Sewage treatment system

Abstract

According to the sewage treatment system, sewage firstly passes through the preliminary filtering assembly to remove large solid particles and then enters the advection deposition assembly, and particles with large specific gravity are removed through physical sedimentation. The sewage subjected to preliminary sedimentation enters a biological treatment tank, and is treated by the biological treatment tank to decompose organic matters and remove nitrogen and phosphorus. Then, the sewage enters a membrane bioreactor, suspended solids and microorganisms are removed through a membrane separation technology, and residual fine particles are further removed through a high-density sedimentation tank; then, the sewage flows into a denitrification filter tank to be subjected to deep denitrification treatment; and finally, the sewage is disinfected by ultraviolet, so that the sewage can be reused after the water quality is safe and reaches the standard. The sewage treatment system can effectively remove organic matters, nitrogen and phosphorus in sewage and avoid the eutrophication problem of a water body. And suspended solids and microorganisms in the sewage are thoroughly filtered through MBR membrane separation and the high-density sedimentation tank, so that the high stability of the effluent quality is ensured.

Description

Technical Field

[0001] This application relates to the field of sewage treatment, and particularly to a sewage treatment system. Background Art

[0002] With the process of urbanization, the sewage in cities is increasing day by day. Currently, for sewage treatment, it is mainly to remove the organic matter and suspended solids in domestic sewage to achieve the effect of sewage treatment.

[0003] In the process of existing sewage treatment methods, the removal effect of inorganic nutrients such as nitrogen and phosphorus is very poor. The removal rate of nitrogen is only 20%-30%, and the removal rate of phosphorus is only 10%-20%. With the discharge of high-concentration nitrogen and phosphorus industrial wastewater such as chemical fertilizers, pesticides, and detergents, the concentration of nitrogen and phosphorus in domestic sewage has increased sharply, resulting in a decrease in dissolved oxygen in the water body and water eutrophication, as well as the reuse of treated sewage.

[0004] Existing A 2 / O process can effectively inhibit filamentous bacteria, use anaerobic, anoxic, and aerobic biological environment pools for treatment, and use the method of sludge discharge for phosphorus removal. Due to the traditional A 2 / O process relies on the gravity sedimentation method of the secondary sedimentation tank, resulting in limited solid-liquid separation efficiency, being easily affected by problems such as sludge bulking, leading to large fluctuations in the effluent water quality and affecting subsequent reuse. Summary of the Utility Model

[0005] In view of this, it is necessary to provide a sewage treatment system to solve the above problems.

[0006] An embodiment of this application provides a sewage treatment system, including:

[0007] A preliminary filtration component, one end of which is connected to the inlet channel;

[0008] A horizontal flow sedimentation component, one end of which is connected to the other end of the preliminary filtration component;

[0009] A biological treatment pool, the input pipe of the biological treatment pool is connected to the side of the horizontal flow sedimentation component away from the preliminary filtration component;

[0010] A membrane bioreactor, one end of which is connected to the output pipe of the biological treatment pool, and the other end is connected to the input pipe of the biological treatment pool;

[0011] A high-density sedimentation tank, the output pipe of the membrane bioreactor is connected to the input pipe of the high-density sedimentation tank;

[0012] A denitrification filtration pool, which is connected to the output pipe of the high-density sedimentation tank;

[0013] The ultraviolet disinfection tank is connected to the output pipe of the denitrification filter tank at one end and to the water outlet channel at the other end.

[0014] In at least one embodiment of the present application, the preliminary filtration assembly includes:

[0015] A coarse grid filter element located in the input pipe of the water inlet channel;

[0016] A lift pump, one end of which is connected to the coarse grid filter element;

[0017] A fine grid filter element is connected to the output pipe of the lift pump away from the coarse grid filter element.

[0018] In at least one embodiment of the present application, the angle between the coarse grid filter element and the water inlet channel is α, satisfying the relationship: 60° ≤ α ≤ 90°;

[0019] The angle between the fine grid filter element and the water inlet channel is β, satisfying the relationship: β = 35°.

