United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EMB Report 87CEP7
March 1987
Air
Chromium
Electroplaters
Emission Test
Report
Delco Products Division
General Motors Corporation
Livonia, Michigan
-------
EPA Report No.
September 1987
FINAL REPORT
DETERMINATION OF TOTAL CHROMIUM
AND HEXAVALENT CHROMIUM EMISSIONS
FROM CHROME PLATING TANKS
Candidate Plant
Delco Products Division
General Motors Corporation
Livonia, Michigan
by
Helen J. Owens
Joseph T. Swartzbaugh
PEER Consultants, P.C.
Dayton, Ohio 45432
and
Franklin Meadows
Pacific Environmental Services. Inc.
Cincinnati, Ohio 45246
and
Randy P. Strait
Midwest Research Institute
Raleigh, North Carolina 27612
EPA Contract No. 68-02-4346
Work Assignment 01
Technical Directive 1
Task Manager
Frank R. Clay
Emission Standards and Engineering Division
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
-------
TABLE OF CONTENTS
SECTION
Page
Tables v
Figures vi
1.0 INTRODUCTION 1-1
2.0 PROCESS AND OPERATIONS 2-1
2.2 Air Pollution Control 2-2
2.3 Process Conditions During Testing 2-2
3.0 SUMMARY OF RESULTS 3-1
3.1 Introduction 3-1
3.2 Hexavalent and Total Chromium Emissions
Results 3-2
3.3 Process Sample Analysis 3-4
4.0 SAMPLE LOCATIONS AND TEST METHODS USED 4-1
4.1 Location of Measurement Site 4-1
4.2 Hexavalent and Total Chromium Sample Extraction
and Analysis 4-4
4.3 Process Samples 4-8
5.0 PROJECT QUALITY ASSURANCE 5-1
References R-l
iii
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TABLE OF CONTENTS
SECTION Paoe
Appendices
A Field Data Sheets A-l
B Calculations B-l
C Laboratory Analytical Results C-l
D Determination of Cr+s and Total Cr Emissions .... D-l
E Pretest Calibration Data E-2
F Project Participants and Activity Log F-l
G Analytical Methods for Determining Cr+6 and
Total Cr G-l
iv
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LIST OF TABLES
Page
2-1 Average Operating Conditions Recorded During Each
Emission Test Run 2-4
2-2 Total Current Consumed During Each Emission
Test Run 2-4
3-1 Test Schedule for Cr+6 and Cr Emissions
Testing at Delco Products, Livonia, Michigan .... 3-16
3-2 Summary of Sample and Flue Gas Conditions
(Delco Products - Livonia, Michigan) 3-3
3-3 Summary of Cr+6 and Total Cr Emission Data
(Delco Products - Livonia, Michigan) 3-3
3-4 Summary of Results from the Laboratory Analysis
of Plating Tank Solutions 3-5
4-1 Inside Dimensions of the Duct at Each Sample Port . . 4-4
4-2 Summary of Traverse Point Locations 4-5
5-1 Equipment Used in the MM 13B Sampling Program .... 5-3
5-2 Summary of Blank Analysis 5-4
5-3 Summary of Analytical Results from Duplicate and
Spiked Samples 5-4
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LIST OF FIGURES
Number Page
1-1 Process Diagram of Chrome Plating Tank on
Line No. 4 1-3
2-1 Schematic of Decorative Chromium Plating Tank
Tested on Line 4 at Delco Products Division,
General Motors Corporation, Livonia, Michigan . . . 2-3
4-1 Simplified Process Flow Diagram 4-2
4-2 Orthogonal Sketch of Inlet Sampling Location . . . 4-3
4-3 Cross-Section of Sample Location Indicating
Traverse Points 4-6
VI
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SECTION 1.0
INTRODUCTION
The U.S. Environmental Protection Agency (EPA) is currently evaluating
whether air emissions of chromium and other potentially toxic metals should
be regulated. Chromium emissions are not included in the New Source
Performance Standards (NSPS) for stationary sources or the National
Emissions Standards for Hazardous Air Pollutants (NESHAP).
