KR100350892B1 - Nitrogen & Phosphorous Removing Methods & Equipment with Intermittent Aeration, Dynamic Flow and Variation of Hydraulic Level - Google Patents

Abstract

The present invention relates to a method and apparatus for treating sewage or wastewater, comprising two or more systems combining sedimentation built-in oxidizing sphere, sedimentation-site oxidizing sphere or activated sludge process to construct a sewage waste water treatment facility, and operating in a channel changing method and intermittent aeration method. However, especially in the reaction tank in the stage of denitrification and phosphorus discharge reaction under aerobic agitation conditions, the water level rises as the inflow is stopped and the organic matter in the influent wastewater undergoes denitrification and phosphorus release reaction. Since it is utilized to the maximum, it relates to a wastewater treatment system that can remove nitrogen and phosphorus with high efficiency.

Description

Nitrogen & Phosphorous Removing Methods & Equipment with Intermittent Aeration, Dynamic Flow and Variation of Hydraulic Level

The present invention relates to a method and apparatus for removing nitrogen and phosphorus in a wastewater treatment plant. More particularly, the present invention relates to a combination of two or more unit systems comprising a sedimentation basin in an oxidization ditch, an intermittent aeration, a flow path and The present invention relates to a method and apparatus for operating organically, sewage and wastewater, nitrogen and phosphorus in high efficiency by changing the level of the reactor.

The biological removal process of nitrogen and phosphorus used in the sewage treatment plant undergoes an anoxic process, an anaerobic process that does not supply free oxygen, and an aerobic process that supplies oxygen. In an aerobic reactor, organic nitrogen and ammonia nitrogen are oxidized to nitrate nitrogen, and in the anoxic reactor, denitrification is carried out to reduce nitrate nitrogen to nitrogen gas. Phosphorus is released from the activated sludge in the anaerobic reactor, and the phosphorus thus released is excessively ingested by the microorganisms in the aerobic reactor, and finally, the phosphorus is removed by removing the excess of the phosphorus from the activated activated sludge.

In the conventional nitrogen and phosphorus removal method, the anaerobic tank, the anaerobic tank, and the aerobic tank are separated separately and fixedly installed at a predetermined capacity, so that the inflow water quality and the inflow flow rate cannot be flexibly coped with. In addition, the injection of methanol for the denitrification has a problem in that a large chemical cost or a large pump facility cost, power costs and maintenance costs for the internal circulation using the organic matter in the sewage.

In order to improve the above problems, the intermittent aeration method and the flow path change method have been proposed, and the conventional method (Phased Isolation Ditch) method, which is representative of the conventional technology adopting this method, is a preliminary denitrification tank, an optional tank, an anaerobic tank, and a sedimentation basin and a unit. Installation costs, power costs, and facility management costs due to the installation and operation of agitators, sludge collectors, and sludge conveying pumps, which are facilities, have a problem.

In addition, in the PID method, the sludge that has undergone phosphorus release in an anaerobic tank is introduced into an oxidizing sphere under anoxic conditions, which is not aerobic, and thus, microorganisms are not sufficiently activated, and the phosphorus intake efficiency may be lowered. Since the adsorbed sludge continues to flow out, the denitrification efficiency may be lowered.

In order to solve the above-mentioned problems of the PID method, the applicant invented and named the PhICD (Phased Isolated Intra Clarifier Ditch) and published in Korea. U.S. Patent No. US006030528A, "Water Treatment Plant for Removing Nitrogen and Phosphorous", filed with US Patent No. US006030528A, in which oxygen free radicals or nitrogen oxides are not introduced from the aerobic oxidation spheres and organic matters are not lost from the aerobic oxide spheres. Improved denitrification efficiency. In addition, the aerobic oxidized spheres undergoing nitrification prevented the inflow of organic matter from anoxic or anaerobic oxidized spheres to improve the nitrification efficiency. The flow path and flow control means that can be changed are introduced.

However, even in PhICD, when the influent C / N ratio is low, it is difficult to maintain the nitrogen removal efficiency sufficiently high, and it is important to ensure that organic matter in the influent wastewater is not wasted and utilized to the denitrification reaction. Particularly, steps (b) and (d) of PID and steps (b) and (d) of PhICD correspond to a preliminary step for changing the flow path and phase, so that all of the oxidizers are aerobic. Therefore, in these stages, organic matter in the influent wastewater does not contribute to the denitrification reaction and is consumed. Therefore, the method of utilizing the influent organic matter to the denitrification reaction should be continuously improved.

