Anammox expanded granular sludge bed reactor and wastewater treatment method thereof

Abstract

The application provides an ammonia oxidation expanded granular sludge bed reactor and a sewage treatment method thereof, and belongs to the technical field of biological denitrification of sewage. The reactor comprises a reactor main body, a reagent adding box connected with the reactor main body, a clean water temporary storage tank, a membrane assembly and a high-pressure gas cylinder connected with the membrane assembly. The reactor is based on a nitrite-dependent anaerobic methane oxidation process. The reactor is inoculated with n-DAMO bacteria after enrichment culture. The n-DAMO bacteria, methane and nitrite are used to realize the ammonia oxidation process in wastewater. The energy and resource consumption in the traditional ammonia oxidation process is greatly saved, the global warming problem caused by greenhouse gas emission is solved, and the implementation of the new ammonia oxidation process is possible.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biological denitrification of sewage, and particularly relates to an ammonia oxidation expanded granular sludge bed reactor and a sewage treatment method thereof. BACKGROUND

[0002] In recent years, with the rapid development of urbanization and the gradual improvement of people's living standards, a large amount of household garbage is produced along with the gradual improvement of people's living standards. The leachate produced by household garbage contains a large amount of ammonia nitrogen. If the wastewater containing high-concentration ammonia nitrogen is not treated in time, it will seep into the water body once, which will cause eutrophication of the water body, threaten water quality safety, and harm human health and the balance of the ecological system. The ammonia oxidation mode in the traditional process needs to go through a complex nitrification-denitrification or nitrification-anaerobic ammonia oxidation pathway, which not only occupies a large space but also consumes a large amount of energy due to complicated operation. Recently, a newly reported microbial nitrogen conversion pathway can disperse the nitric oxide produced by ammonia oxidation into nitrogen and oxygen through a nitric oxide dismutase. The discovery of this key microorganism opens up new possibilities for treating ammonia oxidation in wastewater. Under the mediation of microorganisms, the nitric oxide produced in the ammonia oxidation process can be directly oxidized into nitrogen and oxygen, bypassing the traditional nitrification-denitrification or nitrification-anaerobic ammonia oxidation pathway, greatly saving energy and resources.

[0003] Nitrite-dependent anaerobic methane oxidation (n-DAMO) is a newly discovered process performed by NC10 bacteria, representing a unique link between global carbon and nitrogen cycles. Recent studies have found that there is a gene for a hydroxylamine oxidoreductase-like protein in nitrite-dependent anaerobic methane-oxidizing bacteria, which is the same as that in ammonia-oxidizing bacteria and ammonia-oxidizing archaea. If the hydroxylamine oxidoreductase of n-DAMO bacteria exhibits similar activity to that of aerobic methanogens, it can be imagined that nitrite-dependent anaerobic methane-oxidizing bacteria can simultaneously oxidize methane and ammonia, and reduce nitrite to nitric oxide, which is then converted into nitrogen and oxygen by a nitric oxide dismutase.

[0004] Therefore, there is an urgent need for an ammonia oxidation method that can bypass the traditional nitrification-denitrification or nitrification-anaerobic ammonia oxidation pathway and directly oxidize the nitric oxide produced by ammonia oxidation into oxygen and nitrogen. SUMMARY

[0005] In view of the above problems, the present application provides an ammonia oxidation expanded granular sludge bed reactor and a sewage treatment method thereof.

[0006] The technical scheme of the present application is: an ammonia oxidation expanded granular sludge bed reactor, comprising a reactor main body, a reagent adding box connected with the reactor main body, a clean water temporary storage tank, a membrane assembly, and a high-pressure gas cylinder connected with the membrane assembly.

[0007] The reactor body is provided with a water outlet, an adding port and an overflow port, the reagent adding tank is connected with the adding port, the clean water temporary storage tank is connected with the water outlet, the water inlet side of the membrane assembly is connected with the overflow port, and the water outlet side of the membrane assembly is connected with the adding port;

[0008] The reactor body is provided with a water outlet, an adding port and an overflow port, the reagent adding tank is connected with the adding port, the clean water temporary storage tank is connected with the water outlet, the water inlet side of the membrane assembly is connected with the overflow port, and the water outlet side of the membrane assembly is connected with the adding port;

[0009] The inner circulation reflux pipe comprises a reflux vertical pipe arranged in the reactor body in the vertical direction and provided with a plurality of reflux outlet groups on the side wall from top to bottom, and a horizontal reflux plate arranged on the outer wall of the reflux vertical pipe and located between adjacent two groups of the reflux outlets, each group of the reflux outlets is composed of a plurality of reflux holes distributed in the circumferential direction of the reflux vertical pipe, a plurality of one-way liquid falling ports are uniformly arranged on the horizontal reflux plate, and an expanded sludge bed is arranged in the reactor body and located at the outer wall of the reflux vertical pipe;

