JP2019098230A - Siphon type air diffusion pipe, membrane separation activated sludge device, and water treatment method - Google Patents

Abstract

To provide a siphon type air diffusion pipe which can adjust a size and an intermittent time of air bubbles, a membrane separation activated sludge device, and a water treatment method.SOLUTION: A siphon type air diffusion pipe 1 comprising a housing 50 which is provided with an upper wall 1A, a side wall 1B and a bottom wall 1C so that a space is formed in the interior of the housing, and a first partition wall 4a and a second partition wall 4b which are provided at an interval so that faces of both walls face each other, and partition the space in the housing 50. A space from a lower end 4aof the first partition wall 4a to an upper end 4bof the second partition wall 4b on a treatment water inflow port 7 side with respect to the first partition wall 4a in the housing 50 becomes a siphon chamber 2, any or both of the first partition wall 4a and the second partition wall 4b, and the housing 50 are relatively moved in a vertical direction, whereby a volume of the siphon chamber 2 is changed.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a siphon type aeration tube, a membrane separation activated sludge apparatus, and a water treatment method.

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

  Moreover, in recent years, the treatment by the membrane separation activated sludge (MBR) method which combined the treatment by the activated sludge method and the membrane filtration by the separation membrane module has come to be performed. In the treatment by the MBR method, as the organic membrane and the like are deposited on the surface of the separation membrane as the membrane filtration is continued, the filtration flow rate may decrease and the transmembrane differential pressure may increase.

With respect to this problem, in the treatment by the MBR method, the deposition of the organic matter on the membrane surface is suppressed by the aeration tube installed below the membrane module. Specifically, deposition of organic matter and the like on the film surface is suppressed by vibrating the film itself by an impact when air bubbles generated from the air diffusion pipe contact the film surface or a water flow accompanying the generation of the air bubbles.
The bubble size is preferably large from the viewpoint of the cleaning property of the membrane surface. Patent Document 1 discloses a siphon-type aeration tube that efficiently releases large air bubbles.

JP 2003-340250 A

  However, since the siphon type aeration pipe described in Patent Document 1 can not adjust the size and the intermittent time of the air bubbles, the large air bubbles continue to be released even in a situation where high washability is not required. Therefore, in the process by the MBR method to which the siphon-type aeration pipe is applied, the energy efficiency may be low. In addition, since the dissolution efficiency in water decreases as the bubble size increases, oxygen necessary for biological treatment may be insufficient, and the properties of sludge and the water quality of treated water may be deteriorated.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a siphon type aeration tube, a membrane separation activated sludge apparatus, and a water treatment method capable of adjusting the size and intermittent time of air bubbles. I assume.

The present invention has the following aspects.
[1] A siphon type aeration tube that performs aeration,
A housing provided with an upper wall, a side wall, and a bottom wall so as to form a space therein; and a first partition wall and a second partition wall which partition the space in the housing,
The first partition extends downward from the top wall of the housing, and the lower end of the first partition is spaced from the bottom wall of the housing.
The second partition wall extends upward from the bottom wall of the housing, the upper end of the second partition wall is separated from the top wall of the housing, and the first partition wall faces each other. Spaced apart, and
A treated water inlet is formed on the lower side of the casing on the opposite side to the first partition of the second partition, and an aeration hole is formed on the second partition of the first partition on the upper side of the casing. It is formed on the opposite side of the wall,
A siphon type diffuser, wherein the first partition wall, one or both of the second partition wall, and the housing move relative to each other in the vertical direction.
[2] A siphon type aeration tube that performs aeration,
A housing provided with an upper wall, a side wall, and a bottom wall so as to form a space therein; and a first partition wall and a second partition wall which partition the space in the housing,
The first partition extends downward from the top wall of the housing, and the lower end of the first partition is spaced from the bottom wall of the housing.
The second partition wall extends upward from the bottom wall of the housing, the upper end of the second partition wall is separated from the top wall of the housing, and the first partition wall faces each other. Spaced apart, and
A treated water inlet is formed on the lower side of the casing on the opposite side to the first partition of the second partition, and an aeration hole is formed on the second partition of the first partition on the upper side of the casing. It is formed on the opposite side of the wall,
At least one through hole is formed in the first partition wall,
A siphon type diffuser, provided with opening and closing means for opening and closing the through hole.
[3] The siphon system according to [2], wherein the opening and closing means is an opening and closing plate which is moved up and down relative to the casing along the surface of the first partition wall to open and close the through hole. Aeration tube.
[4] [1] [1]-[3] The siphon type aeration pipe according to any one of
A membrane module for membrane separation of sludge containing treated water including activated sludge;
A membrane separation activated sludge device, comprising: a membrane separation tank in which the siphon type aeration pipe and the membrane module are installed.
[5] Activated sludge treatment of raw water using activated sludge,
A water treatment method, wherein the activated sludge-treated sludge-containing treated water is subjected to a membrane separation treatment by the membrane separation activated sludge apparatus according to [4].

