Hygiene III The Hygiene Hypothesis ENVR 890 Mark D. Sobsey Spring 2007.
Envr 890: Lecture 1
description
Transcript of Envr 890: Lecture 1
Envr 890: Lecture 1Envr 890: Lecture 1
Department of Environmental Science and Engineering
UNC, Chapel Hill
http://www.unc.edu/courses/2008fall/envr/890/001/
Class Objective:Class Objective: Begin Development of a Begin Development of a Secondary Organic Aerosol mechanism Secondary Organic Aerosol mechanism for Isoprene and learn how to run the for Isoprene and learn how to run the
ESE Aerosol Smog Chamber in PittsboroESE Aerosol Smog Chamber in Pittsboro
C=C-C=CC=C-C=CH
HCH3
H
HH
Class Objective:Class Objective: Begin Development of a Begin Development of a Secondary Organic Aerosol mechanism Secondary Organic Aerosol mechanism for Isoprene and learn how to run the for Isoprene and learn how to run the
ESE Aerosol Smog Chamber in PittsboroESE Aerosol Smog Chamber in Pittsboro What are organic aerosols? What fraction of the aerosol environment
are they? What do we need to build a chemical
mechanism? What do we need to measure? Start collecting papers on Isoprene and
SOA formation
Aerosol Associated Organics:Aerosol Associated Organics: An Historical PerspectiveAn Historical Perspective
Secondary organic aerosols how much Secondary organic aerosols how much is out thereis out there
Modeling approaches for SOAModeling approaches for SOA AnalysisAnalysis SamplingSampling Where do we go from hereWhere do we go from here
What should you get from these What should you get from these lectures?lectures?
What are SOA Why are they important? How much is there?
Are they a constant fraction of TSP or the organic fraction?
How are they measured? How are they formed? Which
compounds are involved? How do we model them?
What should you get from these What should you get from these lectures?lectures?
How do we model them?How do we model them? What is equilibrium partitioningWhat is equilibrium partitioning What is a numerical solution What is a numerical solution
approachapproach How does this differ from a chemical How does this differ from a chemical
mechanism approach?mechanism approach? What are vapor pressure and activity What are vapor pressure and activity
coefficients?coefficients? Which compounds contribute to SOA?Which compounds contribute to SOA? What are two major unknowns in What are two major unknowns in
current models?current models?
Reasons to study secondary organic aerosol formation (SOA)
Global model calculations are sensitive to fine particles in the atmosphere
Biogenic SOA particles serve as sites for the condensation of other reacted urban organics
The result is haze and visibility reductions
Do SOA push us beyond the AAQS PM2.5 standard? Are SOA more/less toxic than primary particle emissions?
red= +2oC, yellow =+3 oC, blue = +10C
red= +2oC, yellow =+3 oC, blue = +10C
Thailand
Beijing, in July 1987
Beijing, April 2006
A sunny day in Beijing, April 2006
Air Pollution in Northern Thailand
ChiangMai is similar to Los Angeles in the US; it is surrounded by mountains
MasteryMastery of Fire of Fire
400,000 years ago in Europe 400,000 years ago in Europe
100,000 years ago in Africa100,000 years ago in Africa
M. N. Cohne, 1977M. N. Cohne, 1977
From a global perspective, fire From a global perspective, fire results in huge emissions of black results in huge emissions of black carbon into the atmospherecarbon into the atmosphere
Biomass burningBiomass burning 6x106x1012 12 gg Fossil fuel burningFossil fuel burning 7x107x1012 12 gg
Biogenic aerosolsBiogenic aerosols 13-60x1013-60x101212gg
What is the Composition of Particulate Matter???
Composition of LA Particulate Matter (adjusted for smoggy days)((Rogge &Cass et al, 1993, Turpin et al, 1991)
NH4 10nitrate 20sulfate 11EC 6other 23OC 30
Percent mass
What are Organic AerosolsWhat are Organic Aerosols??
organic liquid layer
inner solid core inorganic/carbon
H2O
H2SO4
Semi-volatile organics
What fraction of ambientParticulate matter is organic???
