AAO-MBR integrated sewage treatment equipment

Abstract

The utility model relates to AAO-MBR (anaerobic-anoxic-oxic-membrane bioreactor) integrated sewage treatment equipment, which combines an advanced AAO process with an MBR technology and realizes efficient treatment and purification of sewage. The equipment realizes the functions of organic matter degradation, biological nitrogen removal, biological phosphorus removal and the like through treatment stages of the anaerobic zone, the anoxic zone, the aerobic zone and the like. Particularly, the oxygen elimination area arranged at the tail end of the aerobic area effectively eliminates oxygen in the mixed liquid, and damage to the environment of the anoxic area is avoided. The application of the MBR membrane component realizes the efficient separation of mud and water, and the effluent quality is stable and reaches the discharge standard. The built-in corollary equipment area adopts a double-layer design, the upper-layer equipment area is provided with a clean water tank and an air blower, and the lower-layer equipment area is provided with various pumps and dosing devices, so that the space is fully utilized, and the equipment size and the occupied area are reduced. In addition, pipelines and valves of the water pumps are reasonably designed, so that the water production pump and the backwashing water pump can be used together, and the engineering investment and the operation cost are further reduced. The integrated sewage treatment equipment has the characteristics of compact structure, high integration level, stable and reliable treatment effect and the like, and is suitable for sewage treatment projects with different scales and treatment requirements.

Description

Technical Field

[0001] The utility model belongs to the technical field of sewage treatment, and relates to an AAO-MBR integrated sewage treatment device, which belongs to an anaerobic anoxic aerobic membrane bioreactor. Background Art

[0002] When the scale of sewage treatment is large, a complete sewage treatment plant is generally built, and the main structure adopts a reinforced concrete structure; on the contrary, when the scale of sewage treatment is small, integrated sewage treatment equipment is often used. Integrated sewage treatment equipment is commonly used in township or rural sewage treatment projects. The characteristics of integrated sewage treatment equipment are modular equipment, system integration, short production period, small footprint, and low project investment.

[0003] At present, there are many types of integrated sewage treatment equipment commonly seen in the market, with uneven quality, and the sewage treatment processes used are also varied, with different actual treatment effects. The more common sewage treatment processes are mainly anaerobic anoxic aerobic (abbreviated as "AAO") process, moving bed biofilm reactor (abbreviated as "MBBR") process, and membrane bioreactor (abbreviated as "MBR") process. Among them, the AAO process is a traditional activated sludge process for biological nitrogen and phosphorus removal. It is a commonly used process in large and medium-sized sewage treatment plants. When used in integrated equipment, it has the advantages of simple structure and low cost, but it also has the disadvantages of easy loss of sludge and easy expansion of sludge, resulting in unstable treatment effect. The MBBR process adds suspended fillers to the conventional process. It is essentially a treatment process between the activated sludge process and the biofilm process. Therefore, it has the advantages of both the activated sludge process and the biofilm process, and has the advantages of good treatment effect, sludge is not easy to lose, and good impact resistance. Its disadvantages are high cost of suspended fillers and easy failure of fluidization of suspended fillers. The MBR process uses a microfiltration membrane to replace the secondary sedimentation tank in the conventional process. It has the significant advantage of good effluent quality and the disadvantages of high construction cost and high operating costs.

[0004] The AO process consists of an anoxic unit and an aerobic unit. The main function of the aerobic unit is to remove organic matter from sewage through aerobic biochemical reactions and convert ammonia nitrogen into nitrate nitrogen through nitrification reactions; the main function of the anoxic unit is to convert nitrate nitrogen returned from the aerobic pool into nitrogen gas through denitrification reactions, thereby achieving biological denitrification of sewage. The AAO process consists of anaerobic, anoxic and aerobic units, and the main function of the additional anaerobic unit is to achieve biological phosphorus removal. Sewage treatment systems with smaller treatment scales pay more attention to practicality, and often consider giving priority to the limited carbon source in sewage for biological denitrification, while phosphorus removal mainly adopts chemical phosphorus removal. Therefore, the biochemical system generally adopts the AO process. On the contrary, when the treatment scale reaches a certain scale, a more complete AAO process with both denitrification and phosphorus removal is generally adopted.