By using the siphon type aeration pipe and membrane separation activated sludge apparatus of the present invention, the size and intermittent time of air bubbles can be adjusted.
According to the water treatment method of the present invention, water treatment can be performed while adjusting the bubble size and the intermittent time.

It is the schematic diagram which showed an example of the water treatment apparatus used for the water treatment method of this invention. It is the perspective view which showed an example of the siphon type aeration pipe of the 1st aspect of this invention. It is II sectional drawing of the siphon type aeration pipe of FIG. It is sectional drawing explaining the action | operation mechanism of the siphon type aeration pipe of FIG. It is sectional drawing which showed a mode that the volume of the siphon chamber of the siphon aeration pipe | tube of FIG. 2 was changed. It is sectional drawing which showed a mode that the volume of the siphon chamber of the siphon aeration pipe | tube of FIG. 2 was changed. It is sectional drawing which showed an example of the siphon type aeration pipe of 2nd aspect of this invention. It is sectional drawing which showed a mode that the volume of the siphon chamber of the siphon aeration pipe | tube of FIG. 7 was changed. It is sectional drawing which showed a mode that the volume of the siphon chamber of the siphon aeration pipe | tube of FIG. 7 was changed. It is sectional drawing which showed a mode that the volume of the siphon chamber of the siphon aeration pipe | tube of FIG. 7 was changed. It is the figure which showed the average intermittence time to the distance d of the lower end of the 1st partition wall in Example 1, and the upper end of the 2nd partition wall.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. Note that the dimensions and the like of the drawings illustrated in the following description are merely examples, and the present invention is not necessarily limited to them, and can be appropriately modified and implemented without changing the gist of the invention. .

[First aspect]
Hereinafter, an example of the first aspect of the present invention will be described.
FIG. 1: is the schematic diagram which showed the water treatment apparatus 1000 which is an example of the water treatment apparatus used for the water treatment method of the 1st aspect of this invention. As shown in FIG. 1, the water treatment apparatus 1000 may be referred to as an activated sludge treatment tank 11 and a membrane separation activated sludge apparatus 100 (hereinafter, referred to as “MBR apparatus 100” provided at a stage subsequent to the activated sludge treatment tank 11. And the processing water tank 41 provided at the rear stage of the MBR device 100. Furthermore, although not shown, the water treatment apparatus 1000 is a flow rate adjustment tank that adjusts the flow rate of the raw water flowing into the activated sludge treatment tank 11, a withdrawal pump that pulls excess sludge from the MBR device 100, a chemical solution and the MBR device 100 It includes a liquid feeding means for feeding dilution water, and a discharge means for discharging treated water from a treatment water tank 41 to a factory or a river.

The activated sludge treatment tank 11 is for filling activated sludge in order to perform activated sludge treatment.
A first flow passage 12 and a second flow passage 13 are connected to the activated sludge treatment tank 11. The first flow path 12 is a flow path for causing raw water discharged from a factory or a home to flow into the activated sludge treatment tank 11. The second flow path 13 is a flow path for causing the sludge-containing treated water (treated water) discharged from the activated sludge treatment tank 11 to flow into the MBR device 100.

A diffuser 14 is installed in the activated sludge treatment tank 11 to maintain the inside of the tank under aerobic conditions.
The air diffuser 14 includes a diffuser 14a for diffusing air into the activated sludge treatment tank 11, an introduction pipe 14b for supplying the air to the diffuser 14a, and a blower 14c for supplying the air.
The air diffuser 14a is not particularly limited as long as the air supplied from the blower 14c can be discharged upward, and examples thereof include a perforated single pipe and a membrane type.

  The treatment water tank 41 stores treated water after membrane separation of the sludge-containing treated water.

