Abstract: Modified, polyacrylonitrile-containing membranes suitable for ultrafiltration are prepared by reacting polyacrylonitrile or copolymers of acrylonitrile and other ethylenically unsaturated monomers with, successively, hydroxylamine, at least difunctional compounds, which act as bridge members, e.g. cyanuric chloride, a polyfunctional oligomer or polymer, e.g. polyethyleneimine, and, finally, a reactive compound containing at least one ionic group, e.g. an anionic reactive azo dye. The latter compound must be able to react with the polyfunctional oligomer or polymer and is required only if the said polymer does not already itself contain ionic groups.

Abstract: Modules for use in forming rigid filter beds by laying a plurality of the modules upon a planar base comprise a bottom grid unit to the top of which is fixed a rigid, porous layer. The grid unit has several intersecting series of strip elements with structured portions to promote drainage of liquid through and away from the porous layer. The grid unit may also include portions to insure interlocking of the top porous layer thereto.

Abstract: A method for dehydrating sludge, and particularly sewage sludge, includes adding a particulate, thermally expanded volcanic material and a polyelectrolyte to said sludge prior to filtration, said volcanic material having a bulk density of less than 0.09 kg/liter and an average particle size ranging from 20 to 300 microns.

Abstract: Organopolysiloxanes with Bunte salt groups having the formula ##EQU1## the Bunte salt groups being linked to a silicon atom by way of a carbon atom and in whichR.sup.1 is methyl with the proviso that up to 10% of the R.sup.1 groups may be alkyl with up to 18 carbon atoms or vinyl phenyl, hydrogen or hydroxyl,R.sup.2 is the ##STR1## group or the ##STR2## group, in which one of the R.sup.3, R.sup.4 groups represents an OH group and the other an --S.sub.2 O.sub.3 Me group (Me=alkali or the optionally substituted ammonium group), whereby the R.sup.3 and R.sup.4 radicals can be hydroxyl or together the oxygen of an oxirane ring in an amount up to 50% of the R.sup.2 group,a has any value from 1 to 2.33 andb has any value from 0.02 to 1.The compounds can be synthesized from the corresponding organopolysiloxanes having epoxy groups by reaction with alkali or ammonium thiosulfate and used for the surface treatment of inorganic or organic materials, for example, textiles, paper or rock wool.

Abstract: A compound selected from some classes of coloring substances having good resistance to light and oxidation is found to have a high photosensitive activity when it is supported in an actively dispersed form on a carrier. The sensitizer obtained is useful for heterogeneous system photosensitive oxidation for various purposes, for example, treatment of harmful organisms or impurities contained in the air or water. The sensitizer has also good resistance to light and oxidation and can be used repeatedly for a long time.

Abstract: A multi-layer filter combination having a macrofilter layer with a predetermined thickness and two major sides including porous material impregnable with bacteria-destroying medication and having pore sizes in the range from about 1 micron to about 120 microns. There is also a microfilter layer having a prearranged thickness smaller than the thickness of the macrofilter and including a porous membrane having pore sizes from about 0.1 micron to about 10 microns. The microfilter layer is mechanically bonded to at least a major side of the macrofilter layer, whereby inhibiting transfer of any remaining live bacteria which may have survived exposure to the bacteria-destroying medication, and which may attempt to pass outwardly beyond the microfilter layer. The medication is either an antibiotic and an iodophore.

Abstract: A membrane treating agent for rejuvenating and improving a rejection performance of a semipermeable membrane, which contains an effective amount of a modified vinyl polymer having acetoxy groups and at least one group represented by the Formula (I) and/or (II): ##STR1## wherein R is a radical selected from the group consisting of aliphatic, aromatic and heterocyclic radicals having from 1 to 9 carbon atoms, and n is an integer from 1 to 3.Valuable modified vinyl polymers are obtained by reacting a partially saponified vinyl polymer with at least one carboxylic acid such as maleic acid, phthalic acid, succinic acid, butane tetracarboxylic acid and/or acid anhydrides or acid chlorides thereof.

Abstract: A method for forming a hydrophilic coating upon a porous substrate such as a reticulate electrode or a filter from a dispersed, perfluorocarbon copolymer. Perfluorocarbon copolymer is dispersed in a solvating medium, a substantial portion, but not necessarily all of the perfluorocarbon being solvated. The dispersion is applied to the substrate and the dispersion medium is removed.