[0020] In at least one embodiment of the present application, the preliminary filtration assembly further includes:

[0021] A collecting tank, and the lift pump is located in the collecting tank.

[0022] In at least one embodiment of the present application, the horizontal flow sedimentation assembly includes:

[0023] A horizontal flow grit chamber having two grit chambers and a grit hopper located between the two grit chambers. The inclination angle between the hopper wall of the grit hopper and the horizontal plane is denoted as γ, satisfying the relationship: γ = 60°;

[0024] The inclination angle between the bottom of the grit chamber and the horizontal plane is denoted as i, satisfying the relationship: i = 6°, and the bottom of the grit chamber is inclined towards the hopper wall of the grit hopper;

[0025] A sand discharge pump is provided at the bottom of the grit chamber, and one end of the sand discharge pump is connected to the outside.

[0026] In at least one embodiment of the present application, the horizontal flow sedimentation assembly further includes:

[0027] A horizontal flow primary sedimentation tank having a sludge sedimentation area and a sludge sedimentation hopper. The sludge sedimentation area is connected to the sludge sedimentation hopper. The angle between the sludge sedimentation hopper and the horizontal plane is θ, satisfying the relationship: θ = 60°. The bottom slope of the sludge sedimentation area is b, satisfying the relationship: b = 0.01;

[0028] The horizontal flow primary sedimentation tank is connected to the biological treatment tank.

[0029] In at least one embodiment of the present application, the biological treatment tank includes:

[0030] An anaerobic tank, one end of which is connected to the advective sedimentation assembly;

[0031] A first anoxic tank, one end of which is connected to the anaerobic tank;

[0032] A second anoxic tank, which is connected to the first anoxic tank;

[0033] An aerobic tank, which is connected to the second anoxic tank, and the first anoxic tank and the second anoxic tank are located between the anaerobic tank and the aerobic tank;

[0034] The aerobic tank is connected to the membrane bioreactor.

[0035] In at least one embodiment of the present application, the sewage treatment system further includes:

[0036] A membrane bioreaction tank, and the membrane bioreactor is arranged in the membrane bioreaction tank.

[0037] In at least one embodiment of the present application, the sewage treatment system further includes:

[0038] A sludge storage tank, and one end of the output pipe of the membrane bioreaction tank is connected to the sludge storage tank and the anaerobic tank.

[0039] In at least one embodiment of the present application, the sewage treatment system further includes:

[0040] A sludge thickening and dewatering room, which is connected to the output pipe of the sludge storage tank.

[0041] Implementing the sewage treatment system of this embodiment will at least have the following beneficial effects:

[0042] For the sewage treatment system provided above, the sewage first passes through the preliminary filtration assembly to remove larger solid particles, and then enters the advective sedimentation assembly to remove particles with a larger specific gravity through physical sedimentation. The sewage after preliminary sedimentation enters the biological treatment tank, and after being treated in the biological treatment tank, the decomposition of organic matter and the removal of nitrogen and phosphorus are carried out. Then, the sewage enters the membrane bioreactor, and the suspended matter and microorganisms are removed through membrane separation technology, and the remaining fine particles are further removed through the high-density sedimentation tank. Then, the sewage flows into the denitrification filtration tank for in-depth denitrification treatment. Finally, the sewage is disinfected by ultraviolet light to ensure that the water quality meets the safety standards and can be reused.

[0043] The sewage treatment system can effectively remove organic matter, nitrogen, and phosphorus in the sewage, and avoid the problem of water eutrophication.

[0044] Through MBR membrane separation and high-density sedimentation tank, the suspended matter and microorganisms in the sewage are thoroughly filtered, ensuring the high stability of the effluent water quality.

