Denitrification equipment and sewage treatment method using the same

Abstract

The present invention relates to a denitrification device and a sewage treatment method using the denitrification device, wherein a denitrification device includes a first aerobic tank and a first anoxic tank, the first anoxic tank is connected to the first aerobic tank, and is characterized in that: it also includes a first aerated biological filter, a second anoxic tank, a second aerobic tank and a second aerated biological filter, along the water flow path, the first aerobic tank, the first anoxic tank, the second anoxic tank and the second aerobic tank are located between the first aerated biological filter and the second aerated biological filter, and the first aerated biological filter, the first aerobic tank, the first anoxic tank, the second anoxic tank, the second aerobic tank and the second aerated biological filter are sequentially connected. The whole denitrification process is simple, and the whole denitrification device has a simple and reasonable structure.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and in particular relates to a denitrification device and a sewage treatment method using the denitrification device. Background Art

[0002] With the continuous development of urbanization and the continuous improvement of economic development level, water treatment in urban rivers has become an issue of great concern.

[0003] At present, domestic sewage enters the surface water and finally flows into nearby rivers, which will cause the nitrogen and phosphorus in the river water to exceed the standard and the water quality to deteriorate. Since the domestic sewage discharge is relatively scattered, it is difficult to treat it centrally on a large scale. In addition, the flow of river water is large, and the water quality has the characteristics of low concentration and low biodegradability, which cannot be treated by centralized treatment of urban sewage treatment plants.

[0004] In order to solve the above technical problems, the Chinese invention patent application "Biological Pool MBBR Process Coupled Denitrification Deep Bed Filter Denitrification and Phosphorus Removal System and Method", whose patent application number is CN201811580001.2 (application publication number is CN109650652A) discloses a biochemical pool MBBR process coupled denitrification and phosphorus removal system for deep bed filter, including a biochemical pool and a secondary sedimentation tank, the biochemical pool is divided into at least two chambers, and a plurality of suspended fillers are arranged in the chamber near the outlet; the denitrification deep bed filter is located downstream of the secondary sedimentation tank, and includes: The flocculation tank is provided with a stirring mechanism, a carbon source dosing mechanism and a flocculant dosing mechanism on the top, a water inlet main is connected downstream, a water inlet gate is provided in the water inlet main channel, a filter grid is connected downstream, a water inlet channel is provided under the filter grid, a filter tank is provided under the water inlet channel, and the filter tank has a filter material layer, a supporting layer, a filter plate and a filter head provided on the filter plate from top to bottom; it also includes a backwash fan and a backwash water pump, the outlet of the backwash fan extends to the supporting layer through a pipeline, and the outlet of the backwash water pump extends to the filter tank below the filter plate through a pipeline, and a control valve is provided on the pipeline. This patent can achieve denitrification treatment of sewage, but it is necessary to set up a flocculation tank with a stirring mechanism, a carbon source dosing mechanism and a flocculant dosing mechanism inside, and configure a backwashing structure such as a backwash water pump, and the entire system structure and process flow are complex and costly.

[0005] Therefore, it is necessary to further improve the existing denitrification equipment. Summary of the invention

[0006] The first technical problem to be solved by the present invention is to provide a denitrification device with high denitrification efficiency in view of the current status of the above-mentioned prior art.

[0007] The second technical problem to be solved by the present invention is a denitrification device that can achieve the purpose of backwashing without a backwashing structure.

[0008] The third technical problem to be solved by the present invention is to provide a sewage treatment method which has high denitrification efficiency and can achieve the purpose of backwashing without a backwashing structure.

[0009] The technical solution adopted by the present invention to solve the above-mentioned first technical problem is: a denitrification equipment, including a first aerobic tank and a first anoxic tank, the first anoxic tank is connected to the first aerobic tank, and is characterized in that it also includes a first aerated biological filter, a second anoxic tank, a second aerobic tank and a second aerated biological filter, along the water flow path, the first aerobic tank, the first anoxic tank, the second anoxic tank and the second aerobic tank are located between the first aerated biological filter and the second aerated biological filter, and the first aerated biological filter, the first aerobic tank, the first anoxic tank, the second anoxic tank, the second aerobic tank and the second aerated biological filter are sequentially connected.

