85 results about "Forward osmosis" patented technology

The invention discloses a printing and dyeing wastewater zero-discharge treatment process based on low-pressure high-power membrane concentration and salt separation synergy. The wastewater is sequentially subjected to the steps of double-alkali softening pretreatment, organic pollutant treatment, forward osmosis low-pressure high-power concentration treatment, salt separation treatment and evaporative crystallization. Wherein the forward osmosis low-pressure high-power concentration treatment is performed in a partitioned manner along the flow direction, the osmotic pressure difference is gradually increased, the transmembrane pressure difference is gradually decreased, and interface electrochemical buffer and low-frequency gas-liquid disturbance can be set to inhibit concentration polarization and pollution. Carrying out nanofiltration and salt separation on the concentrated solution to obtain two paths of saline water mainly comprising Na2SO4 and NaCl, and respectively carrying out evaporative crystallization on the two paths of saline water; and refluxing and reusing the water produced by the draw solution. According to the process, high-power concentration and stable salt separation are realized under low mechanical pressure, the energy consumption is reduced, the water recovery rate and the crystal purity are improved, and zero discharge of wastewater is realized.

The application provides an assisted permeation roll type membrane assembly. Compared with the prior art, the assisted permeation roll type membrane assembly provided by the application can realize high concentration of raw liquid under low operating pressure; in addition, the membrane assembly can also be used in a forward osmosis membrane separation process. By introducing an assisted permeation liquid on the permeation liquid side of the RO or NF membrane in the assembly, the osmotic pressure on both sides of the membrane can be reduced, and then the pressure applied on the raw liquid side can be reduced, and the pressure can be regulated by adjusting the components of the assisted permeation liquid, so as to reduce the pressure and cost of solution concentration and improve the concentration ratio. The assisted permeation roll type membrane assembly provided by the application can be applied to industrial wastewater zero discharge, seawater desalination, material separation and other industrial fields, and can also be used as a forward osmosis, diffusion dialysis, gas separation, organic solvent nanofiltration and organic solvent reverse osmosis and other membrane separation processes in addition to reverse osmosis and nanofiltration.

A control device (10) and method for determining the permeability state of a forward osmosis (FO) membrane (2c) of a FO device (2) in a dialysate generator (1). The FO membrane (2c) separates a feed side (2a) and a draw side (2b) of the FO device (2). The FO device (2) has a feed inlet port (E) in fluid communication with the feed side (2a). in ) and the feed outlet port (E out ) and a draw inlet port (L ) in fluid communication with the draw side (2b). in ) and draw outlet port (L out ). The method includes providing (S1) a flow of pure water to the feed side (2a) and providing (S2) a flow of pure water to the draw side (2b). The method further includes monitoring (s3) one or more pressures indicative of a transmembrane pressure, TMP, between the feed side (2a) and the draw side (2b). The method further includes stopping (S4) the flow through one of the ports such that the TMP is maintained constant and of a non-zero magnitude, controlling (S5) the flow to or from one of the feed side (2a) and the draw side (2b) with the flow stopped based on the monitored one or more pressures, and determining (S7) a permeability state of the FO membrane based on a characteristic indicative of the flow.

The invention provides a seawater hydrogen production and storage system and a seawater hydrogen production and storage process using offshore wind power. The seawater hydrogen production and storage system comprises a permeable membrane system, a two-stage RO membrane system, an EDI ultrapure water system and a hydrogen production and storage system, and the permeable membrane system, the two-stage RO membrane system, the EDI ultrapure water system and the hydrogen production and storage system are connected in sequence; in the seawater purification direction, the permeable membrane system comprises a forward osmosis module and permeable membrane modules, the forward osmosis module comprises a forward osmosis membrane and absorption liquid, the absorption liquid is selected from a sodium chloride solution with the mass concentration of 3-15%, and the number of the permeable membrane modules connected in series is 1-3. According to the seawater hydrogen production and storage system, the seawater is subjected to graded purification, the purified seawater can be directly discharged to the sea, the purified ultrapure water can thoroughly avoid a series of problems of chlorine, calcium and magnesium precipitation and the like in the subsequent water electrolysis hydrogen production process, and liquid hydrogen storage oil is directly prepared through the hydrogen production and storage system and is convenient to transport on the sea and other scenes.

