JP2024045071A - Structure of hollow fiber membrane for water treatment - Google Patents

Abstract

To provide a hollow fiber membrane module having a structure of effectively removing dust and dirt from between hollow fiber membranes, and to provide a water purification treatment system including the same.SOLUTION: A hollow fiber membrane module includes: a plurality of hollow fiber membranes extending in a vertical direction; and a pair of holding members for fixing upper ends and lower ends of the plurality of hollow fiber membranes, where the plurality of hollow fiber membranes are arranged in a zigzag manner.SELECTED DRAWING: Figure 1

Description

The present invention relates to a hollow fiber membrane module and a water purification treatment system.

The membrane bioreactor (MBR) is known as one of the methods for purifying sewage, wastewater, etc. In MBR, treated water and activated sludge are separated using a separation membrane (membrane unit) such as a microfiltration membrane or ultrafiltration membrane, but the separation membrane needs to be cleaned periodically to prevent clogging.

Here, hollow fiber membrane modules are known as membrane units used in MBRs. Patent Documents 1 and 2 disclose hollow fiber membrane modules in which multiple hollow fiber membranes are arranged in a lattice pattern (Figure 4 in Patent Document 1, Figure 2 in Patent Document 2).

JP 2019-130445 A JP 2019-166474 A

When cleaning the above-mentioned hollow fiber membrane module, various methods such as backwashing and scrubbing cleaning are used, but it is impossible to effectively remove dust and dirt between the hollow fiber membranes near the upper and lower ends of the hollow fiber membrane. The current situation is that this is not possible. One of the reasons for this is thought to be that the plurality of hollow fiber membranes are arranged in a grid pattern.

The object of this invention is to provide a hollow fiber membrane module that is structured to effectively remove debris and dirt between hollow fiber membranes, and a water purification treatment system that includes the same.

[1]
A plurality of hollow fiber membranes extending in the vertical direction;
A pair of holding members that fix upper and lower ends of the plurality of hollow fiber membranes;
A hollow fiber membrane module having
A hollow fiber membrane module, characterized in that the plurality of hollow fiber membranes are arranged in a staggered pattern.

[2]
A water purification treatment system comprising: a purification treatment unit having a plurality of hollow fiber membrane modules according to [1], the purification treatment unit being installed in a water tank to be treated and purifying the water to be treated; and an aeration device being installed in the water tank to be treated and aerating the water to be treated stored in the water tank,
the purification processing unit is connected to a cleaning liquid tank that supplies a cleaning liquid for cleaning the purification processing unit and the aeration device through a cleaning liquid flow path;
the air diffuser is connected to a compressed air supply device through an air pipe and is also connected to the cleaning liquid tank through a cleaning liquid flow path;
a control means for controlling switching between supplying compressed air from the compressed air supply device to the air diffuser and supplying the cleaning liquid from the cleaning liquid tank to the purification processing unit and the air diffuser;
The control means
a cleaning liquid tank for cleaning the purification treatment unit and a compressed air supply device for supplying the compressed air to the air diffuser, the cleaning liquid being supplied from the cleaning liquid tank to the purification treatment unit and the compressed air being supplied from the compressed air supply device to the air diffuser, simultaneously when the purification treatment unit is cleaned.

According to the present invention, it is possible to provide a hollow fiber membrane module having a structure for effectively removing dust and dirt between hollow fiber membranes, and a water purification treatment system equipped with the same.

FIG. 1 is an example of a hollow fiber membrane module according to the present embodiment, showing (a) a front view, (b) a side view, and (c) an enlarged sectional view of an upper end portion. FIG. 3 is another example of the hollow fiber membrane module according to the present embodiment, showing (a) a front view, (b) a side view, and (c) an enlarged sectional view of the central portion. (a) A plan side sectional view showing an example of the arrangement of hollow fiber membranes, and (b) a plan side sectional view showing another example of the arrangement of the hollow fiber membranes. 1A and 1B both show examples of installation in a treatment water tank of a purification treatment unit including a hollow fiber membrane module according to this embodiment. 1 is a diagram illustrating an example of the configuration of a water purification system according to the present embodiment. It is a figure showing an example of purification processing of sludge. 11A and 11B are diagrams illustrating an example of a cleaning process for a purification processing unit. FIG. 13 is a diagram showing an example of a cleaning process for an air diffuser. It is a diagram showing another example of the configuration of the water purification treatment system according to the present embodiment, with some elements omitted. FIG. 9 is a diagram illustrating an example of a screen in the water purification system of the illustrated embodiment. It is a diagram showing another example of the configuration of the water purification treatment system according to the present embodiment, with some elements omitted. 12A and 12B are diagrams showing an example of the configuration of an aeration device provided in the water purification treatment system according to the present embodiment, in which (a) is a perspective view and (b) is an enlarged view of a portion indicated by a dashed line in FIG. 12A . 13A and 13B are diagrams illustrating the operation of the air diffuser shown in FIG. 12 .

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of an embodiment of the present invention will be described below with reference to the accompanying drawings.

[Hollow fiber membrane module]
As shown in FIG. 1 as an example, a hollow fiber membrane module 1 according to this embodiment includes a plurality of hollow fiber membranes 2 extending in the vertical direction, an upper holding member 4 and a lower holding member 5 for fixing the upper end and lower end of each hollow fiber membrane 2, and a pair of support members 6, 6 fixed between the upper holding member 4 and the lower holding member 5 (hereinafter, these and a middle holding member 10 described later may be collectively referred to as the "holding members") so that each hollow fiber membrane 2 is in a predetermined tensioned or relaxed state.

The upper holding member 4 is a cylindrical body that is open at the bottom as shown in Figure 1. In this open portion, multiple hollow fiber membranes 2 are fixed, bonded with a resin composition 9, while forming a hollow portion 8 as shown in Figure 1(c).

The hollow portion 8 has a function of collecting filtered water and a function of sending a cleaning liquid to each hollow fiber membrane 2. The hollow portion 8 and a filtrate water flow path, which will be described later, communicate with each other through a tubular member 7.

The structure of the lower holding member 5 is the same as that of the upper holding member 4 except that it is a cylindrical body with an open top, so a description thereof will be omitted.

As shown in FIG. 2, the hollow fiber membrane module 1 may also include a middle holding member 10. The middle holding member 10 is a cylindrical body that is open at the top and bottom except for the left and right ends. The left and right ends of the middle holding member 10 are connected to support members 6, 6 so as to be located in the center of the height direction of the hollow fiber membrane 2. A plurality of hollow fiber membranes 2 bonded with a resin composition 9 are fixed to the open portion while forming a hollow portion 8 as shown in FIG. 2(c). The hollow portion 8 of the middle holding member 10 is connected to the filtrate water flow path described later by a tubular member 7 in the same manner as the explanation of the upper holding member 4 and the lower holding member 5.

In this embodiment, a hollow fiber membrane sheet 3 is formed as a unit consisting of a predetermined number of hollow fiber membranes 2 arranged along one side of the holding member, and multiple hollow fiber membrane sheets 3 are arranged along another side perpendicular to the direction of the one side of the holding member so that the entire hollow fiber membranes 2 are staggered.

