United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EMB Report 88 CEP 11
April 1988
Air
Chromium
Electroplaters
Test Report
Automatic Pie
b
Casting
Saint Clair Shores
Michigan
-------
EPA Contract No. 68-02-4346
Work. Assignment 3
August 31, 1989
FINAL REPORT
MODIFIED METHOD 138 AND THE
CHROMIUM SCREENING METHOD SAMPLING
PROGRAM DESCRIPTION
DETERMINATION OF THE EFFECTS OF
CHEMICAL FUME SUPPRESSANTS ON
HEXAVALENT CHROMIUM EMISSIONS
Automatic Die Casting
St. Clalr Shores, Michigan
Prepared for:
U.S. Environmental Protection Agency
Emission Measurement Branch
Research Triangle Park, North Carolina 27711
Prepared by:
PEER Consultants, P.C.
4134 Linden Avenue, Suite 202
Dayton, Ohio 45432
-------
TABLE OF CONTENTS
SECTION PAGE
-1.Q-- INTRODUCTION 1-1
2.0 - PROCESS OPERATION 2-1
2.1 - PROCESS DESCRIPTION 2-1
2.2 - AIR POLLUTION CONTROL 2-3
2.3 - PROCESS CONDITIONS DURING TESTING 2-5
3.0 - SUMMARY OF RESULTS 3-1
3.1 - INTRODUCTION 3-1
3.2 - HEXAVALENT CHROMIUM EMISSION RESULTS . . 3-3
3.2.1 - Condition 1 3-3
3.2.2 - Condition 2 3-7
3.2.3 - Condition 3 3-10
3.3 - PLATING TANK SOLUTIONS 3-10
4.0 - SAMPLING LOCATIONS AND TEST METHODS 4-1
4.1 - PLATING EMISSIONS 4-1
4.1.1 Location of Measurement Site 4-1
4.1.2 Test Methods 4-3
4.2 - EMISSION SAMPLE ANALYSIS 4-6
5.0 - QUALITY ASSURANCE 5-1
5.1 - INTRODUCTION 5-1
5.2 - FIELD QUALITY ASSURANCE PROCEDURES 5-1
5.2.1 Sample Blanks 5-1
5.2.2 Matrix Effects Check 5-4
5.2.3 Duplicate Samples 5-4
5.2.4 Standards 5-4
5.2.5 Chain of Custody 5-4
5.2.6 Sample Transfer 5-5
5.3 - SAMPLING TRAIN COMPONENTS 5-5
5.4 - VERIFICATION OF CALCULATIONS 5-5
5.4.1 Emission Calculations 5-5
5.4.2 Chromium Concentration 5-5
111
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APPENDIX PAGE
A - Process Monitoring Data A-l
.>(-
- B - Field Data Sheets Flow Rate and Emission
Calculation Sheets B-l
C - Calculation Checks C-l
D - Draft Method - Determination of Hexavalent Chromium 1n
Dry Particulate Emissions from Stationary Sources D-l
E - Cha1n-of-Custody Data Sheets . E-l
F - Equipment Calibration Data F-l
G - Project Participants and Activity Log G-l
LIST FIGURES
FIGURE PAGE
1.1 Diagram Showing Sampling Location, Segment A2 . 1-2
2.1 Plan view of the decorative chromium plating shop
at Automatic Die Casting Specialists, Inc.
St. Clalr Shores, Michigan ..... 2-2
2.2 Diagram of ventilation and control system for
chromium plating tank No. 27 2-4
4.1 Cross-Sectional View of Duct at Measurement Site 4-4
LIST OF TABLES
TABLE PAGE
2-1 Average Operating Parameters for Each Test Run 2-6
2-2 Average Plating Solution and Fume Suppressant Parameters
for Each Test Run 2-8
2-3 Total Current Supplied During Each Emission Test Run 2-9
3-1. Schedule of Activities 3-2
3-2 Summary of Flue Gas Conditions 3-4
3-3 Summary of Sample Volumes, Analytical Results,
and Emission Rates for Condition 1 3-5
1v
-------
LIST OF TABLES (cont)
TABLE
3P4 ^Summary of Sample Volumes, Analytical Results,
and Emission Rates for Condition 2
3-8
3-5 Summary of Sample Volumes, Analytical Results,
and Emission Rates for Condition 3 3~'°
3-6 Summary of Plating Solution Analytical Results 3-11
4-1 Sample Traverse Point Locations 4-2
5-1 Summary of Analytical Results for QA/QC Samples and Blanks 5-2
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SECTION 1.0
INTRODUCTION
During the weeks of April 18 and 25, 1987, an emission measurement
program was conducted at the Automatic Die Casting facility located in
St. Clair Shores, Michigan. The primary purposes of this program were to
collect data to support the development of regulations for hexavalent
chromium (Cr+') emissions from chromium plating operations that use
chemical fume suppressants as a method of emission control and to verify the
efficiency of the chromium screening method that is currently being
developed by the EPA.
The principal reason for selecting Automatic Die Casting for source
testing was that the plant was willing to operate the chromium plating tank
under three different conditions:
1. without fume suppressants;
2. with the addition of a foam blanket; and •
3. with the addition of a foam blanket and wetting agent.
The plant is representative of other plants in the industry that perform
decorative chromium electroplating with an automated plating line. Based on
the operating parameters such as current, voltage, chromic acid
concentration and plating time, their chromium plating tank is typical of
those used in the industry.
Cr*' emissions were measured prior to entering the inlet to the
scrubber serving the chromium plating line and the chromium rework tank.
Figure 1-1 is a diagram showing the sampling location (Segment A ).
Testing was performed using the EPA Modified Method 138 (MM13B) and the EPA
Screening Method. On-site analysis of the samples was performed using the
diphenylcarbazide colorimetric method which will be discussed in Section 4.0
of this report. PEER Consultants P.C., from Dayton, Ohio, and Pacific
Environmental Services, Inc., (PES) from Cincinnati, Ohio, conducted the
MM13B sampling and on-site analysis. Midwest Research Institute (MRI) from
1-1
-------
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Figure 1.1. Diagram showing sanpling location, Segment
-------
Raleigh, North Carolina, monitored the process conditions, and the U.S. EPA
Technical Support Division conducted the chromium screening method, set up
the on-s1te computer ceTiter and observed the test program.