The utility model relates to a system for treating landfill leachate by coupling forward osmosis and membrane distillation, which mainly solves the following problems in landfill leachate concentrated water treatment: high comprehensive energy consumption, membrane pollution risk and difficulty in regeneration of drawn liquid. The device comprises a pretreatment unit, a forward osmosis module, a membrane distillation module and a draw solution storage tank, a water inlet of the pretreatment unit is connected with a landfill leachate concentrated water source, and a discharge port of the pretreatment unit is connected to a leachate side inlet of the forward osmosis module through a first delivery pump; a draw liquid side outlet of the forward osmosis module is connected to a liquid inlet of the membrane distillation module through a membrane distillation heater and a second delivery pump; a concentrated liquid outlet of the membrane distillation module and a draw liquid side inlet of the forward osmosis module form a closed loop through a draw liquid storage tank; an on-line conductivity monitor is arranged in the draw solution storage tank, and a salt supplementing valve is arranged at a feeding port of the draw solution storage tank. And a reflux pump is arranged between the draw solution storage tank and the forward osmosis module. The method is used for treating the leachate concentrated water of the domestic waste landfill.

The invention provides a concentration treatment system and method for strong brine, and the concentration treatment system comprises a multi-stage forward osmosis treatment unit which is configured to perform multiple forward osmosis treatment on the strong brine by using a concentration draw solution so as to concentrate the strong brine to obtain concentrated brine and a diluted draw solution; and the multi-stage draw solution cyclic regeneration unit is configured to perform multiple times of concentration treatment on the diluted draw solution produced by the multi-stage forward osmosis treatment unit to obtain a concentrated draw solution, and the concentrated draw solution is provided for the multi-stage forward osmosis treatment unit. Compared with the prior art, the method has the advantages that the forward osmosis technology is adopted, the high-concentration concentrated draw solution is used for conducting concentration treatment on the to-be-treated concentrated salt wastewater, the natural osmotic pressure difference serves as driving force, water in the concentrated salt water can naturally flow into the draw solution, and therefore concentration treatment on the concentrated salt water is achieved; efficient treatment and resource recycling of the strong brine in the iron and steel industry are achieved, pollution of wastewater discharge to the environment is reduced, and the requirement for sustainable development is met.

The invention discloses a freeze-dried coffee powder preparation method based on an integrated membrane process. The freeze-dried coffee powder preparation method comprises the following steps: baking and frying cleaned coffee beans; the coarse grinding particles are crushed into coffee powder through an airflow impact device; filling the coffee powder into an extraction device, and performing ultrasonic extraction in a low-temperature environment to obtain a coffee extract; filling the coffee extract into a forward osmosis concentration device, concentrating to obtain a coffee concentrated solution, and recycling the drawn solution in the forward osmosis concentration process in a membrane distillation process driven by baking waste heat for regeneration; filtering and sterilizing the coffee concentrated solution by adopting a microfiltration membrane to obtain a sterile concentrated solution; and freeze-drying the sterile concentrated solution in a vacuum environment, and crushing the freeze-dried concentrated solution through a low-temperature crushing device to obtain the freeze-dried coffee powder. High-temperature operation is avoided in the whole preparation process, heat-sensitive functional components in the coffee can be reserved to the maximum extent through low-temperature ultrasonic extraction and normal-temperature non-thermal concentration, and the original flavor and fragrance of the coffee can be effectively reserved through low-temperature freeze drying.

