Wastewater denitrification treatment system and treatment method thereof

Abstract

This invention discloses a wastewater denitrification treatment system and method. The wastewater denitrification treatment system includes a main flow pipe, a side flow pipe, and multiple reaction units. The side flow pipe is connected in parallel to the main flow pipe, and the multiple reaction units are arranged on the main flow pipe. The main flow pipe is used to transport main flow wastewater, and the side flow pipe is used to transport side flow wastewater. A cultivation unit is installed in the side flow pipe. The reaction unit includes an anaerobic ammonia oxidation coupled short-cut nitrification reaction unit. The wastewater denitrification treatment system achieves wastewater denitrification by coupling short-cut nitrification technology and anaerobic ammonia oxidation technology. Simultaneously, the carrier for enriching microorganisms in the reaction unit is made of polyurethane sponge. After the reaction unit has been running for a long time under the conditions of main flow wastewater, the microbial carrier is removed from the reaction unit and then placed separately in the cultivation unit of the side flow pipe for enrichment and activation of anaerobic ammonia oxidation microorganisms, which can effectively improve the efficiency of wastewater denitrification.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a wastewater denitrification system and treatment method. Background Technology

[0002] Among existing technologies, the short-cut nitrification-anaerobic ammonium oxidation integrated technology (CANON) is an effective method for wastewater treatment. Specifically, CANON technology combines nitrification and anaerobic ammonium oxidation processes, using the combined action of ammonia-oxidizing bacteria and anaerobic ammonium-oxidizing bacteria to efficiently convert ammonia nitrogen into nitrogen gas without requiring exogenous organic carbon. CANON technology achieves highly efficient wastewater treatment, reduces energy consumption and carbon source requirements, and simultaneously reduces sludge production.

[0003] However, existing short-cut nitrification-anaerobic ammonium oxidation integrated technologies still have the following drawbacks:

[0004] 1. Unstable Microbial Population: The integrated short-cut nitrification-anaerobic ammonia oxidation technology involves multiple microbial populations, including nitrifying bacteria and anaerobic ammonia oxidizing bacteria. The growth and metabolic processes of these microorganisms can be affected by environmental factors, threatening the stability of the microbial community. In particular, compared to nitrifying bacteria (generally between hours and days), anaerobic ammonia oxidizing bacteria typically have a generation time between days and tens of days. The significant difference in reproduction rates between these two functional microorganisms means that as operating time increases, anaerobic ammonia oxidizing bacteria will gradually be replaced by ammonia oxidizing bacteria. This makes it difficult for reaction systems designed based on existing technologies to operate long-term. Failure to monitor and intervene in the microbial population during operation will lead to decreased treatment efficiency or even system collapse due to microbial instability.

[0005] 2. Challenges in Treating Low-NOx Wastewater: Existing integrated short-cut nitrification-anaerobic ammonia oxidation (ANAO) technology still faces certain challenges in treating wastewater with low nitrogen loads. For example, when treating mainstream wastewater with low ammonia nitrogen concentrations, the lack of nutrients required for ANAO in the wastewater makes it difficult for the ANAO bacteria in the system to grow and reproduce stably. This can lead to a continuous decrease in the amount of ANAO sludge over operating time, resulting in sludge loss, system instability, reduced treatment efficiency, and ultimately, loss of treatment capacity.

[0006] 3. Incomplete reaction: Biological treatment tanks designed based on existing technologies often suffer from incomplete reaction and uneven water quality due to improper design, which affects the treatment effect and the quality of the effluent.

[0007] Therefore, there is an urgent need to study a solution for implementing CANON technology to solve the problems existing in the current technology. Summary of the Invention

[0008] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a wastewater denitrification treatment system that can improve the stability of the microbial community within the system, and provides stable treatment of mainstream wastewater with high reaction efficiency and uniform water quality after treatment.

