improve ion study and other improve special studies · improve ion study and other improve special...
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![Page 1: IMPROVE Ion Study and Other IMPROVE Special Studies · IMPROVE Ion Study and Other IMPROVE Special Studies Jeffrey L. Collett, Jr. Colorado State University (with contributions from](https://reader034.vdocuments.site/reader034/viewer/2022050717/5e150b9b5eea1e4011724387/html5/thumbnails/1.jpg)
IMPROVE Ion Studyand
Other IMPROVE Special Studies
Jeffrey L. Collett, Jr.Colorado State University(with contributions fromcollaborators at CSU, NPS, and UCDavis)
Funding: NPS/IMPROVE Western Resource Advocates
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Outline
The IMPROVE Ion/Nitrate Study– Motivation– Questions and approach– Findings and implications
Other IMPROVE special studies– Yosemite smoke study– IMPROVE denuder tests– Coarse particle speciation– Mobile air quality lab
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Ion StudyMotivation
Nitrate is animportantcontributor toPM at manylocationsNitrate maybe present infine orcoarsemodesSamplingmethodologyissues
HNO3(g) + NH3(g) NH4NO3(p)
HNO3(g) + NaCl(p) NaNO3(p) + HCl(g)
2 HNO3(g) + CaCO3(p) Ca(NO3)2(p) + CO2 + H2O
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Nitrate inBig Bend
High PM2.5nitrateassociatedwith flowfrom Gulf
Nitratereplacedchloride insea saltaerosol
y = 1.14xR2 = 0.72
y = 0.33xR2 = 0.69
0
20
40
60
80
100
120
140
160
180
200
0 20 40 60 80 100 120 140 160 180 200
Na+(neq/m3)
([Cl- ]+
[NO
3- ] ) o
r [C
l- ] (ne
q/m
3 )([C-]l+[NO3-]) vs [Na+]Sea water ratio(Cl-/Na+)[Cl-] vs [Na+]Linear (([C-]l+[NO3-]) vs [Na+])Linear ([Cl-] vs [Na+])
slope for sea water1.164 ([Cl-]/[Na+])
NaCl NaNO3
HNO3 HCl
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Nitrate in Big Bend
Nitrate foundin coarsemodeparticles
– Mode size~4-5 µm
– Sizedistributionsimilar to Na+
PM2.5 includestail of coarsemode
0
50
100
150
200
250
300
350
0.1 1 10 100
dC/d
log(
Dp)
(neq
/m3) sulfate
0
50
100
150
200
250
0.1 1 10 100
Aerodynam ic Diam eter (µm )
dC/d
log(
Dp)
(neq
/m3)
ammonium
0
5
10
15
20
25
0.1 1 10 100
nitrate
0
5
10
15
20
25
30
0.1 1 10 100
Aerodynam ic Diam eter (µm )
sodium
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0
5
10
15
20
0 5 10 15 20Na+ (neq/m3)
Cl-
or (
(NO
3-)+
(Cl-)
)(n
eq/m
3)
Na+ vs. Cl-
Na+ vs.((NO3-)+(Cl-))
Slope for sea water (1.164)
NH4NO3
Yosemiteresults
Carbon-dominated aerosol(NH4)2SO4 dominant saltNO3
- replaced Cl- in sea salt
0
5
10
15
20
25
30
8/12 8 /13 8 /14 8 /15 8 /16 8 /17 8 /18 8 /19 8 /20 8 /21 8 /22 8 /23 8 /24 8 /25 8 /26 8 /27
neq/
m3
C l- NO 3- Na+
2-week excerpt, PILS 15-min data
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IMPROVE ion special study goals
Determine characteristics of ionic aerosol present atselected IMPROVE sites
– Ionic composition– Ion size distributions– Gas-particle distribution of NH3(g)/NH4
+(p) and HNO3(g)/NO3-(p)
Evaluate IMPROVE ion sampling and analysisapproach
– Combination of field and lab studies– Filter choice, filter extraction method, and denuder protocol
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Ion study locations
San Gorgonio
Bondville
Big Bend
Yosemite
Grand Canyon
Brigantine
Sequoia
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Study equipment
• 24 hr URG PM2.5 cyclone/annular denuder/ filter pack sampler
• MOUDI impactor (10-stage)
• 15 min PM2.5 PILS/IC system• Particle into Liquid Sampler• Ion Chromatograph
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36
31
26
21
16
11
6
1
Conc
entra
tion,
ug/
m3
2/2/
2003
2/3/
2003
2/4/
2003
2/5/
2003
2/6/
2003
2/7/
2003
2/8/
2003
2/9/
2003
2/10
/200
3
2/11
/200
3
2/12
/200
3
2/13
/200
3
2/14
/200
3
2/15
/200
3
2/16
/200
3
2/17
/200
3
2/18
/200
3
2/19
/200
3
2/20
/200
3
2/21
/200
3
2/22
/200
3
2/23
/200
3
Date
NH4+_ug/m3 NO3-_ug/m3 SO4=_ug/m3
Bondville 2/03
NO3- and SO4
2- both importantNH4NO3 in submicron mode
0
10
20
30
40
50
< 0.
