An anaerobic ammonia oxidation device and its application

Abstract

This invention provides an anaerobic ammonia oxidation device and its application. The device maintains an oxygen-deficient state by introducing nitrogen gas into the device to eliminate dissolved oxygen in the water. Furthermore, the nitrogen inlet is positioned at the top of the packing layer, effectively preventing excessive shedding of the anaerobic ammonia oxidation biofilm from the support layer and packing layer. In addition, this invention improves denitrification efficiency and maintains long-term stable operation of the anaerobic ammonia oxidation device through various methods, including installing a packing baffle at the outlet of the anaerobic reactor to reduce packing loss, installing dissolved oxygen meters in both the anaerobic reactor and the circulating water tank to improve the accuracy of dissolved oxygen monitoring, and implementing a temperature control system in the straight pipe section of the anaerobic reactor to regulate the reaction temperature. Applying this device to the denitrification treatment of nitrogen-containing wastewater demonstrates high denitrification efficiency and promising development prospects.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically an anaerobic ammonia oxidation device and its application. Background Technology

[0002] With the continuous improvement of China's industrialization and urbanization, water pollution problems are becoming increasingly serious, especially with the large influx of nitrogenous pollutants into water bodies, leading to eutrophication and black, odorous water. If these water problems are not addressed promptly, pollution will worsen with continued economic development, and the negative impacts will become increasingly severe. Methods for removing nitrogenous pollutants from water include physical, chemical, and biological methods. Compared to physical and chemical methods, biological methods have gained significant attention due to their advantages such as low cost, ease of operation, and lack of secondary pollution. Traditional wastewater treatment projects generally employ nitrification / denitrification processes to remove nitrogen from wastewater. However, nitrification / denitrification processes require sufficient aeration for nitrification and a sufficient amount of organic carbon source for denitrification. Even short-cut nitrification / denitrification processes, which are improvements on conventional nitrification / denitrification processes, still require oxygen and organic carbon sources. Anaerobic ammonia oxidation is a novel biological nitrogen removal technology, highly regarded for its high efficiency, low operating costs, and low sludge production when treating wastewater containing high ammonia nitrogen.

[0003] Anaerobic ammonia oxidation technology refers to the process where microorganisms use CO2 or H2CO3 as a carbon source and NH4+ as an active ingredient under anaerobic or hypoxic conditions. + -N, NO2 - A nitrogen removal method uses nitrogen as a substrate and converts it into nitrogen (N2) before releasing it into the atmosphere. Some studies have shown that anaerobic ammonia oxidation (ANAO) technology has good economic and ecological benefits in removing nitrogen from wastewater. However, most current research combines ANAO with other nitrogen removal technologies to achieve efficient nitrogen removal. Patent application CN110127845A discloses an integrated autotrophic nitrogen removal reactor and its wastewater treatment process using immobilized aerobic and anaerobic ammonia-oxidizing bacteria. By coupling immobilization technology with short-cut nitrification-anaerobic ammonia oxidation technology, it can effectively remove ammonia nitrogen from wastewater. Patent application CN112142274A discloses a municipal wastewater treatment device using a short-cut denitrification-anaerobic ammonia oxidation coupled dual-membrane process, which has advantages such as high nitrogen removal efficiency, good water treatment effect, and easy control of various components. It is suitable for the advanced treatment of wastewater with high ammonia nitrogen and low carbon-to-nitrogen ratio. Furthermore, there are still many problems in the current use of anaerobic ammonia oxidation technology for denitrification, which restrict its promotion in practical applications. For example, the proliferation rate of anaerobic ammonia oxidizing bacteria is relatively slow; anaerobic ammonia oxidizing bacteria are relatively sensitive to changes in environmental factors (such as pH, water temperature, dissolved oxygen, etc.) and anaerobic ammonia oxidation devices cannot be precisely controlled; anaerobic ammonia oxidation biofilm is prone to detachment; and packing material is prone to loss and blockage of pipes. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide an anaerobic ammonia oxidation device and its application. The anaerobic ammonia oxidation device of the present invention has a simple structure and can operate stably for a long period. Applying the device of the present invention to the denitrification treatment of nitrogen-containing wastewater demonstrates high denitrification efficiency and promising development prospects.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] In a first aspect, the present invention provides an anaerobic ammonia oxidation device, the device comprising an anaerobic reactor, wherein an inlet, an outlet, a circulating outlet and an air inlet are provided on the outer wall of the anaerobic reactor.

