KR20190119253A - Apparatus and Method for Inhibiting Activity of Nitrite Oxidation Bacteria - Google Patents

Abstract

Disclosed are an apparatus and a method for inhibiting nitrite oxidizing microorganism activity. According to one embodiment of the present invention, in order to inhibit nitrite oxidizing microorganisms grown or cultured by being attached to a membrane diffuser unit including ammonium oxidizing microorganisms and nitrite oxidizing microorganisms to oxidize the nitrite, a nitrite oxidizing inhibitor which inhibits the activity of nitrite oxidizing microorganisms is introduced to provide an inhibition tank for immersing the membrane diffuser unit.

Description

Apparatus and Method for Inhibiting Activity of Nitrite Oxidation Bacteria}

The present invention relates to a nitrite oxidizing microorganism activity inhibiting device and method for inhibiting nitrite oxidizing nitrogen (NOB) from oxidizing nitrite nitrogen in the MABR (Membrane Aerated Biofilm Reactor) process for wastewater treatment.

The contents described in this section merely provide background information on the present embodiment and do not constitute a prior art.

Various methods are used to remove nitrogen that causes eutrophication in the effluent system in wastewater, among which the biological nitrification-denitrification process (or nitrogen removal process) is most used for economic reasons. However, the biological nitrification-denitrification process has a limit of consuming a large amount of energy and carbon source.

In a biological nitrification-denitrification process, when 1 kg of ammonia nitrogen is oxidized, 4.57 kg of oxygen and 7.14 kg of alkalinity are consumed. When 1 kg of nitrate nitrogen is denitrified, 4-5 kg of carbon source is consumed. In addition, when 1 kg of nitrogen is generally removed during nitrification-denitrification, power of typically 4-5 kWh is consumed, and the cost of USD 13-17 is consumed.

Therefore, nitrous acid-nitriding process is sometimes used to reduce energy consumption and carbon source. When 1 kg of ammonia nitrogen is oxidized, 3.42 kg of oxygen is consumed, and 2.86 kg of carbon source is used for denitrification. The atalization process has the advantage of saving 25% oxygen and 40% carbon source compared to nitrification-denitrification.

Partial Nitritation (ANAMMOX, Anaerobic Ammonium Oxidation, or Anaerobic Ammonium Oxidation), which is rapidly increasing in recent years, reduces oxygen by 60% and carbon source by 100% compared to nitrification-denitrification. This is possible. However, even when the partial nitrous oxide-anamox process is applied, 1.9 kg of oxygen is required to remove 1 kg of ammonia nitrogen.

On the other hand, oxygen necessary for nitrogen oxidation is supplied from an acid engine. Therefore, the use of a diffuser with high oxygen transfer efficiency (OTE) is very important to reduce the energy required for oxygen supply. Therefore, various acid engines are being developed, but since the solubility of oxygen gas is not high, the oxygen transfer efficiency (OTE) in fresh water is 40% for existing acid engines and 20% for OT in wastewater treatment processes. It is not over.

In order to solve this problem, MBR (Membrane Aerated Biofilm Reactor) and MBfR (Membrane Bio-film Reactor), which use a membrane as a diffuser, have been developed. In the MABR process, the membrane acts as an diffuser, so that microorganisms can be attached to the membrane and grow at the same time, resulting in an OTE of nearly 100%. When the MABR process is used in the partial nitrous oxide-anamox process, the air demand is only 8% of the existing process.

Nitrification proceeds in two stages as follows.

Step 1 - Ammonium oxide ^{_{(Ammonia Oxidation): NH 4 +}} + 1.5O 2 → NO 2 - + 2H + + H 2 O

- step 2, nitrous oxide ^{_{(Nitrite Oxidation): NO 2 -}} + 0.5O 2 → NO 3 -

The first stage ammonium oxidation reaction is carried out by an ammonium oxidizing microorganism (AOB, Ammonium Oxidation Bacteria), the second stage nitrite oxidation reaction is carried out by a nitrite oxidizing microorganism (NOB, Nitrite Oxidation Bacteria).

In the partial nitrous oxidation-anamox process, the anamox (or anaerobic ammonium oxidation) reaction proceeds as follows.

_{^{1.0NH4 + + 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

Partial nitrous oxidation, which converts a portion of the ammonia nitrogen to nitrite nitrogen, should take place first, so that a subsequent anax reaction occurs.

Therefore, it is very important to stop nitrogen oxidation from nitrite oxidation. If nitrite nitrogen (NO ₂ -N) is oxidized to nitrate nitrogen (NO ₃ -N), since the anoxox reaction does not occur, it is necessary to stop the reaction in nitrous oxide and accumulate nitrite nitrogen. It can be said that the success or failure.

In order to achieve this purpose, an environment in which ammonium oxidizing microorganisms (AOB) are advantageous to survive, and nitrite oxidizing microorganisms (NOB) are difficult to survive, must be created so that an ammonium oxidizing microorganism (AOB) is predominant. For this purpose, various factors such as solid retention time (SRT), dissolved oxygen (DO), free ammonia (FA), free nitrous acid (FNA), and temperature may be considered. Among them, FA (Free Ammonia), FNA (Free Nitrous Acid) and temperature can be applied when the concentration of ammonia nitrogen and pH is kept high, such as reflux water generated in the anaerobic process, but the concentration of ammonia nitrogen And sewage with low pH is not available.

