Environmental impact of desalination: A systematic review of Life Cycle Assessment

Due to the global challenge of water insecurity, desalination capacity in the world has grown in recent decades. At the same time, concerns over desalination's detrimental environmental impact have increased. To evaluate the environmental impact of desalination, Life Cycle Assessments (LCA) are often conducted. Yet, the disparate array of LCA studies do not provide a systematic understanding of the underlying evidence related to specific environmental impacts of desalination. To fill this gap, we reviewed 38 studies with 295 LCA scenarios on desalination published from 2000 to 2018. This paper presents the scope of current research related to LCA methods, databases, and methods. We produced an evidence map to identify identified that maintenance and operation, treatment process, and the energy sector as the main contributors to negative environmental impacts as they relate to key life-cycle phases, the water cycle, and components such as energy, chemicals, and materials. Next, we compared the environmental impact of alternative options including water supply and technologies to reduce the environmental burden of desalination and found the possible future technology interventions for sustainable desalination. At the same time, we reveal that emerging technologies that aim to reduce energy consumption have the potential to increase other environmental burdens such as chemical usage. The systematic review provides an evidence-based framework for future research, which should consider the various impact categories, address gaps between the current studies and the real-world environmental concerns, evaluate social and economic impacts, and examine new and emerging technologies.