Grantee Research Project Results
2004 Progress Report: Center for Air Toxic Metals® (CATM®) 2003-2007
EPA Grant Number: CR830929Subproject: this is subproject number R830929 , established and managed by the Center Director under a main grant
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Center for Air Toxic Metals® (CATM®)
Center Director: Groenewold, Gerald
Title: Center for Air Toxic Metals® (CATM®) 2003-2007
Investigators: Pavlish, John H. , Benson, Steven A. , Galbreath, Kevin C. , Timpe, Ronald C. , Laumb, Jason D. , Zygarlicke, Christopher J. , Holmes, Michael J. , Heebink, Loreal V. , Ralston, Nicholas V.C. , Mibeck, Blaise , Crocker, Charlene , Raymond, Laura
Current Investigators: Pavlish, John H. , Benson, Steven A. , Galbreath, Kevin C. , Schmidt, Darren D. , Laumb, Jason D. , Holmes, Michael J. , Martin, Christopher L. , Heebink, Loreal V. , Ralston, Nicholas V.C. , Mibeck, Blaise , Crocker, Charlene , Zhuang, Ye
Institution: University of North Dakota
EPA Project Officer: Chung, Serena
Project Period: May 1, 2003 through September 30, 2006 (Extended to September 30, 2007)
Project Period Covered by this Report: May 1, 2003 through September 30, 2004
Project Amount: $3,098,736
RFA: Targeted Research Center (2003) Recipients Lists
Research Category: Targeted Research
Objective:
The goal of the research of the Center for Air Toxic Metals (CATM) is to address air toxic trace element emissions, which have become a matter of worldwide concern as well as a regulatory issue in the United States and Canada. The objective of CATM is to develop key information on air toxic metal compounds to support the development and implementation of pollution prevention and control strategies that will effectively reduce air toxic metal emissions and releases to the environment.
Progress Summary:
CATM research activities this year addressed several key issues related to air toxics. These research activities and accomplishments are summarized below.
Mercury Transformations in Coal Combustion Flue Gas
The Energy & Environmental Research Center (EERC) is performing critical fundamental research to understand the mechanisms responsible for the conversion of mercury to other chemical species within combustion flue gas. Salts were cofired with low-acid-gas coals in low amounts, which caused elemental mercury to be converted to oxidized gaseous species and/or particle-associated phases.
Unburned carbon from two full-scale utility boiler fly ashes, one high in mercury and the other low, is being concentrated using separation methods. The chemical composition, morphology, and microstructure of the individual unburned carbon particles will be determined using a host of analytical techniques including X-ray photoelectron spectroscopy. The surface morphology and chemistry of the carbon particles are being evaluated in order to find correlations between carbon characteristics and mercury capture.
Sulfur species in unburned carbon from coal or tire rubber are being explored as possible reaction sites for oxidizing and stabilizing gaseous mercury. Chemical additives will be investigated in combination with tetrasulfide flue gas injection to determine their impact on mercury oxidation and capture.
Bench-scale flue gas simulation was used to study the effects of SO3, SO2, and HCl on mercury oxidation across a selective catalytic reduction (SCR) catalyst. Tests using subbituminous and bituminous ash conditioning showed no conversion of Hg0 to an oxidized form across the SCR catalyst unless HCl was added. SO2 and SO3 alone had little effect. SO3 enhanced oxidization of Hg0, but SO2 hindered the reaction. Oxidation of Hg0 was lessened by the absence of ammonium, but it was still significant. Ammonium addition without the acid gases had no effect on Hg0 oxidation.
Development of a Laser-Based Mercury Continuous Emission Monitor
An apparatus has been assembled for developing a laser-based method for measuring elemental mercury. A diode laser tuned to 407.784 nm has been used with a mercury lamp at 253.7 nm to induce fluorescence at 546 nm in elemental mercury. At this time, modification of the apparatus and more preliminary data are needed before a minimal detection limit can be determined. Instrumentation developed in this area could impact research requiring small, low-power measurement techniques for high-speed mercury determination.
