United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
RTP, NCZ7711
EMB Report 89-CEP-16
MAY 1989
Air
EPA
CHROMIUM
ELECTROPLATERS
TEST REPORT
FUSION, INCORPORATED
HOUSTON
TEXAS
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EPA Contract No. 68-02-4346
Work Assignment 5
September 25, 1989
Determination of the Performance Level of a
Single Packed-Bed Scrubber
Candidate Plant
Fusion, Inc.
Houston, Texas
Prepared for
U.S. Environmental Protection Agency
Emissions Measurement Branch
Research Triangle Park, North Carolina 27711
Prepared by
PEER Consultants, P.C.
4134 Linden Ave., Suite 202
Dayton, Ohio 45432
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CONTENTS
Section Page
1.0 Introduction 1
2.0 Process Description 4
3.0 Summary of Results 15
4.0 Sampling Locations and Test Methods 25
5.0 Quality Assurance 31
APPENDICES
A Process Data Sheets and Ampere-Hour Calculations .... A-l
B Field Data Sheets B-l
C Draft Method for Chromium Analysis C-l
D Chain of Custody Sheets D-l
E Equipment Calibration Data E-l
F Project Participants and Activity Log F-l
G Datachem Quality Control Plan G-l
H Calculation Checks H-l
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FIGURES
Figures Page
1-1 Location of sample points 2
2-1 Side view of capture and control system
at Fusion, Inc., Houston, Texas 6
2-2 Detailed schematic of a Duall horizontal-flow,
single packed-bed scrubber 7
2-3 Side view of capture and control system
at Fusion, Inc., Houston, Texas 9
4-1 Duct area calculations 26
TABLES
Table Page
2-1 Average Scrubber Operating Parameters Monitored
During Each Mass Emission Test Run 11
2-2 Averages of Operating Parameters Monitored During
Each Mass Emission Test Run 13
2-3 Total Ampere-Hours Supplied to Plating Tank
During Each Mass Emission Test Run 14
3-1 Schedule of Activities 16
3-2 Summary of Flue Gas Conditions 18
3-3 Summary of Sample Volumes, Analytical Results
and Emission Rates for the Scrubber Inlet 20
3-4 Summary of Sample Volumes, Analytical Results and
Emission Rates for the Scrubber Outlet 21
3-5 Summary of Cr+6 Removal Efficiencies 23
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TABLES
(continued)
3-6 Summary of Plating Solution Analytical Results 24
3-7 Summary of Plating Solution & Rlnseate
Analytical Results 24
4-1 Sample Traverse Point Locations for the Scrubber
Inlet and Outlet 27
5-1 Summary of Analytical Results for QA/QC Samples
And Blanks 33
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SECTION 1.0
INTRODUCTION
During the week of May 17-24, 1989, an emission measurement program
was conducted at the Fusion, Inc. plant in Houston, Texas. The purpose
of this program was to collect data to determine the efficiency of the
single packed bed scrubber, operating with an overhead washdown system
running under three separate conditions. The conditions tested were:
without the washdown; the washdown system operating periodically; and
with the washdown system operating constantly.
The primary reason for selecting Fusion, Inc. was that the plant was
willing to allow EPA to modify the scrubber by adding an overhead weir
system to determine if the flooding action provided by the weir improves
scrubber performance. The capture and control system on the plating tank
consists of a double-sided draft hood ducted to the scrubber. In order
to assess the control efficiency of the system, hexavalent chromium
(Cr+6) and total chromium emissions were measured at two locations
along the duct. These locations are identified in Figure 1-1 as:
(1) inlet to the single packed-bed scrubber and (2) outlet from the
single packed-bed scrubber.
The emission samples were collected using the Modified Method 13B
(MM13B) sample train. This method will be discussed in Section 4.0.
The samples were analyzed for Cr+6 concentration using the
diphenylcarbazide colorimetric method. This method will also be
discussed in Section 4.0.
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Outlet from the single
packed-bed scrubber
29.69" Dia.
Double-sided lateral hood
30.0'x3.5'x4.0' plating tank
15.8"
wall
Inlet to the single
packed-bed scrubber
30.05"Eq. Dia.
63.2"
76"
19"
Dual!
Single
Packed-Bed
Scrubber
Fan
Figure 1-1. Location of Sample Points
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PEER Consultants, P.C., located in Dayton, Ohio, was responsible
for developing the test protocol, conducting the field test, on-site
analysis of samples and the preparation of draft and final reports. PEER
was supported by its subcontractor, Pacific Environmental Services, Inc.
located in Cincinnati, Ohio. Midwest Research Institute, located in
Raleigh, North Carolina, was responsible for monitoring the process
operation, and EPA personnel conducted Screening Method testing and
monitored the implementation of the test protocol.
3
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SECTION 2.0
PROCESS OPERATION
2.1 PROCESS OPERATION
Fusion, Inc. In Houston, Texas, is a job shop that specializes in
hard chromium electroplating of crankshafts. The plating shop consists
of five hard chromium plating tanks that are operated 24 hours per day,
7 days per week, and 52 weeks per year.
