JPH11277091A - Apparatus and method for treating sewage/waste water by biological reaction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the efficiency of contact of bacteria with air by generating air bubbles by a membrane and developing the functions of an anaerobic tank, an oxygen free tank, an aeration tank and a sedimentation tank being phosphorus, nitrogen and org. matter removing reaction tank in one cylinder to reduce reaction tank capacity. SOLUTION: A sewage/waste water treatment apparatus is constituted of an aeration tank 2, an air bubble providing means 5, an oxygen free anaerobic tank 3 performing the removal of nitrogen and the discharge of phosphorus and a sedimentation tank 4. A sewage/waste treatment method includes a stage wherein inflow water flows in the aeration tank 2, a stage forming fine air bubbles, a stage feeding sludge to the oxygen-free anaerobic tank 3, a stage removing nitrogen from a sludge mixed soln. to discharge phosphorus, a stage oxidizing unremoved org. matter and a nitrogen component to recirculate phosphorus while taking in a large amt. of phosphorus and a stage discharging treated water to a wafer 6. In this case, the aeration tank 2 and the oxygen-free anaerobic tank 3 are constituted as a cylindrical double pipe to maximize the concn. of bacteria and org. matter, phosphorus and nitrogen can be effectively removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a biological treatment and method for sewage and wastewater, and more particularly to an aeration tank for oxidizing organic substances by microorganisms, an oxygen-free and anaerobic tank for removing nitrogen and phosphorus, The present invention also relates to an apparatus and method for treating sewage and wastewater by a biological reaction in which the function of a precipitation tank for precipitating microorganisms is performed by a double cylindrical treatment tank.

[0002]

2. Description of the Related Art Generally, biological treatment apparatuses for sewage and wastewater which are widely used at present are equipped with an aeration tank as an organic matter oxidation tank and a sedimentation tank for sedimenting microorganisms grown in the aeration tank. Is oxidized and removed. In addition,
In addition to the removal of organic substances, in the apparatus for removing nitrogen and phosphorus, a denitrification tank and an anaerobic tank are installed in a lateral flow type separately from the aeration tank to remove nitrogen and phosphorus contained in wastewater. However, since such a conventional biological treatment apparatus is installed in a cross flow type, a large site area is required, and since the structures of the aeration tank and the sedimentation tank are constructed with cement, the construction cost is reduced. There was a problem that becomes high.

[0003] As a method of supplying air to the aeration tank, a ceramic, cloth, or the like is conventionally provided at the bottom of the aeration tank.
Attached to the perforated plate of resin and resin, and a diffuser tube that generates air bubbles by pipes, and oxygen is supplied so that relatively large air bubbles are generated, but the concentration of microorganisms was increased in the aeration tank. In such a case, in such a conventional oxygen supply method, the oxygen consumption rate of microorganisms is faster than the air supply rate,
The phenomenon of lack of dissolved oxygen appears. Therefore, when treating high-concentration organic wastewater, the concentration of microorganisms should be reduced to 40% due to the limitation of the oxygen supply rate.
There was a problem that it could not be made higher than 00 mg / l.

Since the secondary sedimentation tank is provided separately from the aeration tank, another transport pump is required to transfer the settled sludge to the aeration tank. In addition, a scraper is provided to prevent the settled sludge from being clogged in the conveying sludge pipe, and the mechanical and electric devices related to such a scraper and the conveying pump have a very complicated structure.

Further, the conventional activated sludge method is intended only for removing organic substances, so that only an aeration tank, which is an organic substance oxidizing tank, is provided. In the (A ² / O: anaerobic-anoxic-aerobic) method and the Bardenpho (Bardenpho: anaerobic-anoxic-aerobic-anoxic-aerobic) method, in addition to the aeration tank, anoxic for removing nitrogen Denitrification tank
tank) and an anaerobic tank for phosphorus release (Anaerobic tank)
Is further provided. At this time, in the above-mentioned denitrification tank, in order to remove nitrate nitrogen and nitrite nitrogen generated from the aeration tank, a speed that is 2 to 6 times the inflow flow rate for transporting the aeration tank sludge liquid to the denitrification tank is required. An internal circulation pump must be provided, and each reactor such as an anaerobic tank and a denitrification tank must be provided with a stirrer for uniform mixing of the sludge mixture. Therefore, when the phosphorus and nitrogen removing step is additionally performed in addition to the organic substance removing step, the process configuration and the mechanical facilities are more complicated than those of the conventional activated sludge method.