[0005] MBR essentially uses microfiltration membranes to replace traditional secondary sedimentation tanks to achieve mud-water separation. Microfiltration membrane filtration is a physical filtration, water can pass through the microfiltration membrane, and substances larger than the membrane pore size are retained. The significant advantages of MBR are: 1. The pore size of the microfiltration membrane is smaller than the bacteria in the sludge, so the bacteria and other microorganisms in the sludge are completely retained, and the effluent water quality is very good; 2. The activated sludge is efficiently intercepted, and the biochemical system can obtain a very high sludge concentration, and its treatment efficiency is significantly improved; 3. There will be no sludge loss, and there is no need to worry about sludge swelling. Utility Model Content

[0006] In view of this, the purpose of the utility model is to provide an AAO-MBR integrated sewage treatment equipment, which has the advantages of compact structure and high integration, stable and reliable treatment effect and obvious economic advantages.

[0007] In order to achieve the above object, the utility model provides the following technical solutions:

[0008] An AAO-MBR integrated sewage treatment equipment comprises an anaerobic zone, an anoxic zone and an aerobic zone which are connected in series in sequence; a return pump zone is also provided at the end of the anoxic zone, and an anoxic to anaerobic return pump is provided in the return pump zone to return the sewage in the anoxic zone to the anaerobic zone; an aerobic zone return pump is provided in the aerobic zone to return the enriched sludge at the end of the aerobic zone to the front end of the aerobic zone to promote the circulation of sludge in the aerobic zone;

[0009] The anaerobic zone is provided with an inlet pipe, and the clean water tank is provided with an outlet pipe. Sewage enters from the inlet pipe and is discharged from the outlet pipe after being treated in each reaction zone.

[0010] The anaerobic zone is provided with an anaerobic zone submersible mixer to promote the mixing reaction of sewage and sludge to achieve biological phosphorus removal;

[0011] The anoxic zone is provided with an anoxic zone submersible mixer to promote the mixing reaction of sewage and denitrifying bacteria to achieve the denitrification reaction of nitrate nitrogen;

[0012] The aerobic zone is provided with an aeration pipe and an aerator for aeration, and the organic matter in the sewage is degraded by aerobic microorganisms, ammonia nitrogen is converted into nitrate nitrogen, and biological phosphorus removal is achieved by the polyphosphate bacteria in the aerobic zone;

[0013] The end of the aerobic zone is provided with an oxygen elimination zone and a lower equipment zone, and the oxygen elimination zone is not provided with an aerator for releasing oxygen in the mixed liquid to avoid damaging the anoxic environment of the anoxic zone;

[0014] An upper equipment area and a clear water tank are arranged above the lower equipment area; a rotary blower is arranged in the upper equipment area, and the rotary blower is connected to the aerator to provide air for the aerator; a water production / backwash pump, a nitrification liquid reflux pump, a carbon source dosing device, a dephosphorization agent dosing device, and a disinfectant dosing device are arranged in the lower equipment area;

[0015] The nitrification liquid reflux pump connects the deoxidation zone and the anoxic zone, draws the mixed liquid without oxygen from the deoxidation zone, and refluxes it to the anoxic zone; the carbon source dosing device, the dephosphorization agent dosing device, and the disinfectant dosing device are used to add reaction agents;

[0016] The aerobic zone is also provided with an MBR membrane assembly, which is connected to a water production / backwash pump and a clean water tank. The MBR membrane assembly is used to separate mud and water under the suction of the water production / backwash pump, and the effluent is transported to the clean water tank.

[0017] Furthermore, the MBR membrane assembly is equipped with a bottom aeration pipe, which shares a rotary blower with the aerator in the aerobic tank to reduce membrane pollution through air stripping. At the same time, a backwashing system is set up to add sodium hypochlorite to the backwashing water through a disinfectant dosing device.

[0018] Furthermore, the water production / backwashing pump is connected to the backwashing system through pipelines and valves, and also serves as a backwashing water pump. The water production and backwashing working modes are switched by switching the valve.

[0019] Furthermore, the MBR membrane assembly is located at the end of the aerobic zone.

[0020] Furthermore, the MBR membrane components have one or more sets connected in parallel.

