EPA/600/D-85/244
October 1985
IM.NITION OF THE LOKG-TERM CONTROL EFFICIENCY OF CHEMICAL DUST
SUPPRESSANTS APPLIED TO uNPAVED ROADS
by
Gregory E. Muleski
Thomas A. Cuscino, Jr.
Chatten Cowherd, Jr.
Midwest Research Institute
Kansas City, MO 64110
EPA Contract 68-02-3177
EPA Project Officer
Robert C. McCrillis
AIR AND ENERGY ENGINEERING RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
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NOTICE
This document has been reviewed in accordance with
U.S. iinvironmental Protection Agency policy and
approved for publication. Mention of trade names
or commercial products does not constitute endorse-
ment or recommendation for use.
ii
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DEFINITION OF THE LONG-TERM CONTROL EFFICIENCY OF CHEMICAL DUST
SUPPRESSANTS APPLIED TO UKPAVED ROADS
By
Gregory E. Muleski, Thomas A. Cuscino, Jr.,
and Chatten Cowherd, Jr.
Midwest Research Institute
425 Volker Boulevard
Kansas City, Missouri 64110
ABSTRACT
This paper presents the methodology and results of a field testing
program directed toward quantifying the long-term ef-
ficiency of chemical dust suppressants applied to industrial unpaved roads.
Three generic categories of suppressants were evaluated: water, a water-based
petroleum resin, and a water-based asphalt emulsion. The latter two sup-
pressants were the most frequently mentioned in discussions
with iron and steel companies. Watering was also selected because
of its widespread use and to compare its effectiveness to that of the
chemicals.
Knowledge of the long-term performance of dust suppressants is of vital
importance in determining a cost-effective program for reducing emissions from
open dust sources. The information presented in this paper enables one to determine
cost-effectiveness values for the chemicals evaluated.
1
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Trace element analysis of uncontrolled particulate emissions from un-
paved roads is also presented. Because open-source dust emissions may be
used to offset process emissions on a strict mass basis, information about
concentration levels of toxic components in dust emissions is of importance
in credibly implementing the Environmental Protection Agency's (EPA's)
Bubble Policy.
INTRODUCTION
There is strong evidence that open dust sources (such as vehicular
traffic on uapaved and paved roads, aggregate material handling, and wind
erosion) could occupy a prime position in particulate emission control strategy
development in the iron and steel industry. 2, 3 This conclusion is based on
comparisons between industry-wide uncontrolled emissions from open dust Bources
and typically controlled fugitive particulate emissions from major process
sources such as steelmaking furnaces, blast furnaces, coke ovens, and sin-
ter machines. Preliminary cost-effectiveness (dollars expended per unit
mass of reduced particulate emissions) analysis of promising control op-
tions for open dust sources indicated that reducing emissions from these sources
might result in significantly improved air quality at a lower cost compared to
additional reductions of process source emissions.
With the publication of the EPA's Bubble Policy (Alternative Emissions
Reduction Options) in the December 11, 1979, Federal Register (proposed
revisions published April 7, 1982), the steel industry
has recognized the economy of controlling open dust sources as compared to
implementing more stringent control of process stack and fugitive
particulate emissions. At the time of this writing, five emission reduction plans
(bubbles) in the iron and steel industry involving open dust sources have
been published in the Federal Register. The affected plants and the dates
the proposed or final rules appeared are shown below:
2
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Status
Final Rule
Final Rule
Final Rule
Proposed Rule
Proposed Rule
This paper presents long-term emission control efficiency decay curves for
chemical dust suppressants applied to unpaved roads at iron and steel
plants. The testing program described in this paper is a continuation of
MRI's pioneering work in the control of emissions from open dust sources in
the iron and steel industry.3'4 While the earlier study indicates that the control
of particulate emissions from this type of source is more cost-effective than con-
trolling process source emissions, this paper presents the first step in quantifying
the long-term performance and cost-effectiveness of dust suppressants ap-
plied to unpaved roads. Such long-term data are necessary
in order to accurately represent the controlled emission rate for an open
dust source as part of an emissions reduction plan based on the Bubble
Policy. This type of information is also required in examining the opti-
mal cost-effectiveness of a control measure. Because of the similarity of
unpaved roads in a variety of industries, the results pre-
sented in this paper are applicable to several industries in addition to
iron and steel.
