A new and innovative power and treated water co-generation system is provided that includes a modified Kalina cycle and a forward osmosis (FO) membrane. The Kalina cycle of the provided system is used for power production, whereas the system's FO process is used for water production. The provided system modifies a typical Kalina cycle to include a more efficient and relatively low-temperature heat source, while still utilizing the same working fluid, which is ammonia-water. The draw solution for the provided system's FO process is also ammonia-water, which is known and efficient for desalination and wastewater treatment. In some aspects, the working fluid of the system may be a specific ammonia-water composition including between 30-95% ammonia. The presently disclosed system combines the Kalina process and the FO process into an improved and innovative heat integration system to minimize energy requirements and enable operation at both small and large scales.

A forward osmosis filtration cell is provided which includes a fluid passageway and a forward osmosis filtration membrane positioned within the passageway. The filtration membrane divides the fluid passageway into two chambers, a first chamber configured to hold a draw solution, and a second chamber configured to hold a feed solution. The filtration cell further includes a first electrode positioned in the first chamber, and a second electrode positioned in the second chamber. The first and second electrodes are configured to apply an electric field across the filtration membrane to prevent fouling on the filtration membrane. A method of using a forward osmosis filtration cell in a water treatment system, and a method of retrofitting a water treatment system with first and second electrodes are also provided.

[PROBLEM] To provide an evaluation method and evaluation device with which the practical performance of a forward osmosis membrane can more accurately be measured.

[SOLVING MEANS] Provided is a method for evaluating a forward osmosis membrane module. The method includes the steps of, in a forward osmosis membrane module having spaces which are partitioned by a forward osmosis membrane including a porous support body and a separation function layer stacked thereon, connecting a feed solution line to a space on the separation function layer side, and connecting a draw solution line to a space on the porous support body side, and moving a solvent in the feed solution into the draw solution via the forward osmosis membrane while adjusting a physical pressure differential across the forward osmosis membrane to a constant value within the range of more than 0 kPa to 200 kPa.

A method of recovering draw agent utilised in a forward osmosis membrane cell, the method comprising the steps of passing diluted draw agent to a vapour-liquid separator; using the vapour-liquid separator to separate draw agent vapour and solvent; and condensing draw agent vapour.

According to one embodiment, an amine-containing water concentration system includes an osmotic pressure generator and a carbon dioxide introducing unit. The osmotic pressure generator includes a treatment vessel, a first chamber to which the water to be treated is supplied, a second chamber capable of storing a working medium, and a semipermeable membrane that partitions the first chamber and the second chamber, which are located in the treatment vessel. The carbon dioxide introducing unit is capable of introducing carbon dioxide into the water to be treated.

Provided herein is forward osmosis-based water purification process, that includes contacting a solution of a soluble draw agent with a dehydrated insoluble draw agent, separating the now hydrated insoluble draw agent from the now concentrated draw solution, and exerting a stimulus on the hydrated insoluble draw agent for extracting water therefrom, thereby regenerating a dehydrated insoluble draw agent, wherein the osmotic concentration (osmolality) of the insoluble draw agent is greater than the osmotic concentration of the diluted draw solution, and the insoluble draw agent is impermeable to the soluble draw agent.

This disclosure provides systems, methods, and apparatus related to water desalination. In one aspect, a method includes generating a diluted draw solution using forward osmosis. Wastewater is on a first side of an osmotic membrane and a draw solution is on a second side of the osmotic membrane. The draw solution comprises a mixture of water and an ionic liquid. Water in the wastewater diffuses across the osmotic membrane to the draw solution to form the diluted draw solution. The diluted draw solution is heated using a photonic heater to a temperature above a lower critical solution temperature (LCST) of the ionic liquid to phase separate the diluted draw solution into the ionic liquid and treated water.

Provided herein is forward osmosis-based water purification process, that includes contacting a solution of a soluble draw agent with a dehydrated insoluble draw agent, separating the now hydrated insoluble draw agent from the now concentrated draw solution, and exerting a stimulus on the hydrated insoluble draw agent for extracting water therefrom, thereby regenerating a dehydrated insoluble draw agent, wherein the osmotic concentration (osmolality) of the insoluble draw agent is greater than the osmotic concentration of the diluted draw solution, and the insoluble draw agent is impermeable to the soluble draw agent.

A working medium includes a first amine compound and a second amine compound. The first amine compound is a heterocyclic tertiary amine compound including a carbon atom, a nitrogen atom and a hydrogen atom, and in which a ratio (C/N ratio) of a carbon atom number to a nitrogen atom number included in one molecule is from 7 to 9. The second amine compound is a heterocyclic tertiary amine compound including a carbon atom, a nitrogen atom and a hydrogen atom. and in which a ratio (C/N ratio) of a carbon atom number to a nitrogen atom number included in one molecule is in a range of 5 or more to less than 7.

A forward osmosis system is disclosed which use a polymer switchable between a neutral form and an ionized form. The switchable polymer has a higher osmotic pressure at the ionized form than the neutral form, the ratio between the former and the latter is ≥2. There is also disclosed a method for treating the polymer such that the ratio is improved. Use of polymers for forward osmosis is also disclosed.