JP6264346B2 - Nitrogen removing device and method of remodeling nitrogen removing device - Google Patents

Description

  The present invention relates to a nitrogen removing apparatus and a method for modifying the nitrogen removing apparatus.

  Biological nitrogen removal is known as a nitrogen removal (denitrification) method for water to be treated containing organic nitrogen compounds. Biological nitrogen removal involves nitrification in which ammonia nitrogen contained in water to be treated is oxidized to nitrite nitrogen or nitrate nitrogen by the action of nitrifying bacteria in an aerobic atmosphere by aeration, and sublimation in an anaerobic atmosphere. It is carried out by a denitrification reaction in which nitrate nitrogen or nitrate nitrogen is reduced to nitrogen gas by the action of denitrifying bacteria.

  As biological nitrogen removal, a treatment method is known in which nitrification reaction and denitrification reaction are carried out in a single reaction tank by intermittently adding water to be treated. This treatment method secures a time zone during which the denitrification reaction proceeds by making the inside of the tank a relatively anaerobic atmosphere by utilizing the high oxygen consumption activity of the treated water when the treated water is added. When the charging is stopped, the time zone in which the nitrification reaction proceeds can be secured by making the inside of the tank a relatively aerobic atmosphere.

  Patent Document 1 describes a processing method for clearly partitioning an aerobic processing region and an anaerobic processing region by providing a partition in a reaction tank. This treatment method stably forms an anaerobic atmosphere even when the water to be treated becomes undesired for nitrogen removal, such as when the BOD / TN (total nitrogen) ratio of the water to be treated is 3 or less. can do.

Japanese Patent No. 3649632

  However, in the treatment method described in Patent Document 1, some water to be treated may flow from the anaerobic treatment region to the aerobic treatment region via the liquid phase part of the space above the partition wall. Thus, there existed a subject that nitrogen removal became inadequate because to-be-processed water moved to an aerobic treatment area | region, without fully staying in an anaerobic treatment area | region.

  An object of this invention is to provide the nitrogen removal apparatus which enables more stable nitrogen removal, and the remodeling method of a nitrogen removal apparatus.

According to the first aspect of the present invention, the nitrogen removal apparatus has a single aerobic treatment region and an anaerobic treatment region, and performs biological denitrification of water to be treated containing an organic nitrogen compound. A reaction tank comprising a tank, a raw water supply pipe for supplying the water to be treated to the reaction tank, a partition partitioning a liquid phase part of the reaction tank into the aerobic treatment region and the anaerobic treatment region, A raw water inlet that is an outlet of the raw water supply pipe formed in the reaction tank, and a linear distance on the plane and a linear distance in the height direction that are the length and width of the reaction tank from the raw water inlet on the partition wall. The communication water is provided at a position as far as possible in order to communicate the anaerobic treatment region and the aerobic treatment region, and the water to be treated from the aerobic treatment region to the most upstream part of the anaerobic treatment region A circulation channel for circulating the gas.

  According to such a configuration, the liquid phase part of the reaction tank is divided into the anaerobic treatment region and the aerobic treatment region by the partition wall, and the communication port that communicates the anaerobic treatment region and the aerobic treatment region is the raw water inlet. It is provided at a position as far away as possible. Thereby, sufficient residence time required for denitrification of the to-be-processed water thrown in from the raw | natural water inlet can be ensured, and more stable nitrogen removal can be performed.

  In the nitrogen removal apparatus, the raw water inlet and the circulating liquid inlet that is the outlet of the circulation channel are opened to the reaction tank, and the raw water inlet and the circulating liquid inlet are arranged close to each other. It's okay.

  According to such a configuration, since the BOD component contained in the water to be treated and the nitrite-nitrate nitrogen component contained in the circulating liquid are more in contact with each other, the efficiency of nitrogen removal can be improved.

In the denitrification device, the communication port may be provided under end of the partition wall.

  According to such a configuration, the water to be treated in the anaerobic treatment region can be prevented from flowing into the aerobic treatment region in the vicinity of the liquid surface of the water to be treated.

