A method of treating a liquid. The method comprises providing a feed liquid comprising at least one solvent and at least one solute to a first side of a membrane. A single-phase draw solution comprising at least one of an aminium salt, an amidinium salt, and a guanidinium salt is provided to a second side of the membrane. The at least one solvent is osmosed across the membrane and into the single-phase draw solution to form a diluted single-phase draw solution. At least one of CO.sub.2, CS.sub.2, and COS is removed from the diluted single-phase draw solution to form a first multiple-phase solution comprising a first liquid phase comprising the at least one solvent, and a second liquid phase comprising at least one of an amine compound, an amidine compound, and a guanidine compound. A liquid purification system is also described.

A method of treating a liquid. The method comprises providing a feed liquid comprising at least one solvent and at least one solute to a first side of a membrane. A single-phase draw solution comprising at least one of an aminium salt, an amidinium salt, and a guanidinium salt is provided to a second side of the membrane. The at least one solvent is osmosed across the membrane and into the single-phase draw solution to form a diluted single-phase draw solution. At least one of CO.sub.2, CS.sub.2, and COS is removed from the diluted single-phase draw solution to form a first multiple-phase solution comprising a first liquid phase comprising the at least one solvent, and a second liquid phase comprising at least one of an amine compound, an amidine compound, and a guanidine compound. A liquid purification system is also described.

Techniques for solar thermal water purification by recycling photovoltaic reflection losses are provided. In one aspect, a solar thermal water purification system includes: a water purification component for desalinating salt water, the water purification component having multiple stages through which the salt water passes, and condensers in each of the stages; and a photovoltaic component configured to heat the salt water prior to the salt water entering a first stage of the water purification component, wherein desalinated water evaporates and condenses in each of the stages to be collected as pure water. A system using reverse osmosis and a heat-driven water pump is also provided. Methods for water purification are also provided.

Techniques for solar thermal water purification by recycling photovoltaic reflection losses are provided. In one aspect, a solar thermal water purification system includes: a water purification component for desalinating salt water, the water purification component having multiple stages through which the salt water passes, and condensers in each of the stages; and a photovoltaic component configured to heat the salt water prior to the salt water entering a first stage of the water purification component, wherein desalinated water evaporates and condenses in each of the stages to be collected as pure water. A system using reverse osmosis and a heat-driven water pump is also provided. Methods for water purification are also provided.

A process to treat water includes adding a salt-forming base to the water thereby producing saline water, or thereby forming a salt in the water which is different from a salt that the water started out with, if the water started out as saline. The saline water is treated, at a temperature T1 which is above the saturation temperature of the saline water, in a first membrane separation stage to provide clean water and a first brine, the salinity of the first brine being higher than the salinity of the saline water. The first brine is cooled to a temperature T2 to precipitate some of the salt from the first brine and the precipitated salt is separated from the first brine producing a second brine, the temperature T2 being below the temperature T1 but above the freezing temperature of the first brine. The second brine is treated at a temperature T3 above the saturation temperature of the second brine in a second membrane separation stage to provide clean water and a third brine. The salt-forming base, the temperature T1 and the temperature T2 are selected so that the salt which is formed in the saline water has a solubility in water at the temperature T1 which is at least 1.5 times the solubility of the salt in water at the temperature T2.

A microporous membrane has average membrane thickness of 15 m or less, and relative impedance A after a heat compression treatment under a pressure of 4.0 MPa at 80 C. for 10 minutes of 140% or less, the relative impedance A being obtained by the equation below: Relative impedance A=(impedance measured at 80 C. after the heat compression treatment)/(impedance measured at room temperature prior to the heat compression treatment)100.

Provided is a method for separating a specific gas from a raw gas using a gas separation membrane module that includes a gas separation membrane element enclosed in a housing. The element includes a gas separation membrane including a hydrophilic resin composition layer. The method includes: preparing the module; increasing pressure in an interior of the module; increasing a temperature in the interior; and feeding a raw gas to the interior. The layer of the module prepared is adjusted to contain moisture, and a moisture content thereof is an amount that allows an equilibrium relative humidity at a temperature of 23 C. of a gas phase portion in the housing to be 10% RH or more. The raw gas feeding step is performed after the preparation step. The pressure increase step and the temperature increase step are performed after the preparation step and before the raw gas feeding step.

Provided is a method for separating a specific gas from a raw gas using a gas separation membrane module that includes a gas separation membrane element enclosed in a housing. The element includes a gas separation membrane including a hydrophilic resin composition layer. The method includes: preparing the module; increasing pressure in an interior of the module; increasing a temperature in the interior; and feeding a raw gas to the interior. The layer of the module prepared is adjusted to contain moisture, and a moisture content thereof is an amount that allows an equilibrium relative humidity at a temperature of 23 C. of a gas phase portion in the housing to be 10% RH or more. The raw gas feeding step is performed after the preparation step. The pressure increase step and the temperature increase step are performed after the preparation step and before the raw gas feeding step.

The present disclosure provides a system for refining long chain dicarboxylic acid, comprising: a first membrane filtration unit, for a first membrane filtration of a long chain dicarboxylic acid fermentation broth or a treated liquid therefrom; a first decolorization unit, for carrying out a first decolorization treatment to the filtrate obtained after the membrane filtration; a first acidification/crystallization unit, for carrying out a first acidification/crystallization of a filtrate obtained after the membrane filtration to give a solid-liquid mixture; a first separation unit, for a solid-liquid separation of the solid-liquid mixture; a drying unit, for drying the solid separated by the separation unit to give a first solid. By using the refining system according to the present disclosure, the purity of the obtained product is high, and the disadvantages such as poor quality of the product obtained by crystallization from a solvent and environment pollution caused by a solvent can be overcome.

The present application provides a method for extracting an extractable component from a feed liquid using a porous membrane. One embodiment of the method includes temperature-swing solvent extraction of water from saline water using a porous membrane.