This report 1s organized Into several sections each addressing specific
aspects of the test program. Section 2.0 describes the process and Its
operation. Section 3.0 presents a summary and discussion of results.
Section 4.0 describes the sampling location and test methods and
Section 5.0 presents the QA/QC measures. Appendix A presents process
monitoring data sheets; Appendix B, the field data sheets for each test,
Appendix C, calculation sheets for each test; Appendix D, the hexavalent
chromium analytical method; Appendix E, cha1n-of-custody data sheets;
Appendix F, equipment calibration sheets; and Appendix G, project
participants and activity log.
1-3
-------
SECTION 2.0
PROCESS OPERATION
2.1 PROCESS DESCRIPTION
Automatic Die Casting Specialities, Inc., 1s a small job shop that
performs decorative chromium electroplating of automotive trim. The plating
facility consists of two decorative chromium plating lines: the main
plating line and a rework, plating line.
The chromium plating tank 1n the main plating line was tested to
measure the performance of fume suppressants 1n reducing chromic add mist.
The process layout for the main plating line 1s shown 1n Figure 2.1. The
main plating line consists of a series of tanks used for cleaning and
plating the parts. Parts are plated with layers of copper and nickel before
they are chromium plated. The chromium plating segment of the line consists
of a chromium predlp, a plating tank, a chromium saver tank, and three
bisulfite rinse tanks. The plating line 1s serviced by an automatically
controlled overhead conveyor that transfers racks of parts to each tank 1n a
programmed sequence.
The chromium plating tank 1s 3.35 m (11.0 ft) long, 0.85 m (2.8 ft)
wide, and 1.5 m (5.0 ft) deep and 1s divided Into six cells that are each
0.55 m (1.8 ft) long. The plating tank holds approximately 3,860 liters
(1,020 gallons) of plating solution, which contains chromic add in a
concentration of 280 grams per liter (37 ounces per-gallon) of water. The
plating solution contains both fluoride and sulfuric add catalysts. The
temperature of the plating bath 1s maintained between 43*C and 47*C (110'F
and 116*F). Based on size, operating parameters (such as current, voltage,
and plating time), and chromic add concentration, the tank 1s typical of
other decorative chromium plating tanks used 1n the electroplating industry.
2-1
-------
CUrUlcr
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A. UUO«K CHROMIUM PIAIIHG (AUK
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' **"« RINSE (6. ElECli'OUEAii |«|. HAIER RINSE 2J. ClHOMIIH PiAIIMI IANK
• 5'",|''H!C «'" "»- "• «AIERH,«E 20. SEMI-WIGHl NICKEL M aSSIS W$ll
9 »AI1H RINSE ||. HAIER RINSE. V0«. HICM-SlKfUH NICKEL 2t. BlSllUin RINSE
Figure 2.1.
Plan view of the decorative chromium plating shop at Automatic Die Casting
Specialists, Inc., St. Clalr Shores, Michigan.
-------
The plating line operates 20 hours per day. 4 days per week. Six
racks of parts are plated in the chromium plating tank at a time with a
retention time of 3 ml notes and 35 seconds for each rack. The tank 1s
equipped with three rectifiers. For the first 15 seconds of plating, the
parts are activated. During activation, the rectifier connected to Cell No.
1 1s operated at 0 to 5 volts and 0 to 200 amperes. After activation, the
racks are automatically moved toward the center of the plating tank. During
plating, the rectifier connected to cells No. 2 through 5 1s set at 5.2
volts and 3,000 amperes. The rectifier connected to cell No. 6 1s set at
3.0 volts and minimal to no current.
2.2 AIR POLLUTION CONTROL
The chromium plating tank Is equipped with a single-sided draft hood.
The exhaust gases captured by the hood are ducted to a vertical-flow single
packed-bed scrubber. Two other tanks, the alkaline soak tank 1n the main
plating line and the chromium plating tank 1n the rework plating line, are
also vented to the scrubber through a common duct. Figure 2.2 presents a
diagram of the ventilation and control system. The total airflow rate to
the scrubber from the three hoods 1s 130 actual cubic meters per minute
(4,700 actual cubic feet per minute). The hood on the alkaline soak tank
was blocked off during testing to Increase the airflow rate through the hood
on the chromium plating tank.
A fume suppressant, Qu1n-Tec Cam Nos. 3 and 4, manufactured by
3M Corporation and sold by Qu1n-Tec, Inc., 1n Harren, Michigan, 1s normally
used to reduce chromic add mist from the chromium plating tank. During the
source test, the chromium plating tank was operated under three different
conditions: (1) without a fume suppressant, (2) with a foam blanket, and
(3) with a "combination" fume suppressant consisting of a foam blanket and a
wetting agent. The foam blanket forms a layer of foam approximately 2.4
centimeters (1.0 Inch) thick over the plating solution when the plating tank
1s charged. The foam blanket reduces chromic add mist by entrapping the
mist 1n the foam layer. The "combination" fume suppressant forms a layer of
foam 2.5 cm (1.0 1n.) thick over the surface of the plating solution and
lowers the surface tension of the plating solution from 70 dynes/centimeter
2-3
-------
to
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Figure 2.2. Diagram of ventilation and control system for chromium plating tank No. 27,
-------
to below 40 dynes/centimeter. Because the tension of the bath 1s lower, the
gases escape the surface with less of a "bursting" effect and thus, less
jnlst 1s formed. The foam layer captures any mist which 1s formed.
The foam blanket and the "combination" fume suppressant used 1n the
plating tank during the source test were, Zero-Mist™ HT and Zero-Mist1"
HT-2, respectively. Both of these fume suppressants are manufactured and
sold by OMI/Udyl1te« International Corporation 1n Harren, Michigan. These
fume suppressants were selected for use during the source test because they
are representative of the types and brands of fume suppressants widely used
1n the decorative chromium electroplating Industry. The technical data
sheets for each fume suppressant are provided 1n Appendix A.
2.3 PROCESS CONDITIONS DURING TESTING
Nine test runs were conducted to characterize uncontrolled emissions
*
from a decorative chromium plating tank and to determine the performance of
fume suppressants for controlling chromic add mist. Three test runs were
performed under each of the following conditions: (1) no chemical fume
suppressant 1n the plating bath (uncontrolled); (2) a foam blanket,
Zero-Mist1" HT, maintained 1n the plating bath; and (3) a "combination"
fume suppressant, Zero-Mist1" HT-2, maintained 1n the plating bath.
