JP2553218Y2 - Sewage septic tank - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewage treatment tank, and more particularly to an improvement of a sewage treatment tank having a high-concentration activated sludge treatment tank such as a fluidized bed.

[0002]

2. Description of the Related Art Conventionally, as a combined clarification tank, a separation membrane module comprising a ceramic membrane or a glass or plastic microporous tube with an opening of 0.1 to 10 μm is provided in a high-concentration activated sludge treatment tank such as a fluidized bed tank. Sewage treatment tanks are being proposed and are being implemented. This type of sewage treatment tank treats organic matter in sewage with activated sludge and then filters and extracts only the treated water with a separation membrane module, so the purification level of the effluent is very high and it is a compact device, which is convenient as a sewage treatment tank. Has advantages.

[0003]

However, since the supplied wastewater contains a large amount of coarse solids, it is necessary to provide these filtration screens before supplying the wastewater to the high-concentration activated sludge treatment tank. There was a disadvantage that it was not easy to treat the filtrate. In addition, even in treatment in a high-concentration activated sludge treatment tank, it is difficult to completely decompose minute solids contained after filtration,
There was a disadvantage that the separation membrane module was clogged at an early stage due to these residues, resulting in poor filtration. On the other hand,
SS is almost completely pre-processed with a fine automatic screen
If it is removed, the amount of denitrification carbon
In some cases, nitrogen could not be sufficiently performed.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention is capable of sufficiently separating solid coarse substances even if they are contained, and also performing denitrification processing well, and is capable of separating membrane modules and the like. It is an object of the present invention to provide a sewage purification tank capable of effectively preventing clogging.

[0005]

The sewage purification tank of the present invention comprises a sedimentation separation tank into which raw sewage flows, an anaerobic filter bed tank and an anaerobic activated sludge treatment tank into which treated sewage is successively transferred. An aerobic activated sludge treatment tank, a membrane separation device provided in the aerobic activated sludge treatment tank, a suction pump of the membrane separation device, and the anaerobic activated sludge treatment tank from the aerobic activated sludge treatment tank A circulating pump that constantly or intermittently circulates and returns the mixed solution, and is provided in the anaerobic consolidation sludge tank.
A stirring pump .

[0006]

Next, an embodiment of the present invention will be described. FIG. 1 is a sectional view of an embodiment of the present invention. The sewage purification tank 1 of the present invention includes a sedimentation separation tank 2 into which sewage raw water flows, an anaerobic filter tank 3 into which sewage from which coarse solids have been removed is transferred,
Next, an anaerobic activated sludge treatment tank 4 to which sewage is transferred, an aerobic activated sludge treatment tank 5 to which sewage is similarly transferred, and a ceramic membrane, glass, or glass provided in the aerobic activated sludge treatment tank 5 0.1-1 plastic
A membrane separation device 6 comprising a microporous tube having an opening of 0 μm;
A suction pump 7 of the membrane separation device 6, a circulation pump 8 for constantly or intermittently circulating and returning the mixture from the aerobic activated sludge treatment tank 5 to the anaerobic activated sludge treatment tank 4, and an anaerobic activated sludge.
It is composed of a stirring pump 10 provided in the tank 4 . The circulation pump 8 is an air lift pump,
The air supply Ru also serves the blower 9 to supply to the aerobic activated sludge treatment tank 5.

[0007]

In the present invention, raw sewage is first flowed into the sedimentation separation tank 2. In the sedimentation separation tank 2, coarse solids contained in the raw sewage are removed by sedimentation, and the sewage is subjected to anaerobic treatment by being left standing. Then, the sewage from which the bulky solid matter has been removed flows to the anaerobic filter tank 3 which is the next chamber. At this time, the suspended matter contained in the advancing water is filtered by the filter bed 3 and prevented from flowing into the chamber thereafter. Therefore, sewage We row removed, such as suspended solids at the time of advected into the anaerobic bioreactor tank 4 which is the next chamber, the advection load alleviation because it is considerably reduced at the same time sewage SS load anaerobic activated sludge The purification treatment in the treatment tank 4 is performed efficiently. further,
The inside of this anaerobic activated sludge treatment tank 4 is
The treated water is stirred and circulated at the same time as indicated by the arrow in the figure.
It is well stirred and mixed with the treated water returned by the pump 8.
Therefore, this mixing and stirring increases the denitrification efficiency,
Suspended matter is mixed in the treated water flowing from the
Are mixed together by this stirred flow,
It increases the denitrification effect.

[0008] The treated sewage is further transferred to the aerobic activated sludge treatment tank 5 which is the next chamber. In this treatment tank 5 as well, the purification treatment is similarly performed efficiently. Also,
A part of the sewage that is being treated in the aerobic activated sludge treatment tank 5 is always returned to the anaerobic activated sludge treatment tank 4 by the circulation pump 8. Therefore, the denitrification of the treated water is efficiently performed as described above . The sewage decomposed as described above is finally discharged to the outside by the suction pump 7 through the membrane separation device 6. Since the discharged treated water is filtered by the membrane separation device 6, the treated water has a very high purification level.
Since the sewage has gone through each treatment step until it reaches the membrane separation device 6, the amount of suspended matter is very small, and the clogging of the membrane module is also small. Further, the sludge generated in the activated sludge treatment tank is intermittently transferred to a sedimentation separation tank or a separately provided sludge storage tank as needed, so that an excessive MLSS concentration operation can be avoided.

[0009]

[Effects of the Invention] As described above, the sewage treatment tank of the present invention performs sedimentation and separation, separation of suspended matter in the anaerobic filter tank, and anaerobic treatment before the treated water reaches the membrane separation device. The SS load in the aerobic activated sludge treatment tank can be remarkably reduced, and efficient purification of sewage becomes possible, and clogging of the separation membrane module is also prevented accordingly. Moreover, other circulating the mixture between the aerobic activated sludge treatment tank and the anaerobic bioreactor tank, the anaerobic activated sludge tank
Since the treated water is mixed and stirred by a stirring pump, it has various practical effects such as efficient denitrification.

[Brief description of the drawings]

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

[Explanation of symbols]

Reference Signs List 1 sewage purification tank 2 sedimentation separation tank 3 anaerobic bed tank 4 anaerobic activated sludge treatment tank 5 aerobic activated sludge treatment tank 6 membrane separation device 7 suction pump 8 circulation pump 9 blower 10 stirring pump

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Daisuke Harada 2 at Takamatsu, Kosai-cho, Koga-gun, Shiga Prefecture Inside the Kubota Shiga Plant. Kubota Shiga Plant (56) References JP-A-61-200894 (JP, A) JP-A-60-168597 (JP, A)

Claims (1)

(57) [Scope of request for utility model registration] 1. A sedimentation separation tank into which raw sewage water flows, an anaerobic filter tank, an anaerobic activated sludge treatment tank, and an aerobic activated sludge treatment tank into which treated sewage is successively transferred. A membrane separation device provided in the sludge treatment tank, a suction pump of the membrane separation device, and a continuous or intermittent circulation return of the mixed liquid from the aerobic activated sludge treatment tank to the anaerobic activated sludge treatment tank. A circulation pump and the anaerobic activated sludge tank
A sewage purification tank comprising a stirring pump provided .