49 results about "Monovalent ions" patented technology

The invention discloses a composite membrane with MXene directionally modified by alpha-cyclodextrin and a preparation method of the composite membrane, and belongs to the field of ion separation membrane materials, the composite membrane comprises MXene nanosheets and alpha-cyclodextrin; the MXene nanosheets are stacked layer by layer to form a sub-nano channel convenient for ions to pass through, and the alpha-cyclodextrin is connected to the end parts of the MXene nanosheets to form an interlayer channel inlet of the sub-nano channel; an interlayer channel inlet formed by alpha-cyclodextrin can select monovalent ions, the monovalent / divalent ion selectivity of the composite membrane exceeds 10 < 3 >, a sub-nano channel formed by MXene enables the monovalent ions to be transported smoothly, rapid transport of the monovalent ions is guaranteed, and the flux of the monovalent ions reaches 0.1 mol m <-2 > h <-1 >; therefore, the composite membrane provided by the invention can realize synchronous improvement of ion selectivity and ion flux; the structural stability of the composite membrane is improved, and the service life is prolonged.

The invention relates to a monovalent ion selective cation exchange membrane and a preparation method and application thereof, and the preparation method comprises the following steps: mixing polyethyleneimine and a cross-linking agent to obtain a pre-polymerized solution; coating the surface of a cationic base membrane with the pre-polymerized solution, and then heating to carry out a cross-linking reaction, so as to obtain a base membrane after surface cross-linking; and soaking the base membrane subjected to surface crosslinking in an oil phase solution of acyl chloride monomers, and carrying out interfacial polymerization reaction to obtain the monovalent ion selective cation exchange membrane. Through the synergistic effect of a three-dimensional network structure constructed through cross-linking reaction and a selective separation layer constructed through interfacial polymerization, the Li < + > / Mg < 2 + > separation coefficient can be increased, and long-acting and stable operation is achieved.

The invention discloses a preparation and application method of a modified ion exchange membrane for electrodialysis, aiming at the problems of poor selectivity, low mechanical strength, high energy consumption and the like of the existing ion exchange membrane, the high-performance modified membrane is prepared by a base membrane pretreatment-functional grafting-gradient curing synergistic process. The preparation method specifically comprises the following steps: performing ultrasonic cleaning and acid-base activation on a polyethersulfone or sulfonated polystyrene-based membrane, soaking the polyethersulfone or sulfonated polystyrene-based membrane in a modification solution containing an amino / carboxyl / sulfo functional monomer, a cross-linking agent and an initiator, and performing gradient heating curing to form a stable cross-linked network; the grafting rate of the modified membrane is 15-35%, the ion exchange capacity is 1.8-2.5 mmol / g, the water content is 25-40%, and the membrane surface resistance is less than 3 omega.cm < 2 >. When the membrane is applied to an electrodialysis device, the membrane runs under the conditions of 10-30V direct-current voltage, 5-15cm / s flow velocity and 25-45 DEG C, the high-salinity wastewater desalination rate is greater than or equal to 95%, and the monovalent ion selectivity coefficient reaches 5.8-7.2; when the catalyst is used for acid-base recovery, the H < + > migration number is 0.92-0.96, and the energy consumption is reduced by 18-25%.

The invention belongs to the technical field of membranes, and discloses a monovalent / divalent cation selective separation membrane based on an intrinsic microporous polymer, and the preparation route of the membrane is as follows: taking an ether-free polymer synthesized by super acid catalysis as a precursor, introducing an ion exchange site into the polymer by utilizing grafting of a sulfonated monomer, and preparing the monovalent / divalent cation selective separation membrane based on the intrinsic microporous polymer. And improving the separation performance of monovalent ions / divalent ions by using an alkoxy chain graft with specific interaction on the monovalent ions, and greatly improving the mechanical strength of the membrane by using the interaction of hydrogen bonds between main and side chains, thereby finally obtaining the monovalent / divalent cation selective separation membrane. According to the present invention, the industrial production difficulty is significantly reduced by the full solvation reaction membrane synthesis route, the selectivity of the prepared membrane material is superior to the selectivity of the commercial membrane of the same type, the extremely high mechanical strength is maintained, and the large-scale production and application potential is provided.

