Water treatment device, filtration method and leak repair method

Abstract

Proposed is a water treatment device that has less components, that can reduce time required for installation, and that can be implemented in a more space-saving manner as compared to conventional products. This water treatment device comprises at least one unit including: a hollow fiber membrane module group 110 formed of 3-10 hollow fiber membrane modules 100, each including a hollow fiber membrane bundle including a plurality of hollow fiber membranes; a pipe group 120 including a raw water transport pipe 121 connected to the hollow fiber membrane module 100 through raw water introduction openings, a filtration water collection pipe 122 connected to the hollow fiber membrane modules 100 through filtrate discharge openings, and discharged water recovery pipes 123 connected to the respective hollow fiber membrane modules 100 through discharge openings for washing; and a support member group 130 formed of support members 131, 132 that support the hollow fiber membrane modules 100 and the raw water transport pipe 121, the filtration water collection pipe 122, and the discharged water recovery pipe 123. The mass per membrane area of the hollow fiber membranes is at most 1.0 kg / m2.

Description

[Technical Field]

[0001] The present invention relates to a water treatment device, a filtration method, and a leak repair method. More particularly, the present invention relates to a hollow fiber membrane module water treatment device, a filtration method, and a leak repair method that are optimized for a water treatment device that is prefabricated and shipped. [Background technology]

[0002] Solid-liquid separation (clarification) to remove suspended matter is essential for water supply treatment to obtain drinking water, industrial water, etc. from natural water sources such as river water, lake water, and groundwater, which are turbid water. Solid-liquid separation (clarification) to remove suspended matter is also essential for treating domestic wastewater such as sewage to produce reclaimed water or to produce clear water that can be discharged. The main clarification operations required for water supply treatment are the removal of turbid matter (clay, colloids, bacteria, etc.) from turbid water from natural water sources, and for sewage treatment, the removal of suspended matter from sewage and suspended matter (sludge, etc.) from treated water after biological treatment (secondary treatment) using activated sludge, etc.

[0003] Conventionally, these clarification operations have mainly been carried out by sedimentation, sand filtration, coagulation-sedimentation sand filtration, etc. However, in recent years, membrane filtration has become more popular. The advantages of membrane filtration are: (1) The level of turbidity removal in the resulting water is high and stable, and therefore the resulting water is highly safe. (2) The installation space for the filtration equipment is small. (3) Easy automated driving. etc.

[0004] For example, in water treatment, membrane filtration is used as an alternative to coagulation-sedimentation sand filtration, or as a means of further improving the quality of treated water after coagulation-sedimentation sand filtration by installing it after coagulation-sedimentation sand filtration. In sewage treatment, membrane filtration is being studied for separating sludge from secondary sewage effluent. These membrane filtration clarification operations mainly use hollow fiber ultrafiltration membranes and microfiltration membranes (with average pore sizes ranging from several nanometers to several hundred nanometers).

[0005] As mentioned above, membrane filtration has many advantages over conventional sedimentation and sand filtration methods, and as a result, it is becoming increasingly popular in water and wastewater treatment as an alternative or complementary technology to conventional methods.

[0006] Typically, hollow fiber membrane modules are connected to a pipeline through which the liquid to be filtered passes. To achieve the desired treatment capacity of a water treatment system, several filtration modules are connected in series, and several rows of filtration modules are connected in parallel. The filtration modules of a water treatment system are arranged side by side in a rack, and the ends of each filtration module are connected to piping laid in the rack by fittings or the like.

[0007] The drawback of the known system is that the water treatment system requires a very large space and many components such as connectors for connecting pipes, support members for supporting the weight, etc. Furthermore, the construction of the water treatment system is only started after the building in which the water treatment system will be installed is completed at the water treatment site, which is a problem in that it takes a long time to complete the water treatment system.

[0008] As a membrane module water treatment device, a water treatment device has been proposed in which a special header is prepared for the membrane module and the header is connected. For example, Patent Document 1 discloses a water treatment system including a row of filtration modules. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] European Patent No. 1743690 Summary of the Invention [Problem to be solved by the invention]

[0010] In the water treatment system described in Patent Document 1, the filtration modules in each row are connected vertically by horizontal liquid collection pipes for the filtrate and the concentrate. Each filtration module has an upper filtrate branch pipe, which is laid between adjacent modules in adjacent rows. These branch pipes between rows of filtration modules are connected to a filtrate collection pipe that is common to the two adjacent rows and is laid above and parallel to the two adjacent upper liquid collection pipes. Such a design requires a distance between the rows due to the connecting branch pipes between the rows.

[0011] Furthermore, building a water treatment system takes a great deal of time and space, and because it requires many parts, even a single construction error can cause a fatal defect.

[0012] In view of these problems, the problem that the present invention aims to solve is to propose a water treatment device that has fewer components than conventional devices, can reduce the time required for installation, and can also achieve space savings. [Means for solving the problem]

[0013] The present inventors have conducted extensive research to solve the above problems, and as a result have found that the above problems can be solved by selecting an appropriate hollow fiber membrane module and constructing a piping system having a weight and structure that can withstand transportation, thereby completing the present invention.

[0014] That is, the present invention is as follows. <<Aspect 1>> a group of hollow fiber membrane modules consisting of 3 to 10 hollow fiber membrane modules, each including a hollow fiber membrane bundle consisting of a plurality of hollow fiber membranes; a group of pipes including a raw water transport pipe connected to each of the hollow fiber membrane modules via a raw water inlet communicating between the outside of the hollow fiber membrane module and the space outside the hollow fiber membranes, a filtrate collection pipe connected via a filtrate outlet communicating between the outside of the hollow fiber membrane module and the space inside the hollow fiber membranes, and an effluent recovery pipe connected via a cleaning outlet communicating between the outside of the hollow fiber membrane module and the space outside the hollow fiber membranes; and a group of support members consisting of support members supporting the hollow fiber membrane module and the raw water transport pipe, the filtrate collection pipe, and the effluent recovery pipe, The mass per membrane area of ​​the hollow fiber membrane is 1.0 kg / m 2 1. A water treatment device comprising: <<Aspect 2>> The total membrane area per unit of site area of ​​said water treatment equipment is 1,000m 2 / m 2 The water treatment device according to aspect 1 is as described above. <<Aspect 3>> 3. The water treatment device according to aspect 1 or 2, wherein the one unit of water treatment device is configured to be connectable to one another to allow connection of up to five units. <<Aspect 4>> The water treatment device according to any one of aspects 1 to 3, wherein the group of hollow fiber membrane modules and the group of pipes are connected by a flexible joint. <<Aspect 5>> The piping group, the housing of the hollow fiber membrane module, and the support member have a specific gravity of 1.3 g / cm 3 A water treatment device according to any one of aspects 1 to 4, which is made using the following resin: <<Aspect 6>> The hollow fiber membrane module comprises: the hollow fiber membrane bundle consisting of a plurality of the hollow fiber membranes; a housing in which the hollow fiber membrane bundle is housed; adhesive fixing portions that adhesively fix both ends of the hollow fiber membrane bundle to the housing; A hollow fiber membrane module comprising: The hollow fiber membrane is a microfiltration (MF) membrane or an ultrafiltration (UF) membrane, The adhesive fixing portion is a first adhesive fixing layer that adhesively fixes the hollow fiber membranes to each other and the hollow fiber membrane bundle to the inner wall of the housing with a resin material at one end of the hollow fiber membranes; a second adhesive fixing layer that adhesively fixes the hollow fiber membranes to each other and the hollow fiber membrane bundle to the inner wall of the housing with a resin material at the other end of the hollow fiber membranes; and The hollow fiber membrane module meets the following conditions (A), (B), and (C): (A) the hollow fiber membrane filling rate, expressed as 100 × (total cross-sectional area of ​​the hollow fiber membranes) / (internal cross-sectional area of ​​the housing), is 42% or less; (B) the outer diameter of the hollow fiber membrane is 1.3 mm or less; and (C) The total membrane area of ​​the hollow fiber membrane is 50 m 2 Being more than that; 6. The water treatment device according to any one of aspects 1 to 5, which satisfies all of the above. <<Aspect 7>> 7. The water treatment device according to any one of aspects 1 to 6, wherein the hollow fiber membrane has an effective length of 1.6 m or more. <<Aspect 8>> 8. The water treatment device of claim 1, wherein the filtered water collection pipe is located below the wastewater recovery pipe, the filtered water collection pipe is surrounded by the wastewater recovery pipe and its connecting fittings, and the opening for access to the filtered water collection pipe is 30 cm or less. <<Aspect 9>> a hollow fiber membrane module group composed of a plurality of hollow fiber membrane modules, including a hollow fiber membrane bundle composed of a plurality of hollow fiber membranes; a group of pipes including a raw water conveying pipe, a filtered water collecting pipe, and a wastewater recovery pipe connected to each of the hollow fiber membrane modules; A water treatment device comprising: <<Aspect 10>> Aspect 10. The water treatment device according to aspect 9, further comprising a support member for supporting the hollow fiber membrane module, the filtered water collection pipe, and the effluent water recovery pipe. <<Aspect 11>> Aspect 9 or 11. The water treatment device according to aspect 9 or 10, wherein the raw water transfer pipe, the filtered water collection pipe, and the effluent water recovery pipe are laid along the direction in which the plurality of hollow fiber membrane modules are laid. <<Aspect 12>> 11. The water treatment device according to aspect 9 or 10, wherein the support member integrally fixes the hollow fiber membrane module, the filtered water collection pipe, and the effluent water recovery pipe. <<Aspect 13>> The water treatment device according to any one of aspects 9 to 12, wherein the filtrate collection pipe and the effluent recovery pipe are located above the hollow fiber membrane module and are laid in the order of the effluent recovery pipe and the filtrate collection pipe from above the water treatment device. <<Aspect 14>> A filtration method for filtering a liquid to be filtered using the water treatment device according to any one of aspects 1 to 13, The filtration method includes: a filtration step in which the liquid to be filtered is passed through the hollow fiber membrane by external pressure filtration to obtain a filtrate; a washing step carried out after the filtration step; a chemical washing step carried out after repeating the filtration step and the washing step multiple times; Including, The washing step includes: Backwashing is performed by passing the filtrate from the inside to the outside of the hollow fiber membrane, or flushing is performed by introducing the liquid to be filtered from the raw water inlet and discharging it from the cleaning outlet; air scrubbing, in which a liquid to be filtered containing air bubbles is introduced through the raw water inlet and discharged through the cleaning outlet, and the hollow fiber membrane is shaken by the air bubbles; and cleaning the outer surface of the hollow fiber membrane by performing a combination of backwashing and air scrubbing or flushing and air scrubbing simultaneously. Including, The chemical cleaning step includes: a chemical solution cleaning step in which the inside of the hollow fiber membrane module is filled with a chemical solution, the chemical solution is introduced through the raw water inlet, and the chemical solution is discharged through the filtrate outlet and / or the cleaning outlet, and the chemical solution is circulated; a chemical solution discharging step of discharging the chemical solution from the hollow fiber membrane module after the chemical solution cleaning step; a rinsing step of rinsing the inside of the hollow fiber membrane module with filtered water or water after the chemical solution discharging step; a rinse liquid discharging step of discharging the filtered water or the water after rinsing after the rinsing step; A filtration method comprising: <<Aspect 15>> Aspect 15. The filtration method according to aspect 14, wherein in the cleaning step, backwashing or flushing is performed before the backwashing-air scrubbing simultaneous cleaning or the flushing-air scrubbing simultaneous cleaning. <<Aspect 16>> Aspect 16. The filtration method according to aspect 14 or 15, further comprising, after the washing step, a discharge step of discharging a washing wastewater from the outside and hollow portions of the hollow fiber membranes through the raw water inlet or the washing outlet. <<Aspect 17>> Aspect 17. The filtration method according to aspect 16, wherein the discharge step includes introducing compressed air into the hollow fiber membrane module through the raw water inlet or the washing outlet, and discharging the washing wastewater. <<Aspect 18>> 18. The filtration method according to any one of Aspects 14 to 17, wherein the chemical discharge step involves introducing compressed air into the hollow fiber membrane module through the raw water inlet or the washing outlet, and discharging the washing wastewater. <<Aspect 19>> Aspect 19. The filtration method according to aspect 18, wherein the chemical solution discharging step and / or the rinse solution discharging step involves introducing compressed air into the raw water inlet or the cleaning outlet to discharge the chemical solution, the filtered water, or the water. <<Aspect 20>> The volume of the chemical solution and the rinse solution per membrane area is 1.0 L / m 2 A filtration method according to any one of aspects 9 to 19, wherein: <<Aspect 21>> an air bubble inspection step of inspecting whether or not air bubbles are generated from the hollow fiber membranes by introducing compressed air from the filtrate collection pipe into each hollow fiber membrane module in the water treatment device according to any one of aspects 1 to 13; If the air bubble is detected, an identifying step of identifying the hollow fiber membrane in which the bubbles have occurred by exposing the end face of the hollow fiber membrane bundle on the side of the filtrate collection pipe without removing the hollow fiber membrane module in which the bubbles have been detected from the water treatment device; a repairing step of repairing the identified hollow fiber membrane; A method for repairing a leak, comprising: [Effects of the Invention]

