6734results about "Membranes" patented technology

This invention discloses a cost-effective process for separating contaminants and a wide-range of fouling material from surface water, ground water and from industrial effluents. Having undergone effective pre-treatment, the water can be purified further by using high-surface area spirally wound micro-filtration (MF), ultra-filtration (UF), nano-filtration (NF) or reverse osmosis (RO) membranes. High-quality potable water free from pathogen and other contaminants is thus produced at low-cost from the pre-treated surface water and ground-water. Conversely, pre-treated industrial effluents are further purified at a relatively low-cost using NF or RO membranes, thus producing water suitable for recycle or surface discharge. The process of this invention uses cationic inorganic and/or polymeric flocculants to coagulate and flocculate the water-borne colloidal matter (e.g. clays, iron hydroxides, naturally occurring matter (NOM's), etc.), followed by filtration using a multi-media filter, charge neutralization and reversal and final filtration using a 5-micron cartridge filter. These pre-treatment steps provides a good quality water having a low Silt Density Index and a significant negative zeta potential, thereby ensuring against irreversible chemical fouling of the spirally-wound membranes.

A process for purifying 1,3-propanediol from the fermentation broth of a cultured E. coli that has been bioengineered to synthesize 1,3-propanediol from sugar is provided. The basic process entails filtration, ion exchange and distillation of the fermentation broth product stream, preferably including chemical reduction of the product during the distillation procedure. Also provided are highly purified compositions of 1,3-propanediol.

The present invention is directed to novel systems for conducting the filtration of blood using manifolds. The manifolds integrate various sensors and have fluid pathways formed therein to direct fluids from various sources through the requisite blood filtration or ultrafiltration system steps.

Desalination methods that include carbonate compound precipitation are provided. In certain embodiments, feed water is subjected to carbonate compound precipitation conditions prior to desalination. In certain embodiments, desalination waste brine is subjected to carbonate compound precipitation conditions. In yet other embodiments, both feed water and waste brine are subjected to carbonate compound precipitation conditions. Aspects of embodiments of the invention include carbone dioxide sequestration. Embodiments of the invention further employ a precipitate product of the carbonate compound precipitation conditions as a building material, e.g., a cement. Also provided are systems configured for use in methods of the invention.

A composition of enzyme, polymer, and crosslinker forms a network of covalently bound macromolecules. The covalently immobilized enzyme preparation has enzymatic activity, and retains stable activity when dried and stored at ambient conditions. Methods for preparing an immobilized enzyme and methods for using the enzyme are disclosed.

The present invention recognizes that diagnosis and prognosis of many conditions can depend on the enrichment of rare cells from a complex fluid sample. In particular, the enrichment of fetal cells from maternal samples, such as maternal blood samples, can greatly aid in the detection of fetal abnormalities or a variety of genetic conditions. In addition, the present invention recognizes that the enrichment of rare malignant cells from patient samples, can aid in diagnosis, prognosis, and development of therapeutic modalities for patients. The invention includes microfabricated filters for filtering fluid samples and methods of enriching rare cells of fluid samples using microfabricated filters of the present invention. The invention also includes solutions for the selective sedimentation of red blood cells (RBCs) from a blood sample and methods of using selective RBC sedimentation solutions for enriching rare cells of a fluid sample. Yet another aspect of the invention is an automated system for processing a fluid sample that includes: at least one filtration chamber that includes a microfabricated filter; automated means for directing fluid flow through at least one filtration chamber of the automated system, and means for collecting enriched rare cells. The present invention also includes methods of using automated systems for separating rare cells from fluid samples. Preferred fluid samples are blood, effusion, or urine samples, and rare cells that can be enriched from such sample include nucleated red blood cells and cancer cells.

A vertical skein of "fibers", opposed terminal portions of which are held in headers unconfined in a modular shell, is aerated with a gas-distribution means which produces a mass of bubbles serving the function of a scrub-brash for the outer surfaces of the fibers. The membrane device is surprisingly effective with relatively little cleansing gas, the specific flux through the membranes reaching an essentially constant relatively high value because the vertical deployment of fibers allows bubbles to rise upwards along the outer surfaces of the fibers. Further, bubbles flowing along the outer surfaces of the fibers make the fibers surprisingly resistant to being fouled by build-up of deposits of inanimate particles or microorganisms in the substrate provided that the length of each fiber is only slightly greater than the direct center-to-center distance between opposed faces of the headers, preferably in the range from at least 0.1% to about 5% greater. For use in a large reservoir, a bank of skeins is used with a gas distributor means and each skein has fibers preferably >0.5 meter long, which together provide a surface area >10 m2. The terminal end portions of fibers in each header are kept free from fiber-to-fiber contact with a novel method of potting fibers.

