Abstract: The present invention provides for nutrient extraction and recovery devices that use the Donnan Membrane Principle (DMP) to cause spontaneous separation of dissolved ions along electrochemical potential gradients, wherein anions and cations such as H2PO4?, HPO42?, PO43?, Mg2+, Ca2+, NH4+, and K+ are moved from manure containing waste streams through cation and anion exchange membranes into a recovery stream thereby precipitating target compounds including but not limited to struvite, potassium struvite and hydroxyapatite.

Abstract: An electrochemical device converts carbon dioxide to a formic acid reaction product. The device includes an anode and a cathode, each comprising a quantity of catalyst. The anode and cathode each have reactant introduced thereto. Two membranes, a cation exchange polymer electrolyte membrane and an anion exchange polymer electrolyte membrane, are interposed between the anode and the cathode, forming a central flow compartment where a carbon dioxide reduction product, such as formic acid, can be recovered. At least a portion of the cathode catalyst is directly exposed to gaseous carbon dioxide during electrolysis. The average current density at the membrane is at least 20 mA/cm2, measured as the area of the cathode gas diffusion layer that is covered by catalyst, and formate ion selectivity is at least 50% at a cell potential difference of 3.0 V.

Abstract: Imidazole-containing polymer membranes are described herein. Methods of their preparation and use are also described herein. The methods of using the membranes include capturing and reducing volatile compounds from gas streams.

Abstract: A method and a system for process parameter control of a liquid composition in a reverse electro-enhanced dialysis (REED) system comprising at least two Reverse Electro-Enhanced Dialysis (REED) membrane stacks, wherein the direction of the electric field within any one membrane stack is reversed at asynchronical intervals of time relative to the current reversals for any other membrane stack.

Abstract: The present invention provides an efficient method for creating natural gas including the anaerobic digestion of biomass to form biogas, and the electrodeionization of biogas to form natural gas and carbon dioxide using a resin-wafer deionization (RW-EDI) system. The method may be further modified to include a wastewater treatment system and can include a chemical conditioning/dewatering system after the anaerobic digestion system. The RW-EDI system, which includes a cathode and an anode, can either comprise at least one pair of wafers, each a basic and acidic wafer, or at least one wafer comprising of a basic portion and an acidic portion. A final embodiment of the RW-EDI system can include only one basic wafer for creating natural gas.

Abstract: A method for producing succinic acid is provided, which comprises circulating a fermentation broth containing succinate ion through an electrodeionization apparatus. The apparatus comprises an anode; a cathode; a stacked ion-exchange assembly comprising a one or more oriented ion-exchange units between the anode and the cathode. Each ion-exchange unit comprises a porous ion-exchange resin wafer including an inlet and an outlet together are adapted to circulate a liquid reaction stream containing a carboxylate anion from a fermentor through the resin wafer; a flow-distributing gasket for circulating a product stream through a product reservoir; an anion exchange membrane for transporting at least a portion of the carboxylate anion to the product stream; and a bipolar ion-exchange membrane to direct protons toward the cathode and into the product stream and to direct hydroxyl ions toward the anode and into the reaction stream in the resin wafer of an adjacent ion-exchange unit.

Abstract: A method and system are described to treat ammonia-containing wastewater or process waters. Sewage containing human or animal waste and certain process liquids, typically water, contains high levels of nitrogen in the form of ammonia. An electro-chemical method to extract the ammonia from the wastewater is also described. The system described is one implementation of this method. One or more electrolysis cells convert ammonium to ammonia where the generated ammonia gas can readily be extracted for disposal or reuse. Such a system can involve electrolysis cells of numerous types as described herein.

Abstract: A treatment system and method for continuous deionization of a biologically derived feed stream includes a plurality of electrodialysis units (3, 9, 10, 11, 12, 13) arranged in stages along a treatment line, and stages are controlled such that the feed stream attains a certain quality before entering the next stage. The feed and concentrate streams move in generally opposite sense along the line, matching fluid characteristics of dilute and concentrate cells. The treatment line has two or more stages. Systems may have phased staging operations, and cell constructions may adapt the electrodialysis units for enhanced processing of difficult process fluids. A controller sets operating potentials in different electrical stages, and simple control parameters optimize ion removal and current efficiency without polarization of the fluid. The invention also includes phased staging of reversal operation, and cell constructions or fillings that adapt the treatment cells for enhanced processing.