[0009] A wastewater denitrification treatment system according to a first aspect of the present invention includes:

[0010] Mainstream pipeline;

[0011] A side-flow pipe, with both ends connected to the main flow pipe;

[0012] The cultivation unit is located inside the side flow pipe;

[0013] The reaction module includes multiple reaction units arranged along the water flow direction of the main pipeline. Each reaction unit includes a short-range nitrification reaction unit, a short-range nitrification coupled anaerobic ammonium oxidation reaction unit, and a complete nitrification reaction unit arranged in sequence. Each reaction unit is equipped with a tank, a rotating shaft, and a rotating cage. The rotating cage contains a carrier with attached anaerobic ammonium oxidizing bacteria and nitrifying bacteria. The rotating shaft is detachably installed in the tank, and multiple rotating shafts are located on the same axis. The rotating cage is rotatably installed on the rotating shaft. An inlet and an outlet are respectively provided on both sides of the tank. A first valve is provided at the inlet and the outlet. Adjacent tanks are connected through the inlet and the outlet. The tank located at the end is connected to the main pipeline through the inlet and the outlet.

[0014] The circulating pipeline is provided with a main pipe and multiple branch pipes. The two ends of the main pipe are respectively connected to the boxes located at both ends of the reaction module. The boxes located between the reaction modules are connected to the main pipe through the branch pipes. The branch pipes are provided with second valves.

[0015] A gas duct branch is connected to the housing, and the gas duct branch is used to pump in nitrogen and air.

[0016] The wastewater denitrification treatment system according to embodiments of the present invention has at least the following beneficial effects: by retaining anaerobic ammonia-oxidizing bacteria with long generation times through a carrier, its stable growth is reduced and loss is minimized; at the same time, nitrifying bacteria are allowed to operate in a suspended state to limit their growth rate, thereby avoiding weakening the competitive advantage of nitrifying bacteria and maintaining the stability of the microbial population within the system; dividing the system into independent reaction units reduces maintenance costs; side-flow wastewater is activated and cultured, enabling the anaerobic ammonia-oxidizing bacteria to maintain long-term stability in both quantity and activity; structural improvements enhance reaction efficiency and improve the uniformity of the treated water quality.

[0017] According to some embodiments of the present invention, the reaction module further includes a driver and a main shaft, the main shaft passing through the middle of the plurality of rotating shafts and the rotating shafts being fixed to the main shaft, the driver being drively connected to the main shaft to drive the main shaft to rotate.

[0018] According to some embodiments of the present invention, the bottom and side walls of the box are provided with aeration devices, and the aeration devices include aeration discs and aeration strips.

[0019] According to some embodiments of the present invention, the sides of the housing are inclined toward the center.

[0020] According to some embodiments of the present invention, the top of the box is provided with an openable top cover, and the side of the box located below the top cover is provided with an overflow port.

[0021] According to some embodiments of the present invention, a sludge discharge port is provided at the bottom of the box.

[0022] According to some embodiments of the present invention, the top of the housing is provided with an exhaust port, and an exhaust pipe is led out from the exhaust port.

[0023] According to some embodiments of the present invention, the rotating cage is provided with circular mesh, rectangular mesh, annular mesh and hollow column. Two circular meshes are provided and are parallel to each other. The edge of the annular mesh is connected to the edge of the two circular meshes. The end of the hollow column is connected to the center of the two circular meshes. A through hole is provided at the center of the circular mesh. Multiple rectangular meshes are provided and are arranged between two circular meshes and are evenly distributed along the circumferential sidewall of the hollow column to equally divide the space enclosed by the circular meshes and the annular meshes.

[0024] According to some embodiments of the present invention, the ring mesh is provided with an openable mesh plate, and the ring mesh is divided into four equal parts by the rectangular mesh, each part being provided with the mesh plate.

[0025] According to a second aspect of the present invention, a treatment method is applied to a wastewater denitrification treatment system as described in the first aspect of the present invention, wherein the reaction unit comprises a short-cut nitrification reaction unit, a short-cut nitrification coupled anaerobic ammonium oxidation reaction unit, and a complete nitrification reaction unit arranged sequentially, and the treatment method comprises:

[0026] The arrangement order of the multiple short-cut nitrification reaction units, the arrangement order of the multiple short-cut nitrification coupled anaerobic ammonia oxidation reaction units, and the arrangement order of the multiple complete nitrification reaction units are adjusted according to the ammonia nitrogen concentration of the wastewater.