As part of this study, the EPA is evaluating uncontrolled emissions from
decorative chromium plating operations. The purpose of these tests is to
characterize the emission rate and size distribution of uncontrolled
emissions of hexavalent chromium (Cr*6) and total chromium (Cr) from a
representative industrial operation. A production facility of the Delco
Products Division of General Motors Corporation located in Livonia,
Michigan, was the selected site at which these tests were performed. The
Delco facility was chosen because it is a large-size, captive shop that
performs decorative chromium electroplating. At this plant, decorative
chromium plate is applied to automobile bumpers. Based on operating
parameters such as current, voltage, plating time and chromic acid
concentration, the plating tank could be considered typical of other large
decorative chromium plating operations. The results from the Delco Products
Test Program will be used to characterize the uncontrolled emissions from
decorative chrome operations and to revise or confirm uncontrolled emission
factors for this type of process developed during another phase of the test
program.
In an effort to obtain this data, tests were conducted at the
Delco/Livonia plant on March 18 and 19, 1987, under contract to the Emission
Measurement Branch (EMB) of the EPA's Emission Standards and Engineering
Division. Test team members were PEER Consultants, P.C., located in Dayton,
Ohio; Pacific Environmental Services, Inc., (PES), located in Cincinnati,
Ohio; and Midwest Research Institute (MRI) located in Raleigh, North
1-1
-------
Carolina. Triplicate tests using the Modified Method 13B (MM 13B) sampling
train were performed on the exhaust gases from chromium plating Line No. 4.
Line No. 4 chrome plating tank is equipped with single-sided hoods on each
end and two double-sided hoods between each plating cell. The ventilation
hoods on the tank are connected to a common duct that leads to an
evaporator/scrubber. Figure 1-1 presents a process diagram. The results of
these tests were used to determine Cr+6 and total Cr emissions.
Particle size distribution measurements were to be taken at the site, but
these samples were unobtainable due to the length of the nipples on the
sample ports and the inside diameter of each port. Each nipple was
approximately 8 inches in length and the inside diameter of the sample port
was equal to the outside diameter of the impactor. Both of these factors
made it impossible to insert the cascade impactor into the stack. The
particle size data were to be collected using the Andersen Mark III,
eight-stage impactor with a straight nozzle. In addition to the emissions
sampling, samples were taken of the chromium plating solution from each cell
of the plating tank at intervals during each emission sample run and
analyzed for Cr+6 and total Cr.
Some minor modifications to the traverse point locations were required
because the duct walls were concave at the sample port location and because
the sample port nipples extended into the stack cross section. A detailed
discussion of the stack area and traverse point location is presented in
Section 4.0.
The remainder of this report describes the process and its operation in
Section 2.0. Section 3.0 presents a summary and discussion of results.
Section 4.0 describes the sampling locations and test methods while quality
assurance is discussed in Section 5.0. Appendix A presents field data
sheets, Appendix B calculation sheets for each test, Appendix C laboratory
analytical results; Appendix D sampling and analytical procedures,
Appendix E equipment calibration sheets, Appendix F project participants and
activities log, Appendix G methods followed during the analysis of the
samples and Appendix H contains the process monitoring data.
1-2
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AIRFLOW LEGEND
2nd FLOOR
LINE 4 CHROMIUM
- PLATING TANK
EVAPCRATCR/SCRUBBER
Figure 1-1. Process diagram of chrome plating tank on Line No. 4.
-------
SECTION 2.0
PROCESS OPERATION
2.1 PROCESS DESCRIPTION
The Livonia facility of Delco Products Division, General Motors
Corporation (Delco) is a large captive shop that performs decorative
chromium electroplating of automobile bumpers. The plating facility
consists of five decorative chromium plating lines, but only three lines
(Nos. 2, 4, and 5) are currently operated.
Each plating line consists of about 20 tanks containing various cleaning
and plating solutions. The lines are serviced by automatically controlled
overhead conveyors that transfer racks of up to 14 bumpers to each tank in a
programmed sequence. The chromium plating segment of each line consists of
a plating tank and several rinse tanks.
The chromium plating tank on Line No. 4 was tested to characterize
uncontrolled emissions. Based on size; operating parameters such as
current, voltage, and plating time; and chromic acid concentration, the tank
is typical of other large decorative chromium plating tanks used in the
electroplating industry. The chromium plating tank is 6.1 meters (m)
(20 ft) long, 3.65 m (12.0 ft) wide, and 2.75 m (9.0 ft) deep and is divided
into three cells that are each 2.0 m (6.7 ft) long. The tank holds
approximately 61,170 liters (16,160 gal) of plating solution, which contains
chromic acid in a concentration ranging from 250 to 375 grams/liter (2.)
