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Continuous Carbon and NHy Measurements

Continuous Carbon and NHy Measurements. Eric S. Edgerton, ARA, Inc. EMEP PM Measurement and Modeling Workshop New Orleans, LA, USA 4/20-23/04. EMEP 042104. Outline. Continuous Carbon R&P 5400 (SEARCH) Aethelometer (SEARCH) Sunset Labs Particulate Carbon Analyzer (Turner, Robinson)

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Continuous Carbon and NHy Measurements

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  1. Continuous Carbon and NHyMeasurements Eric S. Edgerton, ARA, Inc. EMEP PM Measurement and Modeling Workshop New Orleans, LA, USA 4/20-23/04 EMEP 042104

  2. Outline • Continuous Carbon • R&P 5400 (SEARCH) • Aethelometer (SEARCH) • Sunset Labs Particulate Carbon Analyzer (Turner, Robinson) • Continuous NHy (NH3) • An idea for constraining secondary OC EMEP 042104

  3. 5400 Schematic EMEP 042104

  4. 5400 Principle of Operation • Collect particles in metal impactor (0.12 µM Dp50) for 60 minutes, or longer • Measure ambient CO2 in analytical loop • Heat impactor in 1-4 temperature plateaus, volatilize carbon (final T 600-750C) • Heat afterburner to 750C, complete combustion to CO2 • Quantify ΔCO2 via NDIR (Li-Cor) • Repeat (w/o collection step) for artifact (residual) correction Note: For a 1-hour sample, the system produces 19 ppm of CO2 per ug-C/m3 EMEP 042104

  5. 5400 PrecisionJefferson Street – July 2001 TC (ug/m3) EMEP 042104

  6. 5400i TC vs. TOR TCJefferson Street, GA - 2001 SEARCH 5400i tends to under predict in winter, but over predict in summer EMEP 042104

  7. 5400f TC vs. TOR TCJefferson Street, GA – 2003/4 EMEP 042104

  8. Aethelometer Operation • Collect particles on quartz filter tape at controlled flow • Monitor absorbance continuously with reference ands sensor beam • Advance tape at pre-set time interval or preset absorbance • Wavelength-specific conversion to BC (1-minute + time resolution) • Nafion drier (SEARCH sites) • Activated carbon monolith EMEP 042104

  9. Comparison of AETH-BC and TOR-EC at Jefferson Street (Atlanta), GA We see a consistent relationship across SEARCH sites, with regression slopes between 0.5 and 0.7 EMEP 042104

  10. Time Series of 1-minute AETH-BC Jefferson Street (Atlanta), GA(nafion drier and carbon monolith) Dislocations observed virtually always at virtually all SEARCH sites, noise is instrument specific EMEP 042104

  11. Sunset Labs Carbon Analyzer slide courtesy of Jay Turner, STLU EMEP 042104

  12. Sunset Labs Temperature Program slide courtesy of Jay Turner, STLU EMEP 042104

  13. EMEP 042104

  14. PM2.5 Denuder Denuder Sunset in-situ OC/EC Analyzer PM2.5 Quartz CIF Pittsburgh Air Quality Study: Carbonaceous Aerosol Samplers Sunset in situ CMU Denuder Teflon All Quartz filters analyzed using Sunset Instruments and NIOSH protocol Denuder Dynamic Blank Sample PM2.5 Quartz CIF Rutgers & Carnegie Mellon OC = Sample (Q+CIF) – Dynamic Blank (Q+CIF) EC = Sample Q – Dynamic Blank Q Source: Allen Robinson, Carnegie Mellon University; Barb Turpin Rutgers University EMEP 042104

  15. Comparison of Sunset Labs In Situ with Integrated Samples Source: Allen Robinson, Carnegie Mellon University; Barb Turpin Rutgers University EMEP 042104

  16. Emissions from Biomass Burning HMS Fire and Smoke Summary for 2345 10/21/03 Oak Grove http://www.firedetect.ssd.nesdis.noaa.gov/index.htm EMEP 042104