The invention relates to the technical field of water treatment membranes, in particular to a high-performance composite separation membrane and a preparation method thereof.After the surface of a polymer porous base membrane is infiltrated with an aqueous phase solution containing a first active monomer for at least one second, the redundant aqueous phase solution on the surface is removed, and treatment is conducted immediately under the first microwave condition; contacting the surface of the treated polymer porous base membrane with an oil phase solution containing a second active monomer, immediately performing interfacial polymerization reaction for at least 1 second under a second microwave condition, and then removing the redundant oil phase solution on the surface; and leaching the membrane surface, and drying to obtain the high-performance composite separation membrane. As a seawater desalination membrane, the prepared composite separation membrane has relatively high flux, relatively high desalination rate and relatively high boron removal rate; as a nanofiltration membrane, the prepared composite separation membrane has relatively high flux and relatively high desalination rate; the method is also suitable for preparing ultrafiltration membranes, forward osmosis membranes, gas separation membranes and the like.

The invention provides a forward osmosis membrane based on TFP-DABSA-COF as well as a preparation method and application thereof, and belongs to the technical field of membrane separation. The forward osmosis membrane based on TFP-DABSA-COF provided by the invention is prepared from the following raw material components in percentage by mass on the basis of the total mass of the raw material components of the forward osmosis membrane: 8.0 percent to 18.0 percent of a polymer membrane material, 1.0 percent to 8.0 percent of a pore-foaming agent, 0.05 percent to 0.5 percent of TFP-DABSA-COF and 73.5 percent to 90.95 percent of a mixed solvent. The covalent organic framework material TFP-DABSA-COF is introduced into the polymer to prepare the mixed matrix forward osmosis membrane, the structure and performance of the mixed matrix forward osmosis membrane are effectively improved, and the mechanical performance, permeability and separation performance of the prepared mixed matrix forward osmosis membrane are improved.

A system and method are disclosed for increasing the production yield of CO2 conversion products in an electrochemical reactor assisted by an osmotically driven dewatering system. The system comprises an electrochemical cell including a cathode chamber, an anode chamber, and a central desalination chamber. The cathode chamber includes a cathode active material, and the anode chamber includes an anode active material. The central desalination chamber comprises a plurality of desalination cells, each featuring alternating anion exchange membranes (AEMs) and cation exchange membranes (CEMs). A forward osmosis membrane (FOM) is integrated at the interface between the cathode chamber and the adjacent desalination cell, replacing the conventional terminal CEM. This configuration establishes an osmotic gradient that drives water flux from the cathode chamber into the desalination chamber, thereby concentrating the CO2 conversion product (e.g., formate) in situ and enhancing Faradaic efficiency without requiring post-treatment.

The utility model discloses water purification equipment for solving forward osmosis phenomenon, which comprises an RO (reverse osmosis) membrane filter unit, a booster pump, a PE (polyethylene) water bag, a water supply pump and a water inlet valve, the water inlet valve, the booster pump, the RO membrane filter unit, a first one-way valve, the water supply pump and a faucet are sequentially connected, and the first one-way valve is arranged towards the water supply pump. A zero stale water path is connected between the rear side of the water supply pump and the water inlet side of the RO membrane filtering unit and comprises a first flow meter and a second one-way valve. The RO membrane filtering unit is flushed through the zero-stale-water waterway, the service life of the RO membrane filtering unit is effectively prolonged, the problem that the TDS value of the first cup of water of the water purifier is high is solved, pure water is stored in a water bag made of a medical-grade PE material, the material is zero in precipitation, and drinking water of a user is safer and healthier.

A man-portable dialysate generator with a forward osmosis membrane module, a concentrated aqueous salt solution reservoir, a non-sterile water feedstock inlet, and a collection reservoir that produces sterile dialysate from non-sterile feed water. The dialysate generator does not have an electric-powered pump to move fluids across the osmosis membrane, or does not have electric-powered pumps that generate more than 5 psi for fluid pressure. The dialysate generator is man-portable, less than 50 pounds and maybe less than 31 pounds, and preferably less than 10 pounds. The device is particularly advantageous for use in forward deployed military patient care, disaster response or remote medical care situations away from clean water and electricity.

