KR19980051067A - Simultaneous Biological and Nitrogen Eliminators - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

Simultaneous Removal of Biological and Nitrogen Removal Devices and Methods

2. The technical gist of the invention

The present invention is to modify the post-lip method is carried out for the purpose of removing the conventional phosphorus only in order to achieve the removal of nitrogen as well as phosphorus at the same time only the denitrification tank in front of the aeration tank, the nitrified nitrate nitrogen in the aeration tank to return to the denitrification tank inflow in the denitrification tank By using the whole amount of sewage organic materials, not only the nitrogen removal rate of the whole system is increased, but also the removal of biological phosphorus and nitrogen at the same time by modifying the post-lip method, which can increase the removal rate of phosphorus more than the conventional postlip method, The purpose is to provide a process.

3. Summary of Solution to Invention

The present invention comprises a first step of mixing the primary sedimentation effluent and the conveying sludge in the denitrification tank and then transported to the aeration tank; Removing the organic matter and nitrifying the aeration tank and returning the nitrified mixed sludge solution to the denitrification tank; The denitrification tank is a third step of increasing the nitrogen removal rate of the entire system by removing the nitrate nitrogen returned by using the total amount of the organic matter of the influent sewage introduced; A fourth step of precipitating the microorganisms grown in the aeration tank by solid-liquid separation in a secondary settling cell, returning some of the sludge to the dephosphorization tank and returning some of the sludge to the denitrification tank; Forming a anaerobic condition by solid-liquid separation of the sludge stored in the dephosphorization tank, and then returning the sludge with low phosphorus content and the supernatant with high phosphorus content to an aeration tank which is an aerobic condition; And a sixth step of removing the phosphorus-containing sludge returned from the dephosphorization tank to remove excess phosphorus from the aeration tank so as to remove the phosphorous sludge.

4. Important uses of the invention

In biological treatment facilities of high phosphorus and nitrogen pollutants such as sewage and wastewater, it is possible to maximize the removal of phosphorus by increasing the nitrogen removal rate of the whole system and minimizing the concentration of nitrate nitrogen flowing into the dephosphorization tank from the secondary settler. Simultaneous removal of biological phosphorus and nitrogen.

Description

Simultaneous Removal of Biological and Nitrogen Removal Devices and Methods

The present invention improves the conventional postrip developed only for the removal of phosphorus in biological wastewater and wastewater treatment process, and removes organic matter and at the same time, it is modified biological post phosphorus method that can remove nutrients such as nitrogen and phosphorus. And a simultaneous nitrogen removal apparatus and method.

In general, organic wastewater such as sewage and wastewater is removed organic matter in the secondary treatment process of the standard activated sludge method, but nutrients such as nitrogen and phosphorus are not treated well only by the secondary treatment. It is contained in the treated water and discharged as it is. As a result, eutrophication problems occur in closed waters such as small lakes and bays.

Existing physical and chemical methods for nitrogen removal in sewage and wastewater treatment facilities include air stripping, in which ammonia nitrogen is blown into the air by pH adjustment, and ions by zeolite that selectively replaces ammonia. Exchange methods and removal methods by chlorine injection have been proposed, and methods for removing phosphorus have been proposed by adding chemicals such as alumina sulfate or lime to make soluble phosphorus components into insoluble precipitates and removing them from the final settler. . However, each of the above-described physical, chemical and nitrogen treatment methods require a lot of maintenance costs, and in recent years, the biological and nitrogen removal methods are more economically used than the physical and chemical treatment methods.

Explaining the principle of biological nitrogen removal, ammonium ion (NH4 + -N) in sewage is oxidized to nitrous nitrogen (NO-2-N) or nitric acid (NO-3-N) under aerobic rich aerobic conditions. In the oxygen-free state in which dissolved oxygen is depleted, it is reduced to nitrogen gas and removed by breathable bacteria.

