Method for treating water in order to desalinate said water, including treating concentrates

The invention relates to a method for treating water in order to desalinate said water, including a step of reverse osmosis or distillation of said water in order to produce water that is at least partially desalinated and a first concentrate. According to the invention, said method includes: a first demineralisation step including a step of nanofiltering said first concentrate such as to produce a nanofiltrate and a second concentrate; a second step of demineralising said second concentrate by means of at least one active material including cationic and/or anionic ion-exchange resins, said second demineralisation step including the extraction of a third concentrate and the extraction of at least partially demineralised water, said at least partially demineralised water being mixed with said at least partially desalinated water; a step of regenerating said at least one active material, said regeneration step including a step of recirculating said nanofiltrate.