EPA/600/R-92/003c
March 1992
EMISSIONS OF METALS, CHROMIUM AND NICKEL SPECIES, AND ORGANICS
FROM MUNICIPAL WASTEWATER SLUDGE INCINERATORS
VOLUME III: SITE 6 EMISSION TEST REPORT
Prepared by:
Robin R. Segall
Entropy Environmentalist, Inc.
Research Triangle Park, North Carolina 27709
William G. DeWees
DEECO, Inc.
Cary, North Carolina 27519
F. Michael Lewis
Mountain View, California 94040
EPA Contract No. 68-CO-0027
Work Assignment No. 0-5
Technical Managers:
Harry E. Bostian, Ph.D.
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
Eugene P. Crumpler
Office of Water
U.S. Environmental Protection Agency
Washington, D.C. 20460
RISK REDUCTION ENGINEERING LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This material has been funded wholly or in part by the United States
Environmental Protection Agency's Risk Reduction Engineering Laboratory and Office
ef Water under contract numbers 68-02-4442, Work Assignment No. 81, 68-02-4462,
Work Assignment No. 90-108, and 68-C0-0027, Work Assignment No. 0-5. It has been
subject to the Agency's review and it has been approved for publication as an EPA
document. Mention of trade names or commercial products does not constitute an
endorsement or recommendation for use.
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FOREWORD
Today's rapidly developing and changing technologies and industrial products and
practices frequently carry with them the increased generation of materials that, if
improperly dealt with, can threaten both public health and the environment. The U.S.
Environmental Protection Agency is charged by Congress with protecting the Nation's
land, air, and water resources. Under a mandate of national environmental laws, the
agency strives to formulate and implement actions leading to a compatible balance
between human activities and the ability of natural systems to support and nurture life.
These laws direct the EPA to perform research to define our environmental problems,
measure the impacts, and search for solutions.
The Risk Reduction Engineering Laboratory is responsible for planning,
implementing, and managing research, development, and demonstration programs to
provide an authoritative, defensible engineering basis in support of the policies,
programs, and regulations of the EPA with respect to drinking water, wastewater,
pesticides, toxic substances, solid and hazardous wastes, and Superfund-related activities.
This publication is one of the products of that research and provides a vital
communication link between the research and the user community.
The problem of disposing of primary and secondary sludge generated at municipal
wastewater treatment facilities is one of growing concern. Sludge of this type may
contain toxics such as heavy metals and various organic species. Viable sludge disposal
options include methods of land disposal or incineration. In determining the
environmental hazards associated with incineration, the Risk Reduction Engineering
Laboratory and the Office of Water has sponsored a program to monitor the emissions
of metals and organics from a series of municipal wastewater sludge incinerators. The
following document presents the final results from the Site 6 emissions test program.
E. Timothy Oppelt, Director
Risk Reduction Engineering Laboratory
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ABSTRACT
The U.S. Environmental Protection Agency (EPA) Office of Water (OW) has
drafted risk-based sludge regulations under Section 405d of the Clean Water Act and
EPA's Risk Reduction Engineering Laboratory (RREL) has been assisting OW in the
collection of supporting data for the proposed regulations. Proposed regulations and a
solicitation for public comment was published in the Federal Register on February 6,
1989. Final regulations are scheduled for publication in the Federal Register in January
1992. Because of the associated cancer risk, there is particular concern regarding
chromium and nickel species in the emissions from sludge incineration.
An RREL/OW research program was implemented to determine the ratios of
hexavalent to total chromium and nickel subsulfide to total nickel in sewage sludge
incinerator emissions under varied incinerator operating conditions. Site 6, a multiple
hearth furnace was tested under two operating conditions, normal combustion was
compared with improved combustion conditions as indicated by reduced CO and THC
emissions. This report presents the test results from Site 6, the second of five incinerator
test sites. Four incinerators tested under another project with Radian Corporation are
included in the site numbering convention used. Thus the second site, covered under the
present project, and by this report, is referred to as Site 6.
The effect of lime conditioning on the conversion of total chromium in the sludge
to hexavalent chromium emissions was also a primary concern at Site 6. Secondary
objectives included comparing the results for chromium and nickel subspecies
determined by different analytical procedures, gathering data on other metals and
inorganic/organic gases in incinerator emissions, and assessing pollutant removal
efficiencies by measuring emissions at both the inlet and outlet to the control system.
The Site 6 plant treats 30 million gallons a day of municipal and industrial
wastewater. The blended primary/secondary sludge is dewatered to approximately 28%
solids using recessed plate cloth filters. The dried filter cakes are incinerated in an
eight-hearth unit and emissions are controlled with a venturi scrubber and impingement
tray scrubber.
The flue gas volumetric flow rates at the inlet sampling location were fairly
consistent averaging 475 dry standard cubic meters per minute (dscm/min) for normal
operating conditions and 430 dscm/min for low CO conditions. Averaged temperatures
of the flue gas were 876°F (469°C) for the normal operating conditions and 1027°F
(553°C ) for the low CO conditions with a moisture content of 33.1% and 33.2%,
respectively. The percent dry of oxygen, carbon dioxide were 13.0 and 7.4, respectively
for normal conditions and 11.5 and 7.7 respectively for low CO conditions. The carbon
monoxide emissions corrected to 7% 02 for the normal and low CO operating conditions
were 1290 and 620 ppm, respectively.
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The average flue gas volumetric flow rates at the outlet sampling site ranged from
522.4 dscm/min for normal operating conditions to 531.1 dscm for low CO conditions.
Averaged temperatures of the flue gas were 144°F (62.4°C) for normal operating
conditions and 147°F (64.1°C) with a moisture content of 6.7% and 7.2% respectively.
The percentage of dry oxygen and carbon dioxide were 14.1 and 5.6 respectively for the
normal operating conditions and 13.3 and 6.3, respectively for the low CO condition.
The carbon monoxide levels corrected to 7% oxygen for both the normal and low CO
conditions were 1318 and 592 ppm, respectively. The THC emissions for the normal and
low CO were 24 and 8 ppm, respectively.
The metal mass emissions rate for the inlet runs averaged: Arsenic (As) -not
detected (< 862 mg/hr), Beryllium (Be) - 15.9 mg/hr, Cadmium (Cd) - 5,840 rag/hr,
Chromium (Cr) - 12,400 mg/hr, Lead (Pb) - 86,600 mg/hr, and Nickel (Ni) - 1,220
mg/hr. The metal mass emissions rate for the outlet runs averaged: As - not detected
(< 508 mg/hr), Be - not detected (< 2.2 mg/hr), Cd - 1,450 mg/hr, Cr - 83.3 mg/hr, Pb
- 21,100 mg/hr, and Ni - 73.9 mg/hr. The particulate mass emission rates averaged 42
kg/hr and 0.7 kg/hr, respectively for the inlet and outlet.
A positive correlation between the CO/C02 ratios (an indication of combustion
conditions) and the hexavalent to total chromium ratio was demonstrated for the outlet
location. At low CO levels (good combustion) the ratio of hexavalent chromium to
trivalent chromium was highest, with approximately 10% of the total chromium in the
form of hexavalent chromium. At high CO levels (poor combustion), the ratio of
hexavalent chromium to total chromium was significantly reduced to less than
approximately 1%.
It was anticipated that the nickel subsulfide emissions from multiple hearth
incinerators would constitute less than 1% of the total nickel emissions. A wet chemical
analysis indicated that within the detection limit (< 10%), no nickel subsulfide was
present in the samples. Samples were also analyzed by X-ray absorption near-edge
structure (XANES) and extended X-ray absorption fine structure (EXAFS); no nickel
subsulfide was detected within the instrumental detection limit of 10% of the total
nickel,
EPA is evaluating CO and THC monitoring as a surrogate indicator of organic
emissions. With the exclusion of one run, the correlation coefficient between CO and
THC emissions under the tested conditions was 0.97 for the 2- and 4-hr runs.
This report was submitted in fulfillment of Contract Nos. 68-02-4442, 68-02-4462,
and 68-C0-0027 with the Risk Reduction Engineering Laboratory under the sponsorship
of the U.S. Environmental Protection Agency.
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TABLE OF CONTENTS
Section Page
Disclaimer ii
Foreword iii
Abstract iv
List of Figures ix
List of Tables xi
1.0 Introduction 1-1
2.0 Site 6 Test Summary . . 2-1
2.1 Testing program design 2-1
2.2 Test program results 2-3
2.2.1 Test program 2-6
2.2.2 Particulate/metals results 2-6
2.2.3 Hexavalent chromium results 2-6
2.2.4 Nickel speciation 2-9
2.2.5 Carbon monoxide and total hydrocarbons 2-11
2.2.6 Conclusions 2-11
3.0 Process Description and Operation 3-1
3.1 Facility description 3-1
3.2 Incinerator and pollution control system 3-2
3.3 Incinerator operating conditions during testing 3-5
3.4 Process data results 3-11
4.0 Test Results 4-1
4.1 Flue gas conditions 4-2
4.1.1 Inlet flue gas conditions 4-2
4.1.2 Outlet flue gas conditions 4-2
4.2 Particulates/metal results 4-5
4.2.1 Control device inlet results 4-8
4.2.2 Control device outlet results 4-11
4.2.3 Removal efficiency of control device for metals and particulate 4-14
4.2.4 Sludge feed results 4-16
4.2.5 Scrubber water results '. 4-16
4.2.6 Bottom ash results 4-20
4.2.7 Metal emission factors 4-25
4.3 Hexavalent chromium results 4-28
4.3.1 Control device inlet results 4-28
43.2 Control device outlet results 4-28
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TABLE OF CONTENTS (Continued)
Section Page
4.4 Nickel speciation 4-32
4.5 Continuous emissions measurement 4-35
4.6 Conclusions from Site 6 test 4-43
5.0 Sampling Location Selection and Sampling Procedures 5-1
5.1 Emission sampling locations 5-1
5.1.1 Inlet to the control system 5-1
5.1.2 Outlet of the control system 5-4
5.2 Sampling procedures 5-4
5.2.1 Total metals 5-4
5.2.2 Nickel/nickel subsulfide 5-10
5.2.3 Chromium and hexavalent chromium (recirculating train) .... 5-14
52.4 Chromium and hexavalent chromium (filter train) 5-16
5.2.5 Continuous emissions monitoring systems 5-23
5.2.5.1 Sample and data acquisitions 5-23
5.2.5.2 Carbon monoxide/carbon dioxide analysis 5-24
5.2.5.3 Oxygen analysis 5-24
5.2.5.4 Nitrogen oxides (NOs) analysis 5-24
5.2.5.5 Sulfur dioxide (S02) analysis 5-24
5.2.5.6 Total hydrocarbon analysis 5-24
5.2.6 EPA Methods 1,2,3, and 4 5-25
5.2.6.1 Volumetric gas flow rate determination 5-25
5.2.6.2 Flue gas molecular weight determination 5-26
5.2.6.3 Flue gas moisture determination 5-26
5.2.7 Process samples , 5-27
5.3 Process data 5-27
6.0 Analytical Procedures . . . 6-1
6.1 Chromium speciation and analyses 6-1
6.1.1 IC/PCR analysis for hexavalent chromium 6-4
6.1.2 ICAP analysis for total chromium 6-4
6.1.3 XANES analysis for chromium speciation 6-5
6.2 Nickel speciation and analysis 6-5
6.2.1 XANES analysis for nickel speciation 6-6
6.2.2 NiPERA method for nickel speciation 6-6
6.3 Multiple metals analysis 6-9
6.3.1 Flue gas samples 6-9
6.3.2 Dewatered sludge samples 6-11
6.3.3 Incinerator bottom ash samples 6-11
6.3.4 Scrubber water samples 6-11
6.4 Sludge sample analyses 6-12
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TABLE OF CONTENTS (Continued)
Section Page
7.0 Quality Assurance and Quality Control 7-1
7.1 QA/QC program objectives 7-1
7.2 Flue gas sampling and analysis results 7-5
7.2.1 General flue gas sampling quality control 7-5
7.2.2 Sampling and analysis for particulate, total metals and
nickel/nickel subsulfide 7-6
7.2.2.1 Sampling operations 7-7
7.2.2.2 Sample analysis 7-9
7.2.3 Total chromium and hexavalent chromium sampling
and analysis 7-9
7.2.3.1 Sampling operations 7-9
7.2.3.2 Sample analysis 7-12
7.2.4 Continuous emissions monitoring 7-14
73 Process sample analysis QC results/metal analysis 7-17
References 8-1
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LIST OF FIGURES
Number Page
2-1 Cr+6 to total chromium versus CO to C02 ratios 2-10
2-2 Hydrocarbon emissions versus carbon monoxide emissions 2-12
3-1 Process diagram with sampling locations 3-3
3-2 Hearth temperature profile during Run 3 - normal mode of operation 3-6
3-3 Hearth temperature profile during Run 4 - normal mode of operation 3-7
3-4 Hearth temperature profile during Run 5 - normal mode of operation 3-8
3-5 Hearth temperature profile during Run 9 - improved combustion mode of
operation 3-9
3-6 Hearth temperature profile during Run 13- normal mode of operation 3-10
4-1 Cr+6 to total chromium versus CO to C02 ratios 4-31
4-2 Hydrocarbons emissions versus carbon monoxide emissions 4-42
5-1 Process schematic with sampling locations 5-2
5-2 Inlet sampling locations 5-3
5-3 Outlet sampling location 5-5
5-4 Schematic of multiple metals sampling train 5-7
5-5 Sample recovery procedures for multiple metals train 5-9
5-6 Nickel/nickel subsulfide sampling train 5-11
5-7 Schematic of sample recovery procedures for nickel train 5-13
5-8 Schematic of recirculating reagent sampling train for hexavalent chromium . . 5-15
5-9 Sample recovery scheme for hexavalent chromium recirculating
impinger train 5-18
5-10 Chromium filter sampling train 5-19
5-11 Sample recovery scheme for hexavalent chromium filter train 5-22
6-1 Analytical protocol for quadruplicate recirculatory train hexavalent chromium
sampling at outlet location 6-3
6-2 Analytical protocol for quadruplicate nickel sampling at the scrubber
inlet sampling location 6-7
6-3 Analytical protocol for quadruplicate nickel sampling at the scrubber outlet
sampling location 6-8
6-4 Sample preparation and analysis scheme for multiple metals trains 6-10
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LIST OF TABLES
Number Page
2-1 Test program sampling matrix 2-2
2-2 Specific elements and compounds of interest 2-4
2-3 Summary of sampling and analytical methods 2-5
2-4 Summary of scrubber inlet and outlet flue gas conditions 2-7
2-5 Summary of inlet and outlet particulate and metals mass emission rates .... 2-8
3-1 Incinerator design information 3-4
3-2 Summary of hearth temperatures for Site 6 3-12
3-3 Furnace and control equipment operations 3-13
4-1 Summary of inlet and outlet flue gas conditions 4-3
4-2 Summary of inlet and outlet continuous emission measurements 4-4
4-3 Summary of inlet and outlet particulate mass and target metals 4-6
4-4 Summary of inlet and outlet particulate and metals mass emission rates .... 4-7
4-5 Summary of inlet particulate mass and target metals 4-9
4-6 Summary of inlet particulate and metals mass emission rates 4-10
4-7 Summary of metal concentrations in fly ash 4-12
4-8 Summary of outlet particulate mass and target metals 4-13
4-9 Summary of outlet particulate and metals mass emission rates 4-15
4-10 Metals concentration (ug/g) in sludge on wet basis 4-17
4-11 Feed rate of metals in sludge (g/hr) 4-18
4-12 Results for proximate and ultimate analyses of sludge samples 4-19
4-13 Scrubber water metal concentrations (ug/ml) 4-21
4-14 Discharge rate of metals in scrubber water 4-22
4-15 Metals concentration in bottom ash 4-23
4-16 Mass flow rate of metals in bottom ash 4-24
4-17 Inlet and outlet metal emission factors 4-26
4-18 Ratio of metal to particulate 4-27
4-19 Summary of outlet sampling results for hexavalent and total chromium 4-30
4-20 Stability study of outlet sampling results for hexavalent chromium 4-33
4-21 Summary of nickel species emissions: Site 6 4-34
4-22 Summary of inlet and outlet continuous emission monitoring results
(15-min averages) 4-36,37,38,39,40,41
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LIST OF TABLES (Continued)
Number Page
5-1 Total metals glassware cleaning procedures 5-8
5-2 Sample recovery components for total metals train 5-8
5-3 Nickel/nickel subsulfide glassware cleaning procedures 5-12
5-4 Sample recovery components for the nickel/nickel subsulfide train 5-12
5-5 Cr+6/Cr teflon/glass components cleaning procedures 5-17
5-6 Sample recovery components for the Cr+6/Q* recirculating train 5-17
5-7 Cr/Cr+6 glassware cleaning procedures 5-21
5-8 Sample recovery components for Cr/Cr+< filter train 5-21
5-9 Process monitoring data 5-28
6-1 Summary of sampling and analytical methods 6-2
7-1 Summary of estimated precision, accuracy and completeness objectives 7-4
7-2 Isokinetics and leak check summary; Site 6, outlet location, particulate
matter/total metals and nickel/nickel subsulfide sampling . 7-8
7-3 QC results for field recovery blanks, reagent blanks, and audit samples 7-10
7-4 Isokinetics and leak check summary; Site 6, outlet location, total chromium
and hexavalent chromium sampling 7-11
7-5 Recoveries of 5lCr+6 surrogate 7-13
7-6 Summary of CEM drift checks 7-15,16
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ACKNOWLEDGEMENTS
The authors gratefully acknowledge the following invaluable contributions to the
fforts described in this report: Dr. Joseph E. Knoll of the Quality Assurance Division of
EPA for advice and assistance on hexavalent chromium sampling and analysis, Dr.
Vladimar Zatka of Zatka Chemical Consulting Company for advice and analytical work
on nickel speciation, Dr. Nolan F. Mangelson of Brigham Young University for
instrumental analysis of chromium and nickel species, Dr. Kate K. Luk of Research
Triangle Institute for metals analysis, and Dr. Scott C. Steinsberger, formerly of Entropy
Environmentalists, Inc. for his tireless effort and ingenuity in developing new
methodologies.
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1.0 INTRODUCTION
The U.S. Environmental Protection Agency (EPA) Office of Water (OW) has
been developing new regulations for sewage sludge incinerators and EPA's Risk
Reduction Engineering Laboratory (RREL) has been assisting OW in the collection of
supporting data. There is particular concern regarding chromium and nickel species in
the emissions from incineration of municipal wastewater sludge because of the associated
cancer risk. OW has drafted risk-based sludge regulations under Section 405d of the
Clean Water Act which have been published for comment in the Federal Register.
Volume 54, No. 23, February 6, 1989. Final regulations are scheduled for publication in
the Federal Register in January 1992.
The draft regulations are based on the risk incurred by the "most exposed
individual" (MEI). The MEI approach involves calculating the risk associated with an
individual residing for seventy years at the point of maximum ground level concentration
of the emissions just outside the incinerator facility property line. EPA's proposal for
regulating sewage sludge incinerators is based on ensuring that the increase in ambient
air concentrations of metal pollutants emitted from sludge incinerators is below the
ambient air human health criteria. The increase in ambient air concentrations for four
carcinogenic metals, arsenic, chromium, cadmium, and nickel, are expressed as annual
averages. The concentrations are identified in the proposed regulations as Risk Specific
Concentrations (RSC). Both nickel and chromium emissions from sludge incinerators
presented a specific problem in establishing RSCs, because unknown portions of the
emissions of these metals are in forms which are harmful to human health. In
performing the risk calculations, EPA assumed that 1% of the emissions of chromium
from the sludge incinerators is in the most toxic form, hexavalent chromium. For nickel,
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EPA assumed that 100% of the nickel emissions are in the most toxic form, nickel
subsulfide.
Chromium is likely to be emitted in either the highly carcinogenic hexavalent state
(Cr+<) or in the noncarcinogenic trivalent state (Cr+3). Trivalent chromium has not been
shown to be carcinogenic and is toxic only at levels higher than those normally found in
sewage sludge incinerator emissions. Although hexavalent chromium (as the most
oxidized form) could be reasonably expected to result from combustion processes,
investigators speculate that most of the chromium is likely to be emitted in the trivalent
state.1 This is because hexavalent chromium is highly reactive, and thus likely to react
with reducing agents to form trivalent chromium.
Studies have been conducted to determine the potential for chromium in sewage
sludge to be converted to the hexavalent form. Analysis of laboratory combusted sludges
dosed with various levels of lime and ferric chloride revealed that the hexavalent to total
chromium ratio increased with lime dosage.1 One-hundred percent conversion of
chromium to hexavalent chromium was observed in several of the tests.1 These tests
indicate that when lime and ferric chloride are used as sludge conditioners, high ratios of
hexavalent to total chromium may be formed under certain incinerator operating
conditions.
EPA has previously sponsored emission testing studies for measurement of
hexavalent chromium at two sludge incinerators.24 For one site, the hexavalent
chromium concentrations were below the analytical detection limit; for the other site, a
hexavalent-to-total chromium ratio of 13% was calculated. The 1% value chosen for the
draft regulations may seem low. This is the result, however, of weighting various values
to give the most credible ones more influence. With this approach, lower values were
assigned a stronger contribution. The lack of a substantial data base on hexavalent
chromium emissions prompted the following statement in the EPA's Technical Support
Document for the Incineration of Sewage Sludge: "EPA plans to perform additional tests
of sewage sludge incinerator emissions for hexavalent chromium before this proposed
rule is finalized. The additional data should allow the Agency to better understand how
hexavalent chromium is generated in sewage sludge incinerators." As previously stated,
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EPA assumed that 100% of the nickel emissions are in the subsulfide form to calculate
an RSC. Since the Agency had no nickel subsulfide emission data from sewage sludge
incinerators, it took the most conservative approach in conducting the nickel risk analysis
and assumed that all emitted nickel compounds cause the same health effects as nickel
subsulfide. Again, the Technical Support Document stated: "As additional data become
available on the form of chromium and nickel emissions from combustion sources, the
Agency will consider what changes, if any, would be appropriate for these proposed
regulations."
There were no published EPA emission measurement test methods for the
sampling and analysis of hexavalent chromium or nickel subsulfide. In addition, very
little data exist on the conditions that may cause their formation. The primary objectives
of the RREL/OW research described in this report were to implement sampling and
analysis procedures to determine the ratio of hexavalent to total chromium and the ratio
of nickel subsulfide to total nickel in sewage sludge incinerator emissions under varied
excess air incinerator operating conditions. High excess air in the furnace presents
conditions favorable for the formation of hexavalent chromium; low excess air presents
conditions favorable for the formation of nickel subsulfide. The effect of lime
conditioning on the conversion of total chromium in the sludge to hexavalent chromium
emissions was also a primary concern at this test site. Based on the results under normal
to high excess air, the test program was modified on-site to reflect normal and improved
combustion conditions (reduced CO and THC levels). Secondary objectives include
comparing the results for emissions of chromium and nickel subspecies determined by
different analytical procedures, as well as gathering data on other metals and inorganic
and organic gaseous components in uncontrolled and controlled incinerator emissions.
Continuous emissions monitoring of oxygen (02), carbon dioxide (C02), carbon monoxide
(CO), sulfur dioxide (S02), and oxides of nitrogen (NO,) at the control system inlet and
CO and total hydrocarbons (THC) at the control system outlet stack were used to
establish process and control equipment operation during the manual testing and to
provide additional emissions data.
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This report presents the results for the Site 9 test program, the second in a series
of five emission tests (Sites 5, 6, 7, 8 and 9) completed for this portion of RREL's
research program. This report is organized in two volumes. The Emission Report is
contained in Volume m, while the Appendices are included in Volume IV.
The following sections present detailed descriptions of the testing and results from
the Site 6 program. Section 2.0 presents a summary of the results. Section 3.0 presents
the process description and process operating conditions. Section 4.0 provides a detailed
discussion of the sampling and analytical results. Section 5.0 describes the sampling
location and procedures and Section 6.0 describes the analytical procedures. The quality
assurance/quality control activities and results are presented in Section 7.0.
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2.0 SHE 6 TEST SUMMARY
2.1 TESTING PROGRAM DESIGN
The main emphasis for the testing at Site 6 was to determine the effect of lime
conditioning and excess air on the conversion of total chromium in the sludge to hexavalent
chromium emissions. The following criteria were considered in selecting this test site:
adequate levels of chromium and nickel in the sludge, suitable sampling locations, use of
lime in conditioning sludge, adequate latitude in control of excess air, multiple hearth
furnace, venturi scrubber capable of achieving medium to high pressure drops, and not
previously tested for RREL.
The incinerator emissions were tested under two operating conditions, high and low
levels of excess air in the furnace. High excess air in the furnace presents conditions
favorable for the formation of hexavalent chromium, and low excess air presents conditions
favorable for the formation of nickel subsulfide. In addition to speciation of chromium and
nickel emissions, sampling was also conducted for trace metals and continuous emissions
monitoring (CEM) techniques were used to measure 02) C02, CO, S02, and NOx at the
control system inlet and CO and THC at the control system outlet stack. The monitoring
data were used principally to determine process and control equipment operating conditions
during the chromium and nickel speciation tests.
The emission testing at Site 6 was conducted from October 9 to October 13, 1989.