[0027] According to the system's preset end time, the microbial carrier in the reaction unit is transferred to the culture unit for separate culture.

[0028] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0030] Figure 1 This is a schematic diagram of a wastewater denitrification treatment system according to an embodiment of the present invention;

[0031] Figure 2 for Figure 1 A schematic diagram illustrating the structural principle of a wastewater denitrification treatment system is shown.

[0032] Figure 3 This is a schematic diagram of a rotating cage according to an embodiment of the present invention;

[0033] Figure 4 This is a flowchart of a processing method according to an embodiment of the present invention.

[0034] Figure label:

[0035] Mainstream pipe 100, sidestream pipe 110, culture unit 120, reaction module 200, reaction unit 210, box 211, first valve 212, top cover 213, exhaust port 214, viewing window 215, rotating shaft 216, rotating cage 220, circular mesh 221, rectangular mesh 222, ring mesh 223, hollow column 224, mesh plate 225, main shaft 230, driver 240, circulation pipe 300, main pipe 310, branch pipe 320, second valve 330. Detailed Implementation

[0036] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0037] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0038] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0039] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0040] Among existing technologies, the short-cut nitrification-anaerobic ammonium oxidation integrated technology (CANON) is an effective method for wastewater treatment. Specifically, CANON technology combines nitrification and anaerobic ammonium oxidation processes, using the combined action of ammonia-oxidizing bacteria and anaerobic ammonium-oxidizing bacteria to efficiently convert ammonia nitrogen into nitrogen gas without requiring exogenous organic carbon. CANON technology achieves highly efficient wastewater treatment, reduces energy consumption and carbon source requirements, and simultaneously reduces sludge production.

[0041] However, existing short-cut nitrification-anaerobic ammonium oxidation integrated technologies still have the following drawbacks:

[0042] 1. Unstable Microbial Population: The integrated short-cut nitrification-anaerobic ammonia oxidation technology involves multiple microbial populations, including nitrifying bacteria and anaerobic ammonia oxidizing bacteria. The growth and metabolic processes of these microorganisms can be affected by environmental factors, threatening the stability of the microbial community. In particular, compared to nitrifying bacteria (generally between hours and days), anaerobic ammonia oxidizing bacteria typically have a generation time between days and tens of days. The significant difference in reproduction rates between these two functional microorganisms means that as operating time increases, anaerobic ammonia oxidizing bacteria will gradually be replaced by ammonia oxidizing bacteria. This makes it difficult for reaction systems designed based on existing technologies to operate long-term. Failure to monitor and intervene in the microbial population during operation will lead to decreased treatment efficiency or even system collapse due to microbial instability.

[0043] 2. Challenges in Treating Low-NOx Wastewater: Existing integrated short-cut nitrification-anaerobic ammonia oxidation (ANAO) technology still faces certain challenges in treating wastewater with low nitrogen loads. For example, when treating mainstream wastewater with low ammonia nitrogen concentrations, the lack of nutrients required for ANAO in the wastewater makes it difficult for the ANAO bacteria in the system to grow and reproduce stably. This can lead to a continuous decrease in the amount of ANAO sludge over operating time, resulting in sludge loss, system instability, reduced treatment efficiency, and ultimately, loss of treatment capacity.

[0044] 3. Incomplete reaction: Biological treatment tanks designed based on existing technologies often suffer from incomplete reaction and uneven water quality due to improper design, which affects the treatment effect and the quality of the effluent.

[0045] The main wastewater consists of wastewater with an ammonia nitrogen concentration of 20-60 mg N / L and a temperature of 15-25℃, while the side-flow wastewater consists of wastewater with an ammonia nitrogen concentration of 500-1000 mg N / L and a temperature of 25-35℃.