In addition, in the conventional PhICD, two four-way waterways are used as a channel change method. However, four-way waterways are applied to a treatment facility that has already been constructed as an integrated wall so that two oxidation spheres use one wall together. It is a difficult structure.

Therefore, the present invention is improved to improve the denitrification efficiency by utilizing the influent organic matter in PhICD to maximize the denitrification reaction, it can reduce the facility cost and maintenance costs, intermittent aeration method that can effectively remove nitrogen and phosphorus in sewage It is an object of the present invention to provide a wastewater treatment method and apparatus to which the depth of the reactor is added to the overflow change method.

In order to achieve the above object, in the present invention, the waste water is introduced into the oxidizing sphere in the anaerobic or anaerobic stage for a predetermined time, but the water depth is lowered in advance in the aerobic stage so that there is no outflow. Depth-efficiency is improved because the depth of the water is lowered even if the wastewater flows in due to the conversion of the stages. In addition, if the step is switched to the anaerobic or anaerobic oxidizing sphere is aerobic and the outflow occurs, the water level is lowered when the conditions are changed to the next anaerobic and anaerobic, the process of desalination of the influent wastewater for a certain time without an external outflow will be repeated. Improvements were made to help.

Accordingly, in the sewage treatment apparatus for nitrogen and phosphorus removal according to the present invention, the installation position of the flow path flowing out of the sedimentation basin to the outside as the treated water is lowered so that the water level in the oxidizing sphere may be changed in accordance with the direction in which the wastewater flows. The flow path and flow path control means were introduced, and the flow path control means was adopted in each channel so that the flow path change method was easily adopted even in the completed oxidized sphere.

(A)-(d) is a flowchart of the nitrogen-phosphorus removal method which concerns on this invention,

Figure 2a is a schematic diagram of a first embodiment of the nitrogen-phosphorus removal apparatus according to the present invention,

Figure 2b is a perspective view of the flow path portion of the first embodiment according to the present invention,

Figure 3 (a)-(d) is a flow chart of the operation method of the nitrogen-phosphorus removal apparatus according to the present invention,

4 is a schematic view of a second embodiment of the nitrogen-phosphorus removing apparatus according to the present invention.

* Description of the symbols for the main parts of the drawings *

1: First settler built-in oxidizer 1a: Second settler built-in oxidizer

2: the first precipitated external oxidizing sphere 2a: the second precipitated external oxidizing sphere

3: first oxidation sphere 3a: second oxidation sphere

4: first rechargeable battery 4a: second rechargeable battery

5, 5a: sludge collection device 6, 6a: sludge conveying pump

7: first external settler 7a: second external settler

41: first raw water control valve 41a: second raw water control valve

42: first treatment water control valve 42a: second treatment water control valve 43: first backflow check valve 43a: second backflow check valve

51: inflow of raw water

52: first treated water outflow passage 52a: second treated water outflow passage

53: first oxidation inlet flow path 53a: second oxidation inlet flow path

54: first settler outflow channel 54a: second settler outflow channel

55: first month flow path 55a: second month flow path

61, 62a: stirring means 62, 62a: aeration means

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

1: Flow chart of nitrogen and phosphorus removal method

1 is a flow chart showing a nitrogen, phosphorus removal method according to the present invention, the sedimentation basin built-in oxidizing sphere (4, 4a) is built in the oxidation sphere (3, 3a) equipped with aeration means and stirring means (not shown) ( The wastewater treatment system combining two or more units of 1, 1a) shows the nitrogen / phosphorus removal process by changing the flow path and intermittent aeration.

≪Step (a) of FIG. 1≫

Step (a) of FIG. 1 is a process in which the denitrification reaction, the phosphorus release reaction, the organic decomposition and the nitrification reaction are combined, and the denitrification reaction and the phosphorus release reaction occur in the first settler-type oxidation sphere (1), and the second settler-type oxidation sphere (1a). ) Is the stage where nitrification occurs. In the configuration of the flow path, the inflow water first flows into the first settler built-in oxidizing sphere, and the outflow water of the first settler built-in oxidizing sphere flows out again as treated water through the second settler built-in oxidizing sphere.

