A vertical-flow AO sewage treatment device and a method for treating sewage

Abstract

The present invention relates to the technical field of sewage treatment equipment, and specifically relates to a vertical-flow AO sewage treatment device and a method for treating sewage. The device includes: a tank body, where the inside of the tank body is successively an anaerobic zone, an anoxic zone, and an aerobic zone from bottom to top. The tank body is filled with activated sludge, and an anaerobic packing layer and an aerobic packing layer are respectively filled in the anaerobic zone and the aerobic zone; a water distributor, which is arranged at the bottom of the tank body and is used to introduce sewage into the anaerobic zone; a swirl aeration device, which is arranged between the anoxic zone and the aerobic zone, and the swirl aeration device is connected to an external air supply device through an air inlet; an outlet, which is arranged at the top of the tank body. This vertical-flow AO sewage treatment device integrates the anaerobic, anoxic, and aerobic process in the same tank body, and there is no obvious distinction and boundary between each process. It cleverly utilizes the principle of mechanics to form a circulation system of the whole system. The device has strong adaptability, small floor area, high treatment efficiency, strong shock resistance, and large load volume.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment equipment, and particularly relates to an up-flow AO sewage treatment device and a method for treating sewage with the same. Background Art

[0002] At present, in the conventional AAO process, anaerobic, anoxic and aerobic processes are carried out in different tanks or containers. For example, the prior art CN112960774A discloses a sewage treatment system, which includes an adjustment tank, an anaerobic tank, an anoxic tank, an aerobic tank and a sedimentation tank connected in sequence through a water delivery pipeline. Corresponding fillers are provided in the anaerobic tank, the anoxic tank and the aerobic tank. The inlet of the water delivery pipeline between the anaerobic tank, the anoxic tank and the aerobic tank is located at the top of the end of the previous tank, and the outlet is located at the lower part of the front end of the subsequent tank. In this way, each process unit is relatively independent, and there are multiple pipelines in the middle to complete the sludge reflux and reuse in the whole process; the sewage also completes the process of nutrients and denitrification in the sewage from anaerobic to aerobic and then to anaerobic. Each process link requires a power pump to transfer materials. For individual denitrification processes, a nitrification-denitrification process is also connected in series after the anaerobic reactor. In this way, the zoning is relatively clear, and the utilization rate of oxygen is improved, but the process is very complex, and there are disadvantages such as high energy consumption, large demand for carbon sources, and weak shock load resistance. With the proposal of new denitrification pathways, new denitrification processes have emerged, which have the advantages of saving O2 and organic COD, simple process flow, high removal load rate, etc. However, there are still certain difficulties in coupling anaerobic ammonia oxidation and methanogenic denitrification in one reactor.

[0003] In order to solve these problems, some sewage treatment equipment integrating aerobic, anoxic and anaerobic has begun to appear in the prior art. For example, CN210825614U discloses a sedimentation integrated multi-stage circulation reactor, which forms aerobic, anoxic and anaerobic different functional areas in the integrated device through blower aeration, and strengthens the functions between areas through physical separation. When the sewage flows through each area, specific biological flora completes the removal of organic matter and pollutants. Due to this multi-stage circulation reactor, all aerobic, anoxic and anaerobic sludge (biological bacteria) settle at the bottom and are then pushed to the aerobic area, the anoxic area and the anaerobic area by thrust. The path is long and the flow rate is fast, so it is not easy for biological bacteria to grow. Therefore, it is not suitable for the treatment process of the activated sludge method, and only meets the contact oxidation process with fillers. In addition, the reflux of the digestate cannot be controlled arbitrarily. Therefore, in the actual treatment process, the operation mode is relatively single, and the requirements for the actual water inflow and water quality are relatively high and stable. The treatment ability for changing water quality is weak. Summary of the Invention

[0004] The purpose of the present invention is to provide an up-flow AO sewage treatment device and a method for treating sewage with the same, so as to solve the problems raised in the above background art.

[0005] To achieve the above object, one aspect of the present invention provides the following technical solution:

[0006] A vertical-flow AO sewage treatment device, comprising:

[0007] A tank body, inside which there are an anaerobic zone, an anoxic zone and an aerobic zone in sequence from bottom to top. The tank body is filled with activated sludge, and an anaerobic packing layer and an aerobic packing layer are respectively filled in the anaerobic zone and the aerobic zone;

[0008] A water distributor, which is arranged at the bottom of the tank body and is used to introduce sewage into the anaerobic zone; the water distributor has an annular water inlet pipe, and a plurality of first water inlets are evenly distributed on the inner circle of the annular water inlet pipe. The water outlet directions of the plurality of first water inlets form a 45° angle with the annular water inlet pipe, and a plurality of second water inlets are also evenly distributed on the top of the annular water inlet pipe, and the water outlet directions of the plurality of second water inlets are vertically upward;

[0009] A swirl aeration device, which is arranged between the anoxic zone and the aerobic zone, and the swirl aeration device is connected to an external air supply device through an air inlet;

[0010] A water outlet, which is arranged at the top of the tank body;

[0011] A biofilm attached with anaerobic ammonia-oxidizing bacteria, anaerobic methanogenic bacteria and denitrifying bacteria is attached to the anaerobic packing layer, and a biofilm attached with aerobic ammonia-oxidizing bacteria and nitrifying bacteria is attached to the aerobic packing layer. The activated sludge contains a biological flora, and the biological flora is composed of three flora of anaerobic ammonia-oxidizing bacteria, nitrifying and denitrifying bacteria, and Bacillus subtilis to form a facultative bacterial population that restricts and depends on each other.

