Abstract: The electronics industry demands that hydrogen peroxide for use therein be purified to very low levels of impurities, currently at the level of a few ppb for some impurities, or even lower. However, existing methods are either inherently unsafe because they bring concentrated hydrogen peroxide into contact with a concentrate of transition metal decomposition agents for peroxide and a purification resin which acts as a source of carbon, or are unable to attain the desired impurity level. In the instant purification process, the hydrogen peroxide solution is passed through a membrane having a very small pore size which contains an ion exchange resin that is capable of removing alkali and alkaline earth metal ions from solution. The feed solution in characterized in that it contains no more than a small proportion by weight of transition metals that catalyse hydrogen peroxide decomposition compared with the total metals content.

Abstract: A system is provided for weighing and monitoring flow from multiple fluid sources into a flow system wherein incoming fluid is received in a weighing bag attached to a control system for monitoring the amount of fluid passed through the weighing bag and for preventing admission of air into the flow system. An alarm attached to the weighing bag warns when fluid in the weighing bag is approaching empty, so that the fluid in the weighing bag can be replenished from the fluid source before the weighing bag runs dry. If fluid in the weighing bag is not replenished, the system automatically shuts down.The fluid pump can be absolutely calibrated using the controlled admission of known amounts of fluid into the weighing bag so that the amount of fluid introduced into the flow system through the weighing bag can be calculated automatically.

Abstract: Disclosed is a method for the evaluation of the virus-removing capability of a porous polymeric membrane module for removing viruses by filtration, which comprises testing I in which a transmembrane pressure lowering from predetermined value Ph a predetermined period of time after the termination of the supply of a gas is measured with respect to the porous polymeric membrane module, wherein the value Ph satisfies the formula: d<Ph<c, wherein d and c are respectively the transmembrane pressures at points (d) and (c) in FIG. 1 hereof. By the method of the present invention, it has become possible for the first time to effectively and efficiency select a module which can be suitably used for removing viruses from a virus-containing fluid and to obtain to fluid substantially free of the virus.

Abstract: The invention is directed to an apparatus and method for transforming a sterile pyrogen-free liquid into a substitution liquid using an exchanger. The method includes the steps of flowing first and second liquids over opposite sides of a semipermeable membrane, the first liquid being sterile and pyrogen-free. Both liquids contain at least some electrolytes of blood including at least a buffer agent or a precursor of a buffer agent. At least some of the electrolytes have different concentrations in the two liquids. When purifying blood by hemodiafiltration, this method has the particular advantage that, rather than discarding the second liquid, it can be used for hemodiafiltration.

Abstract: A method for reducing the concentration of target co-ions in a liquid feed mixture comprising target co-ions and counter-ions by adding a colloid such as a polyelectrolyte or surfactant comprising a colloidal ion and colloidal counter-ions to the feed mixture wherein the colloidal ion has the same type of charge as the target co-ion. The feed mixture containing the colloid is filtered through an ultrafiltration membrane having pores small enough to block the passage of the colloidal ion.

Abstract: A process is provided for modifying the properties of a hydrophobic microporous membrane which includes the steps of first providing a hydrophobic microporous membrane, treating it with a surfactant to render the membrane hydrophilic, wetting the membrane with an aqueous solution of a polyol such as polyvinyl alcohol (PVA) and divinyl sulfone (DVS) or a precursor thereof, washing the membrane with water to displace the polyol/DVA from the exterior of the membrane while retaining it in the pores of the membrane, and crosslinking the polyol/DVS into an aqueous gel to yield a hydrophilic microporous membrane having pores filled with an aqueous polyol/DVS gel, the exterior of the membrane being unobstructed by gel. The modified membranes produced according to the process are useful in carrying out chromatographic separations.

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, and wherein the solvent for the oily material ranges in solubility in water from sparingly soluble to substantially water insoluble, in the presence of an added comminuting and dispersing surfactant, to produce by such contacting at least one phase differentiating interface, and to thereby render one or more of the components of the oily substrate separable.

