KR100321231B1 - 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, respectively, to construct a sewage wastewater treatment facility and operate in a flow changing method and intermittent aeration method. In particular, in the reaction tank in which the denitrification reaction and the phosphate release reaction from sludge are performed under aerobic agitation conditions, there is no outflow and only the inflow of raw water, so that organic matter in the influent wastewater can be utilized as much as possible for the denitrification and phosphorus release reaction. The present invention relates to a wastewater treatment method and apparatus for efficiently removing phosphorus.

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 removing organic matter, nitrogen, and phosphorus from sewage and wastewater by operating by changing the water 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, phosphorus is removed by removing the excessively ingested microorganisms through the excess 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 reaction has a problem in that a large chemical cost or pump facility costs, 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 the stirrer, sludge collector and sludge conveying pump, 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. Therefore, microorganisms are not sufficiently activated and phosphorus intake efficiency can 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 present invention, which was invented by the applicant named PhICD (Phased Isolated Intra Clarifier Ditch) and published in Korean Patent No. 2,525,1, the wastewater treatment apparatus and method for removing nitrogen and phosphorus, have anoxic or anaerobic conditions. Oxidation spheres in the required stage were improved so that free oxygen or nitrogen oxides were not introduced from the aerobic oxide spheres and organic matters were not lost, thereby improving the 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. In particular, steps (b) and (d) of PID and steps (b) and (d) of PhICD correspond to preliminary steps for changing the flow path and phase, so that both oxidation zones are operated under aerobic conditions. 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.

Therefore, the present invention has been 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 cost, and intermittent aeration method and flow path that can effectively remove nitrogen and phosphorus in the sewage It is an object of the present invention to provide a wastewater treatment method and apparatus to which the method of changing the depth of the reactor is applied to the 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 wastewater treatment apparatus for nitrogen and phosphorus removal according to the present invention, the level of the effluent can be changed in various ways depending on the direction of the wastewater flow by lowering the installation position of the flow path flowing out to the outside as treated water. Flow paths and flow control means were introduced.

1 (a)-(d) are a flowchart of a nitrogen-phosphorus removal method according to the present 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 operating method of the first embodiment of the nitrogen-phosphorus removal apparatus according to the present invention,

4A is a schematic diagram of a second embodiment of a nitrogen-phosphorus removing apparatus according to the present invention;

Figure 4b is a perspective view of the flow path portion of the second embodiment according to the present invention,

4C is a perspective view of another embodiment of the flow path portion of the second embodiment according to the present invention;

Figure 5 (a)-(d) is a flow chart of the operating method of the second embodiment of the nitrogen-phosphorus removal apparatus according to the present invention,

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

＊ Explanation of symbols for main parts of drawing *

1: first settler built-in oxidizer 2: second settler built-in oxidizer

11: first precipitated external oxidizing sphere 12: 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

21: Four primary waterway 22: Second four-way waterway

31: 1st sluice 32: 2nd sluice

41, 41a: Raw water inflow flow control valve 42, 42a, 43, 43a: Flow control valve between unit elements

45, 45a: treated water outflow flow control valve 46: backflow prevention means

aa ', bb': Direction of flood control 51: Inflow of raw water

52: treated water outflow passage 53: first oxidation inlet flow passage

53a: 2nd oxidation inflow channel 54: 1st settler outflow channel

54a: second settling outflow channel 55: flow path between unit elements

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

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

Figure 1: Flow chart of nitrogen and phosphorus removal method

1 is a flow chart showing the nitrogen and phosphorus removal method according to the present invention, the first system is a unit system in which the settling basins 4, 4a are built in the oxidation spheres 3, 3a provided with aeration means and agitation means [not shown]. , Using the sewage treatment apparatus consisting of the second settler built-in oxidation spheres (1, 2) shows a 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 denitrification, phosphorus release, organic decomposition and nitrification are combined. The denitrification reaction and the phosphorus release reaction occur in the first settler-type oxidizing sphere (1), and the nitrification reaction occurs in the second settler-type oxidizing sphere (2). Looking at the configuration of the flow path first, the inflow water is introduced into the first settler built-in oxidizing sphere (1) and the outflow of the first settler built-in oxidizing sphere (1) is again passed through the second settler built-in oxidizing sphere (2) as treated water.

