Abstract: A process comprising spent metal etching solutions, the process comprising the steps of: 1) extracting the metal ions from the spent etching solution by means of a liquid ion exchanger; 2) washing the liquid ion exchanger by means of water; 3) vaporizing the washing water; 4) crystallizing the concentrate after vaporization; 5) filtering the regenerated etching solution; 6) restoring the quality of the etching solution; 7) reextracting the metal from the metal-loaded ion exchanger; 8) washing the liquid ion exchanger; 9) neutralizing the washing water; 10) filtering after carrying out the neutralization; and 11) recovering metal electrolytically.

Abstract: A novel system for removing contaminants from water utilizes a microfiltration membrane and an adsorbent particle suspension. In the preferred embodiment, the microfiltration membrane is a ceramic membrane and the adsorbent is powdered activated carbon. The adsorbent is added to the water to be decontaminated to form the suspension. The adsorbent particle suspension is recirculated from a recirculation reservoir through a tubular microfiltration membrane. Decontaminated water permeates from the membrane.

Abstract: A process is described for the recovery of raw materials in the aspartame preparation process from aqueous process streams which also contain dissolved salt. The process comprises subjecting the streams to nanofiltration with the aid of a composite membrane having specified retention values to obtain a retentate. The raw materials present in the retentate are recovered or the retentate is returned to the aspartame preparation process without any further processing. An apparatus for carrying out the process is also described.

Abstract: A process for separating scandium from an aqueous solution comprised of a first group of metals, scandium and a second group of metals includes the steps of: (a) providing a scandium-containing material and preparing therefrom an aqueous sulfuric acid solution containing a first group of metals, scandium and a second group of metals; (b) contacting the aqueous sulfuric acid solution with an organic liquid solution whereby scandium and the first and second groups of metals are extracted into the organic liquid solution to create a loaded organic solution; (c) scrubbing the loaded organic liquid solution first with an sulfuric acid solution to remove selected metals in the first group of metals from the organic liquid solution and then with a dilute HF solution to prepare the organic liquid solution for stripping; (d) stripping the remaining metals in the first group of metals from the loaded organic liquid solution with a HF solution so that only scandium and the second group of metals remain on the organic li

Abstract: Process for the recovery of catalyst in the production of ether carboxylic acids by catalytic oxidation with a suspended ether catalyst in which the reaction mixture is subjected to cross-flow filtration.

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 treatment system for removing metal ions from liquids. A metal ion-containing liquid (e.g. water or an acidic mining leachate) is first passed through a nanofiltration membrane system to produce a metal ion-rich retentate and a permeate. The retentate may be saved for metal recovery or discarded. To purify the permeate and remove residual metal ions therefrom, it may thereafter be passed through one or more columns containing metal ion-extracting materials. Specifically, the permeate is passed through at least one and preferably multiple columns filled with porous polymer beads having metal ion extracting agents therein (e.g. biomass materials). As a result, purified liquid is produced. When saturated with metal ions, each bead-containing column is successively cleaned with acid solutions.

Abstract: A plant for the treatment of surface water comprises a safety barrier mounted at the exit from the treatment plant and constituted by a physical filter providing, at the exit from the filter, a predetermined minimum quality irrespectively of the quality of the water on entry into the filter, and a pre-treatment installation located upstream from the safety barrier, the treatment intensity of the pre-treatment installation being adjusted as a function of the characteristics of the surface water to be treated through measuring devices located at the entrance to the physical barrier. The safety barrier is advantageously a nanofiltration membrane, coupled if necessary to one or more reverse osmosis membranes mounted downstream in "series-rejection" mode. The disclosed installation can be applied to the treatment of water liable to show great variability in quality, notably to the treatment of surface water or of water with equivalent characteristics.

Abstract: In a process for separating the exocellular proteins from the micro-organisms of a filtered fermentation liquor, the removal of solid is to be improved while retaining the useful substance. This is achieved by, in a first stage, removing substances preventing protein precipitation with the aid of a solid adsorption agent; concentrating the remaining solution to a protein content of about 30 to 40% by weight; and then precipitating and separating the protein, optionally with the addition of precipitants for protein to accelerate the precipitation, at pH values between 6 and 10.