[0007] According to the anaerobic ammonia oxidation apparatus provided by the present invention, a water flow distributor, a support layer, and a packing layer are arranged from bottom to top inside the anaerobic reactor. Preferably, the water flow distributor is located near the feed inlet of the anaerobic reactor, and may be slightly higher than the feed inlet. After the water flows into the anaerobic reactor from the feed inlet, it is first evenly distributed by the water flow distributor, and then rises through the support layer to the packing layer to fully contact the packing for anaerobic ammonia oxidation reaction.

[0008] According to the anaerobic ammonia oxidation device provided by the present invention, the feed inlet of the anaerobic reactor is located at the bottom of the anaerobic reactor for introducing wastewater to be treated; the outlet is located at the top of the anaerobic reactor for discharging treated wastewater; the circulating outlet is located above the packing layer and below the outlet for circulating wastewater that needs further treatment; and the air inlet is located above the packing layer and below the circulating outlet for introducing nitrogen into the anaerobic reactor to remove dissolved oxygen from the water and maintain an oxygen-deficient state in the anaerobic reactor.

[0009] According to the anaerobic ammonia oxidation device provided by the present invention, at least one layer of packing baffles, preferably 1 to 3 layers, is provided inside the anaerobic reactor at a position below the circulating water outlet and above the packing layer to intercept floating packing. More preferably, at least one layer of packing baffles is below the air inlet and above the packing layer. The packing baffles have holes smaller than the packing particle size. Preferably, the shape of the holes can be set according to the shape and size of the packing, and the size of the holes is preferably slightly smaller than the packing particle size. More preferably, when the number of packing baffle layers is greater than 1, the holes of adjacent packing baffle layers are staggered.

[0010] In some embodiments of the present invention, the packing material of the packing layer is cylindrical or spherical, and the packing baffle and / or water flow distributor is a perforated plate with a plurality of channels evenly distributed on the perforated plate; preferably, the diameter of the packing material is 2.5 to 3 mm; and the diameter of the channels of the perforated plate is 1 to 2 mm.

[0011] More preferably, the water content density of the packing layer is 800–1200 kg / m³. 3 The unit volume is 0.028–0.044 mL / particle, the contact angle is 60°, and the specific surface area is 50 m². 2 / g.

[0012] According to the anaerobic ammonia oxidation device provided by the present invention, the support layer is composed of 1 to 3 layers of ceramic balls, and when there are 2 or 3 layers of ceramic balls, the particle size of the ceramic balls gradually decreases from bottom to top. The support layer composed of 1 to 3 layers of ceramic balls can not only distribute water, but also provide support for the packing layer, so that bacteria can quickly form a biofilm after inoculation in the anaerobic reactor during the initial start-up.

[0013] In some embodiments of the present invention, the support layer is composed of three layers of ceramic balls, with the bottom layer using ceramic balls with a particle size of 8 to 12 mm; the middle layer using ceramic balls with a particle size of 6 to 8 mm; and the top layer using ceramic balls with a particle size of 4 to 6 mm.

[0014] According to the anaerobic ammonia oxidation apparatus provided by the present invention, the apparatus further includes a circulating water tank, which is connected to the circulating outlet and the feed inlet of the anaerobic reactor, thereby forming a loop between the anaerobic reactor and the circulating water tank to realize water circulation between the anaerobic reactor and the circulating water tank. Specifically, the circulating water tank inlet is connected to the circulating outlet of the anaerobic reactor; the circulating water tank outlet is connected to the feed inlet of the anaerobic reactor. Preferably, the circulating water tank outlet is higher than the circulating water tank inlet.

[0015] More preferably, the inlet of the circulating water tank is located at the bottom of one side wall of the circulating water tank, and the outlet of the circulating water tank is located at the top of the circulating water tank.

