JP2022152027A - Air diffusion device with header, and membrane separation activated sludge device - Google Patents

Abstract

To provide an air diffusion device with a header, capable of sufficiently preventing sludge from entering into the air diffusion device from the header and capable of being stably operated even when its operation and stop are repeated, and a membrane separation activated sludge device.SOLUTION: The air diffusion device with a header, comprises an air diffuser and a header 114 immersed in water to be treated, which header 114 comprises an air feeder 142 feeding air into an air storage 140, a plurality of air delivery units 144 for sending out air present in the air storage 140 to an air diffuser, and a first partition 146, with a plurality of air delivery ports 145 positioned above an air feed port 142a, the first partition 146 positioned between the air feed port 142a and the plurality of air delivery ports 145 in the perpendicular direction and extended in the horizontal direction from the air feed port 142a side to the air delivery port 145 side, and the end part of the first partition 146 on the air delivery port 145 side, positioned at least below a first air delivery port 145a disposed nearest to the air feed port 142a.SELECTED DRAWING: Figure 4

Description

TECHNICAL FIELD The present invention relates to an air diffuser with a header and a membrane separation activated sludge apparatus.

Industrial wastewater and domestic wastewater are treated to remove organic substances and the like contained in the wastewater, and then reused as industrial water or discharged into rivers and the like. Examples of methods for treating industrial wastewater include the activated sludge method. The activated sludge method is a method in which aerobic microorganisms decompose organic matters by aeration.

Treatment by the membrane separation activated sludge (MBR) method, which combines the treatment by the activated sludge method and the membrane filtration by the separation membrane module, is also performed. In the treatment by the MBR method, if organic substances and the like accumulate on the surface of the separation membrane as the membrane filtration continues, the filtration flow rate will decrease and the transmembrane pressure difference will increase. Therefore, an air diffuser is installed below the membrane module to release air bubbles from the air diffuser pipe, and the membrane itself is vibrated by the impact when the air bubbles come into contact with the membrane surface or the water flow accompanying the generation of air bubbles. It has been practiced to suppress the deposition of organic matter on the surface.

When the operation of the air diffuser is stopped, the air in the air diffuser flows back and the water containing sludge enters the air diffuser. When the operation is restarted, the sludge may dry and harden in the air diffuser. If the air diffuser is repeatedly operated and stopped, the dried sludge will gradually grow in the air diffuser, and the air diffuser may become clogged. In Patent Document 1, a chamber (header) whose lower end is open is provided on the upstream side of the air diffuser while being immersed in the water to be treated, and a pipe connected to the blower and a pipe connected to the air diffuser are provided in the chamber, respectively. An inserted and connected device is disclosed. In the apparatus, when the operation is stopped, the water to be treated flows in from the lower end opening of the chamber and the water level in the chamber rises, but the rise of the water level stops at the position where the opening of the pipe is blocked. Therefore, even when the operation is stopped, the air remains in the air diffuser pipe, and the infiltration of the water to be treated containing sludge is suppressed.

WO2013/039626

However, even in the apparatus disclosed in Patent Document 1, sludge may enter the air diffuser pipe through the pipe connecting the air diffuser pipe and the header, and the air diffuser pipe may become clogged with sludge when operation and stop are repeated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a header-equipped air diffuser and a membrane separation activated sludge apparatus that can sufficiently suppress the intrusion of sludge from the header into the air diffuser and can operate stably even when operation and stop are repeated. and

The present invention has the following aspects.
[1] An air diffuser immersed in water to be treated and a header, wherein the header includes an air reservoir for storing air, an air supply part for feeding air into the air reservoir, and the air in the air reservoir and a first partition, wherein the water inlet is formed in the lower part of the air reservoir, and the air supply unit and the air diffuser are connected, The air sent from the header through the air supply part is diffused by the air diffuser, and the air supply port of the air supply part opened into the air storage part of the air supply part opens into the air storage part of the air supply part. The first partition part is located above the air supply port, is located between the air supply port and the air supply port in the vertical direction, and extends horizontally from the air supply port side to the air supply port side. direction, and the end of the first partition on the side of the air supply port is positioned at least below the first air supply port closest to the air supply port.
[2] A second partition portion positioned between the air supply port and the air supply port in the horizontal direction and extending vertically upward from the end portion of the first partition portion on the side of the air supply port. The header-equipped air diffuser according to [1], further comprising:
[3] The header-equipped air diffuser according to [2], wherein the upper end of the second partition is connected to the inner surface of the upper side of the air reservoir.
[4] A condition that the length from the air inlet side end of the first partition to the opposite side end is 250 mm or more per 1 Nm ³ /min of air diffused from the air diffuser. , the air diffuser with a header according to any one of [1] to [3].
[5] The air diffuser includes a horizontal pipe connected to the air supply unit and extending in the horizontal direction, and a horizontal pipe extending downward at intervals in the length direction of the horizontal pipe. is distributed, an opening is formed on the side opposite to the horizontal pipe of the distribution part, and the position of the air supply port of the air supply part in the height direction is the opening of the distribution part The header-equipped air diffuser according to any one of [1] to [4], which is at the same position as or above the position of the part.
[6] The air diffuser further comprises a plurality of siphon-type air diffusers provided below the horizontal pipes, and air is supplied to the siphon-type air diffusers from openings of the distribution section. [5] Air diffuser with header described in .
[7] A membrane separation activated sludge apparatus comprising the header-equipped air diffuser according to any one of [1] to [6] and a membrane module for membrane separation of sludge-containing treated water containing activated sludge.

