Pipeline system and method for starting and stopping autotrophic denitrification filter

Abstract

According to the pipeline system and method for starting and stopping the autotrophic denitrification filter, a sewage treatment device based on nitrogen removal of the autotrophic denitrification filter is used, and the sewage treatment device comprises a middle water tank, a sewage lifting pump, a water distribution channel, the autotrophic denitrification filter, a clean water tank, a clean water lifting pump and a next-stage treatment unit which are sequentially communicated, the device comprises an automatic total nitrogen monitor, an overrun pipeline, a backflow pipeline and a controller. According to the real-time data of the total nitrogen automatic monitors for the effluent of the intermediate water tank and the clean water tank, the flow direction of the sewage is reasonably distributed, sulfur disproportionation reaction in a long-term low total nitrogen load period is avoided, the effluent quality is ensured to always meet the discharge standard, and the risk that the water quality exceeds the standard is reduced. Meanwhile, the autotrophic denitrification filter tank is efficiently started and stopped, the contact time and flow of sewage and a filter material are reduced, the adhesion amount of impurities and metabolites on the filter material is reduced, the blockage and aging of the autotrophic denitrification filter tank are effectively delayed, and the service life of the autotrophic denitrification filter tank is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a pipeline system and method for starting and stopping an autotrophic denitrification filter. Background Art

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

[0003] However, in the case of low total nitrogen load in wastewater treatment, the concentration of sulfur heterologous electron acceptors (nitrate nitrogen, nitrite nitrogen, dissolved oxygen, etc.) is low, and sulfur disproportionation reaction plays a key role. Sulfur disproportionation reaction is the process in which sulfur disproportionating bacteria use sulfur to convert it into sulfide and sulfate under anaerobic conditions. The sulfide generated in this process produces odor and causes COD Cr Increased, seriously affecting the drainage quality. Summary of the Invention

[0004] The purpose of the present invention is to provide a pipeline system and method for starting and stopping an autotrophic denitrification filter to solve the problems mentioned in the above background technology.

[0005] To solve the above technical problems, the present invention provides a pipeline system and method for starting and stopping an autotrophic denitrification filter, which uses a sewage treatment device based on denitrification of the autotrophic denitrification filter. The sewage treatment device includes an intermediate water tank, a sewage lifting pump, a water distribution channel, an autotrophic denitrification filter, a clear water tank, a clear water lifting pump and a next-level treatment unit connected in sequence, and includes a total nitrogen automatic monitor, a transcending pipe, a return pipe and a controller. The number of the total nitrogen automatic monitors is two, which are respectively arranged at the water outlet of the intermediate water tank and the water outlet of the clear water tank. The water inlet of the override pipe is connected to the pipe of the water outlet of the sewage lift pump, the water outlet of the override pipe is connected to the pipe behind the water outlet of the clean water tank lift pump, a override pipe valve is provided on the override pipe, the water inlet of the return pipe is connected to the pipe behind the water outlet of the clean water lift pump, the water outlet of the return pipe is connected to the water distribution channel, a return pipe valve is provided on the return pipe, and the controller is electrically connected to the sewage lift pump, the clean water lift pump, the total nitrogen automatic monitor, the override pipe valve and the return pipe valve respectively.

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

[0007] Furthermore, the clean water tank is equipped with a perforated aeration pipe.

[0008] Furthermore, the overflow pipe valve and the return pipe valve are both electric gate valves.

[0009] Furthermore, flow meters are installed on both the overflow pipe and the return pipe, and the flow meters are electromagnetic flow meters.

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

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

[0012] Furthermore, the overtaking pipe and the pipe behind the water outlet of the sewage lifting pump, and the return pipe and the pipe behind the water outlet of the clean water lifting pump are all connected through a three-way valve.