In the example shown in FIG. 3(a), a hollow fiber membrane sheet 3 is formed in which a predetermined number of hollow fiber membranes 2 arranged along the length of a cylindrical holding member are formed as a unit, and the thickness of the holding member is Six hollow fiber membrane sheets 3 are arranged along the direction so that the entire hollow fiber membrane 2 is staggered.

In the example shown in FIG. 3(b), a hollow fiber membrane sheet 3 is formed as a unit consisting of a predetermined number of hollow fiber membranes 2 arranged along the thickness direction of a cylindrical holding member, and 10 unit hollow fiber membrane sheets 3 are arranged along the length direction of the holding member so that the entire hollow fiber membranes 2 are staggered.

As described above, the hollow fiber membrane module 1 of this embodiment is configured with multiple hollow fiber membranes 2 arranged in a staggered pattern, unlike conventional hollow fiber membrane modules in which hollow fiber membranes are arranged in a lattice pattern. By arranging multiple hollow fiber membranes 2 in a staggered pattern, it is possible to effectively remove debris and dirt between the hollow fiber membranes 2 near the upper and lower ends of the hollow fiber membranes 2 when cleaning the hollow fiber membrane module 1.

Multiple hollow fiber membrane modules 1 shown in Figures 1 and 2 are erected in a frame (not shown) to form a purification treatment unit (hollow fiber membrane unit) 13. One or more purification treatment units 13 are installed in the water tank to be treated depending on the volume, water depth, and amount of water to be treated of the water tank to be treated.

For example, if the water tank 12 to be treated is as shown in FIG. 4(a) in which four purification units 13 can be installed, and the water depth is sufficiently deep (for example, about 6 m) relative to the height of the purification units 13, The hollow fiber membrane module 1 shown in FIG. 2 is designed to have a height of about 2 m, and four purification processing units 13 including a plurality of hollow fiber membrane modules 1 are installed in the water tank 12 to be treated as shown in FIG. 4(a).

Alternatively, the hollow fiber membrane module 1 shown in FIG. 3 may be designed to have a height of approximately 4 m, and two purification processing units 13 including a plurality of hollow fiber membrane modules 1 may be installed in the water tank 12 to be treated as shown in FIG. 4(a). good. In this case, the hollow fiber membrane module 1 shown in FIG. Therefore, while reducing the number of installed purification units 13, it is possible to exhibit the same treatment capacity for water to be treated as in the installation example shown in FIG. 4(a).

[Water purification system]
(Embodiment 1)
[Configuration of water purification system]
The water purification treatment system 11 of this embodiment is a system that performs water purification treatment by a membrane separation activated sludge method, as an example, and as shown in FIG. It includes an air supply device 22, a chemical solution tank 24, and a dilution water tank 27.

The treated water tank 12 is a tank that stores treated water such as domestic wastewater or industrial wastewater and purifies it. The treated water tank 12 shown in FIG. 5 is connected to the treated water flow path 16 and the excess sludge discharge path 21. The treated water 32 is introduced into the treated water flow path 16 by the treated water circulation pump 15 and flows into the treated water tank 12. In addition, activated sludge that becomes excess due to the biofilm treatment of the treated water 32 by the purification treatment unit 13 is introduced into the excess sludge discharge path 21 by the excess sludge discharge pump 20 and discharged.

The purification processing unit 13 is a device consisting of a membrane member that filters the water to be treated 32 and separates it into activated sludge containing pollutants and filtrate water. In this embodiment, the purification processing unit 13 is composed of multiple hollow fiber membrane modules 1, and one or more purification processing units 13 are installed so as to be immersed in the water to be treated 32 stored in the water to be treated tank 12. In addition, the hollow portion 8 in the holding member of each hollow fiber membrane module 1 constituting the purification processing unit 13 is connected to the filtrate water flow path 18 via a tubular member 7. The filtrate water filtered by the biological film treatment of the water to be treated 32 by the purification processing unit 13 is introduced into the filtrate water flow path 18 by the filtration pump 17 and the opening and closing valve 19a, and is stored in a filtrate water tank not shown.

The aeration device 14 is a device that aerates the water to be treated 32 stored in the water tank 12 or supplies compressed air to clean the purification processing unit 13. In this embodiment, as shown in FIG. 5, multiple aeration devices 14 are provided below each purification processing unit 13. Each aeration device 14 is connected to an air supply pipe 23, and compressed air supplied from the compressed air supply device 22 is introduced into the air supply pipe 23 and the aeration device 14 by opening and closing valves 19b and 19c, and aerates the water to be treated 32 via the aeration device 14, or sends compressed air to the purification processing unit 13. Each aeration device 14 is a unit aeration means consisting of multiple aeration pipes 40.

The compressed air supply device 22 may be a blower (maximum pressure 1 kgf/cm2) or a compressor (maximum pressure 3-5 kgf/cm2), depending on the wear and tear of the purification processing unit 13 due to the purification processing, for example, the blockage of the hollow fiber membrane 2.

The chemical tank 24 is a tank for storing a chemical liquid constituting a cleaning liquid for cleaning the purification processing unit 13 and the aeration device 14. The chemical tank 24 shown in FIG. 5 is connected to the chemical liquid flow path 26. The chemical liquid flow path 26 is connected to the dilution water flow path 29a and is connected to the cleaning liquid flow path 30 via the mixer 31. The cleaning liquid flow path 30 is bifurcated, one of which is connected to the filtered water flow path 18 and the other is connected to the air supply pipe 23. The chemical liquid is introduced into the chemical liquid flow path 26 by the chemical liquid pump 25 and the opening and closing valve 19f and supplied to the mixer 31. As the chemical liquid in this embodiment, a conventionally known one suitable for cleaning the purification processing unit 13, such as sodium hypochlorite or ozone, can be used. The chemical liquid tank 24 may be a cleaning liquid tank in which a cleaning liquid prepared in advance is stored. In this case, in the embodiment shown in FIG. 1, the dilution water flow path 29a and the mixer 31 are not necessary, and the aeration device 14 is connected to the cleaning liquid tank through the cleaning liquid flow path 30.

The dilution water tank 27 is a tank that stores dilution water that constitutes dilution water for cleaning the air diffuser 14 and cleaning liquid for cleaning the purification unit 13 . A dilution water tank 27 shown in FIG. 5 is connected to dilution water channels 29a and 29b. One dilution water flow path 29a is connected to the chemical liquid flow path 26, and the other dilution water flow path 29b is connected to the air pipe 23. The dilution water is introduced into the dilution water flow path 29a by the dilution water pump 28a and the on-off valve 19g, and is supplied to the mixer 31. Further, the dilution water is introduced into the dilution water flow path 29b and the air pipe 23 by the dilution water pump 28b and the on-off valve 19h, and is supplied to the air diffuser 14.

The chemical solution and dilution water supplied to the mixer 31 are mixed to produce a cleaning solution. This cleaning solution is introduced into the air supply pipe 23 and the filtered water flow path 18 via the cleaning solution flow path 30 and the opening and closing valves 19d and 19e, and is supplied to the purification processing unit 13 and the air diffuser 14.