[0015] According to the present invention, the number of components is reduced compared to the conventional art, the time required for installation can be reduced, and furthermore, space can be saved. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram showing an example of a water treatment device of the present invention. [Figure 2] FIG. 1 is a schematic cross-sectional view showing an example of the structure of a hollow fiber membrane module constituting the water treatment device of the present invention. [Figure 3] 1 is a diagram showing an example of a water treatment system using a water treatment device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] A preferred embodiment of the present invention (hereinafter also referred to as "the present embodiment") will be described in detail below, although the present invention is not limited to the present embodiment.

[0018] [Water treatment equipment] Fig. 1 shows an example of a water treatment device according to this embodiment. As shown in Fig. 1, the water treatment device 1 includes one or more hollow fiber membrane module groups 110 each consisting of three to ten (five in the example of Fig. 1) hollow fiber membrane modules 100, each including a hollow fiber membrane bundle made up of a plurality of hollow fiber membranes; a piping group 120 consisting of three main pipes: a raw water transport piping 121 connected to each hollow fiber membrane module 100 via a raw water inlet (not shown) of the hollow fiber membrane module 100, a filtrate collection piping 122 connected via a filtrate outlet (not shown), and an effluent recovery piping 123 connected via a cleaning outlet (not shown); and a support member group 130 consisting of support members 131 and 132 that support the hollow fiber membrane module group 110 and the piping group 120.

[0019] <<Hollow fiber membrane module>> The water treatment device 1 of this embodiment has a hollow fiber membrane module group 110 consisting of 3 to 10 hollow fiber membrane modules 100. If the hollow fiber membrane modules 100 are 3 to 10, they can be pre-assembled at a processing factory, transported to a water treatment site, and assembled as a water treatment device at the water treatment site, thereby reducing the time required to install the water treatment device 1.

[0020] Figure 2 is a schematic cross-sectional view showing an example of the structure of a hollow fiber membrane module constituting the water treatment device 1 of the present invention. The hollow fiber membrane module 100 shown in Figure 2 is a hollow fiber membrane module 100 comprising a hollow fiber membrane bundle 10 consisting of a plurality of hollow fiber membranes 11, a housing 30 in which the hollow fiber membrane bundle 10 is housed, and adhesive fixing parts 20 that adhesively fix both ends of the hollow fiber membrane bundle 10 to the housing 30. The hollow fiber membrane module 100 has a raw water inlet 54 that communicates between the outside of the hollow fiber membrane module 100 and the space 42 outside the hollow fiber membranes 11, a filtrate outlet 52 that communicates between the outside of the hollow fiber membrane module 100 and the space 41 inside the hollow fiber membranes 11, and a cleaning outlet 53 that communicates between the outside of the hollow fiber membrane module 100 and the space 42 outside the hollow fiber membranes 11.

[0021] <Hollow fiber membrane bundle> The hollow fiber membrane bundle 10 in the hollow fiber membrane module 100 is composed of a plurality of hollow fiber membranes 11, and is housed in a housing 30 for use. The number of hollow fiber membranes 11 in the hollow fiber membrane bundle 10 is preferably set appropriately so as to achieve a predetermined packing rate when housed in the housing 30. The number of hollow fiber membranes 11 in the hollow fiber membrane bundle 10 is, for example, from 1,000 to 100,000, and may be from 2,000 to 50,000, from 3,000 to 40,000, or from 5,000 to 30,000.

[0022] -Hollow fiber membrane- The hollow fiber membranes 11 in the hollow fiber membrane module 100 are microfiltration (MF) membranes or ultrafiltration (UF) membranes. Therefore, the average pore diameter of the hollow fiber membranes 11 is 1 nm (0.001 μm) or more and 10 μm or less, preferably 10 nm (0.01 μm) or more and 700 nm (0.7 μm) or less, and more preferably 20 nm (0.02 μm) or more and 600 nm (0.6 μm) or less. If the average pore diameter is 1 nm (0.001 μm) or more and 10 μm or less, sufficient separation performance can be achieved and interconnected pores can be ensured. The average pore size of the hollow fiber membrane 11 can be measured by the method for measuring mean flow pore size (also known as the half-dry method) specified in ASTM: F316-86.

[0023] The surface opening ratio of the hollow fiber membrane 11 is preferably 25% to 60% inclusive, more preferably 25% to 50% inclusive, and even more preferably 25% to 45% inclusive. This surface opening ratio refers to the surface of the hollow fiber membrane 11 that comes into contact with the liquid to be filtered (raw water) (preferably the outer surface of the hollow fiber membrane 11). If the surface opening ratio of the hollow fiber membrane 11 that comes into contact with the liquid to be filtered is 25% or more, membrane clogging and deterioration of water permeability due to abrasion of the membrane surface can be suppressed, thereby improving filtration stability. On the other hand, if the surface opening ratio of the surface that comes into contact with the liquid to be filtered is 60% or less, the required separation performance can be exhibited.

[0024] The surface open area ratio of the hollow fiber membrane 11 can be determined from an electron microscope photograph of the outer surface of the hollow fiber membrane 11. Specifically, the electron microscope photograph of the surface of the hollow fiber membrane 11 is binarized into black and white to show pores and non-pores that are open on the surface, and the area of ​​each portion is determined, and the obtained area of ​​each portion is substituted into the following mathematical formula to determine the surface open area ratio. Opening ratio [%]=100×(pore area) / {(pore area)+(non-pore area)}

[0025] The magnification of the electron microscope photograph used to calculate the surface opening ratio is preferably large enough to clearly recognize the shape of the pores opening on the outer surface of the hollow fiber membrane 11. On the other hand, from the viewpoint of making the field of view area as large as possible and determining the surface opening ratio as averaged as possible, an excessively large magnification is inappropriate. From these viewpoints, the magnification of the electron microscope photograph can be set, for example, as follows, depending on the cumulative median diameter of the pores opening on the outer surface of the hollow fiber membrane 11 (pore diameter corresponding to 50% of the cumulative area value): When the cumulative median diameter is about 1 to 10 μm, magnification is 1,000 to 5,000 times. When the cumulative median diameter is about 0.1 to 1 μm, 5,000 to 20,000 times When the cumulative median diameter is about 0.03 to 0.1 μm, it is 10,000 to 50,000 times. The black and white binarization process may be carried out using an electron microscope photograph or a copy thereof with a commercially available image analysis system.

[0026] The porosity of the hollow fiber membrane 11 is preferably 50% or more and 80% or less, and more preferably 55% or more and 65% or less. A porosity of 50% or more results in high water permeability, while a porosity of 80% or less results in high mechanical strength.

[0027] The inner diameter of the hollow fiber membrane 11 is preferably 0.10% to 1.00 mm, more preferably 0.30% to 0.80 mm, and the outer diameter of the hollow fiber membrane 11 is preferably 1.30 mm or less, more preferably 0.3% to 1.3 mm, and even more preferably 0.5 mm to 1.00 mm.

[0028] The membrane thickness of the hollow fiber membrane 11 is preferably 80 μm or more and 1000 μm or less, and more preferably 100 μm or more and 300 μm or less. If the membrane thickness is 80 μm or more, the strength of the membrane can be ensured, while if it is 1000 μm or less, the pressure loss due to membrane resistance can be suppressed.

[0029] (Hollow fiber membrane material) The hollow fiber membranes 11 in the hollow fiber membrane module 100 are preferably made of a porous membrane made of synthetic resin. The resin constituting the hollow fiber membranes 11 in this embodiment is preferably a thermoplastic resin, more preferably a polyolefin resin or a fluorine-based polyolefin resin.

