Abstract: A high-flux composite nanofiltration (NF) membrane with an electrical double layer (EDL) and a preparation method thereof are provided. The high-flux composite NF membrane includes: a charged support membrane and a charged separation layer, where a charge carried by the support membrane or the separation layer is a positive charge, a negative charge, or an amphiprotic charge. The high-flux composite NF membrane with an EDL solves the technical problem that the composite NF membrane in the prior art has an unsatisfactory retention rate and a limited application range due to a small charge quantity.

Abstract: A low-pressure high-flux hollow fiber nanofiltration (NF) membrane, and a preparation method and use thereof are provided. The low-pressure high-flux hollow fiber NF membrane includes a base membrane and a negatively-charged separation layer formed on a surface of the base membrane, where a material of the separation layer is a crosslinking product of a negatively-charged sulfonated polymer. The low-pressure high-flux hollow fiber NF membrane of the present disclosure solves the technical problem that the hollow fiber NF membranes in the prior art are difficult to have both high performance and low energy consumption.

Abstract: An air-impermeable water vapor transport membrane comprises an active layer on a microporous polymeric substrate. The active layer comprises a polyethylene-oxide containing copolymer and a polar protic solvent in an amount of about 3% to about 100% of copolymer weight in the active layer. Molecules of the protic solvent are bonded to the copolymer. The polar protic solvent reduces temperature-dependent variability in the water-vapor permeability of the membrane.

Abstract: A method of producing a porous membrane, the method comprising: casting a polymer solution, in which a polymer is dissolved in a mixture of a good solvent, a poor solvent and a non-solvent, over a support, so as to form a casted polymer solution; drying the casted polymer solution, so as to form a cast film; and subjecting the cast film to a phase separation, wherein the porous membrane is produced under a condition where a temperature of a casted surface is lower than a temperature of the polymer solution, and each of a temperature change of the polymer solution and a temperature change of the casted surface is kept within ±3.0° C.

Abstract: A hollow fiber type reverse osmosis membrane including cellulose acetate, characterized in that the filtration rate and the salt rejection rate when an aqueous solution having sodium chloride concentration of 1,500 mg/L is filtered from outer side to inner side of the hollow fiber type reverse osmosis membrane at 25° C. and 1.5 MPa pressure are 180 to 350 L/m2/day and 90.0 to 99.0%, respectively and the outer diameter, the inner diameter and the hollow rate of the hollow fiber type reverse osmosis membrane are 100 to 280 ?m, 50 to 200 ?m and 24 to 42%, respectively. The hollow fiber type reverse osmosis membrane preferably has a dense layer near the outer surface, and thickness of the dense layer is 0.1 to 7 ?m.

Abstract: A method for yielding concentrated ethanol from an ethanol water solution yielded from ethanol fermentation of a water solution of saccharide generated by a saccharification of the lignocellulose by enzyme is provided. Water is separated from the ethanol water solution yielded from ethanol fermentation of the water solution of saccharide generated by the saccharification of the lignocellulose by enzyme with pervaporation method using a water separation membrane. Condensate prepared by condensing ethanol vapor existing in a space above a liquid level of the ethanol water solution is collected.

Abstract: The present invention is an ultrafiltration (UF) membrane having a nominal molecular weight cut off (NMWCO) of from about 0.5 KD to about 10 KD wherein the membrane surfaces have a charge that is either positive or negative. The present invention is also a method of using the charged UF membrane to purify and concentrate synthetic biological molecules by using the charged surface either to repel the synthetic biomolecules retaining them in the retentate or to attract the synthetic biomolecules preferentially for filtration through the membrane.

Abstract: A heavy residual petroleum feed boiling above 650° F.+ (345° C.+) is subjected to membrane separation to produce a produce a permeate which is low in metals and Microcarbon Residue (MCR) as well as a retentate, containing most of the MCR and metals, the retentate is then subjected to hydroconversion at elevated temperature in the presence of hydrogen at a hydrogen pressure not higher than 500 psig (3500 kPag) using a dispersed metal-on-carbon catalyst to produce a hydroconverted effluent which is fractionated to give naphtha, distillate and gas oil fractions. The permeate from the membrane separation may be used as FCC feed either as such or with moderate hydrotreatment to remove residual heteroatoms. The process has the advantage that the hydroconversion may be carried out in low pressure equipment with a low hydrogen consumption as saturation of aromatics is reduced.