Advantageous Effects of Invention According to the present invention, it is possible to provide a header-equipped air diffuser and a membrane separation activated sludge apparatus that can sufficiently suppress the entry of sludge from the header into the air diffuser and can be stably operated even when operation and stop are repeated.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic diagram which showed an example of the water treatment apparatus provided with the membrane-separation activated sludge apparatus of embodiment. It is the front view which showed an example of the diffuser with a header of embodiment. FIG. 3 is a plan view of the header-equipped air diffuser of FIG. 2 ; FIG. 4 is a cross-sectional view of the header of the header-equipped air diffuser of FIG. 3 taken along the line AA. FIG. 3 is a plan view showing one air diffuser in the header-equipped air diffuser of FIG. 2; FIG. 6 is a cross-sectional view of the air diffuser of the header-equipped air diffuser of FIG. 5 taken along the line BB. It is a sectional view explaining the operating mechanism of an air diffuser. It is a sectional view explaining an operating mechanism of a header. FIG. 4 is a cross-sectional view of a header of a header-equipped air diffuser of another embodiment;

An example of an embodiment of the present invention will be described below with reference to the drawings. It should be noted that the dimensions and the like of the drawings illustrated in the following description are only examples, and the present invention is not necessarily limited to them, and can be implemented with appropriate changes within the scope of not changing the gist of the present invention. .

[Water treatment equipment]
The water treatment apparatus 1000 comprises, as shown in FIG. and Furthermore, although illustration is omitted, the water treatment apparatus 1000 includes a flow rate adjustment tank for adjusting the flow rate of raw water flowing into the activated sludge treatment tank 11, a drawing pump for drawing excess sludge from the membrane separation tank 21, and a It is provided with a liquid feeding means for feeding a chemical solution or dilution water, and a discharging means for discharging the treated water from the treated water tank 41 to a factory, a river, or the like.

The activated sludge treatment tank 11 is filled with activated sludge for performing activated sludge treatment.
A first channel 12 and a second channel 13 are connected to the activated sludge treatment tank 11 . The first channel 12 is a channel through which raw water discharged from factories, households, etc. flows into the activated sludge treatment tank 11 . The second flow path 13 is a flow path for allowing sludge-containing treated water (water to be treated) discharged from the activated sludge treatment tank 11 to flow into the membrane separation tank 21 .

An aerator 14 is installed in the activated sludge treatment tank 11 to maintain the inside of the tank in an aerobic condition. The aeration device 14 includes an aeration pipe 14a for aerating the inside of the activated sludge treatment tank 11, an introduction pipe 14b for supplying air to the aeration pipe 14a, and a blower 14c for supplying air. The aeration pipe 14a is not particularly limited as long as it can discharge the air supplied from the blower 14c upward, and examples thereof include a perforated single pipe and a membrane type.

The membrane separation tank 21 stores sludge-containing treated water containing activated sludge and biologically treated water sent from the activated sludge treatment tank 11 . The membrane separation tank 21 includes a membrane separation activated sludge apparatus 100 (hereinafter sometimes referred to as "MBR apparatus 100") to which one aspect of the present invention is applied. The MBR device 100 will be described later.

A sludge return means 30 is connected to the membrane separation tank 21 and the activated sludge treatment tank 11 . The sludge return means 30 returns part of the sludge-containing treated water from the membrane separation tank 21 to the activated sludge treatment tank 11 . The sludge return means 30 has a fourth channel 31 . The fourth channel 31 is a channel for discharging part of the sludge-containing treated water from the membrane separation tank 21 and allowing it to flow into the activated sludge treatment tank 11 . A pump 31 a is installed in the fourth flow path 31 . As a result, part of the sludge-containing treated water in the membrane separation tank 21 can be returned from the membrane separation tank 21 to the activated sludge treatment tank 11 .
The treated water tank 41 stores the treated water after membrane separation of the sludge-containing treated water.

<Membrane separation activated sludge system>
The MBR device 100 includes a plurality of membrane modules 22 and a header-equipped air diffuser 110 provided below the membrane modules 22 .

The membrane module 22 membrane-separates sludge-containing treated water containing activated sludge. The membrane module 22 has a separation membrane, and the separation membrane separates sludge-containing treated water into biologically treated water and activated sludge by solid-liquid separation (membrane separation). The separation membrane is not particularly limited as long as it has separation ability, and examples thereof include hollow fiber membranes, flat membranes, tubular membranes, monolithic membranes, and the like. Among these membranes, hollow fiber membranes are preferred because of their high volume filling factor.