The plating tank (No. 1) tested during this source test program is
9.1 m (30 ft) long, 1.1 m (3.5 ft) wide, and 1.2 m (4.0 ft) deep, and
holds approximately 10,410 liters (JO (2,750 gallons [gal]) of plating
solution. The plating tank is equipped with a single rectifier rated at
15 volts (V) and 8000 amperes (A). The tank contains a conventional hard
chromium plating solution consisting of 240 grams per liter (g/1) (32
ounces per gallon [oz/gal]) of chromic acid and 2.4 g/fi- (0.32 oz/gal)
of sulfuric acid. The plating solution is maintained at 54°C (130°F).
The only portions of the crankshafts that are plated are the cams.
The crankshafts contained from 5 to 15 cams. Semicircular-shaped anodes
are positioned over each cam on the crankshaft. The crankshaft is them
lowered by hoist into the plating tank. The anodes are connected to the
electrical circuit, and the current and voltage are applied stepwise
until the current density reaches 3100 A per square meter (2 A per square
inch). During plating, each crankshaft is rotated continuously in the
tank to ensure that an even plate thickness is applied over the entire
surface area of each cam. Typically, two to three crankshafts are plated
simultaneously over a 24-hr period at a current loading of 3000 to 4000
amperes.
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2.2 AIR POLLUTION CONTROL
The capture and control system on the plating tank consists of a
double-sided draft hood that is vented to a horizontal-flow single
packed-bed scrubber. Figure 2-1 presents a schematic of the capture and
control system on the plating tank.
The scrubber was manufactured by Duall, Industries, Inc., (Model
No. F-101) and installed in 1988. Figure 2-2 presents a detailed
schematic of the scrubber. The design gas flow rate to the scrubber is
450 cubic meters per minute (m3/min) (16,000 cubic feet per minute
[fta/m1n]). The scrubbing water flow rate is approximately 180
liters per minute (48 gallons per minute). The design pressure drop
across the scrubber is 0.5 kilopascal (kPa) (2.0 inches of water column
[in.w.c.]).
Hlthin the scrubber system, the velocity of the gas stream is reduced
to approximately 143 meters per minute (440 feet per minute), and the gas
stream 1s humidified by a spray of water. Water is sprayed
countercurrent to the flow of the gas stream through 10 spray nozzles.
The saturated gas stream then passes through a packed bed of
polypropylene, spherical-type mass packing. The packed bed 1s
approximately 2.0 m (6.4 ft) high, 1.9 m (6.2 ft) wide, and 0.30 m
(1.0 ft) deep. Entrained mist and water droplets impinge on the packing
and drain into a sump. Behind the packed bed is a two-stage mist
elimination section that removes entrained water droplets. The first
stage allows large droplets to settle by gravity to the bottom of the
scrubber. The second stage contains a series of vertically-mounted
chevron blades that change the direction of the gas flow four times at
30° angles, which causes any entrained droplets to impinge on the
blades. The mist eliminator is not washed down.
The scrubber water drains into a sump in the bottom of the scrubber
and is recirculated by a pump. A level indicator (sight gauge) is used
to monitor the water level in the sump, which holds approximately 450 ft
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fan
Dual!
single
packed-bed
scrubber
wall
double-sided lateral hood
30.0'x3.5'x4.0' plating tank
Figure 2-1. Side view of capture and control system at Fusion, Inc., Houston, Texas.
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Water
Spray
Section
Packed
Bed
Mist-Laden
Gas Stream
Inspection Door
Mist
Eliminator
Section
Reclrculatlon
Pump
Controlled
Gas Stream
Figure 2-2. Detailed schematic of a Duall horizontal-flow, single packed-bed scrubber.
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(120 gal) of water. Once a week, the water in the sump is drained into a
5680 2, (1500 gal) holding tank and the sump is recharged with fresh
water. During testing, the chromic acid concentration of the water
samples taken from the sump averaged 0.08 g/2, (0.01 oz/gal) through
test run No. 3 After the scrubber was thoroughly cleaned by draining the
sump and washing down the inside walls, packing media, and mist
elimination section, the chromic acid concentration of the sump water
averaged 4.9 g/fi. (0.65 oz/gal) for the next three runs. Although the
plating tank is operated 24 hours per day, the recirculation system on
the scrubber is turned off from 11:30 p.m. to 7:30 a.m. During this
time, there are no plant employees on site. The company is concerned
that if the pump or water line broke there would be no one on site to
detect the break and prevent a significant spill.
Prior to emissions testing, the scrubber was retrofitted with an
overhead weir so that the scrubber could be operated with and without
periodic washdown of the scrubber packing with fresh water. The scrubber
was also moved back approximately 1.5 m (5.0 ft) and a section of duct
was inserted between the plating tank exhaust plenum and the inlet of the
scrubber to accommodate inlet testing. A stack was also added to the fan
to accommodate outlet testing. Figure 2-3 presents a schematic of the
capture and control system on the plating tank after modifications.
Duall Industries, Inc., the manufacturer of the scrubber, performed the
modifications on the ventilation system and scrubber in addition to
inspecting the scrubber to ensure proper operation.
