aerosol diagnostics via size/time/compositional profiles a proposal to ladco by the uc davis delta...
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Aerosol Diagnostics via Size/Time/Compositional Profiles
A proposal to LADCO by the UC Davis DELTA Group
Tom Cahill, Professor and Head, DELTAJune 13, 2002
Analysis of the problem
• Aerosols can have major impacts via
global climate change, visibility reduction, ecosystem impacts and health effects
• Aerosols are complicated, with both size and composition vital for source identification and impact assessment.
• Aerosols can be highly variable in time, with local, synoptic and diurnal patterns
Limitations of standard techniques
• Filter based sampling integrates over both size (PM2.5 and PM10) and time (24 hrs)
• Filter sampling integrates composition to deliver only mass in most cases
• Filter sampling is usually limited to one-day-in-three or worse
• Filter sampling makes serious personnel and infrastructure requirements
Alternatives to filter sampling
• Sampling via impaction is both theoretically and experimentally well understood, unlike filter sampling, and has fewer sampling artifacts
• Sampling by impaction allows-– Many size cuts, not just one– Continuous sampling with high time resolution– Modest infrastructure requirement– A newly developed DELTA Group suite of non-
destructive compositional and morphological analyses
Problems with impaction sampling that limited use
• Samplers are technically complex and thus can be more expensive than filter samplers
• Collected masses (few mono-layer criterion) are low and sensitivities may suffer
• Until recently, no viable method existed for measuring mass
• Standard chemical methods can’t be used• Particle bounce can lead to poor size cuts
unless special coatings are used
Impaction was still widely used
• All major studies in California, 1969-1977• Monitoring by rotating 3 drum impactor for
the ARB, 1973-1977 – 14,100 days• Almost all NPS and EPA studies, 1980 to
present, including WHITEX and SEAVS• Major international studies, most recently
NSF ACE-Asia (2001, 21 sites, 78,000 samples), and NOAA ITCT (2002 - 2004)
DELTA Group personnel
• Tom Cahill, Physics/Atmospheric Sciences• Pete Kelly, Chemistry (LDI TOF/MS)• Jim Shackelford, Materials Science (SEM, Eng)• Steve Cliff, Applied Science (S-XRF, ALS PRT)• Kevin Perry, Meteorology (Utah)• Graham Bench, Applied Science (CAMS, LLNL)• Michael Jimenez-Cruz, Applied Science (UCD
lab)• Jeanette Martin, MSO, Lee Portnoff and Victor
Rey, graduate students (3), foreign visitors (4), about 20 collaborators, many in Asia
DELTA Group efforts, 1990 - 2002
• Small, inexpensive, low labor continuously sampling rotating drum impactors in the field
• Quick and cheap analyses for mass and optics, then archived for later analyses if desired
• High technology beam based non – destructive mass, elemental and chemical analyses in ex-post-facto experiments at any later time
• Mass closure to allow comparisons with filters• Quality assurance by “integral redundancy” or
overlapping methods for key species
DELTA Group techniques
• Mass by soft beta attenuation• Optical attenuation 320 – 820 nm
– then archive the sample strips
• Elements Na – U via synchrotron-XRF, DELTA Group beam line, ALS LBNL
• Mass and hydrogen via STIM and PESA, CAMS, LLNL
• Anions and speciated organic matter by LDI TOF/MS
• Morphology via SEM
Summary of Proposed Program
• Impaction vastly less expensive per sample– To collect– To analyze– To archive the large number of samples collected
• Better representation of ambient aerosols• Non destructive analyses and easy archiving for
later analyses• Highly diagnostic compositional and
morphological data available
Proposal:
• Purchase 4 3-stage rotating DRUM impactors, 2.5 μm IMPROVE inlet
• Site at least one at existing IMPROVE site for QA, additional species, etc.
