United QtatM Environmental Protection Agtncy Office of Air Quality Panning and Standards Research Triangle Park, NC 27711 EMB Report 31-CEP-18 Vduma I Oacamber 1991 Air Hexavalent Chromium Emission Test Report Precision Engineering Company Seattle, Washington e of Air ------- HEXAVALENT CHROMIUM EMISSION EVALUATION PRECISION ENGINEERING, INC. SEATTLE, WASHINGTON Prepared for U.S. ENVIRONMENTAL PROTECTION AGENCY EMISSION MEASUREMENT BRANCH RESEARCH TRIANGLE PARK, NORTH CAROLINA EPA Contract No. 68-D-90155 DECEMBER 31, 1992 Prepared by ADVANCED SYSTEMS TECHNOLOGY, INC. 3490 Piedmont Road, NE • Suite 1410 Atlanta, GA 30305-4810 (404)240-2930 ------- TABLE OF CONTENTS **##*********************++**************************** Sections Pages TABLES and FIGURES EXECUTIVE SUMMARY i-iii Section 1 INTRODUCTION 1-1 Section 2 PROCESS OPERATION 2-1 2.1 Process Description 2-1 2.2 Air Pollution Control Device 2-2 2.3 Process Conditions During Testing 2-4 Section 3 SUMMARY OF SAMPLE COLLECTION, EMISSION CALCULATIONS AND RESULTS 3-1 3.1 Sample Collection 3-1 3.2 Stack Gas Parameters 3-1 3.3 Emission Calculations and Discussion of Results 3-2 3.3.1 Cr-VI Results From Colorimetry and ICPCR Analyses 3-4 3.3.2 Total Chromium Results From ICP Analysis 3-4 3.3.3 Concentrations In Plating Tank Solution, MPME Water and Train Blank Samples 3-8 3.3.4 Computerized Spreadsheet Calculations 3-8 3.3.5 Removal Efficiency of The Mesh Pad Mist Eliminator 3-8 3.3.6 Penetration of The Mesh Pad Mist Eliminator 3-10 Section 4 SAMPLING AND ANALYSIS METHODS 4-1 4.1 Types of Samples Collected and Sample Recovery Descriptions 4-1 4.1.1 Liquid Grab Samples 4-1 4.1.2 Gaseous Stack Samples 4-1 4.1.3 Sampling Locations 4-2 4.2 Air Sampling Test Methods 4-7 4.2.1 Traverse Points 4-7 4.2.2 Stack Gas Velocity 4-7 4.2.3 Stack Gas Moisture 4-7 4.2.4 Modified Method 13-B Sampling Train 4-8 4.3 Sample Analysis Methods 4-8 4.3.1 Colorimetry 4-10 4.3.2 Inductively Coupled Plasma (ICP) 4-10 4.3.3 lon-Cnromatography With Post Column Reactor (ICPCR) 4-10 Section 5 QUALITY ASSURANCE PROGRAM, TEST PROGRAM PERSONNEL AND SUMMARY OF FIELD ACTIVITIES 5-1 5.1 Quality Assurance Program 5-1 5.2 Data Review Prior To Report Preparation 5-1 5.3 Contract Laboratory Quality Assurance Procedures 5-1 5.4 Test Program Personnel 5-2 5.5 Field Activities 5-3 ------- TABLES and FIGURES Tables Page S-l Summary of Chromium Removal Efficiencies iii 2.1 Average Operating Parameters Monitored During Each Mass Emissions Test Run 2-6 2.2 Total Ampere-Hours Supplied to Plating Tanks During Mass Emission Test Runs 2-7 3.1 Summary of Stack Gas Conditions 3-3 3.2 Comparison of Emission Sample Analysis Results For Chromium-VI Using Colorimetry and ICPCR Techniques 3-5 3.3 Analytical Results of Chromium-VI Mass Emission Testing 3-6 3.4 Analytical Results of Total Chromium Mass Emission Testing 3-7 3.5 Analysis of Plating Tank Solutions, MPME Water and Blank Samples 3-9 3.6 Summary of the Mesh Pad Mist Eliminator Chromium Removal Efficiencies 3-11 3.7 Removal Efficiency and Percent Penetration of Chromium Through the Mesh Pad Mist Eliminator 3-12 *********************** Jlgures 2.1 Schematic of Ventilation and Control System for Chromium Plating Tanks at Precision Engineering, Inc 2-3 4.1 Inlet No. 1 Traverse Point Locations 4-4 4.2 Inlet No. 2 Traverse Point Locations 4-5 4.3 Outlet Traverse Point Locations 4-6 4.4 Schematic of the Modified U.S. EPA Method 13-B Sampling Train 4-9 ------- Appendices Page A Computer Printout of Field Data A-l - A-37 B Field Data Sheets B-l - B-40 C Sampling Sheets and Summary of Results (AST and U.S. EPA) C-l - C-17 D Laboratory Analysis Reports and Chain of Custody Forms D-l - D-8 E On-Site Colorimetric Analysis For Hexavalent Chromium E-l - E-12 F Sample Calculations F-l - F-8 G Draft Method - Determination of Hexavalent Chromium Emissions from Decorative and Hard Chrome Electroplating G-l - G-9 H Ampere-Hour Calculations H-l - H-26 I Laboratory Analysis Procedure Method of Determination of Cr-VI in Alkaline Solution I-1 -1-3 J Equipment Calibration Data J-l - J-9 K Determination of Total Chromium and Hexavalent Chromium Emissions from Stationary Sources (CARB425) K-l - K-22 ------- EXECUTIVE SUMMARY The objective of this project was to evaluate the chromium removal efficiency of the mesh pad mist eliminator (MPME) system at Precision Engineering, Inc., in Seattle, Washington. This objective was achieved by concurrently measuring hexavalent chromium (Cr-VI) and total chromium (Cr-T) mass emissions at the inlets and outlet of a mesh pad mist eliminator (MPME) using a modification of U.S. EPA Method 13-B. During the field work, Precision Engineering, Inc. operated three of its six plating tanks. Plating Tanks 1, 2 and 7 were being used to chrome plate pieces of industrial equipment. The hood exhaust ducting from tanks 1 and 2 were combined in a common duct and formed one leg of the inlet (Inlet No. 1) to the MPME. Tank 7 was ducted separately, forming the second leg (Inlet No. 2) of the inlet to the MPME. The MPME used for controlling chromium mass emissions was located on the roof of the plant shop and consisted of a set of chevron-blades followed by a series of three graded mesh pads. Field testing was conducted during the week of December 16, 1991. Sampling was performed at the two inlets (Inlet No. 1 from Tanks 1 and 2 and Inlet No. 2 from Tank 7), and at the outlet of the mesh pad mist eliminator (MPME) under its normal operating conditions for the plating processes. Three separate isokinetic test runs were conducted during field testing. Sampling times of 240 or 360 minutes assured collection of adequate quantities of chromium for subsequent chemical analysis. In addition, grab samples of MPME water and plating bath solutions were also obtained during each of the Method 13-B test runs for Cr-VI and Cr-T analyses. ------- Upon completion of each test run, the mass emission samples were recovered in the field, labeled, and stored in a cooler. Each sample was analyzed on-site for Cr-VI using the diphenylcarbazide colorimetric method (see Appendix E). Upon completion of field testing, all samples were packed in a cooler and transported to Research Triangle Institute Laboratory (RTIL), Research Triangle Park, North Carolina. RTIL performed analysis for Cr-VI using lon- Chromatography with a Post Column Reactor (ICPCR) and Cr-T using Inductively Coupled Plasma (ICP). Plating tank solution and MPME water samples were also analyzed for Cr-VI and Cr-T at RTIL. This project work has provided an opportunity to assess the accuracy of the analytical results which form the basis to measure control device efficiencies. Field samples were analyzed for Cr-VI using the diphenylcarbazide colorimetric method on-site and later the same samples were analyzed off-site with ICPCR. The analytical data obtained were compared and indicate, colorimetric and ICPCR methods gave overall similar results (see Section 3). Table S-l summarizes the chromium removal efficiencies for the mesh pad mist eliminator (MPME) system. Based upon the measurements performed during this project, the MPME has an average chromium removal efficiency of 96.0%. The average total chromium (Cr-T) concentration at Inlets No. 1 and No. 2 combined was 0.4970 mg/m3. The total chromium emission concentration at the outlet averaged 0.0108 mg/m3. The average Cr-T mass emission rate from Inlets No. 1 and No. 2 combined was 1.50 x 10~2 Ib/hr and for outlet average was 5.75 x 10^* Ib/hr. The average hexavalent chromium (Cr-VI) concentration at Inlets No. 1 and No. 2 combined was 0.4717 mg/m3 and for the outlet 0.0103 mg/m3. These averages translate into Cr-VI mass emission rates of 1.430 x Itf2 Ib/hr and 5.48 x 1Q4 Ib/hr for the MPME inlets and the outlet respectively. 