2.3 PROCESS CONDITIONS DURING TESTING
The primary purpose of this source test was to determine if the
periodic flooding action provided by the scrubber overhead weir system
could significantly improve the scrubber performance. Therefore, eight
mass emissions tests runs were conducted at the inlet and outlet of the
scrubber at each of the following three conditions: (1) the scrubber
recirculation system was in operation and any required makeup water was
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fan
Dual!
/ single
packed-bed
scrubber
wall
double-sided lateral hood '
30.0'x3.5'x4.0' plating tank
Figure 2-3. Side view of capture and control system at Fusion, Inc., Houston, Texas,
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supplied by a hose through one of the scrubber's inspection doors; and
(2) the scrubber recirculation system was in operation and all required
makeup water was supplied through a pipe that extended out about 10 to
13 centimeters (4 to 5 inches) over the top of the packed bed. Two
subsequent test runs were conducted at the inlet and outlet of the
scrubber with the scrubber recirculation system in operation and a
continuous flow of fresh water supplied through the overhead weir at a
rate of 7.6 i/min (2.0 gal/min).
Prior to test runs No. 1 and 3, the sump in the bottom of the
scrubber was drained to the holding tank and the sump was recharged with
fresK water supplied by a hose through one of the scrubber's inspection
doors. During test runs 1 through 3, makeup water required by the
scrubber to replace evaporation losses was added through the inspection
doors with a water hose. Prior to test run No. 4, the scrubber was
inspected and found to contain a heavy buildup of chromic acid resulting
from the overnight shutdown of the recirculation system. Therefore, the
scrubber was thoroughly cleaned by draining the sump and washing down the
inside walls, packing media, and mist elimination section with a
pressurized water hose. During test runs 4 through 6., makeup water
required by the scrubber to replace evaporation losses was supplied
through the pipe located over the top of the packed-bed. Prior to test
run No. 7, the scrubber was cleaned again. During test run Nos. 7 and 8,
makeup water was added continuously over the top of the packed bed
through the overhead weir at a flow rate of 7.6 Jl/m1n (2.0 gal/min).
The scrubber parameters monitored during testing were the pressure
drop across the scrubber, the frequency and, 1f possible, the amount of
makeup water added, the chromic acid concentration of the scrubber water,
and when applicable, the overhead water flow rate. The actual inlet gas
flow rate to the scrubber during testing averaged 575 m3/min
(20,350 ft3/min), and the monitored pressure drop was close to the
design pressure drop of 0.5 kPa (2.0 in. w.c.). The average scrubber
parameters monitored during each test run are presented in Table 2-1.
10
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TABLE 2-1. AVERAGE SCRUBBER OPERATING PARAMETERS MONITORED DURING
EACH MASS EMISSION TEST RUN
Test run No.
Frequency
of water
replacement,
No. of
times per run
Amount of
makeup water
added, i (gal)
Pressure drop, kPa
(in. w.c.)
No washdown
1 6
2 4
3 4
Periodic washdown
4 4
5 5
6 4
Continuous washdown
7 c
8 c
a
a
a
260 (70)5
380 (100)J
260 (70)D
1,590 (420)5
980 (260)°
0.45 (1.8)
0.45 (1.8)
0.45 (1.8)
0.55 (2.2)
0.55 (2.2)
0.55 (2.2)
0.55 (2.2)
0.55 (2.2)
Makeup water was supplied by a garden hose and, therefore, the amount of
.water added was not measured.
Makeup water was added through a flow meter. The quantities of water
provided are based on the amount of time required to fill the sump and
the flow rate measured through the flow meter.
JjFresh water was added continuously at a rate of 2 gallons per minute.
Based on the total amount of time to collect a complete emission sample
and a continuous fresh water flow rate of 2.0 gallons per minute.
11
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Grab samples of the scrubber water were taken from the sump at the end of
each test run. The chromic acid concentration of the scrubber water
samples is reported in Section 3 of this report.
The process was operating normally during the test. Process
operating parameters such as voltage, current, and plating solution
temperature were monitored and recorded during each test run. Also
recorded were the number and approximate size of the crankshafts in the
plating tank during each test run. Averages for the operating parameters
recorded are presented in Table 2-2. The total amount of current
supplied to the plating tank during each test run was calculated in terms
of ampere-hours based on the duration of sampling at the inlet and outlet
test locations. Information on the total ampere-hours supplied to the
plating tank during each test run is presented in Table 2-3. Data sheets
documenting the process parameters that were recorded during each test
run and the ampere-hour calculations are presented in Appendix A.
Grab samples of the plating solution were taken at the beginning,
middle, and end of each test run to determine the chromic acid
concentration of the solution during testing. The chromic acid
concentration of the composite samples is reported in Section 3.0 of this
report.
Test Runs 1 through 6 and test run 8 were each 2 hours in duration.
Test run No. 7 was 3.2 hours in duration. Each test run was interrupted
for 10 to 25 minutes to change test ports. Test run No. 1 was
interrupted for approximately 3 hours because of an electrical problem in
the plating line, which resulted from a current overload. Test run No. 2
was interrupted for 8 minutes because of a problem with maintaining the
isokinetic sampling rate at the outlet test location.