When a hollow fiber membrane is used as the separation membrane, examples of its material include cellulose, polyolefin, polysulfone, polyvinylidene fluoride (PVDF), and polytetrafluoroethylene (PTFE). Among these, PVDF and PTFE are preferable as the material for the hollow fiber membrane because of their chemical resistance and resistance to pH changes. When a monolithic membrane is used as the separation membrane, it is preferable to use a ceramic membrane.
The average pore diameter of the micropores formed in the separation membrane is about 0.001 to 0.1 μm for a membrane generally called an ultraseparation membrane, and about 0.1 to 1 μm for a membrane generally called a precision separation membrane. . In the present embodiment, it is preferable to use a separation membrane having an average pore size within the above range.

A third channel 33 is connected to the membrane module 22 . The third channel 33 is a channel for discharging the treated water that has passed through the separation membrane from the membrane separation tank 21 and allowing it to flow into the treated water tank 41 . A pump 33 a is installed in the third flow path 33 . This allows the treated water that has passed through the separation membranes of the membrane module 22 to be discharged from the membrane separation tank 21 .

[Air diffuser with header]
The header-equipped air diffuser 110 includes an air diffuser 112 and a header 114 provided upstream of the air diffuser 112, as shown in FIGS. In this example, ten air diffusers 112 are connected to one header 114 . The number of air diffusers 112 connected to one header 114 is not limited to ten, and may be nine or less, or may be eleven or more. The number of air diffusers 112 connected to one header 114 can be, for example, 5-20. The air diffuser 112 and the header 114 are provided in the membrane separation tank 21 while being immersed in the sludge-containing treated water (water to be treated).

(Air diffuser)
As shown in FIG. 5, each air diffuser 112 includes a horizontally extending horizontal tube 116 and three air diffusers spaced along the length of the horizontal tube 116 through which the air is distributed. It comprises a distributor 118 and six siphon air diffusers 120 arranged in a horizontal row.

Each distribution portion 118 is connected to the horizontal pipe 116 via a connecting pipe portion 119 and is provided to extend downward from the horizontal pipe 116 . Six siphon air diffusers 120 are arranged below the horizontal tube 116 along the length of the horizontal tube 116 with two siphon air diffusers 120 on either side of each distribution section 118 . ing.

The siphon air diffuser 120 is a box-shaped housing formed by combining a plurality of plate-shaped members. As shown in FIGS. 2, 3, and 5 to 7, the siphon-type air diffuser 120 includes an upper plate portion 120A, two side plate portions 120B, two side plate portions 120C, a bottom plate portion 120D, A first partition wall 122 and a second partition wall 124 are provided.

The two side plate portions 120B and the two side plate portions 120C forming each siphon diffuser pipe 120 are each rectangular, and the side plate portion 120B is wider than the side plate portion 120C. The two side plate portions 120B and the two side plate portions 120C forming each siphon type air diffuser 120 are arranged such that the surfaces of the side plate portions 120B face each other and the surfaces of the side plate portions 120C face each other. It is provided so as to extend downward from the lower surface of 120A. The two side plate portions 120B and the two side plate portions 120C form a rectangular cylinder with a rectangular cross section. In each siphon air diffusion pipe 120 , the surface direction of the side plate portion 120</b>B is parallel to the longitudinal direction of the horizontal pipe 116 .

In the air diffuser 112, the upper plate portions 120A of the six siphon type air diffuser pipes 120 are integrally formed of one flat plate, and the side plate portions 120B on both sides of the six siphon type air diffuser pipes 120 are each integrally formed of one flat plate. is formed in The six siphon-type air diffusers 120 are connected so that the surfaces of the side plate portions 120C of the adjacent siphon-type air diffusers 120 face each other.

A rectangular ventilation hole 126 extending along the side plate portion 120B is formed in a portion of each upper plate portion 120A near the side plate portion 120B on the far side from the horizontal pipe 116 in plan view.
The bottom plate portion 120D is provided so as to extend inward from a portion near the lower end of the side plate portion 120B on the side where the air diffusion holes 126 are formed. The plane direction length of the bottom plate portion 120D from the side plate portion 120C is shorter than the top plate portion 120A. The bottom plate portion 120D covers almost half of the lower opening of the square tube formed by the two side plate portions 120B and the two side plate portions 120C, and the bottom plate portion 120D does not cover the opening portion. A treated water inflow portion 127 is provided.

The first partition wall 122 has a rectangular shape in a front view, and extends downward from the upper plate portion 120A so that the side plate portion 120B and the side plate portion 120B face each other with the air diffusion hole 126 interposed therebetween. . A lower end 122a of the first partition wall 122 is separated from the bottom plate portion 120D. The treated water inflow portion 127 is located below the lower end 122 a of the first partition wall 122 .