[0010] The technical solution adopted by the present invention to solve the above-mentioned second technical problem is: the first aerated biological filter is provided with a first water inlet pipe and a first water outlet pipe, the first water inlet pipe is provided with a first control valve for controlling on and off, the first water outlet pipe is provided with a second control valve for controlling on and off, the second aerated biological filter is provided with a second water inlet pipe and a second water outlet pipe, the second water inlet pipe is provided with a third control valve for controlling on and off, and the second water outlet pipe is provided with a fourth control valve for controlling on and off.

[0011] There are many ways to arrange the first aerobic pool, the first anoxic pool, the second aerobic pool and the second anoxic pool, but preferably, the first anoxic pool and the second anoxic pool are arranged symmetrically, the first aerobic pool and the second aerobic pool are arranged symmetrically, and the first anoxic pool and the first aerobic pool are arranged in sequence from front to back, and the second anoxic pool and the second aerobic pool are arranged in sequence from front to back.

[0012] There are many ways to connect the first aerobic pool, the first anoxic pool, the second anoxic pool and the second aerobic pool, but preferably, the wall plate connecting the first aerobic pool and the first anoxic pool is provided with a first water hole at a position near the upper part to connect the two, and the first water hole is covered with a first filter; the wall plate connecting the first anoxic pool and the second anoxic pool is provided with a second water hole at a position near the bottom to connect the two, and the second water hole is covered with a second filter; the wall plate connecting the second anoxic pool and the second aerobic pool is provided with a third water hole, and the third water hole is covered with a third filter. In this way, while the first aerobic pool, the first anoxic pool, the second anoxic pool and the second aerobic pool are connected in sequence, the sewage can be filtered to a certain extent.

[0013] Preferably, the first aerated biological filter and the second aerated biological filter are both provided with a support plate arranged basically horizontally, and the support plate is provided with a plurality of filter heads arranged at intervals along the length direction of the support plate, and the first aerated biological filter and the second aerated biological filter are provided with a plurality of first aerators arranged at intervals along the length direction of the support plate at a position located above the support plate, and the first aerated biological filter and the second aerated biological filter are both provided with a suspended filler layer and a heavy ceramsite layer arranged in sequence from top to bottom at a position located above the first aerator, and a filter mesh plate supporting the heavy ceramsite layer is provided below the heavy ceramsite layer.

[0014] The presence of the above-mentioned filter screen restricts the heavy expanded clay and suspended filler above the filter screen, preventing the heavy expanded clay and suspended filler from passing through the filter screen. It does not affect water distribution and aeration, but does not hinder the flow of sewage. No filter screen is set above the heavy expanded clay and suspended filler. The purpose is to allow the suspended filler to move in a turbine-like and reciprocating cycle under the action of aeration in the first aerator, thereby relatively increasing the contact time between the sewage and the suspended filler.

[0015] In order to discharge the sludge, a first sludge pump is provided in the first aerobic tank, and a first sewage discharge channel for connecting the first aerobic tank with the outside is connected to the first sludge pump; a second sludge pump is provided in the second aerobic tank, and a second sewage discharge channel for connecting the second aerobic tank with the outside is connected to the second sludge pump. In this way, excessive sludge is prevented from clogging the equipment and affecting the denitrification effect.

[0016] Preferably, the first aerobic tank is provided with a second aerator above the first sludge pump, the second aerobic tank is provided with a third aerator above the second sludge pump, and both the first aerobic tank and the second aerobic tank are filled with a composite filler layer.

[0017] The first sewage discharge channel is connected to a first drainage channel connected to the second anoxic tank, and the first drainage channel is located in the second anoxic tank and has at least two first drainage channels arranged at intervals along the length direction; the second sewage discharge channel is connected to a second drainage channel connected to the first anoxic tank, and the second drainage channel is located in the first anoxic tank and has at least two second drainage channels arranged at intervals along the length direction. In this way, the activated sludge pumped back to the second anoxic tank by the first sludge pump can be more evenly distributed in the second anoxic tank, and the activated sludge pumped back to the first anoxic tank by the second sludge pump can be evenly distributed in the first anoxic tank, thereby ensuring the contact time between the activated sludge and the sewage.