The test program sampling matrix is shown in Table 2-1. Sampling was conducted at the
inlet and outlet of the venturi/impingement tray scrubber used to control the incinerator
emissions. Certain inlet and outlet flue gas conditions (see Table 2-1) were monitored
continuously while establishing incinerator operating conditions.
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TABLE 2-1. TEST PROGRAM SAMPLING MATRIX
Incinerator
Operating
Conditions
Flue Gas Samples*
Control Device
Inlet*
Control Device
Outlet
Solid/Liquid Samples
Sludgef
Scrubberf
Inlet Outlet
Ashf
Normal
Combustion
Low CO
and THC
Hexavalent Chromium Sampling
Cr+6 (F) Cr+6 (RC)
(4x3 runs) (4x3 runs)
CEMS (3 runs) CEMT (3 runs)
Nickel/Metals Sampling
Ni (2x3 runs) Ni (2x3 runs)
Mtl (1x3 runs) Mtl (1x3 runs)
CEMS (3 runs) CEMT (3 runs)
Hexavalent Chromium Sampling
Cr+6 (F) Cr+6 (RC)
(4x2 runs) (4x2 runs)
CEMS (2 runs) CEMT (2 runs)
Nickel/Metals Sampling
Ni (2x3 runs) Ni (2x3 runs)
Mtl (1x3 runs) Mtl (1x3 runs)
CEMS (3 runs) CEMT (3 runs)
3 runs
3 runs
3 runs 3 runs
3 runs 3 runs
3 runs
3 runs
3 runs
3 runs
3 runs 3 runs
3 runs 3 runs
3 runs
3 .runs
*Cr+6 (F) = Filter sampling train for hexavalent chromium.
Cr+6 (RC) = Recirculating sampling train for hexavalent chromium.
CEMS = Continuous emissions monitoring system (02, C02, CO, S02, N0X) .
CEMT = Continuous emissions monitoring system (O^, C02/ CO, S02, N0X, and THC).
Mtl = Multiple metals sampling train, included in the nickel train
Ni = Nickel sampling train
M3 = Method 3 sampling train for C02, 02
t Sludge was grab sampled and analyzed for metals, proximate and ultimate analysis;
scrubber water and ash were grab sampled and analyzed for metals.
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The specific elements and compounds of interest are presented in Table 2-2. A
summary of the sampling and analytical methods used to conduct the testing are presented
in Table 2-3. Two approaches were used for measuring the outlet emissions of
hexavalent chromium: (1) method 5-type sampling system and (2) a recirculating impinger
reagent sampling system. Only the Method 5-type of sampling system was used at the inlet
site for measurement of hexavalent chromium because a high temperature recirculating train
had not been built. Five runs were conducted at the inlet and outlet locations at Site 6 for
arsenic, beryllium, cadmium, chromium, lead, and nickel. The particulate emissions were
also determined using the multiple metals sampling system. Composite sludge feed
samples, bottom ash samples, and scrubber water inlet and outlet samples were taken during
each test series. The sampling and analytical methods are described in detail in Sections
5,0 and 6.0, respectively.
2.2 TEST PROGRAM RESULTS
This section summarizes the test results for the Site 6 test program. Site 6 was
originally scheduled for testing at two process operating conditions: (1) normal to high
excess air and (2) low excess air. Initial testing under normal combustion conditions
resulted in high emissions of CO and THC, which are associated with poor combustion
conditions. In response, the desired process operating conditions for the second series of
runs were modified from low excess air to setting incinerator conditions that would reduce
the levels of CO and THC. This modification was achieved by changing sludge feed rate
and the combustion air distribution and burning more auxiliary fuel oil. The emission
results and associated emission factors are highlighted in this section; the run by run data,
as well as the process sample results, are detailed in Section 4.0. The test program schedule
is presented in Section 2.2.1. Particulate and metal results are summarized in Section 2.2.2,
hexavalent chromium results are summarized in Section 2,2.3, nickel speciation results are
summarized in Section 2.2.4, total hydrocarbon (THC) and carbon monoxide (CO) results
are summarized in Section 2.2.5, and conclusions are presented in Section 2.2,6.
2-3
-------
TABLE 2-2. SPECIFIC ELEMENTS AND COMPOUNDS OF INTEREST
Metals* Chromium Speciest Nickel Species$Combustion Gas
and Criteria
Pollutants
Arsenic Hexavalent chromium Nickel sulfate 02
Beryllium Trivalent chromium Nickel sulfide C02
Cadmium Nickel subsulfide CO
Chromium Metallic nickel S02
Lead Nickel oxide NOx
Nickel THC
* These metals are of specific interest to OW. Analysis by
ICAP; chromium and nickel analysis also by XANES.
t The chromium subspecies are of interest to OW since their
contribution to total sludge incinerator chromium emissions has
been variable, thus giving unreliable estimates of total
chromium emissions,
$ Nickel subspecies are of interest to OW because no data are
available on nickel subsulfide.
2-4
-------
TABLE 2-3. SUMMARY OF SAMPLING AND ANALYTICAL METHODS
Sampling Location
Parameter
Sampling Method
Analysis Method
Inlet to the
•
Total chromium,
EPA Draft *-b
IC/PCR, gamma counter
Control Device
Cr + a
Cr+® Methods
Xanes, ICAP/AA
•
Total nickel,
EPA Draftc
EPA Draft Method,
nickel
Ni Method
Xanes, ICAP/AA
subsulfide
•
Particulates
EPA Draft
ICAP/AA
metals*
Ni Method
•
0 2, C02, CO
3A, 10, 7E
3A, 10, 7E
NOx, S02,
and 6C
and 6C
•
Fixed gases
Method 3
orsat
(02/ C02)
•
Moisture
Method 4
Gravimetric
Outlet to the
•
Total chromium,
EPA Draft #
-------
2.2.1 Test Program
The Site 6 test program schedule is summarized in Table 2-4. Included in the table
are the sampling locations, run numbers, sample times, incinerator operating conditions, and
comments on the sampling and incinerator operating conditions. Testing was conducted
with high THC and CO emissions (normal combustion) and with low THC and CO
emissions (improved combustion). Due to time limitations, one run was conducted during
the transition from normal combustion to improved combustion conditions.
2.2.2 Particulate/Metals Results
The particulate/metals train runs were conducted simultaneously with the nickel
speciation runs. Two runs (Runs 5 and 6) were conducted during normal incinerator
operations (high THC and CO), one run (Run 8) during transition from normal combustion
conditions to improved combustion conditions (low THC and CO), and two runs (Runs 10
and 12) during improved combustion conditions (low THC and CO). Run 8 is presented
with the low THC/CO runs. The results for all the metals except lead (see Table 2-5) were
similar. The lead emissions from the incinerator increased with the improved combustion
(higher furnace temperatures). The particulate and metal removal (collection) efficiency
of the venturi/tray scrubber control system is also presented in Table 2-5. The removal
efficiency for the particulate emissions averaged 98.1%. The removal efficiency for all the
metals was less than the particulate with the exception of chromium which was 99.3%. As
discussed in Section 4.3.2, the measured chromium emissions of the multiple metals train
are about one half of the measured chromium emissions using the hexavalent chromium
sampling train.
2.23 Hexavalent Chromium Results
The hexavalent chromium samples from the Method 5-type trains used to conduct
the inlet sampling and some of the outlet sampling were analyzed by EPA's Environmental
-------
TABLE 2-4. SUMMARY OF SCRUBBER INLET AND OUTLET FLUE GAS CONDITIONS
Flue Gas Conditions
Comments on sampling and
Incinerator Operating Conditions
Run No. &
Condition
Sampling
Location
Test
Date
Run Time
Temperature
<°F)
Moisture
(X H20)
Oxygen
(X dry)
Air Flow Rate
(dscm/min)
Run 2
Normal
Inlet
Outlet
10/09/89
10:10-11:10
1340
6.6
NA*
450.9
Outlet Cr+6 tests for EMSL, data not released
Process data was not taken
Run 3
Normal
Inlet
Outlet
10/09/89
12:45-14:45
12:45-14:45
861
138
30.3
6.1
13.4
14.0
538.4
585.2
Clinkers were removed from furnace
Inlet Cr+6 data not released
Run 4
Normal
Inlet
Outlet
10/09/89
17:00-19:00
17:00-19:00
963
138
29.2
6.9
14.8
14.1
620.8
556.9
Uith 2 min left on test sludge was interrupted
and burnout occurred, should not effect results
Run 5
Normal
Inlet
Outlet
10/10/89
09:00-11:00
09:10-11:10
903
146
40.1
6.3
10.3
13.2
378.1
520.5
Sludge cake which was high in moisture,
lime added. Feed stopped at end of run.
Run 6
Normal
Inlet
Outlet
10/10/89
14:15-16:15
14:30-17:00
928
144
34.9
6.5
12.7
14.4
369.8
466.5
Lost scrubber water at 14:45. Outlet tests
stopped and restarted when water flow resumed.
Run 7
Normal
Inlet
Outlet
10/10/89
18:50-20:50
18:37-21:37
820
135
32.3
7.3
13.5
14.2
451.1
498.3
Sludge cake wet and low in volatiles, more
burners were added to maintain temperatures
Run 8
Transition
Inlet
Outlet
10/11/89
09:45-11:45
09:45-11:45
1045
155
40.9
7.4
9.1
11.9
353.6
463.6
Low 02 caused a lot of smoking during first
part of the sample run.
Run 9
Low CO
Inlet
Outlet
10/11/89
16:22-18:22
15:43-18:43
1084
149
34.5
6.9
11.5
13.4
505.9
634.1
Low CO was achieved with additional burners
to obtain a high Hearth #1 temperature.
Run 10
Low CO
Inlet
Outlet
10/12/89
09:00-11:00
09:00-11:00
1014
143
32.7
7.3
11.5
13.2
372.1
454.2
Fuel pump failure for very short period.
Run 11
Lou CO
Inlet
Outlet
10/12/89
13:15-15:15
12:31-15:31
1050
148
33.1
8.1
11.5
13.1
522.0
629.0
No problems
Run 12
Low CO
Inlet
Outlet
10/12/89
17:45-19:45
17:32-19:32
962
150
32.5
6.6
11.6
13.6
319.6
407.2
No problems
Run 13
Normal
Inlet
Outlet
10/13/89
09:00-11:00
09:00-13:00
783
171
31.9
7.4
13.4
14.5
493.9
578.8
No problems
* Not available
-------
TABLE 2-5. SUMMARY OF INLET AND OUTLET PARTICULATE AND METALS
MASS EMISSION RATES
Run No. and
Location
Particulate
Hass Rate
(kg/hour)
Flue Gas Hetal Mass Emission Rate (mg/hour)
Arsenic
Berylliun
Cadmium
Chromim
Lead
Nickel
Run 5
Inlet
Outlet
50.8
0.7
< 969
< 521
16.9
< 2.3
5650
1260
14600
65.8
83000
16700
1470
90.7
Efficiency*,*
98.6
NAf
> 86.6
77.7
99.5
79.9
93.8
Run 6
Inlet
Outlet
37.0
0.6
< 761
< 591
16.6
< 2.6
3710
1380
11200
113
42400
19300
1110
79.7
Efficiency,*
98.4
NA
> 84.5
62.9
99.0
54.5
92.8
Run 8
Inlet
Outlet
19.8
1.1
< 860
< 531
11.2
2,3
11100
2590
8990
164
148000
30500
1010
109
Efficiency,*
94.6
NA
79.4
76.8
98.2
79.4
89.2
Run 10
Inlet
Outlet
34.4
0.7
< 787
< 573
13.7
< 2.5
5130
1200
11900
47.3
94700
22500
1140
34.9
Efficiency,*
97.8
NA
> 81.8
76.7
99.6
76.2
96.9
Run 12
Inlet
Outlet
47.1
0.6
< 926
< 278
20.1
1.2
4750
987
15100
26.5
89000
19400
1300
44.7
Efficiency,*
98.8
NA
94.0
79.2
99.9
78.2
96.6
Runs 5 and 6
Inlet
Outlet
43.9
0.6
< 865
< 556
16.7
< 2.4
4680
1320
12900
89.5
62700
18000
1290
85.2
Efficiency,*
98.5
NA
> 85,5
71.9
99.3
71.3
93.4
Runs 8,10,&12
Inlet
Outlet
33.8
0.8
< 858
< 461
15.0
< 2.0
7000
1590
12000
77.3
110000
24100
1150
62.7
Efficiency,*
97.6
NA
> 86.7
77.3
99.4
78.1
94.5
Total Average
Inlet
Outlet
38.8
0.7
< 862
< 508
15.9
< 2.2
5840
1450
12400
83.3
86600
21100
1220
73.9
Efficiency,*
98.1
NA
> 86.1
75.1
99.3
75.7
93.9
* Collection efficiency of air pollution control system,
t Not applicable.
2-8
-------
Monitoring Systems Laboratory (EMSL) in Cincinnati, Ohio. The data from these trains
have not been released for publication by EMSL and will not be presented in this report.
The hexavalent chromium results for the recirculating reagent sampling train
testing conducted at the outlet are shown in Figure 2-1 where the ratio of hexavalent
chromium to total chromium is plotted against the combustion efficiency factor (CO
divided by CO:). Three runs (Runs 3, 7 and 13) were conducted during normal
combustion and two runs (Runs 9 and 11) were conducted during improved combustion.
Run 7 has been excluded from the plot which shows a direct relationship between good
combustion and higher concentrations of hexavalent chromium. During normal
combustion (higher THC and CO), the hexavalent chromium constituted only 1% of the
total chromium emissions; during good combustion, the hexavalent chromium constituted
about 8% of the total chromium emissions. A primary concern with draft sampling
methods for hexavalent chromium is the conversion of the collected hexavalent
chromium to trivalent chromium in the sampling system. During the Site 6 testing
program an average of about 10% of the internal isotopically labeled hexavalent
chromium was converted to trivalent chromium. The new procedure instituted for this
test program resulted in the 10% loss of hexavalent chromium. These results were the
best performance of many draft sampling procedure to this point.
2.2.4 Nickel Speciation
The nickel speciation runs were conducted simultaneously with the particulate/
metals train runs. Two runs (Runs 5 and 6) during normal incinerator combustion
conditions, one run (Run 8) during the transition from normal to improved combustion,
and two runs (Runs 10 and 12) during improved combustion (Low CO and THC) were
conducted. Nickel subsulfide cannot be measured directly at levels encountered in these
emissions. A wet chemical technique was used to measure sulfidic nickel, the
combination of both nickel sulfide and nickel subsulfide. No sulfidic nickel was detected
for any of the outlet runs. It was detected in only one of the inlet samples and only at
2-9
-------
Outlet emissions data (excludes Run 7)
Run 11
Run 9
r = -0.98
Run 3
Run 13
60 80 100
CO to C02 Ratio (ppm to %)
120
Figure 2-1. Cr+6 to total chromium versus CO to C02 ratios.
2-10
-------
the limit of detection which may not be a reliable number. Considering the limit of
detection at the outlet, the nickel subsulfide constitutes less than 10% of the total nickel
emissions. Considering the limit of detection for the inlet, the nickel subsulfide
constitutes less than 12% of the total nickel emissions at this location.
2.2.5 Carbon Monoxide and Total Hydrocarbons
EPA is evaluating monitoring CO and THC emissions as a surrogate indicator of
organic emissions. Since no organic compound specific measurements were made at
this site, the relationship between CO and THC emissions under the tested conditions is
shown in Figure 2-2. When data from Run 5 are excluded, the correlation coefficient is
0.97 for the data from the 2- and 4-hr runs.
2.2.6 Conclusions
From a methods development and data quality perspective, the test program
conclusions are as follows:
1. The ratio of hexavalent chromium to total chromium is relatively high
(greater than 10%) when lime is used for sludge conditioning, during good
combustion conditions, and under the long residence times required for
combustion of sludge in a multiple hearth incinerator.
2. The ratio of nickel subsulfide to total nickel was less than detectable (less
than 12%) under both furnace operating conditions.
3. There was good correlation between CO emissions and THC emissions.
4. The recirculating impinger reagent train with certain post-sampling
procedural modifications yielded acceptable results for the measurement of
hexavalent chromium at the outlet.
5. The process operating conditions used for the final series of test runs at
Site 6 greatly reduced the level of CO and THC emissions by about 60%.
2-11
-------
Outlet emissions data (excluding Run 5)
30 r
28 -
26 -
E
24 -
Q_
Q- 22
CO
20
c
o
18 -
n
i_
CO
16 -
o
2
14 -
"a
1? -
>»
X
10
"O
8 -
o
O
6 -
4 -
2 -
0 -¦
0
r = 0.97
200 400 600
Carbon Monoxide (ppm)
800
Figure 2-2. Hydrocarbon emissions versus carbon monoxide emissions.
2-12
-------
3.0 PROCESS DESCRIPTION AND OPERATION
3.1 FACILITY DESCRIPTION
The Site 6 facility processes an average of 30 million gallons of wastewater per
day. The furnace operates 24 hours per day, 5 and three-fourth days a week. The
influent to the wastewater treatment facility comes from predominantly (98%) domestic
sources. The treatment facility serves a population of approximately 150,000.
Incoming wastewater is screened at four facilities at the plant and degritted at two
locations. Screenings and grit are hauled directly to the landfill. The primary treatment
consists of four side by side rectangular tanks which receive the degritted and screened
wastewater. A chain and flight collector mechanism moves the settled material (primary
sludge) to the influent end of the tank and the floating material (grease) to the effluent
end of the tank. The primary sludge is pumped to the gravity thickener; the grease is
hauled directly to the landfill.
The secondary treatment system consists of three side by side four-pass aeration
basins configured to operate in either a step feed or conventional plug flow mode.
Diffused air is used. Six circular clarifiers follow this treatment. The waste sludge from
this process is concentrated in a dissolved air floatation thickener. Only the three most
recent clarifiers have scum removal mechanisms. The secondary scum is pumped to the
primary clarifiers. Site 6 advanced treatment includes phosphorus removal. Sludge
generated by this process goes to the primary clarifiers.
All sludge is dewatered prior to incineration to reduce the water content of the
sludge cake to between 70 to 75% by weight. Dewatering is a critical step in the process
of sludge incineration, because it reduces the thermal demand on the incinerators. A
gravity thickener is used to increase the percentage of solids in the primary sludge. A
3-1
-------
floatation thickener processes the secondary sludge. The combined thickened sludge for
those thickeners is then pumped into a storage tank. Lime slurry and ferric chloride
solution are used to condition the sludge drawn from the storage tank. Four recessed
plate filter presses are available to dewater the conditioned sludge.
The incinerator tested at Site 6 was one of the two identical Nichols eight hearth
incinerator which are 22 ft 3 in outside diameter and operates in an excess air mode.
The air pollution control system associated with this incinerator consists of an
afterburner (which was not used during the test program), a water injection venturi, and
an impingement tray scrubber. The incinerator and flue gas treatment system are
discussed in greater detail in Section 3.2.
A heat recovery system was installed at the facility but was not functional during
the testing program.
3.2 INCINERATOR AND POLLUTION CONTROL SYSTEM
Site 6 has two identical 22 ft 3 in Nichols eight-hearth, multiple hearth furnaces
(MHF). Only one of the furnaces is operated at a time. A schematic diagram of the
MHF and its pollution control system are presented in Figure 3-1. On most MHFs, the
sludge is dropped in through the top, but on this furnace, originally designed for pyrolysis
operation, the sludge is screwed into side of Hearth #1. Many MHFs use recycled shaft
cooling air to reduce auxiliary fuel consumption. However, Site 6 does not use recycled
shaft cooling air due to problems associated with the original design. Air for combustion
is admitted through atmospheric ports located in Hearth #7 and Hearth #8. The
position of the atmospheric port dampers is controlled with manual loading stations
located in the control room. The auxiliary fuel system is oil fired and two (2) burners
are located on each of Hearths #2, #4, #5, and #7. Incinerator design data are
presented in Table 3-1.
The air pollution control system consists of an adjustable throat venturi scrubber
followed by a two (2) plate, impingement tray scrubber. The tray scrubber flue gas exit
temperature is nominally 100°F. The position of the venturi adjustable throat is
3-2
-------
Outlet
Stack
Shaft
Cooling Air.
Dewatered
Sludge
Bypass Stack
©
Scaibber
Inlet
Control Devices
Sampling
Locations
Venturi
Scrubber
to
Water
Bottom
Ash
Flooded
Elbow
3L
Ill
Conveyor System to Ash Disposal
nlet
I.D.
Fan
Impingement
Tray
Scrubber
¦Outlet to
Control Devices
Sampling
Location
Figure 3-1. Process diagram with sampling locations.
-------
TABLE 3-1. INCINERATOR DESIGN INFORMATION
Design Parameter
Incinerator
Manufacturer
Outside Diameter
Number of Hearths
Recommended Sludge Feed Rate
Exhaust Gas Volume (fan rating)
Excess Air
Oxygen: Furnace Exhaust
Fuel
Operating Period
Pollution Control System
Venturi
Tray Scrubber
Sludge Feed
Moisture
Solids
Combustible solids
Ash
Heating Value
Value
Nichols
22 ft - 3 in
8
13,500 lb/hr (wet)
11,518 acfm @ 120 °F
50 - 125%
7 - 13% Auxiliary
Oil
24 hr/day
Normal
233 gpm
776 gpm
72% by wt
28% by wt (wet basis)
60% by wt (dry basis)
35% by wt (dry basis)
6,000 Btu/lb
3-4
-------
controlled with a manual loading station located in the control room.
The sludge feed to the system is very erratic due to the nature of the dewatering
system. The plate and frame filter presses drop sludge into a bunker where the sludge is
removed by drag conveyors and deposited onto a belt conveyor system and transported
to the furnace. The feed rate is not measured directly and the speed of the drag
conveyor is the only indication of the sludge feed rate. Using plant historical data, the
sludge feed rate was estimated to be 1.6 dry tons per hour during the testing period. At
this site, sludge consistency is also a problem. During the testing period, wide swings in
sludge moisture sometimes occurred with each drop of sludge from the filter presses.
3.3 INCINERATOR OPERATING CONDITIONS DURING TESTING
The emission testing at Site 6 was conducted under two separate modes of
incinerator operation. The first mode is called "normal operation" which generally
results in high levels of carbon monoxide and total hydrocarbons and also a noticeably
visible yellow/brown exhaust stack gas. The second mode was an improved operation
and resulted in significantly lower emissions of carbon monoxide and total hydrocarbons
as well as reduced stack opacity. This test condition is referred to as "low CO".
The furnaces were originally designed for pyrolysis operation; therefore, the
auxiliary fuel burner capacity is extremely limited as indicated by the fact that there are
only two (2) burners per hearth instead of the more typical four (4) per hearth. To
achieve good combustion under the improved conditions (low CO) mode, which requires
higher Hearth #1 temperatures, it was necessary to fire burners in Hearths #2, #4, and
#5 to raise the temperature in Hearth #1. The very high temperatures in Hearth #3
and Hearth #5 during the improved combustion runs probably contributed to raising the
level of heavy metals (particularly lead) emissions.
Figures 3-2 through 3-6 are graphs of the furnace temperature profile during Runs
3, 4, 5, 9, and 13. Runs 3 through 5 are typical of normal mode of operation. Run 9 is
typical of improved combustion and Run 13 is an exceptionally steady run in the normal
mode.
3-5
-------
Run #3
u>
I
Ch
1.80
EXHAUST
H-1
1.70 -
1.60 -
1.50 -
o) 1.40 -
r-2 1.30-
1.20-
LUl— 1-10 —
111 1.00
0.90 -
0.80 -
0.70 -
12:30 PM 12:45 PM 01:00 PM 01:30 AM
TIME ON 10/9/90
02:00 PM
02:30 PM
Figure 3-2. Hearth temperature profile during Run 3 - normal mode of operation.
-------
Run #4
1.80
1.70 -
1.60 -
1.50
< >
1.40 -
o>
„ 1 Of) -
uj-a 1 ,ou
tec
1.20-
-------
Run #5
1.80
1.70
1.60
1.50
UL
1.40
CD
1.00
LU
0.90
EXHAUST
H-3
0.80
-t- H-1
H-2
H-5
0.70
0.60 H
09:30 AM
10:30 AM
11:00 AM
10:00 AM
TIME ON 10/10/90
Figure 3-4. Hearth temperature profile during Run 5 - normal mode of operation.
-------
i
VO
1.80
1.70 -
1.60 -
1.50 -
? 1.40 -J
ulS 1 -30 -f
'CC c
—I ro
1.20 H
-------
Run #13
i
o
1.60 -
1.50 -
9 1-40"
uj"o 1 -30
pw 1.20-
Sh 1.10
1.00 -
0.90 -i
0.80 -
0.70 -
08:00 AM
¦ EXHAUST
+ H-1
o H-2
A H-3
X H-4
* H-5
09:00 AM 10:00 AM
TIME ON 10/13/90
11:00 AM
01:00 PM
Figure 3-6. Hearth temperature profile during Run 13 - normal mode of operation.
-------
3.4 PROCESS DATA RESULTS
To ensure that the incinerator was operated in a manner to meet program goals,
F. Michael Lewis was contracted to monitor and record operations and operate the
furnace during special conditions (i.e., low CO condition). Each of the test runs
conducted at Site 6 are listed in Table 3-2 along with the operating conditions and the
average run values for all hearth temperatures. The auxiliary fuel usage, flue gas
temperatures, pressure drop across the venturi scrubber and venturi scrubber/
impingement tray scrubber, and THC and CO concentrations are presented in Table 3-3.
