A pipe system and method for starting and stopping an autotrophic denitrification filter

Abstract

The application discloses a pipeline system and method for starting and stopping of autotrophic denitrification filter, which uses a sewage treatment device based on autotrophic denitrification filter denitrification, and the sewage treatment device comprises an intermediate pool, a sewage lifting pump, a water distribution channel, an autotrophic denitrification filter, a clean water pool, a clean water lifting pump and a next-stage treatment unit which are sequentially communicated, and the next-stage treatment unit comprises a total nitrogen automatic monitor, an overpass pipeline, a backflow pipeline and a controller. According to the real-time data of the total nitrogen automatic monitor of the intermediate pool and the clean water pool, the application reasonably allocates the sewage flow direction, avoids sulfur disproportionation reaction in a long-term low total nitrogen load period, ensures that the effluent quality always meets the discharge standard and reduces the risk of water quality exceeding the standard. Meanwhile, the application realizes efficient starting and stopping of the autotrophic denitrification filter, reduces the contact time and flow of the sewage and filter material, reduces the attachment amount of impurities and metabolic products on the filter material, effectively delays the clogging and aging of the autotrophic denitrification filter and prolongs the service life of the autotrophic denitrification filter.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a pipeline system and method for starting and stopping an autotrophic denitrification filter. Background Technology

[0002] Autotrophic denitrifying bacteria utilize inorganic carbon sources (such as CO2 and CO3) to denitrify. 2- etc.), in reduced inorganic substances (such as S, S2, etc.) 2- S2O3 2- Fe, Fe 2+ Using H2 and other electron donors, denitrification converts nitrate nitrogen into nitrogen gas without the need for an external organic carbon source, reducing operating costs and avoiding secondary pollution.

[0003] However, in wastewater treatment scenarios with low influent total nitrogen load, the concentrations of sulfur heterologous electron acceptors (nitrate nitrogen, nitrite nitrogen, dissolved oxygen, etc.) are low, and sulfur disproportionation plays a crucial role. Sulfur disproportionation is the process by which sulfur-disproportionating bacteria, under anaerobic conditions, utilize elemental sulfur to convert it into sulfides and sulfates. The sulfides generated in this process produce odors and simultaneously increase COD. Cr The temperature rises, seriously affecting the quality of external drainage. Summary of the Invention

[0004] The purpose of this invention is to provide a pipeline system and method for starting and stopping an autotrophic denitrification filter, so as to solve the problems mentioned in the background art.

[0005] To address the aforementioned technical problems, this invention provides a pipeline system and method for starting and stopping an autotrophic denitrification filter. It utilizes a wastewater treatment device based on autotrophic denitrification filter denitrification. The wastewater treatment device includes, in sequence, an intermediate water tank, a wastewater lift pump, a distribution channel, an autotrophic denitrification filter, a clear water tank, a clear water lift pump, and a next-stage treatment unit. The device includes an automatic total nitrogen monitor, a bypass pipe, a return pipe, and a controller. Two automatic total nitrogen monitors are installed at the outlets of the intermediate water tank and the clear water tank, respectively. The bypass pipe inlet is connected to the sewage lift pump outlet, the bypass pipe outlet is connected to the pipe after the clear water tank lift pump outlet, and the bypass pipe is equipped with a bypass valve. The return pipe inlet is connected to the pipe after the clear water lift pump outlet, the return pipe outlet is connected to the water distribution channel, and the return pipe is equipped with a return valve. The controller is electrically connected to the sewage lift pump, the clear water lift pump, the total nitrogen automatic monitor, the bypass valve, and the return valve.

[0006] Furthermore, the next-level processing unit is a V-shaped filter.

[0007] Furthermore, the clear water tank is equipped with perforated aeration pipes.

[0008] Furthermore, both the overpass valve and the return valve are electrically operated gate valves.

[0009] Furthermore, both the bypass pipe and the return pipe are equipped with flow meters, which are electromagnetic flow meters.

[0010] Furthermore, the autotrophic denitrification filter is filled with sulfur autotrophic filter media.

[0011] Furthermore, the water inlet of the water distribution channel is connected to its water outlet via a detachable funnel-shaped pipe.

[0012] Furthermore, the bypass pipe and the pipe after the outlet of the sewage lift pump, the return pipe and the pipe after the outlet of the clean water lift pump are all connected by a three-way valve.