At this time, in the first oxidation sphere (3), which is a unit element constituting the first settler built-in oxidation sphere, the operation of the aeration plant is stopped and the agitating plant is operated under anoxic conditions, and nitrogen oxides are converted into glass nitrogen by the organic matter contained in the influent. Reducing denitrification occurs. At the same time, in the second oxidizing sphere 3a, which is a unit element constituting the second settler built-in oxidizing sphere, the aeration system is operated to cause organic matter decomposition and nitrification reaction in aerobic.

Since the water level of the first settler built-in oxidizing sphere is controlled in advance in the previous step, the inflow and wastewater for a predetermined time from the beginning of this stage is not freshly flowed to the second settler built-in type oxidizing sphere until the water level is continuously raised. . While fresh water is formed in the first settler-type oxidizing sphere and the water level is increased, in the second settler-type oxidizing sphere, the treated water is discharged to the outside in the absence of inflow, and the water level is lowered. Prepare for freshwater when converted to.

In the applicant's conventional invention, PhICD, the symbolic water of the sedimentation basin is overflowed from the first settler-type oxidizing sphere from the beginning of step (a) and flows into the second settling-type oxidizing sphere. However, in step (a) of the present invention, since no outflow occurs for a predetermined time in the first settler-type oxidizing sphere, only inflow of wastewater is made, so that organic matter, which is an electron donor included in the influent, does not leak at all, thereby improving denitrification efficiency. In the second oxidizing zone, the inlet organic load is reduced, so the nitrification efficiency is improved.

When the denitrification is terminated in step (a) and the combined oxygen in the form of nitrogen oxide is also depleted, the first oxidized sphere is converted to completely anaerobic under anoxic conditions, thereby allowing the phosphorus release reaction from the sludge. In other words, the denitrification and phosphorus-release reaction proceeds with time difference in the same reaction tank under the same flow path conditions, so it is more economical in terms of facility and maintenance than the conventional PID, and the operation is simple.

`` Step (b) of Figure 1 ''

In step (b) of FIG. 1, the first settler-containing oxidation sphere 1, which was anaerobic in step (a), is also converted to aerobic. At the same time, since the flow path is changed and operated under no load without inflow, the oxygen consumption is very small because only the oxygen necessary for breathing of activated sludge is consumed. Therefore, in this step, the first settler-containing oxidized sphere rapidly converts into aerobic and sludge which has released phosphorus in the anaerobic phase of the previous stage ingests a larger amount of phosphorus than the state before release, and the concentrated phosphorus sludge It removes phosphorus by removing.

In step (b), the flow path of step (a) is changed so that the inflow water flows directly into the second settler-type oxidizer (1), that is, the second oxidizer (3a), without passing through the first settler-type oxidizer. It flows out into the process water through (4a), and the level of the second settler built-in oxidizing sphere is kept low. The second oxidative sphere is maintained in an aerobic state while decomposing organic matter and nitrification continues.

≪Step (c) of FIG. 1≫

In step (c) of FIG. 1, the reaction forms are different from those of step (a), except that the roles and flow paths of the first and second settler-containing oxidizing spheres 1 and 1a are changed to a process in which denitrification, phosphorus release and nitrification are performed. same. That is, in step (c), the flow path is introduced so that the raw water flows into the second settler built-in oxidizing port (1a) where nitrogen oxides are accumulated and the water level is lowered to allow additional fresh water in step (a) and (b). After changing, the aeration device stops operation and enters the aeration stir state, so that the denitrification reaction and the phosphorus release reaction are performed. At the same time, the first settler built-in oxidizing sphere (1) operates the aeration device and organic decomposition and nitrification reactions continue, and the water level is lowered because the outflow is made without inflow for a certain period from the beginning of the stage.