The sludge feed varied from 3,300 lb/hr to 4,100 lb/hr over the testing period. The
differential pressure drop across the venturi scrubber ranged from 24 inches water
column (in w.c.) to 30 in w.c. and across the venturi scrubber/impingement tray scrubber
ranged from 31 in w.c. to 36 in w.c. During the "normal11 furnace conditions, the THC
and CO emissions averaged 22.8 ppm and 652 ppm, respectively. During the "low CO"
furnace conditions, the THC and CO emissions averaged 7.8 ppm and 322 ppm,
respectively.
3-11
-------
TABLE 3-2. SUMMARY OF HEARTH TEMPERATURES FOR SITE 6
Hearth#1
Hearth#2
Hearth#3
Hearth#4
Hearth#5
Hearth#6 Hearth#7 Hearth#8
Comment(s) on Furnace Operations
Run No. /
Temp
Temp
Temp
Temp
Temp
Temp
Temp
Temp
Condition
(OF)
(OF)
(OF)
(OF)
(OF)
(OF)
(OF)
(OF)
Run 3
881
1091
1223
1433
1396
585
190
96
Clinkers uere removed
Normal
(160)*
(280)
(310)
(65)
(205)
• (40)
(30)
(5)
from furnace
Run 4
996
1428
1586
1331
1029
378
136
89
With 5 min left in run feed was
Normal
(A3)
(73)
(68)
(18)
(53)
(53)
(13)
(3)
interrupted & burn out occurred
Run 5
935
1162
1305
1565
1220
490
135
90
Problem uith sludge cake, high
Normal
(45)
(80)
(90)
(95)
(30)
(60)
(5)
(0)
lime added; feed stopped at 11:00
Run 6
961
1176
1277
1470
1246
577
170
90
Lost scrubber uater at 14:45
Normal
(65)
(153)
(175)
(168)
(200)
(73)
(25)
(5)
Outlet tests stopped
Run 7
848
946
1037
1307
1286
678
320
133
Sludge cake uas uet, more
Normal
(65)
(138)
(148)
(183)
(368)
(183)
(200)
(53)
burners added
Run 8
993
1366
1470
1527
1300
550
163
97
Lou 02 caused a lot of
Transition
(144)
(258) *
(270)
(90)
(210)
(60)
(8)
(3)
smoking
Run 9
1018
1474
1598
1286
1006
316
127
90
Low CO uas achieved with a
Lou CO
(60)
(145)
(165)
(80)
(50)
(40)
(8)
(0)
high Hearth #1 temperature
Run 10
931
1225
1335
1472
1505
602
200
97
Fuel pump failure for very
Lou CO
(93)
(225)
(230)
(120)
(255)
(160)
(35)
(5)
short period
Run 11
1025
1515
1660
1307
1082
365
147
96
No problems
Lou CO
(70)
(60)
(40)
(70)
(55)
(75)
(10)
(5)
Run 12
1096
1413
1600
1146
960
270
126
96
No problems
Lou CO
(50)
(20)
(10)
(30)
(20)
(10)
(5)
(5)
Run 13
827
965
1125
1362
1345
537
155
102
No problems
Normal
(20)
(30)
(75)
(40)
(80)
(30)
(20)
(5)
* ( > -
Indicates the
temperature
range
above
and below
average
for the test run.
-------
TABLE 3-3. FURNACE AND CONTROL EQUIPMENT OPERATIONS
Run No. Auxiliary Fuel Usage (% output) Venturi Scrubber Sludge Outlet Cone.
Condition Oil Burned Numbers AP AP Feed Rate CO THC
2-1 2-2 4-1 4-2 5-1 5-2 7-1 7-2 (in WC) (in WC) lb/hr (ppm) (ppm)
Run 3
Normal
10
20
20
0
0
0
0
0
26
31
4100
. 673
22.6
Run 4
Normal
0
35
40
40
0
0
0
0
24
31
4100
359
12.4
Run 5
Normal
40
25
0
90
90
0
0
0
28
34
3600
903
45.6
Run 6
Normal
5
5
60
60
50
0
0
0
28
34
3600
608
18.0
Run 7
Normal*
80
100
100
100
15
0
0
0
26
35
3600
810
22.2
Run 8
Transition
100
100
85
85
45
5
0
0
29
36
3700
701
21.4
Run 9
Low CO
100
100
100
100
60
40
0
0
29
36
3700
332
7.5
Run 10
Low CO
100
100
80
80
80
80
0
0
29
35
3300
337
8.8
Run 11
Low CO
100
100
100
100
100
100
0
0
29
36
3300
313
7.5
Run 12
Low CO
100
100
100
100
100
100
0
0
31
36
3300
308
7.3
Run 13
Normal 0 0 20 20 20 20 0 0 30 36 3400 554 16.2
* Sludge was wet and low in volatiles, so burners were used to maintain temperature.
-------
4.0 TEST RESULTS
The results of the emission tests performed at Site 6 from October 9 to October
13, 1989 are presented in this section. Site 6 is a typical multiple hearth incinerator
equipped with a venturi scrubber/impingement tray scrubber combination to control
emissions. This site was selected for testing principally because (1) the sludge is
conditioned with lime and (2) a measurable amount of total chromium is introduced into
the process as a contaminant in the ferric chloride used to improve sludge filtration
characteristics. The primary objective of this test program was to determine the effect of
lime conditioning and excess air on the conversion of total chromium in the sludge to
hexavalent chromium emissions. Site 6 was originally scheduled for testing under two
process operating conditions: (1) normal to high excess air and (2) low excess air. The
emissions testing under the first condition showed high emissions of CO and THC, which
are associated with poor combustion. It was decided that the second series of tests
should be conducted under incinerator conditions that would reduce the levels of CO
and THC indicating improved combustion rather than low excess air. The CO and THC
emissions were reduced by changing the sludge feed rate, combustion, air distribution,
and using more fuel oil. The two test conditions are referred to in the text and tables as
"Normal" and "Low CO." One run (Run 8) was conducted during the transition from
normal to improved combustion conditions and is referred to as "Transition".
In addition to the presentation of the results, variability and outliers in the data
are discussed. The incinerator operating conditions and other process parameters are
discussed in relation to the results; however, a complete statistical analysis of the
emission results relating to the operating conditions is not included in this report.
Results are presented in metric units. Flue gas results are presented as measured
and as normalized to an equivalent 7% 02 concentration. Mass emission rates are also
4-1
-------
presented for each of the parameters. In addition, emission factors relating stack
emissions to sludge feed composition and rates are presented where appropriate.
Supporting data for the results presented in this section are included in the appendices in
Volume IV.
4.1 FLUE GAS CONDITIONS
A summary of the Site 6 inlet and outlet flue gas conditions is presented in Table
4-1, along with the run numbers, test dates, and run times. A summary of inlet and
outlet continuous monitoring measurements is present in Table 4-2.
4.1.1 Inlet Flue Gas Conditions
The flue gas volumetric flow rates at the inlet location were fairly consistent
averaging 475 dry standard cubic meters per minute (dscm/min) for normal operating
conditions and 430 dscm/min for low CO conditions. The inlet flue gas flow rate was
calculated by correcting the measured outlet flue gas flow rate with the difference
between the outlet and inlet oxygen concentrations. The average flue gas temperature
was 876°F (469°C) under normal operating conditions and 1027°F (553°C ) under low CO
conditions with moisture contents of 33.1% and 33.2%, respectively. The average
percentages of dry oxygen and carbon dioxide were 13.0 and 7.4, respectively under
normal conditions and 11.5 and 7.7, respectively under low CO conditions. The average
CO concentrations were 1290 and 620 ppm corrected to 7% 02 under normal and low
CO operating conditions, respectively.
4.1.2 Outlet Flue Gas Conditions
The average flue gas volumetric flow rates at the outlet sampling site ranged from
522 dscm/min under normal operating conditions to 531 dscm/min under low CO
conditions. Flue gas average temperatures were 144°F (62.4°C) under normal operating
4-2
-------
TABLE 4-1. SUMMARY OF INLET AND OUTLET FLUE GAS CONDITIONS
Flue Gas
Conditions
Run No. &
Condition
Sampling
Location
Test
Date
Run Time
Temperature
(F)
Moisture
(X H20)
Oxygen
(X dry)
Flow Rate
(dscm/min)
Run 2
Normal
Inlet*
Outlet
10/09/89
10:10-11:10
139.4
6.6
NA*
450.9
Run 3
Normal
Inlet
Outlet
10/09/89
12:45-14:45
12:45-14:45
861.1
138.1
30.3
6.1
13.4
14.0
538.4
585.2
Run 4
Normal
Inlet
Outlet
10/09/89
17:00-19:00
17:00-19:00
962.5
137.7
29.2
6.9
14.8
14.1
620.8
556.9
Run 5
Normal
Inlet
Outlet
10/10/89
09:00-11:00
09:10-11:10
902.7
146.2
40.1
6.3
10.3
' 13.2
378.1
520.5
Run 6
Normal
Inlet
Outlet
10/10/89
14:15-16:15
14:30-17:00
928.0
143.8
34.9
6.5
12.7
14.4
369.8
466.5
Run 7
Normal
Inlet
Outlet
10/10/89
18:50-20:50
18:37-21:37
819.8
135.0
32.3
7.3
13.5
14.2
451.1
498.3
Run 8
Transition
Inlet
Outlet
10/11/89
09:45-11:45
09:45-11:45
1045.2
155.0
40.9
7.4
9.1
11.9
353.6
463.6
Run 9
Low CO
Inlet
Outlet
10/11/89
16:22-18:22
15:43-18:43
1084.1
148.7
34.5
6.9
11.5
13.4
505.9
634.1
Run 10
Low CO
Inlet
Outlet
10/12/89
09:00-11:00
09:00-11:00
1013.7
143.2
32.7
7.3
11.5
13.2
372.1
454.2
Run 11
Low CO
Inlet
Outlet
10/12/89
13:15-15:15
12:31-15:31
1049.3
147.6
33.1
8.1
11.5
13.1
522.0
629.0
Run 12
Low CO
Inlet
Outlet
10/12/89
17:45-19:45
17:32-19:32
962.1
149.7
32.5
6.6
11.6
13.6
319.6
407.2
Run 13
Normal
Inlet
Outlet
10/13/89
09:00-11:00
09:00-13:00
783.1
170.8
31.9
7.4
13.4
14.5
493.9
578.8
* Not available.
4-3
-------
TABLE 4-2. SUMMARY OF INLET AND OUTLET CONTINUOUS EMISSION
MEASUREMENTS
Run No. &
Condition
Sampling
Location
Test
Date
Diluent (X dry)
Pollutant Gases (actual ppm and/or corrected to 7% 0,)
Carbon
Oxygen Dioxide
Sulfur Dioxide
Actual 37% 02
Nitrogen Oxides
Actual 97% 02
Carbon Monoxide
Actual 97% 02
Cold THC
Actual
Run 3
Normal
Inlet
Outlet
10/09/89
13.4 6.3
14.0 5.8
41.5 76.9
21.4 43.1
153 284
142 286
702 1301
673 1357
22.6
Run 4
Normal
Inlet
Outlet
10/09/89
14.8 5.0
14.1 5.7
38.4 87.5
18.2 37.2
115 261
142 290
406 925
359 735
12.4
Run S
Normal
Inlet
Outlet
10/10/89
10.3 8,7
13.2 6.3
32.1 42.1
25.3 45.7
151 198
124 226
1023 1341
903 1631
45.6
Run 6
Normal
Inlet
Outlet
10/10/89
12.7 6.7
14.4 5.3
35.7 60.5
18.4 39.3
207 351
166 355
752 1275
608 1300
18.0
Run 7
Normal
Inlet
Outlet
10/10/89
13.5 6.0
14.2 5.3
29.9 56.2
21.8 45.2
214 401
165 342
894 1679
810 1681
22.2
Run 8
Transition
Inlet
Outlet
10/11/89
9.1 9.9
11.9 7.4
110 130
15.9 24.6
180 212
102 157
848 999
701 1083
21.4
Run 9
Low CO
Inlet
Outlet
10/11/89
11.5 7.6
13.4 6.2
39.7 58.7
16.0 29.7
192 284
133 247
445 659
332 615
7.5
Run 10
Low CO
Inlet
Outlet
10/12/89
11.5 7.8
13.2 6.3
58.0 85.8
18.6 33.6
177 262
141 255
424 627
337 609
8.8
Run 11
low CO
Inlet
Outlet
10/12/89
11.5 7.8
13.1 6.4
65.0 97.2
5.4 9.6
159 238
127 225
395 590
313 557
7.5
Run 12
Low CO
Inlet
Outlet
10/12/89
11.6 7.7
13.6 6.1
45.9 68.6
8.6 16.4
166 249
114 217
403 603
308 587
7.3
Run 13
Normal
Inlet
Outlet
10/13/89
13.4 6.1
14.5 5.3
26.2 48.6
22.7 49.3
191 353
147 320
659 1220
554 1203
16.2
4-4
-------
conditions and 147°F (64.1°C) under low CO conditions with moisture contents of 6.7%
and 7.2%, respectively. The average percentages of dry oxygen and carbon dioxide were
14.1 and 5.6, respectively, under normal operating conditions and 13.3 and 6.3,
respectively, under low CO condition, while the carbon monoxide levels corrected to 7%
oxygen for the normal and low CO conditions were 1318 and 592 ppm, respectively. The
THC emissions measured under the normal and low CO conditions were 24 and 8 ppm,
respectively.
4.2 PARTICULATES/METAL RESULTS
Particulates/metal emissions were determined using the draft EPA method
procedure for "Methodology for the Determination of Trace Metals Emissions in
Exhaust Gases for Stationary Source Combustion Processes" (reproduced in Volume IV:
Site 6 Draft Test Report, Appendices)
Five runs (Runs 5, 6, 8, 10, and 12) were conducted at the inlet and outlet of Site
6 for arsenic (As), beryllium (Be), cadmium (Cd), chromium (Cr), lead (Pb), and nickel
(Ni). The particulate emissions were determined using the multiple metals sampling
system. The emission results for metals and particulates are shown in Table 4-3 on a
concentration basis and in Table 4-4 on a mass emission rate basis. The removal
efficiency for particulates and metals are also shown in Table 4-4.
For Condition 1 "Normal Operation", test runs were conducted over a 2-hr period
with no special effort taken to control the incinerator operating conditions. For
Condition 2, the test runs were also conducted over a 2-hr period, with the incinerator
operated to minimize CO and THC emissions as indicated by the continuous emission
monitoring results. For the inlet sampling, high moisture content required use of a large
first impinger in the particulates/metals train. Results from the test program provide
data on average emissions from sludge incinerators during typical operations (steady-
state and transient operating conditions) and under optimum combustion conditions.
Research Triangle Institute (RTI) analyzed all the total metals samples. Special
sample handling procedures were not required for these samples because mercury was
4-5
-------
TABLE 4-3. SUMMARY OF INLET AND OUTLET PARTICULATE MASS AND TARGET METALS
Run No. /
Location
Particulate
Mass
(mg/dscm)
Flue Gas Metals Concentration
(/xg/dscm)
Arsenic
Beryllium
Cadmium
Chromium
Lead
Nickel
Run 5
Inlet
Outlet
2239
22. 3
<
<
42.7*
16.7
<
0.74
0.07
249
40.3
642
2.1
3660
535
64.8
2.9
Run 6
Inlet
Outlet
1666
21.3
<
<
34.3
21.1
<
0.75
0.09
167
49.1
504
4.0
1910
689
50.1
2.8
Run 8
Inlet
Outlet
934
38.7
<
<
40.5
19.1
0.53
0. 08
525
93.0
424
5.9
6960
1096
47.4
3.9
Run 10
Inlet
Outlet
1542
27.2
<
<
35. 2
21.0
<
0.61
0.09
230
43.9
531
1.7
4244
826
50.9
1.3
Run 12
Inlet
Outlet
2457
24. 1
<
<
48.3
11.4
1. 05
0.05
248
40.4
786
0.8
4641
795
67.8
1.8
Avg. Normal
Inlet
Outlet
1953
21.8
<
<
38.5
18.9
<
0.7
0.1
208
44.7
573
3.1
2785
612
57.5
2.9
Avg. Low CO
Inlet
Outlet
1644
30.0
<
<
41.4
17.2
<
0.7
0.1
334
59.1
580
2.8
5282
906
55.4
2.3
Test Average
Inlet
Outlet
1799
25.9
<
<
39.9
18.0
<
0.7
0.1
271
51.9
577
2.9
4033
759
56.4
2.6
* < - Below the level of detection, less than indicated detection limit.
-------
TABLE 4-4. SUMMARY OF INLET AND OUTLET PARTICULATE AND METALS
MASS EMISSION RATES
Run No. and
Locations
Particulate
Mass Rate
(kg/hour)
Flue Gas Metal Mass Emission Rate (mg/hour)
Arsenic
Beryl Iiun
Cadmium
Chromiun
Lead
Nickel
Run 5
Inlet
Outlet
50.8
0.7
<
<
969
521
16.9
< 2.3
5648
1258
14564
65.8
83037
16710
1471
90.7
Efficiency*,*
98.6
NAf
> 86.6
77.7
99.5
79.9
93.8
Run 6
Inlet
Outlet
37.0
0.6
<
<
761
591
16.6
< 2.6
3708
1375
11173
113
42374
19297
1112
79.7
Efficiency,*
98.4
NA
> 84.5
62.9
99.0
54.5
92.8
Run 8
Inlet
Outlet
19.8
1.1
<
<
860
531
11.2
2.3
11140
2586
8991
164
147661
30475
1006
109
Efficiency,*
94.6
NA
79.4
76.8
98.2
79.4
89.2
Run 10
Inlet
Outlet
34.4
0.7
<
<
787
573
13.7
< 2.5
5131
1196
11851
47.3
94744
22517
1136
34.9
Efficiency,*
97.8
NA
> 81.8
76.7
99.6
76.2
96.9
Run 12
Inlet
Outlet
47.1
0.6
<
<
926
278
20.1
1.2
4752
987
15081
26.5
88996
19432
1301
44.7
Efficiency,*
98.8
NA
94.0
79.2
99.9
78.2
96.6
Ave. Normal
Inlet
Outlet
43.9
0.6
<
<
865
556
16.7
< 2.4
4678
1317
12868
89.5
62705
18003
1292
85.2
Efficiency,*
98.5
NA
> 85.5
71.9
99.3
71.3
93.4
Avg. Low CO
Inlet
Outlet
33.8
0.8
<
<
858
461
15.0
< 2.0
7007
1590
11974
77.3
110467
24141
1147
62.7
Efficiency,*
97.6
NA
> 86.7
77.3
99.4
78.1
94.5
Test Average
Inlet
Outlet
38.8
0.7
<
<
862
508
15.9
< 2.2
5843
1453
12421
83.3
86586
21072
1219
73.9
Efficiency,*
98.1
NA
> 86.1
75.1
99.3
75.7
93.9
* Control device removal efficiency,
t Not applicable.
4-7
-------
not measured, and the other target metals remain stable until analyzed.
A reagent blank was collected to assess background contamination levels of each
target metal. A complete discussion of Quality Assurance/Quality Control procedures
and results is presented in Section 7.0.
4.2.1 Control Device Inlet Results
The flue gas metals and particulate concentrations at the control device inlet are
shown in Table 4-5. The average values for "normal" (Runs 5 and 6) represent metals
emissions during normal furnace operations. The average values for "Low CO" (Runs 8,
10, and 12) represent metal emissions during improved combustion conditions. Arsenic
was below the level of detection, which was about 40 /tg/dscm for all inlet sample runs.
Since arsenic was below the level of detection for all samples it was decided not to have
them reanalyzed by GFAAS. The average beryllium concentration of 0.7 /ig/dscm was
the same for both operating conditions. The cadmium emission concentrations were
approximately the same for both conditions if the transition run (Run 8) is not
considered in the averages of 208 and 239 /tg/dscm for the normal and Low CO
conditions, respectively. The chromium emission concentrations were also similar for
both runs, averaging 573 and 580 /ig/dscm for the normal and low CO conditions,
respectively. The low CO conditions yielded a significant increase in the lead emission
concentrations with averages of 2785 and 5282 /ig/dscm for the normal and low CO
conditions, respectively. The nickel emissions were similar for both operating conditions
averaging 57.5 and 55.4 /tg/dscm for the normal and low CO conditions, respectively.
The particulate concentration were similar for both conditions and averaged 1950 and
2000 mg/dscm, respectively for the normal and low CO conditions.
The flue gas metal and particulate mass emission rates at the control device inlet
are shown in Table 4-6. Because the flue gas flow rate was consistent from run to run,
the mass emission rates showed the same correlations as the metal concentrations. The
metal mass emissions rates for the inlet runs averaged: arsenic - not detected (< 862
mg/hr), beryllium - 15.9 mg/hr, cadmium - 5,840 mg/hr, chromium - 12,400 mg/hr, lead
4-8
-------
TABLE 4-5. SUMMARY OF INLET PARTICULATE MASS AND TARGET METALS
Run No. and
Condition
Particulate
Mass
(mg/dscm)
Flue Gas
Metals
Concentration (g/dscm)
Arsenic
Beryllium
Cadmium
Chromium
Lead Nickel
Run 5
Normal
2239
< 42.7
0.74
249
642
3660
64.8
Run 6
Normal
1666
< 34.3
0.75
167
504
1910
50.1
Run 8
Transition
934
< 40.5
0.53
525
424
6960
47.4
Run 10
Low CO
1542
< 35.2
0.61
230
531
4244
50.9
Run 12
Low CO
2457
< 48.3
1.05
248
786
4641
67.8
Runs 5 & 6
Normal
1953
< 38.5
0.7
208
573
2785
57.5
Runs 8,10,12
Low CO
1644
< 41.4
0.7
334
580
5282
55.4
Test Average
Inlet
1799
< 39.9
0.7
271
577
4033
56.4
-------
TABLE 4-6. SUMMARY OF INLET PARTICULATE AND METALS MASS EMISSION RATES
Run No. and
Locations
Particulate
Mass Rate
(kg/hour)
Flue
Gas Metals
Mass Emission Rate
(mg/hour)
Arsenic
Beryllium
Cadmium
Chromium
Lead
Nickel
Run 5
Normal
50.8
<
969
16.9
5648
14564
83037
1471
Run 6
Norma1
37. 0
<
761
16.6
3708
11173
42374
1112
Run 8
Transition
19.8
<
860
11.2
11140
8991
147661
1006
Run 10
Low CO
34.4
<
787
13.7
5131
11851
94744
1136
Run 12
Low CO
47.1
<
926
20.1
4752
15081
88996
1301
Runs 5 and 6
Normal
43.9
<
865
16.7
4678
12868
62705
1292
Runs 8,10,&12
Low CO
33.8
<
858
15.0
7007
11974
110467
1147
Total Average
Inlet
38.8
•
<
862
15.9
5843
12421
86586
1219
-------
- 86,600 mg/hr, and nickel - 1,220 mg/hr. The particulate mass emission rates were
similar under normal and low CO conditions and averaged 42.9 and 40.8 kg/hr,
respectively.
For each inlet sampling run, the micrograms of each target metal collected was
divided by the grams of particulate collected (see Table 4-7) to yield the concentration of
metal in the fly ash. All metal concentrations in the inlet fly ash samples were similar
under both combustion conditions with the exception of the lead concentrations which
were almost twice as much for the Low CO conditions because of the higher furnace
temperatures. The metals concentrations in terms of microgram of metal per gram of
particulate for the inlet sampling runs averaged: arsenic - not detected (<18 ng/g),
beryllium - 0.43 /tg/g, cadmium - 205 /tg/g, chromium - 342 jig/g, lead - 2980 g/g, and
nickel - 34 /ig/g.
4.2.2 Control Device Outlet Results
The flue gas metals and particulate concentrations at the control device outlet are
shown in Table 4-8. The average values for Runs 5 and 6 represent metals emissions
during normal furnace operations. The average values for Runs 8, 10, and 12 represent
metal emissions during the improved combustion conditions. Arsenic emissions were
below the level of detection, which was about 18 jig/dscm for all outlet sampling runs.
The beryllium emissions were at or below the level of detection, which was about 0.1
/tg/dscm for all outlet runs. The cadmium emission concentrations were approximately
the same under both conditions when Run 8 (the transition run) is not included in the
averages of 44.7 and 42.2 jig/dscm for the normal and low CO conditions, respectively.
