A water purification unit includes an evaporator, a heat exchanger, a pump and a liquid-driven condensing ejector. A liquid inlet of the ejector is in fluid communication with an outlet of the pump. A gas inlet of the ejector is in fluid communication with a vapor outlet of the evaporator. An outlet of the ejector is in fluid communication with a fluid inlet of the heat exchanger. A fluid outlet of the heat exchanger is in fluid communication with an intake of the pump. The heat exchanger is in thermal communication with a fluid inlet to the evaporator.

A method for treating a salt solution, the method comprising (i) introducing a liquid motive fluid into an eductor; (ii) drawing vapor from a distillation tank into the eductor, where said drawing reduces the pressure within the distillation tank; (iii) mixing the motive fluid and the vapor within the eductor to produce a liquid stream, where the vapor condenses within said eductor and thereby releases heat and at least a portion of the heat is transferred to the liquid stream; (iv) transferring at least a portion of the heat associated with the liquid stream to a salt solution; and (v) distilling the salt solution within the distillation tank.