(Membrane separation activated sludge device)
The MBR apparatus 100 includes a membrane separation tank 21, a membrane module 22, and a siphon-type aeration pipe 1 provided below the membrane module 22. The second flow path 13 is connected to the membrane separation tank 21. The membrane module 22 and the siphon type aeration pipe 1 are disposed in the membrane separation tank 21.

  The membrane separation tank 21 is for storing the sludge-containing treated water including the activated sludge and the biological treated water, which has been sent from the activated sludge treatment tank 11.

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 is for returning 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 includes a fourth flow path 31. The fourth flow path 31 is a flow path that discharges a part of the sludge-containing treated water from the membrane separation tank 21 and causes the activated sludge treatment tank 11 to flow.
A pump 31 a is installed in the fourth flow path 31. Thereby, a 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 membrane module 22 is for membrane separation of sludge-containing treated water containing activated sludge. The membrane module 22 includes a separation membrane, and the separation membrane separates the sludge-containing treated water into biological treated water and activated sludge (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, a hollow fiber membrane is preferable because of high volume filling rate.

When a hollow fiber membrane is used as the separation membrane, examples of the material include cellulose, polyolefin, polysulfone, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE) and the like. Among them, PVDF and PTFE are preferable as the material of the hollow fiber membrane from the viewpoint of resistance to chemical resistance and pH change.
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 in a membrane generally called ultrafiltration membrane, and about 0.1 to 1 μm in a membrane generally referred to as a precision separation membrane . In the present embodiment, it is preferable to use a separation membrane having an average pore diameter within the above range.

The third flow path 33 is connected to the membrane module 22. The third flow path 33 is a flow path for discharging the treated water that has permeated the separation membrane from the membrane separation tank 21 and causing it to flow into the treated water tank 41.
A pump 33 a is installed in the third flow path 33. As a result, the treated water that has permeated the separation membrane of the membrane module 22 can be discharged from the membrane separation tank 21.

(Siphon type aeration tube)
The siphon type aeration pipe 1 is provided with the housing | casing 50 and the 1st partition wall 4a and the 2nd partition wall 4b which partition the space in the housing | casing 50, as shown to FIG.2 and FIG.3.
The casing 50 is a cube provided with an upper wall 1A, which is a plate-like member having a rectangular shape in a front view, four side walls 1B, and a bottom wall 1C, so that a space is formed therein. Box-shaped housing.

The four side walls 1B are provided to form a square cylinder. An upper wall 1A is provided on the upper end side of a square tube formed of four side walls 1B. In a portion near one side wall 1B on the upper wall 1A side of the housing 50, an air diffusion hole 6 extending along the side wall 1B is formed.
The bottom wall 1C blocks approximately half of the lower open end of the cylindrical portion formed of the four side walls 1B so as to extend inward from the lower end side of the side wall 1B on the side where the aeration holes 6 are formed. It is provided as. A portion not closed by the bottom wall 1 </ b> C in the lower opening of the housing 50 is the treated water inlet 7.

The first partition wall 4a extends downward from the air diffusion hole 6 side of the upper wall 1A in the housing 50 so that the side wall 1B faces each other with the air diffusion hole 6 therebetween, and the first partition wall 4a bottom 4a ₁ is provided so as to be separated from the bottom wall 1C of the housing 50.
The second partition wall 4 b is provided to extend upward from a tip side of the bottom wall 1 C of the housing 50 opposite to the aeration hole 6 of the first partition wall 4 a. The upper end 4 b ₁ of the second partition 4 b is separated from the upper wall _{1 A} of the housing 50. The first partition wall 4a and the second partition wall 4b are provided at an interval such that the surfaces thereof face each other.

In the siphon type aeration pipe 1, the treated water inlet 7 is disposed on the opposite side to the first partition 4a of the second partition 4b in the lower part of the housing 50, and the first of the first partition 4a in the upper part of the housing 50 An air diffusion hole 6 is disposed on the opposite side to the second partition wall 4b.
In the case 50, when the flow of treated water from the treated water inlet 7 toward the aeration hole 6 is assumed, the treated water inlet 7 side is "upstream" and the aeration hole 6 side is "downstream".

In tracheal 1 diffuser siphon, in the process water inlet 7 side than the first partition wall 4a of the housing 50, the space from the upper end 4b ₁ of the second partition wall 4b to the lower end 4a ₁ of the first partition wall 4a siphon It becomes room 2. The siphon chamber 2 stores air. The siphon chamber 2 is divided into a first siphon chamber 2A and a second siphon chamber 2B by a second partition 4b.

