JP2007021365A - Anaerobic ammonia oxidation reactor and operation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a reduction of dissolved oxygen in raw water supplied to an anaerobic ammonia oxidation reaction tank, efficient denitrification treatment, and reduction of treatment costs. <P>SOLUTION: In the operation method of an anaerobic ammonia oxidation reactor 50 performing denitrification by using anaerobic ammonia-oxidizing bacteria, microorganism group-containing water which contains a microorganism group consuming dissolved oxygen is mixed with the raw water supplied to the anaerobic ammonia oxidation reaction tank 80 in which the anaerobic ammonia-oxidizing bacteria exist to prepare water with reduced dissolved oxygen by biologically reducing dissolved oxygen in the raw water with the microorganism group, and the water with reduced dissolved oxygen is made to flow into the anaerobic ammonia oxidation reaction tank 80. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wastewater treatment method and apparatus, and more particularly to an anaerobic ammonia oxidation reaction apparatus and operation method for removing ammonia in wastewater by anaerobic ammonia oxidizing bacteria.

  Nitrogen components contained in sewage and industrial wastewater need to be removed for reasons such as causing eutrophication of lakes and marshes and reducing dissolved oxygen in rivers. Nitrogen components contained in sewage and industrial wastewater are mainly nitrogen components such as ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, and organic nitrogen.

  Conventionally, this type of wastewater, if the nitrogen concentration is low, is also removed by ion exchange method and oxidation by chlorine, ozone, but in the case of medium to high concentration, biological treatment is adopted, Generally, it is operated under the following conditions.

  In biological treatment, nitrification and denitrification processes are performed by aerobic nitrification and anaerobic denitrification. In aerobic nitrification, ammonia nitrogen and nitrite nitrogen are oxidized by ammonia oxidizing bacteria (Nitrosomonas, Nitrosococcus, Nitrosospira, Nitrosolobus, etc.) and nitrite oxidizing bacteria (Nitrobactor, Nitrospina, Nitrococcus, Nitrospira, etc.). On the other hand, in anaerobic denitrification, denitrification by heterotrophic bacteria (Pseudomonas denitrificans etc.) is performed.

A nitrification tank for performing aerobic nitrification is operated in a load range of 0.2 to 0.3 kg-N / m ³ / day, and a denitrification tank for anaerobic denitrification has a load of 0.2 to 0.4 kg-N / m. It is operated in the range of ³ / day. In order to treat the total nitrogen concentration of sewage of 30 to 40 mg / L, a residence time of 6 to 8 hours was required in the nitrification tank and 5 to 8 hours were required in the denitrification tank, and a large-scale treatment tank was required. In industrial wastewater containing only inorganic substances, nitrification tanks and denitrification tanks are designed with the same load as before, but organic substances are required for denitrification, and methanol with a concentration of 3 to 4 times the nitrogen concentration is added. It was. Therefore, there is a problem that not only the initial cost but also a great running cost is required.

  As means for solving this, for example, Patent Document 1 discloses a nitrogen removal method by an anaerobic ammonia oxidation method. This anaerobic ammonia oxidation method is a method in which ammonia is used as a hydrogen donor, nitrous acid is used as a hydrogen acceptor, and ammonia and nitrous acid are simultaneously denitrified by an anaerobic ammonia oxidizing bacterium according to the following reaction formula.

(Chemical formula 1)
1.00NH ₄ + 1.32NO ₂ + 0.066HCO ₃ + 0.13H ⁺
→ 1.02N ₂ + 0.26NO ₃ + 0.066CH ₂ O _0.5 N _0.15 + 2.03H ₂ O
According to this method, since ammonia is used as a hydrogen donor, there is a merit that the amount of methanol used for denitrification can be greatly reduced and the amount of sludge generated can be reduced. It is considered to be an effective method.
JP 2001-37467 A

  However, anaerobic ammonia-oxidizing bacteria have the property that their activity decreases due to oxygen contamination. In particular, when anaerobic ammonia-oxidizing bacteria are cultured, or when the wastewater treatment apparatus is started or stopped, the activity of the anaerobic ammonia-oxidizing bacteria tends to become unstable. In addition, as raw water supplied to the anaerobic ammonia oxidation reaction tank, waste water after nitrification may be supplied, and this may be 2 to 4 mg / L of dissolved oxygen (DO = Dissolved Oxide). Many. Moreover, when using tap water when culturing anaerobic ammonia oxidizing bacteria, the dissolved oxygen amount (DO7 mg / L or more) close to the saturated oxygen amount is dissolved in this tap water. It cannot be used for reaction. For this reason, in order to remove dissolved oxygen from raw water, a method of aeration with a gas other than oxygen, such as nitrogen gas, or a method of adding a chemical such as sodium sulfite, sodium sulfide, or cysteine-HCl has been performed. However, as the apparatus becomes larger, there is a problem that the amount of raw water increases, a large amount of gas and chemicals are required, and the processing cost increases. Furthermore, there is a problem in using these means from the viewpoint of ensuring safety and preventing environmental pollution.

  The present invention has been made in view of such circumstances, and can reduce the dissolved oxygen in the raw water supplied to the anaerobic ammonia oxidation reaction tank in which anaerobic ammonia oxidizing bacteria are present, thereby efficiently performing the denitrification treatment. And it aims at providing the anaerobic ammonia oxidation reaction apparatus and operating method which reduce processing cost.

  In order to achieve the above object, claim 1 of the present invention is an anaerobic ammonia oxidation reaction apparatus operating method for performing denitrification treatment using anaerobic ammonia oxidation bacteria, wherein the anaerobic ammonia oxidation bacteria are present. The dissolved oxygen in the raw water is biologically reduced by mixing the microorganism-containing water containing the microorganisms that consume dissolved oxygen with the raw water supplied to the basic ammonia oxidation reactor Provided is a method for operating an anaerobic ammonia oxidation reaction apparatus characterized in that water is prepared and the dissolved oxygen-reduced water is caused to flow into the anaerobic ammonia oxidation reaction tank.

  The inventor found that heterotrophic bacteria using organic substances that are metabolites of autotrophic bacteria as a substrate coexist in the microbial community contained in the treated water using autotrophic bacteria such as anaerobic ammonia oxidizing bacteria. It was found that heterotrophic bacteria actively consume dissolved oxygen in water. Based on this knowledge, the present invention biologically reduces dissolved oxygen in raw water supplied to an anaerobic ammonia oxidation reaction apparatus. Here, the raw water refers to the water to be treated immediately before being treated in the anaerobic ammonia oxidation reaction tank. In the previous stage of the anaerobic ammonia oxidation reaction tank, denitrification treatment by anaerobic ammonia oxidation bacteria (anaerobic ammonia oxidation treatment) Processing other than) may be performed.