Abstract: Phosphates which are dissolved or contained in suspension are substantially completely removed from a low-solids waste water which has been clarified. Precipitating and flocculating agents for transforming the dissolved phosphated to an undissolved form are added to the low-solids wate water and precipitation products and suspended matter are removed by microsieving through mesh openings in the range of about 10 to 150 .mu.m. Microsieving is preferably effected in two stages including a preliminary sieving through mesh openings from 60 to 150 .mu.m and a fine sieving through mesh openings from 10 to 80 .mu.m.

Abstract: A method for the purification of a bifidobacteria-proliferating substance is provided which comprises adjusting the temperature of soybean whey to 50.degree. to 100.degree. C. and the pH thereof to 6.5 to 10 either by adding an alkaline substance to the whey and heating it or by heating the whey and adding the alkaline substance, removing the formed precipitate, ultrafiltering the resulting liquid phase part to obtain as the permeate an aqueous solution of a bifidobacteria-proliferating substance, and if necessary subjecting the permeate to further purification steps, i.e. active carbon or adsorbing resin treatment, electrodialysis and ion exchange resin treatment. By the step of the alkali substance treatment and heating in this invention, permeate flux in the succeeding ultrafiltration step is remarkably enhanced. Further, a bifidobacteria-proliferating substance having a high quality can effectively be obtained by the present purification method.

Abstract: A method for enhancing supercritical fluid extraction of sample matrices which contain water. The method involves mixing the samples with an extraction enhancing aid comprising flux-calcined diatomaceous earth which increases the permeability of the sample in a supercritical fluid and controls water during the extraction procedure.

Abstract: The instant invention is a membrane useful for separating organic matter such as proteins from aqueous solutions which resists fouling and maintains a high flux during separation. The membrane is prepared by either drying a polysulfone composite membrane, or first treating a polysulfone composite membrane with aqueous methanol and then drying it. The membrane is then exposed to elemental fluorine in an inert gas in the substantial absence of oxygen at a temperature in the range of about -45.degree. to 70.degree. C. After fluorine treatment, the membrane is exposed to air. The fluorine content in the treatment mixture may be from 0.0125 to about 10 volume percent, preferably 0.025 to 2 volume percent. The fluorine treatment does not significantly alter the membrane pore size.

Abstract: A sterile-filtered colostrum solution that contains casein is made by adjusting the pH of a colostrum solution to 2.5 to 3.5 and then filtering it clear and sterile. It is preferably first defatted, and adjusted to pH 5.5 to 8 after the acid treatment but before being filtered.

Abstract: Disclosed is a process for treating a refinery slurry containing water, oil and a solid fraction, wherein the slurry is brought into contact with carbon dioxide gas in order to adjust the pH value of said slurry to an acidic value and, in that way, improve the separation, by mechanical means, of a first water phase and a first oil phase, from a sludge. The latter is submitted to an extraction with carbon dioxide, under supercritical conditions, in order to separate a second water phase and a second oil phase from a residual sludge, which is disposed of.The process makes it possible to remove most of the water, and, in particular, most of the oil contained in said slurry and a sludge to be disposed of which shows a reduced propensity to the elution of the residual oil.

Abstract: A scrub solution is made up for use in starting up a hafnium liquid-liquid extraction system. An aqueous zirconium oxychloride-containing solution is contacted with methyl isobutyl ketone containing less than 1 Molar thiocyanic acid. The aqueous solution is maintained at a chloride concentration of 1.6 to 3.5 Normal (as HCl) by addition of concentrated hydrochloric acid. Ammonium thiocyanate is added to the acidified aqueous stream to produce thiocyanic acid. The high acidity of the aqueous solution drives the thiocyanic acid into the methyl isobutyl ketone without the chloride anions having a depressing affect on the transfer. The thiocyanic acid-containing MIBK may then be used as a scrubbing solvent to start up the hafnium extraction system.