  17. CO and NOy at Oak Grove – 10/21/03 EMEP 042104

  18. ER (g/kg CO) FUEL NOy (as NO) SO2 PM2.5 TC BC Savannah/Grassland 60 5.4 83 57 3.1 Trop. Forest 15 5.5 88 64 6.4 non-Trop. Forest 28 9 121 78 5.2 Biofuels 27 3.5 92 51 7.6 Ag. Residues 27 4.3 42 36 7.5 This Study (Fires) 28+/-14 5.0 +/-2/7 195 +/- 54 63 +/- 14 10 +/- 6.1 This Study (Urban)# 147 +/-10 n.d. 33 +/- 8 9.6 +/- 2.1 n.d. Andreae and Merlet. Global Geochem Cyclec 15(4):955-966. 2001. (A&M) # Based on Jefferson Street, Atlanta, GA SEARCH data Comparison of ERs with Literature Values EMEP 042104

  19. Continuous Measurements of NHy in SEARCH EMEP 042104

  20. SEARCH NH3 and %NHy 4th Quarter 2003 rural- agricultural urban-industrial % NHy urban-res./ind. urban- residential urban- residential NH3 (ppb) % NHy rural- forested rural- forested suburban 0.32 +/- 0.12 0.49 +/- 0.22 2.54 +/- 2.27 EMEP 042104

  21. SEARCH Total Reduced Nitrogen (NHy) Diagram Hot Pt converts NHy to NO. Hot Mo converts NOy to NO, but is blind to NHy. EMEP 042104

  22. SEARCH NO3/NH4 Diagram

  23. SEARCH Continuous NH3 vs Denuder NH324 Hour Samples Gaseous NH3 is deduced by subtracting particulate NH4 from NHy EMEP 042104

  24. Hourly NH3 and particulate-NH4+ Yorkville, GA – November 2003 EMEP 042104

  25. Continuous NH3 vs. Wind Direction Yorkville, GA – November 2003 EMEP 042104

  26. The Smoking Chicken 4.5 km 2.3 km 1.8 km EMEP 042104

  27. Continuous NH4+ and NO3- vs. Wind DirectionYorkville, GA - November 2003 Wind Direction EMEP 042104

  28. WS and WD Yorkville, GA 11/6-8/01 Transport from Atlanta Low Wind Speed EMEP 042104

  29. Particulate NO3- and NH4+Yorkville, 11/6-8/01 EMEP 042104

  30. An Idea for ConstrainingSecondary OC Primary Secondary Primary Secondary Modern OC OC Fossil OC EMEP 042104

  31. Primary Secondary Total S peciation , Modern Speciation/CMB Models, 14C D ifference S peciation , Fossil Speciation/CMB Models, 14C Difference Simplified OC Source Matrix Combination of CMB and C-14 data allows calculation of secondary OC by difference. EMEP 042104

  32. Primary * Secondary Total # Modern 64 +/- 15 <5 61 +/ - 5 Fossil 36 +/- 15 <5 39 +/ - 5 OC Source MatrixAtlanta, GA – January * 2000 Data: Zheng et al., ES&T, 2002. # from 14Cdata EMEP 042104

  33. Primary* Secondary Total # Modern <5 +/- 10 >50 59 +/ - 6 Fossil 40 * +/- 18 <5 41 +/ - 6 OC Source MatrixAtlanta, GA – July 2001 * Zheng et al. Source Apportionment of Fine Particles at Atlanta, GA, AAAR 2002 # from 14C data EMEP 042104

  34. Summary • For TC, R&P 5400f (with modifications) can reproduce filter-based measurements(+/- 15%), but maintenance (data capture) can be problematic. Log cell pressure. • For BC, aethelometer provides reliable, high time resolution information, but AETH-BC = 0.6(+/- 0.1) TOR-TC. Dislocations and high resolution noise are annoyances that require further investigation. Log fast data. • For OC, TC and possibly EC, early results from Sunset Labs analyzer are promising. Longer term experience necessary. • Continuous carbon and NHy data provide valuable insights into sources, processes, etc.

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