In the water purification system 11 of this embodiment, the pumps 15, 17, 20, 25, 28a, 28b are , each of the on-off valves 19a to 19h, and a computer-based control means (not shown) that controls the operation of the compressed air supply device 22.

[Purification of treated water]
An example of purification treatment of the water to be treated by the water purification treatment system 11 of this embodiment will be described with reference to FIG.

The control means controls the on-off valves 19a to 19c to open and the on-off valves 19d to 19h to close, and operates the water circulation pump 15, the filtration pump 17, the excess sludge discharge pump 20, and the compressed air supply device 22. and stop the chemical solution pump 25 and dilution water pumps 28a and 28b.

When the treated water circulation pump 15 is operated, the treated water 32 is introduced into the treated water flow path 16 and flows into the treated water tank 12.

Compressed air supplied from the compressed air supply device 22 is introduced into the air supply pipe 23 and the aeration device 14, and aerates the water to be treated 32 via the aeration device 14. In the aerated water to be treated 32, the activated sludge promotes the absorption and decomposition of pollutants contained in the water to be treated 32, and the water to be treated 32 is purified.

In the purification treatment unit 13, the water to be treated 32 is filtered and separated into activated sludge containing pollutants and filtered water. By operating the filtration pump 17, the filtered water is introduced into the filtered water flow path 18 and stored in a filtered water tank (not shown). In addition, by operating the excess sludge discharge pump 20, the activated sludge that has become excess due to the biofilm treatment of the water to be treated 32 by the purification treatment unit 13 is introduced into the excess sludge discharge path 21 and discharged.

[Cleaning process of purification processing unit]
An example of a cleaning process for the purification processing unit 13 in the water purification processing system 11 of this embodiment will be described with reference to FIG.

The control means controls the on-off valves 19a, 19d, and 19h to the closed state and the on-off valves 19b, 19c, and 19e-19g to the open state, and operates the compressed air supply device 22, the chemical pump 25, and the dilution water pump 28a. , the treated water circulation pump 15, the filtration pump 17, the excess sludge discharge pump 20, and the dilution water pump 28b are stopped.

Compressed air supplied from the compressed air supply device 22 is introduced into the air pipe 23 and the air diffuser 14, and the compressed air is sent to the purification unit 13 via the air diffuser 14. When the compressed air comes into contact with the membrane surface of the purification unit 13, dirt is removed.

The water purification treatment system 11 of this embodiment employs the hollow fiber membrane module 1 described above. The multiple hollow fiber membranes 2 that make up the hollow fiber membrane module 1 are arranged in a staggered pattern, so that dust and dirt between the hollow fiber membranes 2 near the upper and lower ends of the hollow fiber membranes 2 can be effectively removed by compressed air.

By operating the chemical liquid pump 25, the chemical liquid is introduced from the chemical liquid tank 24 into the chemical liquid channel 26, and is supplied to the mixer 31. Further, by operating the dilution water pump 28a, dilution water is introduced from the dilution water tank 27 into the dilution water flow path 29a, and is supplied to the mixer 31.

The chemical solution and dilution water supplied to the mixer 31 are mixed to generate a cleaning solution. This cleaning solution is introduced into the cleaning solution flow path 30 and the filtered water flow path 18 on the opening/closing valve 19e side, and is supplied to the purification processing unit 13. The supplied cleaning solution cleans the purification processing unit 13.

[Cleaning of the air diffuser]
An example of a cleaning process for the aeration device 14 by the water purification system 11 of this embodiment will be described with reference to FIG.

The control means controls the on-off valves 19a, 19e, and 19h to a closed state and the on-off valves 19b-19d, 19f, and 19g to an open state, operates the chemical pump 25 and the dilution water pump 28a, and stops the treated water circulation pump 15, the filtration pump 17, the excess sludge discharge pump 20, the compressed air supply device 22, and the dilution water pump 28b.

By operating the chemical liquid pump 25, the chemical liquid is introduced from the chemical liquid tank 24 into the chemical liquid channel 26, and is supplied to the mixer 31. Further, by operating the dilution water pump 28a, dilution water is introduced from the dilution water tank 27 into the dilution water flow path 29a, and is supplied to the mixer 31.

The chemical solution and dilution water supplied to the mixer 31 are mixed to produce a cleaning solution. This cleaning solution is introduced into the cleaning solution flow path 30 on the opening/closing valve 19d side and the air supply pipe 23, and is supplied to the air diffuser 14. The supplied cleaning solution cleans the air diffuser 14.

Next, the control means closes the on-off valves 19a, 19d-19g and opens the on-off valves 19b, 19c, 19h, operates the dilution water pump 28b, and operates the water circulation pump 15 and the filtration pump. 17. Stop the excess sludge discharge pump 20, compressed air supply device 22, chemical pump 25, and dilution water pump 28a.

When the dilution water pump 28b is operated, dilution water is introduced from the dilution water tank 27 into the dilution water flow path 29b and the air supply pipe 23, and is supplied to the aeration device 14. The supplied dilution liquid removes any remaining chemicals in the aeration device 14.

In this way, in the water purification treatment system 11 of embodiment 1, the aeration device 14 is connected to the compressed air supply device 22 through the air supply pipe 23 and to the chemical liquid tank 24 through the cleaning liquid flow path 30, and the functions of the compressed air supply device 22, the air supply pipe 23, and the aeration device 14 are used for aeration of the water tank 12 to be treated and cleaning of the purification treatment unit 13 and the aeration device 14. Therefore, it is possible to provide a space-saving water purification treatment system using the membrane separation activated sludge method without constructing a configuration corresponding to each of the functions of aeration of the water tank 12 to be treated and cleaning of the purification treatment unit 13 and the aeration device 14.

The water purification treatment system 11 of this embodiment employs the hollow fiber membrane module 1 described above. The hollow fiber membranes 2 constituting the hollow fiber membrane module 1 are arranged in a staggered pattern, so that the compressed air can effectively remove debris and dirt between the hollow fiber membranes 2 near the upper and lower ends of the hollow fiber membranes 2.

Furthermore, by cleaning the purification processing unit 13 with compressed air and cleaning liquid, it is possible to reduce the cleaning costs associated with using only cleaning liquid and suppress deterioration of the purification processing unit 13.

(Embodiment 2)
[Other configurations of the water purification treatment system]
FIG. 9 illustrates the schematic configuration of an example of a water purification treatment system of the present invention, which is a composite water purification treatment system that combines a fixed bed method and a fluidized bed method, i.e., a catalytic oxidation combination system.

In the embodiment shown in FIG. 9, the only difference from Embodiment 1 is the configuration of the treated water tank 12 and the purification unit 13, so the same components as Embodiment 1 are given the same reference numerals and their explanations will be omitted. . Further, the surplus sludge discharge path 21, the treated water circulation pump 15, the filtration pump 17, the surplus sludge discharge pump 20, the chemical pump 25, and the dilution water pump 28, which are common to the first embodiment, are omitted in FIG.