11 ------- TABLE S-l SUMMARY OF CHROMIUM* REMOVAL EFFICIENCIES Run No. 1 Inlet** Outlet Mass Emission Rate (Ib/hr) 1.32x lO'2 6.75 x KT* Removal Efficiency 94.9 Run No. 2 Inlet** Outlet 1.25 x lO'2 5.53 x 10"* 95.6 Run No. 3 Inlet** Outlet 1.93x lO'2 4.97 x 10" 97.4 AVERAGE REMOVAL EFFICIENCY 96.0 * Expressed as Total Chromium (Cr-T) ** Represents Sum of Inlet No. 1 and Inlet No. 2 in ------- Section 1 INTRODUCTION The objective of this project was to evaluate the chromium removal performance of the mesh pad mist eliminator (MPME) system at Precision Engineering, Inc., in Seattle, Washington. Chromium emission concentrations were measured at the two inlets (Inlet No. 1 and Inlet No. 2) and the outlet of the MPME to determine the efficiency of the system for chromium removal. Testing was conducted during the week of December 16, 1991. Emission samples were collected using a modification of U.S. EPA Method 13-B. This method is briefly described in Section 4 of this report. The emission samples were collected simultaneously from Inlets No. 1 and No. 2 and from the Outlet of the MPME under normal operating conditions. The sampling locations are identified in Figure 2-1. MPME water samples and plating tank solution samples were also collected under the normal operating conditions of the MPME and plating processes. Samples were analyzed on-site, using the diphenylcarbazide method, for hexavalent chromium. The plating tank solution samples were analyzed off-site. After the field activities were completed, the samples were shipped to Research Triangle Institute Laboratory (RTIL) for chromium analyses. RTIL is located in Research Triangle Park, North Carolina. The Inlet and Outlet samples were analyzed at RTIL for total chromium using Inductively Coupled Plasma emission spectrometry (ICP) and for hexavalent chromium using lon-Chromatography with a Post Column Reactor (ICPCR). MPME water samples and plating tank solution samples were analyzed using ICPCR and ICP. The analytical techniques employed in this test program are described in Section 4 of this report. 1-1 ------- The primary organizations involved in this test program were Advanced Systems Technology, Inc. (AST), Precision Engineering, Inc. (PEI), Midwest Research Institute (MRI) and the U.S. EPA, Emission Measurement Branch (EMB). 1-2 ------- Section 2 PROCESS OPERATION 2.1 Process Description Precision Engineering is a medium-size job shop that performs hard chromium plating of industrial rolls, hydraulic cylinders and miscellaneous small parts. The plating shop has six hard chromium plating tanks. The plating shop normally operates 24 hours per day, five days per week. During this source test, tank Nos. 1, 2 and 7 were tested. Plating tank Nos. 1 and 2 are 2.0-meters (m) (6.5-feet) [ft]) long, 1.3-m (4.2-ft) wide, and 3.7m (12.0 ft) deep and hold approximately 9,280 liters (L) (2,450 gallons [gal]) of plating solution. Plating tank No. 7 is 1.2-m (4.0-ft) long, 1.8-m (5.9-ft) wide and 5.5-m (18.0-ft) deep and holds approximately 11,830 L (3,120 gal) of plating solution. The plating solution contains chromic acid at a concentration of about 250 grams per liter (g/L) (33 ounces per gallon [oz/gal]) of water. Sulfuric acid is used as a catalyst at a bath concentration of 2.5 g/L (0.33 oz/gal). The temperature of the plating solution is maintained at approximately 60°C (140°F). The three plating tanks are divided into two cells and each cell is equipped with a rectifier to to control the current flow. Current ratings per cell are 5,000 amperes, 3,000 amperes, and 10,000 amperes for tanks Nos. 1, 2 and 7, respectively. Each rectifier is also equipped with ampere-hour meters that measure the amount of current supplied to the plating tanks over time. All of the plating tanks are serviced by overhead hoists that are used to transfer parts in and out of the tanks. Heating and cooling systems are located in each tank to maintain uniform solution 2-1 ------- temperature. In addition, each tank is equipped with an air agitation system to aid in maintaining uniform bath concentration and temperature. 2.2 Air Pollution Control Device A schematic of the ventilation and control system on the plating tanks is shown in Figure 2-1. The mesh pad mist eliminator system was manufactured by KCH Services, Inc., in Forest City, North Carolina. The system was installed during 1991 by plant personnel. Each tank is equipped with a double-sided ventilation hood. Moisture extractors are located in the hood uptakes to remove large chromic acid mist droplets prior to the mist eliminator. The purpose of the moisture extractors is to reduce the plugging tendency of the mist eliminator by reducing the inlet loading to the device. The takeoffs from tank Nos. 1 and 2 are ducted together and form one inlet leg to the mist eliminator, while tank No. 7 is ducted separately and forms a second leg to the mist eliminator. The ventilation system is rated at 470 cubic meters per minute (16,500 cubic feet per minute). The pressure drop across the mist eliminator is 1.7 kiloPascals (7 inches in water column). The mist eliminator is installed on the roof of the plating shop and consists of a set of chevron- blades followed by a series of three mesh pads. The mist eliminator is designed to remove chromic acid mist in stages depending upon the particle size. The larger droplets (particles greater than 10 microns), which comprise the majority of the emissions, are removed by the moisture extractor located above tanks 1, 2 and 7 but before the mist eliminator and also by the chevron-blade stage of the MPME. The first mesh pad is designed to remove smaller particles (particles between 5 and 10 microns). The first mesh pad is composed of multiple layers of mesh pad material, and each layer is woven from fibers with diameters of 0.09 centimeter (cm) (37 thousandths of an inch [mils]. The second mesh pad (the composite mesh pad) is designed 2-2 ------- HIST ELtMfNATOfTK 'J. f »'»^. *~€t ft | /"~ •«-»-u»«*».i*£vj Jil3~ i i &• •« era TAM 1 " TANK 2 CA; T) ^ vi> ® c\ - SAMPLING LOCATION A AT INLET 1 - SAMPLING LOCATION 3_ AT INLET 2 - SAMPLING LOCATION C AT OUTLET - SAMPLING LOCATION _0 TANK 1 - SAMPLING LOCATION £ TANK 2 - SAMPLING LOCATION £ TANK 7 - SAMPLING LOCATION G HASHDOWN WATE?. lANK 7 Figure 2.1. Schematic of Ventilation and Control System for Chromium Plating Tanks at Precision Engineering, Inc. 2-3 ------- such that the material layers in the center of the pad are composed of extremely small -diameter fibers (0.02 cm [8 mils]). The smaller the fiber diameter, the more dense the material layer. The material layers on either side of the center are composed of progressively larger diameter fibers (0.04 to 0.09 cm [16 to 37 mils]). As the gas stream flows through the composite pad, the small particles that escape the first mesh pad (particles below 5 microns) impinge on the composite pad and coalesce into larger droplets. These enlarged particles are then removed in the backside of the composite pad or in the backup mesh pad located downstream of the composite pad. The third pad or backup mesh pad is composed of layers of material with a fiber diameter of 0.09 cm (37 mils). The thickness of each pad is 15.7 cm (6.2 inches [in.]), 9.7 cm (3.8 in.), and 18.3 cm (7.2 in.) for the first, second, and third pads, respectively. Prior to each mesh pad is a series of spray nozzles that are used to wash down the pads and remove any chromium that has built up on the pads. The pressure drop across each mesh pad is monitored to determine the amount of chromium buildup on the pad. An increase in pressure drop above the normal operating range for a given pad indicates that the pad needs to be washed down. Spray nozzles are also located in the chevron-blade section to allow periodic washing of the blades. 