A membrane for use in an implantable glucose sensor including at least one crosslinked substantially hydrophobic polymer and at least one crosslinked substantially hydrophilic polymer; wherein the first and second polymers are different polymers and substantially form an interpenetrating polymer network, semi- interpenetrating polymer network, polymer blend, or copolymer. The membranes are generally characterized by providing a permeability ratio of oxygen to glucose of about 1 to about 1000 in units of (mg/dl glucose) per (mmHg oxygen). Three methods of making membranes from hydrophobic and hydrophilic monomers formed into polymer networks are provided, wherein according to at least two of the methods, the monomers may be substantially immiscible with one another.

The PRP separator-concentrator of this invention is suitable for office use or emergency use for trauma victims. The PRP separator comprises a motorized centrifugal separation assembly, and a concentrator assembly. The centrifugal separator assembly comprises a centrifugal drum separator that includes an erythrocyte capture module and a motor having a drive axis connected to the centrifugal drum separator. The concentrator assembly comprises a water-removal module for preparing PRP concentrate. The centrifugal drum separator has an erythrocyte trap. The water removal module can be a syringe device with water absorbing beads or it can be a pump-hollow fiber cartridge assembly. The hollow fibers are membranes with pores that allow the flow of water through the fiber membrane while excluding flow of clotting factors useful for sealing and adhering tissue and growth factors helpful for healing while avoiding activation of platelets and disruption of any trace erythrocytes present in the PRP.

The present invention provides a positively charged microporous membrane having a protein binding capacity about 25 mg/ml or greater comprising a hydrophilic porous substrate and a crosslinked coating that provides a fixed positive charge to the membrane. The present invention further provides a positively charged microporous membrane comprising a porous substrate and a crosslinked coating comprising pendant cationic groups. The membranes of the present invention find use in a variety of applications including ion-exchange chromatography, macromolecular transfer, as well as detection, filtration and purification of biomolecules such as proteins, nucleic acids, endotoxins, and the like.

Porous nanofiber bearing substrate materials are provided having enhanced surface area for a variety of applications including as electrical substrates, semipermeable membranes and barriers, structural lattices for tissue culturing and for composite materials, and the like.

The present invention recognizes that diagnosis and prognosis of many conditions can depend on the enrichment of rare cells, especially tumor cells, from a complex fluid sample such as a blood sample. In particular, the present invention is directed to methods and compositions for detecting a non-hematopoietic cell, e.g., a non-hematopoietic tumor cell, in a blood sample via, inter alia, removing red blood cells (RBCs) from a blood sample using a non-centrifugation procedure, removing white blood cells (WBCs) from said blood sample to enrich a non-hematopoietic cell, if any, from said blood sample; and assessing the presence, absence and/or amount of said enriched non-hematopoietic cell.

A unitary humidity exchange cell (HUX) is dislosed that includes at least one composite membrane, disposed between at least one first chamber for flow of the first fluid therethrough and at least one second chamber for flow of the second fluid therethrough. The composite membrane include an at least partially sulfonated humidity-conducting polymer comprising residues derived from at least one arylvinyl monomer; and a reinforcing substrate bonded thereto. The product finds utility in a variety of physical and chemical processes and products whereby moisture or other highly polar liquid or gas transfer, exchange removal or delivery is important. A notable application is the Membrane Energy Recovery Ventilator (MERV) in which both heat, ions and moisture is transferred between two air streams, one intake and one exhaust, from an air-conditioned building.

A method of making a carbon nanotube structure includes providing an array of substantially aligned carbon nanotubes, wetting the array with a liquid, and evaporating the liquid to form the carbon nanotube structure having a pattern in the carbon nanotube array. The structure is preferably a carbon nanotube foam.

The invention relates to a membrane bioreactor process combined with an advanced biological sludge digestion process that provides significant improvements in sludge digestion by reducing the costs and resources required for disposing of digested sludge. The offline treatment vessel is used to solubilize the organic material by operating in a very low oxygen environment. Digested process fluid is transferred back to the membrane bioreactor. The processes and apparatus substantially reduce the production of waste sludge.

