Abstract: Embodiments of the present invention provide for the deposition of spacing elements for spiral wound elements which promote mixing within the feed space during element operation thereby improving element performance and reducing concentration polarization and potential for biological fouling.

Abstract: Systems, devices, and methods are provided for removing carbon dioxide from a target fluid, such as, for example, blood, to treat hypercarbic respiratory failure or another condition. A device is provided including first and second membrane components for removing dissolved gaseous carbon dioxide and bicarbonate from the fluid, which can be done simultaneously. The device can be in the form of a cartridge configured for use in a dialysis system. A method of treatment is also provided, involving drawing blood from a patient and bringing the patient's blood in contact with a first membrane component having a sweep gas passing therethrough, and a second membrane component having a dialysate passing therethrough. The dialysate's composition can be selected such that charge neutrality is maintained.

Abstract: Embodiments of the present disclosure provide a method and apparatus for filtering and surgical procedures. An exemplary apparatus includes an evacuation tube having a filter, a long axis and a hollow conduit extending through the long axis, the hollow conduit fluidly connecting a tube inlet and a tube outlet, the filter located within the hollow conduit operable to remove particles from a flow passing through the hollow conduit from the tube inlet to the tube outlet.

Abstract: A purification system for a colloidal dispersion containing an unwanted dissolved substance in the dispersing liquid phase is described which includes a back-pressure regulating feature, disposed in a first conduit and downstream of a semi-permeable filter element. This is used to force a portion of the unpurified dispersing liquid across the filter element and into a second conduit. The second conduit is associated with an adsorptive element that serves to remove the unwanted dissolved substance from the filtered portion of the dispersing liquid. A mixing chamber is disposed downstream of the back-pressure regulating feature whereby the purified dispersing liquid portion from the second conduit rejoins the bulk flow of the colloidal dispersion passing through the first conduit. In a preferred embodiment, hollow fibers are used which serve as the back-pressure regulating feature, the adsorptive element, and the mixing chamber before being discharged at the outlet of the device.

Abstract: The present invention relates to a powder-type hair thickening agent storage container having a plurality of spurting holes, and to a powder-type hair thickening agent storage container having a plurality of spurting holes, the storage container having a cylindrical protrusion part, which protrudes from an upper surface thereof to spurt a powder-type hair thickening agent to an outside, and including: a barrel-shaped container part having the powder-type hair thickening agent stored therein; a packing part detachably coupled to an inside of the protrusion part, and having a discharge hole such that the powder-type hair thickening agent is spurted to the outside; and a cap part coupled to the protrusion part so as to encompass the same, and allowing the spurting amount of the powder-type hair thickening agent to be adjusted through the discharge hole.

Abstract: An integrated forward osmosis-membrane distillation (FO-MD) module and systems and methods incorporating the module is disclosed providing higher efficiencies and using less energy. The FO-MD module is osmotically and thermally isolated. The isolation can prevent mixing of FO draw solution/FO permeate and MD feed, and minimize dilution of FO draw solution and cooling of MD feed. The module provides MD feed solution and FO draw solution streams that flow in the same module but are separated by an isolation barrier. The osmotically and thermally isolated FO-MD integrated module, systems and methods offer higher driving forces of both FO and MD processes, higher recovery, and wider application than previously proposed hybrid FO-MD systems.

Abstract: A sewage treatment device includes a stirring structure, a filter box, a tank filter, and a detection structure which are connected in sequence. Conveying pipelines are connected to an exterior of the stirring structure to convey sewage to an interior of the stirring structure. First water pumps are connected to the conveying pipelines to provide conveying power. An upper-layer stirrer assembly, a lower-layer stirrer assembly and a rotating shaft configured to install the upper-layer stirrer assembly and the lower-layer stirrer assembly are arranged in the interior of the stirring structure. A lifting driving cylinder drives the upper-layer stirrer assembly and the lower-layer stirrer assembly to move up and down. The upper-layer stirrer assembly includes an engaging block axially engaged with the rotating shaft and stirring blades arranged around the periphery of the engaging block at equal intervals.

