61 results about "Monovalent ions" patented technology

The invention relates to the technical field of ethylene glycol purification, and discloses a purification method of an ethylene glycol solution, a membrane separation device and application of the membrane separation device. The purification method comprises the steps that (1) an ethylene glycol solution is fed for purification treatment, a purification system comprises a membrane separation device composed of a booster pump and a first membrane assembly, and the first membrane assembly at least comprises an I-1 membrane set, an I-2 membrane set and an I-3 membrane set and is used for intercepting ethylene glycol and metal ions; (2) the obtained primary concentrated solution of the purification system is subjected to concentration treatment, a concentration system comprises a membrane separation device composed of a booster pump, a circulating concentration water tank II-1 and a membrane separation assembly II-2 membrane, the II-2 membrane intercepts one or more of monovalent ions, divalent ions and trivalent ions, and purified ethylene glycol clear liquid is obtained. The method is energy-saving and easy to implement, is suitable for purifying the low-concentration ethylene glycol solution, and has a very good industrial application prospect.

The invention discloses a mineral substance adjusting method and system of a water purifier, the water purifier and a medium. The mineral substance adjusting method comprises the following steps: calculating a target divalent ion contribution value according to a monovalent ion rejection rate, a divalent ion rejection rate, first detection data and second detection data; calculating a monovalent ion mineral retention value and a divalent ion mineral retention value according to the monovalent ion rejection rate, the divalent ion rejection rate and the target divalent ion contribution value; and adjusting a water mixing valve based on a comparison result of the monovalent ion mineral retention value or the divalent ion mineral retention value and a set retention value, so that water is introduced into the first water purification system according to a proportion to realize mineral adjustment. The ion mineral retention value is calculated according to the front and back detection data of the first membrane filter element in the second water purification system, the proportion adjusting system is adjusted according to the comparison result of the ion mineral retention value and the set retention value so as to control the water passing amount of the first water purification system, the mineral content is automatically adjusted according to the user requirement, and the user experience degree is enhanced.

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 present invention relates to a process for separating rubidium ions from saline solutions rich in other monovalent ions, particularly sodium and potassium. The process relies on rubidium ions adsorption via ion exchange performed by metal-hexacy anoferrate particles. The process of the present invention provides pure rubidium salt with estimated production costs that do not exceed 20% of the current price.

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.

This method for operating an electrodialysis device includes a step for electrodialyzing an iodide-containing solution which contains an iodide salt and a solvent with use of an electrodialysis device. The electrodialysis device includes an anion exchange membrane that has a monovalent ion permselective layer, in which a minimum appears in a secondary differential value curve that is obtained by acquiring, in accordance with a DC resistance measurement method, an IV curve that shows the relationship between the DC current and the voltage and secondarily differentiating the IV curve. In the step for electrodialysis, 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 DC current (A) corresponding to the minimum appeared in the secondary differential value curve.

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 belongs to the technical field of ion efficient separation materials, and specifically relates to a supramolecular coordination framework compound and a preparation method thereof, a supramolecular coordination framework modified nanochannel membrane and an application thereof. The present invention provides a supramolecular coordination framework compound having the structure shown in Formula 1. The supramolecular coordination framework compound provided by the present invention has a porphyrin group in its structure. When the supramolecular coordination framework compound is used as a sieving host and chemically modified in the nanochannels of the nanochannel membrane, there is a strong coordination interaction between the porphyrin group in the framework and divalent ions, thereby preventing the passage of divalent ions. Therefore, monovalent ions can be selectively passed through, forming a monovalent / divalent ion selective transport. The supramolecular coordination framework compound provided by the present invention shows significant ion sieving performance when used as a sieving host and modified in the nanochannels, and has excellent sieving performance for monovalent / divalent ions.

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.