• Initiate continuous sampling for mass and optics, plus archiving
• Ex-post-facto analyze pollution episodes by S-XRF, STIM/PESA, LDITOF/MS, SEM
30cm
Sampling Technology: 3-DRUM
Inlet @ 2.5m
2.5-1.15 m1.15-0.34 m
0.34~0.1 m
Teflon After-filter
Precision of Soft Beta Mass Measurements – 3 repeated analyses
of a 3 hr DRUM strip
Betaguage Repeat MeasurementsFACES Fresno Stage 8
11/8/00-11/28/00
-100
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1 10 19 28 37 46 55 64 73 82 91 100 109 118 127 136 145 154 163 172 181 190 199 208 217 226 235 244
1/2 mm increments
ug
/cm
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Run1
Run2
Run3
Run1 vs Run 2 Run1 vs Run 3
Run2 vs Run 3
y = 1.0615x - 7.282
R2 = 0.9807
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Series1
Linear (Series1)
y = 1.0922x - 17.299
R2 = 0.9813
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Series1
Linear (Series1)
y = 1.0922x - 17.299
R2 = 0.9813
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Series1
Linear (Series1)
Mass by DELTA GROUP Soft BetaGuage LADCO Detroit Test
2/28/02 10:17 to 4/10/02 10:00
-2.0
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/02
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ug
/m3
StageA (2.5-1.15um)
StageB (1.15-0.34um)
StageC (0.34-0.10um)
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10
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1000
10000
100000
0 2 4 6 8 10 12 14 16 18 20
Energy (keV)
Co
un
ts
S
K
V
Mn
Fe
Ni Cu
Zn
As/Pb
Br
Pb
1007
ng/m3
44 ng/m3
5.4 ng/m3
2.7 ng/m3
Analysis of Atmospheric Aerosols UC Davis DELTA Group (Cahill, Cliff, J imenez-Cruz, Kelly,
Spring, 2000 Perry, Shackelford and McHugo)
UC Davis at Crocker Nuclear LabALS on Beam Line 10.3.1 CNL ALS
ANALYSIS OF FILTERS Filters (1) Filters (1) Filters Focussed FocussedCNL CNL ALS PIXE S-XRF
Areal PIXE XRF S-XRF Area AreaDensitySensitvity of analysis (Fe) 0.12 cm2 0.0004 cm2on filter ng/cm2 ng/cm2 ng/cm2 ng/cm2 ng/cm2
24 hr Sample Duration 7 1 0.1 7 0.3Single PM 2.5 Filter Sample cm2/m3
pg/m3 pg/m3 pg/m3 pg/m3 pg/m3
Hi-Vol EPA 1970-1999 0.26 1,820 260 26 1,820 78 (TSP < 1987; PM 10> 1987) Virtual Imapctor EPA 1985 0.34 2,380 340 34 2,380 102
Stacked Filter Unit UCD 1979 0.95 6,650 950 95 6,650 285Stacked Filter Unit UCD 1982 0.26 1,820 260 26 1,820 78IMPROVE UCD 1988 0.07 490 70 7 490 21Int. Aerosol Sampl. UCD1999 0.07 490 70 7 490 21
WINS EPA 1999 0.56 3,920 560 56 3,920 168
ANALYSIS OF IMPACTORS
4 hr cm2/m3 Sizing, fixed or rotating drum pg/m3 pg/m3 pg/m3 pg/m3 pg/m3
MOUDI U. Minn. 1985 0.16 1,120 160 16 1,120 48DRUM UCD (jets) 1985 1.57 10,990 1,570 157 1,750 0.6DELTA DRUM (slots) 1998 0.15 1,050 150 15 1,050 45
Focussed Focussed
4 hr PIXE S-XRFSizing, fixed or rotating drum 0.12 cm2 0.0004 cm2
ng/cm2 ng/cm2
MOUDI U. Minn. 1985 Time resolution 4 hr 4 hrDRUM UCD 1985 Time resolution 4 hr 24 minDELTA DRUM UCD 1998 Time resolution 4 hr 24 min Note: By increasing DRUM rotation rates: 24 min 44 sec ( pg/m3 = picograms/cubic meter of air, or 0.001 ng/m3) (1) Malm, W.C., Sisler, J .F., Huffman, D., Eldred, R.A. and Cahill, T.A.Spatial and seasonal trends in particle concentration and optical extinction in the United States.J ournal of Geophysical Research, VOL. 99, No. D1, 1347-1370, J anuary 20, 1994.
