A2 / O wastewater treatment integrated device

Abstract

The application relates to an A2 / O wastewater treatment integrated device, which comprises an anaerobic zone, an anoxic zone, an aerobic zone, a sedimentation zone and a sludge storage zone connected in sequence, a water inlet pipe is connected with the anaerobic zone to input wastewater to be treated; the upper part of the sedimentation zone is connected with a water production pipe to discharge produced water obtained after biochemical treatment; the sludge discharge port at the bottom of the sedimentation zone is connected with the top of the sludge storage zone to input separated sludge into the sludge storage zone; a stripping device is arranged in the aerobic zone to return nitrification liquid to the downstream side of the anoxic zone; a circulating liquid return device is arranged at the downstream of the anoxic zone to return water bodies at the downstream of the anoxic zone to the upstream of the anaerobic zone and the upstream of the anoxic zone respectively to provide a micro-oxygen environment; and the sludge discharge port of the sedimentation zone is also connected with the downstream side of the anoxic zone to supplement active sludge.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to an integrated A2 / O wastewater treatment device. Background Technology

[0002] Currently, the most commonly used wastewater treatment process is aerobic biological treatment, and the A2 / O process is a typical aerobic wastewater treatment process. It not only reduces organic load but also has the characteristics of simultaneous nitrogen and phosphorus removal, making it widely used. However, the A2 / O process has problems during operation, such as low nitrogen removal efficiency, odor generation, weak shock resistance, and water quality fluctuations. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides an integrated A2 / O wastewater treatment device, comprising an anaerobic zone, an anoxic zone, an aerobic zone, a sedimentation zone, and a sludge storage zone connected in sequence. An inlet pipe connects to the anaerobic zone to input the wastewater to be treated. A product water pipe connects to the upper part of the sedimentation zone to discharge the product water obtained after biochemical treatment. A sludge discharge port at the bottom of the sedimentation zone connects to the top of the sludge storage zone to input the separated sludge into the sludge storage zone.

[0004] The aerobic zone is equipped with a stripping device to return the nitrified liquid to the downstream side of the anoxic zone; the downstream of the anoxic zone is equipped with a circulating liquid return device to return the water from the downstream of the anoxic zone to the upstream of the anaerobic zone and the upstream of the anoxic zone, respectively, to provide a micro-oxygen environment.

[0005] The sludge discharge port of the sedimentation zone is also connected to the downstream side of the anoxic zone to replenish activated sludge.

[0006] Optionally, the A2 / O wastewater treatment integrated device is a circular nested structure, with the inner layer including an aerobic zone, a sedimentation zone and a sludge storage zone, and the outer layer including an anaerobic zone and an anoxic zone, with each zone separated by a partition.

[0007] The aerobic zone, sedimentation zone, and sludge storage zone are all fan-shaped, forming an inner circle; the outer anaerobic zone and anoxic zone form a ring structure, with both the anaerobic and anoxic zones being fan-shaped.

[0008] Optionally, the anaerobic zone includes an upstream anaerobic zone and a downstream anaerobic zone, arranged in parallel along the outer ring; a first partition wall is provided between the upstream anaerobic zone and the downstream anaerobic zone, with the top of the first partition wall above the liquid surface of the anaerobic zone and the bottom suspended, so that the bottoms of the upstream anaerobic zone and the downstream anaerobic zone are connected.

[0009] The inlet pipe is connected to the top of the anaerobic upstream zone and is used to input raw material wastewater. The anaerobic upstream zone is equipped with a first guide tube with openings at the top and bottom, so that the circulating liquid returning from the downstream of the anoxic zone rises along the first guide tube and mixes with the wastewater input by the inlet pipe.

[0010] Optionally, the anoxic zone is divided into several partitions by several second partitions, with the partition closer to the downstream anaerobic zone being the upstream side and the partition closer to the aerobic zone being the downstream side.

[0011] The top of the first section upstream of the anoxic zone is connected to the top of the downstream anaerobic zone. The water flow direction of the first section is from top to bottom, that is, the water at the top of the downstream anaerobic zone overflows from the top of the partition to the first section. The top of the second partition wall downstream of the first section is above the liquid surface of the anoxic zone, and the bottom is suspended, so that the bottom of the first section and the second section are connected. The bottom of the next second partition wall downstream is fixed to the bottom plate of the anoxic zone, and the top is lower than the top of the previous second partition wall, so that the water at the top of the second section overflows to the third section. This process is repeated, and the water flow direction of the adjacent sections of the anoxic zone is opposite. The last section downstream of the anoxic zone uses the top overflow method to enter the adjacent aerobic zone.