Abstract: An improved rigid filter plate for sludge dewatering is comprised of a filter element of two or more sizes within the range of 0.2 to 0.002 inch of irregular hard particles of aluminum oxide or similar materials, and of a supporting element of larger particles all bonded with an adhesive bonding agent. A process for manufacturing the improved rigid filter plate is also set forth.

Abstract: Modules for use in forming rigid filter beds by laying a plurality of the modules side-by-side upon a flat base are in the form of porous, planar elements having a continuous, polygonal upper surface, a continuous lower surface approximately coterminous to the upper surface, and sides normal to said surfaces of substantially equal depth much shorter than their length, such elements comprising laminated layers, each layer being formed of particulate material of substantially uniform size rigidly fixed together in a matrix of cured binder, the particles of the layers being substantially different in size than the particles of the adjacent layers, the top surface being flat and the bottom surface being channelled. In preferred forms, the modules' surfaces are square, there are only a top layer and a bottom layer, the top layer is much thinner than the bottom layer and the particles in the top layer are appreciably smaller than the bottom layer particles.

Abstract: For forming a perforated pipe a method is employed which includes winding on a mandrel having multiple spaced protrusions thereon angularly related strips arranged between the protrusions. These strips cooperatively define openings through which the protrusions extend. The strips are formed of fibres which are impregnated with a settable resin or plastic which combine with the fibres to form a tube adequate to resist a pressure of about 600 p.s.i. Because the protrusions are employed the fibres can be so impregnated as to be resin-rich. The openings may be screened with resin-poor granules arranged in vaulted configuration. A further strip may be wound around the foregoing arrangement to hold the granules against the resulting pipe.

Abstract: Solutions and membranes formed therefrom are disclosed with solvents having completely halogenated, saturated, hydrocarbon backbones and solubility parameters within a particular range. Preferred solvent have at least one ether linkage. An exemplary solvent is ##STR1## wherein X is F, Cl, Br, and I; n is 0, 1, and 2; m is 1, 2, and 3; and Y is COOCH.sub.3 and SO.sub.2 F. The solutions include perfluorinated copolymers having high equivalent weight which have been prepared from tetrafluoroethylene and perfluorinated sulfonyl fluoride- or carboxyl-containing vinyl monomers.

Abstract: A Bayer process solution is filtered through a bed of particles of a granular substance containing Fe.sub.2 O.sub.3 to remove copper and zinc species from the solution. The particles preferably have an Fe.sub.2 O.sub.3 content of about 40 to 100% by weight. For more effective removal of zinc, the particles are coated with a metal sulfide, preferably zinc sulfide.

Abstract: A filter packing of electrostatically spray formed microfibers, the structure of which is a foamed coating layer containing open cell pores completely surrounding a nonporous fiber core. The pores extend perpendicularly through the foamed coating and have a substantially uniform distribution in cross section. The foamed coating and the fiber core are made of the same polymer composition.

Abstract: A system for the rapid dewatering of sludge in large quantities makes use of a filter plate of design and construction capable of supporting heavy mechanized mobile equipment without damage to the filter media.The filter plate features a monolithic plate of granular filter material used as the filtering medium in sludge beds for dewatering or reducing residual solids or sludge of potable water treatment systems. The filter material is made structurally rugged and with a smooth hard surface for the retention of sludge solids. The filter material is supported upon a substructure of aggregate providing approximately 40% internal voids for the gravity flow or drainage of filtrate and the back flow of chemicals and gases used in the rapid water reduction process. The assemblage is constructed of such strength as to allow for use of heavy handling equipment such as front end loaders in the removal of the dried sludge or cake upon the completion of the rapid water reduction process.

Abstract: An improved rigid filter plate for sludge dewatering is comprised of a filter element of two or more sizes within the range of 8 to 100 grid of jagged, irregular hard particles of aluminum oxide or similar materials, and of a supporting element of larger particles all bonded with an adhesive bonding agent. The particles in the filtering element increase in average diameter progressing from the upper surface to the lower surface of the element. A process for manufacturing the improved rigid filter plate is also set forth.

