JP6108536B2 - Wastewater treatment equipment - Google Patents

Description

  The present invention relates to a technology of a wastewater treatment device, and more particularly to a wastewater treatment device for treating vehicle car wash wastewater.

  2. Description of the Related Art Conventionally, a wastewater treatment apparatus that performs a membrane separation process by a membrane filtering action is known. The waste water treatment apparatus suctions and filters the waste water supplied to a membrane separation tank in which an immersion flat membrane and a hollow fiber membrane (hereinafter simply referred to as “filtration membrane”) are arranged. The waste water treatment apparatus is provided with an aeration means for cleaning the surface of the filtration membrane in order to prevent clogging of the filtration membrane due to filtration. In such wastewater treatment equipment, sludge settled in the membrane separation tank is returned to the biological treatment tank in order to maintain the filtration function of the filtration membrane for a long period of time, and clogging of the filtration membrane due to adhesion of sludge is reduced. It has been known. For example, as in Patent Document 1.

  The waste water treatment apparatus described in Patent Document 1 can clean the surface of the filtration membrane by aeration means during operation. However, in order to clean the inside of the filtration membrane, it is necessary to inject a cleaning agent into the filtration membrane, so the operation of the waste water treatment apparatus must be stopped. For this reason, in a wastewater treatment apparatus installed in a facility that needs to be operated 24 hours a day, for example, a car wash station of a train car, the filtration membrane cannot be properly maintained and the filtration function of the filtration membrane There was a problem that decreased.

JP 2008-264772 A

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a wastewater treatment apparatus capable of maintaining a filtration membrane without stopping wastewater treatment.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

In claim 1, in the wastewater treatment apparatus that sucks and filters the wastewater through the immersion flat membrane or the hollow fiber membrane and coagulates and precipitates the suspended solids, the immersion flat membrane or the hollow fiber membrane is disposed and the wastewater is supplied. Supplying wastewater to a membrane separation tank equipped with a plurality of membrane separation tanks and when the suction pressure of any of the immersion type flat membranes or hollow fiber membranes exceeds a reference value And the suction of the waste water is stopped, the cleaning agent is supplied to the membrane separation tank to wash the immersion type flat membrane or the hollow fiber membrane from the inside , and the immersion type flat type whose suction pressure is less than the reference value. While increasing the amount of drainage supplied to the membrane separation tank in which the membrane or the hollow fiber membrane is disposed, the suction pressure of the submerged flat membrane or the hollow fiber membrane whose suction pressure is less than the reference value is increased.

In Claim 2, when the discharged | emitted waste water amount reduces from reference | standard amount, supply of waste water will be stopped in an order from the said membrane separation tank in which the said suction | inhalation type flat membrane or the said hollow fiber membrane with the said high suction pressure is arrange | positioned. The suction of drainage is stopped and the cleaning agent is supplied to the membrane separation tank to wash the submerged flat membrane or hollow fiber membrane from the inside. The supply of waste water is started in order from the membrane separation tank in which the submerged flat membrane or the hollow fiber membrane is disposed , and the suction of the waste water is started .

  According to a third aspect of the present invention, a concentration tank to which the filtration residue of the membrane separation tank is supplied is provided, and a plurality of membrane separation tanks are arranged adjacent to the concentration tank.

  According to a fourth aspect of the present invention, the waste water supply state and the suction pressure can be remotely monitored.

  As effects of the present invention, the following effects can be obtained.

  In this invention, the fall of the waste-water treatment amount by having stopped supply of the waste_water | drain to the membrane separation tank in which the filtration performance of the filtration membrane fell is suppressed. Thereby, the maintenance of the filtration membrane can be performed without stopping the wastewater treatment.

  In the present invention, the frequency of use of a filtration membrane with reduced filtration performance is reduced, and the opportunity for maintenance increases. Thereby, the maintenance of the filtration membrane can be performed without stopping the wastewater treatment.