[0012] Optionally, a circulating liquid reflux device is provided at the bottom of the last section downstream of the anoxic zone. The circulating liquid reflux device includes a first reflux pipe, a second reflux pipe, and a circulating liquid reflux pump. The inlet ends of the first reflux pipe and the second reflux pipe are connected to the bottom of the last section. The outlet end of the first reflux pipe is located at the bottom of the first guide tube in the upstream anaerobic zone, which facilitates the refluxed circulating liquid to directly enter the first guide tube and flow upward. The outlet end of the second reflux pipe is connected to the bottom of the first section.

[0013] Optionally, an aeration pipe is provided at the bottom of the aerobic zone, and a stripping device is provided on the downstream side of the aerobic zone. The stripping device includes a stripping pipe, and the air supply pipeline of the aeration pipe supplies air to the stripping pipe. The outlet end of the stripping pipe extends to the top of the last section on the downstream side of the anoxic zone, so as to return the nitrified liquid on the downstream side of the aerobic zone to the downstream side of the anoxic zone.

[0014] Optionally, the first partition wall includes an outer mesh cage, filter media, gravel, an inner mesh frame, biomass, an air pipe, and a conveying pipe. The filter media and gravel are filled inside the outer mesh cage to form an outer filter layer. The inner mesh frame is located inside the filter layer, and the biomass is filled within the area of ​​the inner mesh frame. The air pipe and conveying pipe are located in the middle of the inner mesh frame and vertically penetrate the first partition wall.

[0015] Further optionally, the outer mesh cage is a cuboid, the filler filter material is a conventional filter material used for wastewater treatment, and the particle size of the filler filter material is 2-4mm; the gravel is conventional gravel and has a gradation, with the first grade being 3-6mm and the second grade being 7-15mm; the filler filter material and the two grades of gravel are mixed evenly and then filled into the outer mesh cage.

[0016] The volume ratio of the filter media, first-stage gravel, and second-stage gravel is 1:(1-1.5):(2-4).

[0017] Optionally, the internal mesh frame is composed of several interwoven horizontal and vertical mesh panels, with biomass filled within the cavities formed by these mesh panels. The biomass includes fibrous plant strips, humus-containing filter media, and facultative anaerobic microorganisms. The fibrous plant strips are selected from the roots and rhizomes of kelp, aquatic plants, and herbaceous plants. The filter media in the biomass is the same as the filling filter media, serving as a carrier, and its large specific surface area can support the humus and microorganisms. The humus is conventional humus, providing nutrients for the microorganisms. The fibrous plant strips not only increase nutrient availability but also act as a mesh, ensuring the humus-containing filter media is more firmly fixed within the space of the internal mesh frame.

[0018] Optionally, the top end of the vent pipe is connected to an external air supply device, and the side of the vent pipe is evenly covered with air holes to input a small amount of air into the space of the internal mesh frame; the top end of the material conveying pipe is connected to an external carbon source, and the side of the material conveying pipe is evenly covered with through holes to input nutrients into the space of the internal mesh frame.

[0019] The inner mesh frame is pre-installed inside the outer mesh cage. After the filter material and two graded stones are mixed evenly, they are filled into the outer mesh cage. The filter material is first mixed evenly with an equal mass of humus to obtain filter material containing humus. Then, the filter material containing humus is mixed evenly with fibrous strip plants and filled into the space of the inner mesh frame. Finally, the fibrous strip plants are evenly wrapped around and covered on the outer surface of the outer mesh cage, ensuring there are no obvious gaps.

[0020] Further optionally, the ratio of the space occupied by the internal mesh frame to the volume of the filter layer is (5-10):1; the mass ratio of the filter material containing humus to the fibrous strip plants is 1:(1-1.5).

[0021] Most of the wastewater from the upstream side of the anaerobic digester enters the downstream zone from the bottom, while some wastewater passes through the first partition wall to enter the downstream zone. The wastewater is first filtered through a filter layer and then enters the area of ​​the internal mesh frame, where facultative anaerobic microorganisms grow and reproduce in a low-oxygen environment, and perform biochemical treatment on the flowing wastewater. After treatment, it passes through another filter layer and enters the downstream zone. The limited oxygen in this portion of the wastewater is dispersed through the internal mesh frame, biomass, and filter layer, forming micro-oxygen, and then enters the downstream zone.

[0022] Optionally, the structure and internal materials of the second partition wall are the same as those of the first partition wall. The difference is that the biomass in the second partition wall contains aerobic microorganisms, the ventilation pipe supplies more air, and the material conveying pipe inputs more carbon sources.

[0023] The anoxic zone has multiple sections. Some wastewater meanders through each section along the second partition wall, while some wastewater flows through the second partition wall. The wastewater undergoes aerobic treatment within the second partition wall, forming an anoxic-aerobic-anoxic-aerobic treatment process to improve the denitrification effect.

