Abstract: The invention described herein teaches methods of removing microvesicular particles, which include but are not limited to exosomes, from the systemic circulation of a subject in need thereof with the goal of reversing antigen-specific and antigen-nonspecific immune suppression. Said microvesicular particles could be generated by host cells that have been reprogrammed by neoplastic tissue, or the neoplastic tissue itself. Compositions of matter, medical devices, and novel utilities of existing medical devices are disclosed.

Abstract: A separation material includes a matrix that is bound to a saccharide, enabling the separation from a liquid of substances that selectively bind the saccharide. A method for preparing the separation material and a method for separating substances from a liquid that selectively bind a saccharide of the separation material are also described. A device employs the separation material for separating from a liquid substances that selectively bind to the saccharide of the separation material.

Abstract: A hollow fiber for adsorption or filtration. The hollow fiber contains a tubular matrix having a first end and a second end, and a winding channel formed through the tubular matrix and extending between the first end and the second end. The tubular matrix is porous and has a surface-area-to-volume ratio of 10 to 20000 m2/m3, a thickness of 0.05 to 9.95 mm, an outside diameter of 0.1 to 10 mm, and a length 10 to 90% that of the winding channel. Also disclosed is a method of preparing this hollow fiber.

Abstract: A hollow porous membrane with a reduced cost and excellent separation characteristic, water permeability, and mechanical strength and a process of producing the hollow porous membrane with an excellent adhesive property between a support and a porous membrane layer at a low cost are provided. The hollow porous membrane includes a porous membrane layer in which dense layers are disposed in the vicinities of an outer surface and an inner surface. In the process of producing the hollow porous membrane, membrane-forming dopes of a first membrane-forming dope and a second membrane-forming dope, which contain the material of the porous membrane layer and a solvent, are successively applied and stacked onto the outer circumferential surface of a hollow support and the applied membrane-forming dopes are simultaneously coagulated.

Abstract: (Problem to be Solved) To obtain a hollow-fiber membrane blood purification device having excellent blood compatibility and antioxidative performance and highly stable antioxidative performance under severe environments. (Solution) A hollow-fiber membrane blood purification device provided with a hollow-fiber membrane containing a polysulfone-based resin, a polyvinyl pyrrolidone, a fat-soluble vitamin and a polymer having an ester group, in which an abundance of the fat-soluble vitamin on all surfaces of the hollow-fiber membrane is 2 mg or more and 18 mg or less based on 1 g of the hollow-fiber membrane, when the hollow-fiber membrane is extracted with ethanol, an extract is dried and subjected to measurement of an infrared absorption spectrum (IR), a ratio of absorbance (Abs(A)) of peak A in a vicinity of 1720 to 1730 cm?1 to absorbance (Abs(B)) of peak B in a vicinity of 1660 to 1670 cm?1, (Abs(A)/Abs(B)), is 0.01 or more and 0.

Abstract: Disclosed is a porous membrane with high tensile strength, good elongation at break, and good water permeability, and a method for manufacturing the same. The porous membrane comprises a bead structure including plural spherical crystallites, wherein macro voids isolated from one another with the plural spherical crystallites are formed in an outer surface side of the porous membrane.

Abstract: The Invention relates to a membrane formed from a blend of high molecular weight polyvinylidene fluoride (PVDF) (>580,000 Mw) with low molecular weight PVDF (<580,000 Mw). Porous membranes of average pore size from 5 nm to 100 microns made from the blend show improved water permeability compared to membranes formed from a single Mw PVDF.

Abstract: A fluorinated ethylene-propylene polymeric membrane comprising a copolymer comprising 2,3,3,3-tetrafluoropropene and vinylidene fluoride is disclosed. The fluorinated ethylene-propylene polymeric membranes of the invention are especially useful in gas separation processes in air purification, petrochemical, refinery, and natural gas industries.

Abstract: The present invention aims to provide a porous polymer membrane that is excellent not only in water permeability and alkali resistance but also in mechanical strength. The porous polymer membrane of the present invention includes a fluoropolymer (A) that includes a vinylidene fluoride unit and a tetrafluoroethylene unit.