The invention relates to methods and apparatus for controlling water balance during lithium chloride brine electrolysis. A method is provided comprising supplying the anolyte product stream from electrolysis to a flash evaporator without mixing it with any other liquid stream between exiting the electrolyser and entering the flash evaporator, concentrating it by vacuum evaporation and recirculating the concentrated anolyte product to the electrolyser. A method is also provided comprising the use of forward osmosis prior to electrolysis in order to adjust the concentration of the initial feed brine such that it can be purified by ion exchange and then concentrated for electrolysis, in a manner that means that the entire feed brine can be prepared for electrolysis using forward osmosis, which requires very little energy input. Apparatus for performing the above processes is also provided.

To provide an evaluation method and an evaluation device capable of accurately measuring the practical performance of a forward osmosis membrane.SOLUTION: An evaluation method of a forward osmosis membrane module having a space separated by a forward osmosis membrane having a porous support and a separation function layer laminated on the porous support includes: a step to connect a space at a separation function layer side to a raw material liquid line and a space at a porous support side to an induction solution line; and a step to remove a solvent in a raw material liquid into an induction solution while adjusting physical pressure difference between forward osmosis membranes to be substantially constant in a range of more than 0 kPa and 200 kPa or less via the forward osmosis membrane.SELECTED DRAWING: Figure 1

This invention relates to the field of membrane separation materials technology, specifically to an Al material with high swelling resistance and excellent ion sieving performance. 3+ Crosslinked graphene oxide / MXene composite membrane, its preparation method, and its applications. This composite membrane consists of GO nanosheets, MXene nanosheets, and Al. 3+ Ions are formed through cross-linking, Al 3+ Al–O–C and Al–O–Ti bonds are formed with the carboxyl groups of GO and the terminal oxygen groups of MXene, respectively, to construct a stable layered network. The preparation method includes the preparation of a dispersion of MXene and GO, filtration molding of the composite membrane, and Al… 3+ The cross-linking and curing process is simple and controllable. This composite membrane exhibits excellent anti-swelling properties, high-efficiency ion sieving performance, and long-term stability, with a pure water flux reaching 1.19 L / m² / h¹. (Al...) 3+ The dissolution rate is less than 0.6%. This invention solves the problems of easy swelling and unstable performance of existing MXene membranes, and can be widely used in fields such as forward osmosis seawater desalination and precision ion screening, and has important practical application value.

The invention discloses an integrated forward osmosis membrane assembly structure, and particularly relates to the technical field of membrane separation, the integrated forward osmosis membrane assembly structure comprises a forward osmosis membrane box and a membrane support framework, the forward osmosis membrane box comprises an end cover, an integrated assembly box, a reinforcing side plate and a bottom cover, the integrated assembly box is hermetically connected below the end cover, and the reinforcing side plate is connected below the integrated assembly box. The two sides of the integrated assembly box are fixedly connected with reinforcing side plates, the bottom of the integrated assembly box is in sealed connection with a bottom cover, and the forward osmosis membrane box is a sealed container formed by combining a plurality of components. Meanwhile, the flow guide ribs in the membrane supporting frame and the separation net have a synergistic effect, a uniform fluid channel can be formed on the surface of the membrane, so that a raw material solution and an absorbing solution can stably and uniformly flow through the membrane surface, the concentration polarization phenomenon caused by local flow velocity sudden change or turbulent flow is avoided, and the mass transfer process is more stable; and a double-sealing structure of a sealing clamping groove and a positioning bolt between the end cover and the integrated assembly box can effectively prevent leakage of the feed liquid and guarantee the stability of long-term operation of the assembly.

