PM Sampler Placement and Sampler Errors! Why should Regulatory and - - PowerPoint PPT Presentation
PM Sampler Placement and Sampler Errors! Why should Regulatory and Agricultural Industries Care? Dr. Michael Buser USDA Agricultural Research Service Cotton Production and Processing Research Unit Lubbock, TX (806) 746-5353 x 104 Office
USDA Agricultural Research Service Cotton Production and Processing Research Unit
Lubbock, TX (806) 746-5353 x 104 – Office (806) 543-1432 – Cell mike.buser@ars.usda.gov
0.000 0.002 0.004 0.006 0.008 0.010 0.012 5 10 15 20 25 30
Particle Diameter (μm) Mass Density
Ambient PM (MMD - 10 μm; GSD 1.5) PM captured by the pre-collector (Sampler Cutpoint - 10 μm; Slope 1.5) Mass 1 Mass 2 Note: Mass 1 = Mass 0.000 0.002 0.004 0.006 0.008 0.010 0.012 0.014 5 10 15 20 25 30
Particle Diameter (μm) Mass Density
Ambient PM (Urban) (MMD - 5.7 μm; GSD 2.25) PM captured by the pre-collector (Sampler Cutpoint - 10 μm; Slope 1.5) Mass 2 Mass 1 Note: Mass 1 = 0.65 Mass 2 0% 20% 40% 60% 80% 100% 1 10 100
Particle Diameter (μm) Cumulative Penetration Efficiency
0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04
Mass Density
Penetration Curve Mass of particles < 10 μm that are captured by the pre-collector (Mass 1) Mass of the particles > 10 μm that are NOT captured by the pre- collector (Mass 2) True Cut Common Assumption: Samplers produce a "nominal" cut, because it is commonly assumed that Mass 1 = Mass 2. In other words, the errors offset one another. The assumption is only valid when the PSD's are described by a uniform distribution and encompass a sufficient range of particle diameters. Uniform Particle Size Distribution 0.000 0.001 0.002 0.003 0.004 0.005 0.006 5 10 15 20 25 30
Particle Diameter (μm) Mass Density
Ambient PM (MMD - 20 μm; GSD 1.5) PM captured by the pre-collector (Sampler Cutpoint - 10 μm; Slope 1.5) Mass 2 Mass 1 Note: Mass 1 ≠ Mass
EPA Performance Criteria Guidelines Ideal Environment Urban Environment Rural Environment
0.8 1.0 1.2 1.4 1.6 1.8 5 10 15 20 25 30 35 40 MMD (μm) Sampler Concentration True Concentration Cutpoint = 10.5 µm; Slope = 1.6 Cutpoint = 9.5 µm; Slope = 1.6 Cutpoint = 10.5 µm; Slope = 1.4 Cutpoint = 9.5 µm; Slope = 1.4 Ratio range for a 10 μm MMD PSD 0.95 < Ratio < 1.05 (c < Ratio < d) Acceptable PM10 sampler measurement to meet PLC 142 < x < 158 μg/m3 (Ratio * 150 μg/m3) Ratio range for a 20 μm MMD PSD 1.05 < Ratio < 1.39 (e < Ratio < f) Acceptable PM10 sampler measurement to meet PLC 158 < x < 209 μg/m3 (Ratio * 150 μg/m3) a < ratio < b, c < ratio < d, and e < ratio < f are the acceptable ratio ranges for 5.7, 10 and 20 μm particles, respectively based on the interaction of the PM10 sampler performance characteristics and particle size distribution. Regulated PM10 property line concentration (PLC) = 150 μg/m3 d c f e Ratio range for a 5.7 μm MMD PSD 0.92 < Ratio < 0.99 (a < Ratio < b) Acceptable PM10 sampler measurement to meet PLC 138 < x < 149 μg/m3 (Ratio * 150 μg/m3) b a
0.8 1.8 2.8 3.8 4.8 5.8 5 10 15 20 25 30 35 40 MMD (μm) Sampler Concentration True Concentration Cutpoint = 10.5 µm; Slope = 1.6 Cutpoint = 9.5 µm; Slope = 1.6 Cutpoint = 10.5 µm; Slope = 1.4 Cutpoint = 9.5 µm; Slope = 1.4 Ratio range for a 10 μm MMD PSD 0.92 < Ratio < 1.07 (c < Ratio < d) Acceptable PM10 sampler measurement to meet PLC 138 < x < 161 μg/m3 (Ratio * 150 μg/m3) Ratio range for a 20 μm MMD PSD 1.81 < Ratio < 3.43 (e < Ratio < f) Acceptable PM10 sampler measurement to meet PLC 271 < x < 514 μg/m3 (Ratio * 150 μg/m3) Regulated PM10 property line concentration (PLC) = 150 μg/m3 d c f e b a Ratio range for a 5.7 μm MMD PSD 0.87 < Ratio < 0.96 (a < Ratio < b) Acceptable PM10 sampler measurement to meet PLC 131 < x < 144 μg/m3 (Ratio * 150 μg/m3) a < ratio < b, c < ratio < d, and e < ratio < f are the acceptable ratio ranges for 5.7, 10 and 20 μm particles, respectively based
characteristics and particle size distribution.