The application provides a mixed matrix membrane for efficient ion separation and a preparation method thereof, and belongs to the technical field of separation membranes.The application mixes an aluminum salt and sodium hydroxide in an organic solvent, then adds a heterocyclic organic ligand containing nitrogen to obtain a MOF precursor solution; adds polyimide into the MOF precursor solution to obtain a casting solution; pours the casting solution into a mold and performs vacuum heating, then performs peeling, soaks in ethanol, and then performs drying to obtain the mixed matrix membrane for efficient ion separation.The application realizes uniform dispersion of MOF-303 in the whole matrix by controlling the MOF loading, and constructs continuous ion channels by the uniformly dispersed MOF-303 crystal structure, so that the selectivity of the membrane to monovalent ions is further improved.The operation is simple, and the cost is low.

The invention discloses a preparation method of a branched polybenzimidazole side chain grafted monovalent / divalent high-selectivity cationic membrane, which is characterized in that a branched unit is introduced into a main chain to construct a microcavity structure based on the unique tight stacking and rich hydrogen bond network characteristics of polybenzimidazole (PBI), and the pore diameter in the membrane and the free volume of a polymer are regulated and controlled to prepare the branched polybenzimidazole side chain grafted monovalent / divalent high-selectivity cationic membrane. The stable and rapid transmission of monovalent ions is promoted, and a high interception effect on divalent ions is kept. Then molecules containing sulfonic acid groups and hydrophobic side chain molecules are grafted to the branched PBI, the ionic conduction performance is improved, meanwhile, a microphase separation structure can be constructed, the ionic transmembrane energy barrier difference is increased through the ionic hydration energy difference of monovalent and divalent ions, selective transmission of ions is achieved, and the ionic conductivity is improved. Finally, the ion separation membrane with outstanding stability and excellent comprehensive performance of selectivity and flux is obtained.

The application discloses a kind of high selectivity nanofiltration composite membrane and preparation method thereof, belong to nanofiltration membrane related technical field.The application is in the form of in-situ polymerization with anhydride, ester group, amide group on membrane surface, the degree of hydrolysis of polyamide membrane is controlled by the cleaning of post-processing solution, to control the charge density of membrane surface, to improve or reduce the permeability of monovalent ion;By controlling the ratio of trimesoyl chloride and diacyl chloride monomer, the size of pore structure can be adjusted, further improving the permeability of monovalent salt;By adjusting the amount of hydrophilic pore-forming agent to improve the hydrophilic performance of ultrafiltration base film, the flux and monovalent salt permeability of nanofiltration composite membrane are improved.The high selectivity nanofiltration composite membrane prepared by the application has excellent divalent salt ion removal rate, lower monovalent salt removal rate, and higher water flux, suitable for industrial production.

An aqueous suspension of a mineral material, for example calcium carbonate, may be prepared by wet grinding in the presence of an aqueous dispersion of (meth)acrylic polymer neutralized by a combination of at least one monovalent ion and at least one divalent ion. Such an agent may be used for facilitating grinding and such a mineral suspension may be used for preparing a mass filler for the preparation of paper, for preparing a paper coating slip, or for preparing a coating composition.

The application provides a corrosion inhibitor suitable for titanium alloy products. The corrosion inhibitor comprises: an inorganic salt, a synergist and a solvent, wherein the inorganic salt has the general formula: M x AO y wherein M is a monovalent ion, A is selected from one or more of the group consisting of chromium, silicon, tungsten, boron, manganese, iodine, bromine, tin and tellurium, x and y are dynamically adjusted according to the valence of A, and the inorganic salt can form a passivation film / deposition film on the surface of the titanium alloy. In the application process, the inorganic salt can form a passivation film / deposition film protective layer on the surface of the titanium alloy. The protective layer can effectively block the contact between the acid liquid and the substrate, thereby inhibiting the corrosion of the substrate. The synergist can promote the rapid film formation of the inorganic salt on the surface of the titanium alloy, and improve the compactness and integrity of the film. Therefore, the use of the above-mentioned corrosion inhibitor can greatly improve the corrosion resistance of the titanium alloy product in a high-temperature and high-acid environment.

A method of removing pollutants from wastewater, the method including a) separating the wastewater into first treated water containing monovalent ions and second treated water containing multivalent ions, b) concentrating the monovalent ions in the first treated water to produce concentrated water, c) electrochemically reducing nitric acid in the concentrated water, and d) electrochemically oxidizing organic matter in the second treated water. According to the above method, the pollutants in the wastewater can be removed efficiently and environmentally.