  In the present invention, each membrane separation tank is treated with waste water under the same conditions, so that there is little difference in the state of the filtration membrane and management becomes easy. Thereby, the maintenance of the filtration membrane can be performed without stopping the wastewater treatment.

  In the present invention, the state of the waste water treatment apparatus can be easily monitored. Thereby, the maintenance of the filtration membrane can be performed without stopping the wastewater treatment.

The block diagram which showed the whole structure of the waste water treatment equipment which concerns on one Embodiment of this invention. The block diagram which showed the structure of control of the waste water treatment equipment which concerns on one Embodiment of this invention. The figure which showed the flowchart showing the aspect of supply control of the waste_water | drain of the waste water treatment apparatus which concerns on one Embodiment of this invention. The figure which showed the flowchart showing the aspect of the washing | cleaning control of the waste water treatment equipment which concerns on one Embodiment of this invention.

  Next, the waste water treatment apparatus 1 which is one Embodiment of this invention is demonstrated using FIG.

  As shown in FIG. 1, the waste water treatment apparatus 1 is an apparatus for treating waste water containing a surfactant. The waste water treatment apparatus 1 includes a reaction tank 4, a first membrane separation tank 7, a second membrane separation tank 14, a concentration tank 22, a control device 30, and the like. In the present embodiment, two membrane separation tanks are provided. However, the present invention is not limited to this.

  The reaction tank 4 mixes waste water and a flocculant. The reaction tank 4 is disposed above the first membrane separation tank 7 and the second membrane separation tank 14. The reaction tank 4 includes a stirrer 4a that mixes the waste water and the flocculant. The reaction tank 4 is connected to a drain tank 2 in which drainage is stored through a pipe 26a. The drainage tank 2 is provided with a drainage tank water level sensor 2a for detecting the level of drainage (see FIG. 2). A supply pump 3 for supplying the wastewater stored in the drainage tank 2 to the reaction tank 4 is connected to the pipe 26a. Further, the flocculant tank 5 in which the flocculant to be thrown into the wastewater is stored is connected to the pipe 26a. Thereby, the reaction tank 4 is comprised so that the waste_water | drain with which the coagulant | flocculant was supplied is supplied.

  The first membrane separation tank 7 separates suspended substances from the waste water. The first membrane separation tank 7 has a first filtration membrane unit 8 disposed therein. The first membrane separation tank 7 is connected to the reaction tank 4 via a pipe 26b. The 1st membrane separation tank 7 is comprised so that waste_water | drain may be supplied from the reaction tank 4 arrange | positioned upwards by gravity fall. A first flow rate control valve 9 that controls the flow rate of drainage is connected to the pipe 26b. Inside the first membrane separation tank 7, a first water level sensor 7a for detecting the water level of the waste water is provided (see FIG. 2). The 1st membrane separation tank 7 is provided with the 1st sludge pump 10 which attracts | sucks the filtration residual liquid containing sludge in the lower part.

  The 1st filtration membrane unit 8 filters waste water. The first filtration membrane unit 8 is configured such that a plurality of filtration membranes 13, 13, 13. The filtration membrane 13 is a submerged flat membrane immersed in waste water, and is a microfiltration membrane composed of hollow fibers having a large number of fine predetermined pore diameters. In the first filtration membrane unit 8, each filtration membrane 13 is connected to a pipe 26c. The first suction pump 12 is connected to the pipe 26c through the first suction valve 11. Thereby, the 1st filtration membrane unit 8 is comprised so that the surrounding waste_water | drain may be attracted | sucked by the suction effect | action of the 1st suction pump 12, and may be filtered with the filtration membrane 13. FIG. The piping 26c is provided with a first suction pressure sensor 12a that detects the suction pressure of the first suction pump 12 (see FIG. 2). The waste water sucked by the first suction pump 12 is configured to be discharged to a treated water tank (not shown) as treated water.