On the other hand, SRT and dissolved oxygen (DO) can be used to nitrate sewage. In the case of SRT, the specific growth rate values of ammonium oxidizing microorganism (AOB) and nitrous oxidizing microorganism (NOB) are similar. In fact, there is a problem in that it is difficult to apply in the field, in fact, only dissolved oxygen (DO) is a removable factor.

However, it is practically difficult to control dissolved oxygen (DO) concentrations for nitrite in the MABR process to create conditions favorable to ammonium oxidizing microorganisms (AOB). In the case of MABR, microorganisms grow outside the membrane. When oxygen is supplied for the reaction inside the membrane, a large amount of oxygen is supplied to the microorganisms close to the membrane, and oxygen supply to the microorganisms outside is restricted. That is, in a biofilm in which ammonium oxidizing microorganisms (AOB) and nitrite oxidizing microorganisms (NOB) are grown, the concentration of dissolved oxygen (DO) can be given only by being close to the separation membrane. It is technically impossible to supply and to block the oxygen supplied to nitrite oxidizing microorganisms (NOB). Therefore, despite the high oxygen transfer efficiency (OTE), it is very difficult to stably achieve nitrous oxidation using MABR.

An embodiment of the present invention provides an apparatus and method for inhibiting nitrite oxidizing microorganism activity that inhibits the activity of nitrite oxidizing microorganism (NOB) and maintains the ability of ammonium oxidizing microorganism (AOB) in a membrane aerated biofilm reactor (MABR) process The purpose is to help.

An embodiment of the present invention, by immersing the membrane diffuser in a separate tank filled with nitrite oxidation inhibitor for a predetermined time, to provide a nitrite oxidizing microorganism activity inhibition device for reducing the activity of nitrite oxidizing microorganisms (NOB) and a method thereof Dale has a purpose.

In addition, an embodiment of the present invention comprises a solids desorption tank, an inhibitory reaction tank and a washing tank, and in the solids desorption tank, the microorganisms and solids that are excessively attached are desorbed so that the inhibition reaction tank is prevented from being contaminated with solids. The nitrite oxidizing microorganisms control the concentration of the inhibitors and the retention time to optimize the inhibitory effect, while optimizing the inhibitory effect, while minimizing the release of toxic inhibitors into the water along with the treated water by washing the remaining inhibitors. It is an object of the present invention to provide an activity inhibiting device and a method thereof.

According to an aspect of the present invention, in order to inhibit the nitrite oxidizing microorganisms attached to the membrane diffuser unit including ammonium oxidizing microorganisms and nitrite oxidizing microorganisms to oxidize the nitrite, to inhibit the activity of the nitrite oxidizing microorganisms A nitrite oxidation inhibitor is introduced to provide an inhibition tank for immersing the membrane diffuser unit.

According to one aspect of the invention, the nitrite oxidation inhibitor is characterized in that it is composed of at least one of hydroxylamine, NO ₂ , NH ₄ and NO.

According to an aspect of the present invention, the nitrite oxidation inhibitor is characterized in that it can be reused in the partial nitrous acid-anamox process.

According to an aspect of the present invention, the inhibition reaction tank is characterized in that the time for immersing the membrane diffuser unit varies according to the concentration of the nitrite oxidation inhibitor.

According to an aspect of the present invention, a nitrite oxidation activity inhibiting device for inhibiting nitrite oxidation by nitrite oxidizing microorganisms using a nitrite oxidation inhibitor, the desorption tank for removing the microorganisms or solids attached to the membrane diffuser unit, the It provides a nitrite oxidizing microorganism activity inhibiting device comprising a inhibition tank for immersing the membrane diffuser unit detached from the desorption tank to the nitrite oxidation inhibitor and a washing tank for washing the nitrite oxidation inhibitor on the surface of the membrane diffuser unit do.

According to one aspect of the invention, the nitrite oxidizing microorganism activity inhibiting device, characterized in that it comprises a uniaxial nitrogen removal device.

According to one aspect of the invention, the desorption tank is characterized in that it comprises a circulation pump for introducing air to form an upflow.

According to an aspect of the present invention, in the method for inhibiting nitrite oxidizing nitrite by using a nitrite oxidizing microorganism activity inhibiting device, the membrane diffuser unit is immersed in the desorption tank of the nitrite oxidizing microorganism activity inhibiting device Process, immersing the membrane diffuser unit in which the solid desorption is completed in an inhibitor vessel filled with nitrite oxidizing microbial inhibitor, immersing in a washing tank to remove chemicals remaining on the surface of the membrane diffuser unit, and It provides a method for inhibiting nitrite oxidizing microbial activity, characterized in that it comprises a step of reuse in the partial nitrite-anamox process.

