![[logo] US EPA](https://webarchive.library.unt.edu/eot2008/20081106055959im_/http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
2001 Progress Report: Center for Air Toxic Metals (CATM)
EPA Grant Number: R827649Center: Center for Air Toxic Metals® (CATM®)
Center Director: Groenewold, Gerald
Title: Center for Air Toxic Metals (CATM)
Investigators: Groenewold, Gerald , Benson, Steven A. , Galbreath, Kevin C. , Hassett, J. , Holmes, Michael J. , Jensen, Robert R. , Laudal, Dennis L. , Miller, Stanley J. , Olson, Edwin S. , Pavlish, John H. , Zygarlicke, Christopher J.
Current Investigators: Pavlish, John H. , Benson, Steven A. , Galbreath, Kevin C. , Holmes, Michael J. , Miller, Stanley J. , Zygarlicke, Christopher J.
Institution: University of North Dakota
EPA Project Officer: Stelz, Bill
Project Period: October 15, 1999 through October 14, 2003
Project Period Covered by this Report: October 15, 2000 through October 14, 2001
Project Amount: $4,772,400
RFA: Center for Air Toxic Metals (CATM) (1998)
Research Category: Targeted Research
Description:
Objective:The objective of the research conducted by 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. The goal of CATM is to develop key information on air toxic metal compounds to support development and implementation of pollution prevention and control strategies that will reduce air toxic metal emissions and releases to this environment.
Progress Summary:This year, CATM research activities addressed several key issues related to air toxics. A summary of these research activities and accomplishments is provided in the report.
Fundamental Mechanisms of Mercury Species Formation in Coal Combustion Flue Gas
Bench-scale investigations using synthetic flue gas indicate that NO, NO2,
hematite (
-Fe2O3),
and maghemite (
-Fe2O3)
promote the conversion of gaseous elemental mercury (Hg0)
to gaseous oxidized mercury (Hg2+) and/or particle-associated
mercury (Hg[p]) in simulated coal combustion flue gases. Injections of NO2
and -Fe2O3
had a different effect depending on coal type. HCl injection into the subbituminous
coal combustion flue gas converted most of the Hg0 to
Hg2+, whereas HCl injection into the lignitic flue gas
converted most of the Hg0 and Hg2+
to Hg(p). Fabric filters impregnated with -Fe2O3
resulted in Hg0 and Hg2+ removal
efficiencies of about 50 percent.
Development of Sampling and Analytical Tools for Oxidized Mercury Species
Research is underway to develop new analytical tools for the definitive determination of reactive oxidized mercury species in a vapor phase in combustion flue gas streams. Current methods for speciating vapor phase mercury do not distinguish the inorganic forms of Hg(II), but this information is needed to understand and accurately model the behavior of mercury in flue gas and in a control device. Analysis of HgCl2 was improved by derivatizing cryogenically trapped HgCl2, with diazomethane to form bischloromethylmercury, whose peak shape is very sharp in contrast to the very broad elution of HgCl2. Additionally, the chemistry of the gas chromatography-mass spectrometry (GC-MS) analysis of Hg(NO3)2 was elucidated. Several experiments were performed showing that the chromatography and unique spectra obtained for trapped, as well as standard Hg(NO3)2, resulted from on-column reaction of vapors of this highly reactive species.
Development of Mercury Control Technologies
Several new approaches were taken not only to achieve better sorbent performance, but also to better understand the complex physical and chemical process by which sorbents absorb, oxidize, and retain mercury. Carbon impregnation tests with various acids and ligands failed to result in an improved sorbent capacity with a full flue gas matrix. Similarly, carbon impregnation with iron(III) and iron(IV) compounds showed no improvement over the baseline carbon. Longer-term catalyst tests, in which the catalyst bed was exposed to real flue gas, showed that gold with the appropriate substrate and contact geometry can oxidize nearly 100 percent of the elemental mercury. A vanadium titanium catalyst was less effective, achieving 70 percent oxidation, but still may be effective enough to consider for some applications. Further testing of promising catalysts will continue next year.
Application of Database and Models to the Fundamental and Applied Study of Air Toxic Metals
The CATM database now contains more than 390,000 analytical measurements from more than 150,000 analyses from approximately 100 plants. The database also contains all usable data from the U.S. Environmental Protection Agency Information Collection Request. A theoretical model was developed to evaluate mercury-sorbent interactions and gas-phase mass-transfer rates to the sorbent. The model calculations qualitatively reproduced the correct trending of mercury capture with sorbent injection rates and time, as well as the effect of higher sorbent-to-mercury ratios. An empirical model for mercury speciation and transformations focused on developing a neural network to predict mercury emissions. The regression ratio between the actual data and predicted data set is 0.2259 (correlation, r2 = 0.9750), which is within good acceptability limits.