A fluidized bed area is provided in one treated water tank 12 for purification treatment in which the treated water 32 to be purified flows from the upstream side (the left side in FIG. 9) to the downstream side (the right side in FIG. 9). 33 and a fixed bed area 34 are arranged adjacent to each other, and a screen 35 is arranged at the boundary between the fluidized bed area 33 and the fixed bed area 34.

The screen 35 allows the treated water 32 to flow between the fluidized bed region 33 and the fixed bed region 34, while preventing the fluidized bed contact material 36, which flows in the fluidized bed region 33, from flowing into the fixed bed region 34.

A number of individually controlled aeration devices 14a-14f are arranged from the upstream side to the downstream side at the bottom of the treated water tank 12. Each of the aeration devices 14a-14f is a unit aeration means, with each unit being made up of a number of aeration pipes 40.

Individual control of each diffuser 14a-14f can be performed manually or automatically by the control means described in the first embodiment.

A plurality of fluidized bed contact materials 36 are placed in the fluidized bed region 33, and are fluidized in the water to be treated 32 by being aerated by the aeration device 14 installed in the fluidized bed region 33, and become fluidized. Purification treatment is carried out using the bed method.

Here, the air diffuser 14a and the air diffuser 14b, which are arranged in order from the upstream side in the fluidized bed region 33, are individually controlled to open the on-off valve 19i at the position indicated by A in FIG. By closing the on-off valve 19j at the position indicated by B in FIG. 9, an upward flow is generated in FIG. 9 only at the position where the air diffuser 14a is installed, while the air diffuser 14b At the deployed position, a downward flow can be generated in the downward direction as shown in FIG.

In this way, the aeration devices 14a, 14b are individually controlled, and the aeration devices 14a-14f are arranged in sequence from the upstream side to the downstream side at the bottom of the treated water tank 12. By controlling each of the adjacent aeration devices 14a, 14b so that one of them stops diffusing air while the other is performing the aeration operation, the fluidized bed contact material 36 can be effectively fluidized in the treated water 32 in the fluidized bed area 33.

In this way, the biofilm formed on the surface of the fluidized bed contact material 36 can be more efficiently contacted with the water to be treated 32, soluble organic pollutants, suspended solids (hereinafter sometimes referred to as "SS" in this specification), mixed liquor suspended solids (hereinafter sometimes referred to as "MLSS" in this specification), etc., improving the treatment capacity.

In the fixed bed area 34, purification processing is performed using a fixed bed method.

The purification processing unit 13, which is fixedly arranged in the fixed bed area 34, is composed of multiple hollow fiber membrane modules 1 as described above.

Aeration by the aeration device 14 installed in the fixed bed area 34 creates a flow of the treated water 32 rising through each hollow fiber membrane 2.

In the fixed bed area 34, the air diffusers 14c-14f arranged in sequence from the upstream side to the downstream side are individually controlled, and the on-off valve 19k at the position indicated by C in FIG. 9 is opened, and the on-off valve 19l at the position indicated by D in FIG. 9 is closed. This creates an upward flow as indicated by the upward arrow in FIG. 9 inside each hollow fiber membrane 2 at the position where the air diffuser 14c is located, supplying the oxygen required by the microorganisms and allowing the SS and organic matter to be efficiently taken up by the biofilm. On the other hand, a downward flow as indicated by the downward arrow in FIG. 9 is created inside each hollow fiber membrane 2 at the position where the air diffuser 14d is located, allowing the excess sludge to be appropriately peeled off, resulting in efficient purification.

In the water purification treatment system 11 of this embodiment, in both the fluidized bed area 33 and the fixed bed area 34, a plurality of air diffusers are provided at the bottom of the water tank 12 to be treated from the upstream side to the downstream side. 14a to 14b, and by individually controlling each of the aeration devices 14a to 14f, it is possible to perform whole area divided aeration in which the entire surface is divided and aerated. These generate a swirling flow, etc. in the water to be treated 32, thereby improving treatment efficiency.

As the fluidized bed contact material 36, various conventional contact materials can be used as long as they can support the attachment and habitation of microorganisms. For example, a carrier filter material for a fluidized bed made of polypropylene or polyurethane can be used.

A plurality of such fluidized bed contact materials 36 are introduced into the fluidized bed region 33, for example, at a rate of 280,000 pieces/m ³ and a filling rate of 20-40%.

Figure 10 illustrates the screen 35. As described above, the screen 35 allows the water 32 to flow between the fluidized bed region 33 and the fixed bed region 34, while preventing the contact material 36 for the fluidized bed, which flows in the fluidized bed region 33, from flowing into the fixed bed region 34.

In the case of water purification treatment using biofilm treatment, the larger the surface area of the contact material, the more microorganisms will be able to settle on the surface of the contact material, and the greater the treatment capacity. Therefore, in biofilm treatment using the fluidized bed method, the contact material is made hollow or has a structure with a high porosity, thereby making the contact material smaller while increasing its surface area.

In addition, in the case of fluidized bed biofilm treatment, a screen is installed to prevent the fluidized bed contact material 36 flowing in the fluidized bed region 33 from flowing out. However, when the fluidized bed contact material 36 is miniaturized for the purpose of increasing the specific surface area, the mesh width of the screen must also be made finer to correspond to the miniaturization of the fluidized bed contact material 36. In this case, if the mesh width of the screen is made smaller, biofilms will adhere to and live on the screen itself, causing clogging when the inflowing wastewater has a high concentration of SS, is viscous, or has a large load. There is a problem in that the smooth flow of the water to be treated from the upstream side to the downstream side is obstructed.

In this embodiment, this problem is solved by arranging a fluidized bed region 33 and a fixed bed region 34 adjacent to each other in one treated water tank 12, with a screen 35 in between that prevents the fluidized bed contact material 36 flowing in the fluidized bed region 33 from flowing into the fixed bed region 34, while allowing the treated water 32 to flow between the fluidized bed region 33 and the fixed bed region 34.

Here, while allowing the water to be treated 32 to flow between the fluidized bed area 33 and the fixed bed area 34, the fluidized bed contact material 36 flowing in the fluidized bed area 33 flows into the fixed bed area 34. Regarding the screen that prevents the flow of water, as mentioned above, while it is desirable to make the contact material smaller and increase its surface area, it is also important to avoid clogging the screen itself. It is preferable to set it to eye width.

In this embodiment, the inventors have proposed that the water to be treated 32 be transferred from the fluidized bed area 33 to the fixed bed area 34 through the screen 35 or from the fixed bed area 34 to the fluidized bed by aeration by the aeration device 14. For example, by forcibly causing a flow to the region 33, by reducing the size of the fluidized bed contact material 36 to increase the surface area, or by aeration by the air diffuser 14 in the fluidized bed region 33. Taking into account the effects of fluid flow (full-scale aeration, full-scale divided aeration, swirling flow, etc.), it is possible to make the mesh width of the screen 35 approximately 1/2 the outer dimension of the fluidized bed contact material 36. It was confirmed that this method is desirable in terms of water purification effect and water treatment efficiency.

FIG. 10 shows, as an example of the screen 35 when using the contact material 36 for a fluidized bed, a gap 35b of 5 mm between adjacent rod-shaped bodies 35a of 7 mm diameter rod-shaped bodies 35a extending parallel to each other in the vertical direction. A case will be explained in which a screen with a gap width of 5 mm is employed.