Abstract: A process for extracting technetium values from an aqueous alkaline solution containing at least one alkali metal hydroxide and at least one alkali metal nitrate, the at least one alkali metal nitrate having a concentration of from about 0.1 to 6 molar. The solution is contacted with a solvent consisting of a crown ether in a diluent for a period of time sufficient to selectively extract the technetium values from the aqueous alkaline solution. The solvent containing the technetium values is separated from the aqueous alkaline solution and the technetium values are stripped from the solvent.

Abstract: A method for removal of water soluble organics from acidified oil process water is disclosed. The method comprises a step in which free oil is removed from such water by water-wet ultrafiltration to produce a water-rich filtrate stream which is then directed through a reverse osmosis membrane to produce a WSO-depleted stream and a WSO-rich reject stream. The method includes a recycle stream.

Abstract: The invention is directed to precipitating whey lipids from a source material such as whey by adding a sufficient amount of chitosan to form a chitosan-lipid complex, and subsequently precipitating out the lipid from the resulting whey supernatant. The precipitate is removed either by filtration or centrifugation. The supernatant contains all the whey proteins which may then be recovered by conventional means such as ultrafiltration and spray drying.

Abstract: This invention relates to the removal of polychlorinated biphenyl compounds from a mass of particulate material such as soil, sand, or gravel by washing with an aqueous nonionic surfactant solution which is subsequently extracted with a water-immiscible organic solvent in which the nonionic surfactant is not soluble.

Abstract: Disclosed is an improved method for hemoglobin purification utilizing a novel two-step dual-aqueous-phase extraction technique to separate hemoglobin from red cell membrane stroma and other protein contaminants. In the first step, a first dual-aqueous-phase liquid system is prepared which comprises an upper aqueous phase containing polyethylene glycol in water and a lower aqueous phase containing a phosphate buffer at a pH of about 10. In the second step, a second dual-aqueous-phase liquid system is prepared which comprises an upper aqueous phase, which contains the polyethylene glycol phase containing the hemoglobin extracted in the first step, and a lower aqueous phase containing a new phosphate buffer at a pH of less than 7.5. After the second extraction step, purified hemoglobin solution can then be obtained by removing the phosphate salt and the minute amounts of polyethylene glycol contained in the lower phase.

Abstract: A liquid--liquid extraction method for removing metals and hydrous metal colloids from waste streams is provided wherein said waste streams are contacted with a solvent system containing a water-in-oil microemulsion wherein the inverted micelles contain the extracted metal. A silicon alkoxide, either alone or in combination with other metal alkoxide compounds is added to the water-in-oil microemulsion, thereby allowing encapsulation of the extracted metal within a silicon oxide network. Lastly, the now-encapsulated metal is precipitated from the water-in-oil microemulsion phase to yield aggregates of metal-silicate particles having average individual particle sizes of approximately 40 nanometers.

Abstract: The invention provides a method for the solvent-extraction of .beta.-carotene from an aqueous algal biomass suspension, whereby a vegetable oil which is immiscible with water is mixed with an aqueous biomass suspension, the biomass containing the .beta.-carotene, to form a mixture of the organic phase and the aqueous suspension, whereby the .beta.-carotene is caused to dissolve in the organic phase. This is followed by separation of the organic phase from the aqueous phase by passing the organic phase containing the dissolved .beta.-carotene through a semi-permeable membrane to effect microfiltration or ultrafiltration of the organic phase. The membrane is of a material which is hydrophobic and the organic phase is passed through the membrane with a pressure drop across the membrane which is lower than that which causes the aqueous phase to pass through the membrane.

Abstract: Polyether polyamino methylene phosphonates, when added to various industrial water systems in concentrations between 0.1 mg/L and 50 mg/L, control silica/silicate deposition. In particular, this stabilization can be achieved under severe conditions which include elevated pH, high dissolved solids content, and high saturation levels of calcium carbonate.