As shown in FIG. 1, the processing sequence in step (a) is as follows: raw water inflow → first sedimentation-type oxidizing sphere (1) [→ first oxidizing sphere (3) → first sedimentation cell (4)] → second sedimentation-containing oxidizing sphere ( 1a) [→ 2nd oxidation sphere 3a → 2nd settling battery 4a] → treated water outflow. In step (c), the flow path of step (a) is changed so as to be in the opposite direction, so that the raw water inflow → the second precipitated battery-type oxidation sphere 1a [→ the second oxidation sphere 3a → the second precipitated battery 4a] → the first precipitated battery The internal oxidizing sphere (1) [→ the first oxidizing sphere (3) → the first settler (4)] → the treatment water outflow. That is, in step (a), the denitrification and phosphorus releasing reaction and the increase in the water level are performed in the second settler-type oxidation sphere in step (a), and in the second settler-type oxidation sphere in step (a) In the step (c), the nitrification reaction and the lowering of the water level were replaced only to be performed in the first settler-type oxidizing sphere, and the reaction contents of step (c) correspond to the mirror image relations of the reaction contents of step (a).

≪Step (d) of FIG. 1≫

In step (d), the reaction contents of the flow path, the first oxide sphere 3, and the second oxide sphere 3a are the same as those of step (b). That is, the first settler built-in oxidizer (1) is operated in aerobic flow while the inflow and outflow is generated to maintain a low level, the second settler built-in oxidizer (1a) is operated in aerobic no-load conditions without flow and organic load This is the stage.

As shown in FIG. 1, the flow in step (b) is the inflow of raw water into the second settler-type oxidized sphere (1a) [→ the second oxidized sphere (3a) → the second settler (4a)] In step), the flow path is changed from the inflow of raw water into the first settler-type oxidized sphere (1) [→ the first oxidized sphere (3) to the first settler (4)] → treated water outflow. The reaction contents in step (d) are the same as in step (b) except that the reaction contents of the first and second settler-containing oxidized spheres are changed.

In addition, the second settler-type oxidizing sphere of step (b) described above is an aerobic condition in which the aeration device is operated. The conditions are not reached and a significant amount of organic material is wasted. However, in the second settler built-in oxidation sphere of step (b), the treated water flows out to the outside, so if the aeration time is too long to prevent waste of organic matter, it becomes anaerobic and worsens the sludge settling property and the treated water quality deteriorates. Therefore, the denitrification efficiency in step (c) may be improved by dissolving dissolved oxygen at a time when the second oxidizing sphere is aerobic stirred from a certain time before step (b) is terminated. .

In addition, step (d) corresponds to the mirror image of step (b), and in the first settler-type oxidizing sphere, the aerobic agitation is maintained from a certain time before the end of the step and the dissolved oxygen is depleted after the next step ( Switching to step a) can make the best use of organics and improve the denitrification efficiency.

The above steps are summarized in Table 1.

Composition of reaction and flow path for each step [See Figure 1] step Reaction and water level Composition of the euro Relationship with the prior art First settler built-in oxidizing sphere (1) Second settler built-in oxidizer (2) (a) Increased internal circulating water level of raw water inflow anaerobic, anaerobic denitrification and phosphorus release sludge Treated water outflow Aerobic decomposed nitric oxide sludge Raw water inflow → first oxidizing sphere (3) → first immersion battery (4) → second oxidizing bulb (3a) → second sedimentation battery (4a) → treated water effluent The first stage (a) of PID and the anaerobic process and the replacement of the facility, corresponding to the steps (a) and (a-1) of PhICD. (b) No-load (no inflow) Excess intake sludge inside aerobic adult Raw water inflow treatment water outflow aerobic organic sedimentation oxidation sludge internal circulation low water level maintenance Raw water inflow → Second oxidation sphere (3a) → Second settler battery (4a) → Outflow of treated water Corresponds to step 2 (b) of PID. Corresponds to step (b) of PhICD. (c) Treatment Water Outflow Aerobic Organic Sludge Oxidation Reaction Inside Sludge Internal circulating water level in raw water inflow anaerobic, anaerobic, denitrification release sludge Raw water inflow → Second oxidation sphere (3a) → Second precipitation battery (4a) → First oxidation sphere (3) → First settlement battery (4) → Treatment water outflow The third stage (c) of PID and the anaerobic process and the replacement of the facility, corresponding to (c) and (c-1) of PhICD. Symmetry step of step (a) (d) Raw water inflow treatment water outflow aerobic organic sedimentation oxidation sludge internal circulation low water level maintenance No-load (no inflow) Excess intake sludge of aerobic adult Raw water inflow → Oxidation sphere (3) → First settler (4) → Treatment water outflow Corresponds to step 4 (d) of PID. Corresponds to step (d) of PhICD. Symmetry step of step (b)

Fig. 2A: Outline of Apparatus First Embodiment

FIG. 2A is an embodiment in which a flow path required in each step of FIG. Specifically, the raw water inflow channel 51, the treated water flow paths 52 and 52a, the raw water inflow channels 53 and 53a of the first and second oxidation spheres, the first and second settler outflow channels 54 and 54a and the oxidation sphere The sedimentation basins are connected to cross the flow paths 55 and 55a, and as the flow path changing means, the valves 41 to 42a and the non-return valves 43 and 43a in the flow paths are used.