In the process of oxidizing ammonium ion to nitrite or nitrate nitrogen by microorganisms, dissolved oxygen is required.In the anoxic state, which is a denitrification process to reduce nitrate nitrogen to nitrogen gas, injection of organic carbon source is required from outside. Mainly, methanol was used. However, because of the high maintenance costs, the process has recently been developed to use BOD components contained in sewage instead of methanol as an organic source.

The principle of phosphorus removal in the anaerobic-aerobic process, which is a key process for biological phosphorus removal, is as follows.

In anaerobic processes, demineralized microorganisms take in organic matter from the influent sewage and store it in the form of PHB (Polyhydro-β-butyrate) in the cell, and the required energy is obtained by hydrolysis of ATP in the cell. In the process, phosphorus in the cell is released into orthophosphate (PO4 ---- P). Subsequent aerobic baths oxidize the etch ratio accumulated in the cell and at the same time consume more than the amount of phosphorus released from the anaerobic bath for cell resynthesis. In biological secondary treatment, phosphorus is ingested quantitatively and the phosphorus content in cells is 1.5 to 2% by dry weight. However, in the process followed by anaerobic processes followed by aerobic, the phosphorus content in cells reaches 4-8%, much higher than the stoichiometric amount, which is 2-4 times more than typical biological secondary treatment.

Various methods that have been put to practical use using the above-described biological phosphorus and nitrogen removal principles have been proposed, and among them, a postrip method has been proposed as a method having excellent phosphorus removal rate.

The post-lip method removes the organic matter from the influent sewage in the aeration tank, and anaerobic conditions retain some of the sludge returned to the aeration tank from the secondary settler for a long time in the dephosphorization tank, a gravity thickening tank. The organic material produced by the cell decomposition of is used. Sludge whose phosphorus is released from the dephosphorization tank and the phosphorus content is lowered is transferred to the aeration tank to consume phosphorus in excess in the aeration tank, and the dephosphor supernatant concentrated with phosphorus is removed by chemical treatment.

However, in the post-lip method, considering not only phosphorus removal but also nitrogen removal, the operation conditions of the aeration tank not only oxidize organic substances but also oxidize nitrogen substances, are operated in the conveying sludge transported from the secondary settling tank to the dephosphorization tank. The organic material to be discharged by the nitrate nitrogen contained in the nitrate nitrogen is removed to have a negative effect on the phosphorus release in the dephosphorization tank has a problem that the removal rate of phosphorus is lowered.

In order to solve the above problems, in the conventional post-lip method, an improved method for removing nitrogen as well as phosphorus removal is to remove only organic matter in the aeration tank, and further install nitrification and denitrification facilities after the secondary settler, or the secondary settler. In order to reduce the inflow of nitrate nitrogen into the dephosphorization tank by installing a denitrification tank and a denitrification tank, it has been proposed.

However, in the case of the former method, the construction cost is increased by the addition of nitrification and denitrification facilities after the secondary settler. Also, since the concentration of organic matter is very low compared to the inflow wastewater, the denitrification tank There is a problem to supply an organic carbon source such as methanol from the outside. In addition, in the latter method, since only the denitrification tank is installed in comparison with the former method, the construction cost is low but the carbon source is not supplied from the outside, so the residence time of the denitrification tank is increased to 8 hours or more, and the size of the denitrification tank is increased, and the secondary settler battery The flow rate from the to denitrification tank is only about 30%, which implies low total nitrogen removal rate of the whole system.

Therefore, the present invention has been devised to solve the above problems, and only the denitrification tank is placed in front of the aeration tank, and the mixed sludge solution having a high nitric acid nitrate concentration in the aeration tank is returned to the denitrification tank, where the organic matter concentration is high in the denitrification tank. By removing all nitrogen by using all organic materials as carbon source, the nitrogen removal rate of the whole system is increased, and as a result, the removal rate of phosphorus is reduced by minimizing the nitrate nitrogen concentration flowing into the dephosphorization tank by increasing the nitrogen removal rate of the whole system. It is an object of the present invention to provide an apparatus and a method for simultaneously removing biological phosphorus and nitrogen which can be further improved than the method.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram of a process apparatus for carrying out a biological phosphorus and nitrogen simultaneous removal method modified from a post-lip method according to the present invention;