2.3 Process Conditions During Testing Three mass emission test runs were conducted at the two inlet locations and the outlet of the mist eliminator to characterize the performance of a mesh-pad mist eliminator system that incorporated the use of a composite mesh pad. Each test run was 4 or 6 hours in duration. All of the test runs were interrupted briefly to change test ports. No other interruptions occurred during sampling. 2-4 ------- Sampling of Inlet No. 1 and Inlet No. 2 was performed at distances of 18 feet from the nearest downstream disturbance and 4 feet from the nearest upstream disturbance (mist eliminator). Sampling of the Outlet was performed at a distance of 60 inches from the nearest downstream disturbance (outlet base) and 35 inches from the nearest upstream disturbance (top of exhaust stack). Process operating parameters monitored and recorded during each test run included the voltage, current, ampere-hours, and the plating solution temperature for each plating tank. A description (dimensions and surface areas) of each part plated also was recorded for each test run. Process data sheets documenting the process and control device operating parameters during mass emission testing are presented in Appendix H. Data on the average operating parameters recorded during the mass emission test runs are presented in Table 2-1. The total amount of current supplied to the tanks 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. As noted previously, the ampere-hours supplied during testing were monitored and recorded from the ampere-hour meters on each rectifier. However, the sum of the ampere-hours for each rectifier will not match the ampere-hours calculated in Appendix H because of the difference between the actual sampling time and the time required for testing. These time periods are not equal because of the time required to change test ports. Therefore, the ampere-hours measured by the ampere- hour meters will be slightly higher than the actual ampere-hours calculated in Appendix H. 2-5 ------- Table 2.1. AVERAGE OPERATING PARAMETERS MONITORED DURING EACH MASS EMISSIONS TEST RUN Test Run No. 1 2 .3 Tank No. 1A IB 2A 2B 7A 7B 1A IB 2A 2B 7A 7B 1A IB 2A 2B 7A 7B Operating Voltage, Volts 7.0 7.0 7.6 7.6 ~ 8.0 6.4 6.3 7.2 7.4 6.6 6.4 6.4 6.4 7.7 7.8 6.0 7.3 Operating Current, Amperes 4,300 3,700 2,300 1,400 -- 7,000 3,600 3,400 1,700 1,850 1,300 2,000 2,970 2,800 2,000 1,700 1,000 7,200 Operating Temperature oF 140 140 140 140 140 140 140 140 140 140 140 140 140 140 140 140 140 140 2-6 ------- Table 2.2. TOTAL AMPERE-HOURS SUPPLIED TO PLATING TANKS DURING MASS EMISSION TEST RUNS TOTAL CURRENT, AMPERE-HOURS Test Run No. 1 2 3 Inlet No. 1" 67,020 42,000 37,975 Inlet No. 2b 42,025 28,690 32,750 Outlet 109,045 70,690 70,725 a Total current for Tanks 1 and 2 combined b Total current for Tank 7 2-7 ------- Composite samples were taken from each plating tank to determine the chromic acid concentration of the plating solutions during each mass emission test run. The data obtained are reported in Section 3 of this report. MPME operating parameters monitored during each test run consisted of the pressure drop across the unit, and the overall system pressure drop. The Magnahelic gauges are located downstairs in the plating shop; therefore, the pressure drop readings on the Magnahelic gauges are not indicative of the actual pressure drop but are approximate values because of the pressure losses in the tubing that connect the Magnahelic gauges to the mist eliminator. However, the important factor in monitoring the pressure drop is any decrease or increase from the normal operating range. An increase in pressure drop over its normal range indicates that the pad is beginning to plug, and a decrease in pressure drop indicates that the gas stream is bypassing the pad. The pressure drop readings recorded across each pad and the overall unit were consistent for all test runs. 2-8 ------- Section 3 SUMMARY OF SAMPLE COLLECTION, EMISSION CALCULATIONS AND RESULTS 3.1 Sample Collection Emission samples were collected using a modification of U.S. EPA Method 13-B. The samples were collected simultaneously from Inlets No. 1 and No. 2 and from the Outlet of the MPME under normal operating conditions. Three tests were conducted at each sampling location. Sampling times of 4 or 6 hours per test run were used to ensure that adequate quantities of chromium were collected for subsequent chemical analysis. Grab samples from the plating tank solutions (Tanks 1, 2 and 7) and the MPME water were also collected during each sampling run. These samples were obtained at the beginning, middle and at the end of each Method 13-B test run. 3.2 Stack Gas Parameters Stack gas parameters, at each sampling location, are shown in Table 3-1. At Inlet No. 1, the stack gas velocity averaged 50.66 feet per second (fps), the average stack temperature was 78°F and the average moisture content was 1.11%. The volumetric flow rates at Inlet No. 1 were 9,548 actual cubic feet per minute (acfm) and 9,180 dry standard cubic feet per minute (dscfm). At Inlet No. 2, the stack gas velocity averaged 50.34 fps, the average stack temperature was 77°F and the average moisture content was 0.75%. The volumetric flow rates at Inlet No. 2 were 5,337 acfm and 5,159 dscfm. 3-1 ------- At the Outlet, the stack gas velocities averaged 50.11 fps, the average stack temperature was 85 °F and the average moisture content was 0.98%. The average volumetric flow rates at the Outlet were 14,758 acfm and 14,241 dscfm. The stack gas at all sampling locations was essentially ambient air and thus was assigned a dry molecular weight of 28.95 Ib/lb-mole. Variation in isokinetic sampling rates were within allowable limits for all sampling runs of Method 13-B except Run 2 of Inlet 2 which had an isokinetic rate of 88.81%. The evaluation of particle size, from previous test runs, indicate that more than 85% of the particles emitted from a controlled electroplating process are less than 2.5 microns in diameter. Particles less than 2.5 microns behave like a gas rather than a paniculate. In gaseous sampling the isokinetic sampling rate is not considered to be significant. Therefore, no adjustments were made to the data and the results are acceptable. 