KR20200131017A - Apparatus for eliminating nitrogen and method for eliminating nitrogen - Google Patents

Abstract

The present invention relates to a nitrogen removing device which can effectively inhibit the activity of nitrite oxidizing bacteria and, more specifically, to a nitrogen removing device comprising: a first treatment tank in which first ammonia-containing sewage flows, and which includes granules containing anammox bacteria and a fluid carrier on which ammonia oxidizing bacteria (AOB) are supported; a selection inhibiting tank in which the fluid carrier and granules are introduced from the first treatment tank, and which includes an inhibitor selectively inhibiting the activity of nitrite oxidizing bacteria (NOB); and a second treatment tank in which second ammonia-containing sewage flows, and which includes the fluid carrier and granules introduced from the selection inhibiting tank.

Description

Nitrogen removal device and nitrogen removal method {APPARATUS FOR ELIMINATING NITROGEN AND METHOD FOR ELIMINATING NITROGEN}

A nitrogen removal apparatus and a nitrogen removal method for removing nitrogen in sewage containing a nitrogen compound are provided.

As cities expand and population increases, demands for sufficient sewage treatment and recovery are increasing, and as strict regulations on water quality are created in developed countries, many studies on advancement of sewage treatment and performance improvement are being conducted. Currently, the quality of sewage discharged to public waters by the spread of sewage treatment systems is improving year by year, but the concentration of nutrients such as nitrogen and phosphorus is still rising, resulting in red tide and eutrophication, which is a major social problem.

Sewage contains various pollutants such as carbon compounds, nitrogen compounds, and phosphorus compounds, and in the conventional biological nitrogen removal process (activated sludge process), oxygen is injected into sewage to convert carbon, nitrogen, and phosphorus into an oxidized form. In the case of nitrogen compounds such as ammonia, the biological nitrogen removal process includes a nitrification process of oxidizing ammonia nitrogen to nitrate nitrogen and a denitrification process of reducing nitrate nitrogen or nitrite nitrogen to generate nitrogen gas. .

Specifically, ammonia (NH ₃ )-based nitrogen is oxidized to nitrite (NO ₂ ^- ) ^-based nitrogen and nitric acid (NO ₃ ^- ) ^-based nitrogen, and then nitrogen oxide (NO) and dinitrogen monoxide (N ₂ O) by heterotrophic denitrification bacteria. ), nitrogen (N ₂ ) is reduced to gas form and removed from sewage. The oxidation of nitrite nitrogen in the ammonium nitrogen is Nitrosomonas (eg N. europaea, N. Oligocarbogenes), Nitrosococcus, Nitrosopira, ammonia-oxidizing bacteria such as Nitrosolobus (AOB, Ammonia Oxidation Bacteria) is involved, the quality of nitrite Nitrobacter (eg N. agilis , N. winogradski ), Nitrosopira , Nitrococcus, and other nitrite oxidizing bacteria (NOB) participate in the oxidation process to acidic nitrogen.

These two stages of nitrification and various bacteria involved in each reaction weaken or activate their ecological activity when a shocking change in the habitat environment such as substrate occurs. Partial nitrification can be induced by using the difference in the recovery rate of ecological functions in the process of creating such a shocking change in substrate and operating conditions and restoring to the original state. For example, when abundant substrate conditions are formed after exposure to substrate restriction for a long time, the recovery rate of the second-stage nitrification reaction is slower than that of the first-stage nitrification reaction, resulting in the accumulation of nitrite nitrogen. In addition, by shockingly injecting organic substances into the nitrifying bacteria, it may affect the nitrification reaction in the first step and the nitrification in the second step, and the partial nitrification may be induced by using the difference in recovery rate. However, repeated exposure to such a substrate restriction situation requires a separate water tank for the substrate restriction condition, and there is a problem that sewage treatment is restricted while the substrate restriction is performed. In addition, the organic matter impact load injection method requires a large-capacity machine and a control device for shockingly introducing organic matter from the outside into a tank in which microorganisms exist, and it is difficult to maintain partial nitrification continuously for a long time.

The nitrification process of ammonia nitrogen can be divided into the following first step and second step reaction. The first step nitrification is a process of oxidizing ammonia nitrogen to nitrite nitrogen as shown in Formula 1 below, and the second step nitrification is a process of oxidizing nitrite nitrogen to nitrate nitrogen as shown in Formula 2 below.

[Formula 1]

^{_{15CO 2 + 13NH 4 + → 10NO}} 2 - + 3C 5 H 7 O 2 N + 23H + + 4H 2 O

[Formula 2]

^{_{5CO 2 + NH 4 + + 10NO}} 2 - + 2H 2 O → 10NO 3 - + C 5 H 7 O 2 N + H +

The denitrification process is a biological denitrification reaction by heterotrophic denitrification bacteria, dissimilatory nitrate reduction, and can be represented by the following formula (3).

[Formula 3]

_{^{NO 3 - → NO 2 - →}} NO → N 2 O → N 2

Catabolic nitrate reduction is the use of nitrate nitrogen or nitrite nitrogen instead of oxygen as the final electron acceptor, and is called anaerobic respiration and denitrification reaction. Most microorganisms that perform the denitrification reaction can simultaneously use nitrate nitrogen, nitrite nitrogen, and dissolved oxygen as electron acceptors. In aerobic breathing, when 1 mole of glucose is oxidized, approximately 116 kcal of energy can be produced more than anaerobic breathing. Therefore, anaerobic breathing is limited under aerobic conditions in the presence of dissolved oxygen. The denitrifying bacteria used primarily in sewage treatment are Pseudomonas. sp ., Bacillus sp ., Spirillum sp ., Agrobacterium sp ., Acinetobacter sp ., Propionobacterium sp ., Rhizobium sp ., Thibacillus sp ., Alcaligenes sp . Etc.

The stoichiometry of the denitration reaction is very diverse depending on the carbon source and nitrogen type, and when sewage is used as the carbon source, a chemical reaction such as the following formula (4) may proceed.

[Formula 4]

^{_{10NO 3 - + C 10 H 19}} O 3 H → 5N 2 + 10CO 2 + 3H 2 O + NH 3 + 10OH -

In the case of the denitrification reaction by the catalytic nitrate reduction reaction, when about 1 mg of nitrate nitrogen is reduced, about 2.86 mg/L of BOD is consumed, so when the carbon source is insufficient, the carbon source must be artificially supplied from the outside.

Such a conventional biological nitrogen removal process removes nutrients by sequentially inducing anaerobic, anoxic, and aerobic conditions in order to remove nutrients such as nitrogen compounds. In the anaerobic tank and the second treatment tank, by preventing the supply of molecular oxygen, the activity of aerobic heterotrophic bacteria is minimized, whereas in aerobic conditions, dissolved oxygen is supplied to induce nitrification, excessive phosphorus intake, and aerobic organic decomposition reaction.

The nitrogen removal rate of the above-described biological nitrogen removal process may be very low, the oxygen supply cost may be excessive, and if the organic matter required for the denitrification reaction is insufficient, an external carbon source such as methanol must be artificially injected, which may increase the cost. have.

On the other hand, nitrous oxide (N ₂ O) has a greenhouse gas induction factor of about 210 times higher than that of carbon dioxide, so it is very important to reduce the amount of emissions. In the above-described biological nitrogen removal process, nitrous oxide (N ₂ O) gas may be discharged, In particular, in a nitrification reaction under a high organic concentration and a low oxygen concentration, or a denitrification reaction under a low organic concentration, the amount of nitrous oxide may be rapidly increased.