* Explanation of symbols for main parts of the drawings

1: Primary sedimentation drainage sewage 2: Denitrification tank

2a: agitator 3: denitrification tank effluent

4: aeration tank 5: first conveying sludge

6: aeration tank effluent 7: secondary rechargeable battery

8: excess sludge discharged water 9: second conveying sludge

10: third conveying sludge 11: dephosphorization tank

12: dephosphorization supernatant 13: fourth conveying sludge

14: Secondary battery discharged water

In order to achieve the above object, the present invention accommodates the influent sewage through the primary sedimentation battery, and reduces the return sludge mixed liquid with high nitrate nitrogen concentration circulated in the aeration tank using the organic material contained in the influent sewage to nitrogen gas. Denitrification tank to remove by; An aeration tank for receiving the effluent discharged from the denitrification tank and returning the sludge mixture having a high nitrogen nitrate concentration to the denitrification tank; A secondary settling battery which receives and discharges effluent water discharged from the aeration tank and returns a predetermined amount of sludge to the denitrification tank and the dephosphorization tank; Biological phosphorus and nitrogen modified from the post-lip method including a dephosphorization tank for transporting sludge and supernatant to the aeration tank by receiving a predetermined amount of sludge with a very low nitrate nitrogen concentration discharged from the secondary sedimentation cell and separating it by gravity concentration. Provide a simultaneous removal device.

In addition, the present invention is a first step of mixing the primary sedimentation effluent and the conveying sludge in the denitrification tank and then transported to the aeration tank; Removing the organic matter and nitrifying the aeration tank and returning the nitrified mixed sludge solution to the denitrification tank; The denitrification tank is a third step of increasing the nitrogen removal rate of the entire system by removing the nitrate nitrogen returned by using the total amount of the organic matter of the influent sewage introduced; A fourth step of precipitating the microorganisms grown in the aeration tank by solid-liquid separation in a secondary settling cell, returning some of the sludge to the dephosphorization tank and returning some of the sludge to the denitrification tank; Forming a anaerobic condition by solid-liquid separation of the sludge stored in the dephosphorization tank, and then returning the sludge with low phosphorus content and the supernatant with high phosphorus content to an aeration tank which is an aerobic condition; And a sixth step of removing the phosphorus-containing sludge returned from the dephosphorization tank to remove excess phosphorus from the aeration tank so as to remove the phosphorous sludge.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a process apparatus for carrying out a simultaneous removal of biological phosphorus and nitrogen according to the present invention, 1 is a primary sedimentation cell discharge sewage, 2 is a denitrification tank, 2a is a stirrer, 3 is the denitrification tank effluent, 4 is the aeration tank, 5 is the first conveying sludge from the aeration tank to the denitrification tank, 6 is the aeration tank effluent, 7 is the secondary sedimentation cell, 8 is the surplus sludge discharge water, 9 is the second 2 conveying sludge, 10 is the third conveying sludge from the secondary settler to the denitrification tank, 11 is the dephosphorization tank, 12 is the dephosphorization supernatant with high phosphorus content, 13 is the fourth conveying sludge which conveys the til-in sludge with lower phosphorus content to the aeration tank, 14 represents the secondary sedimentation effluent, respectively.

Biological phosphorus and nitrogen removal apparatus and method remodeling the post-lip method according to the present invention, as shown in Figure 1, by receiving the effluent sewage (1) through the primary sedimentation battery using the organic material contained in the effluent A denitrification tank (2) for reducing and removing the return sludge mixed liquid having a high concentration of nitrate nitrogen circulated in the aeration tank (4), and an effluent (3) discharged from the denitrification tank (2) to accommodate The aeration tank 4 for conveying the sludge mixture 5 having a high concentration to the denitrification tank 2 and the effluent 6 discharged from the aeration tank 4 are accommodated and precipitated. The secondary needle battery 7 for conveying a predetermined amount of sludge to 11 and the sludge having a very low nitrate nitrogen concentration discharged from the secondary needle battery 7 are returned in a predetermined amount to solid-liquid separation by gravity concentration. ) And the supernatant (12) to the aeration tank (4) It is composed of a dephosphorization tank (11).