The process was maintained within normal operating limits during each
test run. The operating voltage, operating current, and plating solution
temperature were monitored and recorded during each test run. The number of
racks processed and the type of parts plated also were recorded during each
test run. The operating conditions (average values) for each emission test
run are presented 1n Table 2-1. In addition, grab samples of the plating
solution were taken during each test run to determine the hexavalent
chromium concentration. The analytical results for each sample are
presented 1n Section 3. Data sheets documenting process operating
conditions and the workload during each test run are presented 1n Appendix A.
2-5
-------
TABLE 2-1. AVERAGE OPERATING PARAMETERS FOR EACH TEST RUN
Run Nos.
Operating
temperature,
•C °F
Operating
voltage,.
volts
Operating
current,
amperes
1
2
3
Average
4
5
6
Average
7
8
9
Average
48 (118)
48 (118)
48_(118
48
48 (118)
48 (118)
48 (118)
48 (118)
48 (119)
49 (120)
49 (120)
49 (120)
5.2
4.9
5.0
5.2
5.1
5.1
5TT
5.1
5.1
5.1
571
2,820
2,880
2,800
2,830
2-6
-------
During the test, the Initial addition (makeup) and maintenance additions of
the fume suppressants were made according to vendor recommendations on the
use of each fume suppressant. The makeup addition of the foam blanket, Zero
M1st™ HT, was 910 g (2.0 Ib), and the makeup addition of the "combination"
fume suppressant, Zero-Mist1" HT-2, was 1,800 g (4.0 Ib). For both fume
suppressants a visual observation of the foam over the surface of the plating
solution was used to determine when a maintenance addition was required. A
foam blanket approximately 2.5 cm (1.0 1n.) thick was maintained over the
entire surface of the bath. For the "combination" fume suppressant,
stalagmometer measurements to determine the surface tension plating bath were
used 1n conjunction with visual observations for determining depletion of the
fume suppressant. A surface tension measurement above 40 dynes/centimeter
was specified as an Indication of the need for maintenance additions of the
fume suppressant. When signs of depletion were evident, a maintenance
addition of the fume suppressant was made to the plating tank. The normal
maintenance addition consisted of between 90 and 100 grams (0.2 and 0.3 Ib)
for both types of fume suppressants. Visual observations were made at 10 to
15 minute Intervals for each test run. Surface tension measurements were
performed on the plating solution composite samples at the end of test runs
No. 1 through 9 and at the beginning of test runs No. 7 through 9. The
measured surface tension (average) and the makeup and maintenance additions
of fume suppressant for each test run are presented in Table 2-2.
All test runs were completed without a process Interruption except test
run No. 2, which was Interrupted for 4 minutes because of downtime 1n the
process line. All test runs were stopped 15 to 20 minutes to change test
ports.
The total amount of current supplied to the tank during each test run
1s calculated 1n terms of ampere-hours and 1s Included 1n Appendix A. A
tabular summary of the total current values 1s presented 1n Table 2-3.
2-7
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TABLE 2-2. AVERAGE PLATING SOLUTION AND FUME SUPPRESSANT PARAMETERS
FOR EACH TEST RUN
Run
No.
1
2
3
4
5
6
7
8
9
Test condition
Uncontrolled
Uncontrolled
Uncontrolled
Foam blanket*
Foam blanket4
Foam blanket4
Foam blanket/wetting
agent0
Foam blanket /wetting
agent0
Foam blanket /wetting
agent0
Surface
tension,
dynes/cm
66
72
74
67
71
72
40
38
38
Fume suppressant
additions
Makeup, Mainte-
g (Ib) nance, g (Ib)
0 (0)
0 (0)
0 (0)
910 (2.0)
0 (0)
0 (0)
1,800 (4.0)
0 (0)
0 (0)
0 (0)
0 (0)
0 (0)
0 (0)
140 (0.3)
450 (1.1)
450 (1.0)
590 (1.3)
200 (0.5)
JZero M1st™ HT.
°Zero Mist™ HT-2.
2-8
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TABLE 2-3. TOTAL CURRENT SUPPLIED DURING EACH EMISSION
TEST RUN
Run
No.
1
2
3
4
5
6
7
8
9
Test
time,
hours
3.20
2.15
2.02
3.03
2.00
4.18
4.00
4.00
3.00
Total current,
ampere-hours
8,700
5,200
5,600
8,400
5,300
11,900
11,300
11,700
8,500
Ampere-hours/ha
2,700
2,400
2,800
2,800
2,700
2,900
2,800
2,900
2,800
aT1me-we1ghted average.
2-9
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SECTION 3.0
SUMMARY OF RESULTS
3.1 INTRODUCTION
Modified Method 13B (MM13B) and the Screening Methods samples were
collected 1n triplicate under each of the three different operating
conditions of the plating tank. During each MM13B, a series of four
screening samples were collected simultaneously in a port which was located
1/2 stack-diameter downstream from the MM13B sample location. MM13B run
numbers 1, 2 and 3, and Screening Methods series 1A, IB, 2A, 2B, 3A and 3B
were conducted while the plating tank was operating without a foam blanket.
MM13B run numbers 4, 5 and 6, and screening methods series 4A, 4B, 5U, 6U
and 6P were conducted while the plating tank was being operated with a
temporary-type .fume suppressant. Run numbers 7, 8 and 9 of the MM13B and
the screening methods series 7, 8 and 9 were conducted while the plating
tank was being operated with the addition of a foam blanket combined with a
wetting agent. All of the emission samples were analyzed on site for
Cr+* concentrations using the procedures outlined 1n "Draft Method -
Determination of Hexavalent Chromium 1n Dry Particulate Emissions from
Stationary Sources." This analytical method 1s presented in Appendix D.
In addition to the emission samples, grab samples of the plating bath
were composited during each MM13B run and analyzed using the same procedures
as for the emission samples.
Table 3-1. presents a schedule of the activities during the test
program. The results from the analysis of the MM13B runs, the screening
method runs and the plating tank solutions are presented in the remainder of
this section.