The first siphon chamber 2A and the second siphon chamber 2B communicate with each other at the communication portion 5 above them. A portion from the second siphon chamber 2 </ b> B in the housing 50 to the aeration hole 6 is a path 4. A portion of the first partition wall 4 a faces the siphon chamber 2 and the path 4. In other words, part of the first partition wall 4 a partitions the siphon chamber 2 and the path 4. Further, a part of the second partition wall 4 b faces the siphon chamber 2. The upper end 4b ₁ of the second partition wall 4b is positioned above the lower end 4a ₁ of at least a first partition wall 4a. Process water inlet 7 is formed in the bottom of the housing 50 is positioned below the lower end 4a ₁ of the first partition wall 4a.

  Thus, inside the housing 50, the first siphon chamber 2A, the communication unit 5, the second siphon chamber 2B, and the path 4 are formed in this order from upstream to downstream. Then, an air diffusion hole 6 is formed downstream of the siphon chamber 2 in the housing 50, and a treated water inlet 7 is formed upstream of the siphon chamber 2. The treated water inlet 7 communicates the outside of the siphon type aeration tube 1 with the siphon chamber 2.

The plan view shape of the air diffusion hole 6 is a long rectangular shape. The area of the plan view shape of the aeration holes 6 is preferably 25 cm ² or less, more preferably 20 cm ² or less. Further, the length in the longitudinal direction of the plan view shape is preferably 25 cm or less, more preferably 20 cm or less.
The siphon type aeration tube 1 is provided at a position where the adjacent air separation membranes in the membrane module 22 overlap the air diffusion holes 6 when the membrane separation tank 21 is viewed in plan.

An air supply port 3 is provided in a portion of the housing 50 facing the communication portion 5 of the upper wall 1A. That is, the air supply port 3 is provided in a portion facing the communication portion 5 in the upper portion of the siphon type aeration pipe 1.
A blower 1 b is connected to the air supply port 3 of the housing 50 via an air supply pipe 1 a so that air can be supplied from the air supply port 3 into the housing 50.

  In the siphon type aeration pipe 1 of this example, as shown in FIG. 6, the first partition wall 4a and the housing 50 are relatively moved in the vertical direction. The aspect to which the 1st partition wall 4a and the housing | casing 50 are relatively moved is not specifically limited, You may vertically move the 1st partition wall 4a in the state which fixed the housing | casing 50, The 1st partition wall 4a The housing 50 may be moved up and down in a state in which the housing 50 is fixed. In addition, both the housing 50 and the first partition wall 4a may be moved up and down.

Similarly, in the siphon type aeration pipe 1, as shown in FIG. 5, the second partition wall 4b and the housing 50 are relatively moved in the vertical direction. The aspect to which the 2nd partition wall 4b and the housing | casing 50 are relatively moved is not specifically limited, You may move the 2nd partition wall 4b up and down in the state which fixed the housing | casing 50, The 2nd partition wall 4b The housing 50 may be moved up and down in a state in which the housing 50 is fixed. Further, both the housing 50 and the second partition wall 4b may be moved up and down.
The first partition wall 4a, the second partition wall 4b, and the mechanism for moving the housing 50 up and down are not particularly limited as long as they can move up and down as desired.

In the siphon type aeration pipe 1, only the first partition 4a may move up and down relative to the housing 50, and only the second partition 4b may move up and down relative to the housing 50. It may be movable.
The number of the siphon type aeration pipes 1 is not particularly limited, and can be appropriately set according to the size and the number of the membrane modules 22.

Hereinafter, the operation mechanism of the siphon type aeration pipe 1 will be described.
Before the start of operation, as shown in FIG. 4 (a), the siphon chamber 2, the communication part 5 and the passage 4 in the casing 50 of the siphon type aeration tube 1 are filled with the sludge-containing treated water B (water to be treated) It is done. Air B is continuously supplied from the air supply port 3 to the siphon chamber 2 in the housing 50 through the air supply pipe 1a by the blower 1b. When the air A is continuously supplied from the air supply port 3, as shown in FIG. 4 (b), the sludge-containing treated water B in the siphon chamber 2 is pushed out from the aeration holes 6 and the treated water inlet 7, and the siphon chamber The liquid level S of 2 descends gradually.