Stability of Mercury in Combustion By-Products
The project was designed to determine the mechanisms of mercury release from coal combustion by-products (CCBs) and biomass materials. The results of the project show that there is no clear evidence of the rate of mercury release compared to mercury concentration as determined by bulk analysis of the ash. The mercury release from six samples appears to be extraordinarily low-below 200 picograms per 100 grams of CCB for each 90-day equilibration period. This equates to a release of 4×10-9 pounds per ton in a 90-day period as a worst-case scenario, which is 1.6×10-8 pounds per ton per year. New tests are just beginning for biota experiments.
Investigation of the Fate of Mercury in a Coal Combustion Plume Using a Static Plume Dilution Chamber
Measurements of speciated forms of mercury have been made in combustion stacks and in ambient air. However, little is known about the mercury transformations that occur in the plume. A static plume dilution chamber (SPDC) designed to simulate plume conditions in the atmosphere was used to examine these reactions. Good mass balances were obtained for these tests (100 ± 25 percent). The data appear to indicate that some reduction of Hg2+ to Hg0 does take place in the SPDC. However, because of observed wall effects, the static SPDC may not be the best tool available to generate data to further understand mercury chemistry in combustion plumes.
Mercury Release from Crude Oil
Uncertainty continues over the amount of mercury released into the environment from the extraction, transport, refining, and consumption of crude oil and its products. The project focused on gathering relevant information from a broad range of possible sources and evaluating the information for accuracy, validity, and completeness. While some researchers indicate that there are crude oils with significant levels of mercury, others argue that the average values reported are biased by a sample population that is weighted toward samples high in mercury. In addition to the potential bias in the data from more frequent measurement of samples that are high in mercury, there also is uncertainty associated with sampling and measurement techniques. Sampling and handling issues can be associated with the large variety of mercury forms, difficulties in obtaining homogeneous samples, loss of volatile Hg0 to the headspace of sample containers, and loss of mercury to the sample containers. Analytical methods for the determination of Hg in hydrocarbons have improved dramatically in recent years, but improved quality assurance/quality control procedures need to be followed and documented to add further confidence in results.
Technology Commercialization, Education, and Publication
To facilitate the transfer of technical information produced by CATM, several communication venues are employed, including participation in conferences, symposia, workshops, and other educational programs; annual meetings and peer reviews; and the publication of a semiannual newsletter. The CATM Web Page was maintained throughout the year. Copies of the CATM Newsletter are available through this Web site. The EERC, through CATM, has organized and sponsored two Air Quality: Mercury, Trace Elements, and Particulate Matter Conferences held in 1998 and 2000. A third Air Quality Conference is planned for September 2002.
Future Activities:Future research at CATM will focus on the following:
• Mercury transformation in combustion flue gases
• Development of mercury sampling and analytical techniques
• Mercury control technologies
• Stability of mercury in coal combustion by-products
• Mercury in alternative fuel sources
• Transition metal speciation of fossil fuel combustion flue gases
• Potential impact of selenium on mercury exposure
• Fundamental study of the impact of SCR on mercury speciation
• Education and peer-reviewed publications.
Journal Articles: 52 Displayed | Download in RIS Format
| Other center views: | All 347 publications | 110 publications in selected types | All 52 journal articles |
| Type | Citation | ||
|---|---|---|---|
|
|
Benson S. Air quality conference status of research on mercury. Filtration & Separation 1999;36(6):4. |
R827649 (2000) R827649 (Final) |
not available |
|
|
Benson SA, Erickson TA, Jensen RR, Laumb JD. Transformations model for predicting size and composition of ash during coal combustions. American Chemical Society Fuel Preprints 2002;47(2):796-798. |
R827649 (2002) R827649 (Final) |
not available |
|
|
Benson SA. Air quality III: mercury, trace elements, and particulate matter. Fuel Processing Technology 2004;85(6-7):423-424. |
CR830929 (2004) R827649 (2003) R827649 (Final) |
not available |
|
|
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) |
|
|
|
Benson SA, Laumb JD, Jensen RR, Eylands KE. Characterization of particulate matter collected with a Burkhard sampler. American Chemical Society Fuel Preprints 2001;46(1):296-299. |