3-1
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TABLE 3-1. SCHEDULE OF ACTIVITIES
Date
(1988)
Condition 1 -
4/18
4/18
4/18
4/19
4/19
4/19
4/19
4/19
Condition 2 -
4/20
4/20
4/20
4/20
4/20
4/21
4/21
4/21
Condition 3 -
4/25
4/25
4/26
4/26
4/26
4/26
Test Time
Sample Tvpe Run No. (24 hr. clock)
(no fume suppressant)
138, PS MM13B-1
SM 1A Series
SM IB Series
13B, PS MM13B-2
SM 2A Series
SM 2B Series
13B, PS MM13B-3
SM 3A Series
(addition of temporary-type fume
13B, PS MM13B-4
SM 4A Series
SM 4B Series
13B, PS MM13B-5
SM 5U Series
13B, PS MM13B-6
SM 6U Series
SM 6P Series
(addition of permanent- type fume
13B, PS MM13B-7
SM 7 Series
138, PS MM13B-8
SM 8 Series
13B, PS MM13B-9
SM 9 Series
1408-1738
0758-1026
1157-1508
suppressant)
0932-1311
1415-1629
1010-1513
suppressant)
1458-1941
0903-1330
1423-1752
Parameter
Measured
Cr+6
Cr+<
Cr+6
Cr+s
Cr+6
Cr+6
Cr+6
Cr+6
Cr+6
Cr+6
Cr+6
Cr+s
Cr+s
Cr+6
Cr*6
Cr+6
Cr+*
Cr+«
Cr+s
Cr+s
Cr+6
Cr*s
13B - Modified Method 13B
PS - Plating Solution
SM - Screening Methods
3-2
0145S
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3.2 HEXAVALENT CHROMIUM EMISSION RESULTS
Flue gas conditions*were determined simultaneously with the collection
of the Cr+s samples upstream from the scrubber Inlet. The samples were
collected isokinetlcally using a Method 13B sample train that had been
modified by removing the glass fiber filter and placing 100 mfi. of 0.1 N
NaOH 1n each of the first two implngers. The 1mp1nger solutions were
recovered Into tared polyethylene sample bottles and the total volume of the
recovered 1mp1nger solution was determined grav1metr1cally. An aliquot of
the recovered solution was analyzed for Cr+6. The following subsections
present the flue gas data for each MM13B and the analytical results from the
MM13B and the screening method for each operating condition.
3.2.1 Condition 1
Condition 1 data represent the uncontrolled emissions from the chromium
plating tank. This condition was achieved by depleting the foam blanket,
which the plant normally uses in Its dally .operation, from the plating tank.
3.2.1.1 Modified Method 13B—
A summary of the flue gas conditions at the sampling location while
operating under Condition 1 1s presented 1n Table 3-2. The volumetric flow
rates were consistent and averaged 66.8848 dry standard cubic meters per
minute (dscmm), (2362 dry standard cubic feet per minute (dscfm)). The flue
gas temperature averaged 21°C (70°F) and the moisture content averaged
1.4 percent. The flue gas was essentially ambient air and was assigned a
dry molecular weight of 29.0 Ib/lb mole. The 1sokinet1c sampling rates were
within the allowable limitations for these three sample runs.
A summary of the MM13B sample volumes, analytical results and emission
rates for Condition 1 are presented in Table 3-3. Prior to sampling, it was
decided that the first MM13B should be run at 8 m1n/point for a total sample
time of 192 minutes. This sample time would ensure collection of a
detectable concentration of Cr*6. Following the analysis of the sample,
3-3
-------
TABLE 3-2. SUMMARY OF FLUE GAS CONDITIONS
Condition
MM13B-1
MM13B-2
MM13B-3
Condition
MM13B-4
MM13B-5
MM13B-6
Condition
MM13B-7
MM13B-8
MM13B-9
Date
J.
4/18/88
4/19/88
4/19/88
2.
4/20/88
4/20/88
4/21/88
2
4/25/88
4/26/88
4/26/88
Volumetric Flowrate
66.69 2355
67.59 2387
66.40 2345
66.80 2359
67.34 2378
66.40 2345
66.12 2335
64.31 2271
63.54 2244
Temperature
•C °F
23
20
21
20
18
21
22
24
24
73
68
70
68
65
70
72
75
75
X Moisture
1.6
1.3
1.4
1.0
1.0
1.2
1.2
1.6
1.5
X Isokinetic
100.3
99.1
103.1
101.7
102.6
101.7
99.3
98.3
98.5
3-4
-------
TABLE 3-3. SUMMARY OF SAMPLE VOLUMES, ANALYTICAL RESULTS
AND EMISSION RATES FOR CONDITION 1
Run No.
MM13B-1
MM13B-2
MM13B-3
Screening Methods
1-A-1
l-A-2
l-A-3
l-A-4
1-8-1
1-8-2
1-8-3
1-8-4
2-A-1
2-A^2
2-A-3
2-A-4
2-8-1
2-8-2
2-8-3
2-8-1
3-A-1
3-A-2
3-A-3
3-A-4
3-8-1
3-8-2
3-8-3
3-8-4
Volume Watered
dscin dscf
3.517 124.199
2.202 77.759
2.250 79.461
Screening Volume
7.9833
7.7707
7.5394
7.8214
7.9833
7.7707
7.5394
7.8214
7.9493
7.7376
7.5073
7.7881
8.027
7.781
7.546
7.861
7.9794
7.7669
7.5357
7.8176
7.9794
7.7669
7.5357
7.8176
Total Mass Concentration
Cr+6. ma ma/dscm
3.016
2.027
2.236
Stack DSCFM
2313
2313
2313
2313
2313
2313
2313
2313
2307
2307
2307
2307
2307
2307
2307
2307
2302
2302
2302
2302
2302
2302
2302
2302
0.858
0.921
0.994
Screening Ma/M
.5100
.5626
.5902
.5942
.5874
.5381
.7012
.6732
.1915
.5787
.6129
.7260
.7357
.5568
.8185
.8112
.6559
.5793
.8285
.8104
.2465
.5101
.7760
.7323
ar/dscf
0.0004
0.0004
0.0004
138 Mg/M3
.846
.846
.846
.846
.846
.846
.846
.846
.923
.923
.923
.923
.923
.923
.923
.923
.993
.993
.993
.993
.993
.993
.993
.993
Emission Rates
ka/hr Ib/hr
0.004 0.008
0.004 0.008
0.004 0.008
% of 138
60.3
66.5
69.8
70.2
69.4
63.6
82.9
79.6
20.7
62.7
66.4
78.7
79.7
60.3
88.7
87.9
66.1
58.3
83.4
81.6
24.8
51.4
78.1
73.7
3-5
-------
it was determined that the sample time per point could be reduced to
5 minutes for a total sample time of 120 minutes.