At this time, in the first oxidation sphere (3), which is a unit element constituting the first settled built-in oxidation sphere (1), the operation of the aeration system is stopped and operating in an oxygen-free condition that only the stirring facility is operated, nitrogen oxides by organic matter contained in the influent The denitrification reaction is reduced to this free nitrogen. At the same time, in the second oxidizing sphere 3a, which is a unit element constituting the second settled embedded oxidizing sphere 2, the aeration facility is operated to cause organic matter decomposition and nitrification reaction in aerobic.

Since the water level of the first settler built-in oxidizing sphere (2) is controlled in advance in the previous step, the inflow and wastewater for a predetermined time from the beginning of this stage is not overflowed to the second settler built-in oxidizer and continues to be fresh water until it rises to a certain level. Is done. When 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 flows to the outside in the absence of inflow, and the water level is lowered. Prepare for fresh water.

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 oxidation sphere (1), only the inflow of wastewater is made, so that organic matter, which is an electron donor included in the inflow, does not leak at all. This is improved, and the nitrification efficiency is improved because the inflow organic load is reduced in the second oxidation sphere (3a).

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, and the phosphate release reaction from the sludge is performed. In other words, denitrification and phosphorus-release reactions proceed in the same reaction tank under the same flow path with time difference, so they are more economical in terms of facility and maintenance than PID and are easier to operate.

<< step (b) of FIG. 1 >>

In step (b) of FIG. 1, the first settler-containing oxidation sphere 1, which was anaerobic in step (a), is converted to aerobic. At the same time, since the flow path is changed and operates under no-load condition in which inflow water does not flow, only oxygen necessary for endogenous breathing of activated sludge is consumed, resulting in very low oxygen consumption. Therefore, at this stage, the inside of the first settler-type oxidized sphere 1 is rapidly converted into aerobic, and sludge which has released phosphorus in anaerobic re-ingestion in excess of the amount of phosphorus again than before, and phosphorus is concentrated. Phosphorus is removed by removing sludge.

In step (b), the flow path of step (a) is changed so that the inflow water flows directly into the second settler built-in oxidizer (2), that is, the second oxidizer (3a) without passing through the first settler-type oxidized ball (1). It flows out to the treated water via the two-settlement battery 4a, and the level of the second settler-containing oxidation sphere is kept low. The second oxidizing sphere (3a) is maintained in an aerobic state while decomposing organic matter and nitrification also continues.

<< step (c) of FIG. 1 >>

In step (c) of FIG. 1, the reaction forms are different from those in step (a), except that the roles and flow paths of the first and second settler-containing oxidizing spheres 1 and 2 are changed to the process of denitrification, phosphorus release, and nitrification. same. That is, in step (c), the flow path is operated such that the raw water flows into the second settler built-in oxidizing sphere 2 where nitrogen oxide is accumulated and the water level is lowered to allow additional fresh water in step (a) and (b). The denitrification and phosphorus releasing reactions take place since the aeration system stops operating. 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 ( 2) [→ 2nd oxidation sphere 3a → 2nd settler 4a] → treated water outflow. In step (c), the flow path of step (a) is changed to introduce raw water into the second settler-type oxidized sphere (2) [→ the second oxidized sphere (3a) → the second settler (4a)] → the first settler-type embedded oxidizer (1). ) [→ 1st oxidation sphere (3) → 1st settler (4)] → treated water outflow. That is, the denitrification and phosphorus release reaction and the increase of the water level made in the first settler-type oxidizing sphere (1) of step (a) are made in the second settling-type oxidizing sphere (2) in step (c), and In the step (c), the nitrification reaction and the lowering of the water level made in the second settler-type oxidizing sphere (2) were replaced only to be performed in the first settling-type oxidizing sphere (1), and the reaction contents of the step (c) are the reactions of the step (a). This is a mirror image relationship that matches the contents.

<< 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 aerobic operation while the inflow and outflow is generated to maintain the state of low water level, and the second settler built-in oxidizer (2) is no-load operation in aerobic without flow and organic load Step.