A luminescent material is a complex with the following structural formula: wherein R and R' are independently selected from oxygen, amino, C1-C18 straight-chain or branched alkyl-substituted amino, phosphin, C1-C18 straight-chain or branched alkyl-substituted phosphin, sulfur, and selenium; R1, R2, R3, R4, R5, and R6 are independently selected from hydrogen, C1-C18 straight-chain or branched alkyl or halogen-substituted C1-C18 straight-chain or branched alkyl, aromatic... Aromatic groups such as benzene, thiophene, and furan, n = 1–3, are used to construct cyclic ligand skeletons with different half-ring numbers. Ln is one of the following: cerium trivalent ion, europium divalent ion, ytterbium divalent ion, and samarium divalent ion. M is one of the following: manganese divalent ion, cobalt trivalent ion, chromium trivalent ion, vanadium trivalent ion, and ferric trivalent ion. X is a monovalent ion, such as halogen, cyanide, thiocyanate, isothiocyanate, etc., m = 0–3, l = 3–6. X acts as a monodentate ligand or as a bridging bidentate ligand.

The present application relates to a kind of covalent organic framework film preparation based on biomimetic mineralization strategy and its application in ion separation.In the process of monovalent ion separation, methoxy forms stable interaction with monovalent ion through its unique coordination characteristics and electronegativity, significantly improves the transmission rate of monovalent ion. At the same time, the introduction of functionalized methoxy can also effectively inhibit the passage of divalent ion, so as to realize efficient ion separation. Biomimetic mineralization strategy can significantly improve the mechanical strength and chemical stability of COF membrane by compounding organic polymer with COF. Compared with traditional separation membrane, the biomimetic mineralized COF membrane provided by the present application exhibits higher separation efficiency, more excellent selectivity and longer service life, and is suitable for efficient extraction of lithium and other monovalent ion resources, battery material preparation and ion separation application in related industrial production process. The functionalized methoxy COF membrane material of the present application has the advantages of adjustable structure, simple preparation and potential for large-scale production.

The present invention discloses a nanofiltration membrane modified with tannic acid, a preparation method thereof, and an application thereof, belonging to the technical field of nanofiltration membrane materials. In view of the technical problem that nanofiltration membranes in the prior art are difficult to balance water flux and retention rate, the present application provides a nanofiltration membrane modified with tannic acid, having a thickness of 20 μm to 22 μm; a flow rate of 29.5 L / (bar×h×m 2 )~35.5 L / (bar×h×m 2 ) water flux; during the separation process, the retention rate of monovalent ions is 17.6%~32.2% within 30 min~45 min, and the retention rate of divalent ions is 88.4%~94.5%. The present application introduces tannic acid into the oil phase and performs water-oil two-phase synergistic modification, which can significantly improve the retention effect while maintaining a high water flux, solving the technical problem that traditional modification methods are difficult to balance water flux and retention rate, and providing targeted solutions for different application scenarios. The present application also provides a preparation process and application of the nanofiltration membrane, and the prepared nanofiltration membrane has both excellent separation performance and operational stability.

The invention provides a gradient extraction method of produced water associated resources. According to the produced water associated resource gradient extraction method, a pre-separation step is designed, monovalent ions and divalent ions in produced water are preliminarily separated, bromine extraction, strontium extraction and lithium extraction procedures are organically connected in series or in parallel, the strontium and lithium recovery steps can be synchronously carried out, the technological process is simpler, energy consumption is lower, and the production efficiency is improved. And efficient stepped extraction of bromine, lithium, strontium and other elements with the content reaching a certain abundance and exceeding the comprehensive industrial mining grade in the produced water is comprehensively realized in a complete set.

The invention discloses preparation and application of a gold cluster compound for targeted therapy of acute kidney injury diseases, and relates to the field of nephropathy treatment medicines. The molecular composition (Au) is x (S) y, x is equal to 3-144, y is equal to 1-140, and S is a sulfydryl-containing renal injury target protein binding peptide or a sulfydryl-modified renal injury target protein binding peptide. The method comprises the following steps: mixing a gold salt solution with a sulfydryl-containing ligand to form a mixed solution; under the conditions of certain temperature and pH, the mixed solution system is subjected to a reduction reaction, high-valence Au ions in the gold salt are reduced into Au atoms or monovalent Au ions, and Au forms a gold cluster compound through physical or chemical interaction; the cluster compound disclosed by the invention has remarkable treatment activity in a cis-platinum induced acute kidney injury model, and the acute kidney injury is treated in a targeted manner by inhibiting over transcription and expression of pro-inflammatory cytokines and removing reactive oxygen species (ROS).