[0024] Optionally, in addition to aerobic activated sludge, the oxidation zone is also provided with packing material, which consists of several biological packing cages. The biological packing cages include, from the outside to the inside, a first filter layer, an aerobic biological layer, a second filter layer, an anoxic biological layer, and a third filter layer.

[0025] The raw materials for the aerobic biolayer include plant debris, filter media containing humus, and aerobic microorganisms, while the raw materials for the anaerobic biolayer include plant debris, filter media containing humus, and anaerobic microorganisms.

[0026] Further optionally, the raw materials for the first filter layer, the second filter layer and the third filter layer are all filter media and pebbles. The filter media is the same as the filling filter media of the first partition wall, and the pebbles can be ordinary pebbles with a particle size of 3-6mm and a particle size of 2-4mm.

[0027] The humus-containing filter media in the aerobic and anaerobic biological layers are the same as those in the first partition wall, and the humus can be conventional humus; the plant debris is made from the crushed roots, stems and leaves of conventional herbaceous plants.

[0028] When manufacturing the biochemical packing cage, it is made from the inside out. The filter media and pebbles of the third filter layer are mixed evenly and filled into the innermost packing cage to form the third filter layer. Then, the plant debris, filter media containing humus, and anaerobic microorganisms of the anoxic biological layer are mixed evenly and filled into the next innermost packing cage to form the anoxic biological layer. The second filter layer, the aerobic biological layer, and the first filter layer are then made in sequence according to the above method.

[0029] Further optionally, the volume ratio of the first filter layer, the second filter layer, and the third filter layer is (2-3):(1.5-2.5):1;

[0030] The volume ratio of the third filter layer, the anoxic biological layer and the aerobic biological layer is 1:(3-5):(4-6);

[0031] The humus-containing filter media in the anoxic biolayer is a mixture of equal mass of humus and filter media, with the mass ratio of plant debris to humus-containing filter media being (0.8-1.3):1.

[0032] The aerobic biological layer contains humus-containing filter media, which is a mixture of equal mass of humus and filter media. The mass ratio of plant debris to humus-containing filter media is (2-4):1.

[0033] The present invention sets up the biochemical treatment layer in the aerobic zone, which works in conjunction with activated sludge to perform auxiliary biochemical filtration treatment. The sandwich structure of the biochemical packing cage allows the sewage flowing down from above to undergo a process of filtration, aerobic biochemical treatment, filtration, anoxic biochemical treatment, filtration, re-anoxic biochemical treatment, filtration, re-aerobic biochemical treatment, and filtration in sequence, thereby improving the biochemical treatment effect.

[0034] The first partition wall, the second partition wall, and the biochemical packing cage are started up together with the start-up processes of the anaerobic zone, the anoxic zone, and the aerobic zone, and then wastewater treatment is carried out. Attached Figure Description

[0035] Figure 1 This is a top view schematic diagram of the A2 / O wastewater treatment integrated device of Example 1;

[0036] Figure 2 This is a schematic diagram of the processing flow of Example 1;

[0037] Figure 3 This is a schematic cross-sectional view of the first partition wall in Example 3 (the filling material inside the internal grid is omitted).

[0038] In the attached diagram, 1-anaerobic zone, 2-anoxic zone, 3-aerobic zone, 4-sedimentation zone, 5-sludge storage zone, 6-upstream anaerobic zone, 7-downstream anaerobic zone, 8-first partition wall, 9-second partition wall, 10-first guide tube, 11-second guide tube, 12-first zone, 13-second zone, 14-first return pipe, 15-second return pipe, 16-aeration pipe, 17-stripping pipe, 18-outer mesh cage, 19-internal mesh frame, 20-ventilation pipe, 21-material conveying pipe. Detailed Implementation

[0039] The following examples and comparative examples all treat domestic sewage from a rural area in southern Henan Province, with a treatment capacity of 55m³. 3 / day, wastewater quality is COD Cr The concentrations are 300-400 mg / L, NH3-N 35-45 mg / L, TN 50-60 mg / L, TP 2.0-3.0 mg / L, and SS 150-200 mg / L. After passing through the screen, the wastewater remains in a conventional equalization and grit chamber for 6 hours before being fed into the biological treatment tank.

[0040] Example 1

[0041] The integrated A2 / O wastewater treatment device provided in this embodiment, such as Figure 1 and Figure 2As shown, it includes an anaerobic zone 1, an anoxic zone 2, an aerobic zone 3, a sedimentation zone 4, and a sludge storage zone 5 connected in sequence. The inlet pipe is connected to the anaerobic zone 1 to input the wastewater to be treated; the upper part of the sedimentation zone 4 is connected to the product water pipe to discharge the product water obtained after biochemical treatment; the sludge discharge port at the bottom of the sedimentation zone 4 is connected to the top of the sludge storage zone 5 to input the separated sludge into the sludge storage zone 5.

