Surface Predominance of Trace Elements in Airborne Particles

Linton, Richard W.; Loh, Andrew; Natusch, D. F. S.; Evans, C. A.; Williams, Peter W.

doi:10.1126/science.1251197

Cited by 205 publications

(116 citation statements)

References 6 publications

Supporting

Mentioning

106

Contrasting

Unclassified

Order By: Relevance

“…148,152 The concentration of the trace elements within the submicrometer and supramicrometer ash fraction increases with decreasing particle size. 73,88 • The surfaces of the ash particles are also enriched in volatile elements relative to their core. 88 • The major influence on the fraction of ash that is vaporized is the temperature.…”

Section: Coal-fired Steam Generation Boilersmentioning

confidence: 99%

“…Studies using surface spectroscopic techniques have shown that the surface layers of both the supermicron 88 and submicron 21 ash particles are enriched in the trace elements. By ion milling of the particles, one can show the stratification that results from the sequential deposition of elements.…”

Section: Particle (Soot) Inception By Chemical Reactionmentioning

confidence: 99%

“…Selected field studies have determined the fractions of the trace elements entering a boiler that enter the flue gases and pass out of the unit through the stack. 63,78,88,148,152,179,180 Additional efforts have focused on the effectiveness of APCDs in removing these potentially toxic substances. 63,78,179,180 These studies provide the following information: Figure 12.…”

Section: Coal-fired Steam Generation Boilersmentioning

confidence: 99%

See 2 more Smart Citations

Combustion Aerosols: Factors Governing Their Size and Composition and Implications to Human Health

Lighty

Veranth

Sarofim

2000

Journal of the Air & Waste Management Association

1,008

600

View full text Add to dashboard Cite

Particulate matter (PM) emissions from stationary combustion sources burning coal, fuel oil, biomass, and waste, and PM from internal combustion (IC) engines burning gasoline and diesel, are a significant source of primary particles smaller than 2.5 µm (PM 2.5 ) in urban areas. Combustion-generated particles are generally smaller than geologically produced dust and have unique chemical composition and morphology. The fundamental processes affecting formation of combustion PM and the emission characteristics of important applications are reviewed. Particles containing transition metals, ultrafine particles, and soot are emphasized because these types of particles have been studied extensively, and their emissions are controlled by the fuel composition and the oxidant-temperature-mixing history from the flame to the stack. There is a need for better integration of the combustion, air pollution control, atmospheric chemistry, and inhalation health research communities. Epidemiology has demonstrated that susceptible individuals are being harmed by ambient PM. Particle surface area, number of ultrafine particles, bioavailable transition metals, polycyclic aromatic hydrocarbons (PAH), and other particle-bound organic compounds are suspected to be more important than particle mass in determining the effects of air pollution. Time-and size-resolved PM measurements are needed for testing mechanistic toxicological hypotheses, for characterizing the relationship between combustion operating conditions and transient emissions, and for source apportionment studies to develop air quality plans. Citations are provided to more specialized reviews, and the concluding comments make suggestions for further research.

show abstract

Section: Coal-fired Steam Generation Boilersmentioning

confidence: 99%

Section: Particle (Soot) Inception By Chemical Reactionmentioning

confidence: 99%

Section: Coal-fired Steam Generation Boilersmentioning

confidence: 99%

See 1 more Smart Citation

Combustion Aerosols: Factors Governing Their Size and Composition and Implications to Human Health

Lighty

Veranth

Sarofim

2000

Journal of the Air & Waste Management Association

1,008

600

View full text Add to dashboard Cite

show abstract

“…In addition, from the combustion of nearly 600 millions tons of coal per year in the U. S., it is estimated that thousands of tons of.potentially hazardous trace elements are released into the environment each year (Harvey et al, 1983;Akers, 1989). The airborne particulates that escape the post-combustion cleaning processes are respirable particles having an enriched concentration of trace elements on their surfaces (Natusch et al, 1973;Linton et al, 1976). As a result, the U. S. government is expected to place limits on trace element emissions as part of the Clean Air Act Amendment.…”

Section: Statement Of Problemmentioning

confidence: 99%

Advanced physical coal cleaning to comply with potential air toxic regulations. Quarterly report, 1 March 1995--31 May 1995

