Developments in forward osmosis and membrane distillation for desalination of waters

Membrane technology has become a common separation technology over the past decennia. Membranes are used more and more for the productionof drinkablewater from groundwater, surface water andwastewater. Membranes are now competitive versus conventional techniques. Desalination is predominantly used to eradicate the problem of water scarcity. The sustainability of all desalination processes depends mainly on the reduction of energy costs (production cost) and the increase in water recovery. Forward osmosis and membrane distillation are emerging technologiesfor sustainable desalination. Here we review membrane processes of forward osmosis and membrane distillation and the advancements in membrane material and modules. We alsodiscuss the capability of membrane distillation in treating highly concentrated aqueous solutions derived from other desalination processes. Furthermore, the advancements in fabrication of high-performance membrane isreviewed and the performance of different membranes and optimization of membrane distillation process are summarized.