As described above, the conventional biological treatment apparatus is provided in a cross-flow type, and in addition to an aeration tank, a denitrification tank which is anoxic for nitrogen removal and an anaerobic tank for releasing phosphorus, and Since the sedimentation tanks and the like are separated from each other, not only a large site area is required, but also a stirrer, a transport pump, a scraper, etc. are provided in each reaction tank, and sludge transfer to each process is performed by a pump. Therefore, there is a problem that the mechanical device is complicated and the installation cost is high.

[0007] Also, in the treatment of organic matter, according to the conventional air supply method, when treating high-concentration organic wastewater,
Since the rate of oxygen consumption of microorganisms is higher than the rate of air supply, there is a limitation on the rate of oxygen supply, which involves a problem that it is extremely difficult to maintain a high concentration of microorganisms.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and a microfiltration membrane (microfiltrat) is used as an air supply method instead of a conventional air diffuser.
ion, pore size 0.1 ~ 100μm) and ultrafiltration membrane (ultraf
iltration, 1.5-10μm pore size) using a membrane (Membrane) to generate dissolved oxygen or ultra-fine bubbles, to increase the efficiency of contact between microorganisms and air, By increasing the oxygen supply rate,
An object of the present invention is to provide an apparatus and a method for treating sewage and wastewater by a biological reaction in which the concentration of microorganisms is maintained at 10,000 mg / l or more and the capacity of a reaction tank is greatly reduced.

Further, the present invention provides a double biological reaction tank in a circular or square cylinder, wherein aerobic conditions are formed in a compartment to which air is supplied, and oxygen-free is provided in a compartment to which no air is supplied. Another object of the present invention is to provide an apparatus and method for treating sewage and wastewater by a biological reaction which forms an environment for removing phosphorus and nitrogen as well as removing organic substances in one reaction tank by forming anaerobic conditions. And

[0010] The present invention also provides a biological reaction tank having a vertical double partition so that the air supplied to the aeration tank is released to release phosphorus and remove nitrogen in the anaerobic tank. Provided is an apparatus and method for treating sewage and wastewater by a biological reaction in which a sludge mixture in an aeration tank can be transferred to an oxygen-free and anaerobic tank by force, thereby simplifying a treatment facility compared to a conventional phosphorus and nitrogen reaction facility. For another purpose.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an aeration tank in which an air component is brought into contact with a mixture of activated sludge, and an inside of the aeration tank. A bubble providing means for forming bubbles while having a predetermined driving force so as to convey the inflowing water and the aeration tank sludge mixture flowing into the aeration tank, and covering the outside of the aeration tank, Oxygen-free and anaerobic tanks containing the influent water and the aeration tank sludge mixture that have overflowed to remove nitrogen by a biological reaction and simultaneously release phosphorus, and cover the outside of the oxygen-free and anaerobic tanks, Provided is a sewage and wastewater treatment device for biological reaction, including a sedimentation tank containing sludge that is discharged and settled while circulating between the aeration tank and the oxygen-free and anaerobic tank.

