WO2017110491A1

WO2017110491A1 - Organic waste water treatment device and organic waste water treatment method

Info

Publication number: WO2017110491A1
Application number: PCT/JP2016/086512
Authority: WO
Inventors: 康信岡島; 公博石川
Original assignee: 株式会社クボタ
Priority date: 2015-12-25
Filing date: 2016-12-08
Publication date: 2017-06-29
Also published as: JP6624926B2; JP2017113711A

Abstract

The inside of a treatment tank 2 is divided by dividing members 3 - 6 into a membrane separation area 11, first and second anaerobic areas 12, 13, and first and second aerobic areas 14, 15. A membrane separation device 27 provided with an air diffuser 31 on the lower side thereof is disposed in the membrane separation area 11. Activated sludge passing through the membrane separation device 27 by means of the ascending flow of diffused air from the air diffuser 31 branches from the membrane separation area 11 and flows into the first and second anaerobic areas 12, 13. Part of the activated sludge passing through the first anaerobic area 12 and part of the activated sludge passing through the second anaerobic area 13 flow into the first aerobic area 14, and the remainder of the activated sludge passing through the first anaerobic area 12 and the remainder of the activated sludge passing through the second anaerobic area 13 flow into the second aerobic area 15. The activated sludge of the first aerobic area 14 and the activated sludge of the second aerobic area 15 flow into the membrane separation area 11.

Description

Organic waste water treatment apparatus and organic waste water treatment method

The present invention relates to an organic wastewater treatment apparatus and an organic wastewater treatment method for treating organic wastewater in activated sludge.

Conventionally, as this type of organic waste water treatment apparatus, as shown in FIG. 10, for example, an anaerobic tank 101 for denitrifying treated water by anaerobic microorganisms, and treated water flowing from the anoxic tank 101 are included. There is a sewage treatment facility 104 that has an aerobic tank 102 that nitrifies ammonia to be aerobic microorganisms, and an air lift pump 103 that returns a portion of the water to be treated nitrified in the aerobic tank 102 to the anoxic tank 101.

The aerobic tank 102 is installed on the downstream side of the anoxic tank 101 through the partition wall 105. The inside of the aerobic tank 102 is divided into a first region 107 and a second region 108 by a separation wall 106. A diffuser 109 is installed in the first area 107. In the second region 108, a membrane separation device 110 for solid-liquid separation of the water to be treated is installed. The membrane separation device 110 has an air diffuser 111 at the bottom. Further, the air lift pump 103 is installed on the downstream side of the second region 108.

According to this, the water to be treated is subjected to anaerobic treatment in the anaerobic tank 101 and then aerobic treatment in the first region 107 of the aerobic tank 102, and in the second region 108 by the membrane separation device 110. Solid-liquid separation. In addition, a part of the water to be treated in the second region 108 is returned to the oxygen-free tank 101 by the air lift pump 103, whereby the water to be treated passes through the first region 107 in the aerobic tank 102 from the oxygen-free tank 101. After flowing through the second region 108, it is processed while circulating from the second region 108 to the anoxic tank 101.

Further, by performing aeration from the aeration device 111 of the membrane separation device 110, the sludge adhering to the membrane surface of the membrane separation device 110 can be removed.

In addition, the above sewage treatment facilities are described in, for example, the following Patent Document 1 in Japan.

Patent No. 5260417

However, in the above-described conventional format, since the air lift pump 103 is provided as power generation means for circulating the water to be treated, there is a problem that the sewage treatment facility 104 is enlarged and the cost is increased.

An object of the present invention is to provide an organic wastewater treatment apparatus and an organic wastewater treatment method that can be reduced in size and cost.

In order to achieve the above object, the present invention is a treatment apparatus for treating organic wastewater in activated sludge,
The inside of the treatment tank is partitioned by a partition member into a membrane separation zone, first and second anoxic zones, and first and second aerobic zones,
The membrane separation area and the first oxygen-free area communicate at the top,
The membrane separation zone and the second oxygen-free zone communicate at the top,
The membrane separation area and the first aerobic area communicate with each other at the bottom,
The membrane separation area and the second aerobic area communicate at the bottom,
The first anoxic zone and the first aerobic zone communicate with each other;
The second anoxic zone and the first aerobic zone communicate with each other;
The first anaerobic zone and the second aerobic zone communicate with each other;
The second anoxic zone and the second aerobic zone communicated,
In the membrane separation area, a membrane separation device immersed in activated sludge and equipped with an air diffuser at the bottom is arranged,
The activated sludge that has passed through the membrane separator as an upward flow due to the air diffused from the air diffuser branches in a direction away from the membrane separation zone and flows into the first and second oxygen-free zones,
Part of the activated sludge that has passed through the first oxygen-free zone and part of the activated sludge that has passed through the second oxygen-free zone flow into the first aerobic zone,
The remaining activated sludge that has passed through the first oxygen-free zone and the remaining activated sludge that has passed through the second oxygen-free zone flow into the second aerobic zone,
The activated sludge in the first aerobic zone and the activated sludge in the second aerobic zone flow into the membrane separation zone.

According to this, the activated sludge that has passed through the membrane separation device as an upward flow is branched from the membrane separation zone and flows into the first and second oxygen-free zones by performing aeration with the diffusion device of the membrane separation device. A part of the activated sludge that has passed through the first oxygen-free zone and a part of the activated sludge that has passed through the second oxygen-free zone flow into the first aerobic zone, and the remainder of the activated sludge that has passed through the first oxygen-free zone; The remainder of the activated sludge that has passed through the second anaerobic zone flows into the second aerobic zone, the activated sludge in the first aerobic zone and the activated sludge in the second aerobic zone flow into the membrane separation zone and become an upward flow, Activated sludge circulates in the tank.

Also, sludge adhering to the membrane surface of the membrane separator can be removed by aeration with the diffuser of the membrane separator.

Thus, the air diffuser of the membrane separation device serves as both the power generation means for circulating the activated sludge in the tank as described above and the membrane surface cleaning means of the membrane separation device. Therefore, it is not necessary to separately install power generation means for circulating activated sludge such as an air lift pump or a submersible pump, and the organic waste water treatment apparatus can be reduced in size and cost.

In addition, as described above, activated sludge repeats branching and merging in the middle of circulating in the treatment tank, so that complete mixing of activated sludge in the treatment tank is promoted and the biological treatment efficiency of the organic waste water treatment equipment is increased. Can do.