(33 to 50 ounces/gal) of water. Sulfuric acid is used as a catalyst in a
chromic acid to sulfuric acid ratio of 180:1.
Line No. 4 is operated 16 hr/day, 5 days/wk. Typically, two or three
cells are operated at a time. One rack of bumpers is plated per cell for
about 2.25 minutes (min). Each bumper receives a chromium plate that is
2-1
-------
0.305 micrometer (0.012 mil) thick. Two separate transformer/rectifiers
charge the electrodes in each cell. For the first 15 seconds of plating,
the surface area of the bumpers is activated. During activation, each
rectifier is set at 5 to 6 volts (V) and 2,500 to 3,000 amperes (A). After
activation, the actual plating phase of the cycle begins. During plating,
each rectifier is set at 16 to 17 V and 8,500 to 10,000 A. The electrical
settings are determined by the required current density for a particular
rack of bumpers. Typical current densities range from 1,600 to
2,150 amperes per square meter (150 to 200 amperes per square foot) of
surface area.
2.2 AIR POLLUTION CONTROL
The chromium plating tank on Line No. 4 is equipped with single-sided
draft hoods on each end and double-sided draft hoods between each cell
(Figure 2-1). The hoods on the tank are connected to a common duct that
leads to an extensive evaporator/scrubber system. The total ventilation
rate is about 990 cubic meters per minute (35,000 cubic feet per minute).
2.3 PROCESS CONDITIONS DURING TESTING
Three test runs were conducted at the inlet of the evaporator/scrubber
to characterize the uncontrolled emissions from the decorative chromium
plating tank. The process was operated within normal limits during each
test run.
Process operating parameters such as voltage, current, and plating
solution temperature were monitored and recorded during each test run. The
number of plating cycles and the number of bumpers plated also were recorded
for each test run. Data sheets documenting process operating conditions and
the workload during each test run are presented in Appendix H. Average
values for the operating conditions recorded during each emission test run
are presented in Table 2-1.
2-2
-------
ro
i
oo
AIRFLOW LEGEND
LEGEND:
A = TEST PORT
B = GRAB SAMPLE LOCATION
PLATING TANK
2nd FLOOR
TO FAN
id
-1
- - - —
B
-*«-
i
I
J
J
B
->r
I
I
i
[
1
B
1 • -
X
* —
J
i
)
]A
1st FLOOR
EVAPORATOR/SCRUBBER
Figure 2-1. Schematic of decorative chromium plating tank tested on Line 4 at
Delco Products Division, General Motors Corporation, Livonia, Michigan.
-------
In addition, grab samples of the plating solution were taken from each
cell in the tank during the course of each test run to determine the chromic
acid concentration of the plating solution. The analytical results for each
sample are presented in Section 3.0 of this report.
Test Run No. 1 was interrupted for 13 minutes for electrical repairs on
the plating line. Test Run No. 2 was interrupted three times for 51, 3, and
11 min. The 3-minute interruption was caused by delays at the racking
station where bumpers were being mounted on the racks. The other two
interruptions occurred when the process was stopped for repairs. Test Run
No. 3 was interrupted three times for 3, 5, and 165 minutes. The
interruptions were a result of malfunctions with the overhead conveyor.
The total amount of current supplied to the tank during each test run is
calculated in terms of ampere-hours and is included in Appendix H. A
tabular summary of the total current values is presented in Table 2-2.
TABLE 2-1. AVERAGE OPERATING CONDITIONS RECORDED DURING
EACH EMISSION TEST RUN
Test
run No.