  That is, the present invention provides a method for reducing dissolved oxygen in raw water supplied to an anaerobic ammonia oxidation reaction tank by bubbling a gas other than oxygen, such as nitrogen gas, or a drug such as sodium sulfite as in the prior art. Instead of using it, the microbial group-containing water including the microbial group that consumes dissolved oxygen is mixed with the raw water to biologically reduce the dissolved oxygen in the raw water. As mentioned above, treated water using autotrophic bacteria such as anaerobic ammonia-oxidizing bacteria can be used as this microbial group-containing water, greatly reducing treatment costs compared to conventional dissolved oxygen reduction methods. it can. The microorganism group-containing water may be any one that contains a microorganism group that consumes dissolved oxygen, and may be water other than treated water for denitrification treatment.

  Also, after mixing raw water and microbial group-containing water, do not immediately flow into the anaerobic ammonia oxidation reaction tank, but after mixing time sufficient to reduce dissolved oxygen, for example, 1-12 hours, anaerobic ammonia It is preferable to flow into the oxidation reaction tank.

  The claim 2 is the claim 1, wherein the microbial group-containing water includes autotrophic bacteria and heterotrophic bacteria having an organic substance that is a metabolite of the autotrophic bacteria as a substrate. Bacteria reduce dissolved oxygen in the raw water.

  Claim 2 specifically defines the microbial group contained in the microbial group-containing water and consuming dissolved oxygen.

  Thus, dissolved oxygen in raw water is consumed when metabolites of anaerobic ammonia-oxidizing bacteria are consumed by heterotrophic bacteria or endogenous respiration. Heterotrophic bacteria may be added to consume dissolved oxygen, and it is particularly effective to add the genus Bacillus.

  A third aspect of the present invention is characterized in that in the first or second aspect, the microorganism group-containing water is treated water after denitrification treatment in the anaerobic ammonia oxidation reaction tank. Thus, when the treated water after the denitrification treatment is used as the microorganism group-containing water, no other chemicals or the like are required when the dissolved oxygen in the raw water is reduced. Therefore, the processing cost can be greatly reduced.

  A fourth aspect of the present invention is the method according to any one of the first to third aspects, wherein the operation method is applied to a culture operation for culturing the anaerobic ammonia-oxidizing bacteria, and the raw water is a substrate for the anaerobic ammonia-oxidizing bacteria. It is characterized by using water to which ammonia and nitrous acid are added. In the culture of bacteria, usually, a culture medium obtained by adding a bacterial substrate to water is used as the culture solution. However, oxygen close to the saturated oxygen amount is dissolved in water. For this reason, to culture anaerobic bacteria such as anaerobic ammonia-oxidizing bacteria in tap water, it is necessary to reduce dissolved oxygen in tap water.

  Claim 4 applies the operation method of the present invention to a culture operation for culturing anaerobic ammonia-oxidizing bacteria, which can biologically reduce dissolved oxygen in water and efficiently perform the culture operation. It can be carried out. In addition, since the method of reducing dissolved oxygen according to the present invention is a biological method rather than a conventional method using gas or chemicals, even if microbial groups remain in water, the anaerobic ammonia oxidizing bacteria to be cultured are adversely affected. Absent. In addition, as water in Claim 4, for example, tap water, ground water, industrial water, or the like can be used.

  A fifth aspect of the present invention is the method according to any one of the first to third aspects, wherein the operation method is applied to a start-up operation of a wastewater treatment in which the ammonia and nitrous acid are simultaneously denitrified by the anaerobic ammonia oxidizing bacteria. As raw water, treated water containing at least ammonia and nitrous acid, which are substrates of the anaerobic ammonia-oxidizing bacteria, is used.

  In start-up operation in wastewater treatment using anaerobic ammonia-oxidizing bacteria, start-up is hindered if dissolved oxygen is present in the raw water. For example, when wastewater containing ammonia is treated by denitrification, a part of the wastewater is distributed to a nitrite type nitrification tank, and the ammonia in the wastewater is nitrified to nitrous acid while aeration of air. To-be-treated water in which nitrification liquid containing nitric acid and waste water are combined is introduced into an anaerobic ammonia oxidation reaction tank. Therefore, oxygen is dissolved in the water to be treated which flows into the anaerobic ammonia oxidation reaction tank, and oxygen is particularly anaerobic ammonia oxidizing bacteria during start-up operation of the anaerobic ammonia oxidation reactor sensitive to inhibition by oxygen. Decrease the activity.

  Claim 5 applies the operation method of the present invention to start-up operation in wastewater treatment using anaerobic ammonia oxidizing bacteria, and dissolves dissolved oxygen in the water to be treated flowing into the anaerobic ammonia oxidation reaction tank, It can be reduced biologically. The start-up operation includes an operation in which the anaerobic ammonia-oxidizing bacteria are deactivated and the activity is restored again during the operation of the apparatus.

  A sixth aspect of the present invention is characterized in that, in any one of the first to fifth aspects, the microbial group-containing water is mixed at a ratio of 20 to 75% by volume with respect to the raw water.

  This is because when the ratio of the microbial group-containing water to the raw water is less than 20% by volume, the concentration of the microbial group that consumes dissolved oxygen (concentration of heterotrophic bacteria) is too small. Can not be reduced. Conversely, when the ratio of the microbial group-containing water to the raw water exceeds 75% by volume, metabolites from the microbial group (metabolites of autotrophic bacteria) accumulate, and the activity of anaerobic ammonia-oxidizing bacteria is reduced. It will decrease. Therefore, by setting the ratio to 20 to 75% by volume, the activity of the anaerobic ammonia oxidizing bacteria is maintained, and the dissolved oxygen in the raw water is sufficiently removed. Moreover, it is more preferable to perform mixing with the raw | natural water of microorganisms group containing water in 30-60 volume%.

  A seventh aspect of the present invention is characterized in that, in any one of the first to sixth aspects, a mixing tank for mixing the raw water and the microorganism group-containing water is heated or kept warm.

  This is because when the raw water temperature is low, the dissolved oxygen consumption rate by the microorganism group becomes small, and the consumption rate of dissolved oxygen can be improved by heating the mixing tank. Moreover, the consumption rate of dissolved oxygen can be maintained by keeping the inside of the mixing tank at a constant temperature.

  According to an eighth aspect of the present invention, there is provided an anaerobic ammonia oxidation reaction apparatus for performing a denitrification treatment using anaerobic ammonia oxidizing bacteria in order to achieve the above object, wherein the anaerobic ammonia oxidizing bacteria are present in the tank. By mixing microbial group-containing water containing microbial groups that consume dissolved oxygen into raw water supplied to the basic ammonia oxidation reaction tank and the raw water supplied to the anaerobic ammonia oxidation reaction tank, One or more mixing tanks for preparing a chemically reduced dissolved oxygen reducing water, an inflow pipe for allowing the dissolved oxygen reducing water prepared in the one or more mixing tanks to flow into the anaerobic ammonia oxidation reaction tank, and There is provided an anaerobic ammonia oxidation reaction apparatus comprising an outflow pipe for discharging treated water denitrified in an anaerobic ammonia oxidation reaction tank.