Abstract: The present disclosure of a sewage treatment device includes a compression tank that is cylinderically shaped, a stirring structure communicated with the compression tank by a first intermediate pipe, and a detection box communicated with the stirring structure by a second intermediate pipe. A telescopic driving cylinder is arranged on an upper portion of the compression tank and a conveying pipe is connected to a top surface of the compression tank to deliver external sewage to an interior of the compression tank. A diameter of the conveying pipe ranges from 8-15 cm; A filter interlayer is arranged in an interior of the compression tank and the filter interlayer is annular. An end of a driving shaft of the telescopic drive cylinder is connected with a compression body. An outer periphery of the compression body is contacted with an inner wall of the filter interlayer.

Abstract: Systems and methods used to control tangential flow filtration are provided, including control systems and methods for use with connected systems with upstream processing units, such as chromatography processing units, in fluid communication with a tangential flow filtration processing unit. Also included are control systems and methods for performing continuous concentration using single-pass tangential flow filtration with permeate flow control.

Abstract: A low-cost membrane cartridge and a low-cost method for producing a membrane cartridge, in which fatigue durability can be increased with a simple structure, are provided by focusing on a bonding position of the filtration membrane onto the filtration plate. The membrane cartridge includes a filtration membrane disposed on both faces of a filtration plate made of a thermoplastic resin, such that a joining portion provided at the periphery of the filtration membrane is joined to the filtration plate. At least an inner edge portion of the joining portion has a downward inclination with respect to the surface of the filtration plate inside of the inner edge portion at an angle in a range of 10 to 45 degrees toward an outer peripheral edge of the filtration membrane. The joining portion is pressed and welded using a heating plate or an ultrasonic horn having such an inclined surface.

Abstract: A system and method are provided for controlling fouling and complement protein activation during separation of plasma from whole blood using a spinning membrane separator. The separator includes a pair of relatively rotating surfaces spaced apart to define a gap therebetween, with at least one of the surfaces comprising a membrane that allows plasma to pass therethrough but substantially prevents the passage of red cells. In accordance with the method, the membrane material and membrane fabrication technique are selected so as that the resulting membrane both resists fouling and complement protein activation. In a specific embodiment, the membrane is has a smooth surface and substantially linear pores. The pores have a nominal diameter of less than 2 microns (so as to exclude platelets) and preferably a diameter of from 0.6 microns to 0.8 microns, as may be obtained by use of track-etching.

Abstract: Described herein is a water treatment system for simultaneously removing ammonia and nitrates from a liquid. The water treatment system comprises a nitrifying volume for nitrification of a liquid and a denitrifying volume for denitrification of the liquid. One of the nitrifying volume and the denitrifying volume resides substantially within the other of the nitrifying volume and the denitrifying volume, and the nitrifying volume and the denitrifying volume are in fluid communication. In one aspect, the nitrifying volume is a relatively oxygenated region and the denitrifying volume is a relatively oxygen-depleted region. In another aspect, the nitrifying volume is in communication with an oxygen-supplying source for providing oxygen to create the relatively oxygenated region.

Abstract: A filter assembly consists of four principal components. The principle components include a top housing containing the means to fasten in a leak proof manner to a valved top of a sport bottle; a base housing; an outer independent charged layered membrane filter; and an inner independent charged layered membrane filter. Each charged layered filter is in a cylindrical form with pleats.

Abstract: Provided are a blood purifying filter and a blood purifying apparatus including the same. The blood purifying filter includes a plasma separation filter, a hemodialysis filter, a housing, and a plasma outlet. The plasma separation filter separates plasma from blood. The hemodialysis filter removes toxins and waste products from blood. The housing provides installation spaces for the plasma separation filter and the hemodialysis filter and defines a plasma flow section outside the plasma separation filter and the hemodialysis filter. The plasma outlet is provided at one side of the housing to allow plasma passing the plasma flow section to be discharged out of the blood purifying filter.

Abstract: Described herein is a submerged plate membrane device intended for use in forward osmosis processes, particularly for concentrating various process streams such as those in ponds. Particular examples of feed streams that may be concentrated are for example the following feed solutions: brines, seawater, drilling mud, waste water, bio-digestate, and the like. Thus, the process and device described herein are useful for de-watering, and thus concentrating, the content of solar evaporation ponds and drilling mud ponds.