Methods to Improve Measurement of Mercury and Chlorine in Combustion Flue Gases
The EERC is striving to improve the mercury measurement results obtained with impinger-based methods, such as ASTM International Method D6784-02 (Ontario Hydro method), and continuous mercury monitors (CMM) (e.g., Semtech Hg 2000, PS Analytical Sir Galahad, and Tekran) by investigating two potential sources of analytical bias: (1) the removal of CO2 from flue gas by a SnCl2–NaOH solution; and (2) the mercury–fly ash interactions that occur on filter media (i.e., glass fibers), which promote the formation of Hg1+, 2+ and/or particle-associated mercury forms (Hg[p]), thus negatively biasing Hg0 measurements. The EERC is also striving to use infrared spectroscopy combined with chiller and Nafion® gas-drying systems and a Cl2-to-HCl conversion system to quantify Cl2 and HCl in coal combustion flue gas and other gas streams on a nearly continuous basis.
Development of an Oxidized Mercury-Spiking System
To determine conditioning and conversion system biases, an oxidized mercury-spiking system is being developed. This system will enable CMM operators to detect and troubleshoot biases and provide researchers with an indication of CMM performance.
Development of Mercury Control Technologies in the United States
Based on health, emissions, and scientific data, the U.S. Environmental Protection Agency (EPA) and the Canadian Council of Ministers of the Environment determined that the amount of mercury emitted from utility power plants should be reduced. On March 15, 2005, EPA released the Clean Air Mercury Rule for utility mercury regulations. With the promulgation of mercury regulations, improvements in mercury control options and reductions in costs are extremely important, and they are the primary focus of this project.
Sorbent injection is the most mature technology for reducing mercury emissions. Based on current projections, the amount of sorbent needed to serve the U.S. market is expected to be very large. Sorbents can be either injected as a powder or used in fixed or moving beds. The low concentrations of mercury in flue gases from coal-fired systems and the high fractions of mercury emitted in elemental form from many coals result in a low reactivity between activated carbon and mercury. New methods are being developed to increase this reactivity in order to minimize the changes required for utility systems and to reduce the costs associated with capital equipment and carbon injection. In addition, research continues on the development of control options to optimize the use of pollution control equipment available on scrubbed systems.
Modeling Mercury Speciation in Coal Combustion Systems and Interactions on Activated Carbon
A fundamental model framework has been established that incorporates a homogeneous gaseous reaction mechanism relevant to mercury species and a heterogeneous mercury–particulate interaction mechanism. This model has shown promising predictions of mercury capture by particulates as well as the gaseous split between elemental mercury and oxidized mercury. With the newly integrated model, coal composition including mineral size and composition, bulk ash composition, mercury level, and chlorine level are utilized to predict the fractions of particulate, elemental, and oxidized mercury. The model was used to predict mercury speciation as a function of flue gas temperature and chlorine additive levels. The model-predicted mercury species are reasonably close to the measured mercury species in the flue gas of Caballo coal fired in the particulate test combustor with and without CaCl2 addition.
Developing SCR Technology Options for Mercury Oxidation in Western Fuels
The project was initiated to evaluate the ability of used and new SCR catalysts as well as the use of additives to enhance oxidation. The first catalyst to be tested is manufactured by Haldor Topsoe. A second set of tests will be conducted on several new formulations developed in cooperation with Haldor Topsoe. This past year’s work focused on further developing a finalized research plan for the project and finalizing the contractual agreement with Haldor Topsoe.
Investigation of Mercury and Carbon-Based Sorbent Reaction Mechanisms
This project is just beginning as of the end of 2004. It will build on the previous CATM research regarding mercury capture on carbon-based sorbents, focusing on the effects of halogen pretreatment of sorbent surfaces on mercury capture. The goal of the project is to improve the mercury capture efficiency of carbon-based sorbents through a better understanding of mercury–sorbent reaction mechanisms. This work will mainly be accomplished in 2005.