[0046] To address the technical problems existing in the prior art, this invention proposes a wastewater denitrification treatment system and method, which improves the stability of microbial populations, the stability of mainstream wastewater treatment, reaction efficiency, and water quality uniformity.

[0047] Reference Figures 1 to 4 It is understood that the wastewater denitrification treatment system provided in this embodiment of the invention includes a main flow pipe 100, a side flow pipe 110, a culture unit 120, a reaction module 200, and a circulation pipe 300. Specifically, both ends of the side flow pipe 110 are connected to the main flow pipe 100, and the side flow pipe 110 is equivalent to a branch of the main flow pipe 100. The culture unit 120 is disposed within the side flow pipe 110 and is used to cultivate microbial communities. The wastewater in the main flow pipe 100 is the main flow wastewater, and the wastewater in the side flow pipe 110 is the side flow wastewater.

[0048] The reaction module 200 includes multiple reaction units 210 arranged along the water flow direction of the main flow pipe 100. Each reaction unit 210 is provided with a housing 211, a rotating shaft 216, and a rotating cage 220. The rotating shaft 216 is detachably installed inside the housing 211, and multiple rotating shafts 216 are located on the same axis. The rotating cage 220 is rotatably installed on the rotating shaft 216. Each housing 211 has an inlet on one side and an outlet on the other side. A first valve 212 is provided at the inlet and outlet. Adjacent housings 211 are connected to each other through the inlet and outlet, that is, the outlet of the previous housing 211 is connected to the inlet of the next housing 211. The housings 211 located at the end are connected to the main flow pipe 100 through the inlet and outlet, that is, the main flow pipe 100 is connected to the inlet of the first housing 211, and the outlet of the last housing 211 continues to be connected to the main flow pipe 100 to transport wastewater.

[0049] It should be noted that reaction unit 210 includes a short-range nitrification reaction unit, a short-range nitrification coupled anaerobic ammonium oxidation reaction unit, and a complete nitrification reaction unit arranged in sequence, such as... Figure 2As shown, the initial reaction unit is a short-cut nitrification reaction unit, the middle reaction units are anaerobic ammonium oxidation reaction units, and the final reaction unit is a complete nitrification reaction unit. Multiple units of each type can be set up; that is, multiple short-cut nitrification reaction units, multiple short-cut nitrification coupled with anaerobic ammonium oxidation reaction units, and multiple complete nitrification reaction units can be set up.

[0050] The rotating cage 220 contains a carrier for attaching anaerobic ammonia-oxidizing bacteria and nitrifying bacteria. Specifically, the short-cut nitrification reaction unit uses German sponge and K3 packing as the carrier, the anaerobic ammonia-oxidizing reaction unit uses macroporous sponge and K3 packing as the carrier, and the complete nitrification reaction unit uses German sponge as the primary carrier, macroporous sponge as a secondary carrier, and K3 packing as the secondary carrier. In other embodiments, the carrier can also be polyurethane sponge, PE material, suspended balls, etc.

[0051] The tank 211 is equipped with two air pipe branches for aeration. Specifically, an aeration disc is installed at the bottom of each tank for nitrogen aeration, and aeration strips are installed on the side walls for air aeration. In some embodiments provided by this invention, the rotation speed of the rotating drum 220 is adjustable, ranging from 2-10 rpm / min. The volume of the rotating drum 220 occupies 70% of the wastewater volume, the packing volume occupies 70% of the rotating drum volume, and the packing filling rate is 50%.

[0052] Furthermore, the reaction module 200 also includes a driver 240 and a main shaft 230. The main shaft 230 passes through the middle of multiple rotating shafts 216, and the rotating shafts 216 are fixed to the main shaft 230. The driver 240 is connected to the main shaft 230 to drive the main shaft 230 to rotate. When the main shaft 230 rotates, it can drive all the rotating cages 220 to rotate, saving the need for the driver 240 and reducing costs.

