As described in the introduction, reverse osmosis refers to a process in which the minerals are separated from water by membranes permeable to water and impermeable to the minerals. The water containing minerals are entered into the membrane by applying pressure from the feeding side, and the solute -free water is collected as the leaked flow. The application area of the water separation processes regarding membranes acting based on pressure gradient (reverse osmosis, ultrafiltration and microfiltration) is shown in Figure 2 (S.S. Madaeni., 1999).