The chromium emission concentrations were also similar under both normal and low CO
conditions averaging 3.1 and 2.9 g/dscm, respectively. A greater control device removal
efficiency average of 906 fig/dscm was obtained for the higher emission concentrations of
lead encountered during the low CO conditions versus 612 jig/dscm under normal
operating conditions. The nickel emissions were similar under both normal and low CO
conditions and averaged 2.9 fig/dscm and 2.3 jig/dscm, respectively. The
4-11
-------
TABLE 4-7. SUMMARY OF METAL CONCENTRATIONS IN FLY ASH
Run No./
Location
Metals Concentration in Fly Ash
(^g metal/g particulate)
Beryllium
Cadmium
Chromium
Lead
Nickel
Run 5
Inlet
Outlet
0.33
< 3.3*
111
1811
287
111
1635
24046
29
131
Run 6
Inlet
Outlet
0.45
< 4.3
100
2301
303
211
1146
32301
30
133
Run 8
Inlet
Outlet
0.57
2.1
562
2401
455
163
7455
28296
51
101
Run 10
Inlet
Outlet
0.40
< 3.4
149
1613
345
81
2752
30387
33
47
Run 12
Inlet
Outlet
0.43
2.1
101
1676
320
55
1889
32992
28
76
Runs 5 & 6
Inlet
Outlet
0.39
< 3.8
106
2056
295
161
1390
28173
30
132
Runs 10 & 12
Inlet
Outlet
0.41
< 2.7
125
1645
333
68
2320
31689
30
61
Average
Inlet
Outlet
0.43
< 3.0
205
1960
342
124
2975
29604
34
97
* < - Below the level of detection, less than indicated
detection limit.
Note: Arsenic was below the limit of detection in all runs, inlet
values were less than 25 /ng and outlet less than 695 /ng.
4-12
-------
TABLE 4-8. SUMMARY OF OUTLET PARTICULATE MASS AND TARGET METALS
Run No. and
Location
Particulate
Mass
(mg/dscm)
Flue Gas Metals Concentration (|xg/dscm)
Arsenic
Beryllium
Cadmium
Chromium
Lead
Nickel
Run 5
Normal
22.3
< 16.7
< 0.07
40.3
2.1
535
2.9
Run 6
Normal
21.3
< 21.1
< 0.09
49.1
4.0
689
2.8
Run 8
Transition
38.7
< 19.1
0.08
93. 0
5.9
1096
3.9
Run 10
Low CO
27.2
< 21.0
< 0.09
43.9
1.7
826
1.3
Run 12
Low CO
24.1
< 11.4
0.05 '
40.4
0.8
795
1.8
Runs 5 & 6
Normal
21.8
< 18.9
< 0.1
44.7
3.1
612
2.9
Runs 8,10,12
Low CO
30.0
< 17.2
< 0.1
59. 1
2.8
906
2.3
Test Average
Outlet
25.9
< 18.0
< 0.1
51.9
2.9
759
2.6
-------
particulate concentrations were slightly increased under the low CO conditions averaging
25.7 mg/dscm, as opposed to 21.8 /tg/dscm under normal conditions.
The flue gas metal and particulates mass emission rates at the control device inlet
are shown in Table 4-9. Because the flue gas flow rate was consistent from run to run,
the mass emission rates show the same correlations as the metals concentrations. The
metal mass emissions rates for all outlet runs averaged: arsenic - not detected (< 508
mg/hr), beryllium - not detected (< 2.2 mg/hr), cadmium - 1,450 mg/hr, chromium -
83.3 mg/hr, lead - 21,100 mg/hr, and nickel - 73.9 mg/hr. The particulate mass emission
rates were similar under both normal and low CO conditions averaging 0.7 and 0.7
kg/hr, respectively.
For each outlet sampling run, the micrograms of each target metal collected was
divided by the grams of particulate collected (see Table 4-7) to provide the concentration
of metal in the fly ash. All metal concentrations in the outlet fly ash samples were
higher under the low CO conditions with the exception of the lead concentration which
was slightly higher under the low CO conditions. The metal concentrations in terms of
microgram of metal per gram of particulate for the outlet sample runs averaged: arsenic
- not detected, beryllium - not detected, cadmium - 1960 ug/g, chromium - 124 ug/g,
lead - 29,600 ug/g, and nickel - 97 ug/g.
4.2.3 Removal Efficiency of Control Device for Metals and Particulate
The pollutant removal (collection) efficiencies reported for the venturi
scrubber/impingement tray scrubber were based on the mass emission rates, see Table 4-
4. The efficiencies cannot be based on the emission concentrations, unless corrected for
dilution air, since the cooling shaft air enters the ducting between the inlet and outlet
locations. The pollutant removal efficiencies measured for the particulate and target
metal runs were similar for both operating conditions and averaged: particulate - 98.1%,
arsenic - inlet and outlet samples were below the level of detection, beryllium - > 86.1%
(all outlet sample values were at or below the limit of detection), cadmium - 75.1%,
chromium - 99.3%, lead - 75.7%, and nickel - 93.9%. The lower removal efficiencies for
4-14
-------
TABLE 4-9. SUMMARY OF OUTLET PARTICULATE AND METALS MASS EMISSION RATES
Run No. and
Locations
Particulate
Mass Rate
(kg/hour)
Flue Gas Metal
Mass Emission Rate
(mg/hour)
Arsenic
Beryllium
Cadmium
Chromium
Lead Nickel
Run 5
Normal
0.7
<
521
<
2.3
1258
65.8
16710
90.7
Run 6
Normal
•
0.6
<
591
<
2.6
1375
113
19297
79.7
Run 8
Transition
1.1
<
531
2.3
2586
164
30475
109
Run 10
Low CO
0.7
<
i
573
<
2.5
1196
47.3
22517
34.9
Run 12
Low CO
0.6
<
278
1.2
987
26.5
19432
44.7
Runs 5 and 6
Normal
0.6
<
556
<
2.4
1317
89.5
18003
85.2
Runs 8,10,&12
Low CO
0.8
<
461
<
2.0
1590
77.3
24141
62.7
Total Average
Outlet
0.7
<
508
<
2.2
1453
83.3
21072
73.9
-------
many of the metals compared to the total particulate are expected because the metals
are typically concentrated in the smaller diameter particles which are in turn more
difficult to collect. It is not known why the collection efficiency of chromium was greater
than the particulate removal efficiency. •
4.2.4 Sludge Feed Results
A composite sludge feed sample was collected over the duration of each of the
test runs. The sludge feed metal concentrations on a wet basis are presented in Table 4-
10. The concentrations of metals in the sludge were fairly consistent and averaged:
arsenic - not detected (< 4.6 /ig/g), beryllium - 0.088 /ig/g, cadmium - 1.28 ftg/g,
chromium - 18.5 ng/g, lead - 81 ft g/g, and nickel - 6.1 /ig/g-
The metal feed rates based on the concentration of metals in the sludge and the
sludge feed rates are presented in Table 4-11. The mass feed rates of metals in the
sludge were fairly consistent and averaged: arsenic - not detected (< 8 g/hr), beryllium -
0.088 g/hr, cadmium - 1.28 g/hr, chromium - 18.5 g/hr, lead - 81 g/hr, and nickel - 6.1
g/hr.
The results of the slyidge proximate and ultimate analyses are presented in Table
4-12. All of these results were fairly consistent from run-to-run with the exception of the
moisture content on Run 4. The results for the metals runs (Runs 5, 6, 8, 10, and 12)
averaged: moisture - 73.25%, volatile matter - 57.96% (dry basis), fixed carbon - 4.23%
(dry basis), ash - 37.85% (dry basis), sulfur - 0.53% (dry basis), carbon - 32.24% (dry
basis), hydrogen - 4.6% (dry basis), nitrogen - 3.44% (dry basis), oxygen - 21.34% (dry
basis), and BTU per pound - 5953 (dry basis).
4.2.5 Scrubber Water Results
Scrubber water influent and effluent samples were collected for all sampling runs.
The scrubber water effluent samples had to be collected from the bottom of the
discharge pipe. The water effluent samples therefore may not be representative of the
4-16
-------
TABLE 4-10. METALS CONCENTRATION (/ig/g) IN SLUDGE ON WET BASIS
Metal Concentration
(Atg/g,
wet basis)
Run Number
As
Be
Cd
Cr
Pb
Ni
3-Sludge
ND*
0.06
0.675
53.0
8.88
4.86
4-Sludge
ND
0.039
0.808
57.9
10.5
4.65
5-Sludge
ND
0.059
0.867
60.7
9.6
4.91
6-Sludge
ND
0.059
0.846
52.5
11.9
4.46
7-Sludge
ND
0.059
0.825
62.1
16.8
4.36
8-Sludge
ND
0.059
0.691
52.1
12.8
3.73
9-Sludge
ND
0.040
0.818
52.7
9.24
4.63
10-Sludge
ND
0.08
1.00
50.6
13. 3
4.06
11-Sludge
ND
0.040
0.774
52.0
13.4
2.72
12-Sludge
ND
0.02
0.62
36.6
10.5
1.98
13-Sludge
ND
0.020
0.909
61.1
11.0
3.20
Detection
Limitf
4.6
0.02
0.06
0.02
1.68
0.24
* ND - Below the analytical limit of detection.
t Detection Limit - Values shown represent limit of detection in
Mg of metal divided by g of wet sludge.
4-17
-------
TABLE 4-11. FEED RATE OF METALS IN SLUDGE (g/hr)
Feed Rate
of Specified Metal (g/hr)
Run No.
As*
Be
Cd
Cr
Pb
Ni
3
<
9
0.112
1.26
16.5
99
9.05
4
<
9
0.073
1.50
19.5
108
8*66
5
<
8
0.097
1.42
15.7
99
8.02
6
<
8
0.096
1.38
19.4
86
7.29
7
<
8
0.096
1.35
27.5
101
7.13
8
<
8
0.100
1.16
21.5
88
6.27
9
<
8
0.067
1.37
15.5
89
7.78
10
<
7
0.120
1.50
19.9
76
6.08
11
<
7
0.059
1.16
20.1
78
4.08
12
<
7
0.030
0.93
15.7
55
2.97
13
<
7
0.030
1.36
16.5
92
4.79
Average
Metals
Runst
<
8
0.088
1.28*
18.5
81
6.1
* < - not detected, value represents detection limit,
f Runs 5, 6, 8, 10, and 12,
4-18
-------
TABLE 4-12. RESULTS FOR PROXIMATE AND ULTIMATE ANALYSES OF SLUDGE SAMPLES
Dry
Basis Analysis
(Percent)
*
Run
No
Moisture
(percent)
Volatile
matter
Fixed
Carbon
Ash
S
C
H
N
0
Btu/lb
3
4
70.25
82.47
58.93
57.32
6.68
7.73
34.39
34.95
0.52
0.56
34.11
34.74
5.00
4.78
3.17
3.26
22.82
21.72
6272
6361
5
6
72.40
72.74
58.40
58.97
4.84
5. 60
36.76
35.43
0.53
0.52
32.98
33.28
4.90
4.77
3.06
3.48
21.77
22.52
5998
6368
7
8
75.98
74. 13
59.56
59.33
5. 64
4.99
34.80
35. 68
0.53
0.54
34.52
33.54
4.56
4.51
3.59
3.78
22.01
21.96
6086
6304
9
10
72.37
74.43
55.85
57.36
2.76
3.31
41.39
39.33
0.44
0.54
29.25
32.66
4.37
4.51
1.62
3.61
22.92
19.36
5280
5897
11
12
13
73.45
72.55
72 . 08
56. 61
55.51
61.24
3.87
2.43
0. 04
39.52
42.06
38.72
0.51
0.51
0.48
31. 00
28.74
30.08
4. 64
4.31
4.50
3.57
3.28
3.18
20.76
21.10
23.05
5548
5199
5477
Avg 73.25
Metals
Runsf
57.96
4.23
37.85
0.53
32.24
4. 60
3.44
21.34
5953
* Elemental analysis - S (Sulfur), C (Carbon), H (Hydrogen), N (Nitrogen), and O
(Oxygen).
t Runs 5, 6, 8, 10, and 12.
-------
discharge effluent emissions. Due to the nature of the scrubber water effluent sampling
location, the results should be treated as an approximation. The scrubber water flow
rate is not routinely measured by the facility, but was estimated to be 800 gal/min.
The concentrations of metals in the scrubber influent and effluent is presented in
Table 4-13. The mass discharge rates of the metals collected in the scrubber are
presented in Table 4-14. These values represent the effluent concentration minus the
influent concentration times the scrubber water flow rate of 800 gal/min. The average
value for the metals runs were: arsenic - not detected, beryllium - at the level of
detection (0.02 g/hr), cadmium - 1.44 g/hr, chromium - 15.0 g/hr, lead - 29.8 g/hr, and
nickel - 1.0 g/hr.
4.2.6 Bottom Ash Results
Incinerator bottom ash samples were collected from the hopper once per test at
the conclusion of the sample run. The bottom ash metal concentration results are
shown in Table 4-15.
The bottom ash metal concentrations were converted to metal mass flow rates.
The bottom ash flow rate was determined using the percent ash values from the
proximate analyses (in Table 4-12). The percent ash values were then multiplied by the
appropriate sludge feed rates to yield the total ash production rate. The average
particulate emissions measured at the incinerator outlet (scrubber inlet) were subtracted
from the total ash rates to give a bottom ash flow rate for each run. The average ash
flow rate was 11 tons/hr. These results, at best, represent a rough estimate of the
ash flow rate. The metals mass flow rates for the bottom ash are presented in Table 4-
16 and for the metals runs (5, 6, 8, 10, and 12) averaged: arsenic - not detected (0.6
g/hr), beryllium - at the level of detection (0.03 g/hr), cadmium - 0.13 g/hr, chromium
10.4 g/hr, lead 38.4 g/hr, and nickel - 2.7 g/hr.
4-20
-------
TABLE 4-13. SCRUBBER WATER METAL CONCENTRATIONS (/ig/ml)
Run No.\
Location
Sample Analysis Results
(/zg/ml)
As
Be
Cd
Cr
Pb
Ni
SWI-3*
SWE-3*
ND$
ND
ND
0.001
0.003
0.053
0.019
0.771
0.177
1.09
0.016
0.064
SWI-4
SWE-4
ND
ND
ND
ND
ND
0.083
0.01
0.967
ND
2.25
0.021
0.091
SWI-5
SWE-5
ND
ND
ND
ND
ND
0.115
0.019
0.847
0.295
1.66
0.016
0.09
SWI-6
SWE-6
ND
ND
ND
ND
ND
0.052
0.026
0.444
ND
0.671
0.014
0.043
SWI-7
SWE-7
ND
ND
ND
0.001
ND
0.139
0.01
1.26
0.117
1.31
0.067
0.125
SWI-8
SWE-8
ND
ND
ND
ND
ND
0.056
0.015
0.262
ND
2.04
0.037
0.054
SWI-9
SWE-9
ND
ND
ND
0.002
ND
0.164
0.009
1.56
ND
3.27
0.031
0.162
SWI-10
SWE-10
ND
ND
ND
0.001
ND
0.098
0.013
1.27
ND
1.82
0.035
0.12
SWI-11
SWE-11
ND
ND
ND
0.001
ND
0.083
0. 02
1.53
ND
2.51
0.034
0.129
SWI-12
SWE-12
ND
ND
ND
0.002
0.021
0.0959
0.004
1.39
ND
2.3
0.049
0.121
SWI-13
SWE-13
ND
ND
ND
0.002
ND
0.098
0.011
1.96
ND
1.23
0.048
0.406
Detection
Limit
0.23
0.001
0.003
0.005
0.084
0.012
* SWI - Scrubber water influent, SWE - scrubber water effluent,
$ ND - Not detected, below the limit of detection.
4-21
-------
TABLE 4-14. DISCHARGE RATE OF METALS IN SCRUBBER WATER
Run No.
Metal Discharge Emissions in
Scrubber Water
(g/hr)
As
Be
Cd
Cr
Pb
Ni
3
ND*
0.02
0.91
13.66
16.59
0.87
4
ND
ND
1.51
17.39
40.88
1.27
5
ND
ND
2.09
15.04
24.80
1.34
6
ND
ND
0.94
7.59
12.19
0.53
7
ND
0.02
2.53
22.71
21.67
1.05
8
ND
ND
1.02
4.49
37.06
0.31
9
ND
0.04
2.98
28.18
59.41
2.38
10
ND
0.02
1.78
22.84
33.07
1.54
11
ND
0.02
1.51
27.43
45.60
1.73
12
ND
0.04
1.36
25.18
41.79
1.31
13
ND
0 c 04
1.78
35.41
22.35
6.50
Average
ND
0.02
1.44
15.03
29.78
1.01
Metals
Runsf
Detection
4
0.02
0.05
0.1
1.5
0.2
Limit$
* ND - Not detected,
f Runs 5, 6, 8, 10, and 12.
$ Detection Limit - Values represent the detection limit
expressed in g/hr.
4-22
-------
TABLE 4-15. METALS CONCENTRATION IN BOTTOM ASH
Metal
Concentration
in Bottom Ash
(Mg/g)
Run No.
As
Be
Cd
Cr
Pb
Ni
3-Ash
ND*
0.278
0.892
329
76.3
26.2
4-Ash
ND
0.419
0.698
349
56.5
27.5
5-Ash
ND
0.22
0.619
276
50.9
22
6-Ash
ND
0.377
1.41
413
89.3
27.2
7-Ash
ND
0.336
1.68
468
113
30.8
8-Ash
ND
0.217
0.886
329
54.7
25.8
9-Ash
ND
0.359
0.579
369
50.1
28.4
10-Ash
ND
0.279
0.796
334
61.5
24.5
11-Ash
ND
0.3
0.519
163
35.6
19.3
12-Ash
ND
0.139
0.775
270
36.6
19.3
13-Ash
ND
0.118
0.928
271
73 .7
19
Detectionf
Limit
4.6
0.02
0.06
0.02
1.68
0.24
* ND - Not detected, below the level of detection,
f Detection Limit - Values shown represent limit of detection in
/xg divided by g of bottom ash.
4-23
-------
TABLE 4-16. MASS FLOW RATE OF METALS IN BOTTOM ASH
Run No,
Mass
Flow Rate
of Specified Metal
in Bottom
Ash (g/hr)
As
Be
Cd
Cr
Pb
Ni
3
<
0.7*
0.042
0.134
11.48
49.5
3.94
4
<
0.4
0.031
0.052
4.19
25.9
2.04
5
<
0.5
0.024
0.067
5.51
29.9
2.38
6
<
0.6
0.048
0.179
11.33
52.4
3.45
7
<
0.5
0.032
0.162
10.92
45.2
2.98
8
<
0.5
0.024
0.099
6.09
36.6
2.87
9
<
0.7
0.055
0.088
7.62
56.1
4.32
10
<
0.6
0.038
0. 107
8.27
44.9
3.29
11
<
0.7
0.041
0.071
4.85
22.2
2.63
12
<
0.7
0.020
0.114
5.37
39.6
2.83
13
<
0.7
0.017
0.131
10.44
38.4
2.69
Average
<
0.6
0.031
0.113
7.31
40.7
2.97
Metals
runsf
* < - Not detected, value represents detection limit,
f Runs 5, 6, 8, 10, and 12.
4-24
-------
4.2.7 Metal Emission Factors
One of the objectives of the overall sewage sludge incinerator test program was to
develop emission factors relating the stack emissions of the target compounds to the
sludge feed rate of these compounds. At Site 6, metal emissions testing was performed
at both the inlet and outlet of the control device; therefore, uncontrolled and controlled
emissions can be related to the sludge feed composition. The ratios of uncontrolled
metal emissions (outlet of the incinerator or inlet to the control device) to the metal
feed rates in the sludge are presented in Table 4-17. The metals feed rate to the
incinerator was to be calculated based on the sludge feed rate and the metals analyses of
the sludge feed. These ratios were calculated based on the metals at each location
compared to the metals in the ash and the inlet sampling location. The metals in the
sludge feed was not used because they did not seem to be reliable based on the material
balance. The metal feed rate to the incinerator was based on the sludge feed rate, the
percent ash in the sludge, and the metals in ash discharge plus the metals emissions at
the inlet location. The metals at the inlet location .in terms of metals emitted from the
incinerator compared to metals feed to the incinerator averaged: arsenic - not detected,
beryllium - 35.1%, cadmium - 97.8%, chromium - 62.9%, lead - 39.7%, and nickel -
29.1%. The corresponding control device outlet (exhaust stack) emission factors are also
presented in Table 4-17. The metals at the outlet location in terms of metals emitted to
the atmosphere compared to metals feed to the incinerator averaged: arsenic - not
detected, beryllium - at or below detection (< 6.9%), cadmium - 92.2%, chromium -
1.1%, lead - 14.1%, and nickel - 2.4%. The controlled metal emission factors decrease
in the same proportion as the control device removal efficiency.
Another factor used is the ratios of metals in terms of /xg of metal measured in
the emissions to g of particulate (see Table 4-18). The inlet metal emissions factors in
terms of /xg of metal measured in the emissions to g of particulate averaged: arsenic -
not detected for all samples (<19 jxg/g), beryllium - 0.43 /xg/g, cadmium - 205 ng/g,
chromium - 342 /xg/g, lead - 2980 /xg/g, and nickel - 34 /xg/g.
4-25
-------
TABLE 4-17. INLET AND OUTLET METAL EMISSION FACTORS
Run
No.
Location
g metal at
location/g metal
in sludge
As
Be
Cd
Cr
Pb
Ni
Run
5
Inlet
ND*
0.415
0.988
0.726
0.393
0.382
Run
5
Outlet
ND
<
0o087f
0.949
0.012
0.115
0.037
Run
6
Inlet
ND
0.257
0.954
0.497
0.247
0.244
Run
6
Outlet
ND
<
0.051
0.885
0.010
0.130
0.023
Run
8
Inlet
ND
0.317
0.991
0.596
0.530
0.259
Run
8
Outlet
ND
<
0.0,87
0.963
0.026
0.189
0.036
Run
10
Inlet
ND
0.267
0.980
0.589
0.416
0.256
Run
10
Outlet
ND
0.062
0.918
0.006
0. 145
0.010
Run
12
Inlet
ND
0.497
0.977
0.737
0.397
0.315
Run
12
Outlet
ND
0.056
0.897
0.004
0.126
0.016
Average
Inlet
ND
0.351
0.978
0.629
0.397
0.291
Average
Outlet
ND
<
0.069
0.922
0.011
0. 141
0.024
* ND - Not detected, all sample measurements were below the
analytical detection limit,
t < - Outlet samples were below analytical detection limit,
calculated ratio is less than value shown.
4-26
-------
TABLE 4-18. RATIO OF METAL TO PARTICULATE
Run No./
Location
Ratio of
Metal to
Particulate
(ixq metal/g particulate)
As
Be
Cd
Cr
Pb
Ni
Run 5
Inlet
Outlet
< 19*
< 750
<
0.33
3.26
111
1811
287
111
1635
24046
29
131
Run 6
Inlet
Outlet
< 21
< 989
<
0.45
4.30
100
2301
303
211
1146
32301
30
133
Run 8
Inlet
Outlet
< 43
< 493
0.57
2.14
562
2401
455
163
7455
28296
51
101
Run 10
Inlet
Outlet
< 23
< 773
<
0.40
3.36
149
1613
345
81
2752
30387
33
47
Run 12
Inlet
Outlet
< 20
< 471
0.43
2.05
101 '
1676
320
55
1889
32992
28
76
Run 5&6
Inlet
Outlet
< 20
< 870
<
0.39
3.78
106
2056
295
161
1390
28173
30
132
Run 10&12
Inlet
Outlet
< 21
< 622
<
0.41
2.71
125
1645
333
68
2320
31689
30
61
Average
Inlet
Outlet
< 25
< 695
<
0.43
3.02
205
1960
342
124
2975
29604
34
97
* < - Below the level of detection, value indicates detection
limit.
4-27
-------
The ratio of metals for the controlled flue gas metals measured in the emissions
to g of particulate in the controlled emissions averaged: arsenic - not detected in any
sample (< 695 /ig/g)» beryllium - at or below the detection limit (less than 3 /ig/g),
cadmium - 1960 /ig/g, chromium - 124 /ig/g, lead - 29,600 /*g/g, and nickel - 97 /ig/g.
4.3 HEXAVALENT CHROMIUM RESULTS
43.1 Control Device Inlet Results
The inlet location samples collected for hexavalent chromium were analyzed by
EPA/EMSL in Cincinnati but the data were not released by EMSL for publication.
4.3.2 Control Device Outlet Results
The testing for hexavalent and total chromium at Site 6 had three major
objectives: (1) evaluate the emission testing methodology, (2) determine the effect of
lime on the conversion of total chromium in the sludge to hexavalent chromium in the
emissions, and (3) determine the effect of excess air and other combustion conditions on
the conversion of other forms of chromium to the hexavalent state. Testing for
hexavalent chromium was conducted using a recirculating impinger reagent (RC) train
spiked with the hexavalent chromium isotope (5lCr) in all four chromium trains for Runs
3 and 7 and in two of the four trains for Runs 9, 11, and 13. Two of the four trains were
spiked with a second hexavalent chromium isotope (^Cr) for Runs 9, 11, and 13. The
second hexavalent chromium isotope (^Cr) samples were analyzed by the EPA/EMSL
but the results were not released by EMSL for publication.
The inlet and outlet flue gas conditions shown in Tables 4-1 and 4-2 were
monitored continuously while establishing incinerator operating conditions thought to
favor conversion of trivalent to hexavalent chromium. It was also thought that the
concentration of S02 and THC would provide information regarding the conversion of
hexavalent chromium to trivalent chromium during sample collection.