3.3 Emission Calculations and Discussion of Results This subsection of the report provides the following information: 1) Cr-VI results from colorimetry and ICPCR analyses; 2) Cr-T results from ICP analysis; 3) Cr-VI and Cr-T concentrations in the plating tank solutions, MPME water and sampling train blank samples; 4) computerized spreadsheet calculations of emission concentrations and mass emission rates; 5) MPME removal efficiencies; and 6) MPME penetration. 3-2 ------- Table 3.1 SUMMARY OF STACK GAS CONDITIONS Inlet No.l Run No. 1 2 3 Average Velocity fps- 50.77 48.53 52.66 50.66 Stack Temp. °F 96 69 70 78 Flow Rate acfmb 9,570 9,148 9,927 9,548 dscfmc 8,901 8,830 9,810 9,180 Moisture % 0.98 1.14 1.21 1.11 % Isokinetic Rate 101.52 98.99 93.32 97.94 Inlet No. 2 Run No. 1 2 3 Average Velocity fps" 52.14 52.02 46.85 50.34 Stack Temp. °F 93 70 68 77 Flow Rate acfmb 5,528 5,516 4,968 5,337 dscfme 5,183 5,350 4,943 5,159 Moisture % 0.67 0.65 0.94 0.75 % Isokinetic Rate 103.02 88.81 98.37 96.73 Outlet Run No. 1 2 3 Average Velocity fps" 50.88 49.03 50.41 50.11 Stack Temp. °F 111 72 72 85 Flow Rate acfmb 14,986 14,442 14,847 14,758 dscfm0 13,776 14,065 14,882 14,241 Moisture % 0.97 1.08 0.90 0.98 % Isokinetic Rate 109.24 99.68 99.48 102.80 Feet per second b Actual cubic feet per minute c Dry standard cubic feet per minute at 68 °F and 29.92" Hg 3-3 ------- 3.3.1 Cr-VI Results From Colorimetrv and ICPCR Analyses Table 3.2 lists Cr-VI results obtained from two analytical techniques namely: 1) colorimetry using diphenylcarbazide; and 2) ICPCR. The colorimetric technique, used in the field to determine Cr-VI, provided a rapid analysis of chromium concentrations. The results were not used in the emission calculations in this report and are provided in Appendix E for information only. RTIL's analytical results for total chromium (Cr-T) and hexavalent chromium (Cr-VI) were used to make emission calculations in this report. Table 3.3 provides analytical results of Cr-VI mass emission testing at the Precision Engineering, Inc. plant. The samples were analyzed using lon-Chromatography with a Post Column Reactor (ICPCR). RTIL's analytical data report is provided in Appendix D. The average concentration of Inlets No. 1 and No. 2 combined was 0.4717 mg/m3 of Cr-VI and the outlet average concentration was 0.0103 mg/m3 . These averages translate into Cr-VI mass emission rates of 1.43 x 10"2 Ib/hr and 5.48 x 10"* Ib/hr for the inlets and the outlet respectively. 3.3.2 Total Chromium Results From ICP Analysis Presented in Table 3.4 are the total chromium (Cr-T) emission results. RTIL's analytical data report is provided in Appendix D. Table 3.4 shows an average Cr-T emission concentration of 0.497 mg/m3 at Inlets No. 1 and No. 2 combined. The Cr-T emission concentration at the outlet averaged 0.0108 mg/m3. The average Cr-T mass emission rate from Inlets No. 1 and No. 2 combined was 1.50 x 10"2 Ib/hr and the outlet average emission rate was 5.75 x 104 Ib/hr. 3-4 ------- Table 3.2. COMPARISON OF EMISSION SAMPLE ANALYSIS RESULTS' FOR CHROMIUM-VI USING COLORIMETRY" AND ICPCRC TECHNIQUES Inlet No. 1 Test Run No. Run No. 1 Run No. 2 Run No. 3 Average Sampling Time (min) 360 240 240 Total Cr-VI (/ig) Colorimetryb 2,862 743 848 1,484 ICPCR£ 2,889 1,774 2,891 2,518 Inlet No. 2 Run No. 1 Run No. 2 Run No. 3 Average 360 240 240 1,517 808 779 1,035 1,589 770 813 1,057 Outlet Run No. 1 Run No. 2 Run No. 3 360 240 240 123 37.8 50.3 Average 70.4 146 60.6 53.5 86.7 1 Results are expressed as total microgram of Chromium-VI b Colormetric quantification on-site using diphenylcarbazide organic analytical reagent c lon-chromatography with a post column reactor. 3-5 ------- Table 3.3. ANALYTICAL' RESULTS OF CHROMIUM-VI MASS EMISSION TESTING Inlets" Test Run No. 1 2 3 Average Total Cr-VI 0*g)c 4,478 2,544 3,704 3,575 Emission Concentration (mg/m3)1 0.4465 0.4045 0.5640 0.4717 Mass Emission Rate (lb/hr)c 1.276x 10-2 1.175x 10-2 1.838 x 10-2 1.430 x 10 2 Mass Emission Rate (kg/hr)c 5.79 x lO'3 5.33 x 10-3 8.33 x lO'3 6.48 x 10 3 Outlet Test Run No. 1 2 3 Average Total Cr-VI (Mg)° 146 60.6 53.5 86.7 Emission Concentration (mg/m3) c 0.0139 0.0093 0.0078 0.0103 Mass Emission Rate (lb/hr)c 7.19x 10" 4.91 x 10" 4.34 x 10" 5.48 x 10" Mass Emission Rate (kg/hr)£ 3.26 x 10" 2.22 x 10" 1.97x 10" 2.48 x 10" a Analysis method, lon-Chromatography with Post Column Reactor. b The control device has two inlets (Inlet No. 1 and Inlet No.2). 0 Sum of Cr-VI emissions from Inlet No. 1 and Inlet No.2. 3-6 ------- Table 3.4. ANALYTICAL1 RESULTS OF TOTAL CHROMIUM MASS EMISSION TESTING Inletsb Test Run No. 1 2 3 Average Cr-T Otg)c 4,602 2,728 3,921 3,750 Emission Concentration (mg/m3)c 0.4592 0.4341 0.5976 0.4970 Mass Emission Rate (lb/hr)e 1.32x 10-2 1.25 x 10-2 1.93 x ID'2 1.50 x 10 2 Mass Emission Rate (kg/hr)c 5.991 x lO'3 5.656 x 10'3 8.741 x 10'3 6.796 x 103 Outlet Test Run No. 1 2 3 Average Cr-T (/ig)c 137.0 68.3 61.3 88.9 Emission Concentration (mg/m3)£ 0.0131 0.0105 0.0089 0.0108 Mass Emission Rate (lb/hr)c 6.75 x 10-4 5.53 x 10^ 4.97 x IQi4 5.75 x 10-4 Mass Emission Rate (kg/hr)c 3.06 x 10-4 2.51 x 10-4 2.26 x 10-4 2.61 x 10-4 • Analysis method, Inductively Coupled Plasma (ICP) b The control device has two inlets (Inlet No. 1 and Inlet No. 2) c Sum of total chromium emissions from Inlet No. 1 and Inlet No. 2 3-7 ------- 3.3.3 Concentrations In Plating Tank Solution. MPME Water and Train Blank Samples Cr-VI and Cr-T concentrations in the plating tank solution, MPME water and train blank samples were determined by RTIL using ICPCR and ICP. The sample concentrations are presented in Table 3.5. The concentrations of chromium remained essentially constant throughout the testing period. 3.3.4 Computerized Spreadsheet Calculations A computerized spreadsheet, provided by Mr. Frank Clay (U.S. EPA, Task Manager), was used to calculate the emission concentrations and mass emission rates in this report. Manual calculations were made by AST personnel to verify that the computer results were accurate. The computer printouts are provided in Appendix A. Appendix F presents the equations used to make these manual verifications. 3.3.5 Removal Efficiency of The Mesh Pad Mist Eliminator Chromium removal efficiencies for the MPME system were determined by simultaneously sampling the two inlets and outlet of the MPME. The mass emission rates were used to calculate removal efficiencies. Removal efficiency is calculated using the equation below. RE = -^-2 x 100 c, Where: RE = % Removal Efficiency Ci = ]£ of mass emission rates at Inlets 1 and 2, Ib/hr C0 = Mass emission rate at the outlet, Ib/hr 3-8 ------- Table 3.5. ANALYSIS OF PLATING TANK SOLUTIONS, MPME WATER AND BLANK SAMPLES SAMPLES* Tank 1 Run No. 1 Tank 1 Run No. 2 Tank 1 Run No. 3 Tank 2 Run No. 1 Tank 2 Run No. 2 Tank 2 Run No. 3 Tank 7 Run No. 1 Tank 7 Run No. 2 Tank 7 Run No. 3 Sampling Train Blank0 MJ Outlet Run No. 1 MJ Outlet Run No. 2 MJ Outlet Run No. 3 Cr-VP Oig/ml) 1.22x 10+5 8.59 x 10+4 l.OSx 10+5 1.15x 10+5 1.22x 10+5 1.14x 10+s 1.23 x 10+5 1.23 x 10+5 1.20x 10+5 7.37 x 10"3 7.59 x lO'2 (6.4 x 10-2") 7.43 x 1C'2 (5.00 x 10-2**) 1.81 x 10-' (2.03 x 10-'") Cr-Tb Otg/ml) 1.31 x 10+5 1.30x HT5 1.26x 10+5 1.27x 10+5 1.25x 10+5 1.24x 10+5 1.23x 10+5 1.26 x 10+s 1.25 