[0010] The operating temperature of the expanded sludge bed is 32±1℃, the pH value is 7.0-7.5, and the inoculated bacteria on the expanded sludge bed are n-DAMO bacteria, the operating temperature of the expanded sludge bed is limited to 32±1℃, which is beneficial to maintaining high activity of the bacteria, thereby improving the treatment efficiency of the system, the pH value is between 7.0-7.5, which is beneficial to maintaining stable growth of the n-DAMO bacteria, because the pH value range is close to the isoelectric point of most bacteria, so that the bacteria surface is negatively charged, which is beneficial to its adsorption and metabolism in sewage;

[0011] The pressure in the membrane cavity in the membrane assembly is 80kpa, and the gas stored in the high-pressure gas cylinder is a mixture of 95% methane and 5% carbon dioxide, the pressure in the membrane cavity in the membrane assembly is limited to 80kpa, which is helpful to increase the solubility of the gas in water, thereby improving the gas utilization rate, and the mixed gas of accurately proportioned methane and carbon dioxide can provide the most suitable growth environment for the n-DAMO bacteria, thereby improving the growth rate and ammonia removal efficiency.

[0012] Further, the water distributor comprises a water distribution main pipe connected with the adding port, a plurality of water distribution pipe racks arranged on the outer wall of the water distribution main pipe, and a plurality of water distribution holes arranged on the side wall of the water distribution pipe rack, the water distribution pipe rack is composed of a plurality of water distribution branch pipes, one end of the water distribution branch pipe is connected with the side wall of the water distribution main pipe in a penetrating manner, and the other end is distributed in a diverging manner, and a plurality of water distribution holes are arranged on each water distribution branch pipe.

[0013] Description: When the sewage in the reagent adding box enters the reactor main body, it is distributed to each water distribution branch pipe through the water distribution main pipe, and is uniformly sprayed through each water distribution hole on the water distribution branch pipe, ensuring that the flow rate and distribution of the sewage in the reactor main body can be flexibly controlled, reducing turbulence and vortex, improving the stability of the water flow, and ensuring the stable operation of the reactor main body.

[0014] Further, each water distribution hole is provided with an anti-blocking cover, the anti-blocking cover includes an anti-blocking cover body provided outside the water distribution hole and uniformly provided with a plurality of vertical water distribution openings in the circumferential direction, a sliding cover connected with the anti-blocking cover body through a micro spring, and a blocking plate provided on the side wall of the sliding cover and slidingly connected with the vertical water distribution openings one by one.

[0015] Description: When the water flow flows out of each water distribution hole, the water flow pushes the sliding cover to press the micro spring, so that the blocking plate moves upward in the vertical water distribution opening. At this time, the water flow flows out through each vertical water distribution opening. When there is no water flow, each vertical water distribution opening is blocked by the inner wall of the sliding cover, which can prevent each water distribution hole from being blocked and reduce the need for manual cleaning and maintenance. It can adapt to changes in different flow rates, because the opening degree of the water distribution hole will automatically adjust with the change of water flow pressure, ensuring uniform water distribution under different flow rates.

[0016] Further, an external circulation system is provided between the water outlet and the reagent adding box, the external circulation system includes an external circulation tank, an external circulation pipeline provided between the reagent adding box and the external circulation tank and between the water outlet and the external circulation tank, a reflux control valve and a circulating pump provided at the external circulation pipeline between the water outlet and the external circulation tank.

[0017] Description: The external circulation pipeline connects the reagent adding box, the water outlet and the external circulation tank to form a closed circulation path, so that part of the treated sewage can be returned to the reactor main body for further treatment, improving the removal rate of pollutants, especially for difficult-to-degrade organic matter and nitrogen compounds. Multiple cycle treatment can significantly improve the removal efficiency. The reflux control valve is used to adjust the amount of water returned to the reactor main body, and the circulating pump is responsible for driving the flow of sewage in the external circulation pipeline to ensure that the sewage can smoothly return to the reactor main body from the external circulation tank.

[0018] Further, a plurality of reflux channels are provided in the external circulation tank in a matrix distribution and downwardly inclined, and a flow collecting cover is provided on the outer wall of the external circulation tank and corresponds to the upper end position of each reflux channel. Each reflux channel is connected with the water outlet through a connecting pipe at the downwardly inclined end, and a plurality of flow expansion connecting pipes are provided on the reflux channel.