Abstract: An apparatus for and a method of removal of particulate material and boiler-feed additives from pressurized, saturated steam, which apparatus includes a composite cartridge in which particulate matter is removed by a filter tube and boiler-feed additives are removed by contacting the filtered steam with a bed of a hydrogen-form, strong-acid, ion-exchange resin, and saturated, pressurized steam substantially free of particulate matter and volatile, alkaline, boiler-feed additives are recovered for use, for example, in food-preparation and sterilization purposes.

Abstract: A composite semipermeable membrane comprising a porous support and a crosslinked thin film formed on said porous support, said crosslinked thin film being formed by reacting compound (A) which is at least one compound selected from the group consisting of polyalkylenimines and polyalkylenimine derivatives, compound (B) which is at least one compound selected from a group of compounds typified by piperazine, 2,5-dimethylpiperazine, 4-aminomethylpiperidine and 1,4,8,11-tetraazacyclotetradecane, and compound (C) as a crosslinking agent which is a compound having in one molecule two or more functional groups capable of reacting with amino groups; and a process for preparing said composite semipermeable membrane.

Abstract: The present invention is directed to improvements in non-cytotoxic polyurethane compositions. The improvement in the polyurethane compositions is achieved by reacting at least one NCO-terminated prepolymer and at least one polyol in the presence of a dialkyltin dicarboxylated catalyst composition. The catalyst reduces the curing time of the polyurethane resin and cannot be released therefrom. The improved polyurethane compositions are advantageously employed in separatory devices such as hollow fiber separatory devices intended to be used in biomedical applications. The separatory device employs at least one separatory membrane suitable for the intended end use application which is secured, potted or sealed in a housing using a cured flexible polyurethane composition.

Abstract: A hydrophilic oleophobic filter medium in granular form and composed of glass beads dispersed in a matrix of cured cement. The granules may be utilized in conjunction with naturally occurring materials, e.g., sand and/or anthracite. The granular density can be predetermined and varied. The granular shape is regular and controllable and the granular size can be graded for each density, so that the granules in a given filter level are of varient size, having a uniformity coefficient ranging from about 1.2 to 1.7. The method of making such granules includes the steps of casting a sheet of desired density and thickness, partially curing the sheet, severing the partially cured sheet to polygonal granules, curing the granules, optionally tumbling the granules, and finally screening them for final sizing.

Abstract: A method of bonding a cation exchange membrane which comprises melt-bonding a part of the cation exchange membrane of a fluorinated copolymer in the form having ion-exchange groups of --COOY wherein Y represents hydrogen atom or a C.sub.1 -C.sub.20 alkyl group, when the cation exchange membrane is used in the form having ion-exchange groups of--(COO).sub.m Xwherein X represents an alkali metal, an alkaline earth metal or --NHR.sub.1 R.sub.2 R.sub.3 and R.sub.1 to R.sub.3 respectively represent hydrogen atom or a lower alkyl group and m is a valence of X.

Abstract: A method of heat sealing together two untreated layers of a sulfonated perfluorovinyl ether ion exchange diaphragm or membrane material having pendant groups predominantly in the sulfonamide form by placing a layer of untreated sulfonated perfluorovinyl ether material having pendant groups predominantly in the sulfonic acid form between the sulfonamide layers to create a "sandwich". The preferred heat sealing involves applying from 1 to 5, and preferably from 3.5 to 5.0 kg/cm.sup.2 pressure at from 260.degree. to 350.degree. C. and preferably from 280.degree. to 320.degree. C. for from 3.5 to 7.5, and preferably from 3.5 to 5.0 seconds to this "sandwich". It had been previously taught that such untreated sulfonamide layers could not be heat sealed together. The novel heat sealing technique of this invention enables fabrication of a cathode-membrane unit using ion exchange membranes having such a sulfonamide layer facing the cathode of an electrolytic cell.

Abstract: Assembly of a coated screen jacket and a coated pipe base is held together by radially positioned fasteners such as shear pins which pass through overlapping portions of male and female slip fittings which are welded to the screen jacket and pipe base before it is coated. The mating fittings include an internal groove for mounting an O-ring. Since the screen jacket has complementary male and female fittings on its opposite ends, a plurality of short screen jacket portions can be easily mounted in series on a pipe base member.