[0042] The aerobic zone 3 is equipped with a stripping device to return the nitrified liquid to the downstream side of the anoxic zone 2; the downstream of the anoxic zone 2 is equipped with a circulating liquid return device to return the water in the downstream of the anoxic zone 2 to the upstream of the anaerobic zone 1 and the upstream of the anoxic zone 2 respectively, to provide a micro-oxygen environment.

[0043] The sludge discharge port of sedimentation zone 4 is also connected to the downstream side of anoxic zone 2 to replenish activated sludge.

[0044] The A2 / O wastewater treatment integrated device is a circular nested structure. The inner layer includes an aerobic zone 3, a sedimentation zone 4 and a sludge storage zone 5, and the outer layer includes an anaerobic zone 1 and an anoxic zone 2. The various zones are separated by partitions.

[0045] The aerobic zone 3, sedimentation zone 4, and sludge storage zone 5 are all fan-shaped and form an inner circle; the outer anaerobic zone 1 and anoxic zone 2 form a ring structure, and both anaerobic zone 1 and anoxic zone 2 are fan-shaped.

[0046] The anaerobic zone 1 includes an upstream anaerobic zone 6 and a downstream anaerobic zone 7, which are arranged in parallel along the outer ring. A first partition wall 8 is provided between the upstream anaerobic zone 6 and the downstream anaerobic zone 7. The top of the first partition wall 8 is above the liquid surface of the anaerobic zone 1, and the bottom is suspended, so that the bottom of the upstream anaerobic zone 6 and the downstream anaerobic zone 7 are connected.

[0047] The inlet pipe is connected to the top of the anaerobic upstream zone 6 and is used to input raw material wastewater. The anaerobic upstream zone 6 is provided with a first guide cylinder 10, which has openings at the top and bottom, so that the circulating liquid returning from the downstream of the anoxic zone 2 rises along the first guide cylinder 10 and mixes with the wastewater input by the inlet pipe.

[0048] Wastewater fed into the inlet pipe flows from top to bottom through the upstream anaerobic zone 6, then enters the bottom of the downstream anaerobic zone 7 from below the first partition wall 8, then flows from bottom to top through the downstream anaerobic zone 7, and finally crosses the top of the partition between the anaerobic zone 1 and the anoxic zone 2, thus entering the anoxic zone 2. The circulating liquid returning from the downstream of the anoxic zone 2 rises along the first guide tube 10 to the upper part of the upstream anaerobic zone 6, where it meets the wastewater fed into the inlet pipe. It then flows downwards with the wastewater, mixing evenly during the downward flow, achieving a better sludge-water mixing effect, improving pollutant removal efficiency, and reducing the cost of adding subsequent mixing equipment.

[0049] The anoxic zone 2 is divided into several partitions by several second partitions 9. The partitions closer to the downstream anaerobic zone 7 are the upstream side, and the partitions closer to the aerobic zone 3 are the downstream side.

[0050] The top of the first partition 12 upstream of the anoxic zone 2 is connected to the top of the downstream anaerobic zone 7. The water flow direction of the first partition 12 is from top to bottom, that is, the water at the top of the downstream anaerobic zone 7 overflows from the top of the partition to the first partition 12. The top of the second partition 9 downstream of the first partition 12 is above the liquid surface of the anoxic zone 2, and the bottom is suspended, so that the bottom of the first partition 12 is connected to the bottom of the second partition 13. The bottom of the next second partition 9 downstream is fixed to the bottom plate of the anoxic zone 2, and the top is lower than the top of the previous second partition 9, so that the water at the top of the second partition 13 overflows to the third partition. This process is repeated, and the water flow direction of the adjacent partitions of the anoxic zone 2 is opposite. The last partition downstream of the anoxic zone 2 uses the top overflow method to feed water into the adjacent aerobic zone 3. Both the first partition 8 and the second partition 9 are set vertically.

[0051] The bottom of the last section downstream of the anoxic zone 2 is equipped with a circulating liquid return device. The circulating liquid return device includes a first return pipe 14, a second return pipe 15, and a circulating liquid return pump. The inlet ends of the first return pipe 14 and the second return pipe 15 are connected to the bottom of the last section. The outlet end of the first return pipe 14 is located at the bottom of the first guide cylinder 10 in the upstream anaerobic zone 6, which facilitates the direct entry of the returned circulating liquid into the first guide cylinder 10 and upward flow. The outlet end of the second return pipe 15 is connected to the bottom of the first section 12.