In order to solve the problem of the biological nitrogen removal process, research has been actively conducted to reduce the oxygen supply cost consumed by partially nitrifying ammonia to nitrite nitrogen by nitrifying microorganisms.

The partial nitrification technique proceeds the nitrification reaction to nitrite nitrogen, and the activity of AOB should be maintained and the activity of NOB should be suppressed.

Here, NOB is known to have a lower relative activity than AOB due to low dissolved oxygen (DO), high pH, high water temperature, free ammonia (FA), free nitrous acid (FNA), short SRT, and ultrasonic waves. Particularly, FA formed under a high concentration of ammonia and high pH conditions, or FNA formed under the presence of high concentration of nitrite ions may weaken the activity of NOB to achieve partial nitrification. However, the activities of heterotrophic bacteria and phosphorus-removing bacteria may also be reduced under repetitive and chronic high concentrations of FA and FNA. In addition, when NOB is operated for a long time even under a high concentration of FA and FNA, the inhibitory strength is alleviated and the stability of partial nitrification may be lowered.

Partial nitrification is currently limitedly applied to sewage treatment plant reflow water, landfill leachate, and livestock manure wastewater in which high concentrations of ammonia exist.

In contrast, in the case of domestic sewage containing a relatively low concentration of ammonia, it is known that it is very difficult to accumulate nitrous acid by partial nitrification. Methods such as low DO, impact injection of organic matter, intermittent aeration, aerobic granules, short SRT operation, injection of nitrite oxidizing bacteria selectively inhibiting chemicals, ultrasonic contact for partial nitrification under low concentration ammonia conditions have been tried. It is not known that stable partial nitrification has been successful. In particular, it is even more difficult to stably maintain partial nitrification in a confluence-type drainage conduit where the water temperature in winter is low or inflow of unknown water is frequent due to rainfall.

Anaerobic Ammonium Oxidation (ANAMMOX) is a novel nitrogen metabolism process discovered in 1995 at Delft Institute of Technology in the Netherlands. Under anaerobic conditions without oxygen and organic matter, nitrite is converted to ammonium as an oxidizing agent by Anamox bacteria. It refers to a reaction of generating nitrogen gas by using ions as a reducing agent. Anamox bacteria have a unique nitrogen removal mechanism that converts ammonium into nitrogen gas under anaerobic conditions as an electron donor of nitrite, so many studies have been conducted in connection with the aforementioned partial nitritation (see Formula 5 below). ).

[Formula 5]

_{^{NH 4 + + 1.32NO 2 - +}} 0.066HCO 3 - + 0.13H + → 1.02N 2 + 0.256NO 3 - + 0.066CH 2 O 0.5 N 0.15 + 2.03H 2 O

More than 10 species of Anamox bacteria have been discovered until recently, Candidatus Kuenenia ( K. stuttgartiensis ), Brocadia ( B. anammoxidans , B. fulgida , and B. sinica ), Anammoxoglobus ( A. propionicus ), Jettenia ( J. asiatica ) and Scalindua ( S. brodae , S. sorokinii , S. wagneri , and S. profunda ).

The anamox method can greatly reduce energy consumed due to air injection, can greatly reduce the amount of sludge generated, and can minimize greenhouse gas emissions such as CO ₂ , N ₂ O, and NO. In addition, the Anamox method can greatly reduce the amount of nitrous oxide through partial nitrification.

Most of the Anamox processes currently applied to sewage treatment plants are selectively used in the presence of a high concentration of ammonia due to the difficulty in partial nitrification. When the ammonia concentration is relatively low, such as domestic sewage, it may be very difficult to stably maintain the partial nitrification state, and due to the limitation of such partial nitrification, complete nitrification and denitrification (activated sludge process) are applied to the main treatment process. .

In addition, since the types of anamox bacteria are limited, and their activity rapidly decreases at low temperatures, it may not be easy to sufficiently secure the amount of biomass of anamox bacteria required for sewage treatment. In addition, anamox bacteria have a very low growth rate, so it may take a lot of time to stabilize the operation of the sewage treatment system.

On the other hand, recently, biological sewage treatment technology using granules has been actively studied. Granules have the advantage of reducing the residence time of the sedimentation basin due to the high density of microorganisms that can shorten the sewage treatment rate and high sedimentation rate. In particular, it is relatively easy to form granules for sewage treatment plant reflow water, landfill leachate, and livestock manure with a high concentration of ammonia nitrogen and low C/N ratio (carbon/nitrogen ratio). Granules coexist with various microorganisms, so they are highly responsive to changes in inflow water quality and load. In addition, ammonia oxide bacteria live on the surface of the granules, and Anamox bacteria are located inside, which can be very useful for nitrogen removal.

The fluid carrier has an advantage in that a biofilm is formed on the surface and microorganisms adhere to and grow at a high concentration, thereby shortening the sewage or wastewater treatment time. In order to cultivate nitrifying bacteria with a slow growth rate at high concentration, it is necessary to operate with a long SRT (Sludge Retention Time). When microorganisms are attached to the fluid carrier, a biofilm is formed, and as long as the fluid carrier is not lost to the outside, microorganisms useful for sewage treatment can be secured at a high concentration, so it is useful for cultivation of anamox bacteria with slow growth rate and nitrification of ammonia nitrogen. Can be used.

(Prior Document 1) U.S. Patent No. 8,864,993 (Prior Document 2) Korean Patent Registration No. 10-1,830,896 (Prior Document 3) Korean Patent Registration No. 10-1,875,024

A nitrogen removal apparatus and a nitrogen removal method according to an embodiment of the present invention are for stably maintaining partial nitrification in a sewage treatment process containing ammonia at a low concentration.

A nitrogen removal apparatus and a nitrogen removal method according to an embodiment of the present invention are for effectively inhibiting the activity of nitrite oxidizing bacteria in a sewage treatment process.

A nitrogen removal apparatus and a nitrogen removal method according to an embodiment of the present invention are for improving the efficiency of removing nitrogen in sewage.

A nitrogen removal apparatus and a nitrogen removal method according to an embodiment of the present invention is to reduce the cost of sewage treatment.

A nitrogen removal apparatus and a nitrogen removal method according to an embodiment of the present invention is to reduce the amount of energy consumed for removing nitrogen in sewage.

A nitrogen removal apparatus and a nitrogen removal method according to an embodiment of the present invention are for reducing greenhouse gas emissions.

In addition to the above problems, the embodiments according to the present invention may be used to achieve other tasks not specifically mentioned.

The nitrogen removal apparatus according to an embodiment of the present invention includes a first treatment tank including a fluid carrier in which the first ammonia-containing sewage is introduced, and granules containing anamox bacteria and ammonia oxidizing bacteria (AOB) are supported. 1 In the treatment tank, a fluid carrier and granules are introduced, a selective suppression tank containing an inhibitor that selectively inhibits the activity of nitrite oxidizing bacteria (NOB), and a second ammonia-containing sewage is introduced and introduced from the selective suppression tank. It includes a second treatment tank containing a fluid carrier and granules.

At this time, the fluid carrier and granules in the second treatment tank are introduced into the first treatment tank, and the activity of nitrite oxidizing bacteria is selectively suppressed in the second treatment tank.

