JPH0621798U - Septic tank - Google Patents

Abstract

(57) [Summary] [Structure] Abnormal pumping mitigating body that receives abnormal pumping that rapidly rises with bubbles above the air lift pipe Aa in the return passage A and above the steady water level La in the return pipe Ap. 1 is provided to be movable up and down. [Effect] The flow rate returned to the anaerobic filter bed N1 is easily adjusted, the flow rate of the liquid to be treated and the oxygen content are stable, and stable biological treatment can be performed only by providing a small return passage.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 In the present invention, a contact aeration tank is provided downstream of the anaerobic filter bed tank, and a return path for returning the liquid in the tank from the contact aeration tank to the anaerobic filter bed tank is provided with an air lift pipe and its air lift pipe. The present invention relates to a septic tank which is connected to the upper part and is connected to a return pipe for guiding the in-tank liquid to the anaerobic filter bed tank.

[0002]

[Prior art]

 Conventionally, in the above septic tank, in order to remove air bubbles from the pumped water that has been raised by the air lift action, a gas-liquid separator that forms a large space is provided at the upper end of the air lift pipe and above the return pipe. Was only.

[0003]

[Problems to be solved by the device]

 However, in the above-mentioned configuration, the water level in the air lift pipe changes due to the rise of air bubbles blown out into the air lift pipe, and when the water level changes, the water pressure at the air supply pipe connection position also changes due to that effect, and the air lift Since a vicious cycle occurs in which bubbles are not uniformly blown into the pipe, fluctuations in the flow rate of the liquid to be treated returned to the anaerobic filter tank and the liquid to be treated returned from the return pipe due to overflow in the contact aeration tank are caused. And the flow rate of the liquid to be treated returned to the anaerobic filter bed tank is difficult to stabilize.

However, when the flow rate of the liquid to be treated returned to the anaerobic filter bed tank becomes small, the amount of nitrification liquid and the amount of peeled sludge returned to the anaerobic filter bed tank decrease, so that the denitrification treatment for decomposing the nitrification solution is performed. When the amount becomes insufficient, the concentration of peeled sludge in the contact aeration tank tends to increase. Further, if the flow rate of the liquid to be treated returned to the anaerobic filter bed tank becomes too large, the amount of oxygen returned to the inside of the anaerobic filter bed tank will increase, and the anaerobic treatment or denitrification itself will not proceed easily. That is, there is a drawback that the above-mentioned stable biological treatment is difficult to perform.

Further, in order to perform effective gas-liquid separation in order to stabilize the water level by suppressing the bubbles of bubbles in the air lift pipe and stabilize the amount of water to be returned and the amount of oxygen contained therein, it is important In the actual situation where a gas-liquid separation chamber is required and the septic tank main body must be enlarged in some cases, and overall treatment in a limited space is required, installing the large gas-liquid separation chamber inside the septic tank It also has the drawback that it occupies a large space and becomes an obstacle when inspecting the tank.

Therefore, in view of the above-mentioned drawbacks, an object of the present invention is to easily stabilize the flow rate of the liquid to be treated returned to the anaerobic filter bed tank through the return passage, and to perform stable biological treatment in a relatively small amount. It is to provide a septic tank that can be used in space.

[0007]

[Means for Solving the Problems]

 The feature of the present invention to achieve this object is that an abnormal pumping mitigating body that receives the abnormal pumping that rapidly rises with bubbles is provided above the air lift pipe in the return passage and above the steady water level in the return pipe. It is provided so that it can move up and down, and the effects obtained from them are as follows.

[0008]

[Action]

 That is, as the air is supplied from the lower part of the air lift pipe, the liquid to be treated is pumped up together with the air bubbles in the air lift pipe, and the liquid to be treated is discharged from the lower end opening in the air lift pipe toward the location of the abnormal pump mitigating body. Flowing. At this time, the liquid to be treated, which has been pumped to a level higher than the steady water level due to the non-uniform air bubbles, collides with the abnormal pumping body. At this time, the abnormal pumping-up body is pushed up by the liquid to be treated, the pumping power is absorbed, and the bubbles in the liquid to be treated are easily separated from the liquid to be treated due to the collision with the abnormal pumping-up body. The gas-liquid separation chamber becomes unnecessary.