As shown in FIG. 1, the flow in step (b) is the inflow of raw water into the second settler-type oxidized sphere (2) [→ the second oxidized sphere (3a) to the second settler (4a)] In step), the flow path is changed from the inflow of raw water to the first settler-type oxidizing sphere (1) [→ the first oxidizing sphere (3) to the first settler (4)] to the 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 settled internal oxidizing spheres (1, 2) are changed.

The second settler built-in oxidizing sphere of step (b) is an aerobic condition in which the aeration device is operated, and in step (c), even if the wastewater flows in the aerobic agitation state, it is subjected to anoxic conditions until the free oxygen dissolved in the previous step is depleted. Unreachable and a considerable amount of organic matter is wasted. However, since the second settler built-in oxidizing sphere of step (b) is a flow path through which the treated water flows out, if the aeration agitation time is too long, it is anaerobic and worsens the sludge settling property and the treated water quality deteriorates. Therefore, the denitrification efficiency in step (c) is improved because the dissolved oxygen is depleted at the time of switching to step (c) by switching the second oxidation sphere to aerobic agitation from a certain time before step (b) ends. . In the first settling-type oxidation sphere of the step (d) corresponding to the mirror image, the organic matter is converted to the next step (a) after depletion of dissolved oxygen by maintaining the aerobic agitation state for a certain time before the end of the step. It can make the best use of it and improve the denitrification efficiency.

In step (a) to (d), the aerobic, anoxic, anaerobic condition, or the progress of nitrification and denitrification reaction can be determined by installing a sensor at the oxidation spheres (3, 3a) and reducing the redox potential (ORP) and hydrogen ion concentration. (pH), dissolved oxygen concentration (DO), or time elapsed over the reaction can be estimated. 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. This can enable automatic changeover of processes and easy plant operation.

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 to Prior Art PID 1st Settler built-in oxidizer (1) Second settler built-in volcano (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 Process of replacing the first stage (a) of PID and anaerobic process and facility (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 For the second stage (b) of PID

(c) Treatment Water Outflow Aerobic Organic Sludge Oxidation Reaction Inside Sludge Maintain circulating low water level in the inflow of anaerobic oxygen, anaerobic denitrification, and phosphate release sludge Raw water inflow → Second oxidation sphere (3a) → Second precipitation battery (4a) → First oxidation sphere (3) → First sedimentation battery (4) → Treatment water outflow Step 3 (c) of PID and anaerobic process and process to replace facility 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 inside circulation high water level Raw water inflow → Oxidation sphere (3) → First settler (4) → Treatment water outflow Corresponds to the fourth stage (d) of PID 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 outlet channel 52, and the unit elements such as the oxidizing spheres 3 and 3a and the settling basins 4 and 4a are connected by flow paths 53, 53a, 54 and 54a. In this embodiment, the valves 41 to 45a are used as the flow path changing means.

The raw water flows in such a way that the raw water flows into the first oxidation sphere 3 of the first sedimentation-type oxidation sphere 1 or the second oxidation sphere 3a of the second sedimentation-type oxidation sphere 2 through the raw water inflow passage 51. Each flow path is provided with raw water inflow flow control valves 41 and 41a.

The flow path between the unit elements connects the first oxidation sphere 3 and the second oxidation sphere 3a, the first settler 4 and the second settler 4a to each other, and each flow path control valve 42, 42a, 43, 43a are provided. In addition, a pipe connecting two oxidation spheres (3, 3a) and a pipe connecting two sedimentation basins (4, 4a) are connected to each other to form a flow path 55 between unit elements, and to prevent backflow in the flow path 55 between unit elements. Means 46 are provided.

In each flow path branched from the flow path between the first settler 4 and the second settler 4a, the treated water flow path 52 is provided with the treated water flow path control valves 45 and 45a. The treated water outlet passage 52 is advantageously integrated into one pipeline 52 from the treated water outlet passage control valves 45 and 45a in order to reduce facility costs. As the flow path is changed by the valve operation, the sedimentation basin flow passages 54 and 54a, the treated water flow passage 52, and the treated water flow passage control valves 45 and 45a can be changed in order to change the level of the oxidation sphere. 51, 53, 53a, 55 and the flow path regulating valves 41, 41a, 42, 42a, 43, 43a.