The present invention relates to the technical field of membrane separation. Disclosed are a negatively charged composite nanofiltration membrane, a preparation method therefor, and an application thereof. The negatively charged composite nanofiltration membrane sequentially comprises a bottom layer, a porous support layer, and a polyamide separation layer; a sulfonic acid group and / or a sulfonate group represented by formula I are grafted to the polyamide separation layer by means of N atoms; formula I, where M is H, Li, Na, or K, and R1 and R2 are each independently H or C1-C6 alkyl or phenyl; (aa) is the position at which the group represented by formula I and the polyamide separation layer are linked to form a bond; and Ar is derived from a post-reaction residue of a compound containing an electron-withdrawing group. In the composite nanofiltration membrane, a sulfonic acid group and / or a sulfonate group of a specific structure are grafted to the polyamide separation layer such that the surface of the composite nanofiltration membrane is negatively charged, thereby improving selectivity with respect to monovalent ions / divalent ions while maintaining a high water flux.

The invention discloses a tannic acid modification-based nanofiltration membrane as well as a preparation method and application thereof, and belongs to the technical field of nanofiltration membrane materials. Aiming at the technical problem that a nanofiltration membrane in the prior art is difficult to give consideration to both water flux and rejection rate, the invention provides the tannic acid modification-based nanofiltration membrane which has the thickness of 20-22 microns; a water flux of 29.5 L / (bar * h * m < 2 >)-35.5 L / (bar * h * m < 2 >); in the separation process, the retention rate of monovalent ions within 30 min to 45 min is 17.6% to 32.2%, and the retention rate of divalent ions within 30 min to 45 min is 88.4% to 94.5%. According to the method, tannic acid is introduced into an oil phase, and water-oil two-phase synergistic modification is performed, so that the interception effect can be remarkably improved while relatively high water flux is maintained, the technical problem that the water flux and the interception rate are difficult to consider in a traditional modification method is solved, and targeted solutions are provided for different application scenes. The invention further provides a preparation process and application of the nanofiltration membrane. The prepared nanofiltration membrane has excellent separation performance and operation stability.

This invention discloses a composite membrane with MXene directionally modified by α-cyclodextrin and its preparation method, belonging to the field of ion separation membrane materials. The composite membrane comprises MXene nanosheets and α-cyclodextrin; the MXene nanosheets are stacked layer by layer to form sub-nanochannels that facilitate ion passage, and the α-cyclodextrin is connected to the ends of the MXene nanosheets to form interlayer channel entrances for the sub-nanochannels; the interlayer channel entrances formed by the α-cyclodextrin can select for monovalent ions, and the monovalent / divalent ion selectivity of this composite membrane exceeds 10. 3 Furthermore, the sub-nanometer channels formed by MXene ensure unimpeded transport of monovalent ions, guaranteeing rapid transport of monovalent ions with a flux of 0.1 mol m ‑2 h ‑1 It is evident that the composite membrane described in this invention can simultaneously improve ion selectivity and ion flux; and the structural stability of the composite membrane is improved, extending its service life.

The present application relates to the technical field of membrane separation, and in particular to a method for separating monovalent and multivalent ions in water and a method for extracting lithium from salt lake. The method for separating monovalent and multivalent ions in water comprises the following steps: (A) performing first electrodialysis on pretreated liquid to be treated to obtain first electrodialysis dilute liquid and first electrodialysis concentrated liquid; (B) returning the first electrodialysis dilute liquid to step (A) to perform the first electrodialysis, and performing nanofiltration on the first electrodialysis concentrated liquid to obtain nanofiltration water and nanofiltration concentrated water; (C) performing second electrodialysis on the nanofiltration water and the nanofiltration concentrated water to obtain second electrodialysis concentrated liquid. The method for separating monovalent and multivalent ions in water has the advantages of short process, simple operation, small amount of fresh water, high water resource utilization rate, good separation effect of monovalent and multivalent ions, no requirement for the concentrations of monovalent and multivalent ions, etc.

The application discloses a kind of high-efficiency interception polyvalent anion and cation nanofiltration membrane and its preparation method and application.The method includes the following preparation process:1) preparation concentration is 0.1-2wt% of apigenin class of substance aqueous solution, and concentration is 0.1-0.5wt% of multi-acid chloride organic phase solution;2) make polymer support membrane in aqueous solution 1-5min, remove the surface excess solution, then immerse into oil phase solution, react 1-15min;3) after reaction, remove the surface excess solution, solidify 5-20min under 60-80 DEG C, obtain the nanofiltration membrane.The application is with apigenin, apigenin-7-o-glucuronide and / or isofraxidin as aqueous monomer, and multi-acid chloride is prepared by interfacial polymerization reaction to obtain negative NF membrane, not only maintain the high interception rate to polyvalent anion, and also have very high interception rate to polyvalent cation, can efficiently permeate monovalent ion, and water flux is larger.