[0016] More preferably, a circulation pump is installed between the circulation outlet and the circulation tank inlet.

[0017] According to the anaerobic ammonia oxidation apparatus provided by the present invention, a dissolved oxygen meter is provided on the circulating water tank, preferably located at the top of the circulating water tank. And / or, a top dissolved oxygen meter is provided at the top of the anaerobic reactor.

[0018] Preferably, the dissolved oxygen meter at the top and the dissolved oxygen meter in the circulating water tank can achieve real-time online detection.

[0019] According to the anaerobic ammonia oxidation apparatus provided by the present invention, the apparatus further includes a temperature control system, which comprises a jacket disposed outside the anaerobic reactor and a heating tank connected thereto. The temperature control system controls the water temperature inside the anaerobic reactor so that the anaerobic ammonia oxidation reaction occurring inside the reactor can proceed within a set temperature range, ensuring the smooth progress of the anaerobic ammonia oxidation reaction.

[0020] Preferably, the jacket is located in the straight section of the anaerobic reactor, particularly on the outer side corresponding to the support layer and the packing layer. The jacket is circulated with the heating tank, and a heating pump is installed between the liquid inlet of the jacket and the liquid outlet of the heating tank. Liquid heated by the heating tank is pumped into the jacket by the heating pump. After heat exchange with the anaerobic reactor within the jacket, the liquid returns to the heating tank from the liquid outlet of the jacket. The flow direction of the liquid within the jacket can be the same as or opposite to the flow direction of the wastewater within the anaerobic reactor.

[0021] According to the anaerobic ammonia oxidation apparatus provided by the present invention, the apparatus further includes a feed tank, the outlet of which is connected to the inlet of the anaerobic reactor. Preferably, a feed pump is provided between the feed tank and the inlet of the anaerobic reactor to facilitate the pumping of wastewater into the anaerobic reactor. More preferably, the inlet of the anaerobic reactor is simultaneously connected to the outlet of the feed pump and the outlet of the circulating water tank via a three-way valve, so that the wastewater pumped from the feed tank and the circulating water are mixed before entering the anaerobic reactor, thereby adjusting the concentration of nitrogenous pollutants in the incoming water and better maintaining the stable operation of the anaerobic ammonia oxidation reaction in the anaerobic reactor.

[0022] According to the anaerobic ammonia oxidation apparatus provided by the present invention, the apparatus further includes a gas-liquid separator, the inlet of which is connected to the outlet of the anaerobic reactor; and the gas-liquid separator has an outlet at a position higher than the inlet.

[0023] According to the anaerobic ammonia oxidation apparatus provided by the present invention, the apparatus further includes a pressure reducing valve and a time relay, which are used to control the pressure of nitrogen gas introduced into the anaerobic reactor, the aeration duration, and the intermittent duration, respectively. Specifically, the pressure reducing valve is used to reduce the pressure of the nitrogen gas, and the aeration duration and intermittent duration are controlled by the time relay according to process requirements.

[0024] In some embodiments of the present invention, nitrogen is supplied by a nitrogen cylinder, which is connected to the inlet via a pipeline and a pressure reducing valve and a time relay disposed on the pipeline.

[0025] In some embodiments of the present invention, the anaerobic reactor is an upflow reactor with a height-to-diameter ratio of 7 to 20.

[0026] Preferably, the anaerobic reactor may be made of glass, plexiglass or other materials.

[0027] In a second aspect, the present invention provides the application of the anaerobic ammonia oxidation device described in the first aspect in wastewater denitrification.

[0028] Thirdly, the present invention provides a method for denitrifying wastewater using the anaerobic ammonia oxidation device described in the first aspect, comprising: passing wastewater containing nitrogen pollutants into an anaerobic reactor for denitrification treatment; and, depending on the effect of wastewater treatment, directly discharging the treated wastewater from the outlet or discharging the wastewater requiring further treatment from the circulation outlet and then passing it into the anaerobic reactor for denitrification treatment again.