  Claim 8 constitutes the present invention as an apparatus. When the activity of the anaerobic ammonia oxidation bacteria in the anaerobic ammonia oxidation reaction tank is low or unstable, for example, startup in wastewater treatment It can be used for driving. Also, in one or more mixing tanks, raw water and microbial group-containing water are mixed to prepare dissolved oxygen-reduced water (hereinafter referred to as DO-reduced water) in which dissolved oxygen in the raw water is biologically reduced by the microbial group. .

  A ninth aspect is characterized in that, in the eighth aspect, the mixing tank is provided with a dissolved oxygen measuring means for measuring the dissolved oxygen in the dissolved oxygen reduced water.

  If the dissolved oxygen measuring means is provided in the mixing tank, the raw water and the microorganism group-containing water can be mixed and the DO-reduced water in which the dissolved oxygen is sufficiently reduced can be allowed to flow into the anaerobic ammonia oxidation reaction tank.

  A tenth aspect of the present invention is the method according to the eighth or ninth aspect, wherein the microbial group-containing water is treated water that has been denitrified in the anaerobic ammonia oxidation reaction tank, and a plurality of the mixing tanks are provided. And the inflow pipe are connected via a switching means, and the outflow pipe and the plurality of mixing tanks include distribution means for switching part of the treated water to the plurality of mixing tanks in a switchable manner. It is connected by distribution piping.

  Although it is possible to disperse microbial groups in water to prepare microbial group-containing water, it cannot be used when the amount of microbial group-containing water is increased as in a large apparatus. Claim 10 uses denitrified treated water as microbial group-containing water, and since this treated water is always discharged from the anaerobic ammonia oxidation reaction tank, the use of microbial group-containing water is used. There is no problem even if the amount increases. The treated water in the anaerobic ammonia oxidation reactor coexists with anaerobic ammonia oxidizing bacteria and heterotrophic bacteria using organic substances that are metabolites of anaerobic ammonia oxidizing bacteria as substrates, and are used as microbial group-containing water can do.

  Moreover, when there are a plurality of mixing tanks, the DO reduction water can be alternately introduced into the anaerobic ammonia oxidation reaction tank by the switching means. At this time, DO reduction water can be prepared in the mixing tank which is not made to flow. In addition, the treated water after the denitrification treatment can be sent to a predetermined mixing tank by a distribution means in a predetermined amount. This distribution means has a function of switching the piping and a function of distributing the treated water by a predetermined amount to the mixing tank. Specific examples include a valve, a damper, and a solenoid valve.

  In addition to applying the anaerobic ammonia oxidation reaction apparatus to a culture operation for culturing the anaerobic ammonia oxidation bacteria, the anaerobic ammonia oxidation bacteria may be used as the raw water. It is characterized by using water to which ammonia and nitrous acid, which are substrates of the above, are added.

  The eleventh aspect uses the anaerobic ammonia oxidation reaction apparatus in a culture operation for culturing anaerobic ammonia oxidation bacteria, and can biologically reduce dissolved oxygen in water flowing into the anaerobic ammonia oxidation reaction tank. The culture operation can be performed efficiently. In addition, since the method of reducing dissolved oxygen according to the present invention is not a method using conventional gases or chemicals but a biological method, even if a group of microorganisms remains in water, it adversely affects anaerobic ammonia-oxidizing bacteria that are cultured. There is no.

  A twelfth aspect according to any one of the eighth to tenth aspects, wherein the anaerobic ammonia oxidation reaction apparatus is applied to a start-up operation of a wastewater treatment in which the ammonia and nitrous acid are simultaneously denitrified by the anaerobic ammonia oxidation bacteria. In addition, as the raw water, treated water containing at least ammonia and nitrous acid, which are substrates of the anaerobic ammonia-oxidizing bacteria, is used.

  Claim 12 uses the anaerobic ammonia oxidation reaction apparatus for the start-up operation of wastewater treatment using anaerobic ammonia oxidation bacteria, and the dissolved oxygen of the water to be treated flowing into the anaerobic ammonia oxidation reaction tank is used. Biological reduction can be achieved, and start-up operation can be performed efficiently. The start-up operation includes an operation in which the anaerobic ammonia-oxidizing bacteria are deactivated and the activity is restored again during the operation of the apparatus.

  In the twelfth aspect of the present invention, in the twelfth aspect, in the start-up operation of the wastewater treatment, the raw water is flowed into one or more mixing tanks, and the dissolved oxygen-reduced water prepared in the one or more mixing tanks is In the case of flowing into the anaerobic ammonia oxidation reaction tank and shifting from the start-up operation to the steady operation, there is provided switching means for directly flowing the raw water into the anaerobic ammonia oxidation reaction tank.

  In the steady operation, unlike the above-described start-up operation, the raw water stored in the raw water tank is caused to flow into the anaerobic ammonia oxidation reaction tank to perform the denitrification treatment. According to the thirteenth aspect, the raw water and the dissolved oxygen-reduced water can be switched into the anaerobic ammonia oxidation reaction tank by the switching means. Therefore, it is possible to quickly switch between the start-up operation and the steady operation of the wastewater treatment. Further, as described above, it is possible to appropriately switch to the operation when the anaerobic ammonia-oxidizing bacteria are deactivated during the normal operation and the activity is restored again.

  A fourteenth aspect is characterized in that in any one of the eighth to thirteenth aspects, the mixing tank is provided with a heating means or a heat retaining means. This is because when the raw water temperature is low, the dissolved oxygen consumption rate by the microorganism group becomes small, and the dissolved oxygen consumption rate can be improved by heating the mixing tank.

  As described above, according to the present invention, the dissolved oxygen in the raw water supplied to the anaerobic ammonia oxidation reaction tank can be reduced, the denitrification treatment can be performed efficiently, and the processing cost can be reduced.

  Hereinafter, preferred embodiments of an anaerobic ammonia-oxidizing bacterium culture apparatus, an anaerobic ammonia-oxidizing reaction apparatus, and an operation method according to the present invention will be described with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a diagram illustrating the structure of an anaerobic ammonia-oxidizing bacteria culture apparatus 10 to which the present invention is applied. As shown in the figure, anaerobic ammonia-oxidizing bacteria culture apparatus 10 mainly comprises anaerobic ammonia-oxidizing reaction tank 80 in which anaerobic ammonia-oxidizing bacteria are present in the tank, and a substrate for culturing anaerobic ammonia-oxidizing bacteria. 2 tanks of mixing tanks 60A and 60B for preparing dissolved oxygen-reduced water (hereinafter referred to as DO-reduced water) in which the dissolved oxygen of the tap water is biologically reduced. In addition, although demonstrated by the example which used the mixing tank as 2 tanks, 1 tank or 3 tanks or more may be sufficient.

  The anaerobic ammonia oxidation reaction tank 80 and the plurality of mixing tanks 60A and 60B are connected by piping or the like as described below to constitute a liquid feeding line during culture.