In the first treatment tank, ammonia contained in the first ammonia-containing sewage water is partially nitrified to nitrous acid by ammonia oxidizing bacteria, and the nitrite is converted to nitrogen and removed by the anamox bacteria, and in the second treatment tank, ammonia oxidation Ammonia contained in the second ammonia-containing sewage by bacteria is partially nitrified to nitrous acid, and nitrous acid is converted into nitrogen by the anamox bacteria and removed.

It may further include a granule recovery tank in which the granules introduced in the first treatment tank are washed.

Granules washed in the granule recovery tank may be reintroduced into the first treatment tank.

The ammonia concentration of the second ammonia-containing sewage may be greater than the ammonia concentration of the first ammonia-containing sewage.

A third treatment tank including denitrifying bacteria and granules introduced in the first treatment tank, and in which nitric acid produced and introduced in the first treatment tank by the denitrification bacteria is reduced and removed.

In the third treatment tank, nitrous acid introduced untreated in the first treatment tank by anamox bacteria contained in the granules introduced in the first treatment tank may be converted to nitrogen and removed.

The inhibitory substance may include one or more of hydroxylamine, hydrazine, or ammonia nitrogen having a concentration above a predetermined concentration.

The ammonia nitrogen may have a concentration of 500 mg N/L or more.

The concentration of nitrite nitrogen in the second treatment tank may be 100 mg N/L or less.

The flow carrier may comprise one or more of polyethylene, polypropylene, polyester, polyurethane, polyvinylchloride, nylon, or polystyrene.

It may further include a conveying device for moving the flow carrier and the granules, and the conveying device may be a vibration damper or a screw pump.

The nitrogen removal method according to an embodiment of the present invention includes granules containing anamox bacteria and a first treatment tank including a fluid carrier loaded with ammonia oxidizing bacteria, and contained in the first ammonia-containing sewage introduced from the outside. A first treatment step in which ammonia is partially nitrified to produce nitrous acid, and nitrite is converted to nitrogen to be removed, and a fluid carrier and granules in the first treatment tank are separated and supplied to a selective suppression tank to selectively inhibit the activity of nitrite oxidizing bacteria. Selective suppression step, by supplying a fluid carrier and granules in the selective suppression tank to the second treatment tank into which the second ammonia-containing sewage flows from the outside to partially nitrify ammonia contained in the second ammonia-containing sewage to produce nitrous acid, and nitrogen A second treatment step of converting to and removing it, and supplying the fluid carrier and granules in the second treatment tank to the first treatment tank.

Here, in the second treatment step, it is possible to selectively inhibit the activity of nitrite oxidizing bacteria.

In a first treatment step, ammonia is partially nitrified to nitrous acid by ammonia oxidizing bacteria, nitrite is converted to nitrogen by anamox bacteria, and in a second treatment step, ammonia is partially nitrified to nitrite by ammonia oxidizing bacteria, Nitrous acid can be converted to nitrogen by Anamox bacteria.

The granule washing step of supplying and cleaning the granules in the first treatment tank to the granule recovery tank, and reintroducing the washed granules to the first treatment tank may be further included.

Prior to the granulation washing step, the granules in the first treatment tank were supplied to a third treatment tank containing denitrifying bacteria to reduce and remove nitric acid generated in the first treatment tank and introduced into the third treatment tank, and untreated in the first treatment tank. It may further include a third treatment step of converting and removing nitrous acid introduced into the third treatment tank to nitrogen.

In the third treatment step, nitric acid can be reduced by denitrifying bacteria, and nitrite can be converted into nitrogen by anamox bacteria contained in granules.

In the selective inhibition step, the residence time of the flow carrier and granules in the selective inhibition tank may be 30 minutes or less.

The concentration of nitrite nitrogen in the second treatment tank may be 100 mg N/L or less.

The ammonia concentration of the second ammonia-containing sewage may be greater than the ammonia concentration of the first ammonia-containing sewage.

The second ammonia-containing sewage may be supplied to the first treatment tank after passing through the second treatment step.

It may further comprise the step of additionally supplying an inhibitory substance to the selection suppression tank.

The nitrogen removal device and the nitrogen removal method according to an embodiment of the present invention can stably maintain partial nitrification in a sewage treatment process containing a low concentration of ammonia, effectively inhibit the activity of nitrite oxidizing bacteria, and It is possible to improve the nitrogen removal efficiency, reduce the cost of sewage treatment, reduce the amount of energy consumed for removing nitrogen in the sewage, and reduce greenhouse gas emissions.

1 is a diagram conceptually showing a nitrogen removal process in ammonia-containing sewage.
2 is a view showing an example of the nitrogen removal device of FIG.
3 is a diagram illustrating an example of the nitrogen removal device of FIG. 1.

Embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. The present invention may be implemented in various different forms, and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and the same reference numerals are used for the same or similar components throughout the specification. Also, in the case of well-known technologies, detailed descriptions thereof will be omitted.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated.

1 is a diagram conceptually showing a nitrogen removal system in ammonia-containing sewage.

Referring to FIG. 1, a system for removing nitrogen from sewage containing an ammonia component includes partial nitrification, and selective suppression of at least two consecutive steps.

In the partial nitrification step, ammonia oxidizing bacteria (AOB), which are involved in partially nitrifying ammonia with nitrous acid (NO ₂ ^- ), and Anamox bacteria, which synthesize and remove nitrogen using nitrous acid, may be involved, and AOB May be carried on a fluid carrier, and the Anamox bacteria may exist in the form of granules.

In this case, the nitrite oxidizing bacteria (NOB) is active (generation or proliferation) screen is nitric acid without the nitride portion of the ammonia is not stably held (NO ₃ ^-) when the complete nitrification in the form be fulfilled, a nitrite by Ana Comox bacteria nitrogen Since it cannot be converted into gas, the nitrogen removal efficiency can be greatly reduced.

The nitrogen removal system according to the embodiments includes a process of selectively suppressing NOB in at least two steps or more continuously in order to stably maintain the above-described partial nitrification.

NOB may be deactivated when ecological impact is applied, for example, it may be directly contacted with a substance that inhibits its activity, resulting in lower activity, another example, low dissolved oxygen (DO), high The activity may be lowered by pH, high water temperature, free ammonia (FA), free nitrous acid (FNA), short SRT, and ultrasound. In particular, FA formed in high concentration of ammonia and high pH condition, or FNA formed in the presence of high concentration of nitrite ions may significantly weaken the activity of NOB.

The nitrogen removal process according to the embodiments suppresses NOB by applying a continuous ecological shock and stably maintains partial nitrification, thereby greatly improving nitrogen removal efficiency. Continuous ecological shock can be achieved, for example, by exposing the flow carrier and granules to inhibitory substances such as high concentrations of ammonia, followed by exposure to appropriate concentrations of nitrous acid (NO ₂ ⁻ ) nitrogen.

The flow carrier and granules may circulate through a partial nitrification step and a selection suppression step of two or more stages, and the sewage may be discharged to the outside through a partial nitrification step and a selection suppression step of two or more stages.

The nitrogen removal system will be described in more detail below with reference to FIGS. 2 and 3.

In the specification, ammonia nitrogen and ammonia may have the same meaning, nitrite nitrogen and nitrous acid may be used with the same meaning, and nitrate nitrogen and nitric acid may be used with the same meaning.

2 is a view showing an example of a nitrogen removal apparatus according to an embodiment, and may be an example of implementing the nitrogen removal process shown in FIG. 1.

Referring to FIG. 2, a nitrogen removal apparatus 100 for removing nitrogen from sewage containing nitrogen compounds such as ammonia includes a first treatment tank 110, a selection suppression tank 140, and a second treatment tank 150. Include.

