Fugitive Dust Research at DRI

1. Fugitive Dust Research at DRI Portable Wind Tunnel Unpaved Road Dust Emission Factors TRAKER measurements at Lake Tahoe Near Field Deposition Research by: Hampden Kuhns Vicken Etyemezian Jack Gillies Alan Gertler Djordje Nikolic Sean Ahonen Cliff Denney John Skotnik Nicholas Nussbaum Dave Dubois Jin Xu

2. 1. Portable Wind Tunnel USDA-ARS Wind Erosion Research Unit http://www.weru.ksu.edu/vids

3. LWT at Ft. Bliss, TX • J. Gillies and B. Nickling testing emission flux potential • LWT is closest measurement to a “standard” • SWT - e.g. D. James (UNLV), D. Gillette (NOAA) • Concerns with boundary layer development, maximum wind speeds, and accounting for saltation

4. Blower for clean air injection PI-SWIRL Schematic

5. PI-SWIRL v.2

6. The PI-SWIRL-ogram

7. PI-SWIRL Status • Version 3 is currently being tested • Lower weight and smaller size • Faster measurement • Low cost custom circuitry • Patent application filed • PI-SWIRL has been collocated with LWT to draw empirical relationship • Data still being analyzed • Contact Vic Etyemezian (vic@dri.edu) for more information

8. 2. Unpaved Road Dust Emission Factors

9. Emission factor calculated as horizontal flux of PM10 passing instrumented towers

10. Unpaved Emissions Measured on Flux Towers in Ft. Bliss TX (April 2002)

11. EFPM10 = b W S

12. Unpaved Road Dust Emission Factor Status • Emission factors are dependent on vehicle speed and weight • Emission potentials of unpaved road soils were relatively constant in Ft. Bliss TX based on TRAKER. • Need to determine how emission potential varies in other regions. • Time since last rainfall is correlated with unpaved road emission factors John A. GILLIES, Vicken ETYEMEZIAN, Hampden KUHNS, Djordge NIKOLIC & Dale A. Gillette (2004) Effect of Vehicle Characteristics on Unpaved Road Dust Emissions. Accepted in Atmospheric Environment Kuhns H., V. Etyemezian, J. Gillies, S. Ahonen, C. Durham, D. Nikolic (2003) Spatial Variability of Unpaved Road Dust Emissions Factors near El Paso, Texas. Accepted in J. Air & Waste Manage. Assoc. Kuhns H., V. Etyemezian, M. Green, Karin Hendrickson, Michael McGown, Kevin Barton, Marc Pitchford (2004) Vehicle-based road dust emissions mesasurement (II): Effect of precipitation, winter time road sanding, and street sweepers on PM10 fugitive dust emissions from paved and unpaved roads. Atmospheric Environment.

13. 3. Testing Re-entrained Aerosol Kinetic Emissions from Roads (TRAKER) Measurements in Lake Tahoe

14. Particle Sensors • TSI DustTrak 5830 • Grimm Particle Size Analyzer 1.108 • GPS • Ashtech/Magellan Promark X

15. Data Acquisition and Processing • Lab View program displays and logs data from • 6 DustTraks • 3 Grimms • 1 GPS • Uniform time stamp applied to all data for synchronization • Data tables are loaded into MS Access for processing and analysis

16. TRAKER Signal vs Vehicle Speed • T = Ctire – Cbkgrnd • T = a S3 • On the same paved road the TRAKER signal increases with the speed cubed • Factoring out speed leaves a signal proportional to the emission potential of the road.

17. Flux Ladder in Lake Tahoe

18. Roadside PM Flux MeasurementsPM concentration profile drops off with heightReal time instruments help when wind doesn’t cooperate

19. TRAKER vs Horizontal PM Flux

20. Comparison of EF’s with Snow Precip

21. Spatial/Temporal Variability of Road Dust

22. Tahoe TRAKER Status • Road Dust EF’s drop by 70-80% from Spring to Summer • Previous TRAKER Calibration based on unpaved roads was way off • Maybe due to whole fleet vs just TRAKER? • Cities roads are dirtier than high speed rural highways • Something is different b/w CA and NV roads that create less dust Draft report completed for CARB in June. Final expected by Sept.

23. Transportable Fraction of Dust • Basic Problem Statement: Inventory of dust sources appears to be too high compared with what we find in the air • Possible Causes • Our inventory as measured at the source is inaccurate • We are not accounting for removal of dust near the source

24. Evolution of Plume Downwind

25. Approaches • Modeling • Advantages: Inexpensive, easy to simulate countless environments • Disadvantages: Who knows if its right! • Measurement • Disadvantage: Expensive and labor intensive (e.g. Gillies SERDP), unclear if possible to measure • Advantage: Results based on a “Real” data

26. Measurements of TF:>95% at 100 m at Ft. Bliss (Etyemezian et al., 2004)<20% at 100 m at Dugway Proving Grounds Mock Urban Environment (Veranth et al., 2004)USDA Proposal Submitted to measure TF in cornfield over growing season (Gillies et al., 2004)

27. Change in Integrated Horizontal Flux at Ft. Bliss

28. Comparison of Model and Measurements

29. Change is Particle Size Distibution Downwind

30. Transportable Fraction Research: Status • Initial attempt completed (WESTAR report) • Next round of research should target • Additional field studies • Model improvement • Consideration of vegetation, landscape Etyemezian V., J. Gillies, H. Kuhns, D. Gillette, S. Ahonen, D. Nikolic, and J. Veranth (2004) Deposition and removal of fugitive dust in the arid southwest United States: Measurements and model results. Acceptd in J. Air & Waste Manage. Assoc.