[0018] In order to achieve the purpose of denitrification and decarbonization, the first anoxic tank and the second anoxic tank are respectively connected to the first liquid inlet channel and the second liquid inlet channel, and the first liquid inlet channel and the second liquid inlet channel are respectively provided with a fifth control valve and a sixth control valve for controlling the on-off, and the first anoxic tank and the second anoxic tank are both arranged with elastic filler layers. In this way, in the water environment of sewage anoxic, the denitrifying microorganisms on the surface of the elastic filler and the activated sludge pumped back by the first sludge pump and the second sludge pump provide biodegradable organic matter as an organic carbon source, so that the denitrifying microorganisms use the above organic matter and the organic carbon sources such as nitrates, polysaccharides and proteins remaining in the sludge to perform denitrification, thereby achieving the purpose of denitrification and decarbonization.

[0019] The technical solution adopted by the present invention to solve the third technical problem is: a sewage treatment method using the above denitrification equipment, characterized in that it includes the following steps in sequence:

[0020] S1, the first control valve is in an open state, the sewage enters the first aerated biological filter through the first water inlet pipe, and then flows through the first aerobic tank in sequence and enters the first anoxic tank, the fifth control valve and the second sludge pump are in an open state, at this time, the second sludge pump pumps the sludge in the second aerobic tank back to the first anoxic tank for denitrification and decarbonization treatment, and then the sewage in the first anoxic tank flows through the second anoxic tank, the second aerobic tank and the second aerated biological filter in sequence for treatment, because the fourth control valve is in an open state, the treated water flows out through the second outlet pipe, and continues to run for a period of time;

[0021] S2: Then close the first control valve, the fifth control valve, the second sludge pump and the fourth control valve, the third control valve is in an open state, the sewage enters the second aerated biological filter through the second water inlet pipe, and then flows through the second aerobic tank in turn and enters the second anoxic tank. Since the sixth control valve and the first sludge pump are in an open state, the first sludge pump pumps the sludge in the first aerobic tank back to the second anoxic tank for denitrification and decarbonization. Then the sewage in the second anoxic tank flows through the first anoxic tank, the first aerobic tank and the first aerated biological filter in turn for treatment. Since the second control valve is in an open state, the treated water flows out through the first outlet pipe and continues to run for a period of time; repeat the above steps S1 and S2.

[0022] Compared with the prior art, the advantages of the present invention are as follows: two biofilm sewage treatment processes, namely, an aerated biological filter (BAF) and a moving bed biofilm reactor (MBBR), are vertically superimposed to form an aerated biological filter of the MBAF process, so as to achieve complementary advantages of the two, and the entire denitrification equipment is simple and reasonable, the denitrification process is simple and efficient, and the denitrification effect is good; the biological activity of microorganisms can be ensured without a backwashing structure, and the backwashing effect can be achieved while denitrifying the sewage through a two-way water inlet and outlet working mode, so the operation is efficient and energy-saving, and has a competitive advantage; in addition, the suspended filler, the combined filler, and the elastic filler have a long service life, low loss, and low operation and maintenance costs; in addition, there is no loss of activated sludge, and the high activated sludge concentration enables the entire denitrification system to have the characteristics of high hydraulic load, high volumetric load, and high biofilm activity. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A top view of a part of the structure of an embodiment of the present invention;

[0024] Figure 2 is a cross-sectional view of an embodiment of the present invention;

[0025] Figure 3 FIG. 4 is a top view of an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below with reference to the accompanying drawings.

[0027] like Figures 1 to 3 As shown, the denitrification equipment of the embodiment of the present invention includes a first aerated biological filter 1, a first aerobic tank 2, a first anoxic tank 3, a second anoxic tank 4, a second aerobic tank 5 and a second aerated biological filter 6 which are sequentially connected. Figure 1 As shown, the first aerated biological filter 1, the first aerobic tank 2 and the first anoxic tank 3 are arranged from back to front in sequence, the second aerated biological filter 6, the second aerobic tank 5 and the second anoxic tank 4 are arranged from back to front in sequence, and the first aerated biological filter 1 and the second aerated biological filter 6 are arranged symmetrically, the first aerobic tank 2 and the second aerobic tank 5 are arranged symmetrically, and the first anoxic tank 3 and the second anoxic tank 4 are arranged symmetrically. In this embodiment, the left and right, front and back, and up and down directions are specifically referred to Figure 1 and Figure 2 The direction indicated by the arrow.