The first treatment tank 110 is a water tank in which a main stream process in which nitrogen is removed by introducing first ammonia-containing sewage containing a relatively low concentration of ammonia is performed.

In the first treatment tank 110, granules containing Anamox bacteria and a fluid carrier carrying ammonia oxidizing bacteria (AOB) are positioned. Ammonia-oxidizing bacteria and ammonia nitrite (NO ₂ ^-) and bacteria which is involved sikineunde nitrification section, the analog Comox bacteria is the bacteria to synthesize the nitrogen by using a nitrite.

The flow carrier 120 is one or more of polyethylene, polypropylene, polyester, polyurethane, polyvinyl chloride, nylon, or polystyrene. It may include, but is not limited thereto.

Ammonia oxidizing bacteria (AOB) are supported on the flow carrier 120, and nitrite oxidizing bacteria (NOB) may be generated or proliferated in the flow carrier 120 while the nitrogen removal device 100 is operated.

In a first treatment tank 110, an ammonia (NH ₃₎ the nitrous acid contained in the first ammonia-containing wastewater by the ammonia-oxidizing bacteria ^- are the partial nitrification nitrite by Ana Comox bacteria (partial nitrification), and (NO ₂₎ It can be converted to nitrogen (N ₂ ) gas and removed.

When the complete nitrification in the form be fulfilled, ^- However, a first treatment tank 110, the nitrite oxidizing bacteria (NOB) in the activity (generation or proliferation) instead is not a nitride portion of the ammonia remains stable Chemistry nitrate (NO ₃₎ Since nitrous acid cannot be converted into nitrogen gas by the anamox bacteria, the nitrogen removal efficiency may be significantly lowered. The selection suppression tank 140 includes an inhibitory substance that selectively suppresses the activity of NOB.

The granules 130 and the fluid carrier 120 exposed to low-concentration ammonia in the first treatment tank 110 for a long time cannot inhibit the activity of NOB, so the activity of NOB can be restored over time, which will be described later. In the suppression tank 140 and the second treatment tank 150, the generation or proliferation of NOB that may be attached to the flow carrier 120 and the granules 130 and grown may be suppressed.

At this time, the fluid carrier 120 and the granules 130 may be separated from a liquid such as water in the first treatment tank 110 through a transfer device (not shown) and introduced into the selection suppression tank 140, and the transfer device May be, for example, an airlift pump, a vibration damper, or a screw pump.

The inhibitory substance may be hydroxylamine, hydrazine, or ammonia (ammonia nitrogen) having a concentration greater than or equal to a predetermined concentration. Preferably, the inhibitory substance may be ammonia, which is relatively inexpensive in price, can be easily obtained at a place such as a sewage treatment plant, and is not subject to legal restrictions such as the Chemical Substance Control Act, and the concentration of ammonia as an inhibitory substance ( The concentration of ammonia nitrogen) may be about 500 mg N/L or more, and in this range, the production or proliferation of NOB can be effectively inhibited.

The time for the fluid carrier 120 and the granules 130 to stay in the selection suppression tank 140 may be about 30 minutes or less. In spite of such a short residence time, as will be described below, it is combined with the second treatment tank 150 arranged in succession to sufficiently implement the NOB inhibitory effect and the active effect of AOB and anamox bacteria. In addition, even if the time that the fluid carrier 120 and the granules 130 stay in the selection suppression tank 140 is about 10 minutes or less, the NOB suppression effect may be achieved. Therefore, the nitrogen removal apparatus 100 according to the embodiment can rapidly suppress NOB through the selection suppression tank 140.

The selection suppression tank 140 may further include an aeration device (not shown) or an agitator (not shown), and due to this configuration, the contact between the flow carrier 120 and the granules 130 and the inhibitory substance may increase. And, thereby, the NOB inhibitory effect may be further improved.

In this way, the granules 130 and the fluid carrier 120 whose NOB activity is primarily suppressed are moved to the second treatment tank 150 by a transfer device (not shown).

The second ammonia-containing sewage water having a higher ammonia concentration than the first ammonia-containing sewage is introduced into the second treatment tank 150. Here, the second ammonia-containing sewage may be rejected water, and the second treatment tank 150 may be a water tank in which a side stream process is performed.

However, although not shown, the second ammonia-containing sewage having a higher ammonia concentration than the first ammonia-containing sewage may flow into the selection control tank 140 and then move to the second treatment tank 150. In this case, high-concentration ammonia contained in sewage flowing into the selection suppression tank 140 may function as an inhibitory substance, and inhibitory substances such as hydroxylamine or hydrazine may be omitted. For example, the concentration of ammonia nitrogen (NH ₄ ⁺ -N) contained in sewage flowing into the selection suppression tank 140 may be about 500 mg N/L.

In a second treatment tank 150, the ammonia contained in the second ammonia-containing wastewater by the ammonia-oxidizing bacteria (NH ₃₎ the nitrite (NO ₂ ^-) as part nitrification and nitrite nitrogen by Ana Comox bacteria (N ₂ ) Can be converted to gas and removed. Since the granules 130 and the fluid carrier 120 are supplied to the second treatment tank 150 in a state in which NOB activity is suppressed, partial nitrification in the second treatment tank 150-Anamox reaction occurs actively to remove nitrogen and performance can be improved, the second nitrous acid in the treatment tank (150) (NO ₂ ^-) the concentration of can be maintained at about 100 mg N / L or less by Ana Comox reaction, which as a result NOB activity selective It can be (secondarily) suppressed.

Second processing low-nitrite in the tank (150) (NO ₂ ^-) concentration is, the NOB activity in the flow carrier 120 and the granules 130 is introduced in the selected billion Preparation 140, again with one selective Can be suppressed. The NOB activity suppression effect can be maximized through the synergistic effect of the selection suppression tank 140 and the second treatment tank 150 disposed in succession. In addition, since the activity of the AOB and the anamox bacteria in the selection suppression tank 140 is increased, the efficiency of removing nitrogen by the AOB and the anamox bacteria in the second treatment tank 150 may be further increased.

In more detail, when the fluid carrier 120 and the granules 130 stay only in the selection suppression tank 140 containing a high concentration of ammonia as an inhibitory material, or stay only in the second treatment tank 150, The inhibitory effect of NOB activity may be insignificant. However, when the NOB activity in the fluid carrier 120 and the granules 130 passes through the selection suppression tank 140 and the second treatment tank 150, the NOB activity suppression effect can be greatly increased, and the nitrogen removal device (100) NOB activity is suppressed as a whole, so partial nitrification can be stably maintained.

In this way, the activity of NOB is suppressed in two steps, and the granules 130 and the flow carrier 120 in a state in which the activity of AOB and anamox bacteria are improved are supplied to the first treatment tank 110 again. At this time, the granules 130 and the flow carrier 120 may be moved by the above-described transfer device (not shown).

When the two-stage NOB activity suppression in the selection suppression tank 140 and the second treatment tank 150 is not performed, the fluid carrier 120 and the granules 130 stay in the first treatment tank 110 for a long time or If the incoming sewage has suitable conditions for NOB growth, NOB grows (activates) inside or outside the flow carrier 120 or outside the granules 130, and if it cannot be suppressed in a timely manner, partial nitrification-Anamox reaction This cannot be sustained, and it can take a very long time and effort to restore partial nitrification.

