Dear Mahmoud, I wish to express a hard criticism for the first figure (left side) of your presentation, which shows equal elevation of  salty and fresh water before pumping through a membrane. Actually a difference is there and the salty water level is much higher than the fresh water level because of the (direct) natural osmotic pressure. For an average sea water, the difference is about 280 m (two hundred eighty meters ) of salty water higher than fresh water). Hence the concept of desalination through membranes is that the salty water has to be pumped up to 28 bar before the flow starts in the way opposite to direct osmosis. This is not a subject of technology. This is a subject of thermodynamics and is applicable to any desalination process to pass from a system of higher entropy (salty water) to a system of lower entropy. Hence this thermodynamic constraint is the same for any process (either thermal or by mambranes). This equal entropy barrier is called osmotic pressure in membrane desalination and boiling point raise in thermal desalination (equal energy difference)

Published September 29, 2018 11:58 by Marco Rognoni, Owner at WET, Water Edge Technologies