The screen 35 allows the water 32 to flow between the fluidized bed region 33 and the fixed bed region 34, while preventing the contact material 36 for the fluidized bed, which flows in the fluidized bed region 33, from flowing into the fixed bed region 34. Therefore, the screen 35 is not limited to the form shown in FIG. 10, and as long as it has a mesh width of about half the outer dimension of the contact material 36 for the fluidized bed, it is not limited to the one composed of multiple rod-shaped bodies extending in the vertical direction as shown in FIG. 10, and may be a mesh-shaped screen.

In this embodiment, even in the fluidized bed region 33, full aeration and swirling flow are generated by aeration using the aeration device 14, allowing the water to be treated 32 and MLSS to efficiently come into contact with the biofilm formed on the surface of the fluidized bed contact material 36, thereby improving the treatment capacity.

In addition, the air diffusers 14 arranged from the upstream side to the downstream side at the bottom of the treated water tank 12 can be controlled so that adjacent air diffusers 14a-14f stop while one is diffusing air, so that, for example, as shown in FIG. 8, the air diffuser 14b arranged below the screen 35 stops, and the air diffusers 14a and 14c arranged adjacent to the air diffuser 14b on the upstream and downstream sides perform the air diffusion operation. Alternatively, conversely, the air diffuser 14b arranged below the screen 35 can perform the air diffusion operation, and the air diffusers 14a and 14c can be stopped. This forcibly causes the water 32 to flow from the fluidized bed area 33 to the fixed bed area 34, or from the fixed bed area 34 to the fluidized bed area 33, through the screen 35, and more effectively prevents clogging of the screen 35.

Note that, depending on the size of the water tank 12 to be treated and the size of the aeration device 14, it is possible that, although not shown, no aeration device is provided below the screen 35, and aeration devices are provided upstream and downstream from the bottom of the screen 35. Even in such a case, in the aeration devices 14 provided in order from the upstream side to the downstream side at the bottom of the water tank 12 to be treated, by controlling adjacent aeration devices 14a-14f so that while one is performing an aeration operation, the other stops, the water to be treated 32 is forcibly caused to flow through the screen 35 from the fluidized bed area 33 to the fixed bed area 34, or from the fixed bed area 34 to the fluidized bed area 33, and clogging of the screen 35 is more effectively prevented.

In the water purification treatment system 11 of this embodiment, the fluidized bed contact material 36 having a larger specific surface area than the purification treatment unit 13 disposed in the fixed bed area 34 is used to treat the treated water 32 with a high SS concentration. is treated in a relatively short time in the fluidized bed region 33, and the water to be treated 32 having a low concentration of soluble organic contaminants is treated in the fixed bed region 34 by the purification unit 13.

As described above, in the fixed bed region 34, the purification processing unit 13 is arranged above the aeration device 14 and has a shape, structure, and configuration that can provide a rectifying effect to make the flow in the upward direction more orderly than the flow in the water to be treated 32 caused by aeration by the aeration device 14 in the fluidized bed region 33 described above. For example, in the illustrated embodiment, the rectifying effect is provided by the purification processing unit 13 composed of multiple hollow fiber membrane modules 1.

Therefore, in order to effectively allow the treated water 32 to flow from the fluidized bed region 33 to the fixed bed region 34, or from the fixed bed region 34 to the fluidized bed region 33, through the screen 35, while further enhancing the effect of straightening the flow in the fixed bed region 34, in the water purification treatment system 11 of this embodiment, a predetermined gap is provided between the purification treatment unit 13 in the fixed bed region 34, which is arranged adjacent to the screen 35, and the screen 35.

In this embodiment, a fixed bed area 34 is formed downstream of the screen 35, and a predetermined distance is provided between the screen 35 and the hollow fiber membrane module 1 closest to the screen 35 among the multiple hollow fiber membrane modules 1 that constitute the purification processing unit 13 in the fixed bed area 34.

In this embodiment, the size of the gap between the purification processing unit 13 of the fixed bed region 34 arranged adjacent to the screen 35 and the screen 35 can be determined from the viewpoint of effectively flowing the treated water 32 from the fluidized bed region 33 to the fixed bed region 34, or from the fixed bed region 34 to the fluidized bed region 33, through the screen 35, while further enhancing the effect of straightening the flow in the fixed bed region 34. For example, it can be at least 30 cm or more.

[Purification treatment of water to be treated]
Next, the water purification system of Embodiment 2 shown in FIG. 9 is a combination of fixed bed method and fluidized bed method, and is a combined water purification system of fixed bed method and fluidized bed method. An example of water purification using a catalytic oxidation combination system will be described.

By operating the treated water circulation pump 15 (omitted in Figure 9), the treated water 32 (raw water) to be treated is introduced into the treated water flow path 16 and flows into the fluidized bed region 33 of the treated water tank 12.

Fluidized bed contact material 36 is placed in the fluidized bed area 33, and diffusers 14a and 14b are arranged in order from the upstream side to the downstream side at the bottom of the treated water tank 12. The diffusers 14a and 14b are individually controlled so that when one diffuses air, the other stops. For example, only at the position where diffuser 14a is installed, an upward flow indicated by an upward arrow in FIG. 9 is generated, while at the position where diffuser 14b is installed, a downward flow indicated by a downward arrow in FIG. 9 is generated. This allows the fluidized bed contact material 36 to flow effectively into the treated water 32, and the treated water 32, soluble organic pollutants, SS, and MLSS come into contact with the biofilm formed on the surface of the fluidized bed contact material 36 more efficiently and are incorporated into the biofilm.

The treated water 32 that flows into the treated water tank 12 flows from the upstream side (left side in Figure 9) to the downstream side (right side in Figure 9) in the treated water tank 12, undergoes treatment, and is discharged from the treated water tank 12.

At this time, the screen 35 disposed between the fluidized bed area 33 and the fixed bed area 34 has a mesh width that is approximately 1/2 of the outer dimension of the fluidized bed contact material 36, and has a relatively large mesh width. Therefore, even if the inflowing treated water 32 has a high SS concentration, viscous treated water 32, or treated water 32 with a large load, there will be no biofilm on the screen 35 itself. There is a small risk that the particles will adhere to it, live there, and cause clogging.

Moreover, as described above, the air diffusers 14a-14f are arranged in order from the upstream side to the downstream side at the bottom of the water tank 12 to be treated, and for each adjacent air diffuser 14a-14f, one side is the air diffuser. When an operation is performed, the other is individually controlled to stop, and a forced flow of the water to be treated 32 occurs between the fluidized bed area 33 and the fixed bed area 34, and the flow of the water to be treated 32 flowing in is controlled individually. Even if the SS concentration is high, the treated water 32 is viscous, or the treated water 32 has a large load, it is more certain that biofilm will adhere to and live on the screen 35 itself, causing clogging. can be prevented.