Abstract: A heavy residual petroleum feed boiling above 650° F.+ (345° C.+) is subjected to hydroconversion at elevated temperature in the presence of hydrogen at a hydrogen pressure not normally higher than 500 psig (3500 kPag) using a dispersed metal-on-carbon catalyst to produce a hydroconverted effluent which is fractionated to form a low boiling fraction and a relatively higher boiling fraction which is subjected to membrane separation to produce a permeate which is low in metals and Microcarbon Residue (MCR) as well as a retentate, containing most of the MCR and metals. The process has the advantage that the hydroconversion may be carried out in low pressure equipment with a low hydrogen consumption as saturation of aromatics is reduced.

Abstract: The present invention includes systems and methods for treatment of seawater RO system for recovering most of the water (i.e., 85-90%) from the concentrate of a brackish groundwater reverse osmosis treatment system that may use, e.g., a batch method. With proper pH control and antiscalant dosage, the batch-treatment SWRO system of the present invention can be used to recovery water from silica-saturated RO concentrate without fouling the membranes. Silica concentrations of over 1000 mg/L are attainable with relatively minimal pre-treatment of the silica-saturated feed solution.

Abstract: Disclosed are novel water membranes comprising lipid bilayers incorporating functional aqua-porins. The lipid bilayers are arranged in sandwich structures including hydrophilic or hydro-phobic support materials. Also disclosed are water purification devices/systems, including reverse osmosis filtering devices that include membranes having functional aquaporins. Methods of water purification and methods of preparing the membranes are also disclosed. Further, the invention provides for a new type of perforated, hydrophobic polymer film and to membranes containing lipid bilayers having other transmembrane proteins than aquaporins introduced.

Abstract: The invention relates to a process for making porous cross-linked charged cellulosic polymeric membranes capable of binding to a target molecule. The invention provides methods for separating target molecules from other components in a solution comprising use of membranes obtainable by the process of the invention. The method has particular utility in separating proteins and nucleic acids from cell lysates and cultures.

Abstract: The present invention discloses mixed matrix membranes (MMMs) comprising ion-exchanged molecular sieves such as UZM-5 zeolite ion-exchanged with Li+ cation (Li-UZM-5) and a continuous polymer matrix and methods for making and using these membranes. These MMMs, comprising ion-exchanged molecular sieves, in the form of symmetric dense films, asymmetric flat sheets, asymmetric hollow fibers, or thin-film composites, have exhibited simultaneously increased selectivity and permeability (or permeance) over polymer-only membranes and the mixed matrix membranes made from molecular sieves that have not been ion exchanged for gas separations. These MMMs are suitable for a variety of liquid, gas, and vapor separations such as desalination of water by reverse osmosis, deep desulfurization of gasoline and diesel fuels, ethanol/water separations, pervaporation dehydration of aqueous/organic mixtures, CO2/CH4, CO2/N2, H2/CH4, O2/N2, olefin/paraffin, iso/normal paraffins separations, and other light gas mixture separations.

Abstract: The present invention comprises an improved method for refining cellulose that produces a highly refined cellulosic material. The method comprises soaking raw material in a mild NaOH using reduced temperatures and pressures, and refining the material with a plate refiner so that a waste water stream is reduced in volume and has a pH within a range of 8 to 9. The present invention also comprises a HRC gel having a lignin concentration of at least about one (1)% by weight, and a water retention capacity of about 25 to at least about 56 g H2O/g dry HRC.

Abstract: An onboard fuel separation apparatus separates a material fuel (gasoline) into a high-octane fuel having a higher octane value than the material fuel and a low-octane fuel having a lower octane value than the material fuel using a separation membrane which selectively allows high-octane value components (such as aromatic components) permeate through the membrane. The apparatus increases the ratio of the amount of the high-octane value components permeating through the membrane to the amount of the high-octane value components contained in the material fuel by, (A) Controlling the temperature of the material fuel supplied to the membrane (B) Increasing partial pressure of the low-octane value components on the high-octane fuel side of the membrane and removing volatiles from the permeate, and (C) Bypassing volatiles in the material feed around the membrane.

Abstract: The present invention relates to a cellulose compound hollow fiber membrane having high mechanical strength and is hardly degraded by microorganisms, wherein a cellulose compound is comprised as a membrane material, the thickness of the membrane is 50 to 500 &mgr;m, a dense membrane surface having an average pore diameter of 0.001 to 0.05 &mgr;m exists on the internal and/or external surface thereof, the inside of the membrane is composed of a three-dimensional network-like porous structure having voids with an average pore diameter of 0.05 to 2 &mgr;m, and 70% by weight or more of the membrane material is cellulose acetate propionate or cellulose acetate butyrate.