Raw water flows into the first oxidation sphere (3) of the first settling-type oxidation sphere (1) or the second oxidation sphere (3a) of the second settlement-type oxidation sphere (2) via the raw water inflow passage (51). The flow passage branches into the flow passage 53 or the second oxidation inlet flow passage 53a, and each flow passage is provided with raw water control valves 41 and 41a, and each flow passage has a check valve 43 and 43a. It is installed.

In addition, the first and second oxidizing spheres and the two sedimentation basins are connected to each other so that a supernatant flows from the first settler 4 to the second oxidizing sphere and from the second settler 4a to the first oxidizing sphere. February flow passages 55 and 55a are provided.

The first settler outflow channel 54 and the second settler outflow channel 54a are branched into the monthly flow channel and the treated water outlet channel 52 and 52a, respectively, and each of the treated water outlet channel has an outflow water control valve 42, 42a). In order to reduce the facility cost, it is advantageous to integrate the treated water outflow passage after the effluent control valve. The overflow passages are installed at positions higher than the sedimentation outlet flow passage, the treated water outlet flow passage, and the treated water control valves so that the level of the oxidation sphere can be changed as the flow path is changed by the valve operation.

Fig. 2b: Perspective view of the flow path of the first embodiment of the device>

FIG. 2B shows the overflow passages 55 and 55a in the sedimentation basin outflow passages 54 and 54a and the treated water outflow passage so that the water level in the oxidation sphere can be changed as the valve is operated to change the flow passage in FIG. 2A. 52, 52a) and the configuration of the flow path that is installed higher than the position of the treatment water control valve (42, 42a) is shown in a perspective view.

3: Description of Operation Method of Apparatus First Embodiment>

FIG. 3 is a diagram illustrating a method of realizing the flow path of each step shown in FIG. 1 using the apparatus shown in FIG.

≪Step (a) of FIG. 3≫

This step shows an operation state of the flow path in order to realize the reaction contents, the process and the flow path of the step (a) of FIG. 1 in which the first settler-type oxidation sphere 1 is operated in an oxygen-free or anaerobic state.

In this step, the first raw water control valve 41 installed in the flow passage 53 directed to the first oxidation sphere 3 is opened, and the second raw water control valve 41 a installed in the flow passage 53a directed to the second oxidation sphere 3a. ) Is closed so that the raw water is introduced into the first oxidation sphere (3).

Then, the first treated water control valve 42 is closed and the second treated water is adjusted so that the outflow of the first settler 4 flows into the second oxidation sphere, and the outflow of the second settler 4a flows out as the treated water. The valve is operated to open. However, since the water level of the first settler built-in oxidizing sphere is low, the raw water is not flown from the first settler to the second oxidizing sphere until it is higher than the level of the second settler settling oxidizing sphere (a). The inflow does not occur to the second oxidizing sphere until a certain time elapses after the start of the step. That is, since the second treatment water control valve through which the treated water flows out is opened, and the first treatment water control valve 42 on the side of the first settler battery 4 flowing over the second oxidation sphere is closed, the first settler battery 4 As the water level rises so that the treated water does not flow out and flows up the first monthly flow passage 55 in a high position, the symbol water of the first settler flows into the second oxidation sphere, and flows into the second oxidation flow passage 55a. The first non-return valve 43 is closed to prevent the reaction liquid from flowing back.

In addition, when the first treatment water control valve 42 installed on the second settler side is opened, the outflow water of the second settler does not overflow the second monthly flow passage 55a at the high position and the second settler outflow channel at the low position. Since the water flows out through the 54a and the treated water flow passage 52a, the level of the second settler built-in oxidizing sphere is lowered.