As described above, according to an aspect of the present invention, the nitrite oxidizing microorganism activity to suppress the activity of nitrite oxidizing microorganisms (NOB) in the MABR (Membrane Aerated Biofilm Reactor) process and to maintain the ability of ammonium oxidizing microorganisms (AOB) By using the inhibition device and the method, by maximizing the oxygen transfer efficiency (OTE) there is an advantage that the amount of power consumed in the air supply can be less than 10% of the existing process.

According to one aspect of the invention, in order to maintain a stable nitrite, by applying a nitrite oxidizing microorganism (NOB) suppression system for immersing the membrane diffuser in a separate tank filled with nitrite oxidation inhibitor for a certain time, There is an advantage that can selectively inhibit only the activity of NOB).

According to an aspect of the present invention, by configuring a solid desorption tank, an inhibitory reaction tank, a washing tank, in the solids desorption tank to desorb excessively attached microorganisms and solids to prevent contamination of the inhibition reaction tank with solids, filling the inhibition reaction tank The inhibitory effect is optimized by adjusting the concentration of the inhibitor and the residence time.In the washing tank, the residual inhibitor is washed to minimize the release of the toxic inhibitor into the water together with the treated water. There is an advantage that can be dominant reliably.

In addition, according to an aspect of the present invention, when NO ₂ , NH ₄ is used as an inhibitor, it is reused in the partial nitrous oxide-anamox process to control the ratio of NO ₂ , NH ₄ flowing into the anamox reactor. There is an advantage that the maintenance cost can be reduced by the input.

1 is a view showing a uniaxial nitrogen removal apparatus according to an embodiment of the present invention.
2 is a view illustrating a process of removing nitrogen in the wastewater in the membrane diffuser module according to an embodiment of the present invention.
3 is a view showing a device for inhibiting activity of nitrite oxidizing microorganism (NOB) according to a first embodiment of the present invention.
4 is a view illustrating a process in which the membrane diffuser unit is immersed in the desorption tank of the nitrite oxidizing microorganism (NOB) activity inhibiting device according to the first embodiment of the present invention.
FIG. 5 is a view illustrating a process of immersing a membrane diffuser unit in which solid desorption is completed according to a first embodiment of the present invention in an inhibition tank filled with a nitrite oxidizing microorganism (NOB) inhibitor.
FIG. 6 is a view illustrating a process of immersing a membrane diffuser unit in which a suppression reaction is completed according to a first embodiment of the present invention by moving to a washing tank.
FIG. 7 is a view illustrating a process in which the membrane diffuser unit is immersed in the desorption tank when the NO gas according to the second embodiment of the present invention is used as an inhibitor.
FIG. 8 is a view illustrating a process in which a membrane diffuser unit is immersed in an inhibition reaction tank when using NO gas as an inhibitor according to a second embodiment of the present invention.
FIG. 9 is a view illustrating a process of reusing an inhibitor of nitrite oxidizing microorganism (NOB) according to an embodiment of the present invention and adding it to a partial nitrous oxide-anamox process.
10 is a flowchart illustrating a method of inhibiting nitrite oxidation by a nitrite oxidizing microorganism (NOB) activity inhibiting device according to an embodiment of the present invention.

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the drawings, similar reference numerals are used for similar elements.

Terms such as first, second, A, and B may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. It is to be understood that the term "comprises" or "having" in the present application does not exclude in advance the possibility of the presence or addition of features, numbers, steps, operations, components, parts or combinations thereof described in the specification. .

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art.

Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

1 is a view showing a uniaxial nitrogen removal apparatus according to an embodiment of the present invention.

The short-term nitrogen removal device 100 removes nitrogen by controlling the components in the gas using the membrane diffuser unit 310. The influent wastewater measurement unit 140 of the short-term nitrogen removal device 100 measures the flow rate of the influent wastewater 130, the organic matter, and the ammonia nitrogen to calculate the amount of gas supplied into the reactor 110. Since the amount of gas required for mixing the reactor is generally 1 m ³ / hr per reactor volume, the control panel 150 calculates the amount of gas required for mixing the reactor from the reactor volume. The control panel 150 calculates the amount of gas required for mixing the reactor in consideration of the safety factor 10-30% to the amount of gas calculated using the volume of the reactor 110.

The control panel 150 also calculates the amount of oxygen required for the biological reaction, and first determines whether the amount of oxygen contained in the supplied gas can satisfy the amount of oxygen required for the bioreaction. Since the membrane diffuser (not shown) has an oxygen transfer efficiency (OTE) of 100%, the control panel 150 performs the above-described determination using the air supply amount calculation. On the other hand, the conventional diffuser has to consider the oxygen transfer efficiency (OTE) inherent in the diffuser when calculating the air supply amount, and the oxygen transfer efficiency (OTE) includes variables for time and environment. The calculation is very difficult and takes a long time even if the calculation is performed.