R827649 (Final) |
not available |
|
|
Biswas P, Senior C, Chang R, Vidic R, Laudal D, Brown T. Mercury measurement and its control: What we know, have learned, and need to further investigate. Journal of the Air & Waste Management Association 1999;49(12):1469-1473 |
R827649 (Final) |
not available |
|
|
Boschee P. EPA mercury regime risks apples-to-oranges results. Electric Light & Power 1999;77(2). |
R827649 (2000) R827649 (Final) |
not available |
|
|
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) |
|
|
|
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. |
R827649 (2000) R827649 (Final) |
not available |
|
|
Galbreath KC, Zygarlicke CJ. Mercury transformations in coal combustion flue gas. Fuel Processing Technology 2000;65:289-310. |
R827649 (2000) R827649 (Final) |
not available |
|
|
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. |
R827649 (2000) R827649 (Final) |
not available |
|
|
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. |
R827649 (2000) R827649 (Final) |
not available |
|
|
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. |
R827649 (2003) R827649 (Final) |
not available |
|
|
Galbreath KC, Crocker CR, Nyberg CM, Huggins FE, et al. Nickel speciation of urban particulate matter from Davie, Florida. American Chemical Society, Division of Fuel Chemical 2003;48(2):779-781. |
R827649 (2003) R827649 (Final) |
not available |
|
|
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. |
R827649 (2002) R827649 (2003) R827649 (Final) CR830929 (2004) |
|
|
|
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. |
R827649 (2002) R827649 (2003) R827649 (Final) CR830929 (2004) CR830929 (2005) |
|
|
|
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) |
|
|
|
Hassett DJ, Eylands KE. Mercury capture on coal combustion fly ash. Fuel 1999;78(2):243-248. |
R827649 (2000) R827649 (Final) |
not available |
|
|
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. |
R827649 (2002) R827649 (2003) R827649 (Final) CR830929 (2004) |
|
|
|
Heebink LV, Hassett DJ. Release of mercury vapor from coal combustion ash. Journal of the Air & Waste Management Association 2002;52(8):927-930. |
R827649 (2002) R827649 (Final) |
not available |
|
|
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) |
|
|
|
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) |
|
|
|
Laudal DL, Brown TD, Nott BR. Effects of flue gas constituents on mercury speciation. Fuel Processing Technology 2000;65:157-165. |
R827649 (2000) R827649 (Final) |
not available |
|
|
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. |
R827649 (2000) R827649 (Final) |
not available |
|
|
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. |
R827649 (2003) R827649 (Final) CR830929 (2004) |
|
|
|
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. Environmental Manager. 2003;(February):16-22. |
R827649 (2002) R827649 (2003) R827649 (Final) R827649C001 (Final) |
not available |
|
|
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. |
R827649 (2002) R827649 (2003) R827649 (Final) CR830929 (2004) |
|
|
|
Mann MD. Mercury emissions. FGD and DeNOx Newsletter, May 1999, No. 253, pp. 5-6. |
R827649 (2000) |
not available |
|
|
Miller SJ, Dunham GE, Olson ES, Brown TD. Flue gas effects on a carbon-based mercury sorbent. Fuel Processing Technology 2000;65:343-363. |
R827649 (2000) R827649 (Final) |
not available |
|
|
Olson ES, Miller SJ, Sharma RK, Dunham GE, Benson SA. Catalytic effects of carbon sorbents for mercury capture. Journal of Hazardous Materials 2000;74(1-2):61-79. |
R827649 (2001) R827649C001 (2001) R827649C001 (Final) |
not available |
|
|
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. |
R827649 (2002) R827649 (Final) |
not available |
|
|
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 of Physique IV 2003;107(4):979-982. |
R827649 (2003) R827649 (Final) |
not available |
|
|
Olson ES, Laumb JD, Benson SA, Dunham GE, et al. The multiple site model for flue gas-mercury interactions on activated carbons: the basic site. American Chemical Society, Division of Fuel Chemical 2003;48(1):30-31. |
R827649 (2003) R827649 (Final) |
not available |
|
|
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. |
R827649 (2003) R827649 (Final) CR830929 (2004) CR830929 (2005) |
|
|
|
Pavlish JH. Status of particulate matter research and development. Filtration & Separation 1999;36(2):11. |
R827649 (2000) R827649 (Final) |
not available |
|
|
Pavlish JH, Sondreal EA, Mann MD, Olson ES, Galbreath KC, Laudal DL, Benson SA. State review of mercury control options for coal-fired power plants. Fuel Processing Technology 2003; 82(2-3):89-165. |
R827649 (2002) |
not available |
|
|
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. |
R827649 (2003) R827649 (Final) |
not available |
|
|
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. |
R827649 (2003) R827649 (Final) CR830929 (2004) |
|
|
|
