Coal fired power plants, pollution

Point Source a source of pollution that is well defined, such as the smokestack of a coal-fired power plant or smelter. 

Hazardous air pollutants (HAPs) are substances that may cause immediate or long-term adverse effects on human health. HAPs can be gases, particulates, trace metals such as mercui y, and vapors such as benzene. For coal-fired power plants, the HAPs of most concern are metals such as mercury, arsenic, and vanadium. 

Llacuna, S., Gorriz, A., Sanpera, C., and Nadal, J. 1995. Metal accumulation in three species of passerine birds (Emberiza cia, Parus major, and Turdus merula) subjected to air-pollution from a coal-fired power plant. Arch. Environ. Contam. Toxicol. 28 298-303. 

Heit, M. 1985. The relationship of a coal fired power plant to the levels of polycyclic aromatic hydrocarbons (PAH) in the sediment of Cayuga Lake. Water, Air, Soil Pollut. 24 41-61. 

Fossil fuel electrical power plants can be more hazardous to humans than nuclear power plants because of the pollutants. A 1,000 megawatt (MW) coal-fired power plant releases about 100 times as much radioactivity into the environment as a comparable nuclear plant. A 1,000-MW power plant will use 2,000 railroad cars of coal or 10 supertankers of oil but only 12 cubic meters of natural uranium every year. Fossil fuel... 

From a public health point of view, the concentration of nickel associated with small particles that can be inhaled into the lungs is of greatest concern. The nickel content of aerosols from power plant emissions is not strongly correlated with particle size (Hansen and Fisher 1980). In one modem coal plant, 53% and 32% of nickel in emissions were associated with particles <3 and <1.5 pm in diameter, respectively (Sabbioni et al. 1984). Other studies found that only 17-22% of nickel emissions from coal-fired power plants were associated with particles of >2 pm, and that the mass medium diameter (MMD) of nickel-containing particles from a plant with pollution control devices was 5. 4 pm (Gladney et al. 1978 Lee et al. 1975). In one study, 40% of the nickel in coal fly ash was adsorbed on the surface of the particles rather than being embedded in the aluminosilicate matrix (Hansen and Fisher 1980). Surface-adsorbed nickel would be more available than embedded nickel. 

In previous studies we found that improved emission-control devices (such as hot-side electrostatic precipitaters and wet-scrubber systems) now being installed on modern pulverized-coal-fired power plants modify the quantity, chemical composition, and distribution characteristics of fine aerosol emissions (12,13). Such modifications must be understood to adequately assess human health and environmental hazards, and to apportion the contributions of sources to urban pollutant inventories. 

Smog Air pollution caused by the reaction of sunlight and chemical compounds such as nitrogen dioxide and hydrocarbons the compounds are usually produced by car exhaust and the release of gases from industries such as coal-fired power plants. 

Using a source-composition library containing data from 21 studies of coal-fired power plants, we have investigated the effects of particle size, coal type, and pollution control device on the composition of particles emitted from coal-fired power plants. 

Kowalczyk, G. S., "Emission and Atmospheric Impact of Trace Elements from a Reconverted Coal-Fired Power Plant," Preprint for 77th Annual Meeting of the Air Pollution Control Association, San Francisco, CA, June 24-29, 1984. 

The purpose of this paper is threefold (1) to describe the pollution problem quantitatively, (2) to summarize our present understanding of comparative coal-cleaning ECTs, and (3) to analyze the impact of coal-cleaning ECT costs on the economic tradeoffs between coal cleaning at (or near) the mine and FGD at the coal-fired power plant. 

Brown TD, Schmidt CE, Radziwon AS. 1993. Comprehensive assessment of toxic emissions from coal-fired power plants. In Chow W, Connor KK, eds. Managing hazardous air pollutants - state of the art. Boca Raton, Florida Lewis Publishers, 116-125. 

Mercury Pollutant from coal fired power plants... 

A power plant generates 2.76 x 10 megawatt hours (MWh) of electricity per year by burning 1.66 x 10 tons of a low-grade coal containing 3.2% sulfur and 15.4% ash. The ratio of fly ash to bottom ash is 0.65 and the plant s particulate collection efficiency is 85%. Determine the amount of each pollutant (particulates, NO4 and SO2) emitted per year in pounds/kilowatt-hour for the coal-fired power plant. 

Scrubbers are pollution control devices, which remove pollutants from gas streams, particularly from the combustion gases produced by facilities such as coal-fired power plants. Scrubbers may use absorbents in slurry or solution form (wet scrubbers), or in powder form (dry scrubbers), with wet scrubbers being more often used. Modern scrubbers can consist of several cleaning steps such as dust separation, sulfur removal, capture of mercury, lead, or other heavy metals, and breakdown of nitrogen oxides. Scrubbers of the future will also need to capture and sequester carbon dioxide. Currently, the most common application of scrubbers is still the removal of sulfur, frequently combined with capture of fly-ash. 

Wangen LE, Turner FB. 1980. Trace elements in vegetation downwind of a coal-fired power plant. Water Air Soil Pollut 13 99-108. 

The version of this paper presented verbally at Kansas City dwelt at some length on an example drawn from an actual risk analysis performed by the author and his colleagues on a problem involving long range transport and possible human health effects from sulfur air pollution from coal-fired power plants. Interested readers can find details on this work elsewhere (12). 

Research the meaning of the term thermal pollution, and write a news article that traces the possible sources of such pollution in the operation of a coal-fired power plant. Also, explain the impact of thermal pollution. Refer to Figure 20.12 for assistance. 

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