When the amount of oxygen contained in the supplied gas satisfies the amount of oxygen necessary for the bioreaction, the control panel 150 determines whether the amount of the gas except for oxygen is greater than the amount of gas required for mixing the reactor. If the amount of gas except oxygen in the supplied gas is larger than the amount of gas required for mixing the reactor, the control panel 150 reduces the supply of gas within the limit that satisfies the oxygen content condition. On the contrary, when the amount of the gas other than oxygen is insufficient than the amount of gas required for the reaction tank mixing, the control panel 150 increases the supply amount of carbon dioxide so that sufficient gas can be supplied for mixing the reaction tank.

When the amount of oxygen contained in the supplied gas does not satisfy the amount of oxygen required for the bioreaction, the control panel 150 controls to supply only pure oxygen.

Accordingly, the control panel 150 may supply only the required gas amount, not the excessive amount of gas, but may facilitate the bioreaction and the reaction tank mixing.

The inflow wastewater measuring unit 140 measures the flow rate of the wastewater and the concentration of ammonia nitrogen in real time so that the control panel 150 can calculate the amount of gas required for nitrous oxidation.

On the other hand, the uniaxial nitrogen removal apparatus 100 has a high oxygen transfer efficiency (OTE), but nitrous oxide oxidation in the biofilm in which ammonium oxide microorganisms (AOBs) and nitrite oxide bacteria (NOBs) are mixed and grown In order to suppress the oxygen supply to the ammonium oxidizing microorganisms (AOB) selectively, and the oxygen supply of nitrite oxidizing microorganisms (NOB) has a limit that can not be blocked. Therefore, the short-term nitrogen removing device 100 may be provided with a separate device for preventing the nitrite oxidizing microorganism (NOB) from oxidizing the nitrite nitrogen. This device allows the nitrite oxidation in the bioreactor 110 to be suppressed, thereby stably removing nitrogen in the subsequent anamox reaction (ANAMMOX, Anaerobic Ammonium Oxidation, or Anaerobic Ammonium Oxidation). An apparatus and method for inhibiting nitrite oxidation by inhibiting the activity of nitrite oxidizing microorganisms will be described in detail with reference to FIGS. 3 to 10 described below.

2 is a view illustrating a process of removing nitrogen in the wastewater in the membrane diffuser module according to an embodiment of the present invention.

The membrane diffuser module 200 is immersed in the bioreactor 110 to allow microorganisms to adhere and grow on the membrane surface. The gas 120 necessary for the bioreaction and mixing adjusts the air 121, the oxygen 122, and the carbon dioxide 123 at a constant ratio, and supplies the same to the separator diffuser 210. Membrane diffuser 210 may be made of a material that is beneficial to culture by attaching microorganisms, such as fiber yarn, but is not limited thereto. At this time, the microorganisms attached to the membrane surface include ammonium oxidizing microorganisms (AOB) for oxidizing ammonia to nitrite nitrogen and nitrite oxidizing microorganisms (NOB) for oxidizing nitrite nitrogen to nitrate nitrogen. The membrane diffuser module 200 may limit the growth of nitrous oxidizing microorganisms (NOB) by supplying a limited amount of oxygen as necessary to produce nitrite nitrogen. In addition, the ammonium oxidizing microorganism (AOB) and the nitrite oxidizing microorganism (NOB) keep the dissolved oxygen (DO) in the liquid state at zero by consuming 100% of the supplied oxygen amount.

The nitrite nitrogen produced by the ammonium oxidizing microorganism (AOB) is smoothly delivered to the anamok microorganisms (or anaerobic ammonium oxidizing microorganisms) located between the membrane diffusers 210 by the mixing force of the gases. Anamox microorganism removes nitrogen by an anoxix reaction using nitrous acid nitrogen produced by the ammonium oxide microorganism (AOB) attached to the membrane diffuser 210 and ammonia nitrogen present in the liquid phase. In this case, in order to perform the anoxix reaction smoothly, nitrite oxidation which converts a part of ammonia nitrogen to nitrite nitrogen should be performed first. That is, an ammonium oxidizing microorganism (AOB) is predominant so that nitrite nitrogen (NO ₂ -N) is not oxidized to nitrate nitrogen (NO ₃ -N), thereby inhibiting the activity of the nitrite oxidizing microorganism (NOB). It is important to do. Similarly, the apparatus and method thereof will be described later with reference to FIGS. 3 to 10.

On the other hand, for the advantage of the ammonium oxidizing microorganism (AOB), the biofilm formed in the membrane diffuser 210 should be efficiently desorbed, wherein the amount of gas required is two to three times greater than the amount of gas required for mixing. The control panel 150 increases the amount of carbon dioxide 123 to supply a flow rate required for desorption, thereby desorbing the biofilm to maintain an appropriate Sudge (Retention Time).

Since the Anamox microorganism has a low growth rate, the membrane diffuser module 200 can be secured at two to three times higher concentration than the suspended state by arranging modules filled with a separate filter medium (not shown). have.