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

FIG. 2B shows the sedimentation basin outflow paths 54 and 54a, the treated water outflow path 52, and the treated water outflow control valve so that the water level in the oxidation sphere can also be changed as the valve is operated to change the flow path in the flow path configuration of FIG. Perspective view of a flow path having a position of 45, 45a lower than that of the raw water inflow flow path 51 and other flow paths 53, 53a, 55 and the flow path 55 between the unit elements provided with a backflow preventing means 46 It is about.

Here, the non-return means may be configured as a check valve or an automatic valve that operates in conjunction with a water gauge in the oxidation sphere.

Fig. 3: Description of the operating method of the first embodiment of the device>

3 is a diagram illustrating a flow path changing method of the embodiment shown in FIG.

<< Step (a) of FIG. 3 >>

These steps coincide with each other in the reaction contents, the process and the flow path of the step (a) of FIG. 1 in which the first settler-type oxidizing sphere 1 is operated in an anaerobic or anaerobic state.

The raw water inflow passage control valve 41 installed in the flow path directed to the first oxidation sphere 3 is opened and the raw water inflow passage control valve 41a installed in the flow passage directed to the second oxidation sphere 3a is closed so that the raw water is the first oxidation sphere (3). ) Only to enter.

Then, the flow path control valve between the unit elements is operated so that the outflow water of the first settler 4 flows into the second oxidation sphere 3a. However, since the level of the first settler built-in oxidizing sphere is low, the first settler does not have an outflow until the raw water is inflowed and desalted and becomes higher than the level of the second settler built-in oxidizing sphere. That is, the flow path control valves 42a and 43 between the two unit elements are opened and the flow path control valves 42 and 43a between the remaining unit elements are closed. In the first settler 4, the treated water outflow control valve 45 installed on the first settler 4 side is closed so that the treated water does not flow out, and the treated water outlet flow control valve 45a provided on the second settler 4a side is closed. Is opened so that the treated water flows out of the second settler 4a, and the level of the second settler built-in oxidizing sphere is lowered.

In the first settler-type oxidation sphere, the raw water is fresh and the water level is increased, and in the second settler-type oxidation sphere, the treated water flows out and the water level is lowered. When the water level of the first settler-type oxidizing sphere becomes higher than the level of the second settler-type oxidizing sphere, the effluent of the first settler is introduced into the second oxidizing sphere, and the reverse flow occurs in the previous stage, so that the flow path between the unit elements is configured to prevent backflow. .

<< Step (b) of FIG. 3 >>

In step (b) of FIG. 3, the raw water inflow flow control valve 41 of the flow path 53 flowing into the first oxidation ball 3 opened in the previous step (a) is closed, and the second oxidation ball 3a is closed. The raw water inflow passage control valve 41a is opened so that the inflow source water flows into the second oxidation port 3a.

The flow path control valves 42, 42a, 43, and 43a connecting the first oxidation sphere 3 and the second oxidation sphere 3a are all closed, so that no inflow and outflow occurs between the unit elements and the first settling-type oxidation sphere ( 1) In the previous stage, the water level is kept elevated and is operated at no load.

In the second settler built-in oxidizing sphere (2), the treated water flows out through the treated water outlet passage 52, and the state in which the water level is lowered in the previous stage is maintained. At this time, the treated water outlet flow control valve 45 on the first settler 4 side is closed, and the treated water outlet flow control valve 45a on the second settler 4a side is opened.

In the step (b), since both the first and second internally embedded oxidizing spheres 1 and 2 must be operated in aerobic aeration, the aeration means 62 of the first oxidizing sphere 3 starts to operate and gives up the second oxidizing sphere 3a. The means 62a remain in operation as in step (a).

<< step (c) of FIG. 3 >>

Step (c) is identical to step (a) of FIG. 1 in which the second oxidizing sphere 3a is operated in anoxic or anaerobic state, and the reaction contents, the process, and the flow path are consistent with each other. The raw water inflow passage control valve 41a installed in the flow passage 53a directed to the second oxidation sphere 3a is opened to feed the raw water and the raw water inflow passage control valve 41 installed in the passage 53 facing the first oxidation sphere 3. ) Is closed.