Abstract: A low energy water treatment system and method is provided. The system has at least one electrodialysis device that produces partially treated water and a brine byproduct, a softener, and at least one electrodeionization device. The partially treated water stream can be softened by the softener to reduce the likelihood of scale formation and to reduce energy consumption in the electrodeionization device, which produces water having target properties. At least a portion of the energy used by the electrodeionization device can be generated by concentration differences between the brine and seawater streams introduced into compartments thereof. The brine stream can also be used to regenerate the softener.

Abstract: The invention provides methods and devices that use membranes to separate oil/water mixtures. The methods and devices have a wide range of applications, including deep seep oil exploration, oil purification, and oil spill cleanup. In some embodiments, at least one first membrane is provided, the first membrane being hydrophilic and oleophobic. The first membrane allows passage of water therethrough In some embodiments, a second membrane that is hydrophobic and oleophilic is provided in addition to the first membrane. The second membrane allows passage of oil therethrough.

Abstract: A filtration device (3) has: a housing case (15) having a water inlet unit and a water outlet unit arranged on one end side thereof; and a membrane module (17) provided inside this housing case (15). A first flow path (31) for causing raw water that has flowed in from the water inlet unit (21) to flow further to the other end side of the housing case (15) than the membrane module (17), and a second flow path (33) for causing the raw water that has flowed further to the other end side of the housing case (15) along this first flow path (31) to pass through the membrane module (17) and flow to the water outlet unit (23) are provided inside the housing case (15). A spacer (19) is provided on the upstream side of the membrane module (17) in the second flow path (33).

Abstract: A dialyzer composed of: first and second dialyzation chambers, and an intermediate chamber interposed between the first and second dialyzation chambers. Each dialyzation chamber has opposed first and second ends and contains a filter member that separates the chamber into a blood compartment and a dialysate compartment. Each of the compartments extends between first and second ends. Each of the chambers has a respective one of a blood inlet or outlet and a dialysate inlet or outlet arranged so that blood and dialysate flow in counter-current to one another in both chambers. The intermediate chamber is connected to form a dialysate-free blood flow passage between the blood compartments.

Abstract: The present application relates to a molecular exchange device (1) for use with an analysis and control apparatus and a method of manufacturing a molecular exchange device.

Abstract: In a separation membrane module in a module main body, an upper horizontal partition plate forms an upper fluid channel, a lower horizontal partition plate forms a lower fluid channel, a plurality of vertical outer tubes are fixed between the upper horizontal partition plate and the lower horizontal partition plate, and vertical tubular membrane elements extend through the respective outer tubes with a gap. An upper end of the gap is in communication with the upper fluid channel and a lower end of the gap is in communication with the lower fluid channel. An upper end opening of each of the membrane elements is open to outside of the module main body and a lower end opening each of the membrane elements is closed. A vertical partition plate is provided in either the upper fluid channel or the lower fluid channel to form an inlet chamber and an outlet chamber.

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: A microchannel device is provided, the microchannel device containing a microfluidic channel including a sub fluidic channel in which at least one filtration diaphragm is provided, wherein the microfluidic channel has at least a supply port, a first discharge port and a second discharge port, the supply port and the first discharge port are connected through the filtration diaphragm, the supply port and the second discharge port are connected without the filtration diaphragm, and the filtration diaphragm is provided parallel to a fluidic channel direction of the microfluidic channel.

Abstract: A portable or personal water filtration apparatus comprising upstream and downstream removable reservoirs and a back-washable filter interposed therebetween. The back-washable filter comprises an upstream housing and a downstream housing, inside of which are fitted a membrane cartridge and a slidable plunger. The downstream housing is rotatable relative to the upstream housing between two or more positions, including, for example, an open flow position, a closed flow position, and a back-wash position. In the back-wash position, the downstream housing and plunger are axially extendable relative to the upstream housing and membrane cartridge in order to obtain a charge of clean water in the plunger that may then be forced backward through the filter by returning the plunger to its starting position. This dislodges accumulated debris from the membrane and reverses the slowing of flow observed through repeated use of the filter.

Abstract: An approach to providing folded flute ends in z-filter media is provided. The approach generally involves providing an initial deformation in a flute or corrugation to form at least one foldable tip and then folding the at least one foldable tip over. Techniques for both supported deformation and unsupported deformation are provided. Preferred corrugated media having fold arrangements, filter constructions having such fold arrangements, and filter system using such filter constructions are provided.