The present invention also relates to a first step in which inflow water including sewage and wastewater from which contaminants have been removed by a screen flows into an aeration tank, and an air component ejected through a diffuser pipe mounted in the aeration tank. A second step of forming fine bubbles by contacting with the inflow water, a third step of flowing the inflow water and aeration tank sludge flowing into the aeration tank into the anoxic and anaerobic tank and transporting them, A fourth step of removing nitrogen in a sludge mixture having a high concentration of nitrate nitrogen and nitrite nitrogen and releasing phosphorus in the sludge using the influent flowing into the anaerobic tank as a carbon source; The sludge and sedimentation tank sludge flowing out of the tank into the aeration tank again to oxidize unremoved organic matter and nitrogen components, thereby ingesting a large amount of phosphorus, and after performing the fifth step, the sludge is formed in the aeration tank. Sludge and from outside A sixth step in which the influent is mixed and recirculated; and after the sixth step, the microorganisms are separated into solid and liquid in the settling tank, the sludge is settled, and the treated water is discharged through the overflow ware. The present invention provides a method for treating sewage and wastewater by a biological reaction including the following seven steps.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to FIG.

As shown in FIG. 1, the apparatus and method for treating sewage and wastewater by biological reaction according to the present invention include an inflow water 1 containing sewage and wastewater from which impurities are removed by a screen (not shown). And an aeration tank 2 forming an internal space for allowing an air component to come into contact with a mixed liquid of activated sludge. At the lower part of the aeration tank 2, there is provided a diffuser pipe 5 which blows out air to form fine bubbles so as to bring the air component into contact with the inflow water flowing into the upper part and the sludge mixture. 5 is provided with a blower 11 or a compressor for providing external air. At this time, the inflow water and the sludge mixture are caused to flow out of the aeration tank 2 by the propulsive force of the air ejected through the air diffuser 5.

In a preferred embodiment of the present invention, the aeration tank 2
If manure or livestock wastewater flows into the wastewater, it is necessary to maintain the concentration of microorganisms at a high concentration. In this case, a membrane such as a microfiltration membrane or an ultrafiltration membrane is used instead of the air diffusion tube 5, In addition, even if a membrane is used in place of the air diffuser 5, sludge conveyance driving force is insufficient,
The structure is such that a submersible agitating pump 8 is mounted on the upper inside of the aeration tank 2 and provides a propulsive force necessary for mixing and transporting sludge.

Outside the aeration tank 2, inflow water formed to be larger than the diameter by a predetermined diameter and flowing out of the aeration tank by the driving force of the air ejected from the air diffusion tube 5,
An anoxic and anaerobic tank 3 is provided to remove the nitrogen by performing a biological reaction on the mixed liquid of the aeration tank sludge having a high concentration of nitrate nitrogen and nitrite nitrogen and to simultaneously release phosphorus. On the inner surface of the oxygen-free and anaerobic tank 3, a large number of mixing guide plates 7 are provided in a zigzag manner to smoothly mix the sludge mixed solution overflowed in the aeration tank 2 with the inflow sewage and wastewater. Can be

As described above, the aeration tank 2 and the anaerobic and anaerobic tank 3 are composed of upright double tubes, and have a structure in which the upper and lower parts are opened. The first support 9 supports the space so as to maintain the interval.
In the present embodiment, the structure in which the double pipe is formed in a cylindrical shape is shown, but the present invention is not limited to this, and may be formed in a polygonal box such as an ellipse, a square, and a hexagon. good. Outside the anoxic and anaerobic tank 3, there is provided a sedimentation tank 4 for precipitating and storing sludge circulating between the anoxic and anaerobic tank 2. 3 is provided with a second support 14 for supporting the position of the support 3 while maintaining a constant interval.

In this embodiment, as shown in FIG. 1, the lower sections of the aeration tank 2, the oxygen-free and anaerobic tank 3, and the sedimentation tank 4 have horizontal sections and circular arcs provided on both sides of the horizontal sections. And the tangent line at the boundary between the horizontal part and the arc part has a structure in which the tangent is inclined at an angle of 1/10 to 1/20 inward with respect to the horizontal part. The sludge and the settling tank sludge flowing out of the tank 3 smoothly flow into the aeration tank 2 by a propulsive force generated by air supply.