[0019] Description: The outer circulation tank is used for temporarily storing the treated water flow from the water outlet of the reactor main body, the water flow first enters the collecting hood, and is then distributed to each reflux channel, and finally flows out of the outer circulation tank, in the process, it is ensured that the water flow can be uniformly dispersed into each reflux channel, which helps to maintain the hydraulic balance of the entire system, the downward inclined design of the reflux channel increases the flow rate of the water flow, which helps to improve the circulation efficiency of the entire outer circulation system, and in each expansion connecting pipe, the impact force of the water flow can be buffered, reducing the vortex and turbulent flow formed in the reflux channel, which helps to reduce energy loss and improve the overall efficiency of the system.

[0020] Further, the outer circulation tank side wall is provided with a sliding adjusting plate penetrating the collecting hood at the bottom end and being in sliding connection with the collecting hood inner wall, the outer circulation tank upper end is provided with a reverse U-shaped mounting rack distributed opposite to the sliding adjusting plate, the reverse U-shaped mounting rack is vertically distributed with a horizontal lifting plate inside, one end of the horizontal lifting plate is connected with the reverse U-shaped mounting rack top end through a hydraulic cylinder, and the other end is connected with the sliding adjusting plate side wall.

[0021] Description: Since each reflux channel is distributed in a matrix shape, the water flow can be adjusted by shielding part of the sliding adjusting plate, specifically, according to the needs, the hydraulic cylinder is started, and the horizontal lifting plate is driven to move upward through the compression action of the hydraulic cylinder, at this time, the sliding adjusting plate also moves synchronously, so as to achieve the effect of adjusting the water flow, the water flow can be quickly adjusted according to the actual treatment demand and water quality change, and the flexibility and adaptability of the system are improved.

[0022] The application also discloses a sewage treatment method based on the ammonia oxidation expanded granular sludge bed reactor.

[0023] S1, after the n-DAMO bacteria are enriched, the bacteria are inoculated on the expanded sludge bed, the operation temperature of the reactor main body is controlled to be 32±1 DEG C, the pH value is controlled to be 7.0-7.5, and the pressure in the membrane cavity of the membrane assembly is controlled to be 80 kpa;

[0024] S2, in the initial stage of reaction, the wastewater containing nitrite in the reagent adding box is introduced into the reactor main body through the adding port, meanwhile, the mixed gas of methane and carbon dioxide in the high-pressure gas cylinder is introduced into the membrane assembly and dissolved in water to form a reaction solution, and the reaction solution is introduced into the reactor main body through the adding port and provides a growth substrate for the inoculated n-DAMO bacteria on the expanded sludge bed;

[0025] S3, in the continuous phase of the reaction, continue to pass into the wastewater into the reactor main body through the adding port, at this time, the wastewater is uniformly dispersed in the reactor main body by the water distributor, with the increase of the water inflow in the reactor main body, the wastewater enters the reflux standpipe through the adding port, and flows into the expanded sludge bed through the reflux holes in the side wall of the reflux standpipe, and is uniformly dispersed through the one-way liquid falling port on each horizontal reflux plate;

[0026] S4, finally, the n-DAMO bacteria inoculated on the expanded sludge bed remove the nitrite and ammonia in the wastewater by using methane, the methane not completely used is recycled into the membrane assembly through the overflow port for continuous use, and the treated clear water flows into the clear water temporary storage tank through the water outlet.

[0027] Compared with the prior art, the beneficial effects of the present application are:

[0028] The ammonia oxidation expanded granular sludge bed reactor of the present application is based on the nitrite-dependent anaerobic methane oxidation process, the reactor is inoculated with n-DAMO bacteria enriched and cultured, the n-DAMO bacteria, methane and nitrite are used to realize the ammonia oxidation process in the wastewater, which greatly saves the energy and resource consumption in the traditional ammonia oxidation process, solves the global warming problem caused by greenhouse gas emission, and provides the possibility for the implementation of the new ammonia oxidation process; meanwhile, the reactor is also provided with an internal circulation reflux pipe, so that the water flow is internally circulated in the reactor, which can ensure the uniform distribution of the microorganisms, methane and nitrite in the reactor, can reduce the dead zone in the reactor, and thus improve the working efficiency of the whole reactor, the external circulation system is arranged outside the reactor, which can reflux part of the treated water to the water inlet of the reactor, so that the water quality can be further optimized without affecting the main reaction process, and the removal rate of pollutants can be improved, especially for the refractory organic matter and nitrogen compounds, multiple circulation treatment can significantly improve the removal efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is the overall structure schematic diagram of the present application;

[0030] Figure 2 is the internal structure schematic diagram of the reactor main body of the present application;

[0031] Figure 3 is the installation structure schematic diagram of the internal circulation reflux pipe of the present application;

[0032] Figure 4 is the external structure schematic diagram of the anti-blocking cover main body of the present application;

[0033] Figure 5 is the internal structure schematic diagram of the anti-blocking cover main body of the present application;

[0034] Figure 6 is the internal structure schematic diagram of the external circulation tank of the present application;