[0030] Polyolefins include polyethylene, polypropylene, polyvinyl alcohol, and ethylene-vinyl alcohol copolymers, and mixtures thereof. Examples of fluorine-containing polyolefin resins include those selected from the group consisting of vinylidene fluoride resin (PVDF), chlorotrifluoroethylene resin, tetrafluoroethylene resin, ethylene-tetrafluoroethylene copolymer (ETFE), ethylene-monochlorotrifluoroethylene copolymer (ECTFE), ethylene-chlorotrifluoroethylene copolymer, polyvinylidene fluoride (which may contain domains of hexafluoropropylene), and hexafluoropropylene resin, and mixtures of these resins.

[0031] These resins are easy to handle and strong, making them excellent materials for the hollow fiber membrane 11. Among these, one homopolymer selected from the group consisting of vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, ethylene, tetrafluoroethylene, and chlorotrifluoroethylene, or a copolymer of two or more selected from the group, or a mixture of the homopolymer and the copolymer, is preferred because of its excellent mechanical strength, chemical strength (chemical resistance), and moldability. More specifically, fluororesins such as polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer, and ethylene-chlorotrifluoroethylene copolymer are preferred.

[0032] In addition, the thermoplastic resin constituting the hollow fiber membrane 11 in this embodiment preferably has a three-dimensional network structure rather than a spherulite structure. By forming the hollow fiber membrane 11 from a thermoplastic resin having a three-dimensional network structure, the pores of the hollow fiber membrane 11 can be more easily connected from the inner surface to the outer surface.

[0033] (Physical properties of hollow fiber membranes) The initial value of the tensile elongation at break of the hollow fiber membrane 11 is preferably 60% or more, more preferably 80% or more, even more preferably 100% or more, and particularly preferably 120% or more. The compressive strength of the hollow fiber membrane 11 is preferably 0.2 MPa or more, more preferably 0.3 MPa or more and 1.0 MPa or less, and even more preferably 0.4 MPa or more and 1.0 MPa or less.

[0034] (Method for manufacturing hollow fiber membrane) The hollow fiber membrane 11 in this embodiment can be produced by a known method or a method with appropriate modifications made by a person skilled in the art. The hollow fiber membrane 11 in this embodiment can be produced, for example, by extrusion molding of a melt-kneaded material containing a thermoplastic resin as a raw material.

[0035] <Housing> The housing 30 in the hollow fiber membrane module 100 is a container that houses the hollow fiber membrane bundle 10. After the housing 30 and the hollow fiber membrane bundle 10 are fixed by adhesive fixing parts 20 described below to form the hollow fiber membrane module 100, the inside of the module 100 is divided into an outer space 42 of the hollow fiber membranes 11 and an inner space 41 of the hollow fiber membranes 11, and these spaces 41, 42 are in contact with each other via the hollow fiber membranes 11.

[0036] The housing 30 in this embodiment has a raw water inlet 54, a filtrate outlet 52, and a cleaning outlet 53. After the housing 30 and the hollow fiber membrane bundle 10 are fixed by the adhesive fixing part 20 described below, the raw water inlet 54, the filtrate outlet 52, and the cleaning outlet 53 have the following functions as the raw water inlet 54, the filtrate outlet 52, and the cleaning outlet 53 of the hollow fiber membrane module 100, respectively. Raw water inlet 54: Functions to connect the outside of the module 100 with the outer space 42 of the hollow fiber membrane 11 Filtrate outlet 52: Functions to communicate the outside of the module 100 with the inner space 41 of the hollow fiber membrane 11 Cleaning outlet 53: Functions to communicate the outside of the module 100 with the outer space 42 of the hollow fiber membrane 11

[0037] The housing 30 may have a first cylindrical member 31 for accommodating the hollow fiber membrane bundle 10 and a second cylindrical member 32 for arranging the adhesive fixing part 20. The second cylindrical members 32 are preferably arranged on both ends of the first cylindrical member 31.

[0038] The second cylindrical member 32 may have the above-mentioned raw water inlet 54, filtrate outlet 52, and washing outlet 53. Preferably, the second cylindrical member 32 may be composed of a second cylindrical member 32a, which is disposed on the side of the hollow fiber membrane module 100 where the filtrate is removed and has the filtrate outlet 52 and washing outlet 53, and a second cylindrical member 32b, which is disposed on the side of the hollow fiber membrane module 100 where the liquid to be filtered is introduced and has the raw water inlet 54.

[0039] The inner diameter of the first cylindrical member 31 of the housing 30 is preferably 170 mm or more, more preferably 190 mm or more, and preferably 250 mm or less, and more preferably 230 mm or less. The outer diameter of the first cylindrical member 31 may be, for example, 170 mm or more and 300 mm or less. The length of the first cylindrical member 31 may be set appropriately depending on the desired effective length of the hollow fiber membranes 11, and may be, for example, 1.0 m or more and 3.0 m or less, and preferably 1.5 m or more and 2.0 m or less. The inner diameter of the second cylindrical member 32 of the housing 30 may be larger than the inner diameter of the first cylindrical member 31, and is preferably 180 mm or more, more preferably 200 mm or more, and preferably 280 mm or less, and more preferably 250 mm or less. The outer diameter of the second cylindrical member 32 may be, for example, 180 mm or more and 330 mm or less. The length of the second cylindrical member 32 may be set appropriately, and may be, for example, 0.2 m or more and 1.0 m or less. The second cylindrical member 32 is always configured as a set of two members (second cylindrical members 32a and 32b).

[0040] The material of the housing 30 is preferably selected from the viewpoints of moldability, cost, mechanical durability, chemical durability, and specific gravity. 3 It is preferable that the housing 30 is made of the following lightweight resins: The housing 30 is preferably made of the above lightweight resins selected from, for example, ABS, nylon, PE, PP, PPE, and the like.

[0041] It is preferable that the second cylindrical member 32 of the housing 30 further includes a flow straightening cylinder 50, which is an optional member, inside the second cylindrical member 32. In FIG. 2, the distance between the first adhesive fixing layer 21 and the second adhesive fixing layer 22, which defines the effective length of the hollow fiber membrane 11, is indicated by the symbol "L".

[0042] <Fixing the hollow fiber membrane bundle to the housing> In the hollow fiber membrane module 100 , the hollow fiber membrane bundle 10 and the housing 30 are fixed by an adhesive fixing part 20 .

[0043] <Adhesive fixing part> The adhesive fixing part 20 in the hollow fiber membrane module 100 has the function of adhesively fixing both end portions of the hollow fiber membrane bundle 10 to the housing 30. This adhesive fixing part 20 has a first adhesive fixing layer 21 at one end portion of the hollow fiber membranes 11 that adhesively fixes the hollow fiber membranes 11 to each other and between the hollow fiber membrane bundle 10 and the inner wall of the housing 30 with a resin material, and a second adhesive fixing layer 22 at the other end portion of the hollow fiber membranes 11 that adhesively fixes the hollow fiber membranes 11 to each other and between the hollow fiber membrane bundle 10 and the inner wall of the housing 30 with a resin material.

[0044] The material constituting the first adhesive fixing layer 21 and the second adhesive fixing layer 22 of the adhesive fixing part 20 is a resin material. Examples of this resin material include urethane resin, epoxy resin, acrylic resin, and silicone resin.

[0045] (Requirements for hollow fiber membrane modules) The hollow fiber membrane module 100 satisfies the following conditions (A), (B), and (C), namely: (A) The hollow fiber membrane filling rate is 42% or less, preferably 38% or less; (B) the outer diameter of the hollow fiber membrane is 1.3 mm or less, preferably 1.1 mm or less; and (C) The total membrane area of ​​the hollow fiber membrane is 50 m 2 More than 70m, preferably 2 Being more than that; It is preferable that the hollow fiber membrane module 100 satisfies all of the above.

[0046] In the above, the "hollow fiber membrane filling rate" is calculated by "100 × (total cross-sectional area of ​​hollow fiber membranes) / (internal cross-sectional area of ​​housing)." Furthermore, when the housing 30 is composed of a first cylindrical member 31 and a second cylindrical member 32, the "internal cross-sectional area of ​​the housing" refers to the internal cross-sectional area of ​​the first cylindrical member 31 that houses the hollow fiber membrane bundle 10.

[0047] The hollow fiber membrane module 100 in this embodiment is preferably configured with relatively thin hollow fiber membranes 11 having an outer diameter of 1.3 mm or less. This allows the membrane area of ​​the hollow fiber membranes 11 to be increased even when the packing rate of the hollow fiber membranes 11 is reduced to 42%. Furthermore, reducing the packing rate of the hollow fiber membranes 11 to 42% or less is advantageous in that it improves the discharge of suspended matter and ensures a large membrane area.

[0048] From the viewpoint of suspended solid discharge performance, the hollow fiber membrane filling rate is 42% or less, preferably 38% or less, or preferably 30% or more, more preferably 35% or more.

[0049] From the viewpoint of filtration efficiency, the effective length L of the hollow fiber membrane 11 is preferably 1.5 m or more, more preferably 1.6 m or more, even more preferably 1.7 m or more, and particularly preferably 1.8 m or more. The "effective length L of the hollow fiber membrane" refers to the length of the hollow fiber membrane 11 that contributes to filtration, and as shown in Figure 2, refers to the average length of the hollow fiber membrane 11 that is exposed between the first adhesive fixing layer 21 and the second adhesive fixing layer 22.

[0050] The total membrane area of ​​the hollow fiber membrane 11 is 50 m 2 or more, preferably 70m 2 More preferably, 80m 2 The hollow fiber membrane module 100 in this embodiment has a total membrane area of ​​the hollow fiber membranes 11 of 50 m 2 The "total membrane area of ​​the hollow fiber membranes" refers to the total membrane area of ​​the hollow fiber membranes 11 that contributes to filtration, and refers to the total outer area of ​​the parts of the hollow fiber membranes 11 that are exposed between the first adhesive fixing layer 21 and the second adhesive fixing layer 22.

[0051] <<Piping group>> The piping group 120 consists of three main pipes: a raw water transport pipe 121, a filtrate collection pipe 122, and an effluent recovery pipe 123. These pipes are fluidly connected to the raw water inlet 54, the filtrate outlet 52, and the cleaning outlet 53 of the hollow fiber membrane module 100, respectively. The diameter of each main pipe is not particularly limited, but it is preferable to design it so that the linear velocity of the water flowing through the main pipe does not exceed 3 m / s. The flow rate of the water flowing through the main pipe depends on the filtration capacity of the installed hollow fiber membrane module 100, and the linear velocity is calculated from this. For example, the diameter of the main pipe is preferably in the range of 100 mm to 250 mm, more preferably 120 mm to 200 mm. The length of each main pipe is not particularly limited, but it is preferably 2000 mm or less.