Abstract: The present invention generally relates to gas separation membranes and, in particular, to high selectivity fluorinated ethylene-propylene polymer-comprising polymeric blend membranes for gas separations. The polymeric blend membrane comprises a fluorinated ethylene-propylene polymer and a second polymer different from the fluorinated ethylene-propylene polymer. The fluorinated ethylene-propylene polymers in the current invention are copolymers comprising 10 to 99 mol % 2,3,3,3-tetrafluoropropene-based structural units and 1 to 90 mol % vinylidene fluoride-based structural units. The second polymer different from the fluorinated ethylene-propylene polymer is selected from a low cost, easily processable glassy polymer.

Abstract: A membrane filter unit includes a hollow fiber membrane module with a plurality of sheet-like hollow fiber membrane elements arrayed in parallel at predetermined intervals, each of the hollow fiber membrane elements obtained by arranging a great number of porous hollow fiber membranes in parallel, and an air diffuser arranged below the hollow fiber membrane module for releasing minute bubbles toward a lower end of the hollow fiber membrane module and generating a gas-liquid mixed flow vertically swirling between an inner space and an outer space of the hollow fiber membrane module. The membrane filter unit has a residue eliminating mechanism for forming a forced flow in part of the mixed flow between the porous hollow fiber membranes and between the sheet-like hollow fiber membrane elements of the fiber membrane module.

Abstract: This repair method for a hollow fiber membrane module is a method for repairing a leaking section occurring in the hollow fiber membrane module, the repair method having a repair step for using a repair adhesive that hardens due to a composite curing function that comprises a moisture-curing function and a photo-curing function, to repair the leaking section.

Abstract: The invention offers a separation membrane element that can be produced by a method in which a membrane-sealing portion is formed by, first, immersing end portions of hollow-fiber-shaped porous separation membranes in a resinous liquid and, then, curing the resin, that has a feature in that the membrane-sealing portion is formed of a casting resin and pores of the hollow-fiber-shaped porous separation membranes are filled with a pore-filling resin at the portion at which the membranes are in contact with the membrane-sealing portion, so that the casting resin is strongly bonded with the pore-filling resin, and that has the hollow-fiber-shaped porous separation membranes whose basal portions are flexible, so that breakage of the basal portions and leakage of gas or liquid are less likely to occur when in use; a separation membrane element that has a feature in that in the membrane-sealing portion, at least the surface at a side that is to be in contact with a liquid to be treated is formed of a thermosetting f

Abstract: This disclosure relates to an anisotropic polyvinylidene fluoride hollow fiber microporous membrane containing a polyvinylidene fluoride resin. The hollow fiber microporous membrane does not include macrovoids, and has mainly a net-like structure. In addition, the hollow fiber microporous membrane has a dense outer layer on an outer surface, and a homogeneous bulk layer that is internally adjacent to the outer layer and has a coarser structure than the outer layer. The porosity of the bulk layer is at least 1.5 times the membrane surface porosity of the outer layer. The dense structure of the outer layer changes substantially discontinuously into the coarse structure of the bulk layer.

Abstract: A concentrator is used for concentrating a fluid, particularly a plasma component out of blood, for treatment of a patient. The concentrator apparatus includes a main housing defining a centrifuge chamber, that also holds the filter. The concentrator allows viewing of the fluid after centrifuging, with an outlet port positionable at a height corresponding to the level of the fraction of the fluid to be further concentrated. Once the fluid is centrifuged, a portion of the fluid is drawn through the outlet, and then pressured past the filter to further concentrate the fluid using the same vessel as used for centrifuging. The same plunger is preferably used to draw centrifuged fluid from the centrifuge chamber as to pressure the centrifuged fluid past the filter.

Abstract: A hydrophilic filtration membrane having high chemical resistance, high strength, high water permeability and high blocking performance, and being superior in fouling resistance is provided. A hydrophilic filtration membrane containing a hydrophilic polyethersulfone having a contact angle of 65 to 74 degree, a molecular weight of 10,000 to 100,000, and the number of hydroxy groups of 0.6 to 1.4 per 100 polymerization repeating units. The hydrophilic filtration membrane may additionally contain a polyvinylpyrrolidone having a molecular weight of 10,000 to 1,300,000.

Abstract: The present invention provides a hollow fiber membrane module having fixing layers to which one or more hollow fiber membrane bundles each including a plurality of hollow fiber membranes are fixed at respective ends thereof using a casting resin, a hollow portion of each of the hollow fiber membranes being open at one or both of the ends, wherein the hollow fiber membrane bundle is divided into a plurality of small bundles at least one of the fixing layers on the open side of the hollow portion, and an outer circumference of each of the small bundles is covered with an elastic body near a filtration portion interface of the fixing layer.

