Biodopp biochemical reaction system and wastewater treatment method

Abstract

Provided is a BioDopp biochemical reaction system, comprising an anaerobic zone (1), an anoxic zone (2), a first aerobic zone (3), a second aerobic zone (4), a three-phase separator (5), and a degassing and deoxygenation zone (6), wherein the anaerobic zone (1) is communicated with the anoxic zone (2), the anoxic zone (2) is communicated with the first aerobic zone (3), the first aerobic zone (3) is communicated with the second aerobic zone (4), the second aerobic zone (4) is communicated with the degassing and deoxygenation zone (6), and the degassing and deoxygenation zone (6) is communicated with the anoxic zone (2); the three-phase separator (5) is arranged at the top of a tail end of the second aerobic zone (4), and the three-phase separator (5) comprises a gas collection unit and a water collection unit; the gas collection unit comprises a main gas collection hood (501), an exhaust pipe (502), and a plurality of branch gas collection hood layers; the main gas collection hood (501) covers the branch gas collection hood layers located at the top; an air inlet end of the exhaust pipe (502) is communicated with the main gas collection hood (501), and an air exhaust end of the exhaust pipe (502) is communicated with the first aerobic zone (3). Further provided is a wastewater treatment method for the BioDopp biochemical reaction system. The BioDopp biochemical reaction system and the wastewater treatment method can realize dual use of carbon, show a simple structure, effectively reduce carbon source consumption for nitrogen and phosphorus removal, and lower both construction cost and operation cost.

Description

BioDopp Biochemical Reaction System and Wastewater Treatment Method

[0001] Cross-referencing

[0002] This application claims priority to Chinese Patent Application No. 202410806634X, filed on June 21, 2024, entitled “BioDopp Biochemical Reaction System and Wastewater Treatment Method”, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This invention relates to the field of wastewater treatment technology, and in particular to a BioDopp biochemical reaction system and wastewater treatment method. Background Technology

[0004] Compared with traditional bioreactors, BioDopp bioreactors have advantages such as saving space, continuous and efficient operation, increasing the ratio of simultaneous nitrification and denitrification and short-cut nitrification and denitrification reactions, saving operating costs, and being easy to operate.

[0005] In existing BioDopp bioreactors, two technical solutions are typically used to return the sludge separated in the sludge-water separation zone to the biochemical tank: one solution uses pure hydraulic transport, where air lift is used to ensure an average hydraulic velocity of over 0.3 m / s in the bottom channel of the sludge-water separation zone, carrying the settled sludge back to the biochemical tank; the other solution uses mechanical sludge suction machines, scrapers, or suction-scraper machines for directional transport back to a suitable location in the biochemical tank. However, in the pure hydraulic transport solution, once the length of the sludge-water separation zone exceeds a certain limit, the transport efficiency is affected, severely impacting the sedimentation effect and thus affecting the entire biochemical system. In the pure mechanical transport solution, on the one hand, equipment investment is increased; on the other hand, since the main working elements of the sludge suction machines, scrapers, or suction-scraper machines operate in a submerged mode, mechanical failures are relatively difficult to repair, causing inconvenience to actual operation.

[0006] Therefore, there is an urgent need for a BioDopp biochemical reaction system and wastewater treatment method to solve the above problems.

[0007] Summary of the Invention

[0008] This invention provides a BioDopp biochemical reaction system and wastewater treatment method to solve the defects of existing BioDopp biochemical reactors, such as unstable carrying capacity, high energy consumption, and difficult maintenance. It achieves dual use of carbon, effectively saving carbon source consumption for nitrogen and phosphorus removal. Moreover, it has a simple structural layout, saves floor space, reduces mechanical equipment, and effectively reduces construction and operating costs.

[0009] The present invention provides a BioDopp biochemical reaction system, comprising: an anaerobic zone, an anoxic zone, a first aerobic zone, a second aerobic zone, a three-phase separator, and a gas release and deoxygenation zone;

[0010] The end of the anaerobic zone is connected to the anoxic zone, the end of the anoxic zone is connected to the first aerobic zone, the end of the first aerobic zone is connected to the second aerobic zone, the end of the second aerobic zone is connected to the gas release and deoxygenation zone, and the end of the gas release and deoxygenation zone is connected to the anoxic zone.

[0011] The three-phase separator is located at the top end of the second aerobic zone, and the three-phase separator includes an air collection unit and a water collection unit.

[0012] The gas collection unit includes a main gas collection hood, an exhaust pipe, and multiple branch gas collection hood layers. The main gas collection hood is located at the top of the branch gas collection hood layer. The air inlet end of the exhaust pipe is connected to the main gas collection hood, and the air outlet end of the exhaust pipe is connected to the first aerobic zone. Each branch gas collection hood layer includes multiple branch gas collection hoods spaced apart. A gas collection space is formed inside each branch gas collection hood. A sludge guiding surface is formed on the outer wall of each branch gas collection hood. The branch gas collection hoods of adjacent branch gas collection hood layers are arranged in an alternating manner. A tortuous gap is formed between the branch gas collection hoods of multiple branch gas collection hood layers. The tortuous gap is connected to the second aerobic zone.

[0013] The water collection unit includes a water collection tank and a drainage channel. The water collection tank is located on top of the main gas collection hood, and the drainage channel is connected to the water collection tank.

[0014] The BioDopp biochemical reaction system provided by the present invention further includes a first flow channel, the first end of the first flow channel being connected to the end of the anoxic zone, and the end of the first flow channel being connected to the first aerobic zone.

[0015] The first flow channel is provided with a first reflux device. The first end of the first reflux device is connected to the end of the anoxic zone, and the end of the first reflux device is connected to the anaerobic zone.