After uniaxial nitrogen removal, 10% of the ammonia nitrogen removed is generated as a byproduct. Nitrate nitrogen, a by-product of the uniaxial nitrogen removal reaction, can be removed together with the organics in the liquid phase by suspended denitrifying microorganisms. Existing uniaxial nitrogen removal process directly injects oxygen necessary for nitrous oxidation into the liquid phase, so that all organic substances in the liquid phase are oxidized. The carbon source used to remove nitrate nitrogen, a byproduct of the uniaxial nitrogen removal reaction, is also oxidized. As a result, the carbon source for the removal of nitrate nitrogen is insufficient, and it is impossible to remove the nitrate nitrogen by general denitrification. For this reason, the prior art has a separate process and externally supplied carbon source to remove nitrate nitrogen.

However, in the membrane diffuser module 200 according to an embodiment of the present invention, oxygen required for nitrite is supplied only to the ammonium oxidizing microorganism (AOB) or the nitrite oxidizing microorganism (NOB) through the membrane diffuser 210 to consume 100%. As such, nitrate nitrogen can be removed together with the organics present in the liquid phase by common denitrification microorganisms. Accordingly, the membrane diffuser module 200 according to an embodiment of the present invention has an advantage of not having a separate carbon source.

3 is a view showing a device for inhibiting activity of nitrite oxidizing microorganism (NOB) according to a first embodiment of the present invention.

The device 300 for inhibiting the activity of nitrite oxidizing microorganism (NOB) may be further configured in the short axis nitrogen removing device 100 in which the partial nitrous oxide-anamox process is performed. As described above in FIGS. 1 and 2, the method of effectively removing nitrogen is to prevent oxidation of nitrous acid. However, since the nitrite oxidizing microorganism (NOB) and the ammonium oxidizing microorganism (AOB) coexist in the membrane diffuser unit 310, the present invention provides a device for inhibiting the nitrite oxidizing microorganism (NOB) activity in the uniaxial nitrogen removal device 100. By further including), it is possible to inhibit the activity of nitrite oxidizing microorganisms (NOB).

The nitrite oxidizing microorganism (NOB) activity inhibiting device 300 is a desorption tank 320 for desorbing microorganisms and solids attached to the surface of the membrane diffuser unit 310, inhibitor for inhibiting the activity of the nitrite oxidizing microorganism (NOB) Inhibitor reaction tank (or Inhibition tank) is filled with 330 and the washing tank 340 for washing the inhibitor remaining on the membrane surface.

The desorption tank 320 desorbs excess microorganisms and solids attached to the membrane diffuser unit 310. The residence time for desorption depends on the state of the attached microorganisms and solids, and the separation membrane diffuser unit 310 having been detached is transferred to the inhibition reaction tank 330.

Inhibition reaction tank 330 inhibits the activity of the nitrite oxidizing microorganism (NOB) to convert the nitrite to nitrate nitrogen. The inhibition reaction tank 330 includes an inhibitor that inhibits the activity of nitrite oxidizing microorganism (NOB), and the time for which the membrane diffuser unit 310 is immersed depends on the type and concentration of the inhibitor.

The washing tank 340 washes away the components of the inhibitor remaining in the membrane diffuser unit 310 immersed in the inhibition reaction tank 330. In particular, the wash bath 340 removes residues of the highly toxic hydroxylamine from the components of the inhibitor, thereby preventing the hydroxylamine from entering the reactor or being discharged with the effluent after the partial nitrification-anax process. prevent.

After the washing is completed, the membrane diffuser unit 310 is transferred to an anaox reactor (not shown) of the uniaxial nitrogen removal device 100 and subsequently undergoes partial nitrous oxide-anamox process.

An apparatus for inhibiting the activity of nitrite oxidizing microorganism (NOB) and a method using the same will be described in detail with reference to FIGS. 4 to 10.

4 is a view illustrating a process in which the membrane diffuser unit is immersed in the desorption tank of the nitrite oxidizing microorganism (NOB) activity inhibiting apparatus according to the first embodiment of the present invention.

The membrane diffuser unit 310 installed in the bioreactor 110 has a nitrite oxidizing microorganism (NOB) composed of three tanks 320, 330, and 340 in a state where air flowing into the bioreactor 110 is blocked. It is transferred to the desorption tank 320 which is the first join of the activity inhibiting device 300. The separator diffuser unit 310 is immersed in the desorption tank 320 to remove excess microorganisms and solids attached to the separator diffuser surface.

The desorption tank 320 secures a depth at which the membrane diffuser unit 310 can be completely immersed by utilizing the discharged water. The desorption tank 320 is provided with an air diffuser (not shown) for supplying air and a circulation pump 350 for forming an upflow in order to secure shear force necessary for desorption.

In the desorption tank 320, in consideration of the state of the microorganisms attached to the immersed membrane diffuser unit 310, air is supplied such that the surface velocity of the air in the biological reaction tank 110 becomes 5 to 25 m / hr. The nitrite oxidizing microorganism (NOB) activity inhibiting device 300 is to generate an additional shear force, by operating the circulation pump 350 to supply the circulating water to form the upward flow rate of the desorption tank to facilitate the desorption. At this time, the surface upward flow rate (flow rate / reactor area) of the biological reaction tank 110 is adjusted to the circulation amount to be 30 ~ 90m / hr. The time for the membrane diffuser unit 310 to stay in the desorption tank 320 may take about 50 to 60 minutes depending on the state of the attached microorganism.