[0029] Preferably, the method includes the following steps:

[0030] (1) The wastewater containing nitrogen pollutants is fed into the anaerobic reactor, and the wastewater is circulated between the anaerobic reactor and the circulating water tank. The feed pump and the circulation pump are used to adjust the influent flow rate and the concentration of nitrogen pollutants in the influent according to the wastewater treatment effect.

[0031] (2) Use a temperature control system to control the water temperature in the anaerobic reactor between 22 and 35°C.

[0032] (3) The dissolved oxygen content in the anaerobic reactor and the circulating water tank is monitored in real time using a top dissolved oxygen meter and a circulating water tank dissolved oxygen meter, respectively. When the dissolved oxygen is detected to be greater than 2 μmol / L, nitrogen gas is introduced into the anaerobic reactor until the dissolved oxygen content no longer decreases. After the nitrogen gas is introduced, the oxygen in the anaerobic reactor is discharged to the gas-liquid separator through the outlet and then overflows into the atmosphere through the outlet of the gas-liquid separator.

[0033] (4) The water that has been removed by anaerobic ammonia oxidation reaction and has removed nitrogen pollutants overflows from the outlet to the gas-water separator and is then discharged or reused through the outlet of the gas-water separator.

[0034] The beneficial effects of the present invention are as follows:

[0035] The anaerobic ammonia oxidation device of this invention has an air inlet for introducing nitrogen gas into the anaerobic reactor. By introducing nitrogen gas into the anaerobic reactor to remove dissolved oxygen from the water, the impact of dissolved oxygen on the anaerobic ammonia oxidation reaction can be effectively reduced. In particular, placing the nitrogen gas inlet above the packing layer can prevent excessive shedding of the biofilm from the packing layer, thereby reducing packing loss and preventing the effluent pipe or circulating water pipe from being blocked by the packing.

[0036] The anaerobic ammonia oxidation device of the present invention, while introducing nitrogen to remove dissolved oxygen, uses a dissolved oxygen meter to monitor the dissolved oxygen content in the device in real time. The monitored dissolved oxygen content is used as an indicator to adjust the nitrogen aeration time and intermittent time, so as to maintain the dissolved oxygen content in the anaerobic reactor within a low range as much as possible, thereby eliminating the influence of dissolved oxygen on the anaerobic ammonia oxidation reaction. In particular, when dissolved oxygen meters are installed on both the anaerobic reactor and the circulation tank, the dissolved oxygen content indicator is more accurate, which helps to ensure that the dissolved oxygen content in the water at both the inlet and outlet of the anaerobic reactor is within a controllable range.

[0037] The anaerobic ammonia oxidation device of the present invention has a packing baffle installed in the anaerobic reactor at a position below the circulating water outlet. This can prevent the packing from entering the water circulation pipe and clogging the pipe, and also prevent the packing from flowing out with the external drainage. This improves the utilization rate of the packing and the purity of the external drainage, which is conducive to maintaining the long-term stable operation of the anaerobic ammonia oxidation device.

[0038] The anaerobic ammonia oxidation device of this invention features a water distributor at the inlet of the anaerobic reactor to uniformly distribute the incoming water. This facilitates the even distribution of nitrogenous pollutants, ensuring sufficient contact between the pollutants and the packing material for anaerobic ammonia oxidation. Above the water distributor, a support layer consisting of 1-3 layers of ceramic balls is further installed. This support layer not only achieves secondary uniform water distribution but also provides support for the packing material and attachment points for bacteria, promoting rapid bacterial biofilm formation after inoculation during initial startup and shortening start-up time. When the support layer consists of multiple layers of ceramic balls, each layer functions as a water distributor, further enhancing the uniformity of water distribution. Furthermore, the progressively smaller particle size of the ceramic balls from bottom to top corresponds to progressively smaller orifice sizes in the water distributor, resulting in even more uniform water distribution.