[0012] Preferably, an annular partition plate is arranged in the aerobic zone. A sludge sedimentation area is formed between the annular partition plate and the inner wall of the tank body, and an overflow port is arranged at the top of the annular partition plate.

[0013] Preferably, a baffle is arranged outside the annular partition plate, and the middle part of the tank body is narrowed to form a sludge return seam with the annular partition plate.

[0014] Preferably, a first annular water collecting tank is arranged at the top of the sludge sedimentation area, and the first annular water collecting tank is communicated with the water outlet.

[0015] Preferably, a denitrification area is arranged outside the tank body, a denitrification area water inlet is arranged on one side of the denitrification area, and the water outlet is communicated with the denitrification area water inlet through a diversion pipe.

[0016] Preferably, the denitrification zone is filled with an autotrophic denitrification filter layer. A second annular water collection tank is arranged at the top of the denitrification zone, and the second annular water collection tank is communicated with a drain outlet.

[0017] Preferably, a sludge discharge pipe is further arranged at the bottom of the tank body. The sludge discharge pipe extends into the tank body and has a plurality of branch pipes.

[0018] Preferably, an emptying pipe is further arranged at the bottom of the tank body.

[0019] On the other hand, the present invention provides a method for treating sewage by a vertical-flow AO sewage treatment device, including:

[0020] S1. Sewage enters the tank body through a water distributor at the bottom of the tank body, forms a vortex on the horizontal plane through a plurality of the first water inlets, and at the same time, the sewage also sprays vertically upward from the second water inlet; the activated sludge and the biological bacteria in the anaerobic zone accumulate in the swirl due to the centrifugal force generated by the vortex. When rising to a certain height, since the upward thrust is less than the self-gravity of the activated sludge and the biological bacteria in the anaerobic zone, the activated sludge and the biological bacteria begin to settle, so that the biological bacteria are gradually separated from the water, and the supernatant enters the anoxic zone and the aerobic zone for further treatment upward.

[0021] S2. The supernatant enters the anoxic zone as the water level rises, and the ammonia nitrogen in the water is converted into nitrogen, nitrite and nitrate by the combined action of the biological bacteria; in the anoxic zone, due to the action of gravity, part of the activated sludge and sewage sink and enter the anaerobic zone again, and part escapes and enters the aerobic zone by the suction of the swirl aeration. The swirl aeration in the aerobic zone will generate an up-and-down flowing vortex, and part of the activated sludge and sewage escape to the lower anoxic zone due to the action of gravity.

[0022] S3. When the gas enters the internal part of the swirl aeration device from the air inlet, the air flow pushes the blades inside the swirl aeration device to rotate at a high speed. The sewage is sucked from the bottom of the swirl aeration device, mixed with the air entering the swirl aeration device, and then sent to the shearing cutter head at the topmost part of the swirl aeration device by the high-speed rotating blades. The shearing cutter head shears the incoming substances layer by layer, making the bubbles become smaller and smaller, ensuring that the oxygen molecules in the gas are fully free in the water body and are utilized by the biological bacteria, and maintaining the metabolic process of self-reproduction and aerobic function.

[0023] S4. After the air flow rises, the movement rate of the air pressure towards the water surface slows down slowly. At this time, the activated sludge and the biological bacteria in the water body sink due to the action of gravity, collide with the sludge and water body in the rising process, and generate a vertical vortex; the muddy water mixture in the aerobic zone continuously rises and escapes to the horizontal plane, flows into the sludge sedimentation zone through the overflow port and realizes the separation of mud and water due to the self-gravity of the sludge. The sludge flows back into the tank body through the sludge return seam to continue the aerobic cycle, and the supernatant overflows from the horizontal plane.

[0024] S5. The supernatant flows out from the outlet through the diversion pipe and enters the denitrification zone from the water inlet. As the water volume increases, it slowly rises from the bottom and fully contacts with the denitrifying bacteria in the autotrophic denitrification filter layer for deep denitrification. Finally, it overflows from the drain outlet through the second annular water collection tank and is discharged.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The embodiment of the present invention provides a vertical flow AO sewage treatment device, which concentrates anaerobic, facultative aerobic and aerobic processes in the same tank body. The tank body is filled with activated sludge. The activated sludge contains biological bacteria. It is formed by combining three different types of bacteria groups, anaerobic ammonia oxidizing bacteria, nitrifying and denitrifying bacteria, and Bacillus, into a mutually restrictive and interdependent facultative bacteria group. That is, it can carry out aerobic metabolism in an aerobic environment and will not die in an anaerobic environment. It can complete its own digestion, metabolism and synergistic coupling in an anoxic environment to remove COD and nutrient nitrogen components. In addition, a sawtooth weir is provided at the intersection of the upper part of the aerobic zone and the first annular water collection tank. The mud and water mixture containing biological bacteria enters the sedimentation zone from the sawtooth weir to achieve mud and water separation, bacteria and water separation, and bacteria and sludge enter the facultative aerobic zone again by gravity, and the entire cycle can be completed in the system.