40 80 120 160 200 5 10 15 20 25 30 35 40 MMD (μm) Sampler Concentration True Concentration Cutpoint = 2.7 µm; Slope = 1.33 Cutpoint = 2.3 µm; Slope = 1.27 Ratio range for a 10 μm MMD PSD 2.85 < Ratio < 13.14 (c < Ratio < d) Acceptable PM2.5 sampler measurement to meet PLC 185 < x < 854 μg/m3 (Ratio * 65 μg/m3) Ratio range for a 20 μm MMD PSD 14.81 < Ratio < 183.5 (e < Ratio < f) Acceptable PM2.5 sampler measurement to meet PLC 963 < x < 11,929 μg/m3 (Ratio * 65 μg/m3) a < ratio < b, c < ratio < d, and e < ratio < f are the acceptable ratio ranges for 5.7, 10 and 20 μm particles, respectively based on the interaction of the PM2.5 sampler performance characteristics and particle size distribution. Proposed PM2.5 property line concentration (PLC) = 65 μg/m3 d c f e Ratio range for a 5.7 μm MMD PSD 1.24 < Ratio < 2.96 (a < Ratio < b) Acceptable PM2.5 sampler measurement to meet PLC 81 < x < 193 μg/m3 (Ratio * 65 μg/m3) b a
True PM10 = 0.55 * Sampler PM10 R2 = 0.81 200 400 600 800 1000 1200 1400 1600 200 400 600 800 1000 1200 1400 1600 1800
PM10 Sampler Concentration (μg/acm) True PM10 Concentration (μg/acm)
True PM10 = Sampler PM10
Theoretical Errors - Assuming the Sampler Performance Characteristics Remain within the EPA defined tolerances Source MMD = 12.3 μm GSD = 1.94
MMD = 13.4 μm GSD = 2.0 D50 = 24.1 μm Slope = 2.9
0.2 0.4 0.6 0.8 1 10 100
Particle Diameter (μm) Differential Volume (%)
TSP Filter 347 - PSD Data Lognormal Fit (MMD = 11.8; GSD = 2.02)
Bottom Line!
Cutpoint = 24.1 μm
Slope = 2.9
Source PM10 Over- Sampling Rate Cotton Gin 181 % Cattle Feed Yard 185 % Almond Harvesting 139 %
0% 50% 100% 150% 200% 250% 300% 350% 1 2 3 4 5 6 7 8 9 10 11 12
Run Oversampling Rate (%)
In Field Measurement Theoretical (D50=10.5, Slp=1.6)
Stack Ambient
1) Health based studies – are the PM data used in the studies comparable?
A. Are we comparing apples to apples?
2) If I stand at the property line that separates Plant A and B will Plant B’s (higher PM10 sampler based concentration) emissions more negatively impact my health? 3) If I’m evaluating regional PM air quality models using FRM PM sampler concentrations, how good are my modeling results?
A. Garbage in – garbage out
4) Are these plants being equally regulated? 5) How will you answer the same questions for PM2.5?
1) The PSD differences are greater
1 10 100
Particle Diameter (μm)
0.2 0.4 0.6 0.8 1
Volume (%)
Plant B (M-201a)
MMD = 12.9 μm GSD = 1.7 PM10 = 56% PM2.5 = 1.3%
Plant A (M-201a)
MMD = 3.7 μm GSD = 1.8 PM10 = 96% PM2.5 = 27% C= 60 mg/dscm C= 54 mg/dscm
Source MMD (μm) GSD Particle Density (g/cm3) Reference Urban Urban Dust 5.7 2.25 NR USEPA (1996a) Agricultural Rice 21.75 NR NR Plemons (1981) Rice 12.10 2.24 1.46 Parnell et al. (1986) Corn 19.57 NR NR Plemons (1981) Corn 13.70 NR NR Wade (1979) Corn 13.60 1.80 1.50 Parnell et al. (1986) Soybeans 25.17 NR NR Plemons (1981) Soybeans 30.00 NR NR Martin (1981) Soybeans 15.50 NR NR Wade (1979) Soybeans 14.80 1.87 1.69 Parnell et al. (1986) Wheat 32.97 NR NR Plemons (1981) Wheat 14.70 2.08 1.48 Parnell et al. (1986) Sorghum 36.92 NR NR Plemons (1981) Sorghum 15.70 2.16 1.43 Parnell et al. (1986) Cotton Gin (Combined Streams) 20 - 23 1.82 – 2.00 1.8 - 2.0 Wang (2000) Cotton Lint Fibers 12.94 2.25 NR Parnell and Adams (1979) Cattle Feedlot (Downwind) 14.2 2.25 1.71 Sweeten et al. (1989) Swine Finishing House (Aerial) 14.3 2.02 NR Barber et al. (1991) Swine Finishing House (Settled) 18.4 1.99 NR Barber et al. (1991) Swine Production Facility 17.97 NR NR Barber et al. (1991) Poultry Production Facility 24.0 – 26.7 1.6 NR Redwine and Lacey (2001) Typical Soil 25 2.0 2.5 Pargmann et al. (2000) NR – Data not reported in the reference.