[0039] The anaerobic ammonia oxidation device of this invention improves denitrification efficiency and maintains the long-term stable operation of the anaerobic ammonia oxidation device through several methods, including: installing a packing baffle at the outlet of the anaerobic reactor to reduce packing loss; moving the backwashing and aeration position to the top of the packing layer to avoid excessive shedding of the anaerobic ammonia oxidation biofilm in the support layer and packing layer when nitrogen is introduced; installing dissolved oxygen meters in both the anaerobic reactor and the circulating water tank to improve the accuracy of dissolved oxygen monitoring; and installing a temperature control system in the straight pipe section of the anaerobic reactor to regulate the reaction temperature. When applied to the denitrification treatment of nitrogen-containing wastewater, this device exhibits high denitrification efficiency and shows promising development prospects.

[0040] The anaerobic ammonia oxidation device of this invention is used to denitrify wastewater containing nitrogen pollutants. It has a high degree of water distribution uniformity, low loss of packing material, and can achieve relatively precise control of reaction conditions (temperature and dissolved oxygen content). The device can start up quickly, the denitrification process is easy to operate, and the denitrification effect is good with a high total nitrogen removal load. It can realize the industrial application of anaerobic ammonia oxidation denitrification. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the anaerobic ammonia oxidation device of the present invention;

[0042] Figure 2 This is a top view of the perforated plate of the present invention.

[0043] Markings in the image:

[0044] 1. Nitrogen cylinder; 2. Pressure reducing valve; 3. Time relay; 4. Feed inlet; 5. Water flow distributor; 6. Jacket; 7. Support layer; 8. Packing layer; 9. Anaerobic reactor; 10. Heating pump; 11. Heating tank; 12. Air inlet; 13. Packing baffle; 14. Top dissolved oxygen meter; 15. Water outlet; 16. Circulating water outlet; 17. Gas-liquid separator; 18. Gas-liquid separator outlet; 19. Circulating water tank dissolved oxygen meter; 20. Circulating water tank; 21. Circulating water tank inlet; 22. Circulating water tank outlet; 23. Circulating pump; 24. Feed tank; 25. Feed pump; 26. Orifice plate channel. Detailed Implementation

[0045] The following examples further illustrate the technology of the present invention. These examples are illustrative and exemplary of the present invention and do not limit the scope of the invention in any way.

[0046] Example 1

[0047] An anaerobic ammonia oxidation device includes a nitrogen cylinder 1, a pressure reducing valve 2, a time relay 3, a feed inlet 4, a water flow distributor 5, a jacket 6, a support layer 7, a packing layer 8, an anaerobic reactor 9, a heating pump 10, a heating tank 11, an air inlet 12, a packing baffle 13, a top dissolved oxygen meter 14, a water outlet 15, a circulating water outlet 16, a gas-liquid separator 17, a gas-liquid separator outlet 18, a circulating water tank dissolved oxygen meter 19, a circulating water tank 20, a circulating water tank inlet 21, a circulating water tank outlet 22, a circulating pump 23, a feed tank 24, a feed pump 25, and a perforated plate channel 26. A schematic diagram of the anaerobic ammonia oxidation device of this invention is shown below. Figure 1 As shown.

[0048] The anaerobic reactor 9 is provided with an outlet 15 at the top, which is connected to the inlet of the gas-liquid separator 17. The gas-liquid separator 17 is provided with an outlet 18 at a position higher than the inlet.

[0049] The bottom of the anaerobic reactor 9 is provided with a feed inlet 4, which is connected to the discharge port of the feed tank 24. A feed pump 25 is provided between the feed tank 24 and the feed inlet 4 to facilitate the pumping of wastewater into the anaerobic reactor 9.

[0050] A circulation outlet 16 is located on the anaerobic reactor 9, above the packing layer 8 and below the outlet 15. The circulation outlet 16 is connected to the circulation tank inlet 21 located at the bottom of one side wall of the circulation tank 20. A circulation pump 23 is installed between the circulation outlet 16 and the circulation tank inlet 21, pumping water from the upper section of the anaerobic reactor 9 into the circulation tank 20 for recirculation. A circulation tank outlet 22 is located at the top of the circulation tank 20, connected to the feed inlet 4, thus forming a loop between the anaerobic reactor 9 and the circulation tank 20, achieving water circulation between the anaerobic reactor 9 and the circulation tank 20.

