A water treatment system is configured to remove salt from a feed brine. The water treatment system includes a primary freezing chamber configured to receive the feed brine and a source of cooled intermediate cold liquid connected to the primary freezing chamber. The cooled intermediate cold liquid and feed brine are mixed within the primary freezing chamber, where ice particles are formed. The water treatment system includes a rotary separator connected to a discharge from the primary freezing chamber. The rotary separator is configured to separate solid ice particles from liquid components in the discharge from the primary freezing chamber. In some embodiments, the rotary separator includes a mesh inner filter tube that is configured for rotation within a solid outer filter tube, where the mesh inner filter tube allows liquid components to drain into the outer filter tube while conveying solid ice particles to an ice recovery tank.