[0027] (2) The embodiment of the present invention provides a vertical flow AO sewage treatment device. Sewage enters the tank from the bottom of the vertical flow AO system through a dispersed water distributor, enters the anaerobic zone microcirculation, and enters the facultative aerobic zone as the water level rises. In the facultative aerobic zone, due to the action of gravity, part of the sludge and sewage sinks and enters the anaerobic zone again. Part of the sludge and sewage escapes and enters the aerobic zone by the suction of the cyclone aeration. The cyclone aeration in the aerobic zone will produce a vortex that flows up and down. Under the action of gravity, part of the sludge and sewage will also escape to the lower facultative aerobic zone, thus completing the entire large internal circulation. The device uses a simpler process and physical means in a unified structure to combine mechanical effects such as gravity, air lift, and suction. It cleverly utilizes the powerful thrust and attraction generated by cyclone aeration to complete the exchange and conversion of sewage, sludge, and biological cells in three different environments in the anaerobic, facultative, and aerobic zones. At the same time, it also ensures the self-circulation of sewage, sludge, and biological cells in each zone. Therefore, there is no need for an internal reflux pump, which reduces energy consumption and equipment investment.

[0028] (3) A vertical-flow AO sewage treatment device provided by an embodiment of the present invention is provided with a special water distributor for introducing sewage into the anaerobic zone. The water distributor has an annular inlet pipe, and a plurality of first inlet ports are evenly distributed on the inner circle of the annular inlet pipe. The water outlet directions of the plurality of first inlet ports form a 45° angle with the annular inlet pipe. When the sewage jets out from the outlet, a horizontal swirl will be formed in the horizontal direction. A plurality of second inlet ports are also evenly distributed on the top of the annular inlet pipe, and the water outlet directions of the plurality of second inlet ports are vertically upward. The sewage jets vertically upward from the outlet, which can effectively maintain the dynamic balance of the anaerobic area.

[0029] (4) A vertical-flow AO sewage treatment device provided by an embodiment of the present invention concentrates the anaerobic, anoxic, and aerobic process in the same tank body, and there is no obvious distinction and boundary between each process. Through a central swirl aeration device, the anaerobic, anoxic, and aerobic processes are completed, and the ammonia oxidation, methanation, and denitrification are organically coupled in different areas of the same tank body. At the same time, through the high-speed operation of biological bacteria in the whole tank body, the sewage treatment capacity is improved. Based on the above technologies combined with the immobilized biological enzyme technology and the non-powered internal circulation technology, the energy utilization rate and the contact efficiency between the strains and the sewage are improved, and the volume load of the biochemical device is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic structural diagram of a vertical-flow AO sewage treatment device provided by an embodiment of the present invention;

[0031] Figure 2 is a schematic diagram of the upper-layer circulation system and the lower-layer circulation system in a vertical-flow AO sewage treatment device provided by an embodiment of the present invention;

[0032] Figure 3 is a schematic structural diagram of the water distributor of a vertical-flow AO sewage treatment device provided by an embodiment of the present invention.

[0033] In the figure: 1, tank body; 2, water distributor; 3, swirl aeration device; 4, air inlet; 5, water outlet; 6, annular partition; 7, overflow port; 8, baffle; 9, sludge return seam; 10, first annular water collecting tank; 11, anoxic zone water inlet; 12, diversion pipe; 13, second annular water collecting tank; 14, drain port; 15, sludge discharge pipe; 16, emptying pipe; 17, autotrophic denitrification filter layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] Figure 1 FIG. 4 is a schematic structural diagram of a vertical-flow AO sewage treatment device provided for an embodiment of the present invention. Figure 2 FIG. 5 is a schematic diagram of the upper-layer circulation system and the lower-layer circulation system in a vertical-flow AO sewage treatment device provided for an embodiment of the present invention. An embodiment of the present invention provides a vertical-flow AO sewage treatment device, as Figure 1 or Figure 2 shown. The vertical-flow AO sewage treatment device includes:

[0036] A tank body, in which an anaerobic zone, an anoxic zone, and an aerobic zone are arranged in sequence from bottom to top. The tank body is filled with activated sludge, and an anaerobic packing layer and an aerobic packing layer are respectively filled in the anaerobic zone and the aerobic zone;