Abstract: The present invention relates to a membrane including a reaction product of an epoxy-functional organopolysiloxane and an amino-functional curing agent, wherein the organopolysiloxane has an average of at least two silicon-bonded epoxy-substituted organic groups per molecule and the curing agent has an average of at least two nitrogen-bonded hydrogen atoms per molecule. The invention further relates to a method of separating gas components in a feed gas mixture by use of the membrane.

Abstract: A separation membrane includes a membrane comprising a polymer, characterized in that a functional layer is formed on the surface in one side of the membrane, the peak area percentage of carbon derived from ester group measured by the electron spectroscopy for chemical analysis (ESCA) on the surface of the preceding functional layer is 0.1% (by atomic number) or more but not more than 10 (% by atomic number), and the peak area percentage of carbon derived from ester group measured by the electron spectroscopy for chemical analysis (ESCA) on the surface opposite to the functional layer is not more than 10 (% by atomic number). A separation membrane module suffering from little sticking of organic matters, proteins, platelets and so on is provided with the separation membrane as a built-in membrane.

Abstract: A tubular support for use with a hollow fiber membrane is made with an apparatus that comprises a forming machine and an ultrasonic welding machine. The apparatus may also include a coating nozzle for depositing a dope on the support. In operation, filaments are formed into a tubular structure in which the filaments cross each other in radial and circumferential directions, for example a braid. The filaments are ultrasonically welded together at intersections between them. The support is combined with a polymeric membrane wall to form a hollow fiber membrane.

Abstract: The present invention provides a sugar-immobilized polymer substrate for removing a virus, the polymer substrate allowing efficient removal of a hepatitis virus or the like in a fluid, and a method for removing a virus. In particular, the present invention provides a sugar-immobilized polymer substrate for removing a hepatitis virus or the like, the polymer substrate allowing, in the case of an application to blood of a living body, reduction in the amount of blood taken out of the body, reduction in the removal amount of blood useful components, low invasiveness, and shortening of the operation cycle; and a method for removing a virus. A hollow fiber membrane according to the present invention can be used as a module having a function of effectively removing a virus and a function of not removing useful plasma components.

Abstract: The present invention relates to high cut-off hemodialysis membranes for the treatment of chronic hemodialysis (CHD) patients, with the potential to improve long-term survival of these patients by reducing the risk of cardiovascular disease, through down-regulation of monocyte activation in the blood. Monocytes are the major circulating blood cells involved in the progression of cardiovascular disease. High cut-off hemodialysis in chronic dialysis patients results in a sustained decrease in expression of monocyte cell-surface proteins that direct the movement of these cells from the blood to the walls of blood vessels, where they promote the progression of arterial disease (atherosclerosis) that leads to cardiovascular disease (CVD); heart disease, strokes and peripheral vascular disease.

Abstract: A hydrophilic semipermeable hollow-fiber membrane for blood treatment, with an integrally asymmetric structure based on a synthetic polymer. The hollow-fiber membrane possesses on its inner surface a separating layer and an adjoining open-pored supporting layer, and has an ultrafiltration rate in albumin solution of 5 to 25 ml/(h·m2·mmHg). The hollow-fiber membrane is free from pore-stabilizing additives and has a maximum sieving coefficient for albumin of 0.005 and a sieving coefficient for cytochrome c that satisfies the equation SCCC?5·10?5·UFRAlb3?0.004·UFRAlb2+1.081·UFRAlb?0.25.

Abstract: A hollow fiber membrane fluid transport device is disclosed wherein the fibers are comprised of Polytetrafluoroethylene (PTFE), and the potting materials are comprised of fluorocopolymer and or fluoroterpolymer based materials. The potting of the device utilizes a compressed chemically resistant fluorocopolymer and or fluoroterpolymer film, allows for ease of manufacture without destruction of the PTFE hollow fibers, with high packing densities, and without the processing complexity of pre-melting, extruding, or chemical crosslinking of any polymeric adhesives. Furthermore, the PTFE hollow fibers can be treated with a fluoropolymeric solvent solution before the chemically resistant film is applied to enhance the adhesion of the PTFE fiber to the film.