Fresh wood soot (0.5 m scale)
Benzo[a]fluorene
Benzo[ghi]perylene
Naphthalene
Associated with combustion emissionsAre PAHs
Professor Grimmer fractionated Professor Grimmer fractionated different exhaust extractsdifferent exhaust extracts
PAH 2&3 rings
PAHs>3 rings
Total
Total-PAHs
uv orfluorescencedetector
HPLCTotal
hexane MeCl2 ACN
painted on the skin of micepainted on the skin of mice implanted in the lungs of ratsimplanted in the lungs of rats
0
10
20
30
40 %
can
cers
TotalTotal-PAHs
PAHs 2&3 ringsPAHs > 3 rings
rat lungs Mouse-skin
0
10
20
30
40 %
can
cers
TotalTotal-PAHs
PAHs 2&3 ringsPAHs > 3 rings
rat lungs Mouse-skin
Total minus the Total minus the PAH fractionPAH fraction
0
10
20
30
40 %
can
cers
TotalTotal-PAHs
PAHs 2&3 ringsPAHs > 3 rings
rat lungs Mouse-skin
0
10
20
30
40 %
can
cers
TotalTotal-PAHs
PAHs 2&3 ringsPAHs > 3 rings
rat lungs Mouse-skin
In the 1980s many studies were showing In the 1980s many studies were showing that combustion particle extracts that combustion particle extracts expressed Ames bacterial mutagenicityexpressed Ames bacterial mutagenicity
Atmospheric reactions and aging Atmospheric reactions and aging could could alter the mutagenic responses of alter the mutagenic responses of combustion particlescombustion particles
aged wood smoke +O3+NO2
aged wood smoke +NO2
fresh wood smoke
0
100
200
300
400
500
600
700
reve
rta
nts
/pla
te
0 100 200 300 400 500 600 ug extract/plate
Kamens et al, ES&T, 1984,1985
Nitro-PAH were implicated in Nitro-PAH were implicated in giving rise to mutagenic giving rise to mutagenic increases increases
NO2
Gas Phase PAH reactionsGas Phase PAH reactions NPAH NPAH((Arey and Atkinson et al.)Arey and Atkinson et al.)
Fluoranthene
2-nitrofluoranthene
NO2
+ H2O
+ OH HOH
+ NO2
HOH
NO2 H
Kinetic models Kinetic models at UNCat UNC predicted nitro-PAH predicted nitro-PAH in the particle phase from gas phase PAH in the particle phase from gas phase PAH reactions in sunlight reactions in sunlight (Fan et al., Atmos. (Fan et al., Atmos. Envir.1995, 1996)Envir.1995, 1996)
NONO22
Do other atmospheric reactions Do other atmospheric reactions bring about the production of new bring about the production of new aerosol matter???? aerosol matter????
Secondary organic Secondary organic aerosolsaerosols (SOA)(SOA) are organic are organic compounds thatcompounds that reside in the reside in the aerosol phaseaerosol phase as a result of as a result of atmospheric reactions that occur in atmospheric reactions that occur in
either theeither the gasgas or or particle particle phasesphases..
Do we see any Do we see any chemical chemical evidence for SOA formation?evidence for SOA formation?
F.W.Went published papers on biogenic emissions from vegetation over 40 years ago.
He posed the question, “what happens to the 17.5x107 tons of terpene-like hydrocarbons or slightly oxygenated hydrocarbons once they are in the atmosphere each year?”
Went suggests that terpenes are removed from the atmosphere by reaction with ozone
attempts to demonstrate “blue haze” formation
Went suggests that terpenes are removed from the atmosphere by reaction with ozone
attempts to demonstrate “blue haze” formation by adding crushed pine or fir needles to a jar with dilute ozone.
