naydene maykut, puget sound clean air agency joellen lewtas, u.s. epa

Source Apportionment of PM2.5 Mass and Carbon in Seattle using Chemical Mass Balance and Positive Matrix FactorizationNaydene Maykut, Puget Sound Clean Air AgencyJoellen Lewtas, U.S. EPATim Larson, University of Washington

IntroductionExtensive PM2.5 speciation data available from an urban IMPROVE site in Seattle (284 days over three years)

Source Apportionment comparison between traditional CMB approach with newer PMF method

For PMF method: include temperature resolved carbon fractions rather than traditional OC/EC split

Beacon Hill SiteSeattle

Measured Species in Seattle(IMPROVE protocol)

>45 species measured on Wednesdays and Saturdays 4/96 to 1/99 (289 samples)XRF (Fe to Zr, Pb) , PIXE (Na to Mn, Mo) , ICCarbon measurements: OC & EC temperature dependent volatilization (TOR)

PMF MethodUsed 7 carbon fractions from TOR(O1, O2, 03, O4, E1, E2, E3) as well as usual elements and ionsInput species and uncertaintiesRobust Mode : FPEAK = +0.2

TOR Analysis2004006008001000120014001600180020002200Time (sec)OC1OC2OC3OC4EC1EC2EC3100200300400500600700800Temperature (C)Temperature ProfileLaser SignalCH4 CalibrationFID BaselineOrganic CarbonElemental CarbonPyrolized carbonHeHe + O2

Seattle PMF Results(288 Samples: all seasons)*Standard Error

0102030400246800.10.20.30.4E3ZnMnTiAsCuCrBr01020304002468E2HSiAlFeCaVNiKPb00.10.20.30.4E3ZnMnTiAsCuCrBr01020304002468E2HSiAlFeCaVNiKPb00.10.20.30.4E3ZnMnTiAsCuCrBr01020304002468E2HSiAlFeCaVNiKPb00.10.20.30.4E3ZnMnTiAsCuCrBrRoad DustMarineMarine/Secondary/Pulp MillSecondarySource Profiles from PMF (Mass %)

010203040024680246800.10.20.30.4E3ZnMnTiAsCuCrBr00.10.20.30.4E3ZnMnTiAsCuCrBr0102030400246800.10.20.30.4E3ZnMnTiAsCuCrBr0102030400246800.10.20.30.4E3ZnMnTiAsCuCrBrDieselGasolineVegetativeFuel OilSource Profiles from PMF (Mass %)

Carbon Apportionment

Source Apportionment of Organic and Elemental Carbon using PMFSourceOC(%)EC(%)Vegetative Burning5747Diesel Vehicles1936Gasoline Vehicles 5 1Secondary12 9Fuel Oil 3 4Road Dust 2 2Marine (Sea Salt) 2 0