12
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TABLE 2-3. TOTAL AMPERE-HOURS SUPPLIED TO PLATING TANK
DURING EACH MASS EMISSIONS TEST RUN
Test Run No.
1
2
3
4
5
6
7
8
Test
time, hours
2
2
2
2
2
2
3.2
2
Total
current, ampei
Inlet
5,500
6,000
4,600
7,200
7,200
7,400
10,000
5,600
'•e-hoursa
Outlet
5,400
6,000
4,600
7,100
7,200
7,400
10,000
5,600
aNumbers were rounded to the nearest 100.
13
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TABLE 2-2. AVERAGES OF OPERATING PARAMETERS
MONITORED DURING EACH MASS EMISSION TEST RUN
Run No.
1
2
3
4
5
6
7
8
Operating
voltage, volts
5.5
5.8
6.0
5.6
5.6
5.6
6.6
6.2
Operating
current, amperes a
2,600
3,000
2,300
3,600
3,600
3,700
3,100
2,800
Operating
bath
temp., °F
127
127
127
127
127
128
126
127
aRounded to nearest 100.
14
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SECTION 3.0
SUMMARY OF RESULTS
INTRODUCTION
Eight Modified Method 13B (MM13B) samples were collected at each
sample location. All of-the emission samples were analyzed on site for
Cr+6 concentrations using the procedures outlined in the method
entitled "Draft Method - Determination of Hexavalent Chromium in Dry
Particulate Emissions from Stationary Sources." Upon completion of the
test program, two emission samples from each location were analyzed for
total chromium concentrations using the procedure outlined in EPA
Method 218.1. These analytical methods are presented in Appendix D.
Testing was carried out under three separate conditions. Under the
first condition (Condition 1), three tests were run when the scrubber's
overhead washdown system was not in operation. For the second condition
(Condition 2), the scrubber was cleaned and the overhead washdown system
was in operation periodically; this condition was also tested for three
runs. Under the final condition (Condition 3), the overhead washdown
system was operating continuously; testing under this condition was only
carried out for two runs.
In addition to the emission samples, grab samples of the plating bath
were composited during each MM13B run and analyzed using the same
colorimetric procedures used for the emission samples. Table 3-1
presents a schedule of the activities during the test program. The
results from the sampling program are presented in the remainder of this
section.
15
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TABLE 3-1. SCHEDULE OF ACTIVITIES
Date
(1989)
5/19/89
5/19/89
5/19/89
5/19/89
5/19/89
5/19/89
5/19/89
5/19/89
5/20/89
5/20/89
5/20/89
5/20/89
5/21/89
5/21/89
5/21/89
5/21/89
5/21/89
5/21/89
5/21/89
5/21/89
5/21/89
5/21/89
5/21/89
5/21/89
5/23/89
5/23/89
5/23/89
5/23/89
5/23/89
5/23/89
5/23/89
5/23/89
Sample
Tvoe
MM13B
SM
Plating Sol.
Scrubber Rinse
MM13B
SM
Plating Sol .
Scrubber Rinse
MM13B
SM
Plating Sol.
Scrubber Rinse
MM13B
SM
Plating Sol.
Scrubber Rinse
MM13B
SM
Plating Sol.
Scrubber Rinse
MM13B
SM
Plating Sol.
Scrubber Rinse
MM13B
SM
Plating Sol .
Scrubber Rinse
MM13B
SM
Plating Sol.
Scrubber Rinse
Run
1-1
1-1
1
1
1-2
2-1
2
2
1-3
3-1
3
3
1-4
4-1
4
4
1-5
5-1
5
5
1-6
6-1
6
6
1-7
7-1
7
7
1-8
8-1
8
8
Test Time
No. (Minutes)
, 0-1 120
, i-o
, 0-2 120
, 2-0
, 0-3 120
, 3-0
. 0-4 120
. 4-0
, 0-5 120
, 5-0
. 0-6 120
, 6-0
, 0-7 192
. 7-0
, 0-8 120
, 8-0
Parameter
Measured
Cr"
Cr"
Cr"
Cr"
Cr", Total
Cr", Total
Cr"
Cr"
Cr"
Cr"
Cr"
Cr"
Cr"
Cr"
Cr"
Cr"
Cr", Total
Cr", Total
Cr"
Cr*6
Cr"
Cr"
Cr"
Cr"
Cr"
Cr*6
Cr"
Cr"
Cr"
Cr"
Cr*6
Cr"
Cr.
Cr
Cr
Cr
16
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CHROMIUM EMISSION RESULTS
Emission samples were collected isokinetically using a Method 13B
sample train that had been modified by removing the glass fiber filter
and placing 100 mil of 0.1N NaOH in each of the first two impingers.
The impinger solutions were recovered into tared polyethylene sample
bottles and the total volume of the recovered samples was determined
gravimetrically. Following recovery of the samples, an aliquot of the
solution was analyzed for Cr+6. The following subsections present
the flue gas data and analytical results for each sample location.