Over a eucalyptus forest in Over a eucalyptus forest in Portugal Portugal Kavouras et al.Kavouras et al. (1998,1999)(1998,1999) show evidence for show evidence for terpene reaction products in terpene reaction products in aerosolsaerosols
Terpenes products
Kavouras et al, 1998 ng m-3
pinic acid 0.4 - 85pinonic acid 9 - 141norpinonic acid 0.1 - 38Pinonaldehyde 0.2 - 32
Nopinone 0.0 - 13
-pinene -pinene
Turpin and co-workersTurpin and co-workers
In the LA area (estimated on smoggy In the LA area (estimated on smoggy
days from days from OC OC //ECEC ratios ratios), as much as ), as much as 50 - 50 - 80%80% of the of the aerosolaerosol organic carbonorganic carbon comes from comes from secondary aerosol secondary aerosol formationformation (1984 and 1987 samples) (1984 and 1987 samples)
In Atlanta in 1999, SOA averaged 46% of the In Atlanta in 1999, SOA averaged 46% of the total OC but with highs of 88% total OC but with highs of 88%
Turpin Approach for SOA formationTurpin Approach for SOA formation The primary aerosol elemental carbon The primary aerosol elemental carbon (EC)(EC)pripri and and
particle organic content particle organic content (OC)(OC)pripri in an un-reacted in an un-reacted
airshed are measured and a primary ratio of airshed are measured and a primary ratio of {{OC OC //ECEC}}pripri is determined is determined (Turpin et al for 1984 and 1987 aerosol (Turpin et al for 1984 and 1987 aerosol samples)samples)
Under SOA formation OCUnder SOA formation OCtottot and EC and ECtottot are measured are measured
OCOCsecsec= = OCOCtottot- - OCOCpri pri
OCOCpripri = EC = EC {{OCOC /EC} /EC} pripri
On smoggy days in California ~50 - 80% of the organic On smoggy days in California ~50 - 80% of the organic carbon comes from secondary aerosol formationcarbon comes from secondary aerosol formation
Spyros Pandis also recently looked Spyros Pandis also recently looked at OC/EC ratios (Pittsburgh area)at OC/EC ratios (Pittsburgh area)
He estimates that SOA formation can He estimates that SOA formation can account for 35-50% of the organic account for 35-50% of the organic carboncarbon
OC/EC Ratio and Photochemical Activity
0
2
4
6
8
10
12
14
15-Jul 16-Jul 17-Jul 18-Jul 19-Jul
OC
/EC
Ra
tio
0
10
20
30
40
50
60
70
80
90
100
O3
(p
pb
)
OC/ECO3
Pittsburgh, 2001
Characteristics of carbonaceous aerosols in Beijing, ChinaYele Suna, Guoshun Zhuang, Ying Wang, Lihui Han, Jinghua Guo, Mo Dan, Wenjie Zhang, Zifa Wang, Zhengping Hao, Atmos, Environ. 38 (2004) 5991–6004
coal burning, traffic exhaust, and dustcoal burning, traffic exhaust, and dust from the long-range transportfrom the long-range transport
Mineral aerosol from outsideMineral aerosol from outside Beijing Beijing accounted for 79% of the total PM10 accounted for 79% of the total PM10 minerals and 37% of the PM2.5 in minerals and 37% of the PM2.5 in winter. winter.
Characteristics of carbonaceous aerosols in Beijing, ChinaFengkui Duan, Kebin He, Yongliang Ma, Yingtao Jia,Fumo Yang, Yu Lei, S. Tanaka, T. Okuta, Chemosphere 60 (2005) 355–364
OC/EC ratio (on a 1.5 basis showed that OC/EC ratio (on a 1.5 basis showed that SOC accounted more than SOC accounted more than 50%50% for the total for the total organic carbon. In winter, the SOC organic carbon. In winter, the SOC contribution to OC was also significant, and contribution to OC was also significant, and as high as as high as 40%.40%.
If we look at the IR spectra of aerosols collected from the smoky mountains, they look like lab aerosols from acid catalyzed
particle phase reactions of carbonyls…
0
0.001
0.002
0.003
0.004
0.005
5001000150020002500300035004000
wavelength (cm-1)
ab
so
rba
nc
e (
gly
ox
al)
glyoxal/acid-catalyst
Heterogeneous reactions as seen in Heterogeneous reactions as seen in the IR region (Myoseon Jang)the IR region (Myoseon Jang)
0
0.001
0.002
0.003
0.004
0.005
5001000150020002500300035004000
wavelength (cm-1)
ab
so
rba
nc
e (
gly
ox
al)
-0.1
-0.05
0
0.05
0.1
0.15
ab
so
rba
nc
e (
Sm
ok
y M
ou
nta
ins
)
glyoxal/acid-catalyst
Smoky Mountains SOA
C-O-C bonds
How does the scientific community How does the scientific community treat toxic organics that are in the treat toxic organics that are in the
gas and particle phases ?gas and particle phases ?