Here, the denitrification tank 2 has a built-in agitator 2a for evenly mixing the sludge 8 conveyed from the aeration tank 4 and the secondary settling battery 7 and the inflow sewage, and the denitrification tank 2 is The total amount of effluent sewage (1) leaked from the primary sedimentation battery is formed in an anoxic tank so as to increase the nitrogen removal efficiency of the entire system by taking only the denitrification process.

Referring to the contents of the present invention according to the process of Figure 1 in detail as follows.

The denitrification tank 1 has a high concentration of nitrate nitrogen from the effluent sewage 1 which has passed through the primary sedimentation battery (not shown), the third conveying sludge 10 of the secondary sedimentation battery 7, and the aeration tank 4. The first conveying sludge 5 is mixed, and the nitrogenous nitrate in the first conveying sludge 5 having a high nitrate nitrogen concentration conveyed from the aeration tank 4 is organic matter of the influent sewage 1 passing through the primary settling cell. It is removed by reducing with nitrogen gas.

Here, the function of the denitrification tank 2 of the present invention is different from the function of nitrogen removal facility of the conventional modified post-lip method. In the conventional method, the nitrogen removal facility is installed in the process after the secondary sedimentation cell. Since treated water is used as a carbon source, the nitrogen removal rate of the entire system is low, and as a result, the content of nitrogen nitrate introduced into the dephosphorization tank is high, so that the phosphorus is not easily released in the dephosphorization tank. Is consumed in the denitrification process installed in front of the aeration tank, and the nitrogen removal rate of the entire system is increased. In addition, since most of the inflow organic matter is consumed in the denitrification tank, even if the hydraulic retention time of the aeration tank is very short, the aeration tank 4 may exhibit high efficiency of organic matter removal rate. The hydraulic residence time of the denitrification tank 2 is suitable if it is about 1 to 2 hours on the basis of the inflow flow rate after the primary settling tank, and an agitator 2a is installed for even mixing of the influent sewage and the return sludge.

In the aeration tank 4, phosphorus is discharged from the outflow water 3 including the mixed sludge passed through the denitrification tank 2 and the dephosphorization tank 11 to introduce a sludge 13 having a low phosphorus content. In the aeration tank 4, oxidation of the organic matter of the influent sewage through the denitrification tank 2, oxidation of ammonia nitrogen to nitrate nitrogen, and excessive intake of phosphorus occur. The aeration tank 4 has an organic load of 0.1 kg BOD / kg MLVSS · d ~ 0.3 kg BOD / kg MLV SS · d in order to provide favorable conditions for the growth of nitrifying microorganisms, the hydraulic retention time is about 4 hours .

The mixed sludge, which is nitrified in the aeration tank 4 and has a high concentration of nitrate nitrogen, is returned to the denitrification tank 2 to undergo a denitrification process, and then flows back into the aeration tank 4. The internal conveyance ratio from the aeration tank 4 to the denitrification tank 2 is in the range of 1 to 4 times the amount of the inflow sewage 1, while the nitric acid loading rate in the denitrification tank 2 is about 1/4 of the inflow COD value. The return cost is appropriate.

The microorganisms grown in the aeration tank 4 are precipitated by solid-liquid separation in the secondary settling battery 7, and the third conveying sludge 10, which is about 50% of the precipitated sludge, is returned to the denitrification tank 2, and about 10 The 2nd conveyance sludge 9 which is -15% is conveyed to the dephosphorization tank 11. As shown in FIG.

