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Multiphase Chemical Kinetics of NO3 Radicals Reacting with Organic Aerosol Components from Biomass Burning
- Source :
- Environmental Science & Technology
- Publication Year :
- 2012
- Publisher :
- American Chemical Society (ACS), 2012.
-
Abstract
- Multiphase reactions with nitrate radicals are among the most important chemical aging processes of organic aerosol particles in the atmosphere especially at nighttime. Reactive uptake of NO(3) by organic compounds has been observed in a number of studies, but the pathways of mass transport and chemical reaction remained unclear. Here we apply kinetic flux models to experimental NO(3) exposure studies. The model accounts for gas phase diffusion within a cylindrical flow tube, reversible adsorption of NO(3), surface-bulk exchange, bulk diffusion, and chemical reactions from the gas-condensed phase interface to the bulk. We resolve the relative contributions of surface and bulk reactions to the uptake of NO(3) by levoglucosan and abietic acid, which serve as surrogates and molecular markers of biomass burning aerosol (BBA). Applying the kinetic flux model, we provide the first estimate of the diffusion coefficient of NO(3) in amorphous solid organic matrices (10(-8)-10(-7) cm(2) s(-1)) and show that molecular markers are well-conserved in the bulk of solid BBA particles but undergo rapid degradation upon deliquescence/liquefaction at high relative humidity, indicating that the observed concentrations and subsequent apportionment of the biomass burning source could be significantly underestimated.
- Subjects :
- Aerosols
010504 meteorology & atmospheric sciences
Chemistry
Radical
Levoglucosan
Diffusion
Kinetics
food and beverages
General Chemistry
010501 environmental sciences
01 natural sciences
Chemical reaction
Aerosol
Chemical kinetics
chemistry.chemical_compound
Chemical engineering
13. Climate action
Environmental chemistry
Phase (matter)
Environmental Chemistry
Nitrogen Oxides
0105 earth and related environmental sciences
Subjects
Details
- ISSN :
- 15205851 and 0013936X
- Volume :
- 46
- Database :
- OpenAIRE
- Journal :
- Environmental Science & Technology
- Accession number :
- edsair.doi.dedup.....465ea06c19af23446d87b243de982b2c