When the desorption of the solids is completed, the nitrite oxidizing microorganism (NOB) activity inhibiting device 300 preferentially stops the operation of the circulation pump 350 and supplies only 5 to 10 minutes of air. The amount of air supplied to the desorption tank 320 is set to decrease sequentially as time passes, and to be zero when the set time is reached. This generates an upward flow rate in the desorption tank 320 by operating the circulation pump 350 to move the desorbed solids to the upper portion of the reaction tank, and supplies air only by stopping the operation of the circulating pump 350 to desorb the solids. This is to allow the solids to migrate to the bottom of the desorption tank and settle without reattaching to the membrane diffuser. The membrane diffuser unit 310 is removed from the desorption tank 320, and the solid precipitated under the beam of the desorption tank 310 is discharged to the primary treatment facility (not shown), and the desorption from which the solid is discharged. Further water is supplied to the desorption tank 310 to maintain the depth of the tank 310.

FIG. 5 is a view illustrating a process of immersing a membrane diffuser unit in which solid desorption is completed in an inhibition tank filled with a nitrite oxidizing microorganism (NOB) inhibitor according to a first embodiment of the present invention.

The nitrite oxidizing microorganism (NOB) activity inhibiting device 300 moves the membrane diffuser unit 310 in which solid detachment is completed, to the inhibition reaction tank 330. Inhibitors filled in the inhibition reaction tank 330 may be used, such as hydroxylamine (Hydroxylamine), NO ₂ and NH ₄ , but is not limited thereto.

Hydroxylamine is a small white lump that is a needle-like solid or colorless liquid that is used to remove leather or textile-free leather or as a disinfectant. It is known as an effective nitrite oxidizing microorganism (NOB) inhibitor. When hydroxylamine is used as an inhibitor, the time for which the membrane diffuser unit 310 stays in the inhibition reaction tank 330 depends on the concentration of the inhibitor. Typically, the time for staying in the inhibition reaction tank 330 is concentration (mg / L) × Adjust so that the value of time (minutes) is 50 ~ 200. As such, the limiting factor is that ammonium oxidizing microorganisms (AOB) are also inhibited after a certain period of time even if the concentration is excessively high or low. Since the present invention aims to suppress nitrite oxidizing microorganisms (NOB), when the ammonium oxidizing microorganisms (AOB) are inhibited, the efficiency of the entire process is impaired. In more detail, the process of the present invention inhibits the activity of nitrite oxidizing microorganisms (NOB) but does not remove the nitrite oxidizing microorganisms (NOB). However, by continuously creating an environment favorable to ammonium oxidizing microorganisms (AOB), the ammonium oxidizing microorganisms (AOB) is dominant to reduce the immersion time and the number of immersion to inhibit nitrite oxidizing microorganisms (NOB). At this time, by grasping the degree of nitrous oxidation of the entire process, if the nitrous oxidation is made stable can reduce the number of immersion, if the concentration of nitrate nitrogen is increased can be increased the number of immersion.

That is, this is to suppress the activity of nitrite oxidizing microorganisms (NOB) and to create an environment in which ammonium oxidizing microorganisms (AOB) is dominant, the concentration of the inhibitor and the time to be immersed in the inhibition reaction tank 330 is the nitrite oxidation of the entire process You can adjust the degree.

When NO ₂ or NH ₄ is used as an inhibitor, it is important to maintain an appropriate pH. When NO ₂ or NH ₄ is used as an inhibitor, the method of inhibiting the activity of nitrite oxidizing microorganisms (NOB) is FNA (Free Nitrous Acid) and FA (Free Ammonia) formed according to pH, NO ₂ and NH ₄ concentration. This is because it uses.

In general, nitrite oxidizing microorganisms (NOB) are known to be inhibited in the concentration of FNA range 0.2 ~ 2.8mg / L, the concentration of FNA depends on the pH and NO ₂ concentration, the lower the pH, the NO ₂ concentration The higher the value, the higher the concentration of FNA. In the present invention, the concentration of the concentration (mg / L) × time (minutes) to be 24 to 50 by adjusting the concentration of FNA by adjusting the concentration and pH of NO ₂ . In addition, to reduce the amount of inhibitor used, the pH should be 4.5 to 6.0. Likewise, the concentration of the inhibitor and the time to be immersed in the inhibition reaction tank 330 can be adjusted in consideration of the conditions of the entire process.

When NH ₄ is used, FA (Free Ammonia) concentration varies according to pH and NH ₄ concentration. It is known that inhibition of nitrous oxide oxidizing microorganism (NOB) occurs when the concentration of FA is 0.1 to 1.0 mg / L. In the present invention, it is possible to change the FA concentration by adjusting the pH and NH ₄ concentration and to adjust the FA concentration (mg / L) x residence time (minutes) value is 2.5 ~ 25. Since FA is well formed when the pH is high, in the present invention, by adjusting the pH in the range 7.5 ~ 9.0 to reduce the amount of drugs.

