Bottom ash derived from municipal solid waste and sewage sludge co-incineration: First results about characterization and reuse. (October 2020)

• Record Type: Journal Article
• Authors: Assi, Ahmad; Bilo, Fabjola; Federici, Stefania; Zacco, Annalisa; Depero, Laura E.; Bontempi, Elza
• Is Part Of: Waste management. Volume 116(2020)
• Page Start: 147
• Page End: 156
• Publication Date: 2020-10
• Subjects: MSW municipal solid waste -- MSWI municipal solid waste incineration -- BA bottom ash -- FA fly ash -- MIBA municipal solid waste incineration bottom ash -- MIFA municipal solid waste incineration fly ash -- COBA Bottom ash derived from co-combustion of municipal solid waste and sewage sludge -- SS sewage sludge; Municipal solid waste -- Sewage sludge -- Bottom ash -- Heavy metals -- Stabilization; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2020.07.031
• Languages: English
• ISSNs: 0956-053X

Abstract

Graphical abstract: Highlights: Bottom ash from co-incineration with sewage sludge (COBA) is characterized. All COBA particle size fractions have large amount of amorphous content. The finest COBA size fraction (<300 μm) has more leachable Pb and Zn metals. The finest COBA size fractions show a good hydraulic behaviour. COBA size fractions range from 1000 to 1400 μm is suggested to produce glass/ceramic. Abstract: This paper reports a complete characterization of the lowest fractions of bottom ash derived from co-combustion of municipal solid waste with sewage sludge (COBA), with the aim to suggest suitable reuse strategies of this by-product. X-Ray Microanalysis is coupled with mineralogical characterization, based on X-Ray Diffraction and Rietveld refinement, to extract information about COBA crystalline and amorphous phases. The composition of different particle size fractions shows that amount of amorphous increases with the increase of fractions sizes. In particular, the finest COBA size fraction (<300 μm) shows more leachable heavy metals (i.e. Pb, and Zn) compared to the investigated fraction with the highest sizes (1400 µm). On the basis of their composition, lowest particle size fractions show a better hydraulic behavior compared to bottom ash obtained from incineration of only municipal solid waste, suggesting possible attractive COBA applications, as for example, Portland cement substitution. In addition, COBA with size fractions in the range of 1000–1400 μm are proposed to be used to produce glass and ceramic. Finally, due to its high amount of reactive amorphous phase (about 73% for fraction size of 1400 μm) COBA is used, in combination with other by-products (coal fly ash and flue gas desulphurization residues), to stabilize municipal solid waste incinerator fly ash produced at the same incinerator plant, following the azure chemistry principle of use a waste to stabilize another waste.