[0053] In addition, the sides of the chamber 211 slope towards the center. The top of the chamber 211 is equipped with an openable top cover 213, and an overflow port is located on the side of the chamber 211 below the top cover 213. A sludge discharge port is located at the bottom of the chamber 211. An exhaust port 214 is located on the top of the chamber 211. A viewing window 215 is also provided on the side of the chamber 211 for easy observation of the reaction inside. The top cover 213 is typically sealed with a water seal, and its degree of freedom of movement is 90 degrees, facilitating opening and closing. An exhaust pipe can be led out from the exhaust port 214.

[0054] The circulation pipeline 300 is provided with a main pipe 310 and multiple branch pipes 320. The two ends of the main pipe 310 are respectively connected to the boxes 211 located at both ends of the reaction module 200. The boxes 211 located between the reaction modules 200 are connected to the main pipe 310 through the branch pipes 320. The branch pipes 320 are provided with second valves 330.

[0055] It should be noted that the technical solution of the present invention places the functional microbial carrier inside the rotating cage 220, which restricts and fixes it in a certain area of ​​the box. At the same time, the driver 240 drives the rotating cage 220 to rotate, so that the functional microorganisms will not settle and accumulate, effectively improving the contact between the functional microorganisms and the wastewater.

[0056] The rotating cage 220 is equipped with circular mesh 221, rectangular mesh 222, annular mesh 223, and hollow columns 224. Two circular meshes 221 are provided and are parallel to each other. The edge of the annular mesh 223 connects to the edges of the two circular meshes 221. The end of the hollow column 224 connects to the center of the two circular meshes 221. A through hole is provided at the center of each circular mesh 221. Multiple rectangular meshes 222 are provided, positioned between two circular meshes 221 and evenly distributed circumferentially along the sidewall of the hollow column 224 to equally divide the space enclosed by the circular meshes 221 and the annular mesh 223. The annular mesh 223 is equipped with an opening and closing mesh plate 225. In some embodiments provided by this invention, the annular mesh 223 is divided into four equal parts by the rectangular meshes 222, each part being equipped with a mesh plate 225.

[0057] Based on our experimental results, the anaerobic ammonia oxidation reaction is inhibited due to the high COD concentration and low nitrogen load in the mainstream wastewater, resulting in a decrease in the number of anaerobic ammonia oxidizing bacteria during operation in the mainstream wastewater (where the nitrogen concentration is insufficient). However, when the reactor operates with sidestream wastewater (initial sludge concentration 1.6 g VSS / L, total nitrogen above 500 mg N / L), anaerobic ammonia oxidizing microorganisms can grow rapidly, with a doubling time of less than 30 days.

[0058] The wastewater denitrification treatment system provided in this embodiment of the invention differs from the prior art mainly in the following aspects:

[0059] 1) Improvement of microbial population stability:

[0060] a. Different operating modes are adopted for nitrifying bacteria and anaerobic ammonia oxidizing bacteria: During system operation, anaerobic ammonia oxidizing bacteria are allowed to attach to a carrier for growth, and then the carrier is placed in the rotating cage 220, allowing nitrifying bacteria to grow in suspension. Nitrifying bacteria are then directly introduced into the tank 211. Using a carrier to cultivate microorganisms provides a more stable and suitable growth environment, which is conducive to the growth, metabolism, and degradation of harmful substances in wastewater. The carrier retains the anaerobic ammonia oxidizing bacteria, which have a longer generation time, ensuring stable growth and reducing loss. Simultaneously, allowing nitrifying bacteria to operate in suspension limits their growth rate, thus avoiding weakening their competitive advantage and maintaining the stability of the microbial population within the system.

[0061] b. Dividing the system into independent reaction units 210: Because existing systems require complete system shutdown for repair when problems occur, resulting in significant maintenance costs, the proposed solution divides the three reaction zones—short-cut nitrification, short-cut nitrification coupled with anaerobic ammonium oxidation, and complete nitrification—into multiple independent units using stainless steel plates (i.e., independent housings 211). Each unit can be isolated and operated independently. When a system problem occurs, operators do not need to shut down the system. They only need to close the first valves 212 on both sides of the target unit and manually switch the system's water flow direction via the circulation pipe 300 and the second valve 330. This connects the target unit to the next unit via the circulation pipe 300 and the opening and closing of the second valve 330, thus isolating the target unit for independent debugging. Once the debugging is successful, it can be reconnected to the system. Using this method to check each unit individually allows for timely regulation of the microbial population during a specific reaction stage, greatly reducing system maintenance difficulty and repair costs.