x 10+s 3.20 x lO'2 2.69 x lO'1 2.86 x 10-1 6.00 x 10-3 * Liquid grab samples from tanks 1, 2, 7 and the MPME were collected at the beginning, middle and end of each Method 13-B run. All samples are composites. * ICPCR was used for analysis b ICP was used for analysis 0 The Method 13-B sampling train was cleaned between test runs. The blank sample, is a rinseate, was collected after cleaning the train components. ** In-field colorimetric analysis results for MPME water 3-9 ------- Mass emission rates are presented in Tables 3.3 and 3.4. The data in Tables 3.3 and 3.4 indicate that more than 95% of the mass emissions are of Cr-VI and less than 5% of the emissions are of Cr-III. 3.3.6 Penetration of The Mesh Pad Mist Eliminator Penetration can be used to evaluate the performance of a chromium emission control device such as a MPME. Penetration is defined as the percentage of chromium that escapes or is not collected by an emission control device. Percent penetration is calculated using the equation below. Percent Penetration= 100% - RE Where: RE = % Removal Efficiency Often, the percent penetration results reveal more about the process conditions than the percent efficiency results. The calculated removal efficiencies are tabulated in Table 3.6. The average removal efficiency for Cr-VI was 95.94%. The average removal efficiency for Cr-T was 95.96%. The removal efficiencies for Cr-T and Cr-VI are essentially the same. As pointed out earlier, most of the mass emissions are of Cr-VI (—95%). The percent penetration for each test run was also calculated. Table 3.7 lists the results of the removal efficiency and the percent penetration calculations. Table 3.7 shows that about 4% of the chromium emissions penetrated the mesh pad mist eliminator. 3-10 ------- Table 3.6. SUMMARY OF THE MESH PAD MIST ELIMINATOR CHROMIUM REMOVAL EFFICIENCIES Analyte Cr-VI Cr-VI Cr-VI Average Cr-T Cr-T Cr-T Average Analytical Technique Used ICPCR ICPCR ICPCR NA ICP ICP ICP NA Test Run No. 1 2 3 NA 1 2 3 NA Mass Emission Rates at Inlets No. 1 and No. 2* (Ib/hr) 1.276x lO'2 1.175x ID'2 1.838x lO'2 1.430 x 10 2 1.320x ID'2 1.247x ID'2 1.927x lO'2 1.498 x 10 2 Mass Emission Rate at Outlet (Ib/hr) 7.190x 10" 4.906 x 10" 4.340 x 10" 5.479 x 10" 6.747 x 10" 5.530 X 10" 4.972 x 10" 5.750 x 10" Removal Efficiency (%) 94.37 95.82 97.64 95.94 94.89 95.57 97.42 95.96 * - Inlets 1 and 2 mass emission rates were combined. NA - Not Applicable 3-11 ------- Table 3.7. REMOVAL EFFICIENCY AND PERCENT PENETRATION* OF CHROMIUM THROUGH THE MESH PAD MIST ELIMINATOR Test Run No. 1 2 3 Average % Removal Efficiency Cr-VI 94.37 95.82 97.64 95.94 Cr-T 94.89 95.57 97.42 95.96 % Penetration Cr-VI 5.63 4.18 2.36 4.06 Cr-T 5.11 4.43 2.58 4.04 * Percent Penetration = 100% - % Removal Efficiency 3-12 ------- Section 4 SAMPLING AND ANALYSIS METHODS 4.1 Types of Samples Collected and Sample Recovery Descriptions Two types of samples were collected during field testing at the Precision Engineering, Inc. plant: 1) liquid grab samples; and 2) gaseous stack samples. A description for each sample type collected is provided below. 4.1.1 Liquid Grab Samples The plating tank solution and the mesh pad mist eliminator water samples were collected during each sampling run, in pre-cleaned Mason jars. For example, one plating tank solution sample consisted of three sample fractions collected in the same Mason jar. Each sample fraction was collected at different periods (i.e., beginning, middle and end) of a test run. Nine (9) composite plating tank solution samples were collected from plating tanks (1,2 and 7) and 3 composite samples were collected from the mesh pad mist eliminator during this project. Each sample was labeled with date, run number and sample location. •4.1.2 Gaseous Stack Samples Gaseous stack samples were collected from two inlet locations (Inlet No. 1 and Inlet No. 2) and one Outlet location, using Method 13-B. Method 13-B stack samples were recovered immediately after each test run. The contents of impingers 1 and 2 were measured for volume increase and then transferred to a pre-weighed and pre-cleaned plastic bottle. The nozzle, probe and glass tubing connecting the impingers were washed with 0. IN NaOH. These washings were added to the same plastic bottle. Silica gel from the fourth impinger was weighed to determine 4-1 ------- weight gain from moisture absorption. The silica gel was then placed in a container, labeled and stored in the cooler. A sampling train blank sample was collected after each Method 13-B test run. This was performed by thoroughly rinsing the inside of the sampling train components with a 0. IN NaOH solution and then placing the rinseate into a container labeled "Sampling Train Blank." The sampling train blank was stored in the cooler. Field blank samples were also prepared, labeled and stored in the cooler. 4.1.3 Sampling Locations Inlet No. 1 Inlet No. 1 was located on a straight run of 24-inch diameter duct work just before the mesh pad mist eliminator. Sampling ports were cut at a location approximately 18 feet downstream and 4 feet upstream from the nearest disturbance. According to U.S. EPA Method 1 criteria, this location required 12 traverse points, six along each of the two perpendicular diameters. Figure 4.1 shows Inlet No. 1 traverse point locations. Inlet No. 2 Inlet No. 2 was located on a straight run of 18-inch diameter duct work just before the control .device. Sampling ports were cut at a location approximately 18 feet downstream and 4 feet upstream of the nearest disturbance. Twelve traverse points were also required at this location. Figure 4.2 shows Inlet No. 2 traverse point locations. 4-2 ------- Outlet The Outlet of the mesh pad mist eliminator was a 30-inch diameter stack. The total height of the stack was about 95 inches. This total height included a 24-inch stack extension attached to the stack during the test. A butterfly-type cap was installed to prevent extraneous materials from entering into the stack. Sampling ports were cut at a location approximately 60 inches downstream and 35 inches upstream of the nearest disturbance. Figure 4.3 shows the Outlet traverse point locations. Twenty-four traverse points were required at this location; 12 along each of the two perpendicular diameters. Figure 4.3 shows the Outlet traverse point locations. Figures 4.1 through 4.3 show traverse point locations along one perpendicular diameter. The total number of traverse points, in these figures, are obtained by multiplying the traverse point locations shown by two. 4-3 ------- DIAMETER 24.0" Figure 4.1. Inlet No. 1 Traverse Point Locations 4-4 ------- DIAMETER 18.0" Figure 4.2. Inlet No. 2 Traverse Point Locations 4-5 ------- DIAMETER 30" Figure 4.3. Outlet Traverse Point Locations 4-6 ------- 4.2 Air Sampling Test Methods The test methods used during this project were in accordance with U.S. EPA Methods 1, 2, 4 and a modification of Method 13-B. Method 13-B, designed for total fluoride emission testing was used for the chromium paniculate collection. A brief description of each method used in given below. 4.2.1 Traverse Points U.S. EPA Method 1 "Sample and Velocity Traverses for Stationary Sources" was used to determine the location of traverse points. Cyclonic flow checks were made prior to testing. These checks indicated that cyclonic flow conditions did not exist at the sampling locations. 