[0028] like Figure 1As shown, along the water flow path, the first aerobic tank 2, the first anoxic tank 3, the second anoxic tank 4 and the second aerobic tank 5 are located between the first aerated biological filter 1 and the second aerated biological filter 6, the first aerobic tank 2 is located between the first aerated biological filter 1 and the first anoxic tank 3, and is connected to the first aerated biological filter 1, the second anoxic tank 4 is located between the first anoxic tank 3 and the second aerobic tank 5, and is connected to the first anoxic tank 3, the second aerobic tank 5 is located between the second anoxic tank 4 and the second aerated biological filter 6, and is connected to the second anoxic tank 4 and the second aerated biological filter 6.

[0029] like Figure 1 As shown, the first aerated biological filter 1 is provided with a first water inlet pipe 100 and a first water outlet pipe 101, the first water inlet pipe 100 is provided with a first control valve 10a for controlling on and off, the first water outlet pipe 101 is provided with a second control valve 10b for controlling on and off, the second aerated biological filter 6 is provided with a second water inlet pipe 60 and a second water outlet pipe 61, the second water inlet pipe 60 is provided with a third control valve 60a for controlling on and off, and the second water outlet pipe 61 is provided with a fourth control valve 60b for controlling on and off. In this way, water can be introduced through the first water inlet pipe 100 or through the second water inlet pipe 60, so that the first aerated biological filter 1, the first aerobic tank 2, the first anoxic tank 3, the second anoxic tank 4, the second aerobic tank 5 and the second aerated biological filter 6 form a two-way flow channel.

[0030] In order to achieve the connection between the first aerated biological filter 1 and the first aerobic tank 2, as Figure 3 As shown, a first pipe 20 is provided between the first aerated biological filter 1 and the first aerobic tank 2 to achieve communication between the two. The first pipe 20 includes a first pipe body 201, a second pipe body 202 and a third pipe body 203. The first pipe 20 is U-shaped when viewed from above. The first pipe body 201 is located in the first aerated biological filter 1 and is connected to the first aerated biological filter 1. The third pipe body 203 is located in the first aerobic tank 2 and is connected to the first aerobic tank 2. The second pipe body 202 is located between the first pipe body 201 and the second pipe body 203, and spans the wall connecting the first aerated biological filter 1 and the first aerobic tank 2.

[0031] In order to achieve the connection between the first aerobic pool 2 and the first anoxic pool 3, as Figure 3 As shown, the wall plate connecting the first aerobic pool 2 and the first anoxic pool 3 is provided with a first water hole 21 at a position near the upper part. The existence of the first water hole 21 realizes the connection between the first aerobic pool 2 and the first anoxic pool 3, and the first water hole 21 is covered with a first filter screen 211, so as to filter the sewage to a certain extent. In order to realize the connection between the first anoxic pool 3 and the second anoxic pool 4, as shown in FIG. Figure 3As shown, the wall plate connecting the first anoxic pool 3 and the second anoxic pool 4 is provided with a second water hole 31 at a position near the bottom, and the second water hole 31 is covered with a second filter 311. The second water hole 31 realizes the connection between the first anoxic pool 3 and the second anoxic pool 4, and the second filter 311 realizes further filtration of sewage. In order to realize the connection between the second anoxic pool 4 and the second aerobic pool 5, as shown in FIG. Figure 2 As shown, the wall plate connecting the second anoxic pool 4 and the second aerobic pool 5 is provided with a third water hole 41 at a position near the upper part, and the third water hole 41 is covered with a third filter 411. The existence of the third water hole 41 realizes the connection between the second anoxic pool 4 and the second aerobic pool 5, and the existence of the third filter realizes further filtering of the sewage. The first filter, the second filter and the third filter are all in the form of stainless steel wire mesh.