18
0.18
-0.3
2
0.32
-0.5
6
0.56
-1.0
1.0-
1.8
1.8-
3.2
3.2-
5.6
5.6-
10.0
10.0
-18.
0
>18.
0
NO3-, neq/m3SO4=, neq/m3Na+, neq/m3NH4+, neq/m3
Aver
age
Con
cent
ratio
n, n
eq/m
3
Aerodynamic Diameter, µm
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San Gorgonio4/03
Large diurnal variabilitySubmicron NH4NO3 dominant
0
5
10
15
20
25
< 0.
18
0.18
-0.3
2
0.32
-0.5
6
0.56
-1.0
1.0-
1.8
1.8-
3.2
3.2-
5.6
5.6-
10.0
10.0
-18.
0
>18.
0
NO3-, neq/m3SO4=, neq/m3Na+, neq/m3NH4+, neq/m3
Aver
age
Con
cent
ratio
n, n
eq/m
3
Aerodynamic Diameter, µM
700
600
500
400
300
200
100
0
Con
cent
ratio
n, n
eq/m
3
NH4+ , neq/m3 NO 3-, neq/m 3 SO 4=, neq/m3
4/4
4/5
4/6
4/7
4/8
4/9
4/10
4/11
4/12
4/13
4/13
4/14
4/15
4/16
4/17
4/18
4/19
4/20
4/21
4/22
4/23
4/24
4/25
4/26
4/27
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30
20
10
0
Con
cent
ratio
n, u
g/m
3
NO3-, ug/m3 SO4=, ug/m3 NH4+, ug/m3 K+, ug/m3
7/2
7/3
7/4
7/5
7/6
7/7
7/8
7/9
7/10
7/11
7/12
7/13
7/14
7/15
7/16
7/17
7/19
7/18
7/20
7/21
7/22
7/23
7/24
7/25
7/26
7/27
7/28
7/29
San Gorgonio 7/03
More regular diurnal variabilitySome days sulfate-dominated
K+ spikes
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Grand Canyon
0
2
4
6
8
10
12
0 2 4 6 8 10
Na+ (neq/m3)
Con
cent
ratio
n (n
eq/m
3)
Cl-NO3- + Cl-sea salt
Grand Canyon MOUDI average
0
2
4
6
8
10
12
< 0.18 0.18 - 0.32 0.32 - 0.56 0.56 - 1.0 1.0 - 1.8 1.8 - 3.2 3.2 - 5.6 5.6 - 10.0 10.0 - 18.0 >18.0
aerodynamic diameter (µm)
neq/
m3
SO4=NH4+NO3-Na+Ca2+
GrandCanyon
Nitrate in coarse modeAppears to beassociated with Na+
and Ca2+
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Sampling and extraction issues
Does water efficiently extractnitrate from nylon filters?
– HNO3 not efficientlyrecovered with waterextraction
– Typically useNaHCO3/Na2CO3
What happens to NH4NO3volatilized from nylon filters?