Further continuously supplied air A from the air supply port 3, the height of the liquid surface S is lower than the lower end 4a ₁ of the first partition wall 4a, as shown in FIG. 4 (c), in the path 4 and the first Due to the difference in height between the two air-liquid interfaces with the siphon chamber 2A, the air A moves to the path 4 and is expelled from the aeration holes 6 at once to form the air bubbles 20. When the air is aspirated from the aeration holes 6, as shown in FIG. 4A, the siphon chamber 2, the communicating portion 5 and the passage 4 in the casing 50 of the siphon type aeration tube 1 are filled with the sludge-containing treated water B. Return to the state they were And aeration is intermittently performed because the state of FIG. 4 (a)-(c) is performed repeatedly.

The size and intermittence time of air bubbles when aerated by the siphon type aeration tube 1 change according to the volume of the siphon chamber 2 of the siphon type aeration tube 1.
In the siphon type aeration pipe 1, as shown in FIG. 5, the upper end 4b ₁ of the second partition 4b is vertically moved in the vertical direction by moving the second partition 4b downward relative to the housing 50. close to the lower end 4a ₁ one partition wall 4a, the volume of the siphon chamber 2 is reduced. As a result, the size of the air bubble aerated from the siphon type aeration tube 1 becomes smaller, and the intermittent time becomes shorter. On the other hand, by moving relatively upward to the second partition wall 4b with respect to the housing 50, the upper end 4b ₁ of the second partition wall 4b is separated from the lower end 4a ₁ of the first partition wall 4a in the vertical direction, the siphon The volume of the chamber 2 is increased. As a result, the size of the air bubble aerated from the siphon type aeration tube 1 becomes large, and the intermittent time becomes long.

Further, as shown in FIG. 6, by moving relatively upward first partition wall 4a with respect to the housing 50 in the vertical direction the lower end 4a ₁ of the first partition wall 4a of the second partition wall 4b As the upper end 4b ₁ is approached, the volume of the siphon chamber 2 decreases. As a result, the size of the air bubble aerated from the siphon type aeration tube 1 becomes smaller, and the intermittent time becomes shorter. On the other hand, by moving downward relative to the first partition wall 4a with respect to the housing 50, the lower end 4a ₁ of the first partition wall 4a is separated from the upper end 4b ₁ of the second partition wall 4b in the vertical direction, the siphon The volume of the chamber 2 is increased. As a result, the size of the air bubble aerated from the siphon type aeration tube 1 becomes large, and the intermittent time becomes long.
By moving the first partition 4 a and the second partition 4 b up and down relative to the housing 50 as described above, the volume of the siphon chamber 2 can be changed. As the volume of the siphon chamber 2 is smaller, the size of the air bubble is smaller and the intermittent time is shorter.

  In the siphon type aeration pipe 1, when the first partition 4 a is moved upward relative to the housing 50, the portion of the first partition 4 a protruding from the housing 50 comes out from the aeration hole 6. It can be a barrier when bubbles rise. The air bubbles from the air diffusion hole 6 are easily spread to the second partition wall 4b side of the housing 50 in plan view, and the cleaning effect of the membrane module 22 and the improvement effect of the dissolved oxygen concentration are easily obtained. It is preferable to move the wall 4 b up and down relative to the housing 50 to change the volume of the siphon chamber 2.

  In addition, if the second partition wall 4b is moved up and down relative to the housing 50, the volume of the communication part 5 is increased, but the first partition wall 4a is moved up and down relative to the housing 50 Also, the volume of the communication part 5 does not change. As the volume of the communication portion 5 is smaller, the dried sludge is less likely to be deposited on the upper portion in the housing 50. Therefore, it is preferable to move the first partition wall 4a up and down relative to the housing 50 to change the volume of the siphon chamber 2 in that the siphon type aeration tube 1 is not easily clogged with sludge.

(Water treatment method)
Hereinafter, a water treatment method using the water treatment apparatus 1000 will be described. The water treatment method of the present embodiment has an activated sludge treatment step of treating raw water with activated sludge using activated sludge, and a membrane separation step of subjecting the sludge-containing treated water obtained in the activated sludge treatment step to membrane separation. ing.

  In the water treatment method by the water treatment apparatus 1000, waste water (raw water) such as industrial waste water and household waste water discharged from factories and homes flows into the activated sludge treatment tank 11 through the first flow path 12 in the activated sludge treatment process. And treated with activated sludge in activated sludge treatment tank 11 to obtain biologically treated water. The sludge-containing treated water (treated water) after the activated sludge treatment flows into the membrane separation tank 21 of the MBR device 100 through the second flow path 13.

