A water treatment system comprising a mechanical vapour compression apparatus (11), the mechanical vapour apparatus having a evaporation/condensation vessel (11a) and a recirculation circuit (20) whereby recirculated water is pumped from an outlet (18a) of the evaporation/condensation vessel (11A) to an inlet (18B) of the evaporation/condensation vessel (11A), wherein the recirculation circuit (20) comprises a fluidized bed crystallizer (22), and at least part of the recirculated brine is passed through the fluidized bed crystallizer (22) to remove dissolved minerals therefrom.