Plant
Date
Annco-Middletovn Works
Shenango-Neville Plant
National-Weirton
Steel Division
National-Granite City
Steel Division
National-Great Lakes
Steel Division
March 31, 1981
December 29, 1981
December 9, 1982
December 17, 1982
December 17, 1982
Three generic categories of suppressants were evaluated: water, a water-
based petroleum resin, and a water-based asphalt emulsion. The latter two
were the most frequently mentioned chemical suppressants in discussions
with iron and steel companies. ^ Watering was also selected be-
cause of its widespread use and to compare its effectiveness to that of
the chemicals.
One factor affecting the performance of a dust suppressant is the size
(diameter) of the emitted particles being considered. On a microscopic level,
variation in
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control, efficiency for different size particles may be viewed as a result of
variation of bonding forces for particles with different surface-area-to-
volume ratios. Very few data are available to predict how the efficiency of a
specific suppressant will vary with the size of the emitted particles.
Prior MRI testing suggests that the suppressant's effectiveness for reducing
finer particle emissions is less than that for larger particles. ^ The particle size
ranges studied are:
TP Total airborne particulate matter.
IP Inhalable particulate matter consisting of particles
smaller than 15 pm in aerodynamic diameter.
PM10 Particulate matter consisting of particles smaller than
10 pm in aerodynamic diameter.
FP Fine particulate matter consisting of particles smaller
than 2.5 pm in aerodynamic diameter.
Finally, selected samples taken during the uncontrolled tests were
analyzed for trace metals. Dust emissions may currently be traded on a
strict total mass basis for process emissions. Information on the particle
size distributions and the concentration levels of specific toxic components
provides a basis for determining the need for future revisions to the Bubble Policy.
TEST PROCEDURE AND DESCRIPTION
This section presents the test procedure and site description for
this study. The following topics are discussed: (1) study design;
(2) site description; (3) quality assurance; and (4) dust suppressant
effectiveness calculation procedure.
Study Design
In developing a study design to characterize unpaved road
dust suppressant effectiveness, both a sampling methodology and a suppres-
sant application plan must be chosen. The sampling method must be able to
accurately characterize the dust emissions,and the suppressant application plan
4
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Bust be developed with attention paid to possible interference effects
which could impact determining the suppressants' effectiveness.
Unpaved road dust emissions are especially difficult to characterize
for the following reasons:
1. Both uncontrolled and controlled emission rates have a high
degree of temporal variability.
2. Emissions consist of a wide range of particle sizes (includ-
ing coarse particles which deposit immediately adjacent to the source). The
suppressants1 effectiveness can vary substantially, depending on the size of
the particles.
The scheme for quantification of emission factors must effectively
deal with these complications to yield source-specific emission data
needed to evaluate the priorities for emission control and the effective-
ness of emission suppressants.
Two basic techniques have been used in quantifying particulate emis-
sions from vehicular traffic on unpaved roads:
1. The upwind/downwind method involves measurement of concentrations
upwind and downwind of the source, utilizing ground-based samplers (usually
hi-vol samplers) under known meteorological conditions. Atmospheric dis-
persion equations are used to back-calculate the emission rate which most
nearly produces the measured concentrations. The Gaussian dispersion
equations are often applied to cases of near-roadway dispersion. However,
the equations generally used were not formulated for such an application.
2. MRI's exposure-profiling method involves direct measurement of
the total passage of open dust source emissions immediately downwind of
the source by means of simultaneous multipoint sampling over the effective
cross section of the open dust source emission plume. This technique uses
a mass-balance calculation scheme similar to EPA Method 5f rather than re-
quiring indirect calculation through the application of a generalized
atmospheric dispersion model.
