JPH05317872A - Septic tank - Google Patents

Abstract

PURPOSE:To suppress the load fluctuation of the septic tank to a lower level even if large solids are contained in sewage. CONSTITUTION:The body 1 of this septic tank is delineated, successively from an upstream side, by partition walls 2... to an anaerobic treatment chamber 3, an aerobic treatment chamber 4, a settling chamber 5 and a disinfecting chamber 6. The anaerobic treatment chamber 3 is further delineated with a preaeration chamber 8 by a partition wall 7. A sewage inflow pipe 9 from a toilet or kitchen faces this preaeration chamber 8 and a diffuser 10 for blowing the air to the bottom of the preaeration chamber 8 is provided. Further, a communicating port 11 with the anaerobic treatment chamber 3 is formed in the partition wall 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a septic tank for purifying and discharging sewage from a toilet, washroom, bath, kitchen or the like.

[0002]

2. Description of the Related Art As a septic tank for waste water discharged from toilets, toilets, baths, kitchens, etc.
JP-A-2-22791 discloses a septic tank in which one treatment tank is divided into an anaerobic treatment chamber, an aerobic treatment chamber, a precipitation chamber and a disinfection chamber, and these chambers are sequentially purified while passing sewage.
Japanese Patent Publication No. 58-15038 discloses a septic tank in which rotary contact bodies are provided in the anaerobic treatment chamber and the aerobic treatment chamber to lower the molecular weight of organic substances.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
As disclosed in Japanese Unexamined Patent Application Publication No. JP-A No. 2003-242242, one treatment tank is divided into a plurality of chambers, and the anaerobic treatment and the aerobic treatment are performed in each chamber. Remains. That is, if a relatively large solid substance enters the anaerobic treatment chamber, it may be accumulated in the anaerobic treatment chamber. When flowing into the temper treatment chamber, etc.,
The treatment capacity of the aerobic treatment chamber will be exceeded, and it will be discharged with insufficient purification.

On the other hand, as disclosed in Japanese Examined Patent Publication No. 58-15038, large solids can be made finer to some extent by lowering the molecular weight of organic substances in the rotary contact body. However, when the rotary contact body is provided in the processing chamber. The volume of the processing chamber is limited by that much, and the septic tank becomes large in size in order to perform a predetermined amount of processing.

[0005]

In order to solve the above problems, the present invention is directed to the inside of the anaerobic treatment chamber of the septic tank in which the septic tank main body is divided into an anaerobic treatment chamber, an aerobic treatment chamber, a precipitation chamber and a disinfection chamber. A pre-aeration chamber was provided outside, and a sewage pipe was exposed to this pre-aeration chamber and the pre-aeration chamber and the anaerobic treatment chamber were connected to each other.

[0006]

[Function] Sewage from toilets, washrooms, baths, kitchens, etc.
First, it enters the pre-aeration chamber, where large solids are crushed and made smaller, and further sent to the anaerobic treatment chamber after being subjected to aerobic treatment to some extent.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a side sectional view of a septic tank according to the present invention, FIG. 2 is a plan sectional view of the septic tank, and FIG. 3 is a diagram showing a flow of purifying wastewater by the septic tank.
The structure of the septic tank will be described with reference to FIG.

The septic tank is divided into an anaerobic treatment chamber 3, an aerobic treatment chamber 4, a sedimentation chamber 5 and a disinfection chamber 6 in this order from the upstream side (left side in the figure) by the partition walls 2 ... In the chamber 3, a partition wall 7 further defines a front aeration chamber 8. The front aeration chamber 8 faces a wastewater inflow pipe 9 from a toilet or a kitchen, and along the partition wall 7 to the bottom of the front aeration chamber 8. An inlet pipe 10 having an air diffusing pipe is provided at the tip for blowing air, and a communication port 11 to the anaerobic treatment chamber 3 is formed in the partition wall 7. The introduction pipe 10 is also provided in the aerobic treatment chamber 4, and air is blown in using a blower.

The anaerobic treatment chamber 3 is divided into two chambers 3a and 3b which communicate with each other at the lower part, and each chamber 3a and 3b is provided with an anaerobic filter bed 12 in which anaerobic bacteria are immobilized on a filter material such as synthetic resin. It is provided. The anaerobic treatment chamber 3 is connected to the aerobic treatment chamber 4 through the communication port 13 provided in the partition wall 2.

The aerobic treatment chamber 4 is divided into two chambers 4 by a partition wall 14.
a) and 4b. The chambers 4a and 4b are connected to each other through a communication port 15 formed in the partition wall 14, and the chambers 4a and 4b are provided with an aerobic filter bed 16 in which aerobic bacteria are immobilized on the filter medium. There is.

