A high-density bioreactor for wastewater treatment and a wastewater treatment method

Abstract

This invention relates to the field of wastewater treatment technology, disclosing a high-density bioreactor and wastewater treatment method for wastewater treatment. The high-density bioreactor includes a reactor body, a vertical shaft, a water distribution and aeration system, a sludge removal system, and an effluent system. Sludge is located at the bottom of the reactor body. The distributed vortex water distribution and aeration component in the water distribution and aeration system includes a vortex distributor, an annular aerator, and a coarse-pore aerator. The annular aerator is arranged around the vortex distributor to form an annular aeration zone, which generates microbubbles with an average diameter of 1mm to 3mm. Coarse-pore aerators are arranged between adjacent annular aerators, generating large bubbles with an average diameter of 5mm to 6mm. A three-phase mixing channel of sludge, air, and water is formed within the service area of ​​the distributed vortex water distribution and aeration component. Implementing this application allows for the co-cultivation of suspended activated sludge and attached biofilm granular sludge, improving wastewater treatment efficiency and effluent quality while reducing costs.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sewage treatment, and particularly relates to a high-density biological reactor for sewage treatment and a sewage treatment method. BACKGROUND

[0002] With the acceleration of urbanization process and the increasingly stringent environmental protection requirements in China, sewage treatment plants are facing multiple pressures of upgrading and expansion, energy saving and consumption reduction, and sludge reduction. At present, the most widely used biological treatment process section of activated sludge method and its derivative technologies (such as A / O, SBR, oxidation ditch, etc.) has the problems of large occupation area, poor sludge settling property, the need for additional secondary sedimentation system, complex water distribution, aeration layout and sludge return pipe network, large operation energy consumption and maintenance amount, high energy consumption, large residual sludge production, and limited solid-liquid separation efficiency of the secondary sedimentation tank, which restricts the upgrading and sustainable development of the sewage treatment plant. 2

[0003] To solve the above problems, the industry has developed enhanced technologies such as moving bed biofilm reactor (MBBR) and membrane bioreactor (MBR). The MBBR technology improves the biomass by adding suspended carriers to form a biofilm, but still has the shortcomings of easy loss of carriers and limited improvement of sludge concentration in the core area. The MBR technology uses membrane separation to replace the secondary sedimentation tank, achieving high sludge concentration and good effluent water quality, but has the problems of high cost of membrane components, easy pollution, high operation energy consumption, and complex membrane cleaning and maintenance, which significantly increase the investment and operation cost. The existing granular sludge or high-density sludge system usually adopts multi-zone separation arrangement or special filler structure, which is complex in structure and difficult to construct. The traditional hydraulic distribution and aeration layout cannot provide uniform oxygen supply to each zone, and dead zones are easily formed in some areas. The traditional single sludge discharge mode cannot control different particle sizes of sludge, and the system requires high operation and management, has limited adaptability to impact load and water fluctuation.

[0004] Therefore, it is urgent to develop a new type of efficient sewage treatment technology, which can not only integrate the respective advantages of activated sludge and biofilm method to achieve efficient enrichment of microbial concentration and population abundance in the system, but also overcome the technical bottlenecks of MBR, has the comprehensive advantages of small demand for subsequent treatment unit of effluent, low energy consumption, and low residual sludge production rate under the premise of ensuring good effluent water quality, to meet the urgent needs of the current sewage treatment industry for efficient, stable and energy-saving systems. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a high-density biological reactor for sewage treatment, which can realize efficient enrichment of microbial concentration and population abundance in the reactor, comprehensively improve the sewage treatment efficiency and effluent water quality, and reduce the construction investment and operation and maintenance cost.

[0006] ​The technical problem to be solved by the present invention is to provide a wastewater treatment method that improves the removal rates of COD, total nitrogen, ammonia nitrogen and total phosphorus.

[0007] To address the aforementioned technical problems, a first aspect of the present invention provides a high-density bioreactor for wastewater treatment, comprising:

[0008] The reactor body has a vertical shaft inside, and sludge is placed at the bottom of the reactor body. The inner cavity of the vertical shaft is used to introduce sewage.

[0009] A water distribution and aeration system, comprising an adjustable water distributor and a distributed vortex water distribution and aeration assembly, wherein the adjustable water distributor is connected to the inner cavity of the vertical shaft;

[0010] The sludge removal system is used for the discharge and treatment of sludge.

[0011] An effluent system, located at the top of the reactor body, is used to treat and discharge wastewater.

[0012] The distributed vortex water distribution and aeration component includes a vortex water distributor, an annular aerator, and a coarse-pore aerator. The annular aerator is arranged around the vortex water distributor to form an annular aeration zone, which generates microbubbles with an average diameter of 1mm to 3mm.

[0013] A coarse-pore aerator is provided between adjacent annular aerators, which generates large bubbles with an average diameter of 5mm to 6mm.

[0014] The vortex water distributor, annular aerator, and coarse-pore aerator form a mud-air-water three-phase mixing channel within the service area of ​​the distributed vortex water distribution and aeration assembly.

[0015] As an improvement to the above solution, a first fluid flow for mud-water mixing is formed within the service area of ​​the vortex water distributor;

[0016] A second fluid flow for mixing mud, air, and water is formed above the annular aerator;

[0017] A third fluid flow for mixing mud, air, and water is formed within the service area of ​​the coarse-pore aerator.

[0018] As an improvement to the above scheme, the velocity of the first fluid flow is V1, the velocity of the second fluid flow is V2, and the velocity of the third fluid flow is V3, which satisfy the following relationship: V2 < V1 < V3.

[0019] A fluid velocity gradient is established between the second fluid flow and the third fluid flow, V2 = (0.2~0.5)V3.

[0020] As an improvement to the above scheme, the velocity of the first fluid flow is 0.15 m / s to 0.30 m / s;

[0021] The velocity of the second fluid flow is 0.2 m / s to 0.6 m / s;

[0022] The velocity of the third fluid flow is 0.3 m / s to 0.7 m / s.

[0023] As an improvement to the above scheme, the air flow rate of the annular aerator is 3m³. 3 / h~12m 3 / h, the annular aerators are evenly arranged at the bottom of the reactor body;

[0024] The vortex water distributor, annular aerator, and coarse-pore aerator control the dissolved oxygen concentration in the high-density bioreactor to be 2 mg / L to 6 mg / L.

[0025] As an improvement to the above solution, the inner cavity of the vertical shaft is connected to the distributed vortex water distribution and aeration assembly through a water distribution pipe, which includes a horizontally arranged main pipe and multiple branch pipes vertically connected to the main pipe.

[0026] The main pipeline is provided with a branch pipeline at its end, and the branch pipeline is provided with the vortex water distributor at its end. The annular aerator is connected to the air supply equipment through an annular aeration pipe.

[0027] The coarse-pore aerator is connected to the air supply device via a coarse-pore aeration pipe.

