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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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. ------- 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 ------- 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 ------- 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. ------- 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 ------- 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. ------- 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. ------- (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 ------- 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, ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 23 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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. 28 ------- 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. 29 ------- 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. 30 ------- 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 ------- 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. 32 ------- 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 ------- 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. 34 ------- |