The second conveying sludge 9 conveyed from the secondary needle battery 7 is solid-liquid separated in the dephosphorization tank 11 which is a gravity type concentration tank. The dephosphorized sludge layer is anaerobic and phosphorus is released, and the phosphorus is released and sludge having low phosphorus content is returned to the aeration tank for excess absorption of phosphorus in the aeration tank 4 which is an aerobic condition. Although the phosphorus-containing dephosphorized supernatant 12 was discharged after being chemically removed in the conventional post-lip method, the process of the present invention has almost no effect on the phosphorus release by nitrate nitrogen in the process of the present invention. Return it. Sludge Detention Time (SDT) is preferably 8 to 12 hours for the sludge required for the smooth release of phosphorus by using the organic material generated by cell decomposition in the dephosphorization tank (11) as a carbon source. 7), the sludge flow rate 9 from the dephosphorization tank 11 is about 10 to 15% of the inflow flow rate 1, and the sludge transfer amount from the dephosphorization tank to the aeration tank 4 is about 50% of the dephosphorization inflow flow rate 9. The dephosphorization supernatant (12) is about 50% of the dephosphorization inflow (9). In the conventional post-lip method and the improved method of the post-lip method, the return ratio from the secondary needle battery 7 to the dephosphorization tank 11 usually returns 30% of the inflow flow rate of the aeration tank. In the case where the generated nitrate nitrogen is treated in the denitrification tank, the return ratio from the secondary settler to the dephosphorization tank may be 10 to 15% of the inflow flow rate by improving the nitrogen removal rate.

Example 1

The influent sewage used in this experiment was the domestic sewage flowing into the sewage treatment plant, which was carried out for about 6 months while the concentrations of nitrogen and phosphorus were fixed and only the influent organic matter was changed. The characteristics of influent sewage for each condition are shown in Table 1, and the experimental scale was the size of a pilot plant with a treatment capacity of 20M3 / day.

Table 1 Characteristics of Influent Sewage

(Unit: mg / 1)

* Reduced organic matter concentrations such as inflow of sewage treatment plant, ** chemical oxygen demand, biological oxygen demand, etc. were diluted using tap water, and artificial dilution of urea fertilizer or phosphate fertilizer to prevent ammonia nitrogen and total phosphorus concentration during dilution. It was.

The experimental facility was composed of denitrification tank (2), aeration tank (4), secondary sedimentation battery (7), dephosphorization tank (11) as shown in FIG. 1, and the material used was 3.2 mm thick iron plate.

The size of the denitrification tank 2 was about 1.7m 3, and the residence time was about 2 hours based on the inflow flow rate.In the denitrification tank 2, the sludge 5 returned from the inflow water 1 and the aeration tank 2 and the secondary settler battery 7 Agitator having a speed of about 90rpm was installed so that the sludge 10 conveyed from) was evenly mixed. The capacity of the aeration tank 4 was about 3.4m 3, and three partitions were installed in the tank to constitute four compartments, and 150 L / min air was supplied to the blower for proper oxygen supply and mixing in the tank.

The secondary sedimentation cell 7 had a capacity of 3.3m 3, and some of the sludge deposited was directly returned to the denitrification tank, and some of the sludge was returned to the dephosphorization tank. The capacity of the dephosphorization tank 11 was 3.3 m 3, and the sludge in the lower part of the dephosphorization tank and the dephosphorization supernatant were all returned to the aeration tank 4 for the purpose of absorbing phosphorus.

Experimental conditions of each reactor performed in the experiment of the present invention are shown in Table 2.

Table 2 Experimental Conditions of Each Reactor

Inflow Sewage (Q) 20㎥ / day

Denitrification tank hydraulic residence time: 2 hours (based on influent sewage)

Aeration tank hydraulic stay time: 4 hours

F / M ratio: 0.1 to 0.3 kg BOD / kg MLSS · d, microbial concentration: 3,000 to 4,000 mg / l

Desalination sludge residence time: 8 to 12 hours, microbial concentration: 20,000 to 25,000 mg / l

Return sludge

-Aeration tank → Denitrification tank 4Q

-Secondary Battery → Denitrification Tank 0.5Q

-Rechargeable battery → dephosphorizer 0.1 ~ 0.15Q

-Dephosphorization tank → aeration tank 0.05∼0.75Q

Table 3 summarizes the average sedimentation effluent water quality of the results of the fixed and experimental conditions of Table 2 and performed for each condition.