Abstract: A process for utilizing the material of ammonium-containing effluent which contains further soluble constituents and, possible additional solids, comprising: a) optionally separating off the solids, b) concentrating the substantially solids-free ammonium-containing effluent to give an aqueous concentrate having an increased content of ammonium and additional soluble constituents, with simultaneous recovery of substantially ammonium-free pure water, c) precipitating ammonium as magnesium ammonium phosphate from the ammonium-containing aqueous concentrate, and d) separating off precipitated magnesium ammonium phosphate with recovery of substantially ammonium-free residual concentrate which at least partially contains the additional soluble constituents.

Abstract: Novel solid phase reaction supports are disclosed. The solid phase reaction supports include (a) a solid phase carrier having a multiplicity of NH2 functional groups; (b) a coupling compound covalently bonded to an NH2 group of the solid phase carrier; and (c) a receptor compound coupled to the solid phase carrier through the coupling compound. The coupling compound is preferably ascorbic acid, dehydroascorbic acid or a diketo compound structurally similar to ascorbic acid or dehydroascorbic acid. The solid phase carrier is preferably made of cellulose.

Abstract: Novel solid phase reaction supports are disclosed. The solid phase reaction supports include (a) a solid phase carrier having a multiplicity of NH2 functional groups of the Formula (I): in which R1 and R2 are each H, or R1 is H and R2 is an alkyl or acyl substituent with a degree of substitution ≦1 or R1 is an alkyl or acyl substituent with a degree of substitution ≦1, and R2 is H, or R1 and R2 are each a substituent with a degree of substitution ≦2 and R3 is an aromatic substituent containing at least one free amino group having a substitution degree ≦1; (b) a coupling compound covalently bonded to an NH2 group of the solid phase carrier; and (c) a receptor compound coupled to the solid phase carrier through the coupling compound.

Abstract: Methods and apparatuses for salvaging blood from a patient are disclosed. A blood salvaging and/or blood processing circuit coupled to a cardiopulmonary bypass circuit, cardiotomy circuit, or directly to the patient comprises a hemocentrator for removing water, fluids, and low molecular weight solutes by ultrafiltration and a sorbent-containing plasma separator for removing a selected solute, such as heparin. A combination device for salvaging blood comprises a closed plasma chamber containing a plasma chamber solution, a hollow fiber plasma-separating membrane for receiving blood and permitting plasma to be transported therethrough into the plasma chamber solution and for refiltering the treated plasma back into the blood circuit, a selective sorbent for contacting the selected solute in the plasma and binding the selected solute, and an ultrafiltration membrane for removing water, fluids, and low molecular weight components from the plasma.

Abstract: Cellulose films useful as wound and bum dressings are prepared from a solution of cellulose produced by Acetobacter xylinum in a stirred tank. The materials of this invention comprise a film of microbially produced cellulose, particularly cellulose produced from the culture of Acetobacter xylinum in a stirred tank. The film is made by dissolving the cellulose in a solvent system comprising dimethylacetamide and lithium chloride, casting the resulting solution onto a flat surface and regenerating the film in a gelation bath. Humectant is incorporated into the film by solvent exchange. The film is then sterilized and packaged for long term storage. These films are strong and elastic having mechanical properties superior to plant derived cellulose membranes and similar to that of the human skin and are useful as wound dressings.

Abstract: A method for recovering carboxylic acids from a dilute aqueous solution thereof having a concentration below about ten percent (10%) by weight, which includes passing the dilute acid solution through a reverse osmosis separator, thereby producing a permeate substantially free of acid and a retentate having an acid concentration above about ten percent (10%) by weight. The retentate is contacted with a liquid extractant for acids to produce an acid-rich extractate and an acid-free raffinate. The acid is then recovered from the acid-rich extractate.

Abstract: A method for continuously preparing a sterile culture medium comprises combining separate unsterilized fluid components in separate streams into a single mainstream. The mainstream is applied to a transverse flow filtration module having a membrane which separates the mainstream into a permeate and a retentate. The permeate is fed to a bioreactor and the retentate is diverted to a centrifuge to precipitate contaminants. The clarified retentate is returned into the mainstream upstream of the transverse flow filtration module.