The invention relates to the technical field of wafer manufacturing equipment, and particularly discloses a special ion source for multivalent ion implantation and a use method thereof.The special ion source comprises a first gas supply source, a second gas supply source, an ion generator with a first-stage reaction arc chamber and a second-stage reaction arc chamber, generating an ion beam containing monovalent ions of the source gas supplied by the first gas supply source; and a secondary reaction arc chamber for generating multivalent ions of the source gas supplied by the first gas supply source by means of charge exchange generated by collision between an ion beam containing the monovalent ions of the source gas supplied by the first gas supply source and the source gas supplied by the second gas supply source. The method has the advantages that the size of the multivalent ion beam can be effectively increased, the beam adjustment time and the machine operation time are optimized, and the machine productivity is improved.

The present invention relates to compositions, and in particular to pharmaceutical compositions, comprising, or even consisting of, a suspension of bacteriophages of the class Caudoviricetes, the bacteriophages having lytic activity against at least one Gram-positive bacterial strain, at a titer of at least 108 PFU / mL, in a dispersing medium comprising, or even consisting of: - at least one non-ionic surfactant, and in particular a single non-ionic surfactant, selected from the polysorbate family, at a molar concentration greater than its critical micelle concentration, but not exceeding 2 mg / mL, and / or the poloxamer family, at a concentration ranging from 0.005% (w / v) to 30% (w / v); - one or more neutral salts formed from a pair of monovalent ions, the total molar concentration of which is in the range from 75 to 160 mM; - a buffer mixture imparting to the composition a pH from 6.0 to 7.9, and preferentially from 7.0 to 7.5, typically selected from hydrogen phosphate ion / dihydrogen phosphate, citric acid / citrate ion and citric acid / hydrogen phosphate ion ion pairs, wherein the molarity of the buffer mixture is in the range from 4 mM to 100 mM; - water, wherein the composition comprises less than 0.9 bacterial endotoxin units per mL and a total protein concentration of less than 0.09 mg / mL, and wherein the bacteriophage suspension in the dispersing medium has an osmolality of between 150 mOsm / kg and 600 mOsm / kg; the invention also relates to associated methods and uses.

The present application relates to the field of high molecular polymer separation membrane material, disclose a kind of for monovalent / divalent ion separation cation exchange membrane, both contain rigid aromatic main chain structure, also contain flexible aliphatic side chain structure with hydrophilic cation exchange group. During film forming process, hydrophobic main chain and hydrophilic side chain respectively self-aggregation forms "hydrophobic aromatic region microphase" and "hydrophilic ion cluster microphase", it is helpful to form the ion channel of suitable size;Different aliphatic side chains are introduced on polymer main chain respectively, through the electrostatic interaction difference between different kinds of cation exchange groups carried by side chain and monovalent / divalent cation (such as, Li + / Mg 2+ ) of same charge but different charge, then the ratio of cation mobility and ion exchange equilibrium constant change, thereby promote the transport of monovalent ion in ion exchange membrane, and do not permeate divalent ion.

The application discloses a kind of nitrogen-rich high-energy anti-perovskite materials and preparation method thereof, respectively with nitrogen-rich compound 5,5-bis-tetrazole and 3,5-dinitramino-1,2,4-triazole as negative divalent ion and negative monovalent ion component raw material, with hydroxylamine as positive monovalent ion component raw material, three components are integrated by ionization reaction, and nitrogen-rich anti-perovskite material ANP-1 is obtained.The synthesis method of the application has the characteristics of easy to obtain raw materials, simple operation, high safety, high yield and the like.

A system and method for producing very high concentration brine streams from which commercially efficiently obtained minerals may be obtained is produced by a dual membrane brine concentrator system (DTRI Concentrator). The system includes a nano-filtration system which removes divalent ions from the seawater, a brine concentrator such as a hollow fine fiber forward osmosis system which receives and further concentrates the brine rejected from the nano-filtration system, a SWRO system which receives the NF system permeate and removes monovalent ions, and another brine concentrator which further concentrates the brine rejected from SWRO system. Various permeate and reject brine flow may be forwarded through the Dual Membrane Brine Concentrator system, and multiple stages of the system components may be used, to enhance brine concentration and improve system efficiency.

