Water oxygen control and denitrification device and oxygen control and denitrification method

Abstract

The invention belongs to the technical field of sewage treatment, and discloses a water oxygen control and denitrification device and method, and the device comprises a container body which is divided into an oxygen elimination zone, a water inlet zone, a denitrification carrier zone and a clear water zone from top to bottom; the vacuumizer is communicated with the oxygen elimination area through a vacuum pipeline, and a vacuum valve is arranged on the vacuum pipeline; the lifting pump is connected with the container body through a water inlet pipeline and conveys water to be treated to the oxygen elimination area and / or the water inlet area, and a water inlet valve is arranged on the water inlet pipeline; the water producing pump is connected with the clear water area through a water outlet pipeline, and a water outlet valve is arranged on the water outlet pipeline. The method is carried out based on the device. The method can solve the inhibition effect of high dissolved oxygen in secondary biochemical treatment effluent of natural water and sewage plants on the autotrophic denitrification technology, realizes denitrification treatment of river and lake water and high dissolved oxygen sewage by using the autotrophic denitrification technology, does not need to add an organic carbon source and an oxygen scavenger, and has the advantages of low operation cost, good oxygen elimination and denitrification effects, stable operation and low cost. The secondary pollution risk is small, and the device is simple in structure and small in occupied area.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and specifically relates to a water body oxygen control and denitrification device and an oxygen control and denitrification method. Background Art

[0002] Nitrogen pollutants are the main cause of eutrophication of water bodies and are important control indicators for water bodies. When the total nitrogen in the water exceeds a certain limit, there is a risk of eutrophication. Under suitable temperature and other conditions, it may lead to the rapid reproduction of algae and other plankton, causing a decrease in dissolved oxygen in the water body and deterioration of water quality. At present, the sources of nitrogen in water mainly include: non-point source pollution caused by the use of pesticides and fertilizers in agricultural activities and livestock and poultry farming, centralized discharge from municipal and industrial sewage treatment facilities, overflow sewage from the drainage system when rainwater and sewage are combined during rainfall, and the release of endogenous nitrogen and phosphorus in sediments in lakes and slow-flowing water bodies. In recent years, with the implementation of a series of policies and regulations, the treatment level and emission standards of my country's sewage treatment facilities have been significantly improved, and the total nitrogen discharged into environmental water bodies by existing sewage treatment plants is strictly controlled. However, total nitrogen pollution caused by agricultural non-point source pollution, overflow sewage and endogenous release still significantly affects the water quality of rivers and lakes, especially in some villages and towns that do not have sound sewage collection and treatment facilities. Due to unreasonable sewage discharge and agricultural non-point source pollution, the total nitrogen in some rivers can even reach 5~10 mg / L, and the water body has seriously deteriorated, greatly affecting the living environment and bringing potential health risks. Therefore, such water bodies need to be purified. With the inclusion of total nitrogen in the assessment indicators of key river basin sections and coastal river basin sections in recent years, higher requirements have been placed on the water quality of river and lake water bodies, and the total nitrogen assessment limit for some sections has reached 2 mg / L.

[0003] At present, the control methods for total nitrogen pollutants in river and lake water bodies mainly include source control, ecological restoration and water purification. Among them, the implementation cycle of ecological restoration technology is often long. In the face of rivers and lakes with prominent water pollution, water purification technology must be adopted to quickly reduce the risk of eutrophication. Water purification technology mainly includes two categories: bypass treatment and in-situ treatment. Among them, bypass treatment technology is to extract or introduce polluted water into an artificial branch, and through external treatment devices and artificial wetlands, ecological ditches, facilities and building components with filter beds or contact reaction functions set up on the branch, the pollutants are reduced and discharged back to the original water body. In-situ treatment mainly uses biological floating islands placed in the water body, suspended fillers and combined ecological restoration technologies to reduce total nitrogen.

[0004] The denitrification filter technology based on the principle of sulfur autotrophic denitrification has certain advantages in water denitrification treatment because it does not require an external organic carbon source, greatly reduces operating costs, has a high treatment depth, is simple to operate, has a wide range of adaptability, and can simultaneously remove suspended pollutants in the water body. However, when using bypass treatment technology to reduce total nitrogen in river and lake water bodies, it is often necessary to face the high dissolved oxygen situation in natural water bodies. The dissolved oxygen in the water body can reach 8~10 mg / L, which will have a significant inhibitory effect on anaerobic denitrifying microorganisms. Therefore, it seriously restricts the promotion and application of sulfur autotrophic denitrification technology in the treatment of natural river and lake water bodies.

[0005] In addition, in some sewage treatment projects, due to problems with the control of aerobic aeration / membrane bioreactor processes, the transportation and waterfall of the effluent from the secondary sedimentation tank / membrane tank, etc., the dissolved oxygen in the effluent from the secondary biochemical treatment may be too high, reaching 5~7 mg / L or more, which will also have an adverse effect on the subsequent deep denitrification system. Summary of the invention

[0006] In view of the defects of the above-mentioned prior art, the present invention aims to provide a water body oxygen control and denitrification device and an oxygen control and denitrification method to solve the inhibitory effect of high dissolved oxygen in natural water bodies and secondary biochemical treatment effluent of some sewage treatment plants on autotrophic denitrification denitrification technology, and to realize the denitrification treatment of river and lake water bodies and secondary biochemical treatment effluent with higher dissolved oxygen by using autotrophic denitrification denitrification technology. There is no need to add organic carbon sources and deoxidizers, and the operating cost and operating energy consumption are low, the oxygen removal effect and denitrification effect are good, the operation is stable, the risk of secondary pollution is small, and the device structure is simple and occupies little space.

[0007] To achieve the above purpose, the technical effects adopted by the present invention are as follows: A water body oxygen control and nitrogen removal device, comprising: The container body is a sealed container, which is divided into an oxygen removal zone, a water inlet zone, a denitrification carrier zone and a clean water zone from top to bottom; A vacuum pump connected to the deoxidation zone via a vacuum pipeline, wherein a vacuum valve is provided on the vacuum pipeline; A lifting pump is connected to the container body via a water inlet pipeline to transport the water to be treated to the deoxidation zone and / or the water inlet zone, and a water inlet valve is arranged on the water inlet pipeline; A water production pump is connected to the clean water area via a water outlet pipeline, and a water outlet valve is arranged on the water outlet pipeline.

[0008] In one embodiment of the present application, a water inlet distributor is further included, the water inlet distributor is arranged in the deoxidation zone, connected to the water inlet pipeline, the water inlet distributor includes a plurality of distribution heads, the distribution heads disperse the water flow and spray it into the deoxidation zone, and then the water flow falls into the water inlet zone; and / or, The height of the oxygen elimination zone is 1-2 m, and the height of the water inlet zone is 0.8-2 m.

[0009] In one embodiment of the present application, it also includes a vacuum gauge, a vent valve, a liquid level gauge and a backwash discharge valve; the vacuum gauge and the vent valve are connected to the deoxidation zone; the backwash discharge valve is connected to the lower part of the water inlet zone; the liquid level gauge is arranged to monitor the liquid level in the water inlet zone.