The flow path control valves 42 and 43a between the two unit elements are opened and the flow path control valves 42a and 43 between the remaining unit elements are closed so that the outflow of the second settling battery 4a flows into the first oxidation sphere 3. However, since the level of the second settler built-in oxidizing sphere is low, the second settler does not have an outflow until the raw water enters and becomes higher than the level of the first settler settling oxidizing sphere so that the inflow to the first oxidizing sphere is not generated. At this time, the treated water outflow flow control valve 45a installed on the second settler 4a side is closed so that the treated water of the second settler 4a is closed and the treated water outflow flow control valve installed on the first settler 4 side ( 45) is opened so that the treated water flows out and the level of the second settler built-in oxidizing sphere is lowered. In the second settler-type oxidizing sphere, raw water is desalted and the water level is increased. When the level of the second settler-type oxidizing sphere becomes higher than the level of the second settler-type oxidizing sphere, the effluent of the second settler is introduced into the first oxidizing sphere, and in the previous step, backflow occurs so that the flow path between the unit elements constitutes a backflow prevention means. will be.

In step (c), the aeration means 62 is continuously operated as in the previous step so that the inside of the first oxidation sphere 3 is maintained in aerobicity, and the aeration means 62a is operated in the anaerobic or anaerobic manner. Is stopped.

<< step (d) of FIG. 3 >>

In step (d) of FIG. 3, the raw water inflow flow control valve 41a of the flow path 53a flowing into the second oxidation ball 3a that has been opened in the previous step (c) is closed and the raw water of the first oxidation ball 3 is closed. The inflow passage control valve 41 is opened so that the inflow source water flows into the first oxidation port 3.

The flow control valves 42, 42a, 43, 43a between the unit elements connecting the first settler-type oxidizer (1) and the second settler-type oxidizer (2) are all closed, and the second settler-type oxidizer is The level is kept elevated and operated at no load with no influent.

The treated water outflow control valve 45a on the second settler 4a side is closed, and the treated water outlet flow control valve 45 installed on the first settler 4 side is opened so that the treated water is discharged from the first settler. It flows out through the flow path 52, and the state in which the water level was lowered in the previous stage is maintained.

In step (d), since both the first and the second settling-type oxidation spheres 1 and 2 must be operated in aerobic, the aeration means 62a of the second oxidation sphere 3 starts to operate and the aeration of the first oxide sphere 3 is started. The means 62 continue to operate as in the previous step.

The operation method 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>.

The configuration of the flow path in the present embodiment may be composed of water pipes (pipes) and valves, or the flow path may be composed of various types of waterways and gates, and this is also within the scope of the present invention. It is included.

Valve operation method for the flow path configuration of each step of FIG. step Raw Water Inlet Flow Control Valve Flow control valve between unit elements Treated Water Outflow Flow Control Valve 41 41a 42 42a 43 43a 45 45a (a) ○ × × ○ ○ × × ○ (b) × ○ × × × × × ○ (c) × ○ ○ × × ○ ○ × (d) ○ × × × × × ○ ×

○: valve is open ×: valve is closed

Fig. 4A: Description of Second Embodiment of Device>

Fig. 4A relates to a second embodiment which satisfies a flow path for implementing each step of the wastewater treatment method according to the present invention. Specifically, the flow path changing device between the inflow and outflow flow paths and the unit elements such as the settling basins 4 and 4a and the oxidizing spheres 3 and 3a is composed of two four-way channels 21 and 22, respectively. The furnaces 21 and 22 are provided with the gates 31 and 32.

One channel of the primary four-way channel 21 is connected to the raw water inflow channel 51 through which the raw water flows, and each of the two flow paths facing both sides of the raw water inflow channel 51 is the first oxidation sphere 3. And a first oxidation inlet inflow passage 53 and a second oxidation inlet inflow passage 53a, which are inlets of the second oxidation sphere 3a. The remaining channel is connected to the secondary four-way channel 22 to form a flow path 55 between the unit elements.

The secondary four-way channel 22 also has two flow paths on both sides of the unit element flow path 55 connected to the primary four-way channel 21, respectively, and the outlets of the first settler 4 and the second settler 4a. The first settler outflow channel 54 and the second settler outflow channel 54a are connected to the outlets of The other one flow path of the secondary four-way water channel 22 is connected to the treated water flow path 52 through which the treated water flows out. In addition, rotatable sluices 31 and 32 are installed at the centers of the primary and secondary four-way waterways, and the flow path is changed while rotating at 90 °.