[0032] In order to achieve the connection between the second aerated biological filter 6 and the second aerobic tank 5, as Figure 3 As shown, a second pipe 50 is provided between the second aerated biological filter 6 and the second aerobic tank 5 to achieve communication between the two. The second pipe 50 includes a first pipe segment 501, a second pipe segment 502 and a third pipe segment 503. The second pipe 50 is U-shaped when viewed from above. The first pipe segment 501 is located in the second aerated biological filter 6 and is connected to the second aerated biological filter 6. The third pipe segment 503 is located in the second aerobic tank 5 and is connected to the second aerobic tank 5. The second pipe segment 502 is located between the first pipe segment 501 and the second pipe segment 203, and spans the wall connecting the second aerated biological filter 6 and the second aerobic tank 5.

[0033] The first biological aerated filter 1 and the second biological aerated filter 6 are both provided with a support plate 11 arranged substantially horizontally. The structures of the first biological aerated filter 1 and the second biological aerated filter 6 are completely the same. The structure of the second biological aerated filter 6 is taken as an example for description. Figure 2As shown, a plurality of filter heads 111 are arranged at intervals along the length direction of the support plate 11 on the support plate 11, a plurality of first aerators 12 are arranged at intervals along the length direction of the support plate 11 in the second aerated biological filter 6 at a position located above the support plate 11, and a suspended filler layer 13 and a heavy ceramsite layer 14 are arranged in sequence from top to bottom at a position located above the first aerator 12 in the second aerated biological filter 6, and a filter screen plate 15 carrying the heavy ceramsite layer is arranged under the heavy ceramsite layer 14, the heavy ceramsite in the heavy ceramsite layer 14 has a diameter of 3-5 mm, the diameter of the suspended filler in the suspended filler layer 13 is 25 mm, and the mass ratio of the heavy ceramsite to the suspended filler is about 2:1, and the total thickness of the suspended filler layer and the heavy ceramsite layer is about 1 / 3 of the height of the equipment. The suspended filler in the above-mentioned suspended filler layer 13 adopts the suspended filler in the prior art, and the heavy ceramsite adopts the heavy ceramsite in the prior art, which will not be described in detail in this embodiment.

[0034] like Figures 1 to 3 As shown, a first sludge pump 22 is provided in the first aerobic tank 2. Figure 1 As shown, the first sludge pump 22 is connected to a first sewage channel 221 for connecting the first aerobic tank 2 with the outside world, and a first valve 223 for controlling the opening and closing of the first sewage channel 221 is provided on the first sewage channel 221. The existence of the first valve 223 can discharge the sludge in the first aerobic tank 2 to the outside of the equipment to prevent excessive sludge from clogging the equipment; the first sewage channel 221 is connected to a first liquid discharge channel 222 connected to the second anoxic tank 4, and at least two first discharge channels 2221 are provided on the first liquid discharge channel 222 located in the second anoxic tank 4. In addition, the first aerobic tank 2 is provided with a second aerator (not shown) above the first sludge pump 22.

[0035] like Figure 1 As shown, a second sludge pump 51 is provided in the second aerobic tank 5, and a second sewage discharge channel 511 for connecting the second aerobic tank 5 with the outside is connected to the second sewage discharge channel 511, and a second valve 513 for controlling the on-off of the second sewage discharge channel 511 is provided on the second sewage discharge channel 511. The existence of the second valve 513 can discharge the sludge in the second aerobic tank 5 to the outside of the equipment to prevent excessive sludge from clogging the equipment; the second sewage discharge channel 511 is connected to a second drainage channel 512 connected to the first anoxic tank 3, and at least two second drainage channels 5121 are provided on the pipeline of the second drainage channel 512 located in the first anoxic tank 3. In addition, as Figure 2 As shown, the second aerobic tank 5 is provided with a third aerator 53 above the second sludge pump 51. The first aerobic tank 2 and the second aerobic tank 5 are both filled with a composite filler layer A, wherein the composite filler adopts the composite filler in the prior art, which will not be described in detail in this embodiment.

