EPA/600/A-93/089
Multiple Metals Stack Emission Measurement Methodology
for Stationary Sources, Current Status
Thomas 1. Ward
Source Methods Research Branch
Methods Research and Development Division
Atmospheric Research and Exposure Assessment Laboratory
U, S. Environmental Protection Agency
Research Triangle Park, NC 27711
ABSTRACT
Stack emissions of metals from stationary sources are of
present interest to the United States Environmental Protection
Agency (USEPA), to state and local governments, to industries, and
to the public. When regulations require limitation of metals in
stack emissions, it follows logically that measurement methodology
is necessary for determining compliance to the established limits.
This presentation presents a broad overview of measurement
methodology for the purpose of determining multiple metals stack
emissions of up to sixteen metals using one sampling train
developed by the Atmospheric Research and Exposure Assessment
Laboratory of USEPA.
Isokinetic sampling from a grid of points produces a
representative sample from which the multiple emissions of up to
sixteen metals can be measured in the sample from one train.
Metals in the stack particulate matter and in the gases are
measured separately. The samples are prepared by digestion for
subsequent instrumental analysis by inductively coupled plasma or
atomic absorption spectroscopy. The sixteen metals are total Cr,
Cd, As, Ni, Mn, Be, Cu, Zn, Pb, Se, P, Tl, Ag, Sb, Ba, and Hg.
Emission factor development, research requiring quantification of
metals emissions, and determining emission compliance are important
potential applications of this methodology.
This paper has been reviewed in accordance the U. S.
Environmental Protection Agency's peer and administrative review
policies and approved for presentation and publication. Mention of
trade names or commercial products does not constitute endorsement
or recommendation for use.
INTRODUCTION
Stack emissions of metals from stationary sources are of
present interest to the United States Environmental Protection
Agency (USEPA), to state and local governments, to industries, and
to the public. When regulations require limitation of metals in
stack emissions, it follows logically that measurement methodology
is necessary for determining compliance to the established limits.
This presentation presents a broad overview of measurement
methodology for the purpose of determining multiple metals stack
1
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emissions of up to sixteen metals using only one sampling train
developed by the Atmospheric Research and Exposure Assessment
Laboratory of USEPA. Previous USEPA methods exist for use when
prescribed by regulations for measurement of emissions of only a
single metal in one sampling train. These include a-separatee
individual train and methodology for either Pb , Be , Hg , or As .
The multiple metals methodology is particularly useful in sampling
situations in which one sampling train can be used instead of two
or more trains to measure metals because of the significant
potential for reduced cost and increased efficiencies in emissions
measurement.
DISCUSSION
The multiple metals measurement methodology for up to sixteen
metals in one train is tentatively planned by The Office of Air
Quality Planning and Standards of USEPA to be proposed as Method
29, in 40 CFR 60, Appendix A . The current status of this
methodology is discussed in this presentation. A condensed
description of the methodology is given here. A representative
sample of the stack multiple metals emissions is acquired by using
a single train by isokinetic sampling from a grid of sampling
points. Up to sixteen metals can be measured in the sample
produced by this one train. Within the sampling train a filter
captures the metals in particulate matter and acidic impinger
solutions capture the metals in the gases. The samples are then
recovered from the train, prepared for analysis by digestion, and
finally analyzed by inductively coupled plasma and/or atomic
absorption spectroscopy (AAS) including Graphite Furnace AAS
(GFAAS) or Cold Vapor AAS (CVAAS) as applicable. Calculations are
then performed to determine concentrations of the metals in the
stack effluent from which stack emissions may be determined. The
sixteen metals are total Cr, Cd, As, Ni, Mn, Be, Cu, Zn, Pb, Se, P,
Tl, Ag, Sb, Ba, and Hg. An important use of the methodology would
occur should government entities or others develop additional
regulations in the form of limitations of metals in stack emissions
and determine that the methodology be used to determine compliance
to the emission limits. Emission factor development and other
research requiring quantification of metals emissions are other
important potential applications of this methodology.