In the membrane separation step, in the membrane separation tank 21 of the MBR device 100, the membrane module 22 performs a membrane separation process on sludge-containing treated water (water to be treated) including activated sludge and biological treated water. During the membrane separation process, aeration is performed by the siphon type aeration tube 1.
For example, when organic matter etc. are deposited on the separation membrane surface of the membrane module 22 and the inter-membrane differential pressure of the membrane module 22 becomes large, either or both of the first partition wall 4a and the second partition wall 4b are The relative movement with respect to the body 50 is performed to increase the volume of the siphon chamber 2 to increase the size of the air bubble to be aerated and to increase the intermittent time. Thereby, the cleaning effect of the membrane surface of membrane module 22 becomes high.

  When the concentration of dissolved oxygen in the sludge-containing treated water is low, one or both of the first partition wall 4a and the second partition wall 4b are vertically moved relative to the housing 50 to Make the volume of the air bubble smaller, make the size of the aerated bubble smaller, and shorten the intermittence time. As a result, the oxygen dissolution efficiency of the aerated air bubbles is increased, and the inside of the membrane separation tank 21 can be easily made into an appropriate aerobic condition.

  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. The treated water after membrane separation of the sludge-containing treated water B by the membrane module 22 is sent to the treated water tank 41 through the third flow path 33 and stored. The treated water stored in the treated water tank 41 can be reused as industrial water or discharged to a river or the like.

  As described above, in the first aspect of the present invention, either one or both of the first partition wall and the second partition wall and the housing move relatively in the vertical direction. Thus, by changing the volume of the siphon chamber of the siphon type aeration tube, it is possible to adjust the size and the intermittent time of the air bubble to be aerated. Therefore, for example, depending on circumstances such as giving priority to suppressing deposition of organic matter and the like on the separation membrane surface of the membrane module, or giving priority to making the inside of the tank appropriate aerobic conditions, the size and intermittent of the bubbles The time can be adjusted and the water treatment can be performed stably.

Second aspect
Hereinafter, an example of the second aspect of the present invention will be described.
The water treatment apparatus used in the water treatment method of the present embodiment is the same as the water treatment apparatus 1000 except that the MBR apparatus 100 includes the siphon-type aeration pipe 8 illustrated in FIG. It is.
The number of the siphon type aeration pipes 8 is not particularly limited, and can be appropriately set according to the size and the number of the membrane modules 22.

(Siphon type aeration tube)
In the siphon-type aeration pipe 8, the first partition wall 4a and the second partition wall 4b do not move up and down relative to the housing 50, and a plurality of through holes 52 are formed in the first partition wall 4a. This embodiment is the same as the siphon type aeration tube 1 except that the opening and closing means 54 for opening and closing the hole 52 is provided. In the siphon type aeration pipe 8, the volume of the siphon chamber 2 can be changed by opening and closing the through hole 52 formed in the first partition 4 a by the opening and closing means 54.

  The plurality of through holes 52 are formed at intervals in the vertical direction of the first partition wall 4a. The number of through holes 52 formed at intervals in the vertical direction of the first partition wall 4a is not particularly limited, and can be set as appropriate. The volume of the siphon chamber 2 can be finely changed as the number of the through holes 52 formed at intervals in the vertical direction of the first partition wall 4a increases. The number of through holes 52 formed in the first partition wall 4a may be one.

The front view shape of the through hole 52 is not particularly limited, and examples thereof include a rectangular shape, an elliptical shape, and a perfect circular shape. Each through hole 52 preferably has a rectangular shape extending in the lateral direction of the first partition wall 4 a from the viewpoint that air bubbles are easily generated uniformly from the entire aeration hole 6.
A plurality of through holes 52 may be formed spaced apart in the lateral direction of the first partition wall 4a.
The size of the through hole 52 is not particularly limited, and may be set as appropriate as long as the aeration of the siphon type aeration tube 8 is not impaired.

The opening and closing means 54 in this example is an opening and closing plate that moves up and down along the surface of the first partition wall 4 a to open and close the through hole 52. The opening and closing means 54 is not limited to the opening and closing plate as long as it can open and close the through hole 52 formed in the first partition wall 4a. For example, the opening / closing means 54 may be a lid member individually provided in each through hole 52.
The mechanism for opening and closing the through hole 52 by driving the opening and closing means 54 (in this example, moving up and down) is not particularly limited.