The treated water 32 that has been purified in the fluidized bed area 33 passes through a screen 35 and flows into the fixed bed area 34. Here, as described above, an upward flow indicated by an upward arrow in FIG. 9 is generated inside each hollow fiber membrane 2 of the hollow fiber membrane module 1 at the position where the aeration device 14 that is performing aeration operation is installed, and the oxygen required by the microorganisms is supplied, and SS and organic matter are efficiently taken up into the biofilm. Meanwhile, a downward flow indicated by a downward arrow in FIG. 9 is generated inside each hollow fiber membrane 2 of the hollow fiber membrane module 1 at the position where the aeration device 14 that is not performing aeration operation is installed, and excess sludge is appropriately peeled off.

After treatment has been carried out in the fixed bed region 34, the filtrate pump 17 (not shown in Figure 9) is operated to introduce the filtrate into the filtrate flow path 18 and store it in the treatment tank.

The cleaning of the purification unit 13 and the air diffuser 14 in this embodiment is the same as the [cleaning process of the purification unit] and the [cleaning process of the air diffuser] explained in Embodiment 1, so the explanation thereof will be explained below. omitted.

According to the water purification treatment system 11 of the second embodiment shown in FIG. To efficiently and effectively purify water 32 with a low concentration of sexual pollution by treating it in a fixed bed area 34 and effectively combining fluidized bed treatment and fixed bed treatment. Can be done. This also makes it less susceptible to the effects of filamentous fungi.

Further, according to the water purification system 11 of the second embodiment shown in FIG. 9, the effects described in the first embodiment can also be exhibited.

In addition, in accordance with the properties of the water to be treated 32 that is the target of purification treatment, a fixed bed region 34 is arranged upstream of the water tank 12 to be treated, and a fluidized bed region is arranged downstream of the fixed bed region 34 with a screen 35 interposed therebetween. 33 are arranged in order from upstream to downstream: fluidized bed area 33 - screen 35 - fixed bed area 34 - screen 35 - fluidized bed area 33, fixed bed area 34 - screen 35 - fluidized bed. Various changes can be made, such as the arrangement of the area 33, screen 35, and fixed bed area 34.

In this way, the water purification system of Embodiment 2 is a combination of fixed bed method and fluidized bed method, and is a combined water purification system of fixed bed method and fluidized bed method. According to the system, not only the effects described in Embodiment 1 are exhibited, but also the treated water 32 to be purified flows from the upstream side to the downstream side. A fluidized bed region 33 and a fixed bed region 34 are provided adjacently in the water tank 12 via a screen 35 that prevents the fluidized bed contact material 36 flowing in the fluidized bed region 33 from flowing into the fixed bed region 34. By doing so, it is possible to effectively bring out the advantages of the fixed bed method and the fluidized bed method in biofilm treatment. Furthermore, this can be carried out using one existing water tank 12 for purification treatment, which is advantageous in terms of cost.

(Embodiment 3)
FIG. 11 illustrates the schematic configuration of an example of a water purification treatment system using a full divided aeration method in which the aeration points in the treatment water tank 12 are divided into several blocks and an aeration device is provided in each block.

In the embodiment shown in FIG. 11, only the arrangement of the aeration device 14 in the treated water tank 12 and the connection between the air supply pipe 23 and the aeration device 14 are different from embodiment 1, so the same components as in embodiment 1 are given the same reference numerals and their description is omitted. In addition, the treated water flow path 16, filtered water flow path 18, excess sludge discharge path 21, treated water circulation pump 15, filtration pump 17, excess sludge discharge pump 20, chemical pump 25, and dilution water pump 28, which are common to embodiment 1, are omitted in FIG. 11.

In the water purification treatment system 11 of this embodiment, the entire bottom surface of the water tank 12 to be treated is divided into a plurality of blocks, and an air diffuser 14 is provided in each block. In the embodiment shown in FIG. 11, the entire bottom surface of the water tank 12 to be treated is divided into three blocks, and each block is provided with air diffusers 14g, 14h, and 14i. The air diffusers 14g, 14h, and 14i each have a plurality of air diffusers 40 as a unit air diffuser.

A purification unit 13 is installed above the air diffuser 14h. The aeration devices 14g, 14h, and 14i each aerate the water to be treated 32, but the aeration device 14h also functions to aerate the purification unit 13.

In the embodiment shown in FIG. 11, the aeration devices 14g and 14i are connected to the air pipe 23b, and the compressed air supplied from the compressed air supply device 22b is introduced into the air pipe 23b and the aeration devices 14g and 14i by the opening and closing valves 19q and 19r, and aerates the water to be treated 32 via the aeration devices 14g and 14i. The air pipe 23a is also bifurcated, one of which is connected to the air pipe 23b, and the other is connected to the aeration device 14h. The compressed air supplied from the compressed air supply device 22a is introduced into the air pipes 23a and 23b and the aeration devices 14g and 14h by the opening and closing valves 19o and 19p, and aerates the water to be treated 32 and the purification treatment unit 13 via the aeration devices 14g and 14h.

In the form shown in FIG. 11, the dilution water flow path 29b is connected to the air pipes 23a and 23b, and the cleaning liquid flow path 30 is connected to the air pipes 23a and 23b.

[Purification treatment of water to be treated]
A case where water purification treatment is performed using the water purification treatment system of Embodiment 3 shown in FIG. 11 will be described. A feature of the water purification system 11 of this embodiment is that the aeration location can be changed. Therefore, the control means consisting of a computer, which is common to the first embodiment, cooperates with a timer and a sequencer to control the operations of the on-off valves 19o, 19p, 19q, 19r and compressed air supply devices 22a, 22b.

For example, when aerating the left block of the treated water tank 12 in FIG. 11, the control means controls the opening and closing valve 19q to an open state and the opening and closing valves 19o, 19p, and 19r to a closed state individually, so that compressed air supplied from the compressed air supply device 22b is introduced into the air supply pipe 23b and the aeration device 14g, and the treated water 32 is aerated via the aeration device 14g.

For example, when aerating the central block in FIG. 11 of the treated water tank 12, the control means controls the on-off valve 19o to an open state and the on-off valves 19p, 19q, and 19r to a closed state individually, so that compressed air supplied from the compressed air supply device 22a is introduced into the air supply pipe 23a and the aeration device 14h, and the treated water 32 and the purification treatment unit 13 are aerated via the aeration device 14h.

Further, for example, when aerating the block on the right side of the water tank 12 in FIG. Compressed air supplied from the compressed air supply device 22b is introduced into the air pipe 23b and the air diffuser 14i, and the water to be treated 32 is aerated via the air diffuser 14i.

By continuously performing this type of control process, the entire treated water 32 stored in the treated water tank 12 can be aerated.

As described in the first embodiment, in the purification unit 13, the water to be treated 32 is filtered and separated into activated sludge containing pollutants and filtered water. By operating the filtration pump 17, filtrate water is introduced into the filtrate flow path 18 and stored in a filtration tank (not shown). Furthermore, by operating the surplus sludge discharge pump 20, activated sludge that has become surplus due to the biofilm treatment of the water to be treated 32 by the purification unit 13 is introduced into the surplus sludge discharge path 21 and discharged.

[Cleaning process of purification unit]
An example of the cleaning process of the purification unit by the water purification system 11 of this embodiment will be described with reference to FIGS. 8 and 11.

