JP5306296B2 - Waste water treatment apparatus and waste water treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wastewater treatment apparatus and a waste water treatment method in which the adjusting of the concentration ratio of ammonia nitrogen to nitrite nitrogen in waste water is also unnecessary, and the perfect denitrification of nitrogen is possible. <P>SOLUTION: The wastewater treatment apparatus includes: a first tank; a second tank; a nitrification carrier supplied to the first tank and containing ammonium oxidizing bacteria of non-acclimatization; an autotrophism denitrification carrier supplied to the second tank and containing anaerobic ammonia oxidation bacteria of non-acclimatization; and carrier transfer means for moving the nitrification carrier to the first tank from the second tank, wherein the acclimatization of the ammonium oxidizing bacteria of non acclimatization is performed in the first tank, the acclimatization of the anaerobic ammonia oxidation bacteria of non-acclimatization is performed in the second tank, and the carrier moving means moves all or a part of the autotrophism denitrification carrier in which the anaerobic ammonia oxidation bacteria to which the acclimatization has been performed is contained to the first tank from the second tank. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a wastewater treatment apparatus and a wastewater treatment method, and particularly to a wastewater treatment apparatus and a wastewater treatment method containing wastewater containing ammonia nitrogen.

  In recent years, as a new nitrogen removal method, a method (anaerobic ammonia oxidation method) in which denitrification treatment is performed with anaerobic ammonia oxidizing bacteria has attracted attention. This anaerobic ammonia oxidation method is a group of anaerobic ammonia-oxidizing bacteria, which are autotrophic bacteria, using ammonia nitrogen in nitrogen-containing water as an electron donor and nitrite nitrogen as an electron acceptor. This is a method of simultaneous denitrification with nitrate nitrogen.

  Simultaneous denitrification by the anaerobic ammonia oxidation method is performed according to the following reaction formula (1). As can be seen from this formula, ammonia nitrogen and nitrite nitrogen cause a reaction at a ratio of 1: 1.32. It is considered that the wastewater preferably contains ammonia nitrogen and nitrite nitrogen at this ratio.

_{^{NH 4 + + 1.32NO 2 - +}} 0.66HCO 3 - + 0.13H +
^{_{→ 1.02N 2 + 0.26NO 3 - +}} 0.066CH 2 O 0.5 N 0.15 + 2.03H 2 O (1)
Various wastewater treatment methods using such anaerobic ammonia oxidation methods have been proposed.

  For example, the operation method of the anaerobic ammonia oxidation tank described in Patent Document 1 is to extract a part of the anaerobic ammonia oxidation bacteria from one anaerobic ammonia oxidation tank after the acclimatization of the anaerobic ammonia oxidation bacteria, An anaerobic ammonia-oxidizing bacterium that has been withdrawn is put into the other anaerobic ammonia-oxidizing tank to be acclimatized, and the start-up operation is performed. Ammonia-oxidizing bacteria are provided with a microbial immobilization agent that is fixedly adhered or entrapped on an immobilization material.

  Thereby, the acclimatization period of the anaerobic ammonia-oxidizing bacteria having a slow growth rate can be shortened, and the performance of one anaerobic ammonia-oxidizing tank from which the anaerobic ammonia-oxidizing bacteria are extracted is not reduced.

  Further, the nitrification method of ammonia nitrogen-containing water described in Patent Document 2 is a ratio a between the molar concentration (a) of nitrite nitrogen and the molar concentration (b) of ammonia in the nitrification liquid flowing out from the nitrification tank. / B is set to 1.1 or more. Thereby, the ratio of nitrite nitrogen and ammonia nitrogen in the nitrification process effluent is appropriate, and denitrification treatment can be performed with high efficiency.

  Furthermore, the method for treating wastewater containing ammonia described in Patent Document 3 is a first method of producing an oxidation product of ammonia by nitrifying wastewater containing ammonia by adding oxygen using a nitrifying microorganism. A second step of converting an oxidation product together with ammonia into nitrogen through a denitrifying microorganism, and simultaneously performing the first step and the second step in a single bioreactor. It has. As a result, no additives are required, and wastewater treatment can be performed only with a single reactor.

  Furthermore, Non-Patent Document 1 describes a method (so-called canon method) in which both a nitrification reaction and a denitrification reaction are performed under aerobic conditions in a treatment tank in which nitrifying bacteria and anaerobic ammonia oxidizing bacteria coexist. ing.

  In this cannon method, nitrifying bacteria and anaerobic ammonia oxidizing bacteria coexisting in the same treatment tank try to maintain a balance with each other. Therefore, ammonia nitrogen in wastewater can be reliably obtained without strictly controlling the nitrification rate. It can be decomposed and removed.

JP 2006-000785 A JP 2005-246136 A Special table 2001-506535 gazette

Third, KA, Slieker, AO, Kuenen, JG, Jetten, MSM (2001), The CANON system (completely autotrophic nitrogen-removal over nitrite) under ammonium limitation: interaction and competition between three groups of bacteria.Syst.Appl.Microbiol. 24 (4), 588-596.

  However, in the method of operating the anaerobic ammonia oxidation tank described in Patent Document 1, when actual wastewater is used, the ratio of ammonia nitrogen and nitrite nitrogen represented by the above reaction formula (1) (ammonia Nitrogen: Nitrite nitrogen = 1: 1.32) and is mainly contained in the form of ammoniacal nitrogen. Operation was inefficient and complete denitrification was not possible.

  The nitrification method of ammonia nitrogen-containing water described in Patent Document 2 adjusts the concentrations of ammonia nitrogen and nitrite nitrogen, so that denitrification treatment by ammonia oxidizing bacteria is performed efficiently. And the process of adjusting the concentration of nitrite nitrogen was necessary. In addition, no matter how the ammonia nitrogen and nitrite nitrogen concentrations are adjusted, it is impossible to always maintain a completely ideal concentration. Will be released. That is, even in this method, complete denitrification was impossible.

  The method for treating waste water containing ammonia described in Patent Document 3 and the Canon method described in Non-Patent Document 1 allow nitrifying bacteria and anaerobic ammonia-oxidizing bacteria to coexist in the same tank, thereby allowing nitrification reaction and desorption. It is not necessary to adjust the concentration ratio between ammonia nitrogen and nitrite nitrogen in the wastewater because both nitrogen reactions are performed simultaneously, but the concentration ratio between ammonia nitrogen and nitrite nitrogen is still Since the ideal value shown in the reaction formula (1) was not reached, it was impossible to completely denitrify all nitrogen components in the wastewater.

  In view of such circumstances, the present invention can efficiently adapt nitrifying bacteria and anaerobic ammonia-oxidizing bacteria while performing wastewater treatment with an actual wastewater treatment apparatus. Ammonia nitrogen and nitrite in wastewater It is an object of the present invention to provide a wastewater treatment apparatus and a wastewater treatment method that do not require adjustment of the concentration ratio of nitrogen and that can completely denitrify nitrogen.

