Supplement: Heterogeneous Aging Mechanisms of Combustion and Biomass Burning Emissions

Supplement: Heterogeneous Aging Mechanisms of Combustion and Biomass Burning Emissions Abstract The Environmental Chemical Sciences Program in the Division of Chemistry and the Atmospheric Chemistry Program in the Division of Atmospheric and Geospace Sciences jointly support this project by Professor Marcelo Guzman and his students. They study the reaction of gases in the environment (for example, ozone with pollutants emitted during combustion (e.g., of power plants) and forest fires. Both types of emissions cause tiny particles to be suspended in air. These particles play a major role in visibility and air quality. The project investigates oxidation reactions occurring on the surface of particles because chemical reactions on the surface can further increase or decrease visibility and air quality. This research provides interdisciplinary training in environmental and atmospheric chemistry to graduate and undergraduate students in Kentucky. The project includes a collaboration with the Lexington-Fayette School District by offering hands-on activities in atmospheric chemistry for Kindergarten and first- and second-graders. Thus, Kentucky''s citizens learn about the societal impacts of pollution and the interaction of sunlight with gases and particles in the environment. The project develops a mechanistic understanding of chemical processes that generate complex organic matter via accretion in the troposphere. The production of reactive species and their coupling to form oligomers is being studied. These reactions take place at the air-water and air-solid interfaces. The research addresses the effects of relative humidity on the fate of pollution from combustion and biomass-burning emissions. The team investigates oxidation reactions (with ozone, HO and NO3 radicals) on the surface of aqueous microdroplets and thin solid films under realistic atmospheric conditions. Multiple analytical tools are applied, including several spectroscopy techniques, mass spectrometry, and chromatographic analyses. The project investigates the effects of substituent variation (structural variation) on chemical reactivity of molecules emitted during combustion and biomass-burning toward gas-phase oxidizers. The anticipated outcome of the project is a deeper understanding of oxidation mechanisms with relevance to environmental, biochemical, and technological processes.