Abstract: An apparatus for regulating salt concentration, a lab-on-a-chip including the same and a method of regulating salt concentration using the apparatus are provided. The apparatus includes: a reaction chamber that is defined by a cation exchange membrane and an anion exchange membrane and is selected from the group consisting of a biomolecule extraction chamber, an amplification chamber, a hybridization chamber, and a detection chamber; a first electrode chamber that is defined by the anion exchange membrane and a first electrode and includes an ion exchange medium; and a second electrode chamber that is defined by the cation exchange membrane and a second electrode and includes an ion exchange medium. Even without injecting solutions with different salt concentrations into the reaction chamber by operating pumps and valves for each operation stage, the salt concentration can be reversibly regulated in situ by adjusting the polarity, intensity and application time of a voltage.

Abstract: In one embodiment, a system comprises a filter and at least one electrodeionization (EDI) unit for chemical recovery. The filter is adapted to receive a fluid and to remove a selected chemical element or contaminant from the fluid. The EDI unit is coupled to the filter and adapted to recover a chemical element from the fluid and to separate the recovered chemical element from the fluid.

Abstract: The invention includes novel anion exchange membranes formed by in situ polymerization of at least one monomer, polymer or copolymer on a woven support membrane and their methods of formation. The woven support membrane is preferably a woven PVC membrane. The invention also includes novel cation exchange membranes with or without woven support membranes and their methods of formation. The invention encompasses a process for using the membranes in electrodialysis of ionic solutions and in particular industrial effluents or brackish water or seawater. The electrodialysis process need not include a step to remove excess ions prior to electrodialysis and produces less waste by-product and/or by-products which can be recycled.

Abstract: A method of and apparatus for continuously making an organic ester from a lower alcohol and an organic acid is disclosed. An organic acid or salt is introduced or produced in an electrode ionization (EDI) stack with a plurality of reaction chambers each formed from a porous solid ion exchange resin wafer interleaved between anion exchange membranes or an anion exchange membrane and a cation exchange membrane or an anion exchange membrane and a bipolar exchange membranes. At least some reaction chambers are esterification chambers and/or bioreactor chambers and/or chambers containing an organic acid or salt. A lower alcohol in the esterification chamber reacts with an anion to form an organic ester and water with at least some of the water splitting with the ions leaving the chamber to drive the reaction.

Abstract: Herein are disclosed a method for producing a basic amino acid solution which comprises subjecting a solution of a basic amino acid salt to electrodialysis with the use of an electrodialyser equipped with cation exchange membranes and anion exchange membranes in combination, wherein an alkali aqueous solution is added to the solution of a basic amino acid salt during the electrodialysis, whereby not only desalting is caused but also the counter anions of the basic amino acid are removed to such degree that the said counter anions remain in an amount of 40 mol % or smaller based on the basic amino acid, as well as a method for producing a basic amino acid solution which comprises subjecting a solution of a basic amino acid salt to electrodialysis with the use of an electrodialyser equipped with anion exchange membrane alone, wherein an alkali aqueous solution is added to the solution of a basic amino acid salt to adjust the pH of the solution to 7 to 10 during the electrodialysis, whereby the counter anions ar

Abstract: An electrodeionization method for continuously producing and or separating and/or concentrating ionizable organics present in dilute concentrations in an ionic solution while controlling the pH to within one to one-half pH unit method for continuously producing and or separating and/or concentrating ionizable organics present in dilute concentrations in an ionic solution while controlling the pH to within one to one-half pH unit.

Abstract: The present invention relates to a process for improving the purity of a composition comprising a quaternary ammonium hydroxide comprising the steps of (a) providing an electrolysis cell which comprises an anolyte compartment containing an anode, a catholyte compartment containing a cathode, and at least one intermediate compartment, said at least one intermediate compartment being separated from the anolyte and catholyte compartments by cation selective membranes, (b) charging water, optionally containing a supporting electrolyte, to the anolyte compartment, charging water, optionally containing a quaternary ammonium hydroxide, to the catholyte compartment, and charging the composition comprising the quaternary ammonium hydroxide to be purified to the intermediate compartment, (c) passing a current through the electrolysis cell to produce a purified aqueous quaternary ammonium hydroxide solution in the catholyte compartment, and (d) recovering the purified aqueous quaternary ammonium hydroxide solution from

Abstract: An electrodialysis cell is operated in the presence of organic compounds that binds or chelates with the multivalent metals to form a metal chelating buffer. Among other things, this binding or chelating reduces power consumption, produces a stable cell operation, and avoids a fouling of the membranes while significantly improving membrane life, reliability, and operating costs. When a chelating agent is added to a salt solution containing multivalent cations, the chelating agent strongly binds with the cations, forming large size complexes. An ion exchange membrane retains these complexes within the compartment of the electrodialysis cell containing the feed solution. The multivalent cations is greatly inhibited from being transported across the cation exchange membrane, thus reducing the fouling of the cation membranes. Concurrently, the precipitation of the metals transported to the base loop is substantially abated.