The second partition wall 124 is provided so as to extend upward from the end of the first partition wall 122 of the bottom plate portion 120D located on the side opposite to the diffusion holes 126 . The surfaces of the first partition wall 122 and the second partition wall 124 face each other. The upper end 124a of the second partition wall 124 is separated from the upper plate portion 120A. The upper end 124 a of the second partition wall 124 is located above the lower end 122 a of the first partition wall 122 .

A siphon chamber 128 is formed inside the siphon air diffuser 120 . The siphon chamber 128 is a portion that stores air. The siphon chamber 128 has a height from the upper end 124a of the second partition wall 124 to the lower end 122a of the first partition wall 122 on the treated water inflow portion 127 side of the first partition wall 122 in the siphon air diffusion pipe 120. point to space. The siphon chamber 128 is divided by a second partition wall 124 into a first siphon chamber 128A and a second siphon chamber 128B.

A communicating portion 125 communicates with the upper portion of the first siphon chamber 128A and the upper portion of the second siphon chamber 128B. A portion from the second siphon chamber 128B in the siphon-type air diffusion pipe 120 to the air diffusion hole 126 forms a path 123. As shown in FIG. In the siphon-type air diffuser 120, the treated water inflow portion 127 side is defined as "upstream" and the air diffusion hole 126 side is defined as "downstream" when the water to be treated flows from the treated water inflow portion 127 to the diffusion holes 126. ”.

The material of the siphon air diffuser 120 is not particularly limited, and examples include polyethylene, polypropylene, AS resin, ABS resin, acrylic resin (PMMA), polyvinyl chloride resin (PVC), polyacetal resin (POM), polyamide resin (PA ), polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PBT), polycarbonate resin (PC), modified polyphenylene ether resin (PPE), polyphenylene sulfide resin (PPS), polyether ether ketone resin (PEEK), polysulfone Examples include resin (PSf) and polyethersulfone resin (PES). The material of the siphon type air diffuser 120 may be of one type or a combination of two or more types. It may also be made of metal such as stainless steel (SUS304 series, SUS316 series).

The channel cross-sectional area of the horizontal pipe 116 is larger than the channel cross-sectional area of the connection pipe portion 119 . The shape of the horizontal tube 116 is not particularly limited, and examples thereof include a cylindrical shape and a polygonal tubular shape. For example, when the cross-sectional shape of the horizontal tube 116 is circular, the inner diameter of the horizontal tube 116 is preferably 10 mm or more and 60 mm or less.

The cross-sectional area of the horizontal tube 116 is preferably 100 mm ² or more, more preferably 300 mm ² or more and 2000 mm ² or less. If the cross-sectional area of the horizontal pipe 116 is equal to or greater than the lower limit of the above range, the inside of the horizontal pipe 116 is less likely to be clogged with sludge. If the cross-sectional area of the horizontal pipe 116 is equal to or less than the upper limit of the above range, the air diffuser 112 can be made compact, which is preferable.
The channel cross-sectional area of the horizontal pipe 116 is the area of the channel cross-section cut in a direction (vertical direction) perpendicular to the length direction of the horizontal pipe 116 .

The horizontal pipe 116 is not particularly limited, and examples thereof include fluorine-based resins such as polyvinyl chloride, polyethylene, polypropylene, PTFE, PVDF, tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer (PFA), nylon, polyurethane, and the like. Metal pipes such as resin pipes and tubes and stainless steel (SUS304 series, SUS316 series) can be exemplified. The material of the horizontal tube 116 may be of one type or a combination of two or more types.

The distribution part 118 of this example includes two facing side plate portions 120C of the siphon type air diffuser pipes 120 on both sides, two side plate portions 130 provided to connect the ends of the side plate portions 120C, and two side plate portions 130. It is a cylindrical portion formed of a side plate portion 120C and a top plate portion 132 provided so as to cover the upper open end of a rectangular cylinder composed of two side plate portions 130C. The distribution section 118 in this example shares the side plate section 120C with the siphon air diffusers 120 on both sides. A pair of side plate portions 130 and a top plate portion 132 forming the distribution portion 118 are integrated with the adjacent siphon air diffuser pipes 120 .

An opening 118a is formed on the side of the distribution portion 118 opposite to the horizontal pipe 116 . The opening portion 118a is composed of a lower open end of the distribution portion 118 and a notch portion 134 formed in the lower end portion of the side plate portion 120C shared with the siphon air diffuser 120 in the distribution portion 118 . The opening 118 a of the distribution section 118 functions as an air supply port that supplies air to the siphon air diffuser 120 .

The material of the distribution part 118 is not particularly limited, and for example, the same material as that of the siphon air diffuser 120 can be used. The material of the distribution part 118 may be of one type or a combination of two or more types.

The channel cross-sectional area of the distribution part 118 is preferably 300 mm ² or more, and more preferably 500 mm ² or more and 3000 mm ² or less. If the cross-sectional area of the distribution section 118 is equal to or greater than the lower limit of the above range, the inside of the distribution section 118 is less likely to be clogged with sludge. If the cross-sectional area of the flow path of the distribution part 118 is equal to or less than the upper limit of the above range, the air diffuser 112 can be made compact, which is preferable. The channel cross-sectional area of the distribution part 118 is the area of the channel cross section cut in the direction (horizontal direction) perpendicular to the length direction of the channel in the distribution part 118 .