In the 1980s In the 1980s Yamasaki, Bidelman, Yamasaki, Bidelman, PankowPankow began to investigate the began to investigate the equilibrium distribution ofequilibrium distribution of PAHs, PAHs, alkanes, and chlorinated organicsalkanes, and chlorinated organics between the gas and the particle between the gas and the particle phases.phases.
K PAH
PAH TSPp
part
gas
PAHPAHgas gas + surface + surface PAH PAHpartpart
K P A H
P A H y
g as
p art
TSP
Yamasaki (1982)Yamasaki (1982)
Collects Hi-vol filters+PUFCollects Hi-vol filters+PUF
filter
PUF
Yamasaki (1982)Yamasaki (1982)
Collects Hi-vol filters+PUFCollects Hi-vol filters+PUF Analyzes for PAHsAnalyzes for PAHs
filter
PUF
Yamasaki (1982)Yamasaki (1982)
Collects Hi-vol filters+PUFCollects Hi-vol filters+PUF Analyzes for PAHsAnalyzes for PAHs
BaABaA
log Klog Kyy
1/Tx10001/Tx1000
filter
PUF
Yamasaki (1982)Yamasaki (1982)
filter
PUF
Collects Hi-vol filters+PUFCollects Hi-vol filters+PUF Analyzes for PAHsAnalyzes for PAHs
BaABaA
log Klog Kyy
1/Tx10001/Tx1000
Yamasaki’s relationshipYamasaki’s relationship
This gives a log KThis gives a log Kyy = -a(1/T)+ b = -a(1/T)+ b which is which is
compound specificcompound specific
Ideally from the regression values of Ideally from the regression values of a and b,a and b, one can estimate the partitioning of a given one can estimate the partitioning of a given compound in any atmosphere at a given temp. compound in any atmosphere at a given temp. and TSPand TSP
Kgas
part TSPy [ ]
[ ] /
log Klog Kp p = -log P= -log Pssoo + const. + const.
Relate solid saturated vapor pressures with Kp
log Pso
log Kp
naphthalenenaphthalene
BaPBaP
PyrenePyrene
log Klog Kp p = -log P= -log PooLL + const. + const.
PAHs,PAHs, alkanesalkaneschlorinatedchlorinated organics organics
slope = -1
log Po(L)
log Kp
Problems with the theoryProblems with the theory
many aerosols are composed of 40-100% many aerosols are composed of 40-100% organicsorganics
This gives much more than a mono-layer This gives much more than a mono-layer of coverageof coverage
log Klog Kpp= m log P= m log Poo(L)(L)+ c+ c
KR T
p M wpLo
7 5 0 1
1 0 9
. fom
In 1994 James Pankow fixes the theory for liquid particles
Can we chemically / kinetically Can we chemically / kinetically model SOA Formation???model SOA Formation???
Numerical fittingNumerical fitting Semi-explicitSemi-explicit
From a modelingFrom a modeling perspective perspective Equilibrium Organic Gas-particle Equilibrium Organic Gas-particle partitioningpartitioning provides a context for provides a context for addressing SOA formationaddressing SOA formation
Gas/Particle PartitioningGas/Particle Partitioning
particleParticle typeCompound Temperature
Humidity
gas
Thermodynamic Equilibrium?
TSPC
CK
gas
partp
Cgas +surf Cpart
Kp will vary with 1/Po
Odum-Seinfeld Model SOA modelOdum-Seinfeld Model SOA model
Y= MY= Moo / / HC HC
HC = HC = ROG ROG
Y Y MK
K Mii
o
i om i
om i oi
,
,( )1
Odum theory
- pinene- NOx experiments by Odum
Y Mo(g/m3) 1 0.012 1
2 0.028 7
3 0.059 22
4 0.067 34
5 0.078 38
6 0.122 83
7 0.125 94
Y MK
K MM
K
K Mo
om
om oo
om
om o
1 1
1
2 2
21 1,
,
,
,( ) ( )
Y = M= Moo / / HC HC
-pinene
Y MK
K MM
K
K Mo
om
om oo
om
om o
1 1
1
2 2
21 1,
,
,
,( ) ( )
Y MK
K MM
K
K Mo
om
om oo
om
om o
1 1
1
2 2
21 1,
,
,
,( ) ( )
Numerical fitting values for Kom and for OH, O3, and NO3 reactions with terpenes and sesquiterpenes were developed by Griffin and Sienfeld et al.