[0016] The BioDopp biochemical reaction system provided by the present invention further includes a second flow channel, the first end of which is connected to the anaerobic zone, and the last end of which is connected to the anoxic zone.

[0017] The BioDopp biochemical reaction system provided by the present invention further includes a third flow channel, the bottom of which is connected to the end of the second aerobic zone, the top of which is connected to the gas release and deoxygenation zone, and a gas lifting device is provided in the third flow channel.

[0018] And / or, it also includes a fourth flow channel, the bottom of which is connected to the end of the anoxic zone, the top of which is connected to the first aerobic zone, and an air lifting device is provided in the fourth flow channel.

[0019] According to the BioDopp biochemical reaction system provided by the present invention, the anoxic zone and / or the first aerobic zone are provided with guide walls for extending the water flow path.

[0020] According to the BioDopp biochemical reaction system provided by the present invention, the horizontal inclination angle of the sludge guiding surface is greater than or equal to 45°;

[0021] In each of the aforementioned support gas hood layers, the spacing between adjacent support gas hoods is greater than or equal to 80 mm;

[0022] The overlap spacing between adjacent gas collection hood layers is greater than or equal to 80 mm.

[0023] The width of the tortuous gap is greater than or equal to 80 mm.

[0024] According to the BioDopp biochemical reaction system provided by the present invention, at least one of an online DO monitoring element and an online ORP monitoring element is provided at the end of the second aerobic zone and / or in the gas release deoxygenation zone.

[0025] Another aspect of the present invention provides a wastewater treatment method based on the BioDopp biochemical reaction system as described in any of the preceding claims, comprising:

[0026] Wastewater is introduced into the anaerobic zone, where the carbon source in the wastewater mixes with the denitrified sludge mixture returned from the anoxic zone to the anaerobic zone, and an anaerobic phosphorus release reaction occurs to obtain an anaerobic phosphorus release mixture.

[0027] The anaerobic phosphorus release mixture is introduced into the first end of the anoxic zone and mixed with the nitrified sludge mixture that has undergone gas release and dissolved oxygen removal in the gas release and deoxygenation zone. After mixing, denitrification and dephosphorization reactions and denitrification and decarbonization reactions occur to obtain denitrified sludge mixture.

[0028] A portion of the denitrified sludge mixture is returned to the anaerobic zone for circulation, while another portion of the denitrified sludge mixture sequentially enters the first aerobic zone and the second aerobic zone to undergo aerobic phosphorus uptake, aerobic carbon removal, and nitrification reactions, thereby obtaining a nitrified sludge mixture.

[0029] The nitrified sludge mixture enters the three-phase separator. After gas collection and sedimentation separation, the clear water flows out, and the gas is transported to the first aerobic zone and / or the second aerobic zone for reuse. The nitrified sludge separated by sedimentation slides down to the second aerobic zone and collects at the end of the second aerobic zone, flowing towards the gas release and deoxygenation zone. A portion of the nitrified sludge is discharged at the end of the second aerobic zone and / or discharged in the gas release and deoxygenation zone, while another portion of the nitrified sludge mixture enters the beginning of the anoxic zone through the gas release and deoxygenation zone for circulation.

[0030] According to the wastewater treatment method of the BioDopp biochemical reaction system provided by the present invention, the dissolved oxygen at the end of the second aerobic zone is less than or equal to 2.0 mg / L and / or the oxidation-reduction potential is less than or equal to +150.0 mV;

[0031] And / or, the dissolved oxygen at the end of the deoxygenation zone is less than or equal to 1.0 mg / L and / or the redox potential is less than or equal to +100.0 mV.

[0032] According to the wastewater treatment method of the BioDopp biochemical reaction system provided by the present invention, the reflux ratio from the anoxic zone to the anaerobic zone is less than or equal to 200%, and the circulation ratio from the anoxic zone to the first aerobic zone is greater than or equal to 300%.

[0033] The BioDopp biochemical reaction system provided by this invention firstly replaces the existing sludge-water partitioning with a three-phase separator. On the one hand, this reduces the use of mechanical equipment such as sludge suction machines, sludge scrapers, or suction-scraper machines, saving investment, reducing operating costs, minimizing equipment failures, and facilitating operation and maintenance. On the other hand, the three-phase separator allows for more efficient use of the existing tank volume, as the bottom of the separator can still be used as an aerobic zone, increasing the aerobic biochemical reaction time and thus increasing the treated water volume or saving floor space. Secondly, an aeration and deoxygenation zone is added after the aerobic zone, which can significantly reduce the dissolved oxygen in the nitrified sludge mixture returned to the anoxic zone. This greatly reduces the consumption of carbon sources in the raw water by dissolved oxygen in the anoxic zone, directly saving carbon source addition and operating costs, and directly enhancing the denitrification and nitrogen removal efficiency of the reactor. It also indirectly enhances the phosphorus release efficiency of the anaerobic zone, thereby strengthening the overall nitrogen and phosphorus removal efficiency of the reactor.

[0034] Compared with general A2O bioreactors, the BioDopp biochemical reaction system provided by this invention has a compact integrated tank layout. The use of a three-phase separator not only further saves space, but also eliminates the need for special sludge collection and return facilities. The separated sludge is returned by the nitrification liquid and eventually brought back to the anoxic zone for biochemical reaction.

