JPH0655185A - Purification tank - Google Patents

Abstract

(57) [Summary] [Structure] A sedimentation separation type flow rate adjusting tank 1 is provided between the anaerobic filter bed tank N and the contact aeration tank E, and a sludge return pump P1 is arranged at the bottom of the flow rate adjusting tank 1. The sludge return pump P1 sucks up the treated water containing the settled sludge and returns it to the anaerobic filter bed tank N, while the sludge return pump P1 is provided.
The flow rate adjusting pump P2 is arranged at a higher position than that, and the transfer device 4 for sucking the water to be treated by the flow rate adjusting pump P2 and sending the constant flow rate from the flow rate adjusting tank 1 to the contact aeration tank E is provided. [Effects] Biological treatment can be performed efficiently, and even if the inflow of raw water may suddenly increase, sludge settling in the tank is difficult to be transferred to the next tank. There is no risk of sludge being discharged as it is.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a septic tank having an anaerobic filter bed tank and a contact aeration tank.

[0002]

2. Description of the Related Art A septic tank of this type has an anaerobic filter bed tank and a contact aeration tank arranged from the upstream side, and a settling tank and a disinfection tank are provided on the downstream side of the contact aeration tank so that the water to be treated is In general, each tank from the anaerobic filter bed tank to the disinfecting tank is naturally advected in this order and discharged.

[0003]

However, in such a conventional configuration, when the amount of raw water flowing into the septic tank suddenly increases even if it is temporary, a large amount of treated water flows following it. The sludge that had settled in each tank along with the water may be transferred to the next tank and discharged as it is.

The object of the present invention is to prevent sludge settling in a tank from advancing to the next tank even if there is a sudden increase in the amount of inflow of raw water, and the sludge is discharged as it is as in the conventional case. It is to provide a septic tank that will not be destroyed.

[0005]

To achieve this object, the septic tank according to the present invention is characterized in that a precipitation separation type flow rate adjusting tank is provided between the anaerobic filter bed tank and the contact aeration tank, A sludge suction part is arranged at the bottom of the adjusting tank, and a return device for sucking up treated water containing settled sludge from the sludge suction part and returning it to the anaerobic filter bed tank is provided at a position higher than the sludge suction part. In addition to arranging the upper treated water suction section in the above, there is provided a transfer device for feeding the treated water sucked through the upper treated water suction section from the flow rate adjusting tank to the contact aeration tank at a constant flow rate. And its effects are as follows.

[0006]

[Function] A precipitation separation type flow rate adjusting tank is provided between the anaerobic filter bed tank and the contact aeration tank, and the treated water sucked through the upper treated water suction section is contacted from the flow rate adjusting tank to the contact point. Since a transfer device for sending a constant flow rate to the aeration tank is provided, by setting the transfer flow rate of the treated water of this transfer device to, for example, the average flow rate of raw water, the transfer device sucks sludge accumulated at the bottom. While avoiding this, only the relatively clear upper treated water of the flow rate adjusting tank can be sucked from the sludge suction section and fed into the contact aeration tank at a constant flow rate. Therefore, even if there is a sudden increase in the inflow rate of raw water, the settled sludge in the anaerobic filter bed follows this as in the case of conventional natural advection, and a large amount of treated water is stored in the contact aeration tank. There is no advection, so the flow rate of the water to be treated from each tank to the next tank can be suppressed,
Advancing of sludge from each tank to the next tank due to this is also suppressed, and finally sludge can be prevented from being discharged. Further, at the bottom of the flow rate adjusting tank, a sludge suction section is arranged, and a return device for sucking up treated water containing sedimented sludge from the sludge suction section and returning it to the anaerobic filter bed tank is provided. Therefore, it is possible to return the sludge at the bottom of the flow rate adjusting tank to the anaerobic filter bed tank through this returning device, and further reduce the inflow of the sludge to the contact aeration tank. Even when the inflow of raw water is stopped, the nutrients for the anaerobic microorganisms grown in the anaerobic filter bed for biological treatment of the water to be treated are supplied without interruption, and as a result, anaerobic treatment such as denitrification is possible. Done effectively.

[0007]

[Effects of the Invention] According to the above construction, not only can biological treatment be carried out efficiently, but even if the inflow of raw water may increase temporarily, the sludge that has settled in the tank It was possible to provide a septic tank that is difficult to be transferred to the tank and in which sludge is not discharged as it is as in the past.

[0008]

Embodiments of the septic tank according to 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 flow rate adjusting tank 1, a contact aeration tank E, and a precipitation tank Q. The disinfection tank S is arranged in this order to form a septic tank.

In the first and second chambers N1 and N2 of the anaerobic filter bed tank, anaerobic microorganisms that anaerobically decompose organic substances in the water to be treated are grown, and filter beds F1 and F are used to fix the biofilm.
2 is provided.