Abstract: Oil-in-water emulsions are reprocessed in a particularly effective manner by a process in whicha) an oil-in-water emulsion is first subjected with the aid of a chemical emulsion breaker to a first breaking andb) the resulting water phase is fed to a micro-, nano- and/or ultrafiltration or a reverse osmosis,which is characterised in thatc) the oil phase from stage a) is combined with the oil phase from stage b) andd) the oil phases thus combined are subjected with the aid of organic emulsion breakers to a second breaking.

Abstract: In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or else the filtrate is recycled until the target is achieved.

Abstract: Oil well production fluid composed of oil and water and containing in excess of 100 ppm water soluble petroleum carboxylates in anionic form dissolved in the water is treated by acidifying the fluid to a pH of 6.0 or lower with a combination of a strong organic acid and a strong mineral acid and then is intimately mixed. The oil and water are separated one from the other. The content of the water soluble organics in the water is thereby substantially transferred to the oil phase. In a second aspect of the invention, water used to extract corrosive compounds to render the oil suitable for fueling gas turbine power plants is acidified to a pH of 6.0 or lower and is thereafter intimately mixed with fuel oil.

Abstract: A method for inhibiting calcium sulfate scale formation and deposition and/or dispersing iron from a feedstream passing through a reverse osmosis system which comprises the steps of: controlling the pH of the feedstream within the range between about 6.0 to about 7.0; controlling the temperature of the feedstream within the range between about 50.degree. to about 80.degree. F.; and adding a scale inhibitor and/or iron dispersant to the feedstream in an amount between about 0.002 ppm per ppm hardness (as CaCO.sub.3) of the feedstream to about 0.005 ppm per ppm hardness (as CaCO.sub.3) of the feedstream, the scale inhibitor comprising a water-soluble organic phosphonate, an N-substituted acrylamide polymer, caustic and water.

Abstract: A brine recycling method where the used brine containing metal ions is added with a reaction agent to provide a agent-added brine. The reaction agent is of a kind which, when it is reacted with the metal ions, produces an insoluble substance, excluding an oxidant which, when reacted with oxygen, produces metal oxide. The agent-added brine is subsequently filtrated with the use of a microporous filtration membrane having an average pore size within the range of 0.005 to 1 .mu.m. A brine recycling apparatus is also disclosed which includes a filter module containing a microporous filtration membrane having an average pore size within the range of 0.005 to 1 .mu.m. The used brine is, after having been added with the reaction agent, supplied through a supply passage into the filter module. The filtrate is then removed from the filter module through a recovery passage.

Abstract: This invention provides a fast and efficient method and process to remove lead from washwater streams that are part of the deleading process. By employing a two step process using epsom salts as a precipitating chemical to convert dilute lead concentrations into a very slightly soluble solid and then processing the small residue with a reverse osmosis unit the lead is totally removed from part of the water and the lead containing reject stream from the reverse osmosis unit is recucled through the process to again treat the lead. A reduction in total waste volume of over 90% is achieved.

Abstract: A method in which the storage and processing of the liquid to be dealcoholized is carried out in a dealcoholization circuit in a non-oxidizing atmosphere, partial diafiltration of this un-diluted liquid in a reverse osmosis module is carried out, an exchange of water takes place to compensate partially for the loss of volume due to the separation of the permeate, by the addition of demineralized water which is totally free from any trace of chlorine, and deaerated and natural or synthetic ingredients, not extracted from the original liquid by thermic treatment, are added to the residue. In order to obtain complete desalcoholization, preconcentration of the original liquid to be dealcoholized is carried out at a temperature of between 10.degree. and 15.degree. C. and during processing, at least one concentration, one dialfiltration and one dilution are carried out alternately. This method is mainly used to process wine, beer and cider and allows them to retain their required standards of quality and taste.

Abstract: This invention relates to methods and apparatus for carrying out affinity separations of proteins under conditions optimized for recovering biologically active protein. The method utilizes a membrane-bound ligand first to capture and separate a ligate from a fluid mixture and subsequently to release said ligate in purified form. The present methods enhance the yield of active ligate recovered in the process. The invention has particular relevance to the recovery and purification of proteins from mixtures.