Abstract: A process is described for purifying an amino acid-containing solution by means of electrodialysis, wherein an amino acid-containing solution is employed which is obtained from the fermentation for producing at least one amino acid.

Abstract: A process for preparing salts of methallylsulfonic acid in which the reaction mixture produced from the sulfonation is diluted with water and neutralized with a base.

Abstract: A process for purifying and concentrating a gluconic acid derivative, such as 2-keto-L-gulonic acid, comprising introducing a non-viable and/or acidified fermentation medium or an in-vitro reactor medium comprising at least the gluconic acid derivative and/or salt thereof to electrodialysis thereby purifying and concentrating the gluconic acid derivative.

Abstract: An electrodialysis treatment system utilizing a plurality of disparate layers of an electrodialysis cell stack for separation of components in liquid mixtures. The system for electrodialysis treatment for purification and deionizing liquids includes providing an operation of pretreatment by filtration for removal of inorganic and organic contaminants and generating a filtrate effluent. An adsorbing operation for adsorbing organic contaminants from the filtrate effluent of the pretreatment operation is provided by utilizing activated carbon adsorption and generating a liquid fraction. A deionizing operation for continuously purifying the liquid fraction is provided by utilizing an electrodialysis stack having a plurality of ion exchange membranes and separating gaskets for selectively removing contaminant ions from the liquid fraction of the adsorbing operation.

Abstract: An amino acid-N,N-diacetic acid (AADA) or its salt with an equivalent or less of an alkali metal is produced by reducing, through electrodialysis, alkali metal ions from an aqueous solution of the alkali metal salt of an AADA. By this configuration, an AADA salt can be produced in a much higher yield than conventional equivalents without requiring a regeneration operation of a resin as in the use of an ion exchange resin or without requiring crystallization-separation of crystals of the AADA salt as in the addition of an organic solvent. A salt of an amino acid-N,N-diacetic acid is also produced by reacting an AADA with any of metal oxides, metal hydroxides, metal carbonates, metal hydrogencarbonates, ammonium hydroxide, ammonium carbonate, ammonium hydrogencarbonate or organic amine compounds. By this configuration, a metal salt, aromonium salt or organic amine salt of an AADA can be produced with efficiency without the formation of by-products.

Abstract: A process is disclosed for removing heat stable amine salts using an electrodialysis process. The process of the present invention can be used to reduce the level of heat stable salts in a lean solvent stream in an acid gas removal process. A base is added to the electrodialysis unit in order to permit the recovery of the heat stable amine salts as salts corresponding to the base added. The purified amine solution can be used again to remove acid gases from a gas stream.

Abstract: Processes are provided for the electrodialysis of a (di)alkali metal salt of an aromatic hydroxycarboxylic acid to produce a free aromatic hydroxycarboxylic acid and the alkali metal hydroxide, in the presence of a selected alkali metal salt. These various embodiments represent efficient and economical methods for recovering the alkali metal hydroxide, as well as the parent organic compound, from these dialkali metal salts. These processes also desirably prevent overvoltage during the electrodialysis.

Abstract: A first process involves the partial electrodialysis of a dialkali metal salt of an aromatic hydroxycarboxylic acid or a dicarboxylic acid to produce the approximate monoalkali metal salt and the alkali metal hydroxide. The monoalkali metal salt is then treated with an acid such as a bisulfate to recover the aromatic hydroxycarboxylic acid or dicarboxylic acid. The resulting inorganic salt such as sodium sulfate may then be electrolyzed to sodium bisulfate and NaOH. A second process involves the electrodialysis at elevated temperatures of a (di)alkali metal salt of p-hydroxybenzoic acid produce free p-hydroxybenzoic acid and the alkali metal hydroxide. These are efficient and economical methods for recovering the acid and alkali metal hydroxide values, as well as the parent organic compound, from these dialkali metal salts.

Abstract: An amino acid-N,N-diacetic acid (AADA) or its salt with an equivalent or less of an alkali metal is produced by reducing, through electrodialysis, alkali metal ions from an aqueous solution of the alkali metal salt of an AADA. By this configuration, an AADA salt can be produced in a much higher yield than conventional equivalents without requiring a regeneration operation of a resin as in the use of an ion exchange resin or without requiring crystallization-separation of crystals of the AADA salt as in the addition of an organic solvent.