Honaker¹,

Paul²,

Mohanty³

et al. 1995

View full text Add to dashboard Cite

Studies have indicated that the potentially hazardous trace elements found in coal have a strong affinity for coal pyrite. Thus, by maximizing the rejection of pyrite, one can minimize the trace element content of a given coal while also reducing sulfur emissions. The pyrite in most Illinois Basin coals, however, is finely disseminated within the coal matrix. Therefore, to remove the pyrite using physical coal cleaning techniques, the pyrite must be liberated by grinding the coal to ultrafine particle sizes. Fortunately, the coals being fed to pulverized coal boilers (PCB) are already ground to a very fine size, Le., 70% passing 200 mesh. Therefore, this research project will investigate the use of advanced fine coal cleaning technologies for cleaning PCB feed as a compliance strategy.Work in this quarter has focused on the processing of a run-of-mine coal sample collected from Amax Coal Company's Delta Coal mine using column flotation and an enhanced gravity separator as separate units and in circuitry arrangements. The -60 mesh run-ofmine sample having an ash content of-about 22 % was cleaned to 6 % while achieving a very high energy recovery of about 87% and.a sulfur rejection value of 53 % in a single stage column flotation operation. Enhanced gravity treatment is believed to be providing excellent total sulfur rejection values, although with inferior ash rejection for the -400 mesh size fraction. The circuitry arrangement with the Falcon concentrator as the primary cleaner followed by the Packed-Column resulted in an excellent ash rejection performance, which out performed the release analysis. Trace element analyses of the samples collected from these tests will be conducted during the next report period. DISTRIBUTION OF THIS DOCUMENT IS U N U M m & r / EXECUTIVE SUMMARYThe Clean Air Act Amendment of 1990 requires U. S . utilities to comply with an increasing variety of environmental regulations. The restrictions on sulfur dioxide emissions in particular have received the most attention due to their impacts on medium and high sulfur coal markets. Another regulation that the Clean Air Act Amendment will impose in 1995 is the limitation of air toxic emissions. It has been estimated that, due to the combustion of over 600 million tons of coal per year, thousands of tons of potentially hazardous trace elements are released into the atmosphere. Thus, it is important to develop a pre-combustion coal cleaning strategy that will effectively reduce the trace element and sulfur contents of Illinois Basin coal.The results of conventional float-sink tests have indicated that most trace elements are largely inorganically associated with the coal matrix, although a few of them, such as boron, beryllium and germanium, are strongly bound to the organic portion of coal and probably present as metal chelates. This conclusion has provided a basis for the reduction of the levels of many trace elements by physical coal cleaning methods. For example, it was found that many elements of environmental concern, including ar...

show abstract

“…Recent results (30) have established that a number of trace elements, including several potential carcinogens are more highly concentrated on the surfaces of coal fly ash particles than in their interior. This phenomenon is probably due to particle surface deposition of elements volatilized during combustion and is found to occur for particles derived from a variety of high temperature combustion or smelting operations, e.g., automobile exhaust particulates and blast furnace dusts (31).…”

Section: Surface Association Of Trace Elementsmentioning

confidence: 99%

Potentially carcinogenic species emitted to the atmosphere by fossil-fueled power plants.

Natusch¹

1978

Environ Health Perspect

100

View full text Add to dashboard Cite

The identities and physicochemical characteristics of potentially carcinogenic species emitted to the atmosphere by fossil-fueled power plants are presented and discussed. It is pointed out that many so-called carcinogens are preferentially concentrated on the surface of respirable fly ash particles thus enabling them to come into intimate contact with lung tissues when inhaled. Relatively little information is available about the identities of particulate polycyclic organic compounds whose emission from coal fired power plants may well be substantially greater than hitherto supposed. The importance of chemical changes, which several species may undergo following emission (but prior to inhalation) in determining their potential carcinogenic impact, is stressed.

show abstract

Surface Predominance of Trace Elements in Airborne Particles

Cited by 205 publications

References 6 publications

Combustion Aerosols: Factors Governing Their Size and Composition and Implications to Human Health

Combustion Aerosols: Factors Governing Their Size and Composition and Implications to Human Health

Advanced physical coal cleaning to comply with potential air toxic regulations. Quarterly report, 1 March 1995--31 May 1995

Potentially carcinogenic species emitted to the atmosphere by fossil-fueled power plants.

Contact Info

Product

Resources

About