[0062] 2) Improvements in the stability of mainstream wastewater treatment:

[0063] a. Sidestream Wastewater Activation and Cultivation: Anaerobic ammonia oxidizing bacteria can easily achieve rapid growth and enrichment in sidestream wastewater. However, due to the low ammonia nitrogen concentration in the mainstream wastewater, it is difficult for anaerobic ammonia oxidizing bacteria to maintain a good growth state in the mainstream wastewater. To avoid the loss of anaerobic ammonia oxidizing bacteria, an operating method based on this scheme is provided: Since the scheme operates in the form of independent reaction units 210, the anaerobic ammonia oxidation section unit can be periodically removed during the system's treatment of mainstream wastewater and placed into the cultivation unit 120 in the sidestream pipe 110110. That is, it is replaced by sidestream wastewater suitable for anaerobic ammonia oxidation to complete activation and re-cultivation before continuing to treat mainstream wastewater. The removed anaerobic ammonia oxidation section unit then treats the sidestream wastewater separately to re-enrich the anaerobic ammonia oxidizing bacteria until the next replacement cycle. This operating method can maintain the long-term stability of the anaerobic ammonia oxidizing bacteria community in terms of quantity and activity.

[0064] 3) Improvements in reaction efficiency and water quality uniformity:

[0065] a. Rotary cage 220 housing: The carrier is loaded into the rotating cage 220 and driven by the mechanical rotating shaft 216 to make full contact between the sewage and the carrier, thereby improving the reaction rate.

[0066] b. Mixing facilities: Two mixing facilities, including mechanical stirring and gas lifting devices, are used to ensure that the wastewater is mixed evenly in the tank and to avoid incomplete reactions caused by the accumulation of suspended particles, microorganisms and wastewater components in the wastewater.

[0067] c. Design optimization: The inward tilting design on both sides reduces the dead zone inside the chamber, avoids incomplete reaction, and increases the effective reaction volume of the system.

[0068] 4) Multi-stage wastewater treatment method: Through the orderly arrangement of short-cut nitrification zone, short-cut nitrification coupled anaerobic ammonia oxidation integrated zone and complete nitrification zone, ammonia nitrogen in wastewater is gradually oxidized into nitrate, achieving efficient wastewater treatment.

[0069] The treatment method proposed in this invention for use in wastewater denitrification systems includes:

[0070] The arrangement order of the multiple short-cut nitrification reaction units, the multiple short-cut nitrification coupled anaerobic ammonium oxidation reaction units, and the multiple complete nitrification reaction units is adjusted according to the ammonia nitrogen concentration in the wastewater to gradually oxidize the ammonia nitrogen in the wastewater into nitrate, achieving efficient wastewater treatment. Due to increased operating time, the microbial activity in the front reaction unit 210 decreases, thus reducing wastewater treatment efficiency. In this case, the rear reaction unit 210 can be moved to the front, utilizing the more active microorganisms in the rear reaction unit 210 to treat the wastewater, thereby improving microbial utilization and ultimately increasing wastewater treatment efficiency. It is important to note that the order of the short-cut nitrification reaction units, the short-cut nitrification coupled anaerobic ammonium oxidation reaction units, and the complete nitrification reaction units cannot be changed. The difference between the three units lies in the types and proportions of microorganisms introduced. Specifically, ammonia nitrogen is converted into nitrite nitrogen by ammonia-oxidizing bacteria. The remaining ammonia nitrogen then reacts with the converted nitrite nitrogen to form nitrogen gas under the action of anaerobic ammonia-oxidizing bacteria, with a small amount of nitrate nitrogen also produced. This denitrification process requires no added carbon source, has low aeration energy consumption, and exhibits significant low-carbon and energy-saving advantages. The main reaction equations are shown below:

[0071]

[0072]

[0073] According to the system's preset end time, the microbial carriers in the reaction unit are transferred to the culture unit for separate culture.