Abstract: The invention is directed to a method for improving the filtration efficiency of an altered substrate filter element comprising a porous solid substrate, one side of which is impregnated with sintered solid particles, by treating the solids-oxide-impregnated side with an aqueous suspension of small non-agglomerated solid particles which are deposited upon the sintered solid particles.

Abstract: The invention relates to a process for treating industrial waste water which comprises either: (a) pretreating the waste water with at least two different pretreatments selected from adsorption, membrane filtration and oxidation and then, biologically purifying the waste water or, (b) neutralizing and biologically purifying the waste water and then after-treating the waste water either by membrane filtation in combination with adsorption or oxidation or, by oxidation optionally in combination with adsorption or filtration on a nanofiltration membrane or, by filtration on a nanofiltration membrane.

Abstract: An improved, continuous, cyclic process for selective coagulant recovery from clarifier sludge in water treatment plants. The improvement comprises several steps. First, the pH of the clarifier sludge is adjusted to about 3.5. Next, a composite membrane is provided having a chelating exchanger enmeshed in porous polymeric thin sheets. That composite membrane is placed in contact with the acidified sludge for selectively sorbing metal ion from the acidified sludge onto the composite membrane. The composite membrane, now carrying the metal ion, is withdrawn from contact with the acidified sludge and introduced into a stirred regeneration tank containing acid. In that tank, the chelating exchanger of the composite membrane is regenerated by desorbing the metal ion, thereby recovering the coagulant substantially devoid of organic material and undesirable metals.

Abstract: A method for the concentration and purification of biomolecules is described and comprises introducing the biomolecule into an aqueous/organic solvent system and bringing about a phase separation by addition of salts, where the pH at which the concentration takes place, the solvents suitable for the aqueous/organic solvent system, and the nature of the salt are determined in a series of tests one embodiment concerns concentration of hirudin by using propanol, butanol or acetone a the solvent and sodium chloride as the salt.

Abstract: A method for removing toxic anions from water is provided. A complexing agent, such as a cationic polyelectrolyte, is added to untreated water. The cationic polyelectrolyte complexes with anions, such as chromate, and the complex is filtered out of the water. The complex is then treated with barium chloride, lead chloride, aluminum, iron, or zinc to precipitate chromium ions and to regenerate the complexing agent. The regenerated complexing agent can be reused for water treatment.

Abstract: The composite membrane is disclosed having a microporous support which is coated with an aqueous polyeurethane dispersion composition wherein the microporous support is surface treated. A process for making and a process for using the membrane is also disclosed.

Abstract: A method is provided for environmentally benign paint spraying with a dispersion of oven-curable lacquer in water in a paint spraying station having a cubicle with water-rinsed rear wall for collecting and washing out of overspray in cubicle waste water. The entire cubicle waste water is separated by ultrafiltration into permeate and lacquer-containing residue, the permeate being returned to the paint spraying station, the lacquer-containing residue being enriched with lacquer by removing water until its lacquer content is essentially equal to that of dispersion that is freshly fed to the spray painting station. The residue that is enriched with lacquer is admixed to the freshly fed dispersion for reuse in spray painting.

Abstract: The present invention is directed to a process for treating an oily substrate, including a mixture comprising water and oily material or a mixture comprising water, solids and oily material as components, and wherein such treatment comprises contacting the oily substrate with a solvent for the oily material, a comminuting surfactant, and a flocculant, wherein said solvent for said oily material ranges in solubility in water from sparingly soluble to substantially water insoluble, to produce at least one phase differentiating interface and to thereby render one or more components of said oily substrate separable.