[0036] like Figure 3 As shown, the combined packing layer A in the first aerobic tank 2 is arranged around the first sludge pump 22, and the spacing between the combined packing layer A and the first sludge pump 22 is 200 mm, and the combined packings in the combined packing layer A are arranged sequentially from top to bottom, and the spacing between adjacent combined packings is 200 mm. The combined packing layer A in the second aerobic tank 5 is arranged around the second sludge pump 51, and the spacing between the combined packings and the second drainage channel 512 is 200 mm, and the combined packings in the combined packing layer A are arranged sequentially from top to bottom, and the spacing between adjacent combined packings is 200 mm.

[0037] like Figure 3 As shown, the first anoxic pool 3 is connected to a first liquid inlet channel 32, and the first liquid inlet channel 32 is provided with a fifth control valve 321 for controlling on and off; the second anoxic pool 4 is connected to a second liquid inlet channel 42, and the second liquid inlet channel 42 is provided with a sixth control valve 421 for controlling on and off. Figure 3 As shown, the first anoxic pool 3 and the second anoxic pool 4 are both provided with an elastic filler layer B. Figure 3 As shown, the elastic packing layer B in the first anoxic pool 3 is arranged around the first drainage channel 222, and the spacing between adjacent elastic packings is 150 mm. The elastic packing layer B in the second anoxic pool 4 is arranged around the second drainage channel 512, and the spacing between the elastic packing layer B and the second drainage channel 512 is 150 mm. The elastic packing in the above elastic packing layer adopts the elastic packing in the prior art, which will not be described in detail in this embodiment.

[0038] The sewage treatment method using the above denitrification equipment comprises the following steps in sequence:

[0039] S1, the first control valve 10a is in the open state, the sewage enters the first aerated biological filter 1 through the first water inlet pipe 100, and then flows through the first aerobic tank 2 to the first anoxic tank 3, while the fifth control valve 321 and the second sludge pump 51 are in the open state. At this time, the second sludge pump 51 also pumps the sludge in the second aerobic tank 5 back to the first anoxic tank 3 for denitrification and decarbonization treatment, and then the sewage in the first anoxic tank 3 flows through the second anoxic tank 4, the second aerobic tank 5 and the second aerated biological filter 6 for treatment. Since the fourth control valve 60b is in the open state, the treated water flows out through the second outlet pipe 61, and the operation continues for 2 hours;

[0040] S2: Then close the first control valve 10a, the fifth control valve 321, the second sludge pump 51 and the fourth control valve 60b, open the third control valve 60a, the sewage enters the second aerated biological filter 6 through the second water inlet pipe 60, and then flows through the second aerobic tank 5 to the second anoxic tank 4 in turn. The sixth control valve 421 and the first sludge pump 22 are in the open state. At this time, the first sludge pump 22 also pumps the sludge in the first aerobic tank 2 back to the second anoxic tank 4 for denitrification and decarbonization treatment. Then the sewage in the second anoxic tank 4 flows through the first anoxic tank 3, the first aerobic tank 2 and the first aerated biological filter 1 in turn for treatment. Since the second control valve 10b is in the open state, the treated water flows out through the first outlet pipe 101 and continues to run for a period of time; repeat the above steps S1 and S2, thereby switching the water inlet in turn to achieve positive circulation and reverse circulation.

[0041] For example, in a positive cycle, sewage enters the MBAF1 pool, where the suspended filler layer provides a comfortable environment for the biological flora. Heavy ceramsite is used as a microbial carrier, and a layer of biofilm formed on the surface of the heavy ceramsite is used to purify the sewage. Then, it enters the first aerobic pool, where the activated sludge undergoes aerobic respiration, thereby decomposing organic matter into inorganic matter. Then, it enters the first anoxic pool, where anaerobic bacteria are used to further remove organic matter from the sewage. The first liquid inlet channel of the first anoxic pool acts as an elastic filler surface and the first sludge pump and the second The denitrifying microorganisms of the activated sludge pumped back by the sludge pump provide biodegradable organic matter as an organic carbon source, so that the denitrifying microorganisms can use the above organic matter and the organic carbon sources such as nitrates, polysaccharides and proteins remaining in the sludge to carry out denitrification, thereby achieving the purpose of denitrification and decarbonization; then it enters the second anoxic tank for further denitrification and decarbonization treatment, flows into the second aerobic tank, further decomposes the organic matter into inorganic matter, and then enters the second aerated biological filter to further purify the water quality before flowing out; conversely, the reverse cycle is also the same.