According to the second aspect of the present invention, a method for remodeling a nitrogen removing apparatus is provided from a single tank that performs anaerobic treatment and aerobic treatment in biological denitrification of water to be treated containing organic nitrogen compounds. A raw water supply pipe that supplies the treated water to the reaction tank, a raw water inlet that is an outlet of the raw water supply pipe formed in the reaction tank, and the treated water from the reaction tank. A method for remodeling a nitrogen removing device having a discharge pipe for discharging, and a circulation channel for circulating the water to be treated from the discharge pipe to the reaction tank, wherein the liquid phase part of the reaction tank is an aerobic treatment region And an anaerobic treatment region, provided at a position as far away as possible from the raw water inlet in a linear distance on the plane consisting of the length and width of the reaction tank and a linear distance in the height direction. The anaerobic treatment region and the aerobic treatment region And forming a partition wall having a communication port to communicate, and moving the outlet of the circulation passage to the uppermost stream portion of the anaerobic treatment region.

  According to the present invention, the liquid phase part of the reaction tank is partitioned into an anaerobic treatment region and an aerobic treatment region by the partition wall, and a communication port for communicating the anaerobic treatment region and the aerobic treatment region is possible from the raw water input port. As far as possible. Thereby, sufficient residence time required for denitrification of the to-be-processed water thrown in from the raw | natural water inlet can be ensured, and more stable nitrogen removal can be performed.

It is a schematic block diagram of the nitrogen removal apparatus of 1st embodiment of this invention. It is a perspective view of the reaction tank of a first embodiment of the present invention. It is a schematic block diagram explaining the remodeling process of 1st embodiment of this invention. It is a schematic block diagram explaining the remodeling process of 1st embodiment of this invention. It is a schematic block diagram of the nitrogen removal apparatus of 2nd embodiment of this invention. It is a perspective view of the reaction tank of the second embodiment of the present invention.

(First embodiment)
Hereinafter, the nitrogen removal apparatus 1 of 1st embodiment of this invention is demonstrated in detail with reference to drawings. The nitrogen removal apparatus 1 of this embodiment is an apparatus that performs biological denitrification in a facility such as a sewage treatment plant. To-be-treated water W (waste water containing human waste E and septic tank sludge S) to be treated by the nitrogen removing device 1 is an organic nitrogen compound, SS (floating matter), phosphorus content, BOD (biochemical oxygen demand), Contains COD (chemical oxygen demand) and the like.

  As shown in FIG. 1, the nitrogen removal apparatus 1 of this embodiment is a reaction in which raw water of the treated water W1 supplied from the mixing tank 2 and the mixing tank 2 into which the human waste E and the septic tank sludge S1 are introduced, is introduced. From the tank 3, the stirring tank 4 into which the treated water W2 discharged from the reaction tank 3 is introduced, the membrane raw water tank 5 into which the treated water W3 discharged from the stirring tank 4 is introduced, and the membrane raw water tank 5 And a solid-liquid separation device 6 into which the treated water W4 to be discharged is introduced.

The mixing tank 2 and the reaction tank 3 are connected via a raw water supply pipe 8. The reaction tank 3 and the stirring tank 4 are connected via a discharge pipe 9.
The nitrogen removing apparatus 1 has a circulation line 11 (circulation flow path) that circulates a part of the water to be treated W2 discharged from the reaction tank 3 to the reaction tank 3 as a circulating liquid R. The circulation line 11 branches off from the discharge pipe 9. Alternatively, the circulation line 11 may be taken out from the aerobic treatment region A2 of the reaction tank 3.

The circulation line 11 has a branch line 31 for supplying the circulating fluid R to the aerobic processing region A2, and a flow rate adjusting device such as a valve for adjusting the flow rate of the circulating fluid R can be provided. The branch line 31 may be provided not only on the aerobic processing region A2 side but also on the anaerobic processing region A1 side.
Further, the nitrogen removing device 1 includes a return line 10 that returns at least a part of the sludge S2 separated by the solid-liquid separator 6 (returned sludge S3) to the reaction tank 3.