[0045] The ultraviolet disinfection technology avoids the secondary pollution problem caused by chemical disinfection and ensures that the water quality is environmentally friendly and harmless. Description of the Drawings

[0046] Figure 1 It is a structural block diagram of a sewage treatment system in an embodiment;

[0047] Figure 2 It is a structural block diagram of a sewage treatment system in another embodiment;

[0048] Figure 3 It is a three-dimensional view of a membrane bioreactor;

[0049] Figure 4 It is Figure 3 Another three-dimensional view of the membrane bioreactor in

[0050] Figure 5 It is a state diagram of the coarse grid filter in the inlet channel;

[0051] Figure 6 It is Figure 5 Another state diagram of the coarse grid filter in the inlet channel in

[0052] Figure 7 It is a state diagram of the fine grid filter in the inlet channel;

[0053] Figure 8 It is Figure 7 Another state diagram of the fine grid filter in the inlet channel in

[0054] Figure 9 It is a structural diagram of a horizontal flow grit chamber;

[0055] Figure 10 It is a structural diagram of a horizontal flow primary sedimentation tank;

[0056] Figure 11 It is a cross-sectional view of a biological treatment tank.

[0057] Description of the Main Component Symbols

[0058] 100, Sewage treatment system;

[0059] 110, Preliminary filtration assembly; 111, Coarse grid filter; 112, Fine grid filter; 113, Inlet channel; 114, Outlet channel;

[0060] 120, Horizontal flow sedimentation assembly; 121, Horizontal flow grit chamber; 121a, Grit chamber; 121b, Grit hopper; 122, Horizontal flow primary sedimentation tank; 122a, Sludge sedimentation area; 122b, Sludge sedimentation hopper;

[0061] 130. Biological treatment tank; 131. Anaerobic tank; 132. First anoxic tank; 133. Second anoxic tank; 134. Aerobic tank;

[0062] 140. Membrane bioreactor tank; 141. Membrane bioreactor;

[0063] 150. High-density sedimentation tank;

[0064] 160. Denitrification filter tank;

[0065] 170. UV disinfection tank;

[0066] 180. Sludge storage tank;

[0067] 190. Sludge thickening and dewatering room;

[0068] 200. Lift pump. Detailed implementation manners

[0069] Next, the embodiments of the present application will be described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments.

[0070] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component at the same time. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component at the same time. The terms "top", "bottom", "upper", "lower", "left", "right", "front", "rear", and similar expressions used herein are only for the purpose of illustration.

[0071] Next, some embodiments of the present application will be described in detail with reference to the accompanying drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0072] An embodiment of the present application provides a sewage treatment system 100, including:

[0073] A preliminary filtration component 110, one end of which is connected to the water inlet channel 113;

[0074] A horizontal flow sedimentation component 120, one end of which is connected to the other end of the preliminary filtration component 110;

[0075] A biological treatment tank 130, the input pipe of the biological treatment tank 130 is connected to the side of the horizontal flow sedimentation component 120 away from the preliminary filtration component 110;

[0076] A membrane bioreactor 141, one end of which is connected to the output pipe of the biological treatment tank 130, and the other end is connected to the input pipe of the biological treatment tank 130;

[0077] A high-density sedimentation tank 150, and an output pipe of the membrane bioreactor 141 is communicated with an input pipe of the high-density sedimentation tank 150;

[0078] A denitrification filter tank 160, which is communicated with an output pipe of the high-density sedimentation tank 150;

[0079] An ultraviolet disinfection tank 170, one end of which is communicated with an output pipe of the denitrification filter tank 160, and the other end of which is communicated with an effluent channel 114.

[0080] Please refer to Figure 1 - Figure 2 , in this embodiment, the sewage first passes through a preliminary filtration assembly 110 to remove larger solid particles, and then enters a horizontal flow sedimentation assembly 120 to remove particles with a larger specific gravity through physical sedimentation. The sewage after preliminary sedimentation enters a biological treatment tank 130, and after being treated in the biological treatment tank 130, the decomposition of organic matter and the removal of nitrogen and phosphorus are carried out. Then, the sewage enters the membrane bioreactor, and suspended solids and microorganisms are removed through membrane separation technology, and residual fine particles are further removed through the high-density sedimentation tank 150. Then, the sewage flows into the denitrification filter tank 160 for advanced denitrification treatment. Finally, the sewage is disinfected by ultraviolet rays to ensure that the water quality meets the safety standards and can be reused.

[0081] The sewage treatment system 100 can effectively remove organic matter, nitrogen and phosphorus in the sewage and avoid the problem of water eutrophication.

