Increased Leaching of As, Se, Mo, and V from High Calcium Coal Ash Containing Trona Reaction Products
The trona (trisodium hydrogendicarbonate dihydrate) injection method is being tested to control SOx emission from coal-fired power plants. A pair of moderately high calcium coal fly ashes, with and without trona injection, were used to determine the impact of trona injection on the leaching characteristics of anionic elements, including As, Se, Mo, and V, under different pH conditions. The results showed that trona ash (trona reaction products captured with fly ash) leached significantly more As, Se, Mo, and V than the control fly ash did, especially under the natural pH condition. In addition, trona ash had a significantly greater soluble fraction than the control ash. Further investigation indicated that greater amounts of the studied anionic elements in the trona ash were associated with the soluble, trona reaction products. Moreover, the insoluble fraction of the trona ash lost its capability to adsorb these elements under the natural pH condition. The competition from other major anions in the trona ash leachate might also have contributed to the reduced adsorption of the anionic elements under other pH conditions. As a result, the trona ash leached significantly more As, Se, Mo, and V than the control ash did. © 2013 American Chemical Society.
Y. Dan et al., "Increased Leaching of As, Se, Mo, and V from High Calcium Coal Ash Containing Trona Reaction Products," Energy and Fuels, American Chemical Society (ACS), Jan 2013.
The definitive version is available at http://dx.doi.org/10.1021/ef3020469
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