Inhibitors used in the reaction tank 330 may be used in the gaseous NO in addition to the hydroxyl form (Hydroxylamine), NO ₂ and NH ₄ in the liquid form. Examples of a nitrite oxidizing microorganism (NOB) activity inhibiting apparatus using NO as an inhibitor will be described later with reference to FIGS. 7 to 8.

FIG. 6 is a view illustrating a process of immersing the membrane diffuser unit in which the suppression reaction according to the first embodiment of the present invention is completed by moving to a washing tank.

The membrane diffuser unit 310 in which the suppression reaction is completed is moved to the washing tank 340, and the washing tank 340 removes the chemicals remaining on the membrane diffuser surface. The washing utilizes treatment plant effluent and the washing time can be carried out within 5 minutes, but can be adjusted according to the adsorbed residual inhibitor or the operating time of the entire process.

FIG. 7 is a view illustrating a process in which the membrane diffuser unit is immersed in the desorption tank when the NO gas according to the second embodiment of the present invention is used as an inhibitor.

As mentioned above, gaseous NO in addition to hydroxylamine, NO2 and NH4 may be used as inhibitor. NO exists as a colorless gas at room temperature, melting point is -161 ℃, boiling point is -151 ℃. The density of gaseous NO is 1.34g / cm ³ , which is higher than the air density of 0.0012g / cm ³ , so that it can be minimized to be discharged out of the tank even when injected into the inhibition reaction tank 330. have. In the nitrite oxidizing microorganism (NOB) activity inhibiting apparatus 700 using NO gas as an inhibitor, the membrane diffuser unit 310 is separated from the bioreactor 110 and transferred to the desorption tank 320. Operation conditions of the tali tank 320 are the same as described above, and thus will be omitted.

FIG. 8 is a view illustrating a process in which a membrane diffuser unit is immersed in an inhibition reaction tank when using NO gas as an inhibitor according to a second embodiment of the present invention.

The separation membrane diffuser unit 310 of which solid desorption is completed is transferred to the NO reaction tank 330 filled with NO in the gas state, and the inhibition reaction tank 330 activates the nitrite oxidizing microorganism (NOB) in the membrane diffuser unit 310. Carry out a reaction that inhibits. Since the NO concentration of the inhibition reaction tank 330 affects not only nitrite oxidizing microorganisms (NOB) but also ammonium oxidizing microorganisms (AOB), an appropriate level should be maintained. Dissolved amount in the membrane diffuser is about 2 ~ 5㎍ / L, NO concentration can be configured to about 4 ~ 10mg / L, but is not limited to this, concentration that is effectively inhibited nitrite oxidizing microorganisms (NOB) Keep it.

FIG. 9 is a view illustrating a process of reusing an inhibitor of nitrite oxidizing microorganism (NOB) according to an embodiment of the present invention and introducing the same into a partial nitrous oxide-anamox process.

NO ₂ and NH ₄ used as inhibitors of the inhibitory reaction tank 330 may decrease purity and function as the period of use elapses. In order to prevent this, the chemicals can be reused as inhibitors by maintaining the concentration, but in the nitrite oxidizing microorganism (NOB) activity inhibiting apparatus 300 according to the present invention, the concentration is lowered and NO ₂ and NH ₄ which cannot be used as inhibitors are used. By inputting into the partial nitrous oxide-anamox process and recycling, the cost of the process can be reduced.

In more detail, in the partial nitrous oxide-anamox process, the ratio of NO ₂ -N: NH ₄ -N in the sewage flowing into the anamox process is maintained to be 1.32: 1.0. Therefore, in the partial nitrous oxide-anamox process, a portion of nitrogen introduced from the partial nitrous acid tank 920 at the front end of the anamox bath 910 is oxidized to adjust the ratio of NO ₂ -N: NH ₄ -N to 1.32: 1.0. do. To this end, the partial nitrous oxide-anamox process injects a chemical that can control the ratio of NO ₂ -N and NH ₄ -N to a separate reactor (not shown), so that the NO ₂ -N: NH ₄ -N ratio is 1.32: Let it be 1.0. At this time, as shown in FIG. 9, the nitrite oxidizing microorganism (NOB) activation inhibitor 300 purifies NO ₂ and NH ₄ used in the inhibition reaction tank 330 and inputs the NO ₂ to the anamox reaction tank 910. -N: NH ₄ -N ratio is adjusted.

10 is a flowchart illustrating a method of inhibiting nitrite oxidation by a nitrite oxidizing microorganism (NOB) activity inhibiting device according to an embodiment of the present invention. Since it has been described in detail with reference to Figures 4 to 9, detailed description thereof will be omitted.

The nitrite oxidizing microorganism (NOB) activity inhibiting device 300 immerses the separator diffuser unit 310 in the desorption tank 320 to desorb microorganisms and solids grown excessively in the separator diffuser unit 310 (S1110). .

The nitrite oxidizing microorganism (NOB) activity inhibiting device 300 immerses the membrane diffuser unit 310, in which solid desorption is completed, in an inhibitor reaction tank 330 filled with an inhibitor in order to suppress nitrite oxidation (S1120).