5
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In addition to the above measurement techniques, the study design must
also include a suppressant application plan. Two major types of plans have
been used:
1. Testing is conducted on two or nore contiguous road segments.
One segment is left untreated,and the others are treated with a separate
dust suppressant.
2. Uncontrolled testing is initially performed on one or more road
segments. These segments are then treated with different chemicals,and
there is no segment left untreated as a reference. A normalization of
emissions is required to allow for differences in vehicle characteristics
during the uncontrolled and controlled tests which do not occur simultane-
ously.
Because of the two choices each for sampling method and control appli-
cation plan, there are four possible study designs. The first control applica-
tion plan allows concurrent testing of controlled and uncontrolled emissions.
Significant variation in the uncontrolled road surface, from segment to segment,
would distort the results. Also, it is necessary that a long road be
available in order to accommodate the additional uncontrolled segment and
to ensure that the control efficiency associated with a treated segment is
not affected by the track-on of dust from neighboring uncontrolled seg-
ments. None of the candidate test sites at surveyed plants had road
lengths amenable to this plan. Consequently, control plan 2 listed above
was selected.
A measurement technique was then required to complete the study de-
sign. Because the cost-effectiveness of a control measure cannot be cal-
culated without reliable uncontrolled emission factors, an accurate tech-
nique is required to quantify particulate emissions. The roost suitable
and accurate technique for quantifying unpaved road emissions in the iron
and steel industry has been shown to be exposure profiling.1 The method
is source-specific and its increased accuracy over the upwind/downwind
method is a result of the fact that emission factor calculation is based
on direct measurement of the variable sought; i.e., mass of emissions per
unit time.
6
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Thus, the study design used in this testing program employed exposure
profiling to first quantify uncontrolled particulate emissions from vehic-
ular traffic on unpaved roads and to then determine control efficiency from
normalized controlled emission factors. This design allowed MRI to accur-
ately determine not only the control performance but also the cost-effec-
tiveness of the dust suppressants evaluated.
Site Description
An asphalt emulsion was evaluated at Jones and Louehlin Sfel'p Indiana
Harbor Works,while watering and a petroleum resin were tested at Armco's
Kansas City Works. J&L initiated an experimental open dust emission re-
duction program just before the onset of the field testing. The test road
at the Indiana Harbor Works was not treated until MRI had conducted uncon-
trolled tests to establish a baseline for emissions. Following these tests,
MRI personnel supervised the application of the suppressant on the test road.
Application of the dust suppressant at the Kansas City site was contracted
and closely regulated by MRI.
Quality Assurance
The sampling and analysis procedures followed in this field testing
program were subject to certain quality assurance guidelines. Affected
areas included: (1) auditing procedure for gravimetric analysis of fil-
ters; (2) filter handling procedures in the field and laboratory; (3) equip-
ment flow rate calibration technique and frequency; (4) field data record-
ing procedures; (5) standard procedures for physical analysis of road ag-
gregate; and (6) calculation techniques and accuracy. A detailed descrip-
tion of the quality assurance procedures can be found in the final report.0
Suppressant Effectiveness Calculation
Although tests with and without suppressants were conducted at the same
site, it was necessary to obtain normalized values of emission factors in
order to make meaningful comparisons. This is true simply because the
vehicle mix on the test road varied not only from day to day but also dur-
ing different shifts during individual days. Thus, mcasurcment-b3sed
7
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emission factors required normalization in order that a change in vehicle
six was not mistakenly interpreted as part of the efficiency of the suppres-
sant being tested.
The method used in this study to normalize emission factors was based
on MRI's experimentally determined predictive emission factor equation for
emissions from vehicles traveling on unpaved roads.2 Basically, average
vehicle weight, number of wheels, and speed during a test were compared to
a standard set of values and the comparison used to normalize the roeasure-
ment-based emission factors.
