Circular internal reflux sewage denitrification treatment device

Abstract

The utility model discloses a circular internal reflux sewage denitrification treatment device which comprises a device main body, a secondary sedimentation tank is arranged in the middle of the device main body, an anoxic zone is arranged in one side of the device main body, an aerobic reflux zone is arranged between the anoxic zone and the secondary sedimentation tank, and a secondary sedimentation tank is arranged in the other side of the device main body. An aerobic zone is arranged at one end, far away from the anoxic zone, in the device main body; the device comprises a device body and an anoxic tank, the anoxic tank is provided with an anoxic area and an aerobic reflux area, the anoxic area is communicated with the aerobic reflux area, water flow inlets and outlets of the anoxic area and the aerobic reflux area are communicated with the aerobic area, a water inlet pipeline is arranged on the device body and communicated with the anoxic area, and the anoxic tank adopts an arc-shaped gallery design, so that mixed liquid flows back and forth along the arc-shaped gallery in the anoxic area by means of the flow pushing effect of a flow pusher; and a submersible stirrer and a nitrification liquid reflux pump of the traditional anoxic tank are omitted. And meanwhile, the water impeller can provide higher nitrification liquid reflux quantity for the anoxic zone, and the energy consumption is lower.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage treatment equipment, in particular to a circular internal return sewage denitrification treatment device. Background Art

[0002] The basic principle of biological denitrification in sewage treatment is that under the combined action of microorganisms, the organic nitrogen and ammonia nitrogen in the sewage undergo ammoniation, nitrification, and denitrification reactions, and finally are converted into nitrogen gas. Among them, nitrification and denitrification reactions are the key links in biological denitrification, but the reaction conditions of the two are exactly opposite. Nitrifying bacteria are chemoautotrophic bacteria, and they need to carry out nitrification reactions under aerobic conditions with low organic matter solubility to oxidize ammonia nitrogen into nitrite and nitrate; while denitrifying bacteria are chemoheterotrophic bacteria, and they must carry out denitrification reactions under anaerobic conditions with high organic matter solubility to reduce nitrate and nitrite to nitrogen gas. Therefore, how to balance and control the reaction conditions of nitrification and denitrification in the same system is crucial to the biological denitrification process.

[0003] At present, the AO denitrification process commonly used in sewage treatment is to set up anoxic tanks and aerobic tanks respectively, denitrification reaction is carried out in the anoxic tank, and nitrification reaction is carried out in the aerobic tank. Then the nitrification liquid produced in the aerobic tank (section O) is pumped back to the anoxic tank (section A) to provide nitrate and nitrite for the denitrification reaction. If you want to achieve a good biological denitrification effect, you need a high nitrification liquid return. Theoretically, four times the nitrification liquid return can make the AO process total nitrogen removal rate reach more than 80%, but the high sewage return consumes a lot of electricity, which increases the operating cost. In recent years, with the continuous improvement of sewage discharge standards in various places, the requirements for ammonia nitrogen and total nitrogen removal rates in sewage treatment plants are also constantly increasing. How to balance the contradiction between high total nitrogen removal rate and high energy consumption has become a major difficulty of the traditional AO denitrification process. Utility Model Content

[0004] The utility model aims to provide a circular internal return sewage denitrification treatment device to solve the problems raised in the above background technology.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A circular internal return sewage denitrification treatment device comprises a device body, a secondary sedimentation tank is arranged in the middle of the device body, an anoxic zone is arranged inside one side of the device body, an aerobic return zone is arranged between the anoxic zone and the secondary sedimentation tank, and an aerobic zone is arranged at one end of the device body away from the anoxic zone;

[0007] The water inlets and outlets of the anoxic zone and the aerobic recirculation zone are both used to communicate with the aerobic zone. A water inlet pipe is provided on the device body, and the water inlet pipe is communicated with the anoxic zone.

[0008] As a further solution of the utility model: the anoxic zone adopts an arc-shaped corridor design, with water inlets and outlets at both ends, and a water flow corridor is arranged in the anoxic zone, and the water flow corridor is arranged in an S shape.

[0009] As a further solution of the utility model: the water inlet of the anoxic zone and the aerobic recirculation zone is connected to the water outlet of the aerobic zone, and the water outlet of the anoxic zone and the aerobic recirculation zone is connected to the water inlet of the aerobic zone.

[0010] As a further solution of the utility model: a first flow producer is provided at the water inlet end of the anoxic zone, and a second flow producer is provided at the water outlet end of the aerobic recirculation zone.

[0011] As a further solution of the utility model: the secondary sedimentation tank is a circular structure, and the secondary sedimentation tank is arranged concentrically with the device body.

