JPH04110195U - Batch type sewage treatment equipment - Google Patents

Abstract

(57) [Summary] (with amendments) [Purpose] To provide a sewage treatment device that can completely prevent external discharge of sludge when discharging supernatant after precipitation in a batch type sewage purification device. [Structure] In a sewage treatment device that performs sewage treatment using a batch activated sludge method, after the activated sludge tank 1 is left still, the suction portion 4 of the supernatant liquid discharge pipe 3 for discharging the supernatant liquid W is connected to the suction portion 4 of the supernatant liquid discharge pipe 3. 4, and includes a sludge return pipe 5 leading to the front-stage treatment tank and a suction device 6 for the sludge return pipe.
Prior to discharge, the sludge return pipe 5 is activated.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to improvements in batch-type sewage treatment equipment.

0002

[Conventional technology]

Traditionally, sewage treatment systems such as combined septic tanks have been using batch activated sludge systems. Water treatment devices are known. This batch activated sludge method uses one activated sludge tank and charges activated sludge. After the sewage flows into the tank, the sewage is stirred to promote sewage purification using activated sludge. Once the treatment is complete, the treated sewage is allowed to stand still to allow the activated sludge to settle, and the supernatant liquid is used as purified water in the tank. A treatment method that repeatedly discharges waste to the outside. By the way, when discharging the above supernatant liquid out of the tank as purified water, the sludge must be sucked out. However, care must be taken to ensure that the treated water discharge device used for this purpose does not A float is floated on the clear liquid, and the supernatant liquid discharge pipe is supported by this float to remove the supernatant liquid from the water surface. A device that sucks liquid from the water, or a device that gradually opens the tank from the water surface to the depth direction. A suction pipe with a A variety of things are known, such as things that drain water (for example, ``Water and Drainage'' vol 32 No.68 1 990).

0003

[Problems with conventional technology]

However, in any of the above discharge methods, after the precipitation process, the supernatant liquid When discharging waste water, activated sludge may be mixed in with the waste water, and this should not be discharged as is. Then, there was a drawback that caused some inconvenience. The reason for this is that during the agitation purification process using activated sludge, activated sludge is mixed in the discharge pipe. treated wastewater flows in and remains in the discharge pipe even after the sedimentation process. Depends on. Therefore, conventionally, when draining supernatant liquid, this drained water was removed for a while after the start of draining. It was necessary to take measures to prevent the leakage to other departments.

0004

[Problem that the idea aims to solve]

In view of the above problems, this idea was developed in a batch-type sewage purification system, in which the supernatant is discharged after sedimentation. Our aim is to provide a sewage treatment system that can completely prevent sludge from being discharged to the outside. This was done as a target.

[0005]

[Means to solve the problem]

In other words, the batch-type sewage purification device of this invention performs sewage treatment using the batch-type activated sludge method. In sewage treatment equipment, after the activated sludge tank is left standing, the supernatant liquid is discharged. A sludge return pipe that communicates with the suction part of the liquid discharge pipe and leads to the pre-treatment tank. The present invention is characterized in that a suction device for the sludge return pipe is provided.

[0006]

【Example】

Next, an example of this invention will be described. FIG. 1 is a longitudinal sectional view of an embodiment of this invention, and FIG. 2 is a plan sectional view of the embodiment. The batch-type sewage purification device 1 of this invention is a sewage treatment device 1 that performs sewage treatment by a batch-type activated sludge method.After the activated sludge tank 2 is left standing, the sludge S is precipitated, and the supernatant liquid W above the interface thereof is A sludge return pipe 5 communicating with the suction part 4 and leading to a pre-treatment tank 6 such as a sludge storage tank, and a suction device P ₁ for this sludge return pipe 5 are installed in the suction part 4 of the supernatant liquid discharge pipe 3 that discharges the supernatant liquid. It is composed of In the figure, P ₂ indicates a supernatant liquid discharge pump, which discharges the supernatant liquid through a discharge pipe 8 to a drained liquid storage tank 9 of the next tank. Further, 10 indicates a disinfection cylinder for disinfecting the supernatant liquid, 11 indicates a pump for discharging purified water from the drained liquid storage tank 9, and 12 indicates its discharge pipe.