[0035] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0037] Figure 1 is a schematic diagram of one embodiment of the BioDopp biochemical reaction system provided by the present invention;

[0038] Figure 2 is a cross-sectional view of AA in Figure 1;

[0039] Figure 3 is a cross-sectional view of BB in Figure 1;

[0040] Figure 4 is a schematic diagram of a second embodiment of the BioDopp biochemical reaction system provided by the present invention;

[0041] Figure 5 is a cross-sectional view of CC in Figure 4;

[0042] Figure 6 is a cross-sectional view of DD in Figure 4;

[0043] Figure 7 is a schematic diagram of a third embodiment of the BioDopp biochemical reaction system provided by the present invention;

[0044] Figure 8 is a cross-sectional view of EE in Figure 7;

[0045] Figure 9 is a cross-sectional view of FF in Figure 7;

[0046] Figure 10 is a schematic diagram of the fourth embodiment of the BioDopp biochemical reaction system provided by the present invention;

[0047] Figure 11 is a cross-sectional view of GG in Figure 10;

[0048] Figure 12 is a cross-sectional view of HH in Figure 10;

[0049] Figure 13 is a schematic diagram of the fifth embodiment of the BioDopp biochemical reaction system provided by the present invention;

[0050] Figure 14 is a cross-sectional view of section II in Figure 10;

[0051] Figure 15 is a cross-sectional view of JJ in Figure 10;

[0052] Figure 16 is a schematic diagram of the wastewater treatment method based on the BioDopp biochemical reaction system provided by the present invention.

[0053] Attached reference numerals: 1. Anaerobic zone; 2. Anoxic zone; 3. First aerobic zone; 4. Second aerobic zone; 5. Three-phase separator; 501. Main gas collection hood; 502. Exhaust pipe; 503. Branch gas collection hood; 504. Water collection tank; 505. Drainage channel; 6. Gas release and deoxygenation zone; 7. First flow channel; 8. Second flow channel; 9. Third flow channel; 10. Anaerobic mixing zone; 11. First reflux device; 12. Reflux pipe; 13. Air lifting device; 14. Fourth flow channel; 15. DO online monitoring element; 16. ORP online monitoring element. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0055] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0056] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0057] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0058] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0059] The BioDopp biochemical reaction system and wastewater treatment method provided by the present invention are described below with reference to Figures 1 to 16.

[0060] It should be noted that the term "first end" in the following text specifically refers to the inflow end of sewage, and the term "last end" in the following text specifically refers to the outflow end of sewage. For example, "the first end of the first flow channel 7 is connected to the last end of the anoxic zone 2" specifically means that the inlet end of the first flow channel 7 is connected to the outlet end of the anoxic zone 2.

[0061] Referring to Figures 1 to 3, the BioDopp biochemical reaction system provided in one embodiment of the present invention includes: an anaerobic zone 1, an anoxic zone 2, a first aerobic zone 3, a second aerobic zone 4, a three-phase separator 5, and a gas release and deoxygenation zone 6.

[0062] The end of anaerobic zone 1 is connected to anoxic zone 2, the end of anoxic zone 2 is connected to first aerobic zone 3, the end of first aerobic zone 3 is connected to second aerobic zone 4, the end of second aerobic zone 4 is connected to gas release and deoxygenation zone 6, and the end of gas release and deoxygenation zone 6 is connected to anoxic zone 2.

[0063] The three-phase separator 5 is located at the top end of the second aerobic zone 4. The three-phase separator 5 includes an air collection unit and a water collection unit.

[0064] The gas collection unit includes a main gas collection hood 501, an exhaust pipe 502, and multiple branch gas collection hood layers. The main gas collection hood 501 covers the branch gas collection hood layer located at the top. The air inlet end of the exhaust pipe 502 is connected to the main gas collection hood 501, and the exhaust end of the exhaust pipe 502 is connected to the first aerobic zone 3. The branch gas collection hood layer includes multiple branch gas collection hoods 503 arranged at intervals. A gas collection space is formed inside the branch gas collection hood 503. A sludge guiding surface is formed on the outer wall of the branch gas collection hood 503. The branch gas collection hoods 503 of adjacent branch gas collection hood layers are arranged in an alternating manner. A tortuous gap is formed between the branch gas collection hoods 503 of multiple branch gas collection hood layers. The tortuous gap is connected to the second aerobic zone 4.

[0065] The water collection unit includes a water collection tank 504 and a drainage channel 505. The water collection tank 504 is located on the top of the main gas collection hood 501, and the drainage channel 505 is connected to the water collection tank 504.

[0066] The BioDopp biochemical reaction system provided by this invention firstly replaces the existing sludge-water partition with a three-phase separator 5. On the one hand, this reduces the use of mechanical equipment such as sludge suction machines, sludge scrapers, or suction-scraper machines, saving investment, reducing operating costs, reducing mechanical equipment failures, and facilitating operation and maintenance. On the other hand, the three-phase separator 5 can make more efficient use of the existing tank volume, and the bottom of the three-phase separator 5 can still be used as an aerobic zone, increasing the aerobic biochemical reaction time and helping to increase the treated water volume or save floor space. Secondly, an aeration and deoxygenation zone 6 is added after the aerobic zone, which can significantly reduce the dissolved oxygen in the nitrified sludge mixture returned to the anoxic zone 2. This can greatly reduce the consumption of carbon source in the raw water by dissolved oxygen in the nitrified sludge mixture in the anoxic zone 2, which not only directly saves carbon source addition and operating costs, but also directly enhances the denitrification and nitrogen removal efficiency of the reactor, while indirectly enhancing the phosphorus release efficiency of the anaerobic zone 1, thereby enhancing the overall nitrogen and phosphorus removal efficiency of the reactor. Furthermore, the aerobic zone is divided into two sections (first aerobic zone 3 and second aerobic zone 4), which facilitates different aeration intensities in each zone. This allows for better control of the aerobic biochemical reaction rate and the low dissolved oxygen in the nitrified sludge return liquid at the end of the aerobic zone, thereby further enhancing the overall removal efficiency of pollutants such as carbon, nitrogen, and phosphorus in the reactor. Compared with general A2O biochemical reactors, the BioDopp biochemical reaction system provided by this invention features a compact integrated tank layout. The use of a three-phase separator 5 not only further saves space but also eliminates the need for dedicated sludge collection and return facilities. The separated sludge is returned to the anoxic zone 2 by the nitrified liquid for further biochemical reaction.

