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ASSESSING SPECIATION AND RELEASE OF HEAVY METALS FROM COAL COMBUSTION PRODUCTS
Citation:
AL-ABED, S. R., G. JEGADEESAN, AND P. PINTO. ASSESSING SPECIATION AND RELEASE OF HEAVY METALS FROM COAL COMBUSTION PRODUCTS. Presented at 232ND American Chemical Society National Meeting, San Francisco, CA, September 10 - 14, 2006.
Impact/Purpose:
to present information
Description:
In this study, the speciation of heavy metals such as arsenic, selenium, lead, zinc and mercury in coal combustion products (CCPs) was evaluated using sequential extraction procedures. Coal fly ash, bottom ash and flue gas desulphurization (FGD) sludge samples were used in the experiments. Extraction fluids of increased strength were used to chemically extract heavy metals from the CCPs to determine their geochemical association in the solid. Arsenic, selenium and lead were associated with the oxide phases of iron, mainly iron oxide. Mercury in FGD sludge was mainly in the form of inorganic chlorides. Metal leaching from CCPs was also determined using various extraction tests such as the TCLP, SPLP, availability and deionized water tests. The amount of metal released was dependent on its total amount in the solid and the extraction fluid used. A correlation of heavy metal speciation with the metal release under different disposal scenarios is illustrated.