JPH11267680A - Sewage treatment equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To always maintain the sludge concentration within a certain level to stabilize biological treatment and protect a membrane. SOLUTION: A contaminant removal tank 5 into which sewage flows from outside.
And a sewage treatment tank 1 for aerating the sewage supplied from the impurity removing tank 5. A membrane treatment device 2 is provided in a sewage treatment tank 1, and an air diffuser 3 for supplying air to the membrane treatment device 2 is disposed below the membrane treatment device 2 in the sewage treatment tank 1. A return pipe 20 provided with a return pump 21 for returning sludge in the membrane treatment tank 1 to the impurity removing tank 5 is provided. A control unit (15) is provided which controls the return pump (21) for a predetermined time for each predetermined amount of treated water in the sewage treatment tank (1) to return sludge in the sewage treatment tank (1) to the impurity removing tank (5).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sewage purification apparatus.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, a sewage treatment tank 1 is provided with a membrane treatment apparatus 2 provided with a treatment membrane 2a such as a hollow fiber membrane. A diffuser pipe 3 for supplying air to the membrane processing apparatus 2 is disposed, and aeration is performed by supplying air from the diffuser pipe 3 to the membrane processing apparatus 2 to perform aeration processing. A sewage treatment apparatus in which the supply is stopped to perform an anaerobic treatment in an anaerobic state, the aeration treatment and the anaerobic treatment are alternately repeated to perform the sewage treatment, and the treated water is discharged through the treatment membrane 2a. It has been known.

However, in the above-described conventional example, the sludge concentration in the sewage treatment tank 1 gradually increases, and it is difficult to maintain the sludge concentration in the sewage treatment tank at a certain level. In addition, there is a problem in protection of the treated film. Conventionally, the sludge concentration in the sewage treatment tank 1 is adjusted, for example, every six months, and the sludge in the sewage treatment tank 1 is drawn out.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and keeps the sludge concentration within a certain level at all times to stabilize biological treatment and protect the membrane. It is an object of the present invention to provide a sewage purification device capable of performing the above.

[0005]

In order to solve the above-mentioned problems and achieve the object of the present invention, a sewage purification apparatus of the present invention comprises:
In a sewage treatment apparatus provided with a dirt removal tank 5 into which sewage flows in from outside and a sewage treatment tank 1 for aerating the sewage supplied from the dirt removal tank 5, membrane treatment is performed in the sewage treatment tank 1. The apparatus 2 is provided, and the membrane treatment apparatus 2 in the sewage treatment tank 1 is provided.
An air diffuser 3 for supplying air to the membrane processing apparatus 2 is disposed below, and a return pipe 20 provided with a return pump 21 for returning sludge in the membrane processing tank 1 to the impurity removing tank 5 is provided. ,
Return pump 2 for each predetermined amount of treated water in sewage treatment tank 1
1 is operated for a predetermined time, and a control unit 15 for controlling the sludge in the sewage treatment tank 1 to be returned to the impurity removing tank 5 is provided. With such a configuration, the sludge concentration in the sewage treatment tank 1 can be kept constant.

Further, it is preferable that the aeration process and the anaerobic process are controlled alternately in the sewage treatment tank 1, and the number of the aeration process or the anaerobic process is counted to convert the amount of the treated water. With such a configuration, the amount of treated water can be easily converted. Further, a transfer pipe 10 provided with a transfer pump 11 for supplying sewage in the impurity removing tank 5 to the sewage treatment tank 1 is provided, and treated water treated by the membrane treatment device 2 provided in the sewage treatment tank 1 is provided. An outflow pipe provided with a suction pump 16 for outflow is provided, and an upper limit water level detection sensor for detecting an upper limit water level and a lower limit water level sensor 23 for detecting a lower limit water level are provided in the sewage treatment tank 1. The operation of the suction pump 16 is started by detecting the water level, the operation of the suction pump 16 is stopped by detecting the lower limit water level by the lower limit water level sensor 23, and the lower limit water level is detected by the lower limit water level sensor 23. The operation is started and the upper limit water level is detected by the upper limit water level sensor 22 to control the operation of the transfer pump 11 to be stopped. It is preferable to be a return pump 21 is provided a control unit 15 which controls to operate a predetermined time. With such a configuration, the amount of treated water required for returning sludge can be obtained with a simple configuration in which the number of times of detection of the upper limit water level by the upper limit water level sensor 22 is counted.