The control efficiency c (in percent) for a given test is then calcu
lated as follows:
100%
a)
where:
normalized emission factor for controlled road for
a given test
geometric mean of normalized emission factors for
uncontrolled roads
ANALYSIS OF FIELD TEST RESULTS
Long-Term Suppressant Efficiencies
Three suppressants used to reduce unpaved road dust emissions
were evaluated during the study: (1) a 20% solution of an emulsified as-
phalt applied at an intensity of 3.2 Z/m2 (0.70 gal/yd2); (2) water applied
at an intensity of 2.0 Z/m2 (0.43 gal/yd2); and (3) a 20% solution of a
petroleum resin applied at an intensity of 3.8 Z/m2 (0.83 gal/yd2).followed
by a repeat application of 4.5 Z/m2 (1.0 gal/yd2) of 12% solution UU days
later. The results presented in this report are only directly applicable
to these dilution ratios and application intensities which, for the chemi-
cal dust suppressants, were recommended by the manufacturers. These ap-
plication parameters are, in general, much higher than those currently
used at iron and steel plants.
8
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Table I .presents the least-squares fit of control efficiency as a func
tion of Dumber of vehicle passes following application for the dust suppres-
sants evaluated during this study. It should be noted that the decay in
the efficiency of a chemical control is primarily a function of vehicle
passes and is only indirectly dependent on time because traffic is itself
a function of tine. Also shown in Table 1 are statistics that determine
the level of significance of the equation as well as source/application
parameters that affect the suppressant's performance.
In the case of the linear control efficiency (dust suppressant
effectiveness) decay functions shown in
Table I, the time T (in days) required between applications to
achieve an average control efficiency C is:
( _2_ (a - C), a > C > §
bKt
T = { T (2)
I 2fflR^C » 2 " C > 0
where:
a = intercept of the decay curve (%)
d = decay constant (%/vehicle pass)
Rp = traffic rate on road of interest (vehicle passes/day)
The asphalt emulsion was tested over a period of approximately four
months and nearly 50,000 vehicle passes. TP emissions showed the lowest
initial control efficiency. The control efficiency values associated with
particulate emissions in the smaller size ranges, however, showed a much
greater rate of decay than that for TP. The most extreme example of dif-
fering decay rates occurs during the comparison of TP and FP control effi-
ciencies. Initial FP control was substantially greater than that of TP,
but a sharp decrease in FP control efficiency occurred with the result
that FP emissions nearly match the uncontrolled state at a time when TP
emissions were still controlled at the 50% level.
The tests of watering of unpaved roads indicated high initial control
efficiency which decreased at a rate of approximately 8% per hour. The
rate of control efficiency decay was found to decrease as the size range
of particulate emissions decreased.
9
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TABLE I. DUST SUPPRESSANT eimiimict as a FtmrTin* o* vniia.r. passes
Average
No. of
VHiir le
Mean
VrMclr firamrters
Part Ir le
Suppressant
Time After
Applicat ton
Passes
per Dty
Weight
(Jig) (tnnsl
No of
Wheels
Si re
Range
l.east-Squares Pit
of Control Efficiency* (X)
CorrelatIon
Coef f11ient
level of
Sign if fcance
Asphalt t»nlsion
12 9/m*
(o ;o gal/yd')
of 20% solution
in water
2-116 Hays
410
2/ 10
9 2
Tp
IP
'•Hl0
fP
92.9-0 OOOBOO V
102-0 OOI24 V
102-0 0011) V
100-3.54 (lO*®) V*
-0.913
-0.915
-0.921
-0.986
991
991
9,1 h
99.91°
Pelroleuat Resin -
initial applica-
t ion
18 tfm*
(0 83 gal/y.l*)
of 20% solution
In water
7-41 days
94
14 18
6.2
TP
IP
P"|0
rr
79.1-0.0119 V
92 .2-0.0144 V
94.9-0.0134 V
102-0.0127 V
-0.717
-0.869
-0.892
-0.796
< 90%
951
981
90%
Tel roletim Resin •
reappli cat ion
4 5 f/m*
(l.o gil/yrf2)
of 121 solut ion in
water
4-35 Hays
9/
.19 4 J
6 0
TP
ip
rn,0
fp
97.0-0.00225 V
99 1-0.001/5 V
100-0.00410 V
lOU-0.00568 V
-0.648
-0.958
-0.960
-0 890
< 9 OX
95X
9SX
< 90X
Watering
2.0 tfm1
0.43 gal/ydz)
0-2.8 hr
1.200
44 49
6.0
TP
IP
P»io
FP
101-0.209 V
102-0.181 V
102-0.179 V
101-0.156 V
-0.958
-0.969
-0.963
-0.990
N/A
N/A
N/A
N/A
V rfprrsrnls ninnlallve vfliirlr passes after application. Complete uMigatinu is assumed imfdialrly after Application.