This invention provides a wastewater concentration system and method coupled with forward osmosis and evaporation crystallization. The wastewater concentration system includes an organic wastewater pretreatment unit, a biochemical treatment unit, a membrane concentration unit, an evaporation crystallization unit, and a forward osmosis concentration unit. The wastewater concentration system provided by this invention removes impurities from organic wastewater through filtration in the organic wastewater pretreatment unit; treats wastewater through the biochemical treatment unit, membrane concentration unit, and evaporation crystallization equipment to obtain evaporation crystallization mother liquor; pretreats the mother liquor through the mother liquor treatment equipment to remove organic matter, hardness, and suspended solids, obtaining a driving fluid and simultaneously enabling the rational utilization of the mother liquor to reduce disposal costs; and concentrates organic wastewater through the forward osmosis concentration unit. Compared with other membrane concentration processes, forward osmosis membranes exhibit less fouling, and the concentrated solution has a high organic matter concentration and small volume, effectively reducing environmental pollution and energy consumption.

The application discloses a printing and dyeing wastewater zero discharge treatment process based on low-pressure high-multiple membrane concentration and salt separation cooperation. The wastewater sequentially passes through double-alkali softening pretreatment, organic pollutant treatment, forward osmosis low-pressure high-multiple concentration treatment, salt separation treatment and evaporation crystallization steps; wherein the forward osmosis low-pressure high-multiple concentration treatment is operated in sections along the flow direction, the osmotic pressure difference is gradually increased, the transmembrane pressure difference is gradually decreased, and the interface electrochemical buffer and low-frequency gas-liquid disturbance can be set to inhibit the concentration polarization and pollution. The concentrated liquid is separated into two salt water streams mainly containing Na2SO4 and NaCl through nanofiltration, and is evaporated and crystallized respectively; and the water produced by the draw solution is returned and reused. The process realizes high-multiple concentration and stable salt separation under low mechanical pressure, reduces energy consumption, improves water recovery rate and crystal purity, and realizes wastewater zero discharge.

The invention discloses an alkali-resistant composite membrane prepared from polyethyleneimine modified polyolefin-based polyamide as well as a method and application thereof, the membrane has low cost, high selectivity and high alkali resistance, and aims to solve the problems that a water treatment membrane is easy to degrade in an alkaline environment and the performance is difficult to consider. According to the composite membrane, porous polyolefin is used as a supporting layer, and a polyamide composite layer containing polyethyleneimine and a surfactant is constructed in the supporting layer and on the surface of the supporting layer through synergy of different-side cross-base membrane interfacial polymerization and same-side interfacial polymerization; wherein the polyethyleneimine can inhibit alkaline hydrolysis of polyamide through interaction with polyamide, and the surfactant optimizes two-phase wettability and reaction uniformity. The preparation method comprises the following steps: firstly, preparing a water phase containing polyamine, a surfactant and polyethyleneimine and an aromatic acyl chloride alkane organic phase, carrying out dual-mode interfacial polymerization, and then carrying out heat treatment shaping. The membrane can effectively balance selectivity and water flux, and shows good applicability in the scenes of forward osmosis, nanofiltration, reverse osmosis water treatment, seawater electrolysis hydrogen production and the like.

Provided are a concentration method and system for concentrating a raw material solution, and in which a raw material solution containing a solute and a solvent is concentrated to obtain a concentrate of the raw material solution, wherein the solvent contains water and an organic solvent. In the method and system for concentrating a raw material solution, the system includes a combination of: a first concentrating means for removing water in the raw material solution by means of a forward osmosis method; and a second concentrating means for evaporating and removing water and an organic solvent in the raw material solution.