Abstract: A hollow fiber membrane fluid transport device is disclosed wherein the fibers are comprised of Polytetrafluoroethylene (PTFE), and the potting materials are comprised of fluorocopolymer and or fluoroterpolymer based materials. The potting of the device utilizes a compressed chemically resistant fluorocopolymer and or fluoroterpolymer film, allows for ease of manufacture without destruction of the PTFE hollow fibers, with high packing densities, and without the processing complexity of pre-melting, extruding, or chemical crosslinking of any polymeric adhesives. Furthermore, the PTFE hollow fibers can be treated with a fluoropolymeric solvent solution before the chemically resistant film is applied to enhance the adhesion of the PTFE fiber to the film.

Abstract: Embodiments in accordance with the present invention provide forming various polycycloalkyl polynorbornene polymers and copolymers which are useful for forming pervaporation membranes, the membranes themselves and methods of making such membranes.

Abstract: Provided is a separation membrane module which is suitable for filtration of oil-containing wastewater. The separation membrane module for oil-containing wastewater treatment separates water-insoluble oil from oil-containing wastewater that has high turbidity and/or high temperature. The separation membrane module for oil-containing wastewater treatment is characterized by using a hollow fiber membrane which is composed of an alkali-resistant porous membrane selected from polytetrafluoroethylene (PTFE), polysulfone (PSF), and polyether sulfone (PES) and which has a tensile strength of 30 N or more, and characterized in that each of the hollow fiber membrane and an end-sealing member of the hollow fiber membrane has a heat distortion temperature of 100° C. or higher.

Abstract: A hollow fiber membrane module, a hollow fiber membrane module unit, and a water treatment method. The module or the module unit enable the efficient contact of microorganisms on the surface of a membrane with a gas. The module and the unit have excellent durability. The hollow fiber membrane module is formed so that the end parts of sheet-form hollow fiber membranes are formed in a substantially rectangular shape and the end face of the anchoring member on a side where the hollow fiber membranes open is formed in a substantially circular shape. The hollow fiber membrane module unit is formed in such a manner that a plurality of modules is disposed. The water treatment method is used to purify treated water with the microorganisms adhered onto the outer surfaces of the hollow fiber membranes by using the module or the unit.

Abstract: Membranes are made from polymers and heat treated so that they have at least two zones with pores of different sizes. Pores with a smaller size have a lower molecular weight cut off than pores with a larger size. Zones with pores of different sizes may also be made by coating portions of membranes with polymer coatings. Membranes with pores of different sizes may be used in dialyzers for hemofiltration, hemodiafiltration, and other hemodialysis procedures. The membranes may also be used in other separation processes.

Abstract: Present invention relates to a method for forming a nanofiltration hollow fiber membrane comprising a poly(amide-imide) (PAI) hollow fiber substrate having a polyethyleneimine (PEI)-cross-linked PAI surface layer. This membrane is suitable for forward osmosis applications. The method comprises contacting the PAI hollow fiber substrate with an aqueous solution of polyethyleneimine (PEI) under conditions suitable for cross-linking PAI in the surface layer of the PAI hollow fiber substrate by PEI.

Abstract: A method of cleaning a membrane surface immersed in a liquid medium with a fluid flow, including the steps of providing a randomly generated intermittent or pulsed fluid flow along the membrane surface to dislodge fouling materials therefrom. A membrane module is also disclosed comprising a plurality of porous membranes (6) or a set of membrane modules (5) and a device (11) for providing a generally randomly generated, pulsed fluid flow such that, in use, said fluid flow moves past the surfaces of said membranes (6) to dislodge fouling materials therefrom.

Abstract: Embodiments of the invention provide a membrane module including a first plurality of fibers capable of filtering fluids that are helically wound in layers creating a mono helix. Fluids to be treated can flow radially with respect to a longitudinal axis of the mono helix or parallel to the longitudinal axis of the mono helix. The membrane module can further include a second plurality of fibers that are helically wound with the first plurality of fibers to create a dual helix. The second plurality of fibers can have different properties than the first plurality of fibers in order to achieve different filtering functionalities.

Abstract: The present invention concerns a semipermeable hollow fiber membrane having an outer wall surface, an inner wall surface and an interior lumen extending along the length thereof and having the selective layer on the outer wall surface with a surface roughness below 10 nm. According to the invention the membrane has the smallest pore size on the outer wall surface, and has an outer wall surface which is smooth, continuous and homogeneous in a nanoscopic scale and four to five distinct layers of different pore size and density. Further the present invention concerns a prone:is for manufacturing thereof and the use thereof.