From the averages for OH, O3, and NO3 , the amounts of atmospherically reacted terpenes and sesquiterpenes were estimated ( HC HC ) ) by Griffin and Sienfeld et al.
Y= MY= Moo / / HC HC
Globally, biogenic emissions
13-24x1012g y-1 of aerosol mass
Gives little insight into the chemical nature of products involve in SOA formation
From a global perspective, fire From a global perspective, fire results in huge emissions of black results in huge emissions of black carbon into the atmospherecarbon into the atmosphere
Biomass burningBiomass burning 6x106x1012 12 gg Fossil fuel burningFossil fuel burning 7x107x1012 12 gg
Biogenic aerosolsBiogenic aerosols 13-60x1013-60x101212gg
Semi explicit models link gas and particle phases
C=OO
cis-pinonaldhyde
particleC=OO
Gas phase reactions
K
R T
p M wpLo
7 5 0 1
1 0 9
. fom
Kp = kon/koff
[ [ iigasgas] + [part] ] + [part] [ [ iipartpart]] kon
koff
particle
kon
koff
C=OO
Kp = kon/koff
koff = kbT/h e -Ea/RT
CHOOO
CH3
OO
O
Criegee2
Criegee1OO O
-pinene
O3
COOHCOOH
pinic acid
+ otherproducts
O
pinonic acid
CHOO
COOH
+ CO, HO2, OH
COOHO
norpinonaldehyde
norpinonic acid
Mechanism
pinonaldehyde
OH
OO
O2
+
(a)(b)
(c)
(d)
(e)
pinonaldehyde
acetone
O
OO.
NO2NO
O
O.
pinald-oo
OH
pinonic acid
O
pinO2
OO.
NO2
NO
organic nitrate
+HO2
+NO2
pinald-PAN
=o
=o
=o
=o
=o
=o
=o
OO.
O2
=o
OO=C8=O
C8-oo.
O2
NO2NO
O
+ h
+
+CO+HO2=o
OO.
NO2NO
=o
=o+HO2
+ h
NO2NO
=o
OO.
C8-oo. (C8O2)
+CO+HO2
NO2
NO
(f)
(g)
CO2+
pinO2H2O+
+HO2
O2
OO
H3C-OO.
+oxygenated products
+NO2
+H3C-OONO2PAN
(stab-oxy)
+HO2
norpinonaldehyde
OOH
O=o+
pin-ooH
+OH
O
OO.
=o
NO2
NO
+CO2
norpinaldPAN
+NO2
+HO2
norpinonic acid+norpin-ooH
O
OONO2
=o
+O2
ONO2
=o
+
=o
ONO2
+
organic nitrate
Overall kinetic MechanismOverall kinetic Mechanism
linked gas and particle phase rate linked gas and particle phase rate expressionsexpressions
Particle Phase reactions
particle
C=OO
cis-pinonaldhyde
C=OO
polymers
Gas phase reactions
Particle Phase reactions
particle
C=OO
cis-pinonaldhyde
C=OO
polymers
Gas phase reactions
Particle Phase reactions
C=OO
cis-pinonaldhyde
C=OO
polymers
Gas phase reactions
A
B
C
D
[H3O+]
O
OOH
O
O
OH
O
OH
O
[H3O+]
O
OH
OH
OO
O
O
O O
HO
O
O
1
[H3O+]
4
2
OH
H2C
O
O O
[H3O+]
O
O
O
HO
O O
HO
3
O
O
OH
O
O CH2
O
O
OH
2
2
9
O O
HO
4
O
6
O
HOb
a
a
5
b
7 8
O
O
2
2
10 11
A
B
C
D
[H3O+]
O
OOH
O
O
OH
O
OH
O
[H3O+]
O
OH
OH
OO
O
O
O O
HO
O
O
1
[H3O+]
4
2
OH
H2C
O
O O
[H3O+]
O
O
O
HO
O O
HO
3
O
O
OH
O
O CH2
O
O
OH
2
2
9
O O
HO
4
O
6
O
HOb
a
a
5
b
7 8
O
O
2
2
10 11
pinonaldehyde
2 x
Pinonaldehyde dimerization
ESI-QTOF mass spectrum of SOA from ESI-QTOF mass spectrum of SOA from reaction of reaction of -pinene + O-pinene + O33 + acid seed + acid seed
aerosolaerosol (Tolocka et. al (Tolocka et. al., ., 20042004))
200 300 400 500 600 700 800 900 1000
m/z
337.