4.2.2 Stack Gas Velocity U.S. EPA Method 2 "Determination of Stack Gas Velocity and Volumetric Flow Rate (Type "S" Pilot Tube)" was used to measure the stack gas velocity and temperature at each test point. Type K" thermocouples were affixed to type "S" pilot tubes having an assigned coefficient of 0.84. The velocity pressure was measured on an inclined manometer. The volumetric flow rate was calculated from the stack gas velocity and the stack cross-sectional area. Since this was an ambient source, a dry molecular weight of 28.95 Ib/lb-mole was used. 4.2.3 Stack Gas Moisture U.S. EPA Method 4 "Determination of Moisture Content in Stack Gas" was used to determine the stack gas moisture content. These moisture determinations were made during the modified Method 13-B test runs. 4-7 ------- 4.2.4 Modified Method 13-B Sampling Train A modification of U.S. EPA Method 13-B "Determination of Total Fluoride Emission from Stationary Sources" was used to collect chromium emission samples. The sampling train consisted of a glass button-hook nozzle, an unheated "Pyrex" glass-lined probe and a series of four impingers. Isokinetic samples were collected during each test run. During sampling, stack gases were pulled through the nozzle, past the probe and then through four impingers, where the chromium was collected and retained. The contents and the configuration of the impingers are given below. 1. The first impinger contained 100 ml of 0. IN NaOH. 2. The second impinger contained 100 ml of 0. IN NaOH. 3. The third impinger was empty. 4. The fourth impinger contained a weighted amount of silica gel (200 grams). The remainder of the train consisted of a vacuum pump, dry gas meter, calibrated orifice and related temperature and pressure measuring equipment. Figure 4.4 shows a Schematic of the Modified U.S. EPA Method 13-B Sampling Train. 4.3 Sample Analysis Methods The samples collected during the Modified 13-B testing were analyzed using one of three analytical techniques. The techniques were: 1) Colorimetry; 2) Inductively Coupled Plasma (ICP); and 3) lon-Chromatography with a Post Column Reactor (ICPRC). Each analytical technique is briefly described below. ICP and ICPCR analyses were done by RTIL. The colorimetric analyses for hexavalent chromium were performed by AST personnel in the field. 4-8 ------- CONTAINER I.D. Impinger #\ Impinger #2 Impinger #3 Impinger #4 CONTAINER CONTENT Modified Greenburg-Smith - 100 ml ofO.lNNaOH Standard Greenburg-smith - 100 ml Modified Greenburg-Smith - Empty Modified Greenburg-Smith 200 grams of Silica Gel mast Figure 4.4. Schematic of the Modified U.S. EPA Method 13-B Sampling Train 4-9 ------- 4.3.1 Colorimetry Colorimetry was used on-site to analyze samples (i.e., inlet, outlet, sample train blank and MPME water) for Cr-VI. A known aliquot of the sample was made to react with a diphenylcarbazide solution at a pH of 2.00± 0.5. Optimum color development requires 10 minutes. The intensity of the color is measured at 540 nm. The details of this procedure are given in Appendices G and K. 4.3.2 Inductively Coupled Plasma (ICP) ICP was used to determine total chromium in plating tank solution, MPME water, blank and emission samples. ICP is a simple and fast technique used for analysis of major and minor trace elements in samples of all kinds and matrices. It has a detection limit of one part per billion (ppb) or less. Samples are aspirated into a high temperature argon plasma. The argon plasma causes molecular breakdown, atomization and/or ionization and excitation of metals in solution. The excited atoms release characteristic radiation which is detected by a photomultiplier tube (PMT). The PMT produces an electrical current which is transformed into concentration values by reference to a standard. 4.3.3 lon-Chromatographv With Post Column Reactor (ICPCR) ICPCR was used to determine hexavalent chromium (Cr-VI) in the plating tank solution, MPME water, blank and emission samples. Hexavalent chromium is chromatographed as CrO4'2 on an ion column. After separation, the Cr-VI diphenylcarbazide complex is quantified by visible spectrometry at 520 nm. ICPCR has a sub-part per billion detection limit. Typically, ICPCR instrumentation consists of: 1) an ion column; 2) a visible spectrophotometer detector; and 3) an integrator. Details of the ICPCR analytical technique are provided in Appendix I. 4-10 ------- Section 5 QUALITY ASSURANCE PROGRAM, TEST PROGRAM PERSONNEL AND SUMMARY OF FIELD ACTIVITIES 5.1 Quality Assurance Program AST's QA program consisted of the field-related procedural activities and contract laboratory activities. A discussion of the QA activities is given below. The quality assurance activities employed during this project were performed to assure the quality of the data collected. 5.2 Data Review Prior To Report Preparation All field data were recorded on standard data sheets. The field data sheets are in Appendix B. Field data were also recorded on sampling summary sheets. The sampling summary sheets are in Appendix C. Upon returning to the office, AST personnel reduced the field data collected. Afterwards, the results were summarized in a tabular format and reviewed for inconsistencies or other incidences that may indicate errors (data entries or calculations). Prior to reviewing the summary, spot checks of the field data reductions were made to ensure that all raw data were correct and complete. 5.3 Contract Laboratory Quality Assurance Procedures The contract laboratory's QA program was established to ensure that its personnel produce valid analytical results. This goal is accomplished by regularly monitoring the reliability (i.e., precision, accuracy, reproducibility) of the reported results. 5-1 ------- Quality assurance activities taken to ensure high quality analytical results include the following: • Reagent blank samples were prepared and analyzed • QC check standards were analyzed at the beginning of a test run to verify a standard curve Spiked blanks were prepared and analyzed to assure there were no interferences Duplicate samples were prepared and analyzed to assure the analytical precision • Instrumentation performance was regularly monitored and repairs were made when required 5.4 Test Program Personnel The personnel involved in the completion of this test program, their titles and their job affiliations are listed below. Frank Clay - Task Manager, U.S. EPA Tom Yaroch - Project Manager, AST James Parker - Technician, AST Michelle Knox - Laboratory Analyst, AST Ron Kirkland - Meter Reader, AST Jim Dini - Meter Reader, AST Chuck Hames - Meter Reader, AST 5-2 ------- 5.5 Field Activities The following is a summary of the field activities: 12/16/91 Traveled to Seattle, Washington, inventoried equipment, prepared site 12/17/91 Conducted one, six-hour measurement run at each site, recovered and analyzed emission samples 12/18/91 Conducted one, four-hour measurement run at each site, recovered and analyzed emission samples 12/19/91 Conducted one, four-hour measurement run at each site, recovered and analyzed emission samples; restored site, packed and shipped equipment 12/20/91 Traveled to Atlanta, Georgia 5-3 ------- April 29, 1993 NOTE: Attached is an addendum to the source test at the electroplating facility in Seattle, Washington. Frank R. Clay '-«.'