Life Cycle Impact Assessment of Solution Combustion Synthesis of Titanium Dioxide Nanoparticles and Its Comparison with More Conventional Strategies.

This paper represents the first attempt to quantitatively and reliably assess the environmental sustainability of solution combustion synthesis (SCS) with respect to other soft chemistry strategies, which are more conventionally employed in the preparation of engineered oxide nanomaterials, namely hydrolytic and non-hydrolytic sol-gel syntheses (i. e., HSGS and NHSGS). Indeed, although SCS is well known to rely on significant reduction in the energy as well as time required for the obtainment of the desired nanocrystals, its quantitative environmental assessment and a detailed comparison with other existing synthetic pathways represents an absolute novelty of high scientific desirability in order to pursue a more sustainable development in the inorganic chemistry as well as materials science research fields. TiO2 nanoparticles were selected as the material of choice, for the production of which three slightly modified literature procedures were experimentally reproduced and environmentally evaluated by the application of the comprehensive life cycle assessment (LCA) methodology. Particularly, SCS was compared from an environmental perspective with sol-gel approaches performed both in water and in benzyl alcohol. The results of the present study were also framed among those recently obtained in a systematic study assessing seven further chemical, physical, and biological routes for the synthesis of TiO2 nanoparticles, comprising also flame spray pyrolysis (typically used in industrial productions), highlighting and quantifying the excellent environmental performances of SCS.

Environmental life cycle assessment of the recycling processes of waste plastics recovered by landfill mining.

Enhanced Landfill Mining (ELFM) is a powerful tool for the sustainable management of landfill sites, aiming at both land reclamation and material recovery/reuse. To enhance the recovery and recycling rate of excavated plastic fractions, in most cases destined to energy recovery, new convenient, effective and sustainable strategies are needed. In this study, a recovery and valorization process of ELFM excavated plastics has been validated through an integrated experimental and Life Cycle Assessment (LCA) approach, demonstrating the environmental sustainability of the secondary raw material generated, in terms of use of resources and emissions generated. In particular, the secondary granulate from ELFM was compared with a virgin product and the last one resulted to have a higher impact (more than 4.46 times greater than the first one), in particular for the use of the resource crude oil as raw material in the production of primary LDPE. The valorization process of the excavated plastic made the mechanical properties of the secondary raw material comparable to that of a primary material.