Abstract: The permeable membrane assemblies disclosed in this application utilize the bi-leaf edge membrane concept and the lay-flat tubing connector concept presented in prior and pending patents for ionic systems. Herein these concepts are shown and claimed for their utility in transfer systems in general including selective transfer of gaseous fluids and liquid fluids whether ionic or not as well as for transfer of heat. As before the concepts offer advantages of simplicity and reliability and offer economical assembly in leak free equipment. Countercurrent flow of the fluids is obtained. Hydrogen separation from mixed gases is one application. The full range of dialysis and fluid to fluid extraction processes are prospective candidates for these design concepts.

Abstract: A process for preparing a composite amphoteric ion exchange membrane, which comprises forming a thin membrane not exceeding 5 microns thick by applying to a surface of a microporous polymer substrate having a physical, selective permeability of its own, a coating consisting of a polymer having either a cation or anion exchange group and a functional group capable of receiving another ion exchange group having an opposite sign from the cation or anion exchange group or a mixture of two polymers one of which has either a cation or an anion exchange group and the other of which has a functional group capable of receiving an ion exchange group having an opposite sign from the cation or anion exchange group, and introducing the ion exchange group having an opposite sign to said functional group to provide a ratio of anion to cation exchange capacity in the range of from 0.5 to 2.0.

Abstract: A process and composition for producing a permselective composite membrane. The process comprises dissolving a specified imidazolone ring-containing aromatic polymer in an aqueous liquid medium containing a water-miscible amine having a pKa of more than 5.0 in a concentration of at least 5% by weight, coating the polymer solution on a microporous substrate, and drying the coating to form an ultrathin film on the substrate. The permselective composite membrane obtained is especially useful as a reverse osomsis membrane.

Abstract: A ceramic porous body useful as a filtering material for molten metal is disclosed. The ceramic porous body, consisting essentially of cordierite, alumina and silica, is formed by covering surfaces of cell strands of a ceramic porous body skeleton having a bulk specific gravity of 0.25-0.55 with 3-40% by weight per the weight of the skeleton of an activated alumina layer and has an average diameter of interconnected voids of 0.3-5.0 mm, a pressure loss of 0.3-30.0 mm as a water-gauge pressure when passing air through the body of 1 cm thick at a rate of 1 m/sec., a microsurface area of not less than 10 m.sup.2 /g and a porosity of 75-95%.

Abstract: Superior bipolar membranes are prepared having high performances. The improvement is achieved by (1) using high performance component ion exchange membranes, and (2) controlling the method of joining two component membranes into a bipolar membrane. The method of preparation of high performance component ion exchange membranes is also disclosed.

Abstract: An asymmetrical ultrafiltration membrane based on cellulose triacetate, optionally substituted by up to 30% cellulose diacetate, is made wettable without tendency to embrittlement or shrinkage by adding hydrophobic synthetic silicic acid to the casting solution.

Abstract: The apparatus comprises a hollow casing in the form of a solid of revolution having an inlet and an outlet, a spinner for imparting rotary motion within the casing to a fluid being purified, and a hollow filter element closed at one end, positioned coaxially within the casing and snugly fit with the open end in the outlet of the casing. The apparatus also includes a discharge connection piece for removal of the impurities that have been separated from the fluid being purified. The spinner is positioned at the inlet, and the discharge connection piece is attached to the lower portion of the casing. The filter element and the casing define a space tapering from the inlet toward the outlet, and the filter element being a frame with a covering having a water-repellent polymeric foam material applied thereto.

Abstract: A molded polymer body with very fine, discrete, solid particles composed of a metal, metal compound or a mixture of the same incorporated within the molded body in a uniform pattern of distribution, substantially free of agglomeration, as obtained by a process of first impregnating the molded body with a bath solution of a metal compound and then gassing the molded body with a gaseous precipitating agent to precipitate the metal-containing particles. The products are especially useful in catalytic membranes, e.g. as used in artificial lungs or artificial kidneys.

Abstract: A process for the production of a composite membrane consisting of a porous supporting membrane and a thin separating membrane. The separating membrane is produced on the surface of a carrier film (consisting essentially of a soluble polymer). The carrier film coated with the separating membrane is placed with its separating membrane side on a porous supporting membrane such that the separating membrane is between the supporting membrane and the carrier film. The carrier film is then dissolved.

Abstract: Cartridge filters of enhanced capture potential for fine contaminants, prepared by selective interaction of melamine formaldehyde bonding resin and polyamido/polyamine-epichlorhydrin charge modifier.

