Municipal solid waste incineration bottom ash : Physicochemical characterization of organic matter

The aim of this work was to characterize the initial organic content of a selected municipal solid waste incineration (MSWI) bottom ash. This was realized by elemental carbon analysis using pyroanalysis of untreated samples. In addition, MSWI bottom ash extracts obtained by supercritical fluid extraction (SFE) or hot solvent extraction (Soxtec), were analyzed using gas chromatography (GC) coupled to either a mass spectrometry detector (MSD) or a microwave induced plasma atomic emission detector (MIP-AED). The results showed that the labile organic carbon fraction of the MSWI bottom ash is non-negligible (about 1400 μg/g) and that it includes mainly carboxylic acids, n-alkanes, steroids and phthalates. The latter two families, as well as polyaromatic hydrocarbons that were also determined, would appear to confer a toxic character on MSWI bottom ash. In light of the well-designing and operating of the incineration facility, the results seem to be representative of a widespread quality of bottom ash.