Further, since abnormal pumping can be suppressed with a simple device, a small space can be provided inside the septic tank.

[0010]

[Effects of the Invention] Therefore, even if the liquid to be treated suddenly rises with bubbles, the abnormal pumping mitigating body suppresses the abnormal pumping, and the liquid to be treated returned to the anaerobic filter bed is not separated into gas and liquid. Since it is performed, the amount of liquid to be treated returned to the anaerobic filter bed tank is stable and the amount of oxygen supplied to the anaerobic filter bed tank is also stable, so it is possible to prevent excess oxygen in the anaerobic filter bed tank. , The sewage treatment can be maintained well.

Further, since the space occupied by the return passage provided with this abnormal pumping mitigation body can be small, the entire septic tank can be formed compact without any hindrance when inspecting the inside of the septic tank.

[0012]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, from the upstream side, an anaerobic filter bed tank N composed of an anaerobic filter bed tank first chamber N1 and an anaerobic filter bed tank second chamber N2, a contact aeration tank E, a precipitation tank P, and a disinfection layer Q are provided. The septic tank is configured so that the liquid to be treated flows by natural advection in this order.

In the anaerobic filter bed tank N, a filter bed F1 for growing anaerobic microorganisms for anaerobic decomposition of organic matter in the liquid to be treated and denitrification of nitrate nitrogen to fix its biofilm is formed. , F 2 are separately provided in the anaerobic filter bed tank first chamber N1 and the anaerobic filter bed tank second chamber N2.

The contact aeration tank E is provided with a contact material C for fixing aerobic microorganisms that decompose organic substances remaining in the liquid to be treated and nitrify ammoniacal nitrogen, and the contact material C is treated in the tank. A circulation flow of a physical fluid is generated, the aerobic microorganisms fixed on the contact material C are brought into good contact with the water to be treated containing an organic substance, and air is supplied to supply the aerobic microorganisms with necessary oxygen. An air diffuser D is provided.

Further, in order to prevent the biological material or the like from adhering to the contact material C excessively and causing clogging, air bubbles are emitted to the contact material C to collide with the contact material C to remove excess biological film and the like sludge. As a result, a backwash pipe R for peeling is provided below the contact material C, and the suspended sludge in the contact aeration tank E is not increased by the peeling sludge so that the BOD is not increased too much. In order to denitrify the sludge, the return slid sludge and the water to be treated containing the nitrifying solution are connected to the air lift pipe Aa and the upper part of the air lift pipe Aa so as to communicate with the anaerobic filter bed first chamber N1. And a return pipe Ap for guiding the liquid to be treated to the anaerobic filter bed tank N.

As shown in FIGS. 1 and 2, in the return path A, an air lift pipe Aa is vertically raised from the lower part of the contact aeration tank E, and the liquid to be treated is placed at the lower end of the air lift pipe Aa. An opening Ai for taking in is formed, an air supply pipe S for supplying air from an air supply device is communicatively connected near the lower end, and a relaxation body accommodating portion A1 is formed at the upper part of the air lift pipe Aa. A return liquid rectifying portion A2 is also formed in the return pipe Ap, and the return liquid rectifying portion A2 is connected to the relaxation body accommodating portion A1.

The relaxation body accommodating portion A1 is provided with a lid 3 having a vent hole 2 formed on the upper portion thereof, and the lid 3 is provided with a relaxation body 1 for suppressing abnormal pumping.