Mercury in Alternative Fuels
As the United States and other countries investigate ways to use renewable fuels, the content of mercury in various biomass sources must be evaluated. Previous research indicated that some plant and woody materials took up more significant amounts of mercury than others. During the course of this project, various alternative fuels were collected, air-dried, and analyzed for residual moisture and mercury concentration and compared to a National Institute for Standards and Technology biomass standard. The biomass samples were collected in rural areas at least 50 miles from the nearest power plant in Iowa, Minnesota, North Dakota, and Wisconsin. Cattail, a plant that has been considered for co-combustion with coal, had the highest mercury concentration of all of the samples analyzed.
Mercury Metabolism and Selenium Physiology Studies
Studies on the interaction between dietary mercury and selenium are vital to the understanding of risk factors, as well as possible factors that could mediate the harm done by the ingestion of mercury. Well-known studies of the Faroe and Seychelles Islands and the Minamata region of Japan leave much to be explained.
This year’s study confirms previous CATM research that exposure to mercury can result in sequestration of selenium within cells of vulnerable organs. At high dietary-mercury concentrations, formation of these insoluble mercury selenides may result in the diversion of selenium from selenoprotein synthesis and the diminishment of selenoenzyme activities. However, a diet that is rich in selenium mediates these effects. If one considers that saltwater fish are extremely rich sources of selenium, have many beneficial health effects, and are among the lowest-cost sources of protein in the world, these CATM studies do not support the claim that ocean fish should be eliminated from the diet of pregnant women or children.
Mercury and Air Toxic Element Impacts of Coal Combustion By-Product Disposal and Utilization
The second year of a 3-year effort is nearing completion. This effort is focused on the evaluation of coal combustion by-products (CCBs) for their potential to release mercury and other air toxic elements under different controlled laboratory conditions and will investigate the release of these same air toxic elements in select disposal and utilization field settings to understand the impact of various emission control technologies. Results through Year 2 were used to determine if mercury release from CCBs, both as currently produced and as produced with mercury and other emission controls in place, will potentially impact CCB management practices. Preliminary conclusions can be summarized as follows:
- Analysis of the carbon forms data revealed that samples with anisotropic or isotropic coke as the dominant carbon form also had the higher mercury content. Those samples also generally contained activated carbon from mercury emission control.
- No correlation has been observed between total mercury and leachable mercury.
- Most samples of CCBs act as mercury sinks in ambient-temperature vapor-phase release experiments.
- Elevated-temperature release experiments showed that mercury generally released at temperatures greater than 200°C.
- Organomercury compounds were present in leachates from microbiological experiments.
- Some vapor-phase mercury from microbiological experiments showed evidence of methylation.
Technology Commercialization, Education, and Publication
To facilitate the transfer of technical information produced by CATM, several communication vehicles are used, including participation in both domestic and international conferences, symposia, workshops, and other educational programs; annual meetings and peer review; quarterly reports on topical issues related to mercury through a collaborative project funded by CATM Affiliates, U.S. Department of Energy, and the Canadian Electricity Association; and the publication of a semiannual newsletter. In addition, the CATM Director and staff provide input into various public forums during the year to assist in the development of venues of technology transfer that may not be directly funded by CATM.
Conferences and Workshops Held
Western Fuels Symposium: 19th International Conference on Lignite, Brown, and Subbituminous Coals, Billings, MT, October 12-24, 2004.
Western Fuels Symposium Preconference Workshops, Billings, MT, October 11, 2004.
Future Activities:
Future research will focus on the following:
- Mercury transformation in coal combustion flue gas
- Measurement of halogens
- Development of control technologies
- Modeling mercury interactions on activated carbons
- Molecular interactions of toxic metals
- Investigation of mercury and carbon-based sorbent reaction mechanisms
- Canadian Electric Association – Mercury Program R&D Information Clearinghouse
- Mercury and air toxic element impacts of CCB disposal and utilization.