. ^ • > *- ------- ADDENDUM FOR THE U.S. ENVIRONMENTAL PROTECTION AGENCY TEST REPORT FOR THE DECEMBER 1991 SOURCE TEST AT THE PRECISION ENGINEERING, INC. ELECTROPLATING FACILITY IN SEATTLE, WASHINGTON At the request of Midwest Research Institute, this addendum has been prepared for the Precision Engineering Test Report. The changes are minor and correct field data and calculations found in the report. After the first run of the source test, it was discovered that the thermocouple indicator readings used to determine inlet and outlet stack temperatures were biased about 20 degrees F too high. For the remaining runs, dial thermometers were used for stack temperature readings. In the original version of the test report stack temperatures obtained from the thermocouple were used in the data reduction for Run 1. For this addendum, the average stack temperatures from Runs 2 and 3 are used in the reduction of the data from Run 1. Changes were made throughout Chapter 3 wherever the corrected temperatures had an effect. This addendum is composed of two parts: (1) revisions to Chapter 3 and (2) computer print outs. The addendum for Chapter 3 contains the entire chapter and completely replaces the original Chapter 3. The new computer print outs replace the original print outs for Run 1 data from both the inlet and the outlet locations. For reports with appendices, replace both Chapter 3 and the computer print out sheets; for reports without appendices only Chapter 3 need be replaced. ------- Section 3 SUMMARY OF SAMPLE COLLECTION, EMISSION CALCULATIONS AND RESULTS 3.1 Sample Collection Emission samples were collected using a modification of U.S. EPA Method 13-B. The samples were collected simultaneously from Inlets No. 1 and No. 2 and from the Outlet of the MPME under normal operating conditions. Three tests were conducted at each sampling location. Sampling times of 4 or 6 hours per test run were used to ensure that adequate quantities of chromium were collected for subsequent chemical analysis. Grab samples from the plating tank solutions (Tanks 1, 2 and 7) and the MPME water were also collected during each sampling run. These samples were obtained at the beginning, middle and at the end of each Method 13-B test run. 3.2 Stack Gas Parameters Stack gas parameters, at each sampling location, are shown in Table 3-1. At Inlet No. 1, the stack gas velocity averaged48.92feet per second (fps), the average stack temperature was 70°F and the average moisture content was 1.11%. The volumetric flow rates at Inlet No. 1 were 9473 actual cubic feet per minute (acfm) and 9254 dry standard cubic feet per minute (dscfm). At Inlet No. 2, the stack gas velocity averaged49.96fps, the average stack temperature was 69°F and the average moisture content was 0.75%. The volumetric flow rates at Inlet No. 2 were 52.97 acfm and 5198 dscfm. 3-1 ------- At the Outlet, the stack gas velocities averaged49.53fps, the average stacK temperature was 72°F and the average moisture content was 0.98%. The average volumetric flow rates at the Outlet were 14588 acfm and 14406 dscfm. The stack gas at all sampling locations was essentially ambient air and thus was assigned a dry molecular weight of 28.95 Ib/lb-mole. Variation in isokinetic sampling rates were within allowable limits for all sampling runs of Method 13-B except Run 2 of Inlet 2 which had an isokinetic rate of 88.81%. The evaluation of particle size, from previous test runs, indicate that more than 85 % of the particles emitted from a controlled electroplating process are less than 2.5 microns in diameter. Particles less than 2.5 microns behave like a gas rather than a paniculate. In gaseous sampling the isokinetic sampling rate is not considered to be significant. Therefore, no adjustments were made to the data and the results are acceptable. 3.3 Emission Calculations and Discussion of Results This subsection of the report provides the following information: 1) Cr-VI results from colorimetry and ICPCR analyses; 2) Cr-T results from ICP analysis; 3) Cr-VI and Cr-T concentrations in the plating tank solutions, MPME water and sampling train blank samples; 4) computerized spreadsheet calculations of emission concentrations and mass emission rates; 5) MPME removal efficiencies; and 6) MPME penetration. 3-2 ------- Table 3.1 SUMMARY OF STACK GAS CONDITIONS Inlet No.l Run No. 1 2 3 Average Velocity fps" 45.58 48.53 ~ 52.66 48.92 Stack Temp. °F 70 69 70 70 Flow Rate acfmb 9345 9,148 9,927 9473 dscfm' 9122 8,830 9,810 9254 Moisture % 0.98 1.14 1.21 1.11 % Isokinetic Rate 99.05 98.99 93.32 97.12 Inlet No. 2 Run No. 1 2 3 Average . Velocity fps- 51.01 52.02 46.85 49.96 Stack Temp. °F 69 70 68 69 Flow Rate acfmb 5408 5,516 4,968 . 5297 dscfme 5301 5,350 4,943 5198 Moisture % 0.67 0.65 0.94 0.75 % Isokinetic Rate 100.72 88.81 98.37 95.97 T)utlet Run No. 1 2 3 Average Velocity fps" 49.15 49.03 50.41 49.53 Stack Temp. °F . 72 72 72 72 Flow Rate acfmb 14474 14,442 14,847 14588 dscfmc 14272 14,065 14,882 14406 Moisture % 0.97 1.08 0.90 0.98 % Isokinetic Rate 105.45 99.68 99.48 101.54 Feet per second b Actual cubic feet per minute c Dry standard cubic feet per minute at 68 °F and 29.92" Hg 3-3 ------- 3.3.1 Cr—VI Results From Colorimefary and ICPCR Analyses Table 3.2 list Cr-VI results obtained from two analytical techniques, namely: 1) colorimetry using diphenylcarbazide; and 2) ICPCR. The colorimetric technique , used in the field to determine Cr-VI, provided a rapid analysis of chromium concentrations. The results were not used in the emission calculations in this report and are provided in Appendix E for information only. RTIS's analytical results for total chronium (Cr-T) and hexavalent chromium '(Cr-VI") were used* to "make enission calculations in this report. Table 3.3 provides analytical results of Cr-VI mass emission testing at the Precision Engineering, Inc plant. The samples were analyzed using lon-Chromatography with a Post Column Reactor (ICPCR). RTIL's analytical data report is provided in Appendix D. The average concentration at the outlet was 0.0103 mg/m3. The average mass emission rate (Ibs/hr) of the two inlets combined was 1.44 x 10~2 Ib/hr and the outlet had an emission rate of 5.57 x 10~4 Ib/hr. 3.2.2 Total Chromium Results Froia ICP Analysis Presented in Table 3.4 are the total chromium (CR-T) emission results. RTIL's analytical data report is provided in Appendix D. The Cr-T emission concentration at the outlet averaged 0.0108 mg/m3. The average Cr-T mass eiaission rate from Inlets No. 1 and No. 2 combined was 1.51 x 10"2 Ib/hr and the outlet average emission rate was 5.83 x 10~* Ib/hr. 3-4 ------- Table 3.2. COMPARISON OF EMISSION SAMPLE ANALYSIS RESULTS' FOR CHROMIUM-VI USING COLORIMETRY" AND ICPCR£ TECHNIQUES Inlet No. 1 Test Run No. Run No.l Run No. 2 • Run -No-. 3 • Sampling Time (min) 360 240 240 Total Cr-VI G*g) Colorimetryb 2,862 743 :~ .. 848 Average 1,484 ICPCR' 2,889 1,774 . .2,891 2,518 Inlet No. 2 Run No. 1 Run No. 2 Run No. 3 Average 360 240 240 1,517 808 779 1,035 1,589 770 813 1,057 Outlet Run No. 1 Run No. 2 Run No. 3 360 240 240 123 37.8 50.3 Average 70.4 146 60.6 53.5 86.7 ' Results are expressed as total microgram of Chromium-VI b Colormetric quantification on-site using diphenylcarbazide organic analytical reagent c lon-chromatography with a post column reactor. 