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RECORD NUMBER: 13 OF 20

OLS Field Name OLS Field Data
Main Title Proposed Mechanisms on the Formation of Acidic Aerosols from Precursors.
Author Durham, J. L. ; Brock, J. R. ;
CORP Author Environmental Protection Agency, Research Triangle Park, NC. Atmospheric Sciences Research Lab.;Texas Univ. at Austin.
Year Published 1985
Report Number EPA/600/D-85/199;
Stock Number PB86-100765
Additional Subjects Aerosols ; Acids ; Photochemical reactions ; Particles ; Air pollution ; Sulfuric acid ; Nitric acid ; Organic acids ; Nucleation ; Condensation ; Free radicals ; Hydrogen peroxide ; Ozone ; Particle size distribution ; Oxidation reduction reactions ; Troposphere ; Concentration(Composition) ; Urban areas ; Chemical reaction mechanisms ; Atmospheric chemistry ; Acid rain
Holdings
Library Call Number Additional Info Location Last
Modified
Checkout
Status
NTIS  PB86-100765 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 06/21/1988
Collation 21p
Abstract
Atmospheric particles acidify through the processes of nucleation, condensation, coagulation, and gas-particle chemical reactions. The gas-phase pathway depends on the generation of free radicals that oxidize sulfur dioxide, nitrogen dioxide, and organic compounds to acids, followed by either nucleation or condensation. The aqueous-phase pathway acidification proceeds through the reactions of dissolved reductants and oxidants. The pathways for accumulation of sulfuric acid, nitric acid, and organic acids in particles may differ in responses to factors such as liquid water content of the particles and mass accommodation coefficients of reactants. Laboratory chemical kinetic results indicate that photochemical gas-phase and co-absorbed oxidant reaction pathways for S(IV) may be important simultaneously, for example, in industrial-urban air during the summer. However, during the night and during the winter, aqueous-phase pathways should dominate. Laboratory investigations of the oxidation of nitrogen dioxide indicate that the gas-phase photochemical pathway is important, but the aqueous-phase is not. Gas-phase photochemical oxidation of organics is generally established, but the aqueous-pathways have not received sufficient attention to establish their importance.