[0013] Furthermore, the total nitrogen limit in the external wastewater quality standard is named T;

[0014] Based on the real-time data from the automatic total nitrogen monitor in the intermediate water tank, when the total nitrogen in the effluent from the intermediate water tank is less than T-1, the inlet valve, clear water lift pump, and return pipe valve of the distribution channel are closed, and the sewage lift pump and bypass pipe valve are opened. The effluent from the intermediate water tank is then lifted to the V-type filter via the sewage lift pump. The clear water lift pump and return pipe valve are opened for 1 hour every day, and the effluent from the clear water tank enters the distribution channel through the return pipe to maintain the biological activity of the autotrophic denitrification filter.

[0015] Based on the real-time data from the automatic total nitrogen monitoring instruments of the intermediate water tank and the clear water tank, when the total nitrogen in the effluent of the intermediate water tank is ≥T-1 and the total nitrogen in the effluent of the clear water tank is <T-1, the sewage lift pump, the inlet valve of the distribution channel and the clear water lift pump are opened, and the bypass valve and the return valve are closed. The effluent from the intermediate water tank is lifted to the distribution channel by the sewage lift pump, and the effluent from the clear water tank is lifted to the V-type filter by the clear water lift pump.

[0016] Based on real-time data from the automatic total nitrogen monitoring instruments in the intermediate water tank and the clear water tank, when the total nitrogen in the effluent from the intermediate water tank is ≥T-1 and the total nitrogen in the effluent from the clear water tank is ≥T-1, the sewage lift pump, the inlet valve of the distribution channel, the clear water lift pump, and the return pipe valve are opened, and the bypass pipe valve is closed. The effluent from the intermediate water tank is lifted to the distribution channel by the sewage lift pump, and the effluent from the clear water tank is lifted to the V-type filter by the clear water lift pump. At the same time, the return water volume is increased, so that a large amount of effluent from the clear water tank enters the distribution channel through the return pipe, thereby improving the total nitrogen removal effect and making the total nitrogen in the effluent from the clear water tank <T.

[0017] Furthermore, based on the real-time data from the automatic total nitrogen monitoring instruments of the intermediate water tank and the clear water tank, when the total nitrogen in the effluent of the intermediate water tank is ≥ T-1 and the total nitrogen in the effluent of the clear water tank is < T-1, and the inflow rate of the water distribution channel is less than the design load, the return pipe valve is opened to adjust the filtration rate of the effluent from the water distribution channel entering the denitrification filter, in order to prevent side reactions from occurring and causing the water quality of the clear water tank to deteriorate.

[0018] The beneficial effects of this invention are as follows: Based on real-time data from the automatic total nitrogen monitoring instruments of the intermediate water tank and clear water tank, this invention rationally allocates the wastewater flow direction, avoiding sulfur disproportionation reactions during prolonged periods of low total nitrogen load, ensuring that the effluent quality always meets discharge standards, and reducing the risk of exceeding water quality limits. Simultaneously, it enables efficient start-up and shutdown of the autotrophic denitrification filter, reducing the contact time and flow rate between wastewater and filter media, decreasing the amount of impurities and metabolic products adhering to the filter media, effectively delaying clogging and aging of the autotrophic denitrification filter, and extending its service life. In wastewater treatment scenarios where the total nitrogen load exhibits regular changes, it allows for flexible adjustment of the treatment process, saving treatment costs. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating the process flow of an embodiment of the present invention.

[0020] Figure 2 This is a diagram showing the water quality changes in the intermediate water tank after 90 days of operation. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely one embodiment of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0022] To make the objectives, technical solutions and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments.

[0023] In the following description, references to "an embodiment," "an embodiment," "an example," "example," etc., indicate that the described embodiment or example may include a particular feature, structure, characteristic, property, element, or limitation, but not every embodiment or example necessarily includes that particular feature, structure, characteristic, property, element, or limitation. Furthermore, the repeated use of the phrase "an embodiment according to this application," while possibly referring to the same embodiment, does not necessarily refer to the same embodiment.