Moreover, the organic waste water treatment apparatus in the present invention, the membrane separation device has a plurality of flat membrane elements arranged at predetermined intervals in a vertical posture above the air diffuser,
The first and second anoxic zones are arranged such that the activated sludge branches off from the membrane separation zone and flows in a direction perpendicular to the arrangement direction of the flat membrane elements,
The first and second aerobic zones are arranged such that activated sludge flows into the membrane separation zone along the arrangement direction of the flat membrane elements.

According to this, the activated sludge flows upward and downward between the flat membrane elements by performing the aeration with the aeration device of the membrane separation device. The upward flow that has passed between the flat membrane elements branches from the membrane separation zone in a direction perpendicular to the direction in which the flat membrane elements are arranged, and flows into the first and second oxygen-free zones. The activated sludge that has passed through the first and second oxygen-free zones flows from the first and second aerobic zones into the membrane separation zone along the arrangement direction of the flat membrane elements.

As described above, the direction in which activated sludge flows from the membrane separation zone into the first and second anoxic zones is different from the direction in which activated sludge flows from the first and second aerobic zones into the membrane separation zone. Counterflow flows evenly between flat membrane elements. Thereby, it can prevent that sludge adheres locally to a part of flat membrane element.

Further, the organic waste water treatment apparatus in the present invention is connected to a raw water supply path for supplying organic waste water to the first and second anoxic zones.

According to this, the amount of organic wastewater in the treatment tank can be kept at a predetermined amount by supplying organic wastewater to the first and second oxygen-free zones from the raw water supply path.

Moreover, the organic wastewater treatment apparatus in the present invention is a treatment apparatus for treating organic wastewater in activated sludge,
The inside of the treatment tank is divided into a membrane separation area, first and second oxygen-free areas, and an aerobic area by a partition member,
The membrane separation area and the first oxygen-free area communicate at the top,
The membrane separation zone and the second oxygen-free zone communicate at the top,
The membrane separation area and the aerobic area communicate with each other at the bottom.
The first anoxic zone and the aerobic zone communicate
The second anoxic zone and the aerobic zone communicated,
In the membrane separation area, a membrane separation device immersed in activated sludge and equipped with an air diffuser at the bottom is arranged,
The activated sludge that has passed through the membrane separator as an upward flow due to the air diffused from the air diffuser branches in a direction away from the membrane separation zone and flows into the first and second oxygen-free zones,
The activated sludge that has passed through the first oxygen-free zone and the activated sludge that has passed through the second oxygen-free zone flow into the aerobic zone,
Activated sludge in the aerobic zone flows into the membrane separation zone.

According to this, the activated sludge that has passed through the membrane separation device as an upward flow is branched from the membrane separation zone and flows into the first and second oxygen-free zones by performing aeration with the diffusion device of the membrane separation device. The activated sludge that has passed through the first oxygen-free zone and the activated sludge that has passed through the second oxygen-free zone flow into the aerobic zone, and the activated sludge in the aerobic zone flows into the membrane separation zone and becomes an upward flow. Activated sludge circulates.

Moreover, the organic wastewater treatment apparatus in the present invention is a treatment apparatus for treating organic wastewater in activated sludge,
The inside of the treatment tank is partitioned by a partition member into a membrane separation zone, first and second anoxic zones, and first and second aerobic zones,
The membrane separation area and the first oxygen-free area communicate at the top,
The membrane separation zone and the second oxygen-free zone communicate at the top,
The membrane separation area and the first aerobic area communicate with each other at the bottom,
The membrane separation zone and the second aerobic zone communicate with each other at the lower part, and the first anoxic zone communicates with the first aerobic zone,
The second anoxic zone and the second aerobic zone communicated,
In the membrane separation area, a membrane separation device immersed in activated sludge and equipped with an air diffuser at the bottom is arranged,
The activated sludge that has passed through the membrane separator as an upward flow due to the air diffused from the air diffuser branches in a direction away from the membrane separation zone and flows into the first and second oxygen-free zones,
The activated sludge that has passed through the first anoxic zone flows into the first aerobic zone,
The activated sludge that has passed through the second anoxic zone flows into the second aerobic zone,
The activated sludge in the first aerobic zone and the activated sludge in the second aerobic zone flow into the membrane separation zone.

According to this, the activated sludge that has passed through the membrane separation device as an upward flow is branched from the membrane separation zone and flows into the first and second oxygen-free zones by performing aeration with the diffusion device of the membrane separation device. The activated sludge that has passed through the first anaerobic zone flows into the first aerobic zone, the activated sludge that has passed through the second anaerobic zone flows into the second aerobic zone, and the activated sludge and the second in the first aerobic zone. The activated sludge in the aerobic zone flows into the membrane separation zone and becomes an upward flow, and the activated sludge circulates in the tank.

Further, in the organic waste water treatment apparatus according to the present invention, the membrane separation apparatus has a plurality of flat membrane elements arranged at predetermined intervals in a vertical posture above the air diffuser.

According to this, the activated sludge flows upward and downward between the flat membrane elements by performing the aeration with the aeration device of the membrane separation device. Thereby, the sludge adhering to the membrane surface of the flat membrane element can be removed.

The present invention also provides an organic wastewater for treating organic wastewater in activated sludge using a treatment device in which a treatment tank is partitioned into a membrane separation zone, a first and second oxygen-free zone, and an aerobic zone. A processing method,
While taking out treated water from a submerged membrane separator placed in the membrane separation area,
The activated sludge that has passed through the inside of the membrane separator due to the air diffused from the air diffuser provided at the lower part of the membrane separator is branched into one and the other treatment path, and flows.
Activated sludge flowing through one treatment path passes through the first oxygen-free zone and is supplied to the aerobic zone,
The activated sludge flowing through the other treatment path passes through the second anoxic zone and is supplied to the aerobic zone,
The activated sludge from one treatment path and the activated sludge from the other treatment path that have joined together in the aerobic zone are introduced into the membrane separation zone.

According to this, by performing aeration with the aeration device of the membrane separation device, the activated sludge in the membrane separation area flows upward from below to generate an upward flow, and the activated sludge circulates in the tank, and the membrane Sludge adhering to the membrane surface of the separator can be removed.

As described above, the air diffuser of the membrane separation device combines the power generation means for circulating the activated sludge in the tank and the membrane surface cleaning means of the membrane separation device. There is no need to separately install power generation means for circulating the activated sludge, and the organic waste water treatment apparatus can be reduced in size and cost.