[0012] As a further solution of the utility model: the secondary sedimentation tank is provided with a secondary sedimentation tank water inlet and a secondary sedimentation tank water outlet, the secondary sedimentation tank water inlet is connected to the aerobic recirculation zone, and the secondary sedimentation tank water outlet is located at the upper part of the secondary sedimentation tank.

[0013] As a further solution of the utility model: a sludge discharge pipe is provided at the bottom of the secondary sedimentation tank, and a sludge return pipe connected to the anoxic zone is provided at the lower part of the secondary sedimentation tank.

[0014] As a further solution of the utility model: an aeration device is provided at the bottom of the aerobic recirculation zone and the aerobic zone.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] 1. The anoxic pool of this application adopts an arc-shaped corridor design. Relying on the flow-pushing effect of the flow-pushing device, the mixed liquid flows back and forth along the arc-shaped corridor in the anoxic zone, eliminating the need for a submersible mixer and a nitrification liquid reflux pump in a traditional anoxic pool. At the same time, the flow-pushing device can provide a higher nitrification liquid reflux volume for the anoxic zone with lower energy consumption.

[0017] 2. This application adopts a high-multiple internal circulation, which greatly reduces the gradient difference of pollutant concentration before and after the aerobic zone, and the microorganisms are in more complete contact with the pollutants, thereby achieving rapid degradation of organic pollutants and ammonia nitrogen.

[0018] 3. The middle of this application is the secondary sedimentation tank, and the outer ring of the secondary sedimentation tank is the aerobic zone. Compared with the system where the aerobic tank and the secondary sedimentation tank are built separately, the hydraulic process of this system is shorter, and the required elevation difference from the aerobic tank to the secondary sedimentation tank is smaller, which is conducive to reducing the overall elevation of the system, and then can reduce the energy consumption required to lift the sewage to this system; at the same time, the lifting elevation required for the sludge of the secondary sedimentation tank to return to the anoxic zone is lower, which is conducive to saving the energy consumption required for the sludge return.

[0019] 4. The sludge from the secondary sedimentation tank of the present application is returned to the front end of the anoxic zone and mixed with the returned nitrification liquid to accelerate the consumption of dissolved oxygen in the nitrification liquid. The sewage enters the anoxic zone and mixes with the sludge and nitrification liquid. At this time, the nitrification liquid is basically in anoxic state, and the concentration of organic pollutants is high, which just meets the conditions required for denitrification reaction. A good denitrification reaction can be carried out in the rear anoxic zone, making the total nitrogen removal rate closer to the theoretical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a top view of the sewage treatment device of this embodiment;

[0021] In the figure: 1-device body, 2-anoxic zone, 3-aerobic recirculation zone, 4-aerobic zone, 5-secondary sedimentation tank, 6-water inlet pipe, 7-secondary side water inlet, 8-secondary sedimentation tank outlet, 9-first flow pusher, 10-second flow pusher. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] See also Figure 1 In an embodiment of the utility model, a circular internal return sewage denitrification treatment device includes a device body 1, a secondary sedimentation tank 5 is provided in the middle of the device body 1, the secondary sedimentation tank 5 is a circular structure, the secondary sedimentation tank 5 is concentrically arranged with the device body 1, and a secondary sedimentation tank water inlet 7 and a secondary sedimentation tank water outlet 8 are provided on the secondary sedimentation tank 5. The secondary sedimentation tank water inlet 7 is connected to the aerobic recirculation zone 3, and the secondary sedimentation tank water outlet 8 is located at the upper part of the secondary sedimentation tank 5.

[0024] An anoxic zone 2 is provided inside one side of the device body 1, an aerobic reflow zone 3 is provided between the anoxic zone and the secondary sedimentation tank 5, and an aerobic zone 4 is provided at one end of the device body 1 away from the anoxic zone 2. The water inlet and outlet of the anoxic zone 2 and the aerobic reflow zone 3 are both used to communicate with the aerobic zone 4, a water inlet pipe 6 is provided on the device body 1, and the water inlet pipe 6 is communicated with the anoxic zone 2, a sludge discharge pipe is provided at the bottom of the secondary sedimentation tank 5, a sludge reflow pipe connected to the anoxic zone 2 is provided at the lower part of the secondary sedimentation tank 5, and an aeration device is provided at the bottom of the aerobic reflow zone 3 and the aerobic zone 2.