[0052] The bottom of the aerobic zone 3 is provided with an aeration pipe 16, and the downstream side of the aerobic zone 3 is provided with a stripping device, which includes a stripping pipe 17. The air supply pipeline of the aeration pipe 16 supplies air to the stripping pipe 17. The outlet end of the stripping pipe 17 extends to the top of the last section downstream of the anoxic zone 2, so as to return the nitrified liquid downstream of the aerobic zone 3 to the downstream side of the anoxic zone 2.

[0053] Wastewater from the last section downstream of anoxic zone 2 flows upwards, while the returned nitrified liquid flows downwards. This counter-current contact allows for thorough mixing with the water in that section. The mixed nitrified liquid then flows back to the upstream anaerobic zone 6 and the first section 12 of anoxic zone 2 via a circulating liquid return device. Both the first return pipe 14 and the second return pipe 15 form upward-flowing circulating liquid, which mixes thoroughly with the downward-flowing water. Because the stripping device contains some oxygen, the mixing and dispersion of the circulating liquid disperses the dissolved oxygen, creating a microaerobic environment. This environment not only promotes the growth of microorganisms in the upstream anaerobic zone 6 and the first section 12, accelerating the degradation of organic matter, but also increases the tolerance of sulfate ions in the wastewater, making it suitable for the removal of high-sulfate wastewater. The microaerobic environment also prevents the conversion of sulfate ions in the water to H2S, thereby reducing odor generation.

[0054] A second guide cylinder 11 is located at the center of the sedimentation zone 4. The second guide cylinder 11 is open at the top and bottom, and its top is higher than the liquid level in the sedimentation zone 4. A reflector plate is located below the second guide cylinder 11. A water outlet pipe is located on the downstream side of the aerobic zone 3. The water outlet pipe is connected to the upper part of the second guide cylinder 11, and the water from the aerobic zone 3 is fed into the second guide cylinder 11. The water flows downward to the reflector plate and spreads outward to achieve uniform water distribution. The water then flows upward, and the sludge settles downward, thus achieving mud-water separation.

[0055] The top edge of the sedimentation zone 4 is equipped with an outlet weir, which is connected to the product water pipe to discharge the supernatant, which is the product water. The product water can be used as recycled water. The bottom of the sedimentation zone 4 is conical to facilitate the discharge of collected sludge.

[0056] The bottom of the sludge storage area 5 is conical to facilitate the discharge of collected sludge. The bottom of the sludge storage area 5 is equipped with a sludge conveying port, which is connected to the bottom of the upstream anaerobic zone 6 through a pipeline. This can quickly and effectively replenish the sludge loss caused by the flow of wastewater, maintain the sludge concentration in the anaerobic zone 1 and the subsequent anoxic zone 2, and ensure a certain amount of microorganisms.

[0057] The hydraulic retention time (HRT) of wastewater in the anaerobic zone is 2 hours, with a sludge concentration of 3800-4000 mg / L. The HRT in the anoxic zone is 2 hours, with a sludge concentration of 3500-3800 mg / L. The HRT in the aerobic zone is 4 hours, with a sludge concentration of 3500-4000 mg / L. Effluent quality from the sedimentation zone: COD Cr The concentrations of pollutants are <50 mg / L, NH3-N is <5 mg / L, TN is <15 mg / L, TP is <0.5 mg / L, and SS is <10 mg / L, which meets the Class A discharge standard of the "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002).

[0058] Comparative Example 1

[0059] The A2 / O wastewater treatment integrated device provided in this comparative example is the same as that in Example 1, except that a circulating liquid return device is not set up, and the water downstream of the anoxic zone cannot be returned to the anaerobic zone and the upstream of the anoxic zone.

[0060] Example 2

[0061] The A2 / O wastewater treatment integrated device provided in this embodiment is the same as that in Embodiment 1, except that the anaerobic zone does not have a first partition wall, does not distinguish between the upstream and downstream anaerobic zones, and the anoxic zone does not have a second partition wall, and there are no separate zones.

[0062] Example 3

[0063] The integrated A2 / O wastewater treatment device provided in this embodiment is the same as that in Embodiment 1, except that the first partition wall of the anaerobic zone is, as shown in the embodiment. Figure 3 As shown, it includes an outer mesh cage 18, filter media, gravel, an inner mesh frame 19, biomass, an air pipe 20, and a conveying pipe 21. The filter media and gravel are filled inside the outer mesh cage 18 to form an outer filter layer. The inner mesh frame 19 is located inside the filter layer, and biomass is filled within the area of ​​the inner mesh frame 19. The air pipe 20 and the conveying pipe 21 are located in the middle of the inner mesh frame 19 and vertically penetrate the first partition wall.