1
2
3
Bath
temperature,
•C (-F)
54 (130)
54 (130)
55 (131)
No. of
cycles
138
139
120
Voltage,
volts
22.3
22.0
22.8
Current,
amperes
20,507
21,697
21.747
No. of
bumpers
1.043
1,143
984
TABLE 2-2. TOTAL CURRENT CONSUMED DURING
EACH EMISSION TEST RUN
Test Run No. Total current, ampere-hr
1 97,392
2 103,519
3 89,609
2-4
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SECTION 3.0
SUMMARY OF RESULTS
3.1 INTRODUCTION
Table 3-1 presents the testing schedule along with the sample and
analytical parameters. The samples collected from the triplicate emissions
tests performed at the inlet and the plating solution sampling from
Line No. 4 were analyzed for total Cr and Cr*6. Cr+6 analysis was
performed using the procedures outlined in "Determination of Hexavalent
Chromium Emissions From Stationary Sources." This method is presented in
Appendix G. Total Cr concentration was determined by the Inductively
Coupled Argon Plasmography (ICAP) Analytical Procedure. This procedure is
outlined in EPA Method 3050 of EPA document SW-846, and is also presented in
Appendix G. The results of these analytical procedures are presented in the
remainder of this section.
TABLE 3-1. TEST SCHEDULE FOR Cr+6 and Cr EMISSIONS TESTING
AT DELCO PRODUCTS, LIVONIA, MICHIGAN
Samole Parameters Analytical Parameters
Run
No.
1-1
1-2
1-3
Date
(1987)
3/18
3/19
3/19
Time
0934 to
1259
1437 to
1851
0945 to
1549
MM 13B
X
X
X
Cr+6
Diphenylcarbazide
Col ori metric Method
X
X
X
Total Cr
ICAP
X
X
X
3-1
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3.2 HEXAVALENT AND TOTAL CHROMIUM EMISSIONS RESULTS
Table 3-2 summarizes pertinent sample and flue gas data for the chromium
tests, and Table 3-3 presents the Cr+6 and total Cr emissions results.
Sample volumes are expressed in dry standard cubic feet (dscf) and dry
normal cubic meters (dNm3). Volumetric flow rates are corrected to
standard conditions (68°F and 29.92 inches Hg C20°C and 760 mm Hg]
and zero percent moisture) and are expressed as dry standard cubic feet per
minute (dscfm) and dry normal cubic meters per minute (dNm3/min).
Concentrations of Cr+6 and total Cr are expressed in grains per dry
standard cubic feet (gr/dscf) and milligrams per dry normal cubic meter
(mg/dNm3). Mass emissions rates are expressed in pounds per hour (Ib/h)
and kilograms per hour (kg/h). Each recovered sample consisted of the
rinseate from the nozzle and probe combined with the impinger solutions and
the rinseate from all connecting glassware. The sample was collected in a
polyethylene sample bottle.
As reported in Table 3-2 sample volumes were consistent and ranged from
151.110 to 155.638 dscf for the sample trains. The isokinetic variation
ranged from 98.0 to 98.5 percent which is within the acceptable range of
90 to 110 percent.
At the scrubber inlet, the average volumetric flow at standard
conditions was 23,000 dscfm (650 dNm3/min). Flue gas temperatures
ranged from 74 to 76°F and averaged 75°F (23 to 24°C and averaged
24°C). The moisture content of the gas stream averaged 0.92 percent
(based on the average of Runs 1-2 and 1-3). During the sample recovery of
Run 1-1, the final impinger weight was incorrectly recorded which resulted in
erroneous moisture data. Thus, the average moisture content (0.92 percent)
was used in the calculations for Run 1-1. The static pressure was checked
during the collection of preliminary data and recorded using a 0- to
10-inch H20 manometer during each test. The static pressure was measured
from the negative side of the pitot tube and measured 3.0 inches H20.
3-2
-------
TABLE 3-2. SUMMARY OF SAMPLE AND FLUE GAS CONDITIONS (DELCO PRODUCTS - LIVONIA, MICHIGAN)
Sample Parameter
Run No.