[0037] A water distributor 2, which is arranged at the bottom of the tank body 1 and is used to introduce sewage into the anaerobic zone; the water distributor 2 has an annular water inlet pipe, and a plurality of first water inlets are evenly distributed on the inner circle of the annular water inlet pipe. The water outlet directions of the plurality of first water inlets form a 45° angle with the annular water inlet pipe, and a plurality of second water inlets are also evenly distributed on the top of the annular water inlet pipe. The water outlet directions of the plurality of second water inlets are vertically upward;

[0038] A swirl aeration device 3, which is arranged between the anoxic zone and the aerobic zone, and the swirl aeration device 3 is connected to an external air supply device through an air inlet 4;

[0039] A water outlet 5, which is arranged at the top of the tank body 1;

[0040] A biofilm attached with anaerobic ammonium-oxidizing bacteria, anaerobic methanogenic bacteria, and denitrifying bacteria is attached to the anaerobic packing layer, and a biofilm attached with aerobic ammonium-oxidizing bacteria and nitrifying bacteria is attached to the aerobic packing layer.

[0041] The activated sludge contains biological flora, which combines three different types of flora, namely anaerobic ammonium oxidizing bacteria, nitrifying and denitrifying bacteria, and bacillus, into a facultative bacterial population that restricts and depends on each other. They can not only carry out aerobic metabolism in an aerobic environment, but also will not die in an anaerobic environment, and can complete their own digestion, metabolism and synergistic coupling in an anoxic environment, and have strong biological metabolic activity, with a water activity of 0.02 - 0.47. The three types of flora depend on and inhibit each other. When contacting with organic matter under different environmental conditions, the advantages transform with each other, forming a highly efficient degradation biological system with strong adaptability of the bacteria, resistance to impact and high load tolerance, avoiding the increase of sludge and the exceeding standard of suspended solids caused by the too fast growth of the bacteria. In this way, the characteristics and functions of the biological bacteria can be fully exerted, the facultative bacteria multiply in large numbers, the bacteria have strong adaptability, and can complete their own digestion, metabolism and synergistic coupling in an anoxic environment, removing COD and nutrient nitrogen components.

[0042] Figure 3 Schematic diagrams of the upper circulation system and the lower circulation system in a vertical-flow AO sewage treatment device provided by an embodiment of the present invention. As Figure 3 shown, in an embodiment of the present invention, the water distributor 2 of the vertical-flow AO sewage treatment device has an annular water inlet pipe, and a plurality of first water inlets are evenly distributed on the inner circle of the annular water inlet pipe. The water outlet direction of the plurality of first water inlets forms a 45° angle with the annular water inlet pipe. A plurality of second water inlets are also evenly distributed on the top of the annular water inlet pipe, and the water outlet direction of the plurality of second water inlets is vertically upward.

[0043] Sewage enters the tank body 1 through the water distributor 2 at the bottom of the tank body 1. Since the water distribution angle is 45°, when the sewage is ejected from the water outlet, a horizontal swirl will be formed in the horizontal direction. The water outlet direction of the second water inlets evenly distributed on the top of the annular water inlet pipe is vertically upward, and the sewage can be ejected vertically upward from the water outlet, which can effectively maintain the dynamic balance of the anaerobic area. The biological bacteria in the activated sludge or anaerobic area accumulate in the swirl due to their own weight and the centrifugal force generated by the vortex, avoiding the deposition of the activated sludge and the biological bacteria in the anaerobic area at the bottom of the tank body 1. When rising to a certain height, when the upward thrust is less than the gravity of the biological bacteria themselves, the sludge and biological bacteria begin to settle, causing the biological bacteria to gradually separate from the water. The supernatant enters the anoxic area and aerobic area for further treatment upward, while the activated sludge and the biological bacteria in the anaerobic area settle downward, forming a lower circulation system powered by the water distributor 2.

[0044] The swirl aeration device 3 is arranged above the interface between the anoxic zone and the aerobic zone. When gas enters the interior of the swirl aeration device 3 from the air inlet 4, the air flow will push the blades inside the swirl aeration device 3 to rotate at high speed. The rotating blades generate an upward thrust in the same direction as the air flow, creating a low-pressure area below the swirl aeration device 3. Due to the action of pressure and the upward thrust, sewage will be sucked in from the bottom of the swirl aeration device 3, mixed with the air entering the swirl aeration device 3, and then sent by the high-speed rotating blades to the shearing cutter head at the topmost part of the swirl aeration device 3. The shearing cutter head will layer by layer shear the incoming substances, making the bubbles become smaller and smaller, reducing the rising speed of the bubbles, increasing the suspension time of the bubbles in the water body and the efficiency of dissolved oxygen, thus ensuring that the oxygen molecules in the gas are fully utilized by the sludge and the biological bacteria in the water body to complete the aerobic process. After the air flow rises, it will move towards the water surface along with the air pressure and its rate will gradually slow down. At this time, the activated sludge and the biological bacteria in the water body will start to sink due to the action of gravity, thus forming an upper circulation system powered by the swirl aeration device 3.