The control means controls the on-off valves 19a, 19d, 19h, 19p, 19q, and 19r to the closed state and the on-off valves 19o, 19e-19g to the open state, and also controls the compressed air supply device 22a, the chemical pump 25, and the dilution water pump. 28a is activated, and the treated water circulation pump 15, filtration pump 17, excess sludge discharge pump 20, compressed air supply device 22b, and dilution water pump 28b are stopped (see FIG. 8 for on-off valves 19a, 19e and various pumps).

Compressed air supplied from the compressed air supply device 22a is introduced into the air supply pipe 23a and the air diffuser 14h, and the compressed air is sent to the purification processing unit 13 via the air diffuser 14h. The compressed air comes into contact with the membrane surface of the purification processing unit 13, removing dirt.

When the chemical pump 25 is operated, the chemical is introduced from the chemical tank 24 into the chemical flow path 26 and supplied to the mixer 31. Also, when the dilution water pump 28a is operated, dilution water is introduced from the dilution water tank 27 into the dilution water flow path 29a and supplied to the mixer 31.

The chemical solution and dilution water supplied to the mixer 31 are mixed to generate a cleaning solution. This cleaning liquid is introduced into the cleaning liquid flow path 30 and the filtrate flow path 18 on the side of the on-off valve 19e, and is supplied to the purification processing unit 13. The purification unit 13 is cleaned by the supplied cleaning liquid (see FIG. 8 for the filtrate flow path 18).

[Cleaning of the air diffuser]
An example of a cleaning process for the aeration device 14 by the water purification system 11 of this embodiment will be described with reference to FIGS.

The control means controls the on-off valves 19a, 19e, and 19h to be closed and the on-off valves 19d, 19f, 19g, and 19o-19r to be open, and operates the chemical pump 25 and dilution water pump 28a to circulate the water to be treated. The pump 15, the filtration pump 17, the excess sludge discharge pump 20, the compressed air supply devices 22a and 22b, and the dilution water pump 28b are stopped (see FIG. 8 for the on-off valves 19a and 19e and various pumps).

When the chemical pump 25 is operated, the chemical is introduced from the chemical tank 24 into the chemical flow path 26 and supplied to the mixer 31. Also, when the dilution water pump 28a is operated, dilution water is introduced from the dilution water tank 27 into the dilution water flow path 29a and supplied to the mixer 31.

The chemical solution and dilution water supplied to the mixer 31 are mixed to generate a cleaning solution. This cleaning liquid is introduced into the cleaning liquid flow path 30 on the opening/closing valve 19d side and the air supply pipes 23a, 23b, and is supplied to the air diffusers 14g-14i. The supplied cleaning liquid cleans the air diffusers 14g-14i.

The control means then controls the on-off valves 19a, 19d-19g to a closed state and the on-off valves 19h, 19o-19r to an open state, operates the dilution water pump 28b, and stops the treated water circulation pump 15, the filtration pump 17, the excess sludge discharge pump 20, the compressed air supply devices 22a, 22b, the chemical pump 25, and the dilution water pump 28a.

By operating the dilution water pump 28b, dilution water is introduced from the dilution water tank 27 into the dilution water flow path 29b and the air supply pipes 23a, 23b, and is supplied to the air diffusers 14g-14i. The supplied diluent removes the chemical solution remaining in the diffusers 14g-14i.

In this manner, the water purification system 11 of the third embodiment shown in FIG. This is a system in which aeration by the air diffuser 14 is switched individually. By individually controlling the aeration device 14 in each block, the water to be treated 32 in the water tank to be treated 12 can be effectively aerated with a small flow rate of compressed air.

In a water purification treatment system using a conventional membrane separation activated sludge method, simply aerating the hollow fiber membranes when cleaning the hollow fiber membranes creates a dead space within the treatment tank, and this space becomes an anaerobic area. This anaerobic area must be aerated using a separate blower, but this increases the power cost. According to the water purification treatment system 11 of the third embodiment, the entire bottom surface of the water tank 12 to be treated is divided into a plurality of blocks, each block is provided with an aeration device 14, and the aeration by the aeration device 14 in each block is divided into a plurality of blocks. By individually switching the two, the entire water tank 12 to be treated can be aerated with the same power cost, and the formation of the dead space can be suppressed.

Further, by individually controlling the on-off valve 19 in each block, an upward flow is generated in the block where the on-off valve 19 is "open", and a downward flow is generated in the block where the on-off valve 19 is "closed". By controlling such an operation by the control means, turbulent diffusion occurs within the water tank 12 to be treated, and short paths caused by the rotation of the water 32 to be treated can also be suppressed.

Furthermore, according to the water purification treatment system 11 of embodiment 3 shown in FIG. 11, the effects described in embodiment 1 can also be achieved.

(Embodiment 4)
FIG. 12 illustrates an example of the configuration of the air diffuser 14 provided in the water purification treatment system 11 according to the above-mentioned embodiment 1-3.

In the embodiment shown in FIG. 12, a plurality of aeration devices 14 each having a unit aeration means 37 each including a plurality of aeration tubes 40 are arranged in the water tank 12 to be treated. Each air diffuser 14 is communicated with a compressed air supply device 22 through an air pipe 23. Moreover, each diffuser 14 is installed at a depth H in the water tank 12 to be treated, as shown in FIG. 12(a).

Each air diffuser 40 has multiple pores 41 that discharge the compressed air supplied from the compressed air supply device 22. In this embodiment, as shown in FIG. 12(b), the air diffuser 40 has pores 41 that open downward.

Further, both ends of each air diffuser pipe 40 are open or provided with openings. In this embodiment, as shown in FIG. 12(b), the end 42 of the air diffuser 40 is bent in a direction perpendicular to the air diffuser 40, and has an end opening 43 that opens downward. There is. Thereby, the position of the pore 41 provided in the air diffuser pipe 40 is higher than the position of the end opening 43 in the end portion 42 by h.

Each air supply pipe 23 is equipped with a first opening/closing valve 38 and a second opening/closing valve 39. The opening and closing of these opening/closing valves is controlled by the control means described in embodiments 1-3.

In the [purification treatment of water to be treated] described in the first embodiment, the control means controls the first on-off valves 38a, 38b, and 38c to be in an open state, and the second on-off valves 39a, 39b, and 39c to be in a closed state. At this time, compressed air corresponding to the water pressure at depth H is supplied from the compressed air supply device 22 to each diffuser 14 via the air pipe 23, and is discharged from the pores 41 to aerate the water 32 to be treated. , or supply compressed air to the purification processing unit 13.

Next, the control means controls the first opening/closing valve 38a to the closed state. At this time, the inside of the air diffuser 14 and the air supply pipe 23 on the side where the first opening/closing valve 38a is installed are filled with compressed air related to the water pressure at depth H.

Next, the control means controls the second on-off valve 39a to open. The compressed air that is filled (residual) inside the air diffuser 14 and the air pipe 23 on the side where the first opening/closing valve 38a is disposed is released to the outside air. At the same time, as shown in FIG. 13(a), the water to be treated 32 enters through the pores 41 and the end openings 43.

