Skip to main content

LUP Student Papers

LUND UNIVERSITY LIBRARIES

Investigation of possible non-additive behavior in the formation of secondary organic aerosol from a mixture of anthropogenic and biogenic VOC precursors

Falk, John LU (2014) PHYM01 20141
Nuclear physics
Department of Physics
Abstract
Secondary organic aerosol (SOA) mass yields were tested for six combinations of two anthropogenic volatile organic compounds (AVOC); m-xylene & toluene, and three biogenic volatile organic compounds (BVOC); α-pinene, myrcene & isoprene. The purpose was to investigate any non-additive results in SOA formation from mixtures of AVOCs and BVOCs by comparing experimental yield with corresponding two-product model yields. No seed particles were used. Mass and number size distributions from generated SOA was investigated. The measurements were performed by aging the VOC gases using a potential aerosol mass (PAM) chamber and measuring the resulting SOA mass with a scanning mobility particle sizer (SMPS), and to a limited extent an aerosol mass... (More)
Secondary organic aerosol (SOA) mass yields were tested for six combinations of two anthropogenic volatile organic compounds (AVOC); m-xylene & toluene, and three biogenic volatile organic compounds (BVOC); α-pinene, myrcene & isoprene. The purpose was to investigate any non-additive results in SOA formation from mixtures of AVOCs and BVOCs by comparing experimental yield with corresponding two-product model yields. No seed particles were used. Mass and number size distributions from generated SOA was investigated. The measurements were performed by aging the VOC gases using a potential aerosol mass (PAM) chamber and measuring the resulting SOA mass with a scanning mobility particle sizer (SMPS), and to a limited extent an aerosol mass spectrometer (AMS). AMS data was used to calculate an average SOA density of ≈ 2.0 g cm^−3 , although for calculations a value ≈ 1.4 g cm^−3 was used. The VOC air flow was at RH = 30.6±0.3 %, and PAM chamber O3 concentrations were for all experiments 5400 ± 880 ppb. Differences in experimental and model yields were observed with a maximum difference of 30 % and a minimum of 4 %, although for all experiments model yields were mostly or completely inside experimental uncertainty limits, and so no non-additive effects could be concluded. Aging of a mixture with isoprene added showed a factor ≈ 4 decrease in overall number concentration, and a slight shift of mass size distribution to larger particle sizes. The experiment set-up used was also investigated, and showed several shortcomings. Most notably was the uncertainty regarding VOC emission rate, to a part caused by a lack of instrumentation measuring diffusion chamber parameters. (Less)
Please use this url to cite or link to this publication:
author
Falk, John LU
supervisor
organization
course
PHYM01 20141
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Volatile organic compounds, Biogenic, Anthropogenic, Secondary organic aerosol, Non-additive, Flow reactor, Scanning Mobility Particle Sizer
language
English
additional info
Funding for experiments was provided by the Swedish Re-
search Council for Environment, Agricultural Sci-
ences and Spatial Planning (FORMAS) project
'Natural organic aerosols under anthropogenic con-
trol: formation and implications for climate feed-
back' (Reg.Nr. 2011-732).
id
4529898
date added to LUP
2015-05-04 09:24:47
date last changed
2015-12-14 13:32:58
@misc{4529898,
  abstract     = {{Secondary organic aerosol (SOA) mass yields were tested for six combinations of two anthropogenic volatile organic compounds (AVOC); m-xylene & toluene, and three biogenic volatile organic compounds (BVOC); α-pinene, myrcene & isoprene. The purpose was to investigate any non-additive results in SOA formation from mixtures of AVOCs and BVOCs by comparing experimental yield with corresponding two-product model yields. No seed particles were used. Mass and number size distributions from generated SOA was investigated. The measurements were performed by aging the VOC gases using a potential aerosol mass (PAM) chamber and measuring the resulting SOA mass with a scanning mobility particle sizer (SMPS), and to a limited extent an aerosol mass spectrometer (AMS). AMS data was used to calculate an average SOA density of ≈ 2.0 g cm^−3 , although for calculations a value ≈ 1.4 g cm^−3 was used. The VOC air flow was at RH = 30.6±0.3 %, and PAM chamber O3 concentrations were for all experiments 5400 ± 880 ppb. Differences in experimental and model yields were observed with a maximum difference of 30 % and a minimum of 4 %, although for all experiments model yields were mostly or completely inside experimental uncertainty limits, and so no non-additive effects could be concluded. Aging of a mixture with isoprene added showed a factor ≈ 4 decrease in overall number concentration, and a slight shift of mass size distribution to larger particle sizes. The experiment set-up used was also investigated, and showed several shortcomings. Most notably was the uncertainty regarding VOC emission rate, to a part caused by a lack of instrumentation measuring diffusion chamber parameters.}},
  author       = {{Falk, John}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Investigation of possible non-additive behavior in the formation of secondary organic aerosol from a mixture of anthropogenic and biogenic VOC precursors}},
  year         = {{2014}},
}