[0045] By designing the upper circulation system and the lower circulation system, due to the mutual integration of the anaerobic and aerobic boundaries, the microcirculation generated by these two power sources influences each other to form a large circulation system, enabling the return of sludge and sewage to be completed through the impact force generated by the water inlet of the water distributor 2 and the power generated by the swirl aeration device 3, as well as the pressure difference, to complete the return of aerobic sludge, the return of anaerobic sludge, and the circulating flow of sewage in the whole system, and no additional power is required.

[0046] This treatment device combines the gravity, air lift, suction and other mechanical theories through a more concise process and physical means in a unified structure, and cleverly utilizes the powerful thrust and attraction generated by swirl aeration to complete the exchange and conversion of sewage, sludge and biological bacteria in three different environments in the anaerobic, anoxic and aerobic zones, while also ensuring the self-circulation of sewage, sludge and biological bacteria in each zone. Sewage enters the tank body from the bottom of the vertical-flow AO system through the decentralized water distributor, enters the microcirculation of the anaerobic zone, and enters the anoxic zone as the water level rises. In the anoxic zone, due to the action of gravity, part of it sinks and re-enters the anaerobic zone, and part escapes. It enters the aerobic zone due to the suction of swirl aeration. The swirl aeration in the aerobic zone will generate an up-and-down flowing vortex, and part of it will also escape to the lower anoxic zone under the action of gravity, thus completing the entire large internal circulation. Therefore, no internal reflux pump is required, reducing energy consumption and equipment investment.

[0047] In addition, the position of the swirl aeration device 3 can be adjusted according to the water quality and quantity of the sewage to regulate the spatial sizes of the anaerobic zone, anoxic zone, and aerobic zone of the vertical-flow AO sewage treatment device, so as to meet the residence time of the sewage in each zone and enable the biological bacteria to fully decompose, remove, and transform the organic matter in the sewage and maintain the self-reproduction of the biological bacteria.

[0048] Furthermore, the recirculated digestate can be adjusted by the acting force, that is, when the water quality pollutants are relatively high, the inlet water pressure and the gas volume of the swirl aeration can be reduced, the internal circulation volume can be increased, the external circulation rate can be decreased, and the residence time of the water body in different zones can be increased to meet the requirements of the effluent water quality; on the contrary, if the water volume is large and the load is low, the water pressure and gas volume can be increased to accelerate the circulation efficiency and improve the treatment speed. In addition, the autotrophic denitrification filter layer provided on the outer layer of the lower part of the tank body of the vertical-flow AO sewage treatment device can further ensure and improve the water quality of the effluent.

[0049] The present invention can control parameters such as dissolved oxygen, oxidation-reduction potential, and nitrification liquid reflux ratio. Among them, the dissolved oxygen is controlled at 2-3 mg / L, and the nitrification liquid reflux ratio is controlled at 100-300%. This can make the ammonia nitrogen and nitrite nitrogen reach certain values, and simultaneously achieve ammonia oxidation, shortcut nitrification, and denitrification. First, under the condition of limited oxygen, aerobic ammonia-oxidizing bacteria carry out autotrophic denitrification. Second, under the condition of anaerobic ammonia-oxidizing bacteria, anaerobic ammonia oxidation denitrification occurs between ammonia and nitrite. Through the above technical solutions, the three are coupled and regulated and catalyzed in a micro-ecosystem, so that carbon and nitrogen removal can be achieved simultaneously, the energy consumption of aeration in the aerobic process can be saved, and the treatment efficiency is high.

[0050] As Figure 1 and Figure 2 shown, in an embodiment of the present invention, an annular partition 6 is provided in the aerobic zone of the vertical-flow AO sewage treatment device. The area between the annular partition 6 and the inner wall of the tank body 1 is a sludge sedimentation area, and an overflow port 7 is provided at the top of the annular partition 6.

[0051] Furthermore, a baffle 8 is provided on the outer side of the annular partition 6 of the vertical-flow AO sewage treatment device, and the middle part of the tank body 1 is narrowed to form a sludge return seam 9 with the annular partition 6.

[0052] Through the above technical solutions, the mud-water mixture in the aerobic zone continuously rises and flows into the sludge sedimentation area through the overflow port 7. The sludge sedimentation area is a relatively static area. In the area of the sludge sedimentation area, the mud-water mixture sinks due to the self-weight of the sludge, achieving the purpose of mud-water separation. The sludge returns to the tank body 1 through the sludge return seam 9 for continuous circulation, and the supernatant flows upward. The setting of the baffle 8 can prevent the mud-water mixture from splashing when passing through the overflow port 7, and promote the mud-water mixture to flow down along the annular partition 6, keeping the sludge sedimentation area in a relatively static state.

[0053] In an embodiment of the present invention, asFigure 1 and Figure 2 As shown in Figure 2 , a first annular water collecting tank 10 is provided at the top of the sludge sedimentation area of the vertical flow AO sewage treatment device. The first annular water collecting tank 10 is communicated with the water outlet 5. The supernatant in the sludge sedimentation area flows out from the water outlet 5 through the first annular water collecting tank 10.