The uncontrolled emissions for each MM13B were very consistent and
averaged 0.924 milligrams per dry standard cubic meter (mg/dscm). or
.000404 grains per dry standard cubic feet (gr/dscf)).
3.2.1.2 Screening Method—
A summary of the sample volumes, analytical results and emission rates
for the Screening Methods conducted under Condition 1 1s presented 1n
Table 3-3. In an effort to determine 1f any Cr*' 1s lost 1n the sample
recovery of the Screening Method (I.e., adhere to side of tubing that Is not
rinsed), 1t was decided to rinse the tygon tubing that connected the probe
to the pump Into a separate sample bottle for analysis. The results from
the analysis proved that the tubing contained a significant concentration of
Cr*'. Therefore, all subsequent sample recoveries of the Screening
Method trains Included rinsing the tygon tubing Into the same sample bottle
as the probe.
Screening method runs consisted of fixed flow rate single point
sampling. While the data generated during this test were fairly
encouraging, later tests showed that single point sampling was not the best
approach for developing an alternate sampling method for chromium. The
results presented show the percent of sample collected when compared to the
MM13B train. The screening method was about 701 successful for this
particular test.
3.2.2 Condition 2
Condition 2 data represent emissions generated with the use of a foam
blanket in the chromium plating tank. This condition was achieved by adding
tablets to the plating tank to generate the foam blanket.
3.2.2.1 Modified Method 13B—
A summary of the flue gas conditioned at the sampling location while
operating under Condition 2 is presented in Table 3-2. The volumetric flow
3-6
-------
rates were consistent and averaged 67 dscmm (2361 dscfm). The flue gas
temperature averaged 20*C (68*F) and the moisture content averaged
J.I percent. The flue gas was essentially ambient air and was assigned a
dry molecular weight of 29.0 Ib/lb mole. The 1sok1net1c sampling rates were
within the allowable limitations for these sample runs.
A summary of the MM13B sample volumes, analytical results and emission
rates for Condition 2 are presented 1n Table 3-4. Prior to sampling, 1t was
decided that run MM13B-4 should be made at 8 m1n/po1nt for a total sample
time of 192 minutes. This sample time would ensure collection of a
detectable concentration of Or*'. Following the analysis of the sample,
1t was determined that the sample time per point for MM13B-5 could be
reduced to 5 minutes for a total sample time of 120 minutes.
The sampling and sample recovery techniques were modified for MM13B-6.
The sampling time was Increased to 10 m1n/po1nt for a total sample time of
240 minutes. The Increase 1n sample time was made,at the request of the
Industrial Studies Branch. Their reasoning was that with the low
concentrations of Or*' that were reported 1n MM13B-4 and 5, a larger
sample volume should produce more accurate results. The modification of the
sample recovery technique consisted of recovering the nozzle and probe rinse
1n one sample bottle and recovering the Implnger catch Into a second sample
bottle. Each sample was analyzed separately, then the analytical results
were combined to determine the total mass of Cr*' collected. This
method was devised 1n an attempt to reduce the total volume of the recovered
solutions, concentrate Cr*' concentrations and Increase the accuracy of
the analytical results. This technique was carried out through the
remainder of the MM13B runs.
3.2.2.2 Screening Method—
A summary of the sample volumes, analytical results and emission rates
for the Screening Methods conducted under Condition 2 1s presented 1n
Table 3-4.
3-7
-------
TABLE 3-4. SUMMARY OF SAMPLE VOLUMES. ANALYTICAL RESULTS, AND EMISSION RATES FOR CONDITION 2
_ _ Volume
Run No. dscm
MM13B-4
MM13B-5
MM13B-6
4-A-1
4-A-2
4-A-3
4-A.-4
4-B-l
4-B-2
4-B-3
4-B-4
5-1-U
5-2-U
5-3-U
5-4-U
6-1 -U
5-2-U
6-3-U
6-4-U
6-1 -P
6-2-P
6-3-P
6-4-P
3.573
2.273
8.204
Screening Vol
7.9548
7.7429
7.5124
7.7934
7.9548
7.7429
7.5124
7.7934
7.9221
7.7110
7.4815
7.7614
8.0013
7.7882
7.5564
7.8390
8.0013
7.7882
7.5564
7.8390
Metered Total Mass Concentration
dscf Cr**. ma ma/dscm ar/dscf
126.150
80.256
289.681
Stack DSCFM
2316
2316
2316
2316
2316
2316
2316
2316
2309
2309
2309
2309
2299
2299
2299
2299
2299
2299
2299
2299
0.012 0.0034
0.012 0.0053
0.031 0.0038
Screen Mo/M3
1.43x10"'
2.30x10"'
1.65x10*'
MH 138 Mq/M3
All below detection limit of
.00306
.00369
.00564
.00589
.002377
.003816
.002517
.001972
.002094
.003290
.002608
.002766
.001153
.002231
.002792
.002447
.00339
.00339
.00339
.00339
.006805
.006805
.006805
.006805
.003811
.003811
.003811
.003811
.003811
.003811
.003811
.003811
Emission Rates
ka/hr Ib/hr
1.31x10"* 2.89xlO~5
2.13x10"* 4.69x10~5
1.51x10"' 3.32x10"*
* of MM 13B
Analytical Method
90.4
109.0
166.5
173.8
34.9
56.07
37.0
28.98
55.0
86.3
68.4
72.6
30.3
58.5
73.3
64.2
U - previously used tubing
P • polyethylene tubing
3-8
-------
3.2.3 Condition 3
Condition 3 data represent emissions generated from the plating tank
while using a foam blanket combined with a wetting agent to control the
emissions. The wetting agent 1s added to reduce the surface tension of the
plating bath. The condition was achieved by adding tablets to the bath to
generate the blanket and granules to reduce the surface tension.
3.2.3.1 Modified Method 13B—
A summary of the flue gas conditions at the sampling location while
operating under Condition 3 1s presented 1n Table 3-2. The volumetric flow
rates were consistent and averaged 65 dscmra (2283 dscfm). The flue gas
temperature averaged 23*C (74*F) and the moisture content averaged 1.4
percent. The flue gas was essentially ambient air and was assigned a dry
molecular weight of 29.0 Ib/lb mole. The 1sok1net1c sampling rates were
within the allowable limitations for these three sample runs.