In the middle part of the settling tank 4, a specific surface area (specific surface area) of the settling tank sludge is increased by nitrogen gas or air balls.
A sludge floating prevention net 13 is provided to prevent the surface area from becoming large and floating, and the outer peripheral surface of the upper part of the sedimentation tank 4 accommodates the treated water overflowed therethrough and discharges it to the outside. Overflow Wear (weir) 6
The sedimentation tank 4 is provided with an openable / closable lid 15 at the upper part of the sedimentation tank 4 to prevent rainwater or the like from flowing.

The operation of the present invention configured as described above will be described as follows.

First, when the inflow water 1 from which contaminants have been removed by the screen flows into the upper part of the aeration tank 2, the inflow water 1 is transferred to the upper part by the driving force of the air discharged from the diffusion pipe 5. Along with the sludge, it is evenly dispersed and flows into the anoxic and anaerobic tank 3. As a result, the inflow water 1
Before being oxidized under aerobic conditions, it is used as a carbon source required for nitrogen removal and phosphorus release in anoxic and anaerobic tanks 3.

Between the upper part and the middle part of the oxygen-free and anaerobic tank 3, the inflow water and the mixed liquid of the aeration tank sludge are completely mixed while hitting the mixing guide plate 7 in a zigzag form. Is depleted in oxygen, and a reaction occurs in which nitrate nitrogen and nitrite nitrogen contained in the aeration tank sludge mixture are reduced to nitrogen gas and removed using the organic matter of the inflow water as a carbon source. And in the middle part and lower part of the anoxic and anaerobic tank 3, dissolved oxygen, nitrate nitrogen,
And anaerobic conditions are formed by the depletion of nitrite nitrogen,
The intracellular phosphorus is released using the organic matter of the influent water 1 remaining after the nitrogen removal as a carbon source. The residence time in the anoxic and anaerobic tank 3 is within one hour based on the inflow rate, and is desirably about one hour.

The sludge and sedimentation tank sludge flowing out of the oxygen-free and anaerobic tank 3 flow into the aeration tank 2 by the propulsion generated by air supply. At this time, the lower floor of the sedimentation tank 4 serving as a sedimentation tank, the aeration tank 2 and the oxygen-free and anaerobic tank 3
Is slanted inward at an angle of about 1/10 to 1/20 as described above, so that the sedimentation tank sludge and the transport sludge smoothly move to the aeration tank 2 by the propulsive force of the air supply from the aeration tank 2. Can be done.

After the above process, the aeration tank 2 oxidizes organic substances not removed in the anoxic and anaerobic tank 3 and oxidizes nitrogen components contained in the influent water. A large amount of the released phosphorus and the phosphorus contained in the influent water will be consumed. The aeration tank sludge is again mixed with the influent water 1 by the air supply driving force, flows again into the anoxic and anaerobic tank 3, and continuously repeats such a circulation path. Sludge on the settling tank floor is intermittently removed.

Here, the hydraulic pressure in the aeration tank 2
aulics) The residence time, i.e., the time from inflow of water to retention and exit, is maintained at 4-8 hours, and F / M (Food / Microo
rganism) ratio is maintained at approximately 0.1 kgBOD / kg MLSS · d.

When the inflowing water flowing into the aeration tank 2 is a high-concentration organic substance such as manure or livestock wastewater, it is necessary to maintain the concentration of microorganisms at a high concentration. In this case, sufficient dissolved oxygen is supplied by using a membrane to maintain the concentration of microorganisms at a high level.If the membrane alone does not provide sufficient sludge transfer driving force, the sludge is mixed and transferred. Underwater stirring pump 8 for propulsion
Obtained by On the other hand, when the microorganism concentration is 4000 mg / l or less, a conventional general air diffuser is used to obtain the driving force necessary for oxygen supply and sludge transport.

The microorganisms that have passed through the aeration tank 2 and the oxygen-free and anaerobic tank 3 are separated into solid matter and treated water in a sedimentation tank 4 having a residence time of 2 to 3 hours. Numeral 12 is moved to the upper part, overflowed through the sedimentation tank 4, and then discharged through the ware 6.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in comparison with a conventional apparatus.