0
5
10
15
20
Day, November, 2000
Mic
rog
ram
s/m
3
8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
Mass by STIM Organic matter by PESA
Ultra-fine Aerosols at Fresno, CA0.24 > Dp > 0.07 micrometers diameter
0
10
20
30
Day, November, 2000
Nanogra
ms/m
3
8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
Copper x 20 Iron Zinc
0
100
200
300
400
Day, November, 2000
Nanogra
ms/m
3
8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
Sulfur Chlorine Potassium
ug
/m3
ug
/m3
ug
/m3
2812
34
56
78
910
1112
1314
1516
1718
1920
2122
2324
2526
2728
2930
311
23
45
67
89
March April, 2001
0
100
200
300
400
500
Nan
ogra
ms/
m3
Silicon
Sulfur
Chlorine
Potassium
Iron
Aersosls in LADCO Detroit IntercomparisonStage A, 2.5 > Dp > 1.15 micrometers
Aerosols
281
23
45
67
8910
1112
1314
1516
1718
1920
2122
2324
2526
2728
2930
3112
34
56
78
9
March April, 2001
0
500
1000
1500
2000
2500
3000
3500
Nan
ogra
ms/
m3
Silicon
Sulfur
Chlorine
Potassium
Iron
Aersosls in LADCO Detroit IntercomparisonStage B, 1.15 > Dp > 0.34 micrometers
Aerosols
2812
34
56
78
910
1112
1314
1516
1718
1920
2122
2324
2526
2728
2930
311
23
45
67
89
March April, 2001
0
100
200
300
400
500
600
Nan
ogra
ms/
m3
Silicon
Sulfur
Chlorine
Potassium
Iron
Aersosls in LADCO Detroit IntercomparisonStage C, 0.34 > Dp > 0.1 micrometers
AerosolsAerosols
281
23
45
67
8910
1112
1314
1516
1718
1920
2122
2324
2526
2728
2930
3112
34
56
78
9
March April, 2001
0
500
1000
1500
2000
2500
3000
3500N
anogra
ms/m
3 Silicon
Sulfur
Chlorine
Potassium
Iron
Aersosls in LADCO Detroit IntercomparisonStage B, 1.15 > Dp > 0.34 micrometers
2812
34
56
78
910
1112
1314
1516
1718
1920
2122
2324
2526
2728
2930
311
23
45
67
89
March April, 2001
0
100
200
300
400
500
600
Nanogra
ms/m
3
Silicon
Sulfur
Chlorine
Potassium
Iron
Aersosls in LADCO Detroit IntercomparisonStage C, 0.34 > Dp > 0.1 micrometers
Aerosols
281
23
45
67
8910
1112
1314
1516
1718
1920
2122
2324
2526
2728
2930
311
23
45
67
89
0
100
200
300
400
500
600N
anogra
ms/m
3
Silicon
Sulfur
Chlorine
Potassium
Iron
Aersosls in LADCO Detroit IntercomparisonStage C, 0.34 > Dp > 0.1 micrometers
281
23
45
67
89
1011
1213
1415
1617
1819
2021
2223
2425
2627
2829
3031
12
34
56
78
9
March April, 2001
0
2
4
6
8
10
Nanogra
ms/m
3 Vanad./3
Nickel x 10
Copper
Zinc
Iron/10
Aerosols
281
23
45
67
8910
1112
1314
1516
1718
1920
2122
2324
2526
2728
2930
311
23
45
67
89
March April, 2001
0
500
1000
1500
2000
2500
3000
3500N
anogra
ms/m
3
Silicon
Sulfur
Chlorine
Potassium
Iron
Aersosls in LADCO Detroit IntercomparisonStage B, 1.15 > Dp > 0.34 micrometers
281
23
45
67
89
1011
1213
1415
1617
1819
2021
2223
2425
2627
2829
3031
12
34
56
78
9
March April, 2001
0
50
100
150
200
Na
no
gra
ms/m
3
Vanad./3
Nickel x 10
Copper
Zinc
Iron/10
Aerosols
281
23
45
67
8910
1112
1314
1516
1718
1920
2122
2324
2526
2728
2930
311
23
45
67
89
0
500
1000
1500
2000
2500
3000
3500N
anogra
ms/m
3
Silicon
Sulfur
Chlorine
Potassium
Iron
Aersosls in LADCO Detroit IntercomparisonStage B, 1.15 > Dp > 0.34 micrometers
281
23
45
67
89
1011
1213
1415
1617
1819
2021
2223
2425
2627
2829
3031
12
34
56
78
9
March April, 2001
0
50
100
150
200
Na
no
gra
ms/m
3 Vanad./3
Nickel x 10
Copper
Zinc
Iron/10
Arsenic x 30
Associated with arsenic
Not associated with sulfur
Aerosols
281
23
45
67
8910
1112
1314
1516
1718
1920
2122
2324
2526
2728
2930
311
23
45
67
89
0
100
200
300
400
500N
anogra
ms/m
3 Silicon
Sulfur
Chlorine
Potassium
Iron