The sedimentation basin outflow passages 54 and 54a, the treated water outflow passage 52, and the primary four-way water passage 21 are connected to the other flow passages 51, so that the water level of the oxidizing sphere may be changed as the flow passage is changed by the hydrological manipulation. 53, 53a, 55) and lower than the primary four-way channel 21, and the flow path 55 between the unit elements to prevent the reverse flow from the primary four-way channel in the direction of the secondary four-way channel. The backflow prevention means 46 was configured.

Fig. 4b: Perspective view of the flow path part of the second embodiment of the apparatus>

4B is a perspective view of a flow path configuration in which the installation positions of the secondary four-way waterway 22, the sedimentation basin outflow paths 54 and 54a, and the treated water outflow path 52 are lowered so that the water level can also be changed as the flow path is changed. . In this case, since the depth of the four-way sluice is low, the secondary four-way sluice is preferably watertight. The difference in water level is generated in the oxidation zone by the difference in the installation position of the flow path between the unit elements and the settling outflow channel.

4c is a perspective view of another embodiment of the flow path portion of the second embodiment of the apparatus;

4C shows that the second four-way waterway 22 and the water gate are deepened so that the water level can also be changed as the flow path is changed, so that the flow path 55 between the unit elements is connected to the upper portion of the second four-way waterway and the sedimentation basin flow path 54 , 54a) and a treated water outlet flow path 52 are installed in the lower portion of the secondary four-way waterway, so that a water level difference is generated.

Fig. 5: Description of the operating method of the second embodiment of the apparatus>

5 shows a situation in which the water gate of the water channel is opened and closed at each step in the wastewater treatment facility shown in FIG. 4 employing the four-way water channel.

Referring to the flow path change method shown in Figure 5 for each step as follows.

<< step (a) of FIG. 5 >>

This step is identical to step (a) of FIG. 1 in which the first settler built-in oxidizing sphere 1 is operated in anoxic or anaerobic state, and the reaction contents and flow paths coincide with each other. That is, the water gate 31 of the first four-way water channel is operated in the aa 'direction so that the raw water is supplied through the first water inflow channel 51, the first four-way channel 21, and the first oxidation inlet channel 53. It flows into the oxidizing sphere (3).

At the same time, the sluice gate 32 of the secondary four-way channel 22 is also operated in the aa 'direction so that the first settler 4 effluent flows into the first settler outflow channel 54, the second four-way channel 22, and the unit. It is operated to be introduced into the second oxidation sphere (3a) through the urea flow passage 55, the first four-way channel 21 and the second oxidation sphere inlet passage (53a). However, since the level of the first settler built-in oxidizing sphere is low, the first settler does not have an outflow until the raw water is sufficiently inflowed and desalted to be higher than the level of the second oxidizing sphere, so that the inflow into the second oxidizing sphere is not made.

Since the water gate 32 of the secondary four-way channel 22 is operated in the aa 'direction, the treated water of the second settler 4a naturally flows out of the second settler outflow channel 54a and the secondary without any hydrological manipulation. The water flows through the four-way water channel 22 and the treated water outflow channel 52 to lower the level of the second settler-type oxidation sphere.

In step (a) of the second embodiment, as in the first embodiment, the operation of the aeration means 62 is stopped so that the inside of the first oxidation sphere 3 is operated in anoxic or anaerobic condition, and the aerobic maintenance is maintained in the second oxidation sphere. The aeration means 62a continues to operate so that it can be made.

<< step (b) of FIG. 5 >>

The first settler built-in oxidizer (1) is operated aerobic in the no-load state without the inflow and outflow, and the inflow and outflow occurs only in the second settler built-in oxidizer (2), the reaction content and process as in step (b) of FIG. The primary water gate 31 is rotated 90 degrees from the aa 'direction to the bb' direction for conversion.

Raw water flows along the raw water inflow channel 51 and enters the second oxidation channel 3a via the first four-way channel 21 and the second oxidation inlet channel 53a, and the water level is lowered as in the previous step. Keeps going.

The secondary sluice 32 has no separate hydrologic operation in the aa 'direction as in step (a).