In the organic wastewater treatment method of the present invention, the aerobic zone is separated into a first aerobic zone and a second aerobic zone,
The activated sludge flowing through one of the treatment paths branches to the first branch path and the second branch path when passing through the first oxygen-free zone, and is supplied to the first aerobic zone and the second aerobic zone. ,
The activated sludge flowing through the other treatment path branches to the third branch path and the fourth branch path when passing through the second oxygen-free zone, and is supplied to the first aerobic zone and the second aerobic zone. ,
Activated sludge from the first branch path and activated sludge from the third branch path are merged in the first aerobic zone and introduced into the membrane separation zone, and from the activated sludge from the second branch path and the fourth branch path The activated sludge is combined in the second aerobic zone and introduced into the membrane separation zone.

The present invention also provides a method for treating organic wastewater in activated sludge using a treatment apparatus in which a treatment tank is partitioned into a membrane separation zone, first and second anoxic zones, and first and second aerobic zones. An organic wastewater treatment method for processing,
While taking out treated water from a submerged membrane separator placed in the membrane separation area,
The activated sludge that has passed through the inside of the membrane separator due to the air diffused from the air diffuser provided at the lower part of the membrane separator is branched into one and the other treatment path, and flows.
Activated sludge flowing through one treatment path is introduced into the membrane separation zone through the first anoxic zone and the first aerobic zone,
Activated sludge flowing through the other treatment path is introduced into the membrane separation zone through the second anoxic zone and the second aerobic zone,
The activated sludge introduced from one treatment path and the activated sludge introduced from the other treatment path are merged in the membrane separation section, and passed through the membrane separation apparatus in an upward flow by the diffused air from the diffuser. Is.

Moreover, the organic wastewater treatment method in the present invention, the direction in which the activated sludge that has passed through the membrane separator in an upward flow is branched into one and the other treatment path is a branch direction,
The direction in which the activated sludge in the first aerobic zone is introduced into the membrane separation zone is the first introduction direction,
When the direction in which the activated sludge in the second aerobic zone is introduced into the membrane separation zone is the second introduction direction,
Making the branch direction and the first introduction direction orthogonal, and making the branch direction and the second introduction direction orthogonal,
The first introduction direction and the second introduction direction are made to approach each other.

According to this, since the upward flow generated in the membrane separation area by the air diffuser flows evenly between the flat membrane elements, it is possible to prevent the sludge from being locally biased to a part of the flat membrane element. .

The organic wastewater treatment method in the present invention supplies organic wastewater to one and the other treatment path.

As described above, according to the present invention, the air diffusing device of the membrane separation device combines the power generation means for circulating the activated sludge in the tank and the membrane surface cleaning means of the membrane separation device. There is no need to separately install power generation means for circulating activated sludge such as a pump and a submersible pump, and the organic wastewater treatment apparatus can be reduced in size and cost.

It is a schematic plan view of the organic waste water treatment apparatus in the 1st Embodiment of this invention. It is a schematic plan view which shows the path | route through which the to-be-processed water in the processing tank of an organic waste water treatment apparatus flows. FIG. 2 is a view on arrow XX in FIG. 1. It is the perspective view which notched a part of organic waste water treatment equipment same as the above. It is a schematic plan view of the organic waste water treatment apparatus in the 2nd Embodiment of this invention. It is a schematic plan view of the organic waste water treatment apparatus in the 3rd Embodiment of this invention. It is a schematic plan view of the organic waste water treatment apparatus in the 4th Embodiment of this invention. It is a schematic plan view of the organic waste water treatment apparatus in the 5th Embodiment of this invention. It is a schematic plan view of the organic waste water treatment apparatus in the 6th Embodiment of this invention. It is a schematic plan view of the conventional organic waste water treatment equipment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
In the first embodiment, as shown in FIGS. 1 to 4, reference numeral 1 denotes a treatment apparatus for treating organic wastewater such as sewage in activated sludge. The processing apparatus 1 has a processing tank 2, and the inside of the processing tank 2 is separated from the first and fourth partition walls 3 to 6 (an example of a partition member) by the membrane separation tank 11 (an example of a membrane separation area) and the first and The second anaerobic tanks 12 and 13 (an example of an anaerobic area) and the first and second aerobic tanks 14 and 15 (an example of an aerobic area) are partitioned.

The membrane separation tank 11 is formed at the center of the treatment tank 2, and the first and second oxygen-

free tanks

12 and 13 and the first and second

aerobic tanks

14 and 15 are formed so as to surround the periphery of the membrane separation tank 11. Has been. The first and second oxygen-

free tanks

12 and 13 are provided with a stirrer (not shown). The first and second

aerobic tanks

14 and 15 are provided with an air diffuser 17 for supplying oxygen to the water 8 to be treated containing activated sludge.

The first partition wall 3 is a wall that partitions the membrane separation tank 11 and the first oxygen-free tank 12, and the second partition wall 4 is a wall that partitions the membrane separation tank 11 and the second oxygen-free tank 13. is there. The upper ends of the first and

second partition walls

3 and 4 are slightly below the water surface 8a of the water to be treated 8 (activated sludge) in the treatment tank 2, respectively. Thereby, the membrane separation tank 11 and the first oxygen-free tank 12 communicate with each other at the upper part, and the membrane separation tank 11 and the second oxygen-free tank 13 communicate with each other at the upper part.

The third partition wall 5 is provided between the membrane separation tank 11 and the first aerobic tank 14, between the first anaerobic tank 12 and the first aerobic tank 14, and between the second anoxic tank 13 and the first aerobic tank. A wall that partitions the air tank 14. The fourth partition wall 6 is provided between the membrane separation tank 11 and the second aerobic tank 15, between the first anaerobic tank 12 and the second aerobic tank 15, and between the second anaerobic tank 13 and the second aerobic tank 13. 2 is a wall that partitions the aerobic tank 15. The upper ends of the third and

fourth partition walls

5 and 6 protrude upward from the water surface 8a of the water 8 to be treated in the treatment tank 2, respectively.

In the membrane separation tank 11, a membrane separation device 27 immersed in the water to be treated 8 is disposed. The membrane separation device 27 includes a membrane filling unit 28, an air diffusion unit 29 formed below the membrane filling unit 28, a plurality of flat membrane elements 30 filled in the membrane filling unit 28, and the air diffusion unit 29. And an air diffuser 31 provided.

As shown in FIG. 3, the membrane filling portion 28 and the diffuser portion 29 communicate with each other in the vertical direction. The upper end of the film filling portion 28 is open.