Journal Articles: 39 Displayed | Download in RIS Format
Other center views: | All 137 publications | 53 publications in selected types | All 39 journal articles |
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Benson SA. Air quality III: mercury, trace elements, and particulate matter--Preface. Fuel Processing Technology 2004;85(6-7):423-424. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) R827649 (2003) R827649 (Final) |
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Benson SA, Laumb JD, Crocker CR, Pavlish JH. SCR catalyst performance in flue gases derived from subbituminous and lignite coals. Fuel Processing Technology 2005;86(5):577-613. |
CR830929 (2005) |
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Benson SA, Pavlish JH, Holmes MJ, Crocker CR, Galbreath KC, Zhaung Y. Mercury control testing in a pulverized lignite-fired system. Fuel Processing Technology 2009;90(11):1378-1387. |
CR830929 (2006) |
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Brown TD, Smith DN, Hargis Jr. RA, O’Dowd WJ. Mercury measurement and its control: what we know, have learned, and need to further investigate. Journal of the Air & Waste Management Association 1999;49(6):628-640. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) |
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Dronen LC, Moore AE, Kozliak EI, Seames WS. An assessment of acid wash and bioleaching pre-treating options to remove mercury from coal. Fuel 2004;83(2):181-186. |
CR830929 (2004) R827649 (2003) R827649 (Final) |
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Galbreath KC, Zygarlicke CJ. Mercury transformations in coal combustion flue gas. Fuel Processing Technology 2000;65-66:289-310. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) R827649 (2000) R827649 (Final) |
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Galbreath KC, Toman DL, Zygarlicke CJ, Huggins FE, Huffman GP, Wong JL. Nickel speciation of residual oil fly ash and ambient particulate matter using X-ray absorption spectroscopy. Journal of the Air & Waste Management Association 2000;50(11):1876-1886. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) R827649 (2000) R827649 (Final) |
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Galbreath KC, Toman DL, Zygarlicke CJ, Pavlish JH. Trace element partitioning and transformations during combustion of bituminous and subbituminous U.S. coals in a 7-kW combustion system. Energy & Fuels 2000;14(6):1265-1279. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) R827649 (2000) R827649 (Final) |
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Galbreath KC, Zygarlicke CJ, Olson ES, Pavlish JH, Toman DL. Evaluating mercury transformation mechanisms in a laboratory-scale combustion system. Science of the Total Environment 2000;261(1-3):149-155. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) R827649 (2000) R827649 (Final) |
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Galbreath KC, Crocker CR, Nyberg CM, Huggins FE, Huffman GP, Larson KP. Nickel speciation measurements of urban particulate matter: method evaluation and relevance to risk assessment. Journal of Environmental Monitoring 2003;5(3):56N-61N. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) R827649 (2003) R827649 (Final) |
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Galbreath KC, Zygarlicke CJ. Formation and chemical speciation of arsenic-, chromium-, and nickel-bearing coal combustion PM2.5. Fuel Processing Technology 2004;85(6-7):701-726. |
CR830929 (2004) R827649 (2002) R827649 (2003) R827649 (Final) |
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Galbreath KC, Zygarlicke CJ, Tibbetts JE, Schulz RL, Dunham GE. Effects of NOx, α-Fe2O3, γ-Fe2O3, and HCl on mercury transformations in a 7-kW coal combustion system. Fuel Processing Technology 2005;86(4):429-448. |
CR830929 (2004) CR830929 (2005) R827649 (2002) R827649 (2003) R827649 (Final) |
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Galbreath KC, Schulz RL, Toman DL, Nyberg CM, Huggins FE, Huffman GP, Zillioux EJ. Nickel and sulfur speciation of residual oil fly ashes from two electric utility steam-generating units. Journal of the Air & Waste Management Association 2005;55(3):309-318. |