Scrubber Inlet
Modified Method 13B—
A summary of the flue gas conditions at this location are presented
in Table 3-2. The volumetric flowrates were consistent and averaged
541 dry standard cubic meters per minute (dscmm) [19,100 dry standard
cubic feet per minute, (dscfm)]. The flue gas temperature averaged 31°C
(88°F) and the moisture content averaged 2.41 percent. The flue gas was
essentially ambient air and was assigned a dry molecular weight of
28.95 Ib/lb mole. The isokinetic sampling rates were within the
allowable limitations for these sample runs.
Prior to sampling, it was decided that the MM13B runs should be run
at 5 minutes per point for a total sample time of 120 minutes. This
sample time was chosen to ensure the collection of a detectable
concentration of Cr+6. To ensure collection of a detectable sample
during Run 7, testing was carried out at 8 minutes per point for a total
sample time of 192 minutes. Following the analyses of the sample, it was
determined that the subsequent sample time per point could be reduced to
5 minutes. The uncontrolled emissions as measured in each MM13B run were
consistent and averaged 0.697 mg/dscm (0.00030 gr/dscf). It should be
noted that results for 1-1 came out significantly lower than the other
17
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TABLE 3-2. SUMMARY OF FLUE GAS CONDITIONS
Run No.
Condition
1-1
0-1
1-2
0-2
1-3
0-3
Condition
1-4
0-4
1-5
0-5
1-6
0-6
Condition
1-7
0-7
1-8
0-8
Volumetric
Date ds cm/mi n
_1 - No Washdown
5/19/89
5/19/89
5/19/89
5/19/89
5/20/89
5/20/89
2. - Periodic
5/21/89
5/21/89
5/21/89
5/21/89
5/21/89
5/21/89
542
500
537
507
537
504
Washdown
546
510
543
499
536
503
Flowrate
dscf/min
19,140
17,670
18.940
17,880
18,960
17,800
19,290
18.000
19.160
17,610
18.910
17.730
Temperature
°C °F
29
28
28
28
31
29
31
27
34
29
31
28
85
83
83
82
88
84
87
81
93
84
88
82
X Moisture
2.44
2.68
2.39
3.01
2.67
2.88
2.31
2.52
2.31
2.86
2.52
3.06
% Isokinetic
108.4
104.0
108.2
102.0
107.0
101.8
104.9
101.8
104.4
101.6
104.7
102.1
_3_ - Continuous Washdown
5/2*3/89
5/23/89
5/23/89
5/23/89
548
504
540
508
19,330
17,780
19,080
17,930
31
28
33
28
88
82
91
82
2.33
2.87
2.30
2.86
105.0
98.00
105.1
97.4
18
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seven runs. Noticeable discoloration of the sample could be seen and may
have been caused by accidental contact with the duct wall. Due to this
probable contamination the results of Run 1-1 were not used in any
calculations. A summary of the MM13B sample volumes, analytical results
and emission rates by test condition for this location are presented in
Table 3-3.
Scrubber Outlet
Modified Method 13B—
A summary of the flue gas conditions at this location are presented
in Table 3-2. The volumetric flowrates were consistent and averaged
504 dry standard cubic meters per minute (dscmm) [(17,800 dry standard
cubic feet per minute, (dscfm)]. The flue gas temperature averaged 28°C
(83°F) and the moisture content averaged 2.84 percent. The flue gas was
essentially ambient air and was assigned a dry molecular weight of
28.95 Ib/lb mole. The isokinetic sampling rates were within the
allowable limitations for these sample runs.
Prior to sampling, it was decided that testing should be run at
5 minutes per point for a total sample time of 120 minutes. This sample
time ensured the collection of a detectable concentration of Cr*6.
As with the inlet samples, testing during run 7 was done at 8 minutes per
point to assure a detectable sample. Following the analysis of the
sample, it was determined that the sample time per point could be reduced
to 5 minutes as was done for the inlet samples. When the scrubber was
operating without the overhead washdown system in use (Condition 1) the
emissions were consistent and averaged 0.0392 mg/dscm (0.000017 gr/dscf);
furthermore, emissions were consistent and averaged 0.0230 mg/dscm
(0.000010 gr/dscf) when the overhead washdown system was used
periodically (Condition 2), and 0.0214 mg/dscm (0.000010 gr/dscf) with
the overhead washdown in constant use (Condition 3). Outlet emissions
over the course of all eight test runs averaged 0.0287 mg/dscm
(0.000012 gr/dscf). A summary of the MM13B sample volumes, analytical
results and emission rates broken down by condition for this location is
presented in Table 3-4.