Abstract: A process for producing nuclear grade zirconium and a liquid-liquid separation circuit for separating zirconium from hafnium are provided. The process employs an aqueous feed of ZrOCl.sub.2 in the presence of thiocyanate, an organic solvent and acid and a series of high mass transfer efficiency pulse columns in which are conducted the iron extraction, hafnium extraction, zirconium stripping, hafnium scrubbing and zirconium and hafnium thiocyanate recovery processes required to produce substantially hafnium-free nuclear grade zirconium. A feed zone mixer-settler separates thiocyanate and zirconium injection points and permits the prestripping of zirconium prior to the main stripping operation. All of the scrubbed solvent and the thiocyanate are regenerated. Higher concentrations, smaller flows, and compact equipment result in the present process requiring substantially reduced in-process inventories as compared to previously known Zr/Hf separation processes.

Abstract: A process for the removal of ammonium from aqueous liquids, especially from fermentation broths, is disclosed. The process uses a cation exchanger membrane which separates a liquid on a donor side that is to be depleted of NH.sub.4.sup.+ from a solution on an acceptor side whose pH is higher than on the donor side. Because of the equilibriumNH.sub.4.sup.+ .revreaction.NH.sub.3 +H+there is on the acceptor side increased formation of NH.sub.3. This is continuously removed, in particular by reducing the pressure and/or passing through inert gas, or by selective transport through another microporous membrane into an acid protonation solution, so that a NH.sub.4.sup.+ concentration gradient is maintained across the membrane. A similar content, apart from the ammonium concentration, of concomitant cations on the donor and acceptor side and/or a high ratio of the solution volumes on the donor side and the acceptor side ensures that the solution on the donor side to be depleted of NH.sub.4.sup.

Abstract: A method and apparatus for polishing a condensate is provided wherein the condensate contains both suspended and colloidally dispersed solid impurities, and also intermittent and variable levels of ionic impurities and dissolved silica. When the ionic impurities exceed a preselected level, a finely divided ion exchange resin mixture is first admixed with the condensate at a rate sufficient to reduce the level of such impurities to a preselected level within a preselected contact time period. Thereafter, the resulting condensate is passed through a membrane filtration device to remove such suspended and dispersed solid impurities. A simple, effective and reliable retrofittable apparatus adapted for use with BWR's fitted with precoat filter systems is provided.

Abstract: This invention discloses a process for making a refractory filter for liquid ferrous and non-ferrous metal with improved priming action. A carbonaceous resin onto the surfaces of a hard-fired ceramic or refractory cloth filter for liquid metal which protects the filter against abrasion and the absorption of water and also holds and protects particulate additives in place on the surface of the filter where they can later react with the liquid metal. When the liquid metal approaches and then touches the surface of the filter, the resinous coating chars. The resulting porous layer of mechanically strong carbon retards heat transfer from the hot liquid metal to the otherwise unheated filter, aiding the priming of the filter and also controlling the rate of dissolution of the particulate additives into the liquid metal. The preferred resin has a high char-forming tendency and a mechanically strong porous carbon coating on the filter when the filter is exposed to the hot, liquid metal.

Abstract: Devices for and a method of manufacturing glass bodies, in which a porous green body is formed from the starting material for the glass body, being an aqueous suspension comprising a highly disperse solids content, which green body is then purified and sintered, and deposited by separating the phases of the suspension through electrophoresis, in such a manner that the solids content of the suspension is deposited on a porous deposition membrane having pores whose diameter is smaller than the average particle diameter of the solid particles present in the suspension, said membrane being arranged between the anode and the cathode, and the space between said membrane and the anode being filled with an electrically conducting liquid, a porous auxiliary membrane being arranged between and at a distance from the deposition membrane and the cathode, said auxiliary membrane having pores with a diameter which is smaller than the average particle diameter of the solid particles present in the suspension, and the space

Abstract: A method and apparatus are disclosed for the supercritical extraction of a sample from a liquid medium. The method and apparatus provide for the recirculation of the supercritical fluid containing the sample through the liquid containing sample until at least a portion of the sample has been extracted.