Abstract: A method for fermentation of lactic acid from a sugar-containing fermentation liquid in a fermentor by means of lactic acid-forming bacteria, in which whey protein is present or is added as a nutrient substrate for the lactic acid-forming bacteria, wherein at least one protease is added to the fermentor during the fermentation, so that hydrolysis of protein to amino acids takes place simultaneously with the fermentation of sugar into organic acid, and wherein lactic acid resulting from the fermentation is isolated from the fermentation liquid. Ammonia is preferably added to result in the formation of ammonium lactate, and lactic acid is preferably isolated by a process comprising ultra filtration, ion exchange, conventional electrodialysis and electrodialysis with bipolar membranes.

Abstract: The invention concerns a method for extracting by electrodialysis a compound comprising at least amine functions capable of protonation from a liquid medium. More particularly it concerns a method for extracting, and separating at least the monomers comprising amine functions capable of protonation from a liquid medium derived from the hydrolysis of polyamides. The method of extraction from a liquid medium consists in subjecting to protonation the amine function(s) of the compounds to be extracted by adjusting the pH of the medium and in separating the compounds by passing them through a cationic membrane under the effect of an electric current. The invention is particularly applicable in processes for the chemical stabilisation of polyamides such as the PA 66 PA 6.

Abstract: An apparatus and the process produces salts by an electrodialysis operation. The basic electrodialysis apparatus is a cell having a number of compartments separated by membranes. A DC source is connected to drive a current through a feed stream passing through the cell which splits the salt stream into an acid and a base. The incoming feed may be nanofiltered to remove divalent metal. The base loop may be in communication with an ion exchange column packed with a material that removes multivalent cations. Depending upon the material being processed and the desired end result either or both the nanofiltration and the ion exchanged column may be used in the apparatus.

Abstract: Bases and organic acids are simultaneously separated from aqueous solutions comprising bases and organic acids by electrochemically treating aqueous solutions containing these components, particularly the aqueous waste solution obtained from an aldolization reaction.

Abstract: The present invention relates to a process for separating organic acids from aqueous solutions by the use of electrochemical processes such as electrolysis and electrodialysis. These processes can be used, for example, to purify aqueous solutions produced in aldol condensation processes.

Abstract: An apparatus and process produces salts by an electrodialysis operation. The basic electrodialysis apparatus is a cell having a number of compartments separated by membranes. A DC source is connected to drive a current through a feed stream passing through the cell which splits the salt stream into an acid and a base. The incoming feed may be nanofiltered to remove divalent metal. The base loop may be in communication with an ion exchange column packed with a material that removes multivalent cations. Depending upon the material being processed and the desired end result either or both the nanofiltration and the ion exchanged column may be used in the apparatus.

Abstract: An apparatus and process produces salts by an electrodialysis operation. The basic electrodialysis apparatus is a cell having a number of compartments separated by ion exchange membranes. A DC source is connected to drive a current through a feed stream passing through the cell which splits the salt stream into an acid and a base. The incoming feed may be nanofiltered to remove divalent metal. The base loop may be in communication with an ion exchange column packed with a material that removes multivalent cations. Monovalent selctive cation membranes may be used to effect preferential treatment of the monovalent cations to the base loop. Depending upon the material being processed and the desired end result either or both the nanofiltration and the ion exchanged column may be used in the apparatus.

Abstract: The present invention relates to a process for isolating, by membrane electrodialysis, a catalyst from a solution containing it. More precisely, it relates to the isolation of a catalyst used in a homogeneous phase molecular oxidation reaction. The invention consists of a process for isolating a homogeneous catalyst dissolved in a mixture also containing at least one aliphatic diacid, characterized in that the catalyst contains cobalt and the isolation is performed by membrane electrodialysis.

Abstract: A process for purifying and concentrating a gluconic acid derivative, such as 2-keto-L-gulonic acid, comprising introducing a non-viable and/or acidified fermentation medium or an in-vitro reactor medium comprising at least the gluconic acid derivative and/or salt thereof to electrodialysis thereby purifying and concentrating the gluconic acid derivative.