18 351.
18
361.
21
377.
2
393.
2
407.
2
423.
2
439.
2
453.
21 489.
32
300 320 340 360 380 400 420 440 460 480 500
321.
21
m/z
17
7.0
7
19
1.1
2 20
7.1
1
22
5.1
12
33
.14
24
5.1
2
25
5.1
82
61
.11
28
9.1
8
30
1.1
8
31
3.2
3
32
7.1
6
34
1.2
35
9.2
36
0.2
150 200 250 300 350
Inte
nsity,
A.U
.
m/z
O
OH
O
H2C
O
177
207
341
261289
91
77
.07
19
1.1
2 20
7.1
1
22
5.1
12
33
.14
24
5.1
2
25
5.1
82
61
.11
28
9.1
8
30
1.1
8
31
3.2
3
32
7.1
6
34
1.2
35
9.2
36
0.2
150 200 250 300 350
Inte
nsity,
A.U
.
m/z
O
OH
O
H2C
O
177
207
341
261289
9
M Na+ (ESI-QTOF Tolocka et al, 2003)
Particle phase pinonaldehyde dimers Particle phase pinonaldehyde dimers from from -pinene +O-pinene +O3 3 on on acid particlesacid particles
Similar results were obtained by Hartmut Herrmann’s Similar results were obtained by Hartmut Herrmann’s group group (Atmos Envir, 2004)(Atmos Envir, 2004)
Chemical SystemChemical System
-pinene
+ NOx+ sunlight + ozone----> aerosols
Simulations of outdoor smog Simulations of outdoor smog chamber datachamber data
0.95 ppm -pinene + 0. 44ppm NOx
O3NO
NO2
NO2
model
data
Time in hours EST
pp
mV
Gas phase pinonaldehdye
OO
mg
/m3
Time in hours EST
Particle phase
model TSP
mg
/m3
Particle phase
model TSP
mg
/m3
Measured particle mass vs. model
data
Time in hours EST
Much lower terpene concentrations Much lower terpene concentrations
Different background aerosols which Different background aerosols which have different chemical and physical have different chemical and physical propertiesproperties
Low volatility gas phase products will Low volatility gas phase products will have different interactions with have different interactions with different pre-existing particlesdifferent pre-existing particles
The Real AtmosphereThe Real Atmosphere
New UNC aerosol smog chamberNew UNC aerosol smog chamber
Dual 270mDual 270m33 chamber chamber fine particle t fine particle t 1/21/2 >17 h >17 h
0.1 ppmV Toluene 0.1 ppmV Toluene + 0.1 ppm NOx+ 0.1 ppm NOx
072705S
0.0
0.1
0.2
0.3
0.4
0.5
8:00 10:00 12:00 14:00 16:00
LDT (hours)
To
luen
e, N
Ox-
O3
con
c (p
pm
)
-20
-10
0
10
20
Par
ticl
e m
assc
on
c (
g/m
3)
TSP
O3
Toluene
TotNO3
NO
NO
2
Toluene SOA behavior Toluene SOA behavior within an atmospheric HC within an atmospheric HC
mixturemixture
SOASOA from 0.1 ppmV from 0.1 ppmV toluene+0.1ppm NOx toluene+0.1ppm NOx
w/wo 3ppmC HC mixture w/wo 3ppmC HC mixture
0
5
10
15
20
25
8:00 10:24 12:48 15:12 17:36
g/m
3
Without HC mix
SOASOA from terpene mixturesfrom terpene mixtures
0.05 ppmV 0.05 ppmV -pinene-pinene0.02 ppmV d-0.02 ppmV d-
limonenelimonene0.05 ppm NO0.05 ppm NOXX
SOASOA from terpene mixturesfrom terpene mixtures
042006S
-0.01
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.07
6.0 7.5 9.0 10.5 12.0 13.5 15.0
EDT (Hour)
NO
/NO
2 C
on
c (
pp
m)
-0.05
0.00
0.05
0.10
0.15
0.20
0.25
0.30
O3
Co
nc
(p
pm
)
NO dataNO2 dataNO simNO2 simO3 dataO3 sim
SOA SOA from terpene mixturesfrom terpene mixtures
0.00
0.01
0.02
0.03
0.04
0.05
0.06
6.0 7.5 9.0 10.5 12.0 13.5 15.0EDT (Hour)
AP/
d-L
im c
onc
(ppm
)
0
20
40
60
80
100
120
TSP
Con
c (u
g/m
3)
A-P
d-lim
a-P sim
d-Lim
TSP d=1.2
TSP Sim
042006S
How do we represent changing How do we represent changing particle size distributions??particle size distributions??