[0054] As Figure 1 and Figure 2 As shown in Figure 2 , in an embodiment of the present invention, a denitrification area is provided outside the tank body 1 of the vertical flow AO sewage treatment device. A denitrification area water inlet 11 is provided on one side of the denitrification area. The water outlet 5 is communicated with the denitrification area water inlet 11 through a diversion pipe 12.

[0055] Furthermore, an autotrophic denitrification filter layer 17 is filled in the denitrification area. A second annular water collecting tank 13 is provided at the top of the denitrification area. The second annular water collecting tank 13 is communicated with a drain port 14.

[0056] Denitrifying bacteria grow in the autotrophic denitrification filter layer 17. The supernatant flows out from the water outlet 5, enters the denitrification area through the denitrification area water inlet 11, slowly rises from the bottom and fully contacts with the denitrifying bacteria on the sulfur autotrophic denitrification filter material for deep denitrification, and finally overflows and discharges from the drain port 14 through the second annular water collecting tank 13.

[0057] As Figure 1 and Figure 2 As shown in Figure 2 , in an embodiment of the present invention, a sludge discharge pipe 15 is provided at the bottom of the tank body 1 of the vertical flow AO sewage treatment device. The sludge discharge pipe 15 extends into the tank body 1 and has a plurality of branch pipes. After the sewage treatment operates stably for a period of time, the sludge will gradually deposit at the bottom of the tank body 1. The deposited sludge can be discharged through the sludge discharge pipe 15 to complete regular cleaning.

[0058] As Figure 1 and Figure 2 As shown in Figure 2 , in an embodiment of the present invention, an emptying pipe 16 is provided at the bottom of the tank body 1 of the vertical flow AO sewage treatment device. The emptying pipe 16 is used to discharge the remaining sewage in the tank body 1.

[0059] An embodiment of the present invention also provides a method for treating sewage by the vertical flow AO sewage treatment device, which specifically includes:

[0060] Sewage enters the tank body 1 through the water distributor 2 at the bottom of the tank body 1. Since the water inlet directions of multiple first water inlets are 45°, a vortex will be formed on the horizontal plane. At the same time, the sewage also sprays vertically upward from the second water inlet. Sludge or biological bacteria in the anaerobic zone accumulate in the swirl due to their own weight and the centrifugal force generated by the vortex, avoiding the deposition of sludge and biological bacteria in the anaerobic zone at the bottom of the tank body 1. When the upward thrust is less than the self-gravity of the sludge and biological bacteria in the anaerobic zone at a certain height, the sludge and biological bacteria begin to settle, causing the sludge, biological bacteria in the anaerobic zone to gradually separate from the water. The supernatant enters the anoxic zone and aerobic zone for further treatment. Anaerobic flora such as hydrolytic fermentation flora and anaerobic ammonia-oxidizing bacteria, etc., which are bacilli, have the functions of producing acetic acid, hydrogen, and methane. In an anaerobic environment, they mainly decompose macromolecular organic substances into small-molecular substances to ensure that the anoxic and aerobic microorganisms at the back end can better utilize small-molecular substances to promote their own growth, produce active proteins to reduce the content of pollutants in the water body, and decompose fats, cellulose lignin, and high-molecular substances into fatty acids, proteins, amino acids, and sugars. In addition, anaerobic ammonia-oxidizing flora can also nitrify and denitrify ammonia nitrogen in water to generate acetic acid, hydrogen, and carbon dioxide. In the anoxic zone, nitrogen-containing organic substances (such as proteins, ammonia nitrogen, nitrate nitrogen) use the combined action of anaerobic heterotrophic microorganisms, nitrifying bacteria and denitrifying bacteria to convert ammonia nitrogen in the water into nitrogen gas, nitrite, and nitrate (i.e., nitrate nitrogen). Denitrifying bacteria generate nitrogen gas under the combined action of an anoxic environment (anoxic zone) and partially undigested ammonia nitrogen and overflow from the water body.

[0061] When the gas enters the internal part of the swirl aeration device 3 from the air inlet 4, the airflow will push the blades inside the swirl aeration device 3 to rotate at high speed. The rotating blades generate an upward thrust in the same direction as the airflow direction, forming a low-pressure area below the swirl aeration device 3. Due to the action of pressure and upward thrust, sewage is sucked in from the bottom of the swirl aeration device 3, mixed with the air entering the swirl aeration device 3, and then sent to the shearing cutter head at the top of the swirl aeration device 3 by the high-speed rotating blades. The shearing cutter head will shear the incoming substances layer by layer, making the bubbles become smaller and smaller, so as to ensure that the oxygen molecules in the gas are fully utilized by the sludge and biological bacteria in the water body to complete the aerobic process. Aerobic biological flora is a huge bacterial system. The metabolic products and survival modes, that is, the energy metabolism pathways of facultative aerobic bacteria such as anaerobic ammonia-oxidizing bacteria, nitrifying and denitrifying bacteria, and bacilli are very different in an anaerobic environment. A large number of algae, protozoa, and metazoans will be produced in the aerobic biological population. These organisms feed on bacteria and small-molecular nutrients, and the special proteins and substances secreted are used by the aerobic flora, and autotrophic and heterotrophic living orientations are generated, each using inorganic substances (CO2, HCO3 - 、NO 3- 、PO4 3-etc.), organic carbon sources and nitrogen sources (sugar, ammonia nitrogen, nitrate nitrogen, etc.) are synthesized into cell substances and converted into CO2, H2O, NO3 - , CH4, NH3 and other inorganic substances, releasing energy. The unique physical structure of the vertical flow AO sewage treatment device greatly enriches the facultative oxic autotrophic and heterotrophic bacteria of oxygen-ammonia oxidizing bacteria, anaerobic methanogens, and denitrifying bacteria. In particular, the large autotrophic bacteria become the dominant bacteria in different areas, absorbing nutrients from the sewage, synthesizing their own cells through complex biochemical reactions, and excreting waste, achieving the goal of efficiently removing pollutants from the water.