[0007] In the above embodiment, the suction device _P1 for the sludge return pipe 5 is an air lift pump, and the suction device P1 for the sludge return pipe 5 is used as an air lift pump. Configured to operate automatically. The above embodiment shows a case where the sludge return pipe 5 is provided in a separate system from the supernatant liquid discharge pipe 3, but it is also possible to use the same pipe as the sludge return pipe 5 as shown in FIG. . That is, in FIG. 3, the supernatant liquid discharge pump P is also used as a suction device for the sludge return pipe 5, and the supernatant liquid discharge pipe 3 is communicated with the sludge return pipe 5 via the solenoid valve 7. The solenoid valve 7 is configured to be automatically closed by the control device (not shown) of the batch-type sewage purification system prior to the supernatant liquid discharge step, and opened after the sludge is discharged to allow the supernatant liquid W to flow in the direction of the discharge pipe 8. ing. In addition, it is preferable that the supernatant liquid discharge pipe 3 leading from the inside of the tank 1 to the suction device P be inclined toward the suction device P side as shown in FIG. In addition, in the above embodiment, the type of supernatant liquid discharge pipe 3 is fixed in the tank above the interface of the sludge S. The same method can be implemented by providing a sludge return pipe 5 in the section.

[0008]

[Effect]

In batch-type sewage treatment, a settling step is performed after the stirring step with activated sludge is completed, and when the sludge S settles, the control device operates the solenoid valve 7, the suction device P for the sludge return pipe 5 is operated, and the suction unit The sludge that has entered the tank 4 and remains therein is returned to a pre-treatment tank 6 such as a sludge storage tank. Since the amount of sludge remaining in the suction section 4 is small, this return process is completed in a short time. Next, by closing (Fig. 1) or opening (Fig. 3) the solenoid valve 7, the supernatant liquid is discharged in the direction of the discharge pipe 8 by the pump _P2 or P, but at this time, the sludge in the pipe 3 is treated in the previous stage. Since it has been returned to the tank 6, it is prevented from being discharged to the outside.

[0009]

[Effect of the idea]

As explained above, this device handles activated sludge treatment, sedimentation, and supernatant liquid in one tank. In batch-type sewage treatment equipment that processes wastewater by repeatedly discharging it, the supernatant liquid discharge It is possible to reliably prevent sludge discharge during the process, and this can be automatically controlled by a control device. This greatly simplifies the operation management of this type of sewage treatment equipment. It is. It is also possible to use both the supernatant liquid discharge pipe and the sludge return pipe, and the structure is simple. It has various practical effects such as.

0010

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the invention.

FIG. 2 is a cross-sectional view of an embodiment of the invention.

FIG. 3 is a longitudinal sectional view of another embodiment.

[Explanation of symbols]

Single batch sewage purification equipment 2 Activated sludge tank 3 Supernatant liquid discharge pipe 4 Suction part 5 Sludge return pipe 6 Pre-treatment tank 7 Solenoid valve P Suction device W Supernatant liquid

Continuation of front page (72) Creator Yoshito Kitai 2-1 Takamatsu, Kosai-machi, Koka-gun, Shiga Prefecture Stocks Inside Kubota Shiga Factory (72) Creator Dai Harada 2-1 Takamatsu, Kosai-machi, Koka-gun, Shiga Prefecture Stocks Inside Kubota Shiga Factory (72) Creator Kazuyuki Honda 2-1 Takamatsu, Kosai-machi, Koka-gun, Shiga Prefecture Stocks Inside Kubota Shiga Factory

Claims (1)

[Scope of utility model registration request] Claim 1: In a sewage treatment device that performs sewage treatment using a batch activated sludge method, after the activated sludge tank is left standing, the suction portion of a supernatant liquid discharge pipe for discharging the supernatant liquid is connected to the suction portion. A batch-type sewage treatment apparatus, comprising: a sludge return pipe leading to a pre-treatment tank; and a suction device for the sludge return pipe.