[0052] A branch pipe is connected to the main pipe to connect the hollow fiber membrane module 100 to the main pipe. The diameter of the branch pipe is preferably designed so that the linear velocity of the flowing water does not exceed 3 m / s. For example, a diameter of 40 A to 80 A is preferred, and 50 A to 65 A is even more preferred. The method for connecting the branch pipe to the main pipe is not particularly limited, and includes welding with a welding rod and bonding with an adhesive. However, a welding method in which the main pipe and branch pipe are melted to connect them is preferred because it provides high strength and stable dimensions. The length of each branch pipe is also not particularly limited, but is preferably 100 mm to 200 mm in terms of ease of joint operation.

[0053] The piping group 120 has a specific gravity of 1.3 g / cm 3 It is preferable that they are made using the following resins. The material of the pipes 121 to 123 constituting the pipe group 120 is preferably set in terms of moldability, cost, mechanical durability, chemical durability, etc., as well as specific gravity. The pipes 121 to 123 are preferably made of a material selected from, for example, ABS, nylon, PE, PP, PPE, etc. Of these, PE and PP are preferred because they are particularly good in terms of cost, durability, and moldability.

[0054] As shown in FIG. 1, it is preferable that a raw water transport pipe 121, a filtered water collection pipe 122, and an effluent water recovery pipe 123 are laid along the laying direction of the plurality of hollow fiber membrane modules 100 (i.e., the direction in which the hollow fiber membrane modules are lined up).

[0055] <<Supporting members>> The support member group 130 consists of a support member 131 that directly supports the hollow fiber membrane module 100 and the raw water transport pipe 121, and a support member 132 that directly supports the filtered water collection pipe 122 and the wastewater recovery pipe 123. Since the support members 131 and 132 support the hollow fiber membrane module 100 and the pipes 121 to 123 that contain water, they need to be strong enough to withstand their weight, but they need to be designed in a way that balances strength with the overall weight, taking into account ease of assembly and the overall weight.

[0056] Although not limited to the following examples, the support member group 130 can have, for example, the following structure: That is, the support member 131 on which the hollow fiber membrane module 100 is placed is disposed below the hollow fiber membrane module 100 while fixing the raw water transport piping 121 connected to the raw water inlet 54. The raw water transport piping 121 can be fixed, for example, by forming the support member 131 from two support members 131a and 131b with semicircular openings, and sandwiching the raw water transport piping 121 between the two support members 131a and 131b from above and below. According to this fixing method, the support member 131 supporting the hollow fiber membrane module 100 is fixed to the raw water transport piping 121, and further, the nut N (see Figures 1 and 2) of the hollow fiber membrane module 100 is placed on the support member 131, and the raw water inlet 54 and the raw water transport piping 121 are connected by a connecting joint 124 such as a flexible joint.

[0057] Next, it is preferable that the filtrate collection pipe 122 and the effluent water recovery pipe 123 are installed above the hollow fiber membrane module 100, since this shortens the connection joint 124. The filtrate collection pipe 122 and the effluent water recovery pipe 123 can be fixed in the same manner as the raw water transfer pipe 121, using a support member 132 composed of, for example, three support members 132a, 132b, and 132c. That is, first, the support member 132a having a semicircular opening is placed on the nut N on the filtrate side (see Figures 1 and 2) with the opening facing upward, and the filtrate collection pipe 122 is placed on the semicircular opening. Next, the filtrate collection pipe 122 is sandwiched between support member 132b, which has two semicircular openings, one above the other, and the effluent recovery pipe 123 is placed on the other semicircular opening of support member 132b, with support member 132c placed on top of it and sandwiched between them. The filtrate outlet 52 and the cleaning outlet 53 are then connected to the filtrate collection pipe 122 and the effluent recovery pipe 123, respectively, using connecting joints 124, such as flexible joints, thereby integrating the pipe group 120 and the hollow fiber membrane module group 110. In this way, the support member 132 can fix the hollow fiber membrane module 100, the filtrate collection pipe 122, and the effluent recovery pipe 123 together. Furthermore, the support member 132 can fix the hollow fiber membrane module 100, the raw water transport pipe 121, the filtered water collection pipe 122, and the effluent water recovery pipe 123 together.

[0058] With this arrangement, the raw water transport pipe 121, hollow fiber membrane module 100, filtered water collection pipe 122, and effluent water recovery pipe 123 can be assembled in this order from bottom to top, and each pipe can be connected to the hollow fiber membrane module 100 using a connecting joint 124. In this way, the filtered water collection pipe 122 is surrounded by the support member group 130, the effluent water recovery pipe (horizontal pipe) 123, and the connecting joint (vertical pipe) 124 connecting the effluent water recovery pipe 123 to the hollow fiber membrane module 100, and can be protected from falling or collapsing objects. In this case, the size of the opening through which the filtered water collection pipe 122 can be accessed (the gap between the pipe group 120 and the support member group 130) is preferably 30 cm or less. Here, the "size of the opening" refers to the length of the longest part of the opening when viewed from the direction in which the opening appears widest (for example, from the front (a direction perpendicular to the direction in which the hollow fiber membrane modules 100 are lined up)). The opening may be rectangular, in which case the "opening size" is the length of the longer side of the rectangle. If the opening is not rectangular, the "opening size" is the length of the longer side of the rectangle with the largest area included in the opening.

[0059] The support members 131 and 132 constituting the support member group 130 are preferably made by injection molding using resin. The material of the support members 131 and 132 is preferably selected from the viewpoints of moldability, cost, mechanical durability, chemical durability, and specific gravity. The support members 131 and 132 have a specific gravity of 1.3 g / cm 3 It is preferable that they are made using the following resins. The support members 131, 132 are preferably made of a material selected from, for example, ABS, nylon, PE, PP, PPE, etc., and are more preferably made of a material reinforced with glass fiber, with glass fiber-reinforced ABS, nylon, and PP being particularly preferable due to their excellent cost, durability, and moldability. The glass fiber content is preferably 20% to 40%, and more preferably 30% to 40%. Furthermore, long glass fibers are preferable because they entangle with each other better than short fibers and are therefore easier to strengthen.

[0060] <<Connection fittings>> When the housing 30, piping group 120, and support member group 130 of the hollow fiber membrane module 100 are made by resin injection molding, slight dimensional variations exist. In this case, by using a flexible joint for the connection joint 124 that connects the above components to each other or the components to the piping, these dimensional variations can be absorbed and the above components can be connected to each other or the components to the piping in a satisfactory manner. Furthermore, by using a flexible joint for the connection joint 124, vibrations that occur during transportation can be absorbed, preventing damage to the water treatment device 1 during transportation. Furthermore, when connecting multiple units of one water treatment device 1, using a flexible joint for the connection joint 124 can absorb slight dimensional variations between the individual water treatment devices 1.

[0061] Examples of flexible joints include, but are not limited to, a method in which one connection port and the other connection port are connected with a flexible tube such as rubber, and the tube is fixed from the outside with a rigid material to prevent it from coming loose, as well as expansion joints and rubber vibration-proof joints. For example, a Victrick joint manufactured by Victrick, a cap nut-tightened union joint manufactured by Maezawa Chemicals, and a bolt-tightened union joint are preferably used.

[0062] Furthermore, by making a part of the filtrate collection pipe 122 or the effluent water recovery pipe 123 transparent, it becomes possible to confirm the presence of air bubbles and easily detect leaks when inspecting for compressed air leaks in the hollow fiber membrane module 100. For example, as shown in Fig. 1, it is conceivable to connect the connection joint 124 between the effluent water recovery pipe 123 and the cleaning outlet 53 of the hollow fiber membrane module 100 with a partially transparent flexible joint 124a.

[0063] The material of the flexible joint is preferably selected from the viewpoints of moldability, cost, mechanical durability, chemical durability, etc. The flexible joint is preferably made of a material selected from, for example, ABS, nylon, PE, PP, PPE, PVC, etc. The transparent flexible joint 124a can be realized by manufacturing a portion of the flexible joint from a transparent material such as transparent ABS or transparent PVC. For example, a transparent expansion joint that is a union joint tightened with a cap nut can be used.

[0064] In the present invention, the mass per unit area of ​​the hollow fiber membrane 11 of the water treatment device 1 having the above-described configuration is set to 1.0 kg / m 2 As a result, the area of ​​the hollow fiber membranes 11 that can be transported at one time becomes larger, and transportation becomes more efficient.

[0065] In the present invention, the total membrane area of ​​the hollow fiber membranes 11 per site area of ​​the water treatment device 1, i.e., the footprint, is 1,000 m 2 / m 2 This increases the membrane area that can be transported at one time, making transportation more efficient.

[0066] Furthermore, it is preferable that the hollow fiber membrane module group 110, the pipe group 120, and the support member group 130 are connected to one another as one unit, and that up to five units can be connected. This makes it possible to prevent the linear velocity of the liquid flowing through the pipes from becoming excessively high, which would increase the pressure loss in the pipes. For example, if five hollow fiber membrane modules 100 are provided in one unit, by connecting no more than five units (i.e., a total of 25 hollow fiber membrane modules), the linear velocity of the liquid in the pipes can be kept at 3 m / s or less, thereby preventing the increase in pressure loss in the pipes.

[0067] <<Operation method of water treatment equipment>> FIG. 3 shows a flow diagram of an example of a filtration system for performing a filtration step, a cleaning step, and preferably a discharge step, and further a chemical cleaning step, using the water treatment device 1 of this embodiment.

[0068] The filtration system 1000 shown in Fig. 3 has a configuration in which the water treatment device 1 of the present invention, a tank for filtrate 200, a strainer 210, a filtrate tank 300, and a compressor 400 are connected by piping with valves appropriately arranged. Fig. 3 does not include pumps for liquid delivery, drain piping normally installed in each tank, a chemical tank for chemical cleaning and associated piping, sensors for checking the operating status, etc.

[0069] Using the filtration system 1000 of FIG. 3, the filtration method of the present invention, which includes predetermined filtration steps and cleaning steps, can be carried out, for example, as follows.

[0070] <<Filtration process (F)>> In the filtration step, the liquid to be filtered is passed through the hollow fiber membranes in the hollow fiber membrane module 100 in the water treatment device 1 to obtain a filtrate. In the filtration system 1000 shown in Fig. 3, a raw liquid such as a suspension or a process liquid is temporarily stored in a raw liquid tank (not shown), and then roughly filtered through a strainer 210 to obtain a filtrate, which is used as the liquid to be filtered in the filtration method of the present invention. The liquid to be filtered is stored in a liquid to be filtered tank 200. The filtered liquid in the filtered liquid tank 200 is introduced into the water treatment device 1 from the raw water inlet 54 via the filtered liquid delivery valve V1, and is filtered from the outside of the hollow fiber membrane through the thick part of the hollow fiber membrane, and is stored in the filtrate tank 300.