[0035] Figure 7 is the installation structure schematic diagram of the inverted U-shaped mounting bracket on the upper end of the external circulation tank of the present application;

[0036] Wherein, 1-reactor main body, 10-inlet, 100-three-phase separator, 11-outlet, 12-addition port, 13-overflow port, 14-distributor, 140-distributor main pipe, 141-distributor pipe bracket, 142-distributor hole, 143-distributor branch pipe, 15-internal circulation reflux pipe, 150-reflux outlet, 151-reflux vertical pipe, 152-horizontal reflux plate, 153-reflux hole, 154-one-way liquid falling port, 155-swelling sludge bed, 16-anti-blocking cover, 160-vertical water distribution port, 161-anti-blocking cover main body, 162-micro spring, 163-sliding cover, 164-plugging plate, 3-reagent addition tank, 4-fresh water temporary storage tank, 5-membrane assembly, 6-high-pressure gas cylinder, 7-external circulation system, 70-external circulation tank, 700-reflux channel, 701-flow collection cover, 702-flow expansion connecting pipe, 703-sliding adjustment plate, 704-inverted U-shaped mounting bracket, 705-horizontal lifting plate, 706-hydraulic cylinder, 71-external circulation pipeline, 72-reflux control valve, 73-circulation pump. DETAILED DESCRIPTION

[0037] In order to further understand the content of the present application, the present application is described in detail through the following examples.

[0038] Example 1

[0039] As shown in the drawing, an ammonia oxidation swelling granular sludge bed reactor comprises a reactor main body 1, a reagent addition tank 3 connected with the reactor main body 1, a fresh water temporary storage tank 4, a membrane assembly 5, and a high-pressure gas cylinder 6 connected with the membrane assembly 5. Figure 1 The reactor main body 1 is provided with an inlet 10, an outlet 11, an addition port 12, and an overflow port 13. The reagent addition tank 3 is connected with the addition port 12. The fresh water temporary storage tank 4 is connected with the outlet 11. The inlet side of the membrane assembly 5 is connected with the overflow port 13. The outlet side of the membrane assembly 5 is connected with the addition port 12.

[0040] The reactor main body 1 is provided with an inlet 10, an outlet 11, an addition port 12, and an overflow port 13. The reagent addition tank 3 is connected with the addition port 12. The fresh water temporary storage tank 4 is connected with the outlet 11. The inlet side of the membrane assembly 5 is connected with the overflow port 13. The outlet side of the membrane assembly 5 is connected with the addition port 12.

[0041] The reactor main body 1 is provided with an inlet 10, an outlet 11, an addition port 12, and an overflow port 13. The reagent addition tank 3 is connected with the addition port 12. The fresh water temporary storage tank 4 is connected with the outlet 11. The inlet side of the membrane assembly 5 is connected with the overflow port 13. The outlet side of the membrane assembly 5 is connected with the addition port 12.

[0042] Figure 2 , 3 ​As shown, the inner circulation reflux pipe 15 includes a reflux vertical pipe 151 arranged inside the reactor body 1 in the vertical direction and having a plurality of reflux outlet groups 150 arranged on the side wall from top to bottom, and a horizontal reflux plate 152 arranged on the outer wall of the reflux vertical pipe 151 and located between adjacent two reflux outlet groups 150. Each reflux outlet group 150 is composed of four reflux holes 153 distributed in the circumferential direction of the reflux vertical pipe 151. The horizontal reflux plate 152 is uniformly provided with ten one-way liquid falling ports 154. An expanded sludge bed 155 is arranged inside the reactor body 1 and located at the outer wall of the reflux vertical pipe 151. The sewage is uniformly dispersed in the reactor body 1 by the water distributor 14. With the increase of the water inflow in the reactor body 1, the sewage flows into the expanded sludge bed 155 from the bottom end of the reflux vertical pipe 151 and through each reflux hole 153 in the side wall of the reflux vertical pipe 151, and is uniformly dispersed through each one-way liquid falling port 154 on each horizontal reflux plate 152. In this way, the water flow is internally circulated in the reactor, which can ensure the uniform distribution of microorganisms, methane and nitrite in the reactor, can reduce the dead zone in the reactor, and thus improve the working efficiency of the entire reactor.

[0043] Among them, the membrane assembly 5, the water distributor 14, and the three-phase separator 100 all adopt the prior art.

[0044] The operating temperature of the expanded sludge bed 155 is 31℃, and the pH value is 7.0. The bacteria inoculated on the expanded sludge bed 155 are n-DAMO bacteria. The operating temperature of the expanded sludge bed 155 is limited to 32±1℃, which is beneficial to maintaining high activity of the bacteria and thus improving the treatment efficiency of the system. The pH value is between 7.0 and 7.5, which is beneficial to maintaining stable growth of the n-DAMO bacteria, because this pH value range is close to the isoelectric point of most bacteria, so that the bacteria surface is negatively charged, which is beneficial to its adsorption and metabolism in the sewage.