Abstract: A method for recovering carboxylic acids from a dilute aqueous solution thereof having a concentration below about ten percent (10%) by weight, which includes passing the dilute acid solution through a reverse osmosis separator, thereby producing a permeate substantially free of acid and a retentate having an acid concentration above about ten percent (10%) by weight. The retentate is contacted with a liquid extractant for acids to produce an acid-rich extractate and an acid-free raffinate. The acid is then recovered from the acid-rich extractate.

Abstract: A method for producing an aqueous solution of an aminocarboxylic acid from an aqueous solution of an alkali metal salt of the aminocarboxylic acid is disclosed. The first step of the method is to adjust the pH of the aqueous solution of the alkali metal salt of the aminocarboxylic acid to between about 1.0 and about 3.0. This is done by adding a monovalent inorganic acid to the aqueous solution of the alkali metal salt of the aminocarboxylic acid to form an aqueous feed solution containing protonated aminocarboxylic acid and an inorganic alkali salt having an inorganic anion and an alkali metal cation. The second step of the method is to pass the aqueous feed solution through at least one membrane using a diafiltration process to separate the aqueous feed solution into an aqueous permeate solution, containing the alkali metal cation, and an aqueous retentate solution containing the aminocarboxylic acid.

Abstract: A method and apparatus for recycling water based workpart cleaning fluid of the type used to wash workparts (B) free of soils, such as emulsified and non-emulsified cutting oils and lubricants, particulate matter and other hydrophobic fluids. A parts washer (12) is provided for cleaning workparts (B) contaminated with soils. The contaminated cleaning fluid is discharged from the parts washer (12) in a slip stream and directed to a process tank (22). The contaminated cleaning fluid is pumped from the process tank (22) to a prefilter (28) where large particles are screened. The cleaning fluid is then directed to regenerated cellulose membrane filters (34) where the water based cleaning fluid and the hydrophilic water soluble substances in the base, i.e., the detergents, are imbibed through the membrane (34) as permeate while the soils pass as retentate. The permeate is returned to the parts washer (12), whereas the retentate is directed back to the process tank (22).

Abstract: An insoluble material for adsorbing a pyrogen comprising a polymer of an aziridine compound. According to the present invention, a large mount of the pyrogen can be easily removed from a solution containing pyrogen, and a large amount of the material for adsporbing the pyrogen can be prepared in easy steps. Therefore, the adsorbing material can greatly contribute to the preparation of medicines.

Abstract: In an apparatus and method for purifying water, an oxidation forcibly turns colloidal substances into fine particles of oxides, thus increasing the size of the particles. The effluent of oxidation process is treated by ion exchange process, and then treated by membrane process. Because of the increased size of the particles, they are easily removed in the subsequent ion exchange process. The membrane process is thereby prevented from clogging up, and then removes fine particles that cannot be removed by the ion exchange process. Colloidal substances are thus removed effectively from raw water.

Abstract: This invention relates to cross-flow filtration and more particularly towards disposable, compact cross-flow filters and filtration methods incorporating a novel pressure-balancing arrangement comprising a flexible wall which expands and contracts in response to fluid pulsations. The invention further relates to methods of fluid concentration employing such a device to a fluid concentration system, and to methods of making such a filtration device.

Abstract: A single filtration device containing coated filter membranes and absolute pore filters is provided in which the membranes and absolute pore filters are present in two sections of the filter device. The filter device will remove up to about 98% of the endotoxins in addition to removing viruses with an efficiency of at least 4.6.times.10.sup.5 and DNA to less than 10 picograms per 500 mg sample.

Abstract: A medical material comprising a high-molecular weight material and a heparin derivative is provided, which high-molecular weight material comprises a high-molecular weight compound having functional groups capable of binding with epoxy groups, a compound having at least two amino groups and a polymer having a number of epoxy groups, said functional groups and some of said amino groups being bound to said epoxy groups, and which heparin derivative comprises heparin and an epoxy compound having at least two epoxy groups part of which is bound to amino groups in the heparin, the amino groups not bound to the epoxy groups in said high-molecular weight material being bound to the epoxy groups not bound to the amino groups in the heparin derivative. Also provided are an intermediate (high-molecular weight material) to be used for said medical material, as well as processes for producing said medical material and said intermediate.