Methods are disclosed to de-sulfate saline streams such as seawater, brine from seawater desalination plants, and the like. The disclosed methods can also co-produce de-ionized water and inorganic materials from such de-sulfated saline streams.

A filtration system is provided with hollow membrane filter elements operable to remove solids, particulate and colloidal matter from a process fluid. Acoustic, vibration and ultrasonic energy may be used to clean exterior portions of the hollow membrane filter elements to allow substantially continuous filtration of process fluids. The filtration system may be satisfactorily used with process fluids having a relatively high concentrations of solids, particulate and colloidal matter.

A process for removing soluble and insoluble inorganic, organic, and microbiological contaminants from a fluid stream employing a pretreatment module, a post-treatment module, a recycle stream module or any combination thereof, and a membrane module, is provided. The process provided reduces the problems associated with membrane fouling and increases contaminant removal capacity.

Composite membranes that exhibit long-term resistance to biofouling comprise a porous support and a crosslinked polyamide discriminating layer having an external surface, the discriminating layer comprising a branched poly(alkylene oxide) (PAO) polymer attached to its external surface. The branched PAO polymer typically has the structure of a molecular comb or brush, and is made by polymerization of a PAO macromonomer of the following formula:

RO—[(CHR′)_n—O]_m-V

in which R is hydrogen or a C_1-20 aliphatic or aromatic group, V is any group containing a polymerizable site, each R′ is independently hydrogen or a short chain alkyl group, n is an integer of 1-6, and m is an integer of 1 to about 200. The α end group can be either polymerized or copolymerized.

A cross flow filtration apparatus for nanofiltration or reverse osmosis has pressure vessels with a plurality of filter cartridges in each vessel. A feed port is provided at an intermediate position on the side of the vessel, and two permeate flows or branches exit opposite ends of the vessel, and the first branch has a characteristically high “upstream” flux and quality, while the second is of lesser flux and/or quality. The system provides a high degree of moduarity, enhancing flux or yield at a reduced driving pressure or overall pressure drop. Centered or off-center port, and a stop or valve in the permeate stream may apportion flows between the two outlets. Staged systems may employ a first stage bypass to achieve a target quality with increased yield. A flow divider or adaptor permits the cartridges to fit and seal in the vessel and an installation tool or sleeve may facilitate installation or replacement of cartridges having a directional perimeter seal. A tool permits modules to be bi-directional installed in the pressure vessel. Other embodiments involve adapting a conventional vessel designed for end-to-end feed flow utilizing a restrictor, obstruction or valve inside the filter cartridge to bifurcate or otherwise split or apportion the permeate. RO elements may be modified to movably position an obstruction or valve along a string of the elements and vary the take-off to two or more permeate outlets, or to provide pressure relief valves that present different pressure conditions for different elements of a string. A pressure vessel may have an intermediate inlet, with symmetric or asymmetric branching of permeate flow to opposed ends of the vessel, enhancing permeate flux, permeate quality and/or energy efficiency.

Novel porous PTFE membranes are described possessing a unique combination of high strength, low flow resistance, and small pore size. Additionally, unique constructions with superior filtration and venting properties incorporating porous PTFE membranes are described.

The invention relates to a new and improved process and apparatus for the production of high purity hydrogen by steam reforming. The apparatus is an integrated flameless distributed combustion-membrane steam reforming (FDC-MSR) or reactor for steam reforming of a vaporizable hydrocarbon to produce H₂ and CO₂, with minimal CO, and minimal CO in the H₂ stream. The flameless distributed combustion drives the steam reforming reaction which pro-vides great improvements in heat exchange efficiency and load following capabilities. The reactor may contain multiple flameless distributed combustion chambers and multiple hydrogen-selective, hydrogen-permeable, membrane tubes. The feed and reaction gases may flow through the reactor either radially or axially. A further embodiment of the invention involves producing high purity hydrogen by dehydrogenation using an integrated FDC-membrane de-hydrogenation reactor. A still further embodiment of the invention involves a zero emission hybrid power system wherein the produced hydrogen is used to power a high-pressure internally manifolded molten carbonate fuel cell. In addition, the design of the FDC-SMR powered fuel cell makes it possible to capture good concentrations of CO₂ for sequestration or use in other processes.