[0010] In one embodiment of the present application, it also includes a water outlet box / tank, a nitrogen drive / backwash water distributor and a nitrogen drive / backwash pipeline; the water outlet box / tank is connected to the water outlet pipeline; the nitrogen drive / backwash water distributor is arranged in the clean water area; one end of the nitrogen drive / backwash pipeline is connected to the water outlet box / tank, and the other end is connected to the nitrogen drive / backwash water distributor; the nitrogen drive / backwash pipeline is provided with a nitrogen drive / backwash water inlet valve.

[0011] In one embodiment of the present application, it also includes a backwash air distributor and a backwash air pump, the backwash air distributor is arranged in the clean water area, the backwash air pump is connected to the backwash air distributor via a backwash air inlet pipeline, and a backwash air inlet valve is arranged on the backwash air inlet pipeline; It also includes an enhanced backwash pipeline arranged in parallel with the nitrogen expulsion / backwash pipeline, and the enhanced backwash pipeline is provided with an enhanced backwash water inlet valve and an enhanced backwash water inlet pump.

[0012] In one embodiment of the present application, it further includes a water inlet flow meter, wherein the water inlet flow meter is arranged on the water inlet pipeline; and / or, It also includes a water outlet / backwash flowmeter, one end of which is connected to the nitrogen drive / backwash water distributor, and the other end is connected to the water outlet pipeline, the nitrogen drive / backwash pipeline and the enhanced backwash pipeline.

[0013] A method for controlling oxygen and denitrification in water, using the water oxygen and denitrification device as described in any one of the above, comprises the following steps: S1, pumping the water to be treated into the container body, and stopping the water pumping when the liquid level in the container body reaches the working liquid level setting value; S2, closing the container body, evacuating the deoxidation zone of the container body, and stopping evacuating after the vacuum degree reaches the working vacuum degree setting value; S3, continuously pumping the water to be treated into the container body, so that the water is dispersed into the deoxidation zone and then falls into the water inlet zone, and the water flows from top to bottom through the denitrification carrier zone in the middle of the container body for autotrophic denitrification treatment; at the same time, the denitrification water in the clear water zone at the bottom of the container body is continuously pumped out and discharged, maintaining the working liquid level and vacuum degree in the container body to achieve dynamic balance.

[0014] In one embodiment of the present application, step S3 also includes the following steps: S301, setting a working liquid level upper limit value, a working liquid level lower limit value and a working liquid level setting value for the container body; When the working liquid level in the container body is higher than the working liquid level upper limit, the lifting pump and the water inlet valve are closed, and when the working liquid level drops to reach the working liquid level setting value, the water inlet valve and the lifting pump are reopened; When the working liquid level in the container body is lower than the working liquid level lower limit, the water outlet valve and the water production pump are closed, and when the working liquid level rises to reach the working liquid level setting value, the water outlet valve and the water production pump are reopened; S302, setting a working vacuum lower limit value and a working vacuum setting value for the container body; When the vacuum degree in the container body is lower than the lower limit value of the working vacuum degree, the vacuum pump and the vacuum valve are turned on; when the vacuum degree in the container body reaches the set value of the working vacuum degree, the vacuum pump and the vacuum valve are turned off.

[0015] In one embodiment of the present application, when step S3 is run for a period of time and the container body needs to be nitrogen driven or backwashed, the following steps are also included: S4, nitrogen expulsion procedure: close the lifting pump, the water inlet valve, the water outlet valve and the water production pump; open the nitrogen expulsion / backwash water inlet valve on the nitrogen expulsion / backwash pipeline, the nitrogen expulsion / backwash pipeline connects the water outlet tank / tank and the clean water area, and under the action of negative pressure, the water in the water outlet tank / tank flows from bottom to top through the denitrification carrier area to expel nitrogen; after reaching the set nitrogen expulsion time or the set nitrogen expulsion liquid level, close the nitrogen expulsion / backwash water inlet valve; open the water outlet valve and the water production pump, and when the liquid level reaches the working liquid level setting value, close the water outlet valve and the water production pump; if the vacuum degree is lower than the lower limit of the working vacuum degree, open the vacuum pump and the vacuum valve, and when the vacuum degree reaches the working vacuum degree setting value, close the vacuum pump and the vacuum valve; repeat step S3; S5, backwash procedure: close the lifting pump, the water inlet valve, the water outlet valve and the water production pump; open the nitrogen drive / backwash water inlet valve on the nitrogen drive / backwash pipeline, the nitrogen drive / backwash pipeline connects the water outlet tank / tank and the clean water area, and the water in the water outlet tank / tank flows from bottom to top through the denitrification carrier area under the action of negative pressure for backwashing; after reaching the set backwash time or the set backwash liquid level, close the nitrogen drive / backwash water inlet valve; open the vent valve on the upper part of the container body, break the vacuum, and open the backwash discharge valve to discharge the backwash sewage in the water inlet area; after the discharge is completed, close the vent valve and the backwash discharge valve; open the vacuum valve, the vacuum pump and the nitrogen drive / backwash water inlet valve, when the liquid level reaches the working liquid level setting value, close the nitrogen drive / backwash water inlet valve, when the vacuum reaches the working vacuum setting value, close the vacuum pump and the vacuum valve; repeat step S3; S6, enhanced backwash procedure: close the lift pump, water inlet valve, water outlet valve and water production pump; open the vent valve and backwash discharge valve on the upper part of the container body; open the backwash air inlet valve and backwash air pump on the backwash air inlet pipeline, the backwash air inlet pipeline is connected to the water inlet area, and the backwash gas passes through the denitrification carrier area from bottom to top for air scrubbing; then, continue to open the enhanced backwash water inlet valve and enhanced backwash water inlet pump on the enhanced backwash pipeline, the enhanced backwash pipeline is connected to the water outlet tank / tank and the clean water area, and the backwash gas and backwash water pass through the denitrification carrier area from bottom to top for air-water backwashing; then, close the backwash The air pump and the backwash air inlet valve are used, and only the backwash water passes through the denitrification carrier area from bottom to top for enhanced water backwashing; after the enhanced water backwashing time is reached, the enhanced backwash inlet pump and the enhanced backwash inlet valve are closed; the backwash waste liquid is discharged from the backwash discharge valve, and when the liquid level reaches the lower limit of the working liquid level, the vent valve and the backwash exhaust valve are closed; the vacuum valve, the vacuum pump and the nitrogen removal / backwash water inlet valve are opened, and when the liquid level reaches the working liquid level setting value, the nitrogen removal / backwash water inlet valve is closed, and when the vacuum degree reaches the working vacuum degree setting value, the vacuum pump and the vacuum valve are closed; and step S3 is repeated.