Abstract: In a method for recovering polymers in a substantially pure form from a solution containing the polymers, the solution is first treated with a reactant (e.g. an acid, a sequestrant or a mixture of both) to form the free polymers and salts of the reactant. Second, the solution is treated to remove the salts therefrom and in a final stage the polymer solution is concentrated and the polymers recovered. The second treatment step may consist of membrane-filtration, ion-exchange or electrodialysis.

Abstract: The process comprises: (A) obtainment of N-acetyl-cysteine from L-cystine, by means of the following steps:(i) acetylation of L-cystine to produce N-acetyl-cystine;(ii) electroreduction and desalination by electrodialysis of the N-acetyl-cystine thus produced to give N-acetyl-cysteine; or (B) obtainment of N-acetyl-cysteine from L-cystine, by means of the following steps:(i) acetylation and desalination of L-cystine to produce N-acetyl-cystine;(ii) electroreduction of N-acetyl-cystine which may or may not come from the preceding step (i) to produce N-acetyl-cysteine; (C) obtainment of N-acetyl-cysteine from L-cystine by means of the following steps:(i) electroreduction of L-cystine to produce L-cysteine;(ii) acetylation and desalination by electrodialysis of L-cysteine, which may or may not come from the preceding step (i) to produce N-acetyl-cysteine.The N-acetyl-cysteine thus obtained has important uses in the pharmaceutical sector.

Abstract: The invention uses a stack of three compartment electrodialysis cells in a process for the production amino acid hydrochloride and an alkali. The electrodialysis cell contains bipolar, cation and anion membranes which are arranged to form acid, base and salt compartments. The process begins with supplying a salt solution to the salt compartment, water to the base compartment, and a liquid comprising an amino acid to the acid compartment. Preferably, the feed salt is sodium chloride or potassium chloride or lithium chloride. A direct current driving force is applied across the cell to convert the salt solution to an alkali in the base compartments and an amino acid hydrochloride in the acid compartment. The acid and alkali solutions and a depleted salt solution are withdrawn from their respective compartments. A chelating agent may be added to the salt solution before it is fed into the electrodialysis cell.

Abstract: In order to remove the salts (in particular NH.sub.4 Cl) present in an aqueous sulphonamide solution (in particular CH.sub.3 SO.sub.2 NH.sub.2), the solution is subjected to a two-compartment electrodialysis. By maintaining the pH at a value below 7, the formation of ammonia is avoided. The demineralized solution can be concentrated in order to receover after crystallization, the sulphonamide.

Abstract: The invention is a process for desalting aqueous solutions, which are initially acidified to a pH of about 3 or less. Then, the acidified solution is fed into a desalting compartment of an electrodeionization cell which contains a suitable ion exchange material and is isolated from an adjacent concentrating compartments by an anion and a cation exchange membrane. The concentrate compartment contains a netting or another suitable material that promotes turbulence in a flowing feed stream. Water is supplied to the concentrate compartment. A DC current passes through the electrodeionization cell to produce a substantial desalination of the feed solution. A less acidic desalted solution and a concentrate waste solution are withdrawn from the electrodeionization cell.

Abstract: In one embodiment, the present invention relates to a process for recovering an onium hydroxide from a solution containing an onium compound, including contacting the solution with a cation exchange material so that at least a portion of onium cations from the onium compound are adsorbed by the cation exchange material; contacting an acid with the cation exchange material to elute an onium salt; charging the onium salt to an electrochemical cell containing at least three compartments, a cathode, an anode, and in order from the anode to the cathode, a bipolar membrane and a cation selective membrane, and passing a current through the cell whereby the onium hydroxide is regenerated; and recovering the onium hydroxide from the cell.

Abstract: A process for recovering guanidine salts from diluted and contaminated aqueous solutions is described, wherein the corresponding aqueous solution (diluate) is subjected to electrodialysis and the guanidine salt is concentrated on the concentrate side. The corresponding guanidine salt can thus largely be separated from all contaminants while a relatively highly concentrated product is simultaneously obtained.

Abstract: A first process involves the partial electrodialysis of a dialkali metal salt of an aromatic hydroxycarboxylic acid or a dicarboxylic acid to produce the approximate monoalkali metal salt and the alkali metal hydroxide. The monoalkali metal salt is then treated with an acid such as a bisulfate to recover the aromatic hydroxycarboxylic acid or dicarboxylic acid. The resulting inorganic salt such as sodium sulfate may then be electrolyzed to sodium bisulfate and NaOH. A second process involves the electrodialysis at elevated temperatures of a (di)alkali metal salt of p-hydroxybenzoic acid produce free p-hydroxybenzoic acid and the alkali metal hydroxide. These are efficient and economical methods for recovering the acid and alkali metal hydroxide values, as well as the parent organic compound, from these dialkali metal salts.

