. This evaluation is based upon
ambient measurements collected during field studies in 2000, 2006 and 2009.
The predominant CH2O source (92 ± 4% of total) is secondary
production formed during the atmospheric oxidation of highly reactive
volatile organic compounds (HRVOCs) emitted from the petrochemical
facilities. Smaller contributions are primary emissions from these
facilities (4 ± 2%), and secondary production (~3%) and
primary emissions (~1%) from vehicles. The primary emissions from
both sectors are well quantified by current emission inventories. Since
secondary production dominates, control efforts directed at primary
CH2O emissions cannot address the large majority of CH2O sources
in the Houston area, although there may still be a role for such efforts.
Ongoing efforts to control alkene emissions from the petrochemical
facilities, as well as volatile organic compound emissions from the motor
vehicle fleet, will effectively reduce the CH2O concentrations in the
Houston region. We do not address other emission sectors, such as off-road
mobile sources or secondary formation from biogenic hydrocarbons. Previous
analyses based on correlations between ambient concentrations of CH2O
and various marker species have suggested much larger primary emissions of
CH2O, but those results neglect confounding effects of dilution and
loss processes, and do not demonstrate the causes of the observed
correlations. Similar problems must be suspected in any source apportionment
analysis of secondary species based upon correlations of ambient
concentrations of pollutants. |
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