[0071] <<Cleaning process>> The cleaning process includes simultaneous backwashing-air scrubbing (ASBW) or simultaneous flushing-air scrubbing (ASFL), which combines backwashing (BW) or flushing (FL) with air scrubbing (AS). BW or FL may be performed before ASBW or ASFL, or FL may be performed after ASBW or ASFL. Furthermore, a draining step may be carried out after the cleaning step. When the filtration system 1000 of FIG. 3 is used, the BW, FL, and AS, ASBW and ASFL, and discharge steps can be performed as follows, respectively.

[0072] In this specification, backwashing may be referred to as "BW," flushing as "FL," air scrubbing as "AS," simultaneous backwashing and air scrubbing (simultaneous backwashing-air scrubbing) as "ASBW," and simultaneous flushing and air scrubbing (simultaneous flushing-air scrubbing) as "ASFL."

[0073] <Backwash (BW)> In BW, the filtrate is passed from the inside to the outside of the hollow fiber membranes in the hollow fiber membrane module. In this case, the filtrate in the filtrate tank 300 is introduced into the water treatment device 1 from the filtrate outlet 52 via the backwash valve V3, passes through the thick part of the hollow fiber membrane from the inside of the hollow fiber membrane, and seeps into the space outside the hollow fiber membrane. During this process, suspended solids deposited in the pores in the thick part of the hollow fiber membrane are pushed out to the outside of the hollow fiber membrane, thereby cleaning the hollow fiber membrane. The filtrate that has seeped into the space outside the hollow fiber membrane is discharged to the outside of the system via the washing discharge port 53 and the washing wastewater discharge valve V5.

[0074] <Flushing (FL)> In FL, the liquid to be filtered is passed through the outside of the hollow fiber membrane, washing away the suspended solids adhering to the outer surface of the hollow fiber membrane. In the FL, the filtered liquid in the filtered liquid tank 200 is introduced into the water treatment device 1 from the raw water inlet 54 via the filtered liquid delivery valve V1, then passes through the outer space of the hollow fiber membrane and is discharged outside the system via the cleaning outlet 53 and the cleaning waste liquid discharge valve V5.

[0075] <Air Scrubbing (AS)> In the AS, compressed air is introduced from an air inlet 51 and discharged from a cleaning outlet 53, and the air (air bubbles) passing outside the hollow fiber membranes shakes the hollow fiber membranes. In the AS, air compressed by the compressor 400 is introduced into the water treatment device 1 from the air inlet 51 via the AS valve V6, passes through the outer space of the hollow fiber membrane, and is discharged outside the system via the cleaning outlet 53 and the cleaning wastewater discharge valve V5.

[0076] <Backwashing and simultaneous air scrubbing (ASBW)> In ASBW, the above-mentioned BW and AS are performed simultaneously. That is, the filtrate in the filtrate tank 300 is introduced through the backwash valve V3 and the filtrate outlet 52 into the hollow fiber membrane module 100 in the water treatment device 1, and is then discharged to the outside of the system through the cleaning outlet 53 and the cleaning wastewater discharge valve V5. At the same time, compressed air from the compressor 400 is introduced through the AS valve V6 and the air inlet 51 into the water treatment device 1, and is then discharged to the outside of the system through the cleaning outlet 53 and the cleaning wastewater discharge valve V5.

[0077] <Simultaneous Flushing and Air Scrubbing (ASFL)> In ASFL, the above-mentioned FL and AS are performed simultaneously. That is, the liquid to be treated in the filtrate tank 200 is introduced into the hollow fiber membrane module 100 in the water treatment device 1 from the raw water inlet 54 via the filtrate feed valve V1, and then discharged to the outside of the system via the cleaning outlet 53 and the cleaning wastewater discharge valve V5. At the same time, compressed air from the compressor 400 is introduced into the water treatment device 1 from the air inlet 51 via the AS valve V6 and then discharged to the outside of the system via the cleaning outlet 53 and the cleaning wastewater discharge valve V5.

[0078] <Discharge process> In the discharge step, the washing wastewater remaining inside the hollow fiber membrane module 100 is discharged. This discharge step can be carried out by discharging compressed air introduced from the cleaning outlet 53 of the hollow fiber membrane module 100 in the water treatment device 1 via the discharge step compressed air valve V7, the chemical return valve V8, and the bypass valve V9, together with the cleaning wastewater remaining inside the hollow fiber membrane module 100, out of the system via the raw water inlet 54 and the cleaning wastewater drain valve V4.

[0079] [Filtration method] The filtration method of the present invention is a filtration method for filtering a liquid to be filtered using the water treatment device 1 of the present invention described above, The filtration method includes: a filtration step in which the liquid to be filtered is passed through the hollow fiber membrane 11 by external pressure filtration to obtain a filtrate; a washing step carried out after the filtration step; a chemical washing step carried out after repeating the filtration step and the washing step multiple times; Including, The washing step includes: Backwashing is performed by passing the filtrate from the inside to the outside of the hollow fiber membrane 11, or flushing is performed by introducing the liquid to be filtered from the raw water inlet 54 and discharging it from the cleaning outlet 13; The liquid to be filtered containing air bubbles is introduced from the raw water inlet 54 and discharged from the cleaning outlet 53, and the hollow fiber membranes 11 are shaken by the air bubbles. and washing the outer surface of the hollow fiber membrane 11 by a combination of backwashing and air scrubbing, or by a combination of flushing and air scrubbing. Including, The chemical cleaning step includes: a chemical cleaning step in which the inside of the hollow fiber membrane module 100 is filled with a chemical solution, the chemical solution is introduced through the raw water inlet 54, and the chemical solution is discharged through the filtrate outlet 52 and / or the cleaning outlet 53, and the chemical solution is circulated; a chemical solution discharge step of discharging the chemical solution from the hollow fiber membrane module 100 after the chemical solution cleaning step; a rinsing step of rinsing the inside of the hollow fiber membrane module 100 with filtered water or water after the chemical solution discharging step; a rinse liquid discharging step of discharging the filtered water or the water after rinsing after the rinsing step; A filtration method comprising:

[0080] <Filtration process> The filtration step in the filtration method of this embodiment is external pressure filtration. That is, this is a filtration step in which a liquid to be filtered containing a substance to be filtered is supplied to the outer surface of the hollow fiber membranes 11, passed through the membrane (thick wall) part of the hollow fiber membranes 11, and the liquid that seeps out from the inner surface of the hollow fiber membranes 11 is extracted as filtrate. In the hollow fiber membrane module 100 of this embodiment, a method in which the liquid to be filtered is introduced from the bottom of the module 100 and external pressure filtration is performed is preferred because it makes it easier to discharge turbid substances. In this specification, the term "substance to be filtered" refers to a substance or the like that is contained in the water to be treated that is supplied to the hollow fiber membranes 11 in the filtration step, is removed by filtration, and is to be separated from the filtrate.

[0081] The liquid to be filtered in the filtration step is not particularly limited, and is typically water containing suspended matter that can be removed by the filtration step, such as suspended water and process liquid. As used herein, the term "suspended water" refers to natural water, domestic wastewater (wastewater), and treated water thereof. Examples of natural water include river water, lake water, groundwater, and seawater. Treated water obtained by subjecting natural water to sedimentation, sand filtration, coagulation-sedimentation sand filtration, ozonation, activated carbon treatment, and other treatments is also included in the term "suspended water" in this specification. A typical example of domestic wastewater is sewage. The term "suspended water" as used herein also includes primary sewage effluent that has undergone screen filtration, sedimentation, and other treatments, secondary sewage effluent that has undergone biological treatment, and tertiary sewage effluent that has undergone coagulation-sedimentation sand filtration, activated carbon treatment, ozonation, and other treatments (advanced treatment). These suspended waters may contain fine organic and inorganic matter on the order of μm or smaller, suspended solids consisting of one or more organic-inorganic mixtures (e.g., humus colloids, organic colloids, clay, bacteria), and polymeric substances derived from bacteria and algae.

[0082] The quality of suspended solids can be determined by turbidity and / or organic matter concentration. Both turbidity and organic matter concentration are assessed as average values, not instantaneous values. Using turbidity according to JIS K0101 (kaolin turbidity standard) as a standard, turbid water is classified into low turbidity water with a turbidity of less than 1, medium turbidity water with a turbidity of 1 to less than 10, high turbidity water with a turbidity of 10 to less than 50, and ultra-high turbidity water with a turbidity of 50 or more. Furthermore, 1 degree of turbidity is equal to 0.7 NTU (Nephelometric Turbidity Unit). Using organic matter concentration (total organic carbon (TOC)): mg / L) as the standard, suspended water is classified into low TOC water (less than 1), medium TOC water (1 to 4), high TOC water (4 to 8), and ultra-high TOC water (8 or more). Generally, water with higher turbidity and / or TOC is more likely to clog a porous filtration membrane. Therefore, it is preferable that the average turbidity of the liquid to be filtered supplied to the filtration step in this embodiment is 10 degrees or higher, since this allows the hollow fiber membrane module 100 to optimally exhibit its performance.

[0083] The process liquid refers to the liquid to be separated when separating valuable and non-valuable materials (i.e., the mixed liquid before separation) in the fields of food, pharmaceuticals, semiconductor manufacturing, etc. The above-mentioned suspended water, process liquid, etc. may be roughly filtered using an appropriate strainer 210 or the like and used as the liquid to be filtered in the present invention.

[0084] The filtration step in this embodiment is carried out, for example, by introducing the liquid to be filtered from the raw water inlet 54 of the hollow fiber membrane module 100 into the outer space 42 of the hollow fiber membranes 11, allowing the filtrate to pass through the thick part of the hollow fiber membranes 11 and seep out from the inner surface of the hollow fiber membranes 11, and then removing the filtrate from the inner space 41 of the hollow fiber membranes 11 from the filtrate outlet 52 of the hollow fiber membrane module 100.

[0085] The flow rate of the filtrate is 2 The permeation flow rate (LMH, or L / [m 2 ·h]) is preferably 10 LMH or more and 500 LMH or less, more preferably 50 LMH or more and 200 LMH or less, and even more preferably 75 LMH or more and 150 LMH or less.