[0028] As an improvement to the above solution, the vortex water distributor includes a water distributor body and a reflector located on the lower side of the water distributor body. After the sewage enters from the water distributor body, it flows to the reflector. After the flow state is changed by the reflector, a vortex with a radius of 0.3m to 1.2m is formed.

[0029] As an improvement to the above solution, the annular aerator is composed of several arc-shaped plate aerators. The arc-shaped plate aerator includes a tray, a diaphragm, and an air supply device. The diaphragm is disposed on the tray and has micropores distributed on it. The interior of the tray is provided with channels for gas flow.

[0030] The membrane has a thickness of 1 mm to 2.5 mm, the micropores have a diameter of 0.6 mm to 1.2 mm, and the micropore density is 5 pores / cm². 2 ~15 pieces / cm 2 .

[0031] As an improvement to the above scheme, the sludge discharge system includes a first sludge discharge pipe, a second sludge discharge pipe, and a third sludge discharge pipe that are controlled independently. The first sludge discharge pipe is located at the bottom of the reactor body, the second sludge discharge pipe is located in the middle of the reactor body, and the third sludge discharge pipe is located at the top of the reactor body, so as to classify and manage sludge of different sludge ages in different sections.

[0032] The first mud discharge pipe is located at 3 / 4 to 4 / 5 of the water depth; the second mud discharge pipe is located at 1 / 2 to 2 / 3 of the water depth; and the third mud discharge pipe is located at 1 / 4 to 1 / 3 of the water depth.

[0033] The effluent system is located at the surface of the wastewater. The effluent system includes an effluent tank and an air weir on the effluent tank. The air weir is connected to compressed gas through a pipe to control the liquid level difference in the effluent tank.

[0034] The air intake pressure of the air weir is 0.2 kPa to 2.0 kPa.

[0035] As an improvement to the above scheme, the hydraulic retention time of the wastewater in the high-density bioreactor is 6h~24h;

[0036] When the wastewater is subjected to anoxic or anaerobic treatment, the ORP value in the high-density bioreactor is controlled to be -300mV to 0mV, and the DO value is controlled to be 0mg / L to 0.5mg / L.

[0037] When the wastewater is treated aerobically, the ORP value in the high-density bioreactor is controlled to be 100mV~300mV and the DO value is controlled to be 2mg / L~6mg / L.

[0038] A second aspect of the present invention also provides a wastewater treatment method based on the high-density bioreactor, comprising the following steps:

[0039] (1) The sewage is introduced into the inner cavity of the vertical shaft through an adjustable water distributor;

[0040] (2) The wastewater enters the distributed vortex water distribution and aeration component from the adjustable water distributor for water distribution and aeration treatment, so that the wastewater is evenly distributed at the bottom of the reactor body; the wastewater reacts with sludge in the reactor body for degradation treatment;

[0041] (3) The wastewater after degradation treatment is discharged through the effluent system, and the sludge is discharged through the first sludge discharge pipe, the second sludge discharge pipe and the third sludge discharge pipe.

[0042] Implementing this invention has the following beneficial effects:

[0043] (1) This invention utilizes a water distribution and aeration system, comprising an adjustable water distributor and a distributed vortex water distribution and aeration assembly. The distributed vortex water distribution and aeration assembly includes a vortex water distributor, an annular aerator, and a coarse-pore aerator, forming at least three fluid flows to co-cultivate suspended activated sludge and attached biofilm granular sludge, resulting in a high-biomass, multi-layered microbial community structure. This greatly enriches the concentration and abundance of microorganisms within the reactor, forming a high-density sludge-film symbiosis system. This "sludge-film symbiosis" system facilitates the rapid degradation of organic pollutants in water and achieves efficient synergistic removal of carbon, nitrogen, and phosphorus, improving the system's volumetric loading and treatment efficiency, and ensuring stable and high-quality effluent.

[0044] (2) The present invention effectively promotes the transformation of activated sludge into granular sludge by the shear force field generated by vortex water distribution and multi-stage aeration, thereby achieving rapid high-density or granulation of sludge, and thus a large amount of high-density sludge can be cultivated in a short time. The apparent density and settling rate of sludge are greatly improved, and the sludge-water separation process is accelerated.

[0045] (3) The reactor of the present invention can complete the separation of mud and water in a very short time, which effectively solves the problems of mud runoff and turbid effluent caused by poor settling and easy expansion in the traditional activated sludge process, and improves the operational stability and reliability of the system.

[0046] (4) By setting up sludge discharge pipes at multiple points and adjusting the aeration intensity, sludge with different settling properties can be sorted, thereby controlling the sludge age of granular sludge and flocculent sludge respectively, achieving the purpose of sludge age gradient control. The particles present in the reactor have a long sludge age, which can enhance the endogenous respiration of microorganisms and further oxidize and decompose endogenous carbon, thereby reducing the production of biological sludge and effectively reducing sludge disposal costs. Attached Figure Description

[0047] Figure 1 : A schematic diagram of the high-density bioreactor in this invention;

[0048] Figure 2 : A structural diagram of the water distribution pipe arrangement in this invention;

[0049] Figure 3 : A cross-sectional view of the integrated structure formed by the vortex water distributor and the annular aerator in this invention;

[0050] Figure 4 : A top view of the integrated structure formed by the vortex water distributor and the annular aerator in this invention;

[0051] Figure 5 : A diagram showing the water flow path of wastewater in the vortex distributor in this invention;

[0052] Figure 6: A diagram showing the aeration flow pattern of wastewater in a ring aerator in this invention;

[0053] Figure 7 : COD removal effect before and after municipal sewage treatment;

[0054] Figure 8 Ammonia nitrogen removal effect before and after municipal wastewater treatment;

[0055] Figure 9 : Total phosphorus removal effect before and after municipal wastewater treatment;

[0056] Figure 10 : Total nitrogen removal effect before and after municipal wastewater treatment;

[0057] Figure 11 Particle size distribution of sludge in a high-density bioreactor;

[0058] Figure 12 : A diagram showing the morphology of the high-density granular sludge formed at the bottom of the reactor;

[0059] Figure 13 Microscopic images of sludge morphology at different treatment stages;

[0060] Figure 14 : Microbial community bar graph of sludge after municipal wastewater treatment.