– HNO3 trapped? Decrease inwater extraction efficiency?
– NH3 lost? Bias in measuredPM2.5 ammonium?
NH4NO3
NH3(g)
NH3(g) + HNO3 (g) NH4NO3(p)
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NO3- & NH4
+
on nylon
Nylon filterextraction by watershowed no bias infirst three studies
Significant NH4+
lost from nylonfilter
– Nylon recapturesvolatilized NO3
-
0
2
4
6
8
10
12
14
16
0 2 4 6 8 10 12 14 16
Nylon D.I. H2O, ug/m3, BondvilleNO3-, D.I. H2O, ug/m3, SG AprilNO3- D.I. H2O, ug/m3, Grand Canyon1:1 Line
Nyl
on b
y D
.I. H
2O e
xtra
ctio
n, u
g/m
3
Nylon by IC extraction, µg/m3
0
10
20
30
40
50
60
70
0 5 10 15 20 25 30
BNH4+%, BondvilleBNH4+%, SG AprilBNH4+%, GC
NH
4+ loss
from
Nyl
on fi
lter,
%
Day of Month
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0
20
40
60
80
100
Jul/1 Jul/6 Jul/11 Jul/16 Jul/21 Jul/26 Jul/31
BNH4+%BNO3-%
Date
San GorgonioJuly (latest results)
~ 25% of nitrate not extractedfrom nylon filter with water
NH4+ loss ~ 20-50%
0
1
2
3
4
5
0 1 2 3 4 5
NO3-, D.I. 1:1
NO3-(IC), µg/m3
y = m2 * M0ErrorValue
0.0212750.75792m2 NA1.6439Chisq
NA0.92249R2
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Yosemitespecial study
July-September2002Focus onsmokeAerosoldominatedby OC
POM73%
Black C2%
Soil6% NH4+
4%
Na+1%
K+0%
Ca2+0%
NO2-0%
Cl-0%
Mg2+0%
NO3-3%
Oxalate1%
Ions19%
SO42-10%
POMBlack CSoilCl-NO2-NO3-SO42-OxalateNa+NH4+K+Mg2+Ca2+
Study average PM2.5 composition
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Yosemitespecial study
Large changes in OC– EC remained small
“Contemporary” carbondominant
– Wood smoke– Biogenic production
Molecular markers indicatepresence of wood smokeand secondary biogenicparticles
– Vehicle contribution appearssmall
0
2
4
6
8
10
12
14
7/10 7/15 7/20 7/25 7/30 8/4 8/9 8/14 8/19 8/24 8/29 9/3
Car
bon
( µg
m-3
)
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Yosemite size distributions
Size distributionsmeasured withDifferential MobilityAnalyzer (DMA)Two submicron modespresent during smokeperiod
SMOKE
16 Aug 2002 (DOY 228) 22:30 PST08 Aug 2002 (DOY 220) 03:45 PST
“CLEAN”
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Yosemite size distributions - II
Aerosol Mass Scattering Efficiency– increases during smoky periods
K+
(µg/
m3 )
Mas
s sca
tterin
g ef
ficie
ncy
(m2 /g
)
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Yosemite aerosol hygroscopicity
Hygroscopicity of100 and 200 nmparticles measuredwith HygroscopicTandem DifferentialMobility Analyzer(HTDMA)
Smoke-dominatedaerosol much lesshygroscopic than“normal” Yosemitesummer aerosol
0 2 4 6 8 10 12 14
1.05
1.10
1.15
1.20
1.25
1.30
1.35
1.40
Equation: y = A1*exp(-x/t1) + y0
Chi 2/DoF = 0.001R 2 = 0.723 y0 1.102 ±0.007A1 0.434 ±0.067t1 1.386 ±0.201
GF
(RH
=80%
)
Carbon/Ionic Mass Ratio
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IMPROVE denuder tests (UC Davis)
Differentdenuderconfigurationstested
– Noperformancedifferencesobserved
– Lab testsplanned atCSU
HANC
0100200300400500600700800900
5/1/
03
5/3/
03
5/5/
03
5/7/
03
5/9/
03
5/11
/03
5/13
/03
5/15
/03
5/17
/03
5/19
/03
5/21
/03
5/23
/03
5/25
/03
5/27
/03
5/29
/03
5/31
/03
ng/m
3HNO3(g)
None
New
Bare Al
No glyc
Used
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Coarse particle speciation (UC Davis)
PM10 speciation9 sites
– Bondville– Great Smokies– Grand Canyon– San Gorgonio– Sequoia– Brigantine– Upper Buffalo– Bridger– Mount Rainier