4-28
-------
The outlet emission concentrations of hexavalent chromium are summarized in
Table 4-19. The recirculating impinger reagent train or RC train was used to collect the
hexavalent and total chromium emissions. This train is designed to provide immediate
contact of the incoming hexavalent chromium with a basic solution coupled with
continuous rinsing of the sample probe to reduce conversion of hexavalent chromium to
trivalent chromium during sample collection. The ,,5lCr RC" train (see Table 4-19) was
spiked with 5ICr to assess conversion of hexavalent chromium to trivalent chromium
during sampling and sample recovery. Analysis of this isotope requires use of a
scintillation counter. The level of hexavalent 51Cr spiked is below the detection level of
the other analytical techniques for hexavalent chromium and total chromium. As shown
in Table 4-19, the conversion of hexavalent to trivalent chromium in the RC train
averaged approximately 10% for a sample collection period of two to four hours.
Although the results for the RC trains spiked with sCr are not shown, the conversion
ratio was demonstrated using both the ^Cr and 5iCr spikes. The "MMtl" designation in
Table 4-19 indicates the total chromium results from the multiple metals train sampling
runs. Based on the total chromium results of the hexavalent chromium train, it appears
that the total chromium results of the multiple metals train is probably low by a factor of
about two.
In Figure 4-1, the C0/C02 ratios from Table 4-2 are plotted against the
hexavalent to total chromium ratios from Table 4-19. A relationship between good
combustion and a higher ratio of hexavalent to trivalent chromium is evident. At low
CO levels (good combustion), the ratio of hexavalent chromium to trivalent chromium is
highest, with approximately 10% of the total chromium in the form of hexavalent
chromium. At high CO levels (poor combustion), the ratio of hexavalent chromium to
total chromium is significantly reduced to less than approximately 1%.
The recirculating impinger reagent train approach had demonstrated two
problems prior to the Site 6 test: (1) the recirculating train did not completely prevent
conversion of hexavalent to trivalent chromium in the presence of high levels of sulfur
dioxide, and (2) trivalent chromium in the alkaline collection media was found to slowly
convert to hexavalent chromium. In an effort to correct these problems, two new
4-29
-------
TABLE 4-19. SUMMARY OF OUTLET SAMPLING RESULTS FOR
HEXAVALENT AND TOTAL CHROMIUM
Run
Mo./
Date
Train and
Isotopic
Spike
Sample Fractions
Cr*6 Total Cr
(ug) (ug)
Conversion of
Hexavalent Chromium
During Sampling, X
Ratio of
Cr*6 Total Cr Cr*4 to
(ug/dscm) (ug/dscm) Cr, X
Run 3
10/09
A-51Cr RC*
B-5lCr RC
C-51Cr RC
D-51Cr RC
Average
0.36 13.2
0.10 13.7
0.05 7.9
0.01 12.5
1.2
1.1
24.6
12.7
0.15 5.6 2.7
0.06 8.6 0.7
0.03 4.3 0.6
0.005 6.1 0.1
0.06 6.2 1.0
Run 5
Run 6
10/10
MMtl-D
MMtl-D
5.8
8.8
• • • •
2.1
4.0
Run 7
10/10
A-5lCr RC
B-51Cr RC
C-5lCr RC
D-51Cr RC
Average
0.62 15.0
0.57 14.3
0.55 15.6
0.34 47.9
18.1
12.6
15.3
9.6
0.17 4.1 4.1
0.15 3.9 4.0
0.16 4.4 3.5
0.10 13.7f 2.3$
0.14 4.2 3.5
Run 8
10/11
MMtl-D
14.2
5.9
Run 9
10/11
C-51Cr RC
D-5lCr RC
Average
0.74 13.0
1.33 16.1
6.1
3.3
0.18 3.1 5.7
0.29 3.6 8.2
0.24 2.9 7.0
Run 10
10/12
MMtl-D
3.8
1.7
Run 11
10/12
C-51Cr RC
D-5lCr RC
Average
1.35 16.6
1.49 13.4
5.4
2.7
0.31 3.8 8.1
0.38 3.4 11.1
0.34 3.1 9.6
Run 12
10/12
MMtl-D
1.7
0.8
Run 13
10/13
C-5lCr RC
D-51Cr RC
Average
0.21 15.3
0.12 13.7
6.0
3.2
0.04 2.7 1.4
0.02 2.3 0.9
0.03 3.3 1.1
• RC - Recirculating impinger reagent train for hexavalent chromium,
t Outlier, not included in the average.
$ Average total chromium value used to calculate ratio.
4-30
-------
Outlet emissions data (excludes Run 7)
Run 11
Run 9
-0.98
CO 3
Run 3
Run 13
r
—1
120
—r
100
T
80
60
CO to C02 Ratio (ppm to %)
Figure 4-1. Cr+< to total chromium versus CO to C02 ratios.
4-31
-------
procedures were added to the recirculating train sampling protocol for testing at Site 6:
(1) a 30-minute nitrogen purge of the sample at a rate of 20 L/min immediately after
sample collection, and (2) pressure filtering of the sample through a 0.2 um filter
following the nitrogen purge. The net results of these procedural changes were to purge
oxygen and sulfur dioxide from the sample and to remove all the insoluble trivalent
chromium and other materials from the filtrate solution containing the hexavalent
chromium. Conversion was almost completely eliminated and, as shown in Table 4-20,
the samples remained stable over a 2-month period.
Samples for the inlet and outlet runs were also analyzed for hexavalent and total
chromium using X-ray absorption near-edge structure (XANES) and extended X-ray
absorption fine structure (EXAFS) by BYU; hexavalent chromium was below the
instrument's detection limit for all samples indicating a hexavalent to total chromium
ratio of less than 20%.
4.4 NICKEL SPECIATION RESULTS
The major objective of the nickel speciation testing was to determine the percent
of the nickel emissions in the form of nickel subsulfide. It was anticipated that the
nickel subsulfide emissions from multiple hearth incinerators would constitute less than
1% of the total nickel emissions, because these incinerators typically operate with high
excess air which is not favorable for the formation of nickel subsulfide. The first
laboratory to conduct the wet chemical speciation of nickel experienced problems. Dr.
Vladimir Zatka, the developer of the Nickel Producers Environmental Association
(NiPERA) nickel speciation method, was then contracted to conduct the sample analysis.
This wet chemical analytical method involves sequential leaching. The first leaching step
removes all soluble nickel. Peroxide is used to convert the nickel sulfides and
subsulfides to soluble nickel sulfate which is then leached in the second step. The third
step leaches the metallic nickel compounds and finally total digestion of the remaining
sample typically containing nickel oxides. The results of the sequential leaching nickel
analysis shown in Table 4-21 indicate that within the detection limit of the wet chemical
4-32
-------
TABLE 4-20. STABILITY STUDY OF OUTLET SAMPLING RESULTS FOR HEXAVALENT CHROMIUM
Run No.
Date
Train
Actual
Cr+6
(ug)
Conversion of
Hexavalent Chromium
During Sampling, %
Concentration of Cr+6
10/25/89 12/12/89
(PPb) (ppb)
Difference
Cr+6
(PPb)
Run 9
10/11
C
D
0.74
1.33
6.1
3.3
0.78 0.80
0.46 0.46
0.02
0.00
Average
4.7
0.01
Run 11
10/12
C
D
1.35
1.49
5.4
2.7
0.57 0.59
0.52 0.57
0. 02
0.05
Average
4.1
0.04
Run 13
10/13
C
0.21
6.0
0.25 0.29
0.04
-------
TABLE 4-21. SUMMARY OF NICKEL SPECIES EMISSIONS: SITE 6.
Nickel
Soluble
Sulfidic*
Oxidic
Total
Run
No.
ug/dscm
% Total
ug/dscm
% Total
ug/dscm
% Total
ug/dscm %
Total
Outlet
Run
5
1.6
58
<
0.15f
<
5
1.2
42
2.8
100
Run
6
0.9
42
<
0.18
<
8
1.3
58
2.2
100
Run
10
1.1
60
<
0.18
<
10
0.7
40
1.8
100
Run
12
0.7
39
<
0.20
<
11
1.1
61
1.8
100
Inlet
Run
5
65
41
<
18
<
12
92
59
157
100
Run
6
98
41
<
28
<
12
140
59
238
100
Run
8
18
21
<
6
<
7
66
79
84
100
Run
10
65
41
19
12
74
47
158
100
Run
12
64
77
<
13
<
15
19
23
83
100
Run
8AF±
15
17
<
6
<
7
72
83
87
100
* The sulfidic nickel is a combination of the nickel sulfide and nickel subsulfide.
t < - Below limit of detection, values indicate detection limit.
$ The effect of quartz fibers on the leach recovery was investigated by spreading
one sample portion (inlet Run 8) over one quartz fiber filter (85 mm) and
carrying it through the speciation process. The results are shown above as Run
8AF.
-------
method, no nickel subsulfide was present in the samples. Consideration of the detection
limit indicates nickel subsulfide to total nickel ratio is less than 12% for the inlet
emissions and less than 10% for the outlet emissions. BYU also analyzed samples from
the same runs by XANES and EXAFS; no nickel subsulfide was detected within the
instrumental detection limit of 10% of the total nickel.
4.5 CONTINUOUS EMISSION MONITORING RESULTS
Continuous emission monitoring (CEM) was performed at the inlet and outlet
sampling locations at Site 6. The inlet CEM systems included oxygen (02), carbon
dioxide (C02), carbon monoxide (CO), and oxides of nitrogen (NOx). The outlet CEMSs
included oxygen (02), carbon dioxide (C02), carbon monoxide (CO), oxides of nitrogen
(NOx), and total hydrocarbons (THC). The CEM probes were located upstream of the
manual sampling locations. All measurements were made on a dry basis. The averages
of the CEM data on a run-by-run basis are presented in Table 4-2. The one-minute
averages for each compound for all the runs in included in Appendix E of Volume IV:
Site 6 Report, Appendices. To provide an indication of how the monitored emissions
changed with time, the 15-minute averages are presented in Table 4-22. The indicated
time (i.e., 12:06) is the time at the end of the 15-min average. Runs 3, 4, 5, 6, 7 and 13
represent normal furnace operating conditions. Run 8 represents a transition period
when the furnace operating conditions were being changed to yield low CO emissions.
Runs 9, 10, 11, and 12 represent the low CO conditions. As previously mentioned,
several additional auxiliary burners were put into operation to obtain the low CO
conditions.
EPA is evaluating CO and THC monitoring as a surrogate indicator of organic
emissions. Since no organic compound specific measurements were made at this site,
the relationship between CO and THC emissions under the tested conditions is shown in
Figure 4-2. When Run 5 is excluded, the correlation coefficient between the CO and
THC is 0.97 for the data from the 2- and 4-hr runs.
4-35
-------
TABLE 4-22. SUMMARY OF INLET AND OUTLET CONTINUOUS EMISSION MONITORING RESULTS
(15-min averages)
Inlet Location
Outlet Location
Time
02
C02
CO
S02
NOx
02
C02
CO
S02
NOx
THC
24 hr.
(%)
(%)
(ppm)
(ppm)
(ppm)
(%)
(%)
(ppm)
(ppm)
(ppm)
(ppm)
Run 3
- October 9,
1989
12:06
17.2
3.3
313.1
3.0
60.7
15.1
4.7
458.5
20.8
125.1
13.3
12:21
12.7
3.2
241.2
11.1
36.0
14.1
5.6
501.9
22.1
120.7
16.3
13:02
8.9
10.2
1115.4
45.4
177.1
11.0
8.3
1124.4
31.3
142.7
47.5
13:17
15.8
4.4
770.8
33.2
155.4
15.8
4.2
729.0
24.2
146.5
34.6
13:32
15.0
4.8
668.6
28.4
134.4
14.7
5.0
688.5
27.0
141.2
20.5
13:47
13.4
6.2
806.7
40.3
161.4
13.9
5.8
734.6
31.0
154.0
22.5
14:02
11.9
7.4
625.6
63.1
165.6
13.4
6.2
497.7
27.0
146.1
15.7
14:17
14.1
5.7
584.0
40.5
146.9
14.3
5.5
553.1
26.1
151.6
15.4
14:32
13.0
6.5
573.4
56.7
152.6
13.8
5.9
474.7
24.2
151.1
13.1
14:47
14.1
5.5
453.1
36.9
148.4
14.6
5.1
393.7
23.1
150.9
11.4
Run 4 - October 9, 1989
17:43
14.2
5.6
416.2
19.7
106.9
13.2
6.0
448.7
21.2
132.5
12.4
17:58
9.6
4.2
303.4
30.8
101.4
13.8
5.7
310.9
18.4
125.7
9.1
18:13
14.2
4.7
308.3
41.8
97.1
14.0
5.2
330.5
18.7
125.2
9.6
18:28
15.1
4.7
343.3
40.8
109.4
14.3
5.2
350.5
20.4
140.0
11.4
18:43
15.6
4.2
387.4
38.0
112.6
14.8
4.8
434.4
20.6
146.8
13.3
18:58
13.7
5.9
594.2
48.3
145.1
13.4
6.0
610.4
25.3
176.2
18.8
19:13
11.3
7.5
524.8
116.0
129.8
12.9
6.3
598.4
47.1
111.7
57.6
(Continued)
-------
TABLE 4-22. (Continued)
Inlet Location
Outlet Location
Time
02
C02
CO
S02
NOx
02
C02
CO
S02
NOx
THC
24 hr.
(%)
(%)
(ppm)
(ppm)
(ppm)
(%)
(%)
(ppm)
(ppm)
(ppm)
(ppm)
Run 5
- October 10,
1989
09:28
9.6
9.2
1004.7
28.5
124.7
12.7
6.7
754.6
22.3
111.9
31.4
09:43
8.7
9.9
1249.6
62.0
150.9
12.0
7.3
1512.2
47.2
124.9
107.0
09:58
9.3
9.5
1240.9
42.9
169.4
12.5
6.9
1156.5
34.7
132.9
58.6
10:13
10.9
8.2
882.6
31.3
157.1
13.6
6.1
661.8
26.4
129.7
28.3
10:28
11.8
7.5
562.4
26.7
135.1
14.2
5.6
401.8
24.3
125.4
14.2
10:43
9.8
9.2
916.8
31.1
125.8
12.9
6.7
711.5
27.1
116.6
33.2
10:58
11.6
7.7
1171.8
41.4
153.5
14.0
5.7
940.2
35.4
137.3
43.2
11:13
9.4
9.6
1004.3
43.0
146.0
12.7
6.9
890.9
36.7
132.5
49.3
Run 6
- October 10,
1989
13:58
8.7
9.9
796. 1
23.3
160.9
11.1
8.0
618.3
20.6
125. 3
25.5
14:30
12.1
7.3
677.5
60.2
163.1
13.7
6.1
559.8
20.5
154.1
18.2
14:45
13.4
6.3
752. 8
44.7
169.7
15. 1
4.9
593.8
21. 1
132. 5
20.3
15:40
13.4
6.2
450.4
20.8
142.0
14.9
5.0
353.6
17.1
127.0
11.4
15:55
12.4
6.8
604.3
31.5
191.3
14.8
5.0
437.1
22.1
162.7
12.3
16:10
13.0
6.3
,768.9
37.7
191.9
14.6
5.1
605.6
28.9
180.4
15.2
16:25
12.4
6.7
868.1
39.3
198.9
13.9
5.6
687. 1
32.3
188.1
17.9
16:40
11.8
7.4
892 . 1
42.3
212.4
13.2
6.2
702.5
33.6
200.5
20.8
16:55
12.3
7.0
826. 1
39.9
204.6
13.3
6.2
686.3
33.5
202 . 5
21.8
(Continued)
-------
TABLE 4-22. (Continued)
Inlet Location
Outlet Location
Time
02
C02
CO
S02
NOX
02
C02
CO
S02
NOx
THC
24 hr.
(%)
(%)
(ppm)
(ppm)
(ppm)
(%)
(%)
(ppm)
(ppm)
(ppm)
(ppm)
Run 7
- October 10,
1989
18:27
14.8
4.7
296.7
16.4
148. 3
15.2
4.4
323.2
18.7
148.4
12.0
18:42
14.2
5.2
666.5
23.9
164.2
15.2
4.3
574.4
25.2
146.2
16.2
18:57
13.8
5.3
1138.6
28.3
205.5
15.3
4.2
907.3
26.5
161.1
20.6
19:12
14.6
4.7
1131.8
27.5
169.2
15.5
4.0
963.5
30.1
146.8
26.8
19:27
12.4
6.6
1246.7
36.8
228.8
13.9
5.4
1061.4
37.0
166.2
28.4
19:42
13.5
5.7
1242.4
31.2
242.1
14.1
5.2
1310.8
35.3
189.1
31.1
19:57
13.6
5.6
1089.6
30.0
204.5
13.8
5.5
1005.7
34.8
168.6
25.6
20:12
12. 3
6.8
1012.7
42.8
221.2
12.8
6.4
890.4
35.1
179.5
24.5
20:27
11. 3
7.8
769.7
56.5
197.7
12.0
7.2
692.9
31.8
164.8
22.9
20:42
12.8
6.4
732.1
37.8
200.1
13.4
6.0
684.2
31.8
178.9
22.8
20:57
13.4
5.9
,733.0
32.9
203.5
14.0
5.5
692.8
30.0
181.8
19.9
21:12
13. 1
6.1
639.5
33.7
191.8
14.2
5.3
563.8
29.7
161.3
18.6
21:27
13.0
6.2
657.0
36.2
184.9
14.0
5.5
581.4
33.2
152.9
20.7
(Continued)
-------
TABLE 4-22. (Continued)
Inlet Location
Outlet Location
Time
02
CO 2
CO
S02
NOx
02
C02
CO
S02
NOx
THC
24 hr.
(%)
(%)
(ppm)
(ppm)
(ppm)
(%)
(%)
(ppm)
(ppm)
(ppm)
ppm
Run 8
- October 11,
1989
09:13
10.3
8.5
570.7
51.2
163.5
12.4
6.9
443.7
22.2
114.7
15.4
09:28
8.3
10.6
632.5
90.3
197.2
11.4
7.8
454.2
17.1
131.0
14.9
09:43
7.9
11.1
788.2
114.8
189.9
11.1
8.2
630.2
21.3
121. 6
23.2
10: 00
9.5
9.7
735.5
94.8
186.0
12. 0
7.3
562.9
20.6
114.1
17.5
10:15
9.4
9.6
971. 6
114.6
175.3
11.9
7.4
787.1
21.9
97.1
21.1
10:30
9.4
9.7
911.7
92.1
171.8
12.5
6.9
666.7
20.3
89. 6
18.7
10:45
11.0
8.4
711. 5
90.3
131. 6
13.0
6.5
586.5
20.0
76.6
17.4
11:00
10.1
9.0
760. 6
67.4
165.4
13.3
6.1
496.7
18.8
92.7
14.7
11:15
8.0
10.7
698. 6
107.1
182.9
11.7
7.5
467. 6
19.1
114.7
13.2
11: 30
8.2
10.7
624.2
117.3
174.1
10.7
8.4
481.9
21.2
119.8
15.1
11:45
7.5
11. 3
1044.9
152.2
192.2
10. 1
9.0
962.9
27.0
119.8
27.0
Run 9
- October 11,
1989
15:41
10.8
8.2
436.2
53. 1
178. 3
13. 2
6.4
326.2
12. 3
123.4
6.5
16:00
12.0
7.2
355. 5
44. 1
181.1
13.9
5.7
261.5
13.2
128.2
5.8
16:15
11.7
7.4
325.1
38.5
178.8
14.2
5.5
223.0
13.0
120.0
4.9
16: 30
12.7
6.5
296. 6
33.2
173.1
14. 6
5.2
224.0
13.9
125.1
5.1
16:45
12.0
7.0
439.4
32.1
198.8
14.5
5.1
321.3
18.0
137. 1
8.1
17:00
10.6
8.2
488.5
43.3
217.3
13.2
6.3
364.8
21.4
152.6
9.9
17:15
10.5
8.4
490.9
52.2
202.2
12.5
6.9
398.9
21.1
148.9
9.2
17: 30
10.8
8.2
500.4
50.1
201.1
13.0
6.6
383.3
18. 6
141.8
8.2
17:45
10.6
8.3
537. 1
47.8
206.4
13 .2
6.4
388.4
18. 3
138.2
8.1
18:00
10.9
8.1
556. 6
46.7
198.1
13.2
6.3
423.4
19.2
140.0
8.8
18:15
10.0
8.9
541. 3
58.2
206. 3
12.4
7.1
417.9
18.9
141.3
8.4
18:30
11. 6
7.5
395.8
43.7
169.5
13.0
6.6
327.4
15.7
128.2
7.1
18:45
12.9
6.5
299.5
33.2
137.1
13.3
6.4
277.9
14.9
111.2
6.8
(Continued)
-------
TABLE 4-22. (Continued)
Inlet Location
Outlet Location
Time
02
C02
CO
S02
NOx
02
C02
CO
S02
NOx
THC
24 hr.
(%)
(%)
(ppitl)
(ppm)
(ppm)
(%)
(%)
(ppm)
(ppm)
(ppm)
(ppm)
Run 10
- October 12,
1989
09:25
11.5
7.8
318. 1
33.0
155. 6
13.4
6.4
248.1
16.9
119.2
5.8
09:40
12.3
7.1
331.9
32.5
160.1
13.9
5.9
266.6
18.3
127.6
6.2
09:55
12.2
7.1
431.0
32.8
188.0
14.3
5.6
329.9
18.4
144.0
8.2
10:10
11. 6
7.5
521.1
37.5
211.2
13.6
6.1
404.5
21.7
169.1
10.3
10:25
10. 3
8.8
417. 3
57.9
201.9
12.0
7.7
331.8
23.2
169.5
10.2
10:40
11.5
7.8
362. 1
57.8
175.1
12.2
7.5
318.9
24.0
160.7
9.8
10:55
11.4
7.9
432. 1
54.2
156.3
12.8
7.0
351.0
23.4
132.4
9.5
11:10
11.6
7.7
477.5
59.4
158.4
12.9
6.7
391.7
24.2
130.4
9.9
Run 11
- October 12,
1989
12:22
11.7
7.5
260. 3
59.2
143.4
13.0
6.7
207.7
9.3
133.6
5.3
12:53
11.9
7.3
400.7
61.1
143.8
13.6
6.0
297.9
9.9
117.9
8.3
13:08
11.5
7.7
438. 3
66.4
167.5
12.7
6.8
352.9
9.5
146.3
9.2
13:23
11.7
7.7
345.9
62.6
157.6
12.4
7.2
291.6
7.4
148.7
8.0
13:38
12.1
7.3
385. 5
57.6
148.0
12.8
6.8
323.1
5.3
139.1
8.4
13:53
11.2
7.9
459.7
62.7
161.3
12.8
6.8
352.0
5.2
133.2
8.6
14:08
11.0
8.1
514.8
64.6
164.9
12.6
6.9
394.3
6.3
132.4
9.2
14:23
10.6
8.5
418.8
69.7
170.0
12.0
7.6
322.2
16. 6
109.0
7.6
14:38
11.7
7.5
370.7
56.6
145.3
13.0
6.6
289.4
10.3
122.8
7.1
14:53
10.7
8.3
394.3
61.8
166.5
12.4
7.2
299.6
11.6
137.5
7.2
15:08
12.1
7.1
315.5
50.3
141.1
13.1
6.5
252.8
10.4
128.5
6.2
15:23
11.4
7.7
314. 1
51.9
142.3
13.1
6.5
230.2
10.4
119.6
5.3
15:38
12.0
7.2
319.4
52.7
146.9
13.4
6.2
241.3
10. 1
121.9
5.4
(Continued)
-------
TABLE 4-22. (Continued)
Inlet Location
Outlet Location
Time
24 hr.
02
(%)
C02 CO S02
(%) (ppm) (ppm)
NOx
(ppm)
02
(%)
CO 2 CO S02
(%) (ppm) (ppm)
NOx
(ppm)
THC
(ppm)
Run 12 - October 12, 1989
17:47
11. 3
7.8
465.1
38.4
186.9
13.2
6.6
354.4
12.0
133.9
7.5
18:02
13.2
6.2
339.9
37.3
141.5
13.8
6.1
302 . 8
8.2
115.9
7.1
18:17
12.1
7.1
336.4
41.9
147.8
13.7
6.1
261.9
7.1
107.4
6.0
18:32
11.8
7.4
297.2
42.9
141.5
13.7
6.1
222.1
6.3
101.1
5.3
18:47
11.5
7.6
387.3
40.5
150.6
14.0
5.8
269.8
7.5
98.2
6.5
19:02
9.3
9.2
536.7
51.0
210.0
13.2
6.4
344. 3
11.0
126.8
8.4
19:17
10.7
8.2
455.4
49.2
175.9
12.8
6.8
342.0
10.1
128.4
8.6
19:32
11.1
7.9
393.1
49.0
160.1
12.9
6.8
302.2
8.0
120.8
7.5
19:47
12.4
6.8
365.4
44.3
146.9
13 .5
6.3
303.1
7.8
116.4
7.8
Run 13 - October 13, 1989
09
27
12 .9
6.3
760.2
32.3
190.3
14.2
5.4
631. 5
28.2
157.3
16.9
09
42
12 .9
6.4
659.6
26.1
206.8
14.1
5.5
557.2
26.8
164.9
14.6
09
57
13.2
6.2
643. 9
22. 7
186.9
14.7
5.0
525. 0
24. 3
142.7
14.2
10
12
13.2
6.1
563.9
22.8
189.5
14.7
5.0
454. 0
25.0
144.2
13.3
10
27
14.2
5.5
535.7
20.5
164.5
15.4
4.5
434. 3
24.7
127.8
14.2
10
42
13.3
6.1
532.4
23.7
166.6
14.6
5.1
437.9
28.0
134.3
14.8
10
57
13.5
5.8
508. 1
24.2
161.7
14.5
5.0
438.5
30.0
140.0
16.1
11
12
13.3
5.9
703.0
30.9
184.0
14.6
5.0
574.0
35.2
149.9
18.6
11
27
13.2
6.0
741.0
31.4
191.9
14.3
5.3
629.2
37.6
154.7
20.2
11
42
12.8
6.4
741.6
31.4
207.0
13.8
5.7
621. 0
38. 3
161.3
18.7
11
57
13. 1
6.1
730.7
28.9
202.9
13.9
5.6
642.5
36.5
162.2
18.6
12
12
13.0
6.3
663.2
25.9
196.6
13.8
5.8
587.2
33.6
156.3
17.1
12
27
13.0
6.3
635.1
25.7
189.7
14.0
5.6
546.8
32.0
144.5
15.5
12
42
12.9
6.4
641.0
27.2
196.3
14.1
5.5
531. 1
32.9
146.6
14.5
12
57
13.8
5.7
683.4
24.5
190.5
14.6
5.2
584.5
33.4
149.0
16.8
-------
Outlet emissions data (excluding Run 5)
r = 0.97
200 400 600
Carbon Monoxide (ppm)
800
Figure 4-2. Hydrocarbon emissions versus carbon monoxide emissions.
