JP2014008430A - Separation membrane element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separation membrane element which prevents deposition and growth of a microorganism in a vicinity of a bonded part between separation membranes in the separation membrane element, prevents permeated water from being contaminated by the microorganism, and also suppresses biofouling at a water feeding side even though being stored in water for a long period of time.SOLUTION: In a separation membrane element that is sealed by bonding two separation membranes or a separation membrane and a support sheet, has such a structure that one end of an inner part thereof communicates with a water collecting pipe, and conducts membrane separation treatment, an antimicrobial property is imparted to an adhesive agent.

Description

  The present invention relates to a separation membrane element used for separating components contained in a fluid such as liquid and gas, and a method for producing the same.

  There are various methods for separating components contained in fluid such as liquid and gas. For example, taking a technique for removing ionic substances contained in seawater, brine, etc. as an example, in recent years, the use of separation membrane elements has been expanded as a process for saving energy and resources. Separation membranes used in separation methods using separation membrane elements include microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, reverse osmosis membranes, and forward osmosis membranes in terms of their pore diameter and separation function. These membranes are used, for example, in the production of drinking water or industrial ultrapure water from seawater, brine, water containing harmful substances, wastewater treatment, recovery of valuable materials, etc. It is properly used depending on the separation performance.

  The separation membrane element is common in that the raw fluid is supplied to one surface of the separation membrane and the permeated fluid is obtained from the other surface. The separation membrane element is configured to bundle a large number of separation membranes to increase the membrane area and to obtain a large amount of permeated fluid per unit element. As the shape of the separation membrane element, a spiral type, a hollow fiber type, a plate-and-frame type, a rotating flat membrane type, a flat membrane integrated type, and the like have been proposed so as to suit the application and purpose.

  In addition to the separation membrane, the separation membrane element includes members such as a flow path material and a water collecting pipe. For example, the structure of the spiral separation membrane element includes a bag-shaped separation membrane that is open only on one side of a rectangle, a permeate-side flow passage material inserted into the bag-shaped separation membrane, and an outer surface of the bag-shaped separation membrane. 2. Description of the Related Art A unit that is configured with a supply-side channel material disposed so as to face a side surface is wound around a water collection pipe.

  The feed water treated by the separation membrane element contains a lot of microorganisms such as bacteria. Microorganisms cause biofouling by attaching to the supply-side channel material and proliferating by a long-time treatment. When biofouling occurs, there are adverse effects such as an increase in the load on the supply pump due to an increase in flow resistance, and a decrease in the amount of water produced and the removal performance.

  Therefore, several methods for imparting a bactericidal action to the separation membrane element itself have been proposed as countermeasures against fouling. For example, a method of reforming a membrane by pressurizing water containing an organic substance containing polyphenol and silver ions through the separation membrane (Patent Document 1), and a method using a feed water side channel material having antibacterial properties (Patent Documents 2 and 3).

  In addition, when the supply water flows into the permeate side due to the type of separation membrane, poor adhesion, or a defect in the membrane due to long-term operation, microorganisms enter the permeate side and adhere and proliferate. A large amount of microorganisms may be mixed. In particular, it is known that the adhesion portion between the water collecting pipe and the permeation side flow path agent is liable to cause poor adhesion.

  Therefore, in order to suppress the growth of microorganisms in the permeated water, a method of filling the water collection pipe with an antibacterial adsorbent (Patent Document 4), a method of using antibacterial fibers for the separation membrane support and the permeate side channel material (Patent Document 5) is known.

JP 2008-142596 A JP 2010-89081 A JP-A-8-332489 JP-A-8-267062 JP 2001-340734 A

  However, even if a supply-side channel material having modification of the separation membrane or antibacterial properties is used, the effect of suppressing the growth of microorganisms on the permeation side is low. On the contrary, the method of filling the adsorbent inside the water collection pipe and the method of using the antibacterial fiber for the separation membrane support and the permeate-side channel material have a low effect of suppressing the growth of microorganisms on the supply side.

  In addition, the inventors suppose that in the vicinity of the adhesion part between the separation membranes and in the vicinity of the adhesion part between the separation membrane and another member, the flow rate is slow, so that microorganisms are likely to adhere and proliferate. It has been found that even if the permeate-side flow path material or the support of the separation membrane has antibacterial properties, the conventional technique may not have sufficient antibacterial effects, such as when supply water flows into the permeate side.

  Accordingly, an object of the present invention is to provide a separation membrane element that can effectively suppress deterioration of membrane performance due to biofouling and also suppress the growth of microorganisms in permeated water.

  In order to achieve the above object, a separation membrane element of the present invention is a separation membrane element for obtaining a permeated fluid from a supply fluid, and the separation membrane element includes a separation membrane, a permeation-side channel material, and a separation membrane. An adhesive part for adhering members within the element, and at least a part of the adhesive part has antibacterial properties.

  According to the present invention, it is possible to suppress the adhesion and proliferation of microorganisms in the vicinity of the separation membrane adhesion portion, and to maintain good water quality even when the supply water flows into the permeation side due to poor adhesion. Moreover, since the said adhesion part is also contacting the supply water side in the end surface of an element, the biofouling in the supply water side at the time of long-term storage can also be suppressed.

It is a perspective view which shows the state which is a spiral type separation membrane element, and the one part was cut | disconnected and expand | deployed. It is a perspective view before winding of a spiral type separation membrane element. It is a side view before winding of a spiral type separation membrane element. It is a schematic diagram of a flat membrane type separation membrane element.

Hereinafter, embodiments of the present invention will be described.

A. First Embodiment [1. Separation membrane element)
(1-1) Overview The separation membrane element 100 according to the present embodiment is a so-called spiral element including a perforated water collecting pipe and a separation membrane wound around the perforated water collecting pipe. Specifically, as shown in FIGS. 1 to 3, a water collecting pipe 1, a separation membrane 3, a permeation side flow path agent 5, a supply side flow path agent 6, a first adhesion portion 9, and a second adhesion portion 10 are provided. .

  The water collection pipe 1 is a tubular member that is hollow and has a plurality of holes on the side surface. The separation membrane 3, the supply-side channel material 6, and the permeation-side channel material 5 are stacked and wound around the water collecting pipe 1. As will be described later, the separation membrane 3 is bonded in an envelope shape so that the surfaces on the permeate side face each other. Details of the adhesion will be described later.