The invention discloses a preparation method and application of a monovalent cation selective membrane with an Al-MOF-based layered frame structure, and belongs to the technical field of membrane separation. The monovalent cation selective membrane solves the problems that the ion flux and the selectivity are difficult to consider, the structure of a separation layer is uneven, many polymerization defects exist in a frame pore channel, and the long-term use stability is poor in the existing monovalent cation selective membrane. The method comprises the following steps: preparing a hydrolyzed polyacrylonitrile basement membrane, preparing an Al-MOF modified basement membrane, and carrying out heat treatment and curing after interfacial polymerization reaction. The interfacial polymerization process is regulated and controlled through the confinement of an Al-MOF layered frame structure, a polyamide separation layer with high crosslinking degree, narrow pore size distribution and high positive charge density is cooperatively constructed in combination with a binary mixed amine monomer, the dual effects of electrostatic repulsion and size screening are synchronously enhanced, the Na < + > / Mg < 2 + > monovalent cation selectivity can reach 50.45 under the optimal condition, meanwhile, the high monovalent ion flux is maintained, and the specific surface area is increased. The membrane has excellent long-term operation stability and is suitable for separation of monovalent and multivalent cations in an electrodialysis system.

Carbon dioxide (CO2) mineralization methods. Methods may comprise: (i) providing a high salinity water comprising at least one monovalent and at least one divalent cation selected from the group consisting of: Mg, Ca, Na, K, and Li cations; (ii) if necessary, increasing the high salinity water pH value, thereby forming a Mg(OH)2 precipitate if Mg cations are present; (iii) separating any formed Mg(OH)2 precipitate from a first supernatant comprising monovalent and / or divalent ions selected form the group consisting of: Ca, Na, K, and Li cations; (iv) if necessary, increasing the pH value of the first supernatant to about 12 or greater; (v) introducing CO2 nanobubbles into the first supernatant, thereby forming a CaCO3 precipitate if Ca cations are present; and (vi) separating any formed CaCO3 precipitate from a second supernatant comprising monovalent ions selected from the group consisting of: Na, K, and Li cations.

This method for operating an electrodialysis device comprises a step for electrodialyzing an iodide-containing solution containing an iodide salt and a solvent using an electrodialysis device provided with an anion exchange membrane having a monovalent ion permselective layer. In the anion exchange membrane electrodialysis step, a current-voltage curve indicating the relationship between a direct current and a voltage is obtained by a direct current resistance measurement method, and a minimum value appears in a quadratic differential value curve obtained by performing quadratic differentiation on the current-voltage curve. The current density (A / dm2) is set to a1 / d or more, where d is the effective area (dm2) of the anion exchange membrane and a1 is the value of the direct current (A) corresponding to the minimum value appearing in the quadratic differential value curve.

A system and method for producing very high concentration brine streams from which commercially efficiently obtained minerals may be obtained is produced by a dual membrane brine concentrator system (DTRI Concentrator). The system includes a nano-filtration system which removes divalent ions from the seawater, a brine concentrator such as a hollow fine fiber forward osmosis system which receives and further concentrates the brine rejected from the nano-filtration system, a SWRO system which receives the NF system permeate and removes monovalent ions, and another brine concentrator which further concentrates the brine rejected from SWRO system. Various permeate and reject brine flow may be forwarded through the Dual Membrane Brine Concentrator system, and multiple stages of the system components may be used, to enhance brine concentration and improve system efficiency.

The application discloses a kind of monovalent selective cation exchange membrane containing covalent organic framework modification layer and preparation method and application thereof.The preparation method comprises the following steps: (1) ethidium bromide monomer, catalyst is dissolved in deionized water to obtain aqueous solution;(2) aldehyde monomer is dissolved in organic solvent, to obtain organic phase solution;(3) sulfonated polyether ether ketone-based film is immersed into aqueous solution, after taking out, film surface water droplet is blown dry, then immersed into organic phase solution, take out and air dry, obtain monovalent selective cation exchange membrane containing covalent organic framework modification layer.The application provides the application of the monovalent selective cation exchange membrane containing covalent organic framework modification layer in electrodialysis separation single multivalent cation.Under the condition of ensuring that the monovalent ion of the membrane has higher permeation flux, the membrane surface resistance is small, the tensile strength of the membrane is improved, the water absorption of the membrane is reduced, and the single multivalent selection performance of the membrane is significantly improved.