The first settler built-in oxidizing sphere (1) is in a state in which the water level is increased in the previous stage in a state where the first oxidizing sphere inflow passage (53) and the first settler outflow passage (54) are blocked by the first and second sluice gates (31, 32). Is maintained and no flow is generated and it is operated under no load.

At this stage, since both the first and second settled-type oxidation spheres 1 and 2 are operated aerobicly, the aeration means 62 of the first oxidation sphere 3 starts to operate and the aeration means 62a of the second oxidation sphere 3a is started. Will continue to operate as before.

<< step (c) of FIG. 5 >>

This step coincides with step (c) of FIG. 1 in which the second settler built-in oxidizing sphere 2 is operated in anoxic or anaerobic manner, and the reaction contents and the flow path configuration. The sluice 31 of the primary four-way channel is operated in the bb 'direction so that the raw water passes through the raw water inflow channel 51, the primary four-way channel 21, and the second oxidation inlet channel 53a. Flows into 3a).

At the same time, the sluice 31 of the secondary four-way channel 22 is also operated in the bb 'direction so that the outflow water of the second settler 4a may be the second settler outflow channel 54a, the second four-way channel 22, The unit oxide flow path 55 is introduced into the first oxidation sphere 3 through the first four-way water passage 21 and the first oxidation sphere inflow passage 53. However, since the level of the second settler-type oxidized bulb is low, the raw water is sufficiently inflowed and desalted, and no outflow occurs in the second settler until it is higher than the level of the first settler-type oxidized bulb. .

Since the sluice gate 32 of the secondary four-way channel 22 is operated in the bb 'direction, the first settler 4 effluent flows through the first settler outflow channel 54 and the treated water outflow channel 52. As it flows out as water, the level of the first settler built-in oxidizing sphere is lowered.

The aeration means 62 continues to operate as in the previous step so that the inside of the first oxidation sphere 3 remains aerobic, and the operation of the aeration means 62a is stopped so that the second oxidation sphere 3a is operated in anoxic or anaerobic condition. .

<< step (d) of FIG. 5 >>

At this stage, the second settler-type oxidizer (2) is operated aerobic in a no-load state with no inflow and outflow, and inflow and outflow occurs only in the first settler-type type oxidizer (1). 90 ° in the aa 'direction.

Raw water flows in along the raw water inflow channel 51 and enters the first oxidation sphere 3 through the first four-way water channel 21 and the first oxidation inlet flow path 53. The lowered state is maintained as in.

The secondary sluice 32 does not have a separate hydrologic operation in the bb 'direction. The outflow water of the first settler 4 flows out as treated water through the first settler outflow channel 54, the secondary four-way channel 22, and the treated water outlet channel 52. The second settler built-in oxidizing sphere maintains the level of the water level at the previous stage while the second settling inlet flow passage 53a and the second settler outflow flow passage 54a are blocked, and no inflow and outflow occurs and operation of the aeration means starts. To be aerobic. The aeration means 62 of the first oxidation sphere 3 continues to operate as in the previous step.

A method of operating a hydrogate required to change the flow path required in steps (a) to (d) of FIG. 5 is summarized in the following Table 3.

Hydrologic operation method for the flow path configuration of each step of FIG. step Position of the primary sluice 31 in the primary four-way channel 21 Position of the secondary water gate 32 in the secondary four-way waterway 22 (a) aa ' aa ' (b) bb ' aa ' (c) bb ' bb ' (d) aa ' bb '

In the present embodiment, the flow path may be composed of a water channel and a gate, or various types of water pipes or valves. It can be configured to work in conjunction with.

<Description of Apparatus Third Embodiment of FIG. 6>

Fig. 6 relates to a third embodiment of the nitrogen-phosphorus apparatus by flow path change and intermittent aeration according to the present invention. The configuration of the apparatus is the same as in the second embodiment of the apparatus of FIG. 4, except that the format of the sedimentation basin is changed to the external settler batteries 7 and 7a, and the operation method and the contents of the reaction are the same as those of FIG.