The train and methodology have undergone changes designed to
increase understanding of the management of the methodology
including its allowable options to yield the desired detection
limits for metals concentrations in the stack effluent: these are
termed in-stack detection limits as defined in the methodology.
Also, changes have occurred which decrease chances for
contamination of the sample, increase understanding of the
measurement of metals emissions especially mercury emissions, and
increase understanding of the limits to corrections allowed by the
methodology for certain blank reagent values.
The methodology includes acquisition of a representative
source sample from a grid of points in the sampling plane. In a
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one hour sampling period at a typical average nominal stack aerosol
sampling rate of 21 liters per minute, a sample of 1.25 cubic
meters will ±>e obtained which can yield the in-stack detection
limits (ug/m ) shown in Table 1. For multiple metals sampling a
Method 5 type sampling train which can achieve the above described
nominal sampling rates and sample volume was modified to have glass
components including a glass probe tip, glass probe and glass
filter holder, low metals content quartz fiber filter, Teflon
filter support, and glass impingers. The modification as shown in
Figure 1 of the Method 5 train was selected because of its ease of
operation and availability of equipment to all source samplers, low
cost, and isokinetic sampling capability. Quartz probe tips and
probes are available, also, for special sampling applications.
Acidic absorbing solutions for the metals are used in four of the
seven impingers in the multiple metals train. As described in the
method an aqueous solution of combined 5 percent nitric acid and 10
percent hydrogen peroxide is used in the second and third impingers
which follow the empty first impinger, and an aqueous solution of
combined 4 percent potassium permanganate and 10 percent sulfuric
acid is used in the fifth and sixth impingers which follow the
empty fourth impinger.
The multiple metals methodology describes how the sampler may
design the sampling, digestion and analytical conditions to meet
the specific needs of the test. The in-stack detection limits
shown in Table 1 are for nominal sampling conditions. However, the
in-stack detection limits produced in the actual test may be
lowered, that is, made more sensitive than those shown in Table 1.
For example, if the actual sample volume is 2.50 cubic meters
instead of 1.25 cubic meters, the in-stack detection limits will be
one-half those shown in Table 1. By using the other design options
described in the methodology, the in-stack detection limits could
be one-tenth or even much lower than one-tenth of those shown in
Table 1.
If desired or required, blank corrections according to the
strict guidelines/limitations described in the methodology may be
performed.
SUMMARY
In summary, in its current status the multiple metals
methodology allows measurement of coincidental stack emissions of
up to sixteen described metals in one sampling train. The
methodology describes how the sampler may adjust (design) the
sampling conditions to meet the needs of the test. Preparation for
sampling and the acquisition, digestion and analysis of the sample
are described adequately. Blank corrections according to the
strict guidelines/limitations may be performed.
REFERENCES
1. Code of Federal Regulations. Title 40 - Protection of
Environment, Part 60, Appendix A, Method 12, United States
Government Printing Office, Washington, DC. July 1992,
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40 CFR 60, Appendix A, Method 12.
2. Ibid., 40 CFR 61, Appendix B, Method 104.
3. Ibid., 40 CFR 61, Appendix B, Method 101A.
4. Ibid., 40 CFR 61, Appendix B, Method 108.
5. EMTIC Bulletin Board System, United States Environmental
Protection Agency, Office of Air Quality Planning and
Standards, Technology Transfer Network, Research Triangle
Park, NC 27711, 1993.