It is preferable that the operation of the return pump 21 is performed during the aeration process in the sewage treatment tank 1. With such a configuration, the sewage treatment tank 1
The sludge can be pulled out and returned in a state where the sludge concentration in the inside is uniform.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments shown in the accompanying drawings. FIG. 1 is a schematic configuration diagram of one embodiment of the sewage purification apparatus of the present invention. The sewage purification device is a foreign matter removal tank 5 into which sewage flows from the outside,
The sewage treatment tank 1 for aerating the sewage supplied from the contaminant removal tank 5 and a disinfection tank 6 from which the treated water treated in the sewage treatment tank 1 is discharged.

In the embodiment shown in FIG. 1, the foreign matter removing tank 5 comprises a primary foreign matter removing tank 5a and a secondary foreign matter removing tank 5b.
A drainage inflow pipe 7 into which wastewater such as domestic wastewater flows is connected to the primary contaminant removal tank 5a. It flows into the impurity removing tank 5a. The primary contaminant removal tank 5a and the secondary contaminant removal tank 5b are each provided with a filter medium 8, and the wastewater flowing into the primary contaminant removal tank 5a from the drainage inflow pipe 7 is removed from the primary contaminant removal tank 5a. Filter media inside 8
Thus, the contaminants are removed, flow through the water passage section 9 to the secondary contaminant removal tank 5b, and the contaminants are removed by the filter medium 8 in the secondary contaminant removal tank 5b.

A transfer pipe 10 is provided between the secondary contaminant removing tank 5b and the sewage treatment tank 1, and a transfer pump 11 provided in the transfer pipe 10 removes sewage from the secondary contaminant removing tank 5b into sewage. It is to be transferred to the processing device 1. A membrane treatment device 2 is disposed in the sewage treatment device 1, and the membrane treatment device 2 is surrounded by a circulation plate 12. The upper end of the membrane treatment device 2 and the upper end of the circulation plate 12 are located below the lowest water level in the sewage treatment device 1, and the lower end of the membrane treatment device 2 and the circulation plate 12 are located at the bottom of the sewage treatment device 1. It is arranged above. A diffuser 3 for supplying air to the membrane treatment device 2 is disposed below the sewage treatment device 1 and below the membrane treatment device 2, and is provided from the air supply device 13 via an air pipe 14. 3 is supplied with air, and the supply of air is controlled by the control unit 15.

Then, the air supplied from the air supply device 13 is discharged from the air diffuser 3 to supply air to the membrane processing device 2 so that the processing film 2a such as a hollow fiber membrane of the membrane processing device 2 is formed.
The sewage is aerated by circulating the sewage to prevent clogging of the sewage. The aeration by the supply of air from the diffuser 3 is performed simultaneously with the operation of the suction pump 16 described later. It is set so that air is supplied from, and enters an anaerobic state when the aeration process is completed.

One end of an outflow pipe 17 is connected to the permeation side of the processing membrane 2 a of the membrane processing apparatus 2, and the other end of the outflow pipe 17 is connected to the disinfection tank 6. The outflow pipe 17 is provided with a suction pump 16 for sucking the treated sewage from the membrane processing apparatus 2 and discharging the same to the disinfection tank 6 via the outflow pipe 17. An external discharge pipe 19 for discharging the sterilized treated water in the disinfection tank 6 to the outside is connected to the disinfection tank 6.

The sewage treatment tank 1 has an upper limit water level A and a lower limit water level B
The upper limit water level sensor 22 for detecting the upper limit water level A and the lower limit water level sensor 23 for detecting the lower limit water level are provided. Upper water level sensor 22, Lower water level sensor 2
The water level information of the sewage treatment tank 1 detected in 3 is input to the control unit 15 to control the operation of the suction pump 16 and the transfer pump 11.

That is, when the water level in the sewage treatment tank 1 reaches the upper limit water level A, the upper limit water level A is detected by the upper limit water level sensor 22, and the operation of the suction pump 16 is started by the signal from the control unit 15, and the lower limit water level B The operation of the suction pump 16 is continued until the lower limit is reached, and when the lower limit water level B is detected by the lower limit water level sensor 23, the operation of the suction pump 16 is controlled by a signal from the control unit 15 to be stopped. By operating the suction pump 4 from the upper limit water level A to the lower limit water level B, the treated water in the sewage treatment tank 1 passes through the treatment membrane 2 a of the membrane treatment device 2 and flows through the outflow pipe 17. It is discharged to the disinfection tank 6. In addition, while the suction pump 16 is operating, the control unit 15 controls so that air is supplied from the air diffuser 3. During this time, aeration treatment is performed in the sewage treatment tank 1. .