  The appearance of the separation membrane element 100 is cylindrical, and the raw water 71 is supplied from one end surface (left end surface in FIG. 1) of the separation membrane element 100 to the inside of the separation membrane element 100. The raw water that has passed through the end plate is supplied to the supply-side surface of the separation membrane 3 through the supply-side flow path of the separation membrane 3. A part of the raw water 71 passes through the separation membrane 3 and flows into the water collecting pipe 1 as the permeated water 73 through the permeate side flow path. The permeated water 73 that has flowed through the water collecting pipe 1 is taken out from the opposite end face (the right end face in FIG. 1) of the separation membrane element 100. The raw water 71 that has not passed through the separation membrane 3 is discharged as concentrated water 72 from the right end face of the separation membrane element 100.

(1-2) Separation membrane (a) Outline <Outline>
As the separation membrane, a membrane having separation performance according to the method of use, purpose and the like is used. The separation membrane may be formed of a single layer or a composite membrane including a separation functional layer and a substrate. In the composite membrane, a porous support layer may be formed between the separation functional layer and the substrate. The following describes the composite membrane.

<Separation function layer>
The thickness of the separation functional layer is not limited to a specific numerical value, but is preferably 5 to 3000 nm in terms of separation performance and permeation performance. In particular, it is preferably 5 to 300 nm for reverse osmosis membranes, forward osmosis membranes, and nanofiltration membranes.

  The thickness of the separation functional layer can be based on the conventional method for measuring the thickness of the separation membrane. For example, the separation membrane is embedded with resin, and an ultrathin section is prepared by cutting the separation membrane, and the obtained section is subjected to processing such as staining. Thereafter, the thickness can be measured by observing with a transmission electron microscope. Further, when the separation functional layer has a pleat structure, measurement can be made at intervals of 50 nm in the cross-sectional length direction of the pleat structure located above the porous support layer, the number of pleats can be measured, and the average can be obtained. it can.

  The separation function layer may be a layer having both a separation function and a support function, or may have only a separation function. The “separation function layer” refers to a layer having at least a separation function.

  When the separation functional layer has both a separation function and a support function, a layer containing cellulose, polyvinylidene fluoride, polyether sulfone, or polysulfone as a main component is preferably applied as the separation functional layer.

  In this document, “X contains Y as a main component” means that the Y content in X is 50% by mass, 70% by mass, 80% by mass, 90% by mass, or 95% by mass. It means that it is more than%. In addition, when there are a plurality of components corresponding to Y, the total amount of these components only needs to satisfy the above range.

  On the other hand, as the porous support layer separating functional layer, a crosslinked polymer is preferably used in terms of easy control of the pore diameter and excellent durability. In particular, a polyamide separation functional layer obtained by polycondensation of a polyfunctional amine and a polyfunctional acid halide, an organic / inorganic hybrid functional layer, and the like are preferably used in that the separation performance of components in the raw fluid is excellent. These separation functional layers can be formed by polycondensation of monomers on the porous support layer.

  For example, the separation functional layer can contain polyamide as a main component. Such a film is formed by interfacial polycondensation of a polyfunctional amine and a polyfunctional acid halide by a known method. For example, by applying a polyfunctional amine aqueous solution to the porous support layer, removing the excess amine aqueous solution with an air knife or the like, and then applying an organic solvent solution containing a polyfunctional acid halide, the polyamide separation functional layer Is obtained.

Further, the separation functional layer may have an organic-inorganic hybrid structure containing Si element or the like. Examples of the separation functional layer having an organic-inorganic hybrid structure include the following compounds (A) and (B):
(A) a silicon compound in which a reactive group and a hydrolyzable group having an ethylenically unsaturated group are directly bonded to a silicon atom, and (B) a compound other than the compound (A) and having an ethylenically unsaturated group Compounds can be included. Specifically, the separation functional layer may contain a condensate of the hydrolyzable group of the compound (A) and a polymer of the ethylenically unsaturated group of the compounds (A) and / or (B). That is, the separation functional layer is
A polymer formed by condensation and / or polymerization of only the compound (A),
-The polymer formed by superposing | polymerizing only a compound (B), and-At least 1 sort (s) of polymer of the copolymer of a compound (A) and a compound (B) can be contained. The polymer includes a condensate. In the copolymer of the compound (A) and the compound (B), the compound (A) may be condensed through a hydrolyzable group.

  The hybrid structure can be formed by a known method. An example of a method for forming a hybrid structure is as follows. A reaction solution containing the compound (A) and the compound (B) is applied to the porous support layer. In order to condense the hydrolyzable group after removing the excess reaction solution, heat treatment may be performed. As a polymerization method of the ethylenically unsaturated groups of the compound (A) and the compound (B), heat treatment, electromagnetic wave irradiation, electron beam irradiation, and plasma irradiation may be performed. For the purpose of increasing the polymerization rate, a polymerization initiator, a polymerization accelerator and the like can be added during the formation of the separation functional layer.

  For any separation functional layer, the surface of the membrane may be hydrophilized with an alcohol-containing aqueous solution or an alkaline aqueous solution, for example, before use.

<Porous support layer>
The porous support layer is a layer that supports the separation functional layer, and is also referred to as a porous resin layer.

  Although the material used for a porous support layer and its shape are not specifically limited, For example, you may form on a board | substrate with porous resin. As the porous support layer, polysulfone, cellulose acetate, polyvinyl chloride, epoxy resin or a mixture and laminate of them is used, and polysulfone with high chemical, mechanical and thermal stability and easy to control pore size. Is preferably used.

  The porous support layer gives mechanical strength to the separation membrane, and does not have separation performance like a separation membrane for components having a small molecular size such as ions. The pore size and pore distribution of the porous support layer are not particularly limited. For example, the porous support layer may have uniform and fine pores, or the side on which the separation functional layer is formed. It may have a pore size distribution such that the diameter gradually increases from the surface to the other surface. In any case, the projected area equivalent circle diameter of the pores measured using an atomic force microscope or an electron microscope on the surface on the side where the separation functional layer is formed is 1 nm or more and 100 nm or less. preferable. In particular, in terms of interfacial polymerization reactivity and retention of the separation functional layer, the pores on the surface of the porous support layer on the side where the separation functional layer is formed preferably have a projected area equivalent circle diameter of 3 to 50 nm.

  The thickness of the porous support layer is not particularly limited, but is preferably in the range of 20 μm to 500 μm, more preferably 30 μm to 300 μm, for reasons such as giving strength to the separation membrane.

  The form of the porous support layer can be observed with a scanning electron microscope, a transmission electron microscope, or an atomic microscope. For example, when observing with a scanning electron microscope, after peeling off the porous support layer from the substrate, it is cut by the freeze cleaving method to obtain a sample for cross-sectional observation. The sample is thinly coated with platinum, platinum-palladium, or ruthenium tetrachloride, preferably ruthenium tetrachloride, and observed with a high-resolution field emission scanning electron microscope (UHR-FE-SEM) at an acceleration voltage of 3 to 6 kV. A Hitachi S-900 electron microscope or the like can be used as the high-resolution field emission scanning electron microscope. Based on the obtained electron micrograph, the film thickness of the porous support layer and the projected area equivalent circle diameter of the surface can be measured.