[0064] The outer mesh cage 18 is a cuboid, and the filter media is a conventional filter media used for wastewater treatment with a particle size of 2-4 mm. The gravel is conventional gravel with a gradation, with the first grade being 3-6 mm and the second grade being 7-15 mm. After the filter media and the two grades of gravel are mixed evenly, they are filled into the outer mesh cage 18. The inner side of the outer mesh cage 18 also has a cage wall, which can fix the filter layer and prevent it from collapsing inward.

[0065] The volume ratio of the filter media, first-stage gravel, and second-stage gravel is 1:1:2.

[0066] The internal mesh frame 19 is composed of several interwoven horizontal and vertical mesh panels, with biomass filled within the cavities formed by these mesh panels. The biomass includes fibrous plants, humus-containing filter media, and facultative anaerobic microorganisms. The fibrous plants are kelp and aquatic plants. The filter media in the biomass is the same as the filling filter media, and the humus is conventional humus.

[0067] The top end of the vent pipe 20 is connected to an external air supply device, and the side of the vent pipe 20 is evenly covered with air holes to input a small amount of air into the space of the internal mesh frame 19; the top end of the material conveying pipe 21 is connected to an external carbon source, and the side of the material conveying pipe 21 is evenly covered with through holes to input nutrients into the space of the internal mesh frame 19.

[0068] The inner mesh frame 19 is pre-installed inside the outer mesh cage 18. After the filter material and two graded stones are mixed evenly, they are filled into the outer mesh cage 18. The filter material is first mixed evenly with an equal mass of humus to obtain a filter material containing humus. Then, the filter material containing humus is mixed evenly with fibrous strip plants and facultative anaerobic microorganisms and filled into the space of the inner mesh frame 19. Then, the outer surface of the outer mesh cage 18 is evenly wrapped and covered with fibrous strip plants, ensuring there are no obvious gaps.

[0069] The ratio of the space occupied by the internal mesh frame 19 to the volume of the filter layer is 5:1; the mass ratio of the filter material containing humus to the fibrous plant strips is 1:1.

[0070] Example 4

[0071] The A2 / O wastewater treatment integrated device provided in this embodiment is the same as that in embodiment 3, except that the ratio of the space occupied by the internal mesh frame to the volume of the filter layer is 10:1.

[0072] Example 5

[0073] The A2 / O wastewater treatment integrated device provided in this embodiment is the same as that in embodiment 3, except that the ratio of the space occupied by the internal mesh frame to the volume of the filter layer is 4:1.

[0074] Example 6

[0075] The A2 / O wastewater treatment integrated device provided in this embodiment is the same as that in embodiment 4. The difference is that the structure and internal material of the second partition wall in the anoxic zone are the same as those of the first partition wall. The difference is that the biomass in the second partition wall contains aerobic microorganisms, the ventilation pipe supplies more air, and the material conveying pipe inputs more carbon source.

[0076] Example 7

[0077] The A2 / O wastewater treatment integrated device provided in this embodiment is the same as that in embodiment 1. The difference is that, in addition to aerobic activated sludge, a packing material is also provided in the aerobic zone. The packing material consists of several biological packing cages. From the outside to the inside, the biological packing cages include a first filter layer, an aerobic biological layer, a second filter layer, an anoxic biological layer, and a third filter layer.

[0078] The raw materials for the aerobic biolayer include plant debris, filter media containing humus, and aerobic microorganisms, while the raw materials for the anaerobic biolayer include plant debris, filter media containing humus, and anaerobic microorganisms.

[0079] The raw materials for the first filter media layer, the second filter media layer, and the third filter media layer are all filter media and pebbles. The filter media is the same as the filling filter media of the first partition wall, and the pebbles can be ordinary pebbles with a particle size of 3-6mm. The filter media has a particle size of 2-4mm.

[0080] The filter media in the aerobic and anaerobic biological layers containing humus are conventional filter media, and the humus is conventional humus; the plant debris is made from the crushed roots, stems and leaves of conventional herbaceous plants.

[0081] The biochemical packing cage is manufactured from the inside out. An equal mass of filter media and pebbles from the third filter layer are mixed evenly and filled into the innermost packing cage to form the third filter layer. Then, plant debris, humus-containing filter media, and anaerobic microorganisms from the anoxic biological layer are mixed evenly and filled into the next innermost packing cage to form the anoxic biological layer. An equal mass of filter media and pebbles from the second filter layer are mixed evenly and filled into the packing cage outside the anoxic biological layer to form the second filter layer. Then, plant debris, humus-containing filter media, and aerobic microorganisms from the aerobic biological layer are mixed evenly and filled into the packing cage outside the second filter layer to form the aerobic biological layer. An equal mass of filter media and pebbles from the first filter layer are mixed evenly and filled into the packing cage outside the aerobic biological layer to form the first filter layer.

