Conventional and Emerging Desalination Technologies: Review and Comparative Study from a Sustainability Perspective

This work develops a comprehensive review of the main conventional and emerging desalination processes. It presents the state of knowledge of the most known and investigated techniques, highlights their advantages and drawbacks, and draws appropriate conclusions on their respective performances from various angles including their energy consumption and efficiency, environmental impacts, reliability, and flexibility in operations. This review reveals the recent large dominance and deployment of the reverse osmosis technology in the Gulf countries, mainly in Saudi Arabia; the importance of hybridization; and the slow penetration of promising processes including membrane distillation and forward osmosis into the industrial desalination market. In addition, this work aims to develop some comparison exercises between these processes using specific criteria. A cross approach allowing an easier comparison between various desalination processes could help identify the advantages and drawbacks of each technology and select the appropriate process. Therefore, various criteria allowing a clear picture to be drawn of the performance and capabilities of the main conventional and emerging desalination processes have been proposed in the frame of sustainable development. As an illustration of this general approach from sustainability prospects and considering specific weights for each proposed criterion for the case of Saudi Arabia, a comparison exercise reveals that the superiority of reverse osmosis (RO) is confirmed. Multiple effect distillation (MED) and membrane distillation (MD) processes are potentially competitive to RO while multi-stage flash (MSF) comes last due to several drawbacks.