Progress of membrane engineering for water treatment

Together with the supply of energy and the environmental protection, fresh water is one of the three keys elements for the sustainable development of every society. Where the availability of water cannot be carried out by using conventional sources, unavoidable appears the resort of the major water source: the sea. Today, RO is one the most used membrane process for the production of fresh water from seawater and brackish water, reclamation of wastewater and the treatment of various industrial wastewaters. Further improvements can be achieved via the integration of reverse osmosis with other membrane operations, such as membrane distillation and membrane crystallization. The integrated system can lead to important benefits in terms of product quality, compactness of the system, environmental impact and energy consumption. In this work, first a brief introduction to RO process and recent developments will be given. Then, the status and development of membrane distillation and membrane crystallization will be illustrated. Finally, membrane condenser (i.e., another innovative membrane process for water recovery and reuse based on the use of porous hydrophobic membranes) will be described.