Abstract: The invention relates to a method of treating an aqueous liquor, such as effluent liquor formed during coal gasification. The method comprises subjecting the liquor to dephenolation and ammonia stripping treatment to remove phenolic compounds and "free" ammonia from the liquor and then subjecting the resulting liquor, which still contains ammonium compounds and thus "fixed" ammonia, to reverse osmosis treatment to produce a permeate which is substantially free from impurities, including "fixed" ammonia.

Abstract: Operative fluids containing lower glycol are contacted with semi-permeable membranes under reverse osmosis conditions to permeate lower glycol to provide a reclaimed lower glycol product. Exemplary operative fluids include antifreeze solutions, heat transfer fluids, deicers, quenchants, hydraulic fluids, lubricants, solvents and absorbents.

Abstract: The separation of aromatic hydrocarbons from mixtures of aromatic and non-aromatic hydrocarbon feeds under pervaporation conditions, is improved by the control of the amount of oxygen present in the feed. The amount of oxygen in the feed, such as heavy cat naphtha or other cracked feed, should be less than 30 wppm, preferably less than 10 wppm. The oxygen level in the feed can be controlled by the addition of small amount of oxygen scavenger into the feed. Hindered phenols are representative of useful oxygen scavengers.

Abstract: The effluent arising in the production of acrylonitrile can be purified by adjusting it to a pH value from 4 to 9 and then subjecting it to reverse osmosis at a membrane at a temperature from 10.degree. to 50.degree. C. and a differential pressure of 10 to 80 bar. The flow velocity at the membrane is adjusted to a value from 0.5 to 4 m/second. The concentrate is recycled into the acrylonitrile production process.

Abstract: A method for processing aqueous fermentation broths in a bioreactor vessel, in which a foam inhibitor is added to the fermentation broth in the bioreactor vessel in order to prevent the accumulation and buildup of foam in the bioreactor vessel caused by oxygen sparging of the fermentation broth contained therein. The aqueous fermentation broth processed in the bioreactor vessel is conveyed as a feed solution to an ultrafiltration system including a membrane for concentrating the aqueous fermentation broth. The ultrafiltration system is typically located downstream of the bioreactor vessel. The improvement involves reducing the amount of fouling of the membrane in the ultrafiltration system by adding to the aqueous fermentation broth in the bioreactor vessel as the foam inhibitor, an antifoam which is an oil based liquid in the form of droplets, the droplets of the oil based liquid antifoam being dispersed, encased, entrapped, and imbedded, within solid particles of a water soluble encapsulating material.

Abstract: In a diagnostic apparatus system, a one piece porous substrate is located in a container. The substrate serves both to extract an antigen in or on a top layer with the remainder of the substrate serving as a reservoir. The pores in the top surface of the substrate are microscopic for entrapment of microspheres carrying antibodies. A target antigen in a test sample attaches to the antibodies when the test sample is poured through the top layer. The pores in all but the top layer of the substrate have a much greater pore size to define the reservoir portion of the substrate. The invention also includes a method of casting a microporous matrix in surfaces of a plurality of macroporous slugs.

Abstract: This invention relates to a process for treating soil and sludge for removal of contaminants in contact with the soil or sludge. More particularly, this invention relates to a process where contaminants such as inorganic contaminants such as metal or metal salts or organic contaminants such as PCBs are removed from water-wet soil and sludge. In particular, this invention relates to a process for treating or cleaning a contaminated water-wet solid containing mixture by contacting the contaminated water-wet mixture with a solvent, the solvent containing a comminuting surfactant. The solvent used is a solvent for the contaminant and is sparingly soluble in water. The purpose of adding a comminuting surfactant to the solvent is to form a dispersed mixture of the solids, contaminants, and water whereby the contaminants are extractable into the solvent. The solvent containing the contaminants is easily separated from the solids and then the solvents and contaminants are separated and the solvent is reused.