Abstract: An extracorporeal filtration and detoxification system and method generally comprise separating ultrafiltrate from cellular components of blood, treating the ultrafiltrate independently of the cellular components in a recirculation circuit, recombining treated ultrafiltrate and the cellular components, and returning whole blood to the patient. A recirculation circuit generally comprises an active cartridge including active cells operative to effectuate a selected treatment; in some embodiments, the active cells are the C3A cell line.

Abstract: An ultrafiltration filter for an extracorporeal blood circuit having an input for blood withdrawn from a human patient and a blood output for filtered blood to be infused into the patient including: a filter body having a length of at least 20 centimeters (cm) and an interior diameter of no greater than 1.5 cm; an input at a first end of the body to receive the withdrawn blood; an output at a second end of the body to discharge the filtered blood; a filter membrane in the body defining a blood passage through the body, wherein the membrane has an active filter membrane surface area of no greater than 0.2 meters squared (m2) and the filter membrane blocks passage of blood molecules having a molecular weight cut of greater than 60,000 Daltons and a volume of the blood passage in the filter being less than two percent of a cardiac output of the patient, and an ultrafiltrate output to the body and open to a side of the filter surface area opposite to the blood passage.

Abstract: [Problems] To provide a novel hydrophilized separation membrane for use in the treatment of a liquid, which comprises an aromatic ether polymer, is less likely to be degraded by sterilization with a high energy ray and has a controlled pore size and a high water permeability. [Means for Solving Problems] A porous separation membrane for use in the treatment of a liquid which is produced by a wet film formation process using an aromatic ether polymer and a hydrophilizing agent. The separation membrane can be used for medical purposes or in a pharmaceutical of food.

Abstract: The present invention concerns a semipermeable hollow fiber membrane having an outer wall surface, an inner wall surface and an interior lumen extending along the length thereof and having the selective layer on the outer wall surface with a surface roughness below 10 nm. According to the invention the membrane has the smallest pore size on the outer wall surface, and has an outer wall surface which is smooth, continuous and homogeneous in a nanoscopic scale and four to five distinct layers of different pore size and density. Further the present invention concerns a process for manufacturing thereof and the use thereof.

Abstract: A pervaporation membrane may be an acid-resistant polybenzidimazole (PBI) membrane. The acid-resistant PBI membrane may be a PBI membrane chemically modified by a process selected from the group consisting of sulfonation, phosphonation, cross-linking, N-substitution, and/or combinations thereof. The membrane may be thermally stabilized. A method for the dehydration of an acid material may include the steps of: contacting an acidic aqueous solution with a membrane of an acid-resistant polybenzidimazole; taking away a permeate stream rich in water; and taking away a concentrate steam rich in the acid material. The acidic aqueous solution may be acetic acid.

Abstract: The present invention provides a medical material and a blood purification apparatus each having high anti-thrombotic properties and high safety. The apparatus is produced by incorporating therein a medical material which has a hydrophilic copolymerization polymer present on a surface thereof which is to be in contact with blood, wherein particulate protuberances each having a particle diameter of 50 nm or more are present on the surface which is to be in contact with blood at a density of 3 particles/?m2 or less and the relaxation time of adsorbed water in the hydrophilic copolymerization polymer is 2.5×10?8 seconds or shorter and 5.0×10?10 seconds or longer at ?40° C.

Abstract: The present invention provides an absorbent which can remove cells present in blood including activated leukocytes such as granulocytes and monocytes, and cancer cells as well as can remove cytokines which facilitate the activation of the remaining cells, and further has no concern for pressure loss and has high configuration stability. That is, the present invention provides an absorbent which absorbs the granulocytes and the monocytes in blood, an absorbent for cancer therapy which absorbs an immunosuppressive protein and an absorbent having a bilayer structure of a net and a nonwoven fabric, having a zeta potential of ?20 mV or more, as well as a blood circulation column containing any of the absorbents filled therein.

Abstract: A separation membrane for water treatment, comprising a porous layer that is obtained by a phase separation method using a solution containing a resin and at least one of either an N,N-disubstituted isobutylamide or an N-monosubstituted isobutylamide.

Abstract: A negatively charged microporous filtration medium having a high charge density comprising a porous substrate and a polymerized cross-linked polymeric coating located on the inner and outer surfaces of the substrate. The coating may be formed from a reactant solution comprising negatively charged cross-linkable polymerizeable acrylamidoalkyl monomers and acrylamido cross-linking agents which are polymerized in situ on the substrate. The negatively charged microporous filtration medium are suitable for use as prefiltration membranes for selectively removing protein aggregates from a protein solution.