[0024] like Figure 1-2As shown, this invention discloses a pipeline system for starting and stopping an autotrophic denitrification filter. It utilizes a wastewater treatment device based on autotrophic denitrification filter denitrification. The wastewater treatment device includes, in sequence, an intermediate water tank, a wastewater lift pump, a distribution channel, an autotrophic denitrification filter, a clear water tank, a clear water lift pump, and a next-stage treatment unit. It includes an automatic total nitrogen monitor, a bypass pipe, a return pipe, and a controller. Two automatic total nitrogen monitors are installed at the outlets of the intermediate water tank and the clear water tank, respectively. The inlet of the bypass pipe is connected to the outlet of the wastewater lift pump, and the outlet of the bypass pipe is connected to the pipe after the outlet of the clear water lift pump. A bypass valve is installed on the bypass pipe. The inlet of the return pipe is connected to the pipe after the outlet of the clear water lift pump, and the outlet of the return pipe is connected to the distribution channel. A return valve is installed on the return pipe. The controller is electrically connected to the wastewater lift pump, the clear water lift pump, the automatic total nitrogen monitor, the bypass valve, and the return valve, respectively, to achieve interlocked control.

[0025] In this embodiment, the outlet of the intermediate water tank is connected to the distribution channel through a sewage pipe. The distribution channel distributes water evenly to the autotrophic denitrification filter. The effluent from the autotrophic denitrification filter is collected in the clear water tank through a corridor. The sewage pipe is equipped with a flow meter for accurately measuring the amount of water entering the distribution channel.

[0026] When the total nitrogen monitor in the intermediate water tank detects that the influent total nitrogen is below the set value, the bypass valve is opened, allowing some or all of the wastewater to bypass the filter and directly enter the next treatment unit. This avoids the filter operating under low load and reduces the negative impact of disproportionation. When the total nitrogen monitor in the clear water tank detects that the effluent total nitrogen exceeds the standard, the return valve is opened, returning a portion of the treated clear water (containing nitrate nitrogen) to the distribution channel to mix with the raw water and dilute the influent concentration, or increasing the hydraulic retention time in the autotrophic denitrification filter to enhance denitrification efficiency. When the total nitrogen concentrations in the intermediate water tank and clear water tank are moderate, the wastewater is sequentially treated through the autotrophic denitrification filter.

[0027] This invention utilizes real-time data from automatic total nitrogen monitoring instruments in the intermediate and clear water tanks to rationally allocate wastewater flow, avoiding sulfur disproportionation reactions during prolonged periods of low total nitrogen load. This ensures that the effluent quality consistently meets discharge standards and reduces the risk of exceeding quality limits. Simultaneously, it enables efficient start-up and shutdown of the autotrophic denitrification filter, reducing the contact time and flow rate between wastewater and filter media. This decreases the amount of impurities and metabolic products adhering to the filter media, effectively delaying clogging and aging of the autotrophic denitrification filter and extending its service life. In wastewater treatment scenarios where total nitrogen load exhibits regular changes, the treatment process can be flexibly adjusted, saving treatment costs.

[0028] In one embodiment, the next-stage treatment unit is a V-type filter. Continuous filtration is achieved through a single layer of homogeneous filter media (such as quartz sand), while an air-lift sand device lifts dirty sand to a sand washer, where the filter media is regenerated by hydraulic washing. No backwashing is required, forming a synergistic system of "biological denitrification-physical filtration" to achieve simultaneous optimization of multiple water quality indicators.

[0029] In one embodiment, the clear water tank is equipped with perforated aeration pipes. In this embodiment, the perforation diameter of the aeration pipes is 1-3 mm, and the spacing between the perforations is 50-100 mm. Aeration increases the dissolved oxygen (DO) concentration in the clear water tank, preventing the growth of anaerobic microorganisms such as sulfur dismutase bacteria and thus preventing the formation of secondary sulfides. Simultaneously, the rising bubbles generated by aeration create water flow turbulence, preventing sulfur particles and biofilm residue from settling at the bottom of the tank and promoting their entry into the next treatment unit (such as a V-type filter) for retention.

[0030] In one embodiment, both the overpass valve and the return valve are electric gate valves. The electric gate valves have a fast response, which keeps the influent flow to the filter bed low and ensures the stability of the sulfur autotrophic denitrifying bacteria community.

[0031] In one embodiment, flow meters, specifically electromagnetic flow meters, are installed on both the bypass and return pipes. These electromagnetic flow meters can provide real-time feedback on flow changes in the bypass and return pipes, thereby regulating the flow rates in both pipes.

[0032] In one embodiment, the autotrophic denitrification filter is filled with sulfur autotrophic filter media, eliminating the need for an external carbon source.

[0033] In one embodiment, the inlet of the water distribution channel is connected to its outlet via a detachable funnel-shaped pipe, which reduces water drop and oxygenation during use.