Abstract: The present invention provides erythrocyte-retention substrates of the general formula:R.sub.1 --Sp--R.sub.2in which Sp is a bridge serving as a spacer, R.sub.1 is a strongly polar group and R.sub.2 is also a strongly polar group or, when Sp is an electron-conductive group, R.sub.2 can also be a polarizable group.The present invention also provides a process for the separation of erythrocytes from whole blood, wherein whole blood is brought into contact with one of the above substrates and subsequently filtered through a filter layer and the separated plasma obtained.

Abstract: A process for recovering sulfuric acid from an aqueous sulfuric acid solution containing ferrous sulfate is disclosed, which comprises electrolyzing the aqueous sulfuric acid solution containing ferrous sulfate to thereby oxidize ferrous ion dissolved in the solution to ferric ion, and then removing the ferric ion by solvent extraction using a solvent and an extractant.

Abstract: The present invention relates to the use of a 2,3-dihydroxyterephthalamide of the structure (I): ) ##STR1## wherein A is selected from hydrogen or an organic linking group Y attached to a solid substrate Q,R.sub.1 is independently selected from alkyl having from 1 to 20 carbon atoms, or aryl having from 6 to 14 carbon atoms, andR.sub.2 is selected from R.sub.1 or an organic linking group Z bonded to a solid substrate, with the proviso that structure (I) has only one linking group selected from Y or Z to a solid substrate Q, as selective chelating or sequestering to remove at least one metal ion from aqueous solution. These dihydroxy compounds are useful to remove metal ions (e.g., Fe.sup.+3, from industrial waste water, human or mammalian blood or plasma, and the like.

Abstract: Hydrocarbons are recovered from acid sludge by mixing the sludge with methyl ethyl ketone and base. A hydrocarbon-rich methyl ethyl ketone stream and a solids-containing stream are separated from the mixture, and a hydrocarbon stream is separated from the hydrocarbon-rich methyl ethyl ketone stream.

Abstract: Dsiclosed is a method of treating fluoride-containing water, which comprises a reaction step where a calcium compound and/or an aluminium compound are/is added to fluoride-containing water while the pH value of the resulting suspended liquid is adjusted to fall within the range of from 6 to 8, and at least a part of the concentrated suspension to be formed in the membrane-separation step of the following stage is added to the suspended liquid and stirred and the resulting suspension is introduced into the circulation tank; a membrane-separation step where the suspension from the circulation tank is treated by membrane-separation to separate it into a permeated solution and a concentrated suspension; a circulation step where at least a part of the concentrated suspension to be taken out from the membrane-separation step is returned back to the reaction step while the remaining part thereof is circulated to the circulation tank; and a step where the permeated solution is taken out from the membrane-separation s

Abstract: The invention relates to a process for treating industrial waste water which comprises either: (a) pre-treating the waste water with at least two different pre-treatments 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 filtration 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: Water-soluble organic electrolytes, such as anions of lower carboxylic acids in aqueous solution at low pH, are removed by raising the pH and subjecting the resultant charge liquid to nanofiltration.

Abstract: Disclosed are processes for the selective extraction of tin from aqueous acidic solutions bearing tin and other metal cations. Branched tertiary phosphine oxides comprising at least two branches per alkyl group show higher extraction coefficients, E, for tin than other metals, e.g. zinc (III), iron (II), iron (III), copper (II) and lead (II). Novel compositions for selectively extracting tin comprising combinations of symmetrical branched phosphine oxides and unsymmetrical phosphine oxides are also disclosed.