[0051] The feed inlet 4 is connected to both the outlet of the feed pump 25 and the outlet 22 of the circulating water tank via a three-way valve, so that the wastewater pumped from the feed tank 24 and the circulating water can be mixed before entering the anaerobic reactor 9, thereby adjusting the concentration of nitrogen pollutants in the incoming water and better maintaining the stable operation of the anaerobic ammonia oxidation reaction in the anaerobic reactor 9.

[0052] Inside the anaerobic reactor 9, from bottom to top, there are a water flow distributor 5, a support layer 7, and a packing layer 8. The water flow distributor 5 is located near the feed inlet 4 and is slightly higher than the feed inlet. After the water flows into the anaerobic reactor 9 from the feed inlet 4, it is first evenly distributed by the water flow distributor 5, and then rises through the support layer 7 to the packing layer 8 to fully contact the packing for anaerobic ammonia oxidation reaction.

[0053] Among them, the water flow distributor 5 is a strip plate with a channel diameter of 1 to 2 mm.

[0054] The supporting layer 7 consists of three layers of white ceramic balls. The bottom layer uses white ceramic balls with a particle size of 8-12 mm; the middle layer uses white ceramic balls with a particle size of 6-8 mm; and the top layer uses white ceramic balls with a particle size of 4-6 mm.

[0055] The packing material for packing layer 8 is a self-made cylindrical packing material with a diameter of 2.5–3 mm and a length of 1–30 mm; the water content of this packing material is 800–1200 kg / m³. 3 The unit volume is 0.028–0.044 mL / particle, the contact angle is 60°, and the specific surface area is 50 m². 2 / g.

[0056] The apparatus of the present invention also includes a nitrogen replenishment system, which comprises a nitrogen cylinder 1, an inlet 12, a pressure reducing valve 2, and a time relay 3. The inlet 12 is located on the side wall of the anaerobic reactor 9, higher than the packing layer 8 and lower than the circulating water outlet 16. The inlet 12 is connected to the outlet of the nitrogen cylinder 1. The pressure reducing valve 2 and the time relay 3 are sequentially arranged between the inlet 12 and the outlet of the nitrogen cylinder 1 along the nitrogen flow direction. The pressure reducing valve 2 is used to reduce the nitrogen pressure, and the time relay 3 controls the aeration duration and intermittent duration according to process requirements.

[0057] Two layers of packing baffles 13 are installed in the anaerobic reactor 9, positioned below the circulating outlet 16 and above the packing layer 8. The packing baffles 13 are perforated plates with a pore diameter of 1-2 mm. One layer of the packing baffles 13 is positioned above the air inlet 12, and the other layer is positioned below the air inlet 12. The two layers of packing baffles 13 allow for two-stage filtration of the packing material, reducing packing loss and preventing blockage of the circulating and effluent pipes due to packing loss. From a positional perspective, they also reduce the impact of water disturbance caused by nitrogen gas being introduced from the air inlet 12 on the packing layer 8, thereby further reducing packing detachment and loss (or detachment of the anaerobic ammonia oxidation biofilm) caused by water disturbance. Moreover, they provide good aeration and can accelerate the removal of dissolved oxygen from the anaerobic reactor 9 and the circulating water tank 20.

[0058] The perforated plate has a plurality of perforated channels 26 evenly distributed on it; a top view of the perforated plate of the present invention is shown below. Figure 2 As shown.

[0059] The perforated channels 26 on the two layers of packing partition 13 are arranged horizontally in a crisscross pattern.

[0060] A top dissolved oxygen meter 14 is installed at the top of the anaerobic reactor 9 to monitor the dissolved oxygen content within the reactor 9 in real time, especially the dissolved oxygen content in the upper section of the reactor 9. A circulating water tank dissolved oxygen meter 19 is installed on the circulating water tank 20 to enhance the monitoring of dissolved oxygen in the circulating system water. Both the top dissolved oxygen meter 14 and the circulating water tank dissolved oxygen meter 19 can perform real-time online detection.