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

[0014] According to the real-time data of the total nitrogen automatic monitoring instrument of the intermediate water tank, when the total nitrogen in the effluent of the intermediate water tank is less than T-1, the water inlet valve, clean water lifting pump and return pipe valve of the water distribution channel are closed, and the sewage lifting pump and the overflow pipe valve are opened. The effluent of the intermediate water tank is lifted to the V-type filter by the sewage lifting pump; the clean water lifting pump and the return pipe valve are opened for 1 hour every day, and the effluent of the clean water tank enters the water distribution channel through the return pipe to maintain the biological activity of the autotrophic denitrification filter;

[0015] According to the real-time data of the total nitrogen automatic monitoring instrument of the intermediate water tank and the clean water tank, when the total nitrogen of the effluent from the intermediate water tank is ≥T-1 and the total nitrogen of the effluent from the clean water tank is <T-1, the sewage lifting pump, the water inlet valve of the distribution channel and the clean water lifting pump are opened, the overrun pipe valve and the return pipe valve are closed, and the effluent from the intermediate water tank is lifted to the distribution channel by the sewage lifting pump, and the effluent from the clean water tank is lifted to the V-type filter by the clean water lifting pump;

[0016] According to the real-time data of the total nitrogen automatic monitoring instrument of the intermediate water tank and the clear water tank, when the total nitrogen of the effluent from the intermediate water tank is ≥T-1 and the total nitrogen of the effluent from the clear water tank is ≥T-1, the sewage lifting pump, the water inlet valve of the distribution channel, the clean water lifting pump and the return pipe valve are opened, and the overflow pipe valve is closed. The effluent from the intermediate water tank is lifted to the distribution channel by the sewage lifting pump, and the effluent from the clear water tank is lifted to the V-type filter tank by the clean water lifting 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 of the effluent from the clear water tank <T.

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

[0018] The beneficial effects of the present invention are as follows: the present invention rationally distributes the flow direction of sewage based on the real-time data of the total nitrogen automatic monitoring instrument of the effluent from the intermediate water tank and the clear water tank, avoids the generation of sulfur disproportionation reaction during the long-term period of low total nitrogen load, ensures that the effluent water quality always meets the emission standards, and reduces the risk of water quality exceeding the standard. At the same time, the autotrophic denitrification filter is started and stopped efficiently, the contact time and flow rate between the sewage and the filter material are reduced, the amount of impurities and metabolites attached to the filter material is reduced, the blockage and aging of the autotrophic denitrification filter are effectively delayed, and the service life of the autotrophic denitrification filter is extended. In sewage treatment scenarios where the total nitrogen load shows regular changes, the treatment process can be flexibly adjusted to save treatment costs. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0020] Figure 2 This is a diagram showing the water quality changes in the intermediate pool after 90 days of operation. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiment is only one embodiment of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0022] In order to make the objectives, technical solutions and advantages of this application clearer, this application is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] In the following description, references to "one embodiment," "an embodiment," "an example," "an example," etc. indicate that the embodiment or example described may include certain features, structures, characteristics, properties, elements, or limitations, but not every embodiment or example necessarily includes the certain features, structures, characteristics, properties, elements, or limitations. In addition, repeated use of the phrase "according to one embodiment of the present application" may refer to the same embodiment, but does not necessarily refer to the same embodiment.

[0024] like Figure 1-2As shown, the present invention discloses a pipeline system for starting and stopping an autotrophic denitrification filter, which uses a sewage treatment device based on denitrification of the autotrophic denitrification filter, the sewage treatment device comprising an intermediate water tank, a sewage lifting pump, a water distribution channel, an autotrophic denitrification filter, a clean water tank, a clean water lifting pump and a next-level treatment unit connected in sequence, comprising an automatic total nitrogen monitor, an override pipe, a return pipe and a controller, two automatic total nitrogen monitors are respectively arranged at the water outlet of the intermediate water tank and the water outlet of the clean water tank, the water inlet of the override pipe is connected to the pipe at the water outlet of the sewage lifting pump, the water outlet of the override pipe is connected to the pipe behind the water outlet of the clean water tank lifting pump, the override pipe valve is provided on the override pipe, the water inlet of the return pipe is connected to the pipe behind the water outlet of the clean water lifting pump, the water outlet of the return pipe is connected to the water distribution channel, the return pipe valve is provided on the return pipe, and the controller is electrically connected to the sewage lifting pump, the clean water lifting pump, the automatic total nitrogen monitor, the override pipe valve and the return pipe valve respectively to realize chain 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 evenly distributes water to the autotrophic denitrification filter. The effluent from the autotrophic denitrification filter is collected into the clear water tank through a corridor. The sewage pipe is installed with a flow meter for accurately measuring the amount of water entering the distribution channel.