Abstract: The present invention is aimed to fabricate nanoporous anodic oxide ceramic membrane tubes with excellent pore characteristics by anodizing metal tubes located in a cylindrical symmetry with respect to a cathode which itself has a cylindrical symmetry. The membrane tubes may have protruded portions acting as supports and joints. The present invention also deals with stacks and bundles consisted of numbers of the anodic oxide ceramic tubes for filter and dialysis applications.

Abstract: A tubular braid, a hollow fiber membrane using the same, and a manufacturing method thereof. A hollow fiber membrane can maximize or increase adhesion between a polymer coating film and a tubular braid; significantly reduce degradation of film properties caused by non-uniform coating, that is, reduce leakage; obtain a higher percent rejection; and achieve high water permeability since the hollow fiber membrane has a larger inner diameter.

Abstract: The present disclosure relates to a preparation method of a hollow fiber membrane for water treatment that involves preparing a spinning composition including a cellulose-based resin, a poor solvent, a plasticizer, and an organic solvent and then spinning the spinning composition on a nonsolvent to form a hollow fiber membrane. Accordingly, the present disclosure overcomes the drawbacks of the conventional preparation method for hollow fiber membranes and thus provides a nano-filter (NF), reverse osmosis (RO) hollow fiber membrane for water treatment that easily enhances the properties of the separation membrane for water treatment and secures high reproducibility and high efficiency at low costs.

Abstract: A device for separating blood into individual components and/or groups of components, in the form of a sterilizable system includes a filter arrangement forming inlet and outlet chambers using filter elements arranged therein, and respective receptacles for cellular blood components and for blood plasma. The inlet chamber can be connected to the blood source via a line on the inlet side to conduct the blood and is connected, on the outlet side, to the cellular blood components receptacle. The outlet chamber is connected to the blood plasma receptacle via a line on the outlet side. Thermal sterilization is used to sterilize the device by opening a respective line into the inlet-side line of the inlet chamber, into the inlet chamber and the outlet-side line of the outlet chamber, or into the outlet chamber, the line being connected to the exterior via a hydrophobic or hydrophilic filter.

Abstract: A hollow fiber membrane fluid transport device and its method of manufacture are disclosed wherein the fibers are comprised of Polytetrafluoroethylene (PTFE), and the potting materials are comprised of fluorocopolymer and or fluoroterpolymer based materials. The potting method described herein, utilizes a compressed chemically resistant fluorocopolymer and or fluoroterpolymer film, allows for ease of manufacture without destruction of the PTFE hollow fibers, with high packing densities, and without the processing complexity of pre-melting, extruding, or chemical crosslinking of any polymeric adhesives. Furthermore, the PTFE hollow fibers can be treated with a fluoropolymeric solvent solution before the chemically resistant film is applied to enhance the adhesion of the PTFE fiber to the film.

Abstract: The present invention is directed to a method of sealing the free end of a hollow fiber membrane for use in a single header filtration module by dipping the end of the membrane into a low-viscosity light-curable adhesive and curing the adhesive. The invention further encompasses the resulting sealed hollow fiber membrane with a diameter that is only slightly larger than the diameter of the unsealed membrane.

Abstract: This invention relates to articles of high permeability and flux. Particularly useful in dialysis made from filaments produced from a composition of polysulphones and Vitamin ETPGS. This invention also includes a process for producing such articles.

Abstract: A membrane supported biofilm apparatus has a plurality of hollow fiber gas permeable membranes in a tank containing water to be treated. The membranes have an outside diameter of about 200 microns or less and occupy between 0.5% and 4% of the tank volume. A biofilm supported on the membranes occupies between about 40% and 80% of the volume of water to be treated in a reactor. The membranes may be oriented generally vertically and a spreader may be located near the bottom of the apparatus to disperse the membranes. Wastewater treatment processes are described. A process to dentrify water or treat oxidized contaminants comprises introducing hydrogen into an inner volume of the membranes to grow autotrophic organisms in the biofilm near the membrane and heterotrophic organism near the water. Another process is operated at a biomass concentration of at least 10 g/L and up to about 40 g/L to maintain a biofilm having a surface area of over 1000 square metres per cubic metre of tank volume.