[0021] Furthermore, the AAO-MBR integrated sewage treatment equipment includes two or more boxes, which are connected in series as a whole.

[0022] Furthermore, both the anoxic to anaerobic return pump and the nitrification liquid return pump use dry sewage pumps to facilitate pump maintenance and overhaul.

[0023] Furthermore, both the anoxic zone and the aerobic zone are provided with mud discharge ports and mud discharge valves.

[0024] The beneficial effects of the utility model are:

[0025] (1) The integrated sewage treatment equipment of the utility model adopts a mature, stable and reliable sewage treatment process, has strong resistance to shock loads, and has a good treatment effect. The effluent water quality stably reaches the Class A standard or higher standard in the "Pollutant Discharge Standard for Urban Sewage Treatment Plants".

[0026] (2) The integrated sewage treatment equipment of the utility model has the advantages of compact structure and high integration through ingenious design, which fully demonstrates the advantages of integrated equipment, saves engineering cost and improves the convenience of operation and maintenance.

[0027] (3) The utility model innovatively designs a double-layer equipment area, and sets a water production / backwash pump, a reflux pump and a dosing device in the lower equipment area, sets a clear water tank and an upper equipment area in the upper layer, and installs a rotary blower in the upper equipment area. The double-layer design makes full use of the space of the equipment, reduces the size of the equipment, and reduces the floor space of the equipment.

[0028] (4) The utility model utilizes one water pump to serve as both a water production pump and a backwash water pump, and realizes function switching by rationally designing the pipeline and valve of the water pump, which not only saves engineering investment, but also saves space and reduces the size of the equipment.

[0029] (5) The utility model adds an oxygen removal zone, and the nitrification liquid reflux pump draws the mixed liquid from the oxygen removal zone. The function of the oxygen removal zone is to eliminate oxygen in the mixed liquid to prevent the mixed liquid that refluxes to the anoxic zone from containing a large amount of oxygen and destroying the anoxic environment of the anoxic zone.

[0030] (6) The utility model adds an aerobic zone return pump to return the enriched sludge at the end of the aerobic zone to the front end to promote the circulation of sludge in the aerobic zone and avoid excessive enrichment of sludge at the end of the aerobic zone.

[0031] (7) In order to adapt to a larger processing capacity, the utility model can use two or more boxes in series to form a processing system to facilitate equipment transportation and installation. When the total processing capacity is equal, compared with the parallel operation of multiple devices, the mode of using multiple boxes in series has significant advantages. The most obvious advantage is that the number of supporting equipment (internal water pumps, fans, automatic valves, etc.) is greatly reduced, resulting in a reduction in equipment size, lower project investment, and less equipment maintenance workload; secondly, when the sewage treatment capacity of a single set of equipment is increased, the sewage treatment effect is more stable.

[0032] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and will be apparent to those skilled in the art based on the following examination and research, or can be taught from the practice of the present invention to some extent. The objectives and other advantages of the present invention can be achieved and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be described in detail below in conjunction with the accompanying drawings, in which:

[0034] Figure 1 This is the plan view of the lower equipment area of ​​the AAO-MBR integrated sewage treatment equipment in the utility model;

[0035] Figure 2 This is the plan view of the upper equipment area of ​​the AAO-MBR integrated sewage treatment equipment in the utility model;

[0036] Figure 3 It is the aa cross-sectional view of the AAO-MBR integrated sewage treatment equipment in the utility model;

[0037] Figure 4 This is the bb cross-sectional view of the AAO-MBR integrated sewage treatment equipment in the utility model;

[0038] Figure 5 This is the cc cross-sectional view of the AAO-MBR integrated sewage treatment equipment in the utility model.

[0039] Figure markings: 1- anaerobic zone; 2- anoxic zone; 3- aerobic zone; 4- anoxic zone; 5- lower equipment area; 6- clear water tank; 7- upper equipment area; 8- reflux pump area; 11- water inlet pipe; 12- anaerobic zone submersible mixer; 21- anoxic zone submersible mixer; 31- aerator; 32- MBR membrane assembly; 41- aerobic zone reflux pump; 51- water production / backwash pump; 52- nitrification liquid reflux pump; 61- outlet pipe; 71- rotary blower; 81- anoxic to anaerobic reflux pump; 91- carbon source dosing device; 92- dephosphorization agent dosing device; 93- disinfectant dosing device. DETAILED DESCRIPTION

[0040] The following describes the implementation of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. The following embodiments and the features in the embodiments can be combined with each other without conflict.