The flat membrane element 30 has a flat filter plate 33 and filter membranes 34 mounted on both sides of the filter plate 33, and is arranged above the air diffuser 31 with a predetermined interval in a vertical position. Has been. The treated water 36 (permeated water) that has passed through the filtration membrane 34 of each flat membrane element 30 is collected in the water collection pipe 35 and taken out of the treatment tank 2.

As shown in FIGS. 3 and 4, three openings 19 to 21 are formed in the lower part of the third partition wall 5, and three openings 22 to 24 are also formed in the lower part of the fourth partition wall 6. Yes. Thereby, the lower part of the 1st anaerobic tank 12 and the lower part of the 1st aerobic tank 14 are connected via the opening part 19, and the lower part of the 2nd anaerobic tank 13 and the lower part of the 1st aerobic tank 14 are connected. The diffuser 29 provided at the lower part of the membrane separation tank 11 and the lower part of the first aerobic tank 14 communicate with each other via the opening 20.

The lower part of the first anaerobic tank 12 and the lower part of the second aerobic tank 15 communicate with each other through the opening 22, and the lower part of the second anaerobic tank 13 and the lower part of the second aerobic tank 15 are opened. The air diffuser 29 provided at the lower part of the membrane separation tank 11 and the lower part of the second aerobic tank 15 communicate with each other through the opening 24.

The first aerobic tank 14 and the second aerobic tank 15 face each other in the arrangement direction A of the flat membrane elements 30 with the membrane separation tank 11 in between. The first oxygen-free tank 12 and the second oxygen-free tank 13 are opposed to each other in a direction B orthogonal to the arrangement direction A with the membrane separation tank 11 interposed therebetween. The first anaerobic tank 12 and the second anaerobic tank 13 are provided between the first aerobic tank 14 and the second aerobic tank 15 in the arrangement direction A.

As shown in FIG. 2, the water to be treated 8 branches and flows into one and the

other treatment paths

37 and 38 and circulates in the treatment tank 2. One processing path 37 extends from the membrane separation tank 11 over the first partition wall 3 to the first oxygen-free tank 12, reaches from the upper part of the first oxygen-free tank 12 to the lower part, and the first oxygen-free tank 12. The first branch path 37a branches into the first aerobic tank 14 through the opening 19, and the second branch path 37b passes through the opening 22. It passes through and reaches the second aerobic tank 15.

The other processing path 38 reaches from the membrane separation tank 11 over the second partition wall 4 to the second oxygen-free tank 13, reaches from the upper part of the second oxygen-free tank 13 to the lower part, and enters the second oxygen-free tank 13. Branching into a third branch path 38a and a fourth branch path 38b, the third branch path 38a reaches the first aerobic tank 14 through the opening 20, and the fourth branch path 38b passes through the opening 23. It passes through and reaches the second aerobic tank 15.

The first branch path 37 a and the third branch path 38 a are integrated in the first aerobic tank 14 and reach the air diffuser 29 in the membrane separation tank 11 through the opening 21. Further, the second branch path 37 b and the fourth branch path 38 b are integrated in the second aerobic tank 15 and reach the air diffuser 29 of the membrane separation tank 11 through the opening 24.

A raw water supply path 40 for supplying the treated water 8 (organic wastewater) to the first and second oxygen-

free tanks

12 and 13 is connected to the treatment tank 2.

The organic wastewater treatment method using the treatment apparatus 1 will be described below.

Air diffused by the air diffuser 17 of the first and second

aerobic tanks

14 and 15, and the treated water 36 that has permeated the filtration membrane 34 of each flat membrane element 30 of the membrane separator 27 is collected in the water collecting pipe 35. Then, it is taken out of the treatment tank 2 and the treated water 8 is solid-liquid separated.
At this time, air is diffused by the air diffuser 31 of the membrane separator 27, and the upward flow into the membrane separator 11 due to the air lift effect caused by the release and rising of a large number of bubbles 42 from the air diffuser 31. 43 occurs. The upward flow 43 is a flow of the to-be-treated water 8 containing activated sludge, passes between the flat membrane elements 30 of the membrane separation device 27 from the lower side to the upper side, and one and the other at the upper end of the membrane separation tank 11. It branches into the

process paths

37 and 38, and flows into the upper part of the 1st and 2nd oxygen-

free tanks

12 and 13.

In the first and second

anoxic tanks

12 and 13, the water 8 to be treated is denitrified by microorganisms (denitrifying bacteria) that prefer anoxic conditions.

The treated water 8 that has flowed from the upper part to the lower part of the first oxygen-free tank 12 is branched into the first branch path 37 a and the second branch path 37 b, and a part of the treated water 8 passes through the opening 19. Then, it flows into the lower part of the first aerobic tank 14, and the remaining portion of the treated water 8 flows into the lower part of the second aerobic tank 15 through the opening 22.

Moreover, the to-be-processed water 8 which flowed through the 2nd anaerobic tank 13 toward the lower part flows into the 3rd branch path 38a and the 4th branch path 38b, and a part of to-be-processed water 8 is an opening part. 20 flows into the lower part of the first aerobic tank 14 through 20, and the remaining portion of the treated water 8 flows into the lower part of the second aerobic tank 15 through the opening 23.

In the first and second

aerobic tanks

14 and 15, the water to be treated 8 is nitrified by microorganisms (nitrifying bacteria) by performing aeration with the aeration device 17.

The first aerobic tank 14 flows from the first anaerobic tank 12 through the first branch path 37a and flows into the first aerobic tank 14 and the second anaerobic tank 13 flows from the second anaerobic tank 13 through the third branch path 38a. The treated water 8 that has flowed into the water merges and is introduced from the lower portion of the first aerobic tank 14 through the opening 21 to the diffuser 29 in the membrane separation tank 11.

Moreover, the to-be-processed water 8 which flowed into the 2nd aerobic tank 15 through the 2nd branch path | route 37b from the 1st anaerobic tank 12 and the 4th branch path | route 38b from the 2nd anaerobic tank 13 flowed through the 2nd aerobic tank. The treated water 8 that has flowed into the tank 15 joins, and is introduced from the lower part of the second aerobic tank 15 through the opening 24 into the air diffuser 29 in the membrane separation tank 11.

The water 8 to be treated thus introduced into the air diffuser 29 becomes an upward flow 43 due to the air diffused by the air diffuser 31 and flows through one and the

other treatment paths

37, 38, and inside the treatment tank 2. Circulate.

