Pollution control mercury oxidation

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. 

Volatile metals (such as lead, mercury, and arsenic) or their oxides will volatilize. These metals cannot be easily removed from off-gases using conventional air pollution control equipment. 

The fraction of oxidized mercuiy in the stack effluent of a particular power plant depends on the coal type, combustion efficiency and the pollution control equipment used [8]. The specific form of mercury in flue gas has a strong impact on the capture of mercury by air pollution control equipment. 

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