Abstract: Objects of the present invention are to provide a membrane filter for liquids which is used in microfiltration or ultrafiltration of liquids such as chemicals, water, and the like and to provide a filtering device using the membrane. The membrane is a membrane filter for liquids which has been rendered hydrophilic, in which the decrease of the pure water permeation flux of the membrane filter after being subjected to wetting treatment with a liquid having a low surface tension, subjected to replacement with pure water, and then exposed to an atmosphere of 25.degree. C. and 60% for 8 hours, to the pure water permeation flux of the membrane filter before the exposure is 20% or less. Such a membrane filter which has been rendered hydrophilic can be obtained by, for example, rendering the surface of a PTFE porous membrane hydrophilic by treating the surface with a low temperature plasma under conditions that a product of high frequency output density and treatment time is from 0.5 to 50 W.multidot.sec/cm.sup.

Abstract: Disclosed are methods for removing benzene from hydrocarbon process waters. These methods include adding aluminum chlorohydrate to the water and then separating the benzene by solvent extraction.

Abstract: Apparatus and methods for removing polyvalent by-product anions, e.g. borate and orthophosphate ions, from electroless metal plating baths employing borane or hypophosphite reducing agents and typically comprising monovalent anions or neutral zwitterions as metal chelant and/or counterion. The apparatus and methods of this invention employ (a) solvent extraction to remove metal species for recycle, (b) anion filtration to separate polyvalent anions from neutral zwitterions and monovalent anions and (c) ion exchange units to remove metal and metal chelant species from polyvalent anion-containing waste streams.

Abstract: A process for removing oily residues from aqueous waste streams using a cross flow filtration system in which the efficiency of a dynamic membrane system comprising a gel layer and supporting semipermeable membrane is optimized by applying a controlled shear force parallel to the plane of the membrane.

Abstract: The present invention relates to a process for treating and regenerating a spent caustic solution at ambient temperatures which includes oxidizing the spent caustic stream with an air/ozone gas mixture, followed by irradiating the oxidized spent caustic stream with a broad range of ultraviolet radiation and finally filtering the spent caustic solution.

Abstract: A method of separating solute material from a polar fluid in a first polar fluid phase is provided. The method comprises combining a polar fluid, a second fluid that is a gas at standard temperature and pressure and has a critical density, and a surfactant. The solute material is dissolved in the polar fluid to define the first polar fluid phase. The combined polar and second fluids, surfactant, and solute material dissolved in the polar fluid is maintained under near critical or supercritical temperature and pressure conditions such that the density of the second fluid exceeds the critical density thereof. In this way, a reverse micelle system defining a reverse micelle solvent is formed which comprises a continuous phase in the second fluid and a plurality of reverse micelles dispersed in the continuous phase. The solute material is dissolved in the polar fluid and is in chemical equilibrium with the reverse micelles. The first polar fluid phase and the continuous phase are immiscible.

Abstract: An apparatus and method for treating streams containing cyanide, heavy metal and precious metal values to recover those values where the method includes the following steps:a) providing a membrane filtration means having an inlet, a product outlet and an discharge outlet,b) contacting the waste stream to be treated with an effective amount of carbon dioxide to adjust the pH to about 8.0 to about 10.0,c) further contacting the waste stream with an effective amount of a soluble metal compound to react with the cyanide in the waste stream to form membrane rejectable cyanide compounds, andd) passing the treated stream through the membrane filtration means to thereby separate recoverable cyanide and precious metal values from the treated stream and produce an effluent stream for further processing or discharge to the environment.

Abstract: The salt passage of a reverse osmosis membrane is increased by: (a) contacting the membrane with ions to form a membrane-ion complex; (b) treating the membrane-ion complex with an aqueous solution of an alkali metal permanganate to form manganese dioxide crystals in the membrane; and (c) dissolving the manganese dioxide crystals. The process can be repeated any number of times to further open the membrane.

Abstract: A medium containing tanning agents and/or albumens, such as beer, wine, or fruit juice, is simultaneously stabilized and filtrated by means of cross-flow filtration in the ultrafiltration or microfiltration range, in the presence of a stabilizer.