[0061] The apparatus of the present invention further includes a temperature control system comprising a jacket 6 disposed outside the anaerobic reactor 9 and a heating tank 11 connected thereto. The jacket 6 is located at the straight section of the anaerobic reactor 9, particularly on the outer side corresponding to the support layer 7 and the packing layer 8. The jacket 6 is cyclically connected to the heating tank 11. A heating pump 10 is installed between the liquid inlet of the jacket 6 and the liquid outlet of the heating tank 11. Liquid heated by the heating tank 11 is pumped into the jacket 6 by the heating pump 10. After heat exchange with the anaerobic reactor 9 within the jacket 6, the liquid returns to the heating tank 11 from the liquid outlet of the jacket 6. The liquid flow direction within the jacket 6 is the same as the wastewater flow direction within the anaerobic reactor 9.

[0062] The anaerobic reactor 9 is an upflow reactor made of glass with a height-to-diameter ratio of 7 to 20.

[0063] Example 2

[0064] The method for denitrifying wastewater using the anaerobic ammonia oxidation device of Example 1 includes the following steps:

[0065] (1) Wastewater containing nitrogen pollutants is fed into anaerobic reactor 9, and the wastewater is circulated between anaerobic reactor 9 and circulating water tank 20. The feed pump 25 and the circulation pump 23 are used to adjust the influent flow rate of anaerobic reactor 9 and the concentration of nitrogen pollutants in the influent according to the wastewater treatment effect.

[0066] (2) The water temperature inside the anaerobic reactor 9 is controlled between 22 and 35°C using a temperature control system.

[0067] (3) The dissolved oxygen content in the anaerobic reactor 9 and the circulating water tank 20 is monitored in real time using the top dissolved oxygen meter 14 and the circulating water tank dissolved oxygen meter 19, respectively. When the dissolved oxygen is detected to be greater than 2 μmol / L, nitrogen gas is introduced into the anaerobic reactor 9 until the dissolved oxygen content no longer decreases. After the nitrogen gas is introduced, the oxygen in the anaerobic reactor 9 is discharged to the gas-liquid separator 17 through the outlet 15 and then overflows into the atmosphere through the outlet 18 of the gas-liquid separator.

[0068] (4) The water that has been removed by anaerobic ammonia oxidation reaction overflows from outlet 15 to gas-water separator 17 and is then discharged or reused through outlet 18 of gas-water separator.

[0069] Application Examples

[0070] Wastewater containing 1000 mg / L nitrogen (including NH4) was introduced into anaerobic reactor 9 according to the method in Example 2. + -N and NO2 - -N 50mg / L each), control the circulation volume at 150mg / L. 3 / h, and samples were taken periodically at the outlet of the gas-liquid separator at point 18 for analysis. The tests revealed that the anaerobic ammonia oxidation device of this invention effectively denitrifies the wastewater, reducing NH4 content by 100%. + -N and NO2 - The removal rate of -N can reach over 90%, and the total nitrogen removal load can reach up to 5 kg / m³ per day. 3 .

[0071] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The embodiments describe the present invention, and it should be understood that the terms used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention.

Claims

1. An anaerobic ammonia oxidation device, characterized in that, The device includes an anaerobic reactor (9), and inside the anaerobic reactor (9) are arranged from bottom to top a water flow distributor (5), a support layer (7), and a packing layer (8). The anaerobic reactor (9) is provided with a feed inlet (4) at the bottom and a water outlet (15) at the top. A circulating water outlet (16) is also provided at a position higher than the packing layer (8) and lower than the water outlet (15). The anaerobic reactor (9) is provided with an air inlet (12) at a position higher than the packing layer (8) and lower than the circulating water outlet (16) for introducing nitrogen into the anaerobic reactor (9); The anaerobic reactor (9) has at least one layer of packing baffle (13) located below the circulating water outlet (16) and above the packing layer (8). The packing baffle (13) has holes smaller than the packing particle size, and at least one layer of packing baffle (13) is below the air inlet (12) and above the packing layer (8). The device also includes a circulating water tank (20), which is connected to the circulating water outlet (16) and the feed inlet (4) respectively; The water flow distributor (5) is a perforated plate with a number of channels evenly distributed on it; the support layer (7) is composed of 1 to 3 layers of ceramic balls.