Further, as described above, a large number of bubbles 42 are discharged from the air diffuser 31 of the membrane separation device 27 and an upward flow 43 is generated in the membrane separation tank 11, so that the filtration membrane 34 of the flat membrane element 30 is formed. Adhering sludge can be removed.

Thus, the air diffuser 31 of the membrane separation device 27 cleans the membrane surface of the power generation means for circulating the treated water 8 in the treatment tank 2 as described above and the filtration membrane 34 of the flat membrane element 30. It also serves as a means. Therefore, it is not necessary to separately install a dedicated power generation means for circulating the treated water 8 such as an air lift pump or a submersible pump, and the processing apparatus 1 can be reduced in size and cost.

Moreover, since the to-be-processed water 8 (activated sludge) repeats a branch and merge in the middle of circulating in the processing tank 2 as mentioned above, the complete mixing of the to-be-processed water 8 in the processing tank 2 is accelerated | stimulated, and processing apparatus 1 biological treatment efficiency can be increased.

As shown in FIG. 1, the first and second oxygen-

free tanks

12 and 13 have the water 8 to be treated branched from the upper end of the membrane separation tank 11 in a direction B orthogonal to the arrangement direction A of the flat membrane elements 30. And is arranged to flow. Furthermore, the 1st and 2nd

aerobic tanks

14 and 15 are arrange | positioned so that the to-be-processed water 8 may flow into the membrane separation tank 11 along the said sequence direction A.

Thereby, as shown in FIG. 2, the direction in which the upward flow 43 branches into one and the

other treatment paths

37 and 38 is defined as a branch direction D, and the treated water 8 in the first aerobic tank 14 is in the membrane separation tank 11. Assuming that the direction to be introduced into the first introduction direction D1 and the direction in which the treated water 8 of the second aerobic tank 15 is introduced into the membrane separation tank 11 is the second introduction direction D2, the branch direction D and the first introduction direction The direction D1 is orthogonal, the branching direction D and the second introduction direction D2 are orthogonal, and the first introduction direction D1 and the second introduction direction D2 are close to each other.

Thus, the direction (branch direction D) in which the to-be-processed water 8 flows into the 1st and 2nd oxygen-

free tanks

12 and 13 from the membrane separation tank 11, and the to-be-processed water 8 are the 1st and 2nd aerobic tanks 14, Since the direction (first and second introduction directions D1 and D2) flowing from 15 into the membrane separation tank 11 is different, the upward flow 43 flows between the flat membrane elements 30 evenly. Thereby, it can prevent that sludge adheres locally to a part of filtration membrane 34 of flat membrane element 30.

Further, by supplying the treated water 8 (organic waste water) from the raw water supply path 40 to the first and second

anoxic tanks

12 and 13, the amount of the treated water 8 in the treated tank 2 is kept at a predetermined amount. be able to.

Other embodiments will be described below. In addition, about the same member, the same code | symbol is attached and detailed description is abbreviate | omitted.
(Second Embodiment)
In the second embodiment, as shown in FIG. 5, the first anaerobic tank 14 and the second aerobic tank 15 are in the first anoxic direction in the direction B perpendicular to the arrangement direction A of the flat membrane elements 30. It is provided between the tank 12 and the second oxygen-free tank 13.

In the treatment tank 2, the membrane separation tank 11, the first and second oxygen-

free tanks

12, 13 and the first and second aerobic tanks 14 are provided by first to eighth partition walls 51 to 58 (an example of a partition member). , 15.

The first partition wall 51 is a wall that partitions between the membrane separation tank 11 and the first oxygen-free tank 12, and the second partition wall 52 is a wall that partitions between the membrane separation tank 11 and the second oxygen-free tank 13. is there. The upper ends of the first and

second partition walls

51 and 52 are slightly below the water surface 8a of the water 8 to be treated in the treatment tank 2, respectively. Thereby, the membrane separation tank 11 and the first oxygen-free tank 12 communicate with each other at the upper part, and the membrane separation tank 11 and the second oxygen-free tank 13 communicate with each other at the upper part.

The third to fifth partition walls 53 to 55 are respectively provided between the first anaerobic tank 12 and the first aerobic tank 14, between the second anaerobic tank 13 and the first aerobic tank 14, and membrane separation. It is a wall that partitions between the tank 11 and the first aerobic tank 14.

The sixth to eighth partition walls 56 to 58 are respectively provided between the first anaerobic tank 12 and the second aerobic tank 15, between the second anaerobic tank 13 and the second aerobic tank 15, and membrane separation. It is a wall that partitions between the tank 11 and the second aerobic tank 15.

Note that the upper end portions of the third to eighth partition walls 53 to 58 protrude upward from the water surface 8a of the water 8 to be treated in the treatment tank 2, respectively.

The openings 19 to 24 are formed below the third to eighth partition walls 53 to 58, respectively. The lower part of the first anaerobic tank 12 and the lower part of the first aerobic tank 14 define the opening 19. The lower part of the second anaerobic tank 13 and the lower part of the first aerobic tank 14 communicate with each other through the opening 20, and the air diffuser 29 provided at the lower part of the membrane separation tank 11 and the first The lower part of the aerobic tank 14 communicates with the opening 21.

According to this, the same operation and effect as in the first embodiment can be obtained.
(Third embodiment)
In the third embodiment, as shown in FIG. 6, the inside of the treatment tank 2 is separated from the membrane separation tank 11 by the first to eighth partition walls 51 to 58 (an example of a partition member). It is partitioned into

oxygen tanks

12 and 13 and first and second

aerobic tanks

14 and 15.

The first oxygen-free tank 12 and the second oxygen-free tank 13 are opposed to each other in the arrangement direction A of the flat membrane elements 30 with the membrane separation tank 11 in between. The first aerobic tank 14 and the second aerobic tank 15 are opposed to each other in a direction B orthogonal to the arrangement direction A with the membrane separation tank 11 interposed therebetween. The first aerobic tank 14 and the second aerobic tank 15 are provided between the first anaerobic tank 12 and the second anaerobic tank 13 in the arrangement direction A.

second partition walls

The sixth to eighth partition walls 56 to 58 are separated from each other between the first anaerobic tank 12 and the second aerobic tank 15, and between the second anaerobic tank 13 and the second aerobic tank 15, respectively. It is a wall that partitions between the tank 11 and the second aerobic tank 15.

