Nowadays, RO system has become a popular water treatment technology in industry requiring separation of dissolved solute from its solvent (water) including desalination and also, residentially, to improve the taste of water as well as to remove potentially unhealthy contaminants. RO has increased the water supply by making possible the use of brackish waters for potable water supply. Desalination using RO has become a major source to produce fresh water in many arid regions including remote area where the fresh water is hardly found. Recent advances particularly in improvements of the membrane materials and pre-treatment have meant that RO desalination has now become economically attractive even at seawater concentrations [Buckley & Hurt, 1996]. The scale of membrane applications is now very large, plants with capacity in excess of 19,000 m3/d are common