  When the liquid feeding line at the time of culture | cultivation of anaerobic ammonia oxidizing bacteria is demonstrated, the piping 28A which supplies the tap water, the chemical injection piping 29A which supplies the substrate of anaerobic ammonia oxidizing bacteria, etc. are connected to the mixing tank 60A. Similarly, the pipes 28B and 29B are connected to the mixing tank 60B. The pipes 28A and 28B are each provided with a liquid feed pump (not shown). Pipes 12A and 12B extend from the respective mixing tanks 60A and 60B, and are connected to the anaerobic ammonia oxidation reaction tank 80 via the first switching means 31 and the pipe 12 described above. The first switching means 31 switches the culture operation for switching between the pipe 12 and the pipe 12A or the pipe 12B. Further, the switching / distribution means 32 and the mixing tanks 60A and 60B described above are connected by the respective pipes 16A and 16B. This switching / distribution means 32 distributes the switching operation between the mixing tank 60A and the mixing tank 60B and the flow rate of the treated water flow rate supplied to the mixing tank 60A or the mixing tank 60B and the discharged flow rate discharged to the treated water piping 18. Perform both dispensing operations. Thereby, the liquid feeding line at the time of culture | cultivation is formed.

  The mixing tanks 60 </ b> A and 60 </ b> B are means or storage units that mix tap water and treated water after treatment in the anaerobic ammonia oxidation reaction tank 80. Furthermore, DO measuring instruments 67A and 67B are provided in the mixing tanks 60A and 60B, respectively.

  The DO measuring instruments 67A and 67B measure the dissolved oxygen concentration in the mixing tanks 60A and 60B. If the concentration becomes less than a predetermined value, the anaerobic ammonia oxidation reaction tank supplies highly reduced anaerobic DO reduced water from the mixing tanks 60A and 60B. Control to supply to 80 is performed.

  Further, liquid amount adjusting means 65A and 65B are provided at predetermined positions of the mixing tanks 60A and 60B so that equal amounts of tap water and treated water are mixed. Further, when mixing tap water and treated water, it is necessary to prevent oxygen (air) from being mixed and dissolved, and it is preferable to carry out in a sealed container or to stir while aeration of a gas having a low oxygen concentration. .

  As specific means of the liquid volume adjusting means 65A and 65B, the discharge ports 61A and 61B and the valves 63A and 63B are provided in the vicinity of about half of the liquid level when the mixing tanks 60A and 60B are full. It has been. Thereby, when the amount of tap water becomes a predetermined amount or more, it overflows out of the system through the discharge ports 61A and 61B, and the amount of liquid in the mixing tank is maintained at a predetermined value. In this state, the valves 63A and 63B of the discharge ports 61A and 61B are closed, and then the treated water is supplied until it becomes full. Other means may be used as long as it has a function of adjusting the amount of liquid in the mixing tanks 60A and 60B. For example, as shown in FIG. 5 to be described later, water level sensors 65A ′ and 65B ′ are provided on the side surfaces of the mixing tanks 60A and 60B, and the supply amount of tap water or treated water may be controlled so as not to exceed a predetermined amount. it can.

  The mixing tanks 60A and 60B are provided with heating means 66A and 66B, respectively. Thereby, since the liquid temperature of DO reduction water in a mixing tank can be maintained at a predetermined value, a uniform process can be performed. Moreover, consumption of dissolved oxygen by heterotrophic bacteria can be accelerated | stimulated by heating mixing tank 60A, 60B to predetermined temperature. In particular, although it depends on the composition of the wastewater, it is preferable to mix at 20 to 40 ° C. The heating means 66A, 66B is not particularly limited as long as the inside of the mixing tanks 60A, 60B can be maintained at a predetermined temperature and heated.

  The mixing time (retention time) in the mixing tanks 60A and 60B is preferably 12 to 72 hours. Moreover, after mixing for a predetermined time, it can also be controlled to start the supply to the anaerobic ammonia oxidation reaction tank 80. Moreover, it is preferable to provide a mixing means for mixing the inside of the mixing tank. For example, a stirrer can be used.

  The first switching means 31 and the switching / distribution means 32 can be constituted by a plurality of valves as shown in FIG. For example, the first switching means 31 is provided with valves 31B and 31C in the pipes 12A and 12B, respectively, and opens and closes the valves 31B and 31C by a control signal from a control unit (not shown). Further, the switching / distribution means 32 is provided with valves 32A, 32B, 32C on the pipes 16, 16A, 16B, respectively, and controls the opening degree of the valves 32A, 32B, 32C by a control signal from a control unit (not shown). The above switching operation and distribution operation are performed.

  During culture, tap water (and chemicals, etc.) is fed to the mixing tank 60A or 60B, and the valves 31B and 31C are opened and closed, and the DO-reduced water prepared in the mixing tanks 60A and 60B is anaerobically oxidized with ammonia. Supply to reaction vessel 80. The switching / distribution means 32 opens and closes the valves 32B and 32C to perform switching operation, adjusts the opening of the valves 32A and 32B or 32C, and mixes the amount of treated water discharged from the pipe 16 and the mixing tank. The amount of treated water supplied to 60A or 60B is controlled.

  In the present embodiment, the first switching means 31 and the switching / distribution means 32 are configured by a plurality of valves. However, the present invention is not limited to the valves, and the function of switching the piping flow path and / or Alternatively, other means may be used as long as it has a function of distributing the amount of water.

  As the liquid feed pump 4, a diaphragm pump, a syringe pump, etc. are used. However, any other pump may be used as long as it has a function of reliably delivering raw water, DO reduced water, microbial group-containing water, treated water, and the like. It may be a means.

  Next, an operation method of the anaerobic ammonia-oxidizing bacteria culture apparatus 10 according to the present invention will be described.

  2 (A) to 2 (D) are diagrams showing the culture operation of the anaerobic ammonia-oxidizing bacteria culture apparatus 10 according to the present invention, among which FIGS. 2 (A), 2 (B) and 2 (C). 2 (D) is a diagram showing the first, second, third, and fourth steps. Thick line arrows indicate circulation of tap water, DO reduced water, and treated water in the culture apparatus 10.

  First, before the culture operation, the DO reduced water is stored by introducing nitrogen gas bubbling or anaerobic ammonia oxidation sludge into the tap water in the tank 60A as shown in FIG. 2 (A) (in the mixing tank 60A). About half). Moreover, since tap water does not contain ammonia and nitrous acid, which are substrates for anaerobic ammonia-oxidizing bacteria, the required amounts of these substrates are added from the chemical injection pipes 29A and 29B to the mixing tanks 60A and 60B. deep.

  Next, in the second step of FIG. 2B, first, the first switching means 31 is operated, and the DO reduced water is anaerobic ammonia oxidation reaction tank by the liquid feed pump 4 via the pipes 12A and 12. 80. In the anaerobic ammonia oxidation reaction tank 80, ammonia and nitrous acid are oxidized and removed by the anaerobic ammonia oxidizing bacteria in the DO-reduced water with little dissolved oxygen. At the same time, the switching / distribution means 32 is operated, and a part of the treated water treated in the anaerobic ammonia oxidation reaction tank 80 is sent to the mixing tank 60B via the pipes 16 and 16B (thick arrow). In addition, the other treated water is sent to the disposal unit via the treated water pipe 18 or sent to another process (thick arrow).

