Aromatic carboxylic acids generated from MSW incinerator fly ash

The total of 128 aromatic monocarboxylic acids (ACAs) including 36 mono-to tetrachlorinated compounds were qualitatively detected in fly ash from municipal solid waste incinerators (MSWIs) by GC/MS. They are structually classified into five groups; polycyclic aromatic hydrocarbons (PAHs), biphenyls, oxa-PAHs, oxo-PAHs, and hydroxy-PAHs. The demonstration of dicarboxylic acids was unsuccessful. ACAs might afford oxygenated PAHs by intramolecular dehydration and/or other reactions. The detection of polychlorinated benzoic acids and biphenyl carboxylic acids, possibly candidates for the precursors of polychlorinated dibenzo-p-dioxins and dibenzofurans, might imply the existence of novel pathways.