Next, the control means controls the first on-off valves 38b and 38c to the closed state and the first on-off valve 38a to the open state. At this time, compressed air corresponding to the water pressure at depth H is supplied from the compressed air supply device 22 to the air diffuser 14 on the side where the first on-off valve 38a is disposed, via the air pipe 23. The water to be treated 32 that has entered the air diffuser 14 in a forced out manner is discharged from the end opening 43 as shown in FIG. 13(b). Further, the compressed air is discharged from the pores 41 to aerate the water 32 to be treated, or is sent to the purification unit 13. Furthermore, when the water to be treated 32 that has entered the air diffuser 14 is discharged from the end opening 43, foreign matter inside the air diffuser 14 is also discharged from the end opening 43 as shown in FIG. 13(b). be done.

In this way, the water purification treatment system 11 of embodiment 4 shown in Figures 12 and 13 employs an aeration device 14 in which the position of the fine holes 41 provided in the aeration pipe 40 is higher by h than the position of the end opening 43 at the end 42, and the control means controls the opening and closing of the first opening and closing valve 38 and the second opening and closing valve 39 to prevent blockage of the aeration device 14 due to the phenomenon of compressed air being discharged and sucked by the multiple fine holes 41 provided in each aeration device 14. In other words, the first opening and closing valve 38 and the second opening and closing valve 39 function as a release means for releasing compressed air or treated water 32 remaining in the aeration device 14 to the outside of the aeration device 14.

Therefore, according to the water purification treatment system 11 of the fourth embodiment shown in FIGS. 12 and 13, the effect of preventing clogging of the air diffuser 14 can also be exhibited. Further, maintenance can be performed without pulling up or draining the air diffuser 14 installed in the water tank 12 to be treated.

Furthermore, according to the water purification treatment system 11 of embodiment 4 shown in Figures 12 and 13, the effects described in embodiments 1 to 3 can also be achieved.

The above describes preferred embodiments and examples of the present invention with reference to the attached drawings, but the present invention is not limited to such embodiments and examples, and can be modified in various forms within the technical scope understood from the description of the claims.

For example, regarding the air diffuser 14 in the above-mentioned Embodiment 1-4, the pores provided in the air diffuser tube 40 are set as openings with a size that generates air bubbles of less than 100 μm, and the conventionally known method that generates fine air bubbles is used. It can be an air diffuser.

The aeration device 14 in the above-mentioned embodiments 1-4 can be a conventionally known aeration device equipped with a mixing means that takes in the treated water 32 around the aeration pipe 40 into the inside of the aeration pipe 40 when discharging compressed air, and mixes the taken-in treated water 32 with the compressed air.

1 Hollow fiber membrane module 2 Hollow fiber membrane 3 Hollow fiber membrane sheet 4 Upper holding member 5 Lower holding member 6 Support member 7 Tubular member 8 Hollow part 9 Resin composition 10 Middle holding member 11 Water purification treatment system 12 Water tank to be treated 13 Purification Processing unit 14 Aeration device 15 Treated water circulation pump 16 Treated water flow path 17 Filtration pump 18 Filtered water flow path 19 Opening/closing valve 20 Excess sludge discharge pump 21 Excess sludge discharge path 22 Compressed air supply device 23 Air pipe 24 Chemical solution tank 25 Chemical solution pump 26 Chemical solution flow path 27 Dilution water tank 28 Dilution water pump 29 Dilution water flow path 30 Cleaning liquid flow path 31 Mixer 32 Water to be treated 33 Fluidized bed area 34 Fixed bed area 35 Screen 36 Fluidized bed contact material 37 Unit aeration means 38 First Opening/closing valve 39 Second opening/closing valve 40 Diffusion pipe 41 Pore 42 End 43 End opening

Claims (9)

A plurality of hollow fiber membranes extending vertically,
a pair of holding members that fix the upper and lower ends of the plurality of hollow fiber membranes;
A hollow fiber membrane module having
A hollow fiber membrane module, wherein the plurality of hollow fiber membranes are arranged in a staggered manner. The hollow fiber membrane module according to claim 1, further comprising a middle holding member that fixes a portion between the upper end and the lower end of the hollow fiber membrane. A plurality of hollow fiber membrane sheets, each of which is a unit of a predetermined number of hollow fiber membranes formed along one side direction of the holding member in a plan view, are arranged along another side direction perpendicular to the one side,
3. The hollow fiber membrane module according to claim 1, wherein one hollow fiber membrane sheet formed along a direction of one side of the holding member in a plan view and another hollow fiber membrane sheet adjacent to the one hollow fiber membrane sheet are shifted by a predetermined distance in the direction of the one side to form the staggered shape. 2. A purification unit having a plurality of hollow fiber membrane modules according to claim 1, wherein the purification unit is installed in a water tank to be treated and purifies the water to be treated; A water purification system comprising: an aeration device that aerates water to be treated stored in a treated water tank;
The purification unit communicates with a cleaning liquid tank that supplies cleaning liquid for cleaning the purification unit and the air diffuser through a cleaning liquid flow path,
The air diffuser communicates with the compressed air supply device through an air pipe, and communicates with the cleaning liquid tank through a cleaning liquid flow path,
comprising a control means for controlling supply of compressed air from the compressed air supply device to the air diffuser and switching of supply of the cleaning liquid from the cleaning liquid tank to the purification processing unit and the air diffuser,
The control means includes:
When cleaning the purification unit, the cleaning liquid is supplied from the cleaning liquid tank to the purification unit, and the compressed air is supplied from the compressed air supply device to the aeration device at the same time. Water purification treatment system. The air diffusion device is a unit air diffusion means having a plurality of air diffusion tubes as one unit,
5. The water purification treatment system according to claim 4, wherein the control means individually controls switching of the supply of compressed air from the compressed air supply device to each aeration pipe. The air diffuser is provided with a hole for discharging the compressed air,
The end of the air diffuser is open,
The end portion is formed so that the position where the pore is provided is higher than the position of the opening in the end portion,
The air supply pipe is provided with an opening means for releasing compressed air remaining in the air diffusion pipe to the outside,
6. The water purification treatment system according to claim 5, wherein the control means controls switching between supplying compressed air from the compressed air supply device to the air diffuser pipe and discharging compressed air remaining in the air diffuser pipe to the outside. The water purification treatment system according to claim 6, wherein the pores have openings that generate bubbles of less than 100 μm. The water purification treatment system according to claim 6 , wherein the aeration device further comprises a mixing means for taking in the water to be treated around the aeration pipe into the aeration pipe and mixing the taken in water to be treated with the compressed air. In the water tank to be treated, there is a fluidized bed area where a plurality of fluidized bed contact materials flow in the water to be treated to perform purification treatment using a fluidized bed method, and a fluidized bed area where the purification treatment unit is installed to perform purification treatment using a fixed bed method. a fixed bed area where the processing takes place is located adjacent to the fixed bed area;
installing a screen at the boundary between the fluidized bed area and the fixed bed area,
5. The water purification treatment system according to claim 4, wherein a predetermined interval is provided between the purification unit in the fixed bed area that is arranged adjacent to the screen and the screen.

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