First, the air inflow rate was fixed at 30 ml / min,
A general diffuser using a ceramic disk diffuser,
Polysulpho with a pore size of 0.2 μm
ne) The concentration of dissolved oxygen relative to the concentration of microorganisms (MLSS) was compared with the hollow fiber membrane diffuser of the material. In general aeration tubes, the concentration of microorganisms was reduced to less than 2.5 mg / l, which is the appropriate dissolved oxygen concentration in the aeration tank of a biological treatment facility, when the concentration of microorganisms was 6000 mg / l or more, but a microfiltration membrane and an ultrafiltration membrane were used. In this case, the concentration was maintained at 2.5 mg / l or more, and the oxygen supply rate of the membrane air diffuser was very high, indicating that the microorganisms could be maintained at a high concentration.

[0030]

[Table 1]

Next, the method of the present invention and the cross-flow type are provided.
Compare the removal efficiency of organic matter and nitrogen / phosphorus with the conventional method
In order to use the standard activated sludge method,
(A ^Two/ O: Anaerobic tank-anoxic tank-aerobic tank) construction method and book
The method of the invention was operated.

Livestock wastewater having a very high concentration of organic matter and nitrogen / phosphorus is used as influent water, and the treatment flow rate in each step is 500
At l / d, three steps were run in parallel with the same influent.
Table 2 shows the operating conditions of each process, and standard activated sludge (sludg
e) The concentration of microorganisms in the construction method and the Eito method is approximately 4000 mg / l, and in the method of the present invention, the pore size (pore siz
e) Use hollow fiber membrane (Hollow Fiber Membrane) of 0.2μm polysulphone material,
The concentration of microorganisms was maintained between 8000 and 10,000 mg / l.

Table 3 shows the average of the results of the operation performed over a period of approximately six months, and shows the standard activated sludge.
The Aitoo method provided with an anaerobic tank and a denitrification tank step in addition to the aeration tank has a higher removal rate of organic substances, phosphorus and nitrogen than the aeration tank, and can maintain microorganisms at a higher concentration than the Aitoo method. The method of the present invention has excellent removal rates of organic substances, phosphorus, and nitrogen.

[0034]

[Table 2]

Table 3 shows a comparison of the operation results between the standard activated sludge method and the Eito method and the method of the present invention.

[0036]

[Table 3]

Table 4 shows a comparison of the phosphorus content of SVI and sludge between the standard activated sludge method, the Aitoo method and the method of the present invention.

[0038]

[Table 4]

Table 4 shows the sludge sedimentation index of each method and the phosphorus content of the aeration tank sludge. The phosphorus content of the aeration tank sludge is the highest in the method of the present invention, and the sludge sedimentation index is also one. It shows that it is the best.

The present invention described above is not limited by the above-described embodiment and the accompanying drawings, and various substitutions, modifications and changes can be made without departing from the technical scope of the present invention. This will be apparent to those skilled in the art to which the present invention pertains.

[0041]

As described above, according to the present invention, the phosphorus content in the aeration tank sludge is less than 2% in the conventional method in which only the aerobic condition is set, but the anaerobic-aerobic condition is repeated. In the present invention, when the content is 10% or more, the inorganic matter content in the sludge is increased, so that the sludge sedimentation property is improved as compared with the conventional method, and the remaining space other than the circular biological reaction tank is blocked by the air supply, so that the eddy current is reduced. Since generation does not occur, it can be used as a sedimentation basin.

Further, according to the present invention, instead of a conventional air diffuser which generates large air bubbles as an air supply device, a microfiltration membrane or an ultrafiltration membrane (ultrafiltration) which can generate fine air bubbles can be used. Membrane
ane) to improve the oxygen supply rate by microbubbles and maximize the concentration of microorganisms, so that not only sewage and wastewater but also high concentrations of organic matter and nitrogen and phosphorus contained in manure and livestock wastewater, etc. Since the removal is done in one reactor,
It is more effective than the conventional method.