CR830929 (2005) |
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Hassett DJ, Heebink LV, Pflughoeft-Hassett DF. Potential for mercury vapor release from coal combustion by-products. Fuel Processing Technology 2004;85(6-7):613-620. |
CR830929 (2004) R827649 (2002) R827649 (2003) R827649 (Final) |
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Heebink LV, Hassett DJ. Release of mercury vapor from coal combustion ash. Journal of the Air & Waste Management Association 2002;52(8):927-930. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) R827649 (2002) R827649 (Final) |
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Jensen RR, Karki S, Salehfar H. Artificial neural network-based estimation of mercury speciation in combustion flue gases. Fuel Processing Technology 2004;85(6-7):451-462. |
CR830929 (2004) R827649 (2003) R827649 (Final) |
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Gupta H, Benson SA, Fan L-S, Laumb JD, Olson ES, Crocker CR, Sharma RK, Knutson RZ, Rokanuzzaman ASM, Tibbetts JE. Pilot-scale studies of NOx reduction by activated high-sodium lignite chars: a demonstration of the CARBONOX process. Industrial and Engineering Chemistry Research 2004;43(18):5820-5827. |
CR830929 (2005) |
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Laudal DL, Pavlish JH, Graves J, Stockdill D. Mercury mass balances: a case study of two North Dakota power plants. Journal of the Air & Waste Management Association 2000;50(10):1798-1804. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) R827649 (2000) R827649 (Final) |
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Laudal DL, Thompson JS, Pavlish JH, Brickett LA, Chu P. Use of continuous mercury monitors at coal-fired utilities. Fuel Processing Technology 2004;85(6-7):501-511. |
CR830929 (2004) R827649 (2003) R827649 (Final) |
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Laudal DL, Thompson JS, Pavlish JH, Brickett L, Chu P, Srivastava RK, Lee CW, Kilgroe J. Mercury speciation at power plants using SCR and SNCR control technologies. EM Magazine 2003;(Feb):16-22. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) R827649 (2002) R827649 (2003) R827649 (Final) R827649C001 (Final) |
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Laumb JD, Benson SA, Olson EA. X-ray photoelectron spectroscopy analysis of mercury sorbent surface chemistry. Fuel Processing Technology 2004;85(6-7):577-585. |
CR830929 (2004) R827649 (2002) R827649 (2003) R827649 (Final) |
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Olson ES, Sharma RK, Pavlish JH. On the analysis of mercuric nitrate in flue gas by GC-MS. Analytical and Bioanalytical Chemistry 2002;374(6):1045-1049. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) R827649 (2002) R827649 (Final) |
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Olson ES, Laumb JD, Benson SA, Dunham GE, Sharma RK, Mibeck BA, Miller SJ, Holmes MJ, Pavlish JH. Chemical mechanisms in mercury emission control technologies. Journal de Physique IV 2003;107:979-982. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) R827649 (2003) R827649 (Final) |
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Olson ES, Crocker CR, Benson SA, Pavlish JH, Holmes MJ. Surface compositions of carbon sorbents exposed to simulated low-rank coal flue gases. Journal of the Air & Waste Management Association 2005;55(6):747-754. |
CR830929 (2004) CR830929 (2005) R827649 (2003) R827649 (Final) |
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Pavlish JH, Sondreal EA, Mann MD, Olson ES, Galbreath KC, Laudal DL, Benson SA. Status review of mercury control options for coal-fired power plants. Fuel Processing Technology 2003;82(2-3):89-165. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) R827649 (2002) R827649 (2003) R827649 (Final) |
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Pavlish JH, Holmes MJ, Benson SA, Crocker CR, Galbreath KC. Application of sorbents for mercury control for utilities burning lignite coal. Fuel Processing Technology 2004;85(6-7):563-576. |
CR830929 (2004) R827649 (2003) R827649 (Final) |
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Pflughoeft-Hassett DF, Hassett DJ, Heebink LV, Buckley TD. The current state of the science related to the re-release of mercury from coal combustion products. Ash at Work 2006;1:26-27. |