  At this time, the valve 63B is opened in the mixing tank 60B, and after the amount of liquid in the mixing tank 60B is adjusted to be about half of the initial raw water amount, the valve 63B is closed. After the amount of about half or more is supplied, the first switching means 31, the switching / distribution means 32, and the valve 63B are closed.

  Next, in the third step of FIG. 2 (C), tap water having the same volume as the amount supplied to the mixing tank 60B is sent to the mixing tank 60B via a pipe 28B by a not-shown liquid feeding pump. (Bold arrow).

  And in mixing tank 60B, tap water and treated water are mixed for a predetermined time so that it may become tap water: treated water = 1: 1 volume%. By this mixing, dissolved oxygen contained in tap water is consumed by microorganism groups (such as heterotrophic bacteria) in the treated water, and DO-reduced water having a high anaerobic degree is prepared. While being mixed, the DO concentration in the solution is measured by the DO measuring device 67A. After confirming that the DO concentration has been reduced to a predetermined value or less, the DO-reduced water is sent to the anaerobic ammonia oxidation reaction tank 80.

  Further, in the fourth step of FIG. 2D, the first switching means 31 is operated, and the DO reduced water in the mixing tank 60B is sent to the anaerobic ammonia oxidation reaction tank 80 through the pipes 12B and 12. Is done. At the same time, the switching / distribution means 32 is operated, and a part of the treated water treated in the anaerobic ammonia oxidation reaction tank 80 is sent to the mixing tank 60A via the pipes 16 and 16A (thick arrow). The remaining treated water is sent to the waste section via the treated water pipe 18 as described above, or sent to another process.

  Then, as shown in FIG. 2 (D), the DO reduced water is fed from the mixing tank 60B to the anaerobic ammonia oxidation reaction tank 80 by the liquid feed pump 4 via the pipes 12B and 12 (thick arrow). .

  There are two timings for adding the substrate to be added to the mixing tanks 60 </ b> A and 60 </ b> B, immediately after mixing tap water and treated water, or after DO is lowered, but immediately after mixing tap water and treated water is preferable. . This is because the activity of internal microorganisms (heterotrophic bacteria) is increased by supplying the substrate, and dissolved oxygen in tap water can be efficiently reduced.

  In this way, in the mixing tanks 60A and 60B, the anaerobic ammonia in the anaerobic ammonia oxidation reaction tank 80 is supplied by supplying DO-reduced water with reduced dissolved oxygen concentration in the tap water to the anaerobic ammonia oxidation reaction tank 80. The activity of oxidizing bacteria can be increased. Therefore, anaerobic ammonia oxidizing bacteria can be cultured efficiently.

  In addition, in this Embodiment, although the example which prepares DO reduction water using a tap water was demonstrated, it is not limited to this, Groundwater, industrial water, etc. can also be used. Moreover, as a chemical | medical agent added from a chemical injection piping, it is a substance (ammonia, nitrous acid, etc.) used as the substrate of anaerobic ammonia oxidation bacteria, for example, Waste water, chemicals, etc. containing these may be sufficient.

(Second embodiment)
FIG. 3 is an example of an overall view in which the anaerobic ammonia oxidation reaction apparatus 50 is incorporated in the wastewater treatment system 20 as an application example of the anaerobic ammonia oxidation reaction apparatus 50 of the present invention. FIG. 4 is a diagram showing a configuration of an anaerobic ammonia oxidation reaction apparatus 50 which is a main part of FIG.

  The anaerobic ammonia oxidation reaction apparatus 50 in FIG. 4 is a line for feeding raw water from the raw water tank 30 to the mixing tanks 60A and 60B (raw water tank 30, pipes 11, 26, 26A and 26B, liquid feed pump 6 in FIG. The second switching means 33) is configured in the same manner except that it is provided. 3 and 4, the portions denoted by the same reference numerals as those in FIGS. 1 and 2 have the same thing or function.

  First, the overall configuration of the wastewater treatment system 20 in the present embodiment will be described.

  As shown in the figure, a wastewater treatment system 20 mainly includes a nitrite type nitrification tank 40 that oxidizes ammonia in wastewater to nitrous acid, and an anaerobic ammonia oxidation reaction that performs a denitrification treatment by anaerobic ammonia oxidizing bacteria. The apparatus 50 includes a distributor 9 that distributes and distributes wastewater to the nitrification tank 40 and the anaerobic ammonia oxidation reaction apparatus 50.

  The nitrification tank 40 is preferably filled with an immobilization carrier or a contact filter medium on which ammonia-oxidizing bacteria are immobilized. The ammonia-oxidizing bacteria to be immobilized may be separated from microorganisms such as activated sludge or activated sludge containing a group of microorganisms in which ammonia-oxidizing bacteria are preferentially propagated. In this case, the immobilization carrier may be either an entrapping immobilization carrier in which ammonia oxidizing bacteria are entrapped and immobilized inside the carrier, or an adhesion immobilization carrier adhering and fixing on the surface of the carrier.

  Examples of the immobilization material for the immobilization carrier include polyvinyl alcohol, alginic acid, polyethylene glycol gel, and plastic carriers such as cellulose, polyester, polypropylene, and vinyl chloride, but are not limited thereto. . With respect to the shape of the immobilization carrier, those formed into a spherical shape, a cylindrical shape, a cubic shape, a porous shape, a honeycomb shape, a sponge shape, or the like can be preferably used. As the contact filter medium, those made of vinyl chloride or polyethylene can be preferably used. Granules utilizing self-granulation of microorganisms can also be used.

For example, in order to manufacture a nitrite-type entrapping immobilization support, heat treatment is performed on the entrapped immobilization support containing the entrapped immobilization complex sludge containing ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, etc. There is a method for inactivating nitrate oxidizing bacteria. In this case, the heat treatment temperature is preferably 50 to 90 ° C, and more preferably 60 to 80 ° C. The heat treatment time is preferably 20 minutes to 1 week, more preferably 20 minutes to 24 hours. In addition, as a method for suppressing the nitrite oxidation activity of the immobilized carrier and activated sludge in the nitrification tank 40, a method of controlling the dissolved oxygen (DO) in the nitrification tank 40 to 2.0 mg / L or less, a nitrification tank There is a method of increasing the ammonia load in 40 to 1.5 kg-N / m ³ / day or more, but is not limited thereto.

  The filling rate of the immobilization carrier into the nitrification tank 40 is preferably 5 to 40% as a volume%, and more preferably 8 to 20%. On the other hand, about the filling rate of the contact filter medium to the nitrification tank 40, 30 to 80% is preferable as an apparent volume, and 40 to 70% is more preferable.

  The anaerobic ammonia oxidation reaction tank of the anaerobic ammonia oxidation reaction apparatus 50 is preferably filled with an immobilization carrier on which anaerobic ammonia oxidation bacteria are supported or a contact filter medium. The anaerobic ammonia-oxidizing bacteria to be immobilized may be those accumulated from microorganisms such as activated sludge or activated sludge containing anaerobic ammonia-oxidizing bacteria. Although the details of the anaerobic ammonia oxidizing bacteria are unknown, it is said to be a group of bacteria represented by Planctomycete. And it is preferable to fill the anaerobic ammonia oxidation reaction tank 80 with an immobilization carrier or a contact filter medium on which anaerobic ammonia oxidation bacteria are immobilized. The immobilization material and the shape of the immobilization carrier are the same as those in the nitrification tank described above.