A summary of the MM13B sample volumes, analytical results and emission
rates for Condition 3 are presented 1n Table 3-5. Sampling times for MM13B
runs 7, 8 and 9 were run at 10 m1n/po1nt, for a total test time of 240
minutes for each run. Sample recovery was performed as discussed in Section
3.2.2.1.
3.2.3.2 Screening Method—
A summary of sample volumes, analytical results and emission rates for
the Screening Methods conducted under Condition 3 are also presented 1n
Table 3-5.
3.3 PLATING TANK SOLUTIONS
During each MM13B run, grab samples of the plating bath were collected
and composited. The samples were analyzed for Cr*' concentration to
verify the plating solution concentration. The results from the plating
solution analyses are presented In Table 3-6.
3-9
-------
TABLE 3-5. SUMMARY OF SAMPLE VOLUMES. ANALYTICAL RESULTS, AND EMISSION RATES FOR CONDITION 3
Run No.
MM13B-7
MM13B-8
MM13B-9
Screening Method
7-1
7-2
7-3
7-4
8-1
8-2
8-3
8-4
9-1
9-2
9-3
9-4
Volume Mete red Total Mass
dscm dscf Cr . mq
7.966
7.689
5.705
Screening
8.067
7.852
7.619
7.904
8.1016
7.8858
7.6511
7.9373
8.1016
7.8858
7.6511
7.9373
281.298 0.014
271.500 . 0.009
201.429 0.019
Vol Stack DSCFM
2289
2289
2289
2289
2245
2245
2245
2245
2200
2200
2200
2200
Concentration Emission Rates
ma/dscm ar/dscf ka/hr Ib/hr
0.0018
0.0012
0.0033
Screen Mq/M
.0004786
.0010734
.0010066
.0008184
.0009448
.0011957
.0012877
.0012547
.0023298
.0017118
.0019119
.0027473
7.80xlO~7 1.56x10"*
5.11x10"7 4.52x10~'
1 .45x10"* 1.27xlO~5
MM 138 Ma/M3 %
.0019147
.0019147
.0019147
.0019147
.0011877
.0011877
.0011877
.0011877
.0034491
.0034491
.0034491
.0034491
7.08xlO"8
9.96x10"'
2.97xlO"5
of MM 138
25.0
56.1
52.6
42.7
79.5
100.7
108.4
105.6
67.5
49.6
55.4
79.7
3-10
-------
TABLE 3-6. SUMMARY OF PLATING SOLUTION
ANALYTICAL RESULTS
Run No.
Condition 1
MM13B-1
MM!38-2
MM13B-3
Condition 2
MM13B-4
MM13B-5
MM13B-6
Condition 3
MM13B-7
MM13B-8
MM13B-9
Cr+* Concentration.
139,010
141,988
143,276
129,956
133,640
134,882
1,485,704*
141,804
148,818
It 1s suspected by the authors that an error
1n dilution was made (by a factor of 10).
This suspicion cannot be proven because the
samples have since been disposed of.
3-11
-------
SECTION 4.0
SAMPLING LOCATIONS AND TEST METHODS
4.1 PLATING EMISSIONS
4.1.1 Location of Measurement Site
EPA Reference Method 1, "Sample and Velocity Traverses for Stationary
Sources", was used to select a representative measurement site. The
measurement site at the scrubber Inlet was located In a 22.625-1n. (nominal)
inside diameter circular horizontal duct. Two, 3-in. ID holes were cut in
the duct at 90 degrees from each other, resulting in a horizontal and
vertical traverse. Upon measurement of the stack diameter, it was
discovered that the inside diameters through the two ports were not equal.
A visual inspection revealed that there was a deposit of particulate matter
on the bottom of the duct. The inside diameter of the horizontal port was
22-5/8 in., and of the vertical port 20-1/2 in.. Because of this unusual
condition,, the location of the transverse points was discussed with the EPA
Task Manager. It was, subsequently, decided to locate the points using the
two different diameters. The stack diameter of 22-5/8 1n. was used to
determine the number of sample transverse points since using the larger
diameter would have resulted in the least stack diameters from any
disturbance. Using this diameter, the measurement site was 235 in. (10.4
stack diameter) downstream from the nearest flow disturbance (duct
reduction) and 14-1/8 1n. (0.62 stack diameters) upstream from any flow
disturbance (sampling port for EPA's use). According to EPA Method 1
criteria, this site required 24 sample traverse points, 12 along each
diameter. The first point on each traverse was moved to the required 0.5
in. from the wall of the duct. The last point on the horizontal traverse
was moved to 0.5 in. from the wall of the duct, while on the vertical
traverse the last point was moved to 1 in. from the bottom. The reason for
this deviation from the reference method was to prevent loose particulate
matter lying on the bottom of the duct from being entrained. The EPA Task
Manager was consulted and approved this change. Table 4-1 shows the
traverse points used.
4-1
-------
TABLE 4-1. SAMPLE TRAVERSE POINT LOCATIONS
Traverse
Point
No.
1
2
3
4
5
6
7
8
9
10
11
12
Vertical
Traverse
0.5a
1.37
2.42
3.63
5.13
7.30
13.20
15.38
16.87
18.08
19.13
19.50b
Port Location
Horizontal
Traverse
0.5a
1.52
2.67
4.00
5.65
8.05
14.57
16.97
18.62
19.96
21.10
22.13a
* Relocated to the minimum distance from the Inside stack, wall
b Relocated to 1 Inch from residual matter in bottom of duct.
4-2
-------
In order to compute the net cross-sectional areas of the duct at the
measurement site 1t was necessary to correct for the area of the duct that
was blocked. The area was^calculated by first determining the total area of
the circle. Then the area of blockage was determined by subtracting the
area of the triangle ABC from the "pie" shaped area of the circle bounded by
the rad11 AB and BC. The area of the blockage was then subtracted from the
total area of the circle. The area of the duct that 1s unobstructed 1s
402.038 in.2 less 19.083 1n.2which equals 382.955 1n.2 or 2.659 ft2.
The duct 1s represented 1n Figure 4.1.