Abstract: A micro fluidic system comprising at least one tube (1), a membrane (3) and at least one fitting member (4). The fitting member (4) is positioned around the membrane (3) and an end part (2) of the tube(s) (1), thereby fitting the membrane (3) to the end part(s) (2). The fitting member(s) (4) is/are made from a shrinkable material, and it/they is/are fitted tightly around the membrane (3) end part(s) (2). This is obtained by causing the shrinkable material to shrink, e.g. by heating the material, while the fitting member (4) is positioned around the membrane (3) and the end part(s) (2). It is an advantage that the fitting member (4) is made from a shrinkable material because this provides the possibility of fitting the membrane (3) tightly to the end part(s) (2) in an easy and cost effective manner. The micro fluidic system is very suitable for use in a probe, such as a dialysis probe. Also claimed is a method of manufacturing the micro fluidic system.

Abstract: A serviceable device for filtering lubricating oil includes an inlet and an outlet, a first filtering element and an absorption filtering element. The absorption filtering element is configured to absorb a fluidic contaminant present in the lubricating oil when in contact with the absorption filtering element. A flow path for the lubricating oil is from the inlet, through the first filtering element, and out the outlet. The flow path further includes lubricating oil contact with the absorption filtering element.

Abstract: An enclosure for containing a portable hemodialysis unit includes a housing suitable to support components for performing hemodialysis including a dialyzer, one or more pumps to circulate blood through the dialyzer, a source of dialysate, and one or more pumps to circulate the dialysate through the dialyzer. The housing may have a front panel at which blood circuit connections and dialysate fluidic connections are located, e.g., blood line connections for patient blood access, connections for a reagent supply, dialyzer connections for both blood flow and dialysate, etc. The enclosure may also include a pair of vertical, side-by-side doors hingedly mounted to the housing. With the doors in the closed position, access to the patient access and dialysate fluidic connections may be blocked, and the doors may allow for the retention of heat in the housing suitable for disinfection during a disinfection cycle.

Abstract: A wafer-shaped hollow fiber module adapted for in-line use in a piping system. The piping system may include two standard bolted flange connections, and at least one wafer-shaped hollow fiber module sealed between the two standard bolted flange connections. The wafer shaped hollow fiber module includes: a cylindrical housing having an open end and a closed end having a first sealing surface and an inlet port; at least one side port through the cylindrical housing; an end cap united to the open end having a second sealing surface and an outlet port.

Abstract: Separation processes using osmotically driven membrane systems are disclosed generally involving the extraction of solvent from a first solution to concentrate solute by using a second concentrated solution to draw the solvent from the first solution across a semi-permeable membrane. Enhanced efficiency may result from using low grade waste heat from industrial or commercial sources. Pre-treatment and post-treatment may also enhance the osmotically driven membrane processes.

Abstract: The present invention relates to a water treatment system that uses rhamnolipids to prevent fouling and bio-film formation on the membrane and equipment and the method thereof.

Abstract: A liquid membrane matrix is disclosed in the form of an aquaporin containing bulk liquid membrane matrix (BLM), wherein said liquid membrane matrix is formed from a solution of an amphiphilic copolymer detergent wherein transmembrane proteins have been functionally incorporated and wherein said matrix further contains a stabilising oil phase. The uses of the membrane matrix include water extraction from liquid aqueous media by forward osmosis, e.g. for desalination of salt water.

Abstract: A spin column device, which contains a rigid porous filter that retains its shape during centrifugation, chromatography methods using the device to isolate a desired substance, e.g., a biological molecule, from other substances in a mixture, and kits containing the device with one or more reagents for use in the method.

Abstract: A method for treating seawater that includes the step of intaking water into at least one treatment block, wherein the treatment block includes a membrane pressure vessel having at least one membrane element, wherein the treatment block is configured such that the intake water is fed through the at least one membrane element of the membrane pressure vessel, is disclosed. The disclosed method further includes the steps of feeding the intake water through the membrane pressure vessel at a custom pressure based on the at least one membrane element of the membrane pressure vessel, and separating the intake water into at least an aqueous permeate stream and a concentrate reject stream; and outputting the aqueous permeate stream and the concentrate reject stream.

Abstract: A fluid separation system includes a separation membrane having a pattern of features thereon.