The nitrous acid oxidizing microorganism (NOB) activity inhibiting device 300 is the inhibitor used in the reaction tank 330 is a hydroxylamine (Hydroxylamine), NO ₂ and NH ₄ , remaining on the surface of the membrane diffuser unit 310 Move to the washing tank 330 to remove the drug (S1130). In this case, the process may vary depending on the type of inhibitor used in the inhibition reaction tank 330. If the inhibitor used is not a solid or a liquid, that is, a gaseous NO is used in the inhibitor, the washing process may be omitted. .

When the nitrite oxidizing microorganism (NOB) activity inhibiting apparatus 300 uses NO ₂ and NH ₄ as inhibitors, the nitrite oxidizing microorganism (NOB) activity inhibitor 300 is reused and introduced into the partial nitrous acid-anax process (S1140).

In FIG. 10, each process is described as being sequentially executed, but this is merely illustrative of the technical idea of the exemplary embodiment of the present invention. In other words, one of ordinary skill in the art to which an embodiment of the present invention belongs may execute the process described in FIG. 10 by changing the order described in FIG. Since it will be applicable to various modifications and variations by executing in parallel, Figure 10 is not limited to the time series order.

Meanwhile, the processes illustrated in FIG. 10 may be embodied as computer readable codes on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. That is, the computer-readable recording medium may be a magnetic storage medium (for example, ROM, floppy disk, hard disk, etc.), an optical reading medium (for example, CD-ROM, DVD, etc.) and a carrier wave (for example, the Internet Storage medium). The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

The above description is merely illustrative of the technical idea of the present embodiment, and those skilled in the art to which the present embodiment belongs may make various modifications and changes without departing from the essential characteristics of the present embodiment. Therefore, the present embodiments are not intended to limit the technical idea of the present embodiment but to describe the present invention, and the scope of the technical idea of the present embodiment is not limited by these embodiments. The scope of protection of the present embodiment should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present embodiment.

100: microbial culture apparatus
110: biological reactor
120: sedimentation tank
121: air
122: oxygen
123: carbon dioxide
130: influent wastewater
140: influent wastewater measurement unit
150: control panel
210: separator diffuser
220: air
300: apparatus for inhibiting nitrite oxidizing microorganism activity according to the first embodiment
310: separator diffuser unit
320: Talijo
330: inhibition reaction tank
340: washing tank
350: circulation pump
700: device for inhibiting nitrite oxidizing microorganism activity according to the second embodiment
910: Anamox reactor
920: partial nitrite tank

Claims (8)

In order to suppress nitrite oxidation of nitrite oxidizing microorganisms attached to a membrane diffuser unit including ammonium oxidizing microorganisms and nitrite oxidizing microorganisms, nitrite oxidation inhibitors that inhibit the activity of nitrite oxidizing microorganisms are added to the membrane acid. Inhibiting reaction vessel to immerse the engine unit. The method of claim 1,
The nitrite oxidation inhibitor,
A nitrite oxidizing microorganism activity inhibiting device, characterized in that composed of at least one of hydroxylamine, NO ₂ , NH ₄ and NO. The method of claim 1,
The nitrite oxidation inhibitor,
A nitrite oxidizing microorganism activity inhibiting device, characterized in that it can be reused in the partial nitrous acid-anamox process. The method of claim 1,
The inhibition reaction tank,
The nitrite oxidizing microorganism activity inhibiting device, characterized in that the time for immersing the membrane diffuser unit is changed according to the concentration of the nitrite oxidation inhibitor. In the nitrite oxidation activity inhibiting device which inhibits nitrite oxidation by nitrite oxidizing microorganism by using nitrite oxidation inhibitor,
A desorption tank for removing microorganisms or solids attached to the membrane diffuser unit;
An inhibition reaction tank for dipping the membrane diffuser unit detached from the desorption tank in the nitrite oxidation inhibitor; And
A washing tank for washing the nitrite oxidation inhibitor on the surface of the membrane diffuser unit;
Nitrite oxidizing microorganism activity inhibiting device comprising a. The method of claim 5,
The nitrite oxidizing microorganism activity inhibiting device,
A nitrous oxide oxidizing microorganism activity inhibiting device comprising a uniaxial nitrogen removal device. The method of claim 5,
The elimination tank,
A nitrite oxidizing microorganism activity inhibiting device, characterized in that it comprises a circulation pump for introducing air to form an upflow. In the method for suppressing nitrite oxidizing microorganism oxidizing nitrite by using a nitrite oxidizing microorganism activity inhibiting device,
Immersing the membrane diffuser unit in the desorption tank of the nitrite oxidizing microorganism activity inhibiting device;
Immersing the membrane diffuser unit in which the solid desorption is completed in an inhibition tank filled with a nitrite oxidizing microbial inhibitor;
Immersing in a washing tank to remove chemicals remaining on the surface of the membrane diffuser unit; And
Reusing nitrite oxidizing microbial inhibitors for partial nitrite-anamox process
Nitrite oxidizing microbial activity inhibition method comprising a.

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