Title: | Atmospheric organic aerosol production by heterogeneous acid-catalyzed reactions |
Author(s): | Jang M; Czoschke NM; Northcross AL; |
Address: | "Department of Environmental Sciences and Engineering, CB# 7431, Rosenau Hall, The University of North Carolina at Chapel Hill Chapel Hill, NC 27599, USA. mjang@email.unc.edu" |
ISSN/ISBN: | 1439-4235 (Print) 1439-4235 (Linking) |
Abstract: | "Exploratory evidence from our laboratories shows that acidic surfaces on atmospheric aerosols lead to very real and potentially multifold increases in secondary organic aerosol (SOA) mass and build-up of stabilized nonvolatile organic matter as particles age. One possible explanation for these heterogeneous processes are the acid-catalyzed (e.g., H2SO4 and HNO3) reactions of atmospheric multifunctional organic species (e.g., multifunctional carbonyl compounds) that are accommodated onto the particle phase from the gas phase. Volatile organic hydrocarbons (VOCs) from biogenic sources (e.g., terpenoids) and anthropogenic sources (aromatics) are significant precursors for multifunctional organic species. The sulfur content of fossil fuels, which is released into the atmosphere as SO2, results in the formation of secondary inorganic acidic aerosols or indigenous acidic soot particles (e.g., diesel soot). The predominance of SOAs contributing to PM2.5 (particulate matter, that is, 2.5 microm or smaller than 2.5 microm), and the prevalence of sulfur in fossil fuels suggests that interactions between these sources could be considerable. This study outlines a systematic approach for exploring the fundamental chemistry of these particle-phase heterogeneous reactions. If acid-catalyzed heterogeneous reactions of SOA products are included in next-generation models, the predicted SOA formation will be much greater and have a much larger impact on climate-forcing effects than we now predict. The combined study of both organic and inorganic acids will also enable greater understanding of the adverse health effects in biological pulmonary organs exposed to particles" |
Keywords: | Aerosols/*chemistry Air Pollutants/chemistry *Atmosphere Catalysis Hydrogen-Ion Concentration Organic Chemicals/*chemistry; |
Notes: | "MedlineJang, Myoseon Czoschke, Nadine M Northcross, Amanda L eng Research Support, U.S. Gov't, Non-P.H.S. Review Germany 2004/12/08 Chemphyschem. 2004 Nov 12; 5(11):1647-61. doi: 10.1002/cphc.200301077" |