On the other hand, in the case of the nitrogen removal apparatus 100 according to the embodiment, due to the above-described two-stage NOB activity inhibition, partial nitrification in the first treatment tank 110 can be maintained very stably, and the anamox bacteria The MOX reaction efficiency can be greatly improved, and the nitrogen removal efficiency can be remarkably improved.

The flow carrier 120 and the granules 130 may continuously circulate the first treatment tank 110, the selection suppression tank 140, and the second treatment tank 150, and such circulation is performed by a separate control device ( It can be controlled through).

For smooth flow of the flow carrier 120, the flow carrier 120 may have a volume of about 50% or less based on the total volume (volume) of the first treatment tank 110, and the second treatment tank 150 It may have a volume of about 50% or less based on the total volume.

In the nitrogen removal apparatus 100 according to the embodiments, in each of the first treatment tank 110 and the second treatment tank 150, a granule 130 having a relatively small volume is a flow carrier 120 having a relatively large volume. As it is located between the spaces, the nitrogen removal time can be shortened, and even when an impact load inflow occurs, sewage can be stably treated.

In the granule collection tank 170 of the nitrogen removal device 100, some of the granules 130 located in the first treatment tank 110 may be introduced, and the airborne microorganisms may be separated and removed (exuded) by washing.

The time for the granules 130 to stay in the granule collection tank 170 may be about 10 minutes or less, and within this range, while floating microorganisms are removed from the granules 130, the activity of the Anamox bacteria may be maintained.

The granules washed in the granule recovery tank 170 may be reintroduced into the first treatment tank 110 by an airlift pump or the like. Due to this, the nitrogen removal performance of the Anamox bacteria can be further improved.

In the nitrogen removal device 100, looking at the moving path of the fluid carrier 120, the fluid carrier 120 is moved from the first treatment tank 110 to the selection suppression tank 140 along the first path 112 , After the NOB activity is first suppressed in the selection suppression tank 140, it is moved to the second treatment tank 150 along the second path 142, and the NOB activity is secondary in the second treatment tank 150. After being suppressed, it is moved to the first treatment tank 110 along the third path 152. The fluid carrier 120 may continuously circulate the first treatment tank 110, the selection suppression tank 140, and the second treatment tank 150.

In the nitrogen removal apparatus 100, looking at the movement path of the granules 130, the granules 130 are in a first treatment tank along the first path 112, the second path 142 and the third path 152 ( 110), the selection suppression tank 140 and the second treatment tank 150 may be continuously circulated. In addition, the granules 130 are introduced to the first treatment tank 110 along the fourth path 154 after the NOB activity is suppressed in the second treatment tank 150, and the NOB activity suppression power is weakened. 5 After being moved to the granule recovery tank 170 along the path 114 and washed, it may be continuously circulated along the circulation path supplied to the first treatment tank 110 along the seventh path 174.

In the nitrogen removal device 100, looking at the treatment path of sewage, the sewage containing low concentration ammonia is supplied to the first treatment tank 110, and after the nitrogen removal treatment is performed, the first sewage movement path 116 After being introduced into the granule recovery tank 170 through, it may be discharged to the outside through the discharge path 176. On the other hand, the backwash water containing a high concentration of ammonia is supplied to the first treatment tank 110 along the backwash water transfer path 156, and after nitrogen removal treatment is performed, the discharge path ( 176) can be discharged to the outside.

3 is a view showing an example of a nitrogen removal apparatus according to the embodiment.

In the nitrogen removal device of FIG. 3, a description of a portion overlapping with the nitrogen removal device of FIG. 2 may be omitted.

Referring to FIG. 3, the nitrogen removal apparatus 100 includes denitrifying bacteria and granules 130 introduced from the first treatment tank 110, and is produced and introduced in the first treatment tank 110 by the denitrifying bacteria. the nitrate (nO ₃ ^-) can further include a third treatment tank to be removed is reduced (160). Here, the nitric acid generated in the first treatment tank 110 may mean nitric acid that is completely oxidized by activated NOB without being converted to nitrogen by the Anamox bacteria after ammonia is partially oxidized to nitrous acid by AOB. .

In addition, in the third treatment tank 160, nitrous acid introduced untreated in the first treatment tank 110 by the anamox bacteria contained in the granules 130 introduced from the first treatment tank 110 is nitrogen ( N ₂ ) can be converted to and removed. Here, the nitrous acid untreated in the first treatment tank 110 may mean nitrous acid in which ammonia is partially oxidized to nitrous acid by AOB, but is not converted to nitrogen by the Anamox bacteria.

The third treatment tank 160 may be disposed between the first treatment tank 110 and the granule collection tank 170. The sewage treated to remove nitrogen in the first treatment tank 110 is introduced into the third treatment tank 160 through the first sewage transfer path 116, and then the second sewage transfer path ( After moving to the granule collection tank 170 through 166, it is discharged to the outside through the discharge path 176. In addition, the granules 130 are moved to the third treatment tank 160 along the fifth path 114 and then moved to the granule collection tank 170 along the sixth path 164 and washed, and then the seventh path It may be continuously circulated along the circulation path supplied to the first treatment tank 110 along the 174.

Hereinafter, a method of removing nitrogen from sewage according to an embodiment will be described.

The nitrogen removal method includes a first treatment step of removing nitrogen in the first treatment tank 110, a selective suppression step of selectively suppressing the activity of NOB in the selection suppression tank 140, and a partial suppression step in the second treatment tank 150. A second treatment step of removing nitrogen through nitrification and anamox reaction and at the same time secondarily suppressing NOB activity, and the flow carrier 120 and the granules 130 in the second treatment tank 150 were placed in a first treatment tank ( 110).

In the first treatment step, in the first treatment tank 110 including the granules 130 containing the anamox bacteria and the flow carrier 120 carrying ammonia oxidizing bacteria (AOB), the relatively low concentration introduced from the outside a step of generating a, removing converts nitrite to nitrogen (N ₂₎ ^- first to nitrification of ammonia (NH ₃₎ contained in the ammonia-containing wastewater partial nitrous acid (NO _2). Here, the ammonia (NH ₃₎ a nitrite by ammonium oxidizing bacteria ^- have to nitrite by nitrification is part, Ana Comox bacteria can be converted into nitrogen _{(N 2) (NO 2)} .

In the selective suppression step, the flow carrier 120 and the granules 130 in the first treatment tank 110 are separated from sewage and suspended substances, supplied to the selective suppression tank 140, and contacted with the inhibitory substances to selectively nitrite oxidizing bacteria. This is the step of inhibiting the activity of (NOB). For example, a high concentration of ammonia may be introduced from the outside to rapidly inhibit the activity of NOB. As described above, when sewage containing ammonia nitrogen having a concentration greater than that of the first ammonia-containing sewage, for example, about 500 mg N/L or more, is introduced into the selection control tank 140, ammonia contained in sewage By functioning as an inhibitory substance, NOB activity may be suppressed, and in this case, the use of substances such as hydroxylamine, which is relatively expensive, may be omitted.

In the second treatment step, the flow carrier 120 and the granules 130 in the selection suppression tank 140 are supplied to the second treatment tank 150 in which the second ammonia-containing sewage of a relatively high concentration is introduced from the outside to by nitride portion of the ammonia contained in wastewater containing nitrite ^- a step of generating a, removing converts nitrite to nitrogen _{(N 2) (NO 2)} . Ammonia is partially nitrified to nitrous acid by ammonia oxidizing bacteria, and nitrite can be converted to nitrogen (N ₂ ) by anamox bacteria.