Abstract: A potable water system (10) comprises a supply line (18) and a water-purification device (20) incorporated thereinto. The water-purification device (20) comprises a microorganism filter (40) having a housing (42) and replaceable cartridge (42). The cartridge's filter media (50) includes a microorganism-capturing membrane (e.g., comprising an electropositive material) and a microorganism-killing membrane (e.g., comprising a biocidal material).

Abstract: The invention provides a sealing gasket for mounting in a passage (5) of a support plate (4) to surround the end of a tubular-shaped filter element (3) provided with at least one fluid flow channel (31), the channel lying within a flow section Sc, the gasket being constituted in the form of a sleeve: possessing a height h not less than the height hps of the passage (5) in the support plate (4); and presenting an overlap bore (15) for the filter element (3) defined between one end (16) of the sleeve and a shoulder (17) which co-operates with the other end of the sleeve to define a channel bore (19) for the fluid, the shoulder (17) possessing a surface for acting as an abutment for the terminal portion of the filter element and presenting dimensions that are adapted to extend outside the flow section Sc so as to avoid impeding fluid circulation, the overlap bore (15) being provided with a groove (28) adjacent to the shoulder (17) in order to allow the gasket to creep.

Abstract: An apparatus for the transfer of mass and heat including a membrane having a hydrophilic surface and an opposing hydrophobic surface. The construction prevents transmission or leakage of fluids from one side of the membrane to the other regardless of pressure gradients within the membrane bubble point or water intrusion pressure range, but allows the transfer of vaporized fluid from one side of the membrane to the other.

Abstract: A spin column device, which contains a rigid porous filter that retains its shape during centrifugation, chromatography methods using the device to isolate a desired substance, e.g., a biological molecule, from other substances in a mixture, and kits containing the device with one or more reagents for use in the method.

Abstract: A test paper includes a porous membrane capable of separating an object that should be filtered out of a sample by filtration, the porous membrane carrying a reagent capable of reacting with a specified component of the sample to result in coloring. The porous membrane includes a first layer having a surface on which the sample is supplied and a second layer having a surface at which sample percolation and measuring are effected, the first layer composed of large pore portions, the surface of the first layer consisting of a smooth surface having open pore portions, the second layer composed of minute pore portions the surface of the second layer consisting of a surface having open pore portions. The porous membrane has a thickness of 50 to 200 ?m and a porosity of 60 to 95%.

Abstract: In some embodiments, systems and methods are provided for purifying a liquid, such as an impaired water. In some examples, seawater or brackish water is purified, such as to a potable level. Some configurations provide a system which includes a membrane-distillation unit, such as a vacuum-enhanced direct contact membrane distillation unit. The system also includes a forward-osmosis system, which may include one or more forward-osmosis units. A concentrated draw stream from the membrane-distillation unit, such as a concentrated brine solution, serves as a draw solution for a forward-osmosis unit, which may extract water from a source water, such as an impaired water. In some implementations, the forward-osmosis system includes a second forward-osmosis unit which uses the diluted draw solution from the first forward-osmosis unit as a draw solution to extract water from a source water. The system may include additional components, such as a heater or a buffer tank.

Abstract: A method of treating a hollow fiber membrane microfiltration filter having an influent side and an effluent side to improve performance of the filter is disclosed. The method entails sealing imperfections in surfaces of the filter by flushing the filter with a liquid aqueous suspension of particulates. Filter cartridge devices also are disclosed. The devices may include a bactericidal chamber. A radial flow filter may be included in the devices. The filter cartridges may include a drain tube positioned within the filter for removing of effluent generated by the filter. A plurality of filter cartridges may be positioned on the drain tube.

Abstract: A fluted filter medium (74) comprising a corrugated filter sheet, where each flute (120) has an end closure defined by a regular fold arrangement in the corresponding corrugation. Each regular fold arrangement has at least four folds. A process for manufacturing the fluted filter medium comprising deforming a portion of each corrugation to define at least one foldable tip, and folding the said tip in order to close the corrugation.

Abstract: To reuse support plate and to fix a membrane sheet by the same method both in a new product manufacturing and in regeneration. In a flat membrane element including a deposit fixed portion formed by lapping a membrane sheet performing solid-liquid separation onto a support plate supporting the membrane sheet and by emitting a laser to a circumferential edge of the membrane sheet to deposit fix the member sheet onto the support plate, and making an inside of the membrane sheet surrounded by the deposit fixed portion be a solid-liquid separating area; an embrocation having laser absorption property is applied on the surface of the membrane sheet of the deposit fixed portion. At the time of regeneration, such a portion of the membrane sheet that corresponds to the solid-liquid separating area is cut off and, after that, a new membrane sheet is lapped on the embrocation and the new membrane sheet and the embrocation are deposit fixed by a laser.