According to this, the same operation and effect as in the first embodiment can be obtained.
(Fourth embodiment)
In the fourth embodiment, as shown in FIG. 7, the first anaerobic tank 12 and the second anoxic tank 13 are in the first aerobic in the direction B perpendicular to the arrangement direction A of the flat membrane elements 30. It is provided between the tank 14 and the second aerobic tank 15.

According to this, the same operation and effect as in the first embodiment can be obtained.
(Fifth embodiment)
In the fifth embodiment, as shown in FIG. 8, the inside of the treatment tank 2 is separated from the membrane separation tank 11, the first and second oxygen-

free tanks

12, 13 by the first to fifth partition walls 51 to 55. It is partitioned into an aerobic tank 14.

second partition walls

The third to fifth partition walls 53 to 55 are respectively located between the first anaerobic tank 12 and the aerobic tank 14, between the second anoxic tank 13 and the aerobic tank 14, and with the membrane separation tank 11. A wall that partitions the air tank 14.

Note that the upper end portions of the third to fifth partition walls 53 to 55 protrude upward from the water surface 8a of the water 8 to be treated in the treatment tank 2, respectively.

In addition, the openings 19 to 21 are formed below the third to fifth partition walls 53 to 55, respectively, and the lower part of the first oxygen-free tank 12 and the lower part of the aerobic tank 14 are connected via the opening 19. The lower part of the second oxygen-free tank 13 and the lower part of the aerobic tank 14 communicate with each other through the opening 20, and the air diffuser 29 and the aerobic tank 14 provided at the lower part in the membrane separation tank 11 are communicated. The lower portion communicates with the opening 21.

The first oxygen-free tank 12 and the second oxygen-free tank 13 are opposed to each other in the direction B orthogonal to the arrangement direction A of the flat membrane elements 30, and the membrane separation tank 11 and the aerobic tank 14 are the first oxygen-free tank. 12 and the second oxygen-free tank 13.

The treated water 8 branches and flows into one and the

other treatment paths

37 and 38 and circulates in the treatment tank 2. One processing path 37 extends from the membrane separation tank 11 to above the first partition wall 51 and reaches the first oxygen-free tank 12, reaches from the upper part of the first oxygen-free tank 12 to the lower part, and passes through the opening 19. It reaches the aerobic tank 14.

The other processing path 38 extends from the membrane separation tank 11 to above the second partition wall 52 to reach the second oxygen-free tank 13, reaches from the top to the bottom of the second oxygen-free tank 13, and opens the opening 20. Pass through to the aerobic tank 14.

The one processing path 37 and the other processing path 38 are integrated in the aerobic tank 14 and reach the diffuser 29 in the membrane separation tank 11 through the opening 21.

The treated water 36 diffused by the diffuser 17 of the aerobic tank 14 and permeated through the filtration membrane 34 of each flat membrane element 30 of the membrane separation device 27 is collected in the water collecting pipe 35 and is sent to the outside of the treated tank 2. It takes out and the to-be-processed water 8 is solid-liquid separated.
At this time, air is diffused by the air diffuser 31 of the membrane separator 27, and the upward flow into the membrane separator 11 due to the air lift effect caused by the release and rising of a large number of bubbles 42 from the air diffuser 31. 43 occurs. The upward flow 43 is a flow of the to-be-treated water 8 containing activated sludge, passes between the flat membrane elements 30 of the membrane separation device 27 from the lower side to the upper side, and one and the other at the upper end of the membrane separation tank 11. It branches into the

process paths

37 and 38, and flows into the upper part of the 1st and 2nd oxygen-

free tanks

12 and 13.

In the first and second

anoxic tanks

The treated water 8 that flowed from the upper part to the lower part of the first anaerobic tank 12 flowed to the lower part of the aerobic tank 14 through the opening 19 and flowed from the upper part to the lower part of the second anaerobic tank 13. The treated water 8 flows into the lower part of the aerobic tank 14 through the opening 20.

In the aerobic tank 14, the to-be-treated water 8 is nitrified by microorganisms (nitrifying bacteria) by performing aeration with the aeration device 17.

The treated water 8 that flows from the first anaerobic tank 12 through one treatment path 37 and into the aerobic tank 14 and the treated water that flows from the second anoxic tank 13 through the other treatment path 38 and into the aerobic tank 14. The treated water 8 merges and is introduced from the lower part of the aerobic tank 14 through the opening 21 to the diffuser 29 in the membrane separation tank 11.

other treatment paths

37, 38, and inside the treatment tank 2. Circulate.

Further, by supplying the water to be treated 8 from the raw water supply path 40 to the first and second oxygen-

free tanks

12 and 13, the amount of the water to be treated 8 in the treatment tank 2 can be kept at a predetermined amount.
(Sixth embodiment)
In the sixth embodiment, as shown in FIG. 9, the inside of the processing tank 2 is separated from the membrane separation tank 11 by the first to sixth partition walls 71 to 76 (an example of a partition member). It is partitioned into

oxygen tanks

12 and 13 and first and second

aerobic tanks

14 and 15.

free tanks

12 and 13 and the first and second

aerobic tanks

14 and 15 are formed so as to surround the periphery of the membrane separation tank 11. Has been.

The first partition wall 71 is a wall that partitions between the membrane separation tank 11 and the first oxygen-free tank 12, and the second partition wall 72 is a wall that partitions between the membrane separation tank 11 and the second oxygen-free tank 13. is there. The upper end portions of the first and

second partition walls

71 and 72 are slightly below the water surface 8a of the water 8 to be treated in the treatment tank 2, respectively. Thereby, the membrane separation tank 11 and the first oxygen-free tank 12 communicate with each other at the upper part, and the membrane separation tank 11 and the second oxygen-free tank 13 communicate with each other at the upper part.

The third partition wall 73 is a wall that partitions the first oxygen-free tank 12 and the first aerobic tank 14, and the fourth partition wall 74 partitions the membrane separation tank 11 and the first aerobic tank 14. It is a wall. The fifth partition wall 75 is a wall that partitions the second oxygen-free tank 13 and the second aerobic tank 15, and the sixth partition wall 76 is between the membrane separation tank 11 and the second aerobic tank 15. It is a wall that partitions. The upper end portions of the third to sixth partition walls 73 to 76 protrude upward from the water surface 8a of the water 8 to be treated in the treatment tank 2, respectively.

The openings 19 to 22 are formed below the third to sixth partition walls 73 to 76, respectively. The lower part of the first anaerobic tank 12 and the lower part of the first aerobic tank 14 define the opening 19. The air diffuser 29 provided in the lower part of the membrane separation tank 11 and the lower part of the first aerobic tank 14 communicate with each other through the opening 20.

