FIELD TESTING AND EVALUATION OF DUST DEPOSITION AND ...

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the box model was examined, from a theoretical and practical standpoint. The analysis indicated that the model is not practical for wide spread use because the parameterization of dispersion is reliant on assumptions that cannot always be met in reality. Related to the third finding from Countess (2001), “Fugitive dust emission factors need to be appropriate”, the emission factors measured at Ft Bliss with high timeresolution instruments suggest that AP-42 may overestimate PM 10 emissions from unpaved roads. This overestimate was due to the lack of accounting for vehicle speed and to the use of the average weight of all vehicles in calculating the emission factors. All in all, this report concludes that there is no single, “silver bullet” solution to the problem of reconciling fugitive dust emission inventories and ambient source contribution estimates. Progress has been achieved in the quantification of the near-field removal of dust particles and work in that area should continue. There are still uncertainties about the AP-42 emission factors for unpaved road dust that have resurfaced in this study and must be resolved. viii
TABLE OF CONTENTS 1. INTRODUCTION 1-1 1.1 Background 1-1 1.2 Objectives 1-1 1.3 Approach 1-1 1.4 Report Organization 1-2 2. BACKGROUND 2-1 2.1 Dry Deposition 2-2 2.1.1 The Model of Slinn (1982) 2-4 2.1.2 Dry Deposition in the ISC3 2-12 2.1.3 The Model of Raupach (1999) 2-13 2.2 Dispersion in the atmosphere 2-14 3. MEASUREMENT OF DEPOSTION VELOCITY 3-1 3.1 Methods 3-1 3.1.1 Deposition on Flat Substrates 3-1 3.1.2 Deposition on Artificial Vegetation 3-4 3.1.3 Flat Substrate Method Testing 3-5 3.1.4 Vegetative Method Testing 3-5 3.2 Results: Deposition velocities measured by SEM and gravimetric techniques 3-6 3.3 Discussion 3-11 3.3.1 Comparison of results with the model of Slinn (1982) 3-11 3.3.2 Results in the context of the resistance model for deposition 3-13 3.4 Conclusions 3-14 4. MODELS USED TO STUDY PARTICLE REMOVAL BY DRY DEPOSITION DOWNWIND OF AN UNPAVED ROAD 4-1 4.1 Presentation of Models 4-1 4.1.1 The one-dimensional Atmospheric Diffusion Equation (ADE) 4-1 4.1.2 The Integrated Source Complex Model 3 (ISC3) 4-4 4.1.3 The Gillette Box Model This section of the text was provided by Dr. Dale Gillette (NOAA) with some minor adjustments by DRI 4-6 ix
Page 1: FIELD TESTING AND EVALUATION OF DUS
Page 5 and 6: EXECUTIVE SUMMARY The Western State
Page 7: models. Countess (2001) summarized
Page 11 and 12: TABLE OF FIGURES Figure 2-1. Develo
Page 13 and 14: Figure 4-6. The fraction of particl
Page 15 and 16: Figure 5-16. Comparison of fraction
Page 17 and 18: LIST OF TABLES Table 2-1. Parameter
Page 19 and 20: 1. INTRODUCTION 1.1 Background The
Page 21 and 22: 2.BACKGROUND Fugitive dust is emitt
Page 23 and 24: Planetary Boundary Layer (PBL) F =
Page 25 and 26: C D u* = ur The overall drag c
Page 27 and 28: St a vg u g = cA L * Equation 2
Page 29 and 30: Table 2-1. Parameters used in the S
Page 31 and 32: 1E+01 1E+00 z0 = 4.4 cm z0 = 6.4 cm
Page 33 and 34: pathway for deposition for particle
Page 35 and 36: An alternative method for modeling
Page 37 and 38: 3. MEASUREMENT OF DEPOSTION VELOCIT
Page 39 and 40: Department at the University of Uta
Page 41 and 42: In the laboratory, the deposited ma
Page 43 and 44: Table 3-2. Log of all flat substrat
Page 45 and 46: 16 Normalized Deposition Velocity 1
Page 47 and 48: 1.E+05 Deposition Velocity - cm/s 1
Page 49 and 50: are deposition from a horizontally
Page 51 and 52: single element that is intended to
Page 53 and 54: 4. MODELS USED TO STUDY PARTICLE RE
Page 55 and 56: κu ( ) * z 8 fz K zz = exp −
Page 57 and 58: C = −6 ( 1× 10 ) QV 2π u s σ
Page 59 and 60:
oad. M is the mass of particles in
Page 61 and 62:
By making the approximation that dm
Page 63 and 64:
diameters less than 10 microns. Dis
Page 65 and 66:
of such a height is somewhat arbitr
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1 0.9 0.8 1 0.9 0.8 Fraction remain
Page 69 and 70:
Fraction of Particles Remaining in
Page 71 and 72:
gravitational settling. Stable cond
Page 73 and 74:
though it is expected to improve at
Page 75 and 76:
5. DETERMINATION OF PARTICLE REMOVA
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PM 10 measured by the DustTrak must
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100% 90% 80% Relative Frequency (pr
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average wind speed measured at 12 m
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where the subscript i indicates tha
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k C int = peakend k C peeakstart d
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Height z (m) 14 12 10 8 6 T1_data T
Page 89 and 90:
Horizontal fluxes of PM 10 measured
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Table 5-2 enumerates the speed-depe
Page 94 and 95:
6 Ratio of AP-42 Emission Factor to
Page 96 and 97:
to the ground) giving an approximat
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models analyzed in this study is su
Page 100 and 101:
Table 6-1. Screen analysis of test
Page 102 and 103:
value which was used up to the midp
Page 104 and 105:
measured at 3,1. Downwind the dust
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trips, the average readings for the
Page 108 and 109:
Fraction of particles of stated siz
Page 110 and 111:
the ground, where particles have a
Page 112 and 113:
particles through the top of the bo
Page 114 and 115:
deposition. Much of the decrease in
Page 116 and 117:
7-8
Page 118 and 119:
Gifford, F.A. (1961). Use of Routin
Page 120:
Venkatram, A. (1993). The Parametri
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