  Similarly, the second membrane separation tank 14 separates sludge and the like from waste water. The second membrane separation tank 14 has a second filtration membrane unit 15 disposed therein. The second membrane separation tank 14 is connected to the reaction tank 4 via a pipe 26b. The 2nd membrane separation tank 14 is comprised so that waste_water | drain may be supplied from the reaction tank 4 arrange | positioned upwards by gravity fall. A second flow rate control valve 16 that controls the flow rate of drainage is connected to the pipe 26b. Inside the second membrane separation tank 14, a second water level sensor 14a for detecting the water level of the waste water is provided (see FIG. 2). The 2nd membrane separation tank 14 is provided with the 2nd sludge pump 17 which attracts | sucks the filtration residual liquid containing sludge in the lower part.

  In the second filtration membrane unit 15, each filtration membrane 13 is connected to a pipe 26d. A second suction pump 19 is connected to the pipe 26d through a second suction valve 18. Accordingly, the second filtration membrane unit 15 is configured to suck the surrounding waste water by the suction action of the second suction pump 19 and to filter it with the filtration membrane 13. The pipe 26d is provided with a second suction pressure sensor 19a that detects the suction pressure of the second suction pump 19 (see FIG. 2). The waste water sucked by the second suction pump 19 is configured to be discharged into the treated water tank as treated water.

  The filtration membrane units 8 and 15 are equipped with aeration means. The aeration means generates air bubbles below the filtration membrane units 8 and 15. The aeration means is configured to supply air from below the filtration membrane 13 by the blower 13a. Thereby, an aeration means supplies air to an aerobic microorganism and activates the activity of an aerobic microorganism. Moreover, the deposit | attachment on the surface of the filtration membrane 13 is removed.

  The filtration membrane units 8 and 15 are connected to the cleaning agent tank 6 via a pipe 26e. The cleaning agent tank 6 stores a cleaning agent for cleaning the filtration membrane 13 from the inside of the filtration membrane 13. The first cleaning valve 20 and the second cleaning valve 21 are connected to the pipe 26e. Accordingly, the filtration membrane units 8 and 15 are configured such that the cleaning agent from the cleaning agent tank 6 is supplied to the inside of the filtration membrane 13 by opening and closing the first cleaning valve 20 and the second cleaning valve 21. .

  The concentration tank 22 precipitates and concentrates sludge and the like contained in the filtration residual liquid. The concentration tank 22 is disposed adjacent to the first membrane separation tank 7 and the second membrane separation tank 14. Specifically, the concentration tank 22 is disposed between the first membrane separation tank 7 and the second membrane separation tank 14. At this time, the concentration tank 22 is disposed so that the distance from the first membrane separation tank 7 and the distance from the second membrane separation tank 14 are substantially the same. That is, in the waste water treatment apparatus 1, the first membrane separation tank 7 and the second membrane separation tank 14 are arranged so as to be symmetrical with respect to the concentration tank 22.

  The concentration tank 22 is connected to the first sludge pump 10 of the first membrane separation tank 7 through a pipe 26f. Similarly, the concentration tank 22 is connected to the second sludge pump 17 of the second membrane separation tank 14 through a pipe 26g. The pipe 26 f and the pipe 26 g are connected to the upper part of the concentration tank 22. Thereby, the concentration tank 22 has the filtration residue of the first membrane separation tank 7 sucked by the first sludge pump 10 from above and the filtration residue of the second membrane separation tank 14 sucked by the second sludge pump 17. It is comprised so that a liquid may be supplied. A pipe member 22 a formed so as to increase in diameter toward the bottom of the concentration tank 22 is provided in a hole of the concentration tank 22 to which the pipe 26 f and the pipe 26 g are connected. Thereby, as for the concentration tank 22, the waste_water | drain supplied from the piping 26f and the piping 26g is mixed by the stirring effect | action of the pipe member 22a.