[0026] When the total nitrogen monitor in the intermediate tank detects that the total nitrogen in the influent is lower than the set value, the bypass valve is opened, allowing some or all of the sewage to bypass the filter tank and enter the next-level treatment unit directly, preventing the filter tank from operating at a low load and reducing the negative impact of the disproportionation reaction. When the total nitrogen monitor in the clear water tank detects that the total nitrogen in the effluent exceeds the standard, the return valve is opened to return some of the treated clean water (containing nitrate nitrogen) to the distribution channel to mix with the raw water to dilute the influent concentration, or to increase the hydraulic retention time in the autotrophic denitrification filter to enhance denitrification efficiency. When the total nitrogen concentration in the intermediate tank and the clear water tank is moderate, the sewage is treated in the autotrophic denitrification filter in sequence.

[0027] The present invention rationally distributes the sewage flow direction based on the real-time data of the total nitrogen automatic monitoring instrument of the effluent from the intermediate water tank and the clear water tank, avoids the generation of sulfur disproportionation reaction during the long-term period of low total nitrogen load, ensures that the effluent water quality always meets the emission standards, and reduces the risk of water quality exceeding the standard. At the same time, the autotrophic denitrification filter is started and stopped efficiently, the contact time and flow rate between the sewage and the filter material are reduced, the amount of impurities and metabolites attached to the filter material is reduced, the blockage and aging of the autotrophic denitrification filter are effectively delayed, and the service life of the autotrophic denitrification filter is extended. In the sewage treatment scenario where the total nitrogen load shows regular changes, the treatment process can be flexibly adjusted to save treatment costs.

[0028] In one embodiment, the next-level treatment unit is a V-shaped filter tank. Continuous filtration is achieved through a single layer of homogeneous filter media (such as quartz sand). An air sand lifter is used to lift dirty sand to a sand washer, where the filter media is regenerated through hydraulic flushing without stopping for backwashing. This forms a synergistic "biological denitrification-physical filtration" system, achieving simultaneous optimization of multiple water quality indicators.

[0029] In one embodiment, the clear water tank is equipped with perforated aeration tubes. In this embodiment, the perforated aeration tubes have a pore diameter of 1-3 mm and a pore spacing of 50-100 mm. Aeration increases the dissolved oxygen (DO) concentration in the clear water tank, preventing the growth of anaerobic microorganisms such as sulfur disproportionate bacteria within the tank and preventing the formation of secondary sulfides. Furthermore, the rising bubbles generated by aeration create turbulent water flow, preventing sulfur particles and biofilm residues from settling at the tank bottom, and promoting their entry into the next-level treatment unit (such as a V-type filter) with the water flow and their capture.

[0030] In one embodiment, the overrun pipe valve and the return pipe valve are both electric gate valves. The electric gate valves respond quickly, so that the water inflow to the filter tank fluctuates little, ensuring the stability of the sulfur autotrophic denitrifying bacteria group.

[0031] In one embodiment, a flow meter is installed on both the overrunning pipe and the return pipe, and the flow meter is an electromagnetic flow meter. The electromagnetic flow meter can provide real-time feedback on flow changes in the overrunning pipe and the return pipe, thereby adjusting the flow of the overrunning pipe and the return pipe.

[0032] In one embodiment, the autotrophic denitrification filter is filled with sulfur autotrophic filter material without the need for an external carbon source.

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

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

[0035] A method for starting and stopping an autotrophic denitrification filter, comprising any of the above-mentioned pipeline systems for starting and stopping an autotrophic denitrification filter, wherein the total nitrogen limit in the outflow water quality standard is named T;

[0036] Based on the real-time data from the automatic nitrogen monitoring instrument 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 water inlet valve, clean water lifting pump, and return pipe valve of the water distribution channel, opens the sewage lifting pump and the bypass pipe valve, and the effluent from the intermediate water tank is lifted to the V-type filter by the sewage lifting pump; the clean water lifting pump and return pipe valve are turned on for 1 hour every day, and the effluent from the clean water tank enters the water distribution channel through the return pipe to maintain the biological activity of the autotrophic denitrification filter;

[0037] According to the real-time data of the total nitrogen automatic monitoring instrument of the intermediate water tank and the clean water tank, when the total nitrogen of the effluent from the intermediate water tank is ≥T-1 and the total nitrogen of the effluent from the clean water tank is <T-1, the controller opens the sewage lifting pump, the water inlet valve of the distribution channel and the clean water lifting pump, closes the overrun pipe valve and the return pipe valve, and the effluent from the intermediate water tank is lifted to the distribution channel by the sewage lifting pump, and the effluent from the clean water tank is lifted to the V-type filter by the clean water lifting pump;

[0038] According to the real-time data of the total nitrogen automatic monitoring instrument 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 turns on the sewage lifting pump, the water inlet valve of the distribution channel, the clean water lifting pump and the return pipe valve, and closes the override pipe valve. The effluent of the intermediate water tank is lifted to the distribution channel by the sewage lifting pump, and the effluent of the clear water tank is lifted to the V-type filter tank by the clean water lifting 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 of the clear water tank <T.