  The thickness and pore diameter of the porous support layer are average values, and the thickness of the porous support layer is measured at intervals of 20 μm in a direction perpendicular to the thickness direction by cross-sectional observation, and is an average value of 20 points. Moreover, a hole diameter is an average value of each projected area circle equivalent diameter measured about 200 holes.

  Next, a method for forming the porous support layer will be described. For example, the porous support layer is prepared by pouring an N, N-dimethylformamide (hereinafter referred to as DMF) solution of the above polysulfone into a constant thickness on a substrate to be described later, for example, a densely woven polyester cloth or non-woven cloth. It can be produced by molding and wet coagulating it in water.

  The porous support layer is “Office of Saleen Water Research and Development Progress Report” no. 359 (1968). In addition, in order to obtain a desired form, the polymer concentration, the temperature of the solvent, and the poor solvent can be adjusted.

  For example, a predetermined amount of polysulfone is dissolved in DMF to prepare a polysulfone resin solution having a predetermined concentration. Next, this polysulfone resin solution is applied to a substrate made of polyester cloth or nonwoven fabric to a substantially constant thickness, and after removing the surface solvent in the air for a certain period of time, the polysulfone is coagulated in the coagulation liquid. Can be obtained.

<Base material>
From the viewpoint of the strength and dimensional stability of the separation membrane, the separation membrane may have a substrate. As the base material, it is preferable to use a fibrous base material in terms of strength, unevenness forming ability and fluid permeability.

  As a base material, both a long fiber nonwoven fabric and a short fiber nonwoven fabric can be used preferably. In particular, since the long fiber nonwoven fabric has excellent film-forming properties, when the polymer solution is cast, the solution penetrates through the permeation, the porous support layer peels off, and Can suppress the film from becoming non-uniform due to fluffing of the substrate and the like, and the occurrence of defects such as pinholes. In addition, since the base material is made of a long-fiber non-woven fabric composed of thermoplastic continuous filaments, compared to short-fiber non-woven fabrics, it suppresses the occurrence of non-uniformity and film defects caused by fiber fluffing during casting of a polymer solution. be able to. Furthermore, since the separation membrane is tensioned in the film-forming direction when continuously formed, it is preferable to use a long-fiber nonwoven fabric excellent in dimensional stability as a base material.

  In the long-fiber nonwoven fabric, in terms of moldability and strength, it is preferable that the fibers in the surface layer on the side opposite to the porous support layer have a longitudinal orientation than the fibers in the surface layer on the porous support layer side. According to such a structure, not only a high effect of preventing membrane breakage by maintaining strength is realized, but also a laminate comprising a porous support layer and a substrate when imparting irregularities to the separation membrane The moldability is improved, and the uneven shape on the surface of the separation membrane is stabilized, which is preferable.

  More specifically, the fiber orientation degree in the surface layer on the side opposite to the porous support layer of the long fiber nonwoven fabric is preferably 0 ° to 25 °, and the fiber orientation degree in the surface layer on the porous support layer side. And the orientation degree difference is preferably 10 ° to 90 °.

  The separation membrane manufacturing process and the element manufacturing process include a heating process, but a phenomenon occurs in which the porous support layer or the separation functional layer contracts due to the heating. In particular, the shrinkage is remarkable in the width direction where no tension is applied in continuous film formation. Since shrinkage causes problems in dimensional stability and the like, a substrate having a small rate of thermal dimensional change is desired. In the nonwoven fabric, when the difference between the fiber orientation degree on the surface layer opposite to the porous support layer and the fiber orientation degree on the porous support layer side surface layer is 10 ° to 90 °, the change in the width direction due to heat is suppressed. Can also be preferred.

  Here, the fiber orientation degree is an index indicating the direction of the fibers of the nonwoven fabric substrate constituting the porous support layer. Specifically, the fiber orientation degree is an average value of angles between the film forming direction when continuous film formation is performed, that is, the longitudinal direction of the nonwoven fabric base material, and the fibers constituting the nonwoven fabric base material. That is, if the longitudinal direction of the fiber is parallel to the film forming direction, the fiber orientation degree is 0 °. If the longitudinal direction of the fiber is perpendicular to the film forming direction, that is, if it is parallel to the width direction of the nonwoven fabric substrate, the degree of orientation of the fiber is 90 °. Accordingly, the closer to 0 ° the fiber orientation, the longer the orientation, and the closer to 90 °, the lateral orientation.

  The degree of fiber orientation is measured as follows. First, 10 small piece samples are randomly collected from the nonwoven fabric. Next, the surface of the sample is photographed at 100 to 1000 times with a scanning electron microscope. In the photographed image, 10 samples are selected for each sample, and the angle when the longitudinal direction (longitudinal direction, film forming direction) of the nonwoven fabric is 0 ° is measured. That is, the angle is measured for a total of 100 fibers per nonwoven fabric. An average value is calculated from the angles of 100 fibers thus measured. The value obtained by rounding off the first decimal place of the obtained average value is the fiber orientation degree.

  The thickness of the base material is preferably set to such an extent that the total thickness of the base material and the porous support layer is in the range of 30 to 300 μm, or in the range of 50 to 250 μm.

  In addition, each layer such as a base material, a porous support layer, and a separation functional layer included in the separation membrane contains 5% by weight or less of additives such as a colorant, an antistatic agent, and a plasticizer in addition to the components described above. It can contain in the ratio of 2 weight% or less, or 1 weight% or less.

(1-3) Permeation-side channel material The permeation-side channel material functions as a spacer that forms a permeation-side channel between the stacked separation membranes 3. The permeate-side channel material may be a continuous member 5 such as tricot as shown in FIGS. 1 and 3, or may be a resin material arranged directly on the separation membrane.

  The thickness of the permeate-side channel material in the separation membrane element is preferably 30 μm or more and 1000 μm or less, more preferably 50 μm or more and 700 μm or less, and further preferably 50 μm or more and 500 μm or less. Can be secured.

The thickness of the permeate-side channel material 3 may be freely adjusted so as to satisfy the required separation characteristics and permeation performance conditions. The thickness is adjusted by changing the processing temperature and the resin for hot melt to be selected, for example, when disposing a discontinuous permeation-side channel material by a hot melt processing method,
The thickness of the permeate side channel material can be measured using a commercially available shape measurement system or the like. For example, the thickness can be measured from a cross section with a laser microscope, or measured with a high-precision shape measuring system KS-1100 manufactured by Keyence. The measurement can be performed at a location where an arbitrary permeation-side channel material is present, and the value obtained by summing the values of the respective thicknesses can be divided by the total number of measurement locations.