2. The anaerobic ammonia oxidation device according to claim 1, characterized in that, The anaerobic reactor (9) has 2 to 3 layers of packing baffles (13) located below the circulating water outlet (16) and above the packing layer (8).

3. The anaerobic ammonia oxidation device according to claim 2, characterized in that, The holes in the two adjacent layers of packing partitions are staggered.

4. The anaerobic ammonia oxidation apparatus according to any one of claims 1 to 3, characterized in that, The packing baffle (13) is a perforated plate; the perforated plate has a number of channels evenly distributed on it.

5. The anaerobic ammonia oxidation device according to claim 4, characterized in that, The packing material in the packing layer is cylindrical or spherical, and the diameter of the packing material is 2.5 to 3 mm; the diameter of the channels in the perforated plate is 1 to 2 mm.

6. The anaerobic ammonia oxidation device according to claim 1, characterized in that, The supporting layer (7) consists of 2 to 3 layers of ceramic balls, and the particle size of the ceramic balls gradually decreases from bottom to top.

7. The anaerobic ammonia oxidation device according to claim 6, characterized in that, The supporting layer consists of three layers of ceramic balls: the bottom layer uses ceramic balls with a particle size of 8-12 mm; the middle layer uses ceramic balls with a particle size of 6-8 mm; and the top layer uses ceramic balls with a particle size of 4-6 mm.

8. The anaerobic ammonia oxidation device according to claim 1, characterized in that, The circulating water tank (20) is equipped with a circulating water tank dissolved oxygen meter (19).

9. The anaerobic ammonia oxidation device according to claim 8, characterized in that, The anaerobic reactor (9) is equipped with a top dissolved oxygen meter (14).

10. The anaerobic ammonia oxidation device according to claim 1, characterized in that, The device also includes a temperature control system, which includes a jacket (6) disposed outside the anaerobic reactor (9) and a heating tank (11) connected thereto.

11. The anaerobic ammonia oxidation apparatus according to claim 10, characterized in that, The jacket (6) is cyclically connected to the heating tank (11). A heating pump (10) is provided between the liquid inlet of the jacket (6) and the liquid outlet of the heating tank (11). The liquid heated by the heating tank (11) is pumped into the jacket (6) by the heating pump (10). After the liquid exchanges heat with the anaerobic reactor (9) in the jacket (6), it returns to the heating tank (11) from the liquid outlet of the jacket (6).

12. The anaerobic ammonia oxidation device according to claim 1, characterized in that, The device also includes a feed tank (24), the outlet of which is connected to the feed inlet (4); And / or, the device further includes a gas-water separator (17), the inlet of which is connected to the outlet (15); the gas-water separator (17) has an outlet (18) at a position higher than the inlet. And / or, the device further includes a nitrogen cylinder (1), a pressure reducing valve (2) and a time relay (3), the nitrogen cylinder (1) being connected to the air inlet (12) via a pipeline and the pressure reducing valve (2) and the time relay (3) installed on the pipeline, the pressure reducing valve (2) being used to control the pressure of the nitrogen gas introduced into the anaerobic reactor (9), and the time relay (3) being used to control the duration of the nitrogen gas introduced into the anaerobic reactor (9) and the duration of the interval.

13. The anaerobic ammonia oxidation apparatus according to claim 12, characterized in that, A feed pump (25) is provided between the feed hopper (24) and the feed inlet (4); and / or, a circulation pump (23) is provided between the circulation outlet (16) and the circulation tank inlet (21).

14. The anaerobic ammonia oxidation apparatus according to any one of claims 1-3 and 5-9, characterized in that, The water content of the filler in the packing layer is 800–1200 kg / m³. 3 The unit volume is 0.028–0.044 mL / particle, the contact angle is 60°, and the specific surface area is 50 m². 2 / g.

15. The application of an anaerobic ammonia oxidation device as described in any one of claims 1-14 in wastewater denitrification.

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