The sludge return pump P1 is arranged at the bottom of the flow rate adjusting tank 1, and the treated water containing settled sludge is sucked up from the sludge suction part 2a formed at the bottom of the sludge return pump P1. The sludge return pump P1 is connected to the return device 2 for returning to the first bed N1 of the filter bed tank, and the rising pipe 2b which is connected to the discharge part of the sludge return pump P1 and rises to a position higher than the liquid level in the tank, It comprises a return pipe 2c extending from the upper part of the rising pipe 2b to the anaerobic filter bed first chamber N1. Further, the flow rate adjusting pump P2 is arranged at a position higher than the sludge suction section 2a, and the upper treated water suction section 4a is formed under the flow rate regulating pump P2 so that the upper treated water suction section 4a sucks. The transfer device 4 for transferring the treated water to the contact aeration tank E at a constant flow rate is provided with the flow rate adjusting pump P2 and the rising pipe 4b rising from the flow rate adjusting pump P2.
And a box-shaped weighing box 4c connected to the upper portion of the rising tube 4b. Weighing box 4c
Is a box shape without a lid, and is provided with a flow check triangular weir 4d that overflows pumped water to the downstream side and a return weir 4e that overflows excess pumped water to the upstream side. A transfer pipe 4f for feeding water into the contact aeration tank E is provided. The overflow water from the return weir 4e is the return pipe 2c.
It is configured to be guided to the first chamber N1 of the anaerobic filter bed tank through a return path B formed by being connected to. In the flow rate adjusting tank 1,
Also, with a level sensor that detects the level of the liquid level in the tank,
Based on the detection result of the level sensor, the flow rate adjusting pump P2 is turned on / off to provide a control device for keeping the liquid level in the tank within the upper and lower control limits thereof, and an extremely rapid increase in the inflow rate of raw water, In preparation for an emergency such as a power failure, open the emergency overflow port 6 to a level higher than the upper limit of liquid level control above the partition wall 5 between the flow rate adjusting tank 1 and the contact aeration tank. There is. The contact aeration tank E is provided with a contact material C for fixing aerobic microorganisms that decompose organic matters remaining in the water to be treated, nitrification reaction of ammonia nitrogen and the like. In addition, an air that causes a circulating flow of the water to be treated in the tank to bring the water to be treated containing organic matter into good contact with the aerobic microorganisms fixed on the contact material C, and to supply oxygen required for the aerobic microorganisms. An air diffuser D for supplying the air is provided. Also, in order to prevent clogging due to excessive adhesion of biofilm or the like to the contact material C, the backwash pipe R for removing excess biofilm or the like as separation sludge by bubbling air is used as the contact material C. In order to prevent the suspended sludge and the BOD in the contact aeration tank E from increasing too much due to the above-mentioned peeling sludge, the peeling sludge is constantly or intermittently placed in the anaerobic filter bed first chamber N1. As a return means for returning, the air lift pump A is raised from the bottom of the contact aeration tank E, and the upper part of the air lift pump A is connected to the return path B leading to the anaerobic filter bed first chamber N1. is there.

A sedimentation tank P is provided below the contacting aeration tank E and communicates therewith. The supernatant of the precipitation tank P overflows and is guided to the disinfection tank Q. A medicine barrel T containing a solid disinfectant is disposed at the entrance of the disinfectant tank Q, and the medicine barrel T is formed with a plurality of slit-shaped openings for inflow and outflow of the water to be treated at the lower portion thereof. The water to be treated that has come into contact with the disinfectant in the medicine bottle T passes under the baffle plate provided in the middle of the disinfection tank, overflows and is discharged.

With the above-mentioned constitution, even when the amount of raw water input suddenly increases, solid biological treatment can be carried out without releasing the solid content as it is. Even if the sludge return pump P1 and the flow rate adjusting pump P2 are of the air lift pump type, similar effects can be obtained.

It should be noted that reference numerals are given in the claims 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.

[Explanation of symbols]

 N Anaerobic filter bed E Contact aeration tank 1 Flow rate adjusting tank 2 Return device 2a Sludge suction part 4 Transfer device 4a Upper treated water suction part

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

Claims (1)

[Claims] 1. A septic tank provided with an anaerobic filter bed tank (N) and a contact aeration tank (E), wherein precipitation occurs between the anaerobic filter bed tank (N) and the contact aeration tank (E). A separate type flow rate adjusting tank (1) is provided, a sludge suction section (2a) is arranged at the bottom of the flow rate adjusting tank (1), and treated water containing settled sludge is sucked up from the sludge suction section (2a). A return device (2) for returning to the anaerobic filter bed tank (N) is provided, and the upper treated water suction part (4a) is arranged at a position higher than the sludge suction part (2a) and the upper part The treated water sucked through the treated water suction section (4a) is fed from the flow rate adjusting tank (1) to the contact aeration tank (E).
A septic tank provided with a transfer device (4) for feeding a constant flow rate to the inside.