By the way, the pre-aeration chamber 8 and the anaerobic treatment chamber 3a
And a partition wall 7 defining the anaerobic treatment chambers 3a and 3b, and a partition wall 1 defining the aerobic treatment chambers 4a and 4b.
4 and cleaning ports 41, 42, 43, 44 are provided along the partition wall 2 that defines the aerobic treatment chamber 4b and the precipitation chamber 5. These cleaning ports 41, 42, 43, 44 are opened below the filter beds 12, 16.

The bottom of the sedimentation chamber 5 has a funnel-shaped inclined surface 17 to collect sludge in the center of the bottom. A cylindrical center well 18 is fixed above the center of the bottom, and the center well 18 is placed outside the center well 18. Ring (square) inner weir 19
A saw-shaped outer weir 20 is provided, one end of the outflow pipe 21 is opened in the groove between the inner weir 19 and the outer weir 20, and the other end is opened in the disinfection chamber 6. The disinfection chamber 6 is provided with a disinfecting device 22 for supplying a disinfecting liquid and a discharge pipe 23 for discharging the processing liquid after the disinfection to the outside.

Further, the chamber 4b on the downstream side of the aerobic treatment chamber and the inside of the center well 18 of the precipitation chamber 5 are communicated with each other by a quantitative transfer device 24 using an air lift, and further, between the chamber 4b and the center well 18. An overflow pipe 25 is installed.

The quantitative transfer device 24 is an air lift pipe 24.
a, a measuring container 24b to which the upper end of the air lift pipe 24a is connected, and a carrier pipe 24c that connects the measuring container 24b to the center well 18 and blows air to the lower part of the air lift pipe 24a with a blower As the temperature rises, the liquid in the chamber 4b is introduced into the measuring container 24b, and a constant amount of liquid is supplied into the center well 18 through the transfer pipe 24c through an opening or a weir provided in the measuring container 24b. .. When the treated water level drops below the communication port 15, the blower operation is stopped by using a control device such as a solenoid valve or a float valve, and the air lift is stopped to prevent the treated water from flowing into the settling chamber 5. Stop.

Further, a suction tube 26 is vertically inserted through the center of the center well 18. The lower end of the suction pipe 26 extends to near the bottom surface of the settling chamber 5, the base end of the return pipe 27 is connected to the upper end of the suction pipe 26, and the front end of the return pipe 27 is open to the front aeration chamber 8. .. And the suction tube 26
An air supply pipe 28 extending from the pump is connected to the lower part of the pump to perform timer control, and after a certain time has elapsed, the suction pipe 26
By blowing air into the inside, the sludge 29 is sucked up by the air lift action, and the sludge 29 is returned to the front aeration chamber 8 through the return pipe 27. The return pipe 27 is slightly inclined toward the front aeration chamber 8 so that the sludge naturally returns to the front aeration chamber 8.

On the other hand, a transfer device 30 and a fixed transfer device 31 utilizing an air lift are also provided in the aerobic treatment chamber 4. The transfer device 30 includes an air lift pipe 30a and a transfer pipe 30c, and the fixed amount transfer device 31 includes an air lift pipe 31a, a measuring container 31b, and a transfer pipe 31c.

Air lift pipe 31a of the quantitative transfer device 31
The lower end faces the central part of the bottom of the aerobic treatment chamber 4b, that is, the lowest part. The sludge accumulated at the bottom together with the treated water is pulled up to the measuring basin 31b by the action of the air lift together with the treated water, and a certain amount of sludge is discharged from the measuring basin 31b. The treatment liquid containing the above is sent to the return pipe 27 via the carrier pipe 31c, and a part of the treatment liquid containing sludge is returned to the anaerobic treatment chamber 3 directly or through the pre-aeration chamber 8.

Further, the transfer device 30 is composed of an air lift pipe 30a and a transfer pipe 30c, and is used only when cleaning the inside of the aerobic treatment chamber 4a without driving the air lift during a normal cleaning operation. .. Therefore, the measuring cell for quantitative transfer is omitted.

The operation of the septic tank having the above structure will be described below with reference to FIG. First, when sewage from a toilet or a kitchen flows into the pre-aeration chamber 8 through the sewage inflow pipe 9, the sewage is agitated in the pre-aeration chamber 8, large solids are pulverized into small pieces, and aerobic treatment is performed to some extent.