Further, since the sludge in the reaction tank is transferred by the propulsive force generated by the air supply, there is an effect that another sludge conveying pump and various related facilities are not required.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a configuration of an embodiment of a sewage and wastewater treatment apparatus for biological reaction according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 inflow water 2 aeration tank 3 anoxic and anaerobic tank 4 sedimentation tank 5 diffuser tube 6 overflow clothing 7 mixing guide plate 8 underwater stirring pump 9 first holding stand 11 blower 12 treated water 13 sludge floating prevention net 14 second holding stand 15 Lid

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ike Izumi, Korea Construction Technology Research Institute, 231, Dahua-dong, Ilsan-gu, Goyang-si, Republic of Korea (72) Inventor Lee Jang-ho, 2311 Korea Construction Technology, Dahua-dong, Ilsan-gu, Goyang-si, Korea Inside the Research Institute (72) Inventor Kim Dong Key 2311 Daehwa-dong, Ilsan-gu, Goyang-si Republic of Korea Inside Korea Research Institute of Technology (72) Inventor Li Chang-Akira 400 Kiin-dong, Ansan-si, Gyeonggi-do, Korea Inside Korea Water Purification Industry Co., Ltd. (72) Inventor ▲ Wan ▼ Jin-Hang 400 Kinai-dong, Ansan-si, Gyeonggi-do, Republic of Korea

Claims (23)