4-42
A
-------
4.6 CONCLUSIONS FROM SITE 6 TEST
From the perspective of methods development and data quality, the conclusions
that may be drawn from the Site 6 testing are:
1. The ratio of hexavalent chromium to total chromium is relatively high
(greater than 10%) when lime is used for sludge conditioning, during good
combustion conditions, and under the long residence times required for
combustion of sludge in a multiple hearth incinerator.
2. The ratio of nickel subsulfide to total nickel was less than detectable (less
than 12%) under both furnace operating conditions.
3. There was good correlation between CO emissions and THC emissions.
4. The recirculating impinger reagent train with certain post-sampling
procedural modifications yielded acceptable results for the measurement of
hexavalent chromium at the outlet.
5. The process operating conditions used for the final series of test runs at
Site 6 greatly reduced the level of CO and THC emissions by
approximately 60%.
4-43
-------
A
-------
5.0 SAMPLING LOCATION SELECTION AND SAMPLING PROCEDURES
Sampling procedures used during the Site 6 program are briefly described in this
section. Standard EPA methods or draft EPA procedures were used for all sampling.
Emission sampling locations are discussed in Section 5.1, and methods and procedures
are discussed in Section 5.2.
5.1 EMISSION SAMPLING LOCATIONS
Emission sampling was conducted at the inlet to the control system (incinerator
discharge) and outlet of the control system which consists of venturi scrubber/
impingement tray scrubber at the outlet stack. The particulars for each of these
sampling locations are described below.
5.1.1 Inlet to the Control System
The sampling location for the inlet to the control system is shown in Figures 5-1
(Point 1) and Figure 5-2. The flue gas at this point was coming directly from the
incinerator at a temperature of about 1,000°F (538nC). As shown, the ducting exits the
furnace horizontally, turns, and goes down vertically into the venturi scrubber. The exact
direction of the flow was determined using a directional probe and the "Alternative
Measurement Site Selection Procedure" in EPA Method 1, Section 2.5 (40 CFR 60, July
1, 1988). The sampling train nozzles were then directed into the flow path for testing.
As in the majority of incinerators, the duct is not long enough to provide a uniform flow
pattern and meet the EPA Method 1 criteria. The objective of the program was,
however, to determine the ratios of nickel subsulfide to total nickel and hexavalent
5-1
-------
Outlet
Stack
Shaft
Cooling Air.
Dewatered
Sludge
LSI
i
to
=3
nl
Bypass Stack
Inlet
Control Devices
Sampling
Locations
Venturi
Scrubber
evices LJL in
Bottom
Ash
Flooded
Elbow
S^nihhflr
I.D.
Fan
Impingement
Tray
Scrubber
III
Conveyor System to Ash Disposal
Outlet to
Control Devices
Sampling
Location
Figure 5-1. Process diagram with sampling locations.
-------
Damper
(Closed)
—e—
FURNACE
6" Sample Port
o
1" Sample Port
o
To Venturi
Grating
Figure 5-2. Inlet sampling location.
-------
chromium to total chromium, rather than the absolute concentration of these emissions.
Considering this and the fact that four sampling systems were operated simultaneously at
the same point and the samples collected were analyzed separately to provide four
results for each run, the sampling location was adequate for the purposes of this test.
A 6-in sample port was installed at this location for the manual testing and a
1-in sample port was installed for extraction of the continuous emission monitoring
samples. Because of the likelihood of poor gas velocity distribution at this location, and
the fact that the inlet duct is refractory-lined and should not incorporate numerous ports,
the standard flue gas volumetric flow rate at the inlet location was not determined. The
outlet standard flue gas volumetric flow rate corrected using the inlet and outlet oxygen
concentration was used to calculate flow rates and emission for these locations. This
calculation eliminated the contribution from dilution by the shaft cooling air.
5.1.2 Outlet of the Control System
The sampling location at the outlet of the control system (stack) is shown in
Figures 5-1 (Point 2) and Figure 5-3. The flue gas at this point has passed through the
venturi scrubber and dilution air from the shaft cooling air system has mixed with the
flue gas upstream of the sampling location. The flue gas temperature at this point is
typically about 100°F (38°C). The sampling point is located in vertical, circular ducting
which has two ports at 90° apart. Prior to testing a velocity traverse was conducted to
determine the flue gas flow rate. Testing was then conducted at a single point of
average velocity in the outlet stack. The single point of average velocity was then used
to determine the flue gas flow rate for that test run.
5.2 SAMPLING EROCEDURES
5.2.1 Total Metals
%
Sampling for total metals at the inlet and outlet (stack) locations followed the
5-4
-------
Discharge
to Atmosphere
20.9'
r
N
B
19.5'
t
t
Air Flow
t
From
Scrubber
Traverse Points
2 Axes
8 Points / Axis
16 Total Points
36" Diameter
3.5'
SECTION N - N
2 Sampling Ports
i
N
Silencer
Figure 5-3. Duct dimensions with sampling port and point locations.
5-5
-------
procedures in the draft EPA method, "Methodology for the Determination of Trace
Metals Emissions in Exhaust Gases from Stationary Source Combustion Processes.'1 A
diagram of the multiple metals sampling train used in this test program is shown in
Figure 5-4 and a copy of the draft method is reproduced in Appendix B found in
Volume IV: Site 6 Draft Test Report, Appendices. The sampling train is similar to the
EPA Method 5 train (40 CFR Part 60) with the following exceptions:
• A glass or quartz nozzle and probe liner are used;
• a Teflon filter support is used;
• a low metals background quartz fiber filter is used;
• 5% nitric acid/10% hydrogen peroxide solution replaced water in the
impingers;
• the glassware is cleaned according to the procedure in Table 5-1; and
• the sample is recovered as shown in Table 5-2 and Figure 5-5.
For the inlet sampling system, the nozzle and probe liner were quartz glass and
the filter holder was borosilicate glass. For the outlet sampling system, the nozzle, probe
liner, and filter holder were borosilicate glass. In both cases, Teflon frits were used to
support the filters. The probe and filter holder were heated to 248°F _+ 25°F to prevent
moisture condensation. High purity quartz fiber filters without organic binder and with a
99.95% collection efficiency for 0.3 micron dioctyl phthalate (DOP) smoke particles were
used.
For the normal combustion testing, the samples were collected over a 2-hr period
at the inlet sampling site and over 2-, 3- or 4-hour period at the outlet location with no
special effort to control incinerator operating conditions. For the improved combustion
testing, the samples were collected over a 2-hour period at both the inlet and outlet
location, and the incinerator process conditions were modified to reduce the CO and
THC emissions. For the inlet sampling, the high moisture content at this location
required the use of a extra large (2-L) first impinger to allow operation of the train over
the 2-hr period. Sampling for total metals were conducted simultaneously with the nickel
5-6
-------
Thermometer
Glass Filter Holder
Thermocouple
Thermocouple Check
T Valve
Glass probe liner
Glass
Implngers with
Absorbing Solutions
Reverse-Type
Pitot Tube
Heated Area
Pitot x
Manometer
Ice Bath
Silica Gel
5% HNOo /10% H <>0
Empty
Bypass
Valve
Vacuum
Une —
Vacuum
Gauge
Thermocouples
Orifice
Main
Valve
nm
Air-Tight
Pump
Figure 5-4. Schematic of multiple metals sampling train.
-------
TABLE 5-1. TOTAL METALS GLASSWARE CLEANING PROCEDURES
NOTE: Use disposable gloves and adequate ventilation.
1. Soak all glassware in hot, soapy water (Alconox).
2. Rinse with tap water, three times.
3. Rinse with deionized water, three times.
4. Soak in 10% HN03 for 10 hours.
5. Rinse with deionized water, three times,
6. Cap glassware with Teflon tape.
7. Leave cleaned glassware capped until field assembly.
TABLE 5-2. SAMPLE RECOVERY COMPONENTS FOR TOTAL METALS TRAIN
Component Code
Item
4
2
3
1
AR
BH
PR-HNO3
F
Acetone rinses of probe liner, nozzle and front
half of filter housing
0.1 N nitric acid rinses of probe liner, nozzle,
and front half of filter housing
Filter
0.1 N nitric acid rinses of back half of filter
housing, HN03/H202 impinger contents, and
0,1 N nitric acid rinses of impingers 1, 2, 3, and
connecting glassware
5-8
-------
Probe Liner
and Nozzle
Brush line
with non-
metal lie
brush and
rinse with
acetone
Check liner
to see if
particulate
removed: if
not repeat
step above
Front Half of
Filter Housing
FiIter
Rinse with Brush with
nonmetallic
brush and
rinse with
acetone
Rinse three
times with
0.1 N
nitric acid
Rinse three
times with
0.1 N
nitric acid
I
F
<3)'
Carefully
remove filter
from support
with Teflon-
coated tweezer
and place in
petri dish
Brush loose
particulate
onto filter
AR
(2)
F
(D
Filter Support
and Back Half
of Filter
Housing
Rinse
three
times
with
0.1 H
nitric acid
1st Irrpinger
(Empty at
beginning
of test
Measure
impinger
contents
Empty
contents
into
container
Rinse three
times with
0.1 N
nitric acid
BH
<4)
2nd & 3rd
Impingers
HN03/H202
Measure
impinger
contents
Last impinger
Weigh for
moisture
Empty
contents
into
container
Discard
Rinse
three
times
with
0.1 N
nitric
acid
SF
(6)
* Number in parentheses indicates container number.
Figure 5-5. Sample recovery procedures for multiple metals train.
5-9
-------
speciation testing. Four sampling trains (quadruplicate trains) were used to collect the
required number of sampling for the multiple laboratory analyses. Only one sample was
intended for multiple metals analysis, two for nickel speciation, and the last was operated
in the event of sample system failure during testing.
Samples were analyzed by inductively-coupled argon plasma spectroscopy and
atomic absorption spectroscopy for total Cr, Ni, As, Pb, Cd, and Be. Samples were
handled and shipped according to the draft method.
5.2.2 Nickel/Nickel Subsulfide
Sampling for nickel/nickel subsulfide at the inlet and outlet locations followed the
draft EPA method, "Methodology for the Determination of Nickel Compound Emissions
from Stationary Sources." A diagram of the nickel sampling train is shown in Figure 5-6
and the method description is presented in Appendix B found in Volume IV: Site 6
Draft Test Report, Appendices. The sampling train is identical to the EPA Method 5
train (40 CFR Part 60) with the following exceptions:
• A glass or quartz nozzle and probe liner are used;
• a low metals background quartz fiber filter is used;
• the glassware is cleaned according to the procedure in Table 5-3; and
• the sample is recovered as shown in Table 5-4 and Figure 5-7.
For the inlet sampling system, the nozzle and probe liner were quartz glass and
the filter holder was borosilicate glass. For the outlet sampling system, the nozzle, probe
liner, and filter holder were borosilicate glass. Although not required, a Teflon frit was
used to support the filters. The probe and filter holder were heated to 248°F _+ 25°F to
prevent moisture condensation. High purity quartz fiber filters without organic binder
and with a 99.95% collection efficiency for 0.3 micron dioctyl phthalate (DOP) smoke
particles were used.
5-10
-------
Glass
Filter Holder
Thermometer
Quartz
Filter
O'
Thermocouple Check
T Valve
Thermocouple
Glass Nozzle
Glass Probe
Reverse-Type]
PHot Tube
Heated Area
Impinger8
Pitot
Manometer
Ice Bath
Silica Gel
Water
Empty
Bypass
Valve
Vacuum
Line
Vacuum
Gauge
Thermocouples
Orifice
Main
Valve
n rn
Air-Tight
Pump
Figure 5-6. Schematic of nickel/nickel subsulfide sampling train.
-------
TABLE 5-3. NICKEL/NICKEL SUBSULFIDE GLASSWARE CLEANING
PROCEDURES
NOTE: Use disposable gloves and adequate ventilation.
1. Soak all glassware in hot, soapy water (Alconox).
2. Rinse with tap water, three times.
3. Rinse with deionized water, three times.
4. Soak in 10% HN03 for 10 hours.
5. Rinse with deionized water, three times.
6. Cap glassware with Teflon tape.
7. Leave cleaned glassware capped until field assembly.
TABLE 5-4. SAMPLE RECOVERY COMPONENTS FOR THE NICKEL/NICKEL
SUBSULFIDE TRAIN
Component
Code
Item
1
AR
Acetone rinses of probe liner, nozzle and front
half of filter housing
2
F
Filter*
* The samples sent to BYU were immediately placed on dry ice.
The samples sent to RTI were placed in a desiccator and stored under a dry nitrogen
atmosphere.
5-12
-------
Filter and
Cyclone
Particulate
Hatter
(Fraction F)
Acetone
Front Half
Rinse
(Fraction AR)
0.1 N Nitric
Front Half
Rinse
(Discarded)
Back Half
Components
(Discarded)
Label sample
Combine rinses in
sample container
For BYU sample,
seal in petri dish
with Teflon tape
Store and ship
with dry ice
for analysis
Recover silica
gel, weigh, and
discard
Recover filter
and cyclone sample
dry with brush
For Zatka sample,
place in vacuum
filtration device
FiIter acetone
rinses through
particulate
Rinse back half
components with
0.1 M HN03 and
discard
Recover impinger
solution, measure
volune and discard
solution
Recover acetone
and store in labeled
container. Analyze
1 for every 8 samples
Recover particulate
into labeled petri
dish and store in
desiccator under
dry nitrogen until
analysis
Brush and rinse
nozzle, probe,
cyclone, and
front half of
filter holder 3
times with acetone
Brush and rinse
nozzle, probe,
cyclone, and
front half of
filter holder 3
times with 0.1 N
nitric solution
and discard
Figure 5-7. Schematic of sample recovery procedures for nickel train.
5-13
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The nickel speciation sampling trains were operated simultaneously with the
multiple metal train under both operating conditions.
A representative filter from each operational condition at the outlet sampling
location and bulk samples for the inlet location were sent for analyses by XANES and
EXAFS by Brigham Young University (BYU). These filter samples were placed on dry
ice immediately after recovery. The remaining inlet and outlet filters were analyzed Dr.
Vladimir Zatka. The inlet location samples were recovered and stored dry because of
the large volume of sample. For the outlet samples, the acetone probe rinse was vacuum
filtered through the filter. The acetone filtrate was archived with the exception of 6ne
sample for the 12 daily samples. That filtrate sample was analyzed for total nickel
to reaffirm that the nickel compounds are not soluble in acetone. The filters to be
analyzed by Dr. Zatka were stored in a desiccator under a dry nitrogen atmosphere and
sent to Dr. Zatka at the conclusion of each run condition; past experience has shown
that oxidation of nickel compounds can occur over a several week period.
5.2.3 Chromium and Hexavalent Chromium (^Recirculating Train)
Sampling for hexavalent and total chromium (Cr+
-------
GLASS
IMPINGERS-
TEFLON
IMPINGERS
IM
Lft
\
TEFLON
LINES
ASPIRATOR
150 ml
0.1N NaOH
100 ml
0.1 N NaOH
EMPTY
100 ml
0.1N HNCb
SILICA
GEL
RECIRCULATING
LIQUID
ICE BATH
TO
METHOD 5-TYPE
METERBOX
NOZZLE
Figure 5-8. Schematic of recirculating reagent sampling train for hexavalent chromium.
-------
• the entire surface exposed to sample is constructed of Teflon and/or glass;
• the Teflon and/or glass components are cleaned according to the
procedure in Table 5-5;
• the sample is recovered as shown in Table 5-6 and Figure 5-9; and
• the train does not have a filter section.
The sampling system was expected to be operated isokinetically, however, the
pressure drop across the aspirator made it difficult to maintain isokinetic sampling.
Two-, three-, and four-hour quad train runs were conducted at the outlet location under
each of the two test conditions.
The impinger solutions were taken from a common solution that was spiked with
radioactively labelled chromium to serve as a recovery standard for conversion of
hexavalent chromium in the samples. To verify the spike concentration, and as a check
for contamination, control samples of the solution were set aside and analyzed with the
field samples. Immediately after a sample was recovered from the sampling train, the
combined impinger solutions were pressure filtered through a 0.45 micron Teflon filter.
The filtrate was stored and shipped cold for next day analysis for hexavalent chromium.
Problems were encountered with these analyses and the next day analysis could not be
conducted.
The Teflon filters and nitric acid rinse samples analyzed for total chromium did
not require any special handling procedures. Filters and nitric rinse portions were
shipped to the respective laboratories for analysis.
+
5.2.4 Chromium and Hexavalent Chromium (Filter Train)
The Cr+6/Cr train sampling using the filter was conducted at the inlet for all runs
and at the outlet location on two runs (Runs 1 and 2). Sampling followed the
procedures of the draft EPA method, "Determination of Hexavalent Chromium from
Stationary Sources," dated December 13, 1984. A diagram of the sampling train is
shown in Figure 5-10 and the method description is not presented in this report since the
5-16
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TABLE 5-5. Cr+6/Cr TEFLON/GLASS COMPONENTS CLEANING PROCEDURES
NOTE: Use disposable gloves and adequate ventilation.
1. Soak all components in hot, soapy water (Alconox).
2. Rinse with tap water, three times.
3. Rinse with deionized water, three times.
4. Soak in 10% HN03 for 10 hours.
5. Rinse with deionized water, three times.
6. Cap Teflon/glassware with Teflon tape.
7. Leave cleaned Teflon/glassware capped until field assembly.
TABLE 5-6. SAMPLE RECOVERY COMPONENTS FOR THE Cr+6/Cr
RECIRCULATING TRAIN
Component Code Item
1 IMP 0.1 N potassium hydroxide impinger catches
and DI water rinses of Teflon impingers (1, 2,
3, and 4) and connecting tubing
2 NR 0.1 N nitric acid rinses of probe liner, nozzle,
and connecting tubing
3 F Filter*
"The impinger catch and KOH rinses will be pressure filtered on-site through a
0.45 micron Teflon filter immediately after sample recovery. The filter
to be analyzed by BYU will be placed on dry ice. The impinger catch and
rinses will shipped to RREL, General Engineering Laboratories, and Entropy
for next day analysis by the respective laboratories.
5-17
-------
Ueigh
Discard
Silica Gel
Filter
FiItrate
Filter Solution through
0.45 ura Acetate Filter
DI H20 Rinse All Components and
Combine with Impinger Solutions
Recover Teflon Impingers Together and
Measure Volume
Nozzle, Aspirator, Recirculation and
Sample Lines, Teflon Knockout Impinger
Teflon Impingers containing 0.1 N KOH
Nitrogen Purge of Train
Container 3 Container 1 Container 3
Component F Component IMP Component SG
Nitric Acid Rinse All Components
Recover contents of nitric impinger
Container 2
Component NR
Figure 5-9. Sample recovery scheme for hexavalent chromium recirculating impinger
train.
5-18
-------
Thermocouple
Glass Nozzle /^z
-------
data was not released by EPA. This procedure involves the use of the EPA Method 5
sampling train with the following modifications:
• A glass nozzle and probe liner are used;
• the glassware is cleaned according to the procedure in Table 5-7; and
• the sample is recovered as shown in Table 5-8 and Figure 5-11.
The sampling train nozzle, probe liner, and filter holder were made of borosilicate
glass. Both the probe and filter holder were heated to 248°F _+ 25°F to prevent moisture
condensation. High purity quartz fiber filters without organic binder and with a 99.95%
collection efficiency for 0.3 micron diocyly phathalate (DOP) smoke particles were used.
Two quad-train runs (Runs 1 and 2) were conducted at the outlet location under
normal incinerator operating conditions, each for 2 hr. Six of the eight filters were
spiked with isotopically labelled chromium, prior to the tests. To verify the spike
concentration and as a check for contamination, two unused spiked filters were set aside
as control samples. Upon completion of the sampling, the nozzle, probe liner, cyclone (if
applicable) and filter front half were rinsed three times with acetone and the rinses
placed in a sample container. The nozzle, probe liner, cyclone (if applicable), and filter
front half were then rinsed three times with 0.1 N HN03 and the rinses placed in a
separate container.
All inlet location hexavalent chromium sampling was conducted using the filter
train. The sample train preparation and sample recovery procedures were the same as
described above for the outlet hexavalent chromium filter train samples.
The spiked filter samples were analyzed by EPA's Environmental Monitoring
Systems Laboratory (EMSL) for hexavalent and total chromium. Immediately after
recovery they were placed on dry ice and shipped the same day to EMSL for next day
analysis. The unspiked filters and accompanying acetone and nitric rinses were analyzed
by EPA for total chromium only and did not require special handling procedures. The
used and unused isotopically spiked filters were analyzed for native and isotopically
labelled hexavalent chromium. The results of the filter train testing have not been
5-20
-------
TABLE 5-7. Cr/Cr+6 GLASSWARE CLEANING PROCEDURES
NOTE: Use disposable gloves and adequate ventilation.
1. Soak all glassware in hot, soapy water (Alconox).
2. Rinse with tap water, three times.
3. Rinse with deionized water, three times.
4. Soak in 10% HN03 for 10 hours.
5. Rinse with deionized water, three times.
6. Cap glassware with Teflon tape.
7. Leave cleaned glassware remained capped until field assembly.
TABLE 5-8. SAMPLE RECOVERY COMPONENTS FOR Cr/Cr+6 FILTER TRAIN
Component
Code
Item
1
AR
Acetone rinse of probe liner, nozzle, and front
half of filter housing
2
PR
0.1 N nitric acid rinses of probe liner, nozzle,
and front half of filter housing
3
F
Filter*
* Spiked filters placed on dry ice
for next day analysis.
immediately after recovery and sent that day to EMSL
5-21
-------
Fi Iter and
Cyclone
Particulate
Matter
(Fraction F)
Recover filter
and cyclone sample
dry with brush
Seal in petri dish
with Teflon tape
Label sample
Store and ship
with dry ice
for next day
analysis
Acetone
Front Half
Rinse
(Fraction AR)
Brush and rinse
nozzle, probe,
cyclone, and
front half of
filter holder 3
times with acetone
solution
Combine rinses in
sample container
Label sample
Store and ship cold
to laboratory
0.1 N Nitric
Front Half
Rinse
(Fraction PR)
Brush and rinse
nozzle, probe,
cyclone, and
front half of
filter holder 3
times with 0.1 N
nitric solution
Combine rinses in
sample container
Label sample
Store and ship
to laboratory
Back Half
Components
(Discarded)
Recover impinger
solution,
determine volume
and discard
solution
Rinse back half
components with
0.1 N HN03 and
discard
Recover silica
gel, weigh, and
discard
Figure 5-11. Sample recovery scheme for hexavalent chromium filter train.
5-22
-------
released by EMSL and are not presented in this report.
5.2.5 Continuous Emissions Monitoring Systems
Continuous emission monitoring systems (CEMSs) were used at the control device
inlet and outlet to monitor CO, C02, O* NO„ and S02; CO and total hydrocarbons
(THC as propane) were monitored at the stack outlet location. The primary intent of
the continuous monitoring effort was to: (1) determine concentrations of these, and
(2) provide a real-time indication of combustion conditions. The continuous monitoring
systems were calibrated daily, but no attempt was made to certify the monitors using
EPA test methods. The sampling and analytical systems used to determine CO, C02, 02,
NOv S02, and THC are discussed in the following sections.
5.2.5.1 Sample and Data Acquisition - Sample gas was drawn through a sample gas
conditioner consisting of an ice bath and knockout trap to remove moisture and thus
provide a dry gas stream for analysis. Sample gas from the gas conditioner was pumped
through a manifold at a flow rate which exceeded the total sample requirements of the
various gas analyzers. The sample manifold was used to provide slip stream sample
flows to each analyzer. A separate gas conditioning system and sample line was used for
the inlet and outlet sampling locations.