(1-4) Supply-side channel material The supply-side channel material may be a continuous member 6 such as a net as shown in FIGS. 1 to 3, or may be directly disposed on the separation membrane. Good.

  The thickness of the supply-side channel material is preferably 80 μm or more, and more preferably 100 μm or more. A flow resistance can be made small because the thickness of a supply side channel material is 80 micrometers or more. The thickness of the supply side channel material is preferably 2000 μm or less, and more preferably, for example, 1500 μm or less or 1000 μm or less. When the thickness of the flow path material is 2000 μm or less, the film area per element can be increased.

(1-5) Adhesion Portion Some members of the separation membrane element are fixed to other members. “Fixing” includes various forms such as fusion using ultrasonic waves, adhesion using an adhesive, and adhesion using a tape. A portion that adheres between members by bonding is hereinafter referred to as an “bonding portion”. That is, the adhesive part includes an adhesive, a tape, and the like that are applied and solidified.

  At least a part of the adhesive portion has antibacterial properties. “Having antibacterial properties” refers to having an effect of suppressing the growth of microorganisms such as bacteria and includes the case of having bactericidal properties. In addition, the adhesion part should just be able to suppress the proliferation of at least one kind of microorganism.

  Moreover, it is preferable that the position where the adhesion part which has antimicrobial property is provided contacts supply water and permeated water. That is, it is preferable that the bonding portion is a location that becomes a boundary between a space where supply water can exist and a space where permeated water can exist.

  The space where the supply water can exist is a space where the supply water flows under normal conditions. For example, a supply-side flow path (a gap provided between the surfaces on the supply side of the separation membrane in a spiral element), separation It is the both ends in the longitudinal direction of a membrane element. The space in which the permeated water can exist is a space through which the permeated water flows under normal conditions, for example, a permeate-side flow path (a gap provided between surfaces on the permeate side of the separation membrane in the spiral element). .

  As an adhesive part located in the said boundary, the adhesion part of the permeation | transmission side surfaces of the two separation membranes (one separation membrane may be folded) facing each other, or the permeation | transmission side of a separation membrane, for example And the adhesion part of the permeation | transmission side channel material etc. are mentioned. In addition, the bonded portion between the water collecting pipe and the permeate-side channel material in the spiral separation membrane element is also an example of a bonded portion located at the boundary. These adhesion portions are located in the vicinity of the end of the separation membrane, particularly in the vicinity of the end in the longitudinal direction of the water collecting pipe, that is, in the vicinity of the upper or lower surface of the spiral separation membrane element. By being located here, the adhesive portion can be in contact with the permeating fluid inside the element and can be in contact with the supply fluid at the end face of the element. That is, the bonding portion can be in contact with both the supply water and the permeated water. Generally, since the flow velocity is slow in the vicinity of the adhesion part on the permeate side of the separation membrane, microorganisms are likely to adhere and grow. Therefore, if the type of separation membrane or long-term operation causes a defect in the membrane, or if microorganisms are mixed into the permeation side due to inadequate adhesion and the supply water flows into the permeation side, the microorganisms adhere and proliferate in the vicinity of the adhesion part. As a result, the permeating fluid may be contaminated with microorganisms. In particular, the portion where the water collecting pipe and the permeate-side channel material are bonded also has a problem that adhesion failure is likely to occur.

  These problems are solved by the fact that the bonded portion has antibacterial properties. Compared with the permeation side flow path material and the base material of the separation membrane, the adhesion portion has a smaller area than the permeation side flow path material and the base material, and thus the amount of the antibacterial agent used can be greatly reduced. Furthermore, as described above, the adhesive portion is in contact with both the supply side and the permeation side, so that the effect of suppressing biofouling on the supply side of the separation membrane during long-term storage or the like is also realized.

  Hereinafter, these adhesion portions will be described more specifically with reference to the drawings.

  As shown in FIGS. 2 and 3, the separation membrane 3 is stacked and bonded together to form an envelope-like membrane.

  Specifically, the rectangular separation membrane 3 is folded in half so that the surface on the supply side faces inward. The supply-side flow path member 6 is disposed so as to be sandwiched between the supply-side surfaces of the separation membrane 3.

  The separation membrane 3 folded in half is alternately stacked with the permeation-side channel material 5. The bi-fold separation membrane 3 is disposed so that the fold faces the water collecting pipe 1. Adhesive portions 10 are provided in the vicinity of three sides of the four rectangular sides excluding one side corresponding to the crease. The permeation-side surfaces of the separation membranes 3 facing each other are bonded by the bonding portion 10 with the permeation-side flow path member 5 interposed therebetween. That is, the separation membrane 3 is bonded in an envelope shape opened toward the water collecting pipe 1 by the U-shaped bonding portion 10.

  As shown in FIGS. 2 and 3, the permeation side flow path member 5 has a larger area than the separation membrane 3. The separation membrane 3 is disposed so as to be separated from the end of the permeate-side flow path member 5 on the water collecting pipe 1 side. That is, in the region between the separation membrane 3 and the water collecting pipe 1, the plurality of permeation-side flow path members 5 are directly overlapped without passing through the separation membrane 3. In this region, the plurality of permeation-side flow path members 5 are bonded to each other by bonding portions 9 provided in the vicinity of both end portions in the longitudinal direction of the water collecting pipe 1. Specifically, both ends of the U-shape of the bonding portion 10 extend toward the water collecting pipe 1 beyond the fold side end of the separation membrane 3 to form the bonding portion 9.

  Further, the permeate-side flow path member 5 and the separation membrane 3 arranged at the top in FIG. 3 are bonded to the water collecting pipe 1 through the bonding portions 9 and 10 by being wrapped around the water collecting pipe 1. Is done.

  The adhesive forming the adhesive part preferably has a viscosity in the range of 40 PS to 150 PS, and more preferably 50 PS to 120 PS. When the adhesive viscosity is 150 PS or less, the loss of the performance of the separation membrane element due to the generation of wrinkles in the separation membrane when the separation membrane element is produced is suppressed. On the contrary, when the adhesive viscosity is 40 PS or more, the adhesive hardly flows out from the end portion (adhesive portion) of the separation membrane element. If the adhesive flows out, it will contaminate the element manufacturing equipment, and as a result, the adhesive will adhere to unnecessary parts of the separation membrane and impair the performance of the separation membrane element. To do.