Abstract: A filter for filtering contaminants from liquid, wherein the apparatus includes several distinct, adjacent layers of granular filter medium. The layers are carefully graded for size and density, with the granules constituting the layers increasing in density and decreasing in size in the direction of filter flow. At least some of the layers are composed of essentially uniformly sized and shaped, water-wettable synthetic granules of a specific gravity ranging from about 1.04 to about 1.5. For some applications, all of the bed layers are formed of such synthetic granules; for other applications, some of the layers, preferably the lower layers, are formed of naturally occurring materials, such as anthracite, sand, and fruit pit shells or nut shells. In either form of the invention, the distribution of density and size in the direction of flow--normally downwardly--is such that the layers readily stratify after backwashing to reconstitute the bed in its initial, most efficient filtration configuration.

Abstract: Synthetic, granular filter particles which are of substantially uniform size, of controlled density, and water-wettable. A method is provided for manufacturing such particles in uniform sizes ranging from about 1/16 to about 3/8 inch and at controlled densities ranging from a specific gravity of about 1.04 to about 1.5. The particles comprise hollow silica beads dispersed in a matrix of cured cement. In deep bed, multi-layer liquid filters, the particles can be utilized as the upper strata of the filter and act as a barrier for particles that would normally plug a deep bed filter having conventional, natural materials, such as sand in the lower strata. Alternatively, all of the strata of the deep bed filter may be comprised of the particles of the present invention in substantially uniform, controlled sizes and densities, the size of the particles decreasing and the density of the particles increasing in the direction of flow through the filter bed.

Abstract: A filter element for gas or liquid comprises a layer of glass, ceramic, metal, mineral wool or organic fibres containing, wholly within the layer, an apertured sheet, for example of steel or aluminum, the fibres being bound to one another throughout the layer and through the apertures, as well as to the sheet itself, by a synthetic resin such as silicone resin or polyurethane. The filter element is formed by mounting the apertured sheet a selected distance above a filter surface on which the fibres build up while a slurry containing the fibres is drained through the filter surface. When the fibres have built up to a predetermined distance above the sheet, the fibres containing the sheet are removed and the assembly impregnated with a synthetic resin and cured. Two or more grades of slurry mixture may be used in succession to produce a density grading through the thickness of the fibrous layer.

Abstract: An internally smooth disposable column, of various sizes up to 800 ml. internal volume, made of biocompatible polymer is filled with particulate absorbent, e.g. carbon coated with polyHEMA, between support means located as close as practicable to inlet and outlet. L/D ratio is usually 1.5:1-5:1. Various shapes e.g. double frustoconical or trochoid of revolution are proposed for the column, which is preferably symmetrical to facilitate moulding of identical column halves; these shapes usually converge to meet a funnel-shaped connecting piece at inlet and outlet.

Abstract: A porous filter is formed of sintered metal particles and is characterized by having sintered metal particles of relatively large size throughout and a thin subsurface area adjacent the upstream surface containing sintered metal particles of relatively small size, thus providing a thin area of relatively small pore size adjacent the upstream surface while the remaining major portion of the filter has a relatively large pore size. The filter is particularly useful as an inertial filter and as a support for reverse osmosis membranes.

Abstract: Particulate perlite fines are agglomerated to increase the apparent particle size by forming a mixture of the perlite fines with a compound such as boric acid capable of being substantially converted to B.sub.2 O.sub.3 at elevated temperatures. The mixture is heated while mixing to convert the compound to B.sub.2 O.sub.3 and to at least partially coat the particulate perlite.The mixture is then heated above the melting point of B.sub.2 O.sub.3 to agglomerate the perlite fines. The product of this process has particular utility as an improved filter aid.

Abstract: A dialysis membrane for hemodialysis having passages of uniform diameter and positioned uniform distances from each other.

Abstract: The disclosure concerns a technique for forming screen packs which may be used in filtering foreign matter from an extruded plastic material. Such technique involves initially forming a sandwich array which includes a number of sheets of screening, each sheet of screening having a desired orientation with respect to each other sheet of screening. The sandwich array also includes at least one sheet of thermoplastic material. The sandwich array is heated, in order to cause the thermoplastic material to flow into the openings in the sheets of screening, such that the sandwich array will constitute a unitary structure upon the cooling of the thermoplastic material. Thereafter, at least one screen pack, and preferably several screen packs are formed from such unitary structure, e.g., through the performance of a suitable punching operation on the unitary structure.