Abstract: A method is disclosed for removing organic and tungsten from sodium sulfate solutions to render the solutions suitable for ion membrane processing, which comprises contacting the solution wherein the pH of the solution is no greater than about 7, with activated carbon to remove essentially all of the organic and the tungsten therefrom and form a purified sodium sulfate solution.

Abstract: An aryl-ether and/or thioether polymer contains aromatic rings linked to neighboring units Ph X Ph (when Ph is paraphenylene and X is SO.sub.2 and/or CO) through O and/or S and/or a direct link, at least some of said aromatic rings carrying a nuclear suphonamide group having N-aliphatic substitution, preferably with a cationic amino or quaternary ammonium group.A process for making aromatic polymer sulphonyl halides and, thus also sulphonamides, of very low sulphonic acid content, is characterized by working up in substantially anhydrous conditions the mixture resulting from the reaction of an inorganic halide with the corresponding sulphonic acid or salt thereof. The polymer sulphonamides are suitable for separation technologies, especially purification of water by reverse osmosis.

Abstract: Prohibited radioactivity is removed from contaminated aqueous effluents containing both nitrate and radium values, by liquid/liquid extracting such effluents with an organic phase comprising at least one halogenated, preferably fluorinated .beta.-diketone.

Abstract: A closely packed film comprising at least one unimolecular layer which contains at least one amphiphilic compound whose hydrophobic molecular region comprises at least one hydrocarbon chain which has been chemically modified, at least terminally, is distinguished by very good adhesion between the film and the adjacent layer (monolayer or substrate) on contact between the hydrophobic region of the film with the hydrophobic surface of the adjacent layer, and on contact between the hydrophilic region of the film and the hydrophobic region of the adjacent layer, and vice versa.Films of this type can be used with advantage, for example, for improving the surface-slip characteristics of the substrate, in the production of sensors or in semiconductor technology.

Abstract: An arrangement for collecting blood from a source of blood employs a filter chamber having a substantially predefined volume for accumulating the collected blood, and first and second access ports for receiving the collected blood and for venting the filter chamber, respectively. A protamine filter is arranged within the filter chamber, and preferably is formed of regenerated cellulose hollow fibers which have been activated with CNBr and have protamine immobilized thereon. The amount of protamine immobilized thereon is controlled in a variety of ways, prior to installation and sealing of the filter element within the filter chamber. In a practical embodiment, the first port of the filter chamber is coupled to a conventional cannula needle for communicating transdermally with a living being or through a membrane of a blood storage container. The second port is coupled to a conventional syringe which applies a suction for facilitating withdrawal of the blood.

Abstract: In a process for transferring solute from a liquid feed solution to a liquid extractant which is substantially immiscible with the feed solution, one side of a porous membrane is contacted with the feed solution and the other side of the membrane with the extractant. One of the feed solution or the extractant preferentially wets the porous membrane. An interface-immobilizing pressure difference is maintained across the porous membrane in a direction and of a magnitude effective to oppose the tendency of the liquid which preferentially wets the membrane to flow through the membrane and disperse in the liquid on the opposite side. The interface between the feed solution and the extractant is thereby immobilized at the porous membrane.

Abstract: The invention involves a method for making uniformly sized particles from solid compounds. First, a suitable solid compound is dissolved in a suitable solvent. Then, a precipitating liquid is infused, precipitating non-aggregated particles with substantially uniform mean diameter. The particles are then separated from the solvent. Depending on the solid compound and the desired particle size, the parameters of temperature, ratio of non-solvent to solvent, infusion rate, stir rate, and volume can be varied according to the invention. The precipitating liquid may be aqueous or non-aqueous, depending upon the relative solubility of the compound and the desired suspending vehicle.

Abstract: It has been found that certain chemicals such as peroxide may be concentrated in an aqueous solution by increasing the pH of a feed liquor to increase the amount of the chemcial in an ionized form, i.e. increase the ionized fraction and then separating the feed liquor by reverse osmosis through a reverse osmosis membrane into a retentate having an enhanced concentration of chemical in ionized form relative to the feed liquor and a permeate having a reduced concentration of chemical in ionized form relative to the feed liquor. The process is particularly suited to increasing the concentration of hydrogen peroxide.