  Although it does not specifically limit as a kind of adhesive agent, Reaction type adhesive agents, such as hot-melt type | system | groups, such as an ethylene vinyl acetate copolymer and polyolefin resin, an acrylic resin, an epoxy resin, and a urethane resin, can be used. Among them, urethane adhesive is preferable, and in order to make the viscosity in the range of 40 PS to 150 PS, the main component isocyanate and the curing agent polyol are mixed in a ratio of isocyanate: polyol = 1: 1 to 1: 5. Is preferred. The viscosity of the adhesive is measured with a B-type viscometer (JIS K 6833) by measuring the viscosity of the main agent, the curing agent alone, and a mixture in which the blending ratio is defined in advance.

  The amount of the adhesive applied is preferably such that an application width of 10 mm or more and 100 mm or less can be secured after the separation membrane is wrapped around the water collection pipe or after the separation membrane is bonded to the permeate side channel material. If it is this range, inflow to the permeation | transmission side of the supply fluid from the poor adhesion part can be suppressed, and it can suppress that an effective film | membrane area reduces because an adhesive agent spreads.

(1-6) Antibacterial agent The antibacterial property of the adhesion part is realized by the adhesion part containing an antibacterial agent.

  The antibacterial agent contained in the adhesive part is not particularly limited, and one or more kinds of generally known inorganic antibacterial agents and organic antibacterial agents can be arbitrarily selected and used. As the inorganic antibacterial agent, at least one metal ion selected from the group consisting of silver, copper and zinc is preferable. As the organic antibacterial agent, chitosan and its decomposition products, chlorophenols, and dimethylphenylsulfami Preferred is at least one compound selected from the group consisting of

As the antibacterial metal ion, an antibacterial agent supported on porous fine particles such as zeolite can be preferably used. For example, a compound of silver zeolite has the following general formula [I]:
Ag _{x Hy Az} M ₂ (PO ₄ ) ₃ [I]
(A is an alkali metal, M is Zr, Ti or Sn, x, y, and z are each a positive number less than 1, and x + y + z = 1). This is a compound that belongs to the space group R3c and in which each constituent ion forms a three-dimensional network.

A in the above formula is an alkali metal, specifically, a metal such as Li, Na, and K, and M is Zr, Ti, or Sn. Specific examples of the phosphate compound include the following.
Ag _0.01 H _0.95 Li _0.04 Zr ₂ (PO ₄ ) ₃
Ag _0.05 H _0.85 Li _0.10 Zr ₂ (PO ₄ ) ₃
Ag _0.10 H _0.80 Li _0.10 Ti ₂ (PO ₄ ) ₃
Ag _0.10 H _0.85 Li _0.05 Zr ₂ (PO ₄ ) ₃
Ag _0.20 H _0.75 Li _0.05 Ti ₂ (PO ₄ ) ₃
Ag _0.30 H _0.45 Na _0.25 Zr ₂ (PO ₄ ) ₃
Ag _0.35 H _0.60 Na _0.05 Sn ₂ (PO ₄ ) ₃
Ag _0.50 H _0.45 K _0.05 Sn ₂ (PO ₄ ) ₃
Ag _0.50 H _0.40 Li _0.10 Ti ₂ (PO ₄ ) ₃
Ag _0.70 H _0.25 K _0.05 Ti ₂ (PO ₄ ) ₃
Ag _0.92 H _0.05 Li _0.03 Zr ₂ (PO ₄ ) ₃
Said phosphate compound is obtained as follows, for example.

That is, a compound containing an alkali metal such as lithium carbonate (Li ₂ CO ₃ ) or sodium carbonate (Na ₂ CO ₃ ), Zr, Ti or Sn such as zirconium oxide (ZrO ₂ ) or titanium oxide (TiO ₂ ) And a compound containing a phosphate group such as ammonium dihydrogen phosphate (NH ₄ H ₂ PO ₄ ) are mixed at a molar ratio of about 1: 4: 6. By firing the mixture thus obtained at 1100 to 1400 ° C., a compound represented by the general formula AM ₂ (PO ₄ ) ₃ (A and M are the same as above) is obtained. Thereafter, the compound represented by the general formula H _(1-Z) A _Z M ₂ (PO ₄ ) ₃ is immersed in an aqueous inorganic acid solution such as nitric acid, sulfuric acid or hydrochloric acid at room temperature to 100 ° C. [II] is obtained. Further, this is immersed in an aqueous solution containing silver ions at an appropriate concentration to obtain a compound [I] represented by the general formula Ag _{x Hy} A _z M ₂ (PO ₄ ) ₃ .

  In general, a larger value of x and y in the compound [I] can exhibit higher fungicidal and antibacterial properties. Therefore, a smaller value of z in the compound [I] is better and is less than 0.3. It is preferable to use a value. Moreover, it is preferable that the lower limit is 0.05 or more because of the ease of ion exchange reaction between alkali ions and H ions.

  Even when the value of x is extremely small, the fungi and antibacterial properties can be exhibited, but if x is less than 0.001, it may be difficult to exhibit the fungi and antibacterial properties for a long time. In view of economy, it is preferable to set the value to 0.01 or more and 0.5 or less.

  In addition, the value of x can be adjusted as appropriate by adjusting the concentration of silver in the aqueous solution or the time or temperature at which the compound [II] is immersed in the aqueous solution, depending on the required characteristics and use conditions. it can.

  Since the value of y is a value equal to (1-xz), if the values of x and z are in the preferred ranges as described above, the preferred value of y is greater than 0.2 and less than or equal to 0.94. It is determined from the value and self.

  This compound is stable to exposure to heat and light, and its structure and composition are not easily changed even after heating at 800 ° C., and it is not easily discolored by irradiation with ultraviolet rays. Therefore, in the processing conditions for obtaining various molded products, there are few restrictions such as the heating temperature and the light shielding conditions as in the case of conventional organic antibacterial agents.

  The silver compound used as an antibacterial agent exhibits fungicidal and antibacterial properties by a combined action involving silver ions and H ions as follows.

  First, when Compound [I] comes into contact with moisture, a very small amount of silver ions is ionized and eluted. The silver ion concentration necessary for exhibiting antifungal and antibacterial properties is said to be in the range of several μg / L to several hundred μg / L, although it varies depending on the target mold, fungus type and environment.

  The elution amount of the antibacterial agent is preferably suppressed to such a low level that the bonded portion can maintain antibacterial properties. By setting the values of x and y in the general formula to the above ranges, the elution amount of the antibacterial agent can be easily controlled within a preferable range. The reason for this is considered to be that elution can be made extremely small because of the strong affinity in the bond between silver atoms and oxygen atoms in the compound.