[0061] Figure label:

[0062] 1-Reactor body; 11-Vertical shaft; 2-Water distribution and aeration system; 21-Adjustable water distributor; 22-Distributed vortex water distribution and aeration assembly; 221-Vortex water distributor; 2211-Water distributor body; 2211A-Inlet section; 2211B-Mixing section; 2211C-Diffuser section; 2211D-Sewage inlet; 2211E-Nozzle; 2211F-Return hole; 2212-Reflector; 2213-Fixed rib; 222-Annular aerator; 2221-Arc-shaped Plate aerator; 2221A-Tray; 2221B-Membrane; 2221C-Air inlet interface; 2222-Snap-fit ​​structure; 2223-Annular aeration pipe; 223-Coarse-pore aerator; 2231-Coarse-pore aeration pipe; 224-Bracket; 23-Water distribution pipe; 231-Main pipe; 232-Branch pipe; 3-Sludge discharge system; 31-First sludge discharge pipe; 32-Second sludge discharge pipe; 33-Third sludge discharge pipe; 4-Water discharge system; 41-Water discharge trough; 42-Air weir. Detailed Implementation

[0063] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments will be described in further detail below.

[0064] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to their structure and are relative concepts. Therefore, they may vary depending on their location and usage. Consequently, these or other directional terms should not be interpreted as restrictive.

[0065] To address the above problems, the present invention provides a high-density bioreactor body for wastewater treatment, comprising: a reactor body 1, a water distribution and aeration system 2, a sludge discharge system 3, and an effluent system 4.

[0066] Please see Figure 1 The reactor body 1 is provided with a vertical shaft 11, and the bottom of the reactor body 1 is provided with sludge. The inner cavity of the vertical shaft 11 is used to introduce sewage. The water distribution and aeration system 2 includes an adjustable water distributor 21 and a distributed vortex water distribution and aeration component 22. The adjustable water distributor 21 is connected to the inner cavity of the vertical shaft 11. The distributed vortex water distribution and aeration assembly 22 includes a vortex water distributor 221, an annular aerator 222, and a coarse-pore aerator 223. The annular aerator 222 is arranged around the vortex water distributor 221 to form an annular aeration zone, which generates microbubbles with an average diameter of 1mm to 3mm. A coarse-pore aerator 223 is arranged between adjacent annular aerators 222, which generates large bubbles with an average diameter of 5mm to 6mm. The vortex water distributor 221, annular aerator 222, and coarse-pore aerator 223 form a mud-air-water three-phase mixing channel within the service area of ​​the distributed vortex water distribution and aeration assembly.

[0067] In this invention, by optimizing the design of the water distribution and aeration system 2, at least three fluid flows are formed to co-cultivate suspended activated sludge and attached biofilm granular sludge, creating a high-biomass, multi-layered microbial community structure. This greatly enriches the concentration and abundance of microorganisms within the reactor. This "sludge-film symbiosis" system can comprehensively improve wastewater treatment efficiency and effluent quality while reducing construction investment and operation and maintenance costs. It effectively solves problems in existing processes such as large footprint, high energy consumption, high residual sludge production, and low solid-liquid separation efficiency leading to unstable operation.

[0068] It should be noted that the wastewater in this application can be municipal sewage, industrial wastewater, high-concentration organic wastewater, or a mixture of two or three of these types. The sludge can specifically be granular activated sludge, flocculent sludge, etc., and can be aerobic sludge. The reaction type and shape of the sludge can be reasonably adjusted according to actual conditions.

[0069] Optionally, the vertical shaft 11 can be located on the side inside the reactor body 1, and the adjustable water distributor 21 is placed at the top of the vertical shaft 11, specifically connected to the vertical shaft 11 via a pipe. Based on this design, the exchange ratio and influent flow rate can be effectively controlled. During influent / distribution operation, wastewater is stored in the adjustable water distributor 21, and pulsed water distribution is achieved based on the siphon effect, thereby regulating the hydraulic shear force and organic matter impact load. The water distribution duration can be controlled from 5s to 30s.

[0070] Preferably, the inner cavity of the vertical shaft 11 is connected to the distributed vortex water distribution and aeration assembly 22 via a water distribution pipe 23, and the distributed vortex water distribution and aeration assembly 22 is located at the bottom of the reactor body 1. Wastewater enters the distributed vortex water distribution and aeration assembly 22 from the vertical shaft 11 through the water distribution pipe 23, and is evenly distributed at the bottom of the reactor body 1 by the distributed vortex water distribution and aeration assembly 22, forming a uniform upward flow pattern and creating selective pressure to screen and retain granular sludge with excellent settling performance. Both the vortex water distributor 221 and the annular aerator 222 can form a vortex flow field structure, which generates uniform and strong hydraulic shear force within the reactor to shape the granular structure of the sludge. Furthermore, the vortex flow field has a strong mass transfer efficiency, ensuring the activity and stability of the particles. It is understood that the distributed vortex water distribution and aeration components 22 can be evenly distributed at the bottom of the reactor body 1. The reactor body 1 can be a concrete tank with a depth of 6.0m to 12.5m and an area designed according to the amount of water to be treated. Generally speaking, during water distribution and treatment, the clarification zone is about 1.5m to 4m below the liquid surface in the tank, and the lower part will form a sludge expansion bed zone.

[0071] Further, please refer to Figure 2 The water distribution pipe 23 adopts a multi-stage diversion "I"-shaped pipe network arrangement, including a horizontally arranged main pipe 231 and multiple branch pipes 232 vertically connected to the main pipe 231. The main pipe 231 has a branch pipe 232 at its end, and the branch pipe 232 has a vortex water distributor 221 at its end. Wastewater enters the vortex water distributor 221 from the vertical shaft 11 through the branch pipes 232. The annular aerator 222 is connected to the annular aeration pipe 2223, and the main pipe 231 is connected to the coarse-pore aeration pipe 2231 and located between adjacent annular aerators 222. In some embodiments, the branch pipes 232 can be evenly distributed.

[0072] Furthermore, a first fluid flow for sludge-water mixing is formed within the service area of ​​the vortex distributor 221; a second fluid flow for sludge-air-water mixing is formed above the annular aerator 222; and a third fluid flow for sludge-air-water mixing is formed within the service area of ​​the coarse-pore aerator 223. The velocity of the first fluid flow is V1, the velocity of the second fluid flow is V2, and the velocity of the third fluid flow is V3, satisfying the following relationship: V2 < V1 < V3. Based on this design, the mixing capacity of the system is effectively improved, minimizing the possibility of sludge accumulation. The triple vortex mixing effectively increases the shear force within the system, greatly benefiting the aggregation of flocculent sludge and the formation of granular sludge.

[0073] More preferably, a fluid velocity gradient is established between the second and third fluid flows, V2 = (0.2~0.5)V3, which can create a differentiated hydrodynamic microenvironment to meet the different hydrodynamic environment preferences of suspended sludge and attached granular sludge. The second fluid flow has a lower velocity, generating lower hydraulic shear force, preventing the biofilm and granular sludge from being washed away in the early stages of formation. It also prolongs the contact and diffusion time of pollutants such as organic matter and ammonia nitrogen on the surface of the biofilm / granular sludge, improving mass transfer efficiency and facilitating the enrichment and functionalization of slow-growing nitrifying bacteria and other functional microorganisms. The third fluid flow has a higher velocity, generating strong turbulence and lifting effects, ensuring rapid and uniform mixing of suspended sludge, pollutants, and dissolved oxygen within the reactor, preventing sludge deposition, maintaining the entire reactor in a well-mixed state, and improving oxygenation efficiency to quickly meet the oxygen requirements of the rapidly metabolizing microorganisms in the suspended sludge. If V2 > 0.5V3, the shear force difference between the two regions is insufficient, making it difficult to form a distinct ecological niche zone, which makes it difficult for the biofilm to form stably; if V2 < 0.2V3, a stagnant zone will be formed within the service area of ​​the annular aerator, leading to local sludge deposition, DO depletion and anaerobic acidification.