On the other hand, the suction pump 16 is controlled so as to start operation at the upper limit water level A and to stop operation at the lower limit water level B.
When the lower limit water level sensor 23 detects this, the operation of the transfer pump 11 is started by a signal from the control unit 15 and the operation of the transfer pump 11 is continued until the water level in the sewage treatment tank 1 reaches the upper limit water level A. Is continued and the upper limit water level sensor 2
When the upper limit water level A is detected by 2, the operation of the transfer pump 11 is controlled to be stopped by a signal from the control unit 15. By operating the transfer pump 11 from the lower limit water level B to the upper limit water level A, the sewage accumulated in the impurity removing tank 5 is supplied into the sewage treatment tank 1. During this time, air is not supplied from the air diffuser 3 and anaerobic treatment is performed in the sewage treatment tank 1.

As described above, the aeration process and the anaerobic process are performed alternately to treat sewage, and the treated water is subjected to membrane treatment by passing through the treatment membrane 2 a of the membrane treatment device 2, and is passed through the outlet pipe 17. It is discharged to the disinfecting tank 6, further disinfected in the disinfecting tank 6, and discharged to the outside from the external discharge pipe 19. Here, in the present invention, as shown in FIG. 1, a return pipe 20 provided with a return pump 21 is disposed so as to extend over the sewage treatment tank 1 and the primary contaminant removal tank 5a. And sewage treatment tank 1
Each time the processing of a predetermined amount of treated water is performed in
5, the return pump 21 is operated for a predetermined time so that the sludge in the sewage treatment tank 1 is returned to the impurity removing tank 5 so that the concentration of the sludge in the sewage treatment tank 1 is kept constant. ing.

Here, in detecting the predetermined amount of sewage treated in the sewage treatment tank 1, for example, at least one of aeration treatment and anaerobic treatment alternately performed in the sewage treatment tank 1 is performed. By counting the number of times of treatment, the amount of sewage treatment can be converted. Therefore, the number of times of at least one of the aeration process and the anaerobic process is counted, and when the predetermined number of times is reached, it is considered that the predetermined amount of sewage treatment water has been reached, and the control unit 15 operates the return pump 21 for a predetermined time. Then, the sludge in the sewage treatment tank 1 is returned to the impurity removing tank 5.

In order to count the number of times of at least one of the aeration process and the anaerobic process, for example,
The upper limit water level sensor 22 counts the number of times of water level detection. When the predetermined number of times is reached, it is considered that a predetermined amount of sewage treatment water has been reached, and the return pump 21 is operated by the control unit 15 for a predetermined time and the sewage treatment tank 1 Is returned to the impurity removing tank 5. In this case, the amount of treated water required for returning the sludge can be obtained with a simple configuration in which the number of times of detection of the upper limit water level by the upper limit water level sensor 22 is counted. That is, FIG. 2 shows an example of a time chart showing the operation times of the aeration process and the anaerobic process, the water level in the sewage treatment tank 1, and the operation of the return pump. In the embodiment shown in FIG. When the anaerobic treatment and one aeration treatment are defined as one cycle, the return pump 21 is turned on for a certain period of time when the upper limit water level A is detected by the upper limit water level sensor 22 in the tenth cycle, and the operation is performed. .

Here, the operation of the return pump 21 is preferably performed during the aeration process. That is, during the aeration process, air is supplied from the air diffuser 3 and the sewage is circulating in the sewage treatment tank 1, so that the sludge concentration in the sewage treatment tank 1 is uniform, so that a uniform concentration of the sludge is obtained. By returning the sewage for a certain period of time, a desired amount of sludge can be pulled out and returned. The operation start time is shown in FIG.
As shown in the above, the time point of the upper limit water level of the sewage treatment tank 1 is preferable. This is to prevent the water level from dropping due to the return and prevent the treatment membrane 2a from being exposed from the sewage, or to prevent sludge from being pulled out due to the water level being too low, or from running out of sludge to be drawn out.

In the present invention, the return pump 2
When the sludge in the sewage treatment tank 1 is returned to the impurity removing tank 5 by operating the tank 1 for a predetermined time, the return amount may be adjusted according to the site. That is, since the amount of sewage, particularly the concentration of sewage, differs in each household, the amount of sewage is adjusted for each site (for example, the operation time of the return pump 21 is adjusted) to make the sludge concentration in the sewage treatment tank 1 uniform. Can be done.

[0021]

According to the first aspect of the present invention, as described above, a membrane treatment device is provided in a sewage treatment tank,
A return pipe provided with a diffuser pipe for supplying air to the membrane treatment apparatus below the membrane treatment apparatus in the sewage treatment tank and a return pump for returning sludge in the membrane treatment tank to the impurity removal tank is provided. A control unit for controlling the return pump to operate for a predetermined time for each predetermined amount of treated water in the sewage treatment tank to return the sludge in the sewage treatment tank to the contaminant removal tank. It can be kept at a certain level at all times, so that the biological treatment can be stabilized and the membrane can be protected.

