Integrated, sequential stages of nanofiltration, forward osmosis, and reverse osmosis and related membranes provide an Integrated Osmosis structure, systems and methods. By optimally placing and using the desired characteristics of each membrane, performance and cost effectiveness not attainable individually is obtained. Integrated Osmosis systems provide high diffusive and osmotic permeability, high rejection, low power consumption, high mass transfer, and favorable Peclet number, by manipulating convection, advection and diffusion, low concentration polarization gradients, low reverse salt flux and effective restoration of performance after cleaning fouled membranes. Benefits include increased permeate recovery and decreased waste concentrate volume from reverse osmosis processes or other elevated osmotic pressure solutions. Integrated Osmosis first employs nanofiltration for selective harvesting of solutes, proffering a reduced osmotic pressure permeate. Forward osmosis dewaters the lowered osmotic pressure permeate generating a dilute draw solution which serves as feed to a reverse osmosis process. Reverse osmosis permeate provides freshwater and concentrate provides draw solution for the forward osmosis process.

Methods and systems of lowering a concentration of divalent cations in lithium-containing brines are described. A method includes diluting saturated salar brine such that sodium chloride concentration is at most about 80% of saturation. The method also includes feeding the diluted salar brine to a high pressure nanofiltration system operating at pressure above about 60 bar effective to form a permeate and a concentrate. The method also includes collecting the permeate having a lower concentration of divalent cations relative to the saturated salar brine.

Provided are a forward osmosis membrane, a forward osmosis membrane module, and a manufacturing method thereof, wherein a forward osmosis membrane, which achieves an extremely favorable reduction in the reverse diffusion of salt compared to the prior art and has a predetermined water permeability, is developed thereby bringing about: practicality in that a liquid-like raw material solution used in actual concentration operations can be concentrated with suppressed diffusion of an induction solution even when used multiple times; and durability in that the performance of the membrane can be maintained within a predetermined range even when a raw material solution having an osmotic pressure is concentrated multiple times.

A pressurized forward osmotic separation process is disclosed. Generally there are two processes described. One process involves the concentration of a target solute in the first solution; the other process involves the extraction of a solvent from a first solution both by a second solution comprising of water and soluble gas or water, soluble gas, and a compound by creating an osmotic concentration gradient across the semi permeable membrane. The first solution is under pressure from an inert gas and the second solution is under pressure from a soluble gas with equal system pressures greater than 1 atmosphere. The increase or decrease of partial pressure of the soluble gas in the second solution increases or decreases the chemical potential of the second solution to achieve different solution properties. The soluble gas may be carbon dioxide and the compound may be magnesium hydroxide.

The present invention relates to a novel forward osmosis (FO) process for dewatering of a variety of feed solution using low water activity and high osmotic pressure deep eutectic solvent with and without dispersed magnetic nanoparticles as draw solution. In particular, choline chloride-ethylene glycol, choline chloride-glycerol, Fe.sub.3O.sub.4 dispersed in former and latter were utilized as draw solution in FO for one step desalination of brackish and seawater, water recovery from effluent of leather and dye industries, protein and DNA concentration at room temperature. Owing to very low freezing point, the diluted draw solution after FO was recovered through phase separation by chilling at Ca. 10 C. with concomitant production of usable water. Although the present invention focused on specific DES and dispersion of Fe.sub.3O.sub.4 as magnetic nanoparticles but use of other DES having high osmotic pressure and low freezing point and other magnetic nanoparticles dispersion are logical extension of present invention.

Provided are a raw material liquid concentration method and a raw material liquid concentration system that can achieve a high flux even when using a raw material liquid that is rich in an organic solvent. An aspect of the present invention provides a method for concentrating a raw material liquid, said method comprising a concentration step for bringing a raw material liquid and an induction solution in contact via a forward osmosis membrane. The raw material liquid contains not less than 50 mass % of an organic solvent and a valuable substance. The forward osmosis membrane has a base material layer and an active layer. Either the induction solution contains a hydrophobic induction solute and the active layer is hydrophilic, or the induction solution contains a hydrophilic induction solute and the active layer is hydrophobic.

The invention generally relates to osmotically driven membrane systems and processes and more particularly to systems and processes for handling feed streams without pretreatment and increased brine concentration for zero liquid discharge, including forward osmosis separation (FO), direct osmotic concentration (DOC), pressure-assisted forward osmosis (PAFO), and pressure retarded osmosis (PRO). The system includes: a plurality of forward osmosis units, each having a semi-permeable membrane assembly and a tank; and a separation system in fluid communication with the plurality of forward osmosis units and configured to separate the dilute draw solution into the concentrated draw solution and a solvent system.

An osmotic separation process for the extraction of a solvent from a first solution with low osmotic pressure, in a first compartment to a second solution with higher osmotic pressure in the second compartment. The first solution and the second solution are separated by a semi-permeable membrane. An hydraulic pressure gradient is applied and on the first compartment to enhance the water permeation from the first solution to the second solution

[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.

The present invention relates to a thermo-responsive draw solute that can be applied to water desalination and purification based on forward osmosis. The thermo-responsive draw solute has a molar mass of 50 to 3000 g/mol and undergoes a phase transition at a temperature of 0 C. to 70 C. The thermo-responsive draw solute creates optimum conditions for the desalination of seawater and the purification of contaminated water based on forward osmosis. The present invention also relates to a method for water desalination and purification using the thermo-responsive draw solute. The method consumes little energy for water desalination or purification, is simple to apply to water desalination or purification, and enables separation of the draw solute in a very easy manner.