Prior to sampling, verification of the absence of cyclonic flow at each
sample traverse point was assessed based on procedures described 1n EPA
Reference Method 1. In this method the face openings of the Type-S pltot
tube are aligned perpendicular to the duct cross-sectional plane, designated
"0-degree reference." Null (zero) pi tot readings obtained at 0-degree
reference Indicate an acceptable flow condition at a given point. If the
point reading were not zero at 0-degree reference, the pltot was rotated
until a null reading was obtained. The value of the rotation angle (yaw)
was recorded for each point and averaged across the duct. Method 1 criteria
stipulate that average angular rotations greater than 20 degrees Indicate
cyclonic (nonaxlal) flow conditions in the duct. The average of the angular
rotations was 3.9 degrees, which indicated acceptable flow patterns and
enabled the extraction of representative samples form this source. The
cyclonic flow data are contained 1n Appendix B.
4.1.2 Test Methods
Prior to sampling, velocity and static pressures, moisture content, and
temperature were measured to define sampling rates and nozzle sizes as
described in the EPA Reference Methods 1,2 and 4. The stack gas molecular
weight was not determined by procedures outlined in EPA Method 3.
Alternatively, the molecular weight was assigned the value of 29.0 Ib/lb
mole, as stated in the EPA Method 2, paragraph 3.6.
4-3
-------
Figure 4.1. Cross-sectional view of duct at measurement site.
4-4
-------
An EPA modified method MM13B sample train was used to collect the
Cr+6 samples. The sample train was modified by placing 0.1 normal
sodium hydroxide 1n the 1mp1ngers 1n place of water and removing the
f1lter(s) 1n the 1mp1nger section. The sample train consisted of a 316
stainless steel button-hook design nozzle, an unheated Pyrex glass-lined
probe, and a series of four 1mp1ngers. The first, third and fourth
1mp1ngers were Greenburg-Sm1th design, modified by replacing the tip with a
l/2-1n. Inside diameter glass tube extending to l/2-1n. from the bottom of
the flask. The second 1mp1nger was a Greenburg-Smlth 1mp1nger with the
standard tip. In the first and second Implngers, lOOmi of 0.1N NaOH was
placed. The third 1mp1nger was empty, and approximately 200 grams of silica
gel was placed 1n the fourth Implnger. Due to extended sampling times on
Runs MM13B-7, MM13B-8, and MM13B-9 an additional silica-gel filled Implnger
was added to the sampling train. The balance of the sampling system
consisted of a vacuum pump, dry gas meter, calibrated orifice and related
temperature and pressure Indicating apparatus with which to determine dry
gas sample volume, stack gas temperature, volumetric flow rate and
1sok1net1c sampling rates. During sampling, stack gas temperature and the
gas temperature exiting the last Implnger were monitored with thermocouples.
Each point was sampled 1sok1net1cally. The sampling time varied from
run to run due to the changing of conditions of the chrome plating tanks.
On Run MM138-1 each point was sampled for 8 minutes with readings recorded
every 4 minutes for a total sample time of 192 minutes. The analytical
results showed that the Cr*' concentration was high enough to reduce the
sample time to 5 m1n/po1nt for runs MM13B-2 and MMB-3. The addition of the
fume suppressant before run MM13B-4 dictated changing sampling time to
8 m1n/po1nt with a total sampling time of 192 minutes. On run MM13B-5 the
sample time was 5 ra1n/po1nt or 120 m1n/run. It was decided that 1n order to
Increase the accuracy of the analytical method a much higher sample volume
was required. To accomplish this the sample time per point was changed to
10 minutes for a total sample time of 240 minutes. In addition to
Increasing the sample time a larger nozzle was used, requiring a higher
sampling rate 1n order to maintain 1sok1net1c sampling conditions. The
4-5
-------
sample volume was approximately 300 ft3. On Run MM13B-9, the sample
time was again adjusted due to dissipation of the fume suppressant. The
horizontal traverse was held at 10 min/point but the vertical traverse was
adjusted to 5 min/point with a total sample time for the run of 180
minutes. The EPA Task Manager was consulted on all of the changes in the
sampling time and concurred.
The impingers were weighed before and after each test to determine the
moisture content of the flue gas stream. The contents of the Impingers were
placed in a tared polyethylene container. All connecting glassware, the
nozzle and probe were rinsed with 0.1 N NaOH and combined with the Implnger
solution 1n the polyethylene sample bottle. On Runs MM13B-7, MM13B-S and
MH13B-9 the probe and nozzle rinse were separated from the impinger catch in
an effort to concentrate the Cr+6 in a smaller sample volume. The
liquid level was marked on each sample bottle and each bottle was marked
indicating the run number and bottle contents. Appropriate blank solutions
were collected.
The polyethylene containers were all tared before their use and weighed
after the collection of the sample. The volume of each solution was
determined by multiplying the specific gravity of the solution times the net
weight of the solution. Each sample, including blanks, was analyzed for
Cr+s concentration using analytical methodology recently developed by
the EPA.
4.2 EMISSION SAMPLE ANALYSIS
The MM13B samples, the Screening Method samples and the plating tank
solution composite samples were analyzed for Or*' concentration. The
analyses were conducted on site 1n a temporary laboratory. Immediately
following the sample recovery, the samples were submitted to the analyst and
the analyses and the calculations were performed the same day. Initially,
calculations of the analytical results were performed on a calculator and
4-6
-------
subsequently checked using the Hewlett Packard 41CVX computer that was set
up in the on-site computer center. The results of this check method are
presented in Appendix C.
The analytical method entitled "Draft Method - Determination of
Hexavalent Chromium in Dry Partlculate Emissions from Stationary Sources"
was used as a "guideline" 1n conducting the analyses. This method 1s
currently under development by the EPA and 1s presented in Appendix D.
There were several variations between the Draft Method and the
Analytical Method that was performed 1n the field. They are described as
follows.
1. The collected samples were not digested 1n an alkaline solution.
Aliquots of the recovered impinger solutions were pipetted directly
from the sample bottle and prepared as in paragraph 5.7.1 of the
Draft Method.
2. The pH of the sample aliquot was monitored with a pH meter while
adjusting the pH of the aliquot to 2 ± .05.
3. The spectrophotometer was calibrated with standards containing
1 mi, 2 mi, 5 mi, 10 mi, 15 mi and 20 mi of the
5 i*g/mi working standard. The spectrophotometer calibration
factor, K , was calculated as follows:
Ax + 2A2 + 5A, + 10A4 + 15A5 + 20A,
A4 + A
4. The calibration factor was determined using a computer program that
was developed by the EPA Task Manager for the HP41CVX.