Abstract: A single filtration device containing coated filter membranes and absolute pore filters is provided in which the membranes and absolute pore filters are present in two sections of the filter device. The filter device will remove viruses, as modeled by type-C Xenotropic retrovirus, with an efficiency of at least 4.6.times.10.sup.5 ; remove DNA from levels of 10 .mu.g/sample to levels below 10 picograms per 500 mg sample of monoclonal antibody; and will remove at least 97% of some bacterial endotoxins.

Abstract: Multi-ring aromatic hydrocarbons and/or toxins are selectively solvent extracted from hydocarbon feed streams by the process comprising contacting the aromatics and/or toxins containing hydrocarbon stream with one side of a porous, non-selective partition barrier membrane while simultaneously contacting the other side of said membrane with an aromatics selective extraction solvent whereby the multi-ring aromatic hydrocarbons and/or toxins selectively migrate through the porous partition barrier membrane in response to the selective solvent. A preferred extraction solvent is ethylenediamine. The permeate comprising multi-ring aromatics in solvent can be subjected to a membrane separation process to separate the extraction solvent from the aromatics.

Abstract: Composite membranes are provided comprising an underlying membrane selected from the group consisting of microfiltration, ultrafiltration and reverse osmosis membranes; and a coating thereon comprising at least one member selected from the group consisting of polyaromatic polymers and sulfonated poly(haloalkylenes), which has been subjected to a post-coating crosslinking treatment. These coated membranes are useful for various separation processes, especially in the food industry.

Abstract: A method for activating a membrane comprising cellulose as a main component, by reacting the membrane with a compound of the formula Cl-SO.sub.2 -R or Cl-CO-R.sub.1 where R is an optionally substituted alkyl or phenyl group and R.sub.1 is a releasing group, an activated membrane obtained by the method, a method of fixing a physiologically active substance on the activated membrane and a physiologically active substance-fixed membrane obtained by the method. A physiologically active substance can be fixed on the activated membrane by stable chemical bond between the substance and the membrane while maintaining the physiological activity of the substance.

Abstract: A method for designing and making composite membranes having a microporous support membrane coated with a permselective layer. The method involves calculating the minimum thickness of the permselective layer such that the selectivity of the composite membrane is close to the intrinsic selectivity of the permselective layer. The invention also provides high performance membranes with optimized properties.

Abstract: Composite membranes are disclosed having a separation layer comprised of a mixture of poly(methy methacrylate) or a copolymer thereof and at least one cellulosic derivative resulting in enhanced separation and permeating characteristics of the overall composite membrane. Processes for making these composite membranes and the methods of using them are also disclosed. The membranes are particularly useful in gas separation applications and are most suited for the separation of hydrogen from a hydrogen containing stream.

Abstract: A porous polymeric medium having a low affinity for amide group-containing materials is provided comprising a porous polymeric substrate and a surface-modifying polymeric material having a low affinity for amide group-containing materials formed in situ at and covalently bonded to the surface of the porous polymeric substrate, the surface-modifying polymeric material being formed from a monofunctional monomer having at least one hydroxyl group.

Abstract: Reverse osmosis membranes treated with polymers bearing carboxylic acid groups and optionally pendant hydroxyl or amide moieties display enhanced salt rejection and/or increased water flux. This treatment is particularly useful for improving the membrane characteristics of cellulose acetate and polyamide membranes.

Abstract: A method of improving the properties of a reverse osmosis membrane having a polyamide discriminating layer containing residual aromatic primary amine groups is described. In this method, the polyamide discriminating layer of the membrane is treated with an aqueous solution of a reagent which reacts with primary amine groups to form diazonium salt groups or derivatives of diazonium salt groups. This method results in a membrane possessing improved chlorine resistance. When nitrous acid is employed as the reagent in the treatment, the water flux of the polyamide membrane is frequently increased with little or no effect on the salt rejection of the membrane.

Abstract: A process and an apparatus for recovering a precious metal compound, in which the precious metal compound is separated from impurity metals by use of a reverse osmotic membrane, and the separated precious metal compound is recovered in a concentrated state through electrodialysis employing anion-exchange and cation-exchange membranes, whereby the precious metal compound in a process liquid can be recovered efficiently. When the recovered precious metal compound is added in the as-is form to precious metal plating solution, it is possible to control the plating solution.

Abstract: The ability of cellulose membranes to separate solutes from solvents under reverse osmosis conditions is significantly improved by subjecting the membrane prior to use to several cycles of drying and rewetting.

