Abstract: A process for the recovery of purified water from a reverse osmosis reject stream includes preconditioning a reject stream to remove scaling ions and provide preconditioned water; separating any precipitate that forms in the preconditioned water to form a feed stream; subjecting the feed stream to high pressure membrane filtration system including a recirculating, high pressure pump generating a permeate stream and a second reject stream; adding a make-up water stream to the feed stream; and separating the permeate stream as purified water. Additional features and embodiments are also provided.