[0086] <Cleaning process> The washing step in the filtration method of the present invention includes: Backwashing (BW) is a process in which filtrate is passed from the inside to the outside of the hollow fiber membrane 11, or flushing (FL) is a process in which the liquid to be filtered is introduced from a raw water inlet 54 and discharged from a cleaning outlet 53; air scrubbing (AS), in which the liquid to be filtered containing air bubbles is introduced through a raw water inlet 54 and discharged through a cleaning outlet 53, and the hollow fiber membrane 11 is shaken by the air bubbles; The outer surface of the hollow fiber membrane 11 is cleaned by a combination of backwashing and air scrubbing (ASBW) or flushing and air scrubbing (ASFL). Includes: In this case, air for AS can be introduced by providing a connection joint 124 for introducing air in a branch pipe installed in the raw water conveyance pipe 121.

[0087] According to the filtration method of this embodiment, the filtration step and the cleaning step are repeated, and the hollow fiber membrane module 100 can be operated for a long period of time to continue the filtration process. The timing for stopping the filtration process and starting the cleaning process may be set appropriately. For example, the filtration process may be stopped and the cleaning process may be started when a predetermined time has elapsed after the filtration process has been started or resumed. Alternatively, the filtration process may be stopped and the cleaning process may be started when the water permeability in the filtration process reaches a predetermined value. In this case, the cleaning process is preferably started when the water permeability calculated by dividing the filtration flux by the filtration pressure has decreased to 70% of the initial value, and more preferably when it has decreased to 50%. The method of controlling the start of the cleaning process based on time has the advantage that regular membrane cleaning is ensured, and therefore the hollow fiber membrane 11 can always be kept clean. On the other hand, the method of controlling the start of the cleaning process based on water permeability has the advantage that efficient cleaning is possible.

[0088] In the cleaning process of this embodiment, Backwashing (BW) or flushing (FL) may be performed prior to ASBW or ASFL. After ASBW or ASFL, flushing (FL) may be performed. In the cleaning process of this embodiment, it is preferable to perform ASBW or ASFL after performing BW or FL alone, since this allows for more effective removal of suspended matter that has been brought into the hollow fiber membrane module 100. Furthermore, if BW or FL is performed prior to ASBW or ASFL, suspended matter adhering to the outer surface of the hollow fiber membranes 11 is peeled off and adhesion of the hollow fiber membrane bundle 10 is alleviated, thereby suppressing deterioration of the hollow fiber membranes 11 due to abrasion caused by the subsequent ASBW or ASFL.

[0089] -Backwash (BW)- Backwashing (BW) is a cleaning method in which filtrate is passed through the inside of the hollow fiber membrane 11. By BW, suspended matter accumulated in the pores of the thick part of the hollow fiber membrane 11 can be pushed out to the outside of the hollow fiber membrane 11. The flow rate of the filtrate when BW is carried out is preferably 0.5 to 3 times, more preferably 0.7 to 3 times, the permeation flow rate X of the filtration step. When BW is performed prior to ASBW or ASFL, the execution time is, for example, 10 times or more and 120 seconds or less, and preferably 15 seconds or more and 60 seconds or less.

[0090] -Flushing (FL)- Flushing (FL) is a cleaning method in which the liquid to be filtered is introduced through the raw water inlet 54 and discharged through the cleaning outlet 53, thereby passing the liquid to be filtered over the outside of the hollow fiber membrane 11. By this FL, suspended matter adhering to the outer surface of the hollow fiber membrane 11 can be washed away. The flow rate of the liquid to be filtered in the FL is preferably 50 LMH or more and 150 LMH or less, and more preferably 60 LMH or more and 100 LMH or less. When FL is performed prior to ASBW or ASFL, the duration of the FL is, for example, 10 seconds or more and 120 seconds or less, and preferably 15 seconds or more and 60 seconds or less. When FL is performed after ASBW or ASFL, the duration of the FL is, for example, 10 seconds or more and 120 seconds or less, and preferably 15 seconds or more and 60 seconds or less.

[0091] -Air Scrubbing (AS)- Air scrubbing (AS) is a cleaning method in which the inside of the hollow fiber membrane module 100 is filled with water, compressed air is introduced through the air inlet 51, and discharged through the cleaning outlet 53, and the hollow fiber membranes 11 are shaken by air (air bubbles). During AS, the amount of compressed air introduced is 1 m of the cross-sectional area of ​​the housing 30 of the hollow fiber membrane module 100. 2 Preferably 170Nm 3 / h or more 400Nm 3 / h or less, more preferably 200 Nm 3 / h or more 350Nm 3 / h or less, and more preferably 200 Nm 3 / h or more 300Nm 3 / h or less.

[0092] -Backwashing and simultaneous air scrubbing (ASBW)- In ASBW, the above backwashing (BW) and air scrubbing (AS) are carried out simultaneously. The execution time of ASBW is, for example, from 10 seconds to 120 seconds, and preferably from 15 seconds to 60 seconds.

[0093] -Flushing and Air Scrubbing Simultaneous Cleaning (ASFL)- In ASFL, the above flushing (FL) and air scrubbing (AS) are performed simultaneously. The duration of ASFL is, for example, 10 seconds or more and 120 seconds or less, and preferably 15 seconds or more and 60 seconds or less.

[0094] <Discharge process> In the filtration method of the embodiment, after the cleaning step, a discharge step may be carried out, and is preferred, in which the cleaning wastewater remaining inside the hollow fiber membrane module 100, specifically, on the outside and in the hollow portions of the hollow fiber membranes 11, is discharged from the raw water inlet 54 or the cleaning outlet 53. By carrying out the discharge step after the cleaning step, suspended matter inside the hollow fiber membrane module 100 can be more effectively discharged.

[0095] The discharge step can be carried out, for example, under natural flow due to gravity from the raw water inlet 54 of the hollow fiber membrane module 100, or can be carried out forcibly by introducing compressed air into the hollow fiber membrane module 100 from the cleaning outlet 53.

[0096] After the discharge step, the weight of the hollow fiber membrane module 100 is preferably 1.70 times or less, more preferably 1.60 times or less, and even more preferably 1.55 times or less, of the initial dry weight of the hollow fiber membrane module 100.

[0097] <Chemical cleaning process> The chemical washing step in the filtration method of the present invention includes: a chemical cleaning step in which the inside of the hollow fiber membrane module 100 is filled with a chemical solution, the chemical solution is introduced through the raw water inlet 54, and the chemical solution is discharged through the filtrate outlet 52 and / or the cleaning outlet 53, and the chemical solution is circulated; a chemical solution discharge step of discharging the chemical solution from the hollow fiber membrane module 100 after the chemical solution cleaning step; a rinsing step of rinsing the inside of the hollow fiber membrane module 100 with filtered water or water after the chemical solution discharging step; The method includes, after the rinsing step, a rinse liquid discharging step of discharging the filtered water or the water after rinsing.

[0098] In the filtration method of this embodiment, after a series of filtration steps are repeatedly performed, chemical cleaning is performed several times a day to several times a year. Suitable chemicals to be used include, but are not limited to, chlorine-based oxidizing agents such as sodium hypochlorite, oxygen-based oxidizing agents such as hydrogen peroxide, alkalis such as sodium hydroxide, inorganic acids such as hydrochloric acid, organic acids such as citric acid, and reducing agents such as sodium sulfite.

[0099] For example, first, organic contaminants are washed by immersion cleaning in a mixed solution of 0.5% sodium hypochlorite and 1% sodium hydroxide for about 8 hours, and then inorganic contaminants are washed by immersion cleaning in a 1% citric acid solution for about 8 hours. After this, the inside of the hollow fiber membrane module 100 is rinsed with raw water, filtered water, and water to neutralize it, and the filtration process is then resumed.

[0100] Here, the chemicals used for cleaning, such as sodium hypochlorite, sodium hydroxide, and citric acid, cannot be dumped as they are, but are generally rendered harmless by neutralization or reduction before being disposed of as sewage or industrial waste. In this case, if a water treatment device with a small installation area and a large membrane area like the present embodiment is used, the dead space of the piping is small, so not only can the amount of chemicals used be reduced, but the amount of chemicals used for neutralization and reduction can also be reduced.

[0101] In the chemical solution discharge step, it is preferable to allow the solution to flow naturally by gravity, or to introduce compressed air into the hollow fiber membrane module 100 through the cleaning outlet 53 and forcibly discharge the washing wastewater from the raw water inlet 54.

[0102] In addition, in the chemical solution discharge step and / or rinse solution discharge step, it is preferable to allow natural flow by gravity or to introduce compressed air into the cleaning discharge port 53 and forcibly discharge the cleaning wastewater from the raw water inlet 54.

[0103] The volume of the chemical solution and rinse solution per membrane area is 1.0 L / m 2 It is more preferable that the flow rate is 0.8 L / m or less.2 The volume per membrane area is 1.0 L / m or less. 2 If the amount is less than this, the amount of cleaning chemicals and waste liquid to be treated can be reduced.

[0104] [Leak repair method] The leak repair method according to the present invention includes a bubble inspection step of introducing compressed air from the filtrate collection piping into each hollow fiber membrane module in the water treatment device according to the present invention described above to inspect whether or not bubbles are generated from the hollow fiber membranes; an identification step of, if bubbles are detected, exposing the end face of the hollow fiber membrane bundle on the filtrate collection piping side without removing the hollow fiber membrane module in which bubbles are detected from the water treatment device to identify the hollow fiber membrane in which bubbles are generated; and a repair step of repairing the identified hollow fiber membrane.

[0105] <Air bubble inspection process> In the air bubble inspection process, compressed air is introduced into each hollow fiber membrane module 100 from the filtrate collection pipe 122 in the water treatment device 1 via valve V7 to inspect whether or not air bubbles are generated from the hollow fiber membranes. If there is a break in the hollow fiber membrane 11, air bubbles can be detected from the transparent pipe connected to the cleaning outlet 53.

[0106] <Specific process> If bubbles are detected, the hollow fiber membrane module 100 in which the bubbles were detected is not removed from the water treatment device 1, but the end face of the hollow fiber membrane bundle 10 on the filtrate discharge outlet 52 side is exposed, and pressurized air is then sent to the hollow fiber membrane module 100 via V6. If any hollow fiber membranes 11 are broken, bubbles will be generated, and the broken hollow fiber membranes 11 will be identified.

[0107] <Repair process> In the repair process, the identified hollow fiber membrane is repaired. Specifically, the hollow portion of the identified hollow fiber membrane at the top end of the module is plugged with a nail or the like to seal it. This allows the leak to be repaired without removing the hollow fiber membrane module 100 in which the leak occurred from the water treatment device 1. [Example]

[0108] The present invention will now be described in more detail by way of examples. The evaluations in the following examples and comparative examples were carried out by the following methods.