At this time, in the second treatment step, it is possible to selectively inhibit the activity of nitrite oxidizing bacteria (NOB). As described above, the concentration of nitrous acid (NO ₂ ^- ) nitrogen in the second treatment tank 150 may be properly maintained to be less than about 100 mg N/L by the anamox reaction, and thereby NOB activity Can optionally be suppressed once again.

As the selective inhibition step (first ecological shock) and nitrogen removal (second ecological shock) by the anamox reaction of the second treatment step are performed continuously, the selective inhibitory effect of NOB activity can be maximized. In addition, in the selective inhibition step, since the activity of AOB and Anamox bacteria was increased by abundant ammonia nitrogen, the efficiency of nitrogen removal by AOB and Anamox bacteria in the second treatment step may be further increased.

The nitrogen removal method includes a granule washing step of supplying a part of the granules 130 in the first treatment tank 110 to the granule recovery tank 170 and washing (removing the floating matter), and the first treatment of the washed granules 130 It may further include the step of re-introduction to the bath 110 and reuse.

The nitrogen removal method is produced in the first treatment tank 110 by supplying some of the granules 130 in the first treatment tank 110 to the third treatment tank 160 containing denitrifying bacteria before the granulation washing step. the nitrate is introduced third removing converts the ^{- -} (-N NO ₂₎ to nitrogen (N ₂₎ removal by reducing (NO ₃ -N) and the nitrite has 1 is untreated in the treatment tank 110 is introduced It may further include a processing step. At this time, nitrate may be reduced by denitrifying bacteria, and nitrite may be converted into nitrogen (N ₂ ) by anamox bacteria contained in granules.

The granules 130 used in the third processing step may be moved to the granule collection tank 170, washed, and then moved to the first processing tank 110.

The nitrogen removal method may further include the step of additionally supplying an inhibitory substance to the selection suppression tank 140. When it is determined that the NOB suppression performance of the selection suppression tank 140 is deteriorated over time, or when a predetermined period of time elapses, an inhibitory substance is additionally added to the selection suppression tank 140 to improve or maintain the NOB suppression performance I can make it.

Hereinafter, experimental examples of the NOB inhibitory effect in the flow carrier depending on the concentration of the inhibitory substance and the NOB inhibitory effect in the flow carrier depending on the exposure time to the inhibitory substance are presented. From the experimental examples, the partial nitrification retention stability and NOB suppression effect of the nitrogen removal apparatus 100 according to the embodiments may be described.

For the experiments according to the following Experimental Examples 1 and 2, under the condition that low-concentration ammonia sewage (sewage having an ammonia concentration in the same or similar range as the first ammonia-containing sewage described above) is introduced in an actual sewage treatment plant, complete nitrification value The reaction tank filled with 20% of the fluid carrier was operated for 6 months so that nitrite nitrogen did not accumulate, and the fluid carrier in which complete nitrification was occurring was washed three or more times with distilled water, and then used as AOB and NOB microorganisms.

Experimental example 1-NOB inhibition according to inhibitory substance concentration Experiment on the effect

The prepared fluid carrier was exposed to an inhibitory substance (hydroxylamine, hydrazine, ammonia (ammonia nitrogen)) (corresponding to a selection inhibitory tank), and then exposed to ammonia (ammonia nitrogen, NH ₄ ⁺ -N) alone substrate. In case of (Case 1), exposure to nitrite nitrogen (NO ₂ ^-- N) alone after exposure to an inhibitory substance (Case 2), and ammonia nitrogen and nitrite nitrogen (NH ₄₎ after exposure to an inhibitory substance ⁺ -N + NO ₂ ^-- N) In the case of exposure to the substrate (Case 3), the experimental results showing the NOB inhibitory effect according to the concentration of the inhibitor are shown in Table 1 below.

temperament Nitrification HA10 HA20 HA40 HZ10 HZ20 HZ40 AM250 AM500 AM1000 Con NH ₄ ⁺ -N
(Case 1) △mg NH ₃ -N/hr 5.3 5.2 5.2 4.1 4.0 3.9 5.4 5.1 4.4 5.2 △mg NO ₃ -N/hr 5.0 4.4 4.2 5.2 3.8 2.8 5.8 6.2 6.3 6.8 NO ₂ /NOx × 100
(%) 10.3 16.6 23.8 0.0 10.8 40.4 0.0 0.0 0.8 0.0 NO ₂ ^― N
(Case 2) △mg NO ₃ -N/hr 6.2 4.8 2.9 6.5 3.7 2.5 7.2 6.0 3.6 7.3 NO ₂ /NOx Х 100
(%) 24.6 33.9 49.5 16.5 42.9 62.6 5.0 14.0 38.4 1.2 NH ₄ ⁺ -N
+
NO ₂ ^-- N
(Case 3) △mg NH ₃ -N/hr 2.6 2.1 2.0 1.6 1.7 1.9 2.8 3.2 2.6 2.7 △mg NO ₃ -N/hr 2.3 1.5 1.2 3.0 1.5 0.5 7.5 7.0 5.9 8.0 NO ₂ /NOx × 100
(%) 66.5 72.1 75.6 46.0 70.7 85.5 4.2 17.1 25.6 0.0

In Table 1, the ammonia nitrogen of Case 1 is about 30.0 mg N/L, the nitrite nitrogen of Case 2 is about 33.0 mg N/L, and the ammonia nitrogen of Case 3 is about 15.0 mg N/L and nitrite Nitrogen is about 15.0 mg N/L. In addition,'Δmg NH ₃ -N/hr' is the concentration of ammonia nitrogen removed by nitrification for about 1 hour and indicates the activity of AOB. 'Δmg NO ₃ -N/hr' is the concentration of nitrate nitrogen produced for about 1 hour and indicates the activity of NOB. In addition,'NO ₂ /NO _x Х 100 (%)' is the ratio of nitrite nitrogen to nitrite nitrogen and nitrate nitrogen, and the higher the value, the higher the activity of AOB than the activity of NOB, and NOB was effectively suppressed. it means.

In Table 1, HA10 is exposed to about 10 mg/L of hydroxylamine for about 10 minutes, HA20 is exposed to about 20 mg/L of hydroxylamine for about 10 minutes, and HA40 is exposed to about 40 mg/L of hydroxylamine. It means about 10 minutes exposure, HZ10 is about 10 minutes exposure to hydrazine about 10 mg/L, HZ20 is about 10 minutes exposure to about 20 mg/L hydrazine, HZ40 is about 40 mg/L hydrazine. It means 10 minutes exposure, AM250 is about 10 minutes exposure to ammonia nitrogen (NH ₄ ⁺ -N) about 250 mg/L, AM500 is about 10 minutes exposure to ammonia nitrogen about 500 mg/L, AM1000 is ammonia This means about 10 minutes of exposure to about 1000 mg/L of sexual nitrogen. Also, Con means that no action has been taken (control).