Abstract: A method and system using hybrid forward osmosis and nanofiltration is disclosed for treating produced water containing contaminant species. The system comprises a forward osmosis cell and a downstream nanofiltration cell. A draw solution fluid cycles between the forward osmosis cell and the nanofiltration cell. The draw solution contains polyvalent osmotic agents producing polyvalent ions in the draw solution. The passage of monovalent ions through the nanofiltration membrane is hindered due to the presence of conjugate polyvalent ions.

Abstract: The present invention relates to a method for performing desalination and eliminating boron from water, which comprises carrying out a first reverse-osmosis step where the saline water is supplied into a reverse-osmosis membrane container which comprises a plurality of membranes interconnected in series, arranging between two of said membranes a blind interconnector which separates the flows of permeate in two membrane sections, i.e. the flow situated upstream of the blind interconnector and the flow situated downstream of the blind interconnector, defining two respective stages, and carrying out at least one second reverse-osmosis step which comprises low-pressure and high-flow membranes or medium-pressure and medium-flow membranes and which is supplied with some or all of the water obtained from the permeate of the membranes of the first step which are situated upstream of the blind interconnector, i.e. the first stage of the first step.

Abstract: A device for the thermal separation of water into hydrogen and oxygen, including a closed reaction chamber (1) containing water and, in said reaction chamber: —a heating system including one or several heat source elements (4,11), —one or several membranes (3), essentially impermeable to gas, to permit the selective passage of oxygen, —one or several membranes (2), essentially impermeable to gas, to permit the selective passage of hydrogen and —a mechanism (5) to permit the passage of water into said reaction chamber. According to the invention, —said heat source(s) (4, 11) is(are) placed in the water inside said reaction chamber (1), and, —said selective membranes (3) for oxygen are placed in said zones at high temperatures, —said selective membranes (2) for hydrogen are placed in said zones at lower temperatures. Preferably, the heating system is comprised of one or several concentrators (8, 9) of solar rays focusing the rays toward the inside of the reactor.

Abstract: We disclose a device for the production of hydrogen from water using heat. The device employs thermal water splitting and works essentially without electricity. It is based on the concept of a membrane reactor with two kinds of membranes allowing the separation of hydrogen and oxygen simultaneously in stoichiometric quantities from the reactor volume. The device has a special geometry resulting in a temperature distribution inside the reaction chamber to accommodate the use of hydrogen selective membranes. The device will help to reduce the need for hydrogen transport and storage as it will be rather compact for on-site use in households, small factories or gas stations. The use of the device in mobile applications is conceivable. The heat source of the device as described is combustion of a hydrocarbon using porous burner technology; however the device can be modified to exploit any other heat source, especially solar radiation.

Abstract: A transducer protector (TP) and a method for forming the transducer protector are disclosed. The transducer protector is operable in cooperation with a hemodialysis system, and may be mounted between a drip chamber and a pressure transducer. The transducer protector is mounted in an integrally-assembled housing which includes an inlet from the hemodialysis system or drip chamber, and an outlet to the pressure transducer. The transducer includes at least one hydrophobic membrane that is attached permanently to either a first connector, a second connector or a peripheral ring, the connectors integrally attached to each other to form the TP housing.

Abstract: Provided are a pressure vessel for a membrane element in which the membrane element can be easily mounted, a membrane filtration apparatus equipped with the pressure vessel for a membrane element, and a method for manufacturing a membrane filtration apparatus. A rail (protrusion) 60 is formed on the inner circumferential surface of the pressure vessel 40 in such a manner that a ridge line 61 extends along the insertion direction of the membrane element. Consequently, the membrane element 10 can be inserted into the pressure vessel 40 so as to be in a sliding contact onto the ridge line 61 of the rail 60 formed on the inner circumferential surface of the pressure vessel 40. Therefore, the frictional resistance can be reduced as compared with conventional ways, so that the membrane element 10 can be easily mounted onto the pressure vessel 40.