[0074] In some specific and preferred embodiments, the velocity of the first fluid flow is 0.2 m / s to 0.6 m / s; the velocity of the second fluid flow is 0.15 m / s to 0.30 m / s; and the velocity of the third fluid flow is 0.3 m / s to 0.7 m / s.

[0075] Specifically, please refer to Figure 3 and Figure 4The vortex distributor 221 includes a distributor body 2211 and a reflector 2212 disposed on the lower side of the distributor body 2211. Wastewater enters through the distributor body 2211 and flows to the reflector 2212. After the flow pattern is changed by the reflector 2212, a vortex with a radius of 0.3m to 1.2m is formed to agitate the sludge. At this time, a first fluid flow for sludge-water mixing is formed within the service area of ​​the vortex distributor 221. This first fluid flow has a circumferential flow direction. Simultaneously, controlling the velocity of the first fluid flow to 0.2m / s to 0.6m / s can achieve a micro-stirring effect, eliminating dead zones, preventing short-circuiting and sludge compaction, and improving the contact efficiency between microorganisms and wastewater.

[0076] Preferably, the water distributor body 2211 includes an inlet section 2211A, a mixing section 2211B, and a diffusion section 2211C connected in sequence. The reflector 2212 has a reflective surface facing the outlet of the diffusion section 2211C. After entering from the inlet section 2211A, the wastewater is mixed in the mixing section 2211B, and then further mixed in the diffusion section 2211C before entering the reflector 2212. After the flow pattern is changed by the reflective surface, an expanding hydraulic chamber is formed in the reflector 2212, achieving uniform mixing of mud and water. During the treatment process, it forms a... Figure 5 The water flow trajectory shown is as follows. The vortex water flow generated by the water distributor body 2211 and the reflector 2212 work together to generate hydraulic disturbance, which mixes and evenly disperses the sewage and sludge, supports the sludge suspension, and thus forms a sludge suspension bed. This avoids sludge deposition and the formation of dead zones, thereby improving the degradation efficiency of sewage by microorganisms and facilitating the mass transfer of large particles in granular sludge systems.

[0077] Furthermore, a sewage inlet 2211D is provided at the end of the inlet section 2211A away from the mixing section 2211B. The vortex water distributor 221 also includes a nozzle 2211E, which is located within the inlet section 2211A. The inlet of the nozzle 2211E is connected to the sewage inlet 2211D, and the outlet of the nozzle 2211E faces the mixing section 2211B. Sewage flowing in from the sewage inlet 2211D is introduced through the nozzle 2211E, and the etched sewage is sprayed at high speed through the nozzle 2211E to the mixing section 2211B, promoting uniform water distribution and improving the hydraulic mixing effect.

[0078] Furthermore, a return flow hole 2211F is provided on the periphery of the inlet section 2211A. The return flow hole 2211F is evenly distributed along the periphery of the inlet section 2211A and can receive the mud-water mixture in the reaction tank. After flowing into the return flow hole 2211F, the mud-water mixture can be fully mixed with the sewage flowing into the sewage inlet 2211D. The outlet of the nozzle 2211E is flush with the edge of the return flow hole 2211F near the mixing section 2211B. Based on this design, the sewage ejected from the outlet of the nozzle 2211E and the mud-water mixture enter the mixing section 2211B separately and mix. The water pressure of the sewage after passing through the nozzle 2211E creates an impact with the mud-water mixture in the mixing section 2211B, thereby ensuring thorough mixing. In addition, the high water flow velocity at nozzle 2211E will generate a Venturi effect at return hole 2211F, forming a local low pressure. The water inlet at nozzle 2211E is drawn into return hole 2211F, increasing the overall flow rate of water distribution, thereby increasing the agitation intensity of sludge.

[0079] In some specific and preferred embodiments, the nozzle 2211E includes a straight section (not shown in the figure) and a narrowing section (not shown in the figure). One end of the straight section has an inlet for the nozzle 2211E. The narrowing section narrows and extends from one end to the other end. One end of the narrowing section is connected to the other end of the straight section. The other end of the narrowing section has an outlet for the nozzle 2211E. The inner hole of the diffuser section 2211C gradually increases from its connection with the mixing section 2211B to the outlet of the diffuser section 2211C. The nozzle 2211E has a diameter of 0.05m to 0.15m. Wastewater treated by the adjustable distributor 21 enters the nozzle 2211E and impacts the reflector 2212 of the vortex distributor 221, forming a first fluid flow with a radius of approximately 0.3m to 1.2m and a velocity of 0.2m / s to 0.6m / s. This effectively agitates the surrounding sludge, creating a uniform upward flow. Simultaneously, the flow velocity at the nozzle 2211E is not less than 3m / s to ensure uniform water distribution. It should be noted that the diameter of the nozzle 2211E here refers to the diameter at the narrowing section of the nozzle 2211E, i.e., the diameter at the narrowest point of the nozzle 2211E.

[0080] Understandably, the water distributor body 2211 needs to be cylindrical based on its basic function. Specifically, it can be cylindrical, but it is not limited to this. This application does not make any specific limitation in this regard.

[0081] In some embodiments, the middle portion of the reflector 2212 protrudes towards the outlet of the diffuser section 2211C to form a protrusion. The outer surface of the protrusion forms a reflective surface, which alters the flow pattern of the wastewater flowing out of the diffuser section 2211C, forming an expanded hydraulic chamber within a certain range to support the sludge suspension, thereby forming a highly efficient sludge expansion bed. More preferably, the protrusion is a geometric body formed by rotating an arc segment around the line connecting the center of the reflector 2212 and the center of the diffuser section 2211C. The shape of this geometric body is conical, with the smallest cross-sectional area at the end facing the diffuser section 2211C, and the cross-sectional area increasing the further away from the diffuser section 2211C. After the wastewater flows out of the diffuser section 2211C, the contact area with the reflective surface gradually increases, thereby gradually changing the flow pattern. The vortex distributor 221 provides appropriate shear force to promote the formation of the expanded hydraulic chamber.

[0082] Optionally, the vortex water distributor 221 further includes fixing ribs 2213, which are connected between the diffuser section 2211C and the reflector 2212, and can firmly fix the water distributor body 2211 and the reflector 2212. Multiple fixing ribs 2213 can be provided, and the multiple fixing ribs 2213 are evenly distributed circumferentially.