[0016] In one embodiment of the present application, one or more of the following conditions are also included: The working vacuum setting value is a relative vacuum of -0.05 to -0.09 MPa; In step S4, the frequency of the nitrogen removal program is 120-720 minutes, and the nitrogen removal time is set to 30-180 seconds; In step S5, the frequency of the backwashing procedure is once every 1 to 7 days, and the set backwashing time is 3 to 20 minutes; In step S6, the frequency of the enhanced backwashing procedure is once every 7 to 90 days, the time of the air scrubbing is 3 to 20 minutes, the time of the air-water backwashing is 5 to 25 minutes, and the time of the enhanced water backwashing is 3 to 20 minutes.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The water body oxygen control and denitrification device and oxygen control and denitrification method of the present invention are provided with a deoxygenation zone on the upper part of a traditional autotrophic denitrification filter tank and connected with a vacuum pump, etc., so as to realize the combination of deoxygenation and autotrophic denitrification equipment and obtain an integrated water body oxygen control and denitrification device. The device and method can effectively solve the inhibitory effect of high dissolved oxygen in natural water bodies and secondary biochemical treatment effluent of some sewage treatment plants on autotrophic denitrification denitrification technology, and can realize continuous deep denitrification treatment of river and lake water bodies and high dissolved oxygen sewage by using autotrophic denitrification denitrification technology. No organic carbon source and deoxidizer need to be added during the treatment process, the operation cost and operation energy consumption are low, the deoxygenation effect and denitrification effect are good, the operation is stable, the risk of secondary pollution is small, and it is an integrated device with a simple structure and a small footprint.

[0018] 2. Change the water inlet method, set a water inlet distributor in the deoxygenation zone, and fully disperse the water to be treated and spray it into the deoxygenation zone, especially in the form of dispersed rain mist, so that the dissolved gas (including oxygen) in the dispersed water under the vacuum condition of the deoxygenation zone is fully released and extracted, and then falls into the water inlet area; at the same time, the liquid surface of the water inlet area intersects with the deoxygenation zone, and the liquid surface at the interface can be further degassed (including deoxygenated) to ensure that the water in the water inlet area is low dissolved oxygen water, so as to facilitate the denitrification reaction of autotrophic denitrifying microorganisms.

[0019] 3. Set up a water outlet tank / tank, nitrogen drive / backwash pipeline and nitrogen drive / backwash inlet valve, and use the pressure difference between vacuum and atmospheric pressure to achieve backwashing and nitrogen drive without a backwash water pump, which can effectively reduce operating costs.

[0020] 4. Set up enhanced backwash pipelines, enhanced backwash water inlet valves, enhanced backwash water inlet pumps and backwash air inlet pipelines, backwash air inlet valves, and backwash air pumps. When pressure differential backwashing or nitrogen expulsion cannot meet the requirements, enhanced nitrogen expulsion and enhanced gas-water mixed washing can be performed to ensure long-term and stable operation of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic diagram of the structure of the water body oxygen control and denitrification device in the present invention.

[0023] Figure 2 The present invention is a flow chart of the steps in the method for controlling oxygen and denitrification in water.

[0024] Reference numerals: 1. Container body; 11. Deoxidation zone; 111. Vacuum gauge; 112. Vent valve; 12. Water inlet zone; 121. Liquid level gauge; 122. Backwash discharge valve; 13. Denitrification carrier zone; 14. Clean water zone; 15. Water inlet distributor; 151. Distributor flushing and drain valve; 16. Nitrogen drive / backwash water distributor; 17. Backwash air distributor; 18. Water outlet / backwash flowmeter; 2. Vacuum pipeline; 21. Vacuum pump; 22. Vacuum valve; 3. Water inlet pipeline; 31. Lifting pump; 32. Water inlet valve; 33. Water inlet flow meter; 4. Water outlet pipeline; 41. Water production pump; 42. Water outlet valve; 5. Water outlet tank / pool; 6. Nitrogen drive / backwash pipeline; 61. Nitrogen drive / backwash water inlet valve; 7. Backwash air inlet pipeline; 71. Backwash air pump; 72. Backwash air inlet valve; 8. Enhanced backwash pipeline; 81. Enhanced backwash water inlet pump; 82. Enhanced backwash water inlet valve. DETAILED DESCRIPTION

[0025] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0026] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships conventionally placed when the product of the present invention is used, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0027] The terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0029] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention.

[0030] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0031] The embodiment of the present invention provides a water body oxygen control and nitrogen removal device, such as Figure 1 As shown, the water body oxygen control and denitrification device includes: a container body 1, a vacuum pump 21, a lifting pump 31, a water production pump 41, etc.

[0032] The container body 1 is a sealed container, and the interior thereof is sequentially divided into a flavor deoxidation zone 11, a water inlet zone 12, a denitrification carrier zone 13 and a clean water zone 14 from top to bottom. The denitrification carrier zone 13 is filled with a denitrification carrier and inoculated with autotrophic denitrification microorganisms, and the water body can be filtered to perform autotrophic denitrification. The liquid level of the water body to be treated is controlled within the water inlet zone 12.

[0033] The vacuum pump 21 can be a water ring vacuum pump, a rotary vane vacuum pump or a Roots vacuum pump, which is connected to the deoxidation zone 11 on the upper part of the container body 1 through the water inlet pipeline 2, and a vacuum valve 22 is provided on the vacuum pipeline 2. Preferably, the vacuum valve 22 is linked to the vacuum pump 21. The vacuum pump 21 is provided to vacuum the container body 1 so that the container body 1 obtains and maintains a vacuum working condition.

[0034] The lifting pump 31 is arranged at the water inlet end, connected to the upper part of the container body 1 through the water inlet pipeline 3, and transports the water to be treated to the deoxygenation zone 11 and / or the water inlet zone 12, so that the water entering is deoxygenated (including deoxygenated) in the deoxygenation zone 11 and the water inlet zone 12, and the dissolved oxygen concentration of the water is reduced. The water inlet pipeline 3 is provided with a water inlet valve 32, and the water inlet valve 32 is preferably linked with the lifting pump 31. In one embodiment, a raw water tank 30 for temporarily storing the water to be treated is also provided, and the water inlet pipeline 3 is connected to the raw water tank 30 to provide a stable water supply for the lifting pump 31, ensuring the stable operation of the lifting pump 31.

[0035] The water production pump 41 is connected to the clean water area 14 via the water outlet pipeline 4, and is used to extract the water in the container body 1 after being filtered and denitrified by the denitrification packing area 13. The water outlet pipeline 4 is provided with a water outlet valve 42, which is preferably linked to the water production pump 41.

[0036] The lifting pump 31 and the water production pump 41 are preferably variable frequency water pumps.

[0037] The device sets an oxygen removal zone on the upper part of the traditional autotrophic denitrification filter tank and connects it with a vacuum pump, etc., to realize the combination of oxygen removal and autotrophic denitrification equipment to obtain an integrated water oxygen control and denitrification device. The device can effectively solve the inhibitory effect of high dissolved oxygen in natural water bodies and secondary biochemical treatment effluent from some sewage treatment plants on autotrophic denitrification technology, and can realize continuous deep denitrification treatment of river and lake water bodies and high dissolved oxygen sewage using autotrophic denitrification technology. There is no need to add organic carbon source and oxygen remover during the treatment process, the operating cost and energy consumption are low, the operation is stable, the risk of secondary pollution is small, and it is an integrated device with a simple structure and small footprint.

