CHARACTERIZATION OF FLUE-GAS RESIDUES FROM MUNICIPAL SOLID-WASTE COMBUSTORS

Solid residues recovered from treatment of flue gas resulting from the combustion of municipal solid waste (MSW) are of particular concern b ecause of ever-increasing worldwide production rates and their concent rations of potentially hazardous transition elements and heavy metals. Three main residue types have been studied in this study: electrostat ic precipitator ashes, wet filter cakes, and semidry scrubber residues . Using a large number of residues from two French MSW combustion (MSW C) facilities, the aim of this work is to determine their chemistry an d mineralogy in order to shed light on their potential toxicity. We fi nd that pollutant concentrations are dependent not only on the composi tion of MSW but also on the size of particles and flue gas treatment p rocess. Using a procedure based on leaching, grain-size, density, and magnetic separations, we present a detailed description of the mineral ogy of MSWC solid residues. These residues consist of a Very heterogen eous assemblage of glasses, metals, and other crystals in which pollut ing elements are distributed. The results of this characterization wil l therefore help to contribute to the development of adequate waste ma nagement strategies.