Abstract: A device for the purification of water and methods for the use thereof are disclosed. The device comprises a closed container substantially porous to water, a purification agent contained therein and an ingredient dispersed in the purification agent for the purpose of inhibiting fine particles of the agent from escaping the container when the device is immersed in water. The disclosed inhibitory ingredients include certain modified starches, wood flour and aluminium lanolate soap.The device is especially useful in removing incipient impurities from drinking water that can elude customary water treatment and render drinking water organoleptically unsatisfactory.

Abstract: A method for manufacturing a rigid, perforated cloth wherein the cloth is woven, in both the warp and weft directions of core yarns wrapped with a thermoplastic covering yarn. After weaving, the cloth is subjected to heating at a temperature greater than the melting point of the thermoplastic covering yarn. The cloth is thereafter cooled, thereby imparting rigidity to the perforated cloth.The product of the present invention is a rigid, perforated cloth in which the individual yarns of the cloth comprise a core yarn that is covered with a thermoplastic cover. The rigid, perforated cloth displays reinforced structural networks due to the plasticity of the thermoplastic material and enhanced resistance to physical and chemical degradation.

Abstract: The invention relates to a resin binder composition comprising, in combination, a resole resin and a metal salt curing accelerator providing a binder composition that has an improved cure rate in electrical grade laminates without adversely affecting electrical properties. The binder composition provides low viscosity for impregnation and accelerated curing rates for advancing the impregnated substrate prior to laminating and final curing.

Abstract: A coating modification process is provided for use in ultrafiltration systems to improve the adherence of porous coatings of preformed, aggregated, inorganic metal oxide particles, to substrates, particularly those comprised of hollow tubular porous carbon members. The process involves exposure of the coated members, during the initial treatment to water vapor at specific humidity, temperature and times. The ultrafiltration systems so treated are particularly well-suited for prolonged use in the concentration and separation of oil from mixtures of oil, water and detergents, the recovery of polyvinylalcohol from textile wastes, and other useful applications.

Abstract: Particulate porous absorptive material such as carbon is coated with a biocompatible polymer to give a thin (e.g. 1-10 micron) smooth permeable coating without plugging the pores. The resulting material is free from fines and surface debris and useful for haemoperfusion. Coating is best effected by spraying hot washed carbon granules, free from fines and in rapid movement with a solution of polymer (e.g. polyHEMA) so as to bring about rapid evaporation and a coating weight preferably of up to 20% usually 0.25% to 5%.

Abstract: An improved cation-exchange membrane, onto which have been adhered fine particles of a crosslinked high molecular weight substance having anion-exchange groups and which can maintain a specific permselectivity for monovalent cations over a long period of time, is prepared with ease by treating a cation-exchange membrane with a suspension of fine particles of the said crosslinked high molecular weight substance.

Abstract: A device for the purification of water and methods for the use thereof are disclosed. The device comprises a closed container substantially porous to water, a purification agent contained therein and an ingredient dispersed in the purification agent for the purpose of inhibiting fine particles of the agent from escaping the container when the device is immersed in water. The disclosed inhibitory ingredients include certain modified starches, wood flour and aluminium lanolate soap.The device is especially useful in removing incipient impurities from drinking water that can elude customary water treatment and render drinking water organoleptically unsatisfactory.

Abstract: A method of phase separation using ferromagnetic materials. A mixture of phases is treated with particles or granules of ferromagnetic material so that one of the phases is preferentially absorbed or collected onto or into the particles or granules. The particles or granules of the ferromagnetic material together with the absorbed or collected phase may then be recovered from the remainder of the mixture using magnetic means.

Abstract: Composite membranes bearing ion-exchange groups suitable for use in membrane separation processes are produced by providing a porous substrate which is physically semipermeable by itself, applying a coating composition consisting essentially of a filmforming polymeric material to which ion-exchange groups are introduceable and a liquid medium onto the surface of said substrate, removing said liquid medium to provide an ultrathin membrane of said material having a thickness less than 10 microns, and treating said ultrathin membrane to provide said ion-exchange groups throughout said ultrathin membrane.