Patent ID: 8801934
Filing Date: 2014-08-12
Classification: B01D,C02F,Y02A

Abstract:
1. A water treatment method comprising: passing a first solute stream through a low pressure inlet of a first pressure exchanger to produce a pressurized first solute stream; passing the pressurized first solute stream through a booster pump and through an inlet of a pressure desalination unit to produce a stream of desalinated water and a pressurized concentrate stream; passing the pressurized concentrate stream into a high pressure inlet of the first pressure exchanger to produce a depressurized concentrate stream, wherein the pressure from the pressurized concentrate stream is transferred to the first solute stream to produce the pressurized first solute stream; passing the depressurized concentrate stream into a draw solution side of a pressure-retarded osmosis unit; passing a stream of impaired water into a feed side of the pressure-retarded osmosis unit, wherein water from the impaired water crosses a membrane in the pressure-retarded osmosis unit and enters and pressurizes the depressurized concentrate stream, producing a pressurized diluted draw solution stream; passing the pressurized diluted draw solution stream through a high pressure inlet of a second pressure exchanger; passing a second solute stream through a low pressure inlet of the second pressure exchanger, wherein pressure from the pressurized diluted draw solution stream is transferred to the second solute stream to produce a pressurized second solute stream and a depressurized diluted draw solution stream; and passing the pressurized solute stream through the inlet of the pressure desalination unit.