[0074] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A wastewater denitrification treatment system, characterized in that, include: Mainstream pipeline; A side-flow pipe, with both ends connected to the main flow pipe; The cultivation unit is located inside the side flow pipe; The reaction module includes multiple reaction units arranged along the water flow direction of the main pipeline. Each reaction unit includes a short-range nitrification reaction unit, a short-range nitrification coupled anaerobic ammonium oxidation reaction unit, and a complete nitrification reaction unit arranged in sequence. Each reaction unit is equipped with a tank, a rotating shaft, and a rotating cage. The rotating cage contains a carrier with attached anaerobic ammonium oxidizing bacteria and nitrifying bacteria. The rotating shaft is detachably installed in the tank, and multiple rotating shafts are located on the same axis. The rotating cage is rotatably installed on the rotating shaft. An inlet and an outlet are respectively provided on both sides of the tank. A first valve is provided at both the inlet and the outlet. Adjacent tanks are connected through the inlet and the outlet. The tank located at the end is connected to the main pipeline through the inlet and the outlet. The circulating pipeline is provided with a main pipe and multiple branch pipes. The two ends of the main pipe are respectively connected to the boxes located at both ends of the reaction module. The boxes located between the reaction modules are connected to the main pipe through the branch pipes. The branch pipes are provided with second valves. A gas duct branch is connected to the housing, and the gas duct branch is used to pump in nitrogen and air.

2. The wastewater denitrification treatment system according to claim 1, characterized in that, The reaction module further includes a driver and a main shaft. The main shaft passes through the middle of the plurality of rotating shafts and the rotating shafts are fixed to the main shaft. The driver is connected to the main shaft for driving the main shaft to rotate.

3. The wastewater denitrification treatment system according to claim 1, characterized in that, The bottom and side walls of the box are equipped with aeration devices, which include aeration discs and aeration strips.

4. The wastewater denitrification treatment system according to claim 1, characterized in that, The sides of the box are inclined towards the center.

5. The wastewater denitrification treatment system according to claim 1, characterized in that, The top of the box is provided with an opening and closing top cover, and the side of the box located below the top cover is provided with an overflow port.

6. The wastewater denitrification treatment system according to claim 1, characterized in that, The bottom of the box is equipped with a sludge discharge port.

7. The wastewater denitrification treatment system according to claim 1, characterized in that, The top of the box is provided with an exhaust port, and an exhaust pipe is led out from the exhaust port.

8. The wastewater denitrification treatment system according to claim 1, characterized in that, The rotating cage is equipped with circular mesh, rectangular mesh, annular mesh, and hollow columns. There are two circular meshes, which are parallel to each other. The edge of the annular mesh is connected to the edge of the two circular meshes. The end of the hollow column is connected to the center of the two circular meshes. A through hole is provided at the center of the circular mesh. There are multiple rectangular meshes, which are arranged between two circular meshes and are evenly distributed along the circumference of the side wall of the hollow column to equally divide the space enclosed by the circular meshes and the annular meshes.

9. The wastewater denitrification treatment system according to claim 1, characterized in that, The filler filling rate in the carrier is 30% to 50%, and the carrier is polyurethane foam.

10. A treatment method, applied to the wastewater denitrification treatment system as described in any one of claims 1 to 9, characterized in that, The processing method includes: The arrangement order of the multiple short-cut nitrification reaction units, the arrangement order of the multiple short-cut nitrification coupled anaerobic ammonia oxidation reaction units, and the arrangement order of the multiple complete nitrification reaction units are adjusted according to the ammonia nitrogen concentration of the wastewater. According to the system's preset end time, the microbial carrier in the reaction unit is transferred to the culture unit for separate culture.

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