The application provides a preparation method of a modified cellulose buffer layer-based forward osmosis membrane and a product thereof, and comprises the following steps: 1) dispersing cellulose fibers into an aqueous sodium hydroxide solution to prepare an alkaline dispersion solution of the cellulose fibers; 2) adding 2-chloroacetamide into the alkaline dispersion solution of the cellulose fibers, and continuously heating and stirring to prepare modified cellulose fibers; 3) dissolving the modified cellulose fibers in a solvent to prepare a cellulose solution, and then coating the cellulose solution on the surface of a non-woven fabric; and 4) growing an ultrathin polyamide layer on the surface of the cellulose-non-woven fabric in situ by using m-phenylenediamine and 1,3,5-benzene tris-methyl chloride, so as to prepare the modified cellulose buffer layer-based forward osmosis membrane. The modified cellulose buffer layer-based forward osmosis membrane has excellent water flux and salt retention performance, has good stability of separation performance, has a simple preparation process, can reduce the amount of polyamide, is low in cost, and is suitable for large-scale production.

Provided are a concentration method and system for concentrating a raw material solution, and in which a raw material solution containing a solute and a solvent is concentrated to obtain a concentrate of the raw material solution, wherein the solvent contains water and an organic solvent. In the method and system for concentrating a raw material solution, the system includes a combination of: a first concentrating means for removing water in the raw material solution by means of a forward osmosis method; and a second concentrating means for evaporating and removing water and an organic solvent in the raw material solution.

This invention provides a method for treating a feedstock containing a small amount of water as an organic solution under non-heating conditions via forward osmosis to obtain a dehydrated feedstock without decomposition or deterioration of the solute. A method for dehydrating a feedstock containing a first organic solvent, water, and a first solute is provided, comprising a dehydration step in which the feedstock is contacted with a driving organic liquid containing a second organic solvent through a forward osmosis membrane to obtain a dehydrated feedstock with a water content of less than 1% by mass. In one embodiment, the initial water content of the feedstock in the dehydration step is 1% by mass or more and less than 30% by mass, and the initial water content of the driving organic liquid is less than the initial water content of the feedstock.

To provide a wastewater treatment facility which enhances a recovery rate of reusable permeate water in wastewater treatment processes that separate wastewater generated at an incineration plant into concentrated wastewater and permeate water using separation membranes.SOLUTION: A wastewater treatment facility for treating wastewater generated by an incineration plant 1A including an incinerator for burning combustible materials and a heat recovery device for recovering heat from combustion exhaust gas discharged from the incinerator, comprises a forward osmosis membrane module 31 having a forward osmosis membrane 40, a reverse osmosis membrane module 32 having a reverse osmosis membrane 50, and a circulation circuit 33 circulating a drive liquid between a secondary side cell 42 of the forward osmosis membrane module 31 and a primary side cell 51 of the reverse osmosis membrane module 32. The wastewater treatment facility is configured to concentrate wastewater by permeating the wastewater from the primary side to the secondary side of the forward osmosis membrane 40, and to utilize the permeate water obtained in the secondary side cell 52 of the reverse osmosis membrane module 32 in the incineration plant 1A by permeating the drive liquid from the primary side to the secondary side of the reverse osmosis membrane 50.SELECTED DRAWING: Figure 2

This invention relates to lithium extraction equipment technology from salt lakes, proposing a forward osmosis device and its safety monitoring system, including a pretreatment component, a lithium-based adsorption tower, and a forward osmosis unit. The pretreatment component reduces suspended solids in the salt lake brine, and the treated brine is then fed into the lithium-based adsorption tower and the forward osmosis unit. The lithium-based adsorption tower has outlets for the adsorbed raw solution, desorbed water, and desorbed liquid, and uses an aluminum-based adsorbent. The forward osmosis unit incorporates a forward osmosis membrane module, employing a non-woven fabric base membrane coated with cellulose acetate and polyamide. This invention replaces the high-pressure reverse osmosis component with a forward osmosis unit, achieving atmospheric pressure concentration and lithium extraction, reducing energy consumption and safety risks. The forward osmosis unit uses saturated brine as the draw solution, ensuring osmotic pressure differences and increasing desorbed liquid yield. Conventional systems require separate treatment of the diluted draw solution; in this invention, the diluted draw solution is directly returned to the salt lake, utilizing the high salinity of the salt lake to slow the decrease in draw solution concentration and maintain a long-term stable osmotic pressure gradient.