  The problems of the present invention can be solved by the following inventions.

  That is, the wastewater treatment apparatus of the present invention is a wastewater treatment apparatus for denitrifying ammonia nitrogen in wastewater, and the first tank into which wastewater is injected from the outside, and the wastewater from the first tank. A second tank to be poured, a nitrification carrier containing unadapted ammonia-oxidizing bacteria that has been put into the first tank, and an unfamiliar anaerobic ammonia-oxidizing bacteria that has been put into the second tank Including an autotrophic denitrification carrier, carrier transfer means for moving the nitrification carrier from the second tank to the first tank, and a blower for sending air to the first tank; A dissolved oxygen concentration control device that controls the dissolved oxygen concentration of the wastewater in the first tank by controlling the amount of air supplied to the blower, and the unfamiliar ammonia oxidation in the first tank Ammonia nitrogen in the wastewater is converted to nitrite Acclimatizing the unadapted ammonia-oxidizing bacteria while allowing them to nitrify, and in the second tank, the ammoniac in the wastewater poured from the first tank to the unadapted anaerobic ammonia-oxidizing bacteria While simultaneously denitrifying nitrogen and the nitrite nitrogen in the wastewater, the unfamiliar anaerobic ammonia-oxidizing bacteria are acclimatized, and the carrier moving means is an anaerobic ammonia-oxidizing bacterium that has been acclimatized. Is transferred from the second tank to the first tank, and in the first tank, the ammonia oxidizing bacteria and the second tank are moved from the second tank to the first tank. The anaerobic ammonia-oxidizing bacteria that have migrated coexist, and the ammonia-oxidizing bacteria nitrify part of the ammoniacal nitrogen in the wastewater poured from the outside into nitrite nitrogen, and the anaerobic ammonia Of bacteria, and the remaining ammonia nitrogen of the wastewater, the nitrite nitrogen to the ammonia-oxidizing bacteria to produce, mainly characterized in that simultaneously denitrified.

  As a result, in the nitrification tank, the concentration ratio of ammonia nitrogen and nitrite nitrogen is adjusted to a concentration ratio preferable for anaerobic ammonia oxidation bacteria, and waste water is sent to the denitrification tank. Acclimatization can be performed quickly and efficiently.

  In addition, after the acclimatization is completed, the anaerobic ammonia-oxidizing bacteria in the denitrification tank are moved to the nitrification tank and coexist with the nitrification bacteria, so there is no need to adjust the concentration ratio of ammonia nitrogen and nitrite nitrogen in the wastewater. It becomes possible to perform denitrification treatment of waste water.

  Moreover, the wastewater treatment apparatus of the present invention is used as a hydrogen donor by the carrier feeding means for feeding a heterotrophic denitrification carrier containing heterotrophic bacteria into the second tank, and the heterotrophic bacteria. Hydrogen donor charging means for charging an organic substance into the second tank, and the carrier moving means transfers all or part of the autotrophic denitrification carrier from the second tank to the second tank. After the transfer to the first tank, the carrier charging means charges the heterotrophic denitrification carrier to the second tank, and the hydrogen donor charging means charges the organic matter to the second tank. The main feature is that the heterotrophic bacteria denitrify nitrogen components in the wastewater poured from the first tank.

  As a result, nitrogen components that could not be denitrified only by anaerobic ammonia-oxidizing bacteria can be denitrified by heterotrophic bacteria introduced into the second tank, so that complete denitrification of nitrogen components in wastewater Is possible.

  In addition, since denitrification by anaerobic ammonia-oxidizing bacteria is also performed, the supply amount of hydrogen donors such as methanol can be extremely reduced compared to the method using only heterotrophic bacteria, so the running cost is reduced. It can be kept very low.

Furthermore, in the wastewater treatment apparatus of the present invention, the nitrogen removal rate of the anaerobic ammonia-oxidizing bacteria in the second tank is 0.5 kg-N / m ³ / d or more per 1 m ^{3 of} the second tank. Until the anaerobic ammonia-oxidizing bacteria are acclimatized until the carrier moving means removes all or part of the autotrophic denitrifying carrier containing the acclimatized anaerobic ammonia-oxidizing bacteria, The main feature is to move from the tank to the first tank.

  Thereby, even if an anaerobic ammonia oxidizing bacterium is moved to an aerobic atmosphere in which an anaerobic ammonia oxidizing bacterium tends to lose its activity, the anaerobic ammonia oxidizing bacterium can be prevented from losing its activity.

Furthermore, the wastewater treatment apparatus of the present invention, after acclimatizing the anaerobic ammonia oxidizing bacteria until the number of bacteria of the anaerobic ammonia oxidizing bacteria is 1.5 × 10 ⁷ cells / ml or more by FISH direct count, Mainly, the carrier moving means moves all or part of the autotrophic denitrification carrier containing the acclimatized anaerobic ammonia oxidizing bacteria from the second tank to the first tank. It is a feature.

  Thereby, even if an anaerobic ammonia oxidizing bacterium is moved to an aerobic atmosphere in which an anaerobic ammonia oxidizing bacterium tends to lose its activity, the anaerobic ammonia oxidizing bacterium can be prevented from losing its activity.

  Moreover, the wastewater treatment apparatus of the present invention is the unfamiliar anaerobic while simultaneously denitrifying ammonia nitrogen in the waste water poured from the first tank and the nitrite nitrogen in the waste water. When acclimatizing the ammonia-oxidizing bacteria, the dissolved oxygen concentration control device controls the air flow rate of the blower so that the nitrite nitrogen concentration of the wastewater flowing from the first tank into the second tank is The main feature is to control the dissolved oxygen concentration in the first tank so as to be 100 mg-N / L or less.

  Thereby, inhibition of the acclimatization of the anaerobic ammonia oxidizing bacteria in the second tank by excess nitrite nitrogen can be prevented, and the acclimatization of the anaerobic ammonia oxidizing bacteria can be performed efficiently and quickly.