[0045] The pressure in the membrane cavity of the membrane assembly 5 is 80kpa. The gas stored in the high-pressure gas cylinder 6 is a mixture of 95% methane and 5% carbon dioxide. The pressure in the membrane cavity of the membrane assembly 5 is limited to 80kpa, which is helpful to increase the solubility of the gas in water, thereby improving the gas utilization rate. The mixed gas of accurately proportioned methane and carbon dioxide can provide the most suitable growth environment for the n-DAMO bacteria, thereby improving the growth rate and ammonia removal efficiency thereof.

[0046] Example 2

[0047] The difference between this embodiment and Example 1 is that:

[0048] The operating temperature of the expanded sludge bed 155 is 33℃, and the pH value is 7.5. The bacteria inoculated on the expanded sludge bed 155 are n-DAMO bacteria.

[0049] Example 3

[0050] The present embodiment describes a sewage treatment method based on the ammonia oxidation expanded granular sludge bed reactor of embodiment 1, comprising the following steps:

[0051] S1, after enriching n-DAMO bacteria, inoculate them on the expanded sludge bed 155, control the operating temperature of the reactor body 1 to be 31℃, the pH value to be 7.0, and the pressure in the membrane cavity of the membrane assembly 5 to be 80kpa;

[0052] S2, in the initial stage of the reaction, the wastewater containing nitrite in the reagent adding box 3 is introduced into the reactor body 1 through the adding port 12, at the same time, the mixed gas of methane and carbon dioxide in the high-pressure gas cylinder 6 is introduced into the membrane assembly 5 and dissolved in water to form a reaction solution, and the reaction solution is introduced into the reactor body 1 through the adding port 12, and provides growth substrate for the n-DAMO bacteria inoculated on the expanded sludge bed 155;

[0053] S3, in the continuous stage of the reaction, wastewater is continuously introduced into the reactor body 1 through the adding port 12, at this time, the wastewater is uniformly dispersed in the reactor body 1 by the water distributor 14, as the water inflow in the reactor body 1 increases, the wastewater enters the reflux vertical pipe 151 through the adding port 12, and flows into the expanded sludge bed 155 through the reflux holes 153 on the side wall of the reflux vertical pipe 151, and is uniformly dispersed through the one-way liquid falling ports 154 on the horizontal reflux plates 152;

[0054] S4, finally, the n-DAMO bacteria inoculated on the expanded sludge bed 155 remove the nitrite and ammonia in the wastewater by using methane, the methane that is not completely used is recycled into the membrane assembly 5 through the overflow port 13 for continuous use, and the treated clear water flows into the clear water temporary storage box 4 through the water outlet 11 for temporary storage.

[0055] Embodiment 4

[0056] The difference between the present embodiment and embodiment 3 is:

[0057] In step S1, the operating temperature of the reactor body 1 is controlled to be 33℃, and the pH value is controlled to be 7.5.

[0058] Embodiment 5

[0059] The difference between the present embodiment and embodiment 2 is:

[0060] As Figure 2 , 4As shown in FIG. 5, the water distributor 14 includes a water distribution main pipe 140 connected with the adding port 12, two water distribution pipe frames 141 arranged on the outer wall of the vertical section of the water distribution main pipe 140, and five water distribution holes 142 arranged on the side wall of the water distribution pipe frame 141. The water distribution pipe frame 141 is composed of ten water distribution branch pipes 143, one end of which is connected with the side wall of the water distribution main pipe 140, and the other end of which is distributed in a divergent manner. Five water distribution holes 142 are arranged on each water distribution branch pipe 143, so as to ensure that the flow rate and distribution of the sewage in the reactor main body 1 can be flexibly controlled, the turbulence and vortex are reduced, the stability of the water flow is improved, and the stable operation of the reactor main body 1 is ensured.

[0061] A blockage prevention cover 16 is arranged at each water distribution hole 142. The blockage prevention cover 16 includes a blockage prevention cover main body 161 arranged outside the water distribution hole 142 and uniformly provided with four vertical water distribution ports 160 in the circumferential direction, a sliding cover 163 connected with the blockage prevention cover main body 161 through a micro spring 162, and a blocking plate 164 arranged on the side wall of the sliding cover 163 and slidingly connected with the vertical water distribution ports 160 one by one. The micro spring 162 is of the prior art. When there is no water flow, each vertical water distribution port 160 is blocked by the inner wall of the sliding cover 163, so as to prevent each water distribution hole 142 from being blocked, reduce the need for manual cleaning and maintenance, and adapt to the change of different flow rates, because the opening degree of the water distribution hole 142 will be automatically adjusted with the change of the water flow pressure, so as to ensure uniform water distribution under different flow rates.