[0082] The volume ratio of the first filter layer, the second filter layer, and the third filter layer is 2:1.5:1;

[0083] The volume ratio of the third filter layer, the anoxic biological layer, and the aerobic biological layer is 1:3:4;

[0084] The humus-containing filter media in the anoxic biolayer is a mixture of equal masses of humus and filter media, with a mass ratio of plant debris to humus-containing filter media of 0.8:1.

[0085] The aerobic biological layer contains humus-containing filter media, which is a mixture of equal masses of humus and filter media, with a mass ratio of plant debris to humus-containing filter media of 2:1.

[0086] Example 8

[0087] The A2 / O wastewater treatment integrated device provided in this embodiment is the same as that in embodiment 7, except that the volume ratio of the third filter layer, the anoxic biological layer and the aerobic biological layer is 1:5:6.

[0088] Example 9

[0089] The A2 / O wastewater treatment integrated device provided in this embodiment is the same as that in embodiment 7, except that the volume ratio of the third filter layer, the anoxic biological layer and the aerobic biological layer is 1:2:3.

[0090] Table 1 Comparison of wastewater treatment effects between the examples and comparative examples

[0091]

[0092]

[0093] As shown in the table above, the wastewater treatment integrated device of the present invention adopts a process of combined anaerobic, anoxic and aerobic treatment, and performs liquid reflux in the anoxic and aerobic zones to provide a micro-oxygen environment upstream of the anaerobic and anoxic zones. In addition, the use of the first partition wall, the second partition wall and the biological packing cage can significantly improve the treatment effect and ensure that the effluent meets the standards.

Claims

1. An A2 / O wastewater treatment integrated device, characterized by, The wastewater treatment device comprises an anaerobic zone, an anoxic zone, an aerobic zone, a sedimentation zone and a sludge storage zone connected in sequence, a water inlet pipe connected to the anaerobic zone for inputting wastewater to be treated, a water outlet pipe connected to the upper part of the sedimentation zone for discharging treated water, and a sludge outlet connected to the top of the sludge storage zone for inputting sludge into the sludge storage zone. The aerobic zone is provided with a stripping device for returning nitrification liquid to the downstream side of the anoxic zone, and the downstream side of the anoxic zone is provided with a circulating liquid return device for returning water in the downstream side of the anoxic zone to the upstream side of the anaerobic zone and the upstream side of the anoxic zone respectively to provide a micro-oxygen environment. The sludge outlet of the sedimentation zone is also connected to the downstream side of the anoxic zone for supplementing activated sludge. The anaerobic zone comprises an anaerobic upstream zone and an anaerobic downstream zone, and a first partition wall is arranged between the anaerobic upstream zone and the anaerobic downstream zone. The first partition wall comprises an outer net cage, filter material, stones, an inner net rack, biomass, an air pipe and a feed pipe, the filter material and the stones are filled in the outer net cage to form an outer filter layer, the inner net rack is arranged on the inner side of the filter layer, the biomass is filled in the area of the inner net rack, the air pipe and the feed pipe are arranged in the middle part of the inner net rack and vertically penetrate the first partition wall. The inner net rack is formed by crossing a plurality of horizontal and vertical net pieces, and the biomass is filled in the cavity formed by the horizontal and vertical net pieces. The volume ratio of the space occupied by the inner net rack to the filter layer is (5-10):

1. The top end of the air pipe is connected to an external air supply device, the side surface of the air pipe is uniformly and densely provided with air holes for inputting a small amount of air into the space of the inner net rack, the top end of the feed pipe is connected to an external carbon source, and the side surface of the feed pipe is uniformly and densely provided with through holes for inputting nutrients into the space of the inner net rack. The inner net rack is installed in the outer net cage in advance, the filter material and the stones are mixed uniformly and then filled into the outer net cage, the filter material is first mixed with humus of the same quality to obtain filter material containing humus, then the filter material containing humus, the fiber strip-shaped plants and the facultative microorganisms are mixed uniformly and then filled into the space of the inner net rack, and then the fiber strip-shaped plants are uniformly wound and covered on the outer surface of the outer net cage without obvious gaps. The anoxic zone is divided into a plurality of sub-zones by a plurality of second partition walls, the structure and the internal substances of the second partition walls are the same as those of the first partition wall, and the biomass of the second partition wall comprises aerobic microorganisms. In addition to the aerobic activated sludge, the aerobic zone is provided with laid filter material, and the filter material comprises a plurality of biochemical filter cages, which comprise, from the outside to the inside, a first filter layer, an aerobic biological layer, a second filter layer, an anoxic biological layer and a third filter layer. The raw materials of the aerobic biological layer comprise plant debris, filter material containing humus and aerobic microorganisms, and the raw materials of the anoxic biological layer comprise plant debris, filter material containing humus and anoxic microorganisms. The volume ratio of the third filter layer, the anoxic biological layer and the aerobic biological layer is 1:(3-5):(4-6).