  In addition, the immobilization method is not particularly limited, but is a method of adhering and fixing to an adhering immobilization material such as a nonwoven fabric or plastic, a method of including and fixing in a gel material, and a method of immobilizing a biofilm on a plastic carrier. And there is a method of using it as a granule. The filling rate of the immobilization carrier is preferably 10 to 40% by volume, and more preferably 15 to 30%. About the filling rate of a nonwoven fabric, 40-90% is preferable as an apparent filling rate, and 50-80% is more preferable. About the filling rate of a contact filter medium, 30 to 80% is preferable as an apparent volume, and 40 to 70% is more preferable. The granule filling rate is preferably 20 to 80% as volume%, more preferably 30 to 60%.

  According to the waste water treatment system 20 configured as described above, first, waste water containing ammonia is fed to the distributor 9 by the liquid feed pump 2 as shown in FIG. The distributor 9 distributes the waste water into a line 41 sent to the nitrification tank 40 and a line 42 sent to the anaerobic ammonia oxidation reactor 50 at a volume ratio of approximately 1: 1. In the nitrification tank 40, the ammonia in the wastewater is almost completely oxidized to nitrous acid by the action of ammonia oxidizing bacteria. Next, the waste water that has been subjected to nitrification is joined with the other waste water distributed by the distributor 9 at the confluence point A to prepare raw water that is substantially adjusted to a ratio of ammonia: nitrous acid = 1: 1.32. . Next, the raw water is fed to the anaerobic ammonia oxidation reactor 50, and ammonia and nitrous acid are oxidized and removed by anaerobic ammonia oxidizing bacteria using nitrous acid in the wastewater as a hydrogen donor.

  Since such anaerobic ammonia oxidizing bacteria hate oxygen, oxygen is contained in the raw water during the start-up operation of the anaerobic ammonia oxidation reaction apparatus 50 or the restart operation when the anaerobic ammonia-oxidizing bacteria are deactivated for some reason. It is not preferable to mix. Moreover, even when anaerobic ammonia-oxidizing bacteria are cultured using ammonia and nitrous acid, it is not preferable that oxygen is mixed into the raw water. Therefore, in the present embodiment, the anaerobic ammonia oxidation reaction apparatus 50 is configured as follows.

  As shown in FIG. 4, the anaerobic ammonia oxidation reaction apparatus 50 mainly includes a raw water tank 30 that stores raw water containing ammonia and nitrous acid, and anaerobic ammonia oxidation in which anaerobic ammonia oxidizing bacteria are present in the tank. A reaction tank 80; and two tanks 60A and 60B for preparing DO-reduced water in which dissolved oxygen in the raw water supplied from the raw water tank 30 to the anaerobic ammonia oxidation reaction tank 80 is biologically reduced. It is configured. In addition, although demonstrated by the example which used the mixing tank as 2 tanks, 1 tank or 3 tanks or more may be sufficient.

  The raw water tank 30, the anaerobic ammonia oxidation reaction tank 80, and the plurality of mixing tanks 60A and 60B are connected by piping or the like as follows, so that a liquid supply line during steady operation and a start-up operation (anaerobic) Including a start-up due to inactivation of the oxidative ammonia-oxidizing bacteria).

  First, the liquid supply line during steady operation will be described. The raw water tank 30 and the anaerobic ammonia oxidation reaction tank 80 are connected by the pipe 11, the first switching means 31, and the pipe 12. A liquid pump 4 is provided. The anaerobic ammonia oxidation reaction tank 80 is connected to a pipe 16 through which the treated water treated in the anaerobic ammonia oxidation reaction tank 80 flows out, and the treated water pipe 18 (see FIG. 4) via the switching / distribution means 32. ). Thereby, the liquid feeding line at the time of steady operation is formed.

  Next, a description will be given of the liquid supply line during start-up operation and culture of anaerobic ammonia-oxidizing bacteria. The pipe 26 extended from the raw water tank 30 is connected to two pipes 26A and 26B via the second switching means 33. One pipe 26A is connected to the mixing tank 60A, and the other pipe 26B is connected to the mixing tank 60B. A second liquid feed pump 6 is provided in the pipe 26. The second switching means 33 switches the feed of raw water from the raw water tank 30 between the mixing tank 60A and the mixing tank 60B. Pipes 12A and 12B extend from the respective mixing tanks 60A and 60B, and are connected to the anaerobic ammonia oxidation reaction tank 80 via the first switching means 31 and the pipe 12 described above. The first switching means 31 performs switching at the time of steady operation in which the pipe 12 and the pipe 11 are communicated and switching at the start-up operation for switching the pipe 12 and the pipe 12A or the pipe 12B. Further, the switching / distribution means 32 and the mixing tanks 60A and 60B described above are connected by the respective pipes 16A and 16B. This switching / distribution means 32 distributes the switching operation between the mixing tank 60A and the mixing tank 60B and the flow rate of the treated water flow rate supplied to the mixing tank 60A or the mixing tank 60B and the discharged flow rate discharged to the treated water piping 18. Perform both dispensing operations. Thereby, the liquid feeding line at the time of start-up operation is formed.

  The first and second switching means 31, 33 and the switching / distribution means 32 can be constituted by a plurality of valves as shown in FIG. For example, the first switching means 31 is provided with valves 31A, 31B, and 31C in the pipes 11, 12A, and 12B, respectively, and opens and closes the valves 31A, 31B, and 31C by a control signal from a control unit (not shown). The second switching means 33 is provided with valves 33A and 33B in the pipe 26A and the pipe 26B, respectively, and opens and closes the valves 33A and 33B by a control signal from a control unit (not shown). The switching / distribution means 32 performs the switching operation and the distribution operation similar to those in the first embodiment.

  During steady operation, the valves 31A and 33B of the second switching means 33 are closed, the valve 31A of the first switching means 31 is opened, the valves 31B and 31C are closed, and switching / distribution is performed. The valve 32A of the means 32 is opened, and the valves 32B and 32C are closed.

  During start-up operation and culture of anaerobic ammonia-oxidizing bacteria, the valves 33A and 33B of the second switching means 33 are opened and closed to feed the raw water in the raw water tank 30 to the mixing tank 60A or the mixing tank 60B. With the valve 31A of the first switching means 31 closed, the valves 31B and 31C are opened and closed, and the DO reduced water prepared in the mixing tanks 60A and 60B is supplied to the anaerobic ammonia oxidation reaction tank 80. In addition, the switching / distribution means 32 opens and closes the valves 32B and 32C to perform the switching operation, and controls the amount of treated water supplied to the mixing tank 60A or 60B, as in the first embodiment.

  The liquid feed pumps 2 and 6 can be the same as the liquid feed pump 4 described above.

  In the present embodiment, the pipes 12 and 16 are commonly used by switching the pipes to reduce the capacity. However, as shown in another embodiment of FIG. May be provided.