Then, the sewage is sent into the anaerobic treatment chamber 3 through the communication port 11. In the anaerobic treatment chamber 3, first, the organic matter in the wastewater is converted to acetic acid (CH
₃ COOH) and propionic acid (CH ₃ CH ₂ COOH) and other organic acids. Further, these organic acids are decomposed to contain gas of methane (CH ₄ ) and carbon dioxide (CO ₂ ) by methane bacteria and ammonia nitrogen (NH ₄ ⁺ ) which is a decomposition product of nitrogen content of protein and urea. Produces a processing liquid.

The treatment liquid containing the ammonia nitrogen (NH ₄ ⁺ ) and the undecomposed organic matter is sent to the aerobic treatment chamber 4 through the communication port 13. In the aerobic treatment chamber 4, oxidative decomposition is performed by aerobic bacteria such as nitrifying bacteria using the air (oxygen) blown from the blower through the air introduction pipe 10. By this oxidative decomposition, ammonia nitrogen (NH ₄ ⁺ ) is oxidatively decomposed into nitrate nitrogen (NO ₃ ⁻ ) and nitrite nitrogen (NO ₂ ⁻ ).

A part of the treatment liquid containing nitrate nitrogen (NO ₃ ⁻ ) and nitrite nitrogen (NO ₂ ⁻ ) is quantitatively transferred to the anaerobic treatment chamber 3 by the suction pipe 31 via the return pipe 27. Returned,
It is reduced to molecular nitrogen (N ₂ ) or nitrous oxide (N ₂ O) by denitrifying bacteria in the anaerobic treatment chamber 3, and is discharged as a gas out of the tank. In this way, nitrate nitrogen (N
The treated water in which the concentrations of O ₃ ⁻ ) and nitrite nitrogen (NO ₂ ⁻ ) are reduced is sent to the precipitation chamber 5, and the supernatant liquid of the precipitation chamber 5 passes through the groove between the inner weir 19 and the outer weir 20. Sent to the disinfection room 6,
It is discharged after being sterilized with chlorine.

FIG. 4 is a side sectional view of a septic tank according to another embodiment,
FIG. 5 is a plan sectional view of the septic tank shown in FIG. 4. In this embodiment, a substantially funnel-shaped scum collecting member that collects scum disposed on the surface of the processing liquid of the precipitation chamber 5 is set in the precipitation chamber 5. 45
and a scum collecting and returning device 45 provided with a scum collecting member 45a at one end and a U-shaped pipe 45b having the other end connected to the returning pipe 27. The scum floating on the surface of the treatment liquid is sucked, the sucked scum is sent to the return pipe 27 by the air lift action, and is returned to the front aeration chamber 8 via the return pipe 27.

FIG. 6 is a side sectional view of a septic tank according to still another embodiment, and FIG. 7 is a plan sectional view of the septic tank shown in FIG. 6. In this embodiment, the treatment liquid in the aerobic treatment chamber 4b is treated. For transferring the amount of sludge to the settling chamber, the quantitative transfer device 31 for pulling up the treatment liquid containing sludge in the aerobic treatment chamber 4b to the return pipe 27, and the cleaning port 44 are all partition walls defining the aerobic treatment chambers 4a and 4b. It is provided on the 14 side.

In the illustrated example, the processing liquid return pipe for sending a part of the processing liquid in the aerobic treatment chamber to the anaerobic treatment chamber and the sludge returning pipe for returning the sludge in the settling chamber to the previous aeration chamber are common return pipes. But,
These may be separated. Further, in the embodiment, a part of the anaerobic treatment chamber is a recess, and this recess is a front aeration chamber,
The front aeration chamber may be attached to the side surface of the anaerobic treatment chamber so as to project.

[0026]

As described above, according to the present invention,
A pre-aeration chamber is provided inside or outside the anaerobic treatment chamber of the septic tank, and once the sewage is received in this pre-aeration chamber, the solid matter in the sewage is finely crushed and aerobically treated to a certain degree and sent to the anaerobic treatment chamber. Therefore, even if a large solid matter, paper, or the like enters the septic tank, the load fluctuation can be suppressed to be small, and stable purification can be performed.

Further, a part of the treatment liquid in the aerobic treatment chamber is sent to the anaerobic treatment chamber and discharged as nitrogen (N ₂ ) or nitrous oxide (N ₂ O) gas to the outside of the anaerobic bacteria. Since it is possible to prevent an excessive increase of ammonia nitrogen, nitrate nitrogen, and nitrite nitrogen that suppress the activity of aerobic bacteria, it is possible to perform stable purification. Furthermore, by sharing the processing liquid return pipe that sends part of the processing liquid in the aerobic treatment chamber to the anaerobic treatment chamber and the sludge return pipe that returns the sludge in the sedimentation chamber to the previous aeration chamber, sludge is anaerobically treated from the bottom of the sedimentation chamber. Since it can be returned to the chamber and the solid matter does not need to be removed to the outside of the septic tank, maintenance is simplified and the structure of the septic tank itself can be simplified.