FIG. 6 shows a third embodiment in which the four-way water channels 21 and 22 are combined with the sedimentation-site external oxidation spheres 11 and 12 by the unit system constituting the device and the flow path changing method. It is easy to install water level and flow path change facilities and intermittent aeration facilities in the conventional activated sludge process consisting of the conventional sedimentation type external oxidizing sphere (11, 12) or the conventional aeration tank and the sedimentation basin, which are mainly completed or operated for removing organic matter. It can be supplemented with a facility that can 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 the oxidizing sphere and sedimentation basin are integrated, so the utilization of the 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 compared to that of PID, which reduces 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 the wastewater treatment plant of the conventional series activated sludge process and converted to the advanced treatment plant.

Claims (7)

Two or more settling-type oxidation spheres having aeration means and agitation means and built-in sedimentation basins, respectively, raw water inflow passages for introducing raw water, and treated water outlet passages through which the treated water flows out of the sedimentation basins, and unit elements such as the oxidation ports and the sedimentation basins. Oxidation inlet flow passage connecting the unit, and inter-unit urea flow passage and sedimentation basin flow passage are provided, the flow direction of the waste water is changed by manipulating the flow path, the level of the oxidizing sphere from which the treated water flows out of the aerobic flow is lowered, anoxic or anaerobic Nitrogen phosphorus removal device, characterized in that the water level can be changed so that the level of the oxidizing sphere is introduced into the raw water, the aeration means can be operated by intermittent aeration. According to claim 1, wherein the raw water inflow passage is branched to be respectively introduced into the first oxidation sphere and the second oxidation sphere is connected to the oxidation inlet flow passage, each inflow passage is provided with a raw water inflow passage control valve, The sedimentation basin flow passage is connected between the sedimentation basin and the treatment water outlet flow passage with respective treated water outlet flow passage control valves, and the flow path between the unit elements is provided with a flow control valve between the unit elements at each connection portion. And the sedimentation basin outflow passage and the treated water outflow passage and the installation position of the treated water outflow passage control valve are installed at other positions and valves including the flow path control valve between the unit elements and the flow path between the unit elements. Nitrogen phosphorus removal device is installed low, characterized in that the flow path preventing unit is provided in the flow path between the unit elements. According to claim 1, wherein the raw water inflow channel is connected to one channel of the primary four-way channel and each oxidation inlet flow path connected to each oxidation sphere is connected to each of the two opposite channels of the primary four-way channel, respectively The sedimentation basin flow passage connected to the sedimentation basin is connected to two opposite channels of the secondary four-way channel, and the unit element flow path is connected between the primary four-way channel and the secondary four-way channel. The treatment water outlet flow passage is connected to the remaining waterways of the secondary four-way waterway, and the primary and secondary four-way waterways are provided with a water gate so that the flow path may be changed while the water gate is rotated. And the installation position of the treated water outlet flow passage is lower than that of other flow paths including the flow path between unit elements and the first four-way flow path, and the flow path preventing means is provided in the flow path between the unit elements. Nitrogen phosphorus removal device characterized in that. 4. The apparatus as claimed in claim 2 or 3, wherein the backflow preventing means is an automatic valve or an automatic sluice and is configured to be operated in conjunction with a water gauge installed in the sedimentation basin. A raw water inflow channel for introducing raw water, a treated water inflow channel through which treated water flows out of the sedimentation basin, and two or more oxidizing sphere processes each consisting of an oxidizing sphere and a settling basin having an aeration means, a stirring means, and a sludge conveying facility. Oxidation inlet flow passage connecting unit elements such as the sedimentation basin, between the unit elements, and the sedimentation basin flow passage are provided, and the flow direction of the wastewater is changed by manipulating the flow passage, and the level of the aeration tank from which the treated water flows out from aerobic flow is low. The nitrogen phosphorus removal device, characterized in that the water level can be changed so that the level of the oxidizing sphere inflowing raw water from the anaerobic or anaerobic water is high, and the aeration means can be operated by intermittent aeration. 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 condition is performed, 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 in the order of inflow water → second oxidation zone → second settling stage → discharged treatment water, and aeration means are operated in both first and second oxidation zones to operate aerobicly. The oxidizing sphere and the first settler are operated at high water level, and the second oxidizing sphere and the second settler are operated at low water level. (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 of operating the water level to increase the water level or maintain a high water level by introducing the waste water (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 finished. Nitrogen phosphorus removal method characterized in that the dissolved oxygen is consumed before switching to the next denitrification step by operating in aerobic stirring.