[0083] Please refer to Figure 3 and Figure 4 The annular aerator 222 is composed of several arc-shaped plate aerators 2221. Each arc-shaped plate aerator 2221 includes a tray 2221A, a diaphragm 2221B, and an air supply device (not shown in the figure). The diaphragm 2221B is disposed on the tray 2221A and has micropores distributed on it (not shown in the figure). The tray 2221A has a channel for gas flow inside, and an air inlet port 2221C communicating with the channel is provided on the inner side of the tray 2221A facing the vortex water distributor 221. The gas generated by the air supply device enters the channel through the air inlet port 2221C and is then transmitted to the micropores and ejected, generating tiny bubbles at the micropores. At this time, a second fluid flow for mixing mud, air, and water is formed above the annular aerator 222. This second fluid flow has a circumferential flow direction, forming a... Figure 6The aeration flow pattern is shown. Based on this design, the annular aerator 222 can enhance the mixing intensity of horizontal circulation, improve the uniformity of dissolved oxygen in wastewater and oxygen transfer efficiency, and effectively improve the process treatment effect. Specifically, the annular aerator 222 forms an annular structure, which in turn forms a closed hydraulic circulation, promoting horizontal circulation. The resulting vortex is stable, improving the mixing intensity and oxygen transfer efficiency of the aeration zone, and can uniformly supply oxygen to microorganisms, avoiding the existence of low-velocity zones at the edges or center, effectively reducing dead zones in the reaction tank and reducing the deposition of high-density sludge or granular sludge. At the same time, the closed hydraulic circulation enhances water circulation and reduces the need for auxiliary stirring, achieving lower resistance and more energy-efficient system operation at the same air volume.

[0084] Preferably, the membrane 2221B has a thickness of 1 mm to 2.5 mm, a micropore diameter of 0.6 mm to 1.2 mm, and a micropore density of 5 pores / cm². 2 ~15 pieces / cm 2 The average diameter of the formed microbubbles can be controlled to be 1mm~3mm, allowing them to rise and expand better in water and transfer mass with wastewater. From the surface to the core of granular sludge, there is mass transfer / permeation of wastewater. The surface layer of the sludge has the most abundant dissolved oxygen, while the core microorganisms receive very little dissolved oxygen due to consumption and mass transfer losses by surface microorganisms. Forming bubbles of a specific diameter enhances mixing capacity, reduces the possibility of granular sludge deposition, and allows for sufficient contact between the sludge and wastewater. This, to some extent, facilitates internal mass transfer within the granular sludge, further promoting the degree and efficiency of wastewater degradation by the granular sludge.

[0085] Furthermore, the air volume of the annular aerator 222 is 3m³. 3 / h~12m 3 By controlling the velocity of the second fluid flow to 0.15 m / s to 0.30 m / s, combined with the size of the microbubbles, the oxygen utilization rate can be increased to over 40%. The number of arc-shaped plate aerators 2221 can be adjusted according to their diameter and size to achieve higher oxygen utilization. For example, four arc-shaped plate aerators 2221 can be detachably connected to form a ring aerator 222.

[0086] Optionally, adjacent arc-shaped plate aerators 2221 are detachably connected to facilitate quick assembly and disassembly of the arc-shaped plate aerators 2221. In some embodiments, the arc-shaped plate aerators 2221 are connected by a snap-fit ​​structure 2222.

[0087] In some embodiments, the vortex distributor 221 and the annular aerator 222 can be integrated via a bracket 224 to form an integrated structure. This integrated, compact design improves the reliability and scalability of the system, enabling stable operation under varying organic loads, nitrogen and phosphorus loads, and sudden shock conditions in municipal and industrial wastewater. The vortex distributor 221 and the annular aerator 222 are independently configured, allowing for use under different conditions or simultaneously. For example, during the aeration stage, the vortex distributor 221's backflow enables pulsed water distribution, enhancing stirring and further promoting the uniformity of dissolved oxygen and oxygen transfer efficiency in the wastewater, thus improving the operational flexibility of the integrated aeration and water distribution device. Correspondingly, the high-density bioreactor can be used within a hydrolysis acidification reactor or an aerobic treatment reactor. Specifically, the bracket 224 can be bolted to the bottom of the tank, thereby fixing the integrated device to the bottom of the reactor body 1. The diameter of the integrated structure is 0.8m~1.2m, and the service area of ​​the integrated device is 2.5m². 2 ~4.0m 2 The integrated device is 7cm to 10cm away from the bottom of the reactor, minimizing the distance to the bottom of the tank and reducing the possibility of sludge accumulation.

[0088] The coarse-pore aerator 223 is connected to the air supply equipment. The coarse-pore aerator 223 generates large bubbles to agitate the sludge, wastewater, and gas, helping to control the dissolved oxygen concentration and maintain the dense structure of the sludge particles. At this time, a third fluid flow for sludge-air-water mixing is formed within the service area of ​​the coarse-pore aerator 223, and this third fluid flow has an upward flow direction. A stable three-dimensional vortex can be formed within the shared service area of ​​the annular aerator 222 and the coarse-pore aerator 223, realizing a three-phase micro-circulation of gas, wastewater, and sludge. Furthermore, the coarse-pore aerator 223 can also provide appropriate shear force, further increasing the wastewater-gas mixing density within the service area of ​​the annular aerator 222, promoting a downward flow, which is conducive to the formation of more stable and dense bioflocs, further forming high-density activated sludge or granular sludge, reducing the risk of sludge bulking and filamentous bacteria growth, and helping to maintain the dense structure of the sludge particles.

[0089] Furthermore, the velocity of the third fluid flow is 0.3 m / s to 0.7 m / s. Combined with large air bubbles with an average diameter of 5 mm to 6 mm, it can enhance the stirring effect on the three-phase mixing channel of mud, air, and water. In conjunction with the vortex water distributor 221 and the annular aerator 222, the dissolved oxygen concentration in the high-density bioreactor can be controlled to 2 mg / L to 6 mg / L. In some embodiments, the coarse-pore aerator 223 adopts a tubular structure and is evenly distributed among the integrated aeration and water distribution devices.

[0090] In this application, the annular aerator 222 and the coarse-pore aerator 223 are respectively connected to the air supply equipment. Specifically, the air volume can be independently and automatically controlled via electric / pneumatic valves and instruments. They can also adopt alternating or coordinated operation modes according to the water quality load, dynamically regulating the dissolved oxygen gradient within the high-density bioreactor to create a multi-level "aerobic-anoxic-anaerobic" environment, providing conditions for simultaneous nitrification and denitrification as well as the synergistic removal of multiple pollutants. It is understood that the annular aerator 222 and the coarse-pore aerator 223 can be connected to the same air supply equipment through different pipelines, or they can be connected to different air supply equipment respectively. For example, in... Figure 1 In the process, the annular aerator 222 is connected to the air supply equipment through the annular aeration pipe 2223, while the coarse-pore aerator 223 is connected to the air supply equipment through the coarse-pore aeration pipe 2231.