[0067] Specifically, as shown in Figure 1, in this embodiment, there is one anaerobic zone 1, one anoxic zone 2, one first aerobic zone 3, and one second aerobic zone 4, and the anaerobic zone 1, the anoxic zone 2, the first aerobic zone 3, and the second aerobic zone 4 are arranged adjacent to each other in sequence. The anaerobic zone 1 is equipped with an inlet pipe at its first end for introducing wastewater into the anaerobic zone 1. A second flow channel 8 is provided between the anaerobic zone 1 and the anoxic zone 2. The first end of the second flow channel 8 is connected to the end of the anaerobic zone 1, and the end of the second flow channel 8 is connected to the first end of the anoxic zone 2. The end of the anaerobic zone 1 is provided with a water passage hole to connect the anaerobic zone 1 and the second flow channel 8. A first flow channel 7 is provided between the anoxic zone 2 and the first aerobic zone 3. The first end of the first flow channel 7 is connected to the end of the anoxic zone 2, and the end of the first flow channel 7 is connected to the first end of the first aerobic zone 3. The end of the anoxic zone 2 is provided with a water passage hole to connect the anoxic zone 2 and the first flow channel 7. A third flow channel 9 is provided between the second aerobic zone 4 and the deoxygenation zone 6. The bottom of the third flow channel 9 is connected to the end of the second aerobic zone 4, and the top of the third flow channel 9 is connected to the deoxygenation zone 6.

[0068] Referring to Figures 2, 5, 8, 11, and 14, the gas collection unit includes a main gas collection hood 501, an exhaust pipe 502, and two branch gas collection hood layers. Each branch gas collection hood layer includes multiple branch gas collection hoods 503 arranged horizontally at intervals. The cross-section of each branch gas collection hood 503 is an inverted "V" shape, forming a gas collection space inside, and sludge guiding surfaces on both outer walls. In the three-phase separator 5, the gas generated by the reaction is located in the gas collection space and moves upward through the gaps between adjacent branch gas collection hoods 503 to converge into the main gas collection hood 501. Finally, it is discharged into the first aerobic zone 3 through the exhaust pipe 502. The sludge moves downward under the collection and guiding action of the sludge guiding surfaces and reaches the end of the second aerobic zone 4 under the driving action of the water flow. The water collection unit includes multiple water collection tanks 504 and a drainage channel 505. The drainage channel 505 is arranged along the direction of multiple support hoods 503, and its end is connected to a drain pipe. The multiple water collection tanks 504 are spaced apart along the direction of the drainage channel 505 so that water from different locations can be collected into the drainage channel 505 and finally discharged through the drain pipe.

[0069] Anaerobic zone 1 is connected to an anaerobic mixing zone 10 at its head. Both the anaerobic mixing zone 10 and the gas release deoxygenation zone 6 are equipped with mixing devices (such as submersible mixers or anaerobic agitators). These mixing devices promote sufficient contact between wastewater and microorganisms. Through mixing, the distribution of organic matter in the wastewater or its adsorption onto microbial flocs is enhanced, improving the contact between microorganisms and wastewater and increasing wastewater treatment efficiency. Mixing also prevents wastewater and sludge in anaerobic zone 1 and gas release deoxygenation zone 6 from accumulating, maintaining the homogeneity of the reaction system and promoting microbial growth and metabolism. Furthermore, the mixing devices effectively prevent sludge deposition within the reactor.

[0070] Referring to Figure 1, according to some embodiments of the present invention, a first reflux device 11 is provided in the first flow channel 7. The first end of the first reflux device 11 is connected to the end of the anoxic zone 2, and the end of the first reflux device 11 is connected to the anaerobic zone 1. Because the anaerobic zone 1 of a classic A2O bioreactor carries a large amount of nitrate nitrogen electron acceptors in the sludge reflux, from a biochemical perspective, some high-quality carbon sources (VFAs) in the wastewater are wasted and directly used for denitrification, affecting the anaerobic phosphorus release reaction process and thus impacting the entire biological phosphorus removal process. However, the BioDopp bioreactor system provided by the present invention can reflux the denitrified mixed liquor to the anaerobic zone 1 for cyclic anaerobic phosphorus release reaction, minimizing this impact. While the UCT process can mitigate this impact, it requires one sludge return system and two mixed liquor returns: sludge returns to anoxic zone 2, nitrification liquor from the aerobic tank returns to anoxic zone 2, and denitrification liquor from anoxic zone 2 returns to anaerobic zone 1 – three sets of return systems. This solution essentially combines sludge return and nitrification liquor return into one system, saving not only one return system but, more importantly, reducing a control point, simplifying operation, and facilitating maintenance.

[0071] Specifically, the first reflux device 11 preferably uses a submersible axial flow pump or an anaerobic gas lift device, and the first reflux device 11 is connected to a reflux pipe 12 that communicates with the beginning of the anaerobic zone 1. The submersible axial flow pump features high efficiency, compact structure, strong adaptability, and high reliability. It can provide high flow rate and low head, suitable for the pumping requirements of large flow rate and low head. Furthermore, because it is entirely submerged in water, it has a compact structure, small footprint, and is less affected by external factors, ensuring stable and reliable operation.