[0062] Example 6

[0063] The difference between this embodiment and example 4 is that:

[0064] In step S3, when the sewage in the reagent adding tank 3 enters the reactor main body 1 through the water inlet 10, the water is distributed to each water distribution branch pipe 143 through the water distribution main pipe 140, and is uniformly sprayed through each water distribution hole 142 on the water distribution branch pipe 143. When the water flows out of each water distribution hole 142, the sliding cover 163 is pushed to compress the micro spring 162, so that the blocking plate 164 moves upward in the vertical water distribution port 160. At this time, the water flows out through each vertical water distribution port 160. When there is no water flow, each vertical water distribution port 160 is blocked by the inner wall of the sliding cover 163, so as to prevent each water distribution hole 142 from being blocked.

[0065] Example 7

[0066] The difference between this embodiment and example 5 is that:

[0067] As Figure 1 、 6As shown in FIG. 7, the water outlet 11 and the reagent adding tank 3 are provided with an external circulation system 7, the external circulation system 7 comprises an external circulation tank 70, an external circulation pipeline 71 arranged between the reagent adding tank 3 and the external circulation tank 70 and between the water outlet 11 and the external circulation tank 70, a backflow control valve 72 and a circulating pump 73 arranged at the external circulation pipeline 71 between the water outlet 11 and the external circulation tank 70, wherein the backflow control valve 72 and the circulating pump 73 are of the prior art, so that the treated part of the sewage can be returned to the reactor main body 1 for reprocessing, thereby improving the removal rate of pollutants, and especially for the refractory organic matter and nitrogen compounds, multiple circulation treatment can significantly improve the removal efficiency.

[0068] The external circulation tank 70 is provided with nine backflow channels 700 distributed in a matrix shape and inclined downward, and the external wall of the external circulation tank 70 is provided with a flow collector 701 corresponding to the upper end position of each backflow channel 700. Each backflow channel 700 is connected to the water outlet 11 through a connecting pipe at the end inclined downward. The backflow channel 700 is provided with five flow expansion connecting pipes 702. The external circulation tank 70 is used for temporarily storing the treated water flow from the water outlet 11 of the reactor main body 1. The water flow first enters the flow collector 701 and is then distributed to each backflow channel 700, and finally flows out of the external circulation tank 70. In this process, it is ensured that the water flow can be uniformly dispersed into each backflow channel 700, which helps to maintain the hydraulic balance of the entire system. The design of the backflow channel 700 inclined downward increases the flow rate of the water flow, which helps to improve the circulation efficiency of the entire external circulation system 7. In each flow expansion connecting pipe 702, the impact force of the water flow can be buffered, and the vortex and turbulent flow formed in the backflow channel 700 can be reduced, which helps to reduce energy loss and improve the overall efficiency of the system.

[0069] The side wall of the external circulation tank 70 is provided with a sliding adjustment plate 703 penetrating the flow collector 701 at the bottom end and slidingly connected with the inner wall of the flow collector 701. The upper end of the external circulation tank 70 is provided with a reverse U-shaped mounting bracket 704 distributed opposite to the sliding adjustment plate 703. The reverse U-shaped mounting bracket 704 is vertically provided with a horizontal lifting plate 705 inside. One end of the horizontal lifting plate 705 is connected to the top end of the reverse U-shaped mounting bracket 704 through a hydraulic cylinder 706, and the other end is connected to the side wall of the sliding adjustment plate 703. The flow expansion connecting pipe 702 and the hydraulic cylinder 706 are of the prior art. Since each backflow channel 700 is distributed in a matrix shape, part of the backflow channel 700 can be shielded by the sliding adjustment plate 703 to adjust the water flow. The water flow can be quickly adjusted according to the actual processing requirements and water quality changes, thereby improving the flexibility and adaptability of the system.

[0070] Example 8

[0071] The difference between this embodiment and example 6 is that:

[0072] S5, the outer circulation pipeline 71 connects the reagent adding tank 3, the water outlet 11 and the outer circulation pool 70, forming a closed circulation path, so that the treated part of the sewage can be returned to the reactor main body 1 for reprocessing, the backflow control valve 72 is used to adjust the amount of water flowing back to the reactor main body 1, the circulating pump 73 is responsible for driving the flow of sewage in the outer circulation pipeline 71, ensuring that the sewage can smoothly return to the reactor main body 1 from the outer circulation pool 70, the outer circulation pool 70 is used to temporarily store the treated water flowing out of the water outlet 11 of the reactor main body 1, which first enters the flow collector 701 and then flows into each backflow channel 700, and finally flows out of the outer circulation pool 70, in the process, it is ensured that the water flow can be evenly distributed to each backflow channel 700, and since each backflow channel 700 is distributed in a matrix shape, part of the sliding adjustment plate 703 can be shielded to adjust the water flow, specifically, according to the needs, the hydraulic cylinder 706 is started, and the horizontal lifting plate 705 is driven to move upward by the compression action of the hydraulic cylinder 706, at this time, the sliding adjustment plate 703 also moves synchronously, so as to achieve the effect of adjusting the water flow.

