technical and economic considerations of water desalination by reverse osmosis

product flow rate and salt rejection are the key performance parameters. they are mainly influenced by variable parameters such as feed pressure, feed temperature, and feed water salt concentration. the effect of feed temperature on membrane performance is the most important parameter. seawater membrane FT30 SW-2540 included in a test rig is used to perform this study. the membrane water permeability coefficient (Kw) is determined experimentally by the test rig measured parameters and compared with the obtained projected manufacturer system analysis program (ROSA) for the same operating conditions. besides, it correlated and presented with the different operating parameters . the results showed that the permeate flux increases by increasing the feed pressure and/or increase the feed temperature. for the same system productivity, the increase in the feed water temperature leads to reduce the applied feed pressure. for such case the results also showed that; an increase in the feed water temperature by one degree centigrade is associated with a reduction in applied feed pressure by 0.7% to 1.35%, a decrease in the membrane salt rejection of almost 1.4%, an increase of permeates flux from 1.11% to 2.58%, and a decrease of the specific energy consumption by an average value of 0.29 kw/1000 gal, according to the feed salt concentration and feed pressure. moreover, it was showed that an increase in feed salt concentration of one gram per liter decreases permeate flux by an average value of 2.41% to 2.8%, decreases the membrane salt rejection percentage by 0.06 to 0.16, decreases the membrane water permeability coefficient by 1.23%, and increases the specific energy consumption by an average value of 5.073 KW/1000 gal, according to the feed temperature. in addition, the membrane FT30 SW-2540 water permeability coefficient is experimentally determined, compared with manufacturer, and correlated as a function of feed temperature, and feed - brine osmotic pressure