Further, the lower part of the second anaerobic tank 13 and the lower part of the second aerobic tank 15 communicate with each other through the opening 21, and the diffuser 29 provided at the lower part in the membrane separation tank 11 and the second aerobic are provided. The lower part of the tank 15 communicates with the opening 22.

The treated water 8 branches and flows into one and the

other treatment paths

37 and 38 and circulates in the treatment tank 2. One processing path 37 extends from the membrane separation tank 11 over the first partition wall 71 to the first oxygen-free tank 12, reaches from the upper part of the first oxygen-free tank 12 to the lower part, and reaches the first oxygen-free tank 12. The first aerobic tank 14 passes through the opening 19 from the lower part of the gas, and reaches the air diffuser 29 in the membrane separation tank 11 from the first aerobic tank 14 through the opening 20.

The other processing path 38 reaches from the membrane separation tank 11 to the second oxygen-free tank 13 over the second partition wall 72, reaches from the upper part of the second oxygen-free tank 13 to the lower part, and reaches the second oxygen-free tank 13. From the lower part of the tank 13 to the lower part of the second aerobic tank 15 through the opening part 21 and from the lower part of the second aerobic tank 15 to the diffuser part 29 in the membrane separation tank 11 through the opening part 22 Yes.

Air diffused by the air diffuser 17 of the first and second

aerobic tanks

14 and 15, and the treated water 36 that has permeated the filtration membrane 34 of each flat membrane element 30 of the membrane separator 27 is collected in the water collecting pipe 35. Then, it is taken out of the treatment tank 2 and the treated water 8 is solid-liquid separated.

At this time, air is diffused by the air diffuser 31 of the membrane separator 27, and the upward flow into the membrane separator 11 due to the air lift effect caused by the release and rising of a large number of bubbles 42 from the air diffuser 31. 43 occurs. The upward flow 43 is a flow of the to-be-treated water 8 containing activated sludge, passes between the flat membrane elements 30 of the membrane separation device 27 from the lower side to the upper side, and one and the other at the upper end of the membrane separation tank 11. It branches into the

process paths

37 and 38, and flows into the upper part of the 1st and 2nd oxygen-

free tanks

12 and 13.

In the first and second

anoxic tanks

The treated water 8 that has flowed from the upper part toward the lower part in the first anaerobic tank 12 flows into the lower part of the first aerobic tank 14 through the opening 19 and is diffused by the air diffuser 17 of the first aerobic tank 14. By performing aeration, it is nitrified by microorganisms (nitrifying bacteria) and flows from the lower part of the first aerobic tank 14 through the opening 20 into the aeration part 29 in the membrane separation tank 11.

Moreover, the to-be-processed water 8 which flowed through the 2nd anaerobic tank 13 toward the lower part flows into the lower part of the 2nd aerobic tank 15 through the opening part 21, and the diffuser of the 2nd aerobic tank 15 By performing aeration at 17, nitrification treatment is performed by microorganisms (nitrifying bacteria) and flows into the aeration unit 29 in the membrane separation tank 11 through the opening 22 of the second aerobic tank 15.

In this way, the water 8 to be treated introduced into the air diffuser 29 through the one treatment path 37 and the water 8 to be treated introduced into the air diffuser 29 through the other treatment path 38 are separated into the membrane separation tank. 11, and flows upward between the flat membrane elements 30 of the membrane separation device 27 and circulates in the treatment tank 2.

The first and second oxygen-

free tanks

12 and 13 are arranged such that the water to be treated 8 branches off from the upper end of the membrane separation tank 11 in a direction B perpendicular to the arrangement direction A of the flat membrane elements 30 and flows. ing. Furthermore, the 1st and 2nd

aerobic tanks

As a result, the direction in which the upward flow 43 branches into one and the

other treatment paths

37 and 38 is defined as a branch direction D, and the direction in which the water 8 to be treated in the first aerobic tank 14 is introduced into the membrane separation tank 11 is the first. Assuming that the first introduction direction D1 and the direction in which the treated water 8 of the second aerobic tank 15 is introduced into the membrane separation tank 11 is the second introduction direction D2, the branch direction D and the first introduction direction D1 are orthogonal to each other. The branch direction D and the second introduction direction D2 are orthogonal to each other, and the first introduction direction D1 and the second introduction direction D2 are directions close to each other.

free tanks

In each of the above embodiments, the flat membrane element 30 having the flat filter plate 33 and the filter membranes 34 attached to both surfaces of the filter plate 33 is used. However, the present invention is not limited to such a configuration. Alternatively, for example, a hollow fiber membrane element including a hollow fiber membrane bundle in which a plurality of hollow fiber membranes are bundled in a sheet shape and a header provided at an end of the hollow fiber membrane bundle may be used. In the header, a water collecting portion is formed in which permeated water (treated water) that has passed through the hollow fiber membrane bundle is collected.

In each of the above-described embodiments, the membrane separation device 27 is arranged in the membrane separation tank 11, and the membrane filling unit 28 is configured in addition to the membrane separation device 27 that can perform the membrane separation process by itself. A plurality of slits and the like for fixing the flat membrane element 30 are formed on the inner surfaces of the

partition walls

3 and 4, and the flat membrane element 30 is fixed to the

partition walls

3 and 4 to constitute the membrane separation device 27. You may do.