  Furthermore, the upper part of the concentration tank 22 is connected to the first membrane separation tank 7 via a pipe 26h. A first return valve 23 is provided in the pipe 26h. A partition member 22b is provided in an inner portion of the concentration tank 22 to which the pipe 26h of the concentration tank 22 is connected. The partition member 22b is formed in a box shape having an open upper surface, and is disposed so as to surround the hole of the concentration tank 22 to which the pipe 26h is connected. Thereby, only the drainage of the water level higher than the partition member 22b flows into the piping 26h. That is, the concentration tank 22 is configured such that only the supernatant portion of the waste water in which sludge or the like is precipitated is supplied to the first membrane separation tank 7. Similarly, the upper part of the concentration tank 22 is connected to the second membrane separation tank 14 via the pipe 26i. A second return valve 24 is provided in the pipe 26i. A partition member 22b is provided in an inner portion of the concentration tank 22 to which the pipe 26i of the concentration tank 22 is connected.

  The concentration tank 22 is formed in a mortar shape at the bottom. That is, the concentration tank 22 is configured to accumulate in the lowest part of the bottom formed in a mortar shape when sludge or the like in the drainage settles. The concentration tank 22 has a pipe 26 j connected to the lowest part via a concentration tank discharge valve 25. The pipe 26j is connected to a sludge dewatering machine (not shown). Thereby, the concentration tank 22 is configured such that the sludge and the like accumulated at the bottom is supplied to the sludge dewatering machine through the pipe 26j.

  As shown in FIG. 2, the control device 30 controls various on-off valves and various pumps. The control device 30 stores various programs and data for controlling various on-off valves and various pumps. The control device 30 may be configured such that a CPU, a ROM, a RAM, an HDD, and the like are connected by a bus, or may be configured by a one-chip LSI or the like.

  The control device 30 is connected to the drainage tank water level sensor 2a and can acquire the water level of the drainage tank 2 detected by the drainage tank water level sensor 2a.

  The control device 30 is connected to the supply pump 3 and can control the operation of the supply pump 3.

  The control device 30 is connected to the first flow rate control valve 9 and the second flow rate control valve 16, and can control the opening degrees of the first flow rate control valve 9 and the second flow rate control valve 16.

  The control device 30 is connected to the first water level sensor 7a and the second water level sensor 14a, and the first membrane separation tank 7 and the second membrane separation tank 14 detected by the first water level sensor 7a and the second water level sensor 14a. It is possible to acquire the water level L1 and the water level L2.

  The control device 30 is connected to the first sludge pump 10 and the second sludge pump 17 and can control the operation of the first sludge pump 10 and the second sludge pump 17.

  The control device 30 is connected to the first suction valve 11 and the second suction valve 18 and can control opening and closing of the first suction valve 11 and the second suction valve 18.

  The control device 30 is connected to the first suction pump 12 and the second suction pump 19, and can control the operation of the first suction pump 12 and the second suction pump 19.

  The control device 30 is connected to the first suction pressure sensor 12a and the second suction pressure sensor 19a, and the first membrane separation tank 7 and the second membrane detected by the first suction pressure sensor 12a and the second suction pressure sensor 19a. The suction pressure P1 and the suction pressure P2 with the separation tank 14 can be acquired.

  The control device 30 is connected to the first cleaning valve 20 and the second cleaning valve 21 and can control the opening and closing of the first cleaning valve 20 and the second cleaning valve 21.

  The control device 30 is connected to the first return valve 23 and the second return valve 24 and can control the opening and closing of the first return valve 23 and the second return valve 24.

  The control device 30 is connected to the concentration tank discharge valve 25 and can control the opening and closing of the concentration tank discharge valve 25.

  In the wastewater treatment apparatus 1 configured as described above, the control device 30 controls the operation of the supply pump 3 to supply the wastewater from the drainage tank 2 to the reaction tank 4 through the pipe 26a. The control device 30 throws a flocculant (for example, polyaluminum chloride) into the drainage in the middle of the pipe 26a. The drainage and the flocculant are mixed while passing through the pipe 26a. When the waste water and the flocculant are supplied to the reaction tank 4, they are further mixed by the stirrer 4 a of the reaction tank 4.