The horizontal pipe 116 and the distribution section 118 are connected via a connecting pipe section 119 having a flow channel cross-sectional area smaller than that of the distribution section 118 so that the flow channel in the horizontal pipe 116 and the flow channel in the distribution section 118 are connected. ing. The shape of the connecting tube portion 119 is not particularly limited, and examples thereof include a cylindrical shape and a polygonal tubular shape.

The flow passage cross-sectional area of the connecting tube portion 119 is preferably 20 mm ² or more and 350 mm ² or less, more preferably 30 mm ² or more and 150 mm ² or less. If the cross-sectional area of the connecting pipe portion 119 is equal to or greater than the lower limit of the above range, the inside of the connecting pipe portion 119 is less likely to be clogged with sludge. If the flow passage cross-sectional area of the connection tube portion 119 is equal to or less than the upper limit of the above range, the air is easily distributed evenly to the respective siphon air diffusion tubes 120 . The flow channel cross-sectional area of the connection pipe portion 119 is the area of the flow channel cross section cut in the direction perpendicular to the length direction of the flow channel in the connection pipe portion 119 .

The material of the connecting tube portion 119 is not particularly limited, and examples thereof include the same materials as those mentioned for the horizontal tube 116 . The connection pipe portion 119 may be made of one material or a combination of two or more materials.

In the air diffuser 112, the siphon-type air diffusers 120 and the distributors 118 arranged alternately are integrated. Since the air diffuser 112 of this aspect does not require vertical alignment of the openings 118a of the distribution unit 118 and vertical alignment of the siphon air diffusers 120, each siphon air diffuser 120 It becomes easy to evenly disperse from. In addition, the assembly work of the air diffuser 112 is facilitated, and the number of parts can be reduced, which is advantageous in terms of cost.

In the air diffuser 112 , each siphon air diffuser 120 is provided below a horizontal tube 116 . Since the horizontal pipe 116 is positioned above each siphon diffuser pipe 120 , air can be evenly supplied to each siphon diffuser pipe 120 from the opening 118 a of each distribution section 118 . It can be diffused evenly. In addition, since the height of the MBR device 100 can be made lower than in the case of using an air diffuser having members on the upper side of the horizontal pipe, the MBR device 100 can be made compact.

When the membrane separation tank 21 is viewed from above, the air diffuser 112 is provided at a position where the gap between the adjacent separation membranes in the membrane module 22 and the air diffusion holes 126 of the siphon type air diffusers 120 overlap. preferable. Incidentally, the air diffuser 112 may be provided so that the air diffusion holes 126 of the siphon type air diffusion pipes 120 intersect the membrane modules 22 when the membrane separation tank 21 is viewed from above.

(header)
2 to 4, the header 114 includes an air reservoir 140, an air supply portion 142, an air supply portion 144, a first partition portion 146, and a second partition portion 148. .
The air storage portion 140 is a portion that stores air, and includes a cylindrical body portion 141A and an upper plate portion 141B provided to close an upper open end of the body portion 141A. The lower end side of the trunk portion 141A in the air reservoir 140 is open. That is, the air reservoir 140 has a water inlet 140a formed at its lower portion.

The cross ^- sectional area of the air storage portion when the air storage portion 140 is cut in the horizontal direction can be appropriately set according to the ^number of air diffusers 112 to be connected. can do.

The plane view shape of the air reservoir 140 in this example is rectangular. The trunk portion 141A includes a first side wall 141a and a second side wall 141b extending parallel to the longitudinal direction so that their surfaces face each other, and a third side wall 141a extending parallel to the short direction so that their surfaces face each other. It has a side wall 141c and a fourth side wall 141d.

The air supply portion 142 has a cylindrical shape and is provided so as to pass through the end portion of the upper plate portion 141B on the side of the third side wall 141c in the longitudinal direction. The tip portion of the air supply portion 142 inside the air storage portion 140 is bent toward the fourth side wall 141d, and the air supply port 142a faces the side of the fourth side wall 141d. Air supply unit 142 is connected to blower 115 via pipe 113 . As a result, the air sent from the blower 115 through the pipe 113 is sent from the air supply portion 142 into the air storage portion 140 .

The shape of the air supply portion 142 is not particularly limited, and examples thereof include a cylindrical shape and a polygonal tubular shape. The flow passage cross-sectional area of the air supply portion 142 is preferably 2000 mm ² or more, more preferably 3000 mm ² or more and 8000 mm ² or less. If the flow passage cross-sectional area of the air supply part 142 is equal to or greater than the lower limit of the range, the air supply part 142 is less likely to be clogged with sludge. If the cross-sectional area of the flow path of the air supply part 142 is equal to or less than the upper limit of the above range, the air diffuser 112 can be made compact, which is preferable. The flow channel cross-sectional area of the air supply part 142 is the area of the flow channel cross section cut in the direction perpendicular to the length direction of the flow channel in the air supply part 142 .

