Abstract Summary
The use of Minimal Liquid Discharge (MLD) in desalination receives increased attention due to its potential of increasing water and resource recovery while reducing brine volumes and consequently, their related environmental impacts (toxicity). Although MLD desalination is perceived as achieving sustainable brine management and transition to circular economy, few studies have incorporated MLD technologies into desalination life cycle analysis (LCA), while studies measuring and assessing their circularity performance are inexistent. This study not only addresses this gap by performing an integrated environmental and economic sustainability and circularity assessment of an MLD desalination system developed within the Water Mining H2020 project, but further investigates how different LCA approaches (process vs system) and allocation methods (mass vs economic) impact both the environmental impacts and the circularity results of such multifunctional systems. The results indicate that the MLD system has a higher circularity level and reduced toxicity compared to the baseline. The LCA and circularity results vary for the system and process approaches applied. The system approach acts as a black box, potentially limiting fair product comparisons, while the process approach allocates impacts to intermediate process flows and their resulting products. This study enhances the understanding of appropriate LCA and standardised circularity methods in MLD desalination assessments that can facilitate decision-making.