Need to integrate particle sizes into our Need to integrate particle sizes into our mechanismsmechanisms
0.E+00
1.E+03
2.E+03
3.E+03
4.E+03
1 10 100 1000
diameter, nm
#/cc
7.5 nm particles
0.E+00
1.E-03
2.E-03
3.E-03
4.E-03
1 10 100 1000
minutes
con
c
pinald
pinacid
diacid
oxypinald
oxypinacid
pinalic
pinald-PAN
OH-AP-NO3
15 nm particles
0.E+00
5.E-04
1.E-03
2.E-03
2.E-03
3.E-03
1 10 100 1000
minutes
con
c
pinald
pinacid
diacid
oxypinald
oxypinacid
pinalic
pinald-PAN
OH-AP-NO3
10 100 10001
1 10 100 1000nm
minutes
mas
sm
ass
7.5 nm particles
15 nm particles
Model Simulations Model Simulations of UNC of UNC
Toluene/NOx Toluene/NOx ExperimentsExperiments
O3-pinene
10 ppbV 10 ppbV -pinene +40 ppb O-pinene +40 ppb O33
610 17 29 50
85
146
20.5
3 hr
s
02468
1012
14
Nu
mb
er o
f P
arti
cles
/cc
Particle size (nm)
South Chamber particle distributions
20.53 hrs
20.83 hrs
6 8
12
17
24
35
50
71
10
2
14
6
20
9 20.88 hrs
0
20
40
60
80
Nu
mb
er
of
Pa
rtic
les
/cc
Particle size (nm)
South Chamber nucleaton particle distributions
20.88 hrs
20.93 hrs
20.83 hrs
20.98
new particles/cc = 3x107x -pinene reacted1.77
# stable nuclei = Ax10[reacted organic] x [H2SO4]n
Gas phase Sulfuric Acid and nucleation
# stable nuclei = Ax10[reacted organic] x [H2SO4]n
Final point:How important is Isoprene in
the formation of SOA?
C=C-C=CC=C-C=CH
HCH3
H
HH
Primary and SecondaryContributions to Ambient PM in the Midwestern United States
Lewandowki, and Schauer, et al., ES&T 2008
Sesquiterpenes (C15H24)
On a reacted mass basis,On a reacted mass basis, b- b-caryophyllene and a-humulene caryophyllene and a-humulene have much higher have much higher aerosolaerosol potentials than monoterpenes potentials than monoterpenes
(Griffin et al., 1999).(Griffin et al., 1999).
Yield-carophyllene-carophyllene 17 - 62 17 - 62 %%-humulene-humulene 20 - 67 20 - 67d-limonened-limonene 6 - 23 6 - 23-pinene-pinene 2 - 8 2 - 8-pinene-pinene 4 - 13 4 - 13
# stable nuclei = Ax10[reacted organic] x [H2SO4]n
We do not have an Isoprene in the formation of SOA?
Unique SOA poly-ols from isoprene Unique SOA poly-ols from isoprene reaction with OH reaction with OH
(Magda Claeys et al. Science, 2004)(Magda Claeys et al. Science, 2004)