  Further, H ions in the compound [I] are present in the compound by ionic bonds with oxygen atoms, and can be easily liberated until they reach ionic equilibrium by contact with moisture. As a result, the liquidity becomes acidic. It is effective in suppressing the generation of fungi and bacteria that are vulnerable to acid. The above composite action is an action not found in clay minerals such as zeolite.

Silver zeolite having a particle size of 0.3 to 0.8 μm, a true specific gravity of 2.5 to 3.5, an apparent specific gravity of 0.15 to 0.25 g / cm ³ , and a water content of 1% or less does not impair productivity. Shows stable performance.

  As the silver-based inorganic antibacterial agent, “Novalon AG300” manufactured by Toagosei Chemical Industry Co., Ltd. is well known.

  Chitosan and its decomposition products are generally chitosan, a chitin component of crustacean shell such as shrimp, crab and the like, an alkaline solution having a concentration range of 30-50%, for example, an aqueous solution of sodium hydroxide at a temperature of 60 or more. It is a hydrophilic polymer substance obtained by heating to deacetylation. Such chitosan is structurally a polysaccharide having a chemical structure composed of β- (1 → 4) bonds having D-glucosamine as a basic unit, and is not used in dilute aqueous solutions such as acetic acid, hydrochloric acid, and phosphoric acid. Although it forms a salt and dissolves easily, when it is brought into contact with an alkaline aqueous solution, it has the property of solidifying and precipitating again. Such chitosan and its degradation products have antibacterial properties against phytopathogenic fungi and bacteria such as S. aureus.

  A chlorophenol refers to a phenolic compound having a chlorine group. As chlorophenols, triclosan (2,4,4′-trichloro-2′-hydroxydiphenyl ether), o-chlorophenol, m-chlorophenol, p-chlorophenol, 2,4-dichlorophenol pentachlorophenol, o -Cresol, m-cresol, p-cresol, 4-chloro-m-cresol, 2,3,6-trichlorophenol, 2,3-dichlorophenol, 2,4,5-trichlorophenol, 2,4,6- Trichlorophenol, 2,3,4,6-tetrachlorophenol, 4-chloro-3,5-xylenol, 2,4-dichloro-3,5-xylenol, 4-chloro-3-methyl-6-isopropylpropylbenzene P-chloro-o, n-amylphenol, p-chloro-o, n-hexylphenol P-chloro-o, n-octylphenol, p-chloro-o-cyclohexyl phenol, p-chloro-o-cyclopentyl phenol, p-chloro-o-benzyl phenol, p-chloro-o- Benzyl-m-cresol, dichloro- (p-chlorobenzyl) -m-cresol, p-chloro-o-phenyl-phenol dichlorophen, bromochlorophene, hexachlorophene, bithionol, and their derivatives, depending on their antibacterial activity Without limitation. Among these, those having one or two benzene rings are preferable from the balance of antibacterial effect and holding performance, and those having two benzene rings are particularly preferable from the viewpoint of holding performance when used for water treatment.

  An organic antibacterial agent containing dimethylphenylsulfamide as an active ingredient exhibits antibacterial and antifungal effects by inhibiting the action of enzymes that make up cell membranes such as bacteria and fungi. Demonstrate antibacterial properties. It is also safe and stable against heat and chemical substances. Examples of commercially available products include “Inner Mill” manufactured by Epro Corporation.

  As a method for imparting antibacterial properties to the bonded portion, a method of mixing an antibacterial agent in the adhesive in advance or a method of mixing at the time of applying the adhesive is used.

  If the content of the antibacterial agent is too low, a sufficient antibacterial effect cannot be obtained. Conversely, if the content is too high, the amount of antibacterial components to be eluted increases, which may raise safety concerns. It is desirable that the content be 0.05 to 10% by weight based on the total weight of the agent. The total weight of the adhesive is the weight when the adhesive is applied (before curing).

[2. Method for manufacturing separation membrane element]
The separation membrane element is not limited to the following production method, but the separation functional layer is laminated on the porous support layer and the base material, and after forming the separation membrane, the permeation side flow path material is disposed. A typical method for manufacturing a spiral element will be described.

(2-1) Production of Separation Membrane Although the production process of each layer in the separation membrane has been described above, it can be summarized as follows.

  The resin is dissolved in a good solvent, and the resulting resin solution is cast on a substrate and immersed in pure water to form a composite of the porous support layer and the substrate. Thereafter, as described above, a separation functional layer is formed on the porous support layer. Furthermore, chemical treatment with chlorine, acid, alkali, nitrous acid or the like is performed to improve separation performance and permeation performance as necessary, and the monomer is washed to produce a continuous sheet of separation membrane.

  In addition, before or after the chemical treatment, unevenness may be formed on the separation membrane by embossing or the like.

(2-2) Assembling the Element Using a conventional element manufacturing apparatus, for example, an 8-inch element having 26 leaves and an effective area of 37 m ² can be manufactured. As an element manufacturing method, a method described in a reference document (Japanese Patent Publication No. 44-14216, Japanese Patent Publication No. 4-11928, Japanese Patent Laid-Open No. 11-226366) can be used.

  As described with reference to FIG. 2 and FIG. 3, the separation membrane 3 is laminated so as to sandwich the permeation-side channel material 5 and the supply-side channel material 6, and an adhesive is applied between the layers. Adhere to each other. The cured adhesive constitutes the above-described adhesive portion.

  Thus, a laminate called a separation membrane leaf is formed. A spiral membrane structure is formed by winding a separation membrane leaf around the water collecting pipe 1.

  In addition, in the case of forming the supply side channel material or the permeation side channel material using a resin, the coating method is not particularly limited as long as it can be arranged in a desired pattern on the strip-like end portion of the supply side surface of the separation membrane. However, examples thereof include a nozzle type hot melt applicator, a spray type hot melt applicator, a flat nozzle type hot melt applicator, a roll type coater, a gravure method, an extrusion type coater, printing, and spraying.

  The step of applying the resin may be performed at any timing in the production of the separation membrane. For example, the resin can be applied in a step of processing the support membrane at a stage before producing the separation membrane, a step of processing the laminate of the support membrane and the base material, a step of processing the separation membrane, or the like.

  In addition, the heat fusion method used when the resin is fused to the separation membrane includes hot air welding, hot plate welding, laser welding, high frequency welding, induction heating welding, spin welding, vibration welding, ultrasonic welding, DSI. Examples include molding.

  By changing the type of resin, the temperature at the time of heat treatment such as thermal fusion, and the like, the cross-sectional shape, thickness (height difference), etc. of the permeation side channel material and the supply side channel material can be adjusted.