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

[0040] This example was used to treat RO concentrated water from a city sewage treatment plant:

[0041] The sewage treatment plant in this implementation includes an intermediate water tank, a sewage 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 sewage pipe equipped with a flow meter. The effluent from the intermediate water tank is delivered to the distribution channel via the sewage 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 operation. 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 through a corridor and fed to the clear water tank. The clear water tank is equipped with perforated aeration pipes with a 2mm diameter and a 100mm spacing. The outlet of the clear water tank is delivered to the V-shaped filter via the clear water lift pump.

[0042] The piping system includes an automatic total nitrogen monitor, an override pipe, an override valve, a return pipe, a return valve, and a control system. Both the override and return pipes are equipped with electromagnetic flowmeters. Both the override valve and return valve are electric gate valves. The controller is electrically connected to the sewage lift pump, clean water lift pump, automatic total nitrogen monitor, override valve, and return valve, respectively, to achieve interlocking control. One end of the override pipe is connected to the pipe behind the sewage lift pump outlet via a three-way valve, and the other end is connected to the pipe behind the clean water tank lift pump outlet. One end of the return pipe is connected to the pipe behind the clean water lift pump outlet 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 water effluent from the intermediate pool and the clean water tank in real time.

[0043] The total nitrogen limit in the outflow water quality standard is named T. According to the Level A standard of the 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 to 3.0-4.2 m / h.

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

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

[0046] According to the real-time data of the total nitrogen automatic monitoring instrument of the intermediate water tank and the clean water tank, when the total nitrogen of the effluent from the intermediate water tank is ≥14 and the total nitrogen of the effluent from the clean water tank is <14, the controller opens the sewage lifting pump, the water inlet valve of the distribution channel and the clean water lifting pump, closes the overrun pipe valve and the return pipe valve, and the effluent from the intermediate water tank is lifted to the distribution channel by the sewage lifting pump, and the effluent from the clean water tank is lifted to the V-type filter by the clean water lifting pump; when the water inlet flow of the distribution channel is less than 708m 3 / h, open the return pipe control valve and adjust the filtration rate of the water from the distribution channel into the denitrification filter to 4.0-4.2m / h to prevent the occurrence of side reactions that may cause the water quality of the clear water tank to deteriorate;

[0047] According to the real-time data of the total nitrogen automatic monitoring instrument of the intermediate water tank and the clear water tank, when the total nitrogen of the effluent from the intermediate water tank is ≥14 and the total nitrogen of the effluent from the clear water tank is ≥14, the controller starts the sewage lifting pump, the water inlet valve of the distribution channel, the clean water lifting pump and the return pipe valve, closes the override pipe valve, and the effluent from the intermediate water tank is lifted to the distribution channel by the sewage lifting pump, and the effluent from the clear water tank is lifted to the V-type filter by the clean water lifting 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 of the effluent from the clear water tank <15.

[0048] The present invention rationally distributes the sewage flow direction based on the real-time data of the total nitrogen automatic monitoring instrument of the effluent from the intermediate water tank and the clear water tank, avoids the generation of sulfur disproportionation reaction during the long-term period of low total nitrogen load, ensures that the effluent water quality always meets the emission standards, and reduces the risk of water quality exceeding the standard. At the same time, the autotrophic denitrification filter is started and stopped efficiently, the contact time and flow rate between the sewage and the filter material are reduced, the amount of impurities and metabolites attached to the filter material is reduced, the blockage and aging of the autotrophic denitrification filter are effectively delayed, and the service life of the autotrophic denitrification filter is extended. In the sewage treatment scenario where the total nitrogen load shows regular changes, the treatment process can be flexibly adjusted to save treatment costs.