Abstract: An improved process is disclosed for killing and inhibiting growth and reproduction (aftergrowth) of microorganisms comprising adding sufficient chloramine to kill the microorganisms without oxidizing high molecular weight organics, which are not easily assimilated by organisms that survive, into lower molecular weight ones, which are easily assimilated.

Abstract: A complex separation process and apparatus for decreasing non-radioactive salt content of waste solutions of nuclear power stations. The process significantly decreases in non-radioactive salt-content of waste solutions arising from nuclear power stations.Process is essentially based upon a suitable combination of up-to-date separating operations, such as precipitation, filtration, ultra-filtration, reverse osmosis, ion-exchange, evaporation and crystallization. Practically total amount of components carrying radioactivity (except tritium) can be effectively separated from the non-radioactive salts. Part of inactive salts (alkali nitrates) can be handled as industrial waste and the other part (boric acid) can be recycled. In the process precipitation, ion-exchange, reverse osmosis and crystallization are operations completing or replacing each other. Reverse osmosis is used not only for separating water and soluble, but for the separation of solved components.

Abstract: The removal of fluoride ion from potassium chloride containing at least a small amount of an acidic component with water is improved by adjusting the pH of the aqueous solution employed in a fractional crystallization of between about pH6 and about pH9 or adjusting the pH of the extractant used in an aqueous extraction by adding an amount of base so that final pH of the the extract is between about pH6 and about pH9. The fluoride ion contamination of potassium chloride, for example, was reduced from 1000 ppm to 90 ppm by adjusting the aqueous solution employed in a recrystallization of pH6.5 before precipitation.

Abstract: A process for removing at least a portion of salts contained in whey or a liquid based on whey by means of electrolysis while producing an acid mixture and a base mixture useful in food industries. In the process a four-compartment electrolytic cell is used in the electrolysis of the whey or the liquid based on whey. The four compartments between an anode and a cathode are separated from each other by means of ion exchange membranes and an independent liquid recirculation is connected with each one of the four compartments of the electrolytic cell. A three-compartment cell is disclosed, in which anodes and cathodes, except at the ends of the stack, are replaced by bipolar membranes. The modified cell is similarly used on cheese whey concentrate, to produce an acid solution and a base solution.

Abstract: Improvement in cross-flow membrane filtration. Chitosan is admixed with an aqueous dispersion of colloids or finely divided solids to flocculate the solids. The chitosan-flocculated liquid is then filtered on a membrane by cross-flow under pressure. A layer of chitosan-containing flocculant material deposits on the membrane and provides superior flux performance as compared to certain commerical flocculants.

Abstract: A process is disclosed for separating low molecular weight components from complex aqueous organic mixtures. The process includes preparing a separation solution of supercritical carbon dioxide with an effective amount of an entrainer to modify the solvation power of the supercritical carbon dioxide and extract preselected low molecular weight components. The separation solution is maintained at a temperature of at least about 70.degree. C. and a pressure of at least about 1,500 psi. The separation solution is then contacted with the organic mixtures while maintaining the temperature and pressure as above until the mixtures and solution reach equilibrium to extract the preselected low molecular weight components from the organic mixtures. Finally, the entrainer/extracted components portion of the equilibrium mixture is isolated from the separation solution.

Abstract: A reverse osmosis membrane having improved rejection of sulfuric acid and/or isopropanol is described. The membrane is prepared by treating a crosslinked, polyamide discriminating layer with a compatible oxidizing reagent, such as peracetic acid, periodic acid or chloramine, whereby the passage through the treated membrane of sulfuric acid in a 2 percent aqueous solution at a transmembrane pressure of 400 psi is reduced by at least 30 percent.