B. Second Embodiment The present invention can also be applied to a flat membrane type separation membrane element. As shown in FIG. 4, the flat membrane type separation membrane element has a separation membrane 23 bonded to both surfaces of a flat support plate 22 by an adhesive portion 24 at its peripheral portion, so that the inside and outside of the separation membrane 23 can be It has a partitioned structure. The support plate 22 is provided with a water collecting pipe 21 that communicates with the space between the support plate 22 and the separation membrane 23, and is filtered from the outside of the separation membrane 23 to the space between the support plate 22 and the separation membrane 23. The filtered water is discharged from the water collection pipe 21. The bonding portion 24 contacts the permeating fluid inside the element and the supply fluid at the end face of the element.

  As the separation membrane 23, any of the above-described separation membranes can be applied. Moreover, as the adhesive part 24, an adhesive containing the above-described antibacterial agent is applied.

  In the flat membrane type element, the support plate 22 used as the permeation-side flow path agent is not particularly limited as long as it is flat, and the material has a flexural modulus of about 300 MPa or more in D790 of the ASTM test method. There is no particular limitation as long as the material has rigidity. For example, as a material constituting the support plate, an acrylonitrile butadiene styrene copolymer (ABS) resin, a resin such as polyvinyl chloride, high impact polystyrene, polyethylene, polypropylene, or other materials can be selected and used.

  In addition, as the composition and dimensions of each member of the flat membrane separation membrane element and the bonding method other than those described above, the configuration in the spiral separation membrane element described above can be applied.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

<Amount of water produced by separation membrane element>
The amount of permeated water obtained when the feed water was separated into permeated water and concentrated water by the separation membrane element was taken as the separation membrane element water production amount, and the water permeation amount per minute in one element was the water production amount (L / min). ).

<Salt removal rate by separation membrane element>
The salt concentration in the permeate and the salt concentration in the raw water were determined by measuring the electrical conductivity of each solution, and the salt removal rate was determined by the following equation.
Salt removal rate (%) = (1-salt concentration in permeate / salt concentration in raw water) × 100
<Measurement method of viable count>
It measured based on JISK0350-20-10. The outline of the test is shown below. The sample collected in the water collection bottle was transferred 1 mL at a time to three Petri dishes using a measuring pipette. Deoxycholate agar medium is dissolved by heating in a water bath at about 70 ° C., then kept at about 50 ° C., and about 15 mL of it is aseptically added to each Petri dish, while gently rotating while not solidifying. Rock and mix. After standing to cool in a horizontal state, 5 to 10 mL of deoxycholate agar medium was further added, overlaid and solidified. Cover the Petri dish, incubate at 36 ± 1 ° C. for about 20 hours in the incubator, count the number of typical colonies generated in the medium using the colony counter, and calculate the average value to obtain the average value in 1 mL of the sample. The number (pieces / mL) was measured.

<Example 1>
Nonwoven fabric made of polyester long fiber (yarn diameter: 1 dtex, thickness: about 90 μm, air permeability: 1 cc / cm ² / sec, fiber orientation: porous support layer side surface layer of 40 °, opposite to the porous support layer Fiber surface reinforcement by casting a 15.0 wt% polysulfone and dimethylformamide (DMF) solution at a room temperature (25 ° C) at a thickness of 180 µm on the surface layer (20 °) and immediately immersing it in pure water for 5 minutes. A roll of a polysulfone support membrane (thickness 130 μm) was produced.

  Thereafter, the polysulfone of the support membrane was prepared so that the polyfunctional amine was 3.5% by weight as a whole and metaphenylenediamine / 1,3,5-triaminobenzene = 60/40 molar ratio. After applying a polyfunctional amine aqueous solution and blowing nitrogen from an air nozzle to remove excess aqueous solution from the surface of the support membrane, the surface is completely wetted with a 25 ° C. n-decane solution containing 0.15% by weight of trimesic acid chloride. It was applied to. Thereafter, excess solution was removed from the membrane by air blow and washed with hot water at 90 ° C. to obtain a separation membrane continuous sheet.

Subsequently, the separation membrane sheet is cut into an appropriate size, and a polypropylene net (thickness 0.9 mm, pitch 7.5 mm) is sandwiched as a supply-side flow path material so that the separation functional layer is inside, and the separation and separation are performed. Urethane adhesive (isocyanate: polyol = 1: 3) is applied to the surface opposite to the functional layer so that the coating width after winding around the water collecting pipe in a U-shape like the adhesive portion 10 in FIG. 2 is 40 mm. After coating, the tricot as the permeate channel material and the next separation membrane were overlapped to produce two leaves with a width of 300 mm so that the effective area of the separation membrane element was 0.4 m ² . .

  As the urethane-based adhesive, a silver-based inorganic antibacterial agent mixed in the polyol so as to be 1% by weight with respect to the weight before the adhesive and mixed with isocyanate just before coating was used.

  Thereafter, a predetermined portion of the tricot is fixed to the outer peripheral surface of the perforated water collecting pipe with double-sided tape, and a urethane adhesive similar to the adhesive used in the adhesive portion 10 is applied to the position of the adhesive portion 9 in FIG. A separation membrane element wound in a shape was produced, a film was wound around the outer periphery and fixed with tape, and then edge cutting was performed to produce a 2 inch 1/4 size element.

The separation membrane element put in a plastic cylindrical pressure vessel, with the feed water of the sodium chloride concentration 0.5 mg / L, E. coli few 10 ⁵ / L, operating pressure 0.5 MPa, operating temperature 25 ° C., pH 6.5 And then evaluated (recovery rate 15%). After the evaluation, the sample was stored in RO water at 25 ° C. for 3 months, and evaluated again under the same conditions. The evaluation results are shown in Table 1. There was no change in the initial performance and the performance after storage in water for 3 months, and the number of viable bacteria in the permeated water was low.

<Examples 2 to 4>
In Example 2, an element was produced and evaluated in the same manner as in Example 1 except that the content of the silver-based inorganic antibacterial agent was changed to 0.005% by weight with respect to the total weight of the adhesive.

  Similarly, in Example 3, the content of the silver-based inorganic antibacterial agent was changed to 0.05% by weight with respect to the total weight of the adhesive, and in Example 4, the element was changed to 10% by weight in the same manner as in Example 1. Were prepared and evaluated.

  The evaluation results are shown in Table 1. As is clear from Table 1, when the content of the antibacterial agent is too small, the antibacterial property is not sufficient, and the number of viable bacteria in the permeated water is increased.

<Examples 5 and 6>
In Example 5, an element was produced and evaluated in the same manner as in Example 1 except that a copper-based inorganic antibacterial agent was used instead of the silver-based inorganic antibacterial agent.

