Life Cycle Sustainability Assessment of municipal solid waste management systems: a review.

In the context of Circular Economy, the significance of municipal solid waste management systems (MSWMSs) has increased, as well as the need for comprehensive assessment tools of their sustainability. In the Life Cycle Thinking (LCT) framework, the Life Cycle Sustainability Assessment (LCSA), which is a methodology aiming to evaluate the environmental, economic, and social burdens throughout the various phases of waste management, has raised great interest. The paper describes the state-of-the-art of the implementation of LCT tools, with high regard to LCSA, for the evaluation of MSWMSs through their life cycle, with a deep focus on the use of both midpoint and endpoint categories. Drawing insights from an analysis of 69 case studies, the paper identifies the most frequently applied midpoint and endpoint categories for the sustainability assessment of MSWMSs. These categories are exposed in terms of their significance and applicability to specific waste management scenarios, providing valuable guidance for experts and researchers seeking to employ LCSA in MSWMSs assessments. Additionally, the paper outlines the limits associated with the implementation of LCSA, thereby highlighting areas for further research and improvement. In contrast to other reviews in this field, this paper uniquely focuses on the implementation of LCSA in the specific context provided by MSWMSs. By disseminating such insights, the paper aspires to foster the widespread adoption of LCSA by experts and researchers, ultimately advancing the sustainability discourse in municipal solid waste management.

Implementing a sustainable process for the recovery of palladium from spent catalysts at industrial scale: A LCA approach.

Due to its unique physicochemical properties, palladium is widely used in several industry applications (e.g., vehicle emission control). In view of the circular economy, it is essential to explore secondary sources of palladium, such as urban mines. Current technologies for effective palladium recovery involve high energy consumption and severe environmental impact. More recently, a novel green method for recovering palladium from spent catalysts through a combination of mild acidic leaching and photodeposition on ZnO nanoparticles was proposed on a laboratory scale. In the present study, the environmental impacts of this recovery method, properly upscaled and modelled, was assessed by employing the LCA approach. Specifically, a comparative LCA was carried out for the process with as well as without recycling key components, such as Cu (II) and NaCl for the leaching solution and ZnO. The outcomes identified critical areas and drove the investigation of alternative process configurations to reduce its environmental footprint, such as the use of carbon dioxide in the photodeposition process with the aim of decreasing the resulting terrestrial ecotoxicity. This study marks a significant step forward in advancing research toward industrial-scale implementation of palladium recovery. It provides valuable insights for researchers in the field of green physicochemical processes for metal recovery, thus offering guidance for future decision-making towards more sustainable practices.