Abstract: Regenerated cellulose membranes used for the separation of organic liquids, for example, ketone dewaxing solvents from dewaxed oil or NMP extraction solvents from extract, have their solute rejection capability enhanced by chemical modification by contacting said membrane with a bifunctional reagent that is reactive with the hydroxy groups in the anhydroglucose units of the regenerated cellulose polymer. The reaction of the bifunctional reagent with the hydroxy groups in the polymer results in the crosslinking of the polymer which, in turn, results in the improvement of the membrane's selectivity in organic liquid separations applications.

Abstract: An improved reverse osmosis membrane and process for making the same is described. The membrane is prepared by treating a polymer bearing primary amine groups with nitrous acid or a diazonium compound so as to react the resulting diazonium groups with other groups present. The resulting membrane possesses improved chlorine resistance. When the nitrous acid treatment is employed, the water flux of a polyamide membrane is frequently increased with little or no effect on the salt rejection of the membrane.

Abstract: A portable assembly of components that is designed to produce sterile, intravenous solutions and water for injection in the field, under combat conditions and from various sources of raw feedwater. A single frame supports the components of the invention consisting of a pair of manually operated pump handles, a peristaltic pump to which is engaged an inlet feed tube. The device has the ability to suck water from available feedwater sources or from a reserve bottle designed to hold a variety of liquids that may be introduced therein from any available source. Feedwater is pumped into the base of a filter module containing a coarse filter combined with a reserve osmosis filter for an initial prefiltering of the water. Purified water then passes through a carbon exchange column and subsequently an ion exchange column. At this point, ultrapure water is then passed through a sterilizing filter from which it passes through an IV spike in the form of sterile, non-pyrogenic water for injection.

Abstract: There is disclosed a novel porous hollow fiber membrane which is characterized by such a unique porous structure that the inner and outer membrane surfaces have an in-a-plane average pore diameter of 0.01 to 10 .mu.m and the porous membrane wall has an in-a-plane porosity of not less than 10% measured in every plane perpendicular to a radial direction of the annular cross-section of the hollow fiber membrane, wherein the in-a-plane porosity exhibits at least one minimum value between the inner and outer membrane surfaces. The present porous hollow fiber membrane has been found to be especially useful for the removal of a virus from an aqueous protein solution containing a virus. A virus can be effectively removed from an aqueous protein solution with not only an extremely high virus removal percentage but also an extremely high protein permeability, without causing the protein to be denatured.

Abstract: A method and apparatus for purifying and/or separating fluids including passing such fluid from a feed side of a reverse osmosis unit to the product side of such unit and to an ultimate user during a purifying cycle and recirculating residual fluid back to the feed side in bypass relation to the reverse osmosis unit during a treating cycle to introduce suitable treating fluids into the system for disinfecting and rejuvenating the system.

Abstract: A process for separating and condensing at least one selected organic liquid from a feed comprising a mixture thereof in the state of one phase or two phases which comprises conducting ultrafiltration by using a polymeric porous membrane having a mean pore size(2ra ) of at least 10.sup.-6 cm and a porosity (Pr) of at least 50% under the conditions that the effective pressure gradient (.DELTA.P/d) loaded on the polymeric porous membrane satisfies the following equations:.DELTA.P/d<1000 (cmHg/cm) (1)and.DELTA.P/d.ltoreq.1.times.10.sup.-1 d.eta./[(ra).sup.2 .multidot.Pr](cmHg/cm) (2)wherein.DELTA.P (cmHg) is the effective pressure difference between one and the other surfaces of the membrane,d(cm) is a thickness of the membrane,ra(cm) is a mean pore radius of the membrane,Pr(%) is a porosity of the membrane and.eta.(centipoise) is a viscosity of the selected organic liquid.

Abstract: A reverse osmosis process is described for removing alcohols from hydrocarbons, in the additional presence of ethers. Depending on the nature of the membrane used, the methanol can be selectively removed as the membrane permeate or retained as the membrane concentrate. The membrane may be made from cellulose esters, polyethylene, polyvinylchloride, polyvinylidene chloride-polyvinyl chloride, etc.

Abstract: There is disclosed a process for purifying/decolorizing dyeing wastewaters that have been adjusted in a pretreatment step to a pH in the range from 4 to 9 by addition of acid or alkali by means of a membrane separation process. The concentrate obtained after the first step is further decolorized and deionized in the second step. The permeate of the second step is recycled to the pretreatment step, while the permeate of the first step and the concentrated wastewater obtained after the second step are disposed of in conventional manner.