Table 3 Outflow water quality analysis result of invention method

(Unit: mg / 1)

Total nitrogen (T-N): total Kjeldahl nitrogen (TKN) + nitrogen oxides (NOX-N)

Total phosphorus (T-P): suspended solids + soluble

Comparative Example 1

Table 4 shows aeration tank and dephosphorization tank of the same size as in Example 1 for comparative analysis between the present invention method and the post-lip method for the purpose of removing phosphorus only and the nitrogen-removing method. As a result of denitrification with a denitrification tank with a residence time of 8 hours and operating for the same period with the same design conditions and influent as in Example 1, the organic removal rate such as biological oxygen demand, chemical oxygen demand, and suspended solids and total Kjeldahl and ammonia Nitrification rate such as nitrogen was similar to the present invention. However, only the denitrification tank function installed in the secondary precipitator and the dephosphorization irradiator had a very low total nitrogen removal rate of the whole system, and the total phosphorus removal rate was also low compared to the present invention due to the inflow of nitrogen nitrate into the dephosphorization tank.

Table 4 Water Quality Analysis Results of Post-Lip Effluent

(Unit: mg / 1)

Comparative Example 2

Table 5 shows the addition of aeration tank and denitrification tank of the same size as in Example 1 to compare and analyze the removal rate of nitrogen and phosphorus between ATOO method (A2 / O, hum-denitrification-aerobic), which is a simultaneous method of removing the present invention and phosphorus and nitrogen. The anaerobic tank for phosphorus discharge was installed in front of the furnace denitrification tank and operated under the same conditions as in Example 1 and II. Compared with Table 3, which is the result of the method of the present invention, in the conventional A2O method, the phosphorus and nitrogen removal rate fluctuates greatly according to the change in the concentration of organic matter in the influent sewage, but in the present method, the phosphorus and nitrogen removal rate is stable and the A2O method Phosphorus and nitrogen removal rate was more excellent.

Table 5 Water quality analysis results of Atoo method runoff

(Unit: mg / l)

Comparing the processing efficiency between the conventional post-lip method and the present invention method based on the above-described embodiment, the nitrogen removal step in the conventional post-lip method is installed in a facility after the secondary settler, and is oxidized and left in the aeration tank. The nitrogen removal rate of the whole system is low by using only a small amount of organic matter as a carbon source, but in the present invention, as shown in FIG. 1, the nitrate nitrogen nitrate is returned to the denitrification tank 2 installed at the front of the aeration tank as shown in FIG. In this case, the denitrification tank (2) removes nitrate nitrogen from the first conveying sludge (5) having high nitrate nitrogen concentration by using the influent sewage (1) having high organic concentration as a carbon source, thereby improving the nitrogen removal rate of the entire system. . In addition, since most of the inflow organic matter is removed from the denitrification tank 2, the capacity of the aeration tank 4 becomes smaller than the conventional method. In addition, since the nitrate nitrogen removal rate in the denitrification tank 2 is very high, the nitrate nitrogen concentration in the second conveying sludge 9 flowing into the dephosphorization tank 11 from the secondary needle battery 7 becomes very low. As a result, even if the sludge conveyance from the secondary needle battery 7 to the dephosphorization tank 11 flows directly into the dephosphorization tank 11 without the nitrogen removal process between the secondary needle battery 7 and the dephosphorization tank 11, the dephosphorization tank ( In 11), since there is no influence by nitrogen nitrate, phosphorus release in the dephosphorization tank 11 proceeds smoothly, and phosphorus absorption in the aeration tank 4 proceeds smoothly, resulting in a very stable removal rate of phosphorus.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope without departing from the technical spirit of the present invention. It will be apparent to those who have knowledge.

As described above, according to the present invention, compared to the conventional biological phosphorus and nitrogen removal method, by removing the organic material of the influent sewage in the denitrification process in the denitrification tank installed in the front of the aeration tank, the nitrogen removal rate of the whole system can be improved. As a result, the phosphorus is smoothly released due to the minimum inflow of nitrogen nitrate into the dephosphorization tank, and the phosphorus and nitrogen removal rates are much superior to those of the conventional method.