[0034] In one embodiment, the bypass pipe and the pipes after the sewage lift pump outlet, the return pipe, and the pipes after the clean water lift pump outlet are all connected by a three-way valve. This allows the bypass pipe and the return pipe to be flexibly connected to the main process pipe, enabling the diversion or mixing of water flows.

[0035] A method for starting and stopping an autotrophic denitrification filter, comprising a pipeline system for starting and stopping the autotrophic denitrification filter as described above, wherein the total nitrogen limit in the external wastewater quality standard is named T;

[0036] Based on real-time data from the automatic total nitrogen monitor in the intermediate water tank, when the total nitrogen in the effluent from the intermediate water tank is less than T-1, the controller closes the inlet valve, clear water lift pump, and return pipe valve of the distribution channel, and opens the sewage lift pump and bypass valve. The effluent from the intermediate water tank is then lifted to the V-type filter via the sewage lift pump. The clear water lift pump and return pipe valve are opened for 1 hour every day, and the effluent from the clear water tank enters the distribution channel through the return pipe to maintain the biological activity of the autotrophic denitrification filter.

[0037] Based on the real-time data from the automatic total nitrogen monitoring instruments of the intermediate water tank and the clear water tank, when the total nitrogen in the effluent of the intermediate water tank is ≥T-1 and the total nitrogen in the effluent of the clear water tank is <T-1, the controller opens the sewage lift pump, the inlet valve of the distribution channel and the clear water lift pump, and closes the bypass valve and the return valve. The effluent from the intermediate water tank is lifted to the distribution channel by the sewage lift pump, and the effluent from the clear water tank is lifted to the V-type filter by the clear water lift pump.

[0038] Based on real-time data from the automatic total nitrogen monitoring instruments in the intermediate water tank and the clear water tank, when the total nitrogen in the effluent from the intermediate water tank is ≥T-1 and the total nitrogen in the effluent from the clear water tank is ≥T-1, the controller opens the sewage lift pump, the inlet valve of the distribution channel, the clear water lift pump, and the return pipe valve, and closes the bypass valve. The effluent from the intermediate water tank is lifted to the distribution channel by the sewage lift pump, and the effluent from the clear water tank is lifted to the V-type filter by the clear water lift pump. At the same time, the return water volume is increased, so that a large amount of effluent from the clear water tank enters the distribution channel through the return pipe, thereby improving the total nitrogen removal effect and making the total nitrogen in the effluent from the clear water tank <T.

[0039] In one embodiment, based on real-time data from the automatic total nitrogen monitoring instruments of the intermediate water tank and the clear water tank, when the total nitrogen in the effluent of the intermediate water tank is ≥ T-1 and the total nitrogen in the effluent of the clear water tank is < T-1, the return pipe valve is opened when the inflow rate of the water distribution channel is less than the design load, and the filtration rate of the effluent from the water distribution channel entering the denitrification filter is adjusted to prevent side reactions from causing the water quality of the clear water tank to deteriorate.

[0040] This embodiment is applied to treat RO concentrate from a municipal wastewater treatment plant:

[0041] The wastewater treatment device implemented here includes an intermediate water tank, a wastewater lift pump, a distribution channel, an autotrophic denitrification filter, a clear water tank, and a clear water lift pump. The outlet of the intermediate water tank is connected to the distribution channel via a wastewater pipe equipped with a flow meter. The effluent from the intermediate water tank is pumped to the distribution channel via the wastewater lift pump. The inlet of the distribution channel is connected to its outlet via a detachable funnel-shaped pipe, which reduces water drop and oxygenation during use. The distribution channel evenly distributes water to the autotrophic denitrification filter filled with sulfur autotrophic filter media. The effluent from the autotrophic denitrification filter is collected in the clear water tank via a corridor. The clear water tank is equipped with perforated aeration pipes with a perforation diameter of 2 mm and a perforation spacing of 100 mm. The effluent from the clear water tank is pumped to the V-type filter via the clear water lift pump.

[0042] The pipeline system includes an automatic total nitrogen monitor, bypass pipes, bypass valves, return pipes, return valves, and a control system. Both bypass and return pipes are equipped with electromagnetic flow meters. Both bypass and return valves are electric gate valves. The controller is electrically connected to the sewage lift pump, the clean water lift pump, the automatic total nitrogen monitor, the bypass valve, and the return valve, respectively, to achieve interlocked control. One end of the bypass pipe is connected to the pipeline after the outlet of the sewage lift pump via a three-way valve, and the other end is connected to the pipeline after the outlet of the clean water tank lift pump. One end of the return pipe is connected to the pipeline after the outlet of the clean water lift pump via a three-way valve, and the other end is connected to the distribution channel. The automatic total nitrogen monitor monitors the total nitrogen pollutant content in the effluent from the intermediate water tank and the clean water tank in real time.