To maximize representativeness of the CEM measurements, all gases for
calibration were introduced at the inlet of the sample line. The instruments were
calibrated prior to each test run. At the end of each test run, a post-test calibration was
performed. If instrument drift exceeded 2% of the span value for any measurement, the
data was adjusted linearly to account for the drift. Data from the analyzers was collected
and recorded using a microprocessor data acquisition/reduction system. A hard copy of
the reduced data (engineering units) was printed at the end of each sample run and the
raw data were stored on the computer hard drive and on floppy disks.
5-23
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5.2.5.2 Carbon Monoxide/Carbon Dioxide Analysis - A TECO Model 48 analyzer was
used to measure CO concentrations in the flue gas. The TECO Model 48 is a gas filter
correlation (GFC) analyzer. The instrument measures the concentration of CO by
infrared adsorption at a characteristic wavelength. A Fuji 3300 analyzer was used to
determine C02 concentration. The Fuji 3300 is a non-dispersive infrared (NDIR)
analyzer.
5.2.5.3 Oxygen Analysis - A Teledyne Model 320P-4 02 analyzer was used to
continuously measure flue gas oxygen concentrations. The Teledyne analyzer uses an
electro-chemical cell to produce a linearized voltage signal that is proportional to the
ratio of oxygen concentration of a reference gas (ambient air) and the oxygen
concentration of the sample.
5.2.5.4 Nitrogen Oxides (NOx) Analysis - A TECO Model 10 analyzer was used for NOs
measurement. This instrument determines NO, concentrations by converting all nitrogen
oxides present in the sample to nitric oxides and then reacting the nitric oxide with
ozone. The reaction produces a chemiluminescence proportional to the NOt
concentration in the sample. The chemiluminescence is measured using a high-sensitivity
photomultiplier. Also, during the time between the manual sampling runs, the ratio of
NO to N02 was determined. This ratio is of interest because N02 can be effectively
removed by the venturi scrubber.
5.2.5.5 Sulfur Dioxide (S02) Analysis - Sulfur dioxide in the flue gas was measured using
a Maihak IJNOR 6N analyzer. This instrument measures S02 on the basis of infrared
adsorption.
5.2.5.6 Total Hydrocarbon Analysis - A Beckman 400A analyzer was used to measure
total hydrocarbons (THC) as propane in the flue gas. This instrument is a continuous
flame ionization analyzer (FIA). The detector is a burner where a regulated flow of
sample gas passes through a flame sustained by regulated amounts of air and hydrogen.
5-24
-------
Hydrocarbons passing through the flame undergo a complex ionization that produces
electrons that are detected by polarized electrodes. The THC analyzer was calibrated
using propane standards, and the THC concentrations were reported in parts per million
by volume (ppmv) as propane.
5.2.6 EPA Methods 1. 2. 3. and 4
The methods used to determine the flue gas moisture content, molecular weight,
and volumetric flow rate are described in the following sections.
5.2.6.1 Volumetric Gas Flow Rate Determination - The volumetric gas flow rate at the
outlet location was determined during this program using procedures described in EPA
Method 2. Based on this method, the volumetric gas flow rate is determined by
measuring the cross-sectional area of the stack and the average velocity of the flue gas.
The average flue gas velocity is calculated from the average pitot tube pressure (delta P),
the average flue gas temperature, the wet molecular weight, and the absolute static
pressure. Temperature and delta P profile data was obtained by traversing the outlet
stack prior to the each test run. The number of sampling points required to measure the
average gas velocity was determined using the procedures in EPA Method 1. The
sampling points and their distances from the duct wall is a function of the proximity of
the sampling location to the nearest upstream and downstream flow disturbance.
Temperature and pressure profile data was measured at each of the sampling
points using an S-type pitot tube. A calibrated aneroid barometer was used to obtain
barometric pressure readings each day. The static gas pressures at the inlet and outlet
locations were measured by disconnecting one side of the S-type pitot and then rotating
the pitot so that it was perpendicular to the gas flow.
The standard flue gas flow rate at the inlet location was not measured; but was
calculated by correcting the measured standard flue gas flow rate with difference
between the inlet and outlet oxygen concentration. This calculation corrects for the
dilution air from the shaft cooling that is entering the duct between the inlet and outlet
5-25
-------
locations. Isokinetic sampling was achieved by measuring the pitot tube pressure (delta
P) at a single point at regular intervals during sampling. The isokinetic calculations were
performed using these measured values.
5.2.6.2 Flue Gas Molecular Weight Determination - The integrated sampling technique
described in EPA Method 3 was used to obtain composite flue gas samples at the inlet
and outlet locations for fixed gas (02, C02) analysis. A small diaphragm pump and a
stainless steel probe were used to extract a single-point flue gas sample which was
collected in a Tedlar bag. Moisture was removed from the gas sample by a water-cooled
condenser so that the fixed gas analysis is on a dry basis.
The composition of the gas sample was be determined using an Orsat analyzer
only when there was problems with the CEMS. When using the Orsat, if more than six
passes were required to obtain a constant (_<. 0.3% difference, absolute) reading for
either 02 or C02, the appropriate absorbing solution was replaced. The S02
concentration was well below the level at which correction of the C02 concentration is
required (5,000 ppm).
5.2.6.3 Flue Gas Moisture Determination - The moisture content of the flue gas was
determined using the methodology described in EPA Method 4. Based on this method,
a known volume of particulate-free gas was pulled through a chilled impinger train. The
quantity of condensed water was determined gravimetrically and then related to the
volume of gas sampled to determine the moisture content.
During this project, the moisture content of the flue gas was determined
simultaneously during the operation of the manual sampling trains. The volume of
solution in the impingers used with these trains was determined before and after
sampling. The volume increase in water was then related to the volume of gas sampled
to calculate the moisture content.
5-26
A
-------
5.2.7 Process Samples
Samples of sludge feed, bottom ash, and scrubber inlet (influent) and outlet
(effluent) water were collected during the flue gas sampling. These process samples
were composites of grab samples collected at regular intervals and combined after the
run was completed. All process samples were stored in 500-ml polyethylene sample
containers prepared according to EPA Protocol C.
The sludge feed sampling begin approximately 30 min prior to the start of the flue
gas sampling to account for the residence time of the sludge in the furnace. The sludge
feed samples for metals analysis were collected from the feed conveyor at 30-min
intervals. The volume of each grab sample was approximately 250-ml. The grab samples
were combined and homogenized in a plastic bucket using a mortar mixer for at least 10
min. From the homogenized mixture, two 500-ml portions were taken and saved for
metals analysis, proximate and ultimate analyses, and analyses of moisture content and
heating value.
Ash samples were collected from the bottom hearth of the incinerator. A 1-L
grab sample was taken once during each test run using a scoop. The total mass flow of
the ash discharge was estimated based on the sludge feed rate and the sludge ash
content.
Scrubber inlet and outlet water samples consisted of the composite of two equal
grab samples collected during each run. These samples were thoroughly mixed before
aliquots were taken for analysis.
5.3 PROCESS DATA
Incinerator and control system operating parameters were monitored during all
manual test runs to characterize the system operations. The parameters monitored are
presented in Table 5-9.
5-27
-------
TABLE 5-9. PROCESS MONITORING DATA
Parameter
Frequency of
Readings
Source of Readings
Incinerator Operating Data
Hearth Temperatures
Furnace Discharge Temp
Incinerator Outlet 02
Auxiliary fuel usage
Sludge Feed Characteristics
Moisture (wt %)
Volatiles (wt %)
Heating Value
Scrubber System Operating Data
Delta P (in. H20)
Scrubber Inlet Temp (°F)
Scrubber Outlet Temp (°F)
30 minutes
30 minutes
Continuous
As used
Once per run
Once per run
Once per run
30 minutes
30 minutes
•
15 minutes
Plant operating log
Plant operating log
Entropy CEMSs
Plant operating log
Entropy analysis
Entropy analysis
Entropy analysis
Plant operating log
Plant operating log
Plant operating log
5-28
A
-------
6.0 ANALYTICAL PROCEDURES
The laboratory activities for this program involved (1) analytical procedures
designed to speciate chromium and nickel compounds based on their valency state; (2)
analysis of selected samples for arsenic, beryllium, cadmium, chromium, lead, and nickel.
The sample matrices included flue gas samples, sludge samples, bottom ash samples, and
scrubber water samples. Sludge samples were also subjected to moisture, proximate and
ultimate analyses, and heating value determination. A summary of the analytical
methods employed is provided in Table 6-1. Each of these methods are described briefly
in the sections below and detailed procedures are included in Volume IV, Appendices.
6.1 CHROMIUM SPECIATION AND ANALYSES
Several analytical procedures were employed to speciate chromium compounds in
the samples to determine the ratio of hexavalent chromium (Cr+6) to total chromium
(Cr). Since the hexavalent chromium filter train analytical results were not released for
publication in this report and were not conducted under the RREL contracts, the
analytical techniques will not be discussed. Flow diagrams for application of these
procedures are provided in Figure 6-1 for impinger train samples. Samples from the
impinger train were analyzed using ion chromatography with a Cr+6-specific post column
reaction (IC/PCR) for Cr+6 performed by Entropy and inductively-coupled argon plasma
emission spectroscopy (ICAP) for total Cr performed by Research Triangle Institute
(RTI). Entropy also performed gamma emission measurements of labeled hexavalent
chromium (slCr+6) spiked into samples to monitor conversion of chromium species that
may occur during sampling, sample handling, and sample preparation.
6-1
-------
TABLE 6-1. SUMMARY OF SAMPLING AND ANALYTICAL METHODS
Sample Type
Parameter
Analysis Method
Flue Gas
Total chromium, Cr+6>,b
IC/PCR, gamma counter
ICAP/AAS, ICP/MS, XANES
• Total nickel,
nickel subsulfides'
• Particulates, metalsd
EPA Draft Method,
ICAP/AAS, XANES
Gravimetric, ICAP/AAS
Solid/Liquid
Feed sludge
• Scrubber water:
inlet
outlet
• Bottom ash
"Recirculating train for hexavalent chromium, with 0.1 N KOH impinger
solution.
bMethod 5-type sampling train for chromium.
'Method 5-type sampling train for nickel.
dMetals analysis included at a minimum chromium, nickel, arsenic, lead,
cadmium, beryllium, and mercury.
"The sludge samples were analyzed for metals, moisture, proximate and
ultimate analysis, and heating value by the methods described in Section 5.0.
6-2
-------
Residue—>•
Filtrate
FiItrate
Acid Digest
Total Cr
Analysis
Cr and 53Cr
Analysis
by I CP/MS
IC/PCR Analysis
for Cr+6
IC/PCR Analysis
for Cr+6
Ganma Count
of Residue
for 51Cr
Ganvna Count
of Residue
for 51Cr
Filter through
0.45 Micron
Teflon filter
Filter through
0.45 Micron
Teflon filter
1 Contai nation
of Residue and
HN03 Solutions
for Total Cr
Preconcentrate
for 53Cr+6
Analysis by ICP/MS
Recirculatory
Sampling Train
Impinger Sol.
and D.I. Rinse
Recirculatory
Sampling Train
Impinger Sol.
and D.I. Rinse
Ganvna Count
of IC Fractions
for Speciation
of 51Cr
Recirculatory
Sampling Train
HN03 Impinger
and Train Rinse
Recirculatory
Sampling Train
HN03 Impinger
and Train Rinse
Recirculatory Train A
with EHSL 53Cr+6 Spike
Recirculatory Trains B, C, and D
with Entropy 5lCr+6
Figure 6-1. Analytical protocol for quadruplicate recirculatory train hexavalent
chromium sampling at outlet location.
6-3
-------
6.1.1 IC/PCR Analysis for Hexavalent Chromium
The IC/PCR analysis for Cr+* was performed by Entropy on the recirculatory
(RC) impinger train samples. Samples consisted of alkaline impinger solutions from the
recirculatory impinger train.
Entropy performed on-site filtration of the alkaline impinger samples employing
an all-Teflon pressure filtration device and a Teflon membrane filter with a 0.45 micron
pore size (see Figure 6-1). The filtrate was analyzed for Cr+4. For samples with the 5lCr
spike, the gamma emissions from the filter residue were measured before combining the
residue with the HN03 solutions for digestion prior to total Cr analysis.
In all cases, the resulting filtrates were analyzed by the IC/PCR method. To
determine the ratio of the soluble 5lCr+3 and 5lCr+* species in Entropy-spiked samples,
0.5 ml fractions were collected during the IC/PCR analysis, and measured for the
gamma emissions for each fraction.
The IC/PCR system was calibrated with a series of three Cr+6 standard solutions
with concentrations ranging from 1.0-to-100 ng/ml, prepared fresh daily from a working
standard. The laboratory verified the concentration of their working standard solution by
ICAP analysis or ICP/MS analysis for total Cr. A calibration check sample was analyzed
with every ten samples.
6.1.2 ICAP Analysis for Total Chromium
For RC trains, residue samples from the filtration of the alkaline impinger
solution were analyzed with the corresponding HN03 solutions and rinses for total
chromium (see Figure 6-1). Where appropriate, an aliquot of HNOa solutions and rinses
was first measured for gamma emissions prior to the sample being reduced to near
dryness. After being reduced to near dryness, the HN03 sample was combined with
residue sample for HNOa/HF digestion.
Sludge samples, bottom ash samples, and scrubber water samples were analyzed
-------
for total Cr during the ICAP analysis for the other target metals, described in
Subsections 6.3.2, 6.3.3, and 6.3.4, respectively.
6.1.3 XANES Analysis for Chromium Speciation
XANES spectroscopy can determine the chemical state of an element without the
necessity for chemical pretreatment which may alter the chemical state. XANES
spectroscopy requires a high intensity X-ray source provided by synchrotron radiation.
For this test program, Brigham Young University (BYU) arranged for access to the
Brookhaven synchrotron. Eight-hour irradiation times were required to obtain spectra
for samples in the 300-to-1000 ug/g concentration range. The irradiation was performed
at an electron energy of 3.0 GeV with a current of approximately 50 mA. The X-ray
beam is monochromatized with a double crystal silicon spectrometer and a 1-mm
(vertical dimension) entrance slit which, with this configuration, produces a resolution of
approximately 0.4 eV at the vanadium K edge at 5.465 KeV.
A 4-in2 section of each filter sample was placed in the sample chamber at an
angle 45 degrees to the X-ray beam, and the sample chamber was purged with helium.
The sample spectra was measured by the fluorescence extended X-ray absorbance fine
structure technique with a fluorescence detector.
Reference spectra obtained from standards with known ratios of Cr+* to total Cr.
A separate report prepared by BYU is presented in Volume IV Site 6 Draft Test
Report, Appendices.
6.2 NICKEL SPECIATION AND ANALYSIS
Two different procedures were employed to speciate nickel compounds in samples
to determine the ratio of nickel subsulfide (Ni3S2) to total nickel (Ni). The first
procedure, X-ray absorption near-edge structure (XANES) analysis, were performed by
BYU. The second procedure, to be performed by Dr. Zatka, employed the Nickel
Producers Environmental Research Association (NiPERA) method. The analytical
6-5
-------
protocol for the inlet sampling location and outlet location are presented in Figure 6-2
and Figure 6-3, respectively.
6.2.1 XANES Analysis for Nickel Speciation
XANES spectroscopy was employed by BYU to determine the ratio of Ni3S2 to
total Ni. The analytical procedure was identical to the procedure described in
Subsection 6.1.3 for chromium speciation, with the exception that reference spectra was
determined on standards with known ratios of Ni3S2 to total Ni. The detection limit for
Ni3S2 by XANES is reported to be 100 ug/g for a one hour irradiation.
6.2.2 NiPERA Method for Nickel Speciation
The NiPERA sequential leaching method was employed by Dr. Zatka to
determine the ratio of sulfidic nickel species, Ni3S2 and nickel sulfide (NiS), to total Ni.
The NiPERA method is not capable of speciating between Ni3S2 and NiS. The NiPERA
method involved two sequential teachings of the solid sample with a series of solutions
with increasing oxidation strength. The leaching procedure was performed in an all
Teflon vacuum filtration device fitted with a cellulose membrane filter with a 0.2 micron
pore size. The water soluble Ni species was leached during the first step and the sulfidic
Ni species was leached during the second step.
For this test program, the first and second leach solutions were collected
separately. The leached residue was digested prior to Ni analysis following the SW-846,
Method 3050 procedure described below in Subsection 6.3.2.
The three Ni subsamples were be analyzed for total Ni by atomic absorption (AA)
analysis. The AA was calibrated with a series of seven Ni standard solutions ranging in
concentration from 0.5-to-20 ug/ml. An interference check sample was analyzed prior to
sample analysis, and a calibration check sample was analyzed with every 10 samples. A
reagent blank was carried through the procedure and analyzed with the actual samples.
6-6
A
-------
Freeze with Dry Ice
Store Desiccated
under Dry N2
Store Desiccated
under Dry N2
Determine Particulate
Hass by Oraft Protocol
Archive sample fort
Nickel Speciation by
NiPERA Method
Ship Frozen to BYU
for Nickel Speciation
by XANES Method
Ship to RTI for*
Nickel Speciation by
NiPERA Method
ICAP Screen for Target
Metals (As, Be, Cd, Cr,
Pb, and Ni) with GFAA
Confirmation, as needed
AREAl Multi-Metal
Sampling Train D
(Combined Front and
Back Half Analysis)
Particulate Matter
(Filter, Probe Rinse
and Cyclone Catch)
Method 5 - Type
Sampling Train C
Particulate Matter
(Filter, Probe Rinse
and Cyclone Catch)
Method 5 - Type
Sampling Train B
Method 5 - Type
Sampling Train A
Particulate Matter
(FiIter and Dry
Cyclone Catch)
* RTI unable to get reliable results.
t Archived samples were sent to Zatka for sample analyses.
Figure 6-2. Analytical protocol for quadruplicate nickel sampling at the scrubber inlet
sampling location.
-------
Filter and
Cyclone
Particulate
Matter
(Fraction F)
Acetone
Front Half
Rinse
(Fraction AR)
0.1 N Nitric
Front Half
Rinse
(Discarded)
Back Half
Components
(Discarded)
Recover silica
gel, weigh, and
discard
label sample
Combine rinses in
sample container
Store and ship
with dry ice
for analysis
Recover filter
and cyclone sample
dry with brush
For BYU sample,
seal in petri dish
with Teflon tape
For RTI sample,*
place in vacuun
fiItration device
FiIter acetone
rinses through
particulate
Rinse back half
components with
0.1 N HN03 and
discard
Recover impinger
solution, measure
volume and discard
solution
Recover acetone
and store in labeled
container. Analyze
1 for every 8 samples
Recover particulate
into labeled petri
dish and store in
desiccator under
dry nitrogen until
analysis
Brush and rinse
nozzle, probe,
cyclone, and
front half of
fiIter holder 3
times with 0.1 N
nitric solution
and discard
Brush and rinse
nozzle, probe,
cyclone, and
front half of
fiIter holder 3
times with acetone
* RTI unable go get reliable results, archived samples sent to Zatka
Figure 6-3. Analytical protocol for quadruplicate nickel sampling at the scrubber outlet
sampling location.
6-8
A
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6.3 MULTIPLE METALS ANALYSIS
Analysis of flue gas samples, dewatered sludge samples, incinerator bottom ash,
and scrubber water samples for the target metals: arsenic (As), beryllium (Be), cadmium
(Cd), chromium (Cr), lead (Pb), and nickel (Ni), employed matrix-specific preparation
and digestion followed by ICAP analysis. All prepared sample solutions were initially
archived for possible reanalysis for As and Pb by graphite furnace atomic absorption
spectroscopy (GFAAS). Since the sample, sludge, and ash could determine the results
for Cd, Cr, Pb, and Ni, no samples were reanalyzed by GFAAS.
6.3.1 Flue Gas Samples
Flue gas samples were analyzed for the target metals following the procedures
described in the draft AREAL procedure. A copy of the draft method is provided in
Volume IV Site 6 Draft Test Report, Appendices, and an analytical flow chart is
provided in Figure 6-4. The particulate mass was determined for the front half portion
of the sampling train. The particulate matter was subjected to microwave HN03/HF
digestion in a pressure relief vessel. The nitric acid/hydrogen peroxide impinger solution
and nitric acid rinses were reduced to near dryness and digested with HN03. The front
and back half digestates were combined for a single ICAP analysis for As, Be, Cd, Cr,
Pb, and Ni. A portion of the digestate was initially archived for possible reanalysis of As
and Pb by GFAAS. Since all metals of interest were detected, GFAAS was not
performed.
The ICAP was calibrated with a series of five standard solutions containing the
target metals ranging in concentrations from 0-to-100 ug/ml (depending on the element).
The Cr and Ni standards were prepared in one solution and the As, Be, Cd, and Pb was
prepared in a second solution. An interference check sample was analyzed prior to
sample analysis, and a calibration check sample was analyzed with every 10 samples. A
reagent blank was carried through the procedure and analyzed with the actual samples.
6-9
-------
Container 3
HN03 Probe Wash
(Labeled FH)
Container 2
Acetone Probe Uash
(Labeled AR)
Container 1
FiIter
(Labeled F)
Container 4
Knockout &
HN03/H202 Impingers
Acidify to pH2
with core. HN03
Desiccate to
constant weight
Determine residue
weight in beaker
Reduce to dryness
in a tared beaker
Solubilize residue
with conc. HNQ3
Determine filter
particulate weight
Analyze for
metals by GFAAS*
Fraction 1A
Filter and dilute
to known volume
Fraction 1
Analyze by I CAP for
target metals
Fraction 1A
Reduce volivne
to near
dryness and
digest with
HN03 and H202
Acidify half
of remaining
sample to pH
of 2 with
conc. HN03
Fraction 2A
Reduce volume to
near dryness and
digest with HF and
conc. HN03 using
microwave digestion
Divide into 0.5 g
sections and digest
with conc. HF and
HN03 using pressure
relief microwave
digestion procedure
* Analysis by for metals found at less than the ICAP working level.
Figure 6-4. Sample preparation and analysis scheme for multiple metals trains.
6-10
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6.3.2 Dewatered Sludge Samples
Dewatered sludge samples was analyzed for the target metals after determination
of the moisture and ash content, heating value, and proximate and ultimate analyses
following ASTM D3174, D3175, D3177, D3178, D3179, and D2361. A dried portion of
the sludge sample was subjected to microwave HN03/HF digestion in a pressure relief
vessel identical to the flue gas particulate samples described above. This digestion
procedure was chosen to provide for comparison of the metals in the sludge with the flue
gas samples and the bottom ash samples, described below. The digestion solution was
analyzed by ICAP following the procedures described for the flue gas samples and
archived for possible GFAAS analysis.
6.3.3 Incinerator Bottom Ash Samples
Incinerator bottom ash samples were analyzed for the target metals including Hg
after determination of the moisture content following ASTM D3174. The procedures
used as the same as described above for the sludge samples.
6.3.4 Scrubber Water Samples
Portions of the inlet and outlet scrubber water samples was acidified with HN03
and reduced to near dryness on a hot plate. If any solids remain after the initial
digestion, the sample was subjected to the microwave HN03/HF digestion described
above. The digested solutions were analyzed by ICAP for all the target metals except
Hg following the procedures described for the flue gas samples; a portion of the solution
was initially archived for possible GFAAS analysis. No additional GFAAS analyses were
required.
6-11
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6.4 SLUDGE SAMPLE ANALYSES
Dewatered sludge samples were subjected to the following: moisture analysis,
proximate and ultimate analyses. Ultimate and proximate analyses were combinations of
measurements performed with the following ASTM procedures; ash by ASTM D3174,
volatile matter by ASTM D3175, carbon and hydrogen by ASTM D3178, nitrogen by
ASTM D3179, chlorine by ASTM D2361, and sulfur by D3177. These procedures are
detailed in the ASTM methods and the methods are provided in Volume IV Site 6 Draft
Report, Appendices. The heating value was calculated from the carbon and hydrogen
content determined by ASTM D3178.
6-12
-------
7.0 QUALITY ASSURANCE AND QUALITY CONTROL
This section discusses the quality assurance and quality control (QA/QC) program
implemented for the sewage sludge incineration test program and the QA/QC results for
the Site 6 test. The objectives of and basic activities for the QA/QC program are briefly
discussed in the section below. Summaries of the QC data and QA audit data are
presented in Sections 7.2 through 7.4.
7.1 QA/QC PROGRAM OBJECTIVES
For any environmental measurement, a degree of uncertainty exists in the data
generated due inherent limitations of the measurement systems employed. To assess the
quality of the data and to establish limitations on the ultimate use of the data, a
comprehensive QA/QC program was implemented for this test effort. The objective of
the QA/QC program was to produce complete, representative, and comparable data of
known quality. To meet these objectives, a thorough Quality Assurance Project Plan
(QAPP), integrated with the sampling and analysis plan, was prepared. All elements of
the QAPP were implemented during the sampling and analytical phases of the sewage
sludge incinerator test program for Site 6. In the QAPP, the specific EPA methods,
other standard test methods, and state-of-the-art sampling/analytical procedures to be
employed and QC activities performed were described.
The terms used to define the QA/QC objectives established for the test program
are defined as follows:
(1) Data Quality: The total of features and characteristics of a product (measurement
data) that determine its ability to satisfy a given purpose. These characteristics
are defined as follows:
7-1
-------
• Precision - A measure of mutual agreement among individual
measurements of the same property, usually under prescribed similar
conditions. Precision is best expressed in terms of the standard deviation
(or the relative standard deviation). Various measures of precision exist
depending upon the prescribed conditions.