19
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TABLE 3-3. SUMMARY OF SAMPLE VOLUMES. ANALYTICAL RESULTS AND
EMISSION RATES FOR THE SCRUBBER INLET
Volume
Stack Metered
Run No. dscfm dscf
Condition 1
1-1 19,140 162.729
1-2 18,940 160.691
1-3 18,960 159.143
Condition 2
1-4 19,290 158.581
1-5 19,150 156.719
1-6 18,910 155.491
Condition 3
1-7 19.330 254.682
1-8 19.080 157.312
Total Mass Concentration Emission Rates
Cr+6. ma ma/dscm ar/dscf kq/hr Ib/hr
1.3794 0.299 0.00013 0.00097 0.0215
2.9411 0.646 0.00028 0.0208 0.0458
3.5306 0.783 0.00034 0.0252 0.0557
3.8189 0.850 0.00037 0.0279 0.0614
2.5549 0.576 0.00025 0.0187 0.0413
2.5477 0.580 0.00025 0.0186 0.0410
5.4262 0.752 0.00033 0.0247 0.0545
3.0854 0.693 0.00030 0.0225 0.0495
20
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TABLE 3-4. SUMMARY OF SAMPLE VOLUMES, ANALYTICAL RESULTS AND
EMISSION RATES FOR THE SCRUBBER OUTLET
Stack
Run No. dscfm
Condition 1
0-1 17.670
0-2 17,880
0-3 17.800
Condition 2
0-4 18,000
0-5 17,610
0-6 17,730
Condition 3
0-7 17,780
0-8 17,930
Volume
Metered
dscf
141.229
140.140
139.366
140.892
137.619
139.263
214.324
134.313
Total Mass
Cr+6. mq
0.14996
0.15495
0.16240
0.10248
0.08409
0.08582
0.13798
0.07656
Concentration
mq/dscm gr/dscf
Emission Rates
kq/hr Ib/hr
0.0375 0.000016 0.00113 0.00248
0.0390 0.000017 0.00119 0.00261
0.0412 0.000018 0.00124 0.00274
0.0257 0.000011 0.00078 0.00173
0.0216 0.000009 0.00065 0.00142
0.0218 0.000010 0.00066 0.00145
0.0227 0.000010 0.00069 0.00151
0.0201 0.000009 0.00061 0.00135
21
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The Cr"1"6 removal efficiencies for the scrubber without washdown
averaged 94.71 (based on emission rates) and 94.4% (based on
concentration). When periodic washdown was in use, efficiency averaged
96.8% (emission rates) and 96.5% (concentration). Constant washdown
produced efficiencies averaging 97.3% (emission rates) and 97.1%
(concentration). A summary of removal efficiencies for the system is
presented in Table 3-5.
TOTAL CHROMIUM ANALYSIS
Upon returning from Houston the samples from Run 2 and Run 5 were
submitted for total chromium analysis. Based on the concentration
determined from these analyses, the total Cr removal efficiencies for
these runs were: 91.3% for Run 2 and 92.6% for Run 5. The results from
the total chrome analysis are presented in Table 3-6. The analyses were
performed by Datachem Inc. in Cincinnati, Ohio. Their quality.control
plan is presented in Appendix G.
PLATING TANK SOLUTIONS
During each MM13B run, grab samples of the plating bath solution were
collected and composited. The samples were analyzed for Cr+6
concentration. The results from these analyses and the chromic acid
concentrations are presented in Table 3-7.
SCRUBBER RINSE
Prior to the start of the sampling program, and between conditions,
the scrubber was cleaned with fresh water. After every test run, a
sample of the scrubber rinseate was collected and analyzed for Cr+s
concentrations. The results of these analyses are presented in Table 3-7.
22
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TABLE 3-5. SUMMARY OF Cr+6 REMOVAL EFFICIENCIES
Emission Rate Cr+6 Removal
Rgn Np. Ib/hr Cr+6 Efficiency %
Condition 1
*I-1
0-1
1-2
0-2
1-3
0-3
Average Condition
Condition 2
1-4
0-4
1-5
0-5
1-6
0-6
Average Condition
Condition 3
1-7
0-7
1-8
0-8
Average Condition
0.0215
0.00248 88.4
0.0458
0.00261 94.3
0.0557
0.00274 95.1
1 94.7
0.0614
0.00173 97.2
0.0413
0.00142 96.6
0.0410
0.00145 96.5
2 96.8
0.0545
0.00151 97.2
0.0495
0.00135 97.3
3 97.3
Concentration
mq/m3 C_r+6
0.2996
0.0375
0.646
0.0390
0.783
0.0412
0.850
0.0257
0.576
0.0216
0.580
0.0217
0.752
0.0227
0.693
0.0201
Cr*6 Removal
Efficiency %
87.5
94.0
94.7
94.4
97.0
96.3
96.3
96.5
97.0
97.1
97.1
* - This run is not included in the average due to possible contamination of sample 1-1
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TABLE 3-6. TOTAL CHROMIUM DATA FUSION, INC. HOUSTON, TEXAS
Run No. Vmstd
1-2 160.691
0-2 140.140
1-5 156.719
0-5 137.619
TABLE
Qstd Total Cr mass
dscfm mq
18,940 3.59
17.880 0.27
19.160 3.25
17,610 0.21
3-7. SUMMARY OF PLATING
Concentration Emission Rate
mq/m3 qr/dscf kq/hr Ib/hr
0.789 0.00034 0.0254
0.0680 0.000029 0.00207
0.732 0.00032 0.0238
0.0539 0.000024 0.00161
SOLUTION & RINSEATE
0.0560
0.00456
0.0525
0.00355
ANALYTICAL RESULTS
Run No.