[0025] In this embodiment, the anoxic zone 2 adopts an arc-shaped corridor design with water inlets and outlets at both ends. A water flow corridor is arranged in the anoxic zone 2, and the water flow corridor is arranged in an S shape. The water inlet ends of the anoxic zone 2 and the aerobic recirculation zone 3 are connected to the water outlet end of the aerobic zone 4, and the water outlet ends of the anoxic zone 2 and the aerobic recirculation zone 3 are connected to the water inlet end of the aerobic zone 4. The water inlet end of the anoxic zone 2 is provided with a first flow producer 9, and the water outlet end of the aerobic recirculation zone 3 is provided with a second flow producer 10.

[0026] When the utility model is in use, sewage enters the anoxic zone 2 through the water inlet pipe 6 to mix with the sludge and the nitrification liquid. The water flow is affected by the first flow pusher 9 and flows in an S-shaped manner in the return flow corridor along the arc corridor, eliminating the need for a traditional anoxic pool submersible mixer and a nitrification liquid reflux pump. At the same time, the first flow pusher 9 can push the sewage in the aerobic zone 4 into the anoxic zone 2, thereby providing a higher multiple of the nitrification liquid reflux volume for the anoxic zone 2. Since there is no elevation difference between the anoxic zone 2 and the aerobic zone 4 in this embodiment, the energy consumption is lower. After the sewage flows out from the outlet of the anoxic zone 2, it enters the aerobic zone 4. Under the flow-pushing effect of the second flow-pushing device 10 at the end of the aerobic recirculation zone 3, the water flows from the aerobic recirculation zone 3 into the aerobic zone 4, so that a large proportion of the aerobic mixed liquid with low COD concentration is refluxed and fully mixed with the effluent from the anoxic zone 2, so as to achieve the purpose of diluting the influent. The sewage from the aerobic recirculation zone 3 enters the secondary sedimentation tank through the water inlet of the secondary sedimentation tank 5, and the supernatant is discharged from the main body of the device through the water outlet of the secondary sedimentation tank. A part of the bottom sludge enters the anoxic tank through the sludge return pipe, and the remaining sludge is discharged from the main body of the device.

[0027] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

[0028] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A circular internal return wastewater denitrification treatment device, comprising a device body (1), characterized in that: A secondary sedimentation tank (5) is provided in the middle of the device body (1), an anoxic zone (2) is provided inside one side of the device body (1), an aerobic reflow zone (3) is provided between the anoxic zone and the secondary sedimentation tank (5), and an aerobic zone (4) is provided at one end of the device body (1) away from the anoxic zone (2); The water inlets and outlets of the anoxic zone (2) and the aerobic recirculation zone (3) are both used to communicate with the aerobic zone (4). The device body (1) is provided with a water inlet pipe (6), and the water inlet pipe (6) is communicated with the anoxic zone (2).

2. A circular internal return sewage denitrification treatment device according to claim 1, characterized in that: The anoxic zone (2) adopts an arc-shaped corridor design, with water inlets and outlets at both ends. A water flow corridor is arranged in the anoxic zone (2), and the water flow corridor is arranged in an S shape.

3. A circular internal return sewage denitrification treatment device according to claim 1, characterized in that: The water inlet ends of the anoxic zone (2) and the aerobic recirculation zone (3) are connected to the water outlet end of the aerobic zone (4), and the water outlet ends of the anoxic zone (2) and the aerobic recirculation zone (3) are connected to the water inlet end of the aerobic zone (4).

4. A circular internal return sewage denitrification treatment device according to claim 1 or 3, characterized in that: The water inlet end of the anoxic zone (2) is provided with a first flow producer (9), and the water outlet end of the aerobic recirculation zone (3) is provided with a second flow producer (10).

5. A circular internal return sewage denitrification treatment device according to claim 1, characterized in that: The secondary sedimentation tank (5) is a circular structure, and the secondary sedimentation tank (5) is arranged concentrically with the device body (1).

6. A circular internal return sewage denitrification treatment device according to claim 1, characterized in that: The secondary sedimentation tank (5) is provided with a secondary sedimentation tank water inlet (7) and a secondary sedimentation tank water outlet (8), the secondary sedimentation tank water inlet (7) is connected to the aerobic recirculation zone (3), and the secondary sedimentation tank water outlet (8) is located at the upper part of the secondary sedimentation tank (5).

7. The circular internal return sewage denitrification treatment device according to claim 1 is characterized in that: A sludge discharge pipe is provided at the bottom of the secondary sedimentation tank (5), and a sludge return pipe communicating with the anoxic zone (2) is provided at the lower part of the secondary sedimentation tank (5).

8. The circular internal return sewage denitrification treatment device according to claim 1 is characterized in that: Aeration devices are provided at the bottom of the aerobic recirculation zone (3) and the aerobic zone (4).

Images