  The control device 30 controls the opening degree of the first flow rate control valve 9 and the second flow rate control valve 16 and supplies the wastewater to the first membrane separation tank 7 and the second membrane separation tank 14 approximately equally through the pipe 26b. To do. In the wastewater supplied to the first membrane separation tank 7 and the second membrane separation tank 14, suspended substances such as sludge are aggregated by the coagulant.

  When the water level L1 of the first membrane separation tank 7 and the water level L2 of the second membrane separation tank 14 acquired by the first water level sensor 7a and the second water level sensor 14a reach the predetermined values, the control device 30 performs the first suction. The operation of the pump 12 and the second suction pump 19 is controlled to start the suction of the first filtration membrane unit 8 and the second filtration membrane unit 15. The wastewater stored in the first membrane separation tank 7 and the second membrane separation tank 14 is suction filtered by the first filtration membrane unit 8 and the second filtration membrane unit 15 and is discharged to a treated water tank (not shown).

  The control device 30 controls the first sludge discharge valve and the second sludge discharge valve to be in an open state after a predetermined time has elapsed from the start of the supply pump 3. And the control apparatus 30 controlled the operation | movement with the 1st sludge pump 10 and the 2nd sludge pump 17, and contained the sludge which has accumulated in the bottom part of the 1st membrane separation tank 7 and the 2nd membrane separation tank 14. The excess liquid is supplied to the concentration tank 22.

  The control device 30 controls the first return valve 23 and the second return valve 24 to be in the open state, and returns the supernatant portion of the waste water in which sludge has settled to the first membrane separation tank 7 and the second membrane separation tank 14. Then suction filter again. The sludge and the like of the filtration residual liquid supplied to the concentration tank 22 is precipitated at the bottom of the concentration tank 22. The control device 30 controls the concentration tank discharge valve 25 to be in an open state after a predetermined time has elapsed. The concentrated sludge and the like are supplied to a sludge dewatering machine (not shown).

  As described above, the waste water treatment apparatus 1 includes the first membrane separation tank 7 and the second membrane separation tank 14 which are independent from each other, thereby independently controlling the first filtration membrane unit 8 and the second filtration membrane unit 15. Can do. That is, it is possible to perform maintenance of the first filtration membrane unit 8 or the second filtration membrane unit 15 without stopping the waste water treatment apparatus 1.

  Below, the aspect of the water supply control of the waste_water | drain of the waste water treatment equipment 1 which concerns on one Embodiment of this invention is demonstrated.

  When the suction pressure P1 detected by the first suction pressure sensor 12a or the suction pressure P2 detected by the second suction pressure sensor 19a becomes larger than the reference pressure P0, the control device 30 is larger than the reference pressure P0 (hereinafter, simply referred to as “push pressure P1”). Stop the supply of wastewater to the filtration membrane unit. And the control apparatus 30 supplies the washing | cleaning agent to the filtration membrane unit, and wash | cleans the filtration membrane 13 from the inside of the filtration membrane 13. FIG. Further, the control device 30 has the suction pressure P1 detected by the first suction pressure sensor 12a or the suction pressure P2 detected by the second suction pressure sensor 19a, which is smaller than the reference pressure P0 (hereinafter simply referred to as “the other”). ) Increase the supply of wastewater to the filtration membrane unit.

  Next, the aspect of the cleaning control of the waste water treatment apparatus 1 will be specifically described with reference to FIGS. 3 and 4.

  As shown in FIG. 3, in step S110, the control device 30 acquires the drainage tank water level L detected by the drainage tank water level sensor 2a, and shifts the step to step S120.

  In step S120, the control device 30 acquires the suction pressure P1 detected by the first suction pressure sensor 12a and the suction pressure P2 detected by the second suction pressure sensor 19a, and moves the step to step S120.

