Potential uses for Municipal Solid Waste Incineration Ashes: A review

With the global increase in urbanization, the production of municipal solid waste (MSW) has risen significantly, reaching approximately 2.01 × 10 9 tons annually. Among the strategies adopted to manage this waste, incineration has become a widely implemented solution, resulting in the generation of byproducts such as fly ash (FA) and bottom ash (BA). These residues pose environmental challenges due to the presence of potentially hazardous compounds, but they also offer opportunities for recovery and reuse across different industries. This study presents a comprehensive literature review focused on the chemical composition, main physical properties, and potential applications of MSW incineration residues, particularly fly ash and bottom ash. The primary objective is to identify viable and sustainable alternatives for the valorization of these materials, especially in sectors such as construction, agriculture, and environmental remediation. Additionally, the review examines the pre-treatment methods required to ensure safe reuse, as well as the environmental, social, and economic implications of their application. The literature review was primarily conducted using the Scopus database with the keyword" municipal solid waste incineration," and complemented with additional terms such as fly ash, bottom ash, valorization, circular economy, and pre-treatment. Around 80 relevant publications were selected and categorized by publication period to analyze research evolution over time. The novelty of this work lies in the integrative evaluation of MSWI residues through a multidimensional lens and the proposal of a structured framework to guide their responsible use. This study provides valuable insights for advancing circular economy strategies and enhancing sustainable materials management practices.