in. H20
1-1
1-2
1-3
Date
(1987)
3/18
3/18
3/19
Sample
Location
Inlet
Inlet
Inlet
Sample
dNM3
4.28
4.41
4.39
Vol ume
dscf
151.110
155.638
155.156
Volumetric
Percent
Isokinetic
98.0
98.5
98.3
Flow Rate
dNm3/min
641
656
656
dscf /mi n
22,633
23,183
23.161
Flue Gas Condition
Temper-
ature
Op 0C
76
74
75
24
23
24
Moisture
Content X
0.92
1.03
0.82
Static
Pressure
-3.0
-3.0
-3.0
CO
I
U)
TABLE 3-3. SUMMARY OF Cr+6 AND TOTAL CR EMISSION DATA (DELCO PRODUCTS - LIVONIA, MICHIGAN)
Concentration
Run No
1-1
1-2
1-3
Date
. (1987)
3/18
3/18
3/19
Sample
Cr+6
Location mg/dNm3 gr/dscf
Inlet
Inlet
Inlet
1.95
1.30
1.54
0
0
0
.00085
.00056
.00067
Mass Emission Rate
Total Cr Cr*6
mg/dNm33 gr/dscf
1.66
1.21
1.45
0.00072
0.00053
0.00063
kg/h
0.08
0.05
0.06
Ib/h
0.17
0.11
0.13
Total Cr
kg/h
0.06
0.05
0.06
Ib/h
0.14
0.10
0.13
-------
Analysis of the gas stream composition was not performed because the process
was emitting essentially air. The molecular weight was assigned a value of
29.0 Ib/lb-mole.
The Cr+6 content of the gas stream at the inlet to the
evaporator/scrubber ranged from 5.6 x 10~4 to 8.5 x 10"4 gr/dscf
(1.30 to 1.95 mg/dNm3) and averaged 6.8 x 10~4 gr/dscf (1.60 mg/ dNm3)
for the three tests. The total Cr concentration ranged from 5.3 x 10~4 to
7.2 x 10~4 gr/dscf (1.21 to 1.66 mg/dNm3). The average mass emission
rate for total Cr was 0.12 Ib/h (0.06 kg/h).
The total amount of Cr+6 that was captured in the sample trains during
each test was 8.37 mg for Run 1-1, 5.71 mg for Run 1-2 and 6.78 mg for Run
1-3. Total Cr contained in the sample train for these runs was
7.11 mg, 5.37 mg and 6.38 mg, respectively. Note that the Cr+6
concentration in the samples is reported to be higher than the total Cr
concentration. In Section 5.0 of this report it is demonstrated that the
percent recovery of Cr+6 in the colorimetric method exceeds that of the
ICAP method for total Cr. This difference in recovery rates can account for
such apparent discrepancies and the Cr+s would appear to be the more
accurate result. In any case, the results indicate that the majority of
chromium in these samples is in the form of Cr+6. The calculation sheets
for the Cr+6 and total Cr concentrations and emission rates are presented
in Appendix B.
3.3 PROCESS SAMPLE ANALYSIS
Table 3-4 summarizes results for Cr+6 and total Cr from the plating
tank solutions collected during each test period. Plating tank solutions from
Line No. 4 chrome plating tank, cells 1, 2, and 3 were collected and
composited in different bottles for each cell. The samples were taken at
three equal intervals during each of the MM 138 tests. Results for both
Cr+6 and total Cr are expressed in milligrams per liter (mg/Jl).
Analytical procedures were similar to those used for the actual emission
3-4
-------
samples with the Cr+6 determined by the diphenylcarbazide colorimetric
method and total Cr by ICAP.
TABLE 3-4. SUMMARY OF RESULTS FROM THE LABORATORY ANALYSIS
PLATING TANK SOLUTIONS
Sample Total Cr (ma/fi.) Cr+6 (mq/fi.)
Run 1-1
Cell 1 153,000 150,000
Cell 2 147,000 160,000
Cell 3 157,000 153,000
Run 1-2
Cell 1 152,000 152,000
Cell 2 151,000 154,000
Cell 3 146,000 160,000
Run 1-3
Cell 1 151,000 158,000
Cell 2 151,000 158,000
Cell 3 138,000 160,000
3-5
-------
SECTION 4.0
SAMPLE LOCATIONS AND TEST METHODS USED
4.1 LOCATION OF MEASUREMENT SITE
Samples were extracted from the Inlet to the evaporator/scrubber.
Figure 4-1 depicts a simplified process flow diagram and Figure 4-2 vs an
orthogonal sketch of the inlet sample location. At the inlet to the
evaporator/scrubber, six sampling ports were identified (from left to right)
as ports A,B,C,D,E, and F.
The scrubber inlet measurement site (identified in Figure 4-1) was
located in a vertical rectangular duct having nominal dimensions of
24 x 96 inches. The six 3-inch I.D. sample ports were located at equal
distances along the 96-inch side. Upon measurement of the stack's inside
dimension, it was discovered that all six sample ports extended into the
stack cross-sectional area for 3.5 inches past the inside wall. A visual
inspection of the ductwork also revealed that the duct was partially
collapsed along the front and back sides. Measurement of the duct inside
dimensions through each of the six ports resulted in six different values.