3-5 ------- Table 3.3. ANALYTICAL' RESULTS OF CHROMIUM-VI MASS EMISSION TESTING Inlets" Test Run No. 1 2 3 Average Total Cr-VI (Mg)c 4,478 2,544 3,704 3,575 Emission Concentration (mg/m3)' Mass Emission Rate (lb/hr)c 1.30 X 10'2 1.175 x 10-2 1.838x ia2 1-44 x 10'2 Mass Emission Rate (kg/hr)' 5.93 X ID'3 5.33 x ID"3 8.33 x lO'3 6.53 x 10~3 Outlet Test Run No. 1 2 3 Average Total Cr-VI fog)0 146 60.6 53.5 86.7 Emission Concentration (mg/m3) c 0.0139 0.0093 0.0078 0.0103 Mass Emission Rate (Ib/hr)' 7.45 x 10-" 4.91 x 10-* 4.34 x 10-* 5.57 x 10~4 Mass Emission Rate (kg/hr)e 3.38 X 10-4 2.22 x 10-4 1.97 x 1O4 2.52 x 10"1 NOTE: The concentration in milligrams per cubic meter for the two inlets combined is omitted from the inlet data. Since the flow rates for the two inlets were different, a combined concentration number would not reflect the concentration of either inlet and is not needed in this report. Inlet #1 averaged 0.3364 Mg/M3 of hexavalent chromium while Inlet #2 averaged 0.1353 Mg/M3 of hexavalent chromium. • Analysis method, lon-Chromatography with Post Column Reactor. b The control device has two inlets (Inlet No. 1 and Inlet No.2). e Sum of Cr-VI emissions from Inlet No.l and Inlet No.2. 3-6 ------- Table 3.4. ANALYTICAL1 RESULTS OF TOTAL CHROMIUM MASS EMISSION TESTING InJetsb Test Run No. 1 2 3 .Average Cr-T Oig)c 4,602 2,728 3,921 3,750 . Emission Concentration (mg/m3)1 -- • -. Mass Emission Rate flb/hr)e 1.35 X ID'2 1.25x 10"2 1.93x lO"2 1.51 x 10'2 Mass Emission Rate (kg/hr)c 6.14 x lO'3 5.656 x 10-3 8.741 x 10"3 6.846 X 10" Outlet Test Run No. 1 2 3 Average Cr-T 0*g)e 137.0 68.3 61.3 88.9 Emission Concentration (mg/m3)' 0.0131 0.0105 0.0089 0.0108 Mass Emission Rate (lb/hr)c 6.99 x ID"1 5.53 x 104 4.97 x 104 5.83 X 10"4 Mass Emission Rate (kg/hr)c 3.17 x 1CT4 2.51 x 10-* 2.26 x 10-1 2.65 X ID'4 NOTE: The concentration in milligrams per cubic meter for the two inlets combined is omitted from the inlet data. Since the flow rates for the two inlets were different, a combined concentration number would not reflect the concentration of either inlet and is not needed in this report. Inlet #1 averaged 0.3492 Mg/M3 of total chromium while Inlet #2 averaged 0.1478 Mg/M3 of total chromium. 1 Analysis method, Inductively Coupled Plasma (ICP) b The control device has two inlets (Inlet No. 1 and Inlet No. 2) c Sum of total chromium emissions from Inlet No. 1 and Inlet No. 2 3-7 ------- 3.3.3 Concentrations In Plating Tank Solution. MPME Water and Train Blank Samriles Cr-VI and Cr-T concentrations in the plating tank solution, MPME water and train blank samples were determined by RTIL using ICPCR and ICP. The sample concentrations are presented in Table 3.5. The concentrations of chromium remained essentially constant throughout the testing period. 3.3.4 Computerized Spreadsheet Calculations A computerized spreadsheet, provided by Mr. Frank Clay (U.S. EPA, Task Manager), was used to calculate the emission cbncenIraQons"aTfd""niass emission rates in this report. Manual calculations were made by AST personnel to verify that the computer results were accurate. The computer printouts are provided in Appendix A. Appendix F presents the equations used to make these manual verifications. 3.3.5 Removal Efficiency of The Mesh Pad Mist Eliminator Chromium removal efficiencies for the MPME system were determined by simultaneously sampling the two inlets and outlet of the MPME. The mass emission rates were used to calculate removal efficiencies. Removal efficiency is calculated using the equation below. Crc0 RE = — — - x 100 C, Where: RE - % Removal Efficiency of mass emission rates at Inlets 1 and 2, Ib/hr C0 = Mass emission rate at the outlet, lb\hr 3-8 ------- Table 3.5. ANALYSIS OF PLATING TANK SOLUTIONS, MPME WATER AND BLANK SAMPLES SAMPLES* Tank 1 Run No. 1 Tank 1 Run No. 2 Tank 1 Run No. 3 Tank 2 Run No. 1 Tank 2 Run No. 2 Tank 2 Run No. 3 Tank 7 Run No. 1 Tank 7 Run No. 2 Tank 7 Run No. 3 Sampling Train Blank c MJ Outlet Run No. 1 MJ Outlet Run No. 2 MJ Outlet Run No. 3 Cr-VP Oig/ml) 1.22x 10+5 8.59 x 10+4 1.08x 10+5 1.15x 10+5 1.22x 10+s 1.14x 10+5 1.23x 10+5 1.23x 10+5 1.20x 10+s 7.37 x lO'3 7.59 x lO'2 (6.4 x 10-2") 7.43 x lO'2 (5.00 x 10-2") 1.81 x 10"' (2.03 x 10-1") Cr-1* Otg/ml) 1.31 x 10+s 1.30x 10+s 1.26x 10+s 1.27 x 10+s 1.25x 10+5 1.24 x 10+s 1.23x 10+5 1.26 x 10+5 1.25x 10+5 3.20 x 10'2 2.69 x 10'1 2.86 x 10'1 6.00 x lO'3 * Liquid grab samples from tanks 1, 2, 7 and the MPME were collected at the beginning, middle and end of each Method 13-B run. All samples are composites. • ICPCR was used for analysis b ICP was used for analysis e The Method 13-B sampling train was cleaned between test runs. The blank sample, is a rinseate, was collected after cleaning the train components. ** In-field colorimetric analysis results for MPME water 3-9 ------- kass e'mission rates are presented in Tables 3.3 2nd 3.4. The data in Tables 3.3 and 3.4 indicate that more than 95% of the mass emissions are of Cr-VI and less than 5% of the emissions are of Cr-in. 3.3.6 Penetration of The Mesh Pad Mkt Eliminator Penetration can be used to evaluate the performance of a chromium emission control device such as a MPME. Penetration is defined as the percentage of chromium that escapes or is not collected by an emission control device. Percent penetration is calculated using the equation below. Percent Penetration= 100% - RE Where: RE = % Removal Efficiency Often, the percent penetration results reveal more about the process conditions than the percent efficiency results. The calculated removal efficiencies are tabulated in Table 3.6. The average removal efficiency for Cr-VI was 95.94%. The average removal efficiency for Cr-T was 95.96%. The removal efficiencies for Cr-T and Cr-VI are essentially the same. As pointed out earlier, most of the mass emissions are of Cr-VI (—95%). The percent penetration for each test run was also calculated. Table 3.7 lists the results of the removal efficiency and the percent penetration calculations. Table 3.7 shows that about 4% of the chromium emissions penetrated the mesh pad mist eliminator. 3-10 ------- iaoie CHROMIUM REMOVAL EFFICIENCIES Analyte Cr-VI Cr-VI • cr-vr Average Cr-T Cr-T Cr-T Average Analytical Technique Used ICPCR ICPCR ICPCR ~ NA ICP ICP ICP NA Test Run No. 1 2 ' 3 " NA 1 2 3 NA Mass Emission Rates at Inlets No. 1 and No. 2* (Ib/hr) 1.307 X 10'2 i.nsx icr2 • -"1.838 x 10-2 1.440 x 10'2 1.353 x 10"2 1.247x 10-2 1.927x 10-2 1.509 x 10'2 Mass Emission Rate at Outlet (Ib/hr) 7.449 X 10"* 4.906 x 10" 4.340 x 10" 5.65 x 10-* 6.990 x 10'4 5.530 X 10" 4.972 x 10" 5.831 x 10~* Removal Efficiency (%) 94.30 95.82 97.64 95.92 94.83 95.57 97.42 95.94 * - Inlets 1 and 2 mass emission rates were combined. NA - Not Applicable 3-11 ------- Table 3.7. REMOVAL EFFICIENCY AND PERCENT PENETRATION* OF CHROMIUM THROUGH THE MESH PAD MIST ELIMINATOR Test Run No. 1 . .. 2. 3 Average % Removal Efficiency Cr-VI 94.30 95.82 97.64 95.92 Cr-T 94.83 - 95.57 97.42 95.94 % Penetration Cr-VI 5.70 4.18 . 2.36 4.08 Cr-T 5.17 4.43 2.58 4.06 Percent Penetration = 100% - % Removal Efficiency 3-12 ------- |