[0042] In the above embodiment, the first aerated biological filter is referred to as MBAF1 pool, the first aerobic pool is referred to as O1 pool, the first anoxic pool is referred to as A1 pool, the second anoxic pool is referred to as A2 pool, the second aerobic pool is referred to as O2 pool, and the second aerated biological filter is referred to as MBAF2 pool. The above MBAF adopts a novel combination process of vertically stacking an aerated biological filter BAF and a moving bed biofilm reactor MBBR in the prior art.

[0043] This equipment is used to improve the water quality of the river. Under the condition that the hydraulic retention time HRT is 2h, the specific water quality test data are as follows:

[0044]

[0045]

[0046] From the above data, we can see that under the condition of hydraulic retention time HRT of 2h, the ammonia nitrogen removal rate reached about 90%, achieving ideal effect.

[0047] In the specification and claims of the present invention, terms indicating directions, such as "front", "rear", "left", "right", "side", etc., are used to describe various exemplary structural parts and elements of the present invention, but these terms are used here only for the purpose of convenience of description and are determined based on the exemplary orientations shown in the drawings. Since the embodiments disclosed in the present invention can be arranged in different directions, these terms indicating directions are only used as illustrations and should not be regarded as limitations.

Claims

1. A denitrification device, comprising a first aerobic tank (2) and a first anoxic tank (3), wherein the first anoxic tank (3) is connected to the first aerobic tank (2), characterized in that: The invention also comprises a first aerated biological filter (1), a second anoxic tank (4), a second aerobic tank (5) and a second aerated biological filter (6). Along the water flow path, the first aerobic tank (2), the first anoxic tank (3), the second anoxic tank (4) and the second aerobic tank (5) are located between the first aerated biological filter (1) and the second aerated biological filter (6). The first aerated biological filter (1), the first aerobic tank (2), the first anoxic tank (3), the second anoxic tank (4), the second aerobic tank (5) and the second aerated biological filter (6) are sequentially connected. The first anoxic tank (3) and the second anoxic tank (4) are arranged symmetrically, the first aerobic tank (2) and the second aerobic tank (5) are arranged symmetrically, and the first anoxic tank (3) and the first aerobic tank (2) are arranged sequentially from front to back. The second anoxic tank (4) and the second aerobic tank (5) are arranged symmetrically. (5) Arranged from front to back, the first aerated biological filter (1) and the second aerated biological filter (6) are both provided with a support plate (11) arranged substantially horizontally, the support plate (11) is provided with a plurality of filter heads (111) arranged at intervals along the length direction of the support plate (11), the first aerated biological filter (1) and the second aerated biological filter (6) are provided with a plurality of first aerators (12) arranged at intervals along the length direction of the support plate (11) at positions located above the support plate (11), the first aerated biological filter (1) and the second aerated biological filter (6) are both provided with a suspended filler layer (13) and a heavy ceramsite layer (14) arranged in sequence from top to bottom at positions located above the first aerators (12), and a filter screen plate (15) supporting the heavy ceramsite layer (14) is provided below the heavy ceramsite layer (14).

2. The denitrification equipment according to claim 1, characterized in that: The first aerated biological filter (1) is provided with a first water inlet pipe (100) and a first water outlet pipe (101); the first water inlet pipe (100) is provided with a first control valve (10a) for controlling on and off; the first water outlet pipe (101) is provided with a second control valve (10b) for controlling on and off; the second aerated biological filter (6) is provided with a second water inlet pipe (60) and a second water outlet pipe (61); the second water inlet pipe (60) is provided with a third control valve (60a) for controlling on and off; and the second water outlet pipe (61) is provided with a fourth control valve (60b) for controlling on and off.