  Next, an operation method of the anaerobic ammonia oxidation reaction apparatus 50 according to the present invention will be described.

  First, before the start-up operation, nitrogen gas bubbling or anaerobic ammonia oxidation sludge is introduced into the mixing tank 60A to prepare DO-reduced water (about half of the mixing tank 60A). In the start-up operation, in FIG. 6A, first, the second switching means 33 is operated, and the raw water mixed with oxygen is fed from the raw water tank 30 to the mixing tank 60A through the pipes 26 and 26A. (Thick arrow). At this time, the raw water and the treated water are mixed for a predetermined time in the mixing tank 60A so that the ratio of raw water: treated water = 1: 1 volume%. By this mixing, heterotrophic bacteria in the group of microorganisms contained in the treated water reduce dissolved oxygen in the raw water, and DO reduced water is prepared. While being mixed, the DO concentration in the solution is measured by the DO measuring device 67A. After confirming that the DO concentration has been reduced to a predetermined value or less, the DO-reduced water is sent to the anaerobic ammonia oxidation reaction tank 80. In the subsequent steady operation, in the second to fourth steps (FIGS. 2 (B) to (D)) in the first embodiment, the portion for feeding tap water to the mixing tanks 60A and 60B is used, and the raw water is used as the raw water tank. The method is the same except that the portion 30 is changed to the portion for feeding liquid to the mixing tanks 60A and 60B.

  On the other hand, in the steady operation, as shown in FIG. 6B, the raw water to be treated is fed from the raw water tank 30 through the pipe 11 in the state where the activity of the anaerobic ammonia oxidizing bacteria is high. The liquid is fed to the head and steady operation is performed (thick arrow). Then, the treated water is discarded or sent to another process via the treated water pipe 18.

  In the present embodiment, an example is described in which the denitrification treatment is started up, but the present invention can also be applied to cases where anaerobic ammonia-oxidizing bacteria are deactivated during steady operation.

  Thus, in particular, by applying the present invention to the wastewater treatment system 20, the dissolved oxygen in the raw water having a high dissolved oxygen concentration can be reduced. Thereby, anaerobic ammonia oxidation bacteria can be maintained active and reaction can be started efficiently. Further, when the dissolved oxygen in the raw water is reduced, the treated water after the denitrification treatment in the anaerobic ammonia oxidation reaction tank is reused, so there is no need to introduce nitrogen gas bubbling treatment or other chemicals. Therefore, the processing cost can be greatly reduced.

  In addition, when the anaerobic ammonia oxidation shown in FIGS. 2A to 2D is performed, when treated water with reduced dissolved oxygen is not stored in the mixing tanks 60A and 60B, the mixing tank 60A (or 60B) is used. A small amount of anaerobic ammonia-oxidized sludge may be added to the tank.

  In this embodiment, in order to use anaerobic ammonia-oxidizing bacteria substrates (ammonia, nitrous acid), about half of the ammonia-containing wastewater is diverted to a nitrite-type nitrification tank to form nitrous acid. However, the total amount of waste water may be supplied to a nitrite type nitrification tank, and the nitrification rate may be controlled so that about half of the ammonia becomes nitrous acid. In addition, wastewater components are used as substrates for anaerobic ammonia-oxidizing bacteria (ammonia and nitrous acid). For nitrous acid, a nitrous acid solution tank is installed near the anaerobic ammonia-oxidizing tank. You may make it add to a basic ammonia oxidation tank.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

  Using the anaerobic ammonia oxidation reactor 50 according to the present invention shown in FIG. 4, wastewater treatment was performed using the test wastewater shown in Table 1. Specifically, first, tests were conducted on the dissolved oxygen concentration (DO) in the DO-reduced water in the tank with respect to the ratio of the reuse rate of treated water and the activity of anaerobic ammonia-oxidizing bacteria. In addition, the test waste water of Table 1 was used for waste water.

(Processing conditions)
The nitrogen load of the anaerobic ammonia oxidation reaction tank 80 was 1.6 kg-N / m ³ / day. The anaerobic ammonia oxidation reaction tank 80 was filled with a non-woven fabric adhered with anaerobic ammonia oxidizing bacteria so that the apparent filling rate would be 80%. This nonwoven fabric has an opening diameter of 500 μm and is folded into a chrysanthemum shape, and the porosity is 99% or more.

  Moreover, the sludge which accumulated and cultured the anaerobic ammonia oxidizing bacteria was added so that it might become 300 mg-ss / mL. The anaerobic ammonia oxidation reaction tank 80 used was a 20 L capacity, and the mixing tanks 60A and 60B each used a 1000 L capacity.

The operation was performed under an active condition with a denitrification rate of 1.4 kg-N / m ³ / d and a water temperature of 22 ° C. and an HRT of 6 hours. In the measurement of DO, the reuse rate of the treated water was 10, 15, 20, 30, 50, 60, 80 volume%, and the reuse was repeated 10 times. Then, treated water and tap water were mixed at a predetermined ratio, and DO was measured with a DO meter after 24 hours.

  Moreover, in the activity measurement of the anaerobic ammonia oxidizing bacteria, the reuse rate of the treated water was set to 40, 50, 60, 70, 75, 80, 85, and 90 vol%, and the reuse was repeated 10 times. Further, the denitrification rate of the anaerobic ammonia-oxidizing bacteria when treated water was reused by 40% was defined as 100, and the influence on the activity due to the difference in the reuse rate was defined as a relative value.

  As shown in FIG. 7, it was found that when at least 20% of the treated water is reused, DO in the raw water is significantly consumed.

  Moreover, as shown in FIG. 8, the relative activity of the anaerobic ammonia-oxidizing bacteria tended to decrease somewhat as the reuse rate increased. However, it was found that when the recycling rate exceeds 75%, the amount of diluted water decreases, the accumulation of metabolites occurs, and the activity decreases significantly. As mentioned above, it turned out that 20 to 75% of the reuse rate of treated water is preferable from a viewpoint of activity of DO concentration and anaerobic ammonia oxidizing bacteria. Furthermore, it has been found that a recycle rate of 30 to 60% is more preferable.

  As described above, by applying the present invention to the culture of anaerobic ammonia-oxidizing bacteria, it is not necessary to add chemicals or the like from the outside, so that anaerobic ammonia-oxidizing bacteria can be cultured at low cost. Moreover, by applying the anaerobic ammonia oxidation reaction apparatus and operation method of the present invention, dissolved oxygen in the raw water supplied to the anaerobic ammonia oxidation reaction tank can be reduced, and denitrification treatment can be performed efficiently. Moreover, the process cost at the time of reducing the dissolved oxygen in raw | natural water can also be reduced.