Referring to Table 1, in the control group that did not take any action on the flow carrier, no accumulation of nitrite nitrogen was observed in all cases (Case 1, Case 2, and Case 3). On the other hand, after exposing the fluid carrier to various inhibitory substances of various concentrations for 10 minutes, nitrification reaction for 3 hours under the conditions of DO 8.0 ± 0.5 mg/L, pH 7.0 ± 0.2, and water temperature 20.0 ± 0.5℃ as a single substrate with ammonia nitrogen In the case of proceeding, the activity of AOB did not change significantly at all hydroxylamine (10.0 mg/L, 20.0 mg/L, 40.0 mg/L) concentrations, but at all concentrations (10.0 mg/L, 20.0 mg/L) in hydrazine. L, 40.0 mg/L), the ammonia oxidation rate was reduced by about 20.0% or more compared to the control. On the other hand, when ammonia nitrogen was used as an inhibitory substance, there was no significant effect on the activity of AOB at 250 mg N/L and 500 mg N/L, but at 1,000 mg N/L, the ammonia nitrogen oxidation rate was about 15.4% compared to the control. It's slowed down. As a result of the above, it can be seen that hydrazine and ammonia nitrogen of 1,000 mg N/L or more can inhibit the activity of AOB to a certain level, and that hydroxylamine has a relatively weak effect of inhibiting AOB activity.

On the other hand, the influence of hydroxylamine, hydrazine, and ammonia nitrogen on inhibition of NOB activity was relatively large compared to that for AOB. In'Case 1'of Table 1, the rate of nitrate nitrogen generation was lower than that of the control group in all inhibitors. Compared to the control experiment, hydroxylamine concentrations of 10.0 mg N/L, 20 mg N/L, and 40.0 mg N/L were inhibited by about 26.5%, about 35.3%, and about 38.2%, respectively, and hydrazine concentrations of 10.0 mg N/L, At 20 mg N/L and 40.0 mg N/L, about 23.5%, about 44.1% and about 58.8% were inhibited, respectively. However, at 250.0 mg N/L, 500 mg N/L, and 1,000.0 mg N/L ammonia nitrogen were inhibited by about 14.7%, about 8.8%, and about 7.4%, respectively. The nitrite nitrogen accumulation rate showed a large difference due to the influence of hydroxylamine, hydrazine, and ammonia nitrogen on the activity of these AOB and NOB bacteria and their degree. In other words, when the ammonia nitrogen concentration was 1,000.0 mg N/L or less, nitrite nitrogen did not accumulate at all, and hydroxylamine was about 23.8%, the maximum at 40.0 mg N/L, and hydrazine was about the maximum at 40.0 mg N/L. 40.4% accumulated. From the above experimental results, it can be seen that exposure of the nitrifying bacteria to ammonia nitrogen for a short time and then immediately to a low concentration ammonia nitrogen has a weak effect on inhibiting NOB activity.

In contrast, when the fluid carrier is exposed to a water tank containing a single substrate of nitrite nitrogen (NO ₂ ^-- N) (nitrite nitrogen concentration about 33.0 mg N/L) (it may correspond to the second treatment tank) (Case 2) The accumulation of nitrite nitrogen was observed in all cases except the control group (5.0% ~ 62.6%). In addition, it was found that as the concentration of the inhibitory substance increased, more nitrite nitrogen was accumulated.

In particular, about 38.4% of nitrite nitrogen was accumulated in the first exposure to 1,000 mg N/L of ammonia inhibitor and exposure to low concentration nitrite nitrogen (about 33.0 mg N/L). It can be seen from Table 1 that NOB activity was significantly suppressed by showing about 48.0 times higher nitrite nitrogen accumulation rate than that of about 0.8% nitrite nitrogen accumulation when exposed to ammonia alone substrate in Table 1.

On the other hand, exposing the fluid carrier to a substrate having a lower concentration of nitrite nitrogen (about 15.0 mg N/L) and ammonia nitrogen (about 15.0 mg N/L) (may correspond to the second treatment tank) (Case 3) Even in the experiment (NH ₄ ⁺ -N + NO ₂ ^-- N in Table 1), the nitrite nitrogen accumulation rate was very high (4.2% ~ 85.5%) in all cases except for the control group.

From this, the flow carrier and granules are first exposed to the inhibitory substance for a very short time (10 minutes) (which may correspond to a selective suppression tank), followed by a second exposure to a low concentration of nitrite nitrogen (nitrite) ( It can be seen that in the case of the second treatment tank), partial nitrification can be maintained very stably, and the NOB activity inhibiting effect is very excellent. In addition, since the remarkable effect of maintaining partial nitrification and inhibiting NOB activity appeared even though the fluid carrier was brought into contact with the inhibitory substance for a short time of about 10 minutes, the selective suppression tank 140 in the nitrogen removal device 100 functions as a rapid suppression tank. We can infer that we can.

In addition, after the fluid carrier is in rapid contact with the inhibitory substance and the first ecological shock is applied, the second ecological shock must be applied by contacting the water tank in which a low concentration of nitrite nitrogen is present sequentially without a recovery period (inhibitor- It can be seen that the effect of inhibiting NOB is remarkable.

Experimental example 2-NOB inhibition depending on the time of contact with inhibitory substances Experiment on the effect

The prepared fluid carrier was exposed to an inhibitory substance (hydroxylamine, hydrazine, ammonia (ammonia nitrogen)) (corresponding to a selection inhibitory tank), and then exposed to ammonia (ammonia nitrogen, NH ₄ ⁺ -N) alone substrate. In case (Case 1), and when exposed to nitrite nitrogen (NO ₂ ^-- N) alone after exposure to the inhibitory substance (may correspond to the second treatment tank) (Case 2), The experimental results for the effect of exposure time on NOB inhibition are shown in Table 2 below.

temperament Nitrification HA10 HA30 HA60 HZ10 HZ30 HZ60 AM10 AM30 AM60 Con NH ₄ ⁺ -N
(Case 1) △mg NH ₃ -N/hr 5.0 4.9 4.6 4.9 3.8 3.9 4.5 4.6 3.6 4.3 △mg NO ₃ -N/hr 3.3 3.9 1.3 4.9 3.8 3.4 4.2 4.5 4.0 4.3 NO ₂ /NOx × 100
(%) 18.5 20.3 68.6 0.0 0.0 12.7 0.0 0.0 0.0 0.0 NO ₂ ^-- N
(Case 2) △mg NO ₃ -N/hr 4.4 3.5 3.1 6.1 6.7 4.3 2.5 1.6 1.4 7.8 NO ₂ /NOx × 100
(%) 38.4 46.1 54.9 15.0 12.6 36.3 51.6 54.7 56.7 0.8

In Table 2, HA10 is exposed to about 10 mg/L of hydroxylamine for about 10 minutes, HA30 is exposed to about 10 mg/L of hydroxylamine for about 30 minutes, and HA60 is exposed to about 10 mg/L of hydroxylamine for about 60 minutes. HZ10 is exposed to about 10 mg/L of hydrazine for about 10 minutes, HZ30 is exposed to about 10 mg/L of hydrazine for about 30 minutes, and HZ60 is exposed to about 10 mg/L of hydrazine for about 60 minutes AM10 is exposed to about 1000 mg/L of ammonia nitrogen (NH ₄ ⁺ -N) for about 10 minutes, AM30 is exposed to about 1000 mg/L of ammonia nitrogen for about 30 minutes, and AM60 is about ammonia nitrogen. This means about 60 minutes of exposure to 1000 mg/L. Con means no action has been taken.

Referring to Table 1, after exposing the fluid carrier to a high concentration (1000 mg/L) ammonia nitrogen inhibitory substance, a water tank containing ammonia (ammonia nitrogen, NH ₄ ⁺ -N) alone substrate (ammonia nitrogen concentration about 30.0) mg N/L), it can be seen that nitrite nitrogen was not accumulated with the control group. However, when the fluid carrier was exposed to hydroxylamine for about 60 minutes (HA60), the accumulation rate of nitrite nitrogen was exceptionally high.