[0091] When the distributed vortex water distribution and aeration component 22 is running, during the influent / distribution stage, wastewater enters the vortex water distributor 221 and is sprayed from the nozzle 2211E. After mixing and diffusion, it impacts the reflector 2212, forming a vortex within a certain range. This vortex drives the sludge to suspend and form a sludge expansion bed, creating a sludge-water mixing channel. At this time, during the anoxic / anaerobic stage of treatment in the reactor, the ORP value in the high-density bioreactor can be controlled to -300mV to 0mV, and the DO value to 0mg / L to 0.5mg / L. During aeration... In the aeration stage, the air supply equipment is activated, and the annular aerator 222 and / or the coarse-pore aerator 223 uniformly supply oxygen and provide effective mixing. A second and third fluid flow for sludge-air-water mixing are formed above the annular aerator 222 and within the service area of ​​the coarse-pore aerator 223, achieving a three-phase micro-circulation of sludge-gas-sewage. At this time, the reactor is in the aerobic stage, and the ORP value in the high-density bioreactor can be controlled at 100mV~300mV, and the DO value at 2mg / L~6mg / L. Alternatively, the vortex distributor 221, annular aerator 222, and coarse-pore aerator 223 can be used simultaneously during the aeration stage. In this case, the adjustable distributor 21 can be controlled to pulse water distribution, further enhancing the mixing capacity and effectively preventing sludge accumulation and the formation of anoxic dead zones. This is especially suitable for fully mixing denser particles in granular sludge systems to prevent sludge settling. Understandably, controlling the adjustable water distributor 21 to pulse water distribution can make the vertical shaft 11 pulse water distribution once every 1 min to 5 min, with each pulse lasting 5 s to 30 s, controlling the sewage inflow / distribution water exchange ratio to be 20% to 50%.

[0092] Please see Figure 1The sludge discharge system 3 is used to discharge sludge. The sludge discharge system 3 includes independently controlled first sludge discharge pipe 31, second sludge discharge pipe 32, and third sludge discharge pipe 33. The first sludge discharge pipe 31 is located at the bottom of the reactor body 1, the second sludge discharge pipe 32 is located in the middle of the reactor body 1, and the third sludge discharge pipe 33 is located at the top of the reactor body 1, to manage sludge of different ages in different sections. In this invention, the first sludge discharge pipe 31, second sludge discharge pipe 32, and third sludge discharge pipe 33 can be independently opened and closed. By using multiple discharge pipes, sludge can be discharged in zones according to sludge settling properties, achieving the sorting of sludge with different settling properties, and thus controlling the sludge age of granular sludge and flocculent sludge respectively, achieving the purpose of sludge age gradient regulation. The granules present in the reactor have a long sludge age, which can enhance the endogenous respiration of microorganisms, further oxidizing and decomposing endogenous carbon, thereby reducing the production of biological sludge and effectively reducing sludge disposal costs.

[0093] Furthermore, the first sludge discharge pipe 31 is located at 3 / 4 to 4 / 5 of the water depth; the second sludge discharge pipe 32 is located at 1 / 2 to 2 / 3 of the water depth; and the third sludge discharge pipe 33 is located at 1 / 4 to 1 / 3 of the water depth. The first and second sludge discharge pipes 31 and 32 are mainly used to discharge slow-setting flocculent sludge to screen for high-density sludge and granular sludge with good settling performance; while the third sludge discharge pipe 33 can be used to discharge settled sludge when necessary. By controlling the opening time of each sludge discharge pipe, the overall sludge age (SRT) and the particle size distribution of granular sludge in different tank layers can be precisely controlled, thereby optimizing the microbial community structure and constructing a stable, high-density biological system with efficient carbon, nitrogen, and phosphorus removal capabilities. Specifically, sludge is discharged during the sedimentation stage of each operating cycle, and the first and second sludge discharge pipes 31 and 32 can be opened respectively to maintain the overall sludge age of the system within the range of 15 days to 35 days. Of course, the opening duration and sludge discharge volume of the first sludge discharge pipe 31 and the second sludge discharge pipe 32 can be reasonably adjusted according to the actual sludge settling performance. Specifically, the start time of sludge discharge can be adjusted according to the sludge settling performance, and the sludge discharge time and volume can be adjusted and controlled according to the sludge age. It is understood that the water depth refers to the depth below the water surface. In some embodiments, the distance between the first sludge discharge pipe 31 and the bottom of the reactor body 1 is 0.4m to 0.6m.

[0094] In some embodiments, the duration of a single operating cycle is generally 4 to 12 hours, specifically including stages such as water influent distribution, aeration, sedimentation (including sludge discharge), and drainage. Taking a 4-hour cycle as an example, it includes a 30-minute sedimentation stage (including the sludge discharge stage), a 50-70 minute water influent / distribution stage, and a 140-160 minute aeration stage. Flexibly adjusting the operating cycle and nutrient ratio can accelerate the acclimatization and rapid formation of granular sludge.

[0095] Please see Figure 1 The effluent system 4 is located at the top of the reactor body 1 and is used for discharging sludge. Specifically, the effluent system 4 is located at the surface of the wastewater and includes an effluent tank 41 and an air weir 42 on the effluent tank 41. The air weir 42 is connected to compressed gas via a pipe to control the liquid level difference in the effluent tank 41. That is, by connecting the air weir 42 to the air inlet pipe and the air supply equipment via a pipe, a controllable liquid level difference can be formed by adjusting the air pressure in the air weir 42, achieving stable effluent discharge and effectively preventing sludge loss. Specifically, the air weir 42 can be controlled by switching on and off an electrically controlled valve / pneumatically controlled valve. For example, during the aeration stage, the electric / pneumatic air inlet valve is opened and the electric / pneumatic exhaust valve is closed to maintain the water level difference in the effluent tank 41 and prevent the mixed liquor from flowing into the effluent tank 41 and causing loss. At this time, the air inlet pressure of the air weir 42 can be controlled at 0.2 kPa to 2.0 kPa. Of course, the air inlet pressure of the air weir 42 can be adjusted appropriately according to the system scale and the quality of the influent. During the influent exchange stage, the electric / pneumatic air inlet valve can be closed and the electric / pneumatic exhaust valve can be opened to allow the supernatant to overflow into the effluent tank 41 and enter the next process unit.

[0096] The present invention can form a "sludge-film symbiosis" system in which attached biofilm granular sludge and suspended activated sludge coexist through the above technical solution. The system has high biomass, excellent settling properties and rich microbial community, which can quickly remove organic pollutants and achieve synergistic and efficient removal of carbon, nitrogen and phosphorus. At the same time, the system has significant advantages such as strong resistance to shock loads, low energy consumption and low production of residual sludge.