These are summarized in Table 4-1. The inside width was 95.8 inches. Using
stack dimensions of 20.7 x 95.8 inches the gross area of the duct cross-
section at the measurement site was 1983 square inches. In order to compute
the net cross-sectional area it was necessary to correct for the area of the
nipples which extended into the duct. All nipples were 3.5 inches outside
diameter and extended 3.5 inches into the duct cross-sectional area. The
total blockage was 73.5 square inches (3.5 x 3.5 x 6). Thus, the net area
of the duct was 1910 square inches. The equivalent stack dimensions were
\
19.9 x 95.8 inches for an equivalent inside diameter of 33.0 inches.
4-1
-------
AIRFLOW LEGEND
2nd FLOOR
t
T
t
TO FAN
J
LINE 4 CHROMIUM
- PLATING TANK
•»r
I
I
CELL 2
LOCATION OF SAMPLING PORTS
MMM
»f
1-
I
I
1
4
h
CELL 1
i "-•• 4—
I
1
»
1st FLOOR
EVAPORATOR/SCRUBBER
Figure 4-1. Simplified process flow diagram.
-------
96"
24"
~TH "DD D U LT
Top view shewing duct measurements, port location and outline of the partially
collapsed duct walls
72.5'
Transition duct
Direction of Flow
8" . 16"
3.0" (ID)
Front view showing port spacing, port diameter and distance from nearest y
upstream disturbance
4 3/a "
3.5*
^3
44.5"
J_
Side view showing the distance :
port configuration
Direction of
Flow
ran tne nearest
-------
TABLE 4-1. INSIDE DIMENSIONS OF THE DUCT
AT EACH SAMPLE PORT
Port
A
B
C
D
E
F
Average
Inside Depth
(Inches)*
22.4
19.9
19.4
19.5
20.0
22.8
20.7
* Does not include 3.5-inch nipple protrusion
into the duct.
The measurement side was located 72.5 inches (2.2 duct diameters)
downstream of a duct transition and 44.5 inches (1.3 duct diameters)
upstream of an elbow. According to EPA Method 1 criteria, this location
required 30 sample traverse points using a 6 x 5 matrix. Three sets of
sample traverse dimensions were used. Measurements of the distance across
the duct from each sample port indicated that the measurements through ports
A and F were nearly identical, B and E were nearly identical, and C and
D were nearly identical. Thus, three sets of sample traverse points were
used. Due to the protrusion of the sample port nipples into the duct, the
first traverse point was relocated to 1.0 inch past the end of each nipple.
The resultant sample traverse point locations are summarized in Table 4-2,
and a cross section of the inlet showing the traverse points is presented in
Figure 4-3. The figure is exaggerated but demonstrates the methodology
applied in locating the traverse points. This alternative method of
locating the traverse points was discussed and approved by the EPA Task
Manager. Each point was isokinetically sampled for 6.0 minutes to acquire a
total test time of 180 minutes.
4.2 HEXAVALENT AND TOTAL CHROMIUM SAMPLE EXTRACTION AND ANALYSIS
Prior to sampling, velocity, static pressure, 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
4-4
-------
TABLE 4-2. SUMMARY OF SAMPLE TRAVERSE POINT LOCATIONS
Traverse Inside of Nipple Depth Traverse Point
Point Near Wall to Inside Location From
No. Traverse Point of Near Wall Outside of Nicole
Ports A & F (averaae diameter =
1
2
3
4
5
Ports B & E
1
2
3
4
5
Ports C & D
1
2
3
4
5
2.26 (4.5)
6.78
11.30
15.82
20.34
(average diameter
2.00 (4.5)
6.00
10.00
14.00
18.00
(average diameter
1.95 (4.5)
5.85
9.75
13.65
17.55
22.6 inches)
4.375
4.375
4.375
4.375
4.375
= 20.0 inches)
4.375
4.375
4.375
4.375
4.375
= 19.5 inches)
4.375
4.375
4.375
4.375
4.375
6.6 (9.0)
11.2
15.7
20.2
24.7
6.4 (9.0)
10.4
14.4
18.4
22.4
6.3 (9.0)
10.2
14.1
18.0
21.9
4-5
-------
22.4"
I
en
22.8"
Figure 4-3. Cross-section of sample location indicating traverse points.