Further, since the processing liquid is transferred from the aerobic treatment chamber to the precipitation chamber through the quantitative transfer device, stable operation can be performed, and the quantitative transfer device defines the aerobic treatment chamber. By arranging the cleaning port along the partition wall and the cleaning port also along the partition wall, the structure becomes simple and the manufacturing becomes easy. In particular, the aerobic treatment chamber is divided into two chambers, and a cleaning port is provided in each chamber to facilitate cleaning.

Further, if a scum collecting and returning device is provided in the settling chamber and the scum floating in the settling chamber is returned to the pre-aeration chamber or the anaerobic treatment chamber, the work of removing the scum periodically becomes unnecessary.

[Brief description of drawings]

FIG. 1 is a side sectional view of a septic tank according to the present invention.

FIG. 2 is a plan sectional view of the septic tank.

FIG. 3 is a diagram showing a flow of purifying wastewater by the septic tank.

FIG. 4 is a side sectional view of a septic tank according to another embodiment.

5 is a plan sectional view of the septic tank shown in FIG.

FIG. 6 is a side sectional view of a septic tank according to another embodiment.

FIG. 7 is a plan sectional view of the septic tank shown in FIG.

[Explanation of symbols]

1 ... Septic tank main body, 2, 7, 14 ... Partition wall, 3 ... Anaerobic treatment chamber, 4 ... Aerobic treatment chamber, 5 ... Sedimentation chamber, 6 ... Disinfection chamber, 8 ...
Front aeration chamber, 10 ... Air introduction pipe, 11, 13, 15 ... Communication port, 12, 13 ... Filter bed, 24, 31 ... Fixed amount transfer device,
27 ... Return pipe, 41, 42, 43, 44 ... Cleaning port, 45
… Scum collecting and returning device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsumi Nishimura 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu, Fukuoka Prefecture Totoki Kikai Co., Ltd. (72) Takamasa Tsuji 2 Nakajima, Kokurakita-ku, Kitakyushu, Fukuoka 1st, 1st Totoki Co., Ltd. (72) Inventor Yoshinori Takezaki 2-1-1, Nakajima, Kokurakita-ku, Kitakyushu, Kitakyushu, Fukuoka (72) Inventor, Shuhei Kono Kokura Kitakyushu, Fukuoka 2-1-1 Nakajima, Kita-ku Totoki Equipment Co., Ltd. (72) Hirotoshi Oki 3-92 Nishiizumi, Kanazawa-shi, Ishikawa Prefecture In Ams Co., Ltd. (72) Takahiro Sakata 3-chome Nishizumi, Kanazawa-shi, Ishikawa Prefecture Address 92 Ams stock company (72) Inventor Yoshihide Sekigami 3-chome, Nishizumi, Kanazawa, Ishikawa Prefecture 92 Ams stock company

Claims (7)

[Claims] 1. A septic tank in which the inside of the septic tank main body is divided into an anaerobic treatment chamber, an aerobic treatment chamber, a precipitation chamber and a disinfection chamber, and a pre-aeration chamber is provided inside or outside the anaerobic treatment chamber,
A septic tank characterized in that a sewage inflow pipe is exposed to the front aeration chamber and the front aeration chamber and the anaerobic treatment chamber are communicated with each other. 2. A treatment liquid return pipe for feeding a part of the treatment liquid in the aerobic treatment chamber to the anaerobic treatment chamber is provided between the anaerobic treatment chamber and the aerobic treatment chamber. The septic tank according to claim 1. 3. A sludge return pipe for returning sludge in the settling chamber to the front aeration chamber is provided between the pre-aeration chamber and the settling chamber, and the sludge return pipe also serves as a treatment liquid return pipe. The septic tank according to claim 2. 4. The quantitative transfer device for transferring a constant amount of liquid in the aerobic treatment chamber to the settling chamber along a wall surface defining the aerobic treatment chamber, according to claim 1. Septic tank. 5. The aerobic treatment chamber is divided into two chambers, and a cleaning port that opens below the filter bed is provided along a wall surface that defines each chamber. Septic tank. 6. The septic tank according to claim 2, wherein the aerobic treatment chamber is provided with a fixed amount transfer device for transferring sludge in the aerobic treatment chamber to the treatment liquid return pipe by a predetermined amount. 7. The septic tank according to claim 3, wherein the settling chamber is provided with a scum collecting and returning device for collecting floating scum and returning it to the previous aeration chamber through the sludge returning pipe.