4-7
-------
SECTION 5.0
QUALITY ASSURANCE
5.1 INTRODUCTION
The goal of the quality assurance activities for this project 1s to
ensure, to the highest degree possible, the accuracy of data collected. The
procedures contained 1n the "Quality Assurance Handbook for A1r Pollution
Measurement Systems," Volume III, "Stationary Source Specific Methods,"
EPA-600/4-77-027B served as the basis for performance of all testing and
related work activities that were undertaken 1n this testing program. In
addition to the quality assurance measure guidelines presented above,
specific quality assurance activities were conducted for several of the
Individual testing activities, as performed; these are presented 1n the
paragraphs that follow.
5.2 FIELD QUALITY ASSURANCE PROCEDURES
In order to assure a high level of quality control of the sampling for
the comparison of data from these two methods, a field quality assurance
program was followed for the test program. Methods used to obtain the
required level of quality assurance are Itemized below.
5.2.1 Sample Blanks
5.2.1:1 Reagent Blanks—
The 0.1N NaOH absorbing solution was transported to the field in Its
"as-purchased" container. Nhen 1n the field, the 0.1N NaOH was transferred
to a polyethylene wash bottle. From the wash bottle, the NaOH solution was
used for sample train preparation and recovery. A blank sample was
collected from the solution 1n the wash bottle. This sample was given to
the on-s1te laboratory personnel with the emission samples, and analyzed in
the same manner. Results of the blank analyses are presented 1n Table 5-1.
5-1
-------
TABLE 5-1. SUMMARY OF ANALYTICAL RESULTS FOR QA/QC SAMPLES AND BLANKS
Sample No. Date (1988)
1A1 4/18
.25 jjg/mfi. "
MM13B-1 "
.25 pg/mfl- 4/19
.75 ng/mfl. "
l-B-4
MM13B-1
l-B-3
.25 ng/mft. "
l-B-4
3-B-3
.10 ]ig/mH "
.25 iig/mfl, "
.50 tig/ma. "
MM13B-1 PS 4/20
MM13B-2 PS
MM13B-3 PS
.05 \ig/mi "
.25 iig/m& "
MM13B-4 4/21
MM13B-5
.25 pig/mil "
.50 pg/mfl. "
2-A-l
MM13B-4
MM13B-3
MM13B-4
Tvpe
Duplicate
X
X
X
X
X
X
X
X
X
X
X
X
X
of Sample
Spike Standard
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Total jia Cr+«
114.6
25.4
3036.4
25.6
75.2
157.1
2989.5
146.1
25.5
142.9
163.3
10.3
25/6
50.6
139,010
141,988
143,276
4.8
25.0
11.9
14.7
25.3
51.3
38.7
12.7
2222.5
12.7
(continued)
5-2
-------
TABLE 5-1. (continued)
Samole No.
.05 iig/m&
.10 vq/mi
.25 iig/mfc
3-B-l
2-A-4
MM13B-6
.05 pg/mfl.
.25 ]ag/mfc
MM! 38-7 (Imp)
MM13B-8 (Imp)
HM13B-8 (Imp)
MM13B-8 (noz)
.25 yg/mJL
.50 vq/mQ,
MM13B-8 (Imp)
.50 yg/mJl
.50 jig/mi
Blanks
Date (1988)
H
H
II
4/25
H
M
H
n
4/26
it
H
n
u
H
n
n
ii
4/18
4/19
4/20
4/21
4/25
4/26
Tvpe of Samole
Duplicate Solke Standard Total ua Cr+6
X 4.9
X 10.3
X 25.6
X 53.0
X 154.2
X 28.1
X 49.5
X 24.6
X 9.8
X 7.3
X 6.2
X 1.9
X 25.4
X 50.3
X 7.3
X 50.5
X 50.2
0
0
0.19
0
.32
.19
5-3
-------
5.2.1.2 H20 Blanks-
Distilled water blanks were obtained from the wash bottles and
analyzed in the same mariner as the emission samples.
5.2.2 Matrix Effects Check
A Cr+6 stock standard solution was made up 1n the laboratory.
This stock solution was used to make up samples of known concentrations.
Random samples were prepared and analyzed to verify the absence of any
matrix effects.
5.2.3 Duplicate Samples
One sample for every 10 samples analyzed was a duplicate, e.g., if 24
samples were analyzed, 3 duplicate samples would be analyzed. The results
of the duplicated samples are presented in Table 5-1.
5.2.4 Standards
Dally, throughout the analysis of the samples, standards were set up
as a spot check of the spectrophotometer calibration. The results of these
checks are presented in Table 5-1.
5.2.5 Chain of Custody
In an effort to maintain the Integrity of all samples taken at the
test facility, a chain of custody procedure was followed. A copy of the
"Cha1n-of-Custody" data sheets 1s Included 1n Appendix E. These sheets
Include the sample Identification, date of sample recovery, name of person
who performs the recovery, place of recovery as well as the name of the
responsible person from the analytical group who 1s taking custody of the
samples. Once the samples were placed 1n custody of the analytical group,
that group provided for safe storage and maintenance of records sufficient
to maintain sample integrity.
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5.2.6 Sample Transfer
All MM13B samples'collected during testing remained 1n the custody of
PEER Consultants, P.C. All Screening Methods samples were returned to the
EPA after analysis samples were secured 1n the laboratory while 1n the field.
5.3 SAMPLING TRAIN COMPONENTS
The equipment to be used In this test program, Including nozzles,
pltot tubes, dry gas meters, orifices, and thermocouples were uniquely
Identified and were calibrated 1n accordance with calibration procedures
specified 1n the applicable EPA Reference Method prior to and at the
completion of the testing program. The calibration sheets are presented 1n
Appendix F.
5.4 VERIFICATION OF CALCULATIONS
5.4.1 Emission Calculations
Dry gas volumes, percent moisture of the stack gas and gas flow data
were calculated using a partlculate emission calculation sheet. Cr+s
emission rates were calculated on an emission rate calculation sheet. The
data was calculated using a calculator. The results were checked and
verified by the contractor task manager.
5.4.2 Chromium Concentration Calculations
All absorbance data for blanks, standards, samples and QA/QC samples
were documented 1n a notebook. The percent absorbance was calculated from
the percent transmlttance and subsequent calculations were carried out as
described 1n the Draft Method for Hexavalent Chromium Emissions.
5-5
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