[0097] Accordingly, a second aspect of the present invention provides a wastewater treatment method based on the high-density bioreactor, comprising the following steps:

[0098] (1) Place the sludge in the reactor body 1 and introduce the wastewater into the inner cavity of the vertical shaft 11 through the adjustable water distributor 21;

[0099] (2) The wastewater enters the distributed vortex water distribution and aeration component 22 from the adjustable water distributor 21 for water distribution and aeration treatment, so that the wastewater is evenly distributed at the bottom of the reactor body 1; the wastewater reacts with sludge in the reactor body 1 for degradation treatment.

[0100] (3) The wastewater after degradation treatment is discharged through the effluent system 4, and the sludge is discharged through the first sludge discharge pipe 31, the second sludge discharge pipe 32 and the third sludge discharge pipe 33.

[0101] Preferably, the sludge concentration (MLSS) is 2.5 g / L to 10 g / L, the sludge loading is 0.1 kg COD / (kg sludge•d) to 0.45 kg COD / (kg sludge•d), and the sludge duration (SRT) is 15 days to 35 days. It should be noted that in the unit of sludge loading, kg sludge refers to the concentration (MLSS) per kg of sludge.

[0102] Preferably, the pH value of the wastewater is 6.5~8.5. If the pH value of the influent is too high or too low, it can be controlled to be between 6.5 and 8.5 by adding alkaline or acidic regulators before being introduced into the reactor body 1 for lowering treatment.

[0103] Optionally, the hydraulic retention time (HRT) of the wastewater in the high-density bioreactor body 1 is 6h to 24h. Of course, the hydraulic retention time can be adjusted appropriately according to the influent water quality, load, and treatment objectives. It is understood that during reactor operation, the hydraulic retention time and the influent / distribution water exchange ratio can be adjusted according to the reactor's state, thereby adjusting the granularity of the sludge.

[0104] The high-density bioreactor body 1 system and operation method provided by the present invention achieve the goal of stable cultivation of high-concentration sludge in wastewater treatment through the above-mentioned structural configuration and parameter settings.

[0105] The present invention will be further described below with reference to specific embodiments:

[0106] Example 1

[0107] This embodiment provides a wastewater treatment method, including the following steps:

[0108] (1) Place the sludge at the bottom of the HDBR reactor body, and then introduce municipal sewage into the inner cavity of the shaft through an adjustable distributor;

[0109] The sludge concentration was 3.8 g / L, and the sludge load was 0.15~0.3 kg COD / (kg sludge•d).

[0110] (2) Municipal sewage enters the distributed vortex water distribution and aeration component from the adjustable water distributor for water distribution and aeration treatment, so that the sewage is evenly distributed at the bottom of the reactor body and reacts with the sludge in the reactor body for degradation treatment.

[0111] During the influent / distribution stage (anoxic or anaerobic treatment), the ORP value in the reactor body is controlled to be -100mV and the DO value is less than 0.2mg / L; during the aeration stage (aerobic treatment), the ORP value in the reactor body is controlled to be 230mV and the DO value is 2mg / L~4mg / L.

[0112] (3) After the municipal sewage is degraded, it is discharged through the effluent system, and the first sludge discharge pipe, the second sludge discharge pipe and the third sludge discharge pipe are opened selectively on a regular basis to keep the overall sludge age of the system at 15d~35d.

[0113] The hydraulic retention time of synthetic wastewater in the reactor is 8h~13h, and the single cycle time is 4h, including a 30min sedimentation stage (including sludge discharge stage), a 60min influent / distribution stage (exchange ratio 30%~50%), and a 150min aeration stage. Sludge discharge is carried out in each cycle.

[0114] After municipal sewage is discharged, the water quality of the effluent treated by the above methods is measured. The particle size distribution and morphology of the sludge in the HDBR reactor, as well as the 16S rRNA gene sequencing data of the sludge microorganisms, are analyzed. The results are as follows: Figures 7-14 As shown.

[0115] Figures 7-10 It can be seen that the HDBR reactor exhibits highly efficient removal capabilities for organic matter and nitrogen and phosphorus during operation: the average COD removal rate is approximately 91.1%, and NH4+ removal rate is... + The average removal rate of nitrogen (N) was approximately 99.5%, the average removal rate of total nitrogen was approximately 53.8%, and the average removal rate of total phosphorus was approximately 75.9%. Comparison of influent and effluent and time series data showed that the variance of the effluent indicators was small during the transition from system startup to stable operation, indicating stable treatment performance and a certain degree of robustness to short-term load fluctuations.

[0116] Figure 11 The figure shows the particle size distribution of sludge in the high-density bioreactor. As can be seen from the figure, the proportion of particles >0.2mm increased rapidly from 9% in early May to 93% in early June. This occurred simultaneously with the high effluent removal rate, indicating that the system played a synergistic role in improving solid phase retention, enhancing biological retention, and shortening the mass transfer path.

[0117] In summary, the high-density bioreactor described in the table can cultivate a high proportion of granular sludge in a short period of time while maintaining excellent removal performance, making it suitable for stable treatment of high-load or fluctuating influent.

[0118] Figure 12 The diagram shows the morphology of the high-density granular sludge formed at the bottom of the reactor. It can be seen that a stable granular sludge system has been formed in the reactor, indicating that the reactor can effectively form dense granular sludge.

[0119] Figure 13 These are microscopic images of sludge morphology at different treatment stages. The two images on the left are microscopic images of sludge taken on March 19th, showing the sludge as relatively loose flocculent morphology. Figure 11On March 19th, the reactor contained mostly sludge smaller than 0.2mm, i.e., flocculent sludge. The two images on the right are microscopic examination images of the sludge from June 5th, showing the sludge as compact aggregates, i.e., granules. Figure 11 On June 6, the proportion of sludge >0.2mm in the reactor was about 80-90%, which means that a granular system had been formed at this time. Figure 13 The two sets of images show the change in sludge morphology from flocculent sludge to granular sludge.

[0120] Figure 14 This is a bar graph of the microbial community in sludge after municipal wastewater treatment. As shown, the community was relatively diverse in the early stages of operation, but functional community enrichment occurred as operation progressed. The proportions of Candidatus_Competibacter (a typical GAO, i.e., glycogen-accumulating bacteria) and several EPS / gel-forming bacteria (such as Zoogloea and Pseudomonas) increased significantly. These bacteria have a competitive advantage under anaerobic / aerobic or alternating anaerobic-oxygen conditions and controlled hydraulic shear selection pressure, promoting particle nucleus formation and densification. Simultaneously, GAO-type metabolism facilitates internal carbon cycling and particle stability under alternating conditions. The succession of relative microbial abundance coincides with the rapid increase in particle proportion in the same direction, indicating that the engineering hydraulics and operational strategies (pulsed water distribution, annular / coarse-pore synergistic aeration, and multi-layer sludge removal) effectively created a selective environment for the target functional bacteria, supporting the conclusion that granulation and treatment performance are improved simultaneously at the microscopic mechanism level.