[0038] In a preferred embodiment, the water oxygen control and denitrification device is also provided with a water inlet distributor 15, which is arranged in the deoxygenation zone 11 and connected to the water outlet end of the water inlet pipeline 3. The water inlet distributor 15 includes a water inlet distribution pipe and a plurality of distribution heads arranged on the water inlet distribution pipe. After the pressurized water enters the water inlet distributor 15, it is dispersed and sprayed into the deoxygenation zone 11 through the distribution head, and enters the deoxygenation zone 11 under vacuum / negative pressure conditions in the form of water mist / fine water droplets, etc. The contact area between the water and the vacuum / negative pressure environment is increased, and degassing and deoxygenation can be carried out quickly and efficiently. Then the dispersed water falls into the water inlet zone 12 below under the action of gravity, and further continues to be deoxygenated on its liquid surface to ensure that a water body with a low dissolved oxygen concentration is obtained.

[0039] The height of the deoxygenation zone 11 in the container body 1 is set to 1~2m, and the height of the water inlet zone 12 is set to 0.8~2m. The heights of the deoxygenation zone 11 and the water inlet zone 12 are higher than the space above the denitrification carrier zone in the traditional autotrophic denitrification filter to ensure the deoxygenation effect.

[0040] Preferably, the water inlet distribution pipe of the water inlet distributor 15 is connected to a distributor flushing and drain valve 151 via a pipeline. When the water inlet distributor 15 is blocked, the distributor flushing and drain valve 151 can be opened, and the water inlet distributor 15 can be flushed under the impact of the water pumped into the water body by the lifting pump 31. The flushing water can be discharged through the pipeline and the distributor flushing and drain valve 151.

[0041] It also includes a vacuum meter 111, a vent valve 112, a liquid level meter 121 and a backwash discharge valve 122, etc.

[0042] The vacuum meter 11 and the vent valve 112 are connected to the deoxidation zone 11 to detect the vacuum degree in the deoxidation zone 11 and to be opened to connect to the atmosphere to break the vacuum / negative pressure environment. Preferably, the vacuum meter 11 is associated with the vacuum pump 21 and the vacuum valve 22.

[0043] The backwash discharge valve 122 is connected to the lower part of the water inlet area 12, preferably at the same level as the lower limit of the working liquid level set when the device is running, and is used to discharge the water above the denitrification carrier area 13 without exposing the denitrification carrier area 13; it is especially used to discharge backwash wastewater during backwashing.

[0044] The liquid level gauge 121 is arranged on the upper part of the container body 1, and can be a static pressure liquid level gauge, a radar liquid level gauge, a float liquid level gauge, a flap liquid level gauge, etc., for detecting the liquid level change in the water inlet area 12. When the device is in operation, its working liquid level should always be maintained within the range of the water inlet area 12.

[0045] In one embodiment, it also includes a water outlet tank / tank 5, a nitrogen expulsion / backwash water distributor 16 and a nitrogen expulsion / backwash pipeline 6. The water outlet tank / tank 5 is connected to the water outlet end of the water outlet pipeline 4, and the water outlet tank / tank 5 is connected to the atmosphere, and is used to temporarily store the water body after denitrification treatment discharged by the water production pump 41. The nitrogen expulsion / backwash water distributor 16 is arranged in the clean water area 14 under the denitrification carrier area 13; one end of the nitrogen expulsion / backwash pipeline 6 is connected to the water outlet tank / tank 5, and the other end is connected to the nitrogen expulsion / backwash water distributor 16; the nitrogen expulsion / backwash pipeline 6 is provided with a nitrogen expulsion / backwash water inlet valve 61. The water outlet tank / tank 5, the nitrogen expulsion / backwash pipeline 6 and the nitrogen expulsion / backwash inlet valve 61 are provided. The pressure difference between the atmospheric pressure and the pressure in the container body 1 can be used to reversely suck the water in the water outlet tank / tank 5 into the container body 1. The flow rate is adjusted only by the nitrogen expulsion / backwash inlet valve 61, and there is no need to set up a backwash water pump, so that the denitrification carrier area 13 can be backwashed; at the same time, the water after the denitrification treatment of the device itself is used for backwashing, without the need for an external water source. The nitrogen expulsion / backwash water distributor 16 is provided to ensure that the backwash inlet water is dispersed and evenly distributed, and the backwashing of the denitrification carrier area 13 is more uniform.

[0046] In a further embodiment, a backwash air distributor 17 and a backwash air pump 71 are further included. The backwash air distributor 17 is arranged in the clean water area 14 below the denitrification carrier area 13. The backwash air pump 71 is connected to the backwash air distributor 17 via the backwash air inlet pipeline 7. A backwash air inlet valve 72 is also arranged on the backwash air inlet pipeline 7 between the backwash air pump 71 and the backwash air distributor 17. Preferably, the backwash air inlet valve 72 is linked to the backwash air pump 71.

[0047] At the same time, it also includes an enhanced backwash pipeline 8, which is arranged in parallel with the nitrogen expulsion / backwash pipeline 6, one end of which is connected to the nitrogen expulsion / backwash water distributor 16, and the other end is connected to the water outlet tank / tank 5. The enhanced backwash pipeline 8 is provided with an enhanced backwash water inlet valve 82 and an enhanced backwash water inlet pump 81, and preferably the enhanced backwash water inlet valve 82 and the enhanced backwash water inlet pump 81 are linked.

[0048] The nitrogen expulsion / backwash water inlet valve 61, the backwash air inlet valve 72 and the enhanced backwash water inlet valve 82 are preferably one-way valves to prevent the water flow in the container body 1 from being discharged in reverse, so that the operation of the device is more stable and reliable.

[0049] When backwashing using the nitrogen expulsion / backwash pipeline 6 and the nitrogen expulsion / backwash water inlet valve 61 cannot effectively remove pollutants, the backwash air pump 71 can be started to cooperate with the enhanced backwash water inlet pump 81 to perform enhanced backwashing through air scrubbing, air-water mixing, enhanced water backwashing, etc., so as to effectively remove pollutants in the denitrification carrier area 13 and ensure normal, efficient and long-term operation of the device.

[0050] Preferably, the device also includes an inlet flowmeter 33 and / or an outlet / backwash flowmeter 18. The inlet flowmeter 33 is arranged on the water inlet pipe 3, located at the outlet end of the lift pump 31, and is used to detect the inlet flow rate. The outlet / backwash flowmeter 18 is arranged at the outlet of the clean water area 14 at the lower part of the container body 1, and one end of the outlet / backwash flowmeter 18 is connected to the nitrogen expulsion / backwash water distributor 16, and the other end is connected to the outlet pipeline 4, the nitrogen expulsion / backwash pipeline 6 and the enhanced backwash pipeline 8. The outlet / backwash flowmeter 18 can detect the outlet flow rate, the water flow rate of backwashing and the enhanced backwashing, respectively. Preferably, the inlet flowmeter 33 is associated with the outlet / backwash flowmeter 18, and the inlet flow rate and the outlet flow rate are preferably controlled to be equal during operation, so that the container body 1 can operate continuously and stably.