[0062] After rising, the airflow will move toward the water surface with the air pressure, and the speed will slowly slow down. At this time, the sludge and biological bacteria in the water body will begin to sink due to the effect of gravity; the mud-water mixture in the aerobic zone will continue to rise and flow into the sludge sedimentation zone through the flow port 7. The sludge sedimentation zone is a relatively static area. The mud-water mixture sinks in the sludge sedimentation zone due to the weight of the sludge, achieving the purpose of mud-water separation. The sludge flows back to the tank body 1 through the sludge return seam 14 to continue circulation, and the supernatant flows upward; the supernatant flows out from the water outlet 5, enters the denitrification zone through the denitrification zone water inlet 11, slowly rises from the bottom and fully contacts the denitrifying bacteria on the autotrophic denitrification filter layer 17 to carry out deep denitrification, and finally overflows from the drain outlet 14 through the second annular sump 13 and is discharged.

[0063] The vertical-flow AO sewage treatment device of the present invention integrates anaerobic, anoxic, and aerobic process in the same tank, and there is no obvious distinction or boundary between each process. Through a central swirl aeration device, the anaerobic, anoxic, and aerobic processes are completed, and ammonia oxidation, methanation, and denitrification are organically coupled in different regions of a single tank. The activated sludge containing biological strains flows upward from bottom to top in the three regions. When its own gravity is greater than the external force during the flow process, it enters its respective microcirculation system, and anaerobic, anoxic, and aerobic functional zones are formed under its dominant microbial population. Of course, an anaerobic packing layer and an aerobic packing layer can also be filled in the anaerobic zone and the aerobic zone respectively to enhance the effects of each functional region. The water distributor provided at the bottom of the tank adopts a special water distribution to introduce sewage into the anaerobic zone, and ensures that the activated sludge in the sewage gradually swirls and ascends with the water flow, forming eddies in both the horizontal and vertical directions to avoid sinking; the swirl aeration device, which is connected to an external air supply device through an air inlet to provide sufficient oxygen for the aerobic zone, and the swirl provides power for the entire system, and three special regions, namely the anaerobic zone, the anoxic zone, and the aerobic zone, are formed in layers under the balance of gravity; based on the above technologies combined with the immobilized bio-enzyme technology and the non-powered internal circulation technology, the energy utilization rate and the contact efficiency between the strains and the sewage are improved, and the volume load of the biochemical device is greatly increased. The water outlet is provided at the top of the tank, and mud-water separation (separation of bacteria and water) is achieved through natural sedimentation; the supernatant flows to the bottom of the tank and passes through the autotrophic denitrification filter layer 17 on the outer circle of the bottom for deep denitrification, and then is discharged from the middle of the tank.

[0064] This device has strong adaptability, small floor area, high treatment efficiency, strong shock resistance, and large load volume. It is suitable for places with high land requirements and relatively strict discharge indicators, such as small and medium-sized domestic sewage, rural sewage, breeding wastewater, industrial sewage, etc., and can also be used for the upgrading and transformation of low-pollution water quality in surface water, rivers, lakes, etc. It is an integrated water treatment system with low operating costs, no need for manual operation, and energy saving and consumption reduction.