[0109] Example 1 <<Piping group>> The main pipe was a polyethylene pipe with an inner diameter of 148 mm and an outer diameter of 168 mm. Five 42-mm diameter holes were drilled in a row, with a center-to-center distance of 320 mm (the distance from the end of the main pipe to the center of the nozzles on both sides was 160 mm). A polyethylene nozzle with an inner diameter of 42 mm and an outer diameter of 60 mm was welded to each hole, so that the nozzle was 106 mm high from the bottom of the main pipe. Three such main pipes with nozzles were prepared: raw water transport pipe 121, filtered water collection pipe 122, and effluent recovery pipe 123. All nozzles were grooved according to Victrick's installation instructions to fit Victrick's 50A Victrick joints. Both ends of all main pipes were grooved according to Victrick's installation instructions to fit Victrick's 150A Victrick joints. In addition, five sets of pipes were prepared to connect the cleaning outlet 53 of the hollow fiber membrane module 100 (described later) to the wastewater recovery pipe 123. A 50A super transparent expansion joint manufactured by Maezawa Chemicals, Inc. was used midway in the connecting pipe between the outlet and the wastewater recovery pipe 123.

[0110] <<Supporting members>> The support member 131b shown in FIG. 132a The support member 132b is a rectangular parallelepiped with a length of 254 mm, a width of 260 mm, and a width of 36 mm, and has a semicircle with a diameter of 168 mm on one of its horizontal faces. The support member 132b is a rectangular parallelepiped with a length of 232.5 mm, a width of 260 mm, and a width of 36 mm, and has a semicircle with a diameter of 168 mm on both of its horizontal faces. 131aThe support members 131a, 131b, 132a, 132b, and 132c were rectangular parallelepipeds measuring 123.5 mm in length, 260 mm in width, and 36 mm in depth, with a semicircle of 168 mm in diameter on one of the horizontal faces. The support members 131a, 131b, 132a, 132b, and 132c were all manufactured by injection molding using polypropylene containing long glass fiber. Recesses and ribs were provided as necessary. 132a A total of 15 support members 132b, 5 support members 132c, 131a A total of 15 132c were prepared.

[0111] <<Hollow fiber membrane module group>> A total of 16,500 PVDF (polyvinylidene fluoride) hollow fiber membranes 11 (manufactured by Asahi Kasei Corporation) were bundled in a length of 2.3 m, hung vertically, and the lower end was cut to align the surfaces and seal the hollow portion. The resulting hollow fiber membrane bundle 10 was inserted into a housing 30 having a first cylindrical member (pipe inner diameter 204 mm) 31 for housing the hollow fiber membrane bundle 10, and a second cylindrical member (pipe inner diameter 204 mm) 32 with a 196 mm inner diameter straightening cylinder 50 attached to the inside. The hollow fiber membranes 11 used here had an average pore size of 0.1 μm, an inner diameter of 0.6 mm, and an outer diameter of 0.95 mm.

[0112] Next, Second cylindrical member 32b The end of the hollow fiber membrane bundle 10 on the side ( Second adhesive fixing layer 22 ) 40 columnar members (diameter 11 mm) were inserted into the positions where through holes were to be formed.

[0113] Next, the container for forming the adhesive fixing part, to which the tube for introducing the potting material is attached, is fixed to both ends of the housing 30, and while rotating, the potting material is introduced into the housing 30. Inside the second cylindrical member 32a and 32b The potting material used was a two-component thermosetting urethane resin (SA-6330A2 / SA-6330B5 (product name), manufactured by Sanyu Rec Co., Ltd.). When the curing reaction of the potting material progressed and fluidization stopped, the rotation of the centrifuge was stopped, the housing 30 was removed, and the urethane resin was heated to 50°C in an oven to cure.

[0114] Then, the second cylindrical member of the housing 30 32a The end of the membrane bundle on the side of the first cylindrical member was cut to open the hollow fiber membrane 11 on the side that had been sealed before bonding. 32b Side Second adhesive fixing layer 22 The columnar members were removed from the hollow fiber membrane module 100 to form a plurality of through-holes. The effective membrane length of the hollow fiber membrane module 100 was 2.0 m.

[0115] The packing rate of the produced hollow fiber membrane module 100 was 37.2%.

[0116] Conical caps with grooves for 50A Victoric joints are fastened to both ends of the hollow fiber membrane module 100 by tightening nuts N.

[0117] <<Assembly>> The water treatment device 1 was assembled according to the following procedure. 1. Ten support members 131a were lined up in a row on a horizontal surface with the semicircular part facing vertically upward, and fixed to the ground with anchor bolts or the like. At this time, the support members 131a may be fixed to a metal frame, and the metal frame may be fixed to the ground. At this time, the support members 131a were fixed at positions facing each other 90 mm on both sides of the mounting position of the hollow fiber membrane module 100. 2. The raw water transport pipe 121 was placed on the semicircular portion of the support member 131a. 3. Support member 131b is placed on support member 131a so that the semicircular portion fits into raw water transport pipe 121. At this time, support member 131a and support member 131b may be fixed together with adhesive, clips, bolts, or the like. 4. Five hollow fiber membrane modules 100 were placed on each of two support members 131b / 131a, one on top of the other, with the raw water inlet 54 facing vertically downward and with all outlets facing 90 degrees to the axial direction of the raw water transport pipe 121. 5. The raw water inlets 54 of all hollow fiber membrane modules 100 were fixed to the nozzles of the raw water transport pipes 121 with 50A Victoric joints. A 10A joint was provided on the nozzle of the raw water transport pipes 121, and an air intake for AS was provided. 6. For each hollow fiber membrane module, one support member 132a was placed on the nut N of the filtrate discharge outlet 52, in the same orientation as the support member 131b of the raw water transport pipe 121, with the semicircular opening facing up. 7. The filtered water collection pipe 122 was placed on top of the semicircular opening of the support member 132a with the nozzle facing vertically downward. 8. The filtrate discharge ports 52 of all the hollow fiber membrane modules 100 were connected to the filtrate collection pipes 122 with 50A Victoric joints. 9. Support member 132b is placed on support member 132a, sandwiching filtered water collection pipe 122. At this time, support A and support B may be fixed with adhesive, clips, bolts, etc. 10. The effluent water recovery pipe 123 was placed so that the nozzle of the effluent water recovery pipe 123 and the cleaning outlet 53 of the hollow fiber membrane module 100 faced in the same direction. 11. The support member 132c was placed on the support member 132b, sandwiching the wastewater recovery pipe 123. At this time, the support members 132b and 132c may be fixed together with adhesive, clips, bolts, or the like. 12. An L-shaped pipe was connected downward to the nozzle of the effluent water recovery pipe 123, and an L-shaped pipe was also connected upward to the cleaning outlet 53 of the hollow fiber membrane module 100, and both L-shaped pipes were connected to each other with a transparent expansion joint to form a U-shaped pipe. In this way, one unit of water treatment device 1 was assembled.

[0118] The installation area of ​​one unit of water treatment device 1 manufactured in this way is 0.42 m 2 , membrane area is 495m 2 The area of ​​the hollow fiber membrane per footprint is 1179 m 2 / m 2Furthermore, the weight was about 400 kg by using lightweight materials such as polyethylene and polypropylene for the piping material and ABS for the housing 30 of the hollow fiber membrane module 100. Therefore, the weight per unit area of ​​the hollow fiber membrane 11 was 0.8 kg / m 2 Furthermore, the amount of chemicals and neutralization / rinse waste liquid during chemical cleaning was 0.75 L / m 2 This has reduced the workload and the environmental impact.

[0119] The above process can be completed in a dedicated water treatment plant, and the equipment can be transported to the installation site as is. The equipment can also be assembled on site without any problems, and there is no damage to the pipes, making the construction period significantly shorter than that of a regular water treatment plant. In the water treatment device 1 of this embodiment, it is preferable to arrange a set of five hollow fiber membrane modules back to back, since this further restricts access to the filtered water collection pipe 122. Furthermore, by connecting two or three units of water treatment equipment 1 in series, the water treatment capacity can be increased by connecting the raw water transport pipe 121, the filtered water collection pipe 122, and the wastewater recovery pipe 123 of each unit with a 150A Victorian joint.

[0120] Next, two units of the water treatment device shown in Figure 1 (two units of five hollow fiber membrane modules) were arranged in parallel, and a valve unit and a pump were connected to conduct a long-term operation test of the water treatment system obtained above.

[0121] The test was carried out using the following operating settings: Operation sequence: F (28.5 minutes), ASBW (1 minute), and FL (0.5 minutes) set in this order Turbidity of the filtered liquid: 10NTU Filtration Flux: 100LMH Backwash FLUX:80LMH FL flow rate: 3m 3 / hr As a result, the system has been operating stably for over a year without any water leaks from the pipes.

[0122] After one year of operation, a leak test was carried out by closing the outlet valve of the raw water conveyance pipe 121 and introducing 0.1 MPa of compressed air through the AS pipe of the raw water conveyance pipe 121. Air bubbles were detected from the transparent expansion joint connected to the wastewater recovery pipe 123 of one of the ten hollow fiber membrane modules 100 installed. Therefore, all water was drained from the water treatment device 1, the support member 132a supporting the filtrate collection piping 122 placed on the hollow fiber membrane module 100 was removed, and the Victoria joint of the filtrate outlet 52 was removed. Furthermore, the nut N and cap of the hollow fiber membrane module 100 were removed to expose the filtrate side end face. Compressed air was again introduced through the AS piping, the leaking hollow fiber membrane 11 was identified, and the leak was repaired by nailing. In this way, the leak repair could be completed without removing the hollow fiber membrane module 100 from the water treatment device 1. [Industrial Applicability]

[0123] The water treatment device of the present invention can be used, for example, in a water purification method including a step of filtering suspended water to obtain a filtrate. The filtration method of the present invention can also be used in food production, for example, when separating yeast from alcoholic beverages such as sake and wine. In pharmaceutical production, the filtration method of the present invention can be used, for example, for sterilization during protein purification. Furthermore, in semiconductor production, the water treatment device of the present invention can be used, for example, when separating polishing wastewater into abrasives and water. [Explanation of symbols]