Plating Solution
Run 1
Run 2
Run 3
Run 4
Run 5
Run 6
Run 7
Run 8
Scrubber Rinse
Run 1
Run 2
Run 3
Run 4
Run 5
Run 6
Run 7
Run 8
Cr*6 Concentration,
mq/2-
115.039
115,981
117,569
115,981
116,297
115,353
114,416
114.105
14.7
14.1
91.91
1995
2709
29.07
119.5
64.7
Cr03 Concentration
33.0
33.3
33.7
33.3
33.3
33.1
32.8
32.7
0.00422
0.00404
0.0264
0.572
0.777
0.00834
0.0343
0.0186
24
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SECTION 4.0
SAMPLING LOCATIONS AND TEST METHODS
EMISSION SAMPLES
Location of Measurement Sites
EPA Reference Method 1 "Sample and Velocity Traverses for Stationary
Sources" was used to select representative measurement sites. The inlet
measurement site was located in a horizontal duct that was slightly
out-of-round (30.375 in. vertical diameter and 29.5 in. horizontal
diameter). The diameter of 30.05 inches was determined by procedures
shown in Figure 4-1. The site was located 76 inches (2.5 duct diameters)
downstream from the nearest downstream flow disturbance (plating tank)
and 19 Inches (0.6 duct diameters) from the nearest upstream flow
disturbance (scrubber). According to EPA Method 1 criteria, this
location required 24 sample traverse points, 12 along each of two
perpendicular diameters (30.375 and 29.5 inches). Table 4-1 shows the
traverse point locations.
The outlet measurement site was located in a 29.69 in. ID circular
vertical stack, 63.2 Inches (2.1 stack diameters) downstream of the
nearest flow disturbance (ID fan) and approximately 15.8 inches
(0.53 stack diameters) upstream of the nearest flow disturbance
(atmosphere). According to EPA Method 1 criteria, this location required
24 sample traverse points, 12 along each of two perpendicular diameters.
Table 4-1 also shows these traverse point locations.
Prior to sampling, the absence of cyclonic flow at each sample
traverse point was verified based on procedures described in EPA
Reference Method 1. In this method, the face openings of the Type-S
25
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to
.875"
A=3.14(14.75)2 +(29.5)(0.875)
A= 708.96in
708.96
3.14
R=15.026"
0=30.05"
Figure 4-1. Duct Area Calculation
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TABLE 4-1. SAMPLE TRAVERSE POINT LOCATIONS FOR THE
PACKED-BED SCRUBBER INLET AND OUTLET
Traverse
Point
No.
1
2
3
4
5
6
7
8
9
10
11
12
Scrubber
Horizontal
1.0
2.0
3.5
5.2
7.4
10.5
19.0
22.1
24.3
26.0
27.5
28.5
Location (inches)
Inlet
Vertical
1.0
2.0
3.6
5.4
7.6
10.8
19.6
22.8
25.0
26.8
28.3
29.375
Scrubber
Outlet
1.0
2.0
3.5
5.3
7.4
10.6
19.1
22.3
24.4
26.2
27.7
28.7
27
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pitot tube are aligned perpendicular to the duct cross-sectional plane,
designated "0-degree reference." Null (zero) pitot readings obtained at
0-degree reference indicate an acceptable flow condition at a given
point. If the point reading was not zero at 0-degree reference, the
pitot 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. However, both of these sites indicated acceptable flow patterns so
that extraction of representative samples from these sites was performed
using appropriate sampling procedures.
Test Methods
Velocity and static pressures, moisture content, and temperature
were measured prior to sampling in order to define sampling rates and
nozzle sizes as described in the EPA Reference Methods 1, 2 and 4.-
An EPA MM13B sample train was used to collect the Cr+s
samples. The sample train consisted of a 316 stainless steel button-hook
nozzle, an unheated Pyrex glass-lined probe, and a series of four
impingers. The first, third and fourth impingers were Greenburg-Smith
design, modified by replacing the tip with a 1/2-in. inside diameter
glass tube extending to 1/2-in. from the bottom of the flask. The second
impinger was a Greenburg-Smith impinger with the standard tip. The first
and second impingers contained 100 mft, of 0.1N NaOH. The third impinger
was empty and the fourth impinger contained approximately 200 grams of
silica gel. The balance of the sampling system consisted of a vacuum
pump, dry gas meter, calibrated orifice and related temperature and
pressure indicating apparatus to determine dry gas sample volume, stack
gas temperature, volumetric flow rate and isokinetic sampling rates.
During sampling, stack gas temperature and the gas temperature exiting
the last impinger were monitored with calibrated thermocouples.
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The sampling time was initially set at 5 minutes per point
(120 minute total sample time) and increased to 8 minutes per point
(192 minute total sample time) to assure the concentration of Cr+6
was such that good analytical results could be obtained.