  Furthermore, in the wastewater treatment method of the present invention, the first tank into which wastewater is poured from the outside, the second tank into which wastewater is poured from the first tank, and the first tank, A nitrification carrier containing unfamiliar ammonia-oxidizing bacteria, an autotrophic denitrification carrier containing unfamiliar anaerobic ammonia-oxidizing bacteria charged into the second tank, and the nitrification carrier from the second tank By controlling the carrier transfer means for moving to the first tank, the blower for supplying air to the first tank, and the air supply amount of the blower, A wastewater treatment method for denitrifying ammonia nitrogen in wastewater using a wastewater treatment device comprising a dissolved oxygen concentration control device for controlling the dissolved oxygen concentration of wastewater, wherein the first tank is Ammonia nitrogen in the wastewater In the ammonia oxidizing bacteria acclimatization step of acclimatizing the unfamiliar ammonia oxidizing bacteria while nitrifying to nitrite nitrogen, and in the second tank, the unfamiliar anaerobic ammonia oxidizing bacteria in the first tank Anaerobic ammonia-oxidizing bacteria acclimatization step for acclimatizing the unfamiliar anaerobic ammonia-oxidizing bacteria while simultaneously denitrifying ammonia nitrogen in the wastewater poured from the wastewater and the nitrite nitrogen in the wastewater; The carrier moving means transfers all or part of the autotrophic denitrification carrier containing the anaerobic ammonia oxidizing bacteria conditioned in the anaerobic ammonia oxidizing bacteria acclimating step from the second tank to the first. In the first tank, the ammonia oxidizing bacteria nitrify a part of the ammonia nitrogen in the waste water poured from the outside into nitrite nitrogen in the first tank. In the first tank, the anaerobic ammonia-oxidizing bacteria moved to the first tank in the carrier moving step are the remaining ammoniacal nitrogen in the waste water and the ammonia-oxidizing bacteria. And a simultaneous denitrification step of simultaneously denitrifying the produced nitrite nitrogen.

  As a result, in the nitrification tank, the concentration ratio of ammonia nitrogen and nitrite nitrogen is adjusted to a concentration ratio preferable for anaerobic ammonia oxidation bacteria, and waste water is sent to the denitrification tank. Acclimatization can be performed quickly and efficiently.

  In addition, after the acclimatization is completed, the anaerobic ammonia-oxidizing bacteria in the denitrification tank are moved to the nitrification tank and coexist with the nitrification bacteria, so there is no need to adjust the concentration ratio of ammonia nitrogen and nitrite nitrogen in the wastewater. It becomes possible to perform denitrification treatment of waste water.

  The wastewater treatment method of the present invention is also characterized in that the wastewater treatment apparatus has a carrier feeding means for feeding a heterotrophic denitrification carrier containing heterotrophic bacteria into the second tank, and hydrogen by the heterotrophic bacteria. Hydrogen donor charging means for charging an organic substance used as a donor into the second tank; and after the carrier moving step, the carrier charging means is heterotrophic in the second tank. From the carrier feeding step of feeding a denitrification carrier, and after the carrier moving step, the hydrogen donor feeding means puts the organic substance into the second tank, and the hydrogen donor charging process, The main feature is that it further comprises a heterotrophic bacteria denitrification step in which the heterotrophic bacteria denitrify the nitrogen component in the poured wastewater.

  As a result, nitrogen components that could not be denitrified only by anaerobic ammonia-oxidizing bacteria can be denitrified by heterotrophic bacteria introduced into the second tank, so that complete denitrification of nitrogen components in wastewater Is possible.

  In addition, since denitrification by anaerobic ammonia-oxidizing bacteria is also performed, the supply amount of hydrogen donors such as methanol can be extremely reduced compared to the method using only heterotrophic bacteria, so the running cost is reduced. It can be kept very low.

Furthermore, in the wastewater treatment method of the present invention, in the ammonia oxidizing bacteria habituation step, the nitrogen removal rate of the anaerobic ammonia oxidizing bacteria in the second tank is 0.5 kg− per 1 m ^{3 of} the second tank. The main feature is that the carrier transfer step is performed after acclimatization of the anaerobic ammonia-oxidizing bacteria until N / m ³ / d or more.

  Thereby, even if an anaerobic ammonia oxidizing bacterium is moved to an aerobic atmosphere in which an anaerobic ammonia oxidizing bacterium tends to lose its activity, the anaerobic ammonia oxidizing bacterium can be prevented from losing its activity.

Furthermore, in the wastewater treatment method of the present invention, the anaerobic ammonia oxidizing process is performed until the number of bacteria of the anaerobic ammonia oxidizing bacteria is 1.5 × 10 ⁷ cells / ml or more by FISH direct count in the ammonia oxidizing bacteria acclimatization step. The main feature is that the carrier transfer step is performed after acclimatizing the oxidized bacteria.

  Thereby, even if an anaerobic ammonia oxidizing bacterium is moved to an aerobic atmosphere in which an anaerobic ammonia oxidizing bacterium tends to lose its activity, the anaerobic ammonia oxidizing bacterium can be prevented from losing its activity.

  Moreover, in the wastewater treatment method of the present invention, in the anaerobic ammonia-oxidizing bacteria acclimatization step, the dissolved oxygen concentration control device controls the air supply amount of the blower, and the first tank to the second tank. The main feature is that it further includes a step of controlling the dissolved oxygen concentration in the first tank so that the concentration of nitrite nitrogen in the wastewater flowing into the tank becomes 100 mg-N / L or less.

  Thereby, inhibition of the acclimatization of the anaerobic ammonia oxidizing bacteria in the second tank due to the excess nitrite nitrogen can be prevented, and the acclimatization of the anaerobic ammonia oxidizing bacteria can be performed efficiently and quickly.

  According to the wastewater treatment apparatus and the wastewater treatment method of the present invention, the nitrification bacteria and the anaerobic ammonia-oxidizing bacteria are efficiently acclimatized while performing denitrification treatment of the wastewater. Denitrification treatment can be performed without controlling the concentration of nitrogen and nitrite nitrogen.

It is a schematic block diagram of the wastewater treatment apparatus of the 1st state of this invention. It is a schematic structure of the wastewater treatment apparatus of the 2nd state of this invention. It is a schematic block diagram of the wastewater treatment apparatus of the 3rd state of this invention. It is a figure showing the relationship between a nitrogen removal rate and an activity fall rate.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. Here, in the drawing, portions indicated by the same symbols are similar elements having similar functions. In addition, in the present specification, when a numerical range is expressed using “˜”, upper and lower numerical values indicated by “˜” are also included in the numerical range.

<Configuration of wastewater treatment equipment>
An embodiment of a wastewater treatment apparatus according to the present invention will be described with reference to the drawings. One of the features of the wastewater treatment apparatus according to the present invention is that it changes from the first state to the third state as described below. FIG. 1 is a schematic configuration diagram of a wastewater treatment apparatus in a first state of the present invention.

(1) Wastewater treatment apparatus in the first state As shown in FIG. 1, the wastewater treatment apparatus 100 in the first state includes a raw water pump 10, a nitrification tank 20, a denitrification tank 30, a carrier transfer means 40, A dissolved oxygen concentration control device 50, a blower 60, a jet port 70, a screen 80, a stirring device 85, a nitrification carrier 90, and an autotrophic denitrification carrier 92 are mainly provided.

  The raw water pump 10 feeds waste water (raw water) containing ammonia to the nitrification tank 20. The blower 60 supplies air (oxygen), and supplies air (oxygen) from the jet outlet 70 to the water in the nitrification tank 20. The amount of air to be supplied is controlled by a dissolved oxygen concentration control device 50 equipped with a sensor for measuring the dissolved oxygen concentration of water in the nitrification tank 20 so that the dissolved oxygen concentration of water in the nitrification tank 20 becomes a predetermined value. It is controlled by.

