Forward osmosis using dimethyl ether as a draw solute

• Aqueous dimethyl ether was used as a draw solution for forward osmosis experiments.
• Forward osmosis phenomena were observed in both U-tube and cross-flow tests.
• Osmotic pressure of aqueous dimethyl ether did not follow the van't Hoff equation.
• Water permeated from feed to draw solution with a flux of 2.12–2.91 L·m− 2·h− 1.

Forward osmosis experiments were carried out using an aqueous dimethyl ether solution as a draw solution. The osmotic process was examined using membranes (U-tube and flat cell) with differing effective membrane areas. Water permeation was confirmed to proceed from an aqueous feed solution composed of 0.5 wt.% sodium chloride to the draw solution through a forward osmosis membrane. Any dimethyl ether remaining in the draw solution after the forward osmosis process could be volatilized simply by leaving the solution at room temperature. Experimental results using the draw solution proposed in this study indicate the potential of the forward osmosis process as a convenient water recovery system by the energy only of the pressurizing injection of dimethyl ether.