The speciation of potentially toxic elements (PTE) in bottom ashes from municipal solid waste incineration (MSWI) and their relationship with grain size is investigated. The proposed enrichment of several potential toxic elements in lower sized grains is discussed, comparing the literature and new data on Parma’s waste incinerator. Results from X-ray fluorescence spectrometry (XRF), SEM-EDS, and XRD analyses on different grain size show (1) a positive Si-trend, correlated with grain size and few lithophile elements, such as Zr and Rb. In Parma, Al, K, Mg, and Fe also correlate with Si for the portion below 2 mm; (2) a Ca-trend, with a strong negative correlation with Si and a positive correlation with loss on ignition (LOI), S, Cl, Ti, Zn, Pb, and Sn. Mineralogical composition shows a little change in grain size, as in previous investigations, but with substantial differences in amorphous content. SEM-EDS analysis shows that the amorphous portion is highly heterogeneous, with portions coming from melting during incineration, residual glass, and unburnt loss on ignition (LOI). The above results show that PTE elements are either present as metals (such as Cu and Ni, or Zn, Pb and Sn) in carbonate, sulfate, and amorphous residual LOI portions.

Introduction: Bottom ashes (BA) from municipal solid waste incinerators (MSWIs) are currently classified by the European Waste Catalogue as industrial non-hazardous waste. To promote their reuse, identification and characterization of the heavy metal-bearing phases (both glass and minerals), as well as their weathering behavior, must be addressed for what concern the chemical composition, mineralogical phases, and in high concentrations and pollutants’ mobility. An important point to be noted is whether the results from a given plant can be generalized.Materials and methods: In this work, BA from five waste-to-energy (WtE) plants in northern Italy were sorted based on different grain sizes. The area showed similar MSW production, collected from a culturally homogeneous area, and similar collection management. For each grain size, a mineralogical, chemical, and physical characterization was carried out using XRF, XRD, TGA, and the leaching test.Results and discussion: We found that for major elements, the average chemical composition of the incinerators is similar, with some differences in minor elements. Ferrara (FE) and Forlì-Cesena (FC) BA show portlandite, higher ettringite, and less amorphous than the Torino (TO), Parma (PR), and Piacenza (PC) BA. This affects the pH, the release, and toxicity of the leachates. In FE and FC ashes, ettringite is insoluble, and we not only have low sulfate but also Ni and Ba beyond reglementary limits, suggesting that Ni and Ba are present as hydroxides with portlandite, which are soluble. In TO, PR, and PC, Cr and sulfates are beyond limits, suggesting that Cr comes from dissolution in ettringite. Cu and Cl are always beyond limits; the dissolution of chlorides accounts for only 30%–35% of the global Cl leachate. We observe that in the assessment of the potential toxicity of the ashes, mineralogy has a higher effect than the bulk chemical composition. Grain size sorting, although useful together with other techniques, is not by itself able to comply with the PTE risk level.Conclusion: The findings contribute to the development of efficient treatment strategies for BA, highlighting the need for a more thorough investigation to understand composition and properties and to find innovative ways to reuse, promoting the circular economy and sustainable waste management practices.

This study aimed to examine the role of resilience resources in patients' lifestyle changes after the first Acute Coronary event. 275 Italian patients (84.0% men; mean age = 57.5, SD = 7.9) participated in a longitudinal study. Resilience resources (Self-esteem, Dispositional Optimism, Sense of Coherence – SOC, General and Disease-specific Self-efficacy), and lifestyles (diet, physical activity, and smoking) were assessed twice (at baseline and after 6 months). Path analysis using latent change models was performed to model the combined effect of levels and changes of the resilience resources over lifestyle changes. Patients with strong SOC at baseline were less prone to smoke and more prone to decrease smoking; enhancement in SOC was associated with a smoking decrease. High Disease-specific Self-efficacy at baseline was associated with an improvement in all lifestyles; enhancement in Disease-specific Self-efficacy predicted an increase in physical activity. Findings underline the need to design psychological interventions that promote patients' Disease-specific Self-efficacy and SOC.

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