[0041] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present utility model. In order to better illustrate the embodiments of the present utility model, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and descriptions in the drawings may be omitted.

[0042] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "back" and the like indicate directions or positional relationships, they are based on the directions or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0043] See also Figures 1 to 5 , is an AAO-MBR integrated sewage treatment equipment, comprising an anaerobic zone 1, an anoxic zone 2, and an aerobic zone 3 which are serially connected; a return pump zone 8 is also provided at the end of the anoxic zone 2, and an anoxic to anaerobic return pump 81 is provided in the return pump zone 8 to return the sewage from the anoxic zone 2 to the anaerobic zone 1; an aerobic zone return pump 41 is provided in the aerobic zone 3 to return the enriched sludge at the end of the aerobic zone 3 to the front end of the aerobic zone 3 to promote the circulation of the sludge in the aerobic zone 3;

[0044] The anaerobic zone 1 is provided with an inlet pipe 11, and the clean water tank 6 is provided with an outlet pipe 61. Sewage enters from the inlet pipe 11 and is discharged from the outlet pipe 61 after being treated in each reaction zone. An anaerobic zone submersible mixer 12 is provided in the anaerobic zone 1 to promote the mixing reaction of sewage and sludge to achieve biological phosphorus removal.

[0045] An anoxic zone 2 is provided with an anoxic zone submerged mixer 21 to promote the mixing reaction between sewage and denitrifying bacteria to achieve the denitrification reaction of nitrate nitrogen; an aerator 31 is provided in the aerobic zone 3 for aeration, and organic matter in the sewage is degraded by aerobic microorganisms to convert ammonia nitrogen into nitrate nitrogen, and biological phosphorus removal is achieved by the polyphosphate bacteria in the aerobic zone 3;

[0046] The end of the aerobic zone 3 is provided with an oxygen removal zone 4 and a lower equipment zone 5. The oxygen removal zone 4 is not provided with an aerator 31 for releasing oxygen in the mixed liquid to avoid damaging the anoxic environment of the anoxic zone 2. The upper equipment zone 7 and the clear water tank 6 are provided above the lower equipment zone 5. The upper equipment zone 7 is provided with a rotary blower 71, which is connected to the aerator 31 to provide air for the aerator 31. The lower equipment zone 5 is provided with a water production / backwashing pump 51, a nitrification liquid reflux pump 52, a carbon source dosing device 91, a dephosphorization agent dosing device 92, and a disinfectant dosing device 93. The nitrification liquid reflux pump 52 connects the oxygen removal zone 4 with the anoxic zone 2, draws the mixed liquid without oxygen from the oxygen removal zone 4, and refluxes it to the anoxic zone 2. The carbon source dosing device 91, the dephosphorization agent dosing device 92, and the disinfectant dosing device 93 are used to add reaction agents.

[0047] The aerobic zone 3 is also provided with an MBR membrane assembly 32 , which is connected to the water production / backwash pump 51 and the clean water tank 6 , and mud and water are separated under the suction action of the water production / backwash pump 51 , and the effluent is transported to the clean water tank 6 .

[0048] Among them, the MBR membrane assembly 32 is equipped with a bottom aeration pipeline, and the bottom aeration pipeline and the aerator 31 in the aerobic tank share a rotary blower 71, and the membrane pollution is reduced by air stripping. At the same time, a backwashing system is set up, and sodium hypochlorite is added to the backwashing water through a disinfectant dosing device 93. The water production / backwashing pump 51 is connected to the backwashing system through a pipeline and a valve, and also serves as a backwashing water pump. The water production and backwashing working modes are switched by switching valves.

[0049] Among them, the anoxic to anaerobic return pump 81 and the nitrification liquid return pump 52 are both dry sewage pumps.

[0050] With a processing capacity of 500m 3 / d's AAO-MBR integrated sewage treatment equipment is used as an example to treat domestic sewage. The effluent after treatment meets the Level A standard in the "Pollutant Emission Standard for Urban Sewage Treatment Plants".