2. The A2 / O wastewater treatment integrated device according to claim 1, characterized in that, The A2 / O wastewater treatment integrated device is a circular sheath structure, the inner layer comprises an aerobic zone, a sedimentation zone and a sludge storage zone, the outer side comprises an anaerobic zone and an anoxic zone, and each zone is separated by a partition plate; The aerobic zone, the sedimentation zone and the sludge storage zone are all fan-shaped and form a circle as the inner layer; the anaerobic zone and the anoxic zone form a circular ring structure, and both the anaerobic zone and the anoxic zone are fan-shaped.

3. The A2 / O wastewater treatment integrated device according to claim 2, characterized in that, The anaerobic upstream zone and the anaerobic downstream zone are arranged side by side along the circular ring of the outer side; the top of the first partition wall is above the liquid level of the anaerobic zone, and the bottom is suspended, so that the anaerobic upstream zone is in communication with the bottom of the anaerobic downstream zone; The water inlet pipe is connected to the top of the anaerobic upstream zone and is used for inputting raw wastewater; the first flow guide cylinder is arranged in the anaerobic upstream zone, and the first flow guide cylinder is open at the top and the bottom, so that the circulating liquid flowing back from the downstream of the anoxic zone rises along the first flow guide cylinder and then is mixed with the wastewater input by the water inlet pipe.

4. The A2 / O wastewater treatment integrated device according to claim 3, characterized in that, Among the several sub-zones of the anoxic zone, the sub-zone close to the anaerobic downstream zone is the upstream side, and the sub-zone close to the aerobic zone is the downstream side; The top of the first sub-zone of the upstream side of the anoxic zone is in communication with the top of the anaerobic downstream zone, the water flow direction of the first sub-zone is from top to bottom, and the water at the top of the anaerobic downstream zone overflows from the top end of the partition plate to the first sub-zone; the top of the second partition wall of the downstream side of the first sub-zone is above the liquid level of the anoxic zone, and the bottom is suspended, so that the first sub-zone is in communication with the bottom of the second sub-zone; The bottom of the next second partition wall of the downstream side is fixed on the bottom plate of the anoxic zone, and the top is lower than the top of the previous second partition wall, so that the water body at the top of the second sub-zone overflows to the third sub-zone; this is repeated, and the water flow directions of the adjacent sub-zones of the anoxic zone are opposite; the last sub-zone of the downstream side of the anoxic zone uses the top overflow mode to input water to the adjacent aerobic zone.

5. The A2 / O wastewater treatment integrated device according to claim 4, characterized in that, The bottom of the last sub-zone of the downstream side of the anoxic zone is provided with a circulating liquid backflow device, the circulating liquid backflow device comprises a first backflow pipe, a second backflow pipe and a circulating liquid backflow pump, the water inlet ends of the first backflow pipe and the second backflow pipe are connected to the bottom of the last sub-zone, and the water outlet end of the first backflow pipe is arranged at the bottom of the first flow guide cylinder of the anaerobic upstream zone; The water outlet end of the second backflow pipe is connected to the bottom of the first sub-zone.

6. The A2 / O wastewater treatment integrated device according to claim 5, characterized in that, The bottom of the aerobic zone is provided with an aeration pipe, the downstream side of the aerobic zone is provided with a stripping device, the stripping device comprises a stripping pipe, the gas supply pipeline of the aeration pipe supplies gas to the stripping pipe, and the water outlet end of the stripping pipe extends to the top of the last sub-zone of the downstream side of the anoxic zone, so as to return the nitrification liquid of the downstream side of the aerobic zone to the downstream side of the anoxic zone.

7. The A2 / O wastewater treatment integrated device according to claim 1, characterized in that, The outer side net cage is a rectangular parallelepiped, the particle size of the filter material is 2-4 mm; the stones have a grading, the first grade is 3-6 mm, and the second grade is 7-15 mm; after the filter material and the two grades of stones are mixed uniformly, they are filled into the outer side net cage; The volume ratio of the filter material, the first grade of stones and the second grade of stones is 1:(1-1.5):(2-4).

8. The A2 / O wastewater treatment integrated device according to claim 7, characterized in that, The mass ratio of the filter material containing humus and the fiber strip-shaped plants is 1:(1-1.5).

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