  The reaction tank 3 is divided into an anaerobic treatment region A1 on the upstream side and an aerobic treatment region A2 on the downstream side by a partition wall 15. The raw water supply pipe 8 is connected to the anaerobic treatment region A1 of the reaction tank 3. The discharge pipe 9 is connected to the aerobic treatment region A2 of the reaction tank 3. The anaerobic treatment region A1 and the aerobic treatment region A2 communicate with each other through a communication port 19 that is an opening formed in the partition wall 15.

  The mixing tank 2 is a tank that mixes the introduced human waste E and the septic tank sludge S1. The mixing tank 2 is preferably provided with a device for promoting homogenization by mixing the human waste E and the septic tank sludge S1, such as a stirring device for stirring the human waste E and the septic tank sludge S1. Further, it is preferable to provide a pretreatment device for removing impurities contained in the human waste E and the septic tank sludge S1 in the previous stage of the mixing tank 2.

The reaction tank 3 has an aerobic treatment region A2 for performing an aerobic treatment that requires dissolved oxygen and an anaerobic treatment region A1 for performing an anaerobic treatment that does not require dissolved oxygen, and removes nitrogen from the water W1 to be treated. It is a tank to perform.
The reaction tank 3 includes a reaction tank body 13 having a single structure, an aeration device 14, and a partition wall 15 provided inside the reaction tank body 13. The reaction tank body 13 is composed of a single tank. The aeration apparatus 14 is disposed on the bottom surface of the reaction tank 3.

As shown in FIG. 2, the reaction vessel main body 13 is a rectangular parallelepiped tank, for example, and has four side walls 21, an upper surface 22, and a bottom surface 23. In the xyz orthogonal coordinate system, the x-axis direction is the length, the y direction is the width, and the z direction is the height. The shape of the reaction vessel main body 13 is not limited to this, and for example, the shape seen from above may be circular.
In the reaction tank 3, the water to be treated W1 introduced from the mixing tank 2 is stored. The liquid level L of the water to be treated W1 is adjusted so as to maintain a predetermined height from the bottom surface 23 of the reaction tank main body 13. That is, the internal space of the reaction tank 3 is divided into a liquid phase part F by the water to be treated W1 and a gas phase part G above the liquid level L of the water to be treated.

The partition wall 15 is a rectangular plate-like member that divides the internal space of the reaction tank body 13 into an anaerobic processing region A1 and an aerobic processing region A2. The aerobic treatment area A2 defined by the partition wall 15 is aerated from below by the aeration apparatus 14 installed on the bottom surface 23.
The upper end of the partition 15 is formed so as to be higher than the liquid level L of the water to be treated W1. That is, in the vicinity of the liquid level L of the water to be treated W1, the water to be treated W1 in the anaerobic treatment area A1 does not flow into the aerobic treatment area A2.
A gap C is formed between the upper end of the partition wall 15 and the upper surface 22 of the reaction tank body 13. That is, in the internal space of the reaction tank 3, the space above the liquid level L of the water to be treated W <b> 1 is not partitioned by the partition wall 15.

  The partition wall 15 is formed with a communication port 19 through which the water to be treated W1 in the anaerobic treatment area A1 flows into the aerobic treatment area A2. The communication port 19 is formed at the lower end of the partition wall 15 and at one end portion in the width direction of the partition wall 15. The communication port 19 has a rectangular shape.

The reaction tank body 13 is provided with a raw water inlet 17 which is an outlet of the raw water supply pipe 8. That is, the water to be treated W1 mixed in the mixing tank 2 is input to the reaction tank 3 from the raw water input port 17.
The water to be treated W1 is input from the raw water input port 17 to the anaerobic processing region A1 of the reaction tank 3, flows into the aerobic processing region A2 through the communication port 19, and is discharged from the discharge pipe 9.

  The raw water inlet 17 is formed on the side wall 21b of the anaerobic treatment region A1 of the reaction tank body 13. The raw water input port 17 is provided at a position farthest from the communication port 19 by a linear distance on the xy plane. In other words, the communication port 19 of the partition wall 15 is provided at a position farthest from the raw water input port 17. Since the communication port 19 of the present embodiment is formed at the lower end of the partition wall 15, the raw water input port 17 is formed above the side wall 21b. That is, also in the z-axis direction, the communication port 19 is provided at a position farthest from the raw water input port 17 by a linear distance.