[0051] It also includes a control module (not shown in the figure), which is connected to the vacuum pump 21, the vacuum valve 22, the lifting pump 31, the water inlet valve 32, the water production pump 41, the water outlet valve 42, the vacuum gauge, the vent valve 112, the liquid level gauge 121, the backwash discharge valve 122, the nitrogen drive / backwash water inlet valve 61, the backwash air pump 71, the backwash air inlet valve 72, the enhanced backwash water inlet valve 82, the enhanced backwash water inlet pump 81, etc., and the automatic and coordinated operation of the device can be achieved through the control module.

[0052] Based on the same purpose and concept of the invention, an embodiment of the present invention further provides a method for controlling oxygen and denitrification in water bodies, which can be implemented by using the above-mentioned device for controlling oxygen and denitrification in water bodies.

[0053] See also Figure 1 and Figure 2 As shown, the water body oxygen control and denitrification method comprises the following steps: S1, pumping water to be treated into the container body 1, and stopping the water pumping when the liquid level in the container body 1 reaches the working liquid level setting value, so as to realize the water filling operation before starting the device.

[0054] Specifically, open the drain valve 112 and the water inlet valve 32, start the lift pump 31, and transport the water to be treated in the raw water tank / pool 30 from the inlet end to the container body 1 until the liquid level in the container body 1 reaches the working liquid level setting value (liquid level line) in the water inlet area 12, then turn off the lift pump 31 and stop pumping water.

[0055] S2, after completing the water filling in step S1, close the container body 1, and perform vacuum treatment on the deoxidation zone 11 in the container body 1, and stop vacuuming after the vacuum degree of the deoxidation zone 11 in the container body 1 reaches the working vacuum degree setting value. The vacuum degree required for starting operation in the container body 1 is reached, that is, the vacuuming preparation before starting is completed.

[0056] Specifically, the water inlet valve 32, the vent valve 112, etc. are closed, the vacuum valve 22 and the vacuum pump 21 are opened, and the air in the deoxidation zone 11 in the container body 1 is evacuated to make the container body 1 reach a set vacuum degree, preferably set to a working vacuum degree setting value. Then, the vacuum pump 21 and the vacuum valve 22 are closed to stop vacuuming.

[0057] S3, after completing the vacuum pumping operation of step S2, the container body 1 completes the operation start-up preparation, and the liquid level and vacuum degree meet the normal operation requirements. Start the denitrification treatment of the water body, and continuously pump the water body to be treated into the container body 1, so that the water body is dispersed into the deoxidation zone 11, and then falls into the water inlet zone 12 below, and then flows from top to bottom through the denitrification carrier zone 13 in the container body 1 for autotrophic denitrification treatment; the water body after denitrification treatment enters the clear water zone 14 at the bottom of the container body 1, and the denitrified water body in the clear water zone 14 is continuously pumped out and discharged, and the amount of water pumped in and out is controlled to be basically equal, so as to maintain the liquid level and vacuum degree in the container body 1 above and below the working liquid level setting value and the working vacuum setting value, respectively, to achieve dynamic balance, and ensure that the device continuously and stably performs water denitrification treatment.

[0058] Specifically, firstly, the water inlet valve 31 and the lifting pump 31 are opened, and the water to be treated in the raw water tank 30 is continuously pumped into the clean water area 11 at the upper part of the container body 1. The water flows through the water inlet distributor 15 and is dispersed into water mist / fine water droplets and then enters the deoxidation area 11, increasing the contact area between the water and the vacuum environment in the deoxidation area 11 to achieve full degassing and deoxidation; then it falls into the water inlet area 14, and contacts with the vacuum environment at the liquid surface of the water inlet area 14 to continue degassing and deoxidation; the water after degassing and deoxidation (the dissolved oxygen concentration is reduced) flows from top to bottom through the denitrification carrier area 13 set in the middle part of the container body 1, and the nitrate nitrogen in the water is reduced to generate nitrogen gas under the action of autotrophic denitrifying microorganisms, thereby achieving denitrification and filtering suspended pollutants in the water. The water after denitrification treatment enters the clean water area 14, and the outlet valve 42 and the water production pump 41 are opened to extract the water in the clean water area 14 and discharge it to the outlet tank / tank 5 for subsequent treatment, reuse or discharge.

[0059] At the same time, the water inlet valve 32, the lifting pump 31, the water outlet valve 42 and the water production pump 41 are started, and the water outlet / backwash flowmeter 18 is used for detection. The water production pump 41 is frequency-controlled and the water outlet valve 42 is opened to control the water inlet flowmeter 33 and the water outlet / backwash flowmeter 18, so as to achieve a dynamic balance between the working liquid level and the vacuum degree in the container body 1. Preferably, the working liquid level is maintained above the working liquid level setting value, and the vacuum degree is maintained above the working vacuum degree setting value.

[0060] Preferably, the working liquid level setting value is the liquid level value at the middle position of the water inlet area 12 (see Figure 1 The working vacuum setting value is preferably a relative vacuum of -0.05 to -0.09 MPa, which can well achieve degassing and oxygen removal of the water body to obtain the required low dissolved oxygen water body (solvent dissolved oxygen concentration is below 1 mg / L).

[0061] Furthermore, in step S3, when the working liquid level and vacuum degree in the container body 1 are dynamically balanced by the water outlet / backwash flowmeter 18 and the water inlet flowmeter 33, and by the frequency conversion control of the water production pump 41 and the opening control of the water outlet valve 42, there may be errors. If errors occur, they can be regulated by the following steps S301 and S302, that is, step S3 also includes the following steps S301 and S302.

[0062] S301, in the control unit, set the working liquid level upper limit, working liquid level setting value and working liquid level lower limit for the container body 1, the working liquid level upper limit, working liquid level setting value and working liquid level lower limit corresponding to the upper limit, middle line and lower limit position in the water inlet area 12, see Figure 1 As shown by three dotted lines arranged in sequence from top to bottom in the middle water inlet area 12.

[0063] When the liquid level meter 121 detects that the working liquid level in the container body 1 is higher than the upper limit of the working liquid level, the lifting pump 31 and the water inlet valve 32 are closed, and the pumping of water is stopped to maintain water production; when the working liquid level in the container body 1 drops to reach the working liquid level setting value, the water inlet valve 32 is reopened and the lifting pump 31 is started, that is, the water to be treated is pumped again to resume continuous operation.

