METAL DISTRIBUTION IN INCINERATION RESIDUES OF MUNICIPAL SOLID WASTE (MSW) IN JAPAN

This study aimed to identify distribution of metals and the influential factor on metal concentration in incineration residues. Bottom ash and fly ash were sampled from nineteen stoker and seven fluidized bed incinerators, which were selected to have the variety of furnace capacity, furnace temperature and input waste. As results, shredded bulky waste in input waste increased the concentration of some metals, such as Cd and Pb, and the effect was confirmed by the analysis of shredded bulky waste. During MSW incineration, lithophilic metals such as Fe, Cu, Cr and Al remained mainly in the bottom ash while Cd volatilized from furnace and condensed to the fly ash. About two-third of Pb and Zn was found in bottom ash despite their high volatility. Finally, based on the results obtained in this study, metal amount in incineration residues of MSW was calculated and the loss of metal was estimated in terms of mass and money. Considerable amount of metals was found to be lost as waste material by landfilling incineration residues.