[0051] This set of equipment consists of 2 boxes, which are operated in series. The sewage first enters the first box, and after being treated in the first box, it enters the second box for further treatment. Finally, the effluent meets the standards before being discharged.

[0052] The equipment comprises an anaerobic zone 1 with a hydraulic retention time of 1.5 hours. An anaerobic zone submersible mixer 12 is installed in the anaerobic zone 1. Sewage enters from the upper part of the anaerobic zone 1 and flows out from the lower part of the anaerobic zone 1 by gravity into the anoxic zone 2.

[0053] The equipment comprises an anoxic zone 2 with a hydraulic retention time of 4 hours. A submersible mixer is installed in the anoxic zone 2. Sewage enters from the bottom of the anoxic zone 2 and flows out from the top of the anoxic zone 2 by gravity into the aerobic zone 3.

[0054] An independent reflux pump area 8 is provided at the end of the anoxic zone 2 for installing an anoxic to anaerobic reflux pump 81 to return the effluent of the anoxic zone 2 to the anaerobic zone 1, with a reflux ratio of 100% to 200%.

[0055] The equipment includes two aerobic zones 3, of which the first aerobic zone 3 is smaller and located in the first box, and the second aerobic zone 3 is larger and located in the second box. The hydraulic retention time of the aerobic zone 3 is 6.5h. A disc-type rubber membrane microporous aerator 31 is set at the bottom of the aerobic zone 3, and a rotary blower 71 provides air for the aerator 31. Two sets of MBR membrane components 32 are set at the end of the aerobic zone 3, using a hollow fiber membrane made of PVDF, and the designed membrane flux is 15L / (h·m2 ). The MBR membrane assembly 32 is connected to the aeration pipeline and the water production pipeline through a hose and a quick connector.

[0056] An anoxic zone 4 is provided at the end of the aerobic zone 3 . The anoxic zone 4 is not provided with a bottom aerator 31 . After the suspended mixed liquid in the aerobic zone 3 enters the anoxic zone 4 , the oxygen in the sewage is released, and the suspended mixed liquid without oxygen enters the nitrification liquid reflux pump 52 and flows back to the anoxic zone 2 .

[0057] Both the anoxic zone 2 and the aerobic zone 3 are provided with mud discharge ports and mud discharge valves.

[0058] The clear water tank 6 is located at the upper part of the equipment area, and the effective volume of the clear water tank 6 meets the hydraulic retention time of 30 minutes. Finished sodium hypochlorite is added as a disinfectant. After disinfection by sodium hypochlorite, the effluent meets the discharge standard and is discharged from the integrated treatment equipment.

[0059] The lower equipment area 5 is equipped with a sodium acetate dosing barrel, which is used to add sodium acetate as a supplementary carbon source for denitrification in the anoxic area 2. It is equipped with a polyaluminium chloride dosing barrel, which is used to add polyaluminium chloride to the aerobic area 3 to achieve chemical phosphorus removal. It is equipped with a sodium hypochlorite dosing barrel, which is used to add sodium hypochlorite to the water production pipeline for effluent disinfection and backwash disinfection.

[0060] The lower equipment area 5 is equipped with a nitrification liquid reflux pump 52 to reflux the mixed liquid from the aerobic area 3 to the anoxic area 2 to achieve biological denitrification, and the reflux ratio is 250% to 350%.

[0061] The utility model adopts a treatment process with AAO+MBR as the main body, and the specific process flow is "anaerobic→anoxic→aerobic→MBR membrane filtration→disinfection".

[0062] The utility model adopts a relatively complete biochemical treatment process and is suitable for sewage projects with large treatment capacity. If one equipment box is used, it is inconvenient to transport and install the equipment due to its large size. Therefore, two or more boxes can be connected in series.