[0064] When the liquid level meter 121 detects that the working liquid level in the container body 1 is lower than the lower limit of the working liquid level, the water outlet valve 42 and the water production pump 41 are closed to stop the discharge of produced water and continue to pump in the water body to be treated; when the working liquid level in the container body 1 rises to reach the set working liquid level value, the water outlet valve 42 and the water production pump 41 are reopened to pump out the produced water again and resume continuous operation.

[0065] In this way, the working liquid level in the container body 1 is maintained within a certain range to achieve dynamic balance.

[0066] S302, setting a lower limit value of the working vacuum degree and a set value of the working vacuum degree for the container body 1 in the control unit.

[0067] When the vacuum meter 111 detects that the vacuum degree of the deoxidation zone 11 in the container body 1 is lower than the lower limit of the working vacuum degree, the vacuum valve 22 and the vacuum pump 21 are opened to evacuate the deoxidation zone 11. When the vacuum meter 111 detects that the vacuum degree of the deoxidation zone 11 in the upper part of the container body 1 reaches the set value of the working vacuum degree, the vacuum pump 21 and the vacuum valve 22 are closed to stop evacuating. In this way, the vacuum degree in the container body 1 is maintained within a certain range to achieve dynamic balance.

[0068] More preferably, the method further includes steps S4, S5 and S6.

[0069] When the device has been running continuously for a period of time, that is, step S3 has been running for a period of time, the nitrogen generated during the denitrification reaction will accumulate in the carrier / filter material layer, increasing the filtration resistance and reducing the processing volume, and it is necessary to regularly backwash with water to remove the nitrogen in the denitrification carrier area 13; at the same time, the accumulation of suspended pollutants in the water and biofilms shed during the metabolism of microorganisms will cause the filter layer of the denitrification carrier area 13 to be contaminated, the resistance becomes higher, and regular backwashing is required.

[0070] Specifically, S4 is the nitrogen expulsion procedure: close the lifting pump 31, the water inlet valve 32, the water outlet valve 42 and the water production pump 41, that is, close the water inlet and outlet; open the nitrogen expulsion / backwash water inlet valve 61 on the nitrogen expulsion / backwash pipeline 6, and the nitrogen expulsion / backwash pipeline 6 connects the water outlet tank / tank 5 and the nitrogen expulsion / backwash water distributor 16 in the clean water area 14, and through the pressure difference between the vacuum negative pressure in the container body 1 and the atmospheric pressure of the water outlet tank / tank 5, the water in the water outlet tank / tank 5 enters the clean water area 14, and flows backward from bottom to top through the denitrification carrier area 13 for nitrogen expulsion; after reaching the set nitrogen expulsion time or the set nitrogen expulsion liquid level, close the nitrogen expulsion / backwash water inlet valve 61 to stop nitrogen expulsion.

[0071] Then, the water outlet valve 42 and the water production pump 41 are opened to drain water. When the liquid level in the container body 1 reaches the working liquid level setting value, the water production pump 41 and the water outlet valve 42 are closed. At this time, if it is detected that the vacuum degree of the deoxidation zone 11 is lower than the working vacuum degree lower limit, the vacuum pump 21 and the vacuum valve 22 are opened to evacuate the deoxidation zone 11. When the vacuum degree in the deoxidation zone 11 reaches the working vacuum degree setting value, the vacuum pump 21 and the vacuum valve 22 are closed, so that the liquid level and vacuum degree in the container body 1 are restored to the required state for operation. Then, step S3 can be restarted to continue the deoxidation and denitrification treatment of the water body.

[0072] Preferably, the nitrogen removal program of step S4 is run once every 120 to 720 minutes, wherein the nitrogen removal time is preferably set to 30 to 180 seconds, which can achieve a better nitrogen removal effect and ensure efficient operation of the denitrification treatment.

[0073] S5 is the backwash procedure: the lifting pump 31, the water inlet valve 32, the water outlet valve 42 and the water production pump 41 are closed, that is, the water inlet and water outlet are closed; the nitrogen drive / backwash water inlet valve 61 on the nitrogen drive / backwash pipeline 6 is opened, and the nitrogen drive / backwash pipeline 6 connects the water outlet tank / tank 5 and the nitrogen drive / backwash water distributor 16 in the clean water area 14, and through the pressure difference between the vacuum negative pressure in the container body 1 and the atmospheric pressure of the water outlet tank / tank 5, the water in the water outlet tank / tank 5 enters the clean water area 14, and flows from bottom to top through the denitrification carrier area 13 for backwashing; after reaching the set backwashing time or the set backwashing liquid level, the nitrogen drive / backwash water inlet valve 61 is closed to stop backwashing.

[0074] Then, open the vent valve 112 on the upper part of the container body 1 to break the vacuum of the deoxidation zone 11, and then open the backwash discharge valve 122 to discharge the backwash sewage in the water inlet zone 12. After the discharge is completed, close the vent valve 112 and the backwash discharge valve 122. Then open the vacuum valve 22, the vacuum pump 21 and the nitrogen removal / backwash water inlet valve 61, and make the water in the water outlet tank / tank 5 flow back to restore the liquid level in the container body 1 while evacuating the vacuum. When the liquid level in the container body 1 reaches the working liquid level setting value, close the nitrogen removal / backwash water inlet valve 61 to stop water intake; continue to evacuate, and when the vacuum degree in the deoxidation zone 11 reaches the working vacuum degree setting value, close the vacuum pump 21 and the vacuum valve 22, so that the liquid level and vacuum degree in the container body 1 are restored to the required state for operation. Then, step S3 can be restarted to continue the deoxidation and denitrification treatment of the water body.

[0075] Preferably, the backwashing procedure of step S5 is performed once every 1 to 7 days, wherein the backwashing time is preferably set to 3 to 20 minutes, which can better achieve the conventional backwashing effect and ensure the efficient operation of the denitrification treatment.

[0076] When the backwashing procedure of step S5 (ie, backwashing by nitrogen displacement / backwashing pipeline 6 ) cannot effectively remove the pollutants in the denitrification carrier area 13 , enhanced backwashing is required. Therefore, step S6 is set.

[0077] Specifically, S6, enhanced backwash procedure: close the lift pump 31, the water inlet valve 32, the water outlet valve 42 and the water production pump 41, that is, close the water inlet and water outlet; open the vent valve 112 and the backwash discharge valve 122 on the upper part of the container body 1 to break the vacuum; then open the backwash air inlet valve 72 and the backwash air pump 71 on the backwash air inlet pipeline 7, the backwash air inlet pipeline 7 is connected to the backwash air distributor 17 in the clean water area 14, and the air booster pump is pumped into the clean water area 14 and dispersed, so that the backwash gas passes through the denitrification carrier area 13 from bottom to top for air scrubbing; after the set air scrubbing time is reached, continue to open the enhanced backwash water inlet valve 82 and the enhanced backwash water inlet pump 81 on the enhanced backwash pipeline 8, the enhanced backwash pipeline 8 is connected to the water outlet tank / tank 5 and the clean water area The nitrogen drive / backwash water distributor 16 in 14 allows the pressurized backwash water and the pressurized backwash gas to pass through the denitrification carrier area 13 from bottom to top for air-water backwashing at the same time; after the set air-water backwashing time is reached, the backwash air pump 71 and the backwash air inlet valve 72 are closed, and only the enhanced backwash water inlet pump 81 pumps backwash water from bottom to top through the denitrification carrier area 13 for enhanced water backwashing; after the set enhanced water backwashing time is reached, the enhanced backwash water inlet pump 81 and the enhanced backwash water inlet valve 82 are closed to stop the enhanced backwashing; the backwash waste liquid is discharged through the backwash discharge valve 122 opened at the top, and when the liquid level drops to the lower limit of the working liquid level, that is, when the lower limit of the backwash discharge valve 122 is reached, the vent valve 112 and the backwash exhaust valve 122 are closed.