Aersosls in LADCO Detroit IntercomparisonStage A, 2.5 > Dp > 1.15 micrometers
281
23
45
67
89
1011
1213
1415
1617
1819
2021
2223
2425
2627
2829
3031
12
34
56
78
9
March April, 2001
0
50
100
150
200
Na
no
gra
ms
/m3
Vanad./3
Nickel x 10
Copper
Zinc
Iron/10
Aerosols
0 0.5 1 1.5 2 2.5
Vanadium (ng/m3)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Nic
kel (n
g/m
3)
Aerosols in LADCO Detroit Intercomparison Stage C, 0.34 > Dp > 0.1 micrometers
0 0.5 1 1.5 2 2.5
Vanadium (ng/m3)
0
0.5
1
1.5
2
Nic
kel
(ng
/m3)
Stage B, 1.15 > Dp > 0.34 micrometers
281
23
45
67
8910
1112
1314
1516
1718
1920
2122
2324
2526
2728
2930
311
23
45
67
89
0
1
2
3
4
5
6N
anogra
ms/m
3 Chromium
Arsenic
Selenium
Bromine
Lead
Aersosls in LADCO Detroit IntercomparisonStage C, 0.34 > Dp > 0.1 micrometers
281
23
45
67
89
1011
1213
1415
1617
1819
2021
2223
2425
2627
2829
3031
12
34
56
78
9
March April, 2001
0
2
4
6
8
10
Nan
og
ram
s/m
3
Vanad./3
Nickel x 10
Copper
Zinc
Iron/10
Aerosols
Summary of the Detroit study
• The DRUM ran well with minimal oversight– 3 hr resolution and 1000 analyzable samples– Mass, optical, S-XRF elemental = 100,000 values
• The site was characterized by short duration plumes of complex aerosols
• The plumes possessed characteristic size and elemental species that with meteorology could identify urban and remote sources
• The plumes (especially < 0.34 microns) should be traceable into rural and remote areas
Deliverables to LADCO
Assume: 4 sites, 3 hr data, 3 6-week S-XRF intensives, STIM/PESA, partial LDITOF/MS
• 35,000 mass values, 1.75 M optical scans• Available 1 week after samples received UC Davis
• 12,100 elemental analyses, 360,000 data• 12,100 vacuum mass, hydrogen (organics)
• Available 3 months after samples received UC Davis
• 500 + anion, speciated organics• Annual Report in electronic and hard copy
Summary of Proposed Costs
Assume: UC Davis research grant (Year 1)– 48.5% indirect, then 28.5% for future years
• $50,000 operations, mass, optics scans• $40,000 S-XRF analyses elements Na - U• $40,000 STIM and PESA mass and total organics• $25,000 LDI TOF/MS speciated organics,
ions• $ 3,000 SEM particle morphology• $ 5,000 Reports
» TOTAL $123,000 Indirect $60,000
$183,000 Year 1 plus samplers, $30,000 $158,000 Year 2 +
Alternatives to the Proposal
IMPROVE, 4 sites/1 year, one-day-in-three – PM2.5 Teflon, Nylon, quartz
• Mass, organics by hydrogen, elements Na – Pb, anions (NO3, NO2, SO4), Organics by carbon elemental carbon
– PM10 Teflon mass• 480 days/960 mass, 30 species, 14,400 data
Est. $140,000. plus indirect $40,000 =
$180,000/year + samplers $66,000
Good reasons why not to use DELTA DRUMs
• The DELTA Group has only operated one site for a full year under these protocols (Fresno EPA/CARB Super-site) , and thus lacks a serious “track record”
• Data are non-standard, and comparisons to EPA and IMPROVE filters may be difficult
• Only the DELTA Group can do this, making LADCO dependent on a “sole source”
• Voluminous data will require additional personnel or contractors to interpret the results
Acknowledgements
• All the Detroit personnel, but especially Ann Chevalier, who was extremely helpful in setting us up at their site
• Members of the DELTA Group, – Lee Portnoff for the beta mass– Roger Miller for the optical scans– Steve Cliff for the S-XRF analyses– Kevin Perry for data reduction
• Donna and Mike for LADCO who moved very rapidly to get the Detroit study going