`` Step (b) of Figure 3 ''

In step (b) of FIG. 3, the treatment water control valves 42 and 42a maintain the same operation state as the previous step (a), and the first oxidation inlet flow path 53 is opened in step (a). The raw water control valve 41 is closed, and the second raw water control valve 41a of the second oxidation inlet flow passage 53a is opened to stop the raw water inflow of the first oxidation port 3 and flow into the second oxidation hole 3a. do.

Since the first raw water control valve is closed while the second treatment water control valve 42a is open, and the symbol water is not flowed into the first oxidizing sphere in the second settler 4a, the first raw water control valve 42a is opened. 1) is operated with no load and no load while maintaining the water level that was raised in the previous stage.

Since the second treatment water control valve is opened and the treated water is leaked to the outside, the symbol water in the second settler built-in oxidation hole 1a is treated through the second settler outflow passage 54a and the second treatment water outlet flow passage 52a. As the water flows out to the outside, the level of the second settler built-in type is kept low as in step (a).

In step (b), since both the first and second settled internal oxidizing spheres must be operated in aerobic, the aeration means 62 of the first oxidizing sphere starts operation and the aeration means 62a of the second oxidizing sphere is performed in step (a). Keep running as shown.

≪Step (c) of FIG. 3≫

This step shows the operating state of the flow path in order to realize the reaction contents, the process and the flow path of the first step (c) in which the second oxide sphere 3a is operated in an anaerobic or anaerobic state.

The second raw water control valve 41a installed in the second oxidation inlet flow passage 53a is opened so that raw water flows into the second settler built-in oxidation hole 1, and the first raw water control valve installed in the first oxidation inlet flow passage 53 is provided. In (41), the closed state is the same as in the previous step (b).

As the water level of the second settler built-in oxidation tool 1a rises, the second treated water control valve 42a is closed so that the outflow of the second settler flows into the first oxidation hole 3 through the second monthly flow passage 55a. . However, in the previous step, since the level of the second settler built-in oxidizing sphere is lowered and is converted to step (c), the second settler does not overflow from the second settler to the first oxidizing sphere until the water flows in and becomes higher than the level of the first settler settling oxidizing sphere. do. At this time, the second treatment water control valve 42a is closed to prevent the treated water of the second settler from flowing out, and the first treatment water control valve 42 installed at the side of the first settler built-in oxidation opening is opened so that the treated water is discharged to the outside. The level of the oxidizing sphere built-in one-cell battery becomes low. Therefore, in the second settler-type oxidizing sphere, the raw water is fresh and the water level is increased. In the first settler-type oxidized sphere, the treated water flows out and the level is lowered. At the same time, the second backflow prevention valve 43a is closed to prevent the backflow of the reaction liquid by the first monthly flow path 55.

In step (c), the aeration means 62 is continuously operated as in the previous step so that the inside of the first oxidation sphere is maintained aerobic, and the operation of the aeration means 62a is operated so that the second oxidation sphere is operated in anoxic or anaerobic. It stops and the stirring means 61a operate.

≪Step (d) of FIG. 3≫

In step (d) of FIG. 3, the treated water control valves 42 and 42a maintain the same operation state as the previous step (c) while the second oxidation inlet flow path 53a of the second oxidation inlet flow path 53a was opened. The raw water control valve 41a is closed and the first raw water control valve 41 of the first oxidation inlet flow passage 53 is opened to stop the inflow of raw water to the second oxidation hole 3a and flow into the first oxidation hole 3. do.

Since the second raw water control valve is closed and the first treated water control valve 42 is opened to allow the treated water to flow out of the first settler 4, the second settler built-in oxidation hole 1a maintains the level of water that has been raised in the previous step. It is operated at no load without any inflow and outflow.

Since the first treatment water control valve is opened and the treated water is leaked to the outside, the treated water in the first settler built-in oxidation hole 1 is externally supplied through the first settler outflow passage 54 and the first treated water outlet flow passage 52. Is discharged to, and the level of the first precipitator built-in type is continuously maintained as in step (c).

In step (d), since both the first and the second settling-type oxidation spheres must be operated in aerobic, the aeration means 62a of the second oxidation sphere starts operation, and the aeration means 62 of the first oxidation sphere is (c) Keep running as in step.

The operation of the valve required to change the flow path for the process switching between steps (a) to (d) in FIG. 3 is summarized in the following Table 2.