If the raw water inlet 17 cannot be provided at the above position due to interference with other components, etc., this is not the case. That is, the raw water input port 17 may be provided at a position separated from the communication port 19 by a linear distance as much as possible. Moreover, although the raw | natural water inlet 17 of this embodiment is formed in the side wall 21b orthogonal to the partition 15, it is not restricted to this, The side wall 21a arrange | positioned so that it may be parallel to the partition 15 and a straight line You may form in the upper surface 22 of the anaerobic process area | region A1 used as a position as far as possible by distance.
It is desirable that the discharge pipe 9 be located as far as possible from the communication port 19 by a linear distance.

The reaction tank body 13 is formed with a circulating liquid inlet 18 which is an outlet of the circulation line 11. That is, the circulating liquid R that is a part of the water to be treated W2 discharged from the reaction tank 3 is input to the reaction tank 3 from the circulating liquid input port 18.
The circulating fluid inlet 18 is provided in the vicinity of the raw water inlet 17. The raw water inlet 17 and the circulating fluid inlet 18 are arranged as close as possible. Similar to the raw water input port 17, the circulating fluid input port 18 is provided at a position farthest from the communication port 19 by a linear distance or as far as possible.

  The agitation tank 4 is a tank for removing nitric acid remaining without being treated in the reaction tank 3. The stirring tank 4 has a stirring device (not shown) and a methanol addition line 12 for adding methanol as an organic carbon source to the stirring tank 4.

The membrane raw water tank 5 is a tank that converts ammonia that cannot be treated in the denitrification tank into nitric acid by nitrifying bacteria in an aerobic atmosphere.
The solid-liquid separation device 6 includes, for example, a membrane unit such as a UF membrane (ultrafiltration), an MF membrane (microfiltration), etc., and the treated water W4 is separated into a separated liquid (treated water T) and separated sludge. It is a device to do. The surplus sludge S4 separated by the solid-liquid separator 6 is sent, for example, to facilities for performing sludge dehydration, drying, incineration, composting, and the like. At least a part of the excess sludge S4 is returned to the reaction tank 3 via the return line 10 as return sludge S3.

Next, the operation of the nitrogen removing apparatus 1 of the present embodiment will be described.
When the partition wall 15 is provided in the reaction tank 3 and the aeration apparatus 14 operates in the aerobic processing region A2, the oxidation-reduction potential (ORP) is positive in the aerobic processing region A2, and in the anaerobic processing region A1. Has a negative redox potential. That is, the internal region of the reaction tank 3 is divided into an aerobic treatment region A2 in an aerobic atmosphere and an anaerobic treatment region A1 in an anaerobic atmosphere.

  After the impurities contained in the human waste E and the septic tank sludge S1 are removed by the pretreatment device, they are introduced into the mixing tank 2 and homogenized. The homogenized water to be treated W1 is continuously fed into the anaerobic treatment area A1 of the reaction tank 3 through the raw water supply pipe 8. The introduced treated water W1 flows into the aerobic treatment area A2 through the communication port 19.

  Ammonia nitrogen contained in the for-treatment water W1 is converted into nitrite nitrogen or nitrate nitrogen (nitric acid) by the action of nitric acid bacteria in the aerobic treatment region A2. Nitric acid is circulated through the circulation line 11 as a circulating liquid R (nitrification liquid). In the anaerobic treatment region A1, the circulated circulating liquid R is reduced to nitrogen gas by using BOD (electron donor) of raw water by the action of denitrifying bacteria.

  According to the above embodiment, the liquid phase part F of the reaction tank 3 is partitioned into the anaerobic treatment region A1 and the aerobic treatment region A2 by the partition wall 15, and the anaerobic treatment region A1 and the aerobic treatment region A2 are communicated. The communication port 19 is provided at a position as far as possible from the raw water input port 17. Thereby, sufficient residence time required for denitrification of the to-be-processed water W1 supplied from the raw | natural water inlet 17 can be ensured. In other words, the water to be treated W1 introduced from the raw water inlet 17 can be prevented from flowing into the aerobic treatment region A2 without being denitrified, and more stable nitrogen removal can be achieved.