Claims (10)

A denitrification tank accommodating inflow sewage through the primary sedimentation cell and reducing and removing the return sludge mixed liquid having a high concentration of nitrate nitrogen circulated in the aeration tank by using organic materials contained in the inflow sewage with nitrogen gas; An aeration tank for receiving the effluent discharged from the denitrification tank and returning the sludge mixture having a high nitrogen nitrate concentration to the denitrification tank; A secondary settling battery which receives and discharges effluent water discharged from the aeration tank and returns a predetermined amount of sludge to the denitrification tank and the dephosphorization tank; Biological phosphorus and nitrogen modified from the post-lip method including a dephosphorization tank for transporting sludge and supernatant to the aeration tank by receiving a predetermined amount of sludge with a very low nitrate nitrogen concentration discharged from the secondary sedimentation cell and separating it by gravity concentration. Simultaneous removal device. The apparatus of claim 1, further comprising stirring means for mixing the sludge conveyed from the aeration tank and the secondary sedimentation cell and the inflow sewage evenly in the denitrification tank. . According to claim 1 or claim 2, wherein the denitrification tank is an anaerobic tank remodeling the post-lip method, characterized in that the entire intake sewage of the primary precipitating battery to take only the denitrification process to increase the nitrogen removal efficiency of the entire system. And simultaneous nitrogen removal device. A first step of mixing the first settling basin effluent and the return sludge in a denitrification tank and then transferring the resultant to an aeration tank; Removing the organic matter and nitrifying the aeration tank and returning the nitrified mixed sludge solution to the denitrification tank; The denitrification tank is a third step of increasing the nitrogen removal rate of the entire system by removing the nitrate nitrogen returned by using the total amount of the organic matter of the influent sewage introduced; A fourth step of precipitating the microorganisms grown in the aeration tank by solid-liquid separation in a secondary settling cell, returning some of the sludge to the dephosphorization tank and returning some of the sludge to the denitrification tank; Forming a anaerobic condition by solid-liquid separation of the sludge stored in the dephosphorization tank, and then returning the sludge with low phosphorus content and the supernatant with high phosphorus content to an aeration tank which is an aerobic condition; And a sixth step of removing the phosphorus-containing sludge returned from the dephosphorization tank to remove excess phosphorus from the aeration tank so as to remove the phosphorus-containing sludge. According to claim 4, in the second step, the aeration tank is used to provide favorable conditions for the growth of nitrification microorganisms. The organic load is 0.1 kgBOD / kgMLVSS · d˜0.3 kgBOD / Simultaneous removal of biological phosphorus and nitrogen by modifying the post-rip method, characterized in that kgMLVSS · d range, hydraulic retention time is about 4 to 5 hours. 5. The method of claim 4, wherein the organic carbon source required for nitrogen removal in the third step uses influent sewage. 6. 7. The biological method according to claim 4 or 6, wherein the total amount of inflow sewage of the primary settling battery is required only for the denitrification process in order to increase the nitrogen removal efficiency of the entire system in the third step. And simultaneous removal of nitrogen. 7. The conveying sludge from the secondary settler to the dephosphorization tank according to claim 4 or 6, wherein the nitrate nitrogen generated in the aeration tank in the third and fourth steps is treated using the total amount of influent sewage organic matter in the denitrification tank. A method for simultaneously removing biological phosphorus and nitrogen, wherein the post-lip method is modified so as to reduce the nitrate nitrogen contained in the so as not to affect phosphorus release in a dephosphorization tank. 5. The biological phosphor according to claim 4, wherein the organic material required for phosphorus release in the fifth step is to retain the conveying sludge for a predetermined time to use the organic material produced by cell decomposition. And simultaneous removal of nitrogen. The method according to claim 4 or 9, wherein a portion of the return sludge of the secondary sedimentation battery to the dephosphorization tank in order to use the organic material produced by the cell decomposition for the organic material required for phosphorus release in the fifth step. Simultaneous removal of biological phosphorus and nitrogen modified post-lip method, characterized in that it comprises a process of staying for a time.