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) |
not available |
|
|
Raymond LJ, Ralston NVC. Mercury: selenium interactions and health implications. Seychelles Medical and Dental Journal 2004;7(1):72-77. |
R827649 (Final) CR830929 (2004) |
|
|
|
Sondreal EA, Benson SA, Pavlish JH. Status of research on air quality: mercury, trace elements, and particulate matter. Fuel Processing Technology 2000;65:5-19. |
R827649 (2000) R827649 (Final) |
not available |
|
|
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. |
R827649 (2001) R827649C001 (2001) R827649C001 (Final) |
not available |
|
|
Sondreal EA, Jones ML, Groenewold GH. Tides and trends in the world’s electric power industry. The Electricity Journal 2001;14(1):61-79. |
R827649 (Final) |
not available |
|
|
Sondreal EA, Benson SA, Pavlish JH, Ralston NV. 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) |
|
|
|
Thompson JS, Pavlish JH. Cryogenic trapping of oxidized mercury species from combustion flue gas. Fuel Processing Technology 2000;65:167-175. |
R827649 (2000) R827649 (Final) |
not available |
|
|
Timpe RC, Mann MD, Pavlish JH. Organic sulfur and hap removal from coal using hydrothermal treatment. Fuel Processing Technology 2001;73(2):127-141. |
R827649 (2000) R827649 (2001) R827649C001 (2001) R827649C001 (Final) |
not available |
|
|
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) |
|
|
|
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) |
|
|
|
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) |
|
|
|
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) |
|
|
|
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. |
R827649 (2003) R827649 (Final) CR830929 (2004) |
|
|
|
Zygarlicke CJ, Zhuang Y, Galbreath KC, Thompson JS, Holmes MJ, Tibbetts JE, Schulz RL, Dunham GE. Experimental investigation of mercury transformations in pilot-scale combustion systems and a bench-scale entrained flow reactor. Fuel Processing Technology. |
R827649 (2002) |
not available |
air, toxic, air quality, control, modeling, database, emissions, environment, hazardous, mercury, metals, pollutants, air pollution, sampling, measurement, species, transformations. , Air, Sustainable Industry/Business, Scientific Discipline, Waste, RFA, Engineering, Chemistry, & Physics, Chemical Engineering, Analytical Chemistry, Incineration/Combustion, air toxics, Environmental Engineering, cleaner production/pollution prevention, Environmental Chemistry, Environmental Monitoring, combustion contaminants, emissions contol engineering, clean technology, combustion waste recovery, ambient air quality, cleaner production, ambient emissions, atmospheric models, combustion byproducts, combustion technology, combustion control, emission control strategies, hazardous air pollutants, aerosol particles, trace metal emissions, combustion, chemical kinetics of incineration, air pollutants, air quality models, emission control technologies, environmentally friendly technology, atmospheric chemistry, mercury, metals, ambient metal species, air pollution control, energy efficiency, metal vapor emissions, emission controls, green technology, pollution prevention, air emissions
Relevant Websites:
http://www.undeerc.org 
http://www.undeerc.org/catm/catm_home.html
Progress and Final Reports:
2000 Progress Report
Original Abstract
2002 Progress Report
2003 Progress Report
Final Report
Subprojects under this Center:
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R827649C001 Development And Demonstration Of Trace Metals Database
R827649C002 Nickel Speciation Of Residual Oil Ash
R827649C003 Atmospheric Deposition: Air Toxics At Lake Superior
R827649C004 Novel Approaches For Prevention And Control For Trace Metals
R827649C005 Wet Scrubber System
R827649C006 Technology Commercialization And Education
R827649C007 Development Of Speciation And Sampling Tools For Mercury In Flue Gas
R827649C008 Process Impacts On Trace Element Speciation
R827649C009 Mercury Transformations in Coal Combustion Flue Gas
R827649C010 Nickel, Chromium, and Arsenic Speciation of Ambient Particulate Matter in the Vicinity of an Oil-Fired Utility Boiler
R827649C011 Transition Metal Speciation of Fossil Fuel Combustion Flue Gases
R827649C012 Fundamental Study of the Impact of SCR on Mercury Speciation
R827649C013 Development of Mercury Sampling and Analytical Techniques
R827649C014 Longer-Term Testing of Continuous Mercury Monitors
R827649C015 Long-Term Mercury Monitoring at North Dakota Power Plants
R827649C016 Development of a Laser Absorption Continuous Mercury Monitor
R827649C017 Development of Mercury Control Technologies
R827649C018 Developing SCR Technology Options for Mercury Oxidation in Western Fuels
R827649C019 Modeling Mercury Speciation in Coal Combustion Systems
R827649C020 Stability of Mercury in Coal Combustion By-Products and Sorbents
R827649C021 Mercury in Alternative Fuels
R827649C022 Studies of Mercury Metabolism and Selenium Physiology