The utility model belongs to the technical field of fruit juice concentration, and discloses a forward osmosis concentration device for small-pulp fruit juice, which comprises a fruit juice circulation tank for containing small-pulp fruit juice, a forward osmosis concentration component for concentrating small-pulp fruit juice and a drawn liquid circulation component for drawing water, and the fruit juice circulation tank is communicated with a fruit juice circulation pump; the forward osmosis concentration assembly comprises a mold assembly shell and a forward osmosis biomimetic membrane arranged in the mold assembly shell, end seats are arranged on the two sides of the mold assembly shell, and the two sides of the forward osmosis concentration assembly are communicated with the fruit juice circulating tank and the fruit juice circulating pump through the end seats respectively; the draw solution circulating assembly comprises a draw solution circulating tank, a draw solution circulating pump and a reverse osmosis membrane concentration mechanism, and the draw solution circulating tank is filled with an environment-friendly draw solution; according to the utility model, low-temperature forward osmosis concentration is combined with multi-stage pretreatment, so that the membrane pollution risk is reduced, and the consumption of chemicals and the discharge of wastewater are reduced through the cyclic regeneration of drawn liquid and the resourceful treatment of waste liquid while the nutrition of fruit juice is retained.

The invention provides a forward osmosis membrane based on DBA-TPTA-COF as well as a preparation method and application thereof, and belongs to the technical field of membrane separation. The forward osmosis membrane based on DBA-TPTA-COF provided by the invention is prepared from the following raw material components in percentage by mass on the basis of the total mass of the raw material components of the forward osmosis membrane: 7.0 percent to 14.0 percent of a polymer membrane material, 3.0 percent to 12.0 percent of a pore-foaming agent, 0.05 percent to 0.25 percent of DBA-TPTA-COF and 73.75 percent to 89.95 percent of a mixed solvent. The covalent organic framework material DBA-TPTA-COF is introduced into the polymer to prepare the mixed matrix forward osmosis membrane, the structure and performance of the mixed matrix forward osmosis membrane are effectively improved, and the mechanical performance, permeability and separation performance of the prepared mixed matrix forward osmosis membrane are improved.

A method of absorbing CO2 from a gas stream is contemplated where the gas stream is directed into contact with at least one multi-amine molecular solvent liquid stream, thus drawing at least some of the CO2 out of the gas stream to create a CO2 -reduced gas stream and a CO2 -rich solvent liquid stream, the CO2-reduced gas stream is then separated from the CO2-rich solvent liquid stream, and the CO2 is separated from the CO2 -rich solvent liquid stream so that the solvent can be recycled for use again in CO2 absorption. Reduction in energy consumption during solvent regeneration and CO2 separation is done by phase separation or forward osmosis processes.

The invention provides a low-pressure efficient wastewater concentration system based on a reverse osmosis membrane group, and relates to the technical field of wastewater treatment. The low-pressure high-efficiency wastewater concentration system based on the reverse osmosis membrane groups comprises a first-section reverse osmosis membrane group and a plurality of second-section reverse osmosis membrane groups. The second concentrated solution outlet of any second-section reverse osmosis membrane group is communicated with the second liquid inlet of the adjacent second-section reverse osmosis membrane group. And the second liquid inlet of the second-section reverse osmosis membrane group at the head end is communicated with the first concentrated liquid outlet. A forward osmosis membrane group is arranged at the second water outlet of any second section of reverse osmosis membrane group, and a third liquid inlet of the forward osmosis membrane group is respectively communicated with the second water outlet and the second concentrated liquid outlet. And each diluent outlet is communicated with the first liquid inlet. Differential pressure liquid is introduced between the third liquid inlet and the second water outlet corresponding to the third liquid inlet. According to the invention, the osmotic pressure difference between two sides of the second-section reverse osmosis membrane group is ensured to be stable in an external low-pressure environment, so that the wastewater is efficiently concentrated and recycled.