The method of solvent recovery includes using a plurality of solvent recovery units to recover solvent from a dilute solution. The solvent recovery units can include a plurality of reverse osmosis or forward osmosis membrane systems arranged in series. For reverse osmosis, at least some of the concentrate in a last reverse osmosis unit of the series is recycled back to the permeate of that unit to provide a mixed permeate. The mixed permeate is then passed successively to the permeate side of each preceding reverse osmosis unit in the series. For forward osmosis, a draw solution is passed sequentially from the permeate side of each unit to the permeate side of the preceding unit. The draw solution may be prepared by concentrating part of the concentrate stream by evaporation and recycling it back as a draw solution.