[0073] Test example

[0074] In the laboratory, the concentration of nitrite solution is 40gNO2 - -NL -1 , and the wastewater is continuously injected into the reactor main body 1, the operating temperature of the reactor main body 1 is controlled at 32±1℃, the pH value is controlled at 7.0-7.5, the pressure in the membrane cavity of the membrane assembly 5 is controlled at 80kpa, in the initial stage of the reaction, liquid samples are taken from the reactor main body 1 every day, the concentration of nitrite solution in the liquid sample is detected, and the concentration of nitrite solution in the liquid sample is increased to 1-20mgNO2 - -NL -1 by adding nitrite concentrate to the liquid sample in the reagent adding tank 3, in the continuous reaction stage, when the consumption rate of nitrite solution in the reactor main body 1 is 278mgNO2 - -NL -1 d -1 , the wastewater with a concentration of 40gNO2 - -NL -1 of nitrite solution is continuously configured, and ammonia with a concentration of 100mg / L is added to form synthetic wastewater, then the synthetic wastewater is continuously introduced into the reactor main body 1, when the ammonia is introduced for 0-5 days, the ammonia ion load rate is 0.8mgN -1 d -1 , when the ammonia is introduced for 6-10 days, the ammonia ion load rate is 1.6mgN - 1 d -1 , when the ammonia is introduced for 10-15 days, the ammonia ion load rate is 2.4mgN -1 d-1 At the 16th day, the ammonia ion loading rate was increased to 3.2 mgNL -1 d -1 During the whole reaction, the ammonia ion consumption rate was 3.1 mgNL -1 d -1 After the reaction, the ammonia ion concentration in the effluent was stabilized at about 0.06 mgNL -1 , and during the whole continuous operation, the nitrite concentration remained stable and was not accumulated in the effluent, and the consumption rate was maintained at 278 mgNO2 - -NL -1 d -1 ;

[0075] During the above test, the ammonia ion concentration in the influent of the reactor of the application was 100 mg / L, and the ammonia ion concentration in the effluent was stabilized at about 0.06 mgNL -1 , and the calculation showed that the ammonia removal rate of the reactor of the application reached 99.4%, and thus it can be known that the reactor of the application bypasses the traditional nitrification-denitrification or nitrification-anaerobic ammonia oxidation pathway, and directly oxidizes ammonia, that is, ammonia oxidation process in wastewater is realized by using n-DAMO bacteria, methane and nitrite, which not only greatly saves the energy and resource consumption in the traditional ammonia oxidation process, but also achieves the effect of ammonia oxidation, and the role of nitrite is to improve the activity of n-DAMO bacteria and ensure the reliable progress of the ammonia oxidation process.

Claims

1. An ammonia oxidation expanded granular sludge bed reactor, characterized in that, It includes a reactor body (1), a reagent addition tank (3) connected to the reactor body (1), a clean water storage tank (4), a membrane module (5), and a high-pressure gas cylinder (6) connected to the membrane module (5); The reactor body (1) is provided with an outlet (11), an addition port (12) and an overflow port (13). The reagent addition tank (3) is connected to the addition port (12), the clear water storage tank (4) is connected to the outlet (11), the inlet side of the membrane module (5) is connected to the overflow port (13), and the outlet side of the membrane module (5) is connected to the addition port (12). The reactor body (1) is equipped with a water distributor (14) connected to the addition port (12) at the bottom of the interior. An internal circulation return pipe (15) is provided inside the reactor body (1) and above the water distributor (14). A three-phase separator (100) is provided at the top of the reactor body (1). The internal circulation return pipe (15) includes a return vertical pipe (151) arranged vertically inside the reactor body (1) and having multiple sets of return outlets (150) on its sidewall from top to bottom; a horizontal return plate (152) arranged on the outer wall of the return vertical pipe (151) and located between two adjacent sets of return outlets (150); each set of return outlets (150) is composed of multiple return holes (153) distributed circumferentially along the return vertical pipe (151); multiple one-way liquid inlets (154) are uniformly arranged on the horizontal return plate (152); and an expanded sludge bed (155) is provided inside the reactor body (1) and on the outer wall of the return vertical pipe (151). The operating temperature of the expanded sludge bed (155) is 32±1℃, the pH value is 7.0-7.5, and the bacteria inoculated on the expanded sludge bed (155) are n-DAMO bacteria; The membrane chamber pressure in the membrane module (5) is 80 kPa, and the gas stored in the high-pressure gas cylinder (6) is a mixture of 95% methane and 5% carbon dioxide.