[0078] Then, the vacuum pump 21, vacuum valve 22 and nitrogen removal / backwashing water inlet valve 61 are turned on, and the water in the water outlet tank / tank 5 is reversed while vacuuming to restore the liquid level in the container body 1. When the liquid level in the container body 1 reaches the working liquid level setting value, the nitrogen removal / backwashing water inlet valve 61 is closed to stop water inlet; vacuuming is continued, and when the vacuum degree in the deoxidation zone 11 reaches the working vacuum degree setting value, the vacuum pump 21 and vacuum valve 22 are closed, so that the liquid level and vacuum degree in the container body 1 are restored to the required state for operation. Then, step S3 can be restarted to continue the deoxidation and denitrification treatment of the water body.

[0079] Preferably, the enhanced backwashing program of step S6 is run once every 7 to 90 days. Preferably, during each run, the air scrubbing time is controlled to be 3 to 20 minutes, the air-water backwashing time is controlled to be 5 to 25 minutes, and the enhanced water backwashing time is controlled to be 3 to 20 minutes. This can effectively eliminate the influence of pollutants on the denitrification carrier area 13 and ensure efficient operation of the denitrification treatment.

[0080] In summary, the water body oxygen control and denitrification device and oxygen control and denitrification method of the present invention set an oxygen removal zone 11 on the upper part of the traditional autotrophic denitrification filter tank and connect it with a vacuum pump 21, etc., to realize the combination of oxygen removal and autotrophic denitrification equipment, and obtain an integrated water body oxygen control and denitrification device. The device and method can effectively solve the inhibitory effect of high dissolved oxygen in natural water bodies and secondary biochemical treatment effluent of some sewage treatment plants on autotrophic denitrification denitrification technology, and can realize continuous deep denitrification treatment of river and lake water bodies and high dissolved oxygen sewage using autotrophic denitrification technology. There is no need to add organic carbon source and deoxidizer during the treatment process, the operating cost and operating energy consumption are low, the oxygen removal effect and denitrification effect are good, the operation is stable, the risk of secondary pollution is small, and it is an integrated device with a simple structure and small footprint.

[0081] A water inlet distributor 15 is arranged in the deoxygenation zone 11 to change the water inlet mode, so that the water body to be treated is fully dispersed and sprayed into the deoxygenation zone 11, especially in the form of dispersed rain mist, so that the dissolved gas (including oxygen) in the dispersed water body under the vacuum condition of the deoxygenation zone 11 is fully released and extracted, and then falls into the water inlet zone 12; at the same time, the liquid surface of the water inlet zone 12 intersects with the deoxygenation zone 11, and the liquid surface at the interface can be further degassed (including deoxygenated), ensuring that the water body in the water inlet zone 12 is a low dissolved oxygen water body, so as to facilitate the denitrification reaction of autotrophic denitrifying microorganisms.

[0082] By providing a water outlet tank / tank 5, a nitrogen expulsion / backwash pipeline 6 and a nitrogen expulsion / backwash water inlet valve 61, the pressure difference between vacuum and atmospheric pressure is utilized to realize backwashing and nitrogen expulsion without a backwash water pump, which can effectively reduce the operating cost.

[0083] An enhanced backwash pipeline 8, an enhanced backwash water inlet valve 82, an enhanced backwash water inlet pump 82, a backwash air inlet pipeline 7, a backwash air inlet valve 72, and a backwash air pump 81 are provided. When the pressure difference backwashing or nitrogen expulsion cannot meet the requirements, enhanced nitrogen expulsion and enhanced gas-water mixed washing can be performed to better ensure the long-term stable operation of the device.

Claims

1. A water body oxygen control and denitrification device, characterized in that: include: A container body (1), wherein the container body (1) is a sealed container, and is divided into an oxygen removal zone (11), a water inlet zone (12), a denitrification carrier zone (13) and a clean water zone (14) from top to bottom; A vacuum pump (21) is connected to the deoxidation zone (11) via a vacuum pipeline (2), and a vacuum valve (22) is provided on the vacuum pipeline (2); A lifting pump (31) is connected to the container body (1) via a water inlet pipeline (3) to transport the water to be treated to the deoxidation zone (11) and / or the water inlet zone (12); a water inlet valve (32) is provided on the water inlet pipeline (3); The water production pump (41) is connected to the clean water area (14) via a water outlet pipeline (4), and a water outlet valve (42) is provided on the water outlet pipeline (4).

2. The water body oxygen control and denitrification device according to claim 1, characterized in that: It also includes a water inlet distributor (15), which is arranged in the deoxidation zone (11) and connected to the water inlet pipeline (3). The water inlet distributor (15) includes a plurality of distribution heads, which disperse the water flow and spray it into the deoxidation zone (11), and then the water flow falls into the water inlet zone (12); and / or, The height of the deoxidation zone (11) is 1 to 2 m, and the height of the water inlet zone (12) is 0.8 to 2 m.

3. The water body oxygen control and denitrification device according to claim 1 or 2, characterized in that: It also comprises a vacuum gauge (111), a vent valve (112), a liquid level gauge (121) and a backwash discharge valve (122); the vacuum gauge (111) and the vent valve (112) are connected to the deoxidation zone (11); the backwash discharge valve (122) is connected to the lower part of the water inlet zone (12); and the liquid level gauge (121) is arranged to monitor the liquid level in the water inlet zone (12).

4. The water body oxygen control and denitrification device according to claim 1, characterized in that: It also comprises a water outlet box / tank (5), a nitrogen expulsion / backwash water distributor (16) and a nitrogen expulsion / backwash pipeline (6); the water outlet box / tank (5) is connected to the water outlet pipeline (4); the nitrogen expulsion / backwash water distributor (16) is arranged in the clean water area (14); one end of the nitrogen expulsion / backwash pipeline (6) is connected to the water outlet box / tank (5), and the other end is connected to the nitrogen expulsion / backwash water distributor (16); and a nitrogen expulsion / backwash water inlet valve (61) is arranged on the nitrogen expulsion / backwash pipeline (16).

