Social life cycle assessment of brine treatment in the process industry: A consequential approach case study

Social life cycle assessment (SLCA) was developed to complement the environmental life cycle assessment (LCA) and economic assessment. Contrary to LCA, SLCA is not yet standardized, and the consequential approach is little discussed in literature. This study aims to perform a consequential SLCA and investigate the applicability of the method in industrial decision making. The aforementioned assessment is done within the Zero Brine project, which works on zero liquid discharge technology for water, salt, and magnesium recovery from brine efluents. The developed SLCA systems are gate-to-gate, and the analysis is performed at two levels: Hotspot and site-specific. The system boundaries consist of a demineralized water (DW) production company, a chlor-alkali company, an electricity provider, a magnesium distributor in the Netherlands, and a Russian mining company. The latter exists only in the boundaries before the change due to the Zero Brine project, because recovered magnesium is expected to replace the Russian magnesium imported in the Netherlands. Within the system boundaries, the stakeholders contributing the most are the DW and the magnesium distributor companies. The former produces the brine and thus recovers the magnesium and salt. The latter is the exclusive distributor of Russian magnesium in the Netherlands. Overall, we find that the recovered magnesium results in improving social performance mainly in "Freedom of association and collective bargaining", "Fair salary", and "Health and Safety" due to decreasing the dependency of the Netherlands on Russia, while increasing operation in a country with much stronger environmental regulation and corporate commitment to sustainability issues. Modelling with SLCA may not result in the expected societal benefits, as the Russian community and workers may not benefit due to the large geographical boundaries of the system under study. Nevertheless, the application of the consequential approach can be considered suitable, yet complicated, for offering decision makers adequate social information. We recommend that decision makers in the DW company invest in magnesium recovery and that decision makers in the magnesium distributor company distribute the recovered magnesium.