In the present embodiment, the flow path and the flow path adjusting means may be constituted by a water passage and a valve, or may be constituted by various types of water channels and gates. It is included in the scope of the invention.

Valve operation method for the flow path configuration of each step of FIG. step Raw Water Inlet Flow Control Valve Treated Water Outflow Flow Control Valve Non-return valve 41 41a 42 42a 43 43a (a) ○ × × ○ × ○ (b) × ○ × ○ × ○ (c) × ○ ○ × ○ × (d) ○ × ○ × ○ ×

○: The valve is open ×: The valve is closed

In the step (a) to (d), the aerobic, anoxic, anaerobic condition, or the progress of nitrification and denitrification reactions are provided with a redox potential (ORP) and hydrogen ion concentration (pH) by installing a sensor on the oxidizer. This can be estimated by measuring dissolved oxygen concentration (DO) or the time elapsed in the reaction. Therefore, the water gate and valve or aeration device necessary for the step switching are linked to a timer, an ORP controller, a pH controller or a DO controller. Operation can enable automatic changeover of processes and easy plant operation.

<Description of Apparatus Second Embodiment of FIG. 4>

Fig. 4 relates to a second embodiment of the nitrogen / phosphorus removal apparatus by the flow path change and intermittent aeration according to the present invention. The configuration of the apparatus is the same as that of the first embodiment of FIG. 2 except that the type of the sedimentation basin is changed to the external settler batteries 7 and 7a equipped with the sludge collectors 5 and 5a and the conveying facilities 6 and 6a. The content of the reaction is also the same as that of FIG.

4 shows an embodiment in which the unit system constituting the device and the sedimentation type external oxidizing sphere are combined by the flow path changing method, but the conventional conventional activated sludge process or biofilm carrier filled with the facilities already completed or operated for organic matter removal is filled. By installing additional water level and flow path changing facilities and intermittent aeration facilities in the catalytic oxidation process, there is an advantage that it can be supplemented with a facility that can easily remove nitrogen and phosphorus.

As described above, if the wastewater treatment apparatus and method for nitrogen phosphorus removal according to the present invention is used, the efficiency of nitrogen and phosphorus removal is improved and stabilized, thereby reducing the eutrophication of severe rivers and lakes at home and abroad. . In addition, it is possible to provide a nitrogen phosphorus removal system having the following advantages compared to the conventional PID or PhICD without water level change.

Nitrogen removal efficiency is better and more stable than PhICD because denitrification reaction makes fresh use of organic materials in influent water by desalination without external leakage.

The nitrification and denitrification reactions, the release of phosphorus and the inversion of the state required for overdose reactions are rapid and the reaction time is shortened.

Preliminary denitrification tank, selective tank and anaerobic tank are unnecessary, and oxidized sphere is integrated with sedimentation basin, so the utilization of site is high and structure construction cost is reduced.

It is very economical in terms of facility cost such as mechanical work and accompanying electrical instrumentation work because mechanical work such as stirring device installed in pre-denitrification tank, sludge collection device of sedimentation basin, conveying sludge pump are omitted.

The simple process is economical in terms of maintenance such as power and maintenance personnel. The use of sedimentation built-in oxidizing bulb reduces head loss between the oxidizing sphere and the sedimentation basin than in PID, reducing the head of the inlet pumping station.

Since the sedimentation built-in type oxidizing sphere is used and the treated water is discharged only under aerobic conditions, the sedimentation is always aerobic as long as the oxidizing sphere maintains aerobic, so the treated water quality is less likely to be deteriorated due to sludge injury or re-emission of phosphorus in the sedimentation basin.

It can be easily applied to sewage treatment facilities by conventional series activated sludge process or catalytic oxidation process, and can be converted into advanced treatment facilities.It is more reliable than the flow changing method by four-way waterway, and the two oxidation spheres are integrated. PhICD can be easily adopted even in the finished treatment plant.