A microporous polyolefin battery separator membrane is extremely high in porosity, high in puncture strength, very low in shrinkage and with shutdown temperature of 130–140 degrees C. and melt integrity greater than 165 degrees C. It is made of UHMWPE having a weight-average molecular weight of 1×10⁶ or more and an inert filler. A second microporous polyolefin battery separator has a shutdown temperature of between 95 and 110 degrees C. and a melt integrity of more than 165 degrees C. It is made from an UHMWPE having a weight-average molecular weight of 1×10⁶ or more, a shutdown (LMWPE) having a weight-average molecular weight of 4500 or less and an inert filler. Both membranes have a thickness of 5–75 microns, a porosity of 30–95%, an air permeability of 1–200 sec/10 cc, an average pore diameter of 0.001 to 1 micron and puncture strength of more than 300 grams/25 {circumflex over (l)}¼ m.

This invention is based on size and mass separation of suspended particles, including biological matter, which are made to flow in a spiral channel. On the spiral sections, the inward directed transverse pressure field from fluid shear competes with the outward directed centrifugal force to allow for separation of particles. At high velocity, centrifugal force dominates and particles move outward. At low velocities, transverse pressure dominates and the particles move inward. The magnitudes of the two opposing forces depend on flow velocity, particle size, radius of curvature of the spiral section, channel dimensions, and viscosity of the fluid. At the end of the spiral channel, a parallel array of outlets collects separated particles. For any particle size, the required channel dimension is determined by estimating the transit time to reach the side-wall. This time is a function of flow velocity, channel width, viscosity, and radius of curvature. Larger particles may reach the channel wall earlier than the smaller particles which need more time to reach the side wall. Thus a spiral channel may be envisioned by placing multiple outlets along the channel. This technique is inherently scalable over a large size range from sub-millimeter down to 1 μm.

A membrane purification system and method are described in which a first membrane, an osmotically active agent, and a second membrane are utilized to separate fluid components. In general, fluid is moved through the first membrane into an osmosis compartment containing the osmotically active agent by the osmotic force of an osmotically active agent disposed between the first membrane and the second membrane. The fluid is forced from the osmotically active agent and through the second membrane while the second membrane retains the osmotically active agent in the osmosis compartment. The osmotically active agent may include a polymer.

A process for forming a porous nanoscale membrane is described. The process involves applying a nanoscale film to one side of a substrate, where the nanoscale film includes a semiconductor material; masking an opposite side of the substrate; etching the substrate, beginning from the masked opposite side of the substrate and continuing until a passage is formed through the substrate, thereby exposing the film on both sides thereof to form a membrane; and then simultaneously forming a plurality of randomly spaced pores in the membrane. The resulting porous nanoscale membranes, characterized by substantially smooth surfaces, high pore densities, and high aspect ratio dimensions, can be used in filtration devices, microfluidic devices, fuel cell membranes, and as electron microscopy substrates.

A method for distilling ethanol from a mash includes feeding a fluid to a first distillation column. The fluid and a distillate of the first distillation column are delivered to a second distillation column. The fed fluid and/or distillate of the second distillation column is/are purified in a first and/or last step of the method by a membrane separation process.

The present invention relates to filtration media having both hydrophobic (water-repellent) properties. The filtration media are produced using a fluorothermoplastic material, such as a terpolymer of tetrafluoroethylene, vinylidene fluoride, and hexafluoropropylene. The invention also relates to methods of preparing such filtration media using casting solution phase inversion.

A membrane module (5) including a plurality of porous membranes (6) extending in an array and mounted, at least at one end, in a header (8). The header (8) has a number of distribution apertures (11) for distributing a fluid into the module (5) and along a surface or surfaces of the membranes (6). An elongate chamber (10) having one open end (13) and another end is in fluid communication with the distribution apertures (11) for distributing the fluid to the distribution apertures (11).

The present invention relates to methods for producing carbon-based molded bodies. In particular, the present invention relates to methods for producing porous carbon-based molded bodies by carbonizing organic polymer materials mixed with non-polymeric fillers and subsequently dissolving the fillers out from the carbonized molded bodies. The present invention further relates to methods for producing porous carbon-based molded bodies by carbonizing organic polymer materials mixed with non-polymeric fillers which are substantially completely decomposed during the carbonization. The present invention also relates to a method for producing porous carbon-based molded bodies by carbonizing organic polymer materials, the carbon-based molded bodies being partially oxidized following carbonization so as to produce pores. In addition, the present invention relates to porous molded bodies produced according to one of said methods and the use thereof, especially as cell culture carriers and/or culture systems.