Further, in the invention according to claim 2, in addition to the effect of the invention described in claim 1, the aeration and anaerobic treatment are controlled to be alternately performed in the sewage treatment tank, and the aeration is performed. Since the number of times of treatment or anaerobic treatment is counted to convert the amount of treated water, the amount of treated water can be easily converted by a simple method of counting the number of times of aeration treatment or anaerobic treatment.

According to the third aspect of the present invention, in addition to the effects of the second aspect, a transfer pump for supplying sewage in the contaminant removal tank to the sewage treatment tank is provided. A transfer pipe is provided, and an outflow pipe provided with a suction pump for flowing out the treated water treated by the membrane treatment device provided in the sewage treatment tank is provided, and an upper limit water level detection sensor for detecting an upper limit water level in the sewage treatment tank, A lower limit water level sensor for detecting the lower limit water level is provided, and the upper limit water level sensor detects the upper limit level to start the operation of the suction pump, and the lower limit level sensor detects the lower limit level to stop the operation of the suction pump, The lower limit water level is detected by the lower limit water level sensor to start the operation of the transfer pump, and the upper limit water level sensor is controlled to detect the upper limit water level to stop the operation of the transfer pump. Since the count to is provided with a control unit for controlling to operate for a predetermined time and return pump a predetermined number of times, those which can be obtained easily treated water by the number of detection of the upper limit water level due to the upper limit level sensor.

According to the fourth aspect of the present invention, in addition to the effects of the first to third aspects, the operation of the return pump is performed during the aeration process in the sewage treatment tank. Therefore, the sludge can be pulled out and returned in a state where the sludge concentration in the sewage treatment tank is made uniform by the aeration circulation, and the amount of sludge drawn out is stabilized.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.

FIG. 2 is a time chart of the present invention.

FIG. 3 is a schematic configuration diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sewage treatment tank 2 Membrane treatment apparatus 3 Air diffuser 5 Impurity removal tank 10 Transfer pipe 11 Transfer pump 15 Control part 16 Suction pump 17 Return pipe 20 Return pipe 21 Return pump 22 Upper limit water level sensor 23 Lower limit water level sensor

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shin Shin, 1048 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works Co., Ltd. 72) Inventor Keiyoshi Nakaoka 1048 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Inventor Shigeyuki Yamaguchi 1048 Okadoma Kadoma Kadoma City, Osaka Matsushita Electric Works Co., Ltd.

Claims (4)

[Claims] 1. A sewage purification apparatus comprising: a dirt removal tank into which sewage flows in from the outside; and a sewage treatment tank for aerating the sewage supplied from the dirt removal tank. A treatment device is provided, and a diffuser tube for supplying air to the membrane treatment device is disposed below the membrane treatment device in the sewage treatment tank, and a return pump for returning sludge in the membrane treatment tank to the impurity removal tank is provided. A return pipe is provided, and a control unit is provided for controlling the return pump to operate for a predetermined time for each predetermined amount of treated water in the sewage treatment tank to return sludge in the sewage treatment tank to the impurity removing tank. A sewage treatment apparatus characterized by the above-mentioned. 2. The method according to claim 1, wherein aeration treatment and anaerobic treatment are controlled alternately in the sewage treatment tank, and the number of aeration treatments or anaerobic treatments is counted to convert the amount of treated water. Item 2. A sewage treatment apparatus according to Item 1. 3. A transfer pipe provided with a transfer pump for supplying sewage in a contaminant removal tank to a sewage treatment tank, and for discharging treated water treated by a membrane treatment device provided in the sewage treatment tank. An outflow pipe provided with a suction pump is provided, and an upper limit water level detection sensor for detecting an upper limit water level and a lower limit water level sensor for detecting a lower limit water level are provided in the sewage treatment tank, and the upper limit water level sensor detects the upper limit water level and sucks. The operation of the pump is started, the lower limit water level is detected by the lower water level sensor, and the operation of the suction pump is stopped. The lower water level is detected by the lower water level sensor, and the operation of the transfer pump is started. Is controlled to stop the operation of the transfer pump upon detecting the number of times the water level is detected by the upper limit water level sensor. The sewage treatment apparatus according to claim 2, further comprising a control unit. 4. The operation of the return pump is performed during aeration treatment in the sewage treatment tank.
A sewage treatment apparatus according to any one of the preceding claims.