  In addition, since the raw water inlet 17 and the circulating liquid inlet 18 are arranged close to each other, the BOD component contained in the water to be treated W1 and the nitrite / nitric nitrogen component contained in the circulating liquid R can be obtained. Since it contacts more, the efficiency of nitrogen removal can be improved.

In addition, since the water to be treated W1 can be continuously supplied, it is not necessary to perform complicated intermittent water supply or precise aeration control.
Further, in the gas phase portion G of the reaction tank 3, the anaerobic treatment region A1 and the aerobic treatment region A2 communicate with each other, whereby the nitrogen gas exhaust line can be simplified. That is, it is not necessary to provide an exhaust line in each of the anaerobic processing region A1 and the aerobic processing region A2.

Further, by mixing the human waste E introduced into the reaction tank 3 and the septic tank sludge S1 in the mixing tank 2, the water to be treated W1 can be homogenized. Moreover, the fluctuation | variation of the property of the to-be-processed water W1 can be suppressed by mixing previously the septic tank sludge S1 whose property is unstable and the property is unstable in the mixing tank 2 with the urine E.
Further, by providing the stirring tank 4 with the methanol addition line 12, it is possible to remove nitrite and nitrate nitrogen components that have not been treated in the reaction tank 3.
Moreover, by supplying the circulating liquid R to the aerobic treatment region A2 via the branch line 31, the water to be treated W1 in the aerobic treatment region A2 can be appropriately cooled.

In the above embodiment, the partition wall 15 is fixed to the reaction tank main body 13, but the present invention is not limited to this, and the partition wall 15 may be movable. Thereby, according to the property of the to-be-processed water W1, the capacity | capacitance of the aerobic process area | region A2 and the anaerobic process area | region A1 can be adjusted.
Further, the reaction tank 3 may be stirred (mechanical or oxygen-free gas stirring) to improve the nitrogen removal efficiency.
Moreover, in the said embodiment, although it was set as the structure set as aerobic atmosphere by providing the aeration apparatus 14 in the aerobic process area | region A2, it is not restricted to this, The structure set as aerobic atmosphere may be sufficient.

Next, a method for remodeling the nitrogen removing apparatus will be described.
The nitrogen removal apparatus 1 of the present embodiment has a reaction tank composed of a single tank, and a nitrogen removal apparatus (hereinafter referred to as a nitrification reaction and a denitrification reaction) in a single reaction tank by intermittently adding water to be treated. , Which is also referred to as an existing nitrogen removal device).
Specifically, the remodeling method of the nitrogen removing apparatus includes a reaction tank composed of a single tank, a raw water supply pipe for supplying water to be treated to the reaction tank, and raw water that is an outlet of the raw water supply pipe formed in the reaction tank. It can be manufactured by remodeling a nitrogen removing apparatus having an input port, a discharge pipe for discharging the water to be treated from the reaction tank, and a circulation line for circulating the water to be treated from the discharge pipe to the reaction tank.

The remodeling method of a nitrogen removal apparatus includes the process of forming the partition similar to the nitrogen removal apparatus 1 of 1st embodiment in the reaction tank which does not have the existing partition. The partition wall is preferably formed in consideration of the position of the existing raw water inlet. That is, it is preferable to arrange the partition so that the communication port formed in the partition is as far as possible from the raw water inlet.
Moreover, the remodeling method of a nitrogen removal apparatus includes the process of moving the exit of a circulation line to the most upstream part of an anaerobic treatment area | region, and the process of adding the branch line which can adjust flow volume. In the step of moving to the most upstream part of the anaerobic treatment region, the circulating fluid inlet which is the outlet of the circulation line and the raw water inlet are arranged close to each other.
It is preferable that the discharge pipe from the reaction tank (the kinetic treatment region) is arranged as far as possible from the communication port.
In the case where a plurality of aeration apparatuses are arranged in the existing reaction tank, the aeration apparatus arranged in the anaerobic treatment region among the plurality of aeration apparatuses stops operation or is removed.

