Efficient and eco-friendly treatment of municipal solid waste incineration fly ash and municipal sludge for alkali activated material

Concern is arising for the effective treatment and utilization of municipal solid waste incineration (MSWI FA) and municipal sludge (MS). A synergistic thermal treatment method that can energy efficiently and eco-friendly converting MSWI FA and MS into precursor for alkali activated materials (AAMs) synthesis has been developed in our laboratory. This paper delves into the mechanisms of synergistic thermal treatment and alkali activation. The results indicate that the synergistic processing of MSWI FA and MS can effectively reduce the temperature required for thermal treatment. During the thermal treatment process, treatment above 1200 °C leads to the significant formation of amorphous phases, which markedly aids in the strength development of AAMs. The strength of the AAMs is 42.63–48.51 MPa. Additionally, the environmental compatibility of the obtained AAMs was studied, with the toxic equivalent quantity of dioxins reduced to 0.76–1.3 ng TEQ/kg, and the leaching rates of Ni, Cr, Cu, Pb, Zn, Mn, Ba and Cd significantly below the regulatory limits in China. The findings from this work provide theoretical and practical guidance for the efficient, secure, and value-added treatment of MSWI FA and MS.