  In the nitrification tank 20, a nitrification carrier 90 in which ammonia-oxidizing bacteria are immobilized is introduced. The nitrification carrier 90 is preferably a entrapping immobilization carrier in which ammonia-oxidizing bacteria are entrapped and immobilized inside the carrier. This is because if the entrapping immobilization carrier is used, the detachment of the biofilm that may occur in the case of the adhesion immobilization carrier does not occur, and thus the amount of bacteria can be controlled reliably.

  Moreover, if it is a entrapping immobilization support | carrier, in the case of acclimatization, since return of sludge is unnecessary, acclimatization can be performed comparatively easily. However, the present invention is not limited to the entrapping immobilization carrier, and the above advantages are eliminated. However, a contact filter medium or an adhesion immobilization carrier may be used.

  As a fixing material for the nitrification carrier 90, gels such as polyvinyl alcohol, alginic acid, and polyethylene glycol, and plastics such as cellulose, polyester, polypropylene, and vinyl chloride can be used, but are not limited thereto.

  The nitrification carrier 90 is preferably formed into a spherical body, a cylindrical body, a porous body, a cube, a rectangular parallelepiped, a sponge body, a fibrous body, a chrysanthemum body, a honeycomb body, or the like. It is not limited to.

  The size of the nitrification carrier 90 is preferably 1 mm to 10 mm from the viewpoint of preventing blockage in the wastewater treatment apparatus such as clogging of the screen 80. The filling rate of the nitrification carrier 90 (ratio of the volume of the nitrification carrier 90 to the volume of waste water in the nitrification tank 20) is preferably 5 to 50 vol%.

  The screen 80 is installed in the nitrification tank 20 and the denitrification tank 30. Both are intended to prevent the carrier in the tank from flowing out, and have holes of a size and shape that do not allow the carrier to pass even if water is passed. That is, the screen 80 installed in the nitrification tank 20 is for preventing the nitrification carrier 90 from flowing into the downstream denitrification tank 30, and has a hole that is sized to pass water but not the nitrification carrier 90. Yes. The screen 80 installed in the denitrification tank 30 is for preventing the autotrophic denitrification carrier 92 from flowing downstream, and has a size that allows water to pass but does not pass the autotrophic denitrification carrier 92. The hole is open.

  An autotrophic denitrification carrier 92 is introduced into the denitrification tank 30. The autotrophic denitrification carrier 92 is preferably a entrapping immobilization carrier in which anaerobic ammonia-oxidizing bacteria are entrapped and immobilized inside the carrier. This is because if the entrapping immobilization carrier is used, the detachment of the biofilm that may occur in the case of the adhesion immobilization carrier does not occur, and thus the amount of bacteria can be controlled reliably.

  Moreover, if it is a entrapping immobilization support | carrier, in the case of acclimatization, since return of sludge is unnecessary, acclimatization can be performed comparatively easily. However, the present invention is not limited to the entrapping immobilization carrier, and the above advantages are eliminated. However, a contact filter medium or an adhesion immobilization carrier may be used.

  As an immobilizing material for the autotrophic denitrification carrier 92, gels such as polyvinyl alcohol, alginic acid, and polyethylene glycol, and plastics such as cellulose, polyester, polypropylene, and vinyl chloride can be used. is not.

  The autotrophic denitrification carrier 92 is preferably formed into a spherical body, a cylindrical body, a porous body, a cube, a rectangular parallelepiped, a sponge body, a fibrous body, a chrysanthemum body, a honeycomb body, or the like. However, it is not limited to these shapes.

  The size of the autotrophic denitrification carrier 92 is preferably 1 mm to 10 mm from the viewpoint of preventing clogging of the screen 80 and the like in the wastewater treatment apparatus. The filling rate of the autotrophic denitrification carrier 92 (ratio of the volume of the autotrophic denitrification carrier 92 to the wastewater volume in the denitrification tank 30) is preferably 5 to 50 vol%.

  The stirring device 85 is installed in the denitrification tank 30 and stirs the water in the denitrification tank 30.

  The carrier transfer means 40 is a means for moving the autotrophic denitrification carrier 92 put in the denitrification tank 30 to the nitrification tank 20, and various means can be adopted. For example, a means for moving by a pump, a grab type moving means by a net or the like can be adopted.

  Specifically, the stirring device 85 installed in the denitrification tank 30 is stopped, a means for sucking the precipitated autotrophic denitrification carrier 92 by a pump, or a diameter (about 1 mm that does not allow the autotrophic denitrification carrier 92 to permeate). ) Can be used to collect the autotrophic denitrification carrier 92 and lift it to move to the nitrification tank 20.

(2) Wastewater treatment apparatus in the second state Next, the wastewater treatment apparatus in the second state will be described. FIG. 2 is a schematic configuration of the waste water treatment apparatus according to the second state of the present invention.

  Here, since most of the components of the wastewater treatment apparatus 110 in the second state are the same as those of the wastewater treatment apparatus in the first state, the description of the same parts will be omitted, and only the different parts will be described.

  In the wastewater treatment apparatus in the second state, the autotrophic denitrification carrier 92 in the denitrification tank 30 acclimatized in the wastewater treatment apparatus in the first state is moved to the nitrification tank 20 using the carrier transfer means 40. Is. At this time, all the autotrophic denitrification carriers 92 may be moved to the nitrification tank 20 or a part thereof may be moved to the nitrification tank 20.

(3) Wastewater treatment apparatus in the third state Next, the wastewater treatment apparatus in the third state will be described. FIG. 3 is a schematic configuration diagram of the wastewater treatment apparatus according to the third state of the present invention.

  Here, since most of the components of the wastewater treatment apparatus 120 in the third state are the same as those of the wastewater treatment apparatus in the first state, description of the same parts will be omitted, and only different parts will be described.

  The wastewater treatment apparatus in the third state is one in which a heterotrophic denitrification carrier 94 is introduced into the denitrification tank 30 of the wastewater treatment apparatus in the second state. The heterotrophic denitrification carrier 94 is preferably a entrapping immobilization carrier in which heterotrophic bacteria (such as Pseudomonas denitrificans) are entrapped and immobilized inside the carrier. This is because if the entrapping immobilization carrier is used, the detachment of the biofilm that may occur in the case of the adhesion immobilization carrier does not occur, and thus the amount of bacteria can be controlled reliably.

  Moreover, if it is a entrapping immobilization support | carrier, in the case of acclimatization, since return of sludge is unnecessary, acclimatization can be performed comparatively easily. However, the present invention is not limited to the entrapping immobilization carrier, and the above advantages are eliminated. However, a contact filter medium or an adhesion immobilization carrier may be used.