Moreover, tanks, such as an existing preliminary storage tank, can be diverted as a mixing tank. As shown in FIG. 3, when the existing nitrogen removing device introduces urine E and septic tank sludge S1 through the pretreatment device 25 and the storage tank 26, the existing preliminary storage tank is used as the mixing tank 2. A line 27 for connecting the pretreatment device 25 and the mixing tank 2 and the raw water supply pipe 8 may be newly provided.
When there is no suitable tank for the mixing tank 2, etc., as shown in FIG. 4, the existing storage tanks 26 are connected to each other via a connecting pipe 28, and the human waste E and the septic tank sludge S1 are mixed in advance. Also good.

  According to the remodeling method of the nitrogen removing apparatus, the existing nitrogen removing apparatus can be diverted to be a nitrogen removing apparatus that can secure a sufficient residence time required for denitrification of water to be treated.

Next, conditions for carrying out the remodeling method of the nitrogen removing apparatus will be described.
The remodeling of the nitrogen removing device is preferably carried out when any one of the following four conditions is satisfied.
The first condition is when the BOD / TN ratio of the raw water to be treated is 3 or less. In other words, this is a case where the raw water to be treated has undesirable properties for denitrification.
The second condition is a case where TN of the treated water T to be discharged becomes difficult to satisfy the regulation value. In other words, this is a case where the performance of the nitrogen removing device no longer satisfies the requirements.
The third condition is when the ammonia concentration at the inlet of the stirring tank, that is, at the outlet of the reaction tank exceeds the discharge standard value.
The fourth condition is a case where the total nitrogen amount of the raw water to be treated exceeds the total nitrogen-MLSS load 0.05 kg-N / kg-MLSS · day.

  By setting the above conditions, the user of the existing nitrogen removal apparatus can accurately determine whether or not to modify.

(Second embodiment)
Hereinafter, the nitrogen removal apparatus 1B of 2nd embodiment of this invention is demonstrated based on drawing. In the present embodiment, differences from the first embodiment described above will be mainly described, and description of similar parts will be omitted.
As shown in FIG. 5, the nitrogen removing device 1B of the present embodiment includes an ORP measuring device 29 that measures the oxidation-reduction potential (ORP) in the anaerobic treatment region A1, and ammonia that measures the ammonia concentration in the aerobic treatment region A2. Concentration measuring device 30.
Further, the nitrogen removing apparatus 1B of the present embodiment has a branch line 31 that branches from the circulation line 11 and feeds the circulating liquid R into the aerobic treatment region A2. The branch line 31 may be provided not only on the aerobic processing region A2 side but also on the anaerobic processing region A1 side.
Moreover, the nitrogen removal apparatus 1B of this embodiment has the 2nd methanol addition line 32 which adds methanol to the anaerobic process area | region A1.

As shown in FIG. 6, the communication port 19B of the partition wall 15B of the reaction tank 3B of the present embodiment is provided near the center in the vertical direction of the partition wall 15B. The raw water inlet 17 and the circulating fluid inlet 18 are provided near the lower end of the side wall 21.
Here, the communication port 19B needs to be provided in a region near the center in the vertical direction of the partition wall 15 from the lower end of the partition wall 15B. This is because when the communication port 19 is provided in the vicinity of the upper end of the partition wall 15B, the water to be treated W1 in the aerobic treatment area A2 is caused by the upward flow of the water to be treated W1 generated by the aeration apparatus 14. It is because it becomes easy to flow. Therefore, when the raw water inlet 17 and the circulating fluid inlet 18 are provided in the lower part of the reaction tank 3B, the communication port 19B is formed near the center in the vertical direction without being formed above the partition wall 15B.

The nitrogen removing apparatus 1B of the present embodiment has a control device (not shown). The control device can control the amount of aeration air and the flow rate of the circulating fluid R based on the value of the oxidation-reduction potential measured by the ORP measurement device 29. The control device determines whether or not a good anaerobic atmosphere is based on the value of the oxidation-reduction potential, and performs control to adjust the aeration air volume and the flow rate of the circulating fluid R. If the redox potential value in the anaerobic treatment region A1 does not show a negative value even after adjusting the aeration air volume or the flow rate of the circulating fluid R, denitrification is performed by adding methanol to the anaerobic treatment region A1.
Further, the control device can control the aeration air volume, the flow rate of the circulating fluid R, and the pH based on the ammonia concentration value measured by the ammonia concentration measuring device 30.
As an alternative to the ammonia concentration measuring device 30, a pH measuring device for measuring pH may be provided. By providing the pH measurement device, it is possible to prevent inhibition of nitrification / denitrification reaction due to lowering of pH.