Abstract: A process for treating spent aqueous emulsion material formed from a non-volatile hydrocarbon organic portion having a paint solids content greater than about 10% by weight in which the spent emulsion is broken and the organic phase is admixed with sufficient amounts of a hydrocarbon solvent extractant to extract organic portions of the aqueous emulsion. The hydrocarbon solvent extractant and the organic portion/solvent extractant mixture can then be distilled to provide essentially pure hydrocarbon solvent extractant and the hydrocarbon organic portion of the emulsion essentially free from paint solids. The organic portion of the material can then be admixed with quantities of water to reform a reclaimed emulsion. Examples of the paint overspray treatment emulsion on which the process of the present invention is highly effective is one which contains a hydrocarbon such as an alcohol ester, an alcohol ester derivative or mixtures of the two in combination in its organic phase.

Abstract: The method of purifying spent brine from the regeneration of ion exchange resin, for example resin in water softeners. The method comprises acidifying the spent brine to a pH of less than 3 with an acid other than sulfuric acid, which acid is preferably chosen from at least one acid which forms a calcium salt that is more water soluble than calcium sulfate. One passes the brine through a nanofiltration membrane to purify the brine by separating from it a waste stream which comprises the majority of the polyvalent ions present, so that the purified brine has most of its contaminating polyvalent ions removed.

Abstract: This invention relates to an improved thermite coated molten metal filter. According to the invention, a molten metal filter is coated with an aqueous thermite coating slurry containing oleic acid, water-miscible surfactants, water-soluble binders, and water-soluble dispersants.

Abstract: A method for recovering contaminants and the organic solvents used to extract the contaminants from an aqueous solution containing soap liquors comprises extracting the aqueous solution with an organic solvent having a density sufficient to extract the contaminants and to subsequently separate the organic solvent from the aqueous solution containing the soap liquors. The method further comprises shaking the aqueous solution for providing intimate contact between the organic solvent and the aqueous solution, adding an inorganic salt after shaking the aqueous solution for separating the aqueous solution into a plurality of layers, reextracting at least one layer with an organic solvent for producing a second plurality of layers, and separating a layer substantially including the organic solvent and the contaminants for recovering the organic solvent and the contaminants from the aqueous solution containing the soap liquors.

Abstract: A process is disclosed for removing dissolved organics from an aqueous composition, said composition comprising water, carbon dioxide and dissolved organics, and said composition having a pH of 6.5 or less and an inlet organics concentration. The process comprises the steps of feeding said aqueous composition to a centrifugal separation zone, preferably to a hydrocyclone, depressurizing said composition in said centrifugal separation zone to regasify at least a portion of said carbon dioxide. An aqueous product stream is removed from the centrifugal separation zone wherein the concentration of said organics is less than said inlet organics concentration. The process is particularly useful in the cleanup of industrial wastewater, and also for removing organics from water produced in petroleum production operations.

Abstract: A method of enhancing the removal of a benzene from a petroleum refinery desalter effluent brine is described. The method involves treating the effluent brine with a combination of aluminum chlorhydrate and a water soluble cationic polymer followed by solvent extraction. The preferred cationic polymer is polydiallyldimethylammonium chloride.

Abstract: A chemical analysis method for the determination of a first organic acid in the presence of a second organic acid both of which are in a solution to be analyzed, the pK.sub.a of the first acid being at least 2 pK.sub.a units larger than the pK.sub.a of the second acid. The method includes three steps. The first step if to form a pH adjusted solution to be analyzed by adjusting the pH of the solution to be analyzed to be between the pK.sub.a of the first acid and the pK.sub.a of the second acid so that the first acid is predominately in its unionized form and so that the second acid is predominately in its ionized form.

Abstract: Halogen-substitutable hydrogen atoms are linked to nitrogen atoms of a polymer, with ethylenically-unsaturated monomers. By using inorganic or organic hypohalogenites and/or organic N-halogen derivatives as halogenation means, hydrogen atoms on the nitrogen atoms of the polymer membranes or polymer formed materials are replaced by halogen atoms and part of these are removed by reducing agents in the presence of ethylenically unsaturated monomers, with radical grafting of these on to the nitrogen atoms, after which the remaining halogen atoms are removed by reducing agents in the absence of monomers.