Chapter 13 - Management of Hazardous By-products of Urban Waste Incineration: Some Considerations on the Italian Situation

Incineration is regarded as a very efficient technique for municipal solid waste (MSW) management. However, the environmental impact of MSW incineration needs to be carefully taken into account. The most relevant problem originating from MSW incineration is flue gas treatment, since untreated incineration flue gas contains large amounts of macropollutants and micropollutants. Another issue is the disposal of solid by-products of the incineration process. MSW incinerators essentially produce two kinds of solid by-products, i.e., bottom ash and air pollution control (APC) residues. APC residues are regarded as a hazardous waste, and different management strategies have been proposed for their recovery or disposal. In Italy, where this material amounts to about 4 × 108 kg/year, the most common management strategy is disposal via landfilling after solidification with cement or other hydraulic binders. Solidification is usually performed off site, in plants collecting APC residues from different incinerators. Another significant management option is represented by recovery of solidified residues as backfilling material of spent salt mines located in Germany.