According to the above embodiment, the aeration air volume, the flow rate of the circulating fluid R, and the like can be appropriately controlled based on the measured oxidation-reduction potential and ammonia concentration.
Moreover, by supplying the circulating liquid R to the aerobic treatment region A2 via the branch line 31, the water to be treated W1 in the aerobic treatment region A2 can be appropriately cooled.
Further, by adding methanol to the water to be treated W1 in the anaerobic treatment region A1, a nitrate anaerobic atmosphere can be maintained and nitrite and nitrate nitrogen components can be removed well.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the configurations and combinations of the embodiments in the embodiments are examples, and the addition and omission of configurations are within the scope not departing from the gist of the present invention. , Substitutions, and other changes are possible. Further, the present invention is not limited by the embodiments, and is limited only by the scope of the claims.

DESCRIPTION OF SYMBOLS 1,1B Nitrogen removal apparatus 2 Mixing tank 3,3B Reaction tank 4 Stirrer tank 5 Membrane raw water tank 6 Solid-liquid separator 8 Raw water supply pipe 9 Discharge pipe 10 Return line 11 Circulation line (circulation flow path)
12 Methanol addition line 13 Reaction tank body 14 Aeration device 15, 15B Bulkhead 17 Raw water input port 18 Circulating fluid input port 19, 19B Communication port (opening)
21 Side wall 22 Upper surface 23 Bottom surface 25 Pretreatment device 26 Storage tank 27 Line 28 Connection pipe 29 ORP measurement device 30 Ammonia concentration measurement device 31 Branch line 32 Second methanol addition line A1 Anaerobic treatment region A2 Aerobic treatment region C Gap E Human waste F Liquid phase G Gas phase L Liquid level R Circulating fluid S1, S2, S3, S4 Sludge W Water to be treated

Claims (4)

A reaction tank comprising a single tank having an aerobic treatment area and an anaerobic treatment area, and performing biological denitrification of water to be treated containing an organic nitrogen compound;
A raw water supply pipe for supplying the treated water to the reaction tank;
A partition partitioning the liquid phase part of the reaction vessel into the aerobic treatment region and the anaerobic treatment region;
A raw water inlet that is an outlet of the raw water supply pipe formed in the reaction tank;
The anaerobic treatment region and the favorable position are provided as far as possible from the raw water inlet on the partition wall as far as possible in a linear distance on a plane and a linear distance in the height direction of the reaction tank. A communication port for communicating with the tempering treatment area;
A nitrogen removal apparatus comprising: a circulation channel that circulates the water to be treated from the aerobic treatment region to the most upstream part of the anaerobic treatment region.   2. The raw water inlet and a circulating liquid inlet that is an outlet of the circulation channel are opened to the reaction tank, and the raw water inlet and the circulating liquid inlet are arranged close to each other. Nitrogen removal equipment. Said communication port, the nitrogen removal apparatus according to claim 1 or claim 2 is provided below the end of the partition wall. A reaction tank composed of a single tank that performs anaerobic treatment and aerobic treatment in biological denitrification of water to be treated containing an organic nitrogen compound;
A raw water supply pipe for supplying the treated water to the reaction tank;
A raw water inlet that is an outlet of the raw water supply pipe formed in the reaction tank;
A discharge pipe for discharging the treated water from the reaction tank;
A recirculation channel for circulating the water to be treated from the discharge pipe to the reaction tank,
A partition that divides the liquid phase part of the reaction vessel into an aerobic treatment region and an anaerobic treatment region, and a linear distance and a height direction on a plane composed of the length and width of the reaction vessel from the raw water inlet Forming a partition wall having a communication port that is provided as far as possible in a straight line distance and communicates the anaerobic treatment region and the aerobic treatment region;
Moving the outlet of the circulation channel to the most upstream part of the anaerobic treatment region.

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