  As a material for immobilizing the heterotrophic denitrification carrier 94, gels such as polyvinyl alcohol, alginic acid, and polyethylene glycol, and plastics such as cellulose, polyester, polypropylene, and vinyl chloride can be used. is not.

  The heterotrophic denitrification carrier 94 is preferably formed into a spherical body, a cylindrical body, a porous body, a cube, a rectangular parallelepiped, a sponge body, a fibrous body, a chrysanthemum body, a honeycomb body, or the like. However, it is not limited to these shapes.

  The size of the heterotrophic denitrification carrier 94 is preferably 1 mm to 10 mm from the viewpoint of preventing blockage in the wastewater treatment apparatus such as clogging of the screen 80. The filling rate of the autotrophic denitrification carrier 92 (ratio of the volume of the heterotrophic denitrification carrier 94 to the volume of waste water in the denitrification tank 30) is preferably 5 to 50 vol%.

  The denitrification tank 30 is provided with a hydrogen donor charging device (not shown). With this hydrogen donor charging device, a hydrogen donor necessary for the heterotrophic denitrification reaction is charged into the denitrification tank 30.

  Although it does not specifically limit about a hydrogen donor, What becomes BOD components, such as methanol and sodium acetate, can be used. Further, the hydrogen donor is desirably added so as to have a ratio of about 1 to 10 as carbon with respect to nitrogen 1. This charging is preferably performed continuously by a pump, but may be performed batchwise.

<Operation of wastewater treatment equipment>
Next, the operation of the wastewater treatment apparatus according to one embodiment of the present invention will be described with reference to the drawings.

(1) Operation of Waste Water Treatment Device in First State With reference to FIG. 1, the operation of the waste water treatment device in the first state will be described. Raw water, which is waste water containing at least ammonia, is poured into the nitrification tank 20 by the raw water pump 10. The raw water may contain nutrient salts such as nitrogen, phosphorus, carbon, and heavy metals in addition to ammoniacal nitrogen. The ammoniacal nitrogen concentration in the raw water is not particularly limited, but is preferably 100 to 2000 mg / L, particularly preferably 200 to 1000 mg / L.

  The nitrification tank 20 is loaded with a nitrification carrier 90 in which unfamiliar nitrification bacteria (ammonia oxidizing bacteria) are retained. The raw water in the nitrification tank 20 is kept aerobically, and nitrifying bacteria nitrify ammonia nitrogen in the raw water to nitrite nitrogen. The dissolved oxygen concentration control device 50 keeps the DO concentration in the raw water at the set concentration by controlling the air supply amount of the blower 60 while measuring the DO concentration in the raw water using a sensor. The DO (dissolved oxygen) concentration in the raw water in the nitrification tank 20 is not particularly limited, but is preferably 0.5 to 8 mg / L, more preferably 0.5 to 7 mg / L, and most preferably 1 to 7 mg / L. . The dissolved oxygen concentration control device 50 can maintain the DO concentration in the raw water at these preferable concentrations.

  Unfamiliar nitrifying bacteria in the nitrification tank 20 are proliferated and acclimatized by nitrifying a part of ammonia nitrogen contained in the raw water to nitrite nitrogen (nitrite type nitrification). In this way, the nitrification tank 20 is started up. However, in the start-up state of the nitrification reaction by nitrifying bacteria, the ammonia concentration in the tank tends to decrease and the nitrite nitrogen concentration tends to increase. Nitrification to nitrate nitrogen (nitrite type nitrification) can be confirmed.

  Here, “start-up” means that the bacteria can grow to a sufficient number to treat the wastewater by acclimatizing the bacteria, and the required amount of wastewater can be treated in the tank containing the bacteria. It means to make. Therefore, “starting up nitrifying bacteria”, “starting up nitrifying reaction”, and “starting up a nitrifying tank (containing nitrifying bacteria)” have the same meaning. The same can be said for other bacteria and tanks.

In a state where the nitrification reaction by nitrifying bacteria has started, the nitrite production rate is preferably 0.5 kg-N / m ³ / d or more per 1 m ^{3 of} tank. Also, by controlling the DO concentration, about half of ammonia nitrogen (strictly speaking, ammonia amount in which ammonia nitrogen and nitrite nitrogen are in a ratio of 1: 1.32) is nitrified to nitrite nitrogen. Preferably it is.

  The temperature of the raw water is not particularly limited as long as the nitrous acid production rate is maintained in a standing state, but is preferably 10 to 35 ° C. Similarly, the pH is not particularly limited as long as the nitrite production rate is maintained, but pH 6.0 to 8.5 is preferable.

  Thus, raw water in which about half of the ammonia nitrogen has been nitrified to nitrite nitrogen by nitrifying bacteria is sent to the denitrification tank 30. At this time, the screen 80 installed in the nitrification tank 20 prevents the nitrification carrier 90 from flowing into the denitrification tank 30.

  Next, acclimatization of anaerobic ammonia oxidizing bacteria in the denitrification tank 30 will be described. The unfamiliar anaerobic ammonia-oxidizing bacteria contained in the autotrophic denitrification carrier 92 grow while simultaneously denitrifying ammonia nitrogen and nitrite nitrogen in the raw water flowing into the denitrification tank 30 from the nitrification tank 20. And be accustomed. That is, the anaerobic ammonia oxidizing bacteria are acclimatized in the nitrification tank 20 while denitrifying the nitrite nitrogen generated from the ammonia nitrogen by the nitrification bacteria using the ammonia nitrogen in the raw water as a hydrogen donor.

  Here, anaerobic ammonia oxidizing bacteria generally have a slower growth rate than nitrifying bacteria. Therefore, the rise of the anaerobic ammonia oxidizing bacteria in the denitrification tank is delayed from the rise of the nitrification tank. Furthermore, anaerobic ammonia oxidizing bacteria are inhibited in their reaction by high concentrations of nitrite nitrogen. In particular, when the ammonia concentration in the raw water is high, about half of the high concentration of nitrous acid is present after the nitrification tank 20 is started up, so the anaerobic ammonia oxidation reaction is affected by the high concentration of nitrous acid. . This requires more time for startup.

  Therefore, especially at the initial stage of startup, the concentration of nitrite nitrogen in the raw water flowing into the denitrification tank 30 is set to 100 mg-N / L or less, and the concentration of nitrite nitrogen in the raw water in the denitrification tank 30 is always 100 mg-N / L. It is desirable to keep it below L.

  The nitrogen concentration control method for this purpose is not particularly limited, but there are the following methods. The first method is a method of slowly starting up the nitrification layer 20 in accordance with the acclimatization of the anaerobic ammonia oxidizing bacteria in the denitrification tank 30. In the second method, an adjustment tank is provided between the nitrification layer 20 and the denitrification tank 30, and the raw water flowing out of the nitrification tank 20 is adjusted to be in a state suitable for the denitrification tank 30 in this adjustment tank, In this method, water is poured into the denitrification tank 30 with an appropriate amount of water.