  In step S130, the control device 30 determines whether or not the suction pressure P1 is greater than the suction pressure P2. As a result, when it is determined that the suction pressure P1 is greater than the suction pressure P2, the control device 30 shifts the step to step S140. On the other hand, when it determines with the suction pressure P1 not being larger than the suction pressure P2, the control apparatus 30 makes a step transfer to step S240.

  In step S140, the control device 30 determines whether or not the suction pressure P1 is smaller than the reference pressure P0. As a result, when it is determined that the suction pressure P1 is smaller than the reference pressure P0, the control device 30 shifts the step to step S150. On the other hand, when it is determined that the suction pressure P1 is not smaller than the reference pressure P0, that is, when it is determined that the suction pressure P1 is equal to or higher than the reference pressure P0, the control device 30 shifts the step to step S300.

  In step S150, the control device 30 determines whether or not the drain tank water level L is smaller than the lower limit water level L0. As a result, when it is determined that the drainage tank water level L is smaller than the lower limit water level L0, the control device 30 shifts the step to step S160. On the other hand, when it determines with the drain tank water level L not being smaller than the minimum water level L0, the control apparatus 30 opens the 1st flow control valve 9, and returns a step to step S110.

  In step S160, the control device 30 closes the first flow control valve 9 and returns the step to step S110.

  In step S240, the control device 30 determines whether or not the suction pressure P2 is smaller than the reference pressure P0. As a result, when it is determined that the suction pressure P2 is smaller than the reference pressure P0, the control device 30 shifts the step to step S250. On the other hand, when it is determined that the suction pressure P2 is not smaller than the reference pressure P0, that is, when it is determined that the suction pressure P2 is equal to or higher than the reference pressure P0, the control device 30 shifts the step to step S500.

  In step S250, the control device 30 determines whether or not the drain tank water level L is smaller than the lower limit water level L0. As a result, when it determines with the drainage tank water level L being smaller than the minimum water level L0, the control apparatus 30 makes a step transfer to step S260. On the other hand, when it determines with the drain tank water level L not being smaller than the minimum water level L0, the control apparatus 30 opens the 2nd flow control valve 16, and returns a step to step S110.

  In step S260, the control device 30 closes the second flow rate control valve 16, and returns the step to step S110.

  In step S300 in which the first membrane separation tank 7 is used as one membrane separation tank and in step S500 in which the second membrane separation tank 14 is used as one membrane separation tank, the control device 30 starts the cleaning control A, and performs the steps. The process proceeds to step S310 (see FIG. 4).

  As shown in FIG. 4, in step S310, the control device 30 closes the flow control valve and the return valve that are larger (one) than the reference pressure P0 among the suction pressure P1 and the suction pressure P2, and The step moves to step S320.

  In step S320, the control device 30 stops one suction pump, closes one suction valve, and shifts the step to step S330.

  In step S330, the control device 30 increases the opening degree of the flow rate control valve of the suction pressure P1 or the suction pressure P2 that is smaller than the reference pressure P0 (the other), and moves the step to step S340.

  In step S340, the control device 30 controls to increase the suction pressure of the other suction pump, and shifts the step to step S350.

  In step S350, control device 30 opens one of the cleaning valves, and shifts the step to step S360.

  In step S360, after a predetermined time has elapsed, control device 30 closes one of the cleaning valves and shifts the step to step S370.

  In step S370, the control device 30 opens one flow control valve and one return valve, and shifts the step to step S380.

  In step S380, control device 30 opens one of the suction valves, starts one of the suction pumps, and shifts the step to step S390.

  In step S390, control device 30 decreases the opening of the other flow control valve, and shifts the step to step S400.

  In step S400, the control device 30 performs control so as to reduce the suction pressure of the other suction pump, ends the cleaning control A, and returns the step to step S110 (see FIG. 3).