Because a parabola was nse«l to
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The tests of an initial application of a petroleum resin product did
not indicate significant variation in the control efficiency decay rate as
a function of particle size range. During each test in the 41 day period
after application, the measured control efficiency increased as the particle
size range decreased. Unlike the asphalt emulsion, the petroleum resin
appeared to control particulate emissions of different size fractions in a
consistent manner throughout-its lifetime. In other words, the decay rate
for the initial application of the petroleum resin was nearly identical
regardless of the particle size.
The tests of the reapplication of the petroleum resin provided strong
indication of a residual effect from the initial application. Figure 1
compares the PM10 control efficiency decay functions for
the initial and repeat applications. As shown in Figure 1, the rate
of decay for the repeat application was found to be roughly an order of
magnitude less than that associated with the initial application. Compari-
son of the surface aggregate size distribution before and after chemical
retreatment (Table II) suggests that the bonding characteristics of the
reapplication are enhanced by a residual effect of the initial treatment.
Chemical Analysis of Selected Samples
Trace element analysis of uncontrolled particulate emissions from un-
paved roads in the iron and steel industry was also conducted during the
course of this study. Because this type of emissions may be used to offset
process emissions on a strict mass basis, information on the concentration
levels of specific toxic components in the road dust emissions is of impor-
tance in credibly implementing the Bubble Policy.
Twenty-six samples, consisting of 12 exposed filters and 14 road surface
silt samples,were analyzed for trace metals using inductively coupled
plasma (1CP) emission spectroscopy. Both filter and surface samples con-
sisted of two different size fractions. In addition, five blank filters
were analyzed.
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100
90
80
70
e
60
50
40
1 1
sj I
Rood originally
vs.
tteofed with 3.6
\ \
\ 4/n2 of 20%
\ \
\ solution
\ X.
" \
Rood retrcoted ^S.
\
with 4.5 2/tr?
A
of 12% solution
' \
Averoge Vehicle
\
Weight = 36 Mg
\
Averoge No.
\
of Wheels = 6,1
1 1
.1 1
1500 3000 4500 6000
Vehicle Posses After Originol Application
7500
L
0
Figure 1.
1
40
20 40 60
Time Afler Original Application (Doyi)
80
Comparison of the control performance for PM]0 of an
initial and a repeat application of a petroleum
resin illustrating the residual effect.
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TABLE II
COMPARISON 07 SURFACE AGGREGATE SIZE DISTRIBUTION
BEFORE AND AFTER PETROLEUM RESIN REAPPLICATION
Mass Fraction (X) less than Stated £ize
Physical
Particle Before Re-
Size (pm) application
4 days 5 days 17 days
After Rgapplication
Tine
2,000
77
55
35
23
17
13
9.2
5.8
30
35
13
60
35
19
830
420
250
180
150
100
75
4.1
0.069
0.0087
4.4
1.5
0.67
0.36
0.12
0.034
9.4
6.0
4.3
2.3
1.6
For metals detected above a limit of detection in each sample of a
set of three (e.g., the profiler filters from the Indiana Harbor Works or
the subsilt samples from AnDCo),mean mass concentrations were determined.