[0082] Through the MBR membrane separation and the high-density sedimentation tank 150, suspended solids and microorganisms in the sewage are completely filtered, ensuring highly stable effluent water quality.

[0083] The ultraviolet disinfection technology avoids the problem of secondary pollution caused by chemical disinfection and ensures that the water quality is environmentally friendly and harmless.

[0084] In at least one embodiment of the present application, the preliminary filtration assembly 110 includes:

[0085] A coarse grid filter element 111, which is located in an input pipe of the influent channel 113;

[0086] A lift pump 200, one end of which is communicated with the coarse grid filter element 111;

[0087] A fine grid filter element 112, which is communicated with an output pipe of the lift pump 200 far away from the coarse grid filter element 111.

[0088] Please refer to Figure 1 - Figure 11, in this embodiment, the preliminary filtration process of sewage treatment starts from the coarse grid filter element 111. The sewage first enters the coarse grid filter element 111 to intercept larger particulate matters, and then enters the lift pump to be lifted to a higher treatment position. Next, the sewage enters the fine grid filter element 112 to further remove smaller suspended matters and solid impurities. The sewage after preliminary filtration is transported to the next-level treatment units, such as grit chambers, biological reaction tanks, etc.

[0089] Through the two-stage filtration of the coarse grid filter element 111 and the fine grid filter element 112, the solid impurities in the sewage are gradually removed, making the sewage entering the subsequent treatment units cleaner and reducing the impact of suspended matters on biological treatment.

[0090] By removing larger solid particles, the preliminary filtration assembly 110 effectively avoids the blockage or damage of subsequent equipment (such as water pumps, membrane modules, etc.), and improves the service life of the equipment and the stability of the system.

[0091] Adjust the filtration gaps of the coarse grid filter element 111 and the fine grid filter element 112 according to the water quality conditions of different sewage, and flexibly respond to the sewage treatment requirements of different scales and natures.

[0092] In at least one embodiment of the present application, the angle between the coarse grid filter element 111 and the water inlet channel 113 is α, satisfying the relational expression: 60° ≤ α ≤ 90°;

[0093] The angle between the fine grid filter element 112 and the water inlet channel 113 is β, satisfying the relational expression: β = 35°.

[0094] Please refer to Figure 1 - Figure 11 , in this embodiment, the sewage first passes through the coarse grid filter element 111. At an inclined angle of 60° to 90°, the large particulate matters are intercepted under the action of gravity and slide down along with the trend, while the sewage enters the lift pump (not marked in the figure) through the grid. Next, the sewage is transported to the fine grid filter element 112 by the lift pump. At this time, since the angle between the fine grid filter element 112 and the water inlet channel 113 is 35°, the flow rate of the sewage slows down, and the smaller suspended matters are intercepted by the fine grid. Finally, the sewage treated by the fine grid will enter the subsequent treatment units (such as sedimentation tanks, biological reaction tanks, etc.).

[0095] By setting different filtration angles, the large particulate matters and small suspended matters in the sewage are effectively intercepted respectively, ensuring that the sewage has been preliminarily purified when entering the downstream treatment unit after two-stage filtration, and reducing the subsequent treatment burden.

[0096] It should be noted that α = 60°, and the angle of the coarse grid filter element 111 is 60° to 90°, which makes the particulate matter easier to slide off, reduces the frequency of manual cleaning, and improves the self-cleaning ability of the equipment. The 35° angle of the coarse grid filter element ensures the interception effect of fine particulate matter and at the same time avoids frequent blockage of the grid.

[0097] The 35° angle of the coarse grid filter element 111 can effectively reduce the water flow velocity, giving small particulate matter enough time to contact the grid surface and be intercepted, reducing the impact of the water flow on the suspended matter, and improving the solid-liquid separation efficiency.

[0098] It should be further noted that the inlet channel 113 has a first gradual change area, a second gradual change area, and a constant flow area located between the first gradual change area and the second gradual change area. The first gradual change area gradually widens towards the constant flow area, and the inclination angle of the inclined side is 20°.

