Comparison of Desalination Technologies and Assessment of Their Sustainability

Water scarcity is a major issue in socioeconomic progress and a threat to livelihood. Overexploitation of freshwater resources threatens food security and sustainable water usage. Countries, therefore, are looking for new ways to ensure the long-term availability of drinking water sources, among which desalination has a prominent role. Several desalination technologies have been proposed during the last decade, which can be classified into two primary categories, i.e. thermal technologies, and membrane technologies. The former include Multi-Stages Flash distillation (MSF), Multi-Effect Distillation (MED), and Mechanical Vapor Compression (MVC), whereas the membrane technologies include Reverse Osmosis (RO), Electrodialysis (ED), and Forward Osmosis (FO). However, all these technologies are energy-intensive and can have significant environmental impacts. In this context, sustainable desalination technologies, such as solar desalination, are essential in solving this issue. The main objective of this paper is to compare the different desalination technologies based on their environmental, technical, and economic aspect. Based on the results, when considering energy consumption, water cost, and carbon dioxide emissions, membrane technology is the most promising option. However, thermal desalination technologies, particularly MED, coupled with Solar energy are technically more interesting compared to the RO.