[0072] Referring to Figures 1 and 2, according to some embodiments of the present invention, the bottom of the third flow channel 9 is connected to the end of the second aerobic zone 4, and the top of the third flow channel 9 is connected to the deoxygenation zone 6. An air-lift device 13 is provided within the third flow channel 9. By providing the air-lift device 13 within the third flow channel 9, the reflux energy consumption is greatly reduced, and the reflux flow rate can be increased within an acceptable energy consumption range. This not only enhances the denitrification efficiency but also increases the sludge concentration in the reactor, increases the volumetric loading, reduces the tank volume, and further saves land.

[0073] Referring to Figures 4, 7, 10 and 13, according to some embodiments of the present invention, the BioDopp biochemical reaction system further includes a fourth flow channel 14, the bottom of which is connected to the end of the anoxic zone 2, and the top of which is connected to the first aerobic zone 3. An air lifting device 13 is provided in the fourth flow channel 14.

[0074] Specifically, in this embodiment, the fourth flow channel 14 is arranged adjacent to the first flow channel 7, and the bottom of the fourth flow channel 14 is connected to the end of the anoxic zone 2 through the first flow channel 7.

[0075] It should be noted that, in specific implementation, the air lifting device 13 can be installed in the third flow channel 9, or in the fourth flow channel 14, or both the third flow channel 9 and the fourth flow channel 14 can be equipped with the air lifting device 13, depending on different working conditions.

[0076] Referring to Figures 7, 10, and 13, according to some embodiments of the present invention, guide walls for extending the water flow path are provided in the anoxic zone 2 and / or the first aerobic zone 3. By providing guide walls for extending the water flow path in the anoxic zone 2 and / or the first aerobic zone 3, the reaction time of wastewater in the anoxic zone 2 and / or the first aerobic zone 3 can be increased, thereby improving the treatment efficiency of the wastewater treatment system. Extending the water flow path allows wastewater to remain in the anoxic zone 2 and the first aerobic zone 3 for a longer period, which is beneficial for the degradation and removal of organic matter in the wastewater by microorganisms. The provision of guide walls can effectively guide the water flow, causing it to flow along a predetermined path, avoiding eddies and short-circuiting phenomena caused by direct channels, ensuring that the wastewater is fully mixed and in contact with microorganisms throughout the reactor, improving the wastewater treatment efficiency and removal rate, and enhancing the performance and stability of the treatment system.

[0077] Specifically, in some embodiments, the flow guide walls are arranged as shown in Figure 7. Multiple flow guide walls are arranged laterally at intervals along the axis shown in Figure 7 in the anoxic zone 2 and the first anaerobic zone 1. Each flow guide wall is provided with a water passage. The sewage flows meanderingly in the anoxic zone 2 and the first anaerobic zone 1, which can effectively improve its reaction time in the anoxic zone 2 and the first anaerobic zone 1.

[0078] In some embodiments, the flow guide walls are arranged as shown in Figures 10 and 13. Two arc-shaped flow guide walls are arranged opposite each other in the anoxic zone 2. The two arc-shaped flow guide walls are arranged in the transverse direction as shown in Figures 10 and 13. The upper and lower sides of the transversely arranged flow guide walls form flow guide zones to delay the reaction time of sewage in the anoxic zone 2. Multiple flow guide walls are arranged vertically at intervals in the first aerobic zone 3. Each flow guide wall is provided with a water passage. The sewage flows in a meandering manner in the first anaerobic zone 1, which can effectively improve its reaction time in the anoxic zone 2 and the first anaerobic zone 1.

[0079] As can be seen from the above description of the embodiments, in the BioDopp biochemical reaction system provided by the present invention, the flow guide walls in the anoxic zone 2 and the first aerobic zone 3 can be set according to actual needs, and are not limited to the above methods.

[0080] According to some embodiments of the present invention, the horizontal inclination angle of the sludge guiding surface is greater than or equal to 45°. Under the premise of being able to collect and guide the sludge, the sludge collected on the sludge guiding surface can fall smoothly, preventing the sludge from accumulating on the guiding surface.

[0081] According to some embodiments of the present invention, in each branch gas collection hood layer, the spacing between adjacent branch gas collection hoods 503 is greater than or equal to 80 mm, the overlap spacing between branch gas collection hoods 503 in adjacent branch gas collection hood layers is greater than or equal to 80 mm, and the width of the tortuous gap is greater than or equal to 80 mm. With the above arrangement, air bubbles can be prevented from escaping to the upper sedimentation and water collection unit, thus avoiding affecting the sedimentation effect and causing a deterioration in the effluent quality.

[0082] Referring to Figures 1, 4, 7, 10, and 13, according to some embodiments of the present invention, both the end of the second aerobic zone 4 and the deoxygenation zone 6 are equipped with online DO monitoring elements 15 and online ORP monitoring elements 16. The online DO (dissolved oxygen) monitoring element can monitor the dissolved oxygen content in the water in real time. Dissolved oxygen is an important parameter for the survival of aquatic organisms and the wastewater treatment process. It reflects the oxygen content in the water and is crucial for the growth of organisms and the degradation of organic matter in wastewater. Therefore, the online DO monitoring element 15 can help monitor changes in dissolved oxygen in the water, providing real-time data support for the wastewater treatment process for timely regulation and management. The online ORP (oxidation-reduction potential) monitoring element can monitor the oxidation-reduction potential in the water. ORP reflects the balance between oxidizing and reducing substances in the water and is of great significance for chemical reactions and electrochemical processes in wastewater treatment. By monitoring the ORP value, the redox environment in the water can be understood, thereby optimizing the wastewater treatment process, controlling the redox reaction, and ensuring the normal operation of the wastewater treatment system.

