Grantee Research Project Results
Amines in Ambient Particle Formation and GrowthEPA Grant Number: FP917315
Title: Amines in Ambient Particle Formation and Growth
Investigators: Bzdek, Bryan R
Institution: University of Delaware
EPA Project Officer: Just, Theodore J.
Project Period: September 1, 2011 through August 31, 2014
Project Amount: $126,000
RFA: STAR Graduate Fellowships (2011)
Research Category: Academic Fellowships , Fellowship - Clean Air
A significant component of the global aerosol budget arises from new particle formation, whereby gaseous species condense to form new particles and then grow into the size range where they may affect global climate; however, the mechanisms for this process are poorly understood. This project aims to elucidate the roles of nitrogen-containing species on new particle formation so as to clarify mechanisms for particle formation in the atmosphere and enable modelers to better predict aerosol levels under varying conditions.Approach:
This project involves the application of mass spectrometry to study the composition and reactivity of small atmospherically relevant clusters and particles with amines and ammonia. One portion of this project involves use of Fourier transform ion cyclotron resonance mass spectrometry to examine the reactivity of small ammonium bisulfate clusters with various amines. Another portion involves using a flow tube apparatus coupled to a home-built aerosol mass spectrometer to examine the kinetics of amine exchange for ammonia and nanoparticle growth by amines and organic acids. The third portion of this project involves analysis of field measurements of ambient nanoaerosol composition to test predictions resulting from the laboratory measurements.Expected Results:
Results from experiments on small molecular clusters already indicate that amine-ammonia chemistry should be important and observable in small ambient clusters. Flow tube experiments will explore the hypothesis that amine-organic acid salts may be important contributors to nanoparticle growth in the atmosphere and explain the surprising presence of amines in nanoparticles arising from new particle formation. Finally, the field measurements will serve to test hypotheses arising from the laboratory measurements and to adjust understanding of the mechanisms underlying new particle formation.
Potential to Further Environmental / Human Health Protection
An improved understanding of the chemical mechanisms underlying new particle formation will have several benefits related to environmental and human health protection. First, the quantitative kinetics results will enable modelers to more accurately predict ambient aerosol levels under varying conditions, which will improve models of ambient cloud cover and ambient exposure in different environments. Second, the results of this project will indicate species that are significant to the formation and growth of ambient aerosol and will enable regulators to make informed decisions regarding regulation of relevant gasphase species to reduce particulate matter levels.
aerosol kinetics, amine, new particle formation, nucleation,