CR830929 (2006) |
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Ralston NVC. Selenium health benefit values as seafood safety criteria. EcoHealth 2008;5(4):442-455. |
CR830929 (2006) |
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Raymond LJ, Ralston NVC. Mercury: selenium interactions and health implications. Seychelles Medical and Dental Journal 2004;7(1):72-77. |
CR830929 (2004) R827649 (Final) |
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Sondreal EA, Pavlish JH, Benson SA, Feeley T. Status of particulate matter research and development. Filtration & Separation 1999;36(2):11. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) R827649 (2000) R827649 (Final) |
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Sondreal EA, Jones ML, Groenewold GH. Tides and trends in the world's electric power industry. The Electricity Journal 2001;14(1):61-79. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) R827649 (Final) |
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Sondreal EA, Benson SA, Hurley JP, Mann MD, Pavlish JH, Swanson ML, Weber GF, Zygarlicke CJ. Review of advances in combustion technology and biomass cofiring. Fuel Processing Technology 2001;71(1-3):7-38. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) R827649 (2001) R827649C001 (2001) R827649C001 (Final) |
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Sondreal EA, Benson SA, Pavlish JH, Ralston NVC. An overview of Air Quality III: Mercury, Trace Elements, and Particulate Matter. Fuel Processing Technology 2004;85(6-7):425-440. |
CR830929 (2004) R827649 (2003) R827649 (Final) |
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Xin M, Gustin MS, Ladwig K, Pflughoeft-Hassett DF. Air-substrate mercury exchange associated with landfill disposal of coal combustion products. Journal of the Air & Waste Management Association 2006;56(8):1167-1176. |
CR830929 (2006) |
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Zhao Y, Mann MD, Pavlish JH, Mibeck BAF, Dunham GE, Olson ES. Application of gold catalyst for mercury oxidation by chlorine. Environmental Science & Technology 2006;40(5):1603-1608. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) R827649 (Final) |
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Zhao Y, Mann MD, Olson ES, Pavlish JH, Dunham GE. Effects of sulfur dioxide and nitric oxide on mercury oxidation and reduction under homogeneous conditions. Journal of the Air & Waste Management Association 2006;56(5):628-635. |
CR830929 (2004) CR830929 (2005) CR830929 (2006) |
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Zhuang Y, Zygarlicke CJ, Galbreath KC, Thompson JS, Holmes MJ, Pavlish JH. Kinetic transformation of mercury in coal combustion flue gas in a bench-scale entrained-flow reactor. Fuel Processing Technology 2004;85(6-7):463-472. |
CR830929 (2004) R827649 (2002) R827649 (2003) R827649 (Final) |
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Zhuang Y, Thompson JS, Zygarlicke CJ, Pavlish JH. Development of a mercury transformation model in coal combustion flue gas. Environmental Science & Technology 2004;38(21):5803-5808. |
CR830929 (2004) R827649 (Final) |
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Zhuang Y, Laumb J, Liggett R, Holmes M, Pavlish JH. Impacts of acid gases on mercury oxidation across SCR catalyst. Fuel Processing Technology 2007;88(10):929-934. |
CR830929 (2006) |
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Supplemental Keywords:
activated carbon, air, toxic, air quality, coal, control, modeling, emissions, environment, flue gas, hazardous, measurement, mercury, metals, pollutants, pollution, sampling, sorbents, species, toxic, transformations, selenium,, Scientific Discipline, Air, ENVIRONMENTAL MANAGEMENT, air toxics, Health Risk Assessment, Environmental Monitoring, Atmospheric Sciences, Risk Assessment, air quality standards, emission control strategies, aerosol particles, control, mercury emissions, air sampling, airborne metals, exposure assessmentRelevant Websites:
http://www.undeerc.org Exit
http://www.undeerc.org/catm/index.html Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.