Tables III and IV present summary statistics for exposed filters and sur-
face samples, respectively.
The values given for copper in Table IV are considered suspect
because of contamination from the brass screens used in mechanical sieving.
Comparison of split soil samples indicated that the copper concentration
of the sample sieved 40 min was 360^ greater than that of the 20 min sample.
Tin concentrations also increased with sieving time. Thus, it appears that
contamination of the sample occurs during mechanical sieving. Because
nickel was not detected in any of the surface aggregate samples, it is not
known if there is contamination associated with the nickel plated screens
used in sonic sieving.
It is interesting to note the enrichment factors suggested by Tables
III and IV. The mass concentration of an analyte is generally greater for
the sample containing the finer particles. Thus, most of the analytes ap-
pear to be concentrated in the smaller size particulate.
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LOOOOU(S)1
TABLE III
SUMMARY STATISTICS FOR ICP ANALYSIS OF AIRBORNE
PARTICULATE FROM~~UNCONTROLLED UNPAVED ROADS* "
(concentrations in pg analyte/g particulate)
Mean for Particulate Sampled
by Profiler
Mean for Particulate Sampled
Analyte
J&Lb
Armco
J &Lb
Armco
Calcium
246,000
(25)
_ c
310,000
(26)
Iron
75,900
(29)
67,600
(22)
80,400
(34)
32,800
(61)
Magnesium
-
-
-
-
42,800
(37)
-
-
Manganese
9,930
(30)
6,790
(15)
10,500
(34)
-
-
Titanium
1,790
(31)
-
-
1,930
(31)
-
-
Copper
385
(82)
-
-
701
(46)
-
-
Chromium
688
(25)
-
m
729
(33)
-
-
Barium
-
-
-
-
-
-
29,600
(80)
Zinc
-
m
57,600
(50)
-
-
28,900
(41)
Value in parentheses represents relative standard deviation (%).
These concentrations have been scaled using the mean rate of recovery for
NBS Coal Fly Ash for the particular analyte if available, or by the aver-
age recovery rate for all the analytes detected in the samples.
n-n indicates below detection limit.
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TABLE IV
SUMMARY STATISTICS FOR ICP ANALYSIS OF UNCONTROLLED,
UNPAVED ROAD SURFACE AGGREGATE SAMPLES
(concentrations in pg analyte/g particulate)
Mean Concentration for Mean Concentration for
Silt (< 75 pm) Subsilt (< 20 pm)
Analyte
J &Lb
Armco
J&Lb
Armco
Calcium
446,000
(7.9)
83,700
(38)
548,000
(6.3)
111,000
(8.2)
Iron
153,000
(16)
> 96,400
(NA)
250,000
(21)
66,100
(3.3)
Magnesium
75,900
(13)
13,900
(39)
94,300
(2.5)
12,000
(7.1)
Manganese
30,500
(15)
14,900
(16)
39,200
(16)
8,760
(5.4)
Aluminum
13,400
(7.6)
18,800
(51)
16,700
(5.2)
27,800
(8.6)
Potassium
-
6,290
(16)
-
8,370
(7.6)
Titanium
3,660
(17)
1,390
(9.4)
6,580
(8.5)
2,410
(6.2)
Sodium
1,190
(19)
2,300
(42)
1,680
(19)
3,560
(7.3)
Chromium
1,760
(17)
2,230
(14)
2,420
(24)
1,240
(3.5)
Zinc
645
(40)
1,730
(9.6)
1,050
(88)
1,920
(15)
Boron
159
(21)
-
196
(21)
-
Lead
-
331
(29)
418
(8.5)
Barium
145
(7.6)
262
(64)
176
(5.3)
426
(7.9)
Copper
121
(39)
115
(27)
872
(88)
160
(9.5)
Nickel
-
86.1
(17)
-
52.7
(17)
Yttrium
-
-
38.1
(17)
-
Value in parentheses represents relative standard deviation (%).