  By controlling in this way, the waste water treatment apparatus 1 can detect one filtration membrane unit that needs to be washed and can wash the filtration membrane unit. Furthermore, the wastewater treatment apparatus 1 can wash one filtration membrane unit while maintaining the wastewater treatment capacity by increasing the supply of wastewater to the other filtration membrane unit that does not require washing. is there. Moreover, when the discharged | emitted waste water amount falls, the waste water treatment apparatus 1 is used so that the stain | pollution | contamination of several filtration membrane units may become substantially uniform by performing filtration of waste_water | drain using the filtration membrane unit with few stain | pollution | contamination. It is possible.

  The control device 30 according to the present embodiment can be configured to be able to transmit the state of the wastewater treatment device 1 to a server 27 or the like installed at a location separated from the wastewater control device 30 through a wired or wireless communication line. . Specifically, the control device 30 can transmit the supply amount of waste water and the suction pressures P1 and P2 to the server 27 and the like. By configuring in this way, the administrator can easily monitor the state of the wastewater treatment apparatus 1 at a location separated from the wastewater treatment apparatus 1.

  As described above, in the wastewater treatment apparatus 1 according to the present invention, a reduction in the wastewater treatment amount due to the supply of wastewater to the membrane separation tank in which the filtration performance of the filtration membrane 13 has been reduced is suppressed. In addition, the frequency of use of the filtration membrane 13 with reduced filtration performance is reduced, and the opportunity for maintenance increases. Moreover, since each membrane separation tank performs the waste water treatment under the same conditions, there is little difference in the state of the filtration membrane 13, and management is facilitated. Moreover, the state of the waste water treatment apparatus 1 can be easily monitored. Thereby, the maintenance of the filtration membrane 13 becomes possible, without stopping the process of waste_water | drain.

DESCRIPTION OF SYMBOLS 1 Waste water treatment device 7 1st membrane separation tank 13 Filtration membrane 14 2nd membrane separation tank P1 Suction pressure P2 Suction pressure P0 Reference value

Claims (4)

In a wastewater treatment device that sucks and filters wastewater through a flat immersion membrane or hollow fiber membrane, and agglomerates and settles suspended solids,
A submerged flat membrane or a hollow fiber membrane is disposed, and includes a plurality of membrane separation tanks to which drainage is supplied,
If the suction pressure of any submerged flat membrane or hollow fiber membrane exceeds the reference value, supply of wastewater to the membrane separation tank where the submerged flat membrane or hollow fiber membrane is placed is stopped, and the suction of wastewater is stopped. While stopping, supplying a cleaning agent to the membrane separation tank, washing the submerged flat membrane or hollow fiber membrane from the inside,
While increasing the amount of drainage to be supplied to the membrane separation tank where the suction pressure is less than the reference value or the membrane separation tank in which the hollow fiber membrane is arranged, suction of the immersion type flat membrane or the hollow fiber membrane whose suction pressure is less than the reference value Wastewater treatment equipment that increases pressure. When the amount of discharged waste water is reduced below a reference amount, the supply of waste water is stopped in order from the membrane separation tank in which the submerged flat membrane or the hollow fiber membrane having the high suction pressure is arranged, and the suction of waste water is stopped. And supplying a cleaning agent to the membrane separation tank to wash the submerged flat membrane or hollow fiber membrane from the inside,
When the discharged amount of discharged water increases from the reference amount, the supply of waste water is started in order from the membrane separation tank in which the submerged flat membrane or the hollow fiber membrane having a low suction pressure is arranged , and the suction of the waste water is started. The waste water treatment apparatus as described in.   The wastewater treatment apparatus according to claim 1, further comprising a concentration tank to which the filtration residue of the membrane separation tank is supplied, wherein the plurality of membrane separation tanks are arranged adjacent to the concentration tank.   The wastewater treatment apparatus according to any one of claims 1 to 3, wherein the wastewater supply state and the suction pressure are configured to be remotely monitored.

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