The position of the air supply port 142a of the air supply part 142 in the height direction is preferably the same as or higher than the position of the opening 118a of the distribution part 118 of the air diffuser 112 . As a result, when the operation is stopped, the rise of the water surface in the air storage part 140 stops when the air supply port 142a of the air supply part 142 is blocked with the water to be treated, so that the sludge from the header 114 to the air diffuser 112 does not flow. It becomes easy to sufficiently obtain the effect of suppressing the intrusion. The positional relationship in the height direction between the air supply port 142a of the air supply unit 142 and the opening 118a of the distribution unit 118 in the present invention is such that when the air supply port 142a of the air supply unit 142 does not open downward, the air supply port 142a does not open downward. The upper end of the vent 142a is used as a reference.

The height difference between the air supply port 142a of the air supply part 142 and the opening 118a of the distribution part 118 is preferably 5 mm or more and 200 mm or less, more preferably 10 mm or more and 180 mm or less. If the difference is equal to or greater than the lower limit of the range, it is easy to prevent sludge from entering the air diffuser 112 from the header 114 . If the difference is equal to or less than the upper limit of the range, the air diffuser 112 becomes compact, which is preferable.

The air supply portion 144 is a portion from which the air in the air storage portion 140 is sent. In this example, ten air supply portions 144 are provided at equal intervals in the horizontal direction on the fourth side wall 141d side of the air supply portion 142 in the upper portion of the first side wall 141a. When a plurality of air supply units 144 are provided, the arrangement is not limited to providing the air supply units 144 at equal intervals in the horizontal direction. The number of air supply units 144 may be appropriately set according to the number of air diffusers 112 connected to the header 114, and may be 5 to 20, for example.

Each of the air supply ports 145 of the air supply portion 144 that opens into the air storage portion 140 is located above the air supply port 142 a of the air supply portion 142 that opens into the air storage portion 140 . The horizontal pipe 116 of the air diffuser 112 is connected to the air supply section 144 . As a result, the air stored in the air storage section 140 is sent from the air supply section 144 to the horizontal pipe 116 of the air diffuser 112 . The aspect in which the horizontal pipe 116 of the air diffuser 112 is directly connected to the air supply section 144 is advantageous in that the header-equipped air diffuser 110 can be easily made compact.

The first partition portion 146 is a plate-like member and is positioned between the air supply port 142 a and the air supply port 145 in the vertical direction inside the air reservoir 140 . The first partition portion 146 extends horizontally from the air supply port 142a side to the air supply port 145 side, and the end portion of the first partition portion 146 on the air supply port 145 side is at least closest to the air supply port 142a. It is positioned below the first air supply port 145a. Here, "the end of the first partition on the side of the air supply port is positioned at least below the first air supply port closest to the air supply port" means that the first partition is the first partition in bottom view. It means that the air supply port is extended so as to be blocked.
The first partition portion 146 in this example extends from the horizontal air supply port 142a side of the first air supply port 145a to between the third air supply port 145c and the fourth air supply port 145d. That is, the first partition part 146 extends so as to block the first air supply port 145a, the second air supply port 145b, and the third air supply port 145c in bottom view. Since the first partition part 146 is provided between the air supply port 142 a and the air supply port 145 , the sludge scattered by the air supplied from the air supply port 142 a of the air supply part 142 is scattered from the air supply port 145 . Intrusion into the horizontal tube 116 of the air device 112 is suppressed.
The thickness of the first partition portion 146 can be set as appropriate, and can be, for example, 2 mm or more and 10 mm or less.

The angle θ ( FIG. 4 ) formed by the direction in which the first partition 146 extends and the vertical direction is preferably 90° or more and less than 180°. If the angle θ is equal to or greater than the lower limit value, accumulation of sludge on the first partition portion 146 can be easily suppressed. The angle θ is preferably 130° or less in terms of preventing the air supplied from the air supply port 142a of the air supply unit 142 from being blocked by the first partition part 146 and allowing the air to reach all the air supply ports 145 evenly. It is preferably 120° or less, and more preferably 120° or less.

The length L1 (FIG. 4) from the end of the first partition part 146 on the side of the air supply port 142a to the end on the opposite side is 250 mm or more per 1 Nm ³ /min of air diffused from the air diffuser 112. meet. However, "the amount of air diffused from the diffuser 112" means the total amount of air diffused from all the diffusers 112 when a plurality of diffusers 112 are connected to the header 114. It shall be. If the length L1 of the first partition part 146 satisfies the above condition, the sludge scattered by the air supplied from the air supply port 142a of the air supply part 142 flows from the air supply port 145 to the horizontal pipe 116 of the air diffuser 112. Intrusions are easily suppressed. In terms of excellent uniformity of air diffusion from each air diffuser 112, the length L1 of the first partition part 146 is 400 mm or less per 1 Nm ³ /min of air diffused from the air diffuser 112. preferably fulfilled.