Concentrations scaled in the same manner as in Table III.
There is evidence of copper contamination during mechanical sieving, as dis
cussed in the text.
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As- can be seen from Tables III and IV, trace metal concentrations in
the filter samples tend to increase with increases in the concentration in
the surface sample. The two exceptions are 2inc and barium. The concen-
trations in these metals in the filter samples are much greater than the
concentrations in the surface samples.
With the exceptions of copper, zinc, and barium, it was found that an
essentially linear relationship between downwind airborne and surface ag-
gregate mass concentrations is indicated by the limited data available
here:
Ca = k (CS)P (3)
where = airborne mass concentration (pg analyte/g particulate)
C = mass concentration of surface aggregate (pg analyte/g
particulate)
k,P= regression parameters as follows:
Sample Regression
Air Surface Parameters Number of Correlation
Sampler Aggregate k P Data Points Coefficient
Profiler Silt 0.297 1.04 6 0.997
Cyclone Subsilt 0.129 1.10 7 0.994
Because of these relationships, it appears possible to economically esti-
mate airborne elemental mass concentrations by examining the corresponding
concentrations in the surface material. However, more data are required
to substantiate such an approach.
CONCLUSIONS
Earlier studies of the effectiveness of unpaved road dust sup-
pressants have indicated that reducing particulate emissions from
this type of source may result in significantly improved air quality at a
substantially lower cost compared to the further reduction of process source
emissions. However, these earlier studies were directed toward quantifying
initial
16
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effectiveness toon (1 to 2 days) after application. Although decay
in effectiveness was usually noticed, data obtained so
¦hortly after application do not adequately characterize the chemical suppres-
sants long-term performance as commonly applied in the iron and steel industry.
Long-term dust suppression data are needed in order to develop effec-
tive programs for reducing dust emissions from unpaved roads* These data
are necessary to determine (a) average emission reduction over a period
of time, (b) the frequency of application required to achieve a specific
average emission reduction, and (c) the cost-effectiveness of the particu-
lar dust suppressant.
This paper has presented long-term emission control efficiency values associ-
ated with dust suppressants currently in use at iron and steel plants.
The results indicate that the chemical suppressants tested, when applied at the
dilution ratio and application intensity recommended by the manufacturer,
are capable of significantly reducing particulate emissions for at
least one month (under the traffic rate during testing). Furthermore, the
lifetime of a chemical suppressant appears to increase dramatically when
reapplied. However, the lifetime of a suppressant tends to decrease with decreas-
ing particle size.
Enrichment factors were noticed for most of the trace metals detected
in the chemical analysis. The mass concentration of an analyte is gen-
erally greater for the sample containing the finer particles.
Essentially linear relationships were found between downwind airborne
and surface aggregate mass concentrations for the majority of the trace
elements detected in the chemical analysis of uncontrolled, unpaved road
dust emissions. Because of these relationships, it appears possible to
economically estimate airborne elemental mass concentrations by examining
the corresponding concentrations in the surface material. However, more
data are required to substantiate such an approach.
17
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ACKNOWLEDGMENT
This work was performed under U.S. EPA Contract No. 68-02-3177, Task
14. The project officer was Robert C. McCrillis.
REFERENCES
1. Bohn, R.t T. Cuscino, Jr.» and C. Cowherd, Jr. Fugitive Emissions from
Integrated Iron and Steel Plants. EPA-600/2-78-050 (NTIS PB281322), U.S.
EPA, Industrial Environmental Research Laboratory, Research Triangle
Park, NC, March 1978. 262 pp.