Claims (7)

A raw water inflow passage and an oxidative inflow passage for introducing raw water into two or more sedimentation built-in oxidizing spheres each having aeration means and agitation means and having a built-in sedimentation basin, a sedimentation basin flow passage through which treated water flows out of the sedimentation basin, and the oxidation sphere and the Overflow flow passage and cross-flow flow passage are connected to the sedimentation basin flow passage, and the flow direction of sewage water is changed by manipulating the flow path, and the level of the oxidizing port from which the treated water flows out from aerobic flow is lowered. Nitrogen phosphorus removal device, characterized in that the water level can be changed so that the level of the oxidizing sphere is introduced, the aeration means can be operated by intermittent aeration. According to claim 1, wherein the inflow of the raw water inlet flows are divided into two or more oxidizing spheres, each branched inflow constituting the oxidation inlet flow passage, each oxidation inlet flow passage is provided with a raw water control valve, the sedimentation basin flow passage Are each branched to the overflow flow passage and the treated water outflow passage, the treated water flow passage is provided with a treatment water control valve, the overflow flow passage is connected to cross into the oxidation sphere from the sedimentation basin flow passage, the overflow flow passage is Nitrogen phosphorus removal device characterized in that it is installed higher than the installation position of the sedimentation basin flow passage and the treated water flow passage and the treated water control valve. A raw water inflow channel and an oxidation inflow channel for introducing raw water, and a sedimentation basin flow channel through which the treated water flows out of the sedimentation basin in a two or more oxidizing process including an oxidizing port equipped with an aeration means, a stirring means, and a sludge conveying facility and an external settler battery; The overflow flow passage is connected to the oxidation sphere and the sedimentation basin flow passage, and the treated water flow passage is provided, the flow direction of the waste water is changed by manipulating the flow path, the level of the oxidation sphere flows out of the treated water in aerobic flow is lowered, anoxic or Nitrogen phosphorus removal device, characterized in that the water level can be changed so that the level of the oxidative sphere inflowing raw water in anaerobic, the aeration means can be operated by intermittent aeration. 4. The removal apparatus according to claim 3, wherein the oxidizing sphere is a activated sludge reaction tank or a contact oxidation tank filled with a biofilm carrier by flotation. The wastewater treatment process operates the flow path through the inflow of water → first oxidizer → first settler → second oxidizer → second settler → treated water effluent. Maintaining aerobic for the nitrification reaction, lower the water level of the second oxidizing sphere and the second settler, or maintain a low water level, in the first oxidizing sphere to stop the operation of the aeration means anoxic conditions and phosphorus-release reaction is carried out denitrification reaction The anaerobic conditions are made, the first oxidation sphere and the first settling step is to operate the waste water to increase the water level or maintain a high water level (a); In the wastewater treatment process, the flow path is operated to flow in the order of inflow water → second oxidizer → second settler → treated water effluent. The oxidizing sphere and the first settler are operated in the state of high water level, and the second oxidizing sphere and the second settler are operated in the state of low water level, but the first oxidizing sphere and the first settler are operated under no-load aerobicity without any inflow and outflow from the outside. (B) allowing this overdose; The wastewater treatment process operates the flow path through the flow of inflow water → 2nd oxidizer → 2nd settler → 1st oxidizer → 1st settler → treated water effluent. Maintaining aerobic for the nitrification reaction, lower the water level of the first oxidation sphere and the first settler, or maintain a low water level, in the second oxidation sphere stops the operation of the aeration means and the deoxygenation conditions and phosphorus-release reaction The anaerobic condition is made, the second oxidation sphere and the second settling step is to operate the waste water to increase the water level or maintain a high water level (c); The wastewater treatment process is operated by aerobic operation by operating the flow passage through the inflow source → the first oxidation sphere → the first settler → the treated water outflow, and the aeration means are operated in both the first and second oxidation spheres. The 1st oxidized bulb and the 1st settler are operated in the state of high water level, and the 2nd oxidized bulb and the 2nd settler are operated in the state of low water level. Nitrogen phosphorus removal method comprising the step (d) to cause the phosphorus is ingested excessively. The method of claim 6, wherein the step of stopping the operation of the aeration device in the second oxidation sphere of step (b) and the first oxidation sphere of step (d) for a predetermined time before the step (b) and (d) is completed. Nitrogen phosphorus removal method characterized in that the dissolved oxygen is reduced before switching to the next denitrification step by operating in aerobic stirring. The method of claim 6, wherein the oxidizing sphere is nitrogen, characterized in that the activated sludge reaction tank by flotation growth or a catalytic oxidation tank filled with a biofilm carrier.