[0065] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A vertical-flow AO sewage treatment device, characterized in that Comprising: A tank body (1), inside which there are an anaerobic zone, an anoxic zone, and an aerobic zone in sequence from bottom to top. The tank body (1) is filled with activated sludge, and an anaerobic packing layer and an aerobic packing layer are respectively filled in the anaerobic zone and the aerobic zone; A water distributor (2), which is arranged at the bottom of the tank body (1) and is used for introducing sewage into the anaerobic zone. The water distributor (2) has an annular water inlet pipe, and a plurality of first water inlets are evenly distributed on the inner circle of the annular water inlet pipe. The water outlet directions of the plurality of first water inlets form a 45° angle with the annular water inlet pipe. A plurality of second water inlets are also evenly distributed on the top of the annular water inlet pipe, and the water outlet directions of the plurality of second water inlets are vertically upward; A swirl aeration device (3), which is arranged between the anoxic zone and the aerobic zone, and the swirl aeration device (3) is connected to an external air supply device through an air inlet (4); A water outlet (5), which is arranged at the top of the tank body (1); A biofilm attached with anaerobic ammonia-oxidizing bacteria, anaerobic methanogenic bacteria, and denitrifying bacteria is attached to the anaerobic packing layer, and a biofilm attached with aerobic ammonia-oxidizing bacteria and nitrifying bacteria is attached to the aerobic packing layer. The activated sludge contains a biological flora, and the biological flora is composed of three flora, namely anaerobic ammonia-oxidizing bacteria, nitrifying and denitrifying bacteria, and Bacillus, which form a facultative bacterial population that restricts and depends on each other; An annular partition (6) is arranged in the aerobic zone. The space between the annular partition (6) and the inner wall of the tank body (1) is a sludge sedimentation area, and an overflow port (7) is arranged at the top of the annular partition (6); A baffle (8) is arranged outside the annular partition (6), and the middle part of the tank body (1) is narrowed to form a sludge return slit (9) with the annular partition (6); A denitrification zone is arranged outside the lower part of the tank body (1). A denitrification zone water inlet (11) is arranged on one side of the denitrification zone, and the water outlet (5) is communicated with the denitrification zone water inlet (11) through a diversion pipe (12); An autotrophic denitrification filter layer (17) is filled in the denitrification zone, and a second annular water collecting tank (13) is arranged at the top of the denitrification zone. The second annular water collecting tank (13) is communicated with a drain port (14); The swirl aeration device (3) is internally provided with blades.

2. The vertical-flow AO sewage treatment device according to claim 1, characterized in that, A first annular water collecting tank (10) is arranged at the top of the sludge sedimentation area, and the first annular water collecting tank (10) is communicated with the water outlet (5).

3. The vertical-flow AO sewage treatment device according to claim 2, wherein, A sludge discharge pipe (15) is also arranged at the bottom of the tank body (1), and the sludge discharge pipe (15) extends into the tank body (1) and has a plurality of branch pipes.

4. The vertical-flow AO sewage treatment device according to claim 3, characterized in that, An emptying pipe (16) is also arranged at the bottom of the tank body (1).

5. A method for treating sewage by using the up-flow AO sewage treatment device according to any one of claims 3-4, comprising: S1. The sewage enters the tank body (1) through the water distributor (2) at the bottom of the tank body (1), forms a vortex in the horizontal plane through multiple said first water inlets, and at the same time, the sewage also sprays vertically upward from the second water inlet; the activated sludge and the biological bacteria in the anaerobic zone accumulate in the swirl due to the centrifugal force generated by the vortex. When rising to a certain height, since the upward thrust is less than the self-gravity of the activated sludge and the biological bacteria in the anaerobic zone, the activated sludge and the biological bacteria begin to settle, causing the biological bacteria to gradually separate from the water. The supernatant enters the anoxic zone and the aerobic zone for further treatment upward. S2. As the water level rises, the supernatant enters the anoxic zone, and the combined action of the biological flora is used to convert ammonia nitrogen in the water into nitrogen, nitrite, and nitrate; in the anoxic zone, due to gravity, part of the activated sludge and sewage sinks and enters the anaerobic zone again, and part is sucked into the aerobic zone by the suction of the swirl aeration. The swirl aeration in the aerobic zone will generate an up-and-down flowing vortex. Part of the activated sludge and sewage escapes to the lower anoxic zone due to gravity. S3. When the gas enters the inside of the swirl aeration device (3) from the air inlet (4), the air flow drives the blades inside the swirl aeration device (3) to rotate at high speed. The sewage is sucked in from the bottom of the swirl aeration device (3), mixed with the air entering the swirl aeration device (3), and then sent to the shearing cutter head at the top of the swirl aeration device (3) by the high-speed rotating blades. The shearing cutter head shears the incoming substances layer by layer, making the bubbles become smaller and smaller, ensuring that the oxygen molecules in the gas are fully free in the water body and are utilized by the biological bacteria to maintain the metabolic process of their own reproduction and aerobic function. S4. After the air flow rises, the movement speed towards the water surface slows down with the air pressure. At this time, the activated sludge and the biological bacteria in the water body sink due to gravity, collide with the sludge and water body during the rising process, and generate a vertical vortex; the mud-water mixture in the aerobic zone continuously rises and escapes to the water surface, flows into the sludge sedimentation area through the overflow port (7), and realizes mud-water separation due to the self-gravity of the sludge. The sludge flows back into the tank body (1) through the sludge return slit (9) to continue the aerobic cycle, and the supernatant overflows from the water surface. S5. The supernatant flows out from the water outlet (5), passes through the diversion pipe (12), enters the denitrification zone from the denitrification zone water inlet (11), slowly pushes and rises from the bottom as the water volume increases, fully contacts with the denitrifying bacteria in the autotrophic denitrification filter layer (17) for deep denitrification, and finally overflows and discharges from the drain port (14) through the second annular water collecting tank (13).

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