Abstract: A method of forming a gas separation membrane including: depositing a first hydrophilic polymer solution; depositing on top of the first hydrophilic polymer solution a second, different hydrophilic polymer solution, thereby forming a two-layer polymer solution; forming the two-layer polymer solution into one of a forward osmosis membrane and a pressure retarded osmosis membrane by bringing the second, different hydrophilic polymer solution into contact with water to form the dense layer; coating one of the forward osmosis membrane and the pressure retarded osmosis membrane with a thin layer of a third, different, hydrophilic polymer more pH tolerant than the first and second hydrophilic polymer solutions to form a dense rejection layer thereon; and exposing one of the coated forward osmosis membrane and the coated pressure retarded osmosis membrane to a high pH solution. A gas separation membrane formed from the foregoing process.

Abstract: A self-regulating FO system is disclosed comprising a container containing a source water supply, a forward osmosis membrane element located within the container comprising an area of osmotic membranes, an osmotic agent inlet and a drink outlet, an osmotic pump element also located within the container comprising an area of osmotic membranes, an osmotic agent inlet and a drink outlet, and an osmotic agent tank located above the container. The osmotic agent tank comprises a feed tube connected to an outlet located on the bottom of the osmotic agent tank. The feed tube communicates with the osmotic agent inlet of the forward osmosis membrane unit and the osmotic agent inlet of the osmotic pump element. A return tube communicates with the drink outlet of the osmotic pump element and a port near the top of the osmotic agent tank.

Abstract: A center tube is disclosed which allows a draw solution to flow through all membrane elements in a membrane system in parallel. The center tube may include a cylindrical wall with two open ends and a barrier element there between separating an upstream chamber and a downstream chamber within the cylindrical wall. At least one non-perforated bypass tube may be located substantially within the cylindrical wall, which extends a length of the downstream chamber and/or the upstream chamber so that the upstream chamber is configured to communicate with a second upstream chamber of a second center tube and/or the downstream chamber is configured to communicate with a second downstream chamber of the second center tube.

Abstract: A forward osmosis water transfer system is disclosed which recycles water from an incoming wastewater stream into an outgoing dilute process brine stream. The system includes a saturated brine stream, a first portion of which is diverted to form a saturated process brine stream and a second portion of which is diverted to at least one forward osmosis membrane. The at least one forward osmosis membrane moves water from the incoming wastewater stream into the incoming diverted saturated brine stream thereby creating an outgoing concentrated wastewater stream and the outgoing dilute process brine stream.

Abstract: A self-regulating FO system is disclosed comprising a container containing a source water supply, a forward osmosis membrane element located within the container comprising an area of osmotic membranes, an osmotic agent inlet and a drink outlet, an osmotic pump element also located within the container comprising an area of osmotic membranes, an osmotic agent inlet and a drink outlet, and an osmotic agent tank located above the container. The osmotic agent tank comprises a feed tube connected to an outlet located on the bottom of the osmotic agent tank. The feed tube communicates with the osmotic agent inlet of the forward osmosis membrane unit and the osmotic agent inlet of the osmotic pump element. A return tube communicates with the drink outlet of the osmotic pump element and a port near the top of the osmotic agent tank.

Abstract: A center tube is disclosed which allows a draw solution to flow through all membrane elements in a membrane system in parallel. The center tube may include a cylindrical wall with two open ends and a barrier element there between separating an upstream chamber and a downstream chamber within the cylindrical wall. At least one non-perforated bypass tube may be located substantially within the cylindrical wall, which extends a length of the downstream chamber and/or the upstream chamber so that the upstream chamber is configured to communicate with a second upstream chamber of a second center tube and/or the downstream chamber is configured to communicate with a second downstream chamber of the second center tube.