Operational by 1/1/04– Several sites already
operating– Overlap with ion study
Will run for 1 year
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New IMPROVE mobileair quality lab
Mobile platform– Special study deployment– Some on-road
measurement capabilities
Measurement capabilities– Particle and trace gas
composition– Aerosol size distributions– Particle hygroscopicity– Trace gases
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Summary
Nitrate present in– Submicron ammonium nitrate particles
Bondville, ILSan Gorgonio, CA
– Coarse mode sodium or calcium nitrate particlesBig Bend NP, TX Yosemite NP, CAGrand Canyon NP, AZ
Nylon filter– DI water extraction may not always fully recover NO3
-
– Yields negatively biased NH4+ concentrations
Yosemite aerosol dominated by modern carbon– Particles slightly hygroscopic
HNO3 denuder tests show little dependence on coatingCoarse particle speciation study beginningMobile lab being constructed for future special studies
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IMPROVE ion study fieldcampaigns
6 one-month campaignsBondville (midwest) - February2003San Gorgonio (southern CA) –April and July 2003Grand Canyon – May 2003 (co-sponsored by LAWFR)
– Brigantine (NE coastal) –November 2003
– Sequoia (Sierra Nevada) –February 2004
Measurements– MOUDI sampler – ion size
distributions– 3 Parallel URG denuder/filter-
pack samplers running differentprotocols
– PILS sampler – 15 minute PM2.5anions and cations
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Mobile laboratory
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Nitrate replacement
NH4NO3 formation not favoredthermodynamically in acidicaerosol
– NH3(g) will first neutralize sulfateH2SO4 NH4HSO4 (NH4)2SO4
Once aerosol is neutralized,NH4NO3 formation may occur
– f(T,RH)If SO4
2- is decreased, NO3- may
replace it– Two NO3
- replace each SO42-
– Sulfate reduction could producePM mass increase
SO42-
98 g/mole
NO3-
62 g/moleNO3
-
62 g/mole
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HN
O3 denuder
NH
3 denuder PM
2.5 N
H3 denuder
HN
O3 denuder
NH
3 denuder
N filter (IC)
PM2.5
HN
O3 denuder
NH
3 denuder
Filter A
PM2.5
NH
3 denuder
N filter (H2O)
HN
O3 denuder
HN
O3 denuder
•Modules 1 and 2
•Daily, 24 hr samples
•Compare nylon filterextraction (H2O vs.carbonate/bicarbonate)
•Examine loss of HNO3 andNH3 from nylon filter
•Provide gas-particle phasedistribution for N(-III) andN(V)
•Module 3
•Day/night sampling
•Replicates for precision
•Aerosol acidity/NH4NO3volatilization
•Undenuded sampling onTeflon filter
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Initial findings
Nylon filter extraction by water?– EPA study of fall filters collected at numerous STN
and IMPROVE sites gave average 90% extractionefficiency
– CSU Fort Collins samples (Spring 2002) yielded noevidence of lower water extraction efficiency
Fate of volatilized NH4NO3?– EPA study indicated significant ammonia loss
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IMPROVE sampling approach
4 modulesModule B for PM2.5 ions– Carbonate-coated denuder removes acidic gases– Nylon filter
Extracted with carbonate/bicarbonate solution (anion ICeluent) for anion analysisExtracted with water for anion + cation analysis
– Sodium interference from IC eluentAnalyzed by IC