JPH0653279B2 - Batch type water treatment device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a batch-type water treatment device which has a small installation space and is suitable for small-scale wastewater treatment requiring denitrification and dephosphorization.

[Conventional technology]

Sewage such as domestic wastewater generally contains a large amount of organic substances. Therefore, a step of supplying air into the sewage to perform so-called aeration to aerobically treat the organic substance, and to stop the aeration to perform anaerobic treatment, reduce the nitrified nitrogen in the aerobic treatment to nitrogen gas. A batch-type water treatment method has been proposed in which the treated water is drained as supernatant water after performing a cleaning treatment and a precipitation step. A rectangular water tank is used as this batch treatment apparatus, and a production treatment tank and a sludge concentration storage tank are installed.

[Problems to be Solved by the Invention]

If you install the biological treatment tank and sludge concentration storage tank separately in this rectangular shape, the installation area will be large, the piping path for connecting both tanks will be long, and the corners and central parts of each water tank will be Sludge accumulates, and it may spoil over time, causing pollution problems such as foul odors.

In such a small sewage treatment plant, such a large installation space is disadvantageous.

In the present invention, the above-mentioned drawbacks are eliminated by changing the shape of this batch type tank.

[Means for Solving the Problems]

It has a double circular shape and has a biological treatment tank on the outside and a sludge concentration storage tank on the inside to be integrated, and is equipped with an aeration device inside the biological treatment tank, and from the biological treatment tank to the sludge concentration storage tank. A transfer means for transferring sludge is provided.

[Work]

Since a double circular tank is applied to the batch-type water treatment system, and the biological treatment tank is placed outside and the sludge concentration storage tank is placed inside the biological treatment tank in the center, the equipment can be integrated. It saves space and requires only a minimum amount of piping, which can significantly reduce the number of pipes and the length of pipe used. Further, since the tank is circular, the water flow in the tank becomes a circulation flow and the flow velocity can be increased, so that the sludge settled to the bottom of the tank in the precipitation step can be efficiently wound up. In addition, since the water flow in the circular tank becomes a circulating water flow, uniform mixing in the tank can be performed efficiently.
Moreover, it is possible to sufficiently mix and stir with a relatively small power, and it is possible to reduce both equipment power consumption and power consumption.

〔Example〕

 The present invention will be described below with reference to the illustrated embodiments.

In the figure, reference numeral 1 denotes a circular biological treatment tank having a required diameter and depth, and a sludge concentration storage tank 2 having a required diameter is arranged in the center of the biological treatment tank 1. At this time, it is desirable to arrange the biological treatment tank and the sludge concentration storage tank in concentric and different diameters. Then, untreated sewage is supplied into the biological treatment tank 1 through the inflow pipe 5, and the supply amount of the sewage is from a predetermined low water level LWL to a high water level HWL during biological treatment of normal sewage as shown in FIG. Keep the water level between. Further, the inflow position of the sewage is preferably on the opposite side of the supernatant water discharge pipe 6, and when the sewage is continuously introduced, the inflow pipe 5 is provided at the bottom of the tank.

The biological treatment tank 1 is provided with one or a plurality of aerators 3 for aerating the supplied wastewater regularly or continuously to perform aerobic fermentation treatment of organic substances in the wastewater.
By the operation of 1, the biological treatment tank 1 is aerated while agitating sewage in the tank, and causes a water flow to circulate in the circular tank. When this sewage circulates in the tank, aeration and aeration are performed, and a faster flow rate can be obtained even with the aerator with the same power as in the rectangular tank, so the sludge that has settled at the bottom of the tank during the precipitation process can be efficiently wound. Since the mixture is stirred up and mixed, it is possible to prevent sludge from being deposited on the bottom of the tank. Further, the biological treatment tank 1 is provided with a sludge pump 4 having a suction port 4a at the bottom of the biological treatment tank 1, and a discharge port 4b of the pump 4 is arranged in the sludge concentration storage tank 2. As a result, when the sludge pump 4 is driven, the sludge component precipitated and concentrated at the bottom of the biological treatment tank can be sucked up and transferred to the sludge concentration storage tank during the precipitation step.

The biological treatment tank 1 is provided with a supernatant water drainage pipe 6, which is provided with a valve 7 for draining the supernatant water after the precipitation process by opening the valve 7, but keeps the valve 7 closed during the treatment of wastewater. It is a thing.

A sludge discharge bit 8 is provided at the bottom of the sludge thickening storage tank 2,
A sludge discharge pipe 9 for discharging excess sludge from the bit 8 is provided, and a sludge discharge valve 10 provided in the sludge discharge pipe 9 is opened / closed to discharge sludge.

A required amount of sewage flows into the biological treatment tank 1 through the inflow pipe 5,
When the aerator 3 is operated, sewage is agitated and aerated.
As a result, the sewage in the tank circulates and flows back, and the sewage is subjected to a desired biological treatment.

The operation of the aerator 3 is stopped upon detection of a predetermined time or completion of biological treatment of sewage.
When the biological treatment of sewage is completed in this way, the aerator 3
Stop driving. As a result, when biological treatment is performed by operating the aerator, the solids in the wastewater also flow down and circulate in the tank along with the water flow, but when the aerator stops and the water flow stops, it floats in the wastewater. The solid matter settles to the bottom of the tank, and the supernatant water and the solid matter are separated. The supernatant water is drained to the outside of the tank through the drainage pipe 6 by opening the valve 7, sterilized, and then discharged to the river, the sea or the like.

The sludge water generated by this biological treatment and settled on the bottom of the biological treatment tank 1 is transferred to the sludge concentration storage tank 2 by driving the sludge pump 4. In the sludge thickening storage tank 2, sludge is settled and concentrated by its own weight. The sludge concentrated in this tank is discharged through the mud discharge pipe 9 by opening the mud discharge valve 10, and is carried out to the outside by a vacuum car or the like for processing.

Although the self-priming type is used as the aerator 3 in the illustrated embodiment, various types such as a horizontal axis rotating type, a vertical axis rotating type, and an underwater type can be adopted. Further, since stirring is performed in the anaerobic process, it is possible to use underwater stirring, a submersible pump or the like together. As a drainage device for clear water, a float type drainage device, a telescope type drainage device, etc. can also be adopted.

〔The invention's effect〕

According to the present invention, since the biological treatment tank and the sludge enrichment storage tank are integrated, the installation space is small, and the sludge enrichment storage tank is concentrically arranged in the biological treatment tank, which results in the swirl phenomenon. Can be prevented, and sludge can be prevented from accumulating on the bottom during biological treatment. Also, the length of the pipe for transferring the sludge from the biological treatment tank to the sludge thickening storage tank is short, and the aeration machine can be operated to mix and stir the aged water and generate a circulating water flow. Biological treatment can be performed, and shearing force acts between the bottom of the tank and the water surface until inertial force stops the circulating water flow in the sedimentation process, which can enhance sludge sedimentation and concentration effects and save energy. Have the advantage of.

[Brief description of drawings]

FIG. 1 is a plan view and FIG. 2 is a sectional view. 1 is a biological treatment tank, 2 is a sludge concentration storage tank, 3 is an aerator, 4
Is a sludge pump, 5 is an inflow pipe, 6 is a drain pipe, and 9 is a sludge pipe.

Claims (1)

[Claims] 1. A double circular shape, a biological treatment tank is arranged on the outside and a sludge concentration storage tank is arranged on the inside to be integrated, and an aeration device is provided in the biological treatment tank. A batch-type water treatment device comprising a transfer means for transferring sludge to a sludge thickening storage tank.