  Explaining the first method, the nitrite production rate is kept low by keeping the DO concentration of the nitrification layer 20 low. At this time, it is desirable to keep the DO concentration in the nitrification tank 20 low so that the concentration of nitrite nitrogen in the raw water flowing into the denitrification tank 30 is 100 mg-N / L or less. This is because the acclimatization of anaerobic ammonia oxidizing bacteria is not inhibited when the nitrite nitrogen concentration is 100 mg-N / L or less.

  In this way, the nitrification tank 20 is slowly started up. Then, in accordance with the acclimatization of the anaerobic ammonia oxidizing bacteria in the denitrification tank 30, that is, in accordance with the increase in the anaerobic ammonia oxidizing reaction treatment capacity due to the growth of the anaerobic ammonia oxidizing bacteria, the nitrite generation rate in the nitrification tank 20 is increased. As a result, the concentration of nitrous acid in the raw water flowing into the denitrification tank 30 is gradually increased. The nitrite generation rate in the nitrification tank 20 is increased by adjusting the DO concentration in the nitrification tank 20.

  As a result, the raw water flowing from the nitrification tank 20 into the denitrification tank 30 can be adjusted so as not to have a nitrite concentration that hinders the acclimatization of the anaerobic ammonia oxidizing bacteria. It can be done well.

  The second method will be described. The second method is a state in which an adjustment tank is provided between the nitrification layer 20 and the denitrification tank 30, and the raw water flowing out of the nitrification tank 20 is suitable for the denitrification tank 30 in this adjustment tank. Then, the water is poured into the denitrification tank 30 with an appropriate amount of water after adjustment.

  As the raw water adjustment method, a method of adding a chemical containing nitrite nitrogen or a method such as dilution can be used, and thereby the nitrite concentration and the nitrogen load can be adjusted.

  Thereby, since the raw | natural water which flows into the denitrification tank 30 can be adjusted so that it may not become the nitrite density | concentration which inhibits acclimatization of anaerobic ammonia oxidation bacteria similarly to a 1st method, anaerobic ammonia oxidation bacteria Can be well conditioned.

  In this manner, the anaerobic ammonia-oxidizing bacteria held on the autotrophic denitrification carrier 92 in the denitrification tank 30 are acclimatized and started up. As a judgment of start-up, the removal amount of nitrous acid or nitric acid is about 1.32 (nitrite) and 0.26, respectively, with respect to the removal amount of ammonia from the reaction formula of nitrogen removal by anaerobic ammonia-oxidizing bacteria. (Nitric acid) can be adopted.

In the activated state, the nitrogen removal rate is preferably 0.5 kg-N / m ³ / d or more per 1 m ³ of the tank. The temperature of the raw water in the denitrification tank 30 is not particularly limited as long as the nitrogen removal rate in a standing state is maintained, and is preferably 10 to 35 ° C. Similarly, the pH is not particularly limited as long as the nitrogen removal rate is maintained, but is preferably 6.0 to 8.5.

  As described above, the wastewater treatment apparatus in the first state can acclimatize nitrifying bacteria and anaerobic ammonia oxidizing bacteria at the same time while actually performing denitrification treatment of wastewater. In addition, the wastewater treatment apparatus in the first state in the up state has a sufficient denitrification treatment capacity without requiring supply of organic substances from the outside. However, in the wastewater treatment apparatus in the first state, it is necessary to control the ratio of ammonia nitrogen to nitrite nitrogen to be 1: 1.32 strictly in the reaction in the nitrification tank 20. However, this problem is solved by the wastewater treatment apparatus in the second state described below.

(2) Operation of Waste Water Treatment Device in Second State With reference to FIG. 2, the operation of the waste water treatment device in the second state will be described. The operation of the wastewater treatment device in the first state completes the start-up of nitrifying bacteria in the nitrification tank 20 and the start-up of anaerobic ammonia-oxidizing bacteria in the denitrification tank 30, so that the wastewater in the second state Operation of the processing equipment begins.

The carrier transfer means 40 moves all or part of the autotrophic denitrification carrier 92 in the denitrification tank 30 to the nitrification layer 20. At this time, the nitrogen removal rate of the anaerobic ammonia oxidizing bacteria is 0.5 kg-N / m ³ / d or more per 1 m ^{3 of} tank, or the anaerobic ammonia oxidizing bacteria held in the autotrophic denitrifying carrier 92 Must be 1.5 × 10 ⁷ cells / ml or more by FISH method direct count.

FIG. 4 shows an evaluation result indicating that the nitrogen removal rate needs to be 0.5 kg-N / m ³ / d or more per 1 m ^{3 of} the tank. FIG. 4 is a diagram showing the relationship between the nitrogen removal rate and the activity decrease rate.

Here, the nitrogen removal rate was determined from the sum of the ammoniacal nitrogen concentration and the nitrite nitrogen concentration. The formula for determining the nitrogen removal rate is shown below.
Nitrogen removal rate (kg-N / m ³ / d) = {(C _{NH4, AIN} -C _{NH4, AOUT} ) + (C _{NO2, AIN} -C _{NO2, AOUT} )} × 24 / HRT
C _{NH4, AIN} : Ammonia nitrogen concentration in the influent (raw water)
C _{NH4, AOUT} : Ammonia nitrogen concentration in the effluent (treated water)
C _{NO2, AIN} ： Nitrite nitrogen concentration in influent (raw water)
C _{NO2, AOUT} : Concentration of nitrite nitrogen in effluent (treated water) _Indophenol blue method was used for analysis of ammonia nitrogen. Nitrite nitrogen was analyzed using an ion chromatograph (ICS-1500, Dionex, USA).

The rate of decrease in activity (%) is the ratio of the nitrogen removal rate when the DO concentration in the tank is 0.5 mg / L or less and the nitrogen removal rate when the DO concentration in the tank is about 2 mg / L. From The formula for determining the activity reduction rate (%) is shown below.
Activity decrease rate (%) = {(NR ₀ -NR ₁ ) / NR ₀ } × 100
NR ₀ : Nitrogen removal rate under conditions where DO = 0.5 mg / L or less
NR ₁ : Nitrogen removal rate under conditions of DO = 2 mg / L As shown in FIG. 4, when the nitrogen removal rate is 0.5 kg-N / m ³ / d or more, the rate of decrease in activity is 10% or less. Can be suppressed. By reducing the nitrogen removal rate to 1 kg-N / m ³ / d or more, the activity reduction rate can be suppressed to about 5% or less, and by setting the nitrogen removal rate to 4 kg-N / m ³ / d or more, The rate of decrease in activity can be suppressed to 0%.

  For the direct count of FISH method, see `` K. Isaka et al., Growth characteristic of anaerobic ammonium oxidizing (anammox) bacteria in an anaerobic biological filtered (ABF) reactor, Applied Microbiology and Biotechnology, 70, 47-52 (2006). The description is omitted.