[Claims] An aeration tank for bringing an air component into contact with a mixed liquid of activated sludge, and a predetermined mixture such that inflow water flowing into the aeration tank and the aerated tank sludge mixed liquid are transported while being in contact with each other. A bubble providing means for forming bubbles while having a transport driving force of a size, and covering the outside of the aeration tank, containing the inflow water and the aeration tank sludge mixture flowing over the outside of the aeration tank, and performing a biological reaction. Anoxic and anaerobic tanks that simultaneously remove nitrogen and simultaneously release phosphorus, and cover the outside of the anaerobic and anaerobic tanks and flow out and settle while circulating between the aeration tanks and the anaerobic and anaerobic tanks. And a sedimentation tank containing sludge. 2. The method according to claim 1, further comprising a mixing guide plate mounted on the inner surface of the oxygen-free and anaerobic tank so that the inflow water flowing through the aeration tank and the sludge mixture are completely mixed. Sewage and wastewater treatment equipment by biological reactions. 3. The sewage and wastewater due to a biological reaction according to claim 1, wherein the lower part of the aeration tank, anoxic and anaerobic tank, and the sedimentation tank has a shape inclined inward with an inclination angle of 1/10 to 1/20. Processing equipment. 4. The apparatus for treating sewage and wastewater by a biological reaction according to claim 1, wherein the aeration tank further includes a submersible agitating pump for providing a mixing force and a transport driving force of the sludge on an upper side thereof. 5. The apparatus for treating sewage and wastewater by a biological reaction according to claim 1, wherein the means for providing air bubbles comprises a membrane having a large number of micropores. 6. The apparatus for treating sewage and wastewater by a biological reaction according to claim 1, wherein the air bubble providing means comprises an air diffuser. 7. The apparatus according to claim 5, wherein the membrane is formed of one of a microfiltration membrane and an ultrafiltration membrane. 8. The aeration tank and the anaerobic and anaerobic tanks each comprise a double tube having one of a cylindrical box and a polygonal box whose upper and lower portions are open. Sewage and wastewater treatment equipment by biological reactions. 9. The sewage and wastewater treatment apparatus according to claim 1, further comprising a first holding table for supporting the space between the aeration tank and the oxygen-free and anaerobic tank so as to maintain the space. 10. The apparatus for treating sewage and wastewater by a biological reaction according to claim 1, further comprising a second holding table for supporting an oxygen-free and anaerobic tank in an inner space of the settling tank. 11. The method according to claim 1, further comprising a sludge floating prevention means mounted at a predetermined position between the sedimentation tank and the oxygen-free and anaerobic tank, for preventing sludge from floating when the treated water is discharged. Item 5. An apparatus for treating sewage and wastewater by a biological reaction according to any one of Items 4. 12. The overflow garment according to claim 1, further comprising an overflow ware mounted on an outer peripheral surface of the sedimentation tank and configured to receive the overflowed treated water and discharge it to the outside. Sewage and wastewater treatment equipment by biological reaction. 13. The sewage and wastewater treatment apparatus according to claim 1, further comprising a lid mounted on an upper part of the sedimentation tank to prevent inflow of rainwater or the like. 14. A first stage in which inflow water including sewage and wastewater from which contaminants have been removed by a screen flows into an aeration tank, and an air component ejected through an aeration tube attached to the aeration tank to inflow water. A second stage of forming fine bubbles by contacting the aerosol tank; a third stage of flowing the inflow water and aeration tank sludge flowing into the aeration tank into the anoxic and anaerobic tank and transporting them; A fourth step of removing nitrogen from the incoming influent and sludge mixture and releasing phosphorus; and allowing the sludge and sedimentation tank sludge discharged from the anoxic and anaerobic tank to flow again into the aeration tank to remove unremoved organic matter. A fifth step of oxidizing nitrogen components and ingesting a large amount of phosphorus; and a sixth step in which after performing the fifth step, sludge generated in the aeration tank and inflow water flowing in from the outside are mixed and recirculated. Stage 6 execution Thereafter, the microorganisms are separated into solid and liquid in the settling tank,
And a seventh step in which the sludge is settled and the treated water is discharged via overflow ware. 15. The method according to claim 15, wherein the second stage comprises a microorganism concentration (MLSS).
If the concentration is less than 4000mg / l, use a general aeration tube, and if the microbial concentration (MLSS) is higher than 4000mg / l, use a microporous or ultrafiltration membrane The method for treating sewage and wastewater by a biological reaction according to claim 14, comprising: 16. The method according to claim 14, wherein the third step includes a step of overflowing the organic matter in the inflow water flowing into the aeration tank into an oxygen-free and anaerobic tank before being oxidized under aerobic conditions. A method for treating sewage and wastewater by the biological reaction as described. 17. The method according to claim 14, wherein the third step includes a step of transporting the inflow water and the sludge mixture to an oxygen-free and anaerobic tank by a transport driving force of the fine bubbles ejected from the air diffuser. A method for treating sewage and wastewater by the biological reaction according to claim 15. 18. The third step includes a step of operating an underwater stirring pump to transfer the inflow water and the sludge mixture to an oxygen-free and anaerobic tank when the driving force for transporting the fine bubbles is insufficient. A method for treating sewage and wastewater by a biological reaction according to claim 15. 19. The fourth step is to remove nitrate nitrogen and nitrite nitrogen by reducing them to nitrogen gas in the upper part of the anoxic and anaerobic tank, and to form anaerobic conditions in the lower part to remove nitrogen. 16. The method for treating sewage and wastewater by a biological reaction according to claim 14 or claim 15, comprising a step of releasing intracellular phosphorus using the remaining influent water organic matter as a carbon source. 20. The method according to claim 14, wherein the fourth step includes a step of completely mixing the inflow water and the aeration tank sludge by a mixing guide plate attached to the anoxic and anaerobic tank in a zigzag manner. Sewage and wastewater treatment method by biological reaction. 21. The sewage by a biological reaction according to claim 14 or 15, wherein the fourth step includes a process in which the residence time in the anoxic and anaerobic tank is within one hour based on the inflow rate. Wastewater treatment method. 22. The sewage and wastewater due to a biological reaction according to claim 14 or 15, wherein the fifth step includes a step of sludge being re-flowed into the aeration tank by a transport driving force generated by air supply. Processing method. 23. The fifth step comprises maintaining the hydraulic residence time in the aeration tank at 4 to 8 hours and adjusting the F / M ratio to about 0.1 kg BOD / Kg.
15. The method according to claim 14, further comprising a step of maintaining the MLSS · d.
5. A method for treating sewage and wastewater by the biological reaction according to 5.