Abstract: In one embodiment, the present invention relates to a process for recovering organic hydroxide from contaminated solutions containing the organic hydroxide and impurities including charging the contaminated solution to a first electrochemical cell containing at least two compartments, a cathode, an anode and a size selective divider and passing a current through the first electrochemical cell whereby impurities migrate through the size selective divider; recovering a second solution containing organic ions from the first electrochemical cell and charging the second solution to a second electrochemical cell containing at least two compartments, a cathode, an anode and a divider and passing a current through the second electrochemical cell whereby the organic hydroxide is purified; and recovering the organic hydroxide from the second electrochemical cell.

Abstract: In one embodiment, the present invention provides a method of preparing hydroxylamine from a hydroxylammonium salt solution, including providing an electrochemical cell containing an anode, a cathode, a cation selective membrane and an anion selective membrane, wherein the cation selective membrane is positioned between the cathode and the anion selective membrane, and the anion selective membrane is positioned between the cation selective membrane and the anode, thereby defining a feed compartment between the cation selective membrane and the anion selective membrane, a recovery compartment between the cathode and the cation selective membrane, and an acid compartment between the anion selective membrane and the anode; charging a first solution to the acid compartment and a second solution the recovery compartment; charging the hydroxylammonium salt solution to the feed compartment; passing a current through the cell to produce hydroxylamine in the recovery compartment; and recovering hydroxylamine from the

Abstract: A process for reducing the content of organic and inorganic halogen in an aqueous solution of a nitrogen-containing epihalohydrin-based resin, in which process the aqueous resin solution is subjected to an electrodialysis treatment. The aqueous resin solutions obtained by the process are used as additives in the production of paper, board and paper board, in particular as wet-strength agents.

Abstract: In one embodiment, the present invention relates to a process for recovering an organic hydroxide from waste solutions containing the organic hydroxide and impurities including the steps of precipitating the organic hydroxide from the waste solution as an insoluble salt; removing the salt from the waste solution and placing the salt in a liquid to form a second solution; charging the second solution to an electrochemical cell containing at least two compartments, a cathode, an anode and a divider and passing a current through the cell whereby the organic hydroxide is regenerated; and recovering the organic hydroxide from the cell.

Abstract: A process of demineralizing a liquid containing organic matter and inorganic salts in solution, in which the treatment of the liquid comprises the following steps:the liquid is percolated over a strong cationic ion exchange resin for monovalent ions;both a batch of liquid from the preceding step and a brine for receiving ions from that liquid are caused to circulate in loops through at least one "two-compartment" electrodialyzer comprising a plurality of anionic membranes interposed between a plurality of cationic membranes; andthe brine whose salt concentration lies in the range 90 grams per liter (g/l) to 110 g/l is used to regenerate the ion exchange resin.

Abstract: A method for treating waste nitrocellulose, the method comprising the steps f treating nitrocellulose with acid in a hydrolysis process to break the nitrocellulose down to glucose, recovering a majority of the acid by electrodialysis, neutralizing a remainder of the acid, and fermenting the glucose to convert the glucose to a useful product. The invention further comprises a system for performing the above method.

Abstract: Improved electrodialysis (ED) stacks are disclosed having one or more components selected from the group:a) cation exchange membranes having ion exchange groups predominantly sulfonic acid groups and a minor amount of weakly acidic and/or weakly basic groups or membranes which are selective to monovalent cations and simultaneously therewith, cation exchange granules selective to monovalent cations as packing in the dilute compartments;b) anion exchange membranes having as ion exchange groups only quaternary ammonium and/or quaternary phosphonium groups and substantially no primary, secondary and/or tertiary amine and/or phosphine groups or membranes which are selective to monovalent anions simultaneously therewith, anion exchange granules selective to monovalent anions as packing in the dilute compartments;c) as packing in the dilute compartment, anion exchange granules which are selective to monovalent anions, or cation exchange granules which are selective to monovalent cations, or cation exchange granules

Abstract: A process recovers organic acid and ammonia from their salts preferably obtained from microbial fermentation of a saccharide in a nutrient. The fermented materials is passed through a nanofiltration or a chelating resin ion-exchange bed or a combination of both a nanofilter and a chelating resin ion-exchange bed in order to reduce divalent or multivalent metal contaminants. Then, the filtered material is processed in a multi compartment electrodialysis containing bipolar and anion membranes.