The second partition part 148 is a plate-like member and is positioned between the air supply port 142a and the air supply port 145 in the horizontal direction. The second partition portion 148 extends vertically upward from the end portion of the first partition portion 146 on the air supply port 142a side. By providing the second partition part 148 , sludge is more easily suppressed from entering the horizontal pipe 116 of the air diffuser 112 through the air supply port 145 .

The second partition portion 148 in this example is provided so as to hang down from the upper plate portion 141B. That is, the upper end portion of the second partition portion 148 is connected to the upper inner surface of the air reservoir portion 140 . As a result, the sludge scattered by the air supplied from the air supply port 142 a of the air supply part 142 is more easily suppressed from entering the horizontal pipe 116 of the air diffuser 112 through the air supply port 145 . It should be noted that the upper end portion of the second partition portion 148 may not be connected to the upper inner surface of the air reservoir portion 140 as long as the effects of the present invention are not impaired.

The thickness of the second partition portion 148 can be set as appropriate, and can be, for example, 2 mm or more and 10 mm or less.
The angle φ of the second partition portion 148 with respect to the vertical direction is preferably 30° or less, more preferably 15° or less. If the angle φ is equal to or less than the upper limit, the effect of suppressing sludge from entering the air diffuser 112 from the header 114 is likely to be obtained.

The working mechanism of the header-equipped air diffuser 110 will be described below.
Before the operation is started, as shown in FIG. 7A, the siphon chamber 128, the communicating portion 125 and the path 123 in the siphon air diffuser 120 are filled with sludge-containing treated water B (water to be treated). Air is supplied from the blower 115 through the pipe 113, and as shown in FIG. In the header 114, the air A is temporarily stored in the air storage portion 140, and while pushing the water surface S1 below the air supply port 142a of the air supply portion 142, part of the air A is released from each air supply port 145. It is sent to the horizontal tube 116 of each air diffuser 112 . At the start of operation, air A supplied from the air supply port 142a of the air supply unit 142 scatters sludge, but the provision of the first partition 146 and the second partition 148 allows the scattered sludge to flow through the air supply port. Intrusion from 145 into horizontal pipe 116 of air diffuser 112 is suppressed. Therefore, it is possible to prevent the dried sludge from becoming large and clogging the air diffuser 112 .

In each air diffuser 112 , the air sent to the horizontal pipe 116 is distributed to each distribution section 118 , and sent from the treated water inflow section 127 to each siphon type air diffusion pipe 120 through the opening 118 a of the distribution section 118 . When the air A is continuously supplied to the siphon type air diffuser 120 in this way, as shown in FIG. 127, the liquid surface S2 in the siphon chamber 128 gradually drops.

When the air A continues to be supplied and the height of the liquid surface S2 becomes lower than the lower end 122a of the first partition wall 122, as shown in FIG. Due to the difference in the two gas-liquid interface heights, the air A moves to the path 123 and is discharged from the air diffusion holes 126 all at once to form bubbles 200 . When air is diffused from the air diffusion holes 126, as shown in FIG. rises to near the upper end 124a of the . 7(b) to 7(d) are repeated to effect intermittent aeration.

When the operation is stopped, since the airtightness in the vicinity of the blower 115 is not normally high, the sludge-containing treated water B flows from the water to be treated inlet 140a, and the air A in the air reservoir 140 flows backward from the air supply 142. . Then, as shown in FIG. 8B, the water surface S1 in the air reservoir 140 rises to a position where the air supply port 142a of the air supply part 142 is blocked. In the header 114, even when the operation is stopped, the rise of the water surface S1 stops at the position where the air supply port 142a of the air supply unit 142 is blocked, and the air supply port 145 of the air supply unit 144 is separated from the water surface S1. . Therefore, sludge is prevented from entering the air diffuser 112 through the air supply port 145 when the operation is stopped.

[Water treatment method]
A water treatment method using the water treatment apparatus 1000 described above will be described below. The water treatment method of the present embodiment includes an activated sludge treatment process for treating raw water using activated sludge, and a membrane separation process for membrane separation of the sludge-containing treated water obtained in the activated sludge treatment process. ing.

(Activated sludge treatment process)
In the water treatment method using the water treatment apparatus 1000, wastewater (raw water) such as industrial wastewater and domestic wastewater discharged from factories, households, etc. is allowed to flow into the activated sludge treatment tank 11 through the first flow path 12, and Activated sludge is treated in 11 to obtain biologically treated water. The sludge-containing treated water (to-be-treated water) after treatment is allowed to flow into the membrane separation tank 21 through the second flow path 13 .

(Membrane separation process)
In the membrane separation tank 21 , the membrane module 22 of the MBR device 100 membrane-separates sludge-containing treated water (water to be treated) containing activated sludge and biologically treated water. During the membrane separation process, aeration is performed by the air diffuser 110 with a header. A part of the sludge-containing treated water B is returned from the membrane separation tank 21 to the activated sludge treatment tank 11 by the sludge return means 30 . After membrane separation of the sludge-containing treated water B by the membrane module 22, the treated water is sent to the treated water tank 41 through the third channel 33 and stored therein. The treated water stored in the treated water tank 41 can be reused as industrial water or discharged into a river or the like.