[0049] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one 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 present invention is not limited to the embodiments shown herein, but is to be construed in the widest possible manner 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 sewage treatment device based on denitrification of the autotrophic denitrification filter, the sewage treatment device comprising an intermediate water tank, a sewage lifting pump, a water distribution channel, an autotrophic denitrification filter, a clear water tank, a clear water lifting pump, and a next-level treatment unit connected in sequence, characterized in that: It includes an automatic total nitrogen monitor, an override pipe, a return pipe and a controller. There are two automatic total nitrogen monitors, which are respectively arranged at the water outlet of the intermediate water tank and the water outlet of the clean water tank. The water inlet of the override pipe is connected to the pipe of the water outlet of the sewage lifting pump, and the water outlet of the override pipe is connected to the pipe behind the water outlet of the clean water tank lifting pump. The override pipe is provided with an override pipe valve. The water inlet of the return pipe is connected to the pipe behind the water outlet of the clean water lifting pump, and the water outlet of the return pipe is connected to the water distribution channel. The return pipe is provided with a return pipe valve. The controller is electrically connected to the sewage lifting pump, the clean water lifting pump, the automatic total nitrogen monitor, the override pipe valve and the return pipe valve respectively.

2. The pipeline system for starting and stopping an autotrophic denitrification filter according to claim 1, characterized in that: The next-stage processing unit 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 a perforated aeration pipe.

4. The pipeline system for starting and stopping an autotrophic denitrification filter according to claim 1, characterized in that: The overrun pipe valve and the return pipe valve are both electric gate valves.

5. The pipeline system for starting and stopping an autotrophic denitrification filter according to claim 1, characterized in that: Flow meters are installed on both the surpassing pipe and the return pipe, and the flow meters 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 material.

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 communicated with its water 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 overtaking pipe and the pipe behind the water outlet of the sewage lifting pump, the return pipe and the pipe behind the water outlet of the clean water lifting pump are all connected through a three-way valve.

9. A method for starting and stopping an autotrophic denitrification filter, comprising the pipeline system for starting and stopping an autotrophic denitrification filter according to any one of claims 1 to 8, characterized in that: The total nitrogen limit in the outflow water quality standard is named T; According to the real-time data of the total nitrogen automatic monitoring instrument of the intermediate water tank, when the total nitrogen in the effluent of the intermediate water tank is less than T-1, the water inlet valve, clean water lifting pump and return pipe valve of the water distribution channel are closed, and the sewage lifting pump and the overflow pipe valve are opened. The effluent of the intermediate water tank is lifted to the V-type filter by the sewage lifting pump; the clean water lifting pump and the return pipe valve are opened for 1 hour every day, and the effluent of the clean water tank enters the water distribution channel through the return pipe to maintain the biological activity of the autotrophic denitrification filter; According to the real-time data of the total nitrogen automatic monitoring instrument of the intermediate water tank and the clean water tank, when the total nitrogen of the effluent from the intermediate water tank is ≥T-1 and the total nitrogen of the effluent from the clean water tank is <T-1, the sewage lifting pump, the water inlet valve of the distribution channel and the clean water lifting pump are opened, the overrun pipe valve and the return pipe valve are closed, and the effluent from the intermediate water tank is lifted to the distribution channel by the sewage lifting pump, and the effluent from the clean water tank is lifted to the V-type filter by the clean water lifting pump; According to the real-time data of the total nitrogen automatic monitoring instrument of the intermediate water tank and the clear water tank, when the total nitrogen of the effluent from the intermediate water tank is ≥T-1 and the total nitrogen of the effluent from the clear water tank is ≥T-1, the sewage lifting pump, the water inlet valve of the distribution channel, the clean water lifting pump and the return pipe valve are opened, and the overflow pipe valve is closed. The effluent from the intermediate water tank is lifted to the distribution channel by the sewage lifting pump, and the effluent from the clear water tank is lifted to the V-type filter tank by the clean water lifting 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 of the effluent from the clear water tank <T.

10. The method for starting and stopping an autotrophic denitrification filter according to claim 9, characterized in that: According to the real-time data of the automatic total nitrogen monitoring instrument in 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, when the water inlet flow rate of the distribution channel is less than the design load, the return pipe valve is opened and the filtration rate of the effluent of the distribution channel entering the denitrification filter is adjusted to prevent the occurrence of side reactions that may cause the water quality of the clear water tank to deteriorate.

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