As shown in FIG. 3, the relaxing body 1 has a structure in which a rod-shaped support tool 4 is attached to the lid part 3, and a movable plate 5 is inserted into and supported by the support tool 4. The support 4 is provided with first and second retaining portions 4a and 4b at both ends thereof, and the first retaining portion 4a at the upper portion is fixed to the lid portion 3 and the second retaining portion at the lower portion. The portion 4b is located near the steady water level La, holds the movable plate 5 near the steady water level La during normal operation, and receives the power of pumping the liquid to be treated during abnormal pumping to move the movable plate 5 to the upper Lb. When it is pushed up, the movable plate slides in the vertical direction to alleviate the pumping force, and it is possible to reliably suppress abnormal pumping.

A notch 6 for returning surplus water to the contact aeration tank E is formed in the upper part of the return liquid rectifying unit A2, and only the liquid to be treated having less bubbles is provided on the upstream side of the notch 6. A baffle plate 7 is provided to reduce the ripples on the liquid surface by passing through, and a baffle plate 8 is also provided in the vicinity of the notch 6 to reduce fluctuations in the amount of liquid to be transferred.

The baffle plates 7 and 8 have openings in the lower part of the liquid layer, and even if there is a large undulation in the relaxing body accommodating portion A1, a static flow flows from the relaxing body accommodating portion A1 to the return pipe Ap. It is designed to run.

The treated liquid that has been treated in the contact aeration tank E is transferred from the bottom of the contact aeration tank to the settling tank P, and the supernatant liquid of the settling tank P overflows and is guided to the disinfection tank Q, Here, each tank is formed so as to be discharged from the discharge port Z to the outside after being contacted with the solid disinfectant and disinfected.

With the above configuration, the flow rate returned to the anaerobic filter bed tank N1 can be easily adjusted, the flow rate of the liquid to be treated and the oxygen content are stabilized, and a stable product can be obtained only by providing a small return passage. Processing can be performed.

[Other Embodiment] Another embodiment will be described below. Although the anaerobic filter bed tank N is divided into two tanks in this embodiment, it is not always necessary to divide into two tanks, and one tank may be adopted.

The structure of the relaxation body 1 does not necessarily have to be the above-described structure in which the movable plate 5 is hung on the support tool 4. For example, the relaxation body 1 may swing slightly above the steady water level La in the relaxation body housing portion A1. It is also possible to attach the movable plate 5 which is movable to the inner wall of the relaxation body accommodating portion A1. It is also possible to substitute a floating body for the movable plate 5.

The baffle plates 7 and 8 may have any shape as long as they have the same function. In the present embodiment, the shape having an opening at the lower part of the liquid layer portion is used, but a stitch-shaped defoamer may be provided. Further, although the baffles 7 and 8 are not necessarily required, when the baffles 7 and 8 are provided, the flow rate of the liquid to be treated returned further becomes stable, and the amount of oxygen returned to the anaerobic filter bed N is increased. Since it is also stable, more stable biological treatment can be performed.

In the claims for utility model registration, reference numerals are given for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a septic tank according to the present invention.

FIG. 2 is a vertical cross-sectional view of the main part of the return path.

[Explanation of symbols]

 N Anaerobic filter bed E Contact aeration tank A Return path Aa Air lift tube Ap Return tube La Steady water level 1 Relaxant

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kazuyuki Honda, 1 Takamatsu, Kosai-cho, Koga-gun, Shiga 1 at 2 Kubota Shiga factory (72) Inventor Katsumi Hamada 1 of 2 Takamatsu, Kosai-cho, Koga-gun, Shiga Kubota Shiga Factory Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A contact aeration tank (E) is provided downstream of the anaerobic filter bed tank (N), and the tank liquid is returned from the contact aeration tank (E) to the anaerobic filter bed tank (N). The air return pipe (A) is connected to the air lift pipe (Aa) and the upper part of the air lift pipe (Aa), and the return pipe (Ap) for guiding the liquid in the tank to the anaerobic filter bed tank (N) is constructed. In the septic tank, the air bubbles rise sharply with bubbles above the air lift pipe (Aa) in the return passage (A) and above the steady water level (La) in the return pipe (Ap). An abnormal pumping mitigation body (1) for receiving abnormal pumping is provided so as to be vertically movable.