  As described above, the inventors' diligent research has found a condition in which anaerobic ammonia oxidizing bacteria do not lose much activity even in an aerobic atmosphere. That is, in an aerobic atmosphere, which is a desirable environment for aerobic nitrifying bacteria, the activity of anaerobic ammonia-oxidizing bacteria is originally inhibited. Was found.

  As the movement of the autotrophic denitrification carrier 92 by the carrier transfer means 40, for example, a movement by a pump, a grab type movement by a net or the like can be adopted.

  Specifically, the stirring device 85 installed in the denitrification tank 30 is stopped, and the precipitated autotrophic denitrification carrier 92 is sucked up by a pump, or the diameter of the autotrophic denitrification carrier 92 that does not permeate (about 1 mm). The method of collecting the autotrophic denitrification carrier 92 on the net and lifting it to the nitrification tank 20 can be used.

  Thus, by moving a part or all of the autotrophic denitrification carrier 92 in which the anaerobic ammonia-oxidizing bacteria in the denitrification tank 30 are immobilized to the nitrification tank 20, the wastewater treatment apparatus in the second state Is completed. In the wastewater treatment apparatus of this second state, the nitrifying bacteria and the anaerobic ammonia oxidizing bacteria coexisting in the same tank (nitrification tank 20) try to maintain a balance with each other, so the nitrification rate is not strictly controlled. In addition, ammonia nitrogen in wastewater can be reliably decomposed and removed. That is, it is not necessary to manage the ratio of ammonia nitrogen and nitrite nitrogen in the tank. A hydrogen donor is also unnecessary.

  In the operation of the nitrification tank 20, the DO concentration is preferably about 0.5 to 2 mg / L. Moreover, it is preferable that stirring is performed efficiently by supplying oxygen.

  The temperature of the raw water in the tank is not particularly limited as long as the nitrogen removal rate is maintained, but is preferably 10 to 35 ° C. Similarly, the pH is not particularly limited as long as the nitrogen removal rate is maintained, but pH of 6.5 to 8.0 is preferable.

  As described above, by using the wastewater treatment device in the first state and the wastewater treatment device in the second state changed from the first state, two types of unfamiliar bacteria, nitrifying bacteria ( Wastewater treatment can be performed simultaneously while acclimatizing ammonia-oxidizing bacteria) and anaerobic ammonia-oxidizing bacteria at the same time.

  Thereby, even during the acclimatization period of the anaerobic ammonia-oxidizing bacteria usually required for 6 months or more, the wastewater treatment can be performed at the same time, so that the wastewater treatment by the wastewater treatment apparatus during the acclimatization period becomes possible.

(3) Operation of Waste Water Treatment Device in Third State With reference to FIG. 3, the operation of the waste water treatment device in the third state will be described. In the wastewater treatment apparatus in the third state, the carrier feeding means (not shown) has put the heterotrophic denitrification carrier 94 into the denitrification tank 30 of the wastewater treatment apparatus in the second state.

  Most of the nitrogen components in the raw water poured into the nitrification tank 20 by the raw water pump 10 are decomposed and denitrified by the nitrifying bacteria and the anaerobic ammonia oxidizing bacteria in the nitrification tank 20.

  Next, the raw water containing the remaining nitrogen components that could not be completely denitrified is sent to the denitrification tank 30. In the denitrification tank 30, heterotrophic bacteria immobilized in the heterotrophic denitrification carrier 94 using a hydrogen donor that is an organic substance such as methanol and sodium acetate introduced by a hydrogen donor introduction means (not shown), Perform denitrification.

  As a result, a complete denitrification treatment that reliably removes nitrogen that cannot be removed by the anaerobic ammonia oxidation method can be performed. Also, unlike the denitrification process using only heterotrophic bacteria, the anaerobic ammonia oxidation method is also used, so the amount of hydrogen donor used is very small and the running cost can be kept very low. .

  As described above, the wastewater treatment apparatus and the wastewater treatment method of the present invention change the state from the wastewater treatment apparatus in the first state to the wastewater treatment apparatus in the second state and the wastewater treatment apparatus in the third state. Therefore, it is possible to start up bacteria while performing wastewater treatment, and if used in the state of the wastewater treatment device in the second state, wastewater that does not require control of the nitrification rate and does not require a hydrogen donor. Processing becomes possible.

  In addition, if the wastewater treatment apparatus in the third state is used, the wastewater can be completely denitrified with no need to control the nitrification rate and only by adding a very small amount of hydrogen donor.

  Furthermore, in the first state, wastewater can be treated while starting up an unfamiliar ammonia-oxidizing bacterium and an unfamiliar anaerobic ammonia-oxidizing bacterium. It is possible to prevent the apparatus from being stopped during the start-up period.

  Furthermore, since the acclimatization of the bacteria is performed with the same waste water as the full-scale operation after the completion of the acclimatization, the bacteria can become the waste water even during the full-scale operation, so that the ability can be sufficiently exhibited.

  In the above description, the wastewater treatment apparatus and the wastewater treatment method for denitrifying the nitrogen component in the wastewater have been described, but the wastewater treatment water from which the nitrogen component in the wastewater has been removed is produced in exactly the same manner as described above. be able to. Since this wastewater treated water production method has exactly the same contents as described above, a description thereof will be omitted.

  DESCRIPTION OF SYMBOLS 10 ... Raw water pump, 20 ... Nitrification tank, 30 ... Denitrification tank, 40 ... Carrier transfer means, 50 ... Dissolved oxygen concentration control device, 60 ... Blower, 70 ... Jet outlet, 80 ... Screen, 85 ... Stirrer, 90 ... Nitrification Carrier, 92 ... Autotrophic denitrification carrier, 94 ... Heterotrophic denitrification carrier, 100 ... Waste water treatment device, 110 ... Waste water treatment device

Claims (10)

