Circularity and sustainability measurement and assessment of water and resource systems integration

Abstract

Decoupling resource consumption from economic growth and development is essential for long-term sustainability. Water, being a critical resource for sustaining ecosystems and supporting human health and well-being, holds significant social and economic value. However, due to linear consumption practices, water stress is becoming increasingly prevalent, leading to disruptions in essential services. Desalination has emerged as a prominent solution to address water scarcity and meet the growing demand for water across various sectors. Despite its potential, desalination faces significant environmental and economic challenges. While assessment methodologies have been widely employed to evaluate the environmental, economic, and social impacts of desalination systems, they often focus primarily on consequential effects. As the desalination industry embraces circular strategies like Minimal Liquid Discharge (MLD) and Zero Liquid Discharge (ZLD), there is an increasing need to evaluate the intrinsic circularity of these systems. Integrating this assessment is crucial for ensuring that desalination aligns effectively with Circular Economy (CE) principles, promoting long-term sustainability. To address this need, a systematic and comprehensive methodological approach was developed to measure the intrinsic circularity of desalination systems. This approach incorporates CE principles, such as resource flow traceability, which assigns circular and linear properties to flows associated with the desalination process, and assesses the circular value created by actions implemented in the system. The method identifies benefits and hotspots in various system configurations, including conventional desalination, MLD, and ZLD systems. Furthermore, by adopting MLD and ZLD strategies to reduce brine discharge and improve water recovery, the desalination sector is transforming into multifunctional product systems. A criterion-based Life Cycle Assessment framework was developed and applied to evaluate these multifunctional desalination systems. The results revealed that different assessment approaches (e.g., global vs. individual co-production) yield varying outcomes. However, the analysis demonstrated that brine, as a secondary product, can alleviate environmental pressures associated with conventional systems, such as those in the mining and chemical industries. Additionally, a circularity assessment conducted on the integration of desalination systems into the ceramic industry highlighted optimisation opportunities through scenario analysis. Ultimately, this research provides valuable insights into the performance and impact of water and resource recovery systems, like desalination, in contributing to sustainability.