[0124] 1. Water treatment equipment 10 Hollow fiber membrane bundle 11 Hollow fiber membrane 20 Adhesive fixing part 21 1st adhesive fixing layer 22 Second adhesive fixing layer 30 Housing 31 first cylindrical member 32 second cylindrical member 41 Inner space of hollow fiber 42 External space of hollow fiber 50 Rectifier tube 51 Air inlet 52 Filtrate outlet 53 Cleaning outlet 54 Raw water inlet 100 Hollow fiber membrane module 110 Hollow fiber membrane module group 120 Piping Group 121 Raw water transport piping 122 Filtered water collection piping 123 Wastewater recovery piping 124 Connection joint 130 Supporting members 131, 131a, 131b, 132, 132a, 132b, 132c Support members 200 Filtrate tank 210 Strainer 300 Filtrate Tank 400 Compressor 1000 Filtration System L is the distance between the first adhesive fixing layer and the second adhesive fixing layer. V1 Filtrate delivery valve V3 Backwash valve V4 Wash waste drain valve V5 Washing waste discharge valve V6 AS valve V7 Compressed air valve for discharge process V8 Chemical return valve V9 Bypass Valve

Claims

1. a group of hollow fiber membrane modules consisting of 3 to 10 hollow fiber membrane modules, each including a hollow fiber membrane bundle consisting of a plurality of hollow fiber membranes; a group of pipes including a raw water transport pipe connected to each of the hollow fiber membrane modules via a raw water inlet communicating between the outside of the hollow fiber membrane module and the space outside the hollow fiber membranes, a filtrate collection pipe connected via a filtrate outlet communicating between the outside of the hollow fiber membrane module and the space inside the hollow fiber membranes, and an effluent recovery pipe connected via a cleaning outlet communicating between the outside of the hollow fiber membrane module and the space outside the hollow fiber membranes; and a group of support members consisting of support members supporting the hollow fiber membrane module, the raw water transport pipe, the filtrate collection pipe, and the effluent recovery pipe, the raw water transport piping and each hollow fiber membrane module of the hollow fiber membrane module group are connected via the raw water inlet by a first branch pipe and a first flexible joint, the filtrate collection piping and each hollow fiber membrane module of the hollow fiber membrane module group are connected via the filtrate outlet by a second branch pipe and a second flexible joint, and the effluent water recovery piping and each hollow fiber membrane module of the hollow fiber membrane module group are connected via the cleaning outlet by a third branch pipe and a third flexible joint, The support member includes a first support member and a second support member, The first support member is composed of two first members each having one opening, and the raw water transport piping is accommodated and supported between the openings of the two first members, the second support member is composed of two second members each having one opening and one third member having two openings, one of the filtered water collection pipe and the wastewater recovery pipe is accommodated and supported between the opening of one of the two second members and one of the two openings of the third member, and the other of the filtered water collection pipe and the wastewater recovery pipe is arranged and supported between the other of the two openings of the third member and the opening of the other of the two second members, The mass per membrane area of ​​the hollow fiber membrane is 1.0 kg / m ２ 1. A water treatment device comprising:

2. The total membrane area per site area of ​​one unit of water treatment equipment is 1,000 m ２ / m ２ The water treatment device according to claim 1 .

3. The water treatment device according to claim 1 or 2, wherein the water treatment device units are configured to be connectable to each other so that up to five units can be connected.

4. A water treatment device as described in claim 1 or 2, wherein the cross sections of the raw water conveying pipe, the water collection pipe and the wastewater recovery pipe are each circular, and the opening is semicircular.

5. The piping group, the housing of the hollow fiber membrane module, and the support member have a specific gravity of 1.3 g / cm ３ The water treatment device according to claim 1 or 2, which is made using the following resin:

6. The hollow fiber membrane module comprises: the hollow fiber membrane bundle consisting of a plurality of the hollow fiber membranes; a housing in which the hollow fiber membrane bundle is housed; adhesive fixing portions that adhesively fix both ends of the hollow fiber membrane bundle to the housing; A hollow fiber membrane module comprising: The hollow fiber membrane is a microfiltration (MF) membrane or an ultrafiltration (UF) membrane, The adhesive fixing portion is a first adhesive fixing layer that adhesively fixes the hollow fiber membranes to each other and the hollow fiber membrane bundle to the inner wall of the housing with a resin material at one end of the hollow fiber membranes; a second adhesive fixing layer that adhesively fixes the hollow fiber membranes to each other and the hollow fiber membrane bundle to the inner wall of the housing with a resin material at the other end of the hollow fiber membranes; and The hollow fiber membrane module meets the following conditions (A), (B), and (C): (A) the hollow fiber membrane filling rate, expressed as 100 × (total cross-sectional area of ​​the hollow fiber membranes) / (internal cross-sectional area of ​​the housing), is 42% or less; (B) the outer diameter of the hollow fiber membrane is 1.3 mm or less; and (C) The total membrane area of ​​the hollow fiber membrane is 50 m ２ That is more than or equal to; The water treatment device according to claim 1 or 2, which satisfies all of the above.

7. The water treatment device according to claim 1 or 2, wherein the effective length of the hollow fiber membrane is 1.6 m or more.

8. 3. The water treatment device according to claim 1, wherein the filtered water collection pipe is located below the wastewater recovery pipe, the filtered water collection pipe is surrounded by the wastewater recovery pipe and its connecting joints, and the opening through which the filtered water collection pipe can be accessed is 30 cm or less.

9. a hollow fiber membrane module group composed of a plurality of hollow fiber membrane modules, including a hollow fiber membrane bundle composed of a plurality of hollow fiber membranes; a group of pipes including a raw water conveying pipe, a filtered water collecting pipe, and a wastewater recovery pipe connected to each of the hollow fiber membrane modules; a support member for supporting the hollow fiber membrane module, the raw water transport pipe, the filtered water collection pipe, and the wastewater recovery pipe; the raw water transport piping and each hollow fiber membrane module of the plurality of hollow fiber membrane modules are connected by a first branch pipe and a first flexible joint, the filtrate collection piping and each hollow fiber membrane module of the plurality of hollow fiber membrane modules are connected by a second branch pipe and a second flexible joint, and the effluent water recovery piping and each hollow fiber membrane module of the plurality of hollow fiber membrane modules are connected by a third branch pipe and a third flexible joint, The support member includes a first support member and a second support member, The first support member is composed of two first members each having one opening, and the raw water transport piping is accommodated and supported between the openings of the two first members, A water treatment device in which the second support member is composed of two second members each having one opening and one third member having two openings, one of the filtered water collection pipe and the wastewater recovery pipe is accommodated and supported between the opening of one of the two second members and one of the two openings of the third member, and the other of the filtered water collection pipe and the wastewater recovery pipe is positioned and supported between the other of the two openings of the third member and the opening of the other of the two second members.

10. A water treatment device as described in Claim 9, wherein the cross sections of the raw water conveying pipe, the water collecting pipe and the wastewater recovery pipe are each circular, and the opening is semicircular.

11. The water treatment device according to claim 9 or 10, wherein the raw water transport pipe, the filtered water collection pipe, and the effluent water recovery pipe are laid along a direction in which the plurality of hollow fiber membrane modules are laid.

12. The water treatment device according to claim 9 or 10, wherein the support member integrally fixes the hollow fiber membrane module, the filtered water collection pipe, and the wastewater recovery pipe.

13. The water treatment device according to claim 9 or 10, wherein the filtrate collection pipe and the wastewater recovery pipe are located above the hollow fiber membrane module, and are laid in the order of the wastewater recovery pipe and the filtrate collection pipe from above the water treatment device.

14. A filtration method for filtering a liquid to be filtered using the water treatment device according to claim 1 or 2, The filtration method includes: a filtration step in which the liquid to be filtered is passed through the hollow fiber membrane by external pressure filtration to obtain a filtrate; a washing step carried out after the filtration step; a chemical washing step carried out after repeating the filtration step and the washing step multiple times; Including, The washing step includes: Backwashing is performed by passing the filtrate from the inside to the outside of the hollow fiber membrane, or flushing is performed by introducing the liquid to be filtered from the raw water inlet and discharging it from the cleaning outlet; air scrubbing, in which a liquid to be filtered containing air bubbles is introduced through the raw water inlet and discharged through the cleaning outlet, and the hollow fiber membrane is shaken by the air bubbles; and cleaning the outer surface of the hollow fiber membrane by performing a combination of backwashing and air scrubbing, or flushing and air scrubbing. Including, The chemical cleaning step includes: a chemical solution cleaning step in which the inside of the hollow fiber membrane module is filled with a chemical solution, and the chemical solution is introduced through the raw water inlet and discharged through the filtrate outlet and / or the cleaning outlet, thereby circulating the chemical solution; a chemical solution discharging step of discharging the chemical solution from the hollow fiber membrane module after the chemical solution cleaning step; a rinsing step of rinsing the inside of the hollow fiber membrane module with filtered water or water after the chemical solution discharging step; a rinse liquid discharging step of discharging the filtered water or the water after rinsing after the rinsing step; A filtration method comprising:

15. The filtration method according to claim 14, wherein in the cleaning step, backwashing or flushing is performed before the backwashing-air scrubbing simultaneous cleaning or the flushing-air scrubbing simultaneous cleaning.

16. The filtration method according to claim 14, further comprising, after the washing step, a discharge step of discharging a washing wastewater from the outside and hollow portion of the hollow fiber membrane through the raw water inlet or the washing outlet.

17. The filtration method according to claim 16, wherein the discharge step comprises introducing compressed air into the hollow fiber membrane module from the raw water inlet or the washing outlet to discharge the washing wastewater.

18. The filtration method according to claim 14 , wherein the chemical solution discharge step comprises introducing compressed air into the hollow fiber membrane module from the raw water inlet or the cleaning outlet to discharge the cleaning wastewater.

19. 19. The filtering method according to claim 18, wherein the chemical solution discharging step and / or the rinse solution discharging step introduce compressed air into the raw water inlet or the cleaning outlet to discharge the chemical solution, the filtered water, or the water.

20. The volume of the chemical solution and the rinse solution per membrane area is 1.0 L / m ２ 15. The filtration method of claim 14, wherein:

21. a bubble inspection step of inspecting whether bubbles are generated from the hollow fiber membranes by introducing compressed air from the filtrate collection pipe into each hollow fiber membrane module in the water treatment device according to claim 1 or 2; If the air bubble is detected, an identifying step of identifying the hollow fiber membrane in which the bubbles have occurred by exposing the end face of the hollow fiber membrane bundle on the side of the filtrate collection pipe without removing the hollow fiber membrane module in which the bubbles have been detected from the water treatment device; a repairing step of repairing the identified hollow fiber membrane; A method for repairing a leak, comprising:

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