Grantee Research Project Results
2005 Progress Report: Secondary Aerosol Formation from Gas and Particle Phase Reactions of Aromatic Hydrocarbons
EPA Grant Number: R831084Title: Secondary Aerosol Formation from Gas and Particle Phase Reactions of Aromatic Hydrocarbons
Investigators: Kamens, Richard M.
Institution: University of North Carolina at Chapel Hill
EPA Project Officer: Chung, Serena
Project Period: July 28, 2003 through July 27, 2006 (Extended to July 27, 2008)
Project Period Covered by this Report: July 28, 2004 through July 27, 2005
Project Amount: $400,000
RFA: Measurement, Modeling, and Analysis Methods for Airborne Carbonaceous Fine Particulate Matter (PM2.5) (2003) RFA Text | Recipients Lists
Research Category: Particulate Matter , Air Quality and Air Toxics , Air
Objective:
This research project focuses on the elucidation of the fundamental chemistry that brings about the secondary organic aerosol (SOA) formation from aromatic reactions in the atmosphere. The objective of this research project is to develop a “new generation” aromatic chemical mechanism that can integrate newly discovered particle phase heterogeneous processes with the known gas phase chemistry, as a unified, multiphase, chemical reaction mechanism, which will ultimately permit the prediction of SOA formation in the aromatic system.
Progress Summary:
During this reporting period, we have:
- Continued to develop a working chemical mechanism for toluene that reasonably predicts the gas phase chemistry and also has potential to predict the SOA formation from toluene oxidation. Modeling approaches developed from the d-limonene reaction and a-pinene nucleation systems were adapted to the toluene system.
- Conducted additional toluene/NOX daytime outdoor smog chamber experiments at different initial concentrations and environmental conditions.
- Performed other experiments with o-xylene and 1,3,5-trimethybenzene.
- Developed a method to measure the amount of particle off-gassing and associated particle to gas energy barriers of toluene oxygenated aldehyde products.
An illustration of our preliminary model’s ability to fit the chamber aerosol data and particle nucleation is shown in Figures 1 and 2.
Figure 1. Model Simulation (dash) of Total Measured Particle Mass (symbols) From Toluene Reacting in Natural Sunlight in the Presence of NOX
Figure 2. Nucleation of Toluene Reaction Products in the Presence of Background Aerosols
Future Activities:
We will continue with detailed product analysis of the samples from the chamber experiments. We also will continue with our modeling of p-xylene and trimethyl benzene systems. If it is possible, we will try to integrate these compounds into one combined model.
Journal Articles on this Report : 2 Displayed | Download in RIS Format
| Other project views: | All 8 publications | 6 publications in selected types | All 6 journal articles |
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Lee S, Kamens RM. Particle nucleation from the reaction of α-pinene and O3. Atmospheric Environment 2005;39(36):6822-6832. |
R831084 (2005) R831084 (2006) R831084 (2007) R831084 (Final) |
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Leungsakul S, Jeffries HE, Kamens RM. A kinetic mechanism for predicting secondary aerosol formation from the reactions of d-limonene in the presence of oxides of nitrogen and natural sunlight. Atmospheric Environment 2005;39(37):7063-7082. |
R831084 (2005) R831084 (2006) R831084 (2007) R831084 (Final) R828176 (Final) |
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Supplemental Keywords:
secondary organic aerosol formation, aromatics, modeling, organic particle formation, aromatic compounds, gas phase chemistry, particle phase reactions,, RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Environmental Chemistry, Monitoring/Modeling, Atmospheric Sciences, Environmental Monitoring, air quality, secondary organic aerosol, particle phase reactions, gas phase chemistry, environmental measurement, Toluene, organic chemistry, aerosol analyzersProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.