In contrast, in an experiment in which the fluid carrier was exposed to an inhibitory substance and then exposed to a water tank containing low concentration nitrite nitrogen (about 33.0 mg N/L), all except the control showed high nitrite nitrogen accumulation rate. In particular, when exposed to a high concentration ammonia nitrogen (about 1,000 mg N/L) for 10 minutes and then exposed to a tank containing low concentration nitrite nitrogen (AM10), about 51.6% of nitrite nitrogen accumulation was observed. It matches the result of 1.

From this, when the fluid carrier and granules are exposed to an inhibitory substance containing a high concentration of ammonia nitrogen (which may correspond to a selective suppression tank), and sequentially exposed to a water tank containing a low concentration of nitrite nitrogen (corresponding to the second treatment tank) Can be), partial nitrification can be stably maintained, and NOB activity can be effectively inhibited.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention defined in the following claims are also present. It belongs to the scope of rights of

100: nitrogen removal device 110: first treatment tank
120: fluid carrier 130: granules
140: selection suppression tank 150: second treatment tank
160: third treatment tank 170: granule recovery tank

Claims (22)

A first treatment tank comprising a first ammonia-containing sewage inflow, granules containing Anamox bacteria and a fluid carrier carrying ammonia oxidizing bacteria (AOB),
In the first treatment tank, the flow carrier and the granules are introduced, and a selection inhibitor containing an inhibitor selectively inhibiting the activity of nitrite oxidizing bacteria (NOB), and
A second treatment tank including the fluid carrier and the granules, into which the second ammonia-containing sewage is introduced, and introduced from the selection suppression tank,
Including,
The fluid carrier and the granules in the second treatment tank are introduced into the first treatment tank,
In the second treatment tank, selectively inhibiting the activity of nitrite oxidizing bacteria
Nitrogen removal device.
In claim 1,
Wherein in the first processing tank, the ammonia (NH ₃₎ the nitrous acid contained in the first ammonia-containing wastewater by the ammonia-oxidizing bacteria (NO ₂ ^-) to be nitrification section, wherein the nitrous acid by the analog Comox bacteria nitrogen ( Is converted to N ₂ ) and removed,
Wherein the second treatment tank, the ammonia (NH ₃₎ the nitrous acid contained in the second ammonia-containing wastewater by the ammonia-oxidizing bacteria (NO ₂ ^-) to be nitrification section, wherein the nitrous acid by the analog Comox bacteria nitrogen ( A nitrogen removal device that is converted to and removed from N ₂ ).
In claim 1,
A nitrogen removal apparatus further comprising a granule recovery tank in which the granules introduced in the first treatment tank are washed.
In paragraph 3,
A nitrogen removal device in which the granules washed in the granule recovery tank are reintroduced into the first treatment tank.
In claim 1,
A nitrogen removal device in which the ammonia concentration of the second ammonia-containing sewage is greater than the ammonia concentration of the first ammonia-containing sewage.
In claim 1,
A third treatment tank comprising denitrifying bacteria and the granules introduced in the first treatment tank, and in which nitric acid (NO ₃ ⁻ ) produced and introduced in the first treatment tank by the denitrification bacteria is reduced and removed. Nitrogen removal device.
In paragraph 6,
In the third treatment tank, nitrous acid untreated and introduced in the first treatment tank by the anamox bacteria contained in the granules introduced from the first treatment tank is converted into nitrogen (N ₂ ) and removed. Removal device.
In claim 1,
The inhibitory substance is a nitrogen removal device comprising at least one of hydroxylamine, hydrazine, or ammonia nitrogen having a concentration of a predetermined concentration or higher.
In clause 8,
The ammonia nitrogen is a nitrogen removal device having a concentration of 500 mg N / L or more.
In claim 9,
The nitrogen removal device in which the concentration of nitrite nitrogen in the second treatment tank is 100 mg N/L or less.
In claim 1,
The flow carrier includes one or more of polyethylene, polypropylene, polyester, polyurethane, polyvinyl chloride, nylon, or polystyrene. Nitrogen removal device.
In claim 1,
A nitrogen removal device comprising a transfer device for moving the flow carrier and the granules, wherein the transfer device is a vibration damper or a screw pump.
Ammonia (NH ₃₎ contained in the first ammonia-containing sewage introduced from the outside in a first treatment tank including a granule containing anamox bacteria and a fluid carrier loaded with ammonia oxidizing bacteria (AOB) ) to the nitrification section nitrite (NO ₂ ^- first treatment to produce a), and removed by converting the nitrite to nitrogen (N _2),
A selective inhibition step of separating the fluid carrier and the granules in the first treatment tank and supplying them to a selection inhibition tank to selectively inhibit the activity of nitrite oxidizing bacteria (NOB),
The second ammonia-containing wastewater that said flow carrier and nitrite by feeding the granules and the second to nitride portion of the ammonia contained in the ammonia-containing wastewater in the selection billion prepared in Section 2 Processing coming from outside (NO ₂ ^-) to generate And, a second treatment step of converting and removing the nitrous acid into nitrogen (N ₂ ), and
Supplying the fluid carrier and the granules in the second treatment tank to the first treatment tank
Including,
In the second treatment step, selectively inhibiting the activity of nitrite oxidizing bacteria (NOB)
How to remove nitrogen.
In claim 13,
In the first processing step, wherein the ammonia (NH ₃₎ by the ammonia oxidizing bacteria, the nitrite (NO ₂ ^-) and the nitride part, is converted into nitrogen (N ₂₎ the nitrous acid by the analog Comox bacteria,
In the second processing step, by the ammonia oxidizing bacteria, the ammonia (NH ₃₎ is the ^{nitrite-nitrogen} is a nitride and the nitrous acid by the analog Comox bacterial portion is converted into nitrogen (N ₂₎ (NO ₂₎ Removal method.
In claim 13,
A granule washing step of supplying and cleaning the granules in the first treatment tank to a granule recovery tank, and reintroducing the cleaned granules into the first treatment tank.
In paragraph 15,
Prior to the granule washing step,
The first processing is generated in the first treatment tank to supply the granules in Section 3 Processing containing denitrifying bacteria in the crude nitric acid introduced into twos and the third process (NO ₃ ^-) was removed by reducing, the first treatment A nitrogen removal method further comprising a third treatment step of converting and removing nitrous acid untreated in the bath and introduced into the third treatment bath to nitrogen (N ₂ ).
In paragraph 16,
In the third processing step,
The nitrogen removal method in which the nitric acid is reduced by the denitrifying bacteria and the nitrous acid is converted to nitrogen (N ₂ ) by the anamox bacteria contained in the granules.
In claim 13,
In the selective inhibition step,
The nitrogen removal method in which the time that the fluid carrier and the granules stay in the selection suppression tank is 30 minutes or less.
In paragraph 18,
The nitrogen removal device in which the concentration of nitrite nitrogen in the second treatment tank is 100 mg N/L or less.
In claim 13,
The nitrogen removal method in which the ammonia concentration of the second ammonia-containing sewage is greater than the ammonia concentration of the first ammonia-containing sewage.
In claim 13,
The nitrogen removal method in which the second ammonia-containing sewage is supplied to the first treatment tank after passing through the second treatment step.
In claim 13,
Nitrogen removal method further comprising the step of additionally supplying an inhibitory substance to the selection suppression tank.

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