-------
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. In addition,
verification of the absence of cyclonic flow at each sample traverse point
was assessed based on procedures described in the EPA Reference Method 1.
In this method, the face openings of the Type-S pi tot 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 pi tot reading was not zero at 0-degree reference, the pi tot 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 (nonaxial) flow conditions in the duct. The average of
the angular rotations was 7.8 degrees, which indicated acceptable flow
patterns and enabled the extraction of representative samples from this
source. The cyclonic flow data is contained in Appendix A. Following this,
sampling was performed by conducting triplicate tests at the inlet to the
evaporator/scrubber. Samples were collected to determine the uncontrolled
Cr+6 and total Cr emissions from this source.
\
An EPA MM 13B2 sample train was used to collect the Cr+s and
total Cr samples. The sample train consisted of a 316 stainless steel
button-hook design nozzle, an unheated Pyrex glass-lined probe, and a series
of impingers. The first, third and fourth impingers were Greenburg-Smith
design, modified by replacing the tip with a 1/2-inch inside diameter glass
tube extending to 1/2-inch from the bottom of the flask. The second
impinger was a Greenburg-Smith impinger with the standard tip. In the
first, second and third impinger 100 mfi. of 0.1N NaOH was placed, and
approximately 200 grams of silica gel was placed in the fourth impinger.
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
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temperature, volumetric flow rate and isokinetic sampling rates. During
sampling, stack gas temperature and the gas temperature exiting the fourth
impinger were monitored with thermocouples.
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 polyethylene container. All connecting glassware, the nozzle
and probe were rinsed with 0.1 N NaOH and combined with the impinger
solution in the polyethylene sample bottle. The liquid level was marked on
each sample bottle and the pH was checked with pH paper to verify that the
pH was above 7.0. Appropriate blank solutions were collected in the field
for submission to the laboratory for analysis with the samples. The samples
were transported to the laboratory where total volumes of each sample were
measured. The volume recovered from Run 1-1 was 698 mi, Run 1-2 was
770 mi and 672 ma was recovered from Run 1-3. Each sample, including
blanks, was analyzed for Cr*6 concentrations using analytical
methodology recently developed by the EPA. A copy of the draft method
entitled "Determination of Hexavalent Chromium Emissions From Stationary
Sources" is contained in Appendix G of this report. This method entails the
extraction of the sample with alkaline solution, followed by the
diphenylcarbazide colorimetric method.
At the completion of the Cr*6 analysis, a separate portion of each
sample was digested and analyzed for total Cr by use of ICAP analytical
techniques. Appendix G of this report contains the detailed analytical
methodology used for this analysis.
4.3 PROCESS SAMPLES
Process samples (plating tank solutions) were collected by PEER
personnel during each test period. A sample from each cell of the chromium
plating tank was collected and composited at three equal intervals during
the 3-hour test period and placed in corresponding polyethylene containers.
These samples were analyzed for Cr+s and total Cr following procedures
similar to those used for the emission samples.
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SECTION 5.0
PROJECT QUALITY ASSURANCE
The application of quality assurance procedures to source emission
measurement ensures accurate emission-testing results. Quality assurance
guidelines provide the detailed procedures and actions necessary for
defining and producing acceptable data. In this project, three documents
were used in the preparation of a source-specific test plan that would
ensure the collection of acceptable data:
1. Quality Assurance Handbook for Air Pollution Measurement Systems.
Volume III; Stationary Source-Specific Methods. EPA-600/4-77-027B;
2. PEI, Laboratory Quality Assurance Plan:
3. "Determination of Hexavalent Chromium Emissions From Stationary
Sources," December 13, 1984. This method has recently been developed by
the EPA.
In this specific test program, which was reviewed by the EPA's Emission
Measurement Branch, the following steps were taken to ensure that the
testing and analytical procedures produced quality data:
On-site quality assurance checks, such as leak checks of the sampling
train and pitot tube, detailed information on these checks is presented
in Appendix A. On-site quality assurance checks were performed on all
test equipment prior to its use.
Triplicate micrometer measurements of the sampling nozzle. These
measurements were recorded on the field data sheets (Appendix A).