  In Example 6, an element was prepared and evaluated in the same manner as in Example 1 except that a zinc-based inorganic antibacterial agent was used instead of the silver-based inorganic antibacterial agent.

  The evaluation results are shown in Table 1. Under conditions using zinc-based inorganic antibacterial agents, the performance after storage in water for 3 months was slightly lower in both the amount of permeate and the salt removal rate than the initial performance, but the number of viable bacteria in the permeate was low. Met.

<Examples 7 to 9>
In Example 7, an element was produced and evaluated in the same manner as in Example 1 except that triclosan was used instead of the silver-based inorganic antibacterial agent.

  Similarly, in Example 8, except that chitosan was used instead of the silver-type inorganic antibacterial agent, in Example 9, except that dimethylphenylsulfamide was used, an element was prepared and evaluated. went.

  The evaluation results are shown in Table 1. Under conditions using triclosan, the performance after storage in water for 3 months was slightly lower in both the amount of permeated water and the salt removal rate than the initial performance, and the number of viable bacteria in the permeated water was also relatively high. Under the conditions using chitosan and dimethylphenylsulfamide, there was no decrease in performance and the number of viable bacteria in the permeated water was low.

<Examples 10 to 12>
In Example 10, an element was produced and evaluated in the same manner as in Example 1 except that the adhesive application width was changed to 5 mm.

  Similarly, an element was produced and evaluated in the same manner as in Example 1 except that the coating width was changed to 10 mm in Example 11 and that the coating width was changed to 100 mm in Example 13.

  The results are shown in Table 1. As is clear from Table 1, the effective membrane area of the separation membrane is increased by reducing the adhesive application width, so that the amount of permeated water is increased. However, as can be seen from a comparison between Example 12 and other results, when the coating width is larger than 5 mm, there is less leakage from the bonded portion, and a high salt removal rate can be obtained.

<Examples 13 and 14>
In Example 13, an antibacterial adhesive is used only for the bonded portion 9 between the perforated water collecting tube and the permeate-side channel material, and a conventional adhesive is used for the adhesive portion 10 between the separation membrane and the permeate-side channel material. Were manufactured in the same manner as in Example 1 and evaluated.

  In Example 14, an antibacterial adhesive is used only for the adhesion part 10 between the separation membrane and the permeate side flow path material, and a conventional adhesive is used for the perforated water collecting tube and the permeate side flow path material adhesive part 9. Were manufactured and evaluated in the same manner as in Example 1.

  The results are shown in Table 1. In both cases, the performance after storage in water for 3 months was slightly lower in both the amount of permeated water and the salt removal rate than the initial performance, but the number of viable bacteria in the permeated water was The element using the antibacterial adhesive in the bonded portion had a lower value.

<Comparative Example 1>
In Comparative Example 1, a spiral separation membrane element was produced by using an adhesive that did not contain an antibacterial agent. The manufacturing process other than the adhesive was the same as in Example 1.

  The evaluation results are shown in Table 1. The performance after storage in water for 3 months decreased both the amount of permeated water and the salt removal rate compared to the initial performance. This is probably because biofouling occurred on the supply side of the separation membrane. In addition, the number of viable bacteria in the permeate increased.

<Comparative Examples 2-4>
In Comparative Example 2, a separation membrane element was produced in the same manner as in Comparative Example 1, except that a net which was a supply-side flow path agent was provided with 1% by weight of a silver-based antibacterial agent to the net member.

  The evaluation results are shown in Table 1. Since the antibacterial net is in contact with the separation membrane supply side surface, biofouling on the membrane surface was suppressed, and there was no change in the amount of permeate and salt removal rate, but the number of viable bacteria in the permeate increased. did.

  In Comparative Example 3, a separation membrane element was produced in the same manner as in Comparative Example 1, except that a nonwoven fabric that was a base material for the separation membrane was used with 1% by weight of a silver antibacterial agent applied to the nonwoven fabric member.

  The evaluation results are shown in Table 1. Since the substrate having antibacterial properties was in contact with the surface on the permeate side, the number of viable bacteria in the permeate was not increased, but the amount of permeate was reduced because biofouling occurred on the supply side.

  In Comparative Example 4, a separation membrane element was produced in the same manner as in Comparative Example 1 except that a tricot, which is a permeation side flow path agent, was applied with 1% by weight of a silver-based antibacterial agent to the tricot.

  The evaluation results are shown in Table 1. As in Comparative Example 3, since the antibacterial substrate is in contact with the surface on the permeate side, no increase was observed in the number of viable bacteria in the permeate, but biofouling occurred on the supply side. The amount of water decreased.

1: Water collection pipe 3: Separation membrane 5: Permeation side flow path material 6: Supply side flow path material 71: Supply water 72: Concentrated water 73: Permeate water 9: 1st adhesion part (collection pipe and permeation side flow path material Adhesive part)
10: 2nd adhesion part (adhesion part of a separation membrane and permeation | transmission side channel material, adhesion part between separation membranes)
21: Water collecting pipe 22: Support plate 23: Separation membrane 24: Adhesion part (adhesion part of a separation membrane and a support plate)

Claims (7)

  A separation membrane element for obtaining a permeated fluid from a supply fluid, the separation membrane element comprising a separation membrane, a permeate-side flow path material, and an adhesive portion for bonding members within the separation membrane element, A separation membrane element, wherein at least a part of the adhesive portion has antibacterial properties.   2. The separation membrane element according to claim 1, wherein at least a part of the adhesive portion having antibacterial properties forms a boundary between a space in which a supply fluid flows and a space in which a permeated fluid flows.   The separation membrane element is a spiral type including a hollow perforated water collection pipe, a unit including the separation membrane, a supply side flow path material, and a permeation side flow path material and wound around the perforated water collection pipe. The separation membrane element according to claim 1, wherein the separation membrane element is provided.   The separation membrane element according to any one of claims 1 to 3, wherein the adhesive portion contains at least one of an antibacterial metal ion and an organic antibacterial agent as an antibacterial agent.   The separation membrane element according to any one of claims 1 to 4, wherein the antibacterial metal ion contains at least one metal ion selected from the group consisting of silver, copper and zinc.   The organic antibacterial agent comprises at least one antibacterial agent selected from the group consisting of chitosan and its decomposition products, chlorophenols, and dimethylphenylsulfamide, A separation membrane element according to any one of the above.   The said adhesion part is formed with the hardened | cured adhesive agent, and the content of the said antibacterial agent is 0.05 to 10 weight% in the weight before the adhesive agent hardens | cures, The any one of Claims 1-6 The separation membrane element described in 1.

Images