The impingers were weighed before and after each test to determine
the moisture content of the flue gas stream. All connecting glassware,
the nozzle and probe were rinsed with 0.1N NaOH and combined with the
impinger solution into a tared polyethylene sample bottle. The total
volume of the sample was determined gravimetrically. The liquid level
was marked on each sample bottle and each bottle was marked indicating
the run number and bottle contents.
Following the recovery of the samples, all samples, including
blanks, were analyzed for Cr+6 concentration using the analytical
methodology developed by the EPA.
EMISSION SAMPLE ANALYSIS
The MM13B samples and the plating solution were analyzed for
Cr+6 concentration. The analyses were conducted on site in the EPA
Mobile Laboratory. Immediately following the sample recovery, the
samples were submitted to the analyst and the analyses and calculations
were performed the same day. The reported results were calculated on the
Hewlett Packard 41CV computer. The calculations were also performed by
the EPA Task Manager.
The analytical method entitled "Draft Method - Determination of
Hexavalent Chromium in Dry Particulate Emissions from Stationary Sources"
was used as a "guideline" in conducting the Cr+6analyses. This
method is currently under development by the EPA and is presented in
Appendix C.
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There were several variations between the draft method and the
analytical method that was performed in the field. They are described as
follows:
1. The collected samples were not digested in an alkaline
solution. Aliquots of the recovered samples were pipeted
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 ± 0.5.
3. The spectrophotometer was calibrated with standards containing
2 ma, 5 mft, 7 mi, 10 m&, 15 mfl. and 20 mil of the
5 jig/mi working standard. The spectrophotometer calibration
factor, K , was calculated as follows:
2.5A2 + 3.5A3 + 5A4 + 7.5Ag + 10Afi
<
c A; * A; * A; * < + A; * A;
4. The value of this calibration factor was calculated using a computer
program that was developed by the EPA Task Manager for the HP41
calculator.
The total chromium analyses were performed by Datachem Laboratories in
Cincinnati, Ohio. The method used was EPA Method 218. This method is
presented in Appendix C, and the results are given in Appendix G.
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SECTION 5.0
QUALITY ASSURANCE
INTRODUCTION
The goal of the quality assurance activities for this project is to
ensure, to the highest degree possible, the accuracy of data collected. The
procedures contained in the "Quality Assurance Handbook for Air 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 in 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. These are presented in the paragraphs that
follow.
FIELD QUALITY ASSURANCE PROCEDURES
To assure a high level of quality control while sampling in order to
allow the comparison of data from these two methods, a field quality
assurance program was followed during the test program. Methods used to
obtain the required level of quality assurance are itemized below.
Sample Blanks
Reagent Blanks—
The 0.1N NaOH absorbing solution was transported to the field in its
"as-purchased" container. When in 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.
31
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A blank sample was collected from the solution in the wash bottle. This
sample was given to the on-site laboratory personnel with the emission
samples, and analyzed in the same manner. Results of the blank analyses
are presented in Table 5-1.
H20 Blanks--
A distilled water blank was obtained from the wash bottles and
analyzed in the same manner as the emission samples.
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
analytical results for the duplicated samples are presented in Table 5-1.
Standards
Daily, 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.
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. Once the
samples were placed in custody of the analytical group, that group
provided for safe storage and maintenance of records sufficient to
maintain sample integrity. The "Chain of Custody" record sheets are
presented in Appendix D.
Sample Transfer
All MM13B samples collected during testing remained in the custody
of PEER personnel and were secured in the mobile laboratory while in the
field.
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TABLE 5-1. SUMMARY OF ANALYTICAL RESULTS FOR QA/QC SAMPLES AND BLANKS
Sample No.
75 g/100 mfl-
0-2
50 jig/mfl,
75 Jig/100 mfl,
50 Jig/100 mi
75 Jig/100 mft,
Blanks
0.1N NaOH
Date (1989)
5/21
5/21
5/21
5/21
5/22
5/22
5/21
Tvoe of Samole
Duolicate Standard Total JIQ Cr+6
X 74.6
X 161.99 "154.95
X 49.7
X 73.6
X 50.2
X 74.1
0.00
* Original values against which data are to be compared.
33
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SAMPLING TRAIN COMPONENTS
The equipment used in this test program, including nozzles, pi tot
tubes, dry gas meters, orifices, and thermocouples were uniquely identified
and were calibrated in accordance with calibration procedures specified in
the applicable EPA Reference Method prior to, and at the completion of, the
testing program. The calibration sheets are presented in Appendix F.
VERIFICATION OF CALCULATIONS
Emission Calculations
Dry gas volumes, percent moisture of the stack gas, gas flow rates,
and Cr+6 emission rates were calculated using a Hewlett Packard 41CV
programmable calculator. The programs used can be found in the document:
"Source Test Calculation and Check Programs for Hewlett Packard 41
Calculators" (EPA-340/1-85-018). The results were checked and verified by
the PEER Task Manager.
Chromium Concentration Calculations
All absorbance data for blanks, standards, samples and QA/QC samples
were documented in a notebook. The Cr+6 content and total mass of
Cr+6 collected were calculated using a program developed by the EPA Task
Manager for the HP41CV programmable calculator.
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