[0083] In some embodiments, depending on actual needs, either the DO online monitoring element 15 or the ORP online monitoring element 16 may be provided only at the end of the second aerobic zone 4, and either the DO online monitoring element 15 or the ORP online monitoring element 16 may be provided within the gas release deoxygenation zone 6.

[0084] Referring to Figure 16, the wastewater treatment method provided by the present invention includes:

[0085] S1. Wastewater is introduced into the anaerobic zone 1. The high-quality carbon source in the wastewater is mixed with the denitrified sludge mixture returned from the anoxic zone 2 to the anaerobic zone 1, and an anaerobic phosphorus release reaction occurs to obtain an anaerobic phosphorus release mixture.

[0086] S2. Anaerobic phosphorus release mixture is introduced into the head end of the anoxic zone 2 and mixed with the nitrified sludge mixture that has undergone gas release and dissolved oxygen removal in the gas release and deoxygenation zone 6. After mixing, denitrification and dephosphorization reactions and denitrification and decarbonization reactions occur to obtain denitrified sludge mixture.

[0087] S3. A portion of the denitrified sludge mixture is returned to the anaerobic zone 1 for circulation, while the other portion of the denitrified sludge mixture sequentially enters the first aerobic zone 3 and the second aerobic zone 4 to undergo aerobic phosphorus uptake, aerobic carbon removal, and nitrification reactions, thereby obtaining a nitrified sludge mixture.

[0088] S4. The nitrified sludge mixture enters the three-phase separator 5. After gas collection and sedimentation separation, the clear water flows out. The gas is transported to the first aerobic zone 3 and / or the second aerobic zone 4 for reuse. The nitrified sludge separated by sedimentation slides down to the second aerobic zone 4 and collects at the end of the second aerobic zone 4, flowing to the gas release and deoxygenation zone 6. A portion of the nitrified sludge is discharged at the end of the second aerobic zone 4 and / or discharged in the gas release and deoxygenation zone 6. Another portion of the nitrified sludge mixture enters the beginning of the anoxic zone 2 through the gas release and deoxygenation zone 6 for circulation.

[0089] Specifically, in step S1, under anaerobic conditions, phosphorus-removing bacteria (PAOs) can only store high-quality carbon sources (VFAs) in their bodies in the form of PHA or PHB and complete the phosphorus release process when there is no dissolved oxygen or electron acceptors such as nitrate nitrogen. When wastewater is introduced into anaerobic zone 1, the high-quality carbon sources (VFAs) in the wastewater mix with the denitrified sludge mixture returned from anoxic zone 2 to anaerobic zone 1. The sludge mixture after denitrification can better meet the above-mentioned anaerobic phosphorus release environment, with very low dissolved oxygen and electron acceptors such as nitrate nitrogen, which can efficiently complete the anaerobic phosphorus release biochemical reaction process and obtain an anaerobic phosphorus release mixture.

[0090] In step S2, when the anaerobic phosphorus-releasing mixed liquor is introduced into the anoxic zone 2, it mixes with the nitrified sludge returned to the anoxic zone 2 from the gas-releasing deoxygenation zone 6. Under anoxic conditions, denitrification and dephosphorization reactions occur. This mainly involves the conversion of nitrate nitrogen and organic waste. In the denitrification and dephosphorization reaction, PHA or PHB within the phosphorus-removing bacteria (PAOs) are used as electron donors to reduce nitrate nitrogen to nitrogen gas, while simultaneously absorbing excess orthophosphate, thus achieving denitrification and dephosphorization. Simultaneously, in the denitrification and decarbonization reaction, other remaining organic carbon sources in the wastewater are also utilized as electron acceptors, reducing nitrate nitrogen to nitrogen gas under the utilization of denitrifying bacteria, thus achieving denitrification and decarbonization. The wastewater after the denitrification and dephosphorization reactions is transformed into a denitrified sludge mixed liquor.

[0091] In step S3, a portion of the denitrified sludge mixture is fed into anaerobic zone 1 for repeated circulation, continuously supplying phosphorus-removing bacteria and completing the anaerobic phosphorus release reaction. The other portion of the denitrified sludge mixture sequentially enters the first aerobic zone 3 and the second aerobic zone 4, where aerobic phosphorus uptake, aerobic carbon removal, and nitrification reactions occur, ultimately yielding nitrified sludge mixture. Under aerobic conditions, phosphorus in the wastewater is excessively adsorbed and stored by phosphorus-removing bacteria (PAOs) (referred to as aerobic phosphorus uptake). Simultaneously, the remaining organic waste is oxidized and decomposed, further removing carbon. During this process, nitrification also occurs, converting ammonia nitrogen into nitrate nitrogen. In step S3, after the aerobic zone is divided into two sections (first aerobic zone 3 and second aerobic zone 4), it is easier to achieve different aeration intensities in different aerobic zones. This makes it easier to control the aerobic biochemical reaction rate and the low dissolved oxygen content in the nitrification sludge return liquid at the end of the aerobic zone, thereby further enhancing the overall removal efficiency of pollutants such as carbon, nitrogen, and phosphorus in the reactor.