It is a figure which shows the culture apparatus in 1st embodiment of this invention. It is a figure which shows the operation method of the 1st step of the culture apparatus in 1st embodiment of this invention. It is a figure which shows the operation method of the 2nd step of the culture apparatus in 1st embodiment of this invention. It is a figure which shows the operating method of the 3rd step of the culture apparatus in 1st embodiment of this invention. It is a figure which shows the operation method of the 4th step of the culture apparatus in 1st embodiment of this invention. It is a figure which shows the wastewater treatment system in 2nd embodiment of this invention. It is a figure which shows the anaerobic ammonia oxidation reaction apparatus in 2nd embodiment of this invention. It is a figure which shows the modification of the anaerobic ammonia oxidation reaction apparatus in 2nd embodiment of this invention. It is a figure which shows the method of the starting operation of the anaerobic ammonia oxidation reaction apparatus in 2nd embodiment of this invention. It is a figure which shows the method of the steady operation of the anaerobic ammonia oxidation reaction apparatus in 2nd embodiment of this invention. It is a graph of the Example which concerns on this invention. It is a graph of the Example which concerns on this invention.

Explanation of symbols

  1, 2, 3, 4, 6 ... liquid feed pump, 10 ... culture device, 20 ... wastewater treatment system, 50 ... anaerobic ammonia oxidation reaction device, 40 ... nitrification tank, 60A, 60B ... mixing tank (mixing tank), 80 ... Anaerobic ammonia oxidation reaction tank, 9 ... Distributor, 41, 42 ... Pipe, 30 ... Raw water tank, 11, 12, 12A, 12B, 16, 16A, 16B ... Pipe, 18 ... Treated water pipe, 26, 26A , 26B, 28A, 28B ... piping, 31 ... first switching means, 32 ... switching / distributing means, 33 ... second switching means, 31A, 31B, 31C ... valve, 32A, 32B, 32C ... valve, 33A, 33B ... Valve, 65A, 65B ... Liquid volume adjusting means, 65A ', 65B' ... Water level sensor, 66A, 66B ... Heating means, 67A, 67B ... DO measuring instrument, 29A, 29B ... Chemical injection pipe

Claims (14)

In the operation method of the anaerobic ammonia oxidation reactor that performs denitrification treatment using anaerobic ammonia oxidation bacteria,
By mixing microbial group-containing water containing microbial groups that consume dissolved oxygen with raw water supplied to the anaerobic ammonia oxidation reaction tank in which the anaerobic ammonia-oxidizing bacteria are present, dissolved oxygen in the raw water is mixed with the microbial groups. A method for operating an anaerobic ammonia oxidation reaction apparatus, comprising preparing dissolved oxygen reduction water biologically reduced by the method and allowing the dissolved oxygen reduction water to flow into the anaerobic ammonia oxidation reaction tank.   In the microbial group-containing water, autotrophic bacteria and heterotrophic bacteria using an organic substance that is a metabolite of the autotrophic bacteria as a substrate coexist, and the heterotrophic bacteria use dissolved oxygen in the raw water. The method of operating an anaerobic ammonia oxidation reactor according to claim 1, characterized in that it is reduced.   The method for operating an anaerobic ammonia oxidation reaction apparatus according to claim 1 or 2, wherein the microorganism group-containing water is treated water after denitrification treatment in the anaerobic ammonia oxidation reaction tank.   The operation method is applied to a culture operation for culturing the anaerobic ammonia-oxidizing bacteria, and water to which ammonia and nitrite which are substrates of the anaerobic ammonia-oxidizing bacteria are added is used as the raw water. The operating method of the anaerobic ammonia oxidation reactor according to any one of claims 1 to 3.   The operation method is applied to a start-up operation of a wastewater treatment in which the ammonia and nitrous acid are simultaneously denitrified by the anaerobic ammonia-oxidizing bacteria, and the raw water is ammonia as a substrate of the anaerobic ammonia-oxidizing bacteria. The method for operating an anaerobic ammonia oxidation reactor according to any one of claims 1 to 3, wherein water to be treated containing at least nitrous acid is used.   The method for operating an anaerobic ammonia oxidation reaction apparatus according to any one of claims 1 to 5, wherein the microbial group-containing water is mixed at a ratio of 20 to 75% by volume with respect to the raw water.   The method for operating an anaerobic ammonia oxidation reactor according to any one of claims 1 to 6, wherein a mixing tank for mixing the raw water and the microorganism group-containing water is heated or kept warm. In the anaerobic ammonia oxidation reactor that performs denitrification treatment using anaerobic ammonia oxidizing bacteria,
Anaerobic ammonia oxidation reaction tank in which the anaerobic ammonia oxidation bacteria are present in the tank;
Dissolved oxygen in which the dissolved oxygen in the raw water is biologically reduced by mixing the microorganism group-containing water containing the microorganism group that consumes dissolved oxygen with the raw water supplied to the anaerobic ammonia oxidation reaction tank One or more mixing tanks for preparing reduced water;
An inflow pipe for allowing dissolved oxygen-reduced water prepared in the one or more mixing tanks to flow into the anaerobic ammonia oxidation reaction tank;
An anaerobic ammonia oxidation reaction apparatus, comprising: an outflow pipe for discharging treated water denitrified in the anaerobic ammonia oxidation reaction tank.   9. The anaerobic ammonia oxidation reaction apparatus according to claim 8, wherein the mixing tank is provided with dissolved oxygen measuring means for measuring dissolved oxygen in the dissolved oxygen reduced water. The microorganism group-containing water is treated water that has been denitrified in the anaerobic ammonia oxidation reaction tank, and a plurality of the mixing tanks are provided.
The plurality of mixing tanks and the inflow pipe are connected via switching means, and the outflow pipe and the plurality of mixing tanks distribute a part of the treated water to the plurality of mixing tanks in a switchable manner. The anaerobic ammonia oxidation reaction apparatus according to claim 8 or 9, wherein the anaerobic ammonia oxidation reaction apparatus is connected by a distribution pipe provided with a distribution means.   The anaerobic ammonia oxidation reaction apparatus is applied to a culture operation for culturing the anaerobic ammonia oxidation bacteria, and as the raw water, water added with ammonia and nitrous acid as substrates of the anaerobic ammonia oxidation bacteria is used. The anaerobic ammonia oxidation reaction apparatus according to any one of claims 8 to 10, wherein:   The anaerobic ammonia oxidation reaction apparatus is applied to a start-up operation of a waste water treatment in which the ammonia and nitrous acid are simultaneously denitrified by the anaerobic ammonia oxidation bacteria, and as the raw water, a substrate of the anaerobic ammonia oxidation bacteria The anaerobic ammonia oxidation reaction apparatus according to any one of claims 8 to 10, wherein water to be treated containing at least ammonia and nitrous acid is used.   In the case of the start-up operation of the wastewater treatment, the raw water is caused to flow into one or more mixing tanks, and the dissolved oxygen reduced water prepared in the one or more mixing tanks is caused to flow into the anaerobic ammonia oxidation reaction tank. The anaerobic ammonia oxidation reaction apparatus according to claim 12, further comprising switching means for directly flowing the raw water into the anaerobic ammonia oxidation reaction tank when shifting from the startup operation to the steady operation. The anaerobic ammonia oxidation reaction apparatus according to any one of claims 8 to 13, wherein the mixing tank is provided with heating means or heat insulation means.

Images