In the water treatment method, the activated sludge treatment process and the membrane separation process may be performed simultaneously using a water treatment apparatus in which the MBR device 100 is provided in the activated sludge treatment tank 11 .

As described above, the present invention uses a header-equipped air diffuser that includes a header provided with a first partition in the air reservoir. As a result, sludge is prevented from entering the air diffuser from the header even if operation and stop are repeated, so that the operation can be performed more stably. In addition, since the air diffuser with header of the present invention is provided with a header, the air remains in the air diffuser when the operation is stopped. clogging is also suppressed.

The header-equipped air diffuser of the present invention is not limited to the header-equipped air diffuser 110 described above. For example, as shown in FIG. 9, the header-equipped air diffuser may include a header 114A similar to the header 114 except that it does not include the second partition 148 but includes only the first partition 146. FIG.

The air diffuser included in the header-equipped air diffuser is not limited to the air diffuser 112 described above. The number of siphon-type air diffusers in the air diffuser is not limited to six, and can be set as appropriate according to the size and number of membrane modules, and may be five or less, or seven or more. good.
In the air diffuser 112, air is supplied from one distribution section 118 to two siphon type air diffusers 120, but air is supplied from one distribution section to one siphon type air diffuser. Alternatively, air may be supplied from one distribution section to three or more surrounding siphon air diffusers. The notch portion 134 may not be formed at the end portion of the distribution portion 118 .

The air diffuser is not limited to the siphon type air diffuser. For example, the air diffuser 112 may be an air diffuser that does not have the siphon type air diffuser pipe 120 and diffuses air from the opening 118 a of the distribution section 118 . It may be an air diffuser in which a plurality of air diffusion holes are formed in a horizontal pipe. A distribution pipe extending in a direction perpendicular to the horizontal pipe in a plan view may be connected to the horizontal pipe via a connecting pipe portion, and the air diffuser may have a plurality of diffusion holes formed in the distribution pipe.

DESCRIPTION OF SYMBOLS 100... Membrane-separation activated sludge apparatus, 110... Air diffuser with header, 112... Air diffuser, 114, 114A... Header, 115... Blower, 116... Horizontal pipe, 118... Distribution part, 118a... Opening, 119... Connection Pipe portion 120 Siphon type air diffuser 140 Air reservoir 140a Inflow port for water to be treated 142 Air supply unit 142a Air supply port 144 Air supply unit 145 Air supply port 145a One air supply port, 146...first partition, 148...second partition.

Claims (7)

Equipped with an air diffuser and a header immersed in the water to be treated,
The header includes an air storage portion that stores air, an air supply portion that sends air into the air storage portion, at least one air supply portion that sends out the air in the air storage portion, and a first partition portion. prepared,
A water inlet is formed in the lower part of the air reservoir,
the air supply unit and the air diffuser are connected, and the air sent from the header through the air supply unit is diffused by the air diffuser;
an air supply port of the air supply portion that opens into the air storage portion is positioned above an air supply port that opens into the air storage portion of the air supply portion;
The first partition portion is positioned between the air supply port and the air supply port in the vertical direction, and extends horizontally from the air supply port side to the air supply port side, and the first partition The header-equipped air diffuser, wherein the air inlet side end of the portion is located at least below the first air inlet closest to the air inlet. Further provided is a second partition positioned between the air supply port and the air supply port in the horizontal direction and extending vertically upward from the end of the first partition on the side of the air supply port. 2. The headered air diffuser of claim 1, wherein The header-equipped air diffuser according to claim 2, wherein the upper end of the second partition is connected to the upper inner surface of the air reservoir. The length from the air inlet side end of the first partition to the opposite end of the first partition satisfies a condition that the length is 250 mm or more per 1 Nm ³ /min of air diffused from the air diffuser. 4. The header-equipped air diffuser according to any one of 1 to 3. The air diffuser is connected to the air supply unit and includes a horizontal pipe extending in the horizontal direction and a horizontal pipe extending downward at intervals in the length direction of the horizontal pipe, and air is distributed from the horizontal pipe. and a plurality of distribution units,
an opening is formed on the side of the distribution section opposite to the horizontal tube;
With header according to any one of claims 1 to 4, wherein the position of the air supply port of the air supply part in the height direction is the same as the position of the opening of the distribution part or higher. Air diffuser. The air diffuser further comprises a plurality of siphon air diffusers provided below the horizontal pipe,
6. The air diffuser with header according to claim 5, wherein air is supplied to the siphon type air diffuser from the opening of the distributor. A membrane separation activated sludge apparatus comprising the header-equipped air diffuser according to any one of claims 1 to 6 and a membrane module for membrane separation of sludge-containing treated water containing activated sludge.

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