[0092] In step S4, after the nitrified sludge mixture is treated by the three-phase separator 5, three products are obtained: clear water, gas, and nitrified sludge. The clearer water, obtained after gas collection and sedimentation, flows out of the three-phase separator 5. The gas is transported to the first aerobic zone 3 and / or the second aerobic zone 4 for recycling to provide oxygen and promote the wastewater treatment reaction. The nitrified sludge separated by sedimentation slides down to the second aerobic zone 4 and collects at its end. A portion of the nitrified sludge is discharged at the end of the second aerobic zone 4, while the other portion flows to the deoxygenation zone 6; or all of it flows to the deoxygenation zone 6, where a portion of the nitrified sludge is discharged. After passing through the deoxygenation zone 6, the nitrified sludge mixture enters the beginning of the anoxic zone 2 for circulation, thus maintaining the continuous denitrification reaction and ultimately achieving complete nitrogen removal.

[0093] According to some embodiments of the present invention, the dissolved oxygen at the end of the second aerobic zone 4 is less than or equal to 2.0 mg / L and / or the oxidation-reduction potential is less than or equal to +150.0 mV; the dissolved oxygen at the end of the deoxygenation zone 6 is less than or equal to 1.0 mg / L; and the oxidation-reduction potential at the end of the deoxygenation zone 6 is less than or equal to +100.0 mV. These parameters are used to monitor dissolved oxygen (DO) and oxidation-reduction potential (ORP) in the water. In practice, adjusting these parameters can help optimize the operation of the wastewater treatment system. For example, at the end of the second aerobic zone 4, if the dissolved oxygen is less than or equal to 1.0 mg / L and / or less than or equal to +100.0 mV, it may mean that aeration needs to be increased or the oxygen supply increased to ensure that the wastewater is adequately oxidized at this point. At the end of the deoxygenation zone 6, if the dissolved oxygen is less than or equal to 1.0 mg / L and the oxidation-reduction potential is less than or equal to +100.0 mV, it may be necessary to increase aeration or increase the oxygen supply to ensure that the wastewater is adequately oxidized at this point. By monitoring and adjusting the above parameters, the operation of the wastewater treatment system can be better monitored and controlled, ensuring that the system can operate efficiently and stably and achieve the expected wastewater treatment effect.

[0094] According to some embodiments of the present invention, the reflux ratio of the anoxic zone 2 to the anaerobic zone 1 is less than or equal to 200%, and the circulation ratio of the anoxic zone 2 to the first aerobic zone 3 is greater than or equal to 300%. By controlling the reflux ratio of the anoxic zone 2 to the anaerobic zone 1 and the circulation ratio of the anoxic zone 2 to the aerobic zone, the anaerobic phosphorus release reaction, denitrification phosphorus removal reaction, aerobic phosphorus uptake reaction, aerobic carbon removal, nitrification reaction, and denitrification reaction can be controlled. Adjusting the reflux ratio and circulation ratio helps to improve the biological nitrogen and phosphorus removal efficiency of the biochemical reaction system.

[0095] As can be seen from the above description of the embodiments, the BioDopp biochemical reaction system and wastewater treatment method provided by the present invention have at least the following advantages:

[0096] 1. The use of three-phase separator 5 can reduce the use of mechanical equipment such as sludge suction machine, sludge scraper, or sludge suction scraper, save investment, reduce operating costs, reduce mechanical equipment failures, facilitate operation and maintenance management, and further increase the volume of existing tanks for use as aerobic zones, increase aerobic biochemical reaction time, which is conducive to increasing the treated water volume and saving land area.

[0097] 2. The added gas release deoxygenation zone 6 can significantly and effectively reduce the dissolved oxygen in the nitrified sludge mixed liquor returned to the anoxic zone 2, which can directly and effectively save carbon source addition and operating costs, and indirectly enhance the overall nitrogen and phosphorus removal efficiency of the reactor.

[0098] 3. After the aerobic zone is divided into two sections (first aerobic zone 3 and second aerobic zone 4), it is easier to achieve different aeration intensities in different aerobic zones. This makes it easier to control the aerobic biochemical reaction rate and the low dissolved oxygen content in the nitrification sludge return liquid at the end of the aerobic zone, thereby further enhancing the overall removal efficiency of pollutants such as carbon, nitrogen, and phosphorus in the reactor.

[0099] 4. With the addition of a functional anaerobic zone and the adoption of denitrification sludge recirculation, the high-quality carbon source (VFAs) in the raw water can be utilized more efficiently for anaerobic phosphorus release, forming PHA or PHB in the microorganisms. Then, in the subsequent anoxic zone 2 and aerobic zone, denitrification phosphorus removal and aerobic phosphorus uptake reactions are carried out respectively, which greatly improves the phosphorus removal effect and achieves "one carbon for two uses".

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. Industrial applicability

[0101] This invention provides a BioDopp biochemical reaction system and wastewater treatment method. The system includes an anaerobic zone, an anoxic zone, a first aerobic zone, a second aerobic zone, a three-phase separator, and a gas release deoxygenation zone. The anaerobic zone is connected to the anoxic zone, the anoxic zone is connected to the first aerobic zone, the first aerobic zone is connected to the second aerobic zone, the second aerobic zone is connected to the gas release deoxygenation zone, and the gas release deoxygenation zone is connected to the anoxic zone. The three-phase separator is located at the top end of the second aerobic zone and includes a gas collection unit and a water collection unit. The gas collection unit includes a main gas collection hood, an exhaust pipe, and multiple branch gas collection hood layers. The main gas collection hood is located in the top branch gas collection hood layer. The inlet end of the exhaust pipe is connected to the main gas collection hood, and the exhaust end of the exhaust pipe is connected to the first aerobic zone. This invention achieves dual carbon utilization, effectively saving carbon source consumption for nitrogen and phosphorus removal. It also features a simple structural layout, saves floor space, reduces construction and operating costs, and has good economic value and application prospects.