[0043] The total nitrogen limit in the external wastewater quality standard is named T. According to the Class A standard of "Pollutant Discharge Standard for Urban Wastewater Treatment Plants" GB18918-2002, T is 15 mg / L. The filtration rate of the autotrophic denitrification filter is controlled at 3.0–4.2 m / h.

[0044] The steps for starting and stopping the autotrophic denitrification filter in this embodiment are as follows:

[0045] Based on real-time data from the automatic total nitrogen monitor in the intermediate water tank, when the total nitrogen in the effluent from the intermediate water tank is <14, the controller closes the inlet valve, clear water lift pump, and return pipe valve of the distribution channel, and opens the sewage lift pump and bypass valve. The effluent from the intermediate water tank is then lifted to the V-type filter via the sewage lift pump. The clear water lift pump and return pipe valve are opened for 1 hour every day, and the effluent from the clear water tank enters the distribution channel through the return pipe to maintain the biological activity of the autotrophic denitrification filter.

[0046] Based on real-time data from the automatic total nitrogen monitoring instruments in the intermediate water tank and clear water tank, when the total nitrogen in the effluent from the intermediate water tank is ≥14 and the total nitrogen in the effluent from the clear water tank is <14, the controller opens the sewage lift pump, the inlet valve of the distribution channel, and the clear water lift pump, and closes the bypass valve and the return valve. The effluent from the intermediate water tank is then pumped to the distribution channel by the sewage lift pump, and the effluent from the clear water tank is pumped to the V-type filter by the clear water lift pump. When the inflow rate of the distribution channel is less than 708 m³ / h... 3 When the flow rate is 4.0 m / h, open the return pipe control valve and adjust the filtration rate of the water from the distribution channel into the denitrification filter to 4.0-4.2 m / h to prevent side reactions from causing the water quality in the clear water tank to deteriorate.

[0047] Based on real-time data from the automatic total nitrogen monitoring instruments in the intermediate water tank and the clear water tank, when the total nitrogen in the effluent from the intermediate water tank is ≥14 and the total nitrogen in the effluent from the clear water tank is ≥14, the controller opens the sewage lift pump, the inlet valve of the distribution channel, the clear water lift pump, and the return pipe valve, and closes the bypass valve. The effluent from the intermediate water tank is lifted to the distribution channel by the sewage lift pump, and the effluent from the clear water tank is lifted to the V-type filter by the clear water lift pump. At the same time, the return water volume is increased, so that a large amount of effluent from the clear water tank enters the distribution channel through the return pipe, thereby improving the total nitrogen removal effect and making the total nitrogen in the effluent from the clear water tank <15.

[0048] This invention utilizes real-time data from automatic total nitrogen monitoring instruments in the intermediate and clear water tanks to rationally allocate wastewater flow, avoiding sulfur disproportionation reactions during prolonged periods of low total nitrogen load. This ensures that the effluent quality consistently meets discharge standards and reduces the risk of exceeding quality limits. Simultaneously, it enables efficient start-up and shutdown of the autotrophic denitrification filter, reducing the contact time and flow rate between wastewater and filter media. This decreases the amount of impurities and metabolic products adhering to the filter media, effectively delaying clogging and aging of the autotrophic denitrification filter and extending its service life. In wastewater treatment scenarios where total nitrogen load exhibits regular changes, the treatment process can be flexibly adjusted, saving treatment costs.

[0049] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A pipeline system for starting and stopping an autotrophic denitrification filter, which uses a wastewater treatment device based on autotrophic denitrification filter denitrification, the wastewater treatment device comprising, in sequence, an intermediate water tank, a wastewater lift pump, a distribution channel, an autotrophic denitrification filter, a clear water tank, a clear water lift pump, and a next-stage treatment unit, characterized in that: The system includes an automatic total nitrogen monitor, an bypass pipe, a return pipe, and a controller. Two automatic total nitrogen monitors are installed at the outlet of the intermediate water tank and the outlet of the clear water tank, respectively. The inlet of the bypass pipe is connected to the outlet of the sewage lift pump, and the outlet of the bypass pipe is connected to the pipe downstream of the outlet of the clear water lift pump. An bypass valve is installed on the bypass pipe. The inlet of the return pipe is connected to the pipe downstream of the outlet of the clear water lift pump, and the outlet of the return pipe is connected to the water distribution channel. A return valve is installed on the return pipe. The controller is electrically connected to the sewage lift pump, the clear water lift pump, the automatic total nitrogen monitor, the bypass valve, and the return valve, respectively.