Use of sampling equipment as designated in EPA Method 13B.
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Standard forms were used for recording data and in calculating air flow
results.
The sample recovery was performed in the plant in an area isolated from
contamination, and in the van.
Samples were collected in polyethylene sample bottles. Polyethylene
bottles are recommended for storing and shipping of corrosive materials.
Samples were secured upon completion of the sample recovery activities.
The samples and blanks were placed in a designated area in the clean-up
van. The van was locked when unattended. For transportation, the
samples and blanks were secured in a cooler. No special storage was
required for these samples.
Samples were in the custody of PEER Consultants, P.C., at all times.
When the samples were transported to the laboratory, the Sample
Custodian acknowledged the laboratory's receipt of the samples (Appendix A).
All glassware and sample bottles were rinsed with 10 percent nitric acid
before use in the field.
Prior to sampling, the ports were cleaned to minimize the possibility of
contamination of the sample train when inserting or removing the probe.
External contaminated surfaces (probe, nozzle and pi tot tube) were rinsed
prior to sample recovery. This would eliminate the risk of sample
contamination.
A polyethylene dipper was used to take samples of the chrome plating
solution.
While sampling, the ports were capped and the accessed port was sealed with
a rag to prevent the introduction of room air into the duct.
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All field-sampling equipment was calibrated. The pretest and post-test
calibration data for the equipment used in the field is contained in
Appendix E.
Duplicate and spiked samples were analyzed in the laboratory, the
results of which are presented below.
Table 5-1 list the specific sampling equipment used to perform the MM
13B sampling program. The calibration data for this equipment is presented
in detail in Appendix E.
TABLE 5-1. EQUIPMENT USED IN THE MM 13B
SAMPLING PROGRAM
Equipment Identification
Meter Box RAC 1065
Thermometers
- meter box RAC-1
- sample head SH-1
Pi tot Tubes S-l, S-2
Thermocouple 3-T-1A
On-site calculations were made by the EPA Task Manager on the emissions
sampling data to determine the Isokinetic variation and moisture content of
the stack gas. All final calculations were done after the post-test
calibrations had been performed on the equipment following the return from
the field test. The final calculations are presented in Appendix B. The
following summarizes the quality assurance activities performed during the
analytical phase of this project.
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Emission and process samples were analyzed in the same batches. The
linear regression data of the spectrophotometer calibration for these
samples is presented in Appendix C. Standards containing 0, 5, 10, 15,
20 and 25 n9 of Cr*6 per 50 mi were analyzed with the samples. The
ICAP was calibrated prior to the total Cr analysis. This calibration data
is presented in Appendix C. Reagent blanks that were set-up in the field
were analyzed with the actual sample. The blank results are presented in
Table 5-2.
In addition to the analysis of the submitted samples and blanks,
duplicate and spiked samples were analyzed. Table 5-3 summarizes the
results of these QA/QC checks.
TABLE 5-2. SUMMARY OF BLANK ANALYSIS
Blank I.D. No.
Bl.Run 1-1
Bl.Run 1-2
Bl.Run 1-3
Cr+6 (ma/a)
less than 0.02
less than 0.02
less than 0.02
Total Cr (ma/a)
0.011
0.011
0.013
TABLE 5-3. SUMMARY OF ANALYTICAL RESULTS FROM DUPLICATE
AND SPIKED SAMPLES
Sample
Run 1-2
Run 1-1
Run 1-3
Run 1-2
I.D. No.
, tank 2
, emission
, tank 1
, emission
Tvpe of Sample
Cr+6
duplicate
spiked
Total Cr
duplicate
spiked
Results
154,000 mg/fi,
155,000 mg/a
98.5% recovery
153,000 mg/2,
149,000 mg/2,
89.3% recovery
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REFERENCES
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REFERENCES
1. 40 CFR Part 60, Appendix A, EPA Reference Methods 1,2,4, July 1986.
2 40 CFR part 60, Appendix A, EPA Reference Method 13, July 1987.
3 "Test Methods for Evaluating Solid Waste," U.S. EPA SW-846, 2nd Edition,
July 1982, Method 3060.
4 "Test Methods for Evaluating Solid Waste," U.S. EPA SW-846, 2nd Edition,
July 1982, Method 3050.
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