Elaborating Cellulose Acetate Membrane for Forward Osmosis Process

Osmosis is a well-known physical phenomenon widely used in engineering fields especially separation processes in which their efficiency is mainly determined by morphology of semipermeablemembrane [1]. Literature review [2] reveals properties of polymer solution used for membrane synthesisincluding solution concentration, solvent type and additives are the most pertinent factors influencing membrane morphology. Global shortage of potable water as well asproblems associated with fresh water supply has motivated people in dry areas to consider the ocean as a source of freshwater. The advantages of existing desalination techniques such as reverse osmosis are balanced out with high costs and energy consumption. Regarding seawater, for instance, the recovery rate of reverse osmosis is 35% - 50%. Forward osmosis (FO) can be considered as a versatile and promisingmethod through which desalination of saline water with a lower cost and higher recovery efficiency can be performed.In this process, the driving force for water transport through the membrane is provided by gradient of osmotic pressure, such that a concentrated draw solution causes a net flow of water through the membrane to be induced from feed solution into the draw solution. Generally speaking, in contrast of reverse osmosis, in FO there is no need for hydraulic pressure