As shown in FIG. 7, in the siphon type aeration pipe 8, when all the through holes 52 of the first partition wall 4 a are closed, the first on the treated water inlet 7 side with respect to the first partition wall 4 a in the housing 50. space from the lower end 4a ₁ one partition wall 4a to the top end 4b ₁ of the second partition wall 4b becomes the siphon chamber 2. As a result, the size of the air bubble aerated from the siphon type aeration tube 8 becomes large, and the intermittent time becomes long.

Further, as shown in FIGS. 8 and 9, the opening / closing means 54 is moved upward with respect to the housing 50, and in the state where at least one of the through holes 52 is opened, from the first partition wall 4a in the housing 50. also in the process water inlet 7 side, the space from the upper end of the through hole 52 in closest upper opening to the upper end 4b ₁ of the second partition wall 4b becomes siphon chamber 2. As a result, the size of the air bubble aerated from the siphon type aeration tube 8 becomes smaller, and the intermittent time becomes shorter.

In this example, the uppermost through hole 52 in the first partition wall 4a, are formed above the upper end 4b ₁ of the second partition wall 4b. Therefore, as shown in FIG. 10, the siphon chamber 2 is not formed in the housing 50 in the state where the uppermost through hole 52 of the first partition wall 4a is opened. Therefore, in this state, the siphon mechanism does not work, and fine air bubbles are continuously generated from the aeration holes 6.
As described above, in the siphon type aeration pipe 8, the size and the intermittent time of the air bubble to be aerated are adjusted by changing the volume of the siphon chamber 2 by opening and closing the through hole 52 formed in the first partition 4a. Can.

(Water treatment method)
Hereinafter, the water treatment method using the water treatment apparatus 1000 provided with the siphon-type aeration pipe 8 will be described. The water treatment method of the present embodiment has an activated sludge treatment step of treating raw water with activated sludge using activated sludge, and a membrane separation step of subjecting the sludge-containing treated water obtained in the activated sludge treatment step to membrane separation. ing.

The activated sludge treatment process can be performed in the same manner as the method described in the first aspect.
The membrane separation step can be performed in the same manner as the method described in the first embodiment except that the MBR device 100 including the siphon type aeration tube 8 is used.
For example, when an organic substance or the like is deposited on the surface of the separation membrane of the membrane module 22 and the inter-film differential pressure of the membrane module 22 becomes large, as shown in FIG. The volume of the siphon chamber 2 is made larger to make the size of the air bubble to be made larger and the intermittence time to be longer. Thereby, the cleaning effect of the membrane surface of membrane module 22 becomes high.

  When the concentration of dissolved oxygen in the sludge-containing treated water is low, the opening / closing means 54 is moved upward relative to the housing 50 to open the desired number of through holes 52, and the volume of the siphon chamber 2 To make them smaller, to make the size of aerated air bubbles smaller, and to shorten the intermittent time. As a result, the oxygen dissolution efficiency of the aerated air bubbles is increased, and the inside of the membrane separation tank 21 can be easily made into an appropriate aerobic condition.

As described above, in the second aspect of the present invention, at least one through hole formed in the first partition wall is opened and closed by the opening and closing means. Thus, as in the first embodiment, by changing the volume of the siphon chamber of the siphon type aeration tube, the size and the intermittent time of the air bubble to be aerated can be adjusted. Therefore, also in the second embodiment of the present invention, for example, priority is given to suppressing the deposition of organic matter and the like on the separation membrane surface of the membrane module, or giving priority to making the inside of the tank an appropriate aerobic condition. Depending on the size of the air bubbles and the intermittent time, it is possible to perform the water treatment stably.
The siphon type aeration tube of the second aspect is easier to manufacture than the siphon type aeration tube of the first aspect.

In addition, the siphon type aeration pipe of this invention is not limited to the above-mentioned siphon type aeration pipe 1 and 8. FIG.
The membrane separation activated sludge apparatus of the present invention comprises the siphon aeration pipe of the present invention, a membrane module for membrane separation of sludge-containing treated water containing activated sludge, and a membrane separation tank in which the siphon aeration pipe and the membrane module are installed. And the known aspect can be adopted except that
The water treatment method of the present invention may be a method of simultaneously performing the activated sludge treatment step and the membrane separation step using a water treatment apparatus in which the MBR device 100 is provided in the activated sludge treatment tank 11.

EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by the following description.
Example 1
A siphon-type aeration tube of the same configuration as the siphon-type aeration tube 1 illustrated in FIGS. The siphon-type aeration tube was a case of outer size and height H 170 mm × length L 160 mm × width D 80 mm (FIG. 2). The aeration holes are in a rectangular shape of 10 mm × 150 mm in plan view. The thickness of each of the top wall, the side wall and the bottom wall of the housing, the first partition wall and the second partition wall was 5 mm. The distance between the first partition and the upper wall, the distance between the first partition and the second partition, the distance between the second partition and the bottom wall, and the distance between the second partition and the side wall were each 10 mm.

  Air was continuously supplied at a flow rate of 15 L / min to the siphon type aeration pipe from an air supply port formed in the upper wall of the housing. The second partition wall is moved up and down relative to the casing, and the distance d (FIG. 3) between the lower end of the first partition wall and the upper end of the second partition wall is changed to 10 mm, 70 mm, and 140 mm. The appearance of air bubbles from the aeration tube was visually confirmed, and the average intermittence time of aeration was measured. The results are shown in FIG.

  As shown in FIG. 11, as the distance d is smaller and the siphon chamber is smaller, the average intermittence time of aeration is shorter. In addition, the size of the air bubble to be aerated was smaller as the distance d was smaller and the siphon chamber was smaller.

DESCRIPTION OF SYMBOLS 1,8 ... Siphon type | system | group air diffusion tube, 2 ... siphon room, 2A ... 1st siphon room, 2B ... 2nd siphon room, 3 ... air supply port, 4 ... path, 4a ... 1st partition wall, 4a ₁ ... lower end, 4b ... second partition wall, 4b ₁ ... top end, 5 ... communication part, 6 ... aeration hole, 7 ... treated water inlet, 11 ... activated sludge treatment tank, 21 ... membrane separation tank, 22 ... membrane module, 41 ... processing Water tank, 50: housing, 100: membrane separation activated sludge apparatus, 1000: water treatment apparatus.

Claims (5)

It is a siphon type aeration tube that performs aeration,
A housing provided with an upper wall, a side wall, and a bottom wall so as to form a space therein; and a first partition wall and a second partition wall which partition the space in the housing,
The first partition extends downward from the top wall of the housing, and the lower end of the first partition is spaced from the bottom wall of the housing.
The second partition wall extends upward from the bottom wall of the housing, the upper end of the second partition wall is separated from the top wall of the housing, and the first partition wall faces each other. Spaced apart, and
A treated water inlet is formed on the lower side of the casing on the opposite side to the first partition of the second partition, and an aeration hole is formed on the second partition of the first partition on the upper side of the casing. It is formed on the opposite side of the wall,
A siphon type diffuser, wherein the first partition wall, one or both of the second partition wall, and the housing move relative to each other in the vertical direction. It is a siphon type aeration tube that performs aeration,
A housing provided with an upper wall, a side wall, and a bottom wall so as to form a space therein; and a first partition wall and a second partition wall which partition the space in the housing,
The first partition extends downward from the top wall of the housing, and the lower end of the first partition is spaced from the bottom wall of the housing.
The second partition wall extends upward from the bottom wall of the housing, the upper end of the second partition wall is separated from the top wall of the housing, and the first partition wall faces each other. Spaced apart, and
A treated water inlet is formed on the lower side of the casing on the opposite side to the first partition of the second partition, and an aeration hole is formed on the second partition of the first partition on the upper side of the casing. It is formed on the opposite side of the wall,
At least one through hole is formed in the first partition wall,
A siphon type diffuser, provided with opening and closing means for opening and closing the through hole.   The siphon type diffuser according to claim 2, wherein the opening and closing means is an opening and closing plate which moves up and down relative to the casing along the surface of the first partition wall to open and close the through hole. The siphon type aeration pipe according to any one of claims 1 to 3;
A membrane module for membrane separation of sludge containing treated water including activated sludge;
A membrane separation activated sludge device, comprising: a membrane separation tank in which the siphon type aeration pipe and the membrane module are installed. Activated sludge treatment of raw water using activated sludge,
The water treatment method which carries out the membrane separation process of the sludge containing treated water which carried out the activated sludge process by the membrane separation activated sludge apparatus according to claim 4.

Images