6. Code of Federal Regulations. Title 40 - Protection of
Environment, Part 60, Appendix A, Method 5, United States
Government Printing Office, Washington, DC. July 1992,
40 CFR 60, Appendix A, Method 5.
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TABLE 1. XN-STACK METHOD DETECTION LIMITS (ug/ffl3)
FOR TRAIN FRACTIONS USING ICAP AND AAS
Front-half
Back-half
Back-half
Fraction 1
Fraction 2
Fractions
Probe and Filter
Impingers 1-3
*Hg, only"
Metal
Impingers 4-6
Total Train
Antimony
7-7 (0.7)*
3.8 (0.4)*
11.5 (l.D*
Arsenic
12.7 (0.3)*
6.1* (0.1)*
19.1 (0.1)*
Barium
0.5
0.3
0.8
Beryllium
0.07 (0.05)*
0.04 (0.03)*
0.11 (0.08)*
Cadmium
1.0 (0.02)*
0.5 (0.01)*
1.5 (0.03)*
Chromium
1.7 (0.2)*
0.8 (0.1)*
2.5 (0.3)*
Copper
1.4
0.7
2.1
Lead
10.1 (0.2)*
5.0 (0.1)*
15.1 (0.3)*
Manganese
0.5 (0.2)*
0.2 (0.1)*
0.7 (0.3)*
Mercury
0.6**
3.0**
2.0**
5.6**
Nickel
3.6
1.8
5.4
Phosphorus
18
9
27
Selenium
18 (0.5)*
9 (0.3)*
27 (0.8)*
Silver
1.7
0.9
2.6
Thallium
9.6 (0.2)*
4.8 (0.1)*
14.4 (0.35*
Zinc
0.5
0.3
0.8
{ )* Detection limit when analyzed by GFAAS.
** Detection limit when analyzed by CVAAS, estimated for Back-Half and
Total Train.
Note: Actual method in-stack detection limits will be determined based
on actual source sampling parameters and analytical results as
described earlier in this section.
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Al glass sample exposed surface to tier*.
(Except when Teflon filter support is used.).
Thermometer
Glass
Filer
Holder
Thermocouple
Thermocouple
Impingers with
Absorbing Solutions
ftfatt probe bier
Probe
Check
Valve
Healed Area
Reverse-Type
Pilot Tube
t
Empty (Optional Moisture Knockout)
$%HNOa /10%H2O2
4% KMrO a /10% H 9 SO 4
Vacuum
Gauge
Thermocouples
OriSce
Main
Valve
Dry Gas
Meier
Figure 1. Schematic of multiple metals sampling train configuration.
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before compter
1. REPORT NO. 2.
EPA/600/A-93/089
j.
4. title and subtitle
Multiple Metals Stack Emission Measurement Methodology
for Stationary Sources, Current Status
6. REPORT OAT6
6. PERFORMING ORGANIZATION CODE
7. AUTHORS!
Thomas E. Ward
B. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
EPA/ORD/AREAL/SMRB
Research Triangle Park, NC 27711
10. program element NO.
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
EPA/ORD/AREAL/SMRB
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
1*. SPONSORING AGENCY CODE
15. supplementary notes
Presented in Workshop and Published in Journal "Fuel Processing Technology"
16. abstract
Stack emissions of metals from stationary sources are of present interest to the United
States Environmental Protection Agency (USEPA), to state and local governments, to
industries, and to the public. When regulations require limitation of metals stack
emissions, it follows logically that measurement methodology is necessary for
determining compliance to the established limits. This presentation presents a broad
overview of measurement methodology for the purpose of determining multiple metals
stack emissions of up to sixteen metals using one sampling train developed by the
Atmospheric Research and Exposure Assessment Laboratory of USEPA.
Isokinetic sampling from a grid of points produces a representative sample from
which the multiple emissions of up to sixteen metals can be measured in the sample from
one train. Metals in the stack particulate matter and in the gases are measured
separately. The samples are prepared by digestion for subsequent instrumental analysis
by inductively coupled plasma or atomic absorption spectroscopy. The sixteen metals
are total Cr, Cd, As, Ni, Mn, Be, Cu, Zn, Pb, Se, P, Tl, Ag, Sb, Ba, and Hg. Emission
factor development, research requiring quantification of metals emissions, and
determining emission compliance are important potential applications of this
methodology.
17. KEY WORDS AND DOCUMENT ANALYSIS
a DESCRIPTORS
b ID^NTIf lERS'OPEN ENDED TE RMS
c, cosati Field/Croup
18. DISTRIBUTION STATEMENT
Public
19, SECURITY CLASS (This Report)
Unclassified
21 NC OF PAGES
7
20 SECURITY CLASS (This papa
Unclassified
22 PRiCE
EPA Ferm 2220-1 (R«». 4-77) previous ecitiomi oes:.ffc
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