Claims

A treatment device for treating organic wastewater in activated sludge,
The inside of the treatment tank is partitioned by a partition member into a membrane separation zone, first and second anoxic zones, and first and second aerobic zones,
The membrane separation area and the first oxygen-free area communicate at the top,
The membrane separation zone and the second oxygen-free zone communicate at the top,
The membrane separation area and the first aerobic area communicate with each other at the bottom,
The membrane separation area and the second aerobic area communicate at the bottom,
The first anoxic zone and the first aerobic zone communicate with each other;
The second anoxic zone and the first aerobic zone communicate with each other;
The first anaerobic zone and the second aerobic zone communicate with each other;
The second anoxic zone and the second aerobic zone communicated,
In the membrane separation area, a membrane separation device immersed in activated sludge and equipped with an air diffuser at the bottom is arranged,
The activated sludge that has passed through the membrane separator as an upward flow due to the air diffused from the air diffuser branches in a direction away from the membrane separation zone and flows into the first and second oxygen-free zones,
Part of the activated sludge that has passed through the first oxygen-free zone and part of the activated sludge that has passed through the second oxygen-free zone flow into the first aerobic zone,
The remaining activated sludge that has passed through the first oxygen-free zone and the remaining activated sludge that has passed through the second oxygen-free zone flow into the second aerobic zone,
An organic wastewater treatment apparatus, wherein activated sludge in a first aerobic zone and activated sludge in a second aerobic zone flow into a membrane separation zone.
The membrane separation device has a plurality of flat membrane elements arranged at predetermined intervals in a vertical posture above the air diffuser,
The first and second anoxic zones are arranged such that the activated sludge branches off from the membrane separation zone and flows in a direction perpendicular to the arrangement direction of the flat membrane elements,
2. The organic waste water treatment apparatus according to claim 1, wherein the first and second aerobic zones are arranged such that activated sludge flows into the membrane separation zone along the arrangement direction of the flat membrane elements.
3. The organic waste water treatment apparatus according to claim 1, wherein a raw water supply path for supplying organic waste water to the first and second anoxic zones is connected.
A treatment device for treating organic wastewater in activated sludge,
The inside of the treatment tank is divided into a membrane separation area, first and second oxygen-free areas, and an aerobic area by a partition member,
The membrane separation area and the first oxygen-free area communicate at the top,
The membrane separation zone and the second oxygen-free zone communicate at the top,
The membrane separation area and the aerobic area communicate with each other at the bottom.
The first anoxic zone and the aerobic zone communicate
The second anoxic zone and the aerobic zone communicated,
In the membrane separation area, a membrane separation device immersed in activated sludge and equipped with an air diffuser at the bottom is arranged,
The activated sludge that has passed through the membrane separator as an upward flow due to the air diffused from the air diffuser branches in a direction away from the membrane separation zone and flows into the first and second oxygen-free zones,
The activated sludge that has passed through the first oxygen-free zone and the activated sludge that has passed through the second oxygen-free zone flow into the aerobic zone,
An organic wastewater treatment device characterized in that activated sludge in an aerobic zone flows into a membrane separation zone.
A treatment device for treating organic wastewater in activated sludge,
The inside of the treatment tank is partitioned by a partition member into a membrane separation zone, first and second anoxic zones, and first and second aerobic zones,
The membrane separation area and the first oxygen-free area communicate at the top,
The membrane separation zone and the second oxygen-free zone communicate at the top,
The membrane separation area and the first aerobic area communicate with each other at the bottom,
The membrane separation zone and the second aerobic zone communicate with each other at the lower part, and the first anoxic zone communicates with the first aerobic zone,
The second anoxic zone and the second aerobic zone communicated,
In the membrane separation area, a membrane separation device immersed in activated sludge and equipped with an air diffuser at the bottom is arranged,
The activated sludge that has passed through the membrane separator as an upward flow due to the air diffused from the air diffuser branches in a direction away from the membrane separation zone and flows into the first and second oxygen-free zones,
The activated sludge that has passed through the first anoxic zone flows into the first aerobic zone,
The activated sludge that has passed through the second anoxic zone flows into the second aerobic zone,
An organic wastewater treatment apparatus, wherein activated sludge in a first aerobic zone and activated sludge in a second aerobic zone flow into a membrane separation zone.
The organic separator according to claim 4 or 5, wherein the membrane separation device has a plurality of flat membrane elements arranged at predetermined intervals in a vertical posture above the air diffuser. Wastewater treatment equipment.
An organic wastewater treatment method for treating organic wastewater in activated sludge using a treatment apparatus in which a treatment tank is partitioned into a membrane separation zone, a first and second anoxic zone, and an aerobic zone,
While taking out treated water from a submerged membrane separator placed in the membrane separation area,
The activated sludge that has passed through the inside of the membrane separator due to the air diffused from the air diffuser provided at the lower part of the membrane separator is branched into one and the other treatment path, and flows.
Activated sludge flowing through one treatment path passes through the first oxygen-free zone and is supplied to the aerobic zone,
The activated sludge flowing through the other treatment path passes through the second anoxic zone and is supplied to the aerobic zone,
An organic wastewater treatment method characterized by introducing activated sludge from one treatment path and activated sludge from the other treatment path that have joined together in an aerobic area into a membrane separation area.
The aerobic zone is separated into a first aerobic zone and a second aerobic zone,
The activated sludge flowing through one of the treatment paths branches to the first branch path and the second branch path when passing through the first oxygen-free zone, and is supplied to the first aerobic zone and the second aerobic zone. ,
The activated sludge flowing through the other treatment path branches to the third branch path and the fourth branch path when passing through the second oxygen-free zone, and is supplied to the first aerobic zone and the second aerobic zone. ,
Activated sludge from the first branch path and activated sludge from the third branch path are merged in the first aerobic zone and introduced into the membrane separation zone, and from the activated sludge from the second branch path and the fourth branch path The organic sludge treatment method according to claim 7, wherein the activated sludge is combined in the second aerobic zone and introduced into the membrane separation zone.
Organic wastewater treatment in which organic wastewater is treated in activated sludge using a treatment device in which the treatment tank is partitioned into a membrane separation zone, first and second anoxic zones, and first and second aerobic zones A method,
While taking out treated water from a submerged membrane separator placed in the membrane separation area,
The activated sludge that has passed through the inside of the membrane separator due to the air diffused from the air diffuser provided at the lower part of the membrane separator is branched into one and the other treatment path, and flows.
Activated sludge flowing through one treatment path is introduced into the membrane separation zone through the first anoxic zone and the first aerobic zone,
Activated sludge flowing through the other treatment path is introduced into the membrane separation zone through the second anoxic zone and the second aerobic zone,
The activated sludge introduced from one treatment path and the activated sludge introduced from the other treatment path are merged in the membrane separation section, and passed through the membrane separation apparatus in an upward flow by the diffused air from the diffuser. An organic wastewater treatment method characterized by that.
The direction in which the activated sludge that has passed through the membrane separator in an upward flow branches into one and the other treatment path is the branch direction,
The direction in which the activated sludge in the first aerobic zone is introduced into the membrane separation zone is the first introduction direction,
When the direction in which the activated sludge in the second aerobic zone is introduced into the membrane separation zone is the second introduction direction,
Making the branch direction and the first introduction direction orthogonal, and making the branch direction and the second introduction direction orthogonal,
The organic wastewater treatment method according to claim 8 or 9, wherein the first introduction direction and the second introduction direction are made to approach each other.
The organic wastewater treatment method according to any one of claims 7 to 10, wherein the organic wastewater is supplied to one and the other treatment paths.