5. The water body oxygen control and denitrification device according to claim 4, characterized in that: It also includes a backwash air distributor (17) and a backwash air pump (71), wherein the backwash air distributor (17) is arranged in the clean water area (14), and the backwash air pump (71) is connected to the backwash air distributor (17) via a backwash air inlet pipeline (7), and a backwash air inlet valve (72) is provided on the backwash air inlet pipeline (7); It also includes an enhanced backwash pipeline (8) arranged in parallel with the nitrogen expulsion / backwash pipeline (6), and the enhanced backwash pipeline (8) is provided with an enhanced backwash water inlet valve (82) and an enhanced backwash water inlet pump (81).

6. The water body oxygen control and denitrification device according to claim 5, characterized in that: It also includes a water inlet flow meter (33), wherein the water inlet flow meter (33) is arranged on the water inlet pipeline (3); and / or, It also includes a water outlet / backwash flowmeter (18), one end of the water outlet / backwash flowmeter (18) is connected to the nitrogen expulsion / backwash water distributor (16), and the other end is connected to the water outlet pipeline (4), the nitrogen expulsion / backwash pipeline (6) and the enhanced backwash pipeline (8).

7. A method for controlling oxygen and denitrification in water, characterized in that: The method is carried out using the water body oxygen control and denitrification device as described in any one of claims 1 to 6, comprising the following steps: S1, pumping the water to be treated into the container body, and stopping the water pumping when the liquid level in the container body reaches the working liquid level setting value; S2, closing the container body, evacuating the deoxidation zone of the container body, and stopping evacuating after the vacuum degree reaches the working vacuum degree setting value; S3, continuously pumping the water to be treated into the container body, so that the water is dispersed into the deoxidation zone and then falls into the water inlet zone, and the water flows from top to bottom through the denitrification carrier zone in the middle of the container body for autotrophic denitrification treatment; at the same time, the denitrification water in the clear water zone at the bottom of the container body is continuously pumped out and discharged, maintaining the working liquid level and vacuum degree in the container body to achieve dynamic balance.

8. The water body oxygen control and denitrification method according to claim 7, characterized in that: Step S3 also includes the following steps: S301, setting a working liquid level upper limit value, a working liquid level lower limit value and a working liquid level setting value for the container body; When the working liquid level in the container body is higher than the working liquid level upper limit, the lifting pump and the water inlet valve are closed, and when the working liquid level drops to reach the working liquid level setting value, the water inlet valve and the lifting pump are reopened; When the working liquid level in the container body is lower than the working liquid level lower limit, the water outlet valve and the water production pump are closed, and when the working liquid level rises to reach the working liquid level setting value, the water outlet valve and the water production pump are reopened; S302, setting a working vacuum lower limit value and a working vacuum setting value for the container body; When the vacuum degree in the container body is lower than the lower limit value of the working vacuum degree, the vacuum pump and the vacuum valve are turned on; when the vacuum degree in the container body reaches the set value of the working vacuum degree, the vacuum pump and the vacuum valve are turned off.

9. The water body oxygen control and denitrification method according to claim 8, characterized in that: When step S3 is run for a period of time and the container body needs to be nitrogen driven or backwashed, the following steps are also included: S4, nitrogen expulsion procedure: close the lifting pump, the water inlet valve, the water outlet valve and the water production pump; open the nitrogen expulsion / backwash water inlet valve on the nitrogen expulsion / backwash pipeline, the nitrogen expulsion / backwash pipeline connects the water outlet tank / tank and the clean water area, and under the action of negative pressure, the water in the water outlet tank / tank flows from bottom to top through the denitrification carrier area to expel nitrogen; after reaching the set nitrogen expulsion time or the set nitrogen expulsion liquid level, close the nitrogen expulsion / backwash water inlet valve; open the water outlet valve and the water production pump, and when the liquid level reaches the working liquid level setting value, close the water outlet valve and the water production pump; if the vacuum degree is lower than the lower limit of the working vacuum degree, open the vacuum pump and the vacuum valve, and when the vacuum degree reaches the working vacuum degree setting value, close the vacuum pump and the vacuum valve; repeat step S3; S5, backwash procedure: close the lifting pump, the water inlet valve, the water outlet valve and the water production pump; open the nitrogen drive / backwash water inlet valve on the nitrogen drive / backwash pipeline, the nitrogen drive / backwash pipeline connects the water outlet tank / tank and the clean water area, and the water in the water outlet tank / tank flows from bottom to top through the denitrification carrier area under the action of negative pressure for backwashing; after reaching the set backwash time or the set backwash liquid level, close the nitrogen drive / backwash water inlet valve; open the vent valve on the upper part of the container body, break the vacuum, and open the backwash discharge valve to discharge the backwash sewage in the water inlet area; after the discharge is completed, close the vent valve and the backwash discharge valve; open the vacuum valve, the vacuum pump and the nitrogen drive / backwash water inlet valve, when the liquid level reaches the working liquid level setting value, close the nitrogen drive / backwash water inlet valve, when the vacuum reaches the working vacuum setting value, close the vacuum pump and the vacuum valve; repeat step S3; S6, enhanced backwash procedure: close the lift pump, water inlet valve, water outlet valve and water production pump; open the vent valve and backwash discharge valve on the upper part of the container body; open the backwash air inlet valve and backwash air pump on the backwash air inlet pipeline, the backwash air inlet pipeline is connected to the water inlet area, and the backwash gas passes through the denitrification carrier area from bottom to top for air scrubbing; then, continue to open the enhanced backwash water inlet valve and enhanced backwash water inlet pump on the enhanced backwash pipeline, the enhanced backwash pipeline is connected to the water outlet tank / tank and the clean water area, and the backwash gas and backwash water pass through the denitrification carrier area from bottom to top for air-water backwashing; then, close the backwash The air pump and the backwash air inlet valve are used, and only the backwash water passes through the denitrification carrier area from bottom to top for enhanced water backwashing; after the enhanced water backwashing time is reached, the enhanced backwash inlet pump and the enhanced backwash inlet valve are closed; the backwash waste liquid is discharged from the backwash discharge valve, and when the liquid level reaches the lower limit of the working liquid level, the vent valve and the backwash exhaust valve are closed; the vacuum valve, the vacuum pump and the nitrogen removal / backwash water inlet valve are opened, and when the liquid level reaches the working liquid level setting value, the nitrogen removal / backwash water inlet valve is closed, and when the vacuum degree reaches the working vacuum degree setting value, the vacuum pump and the vacuum valve are closed; and step S3 is repeated.

10. The water body oxygen control and denitrification method according to claim 9, characterized in that: Also includes one or more of the following conditions: The working vacuum setting value is a relative vacuum of -0.05 to -0.09 MPa; In step S4, the frequency of the nitrogen removal program is 120-720 minutes, and the nitrogen removal time is set to 30-180 seconds; In step S5, the frequency of the backwashing procedure is once every 1 to 7 days, and the set backwashing time is 3 to 20 minutes; In step S6, the frequency of the enhanced backwashing procedure is once every 7 to 90 days, the time of the air scrubbing is 3 to 20 minutes, the time of the air-water backwashing is 5 to 25 minutes, and the time of the enhanced water backwashing is 3 to 20 minutes.

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