3. The denitrification equipment according to claim 1, characterized in that: A first water passage hole (21) for connecting the first aerobic pool (2) and the first anoxic pool (3) is provided at a position adjacent to the upper portion of the wall plate connecting the first aerobic pool (2) and the first anoxic pool (3), and the first water passage hole (21) is covered with a first filter net (211); a second water passage hole (31) for connecting the first anoxic pool (3) and the second anoxic pool (4) is provided at a position adjacent to the bottom portion of the wall plate connecting the first anoxic pool (3) and the second anoxic pool (4), and the second water passage hole (31) is covered with a second filter net (311); a third water passage hole (41) is provided on the wall plate connecting the second anoxic pool (4) and the second aerobic pool (5), and the third water passage hole (41) is covered with a third filter net (411).

4. The denitrification equipment according to claim 2, characterized in that: A first sludge pump (22) is arranged in the first aerobic tank (2), and a first sewage discharge passage (221) for connecting the first aerobic tank (2) with the outside is connected to the first sludge pump (22); a second sludge pump (51) is arranged in the second aerobic tank (5), and a second sewage discharge passage (511) for connecting the second aerobic tank (5) with the outside is connected to the second sludge pump (51).

5. The denitrification equipment according to claim 4, characterized in that: The first aerobic tank (2) is provided with a second aerator above the first sludge pump (22), and the second aerobic tank (5) is provided with a third aerator (53) above the second sludge pump (51). Both the first aerobic tank (2) and the second aerobic tank (5) are filled with a composite filler layer (A).

6. The denitrification equipment according to claim 5, characterized in that: The first sewage discharge channel (221) is connected to a first liquid discharge channel (222) in communication with the second anoxic tank (4); the first liquid discharge channel (222) is located on a pipe in the second anoxic tank (4) and has at least two first discharge channels (2221) arranged at intervals along the length direction; the second sewage discharge channel (511) is connected to a second liquid discharge channel (512) in communication with the first anoxic tank (3); the second liquid discharge channel (512) is located on a pipe in the first anoxic tank (3) and has at least two second discharge channels (5121) arranged at intervals along the length direction.

7. The denitrification equipment according to claim 5, characterized in that: The first anoxic pool (3) and the second anoxic pool (4) are respectively connected to a first liquid inlet channel (32) and a second liquid inlet channel (42); the first liquid inlet channel (32) and the second liquid inlet channel (42) are respectively provided with a fifth control valve (321) and a sixth control valve (421) for controlling on and off; and the first anoxic pool (3) and the second anoxic pool (4) are both provided with an elastic filler layer (B).

8. A method for treating wastewater using the denitrification equipment according to claim 7, characterized in that: The following steps are included in sequence: S1, the first control valve (10a) is in an open state, the sewage enters the first aerated biological filter (1) through the first water inlet pipe (100), and then flows through the first aerobic tank (2) and enters the first anoxic tank (3), the fifth control valve (321) and the second sludge pump (51) are in an open state, at this time, the second sludge pump (51) pumps the sludge in the second aerobic tank (5) back to the first anoxic tank (3) for denitrification and decarbonization treatment, and then the sewage in the first anoxic tank (3) flows through the second anoxic tank (4), the second aerobic tank (5) and the second aerated biological filter (6) in sequence for treatment, and because the fourth control valve (60b) is in an open state, the treated water flows out through the second outlet pipe (61) and continues to operate for a period of time; S2: Subsequently, the first control valve (10a), the fifth control valve (321), the second sludge pump (51) and the fourth control valve (60b) are closed, and the third control valve (60a) is in an open state. The sewage enters the second aerated biological filter (6) through the second water inlet pipe (60), and then flows through the second aerobic tank (5) in sequence and enters the second anoxic tank (4). Since the sixth control valve (421) and the first sludge pump (22) are in an open state, the first sludge pump (22) pumps the sludge in the first aerobic tank (2) back to the second anoxic tank (4) for denitrification and decarbonization treatment. Subsequently, the sewage in the second anoxic tank (4) flows through the first anoxic tank (3), the first aerobic tank (2) and the first aerated biological filter (1) in sequence for treatment. Since the second control valve (10b) is in an open state, the treated water flows out through the first outlet pipe (101) and continues to run for a period of time. Repeat the above steps S1 and S2.

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