Fly ash (FA), an atmospheric aerosol byproduct of coal fired power plants, is typically a small particulate matter with long atmospheric transport. FA contains metal oxides that vary in proportion depending upon their source region. One of the most prevalent components of fly ash is iron oxide, which is found in oxidation states Fe(II) and Fe(III), and aluminum(III) oxide. When acidic atmospheric water dissolves fly ash cations, including Fe(II), can be deposited on the ocean surface stimulating the growth of phytoplankton. In addition, metals such as iron(III) and aluminum(III) can play an environmental role in the chemical balance of the atmosphere and oceans. This work reports the metal leach from fly ash samples from two distinctive locations under atmospherically relevant conditions. Fly ash samples from power plants in the Midwestern United States and Calcutta India were characterized. In addition, their dissolution under simulated atmospheric acidity was investigated. The kinetics of the proton-promoted dissolution suggests that source region is indeed a determining factor in the metal leach capacity of fly ash, as dissolution from Midwestern fly ash is both faster and of greater magnitude than that of Indian ash. Minor pH dependence on iron leach is also observed. Kinetic constants and yields are also reported.<br/>

Comparative evaluation of the dissolution of fly ash from different source regions under atmospherically relevant conditions

249th National Meeting (2015)

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