[0063] The sewage first enters the anaerobic zone 1. The main function of the anaerobic zone 1 is biological phosphorus removal. There is neither molecular oxygen nor combined oxygen in the anaerobic zone 1. The sludge in the anaerobic zone 1 comes from the return flow at the end of the anoxic zone 2. Biological phosphorus removal mainly relies on the biological characteristics of polyphosphate bacteria. These bacteria can absorb and release phosphorus under anaerobic and aerobic conditions. Under anaerobic conditions, polyphosphate bacteria produce energy by decomposing polyphosphates in the body and release phosphates at the same time. Polyphosphate bacteria use simple soluble organic matrices in sewage to provide the energy required for their own growth. An anaerobic zone submersible mixer 12 is configured at the bottom of the anaerobic zone 1. Under the stirring and mixing action of the submersible mixer, the sewage fully contacts and reacts with the suspended sludge, effectively promoting biochemical reactions and avoiding the formation of dead zones in the anaerobic zone 1.

[0064] The effluent from the anaerobic zone 1 enters the anoxic zone 2. The environment in the anoxic zone 2 is anoxic and there is no molecular oxygen. Denitrifying bacteria are suspended in the sewage. The organic matter in the influent is used to reflux the nitrification liquid from the aerobic zone 3, so that the nitrate nitrogen therein undergoes a denitrification reaction in the anoxic tank and is converted into nitrogen gas, thereby being removed. An anoxic zone submersible mixer 21 is arranged at the bottom of the anoxic zone 2. Under the stirring and mixing action of the submersible mixer, the sewage fully contacts and reacts with the suspended denitrifying bacteria, effectively promoting the denitrification reaction and avoiding the formation of a dead zone in the anoxic zone 2.

[0065] The effluent from the anoxic zone 2 enters the aerobic zone 3. In the aerobic zone 3, air is provided to the aerator 31 at the bottom of the aerobic zone 3 by the rotary blower 71, so as to oxygenate the sewage in the aerobic zone 3 and form an aerobic state. Aerobic microorganisms are suspended in the sewage. In the aerobic zone 3, on the one hand, the organic matter in the sewage is converted into carbon dioxide and water through the metabolism of aerobic microorganisms, and on the other hand, the ammonia nitrogen in the sewage is converted into nitrate nitrogen under the action of nitrifying bacteria. After entering the aerobic environment, the activity of polyphosphate bacteria is restored, and it can absorb phosphorus from the water in excess of its physiological needs and convert it into polyphosphate in the cell body, and the residual sludge with high phosphorus content is removed through the subsequent sludge discharge process to achieve the purpose of biological phosphorus removal.

[0066] After the suspended mixed liquid in the aerobic zone 3 enters the deoxidation zone 4, the oxygen in the sewage is released, and the suspended mixed liquid without oxygen enters the nitrification liquid reflux pump 52 and refluxes to the anoxic zone 2. In order to prevent the sludge from being excessively enriched at the end of the aerobic zone 3, an aerobic zone reflux pump 41 is installed in the deoxidation zone 4 at the end of the aerobic zone 3 to reflux the enriched sludge at the end to the front end, so as to promote the circulation of the sludge in the aerobic zone 3.

[0067] The MBR membrane assembly 32 at the end of the aerobic zone 3 is pumped by the water production / backwash pump 51 in the lower equipment area 5, so that water passes through the MBR membrane assembly 32 and is transported to the clean water tank 6, and the sludge is completely intercepted by the membrane in the aerobic zone 3. The MBR membrane assembly 32 is equipped with a bottom aeration pipeline, and shares a blower with the aerobic tank aerator 31, and the membrane pollution is reduced by the air stripping effect. In order to more effectively reduce membrane pollution, a backwash system for the MBR membrane is also set up. Through reasonable design, the water production / backwash pump 51 is cleverly used as both a water production pump and a backwash pump.

[0068] The water production / backwash pump 51 is connected to the MBR membrane assembly 32 and the clean water tank 6 through pipelines, and bypass pipelines are set up. Electric valves are set up on the pipelines, and different working modes of the water pump are realized by switching the electric valves. When filtering and producing water, the water production inlet valve and the water outlet valve are opened, so that the water pump can absorb water from the MBR membrane assembly 32 and transport it to the clean water tank 6; when backwashing, the backwashing inlet valve and the water outlet valve are opened, so that the water pump can absorb water from the clean water tank 6 and transport it to the MBR membrane assembly 32, and the microfiltration membrane is backwashed. For backwashing, an appropriate amount of sodium hypochlorite is added to the backwashing water through the disinfectant dosing device 93.

