Integrated membrane systems for seawater desalination

In the present work, seven different flow sheets for seawater desalination process have been analyzed. In each of them, except for the first (FS1) constituted by the only RO unit, different membrane units have been integrated in order to reach all the important benefits in the logic of process intensification: RO operates on NF permeate in FS2; both MF and NF have been introduced for the feed water pre-treatment and load reduction to the following RO unit in FS3. Membrane crystallizer module (MCr) completes four of the seven proposed flow sheets and it has the task to increase the quantity of desalted fresh water combined to solid salts production: in FS4, MCr operates on NF brine; in FS5 on RO brine; in FS6 both on RO and NF brine; in FS7 on NF brine while MD operates on RO brine.