2. Cowherd, C., Jr., R. Bohn, and T. Cuscino, Jr. Iron and Steel Plant
Open Source Fugitive Emission Evaluation. EPA-600/2-79-103 (NTIS PB2£9~
385), U.S. EPA, Industrial Environmental Research Laboratory, Research
Triangle Park, NC, May 1979. 139 pp.
3. Cuscino, T., Jr., G. E. Muleski, and C. Cowherd, Jr. Iron and Steel
Plant Open Source Fugitive Emission Control Evaluation. Draft final report
IERL-RTP-1388, U.S. EPA, Industrial Environmental Research Laboratory.
Research Triangle Park, NC, August 1982. 183 pp.
4. Cuscino, T., Jr., G. E. Muleski, and C. Cowherd, Jr. Determination
of the Decay in Control Efficiency of Chemical Dust Suppressants on
Unpaved Roads. Paper presented at the U.S. EPA Symposium on Iron and
Steel Pollution Abatement Technology for 1982, Pittsburgh, PA, Nov. 16-18,
1982.
5. Muleski, G. E., T. Cuscino, Jr. and C. Cowherd, Jr. Evaluation of Un-
paved Road Fugitive Dust Controls in the Iron and Steel Industry.
Draft Final Report, EPA Contract No. 68-02-3177, Task 14. U.S. EPA,
Industrial Environmental Research Laboratory. Research Triangle Park,
NC, April 1983. 150 pp.
18
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TECHNICAL REPORT DATA
(PIcqsc read fnUruc(tom on the reverse be fort' completing)
1 REPORT NO. 7.
EPA/600/D-85/244
3. RECIPIENT'S ACCESSION NO.
•1. TITLE AND SUBTITLE
Definition of the Long-term Control Efficiency of
Chemical Dust Suppressants Applied to Unpaved
Roads
5 REPORT OATE
October 1985
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Gregory E, Muleski, Thomas A. Cuscino, Jr.» and
Chatten Cowherd, Jr.
8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Midwest Research Institute
425 Volker Boulevard
Kansas City, Missouri 64110
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-02-3177, Task 14
12 SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Air and Energy Engineering Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOO COvEREO
Published Paper;
14. SPONSORING AGENCY CODE
EPA/600/13
is. supplementary notes ^EERL proiect officer is Robert C. McCrillis. Mail Drop 65,
919/541-2733.
is. abstract paper presents the methodology and results of a field testing program
to quantify the long-term efficiency of chemical dust suppressants applied to indus-
trial unpaved roads. Three generic categories of suppressants were evaluated: water,
a water-based petroleum resin, and a water-based asphalt emulsion. Knowledge of
the long-term performance of dust suppressants is vital in determining a cost-
effective program for reducing emissions from open dust sources. The information
presented helps determine cost-effectiveness values for the chemicals evaluated.
Trace element analysis of uncontrolled particulate emissions from unpaved roads is
also presented. Because open-source dust emissions may be used to offset process
emissions on a strict mass basis, information about concentration levels of toxic
components in dust emissions is important in credibly implementing EPA!s Bubble
Policy. Study results indicate that the chemical suppressants tested, when applied
at the dilution ratio and application intensity recommended by the manufacturer, can
significantly reduce particulate emissions for at least 1 month (under the traffic
rate during testing). Further, the lifetime of a chemical suppressant appears to in-
crease dramatically when reapplied. However, the lifetime of a suppressant tends to
decrease with decreasing particle size.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
b.IDENTIFIERS/OPEN ENDEO TERMS
c. COSATi I icId/Croup
Pollution Emulsions
Dust Control Cost Effectiveness
Roads Particles
Water Dust
Petroleum Products
Asphalts Toxicity
Processing Leakage
Pollution Control
Stationary Sources
Dust Suppressants
Unpaved Roads
Petroleum Resin
Particulates
Fugitive Emissions
13B 07D
14A
14G
07B 11G
11G
08G.13C 06T
13H
13. LilSTrtlBUTlON STATEMENT
Release to Public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
21
20 SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (1-73)
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