2. The ammonia oxidation expanded granular sludge bed reactor according to claim 1, characterized in that, The water distributor (14) includes a main water distribution pipe (140) connected to the addition port (12), a plurality of water distribution pipe supports (141) provided on the outer wall of the main water distribution pipe (140), and a plurality of water distribution holes (142) provided on the side wall of the water distribution pipe supports (141). The water distribution pipe supports (141) are composed of a plurality of water distribution branch pipes (143), and one end of the water distribution branch pipes (143) is connected through to the side wall of the main water distribution pipe (140), and the other end is distributed in a divergent manner. Each water distribution branch pipe (143) is provided with a plurality of water distribution holes (142).

3. The ammonia oxidation expanded granular sludge bed reactor according to claim 2, characterized in that, Each of the water distribution holes (142) is provided with an anti-clogging cover (16). The anti-clogging cover (16) includes an anti-clogging cover body (161) located outside the water distribution hole (142) and having a plurality of vertical water distribution ports (160) evenly distributed along the circumference, a sliding cover (163) connected to the anti-clogging cover body (161) by a micro spring (162), and a sealing plate (164) located on the side wall of the sliding cover (163) and slidably connected to the vertical water distribution ports (160) one by one.

4. The ammonia oxidation expanded granular sludge bed reactor according to claim 1, characterized in that, An external circulation system (7) is provided between the water outlet (11) and the reagent addition tank (3). The external circulation system (7) includes an external circulation tank (70), an external circulation pipeline (71) located between the reagent addition tank (3) and the external circulation tank (70) and between the water outlet (11) and the external circulation tank (70), a reflux control valve (72) located at the external circulation pipeline (71) between the water outlet (11) and the external circulation tank (70), and a circulation pump (73).

5. The ammonia oxidation expanded granular sludge bed reactor according to claim 4, characterized in that, The external circulation pool (70) is provided with multiple return channels (700) arranged in a matrix and inclined downwards. The outer wall of the external circulation pool (70) is provided with a flow collection hood (701) corresponding to the upper position of each return channel (700). The downward inclined end of each return channel (700) is connected to the outlet (11) through a connecting pipe. Multiple flow expansion connecting pipes (702) are provided on the return channel (700).

6. The ammonia oxidation expanded granular sludge bed reactor according to claim 5, characterized in that, The side wall of the external circulation pool (70) is provided with a sliding adjustment plate (703) whose bottom end penetrates through the flow collector (701) and is slidably connected to the inner wall of the flow collector (701). The upper end of the external circulation pool (70) is provided with an inverted U-shaped mounting bracket (704) that is distributed opposite to the sliding adjustment plate (703). The inverted U-shaped mounting bracket (704) has a horizontal lifting plate (705) vertically distributed inside. One end of the horizontal lifting plate (705) is connected to the top of the inverted U-shaped mounting bracket (704) through a hydraulic cylinder (706), and the other end is connected to the side wall of the sliding adjustment plate (703).

7. A wastewater treatment method, based on an ammonia oxidation expanded granular sludge bed reactor according to any one of claims 1-6, characterized in that, Includes the following steps: S1. After enriching n-DAMO bacteria, inoculate them onto the expanded sludge bed (155), control the operating temperature of the reactor body (1) to be 32±1℃, the pH value to be 7.0-7.5, and control the pressure inside the membrane chamber of the membrane module (5) to be 80kpa. S2. In the initial stage of the reaction, the wastewater in the reagent addition tank (3) is introduced into the reactor body (1) through the addition port (12). At the same time, the mixed gas of methane and carbon dioxide in the high-pressure gas cylinder (6) is introduced into the membrane module (5) and dissolved in the water to form a reaction solution. The reaction solution is introduced into the reactor body (1) through the addition port (12) to provide growth substrate for the n-DAMO bacteria inoculated on the expanded sludge bed (155). S3. During the continuous reaction stage, wastewater is continuously introduced into the reactor body (1) through the addition port (12). At this time, the wastewater is evenly dispersed in the reactor body (1) through the water distributor (14). As the amount of water entering the reactor body (1) increases, the wastewater enters the return pipe (151) through the addition port (12), flows into the expanded sludge bed (155) through each return hole (153) on the side wall of the return pipe (151), and is evenly dispersed through each one-way liquid outlet (154) on each horizontal return plate (152). S4. Finally, the n-DAMO bacteria inoculated on the expanded sludge bed (155) use methane to remove nitrite and ammonia from the wastewater. The unused methane is recycled back into the membrane module (5) through the overflow port (13) for continued use. The treated clean water flows into the clean water storage tank (4) through the outlet (11) for temporary storage.

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