A wastewater treatment apparatus for denitrifying ammonia nitrogen in wastewater,
A first tank into which waste water is poured from the outside;
A second tank into which waste water is poured from the first tank;
A nitrification carrier containing unfamiliar ammonia-oxidizing bacteria, which is put into the first tank;
An autotrophic denitrification carrier containing unfamiliar anaerobic ammonia-oxidizing bacteria charged into the second tank;
Carrier transfer means for moving the nitrification carrier from the second tank to the first tank;
A blower for feeding air to the first tank;
A dissolved oxygen concentration control device that controls the dissolved oxygen concentration of the wastewater in the first tank by controlling the air supply amount of the blower;
With
In the first tank, nitrification of ammonia nitrogen in the wastewater to nitrite nitrogen to the unfamiliar ammonia-oxidizing bacteria, while acclimatizing the unfamiliar ammonia-oxidizing bacteria,
In the second tank, the unfamiliar anaerobic ammonia-oxidizing bacteria simultaneously denitrify ammonia nitrogen in the waste water poured from the first tank and the nitrite nitrogen in the waste water. While acclimatizing the unfamiliar anaerobic ammonia oxidizing bacteria,
The carrier moving means moves all or part of the autotrophic denitrification carrier containing acclimatized anaerobic ammonia oxidizing bacteria from the second tank to the first tank,
In the first tank,
Coexisting the ammonia-oxidizing bacteria and the anaerobic ammonia-oxidizing bacteria that have moved from the second tank,
The ammonia oxidizing bacteria nitrify a part of ammonia nitrogen in waste water poured from the outside into nitrite nitrogen,
The anaerobic ammonia oxidizing bacteria simultaneously denitrify the remaining ammoniacal nitrogen in the wastewater and the nitrite nitrogen produced by the ammonia oxidizing bacteria;
Waste water treatment equipment. A carrier feeding means for feeding a heterotrophic denitrification carrier containing heterotrophic bacteria into the second tank;
A hydrogen donor charging means for charging an organic substance used as a hydrogen donor by the heterotrophic bacteria into the second tank;
Further comprising
After the carrier moving means moves all or part of the autotrophic denitrification carrier from the second tank to the first tank,
The carrier loading means throws the heterotrophic denitrification carrier into the second tank;
The hydrogen donor charging means inputs the organic substance into the second tank,
The heterotrophic bacteria denitrify the nitrogen component in the wastewater poured from the first tank,
The wastewater treatment apparatus according to claim 1. The anaerobic ammonia oxidizing bacteria are removed until the nitrogen removal rate of the anaerobic ammonia oxidizing bacteria in the second tank is 0.5 kg-N / m ³ / d or more per 1 m ^{3 of} the second tank. After acclimatization,
The said carrier moving means moves all or a part of the autotrophic denitrification carrier containing the anaerobic ammonia-oxidizing bacteria that has been acclimatized from the second tank to the first tank. The wastewater treatment apparatus according to 1 or 2. After acclimatizing the anaerobic ammonia oxidizing bacteria until the number of bacteria of the anaerobic ammonia oxidizing bacteria is 1.5 × 10 ⁷ cells / ml or more in FISH direct count,
The denitrification transfer means moves all or part of the autotrophic denitrification carrier containing the anaerobic ammonia-oxidizing bacteria that has been acclimatized from the second tank to the first tank. Item 3. A wastewater treatment apparatus according to item 1 or 2. When acclimatizing the unfamiliar anaerobic ammonia oxidizing bacteria while simultaneously denitrifying ammonia nitrogen in waste water poured from the first tank and the nitrite nitrogen in the waste water,
The dissolved oxygen concentration control device controls the air supply amount of the blower so that the nitrite nitrogen concentration of wastewater flowing from the first tank to the second tank is 100 mg-N / L or less. The wastewater treatment apparatus according to any one of claims 1 to 4, wherein the dissolved oxygen concentration in the first tank is controlled. A first tank into which waste water is poured from the outside;
A second tank into which waste water is poured from the first tank;
A nitrification carrier containing unfamiliar ammonia-oxidizing bacteria, which is put into the first tank;
An autotrophic denitrification carrier containing unfamiliar anaerobic ammonia-oxidizing bacteria charged into the second tank;
Carrier transfer means for moving the nitrification carrier from the second tank to the first tank;
A blower for feeding air to the first tank;
A dissolved oxygen concentration control device that controls the dissolved oxygen concentration of the wastewater in the first tank by controlling the air supply amount of the blower;
A wastewater treatment method for denitrifying ammonia nitrogen in wastewater using a wastewater treatment apparatus comprising:
In the first tank, the ammonia-oxidizing bacteria acclimatization step of acclimatizing the unaccustomed ammonia-oxidizing bacteria while nitrifying ammonia nitrogen in the wastewater into nitrite nitrogen to the unaccustomed ammonia-oxidizing bacteria, ,
In the second tank, the unfamiliar anaerobic ammonia-oxidizing bacteria simultaneously denitrify ammonia nitrogen in the waste water poured from the first tank and the nitrite nitrogen in the waste water. While, the anaerobic ammonia oxidizing bacteria acclimatization step of acclimatizing the unaccustomed anaerobic ammonia oxidizing bacteria,
The carrier moving means transfers all or part of the autotrophic denitrification carrier containing the anaerobic ammonia oxidizing bacteria conditioned in the anaerobic ammonia oxidizing bacteria acclimating step from the second tank to the first tank. A carrier moving step for moving to a tank;
In the first tank, the ammonia oxidizing bacterium nitrifies a part of ammonia nitrogen in waste water poured from outside into nitrite nitrogen; and
In the first tank, the anaerobic ammonia-oxidizing bacteria moved to the first tank in the carrier moving step are the remaining ammoniacal nitrogen in the wastewater and the nitrous acid generated by the ammonia-oxidizing bacteria. A simultaneous denitrification step of simultaneously denitrifying nitrogen.
A wastewater treatment method comprising: The wastewater treatment apparatus is
A carrier feeding means for feeding a heterotrophic denitrification carrier containing heterotrophic bacteria into the second tank;
A hydrogen donor charging means for charging an organic substance used as a hydrogen donor by the heterotrophic bacteria into the second tank;
Further comprising
After the carrier moving step, the carrier feeding means, the carrier feeding step of feeding the heterotrophic denitrification carrier to the second tank,
A hydrogen donor charging step in which the hydrogen donor charging means charges the organic substance into the second tank after the carrier moving step;
A heterotrophic bacteria denitrification step in which the heterotrophic bacteria denitrify the nitrogen component in the wastewater poured from the first tank;
The wastewater treatment method according to claim 6, further comprising: In the ammonia oxidizing bacteria acclimatization step, the nitrogen removal rate of the anaerobic ammonia oxidizing bacteria in the second tank is 0.5 kg-N / m ³ / d or more per 1 m ^{3 of} the second tank. The wastewater treatment method according to claim 6 or 7, wherein the carrier moving step is performed after acclimatizing the anaerobic ammonia oxidizing bacteria. In the ammonia-oxidizing bacteria habituation step, the carrier transfer step after acclimatizing the anaerobic ammonia-oxidizing bacteria until the number of bacteria of the anaerobic ammonia-oxidizing bacteria is 1.5 × 10 ⁷ cells / ml or more in FISH direct count The wastewater treatment method according to claim 6 or 7, wherein:   In the anaerobic ammonia-oxidizing bacteria acclimatization step, the dissolved oxygen concentration control device controls the amount of air supplied to the blower, and the nitrite nitrogen concentration of wastewater flowing from the first tank to the second tank The wastewater treatment method according to any one of claims 6 to 9, further comprising a step of controlling the dissolved oxygen concentration in the first tank so that the concentration is 100 mg-N / L or less.

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