[0069] Since most of the bacteria have been intercepted, the clean water entering the clean water tank 6 only needs to be added with a small amount of sodium hypochlorite to meet the disinfection requirements and reach the discharge standards.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the utility model.

Claims

1. An AAO-MBR integrated sewage treatment equipment, characterized in that: It includes an anaerobic zone, an anoxic zone, and an aerobic zone connected in series in sequence; a return pump zone is also provided at the end of the anoxic zone, and an anoxic to anaerobic return pump is provided in the return pump zone to return the sewage in the anoxic zone to the anaerobic zone; an aerobic zone return pump is provided in the aerobic zone to return the enriched sludge at the end of the aerobic zone to the front end of the aerobic zone to promote the circulation of sludge in the aerobic zone; The anaerobic zone is provided with an inlet pipe, and the clean water tank is provided with an outlet pipe. Sewage enters from the inlet pipe and is discharged from the outlet pipe after being treated in each reaction zone. The anaerobic zone is provided with an anaerobic zone submersible mixer to promote the mixing reaction of sewage and sludge to achieve biological phosphorus removal; The anoxic zone is provided with an anoxic zone submersible mixer to promote the mixing reaction of sewage and denitrifying bacteria to achieve the denitrification reaction of nitrate nitrogen; The aerobic zone is provided with an aeration pipe and an aerator for aeration, and the organic matter in the sewage is degraded by aerobic microorganisms, ammonia nitrogen is converted into nitrate nitrogen, and biological phosphorus removal is achieved by the polyphosphate bacteria in the aerobic zone; The end of the aerobic zone is provided with an oxygen elimination zone and a lower equipment zone, and the oxygen elimination zone is not provided with an aerator for releasing oxygen in the mixed liquid to avoid damaging the anoxic environment of the anoxic zone; An upper equipment area and a clear water tank are arranged above the lower equipment area; a rotary blower is arranged in the upper equipment area, and the rotary blower is connected to the aerator to provide air for the aerator; a water production / backwash pump, a nitrification liquid reflux pump, a carbon source dosing device, a dephosphorization agent dosing device, and a disinfectant dosing device are arranged in the lower equipment area; The nitrification liquid reflux pump connects the deoxidation zone and the anoxic zone, draws the mixed liquid without oxygen from the deoxidation zone, and refluxes it to the anoxic zone; the carbon source dosing device, the dephosphorization agent dosing device, and the disinfectant dosing device are used to add reaction agents; The aerobic zone is also provided with an MBR membrane assembly, which is connected to a water production / backwash pump and a clean water tank. The MBR membrane assembly is used to separate mud and water under the suction of the water production / backwash pump, and the effluent is transported to the clean water tank.

2. The AAO-MBR integrated sewage treatment equipment according to claim 1 is characterized in that: The MBR membrane assembly is equipped with a bottom aeration pipe, which shares a rotary blower with the aerator in the aerobic tank to reduce membrane pollution through air stripping. A backwashing system is also provided to add sodium hypochlorite to the backwashing water through a disinfectant dosing device.

3. The AAO-MBR integrated sewage treatment equipment according to claim 2 is characterized in that: The water production / backwashing pump is connected to the backwashing system through pipelines and valves, and also serves as a backwashing water pump. The water production and backwashing working modes are switched by switching the valve.

4. The AAO-MBR integrated sewage treatment equipment according to claim 1 is characterized in that: The MBR membrane module is located at the end of the aerobic zone.

5. The AAO-MBR integrated sewage treatment equipment according to claim 4 is characterized in that: The MBR membrane components have one or more sets connected in parallel.

6. The AAO-MBR integrated sewage treatment equipment according to claim 1 is characterized in that: The AAO-MBR integrated sewage treatment equipment includes two or more boxes, which are connected in series.

7. The AAO-MBR integrated sewage treatment equipment according to claim 1 is characterized in that: Both the anoxic to anaerobic return pump and the nitrification liquid return pump use dry sewage pumps.

8. The AAO-MBR integrated sewage treatment equipment according to claim 1 is characterized in that: Both the anoxic zone and the aerobic zone are equipped with mud discharge ports and mud discharge valves.

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