Chart1

44

18

17

4

4

7

7

CMB Source Apportionment - Beacon Hill

Vegetative Burning15%

Marine9%

Sheet1

9 SourcesCMB8

Gas Veh37.26.2MarineSource 759.2

Diesel1.4

Sulfate19.6

Burning115.1

Burning22.7

Nitrate6.2

Road Dust3.7

Marine9.2

Residual Oil0.9

Mobile44

Sulfate18

Burning17

Nitrate4

Road Dust4

Marine7

Industry7

Sheet1

0

0

0

0

0

0

0

0

0

CMB SOURCE APPORTIONMENT - BEACON HILL 1996-99

Sheet2

0

0

0

0

0

0

0


Sheet3

Chart1

35

1.2

15.6

5.7

19.9

8.1

9

5.5

PMF SOURCE APPORTIONMENT - SEATTLE BEACON HILL 1996-99 USING CARBON FRACTIONS

Sulfate19%

Secondary 9%


Gas Vehicles5%

Diesel15%

Fuel Oil2%

Marine8%

Sheet1

SourcePMFCMB

SOURCEC-PMF

Burning126174MarineSource 756.8

Burning24Burning135

Diesel16Burning21.2

Gas Veh1144Diesel15.6

Sulfate2118Gas Veh5.7

Nitrate94Sulfate19.9

Road Dust64Nitrate8.1

Marine57Road Dust9

Res Oil11Marine5.5

Burning117

Gas Veh44

Sulfate18

Nitrate4

Road Dust4

Marine7

Res Oil1

Sheet1

0

0

0

0

0

0

0

0

0

PMF SOURCE APPORTIONMENT - BEACON HILL 1996-99

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0

0

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0

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Chart1

28.14

18.09

5.36

33

2.01

2.68

7.37

3.35

King County 1996 Emission Inventory (corrected for secondary pollutants; sulfate, nitrate and sea salt)


Sheet1

King County Emission Inventory corrected for secondary pollutants

%.67xB

Burning4228.14

Diesel2718.09

Gasoline85.36

Industry53.35

Fuel32.01

Dust42.68

Other117.37

Burning28.14

Diesel18.09

Gasoline5.36

Secondary33

Fuel2.01

Dust2.68

Other7.37

Industry3.35

Sheet1

0

0

0

0

0

0

0

0

King County 1996 Emission Inventory (corrected for secondary pollutants)

Sheet2

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Seattle PMF vs. CMB

Chart1

44

18

17

4

4

7

7



Marine9%

Sheet1

9 SourcesCMB8

Gas Veh37.26.2MarineSource 759.2

Diesel1.4

Sulfate19.6

Burning115.1

Burning22.7

Nitrate6.2

Road Dust3.7

Marine9.2

Residual Oil0.9

Mobile44

Sulfate18

Burning17

Nitrate4

Road Dust4

Marine7

Industry7

Sheet1

0

0

0

0

0

0

0

0

0


Sheet2

0

0

0

0

0

0

0


Sheet3

Chart1

35

1.2

15.6

5.7

19.9

8.1

9

5.5


Sulfate19%

Secondary 9%


Gas Vehicles5%

Diesel15%

Fuel Oil2%

Marine8%

Sheet1

SourcePMFCMB

SOURCEC-PMF

Burning126174MarineSource 756.8

Burning24Burning135

Diesel16Burning21.2

Gas Veh1144Diesel15.6

Sulfate2118Gas Veh5.7

Nitrate94Sulfate19.9

Road Dust64Nitrate8.1

Marine57Road Dust9

Res Oil11Marine5.5

Burning117

Gas Veh44

Sulfate18

Nitrate4

Road Dust4

Marine7

Res Oil1

Sheet1

0

0

0

0

0

0

0

0

0

PMF SOURCE APPORTIONMENT - BEACON HILL 1996-99

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ConclusionsCMB source profiles invaluable in identifying PMF factors

PMF factors may approximate local source profilesNext step - use PMF factors as combustion-derived profiles in CMB analysis

Using both models adds insight into the understanding of the composition of the aerosol in the urban airshedPMF urban-specific, combustion-derived profilesCMB minor impacts from known point sources

Why This Study was ImportantUse of Carbon Fractions in PMFcontributed to a defensible split between burning, diesel and gasoline

identified that carbon fractions may prove useful in identifying sources

raised the question whether PMF factors could be improved by de-coupling carbon

Diesel/Gasoline PM RatiosDiesel tailpipe/gasoline tailpipe emission-factor ratio (PM10)3.0 (EPA, 1995)

Diesel/gasoline PM2.5 source-contribution derived ratio3.2 Pasadena and 3.0 West Los Angeles (Schauer et al., 19962.7 (Seattle 8 Factor) and 3.1 (Seattle 9 Factor)2.1 Spokane (Kim et al., 2001)

Source Composition of OC and EC (PMF vs Source Tests)* Watson, Chow and Houck, 1996 **Watson et al., 1994

SourceOC (%)EC (%)PMF Vegetative 48 15Denver RWC* 51 +12 12 +4PMF Gasoline 24 2Phoenix Gasoline** 30 +12 14 +8PMF Diesel 37 26Phoenix Diesel** 40 +7 30 - 60

naydene maykut, puget sound clean air agency joellen lewtas, u.s. epa

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