2. The pipeline system for starting and stopping an autotrophic denitrification filter according to claim 1, characterized in that: The next stage of processing is a V-shaped filter.

3. The pipeline system for starting and stopping an autotrophic denitrification filter according to claim 1, characterized in that: The clear water tank is equipped with perforated aeration pipes.

4. The pipeline system for starting and stopping an autotrophic denitrification filter according to claim 1, characterized in that: Both the overpass valve and the return valve are electrically operated gate valves.

5. The pipeline system for starting and stopping an autotrophic denitrification filter according to claim 1, characterized in that: Both the bypass pipe and the return pipe are equipped with flow meters, which are electromagnetic flow meters.

6. The pipeline system for starting and stopping an autotrophic denitrification filter according to claim 1, characterized in that: The autotrophic denitrification filter is filled with sulfur autotrophic filter media.

7. The pipeline system for starting and stopping an autotrophic denitrification filter according to claim 1, characterized in that: The water inlet of the water distribution channel is connected to its distribution outlet via a detachable funnel-shaped pipe.

8. The pipeline system for starting and stopping an autotrophic denitrification filter according to claim 1, characterized in that: The bypass pipe and the pipe after the outlet of the sewage lift pump, the return pipe and the pipe after the outlet of the clean water lift pump are all connected by a three-way valve.

9. A method for starting and stopping an autotrophic denitrification filter, comprising the piping system for starting and stopping an autotrophic denitrification filter as described in any one of claims 1-8, characterized in that: The total nitrogen limit in the external water quality standard is named T; Based on the real-time data from the automatic total nitrogen monitor in the intermediate water tank, when the total nitrogen in the effluent from the intermediate water tank is less than T-1, the inlet valve, clear water lift pump, and return pipe valve of the distribution channel are closed, and the sewage lift pump and bypass pipe valve are opened. The effluent from the intermediate water tank is then lifted to the V-type filter via the sewage lift pump. The clear water lift pump and return pipe valve are opened for 1 hour every day, and the effluent from the clear water tank enters the distribution channel through the return pipe to maintain the biological activity of the autotrophic denitrification filter. Based on the real-time data from the automatic total nitrogen monitoring instruments of the intermediate water tank and the clear water tank, when the total nitrogen in the effluent of the intermediate water tank is ≥T-1 and the total nitrogen in the effluent of the clear water tank is <T-1, the sewage lift pump, the inlet valve of the distribution channel and the clear water lift pump are opened, and the bypass valve and the return valve are closed. The effluent from the intermediate water tank is lifted to the distribution channel by the sewage lift pump, and the effluent from the clear water tank is lifted to the V-type filter by the clear water lift pump. Based on real-time data from the automatic total nitrogen monitoring instruments in the intermediate water tank and the clear water tank, when the total nitrogen in the effluent from the intermediate water tank is ≥T-1 and the total nitrogen in the effluent from the clear water tank is ≥T-1, the sewage lift pump, the inlet valve of the distribution channel, the clear water lift pump, and the return pipe valve are opened, and the bypass pipe valve is closed. The effluent from the intermediate water tank is lifted to the distribution channel by the sewage lift pump, and the effluent from the clear water tank is lifted to the V-type filter by the clear water lift pump. At the same time, the return water volume is increased, so that a large amount of effluent from the clear water tank enters the distribution channel through the return pipe, thereby improving the total nitrogen removal effect and making the total nitrogen in the effluent from the clear water tank <T.

10. A method for starting and stopping an autotrophic denitrification filter according to claim 9, characterized in that: Based on real-time data from the automatic total nitrogen monitoring instruments in the intermediate water tank and the clear water tank, when the total nitrogen in the effluent from the intermediate water tank is ≥ T-1 and the total nitrogen in the effluent from the clear water tank is < T-1, and the inflow rate of the water distribution channel is less than the design load, the return pipe valve is opened to adjust the filtration rate of the effluent from the water distribution channel entering the denitrification filter, in order to prevent side reactions from occurring and causing the water quality in the clear water tank to deteriorate.

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