[0121] The above results demonstrate that this reactor, through synergistic hydraulic field and aeration / sludge discharge control, can achieve rapid cultivation of a high proportion of granular sludge within several weeks and maintain high levels of COD and NH4. + -N removal; microbial communities enriched in GAO and EPS-producing communities, providing a biological basis for particle nucleation and stability.

[0122] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A high-density bioreactor for wastewater treatment, characterized in that, include: The reactor body has a vertical shaft inside, and sludge is placed at the bottom of the reactor body. The inner cavity of the vertical shaft is used to introduce sewage. The water distribution and aeration system includes an adjustable water distributor and a distributed vortex water distribution and aeration component. The adjustable water distributor is connected to the inner cavity of the vertical shaft so that sewage enters the inner cavity of the vertical shaft through the adjustable water distributor. The sewage is stored in the adjustable water distributor, and pulsed water distribution is achieved based on the siphon effect. The sludge removal system is used for the discharge and treatment of sludge. An effluent system, located at the top of the reactor body, is used to treat and discharge wastewater. The distributed vortex water distribution and aeration assembly includes a vortex water distributor, an annular aerator, and a coarse-pore aerator. The annular aerator is composed of several arc-shaped plate aerators, each including a tray, a diaphragm, and an air supply device. The diaphragm is disposed on the tray and has micropores distributed on it. The tray has channels for gas flow inside. The annular aerators are arranged around the vortex water distributor to form an annular aeration zone, which generates microbubbles with an average diameter of 1mm to 3mm. A coarse-pore aerator is provided between adjacent annular aerators, which generates large bubbles with an average diameter of 5mm to 6mm. The vortex water distributor, annular aerator, and coarse-pore aerator form a three-phase mixing channel of mud, air, and water within the service area of ​​the distributed vortex water distribution and aeration assembly, and form three fluid flows.

2. The high-density bioreactor for wastewater treatment as described in claim 1, characterized in that, A first fluid flow for mud-water mixing is formed within the service area of ​​the vortex water distributor; A second fluid flow for mixing mud, air, and water is formed above the annular aerator; A third fluid flow for mixing mud, air, and water is formed within the service area of ​​the coarse-pore aerator.

3. The high-density bioreactor for wastewater treatment as described in claim 2, characterized in that, The velocity of the first fluid flow is V1, the velocity of the second fluid flow is V2, and the velocity of the third fluid flow is V3, which satisfy the following relationship: V2 < V1 < V3; A fluid velocity gradient is established between the second fluid flow and the third fluid flow, V2 = (0.2~0.5)V3.

4. The high-density bioreactor for wastewater treatment as described in claim 3, characterized in that, The velocity of the first fluid flow is 0.2 m / s to 0.6 m / s; The velocity of the second fluid flow is 0.15 m / s to 0.30 m / s; The velocity of the third fluid flow is 0.3 m / s to 0.7 m / s.

5. The high-density bioreactor for wastewater treatment as described in claim 1, characterized in that, The air flow rate of the annular aerator is 3m³. 3 / h~12m 3 / h, the annular aerators are evenly arranged at the bottom of the reactor body; The vortex water distributor, annular aerator, and coarse-pore aerator control the dissolved oxygen concentration in the high-density bioreactor to be 2 mg / L to 6 mg / L.

6. The high-density bioreactor for wastewater treatment as described in claim 1, characterized in that, The inner cavity of the vertical shaft is connected to the distributed vortex water distribution and aeration assembly through a water distribution pipe, which includes a horizontally arranged main pipe and multiple branch pipes vertically connected to the main pipe. The main pipeline is provided with a branch pipeline at its end, and the branch pipeline is provided with the vortex water distributor at its end. The annular aerator is connected to the air supply equipment through an annular aeration pipe. The coarse-pore aerator is connected to the air supply device via a coarse-pore aeration pipe.

7. The high-density bioreactor for wastewater treatment as described in claim 1, characterized in that, The vortex water distributor includes a water distributor body and a reflector located on the lower side of the water distributor body. After the sewage enters from the water distributor body, it flows to the reflector. After the flow state is changed by the reflector, a vortex with a radius of 0.3m to 1.2m is formed.

8. The high-density bioreactor for wastewater treatment as described in claim 1, characterized in that, The membrane has a thickness of 1 mm to 2.5 mm, the micropores have a diameter of 0.6 mm to 1.2 mm, and the micropore density is 5 pores / cm². 2 ~15 pieces / cm 2 .

9. The high-density bioreactor for wastewater treatment as described in claim 1, characterized in that, The sludge discharge system includes a first sludge discharge pipe, a second sludge discharge pipe, and a third sludge discharge pipe that are controlled independently. The first sludge discharge pipe is located at the bottom of the reactor body, the second sludge discharge pipe is located in the middle of the reactor body, and the third sludge discharge pipe is located at the top of the reactor body, so as to classify and manage sludge of different ages in different sections. The first mud discharge pipe is located at 3 / 4 to 4 / 5 of the water depth; the second mud discharge pipe is located at 1 / 2 to 2 / 3 of the water depth; and the third mud discharge pipe is located at 1 / 4 to 1 / 3 of the water depth. The effluent system is located at the surface of the wastewater. The effluent system includes an effluent tank and an air weir on the effluent tank. The air weir is connected to compressed gas through a pipe to control the liquid level difference in the effluent tank. The air intake pressure of the air weir is 0.2 kPa to 2.0 kPa.

10. The high-density bioreactor for wastewater treatment as described in claim 1, characterized in that, The hydraulic retention time of the wastewater in the high-density bioreactor is 6h~24h; When the wastewater is subjected to anoxic or anaerobic treatment, the ORP value in the high-density bioreactor is controlled to be -300mV to 0mV, and the DO value is controlled to be 0mg / L to 0.5mg / L. When the wastewater is treated aerobically, the ORP value in the high-density bioreactor is controlled to be 100mV~300mV and the DO value is controlled to be 2mg / L~6mg / L.

11. A wastewater treatment method based on the high-density bioreactor according to any one of claims 1-10, characterized in that, Includes the following steps: (1) The sewage is introduced into the inner cavity of the vertical shaft through an adjustable water distributor; (2) The wastewater enters the distributed vortex water distribution and aeration component from the adjustable water distributor for water distribution and aeration treatment, so that the wastewater is evenly distributed at the bottom of the reactor body; the wastewater reacts with sludge in the reactor body for degradation treatment; (3) The wastewater after degradation treatment is discharged through the effluent system, and the sludge is discharged through the first sludge discharge pipe, the second sludge discharge pipe and the third sludge discharge pipe.

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