Claims

1. A BioDopp biochemical reaction system, characterized in that, include: Anaerobic zone, anoxic zone, first aerobic zone, second aerobic zone, three-phase separator and gas release deoxygenation zone; The end of the anaerobic zone is connected to the anoxic zone, the end of the anoxic zone is connected to the first aerobic zone, the end of the first aerobic zone is connected to the second aerobic zone, the end of the second aerobic zone is connected to the gas release and deoxygenation zone, and the end of the gas release and deoxygenation zone is connected to the anoxic zone. The three-phase separator is located at the top end of the second aerobic zone, and the three-phase separator includes an air collection unit and a water collection unit. The gas collection unit includes a main gas collection hood, an exhaust pipe, and multiple branch gas collection hood layers. The main gas collection hood is located at the top of the branch gas collection hood layer. The air inlet end of the exhaust pipe is connected to the main gas collection hood, and the air outlet end of the exhaust pipe is connected to the first aerobic zone. Each branch gas collection hood layer includes multiple branch gas collection hoods spaced apart. A gas collection space is formed inside each branch gas collection hood. A sludge guiding surface is formed on the outer wall of each branch gas collection hood. The branch gas collection hoods of adjacent branch gas collection hood layers are arranged in an alternating manner. A tortuous gap is formed between the branch gas collection hoods of multiple branch gas collection hood layers. The tortuous gap is connected to the second aerobic zone. The water collection unit includes a water collection tank and a drainage channel. The water collection tank is located on top of the main gas collection hood, and the drainage channel is connected to the water collection tank.

2. The BioDopp biochemical reaction system according to claim 1, characterized in that, It also includes a first flow channel, the first end of which is connected to the end of the anoxic zone, and the end of which is connected to the first aerobic zone; The first flow channel is provided with a first reflux device. The first end of the first reflux device is connected to the end of the anoxic zone, and the end of the first reflux device is connected to the anaerobic zone.

3. The BioDopp biochemical reaction system according to claim 1, characterized in that, It also includes a second flow channel, the first end of which is connected to the anaerobic zone, and the second flow channel is connected to the anoxic zone.

4. The BioDopp biochemical reaction system according to claim 1, characterized in that, It also includes a third flow channel, the bottom of which is connected to the end of the second aerobic zone, and the top of which is connected to the gas release and deoxygenation zone. The third flow channel is equipped with a gas lifting device. And / or, it also includes a fourth flow channel, the bottom of which is connected to the end of the anoxic zone, the top of which is connected to the first aerobic zone, and an air lifting device is provided in the fourth flow channel.

5. The BioDopp biochemical reaction system according to claim 1, characterized in that, The anoxic zone and / or the first aerobic zone are equipped with guide walls to extend the water flow path.

6. The BioDopp biochemical reaction system according to any one of claims 1 to 5, characterized in that, The horizontal inclination angle of the sludge guiding surface is greater than or equal to 45°; In each of the aforementioned support gas hood layers, the spacing between adjacent support gas hoods is greater than or equal to 80 mm; The overlap spacing between adjacent gas collection hood layers is greater than or equal to 80 mm. The width of the tortuous gap is greater than or equal to 80 mm.

7. The BioDopp biochemical reaction system according to any one of claims 1 to 5, characterized in that, At least one of an online DO monitoring element and an online ORP monitoring element is provided at the end of the second aerobic zone and / or in the gas release deoxygenation zone.

8. A wastewater treatment method based on the BioDopp biochemical reaction system as described in any one of claims 1 to 7, characterized in that, include: Wastewater is introduced into the anaerobic zone, where the carbon source in the wastewater mixes with the denitrified sludge mixture returned from the anoxic zone to the anaerobic zone, and an anaerobic phosphorus release reaction occurs to obtain an anaerobic phosphorus release mixture. The anaerobic phosphorus release mixture is introduced into the first end of the anoxic zone and mixed with the nitrified sludge mixture that has undergone gas release and dissolved oxygen removal in the gas release and deoxygenation zone. After mixing, denitrification and dephosphorization reactions and denitrification and decarbonization reactions occur to obtain denitrified sludge mixture. A portion of the denitrified sludge mixture is returned to the anaerobic zone for circulation, while another portion of the denitrified sludge mixture sequentially enters the first aerobic zone and the second aerobic zone to undergo aerobic phosphorus uptake, aerobic carbon removal, and nitrification reactions, thereby obtaining a nitrified sludge mixture. The nitrified sludge mixture enters the three-phase separator. After gas collection and sedimentation separation, the clear water flows out, and the gas is transported to the first aerobic zone and / or the second aerobic zone for reuse. The nitrified sludge separated by sedimentation slides down the process to the second aerobic zone and collects at the end of the second aerobic zone, flowing to the gas release and deoxygenation zone. A portion of the nitrified sludge is discharged at the end of the second aerobic zone and / or discharged in the gas release and deoxygenation zone, while another portion of the nitrified sludge mixture enters the beginning of the anoxic zone through the gas release and deoxygenation zone for circulation.

9. The wastewater treatment method of the BioDopp biochemical reaction system according to claim 8, characterized in that, The dissolved oxygen at the end of the second aerobic zone is controlled to be less than or equal to 2.0 mg / L and / or the redox potential is less than or equal to +150.0 mV; And / or, control the dissolved oxygen at the end of the gas release deoxygenation zone to be less than or equal to 1.0 mg / L and / or the redox potential to be less than or equal to +100.0 mV.

10. The wastewater treatment method for the BioDopp biochemical reaction system according to claim 8 or 9, characterized in that, The reflux ratio from the anoxic zone to the anaerobic zone is less than or equal to 200%, and the circulation ratio from the anoxic zone to the first aerobic zone is greater than or equal to 300%.

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