• Accuracy - The degree of agreement of a measurement (or an average of
measurements of the same parameter), X, with an accepted reference or
true value, T, is usually expressed as the difference between two values, X-
T, or the difference as a percentage of the reference or true value, 100 (X-
T)/T, and sometimes expressed as a ratio, X/T. Accuracy is a measure of
the bias in a system.
• Completeness - A measure of the amount of valid data obtained from a
measurement system compared with the amount that was expected to be
obtained under correct normal conditions.
• Comparability - A measure of the confidence with which one data set can
be compared with another.
• Representativeness - The degree to which data accurately and precisely
represent a characteristic of a population, variations of a parameter at a
sampling point, or an environmental condition.
(2) Quality Control: The overall system of activities whose purpose is to provide a
quality product or service: for example, the routine application of procedures for
obtaining prescribed standards of performance in the monitoring and
measurement process.
7-2
-------
(3) Quality Assurance: A system of activities whose purpose is to provide assurance
that the overall quality control is in fact being done effectively.
• It is the total integrated program for assuring the reliability of monitoring
and measurement data.
• It is the system for integrating the quality planning, quality assessment, and
quality improvement efforts of various groups in an organization to enable
operations to meet user requirements at an economical level. In pollution
measurement systems, quality assurance is concerned with the activities
that have an important effect on the quality of the pollutant measurements,
as well as the establishment of methods and techniques to measure the
quality of the pollution measurements. The more authoritative usage
differentiates between "quality assurance" and "quality control," where
quality assurance is the "system of activities to provide assurance that the
quality control system is performing adequately."
The QAPP emphasized: (1) adherence to the prescribed sampling procedures, (2)
careful documentation of sample collection and analytical data, (3) the use of chain-of-
custody records, (4) adherence to prescribed analytical procedures, and (5)
implementation of independent systems audits and performance audits. These QA/QC
efforts provide a mechanism to control data quality within acceptable limits and provide
the necessary information to assess the quality of the data.
The data quality objectives for the measurement parameters are presented in
Table 7-1. These data quality objectives are for analysis of the samples collected during
emission testing at the individual sites. Where possible, the precision and accuracy for
the measurement parameters were obtained from the specified methods or from EPA
collaborative tests. This type of data was not available for the determination of metals
in the flue gas and solid samples.
7-3
-------
TABLE 7-1. PRECISION, ACCURACY AND COMPLETENESS OBJECTIVES
Parameter
Total particulate (EPA Method 5)
Nickel/metals distribution in particulate
Cr+< distribution in particulate
Flue gas total metal
Continuous Emission Monitoring
(02, C02, CO, THC, NO,, S02)
Feed sludge: Metals/Cr/Ni
Velocity/volumetric flow rate (Methods 1&2)
Fixed gases/molecular weight (Method 3)
Moisture (EPA Method 4)
Flue gas temperature (thermocouple)
Scrubber Water Influent and Effluent:
Metals/Cr/Ni
Precision' Accuracy* Completeness1*
(%)
(%)
(%)
± 11
± 10
90
5C
NA
90
5C
NA
90
NA
NA
90
± 20®
± 20f
90
NA
NA
90
± 6
± 10
95
± ky
± 20*
90
± 20
± 10
90
± 2°F
± 5°F
90
NA
NA
90
'When possible, precision and accuracy based on collaborative tests results.
bValid data percentage of total tests conducted.
eEPA collaborative test data not available.
^Percent difference for duplicate analyses, where
Percent = First Value - Second Value x 100
Difference 0.5 (First + Second Values)
Coefficient of variation (CV) determined from daily analyses of a control
sample, where
% CV = Standard Deviation x 100
Mean
Relative error (%) derived from audit analyses, where
Percent - Measured Value - Theoretical Value x 100
Error Theoretical Value
NA = Not applicable. For precision, because multiple samples not to be taken
or analyzed; for accuracy, because audit samples not available.
7-4
A
-------
7.2 FLUE GAS SAMPLING AND ANALYSIS QC RESULTS
Quality control activities for flue gas sampling include: (1) equipment calibrations,
(2) glassware and equipment cleaning, (3) procedural checks during sampling and sample
recovery, (4) sample custody procedures, (5) procedural checks during sample analysis,
and (6) the use of labeled surrogates, field blanks, laboratory blanks, QC check samples,
matrix spikes, and duplicate analyses. The QC results for these activities are discussed in
this section, with activities generally applicable to all the flue gas sampling methods
discussed in Section 7.2.1 and method specific results discussed separately in Sections
7.2.2 and 7.2.3.
7.2.1 General Flue Gas Sampling Quality Control
For all of the flue gas sampling methods, pre-test calibrations were performed on
the sampling nozzles, pitot tubes, temperature sensors, and analytical balances. Both
pre- and post-test calibrations were performed on all dry gas meters employed during
flue gas sampling. All equipment met the criteria specified in the QAPP for this
program. The post-test calibrations for the all dry gas meters employed during sampling
were within the specified 5% agreement with the pre-test calibrations.
All sampling train glassware and Teflon components, sample containers, and
sampling tools were precleaned initially with soap and water followed by a DI water and
0.1 N nitric acid rinse, and a final DI water rinse. During on-site testing, all sampling
train glassware was capped with Parafilm or Teflon tape prior to and immediately after
each test run. A clean, dust-free environment was maintained on-site for sampling train
assembly and sample recovery.
QC activities during flue gas sampling included:
• Visual equipment inspection;
• collection of sample train blanks;
• ensuring the proper location and number of traverse points;
7-5
-------
• conducting pre-test and post-test pitot tube and sample train leak
checks;
• maintaining proper temperature at the sample probe (if applicable),
filter housing, and impinger train outlet;
• maintaining isokinetic sampling rates; and
• recording all data on preformatted field data sheets and noting any
unusual occurrences on a test log sheet.
Leak check and isokinetic calculation results are presented separately for each
method in the sections that follow. The QC criterion for leak checks was a rate less than
or equal to 0.02 cubic feet per minute at 15 in Hg vacuum for the pre-test check and, for
the post-test check, at the highest vacuum encountered during sampling. For isokinetic
sampling, the QC criterion was to have the average sampling rate within 10% of
isokinetic.
Detailed procedures for sample recovery, specific for each method and described
in the QAPP, were followed. Graphic flow charts of each procedure were readily
available in the recovery area.
Sample custody procedures employed for all flue gas samples and process samples
emphasized proper labeling and preparation of chain-of-custody records for transfer of
the samples to the different laboratories involved in the test program. Pre-printed labels
were prepared with a unique alphanumeric code for each sample collected or generated
during sample recovery. Samples were also logged in a master logbook. Each sample
container was sealed with a custody seal to ensure sample integrity. Samples were stored
and shipped to the laboratories following the method-specific procedures. Upon receipt
of the samples, each laboratory logged the samples into their own sample custody system
and stored the samples under the prescribed conditions.
7.2.2 Sampling and Analysis for Particulate. Total Metals and Nickel/Nickel Subsulfide
Sampling and analysis for particulate matter and total metals followed the draft
EPA method, "Methodology for the Determination of Trace Metals Emissions in
7-6
A
-------
Exhaust Gases from Stationary Source Combustion Processes." Sampling for nickel and
nickel subsulfide followed EPA Method 5 for sample collection and the NiPERA method
for sample analyses. Quadruplicate sampling trains were employed with three sampling
trains used to collect samples for nickel speciation (Trains A, B and C) and a single train
used to collect particulate matter/total metals sample (Train D). The results of the QC
operations during sampling and analysis are presented in the following sections.
7.2.2.1 Sampling Operations - Isokinetic calculation and leak check results for the
scrubber outlet sampling location are summarized in Table 7-2. Nine of the 28 sampling
trains operated at the scrubber outlet for collection of particulate matter/total metals
and nickel/nickel subsulfide samples were less than 90% isokinetic. However, all of
these runs were within 6% of the allowable. All the sampling trains (Train D) operated
to collect the particulate matter/total metals met the isokinetic criterion. The nickel
speciation results from Train A were not reported due to analytical problems. The
samples from Train B were sent to BYU for XANES and EXAFS analyses. The
samples from Train C were speciated by Dr. Vladimir Zatka, the developer of the
NiPERA analytical method. The instrumental techniques performed by BYU confirmed
the wet chemical techniques conducted by Dr. Zatka.
Although some bias due to particle size differentiation may have been introduced
by nonisokinetic sampling, it is generally accepted that very small particles are emitted
from venturi scrubbers, and isokinetic sampling is not as critical under these conditions.
The post-test leak check results for all 28 outlet sampling trains met the QC
criteria.
At the inlet sampling location, isokinetic sampling was not performed due to the
duct configuration. The post-test leak check results for all 28 inlet sampling trains met
the QC criteria.
7-7
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TABLE 7-2. ISOKINETICS AND LEAK CHECK SUMMARY; SITE 6, OUTLET
LOCATION, PARTICULATE MATTER/TOTAL METALS AND
NICKEL/NICKEL SUBSULFIDE SAMPLING
Run
Train
Percent
Leak Rate
Vacuum
No.
No.
Isokinetics
(cfm)
(in. Hg)
2
A
95.4
0.006 '
3
2
B
96.5
0.004
2
2
C
88.1
0.007
4
2
D
93.6
0.002
2
4
A
95.2
0.002
8
4
B
93.1
0.004
8
4
C
87.9
0.000
9
4
D
94.2
0.005
9
5
A
89.9
0.005
7
5
B
90.2
0.008
6
5
C
84.1
0.002
6
5
D
101.6
0.010
9
6
A
92.6
0.019
12
6
B
92.9
0.017
9
6
C
87.1
0.015
14
6
D
92.1
0.002
11
8
A
95.7
0.004
8
8
B
87.7
0.012
8
8
C
94.6
0.009
13
8
D
99.2
0.009
11
10
A
82.2
0.013
15
10
B
94.0
0.009
15
10
C
86.7
0.016
15
10
D
94.0
0.018
15
12
A
95.2
0.006
4
12
B
93.3
0.012
8
12
C
88.6
0.007
8
12
D
97.4
0.009
5
7-8
-------
7.2.2.2 Sample Analysis - Analytical results for the metals field recovery blank,
laboratory blanks, and the audit sample are presented in Table 7-3. The field recovery
blank was collected from an outlet sampling train previously used to collect a sample.
After normal sample recovery, the train was prepared as if to collect another sample,
taken to the outlet sampling location, and leak checked. The field recovery blank train
was left at the outlet location during sampling, and then recovered following the normal
sample recovery procedure. The field recovery blank and reagent blanks had non-
detectable quantities of all target metals except chromium. Chromium was found in both
reagent blanks and the field recovery blank, but the quantity was less than those found in
the field samples. An average value of 1.1 ug was used to correct the field sample
results, as well as the audit sample result.
Calibration check samples were analyzed with every ten samples. The results for
the calibration check samples were all within 10% of the expected value.
The audit samples results were generally biased low ranging from -9.1% to -23.0%
less than the true audit value. The audit sample analyzed was provided by EPA's
Quality Assurance Division in Research Triangle Park, NC.
7.2.3 Total Chromium and Hexavalent Chromium Sampling and Analysis
Sampling and analysis for total chromium (Cr) and hexavalent chromium (Cr+<)
was performed following the procedures in the draft EPA method, "Determination of
Hexavalent Chromium from Stationary Sources." The QC activities for the Cr/Cr+<
testing performed at Site 6 are discussed in the following sections.
7.2.3.1 Sampling Operations - Isokinetic and leak check results for the chromium
sampling at the scrubber outlet sampling location are summarized in Table 7-4. Fifteen
of the 20 sampling trains operated at the scrubber for collection of Cr/Cr+6 samples
were less than 90% isokinetic. Since the outlet sampling location was downstream of a
venturi scrubber which tends to emit small particles, the non-isokinetic sampling should
7-9
-------
TABLE 7-3. QC RESULTS FOR FIELD RECOVERY BLANKS, REAGENT
BLANKS, AND AUDIT SAMPLES
Field
Recovery Reagent Blanks (ug) Audit Sample (ug)
Blank Percent
Metal
(ug)
Blank 1
Blank 2
Found
Actual
Error
Arsenic
ND*
ND
ND
<23
9.6
—
Beryllium
ND
ND
ND
4.4
4.85
-9.3
Cadmium
ND
ND
ND
7.7
10.0
-23.0
Chromium
•1.0
1.0
1.3
9.5b
10.3
-6.8
Lead
ND
ND
ND
43.1
50.4
-14.5
Nickel
ND
ND
ND
22.4
25.2
-11.1
'Not Detected
bBlank corrected by 1.1 ug (average value detected in blanks)
7-10
A
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Table 7-4. ISOKINETICS AND LEAK CHECK SUMMARY; SITE 6, OUTLET
LOCATION, TOTAL CHROMIUM AND HEXAVALENT CHROMIUM
SAMPLING
Run
Train
Percent
Leak Rate
Vacuum
No.
No.
Isokinetics
(cfm)
(in. Hg)
3
A
74.6
0.100
12
3
B
51.7
0.006
11
3
C
59.1
0.009
18
3
D
65.1
0.008
14
7
A
90.2
0.001
15
7
B
93.6
0.002
7
7
C
88.0
0.004
15
7
D
67.8
0.015
15
9
A
81.8
0.008
13
9
B
88.8
0.009
11
9
C
84.2
0.011
14
9
D
88.6
0.009
12
11
A
68.2
0.006
8
11
B
89.8
0.001
14
11
C
87.5
0.003
13
11
D
78.7
0.001
13
13
A
79.1
0.020
8
13
B
95.3
0.001
9
13
C
94.5
0.021
10
13
D
95.1
0.019
13
7-11
-------
not have caused a significant bias. The low isokinetic sampling resulted from use of
prototype Teflon sampling nozzles which were larger in diameter than desirable and
required a higher sampling rate to achieve isokinetic sampling. The pressure drop
created by the Teflon aspirator used to recirculate the absorbing solution prevented
sampling at the higher isokinetic rate when higher velocities occurred in the stack.
The post-test leak check results for 19 of the 20 outlet sampling trains met the QC
criteria, with one train having a leak rate of 0.021 cfm.
At the inlet sampling location, isokinetic sampling was not performed due to the
duct configuration. The post-test leak check results for all 20 inlet sampling trains met
the QC criteria.
7.2.3.2 Sample Analysis - Neither Cr or Cr+< were detected in any of the reagent blanks
submitted for analysis. All analyses for Cr+< were performed in duplicate with the
percent deviation of duplicate samples being less than 5%. The Cr+< preconcentration
curve was linear from 0.071 ppb to 0.749 ppb, with a maximum percent deviation of -
10.7%.
To determine the extent of Cr+
-------
TABLE 7-5. RECOVERIES OF 5lCr+< SURROGATE
5lCr+< Surrogate Recoveries (percent of total)
Run
Train
No.
No.
Soluble* Total" Without HNQ3 Rinse
3
A
99.5
96.5
98.8
3
B
99.3
98.8
98.9
3
C
81.0
74.8
75.4
3
D
91.8
81.7
87.3
7
A
83.3
71.8
81.9
7
B
88.3
74.8
87.4
7
C
85.4
79.8
84.7
7
D
91.0
90.0
90.4
9
C
94.4
68.3
93.9
9
D
97.4
82.8
96.7
11
C
95.3
53.7
94.6
11
D
97.6
97.1
97.3
13
C
94.9
33.9
92.7
13
D
97.6
43.3
96.0
Field Blank
96.5
NAC
96.5
Reagent Blank
99.0
NA
99.0
•Radioactivity in soluble NaOH fraction coeluting with native Cr+6.
'Total 5lCr+6 in soluble fraction divided by total radioactivity.
eNot applicable.
7-13
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7.2.4 Continuous Emission Monitoring
Continuous emission monitoring (CEM) was performed at the scrubber inlet and
scrubber outlet for 02, C02, CO, S02, and NOr Total hydrocarbons were also
monitored at the scrubber outlet on a conditioned (cold) sample. Instrument calibrations
were performed at the beginning of each test day, between sampling runs, and at the
conclusion of each test day. Instrument drift checks, the comparison of the post-test
measurement of zero and span gases to the pre-test values, were performed for each run,
and are summarized in Table 7-6. All CEM data were drift corrected assuming linear
drift. Data from an instrument with drift exceeding 20% during a test period was
invalidated.
The drift for both the zero and span were within 1% for almost every run.
Because the monitoring data was not intended to standard setting purposes, four
calibration gases were used for 02> C02, CO, S02, and NOw and three calibration gases
were used in the direct calibration check. Two calibration gases were used for the drift
test after test run, and no performance audit was conducted. All the data meets the
requirements of Method 3A, 6C, 7E, 10, and 25A.
7.3 PROCESS SAMPLE ANALYSIS QC RESULTS/METAL ANALYSIS
Samples of sludge feed, bottom ash, scrubber influent water, and scrubber effluent
water were collected during each test run. These process samples were grab samples
collected at regular intervals, and combined after each test to form composite samples.
QC results for analyses performed on these samples are presented in this section.
Quality control indicators for process samples are method blanks and calibration
checks during analysis.
None of the six target metals were detected in the method blanks for the sludge
feed, bottom ash, scrubber influent, and scrubber effluent samples.
Calibration check samples were analyzed with every ten samples. The results for
the calibration check samples for the sludge feed and bottom ash were all within 10% of
7-14
A
-------
TABLE 7-6. SUMMARY OF CEM DRIFT CHECKS
Date and
Run No.
CEM
Location
0
•
Instrument Zero and Span Drift (% of
2 CO2 O SO2
span)
NOx
Cold
THC
Zero
Span
Zero
Span
Zero
Span
Zero
Span
Zero
Span
Zero
Span
10/09/89
Run 03
Inlet
Outlet
0.0
0.0
-0.8
0.0
0.0
1.0
0.5
0.0
-0.1
-0.2
-0.1
-2.4
0.5
0.4
0.3
0.7
0.5
0.2
0.7
0.6
0.9
1.2
10/09/89
Run 04
Inlet
Outlet
0.8
0.4
0.0
0.4
0.0
0.0
0.0
1.0
-0.9
-1.5
-3.0
-6.3
0.3
0.3
0.9
-0.3
0.3
0.2
-0.9
-0.2
0.3
0.3
10/10/89
Run 05
Inlet
Outlet
0.4
0.4
-0.4
-0.8
0.0
0.5
0.0
0.5
-0.1
-0.1
0.8
-1.0
0.3
0.5
0.2
-0.2
0.0
0.1
-2.0
0.5
0.0
-0.6
10/10/89
Run 06
Inlet
Outlet
0.4
-0.4
0.4
0.4
0.0
0.0
-0.5
-0.5
0.0
-0.3
0.0
-1.2
-0.7
-0.2
1.2
0.2
0.2
0.5
-1.2
-0.1
-0.2
-0.9
10/10/89
Run 07
Inlet
Outlet
-0.8
0.0
-0.8
0.0
0.0
-0.5
0.0
2.0
0.0
0.1
0.0
0.7
0.5
0.6
-0.3
0.0
0.3
-0.1
2.9
-0.7
0.5
1.2
(Continued)
-------
TABLE 7-6. (Continued)
Date and
Run No.
CEM
Location
t
C
Instrument Zero and Span Drift (% of
2 CO2 CO SO2
span)
NOx
Cold
THC
Zero
Span
Zero
Span
Zero
Span
Zero
Span
Zero
Span
Zero
Span
10/11/89
Run 08
Inlet
Outlet
0.4
0.0
-0.4
-1.2
0.0
1.0
0.5
0.5
-0.1
-0.6
-1.0
-1.5
0.4
0.4
-0.5
0.3
0.0
0.2
-0.5
-0.7
0.0
-0.7
10/11/89
Run 09
Inlet
Outlet
-0.4
0.0
0.0
0.0
-0.5
0.5
-0.5
0.0
0.0
0.0
1.1
0.7
-0.8
0.3
0.3
0.7
0.0
0.1
0.8
0.0
-0.2
-0.6
10/12/89
Run 10
Inlet
Outlet
0.0
0.0
-0.4
-0.8
0.0
0.5
0.0
1.0
-0.1
-0.3
-0.1
-1.6
0.3
0.2
1.0
0.5
-0.1
0.3
-0.5
0.6
0.1
-0.3
10/12/89
Run 11
Inlet
Outlet
0.4
0.0
0.0
0.0
0.0
0.5
-0.5
-0.5
0.0
-0.2
0.1
-0.2
-0.2
0.0
0.1
-0.3
-0.2
0.2
-0.4
-0.1
0.0
-0.5
10/12/89
Run 12
Inlet
Outlet
0.0
0.0
0.0
0.4
0.0
1.0
0.5
0.5
0.0
0.3
-0.1
0.7
0.2
-0.7
0.3
-0.7
0.4
-0.5
0.6
-0.5
Not
conducted
10/13/89
Run 13
Inlet
Outlet
0.0
0.0
-0.8
-0.4
0.0
-0.5
0.0
0.0
0.0
-0.4
-0.9
-1.6
0.2
1.1
-0.5
1.4
0.3
0.4
-0.4
0.2
0.0
-0.6
-------
the expected value, except for one analysis where lead measured 14% higher than the
expected value. Calibration check samples for the scrubber water samples were all
within 10% of the expected value.
7-17
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REFERENCES
1. Drees, L.M. Effect of Lime and Other Precipitants or Sludge Conditioners on
Conversion of Chromium to the Hexavalent State When Sludge is Incinerated. Final
Report EPA Contract No. 68-03-3346, WA 05. 1988.
2. Majiam, T.T. Kasakura, N. Naruse and M. Hiraoka. 1977. Studies of Pyrolvsis
Process of Sewage Sludge. Prog. Wat. Tech. Vol. 9,381-396. Great Britain: Pergamon
Press.
3. Umashima, T., M. Naruse and T. Nasakura. 1975. Behavior of Cr-i-6 in Incinerator
Process of Sewage Sludge. Paper presented at the 12th Annual Meeting of the
Association of Japan Sewage Works.
8-1
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before compter
1. REPORT NO. 2.
EPA/600/R-92/003c
3" PB92-1 51570
4. TITLE AND SUBTITLE
EMISSIONS OF METALS, CHROMIUM AND NICKEL SPECIES, AND
ORGANICS FROM MUNICIPAL WASTEWATER SLUDGE INCINERATORS
VOLUME III: SITE 6 EMISSION TEST REPORT
5. REPORT OATE
March 1992
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
William G. DeWees, Robin R. Segall
F. Michael Lewis
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
, Entropy Environmentalists, Inc.
I Research Triangle Park
j North Caroling, 27709
10. PROGRAM ELEMENT NO.
B101
11. CONTRACT/GRANT NO.
Contract No. 68-CO-0027
Work Assianment No. 0-5
2. SPONSORING AGENCY NAME AND ADDRESS
Risk Reduction Engineering Laboratory-
Office of Research and Development
U.S. Environmental Protection Agency-
Cincinnati, OH 4526S
13. TYPE OF REPORT AND PERIOO COVEREO
Final Report 1989 - 91
14. SPONSORING AGENCY CODE
EPA/600/14
15. SUPPLEMENTARY NOTES
EPA Technical Contact: Dr. Harry E. Bostian, (513) 569-7619, FTSs 684-7619
16. ABSTRACT
Site 6, a multiple hearth furnace was tested under two operating conditionsr normal
combustion was compared with improved combuBtion conditions as indicated by reduced
CO and THC emissions. The effect of lime conditioning on the conversion of total
chromium in the sludge to hexavalent chromium emissions was also a primary concern at
Site 6. Secondary objectives included comparing the results for chromium and nickel
subspecies determined by different analytical procedures, gathering data on other
metals and inorganic/organic gases in incinerator emissions, and assessing pollutant
removal efficiencies by measuring emissions at both the inlet and outlet to the
control system. The Site 6 plant treats 30 million gallons a day of municipal and
industrial wastewater. The blended primary/secondary sludge is dewatered to
approximately 28% solids using recessed plate cloth filters. The metal mass
emissions rate for the outlet runs averaged: As - not detected (< 508 mg/hr), Be -
not detected (< 2.2 mg/hr), Cd - 1,450 mg/hr, Cr - 83.3 mg/hr, Pb - 21,100 mg/hr, and
Ni ~ 73-9 mg/hr. The particulate mass emission rates averaged 42 kg/hr and 0.7
kg/hr, respectively for the inlet and outlet. A positive correlation between the
C0/C02 ratios (an indication of combustion conditions) and the hexavalent to total
chromium ratio was demonstrated for the outlet location. At low CO levels (good
combustion) the ratio of hexavalent chromium to trivalent chromium was highest, with
approximately 10% of the total chromium in the form of hexavalent chromium. It was
anticipated that the nickel subsulfide emissions from multiple hearth incinerators
would constitute less than 1% of the total nickel emissions. A wet chemical analysis
indicated that within the detection limit {< 10%), no nickel subsulfide was present.
17.
KEY WORDS ANO DOCUMENT ANALYSIS
a. DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. cosati Field/Group
Wastewater, sludge disposal,
incinerators, combustion products
Emissions
chromium compounds
nickel compounds
total hydrocarbons
dioxin/furans
organic compounds
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (Hits Report}
UNCLASSIFIED
21. NOj^ PAGES
20. SECURITY CLASS (This page}
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (Rtv. 4-77) previous coition ispssoLKTC
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