Environmental impact of emerging desalination technologies: A preliminary evaluation

Emerging desalination technologies are either a group of desalination techniques that have not undergone commercialization due to the need for technological advancements. The main drivers for developing such technologies are to reduce energy consumption, and hence cost, broaden feed water options, to reduce chemical additives, and, most importantly, to reduce the environmental impacts relative to conventional desalination technologies. Environmental impacts significantly vary according to the desalination technology being employed and the feedwater source. In this work, environmental impacts for some of the emerging desalination technologies, namely electrodialysis/electrodialysis reversal (ED/EDR), forward osmosis (FO), and membrane distillation (MD), are thoroughly discussed relative to the environmental impacts of conventional desalination technologies. A preliminary qualitative evaluation of the environmental impacts of these technologies is performed. The evaluation has revealed that the spontaneous FO process shows the highest environmental merits or benefits, i.e., lowest environmental impacts, followed by ED/EDR, and finally, MD, which were all environmentally benign relative to reverse osmosis (RO) desalination. Finally, we provided some conclusions and recommendations to consider while further developing such new desalination technologies to maximize its environmental benefits in the local and global context.