[0099] There are two groups of coarse grid filter elements 111, and the net clearance width of the grid bars of the coarse grid filter element 111 is 16 mm to 25 mm. The width of the grid slot of the coarse grid filter element 111 is 0.01 m.

[0100] The lift pump is composed of 4 submersible sewage pumps, and the 4 submersible sewage pumps are located in the sump.

[0101] There are two groups of fine grid filter elements 112, the grid inclination angle is 35°, the net clearance width of the grid bars is 1.5 mm to 20 mm, and the width of each grid bar is 0.01 m.

[0102] The fine grid filter element 112 is arranged in the outlet channel 114. The outlet channel 114 has a third gradual change area, a fourth gradual change area, and a communication area. The fine grid filter element 112 is located in the communication area, and the gradual change angle of the third gradual change area relative to the communication area is 20°.

[0103] The outlet channel 114 is connected to the horizontal flow grit chamber 121.

[0104] It should be further noted that both the coarse grid filter element 111 and the fine grid filter element 112 are inclined grid structures with filter grooves.

[0105] In at least one embodiment of the present application, the preliminary filtration assembly 110 further includes:

[0106] A sump, and the lift pump is located in the sump.

[0107] Please refer to Figure 1 - Figure 11, in this embodiment, the sewage first enters the coarse grid filter 111 of the preliminary filtration assembly 110 from the inlet channel 113 to remove larger particulate matters. The sewage filtered by the coarse grid filter 111 flows into the sump. The sump plays a role in flow regulation and temporary storage. When the water level reaches a certain height, the lift pump extracts the sewage from the sump and transports it to the fine grid filter 112. The fine grid filter 112 further filters the sewage to remove fine suspended solids or particulate matters. Through this process, the sewage completes the preliminary filtration and provides cleaner raw water for the subsequent treatment process.

[0108] The setting of the sump (not marked in the figure) effectively balances the sewage flow, alleviates the impact of flow fluctuations on the system, and ensures that the lift pump and the fine grid filter 112 can work under stable conditions.

[0109] It should be noted that the sump is a sunken groove.

[0110] In at least one embodiment of the present application, the horizontal sedimentation assembly 120 includes:

[0111] A horizontal grit chamber 121, having two grit chambers 121a and a grit hopper 121b located between the two grit chambers 121a. The inclination angle between the wall of the grit hopper 121b and the horizontal plane is denoted as γ, satisfying the relation: γ = 60°;

[0112] The inclination angle between the bottom of the grit chamber 121a and the horizontal plane is denoted as i, satisfying the relation: i = 6°, and the bottom of the grit chamber 121a is inclined towards the wall of the grit hopper 121b;

[0113] A sand discharge pump is provided at the bottom of the grit chamber 121a, and one end of the sand discharge pump is communicated to the outside.

[0114] In at least one embodiment of the present application, the horizontal sedimentation assembly 120 further includes:

[0115] A horizontal primary sedimentation tank 122, having a sludge sedimentation area 122a and a sludge sedimentation hopper 122b. The sludge sedimentation area 122a is communicated with the sludge sedimentation hopper 122b. The angle between the sludge sedimentation hopper 122b and the horizontal plane is θ, satisfying the relation: θ = 60°. The bottom slope of the sludge sedimentation area 122a is b, satisfying the relation: b = 0.01;

[0116] The horizontal primary sedimentation tank 122 is communicated with the biological treatment tank 130.

[0117] Please refer to Figure 1 - Figure 11, in this embodiment, the sewage enters the horizontal flow grit chamber 121. During the slow flow process, heavy particles (such as sand grains) settle to the bottom of the grit chamber by gravity and flow towards the grit hopper 121b under the action of the inclined bottom of the chamber. The grit hopper 121b is designed with an inclination angle of 60°, enabling the grit to slide naturally to the bottom of the hopper. Subsequently, the grit is discharged from the system through a sand discharge pump.

[0118] Then, the sewage enters the horizontal primary sedimentation tank 122. In the primary sedimentation tank, the lighter suspended solids and smaller particles settle to the sludge sedimentation area 122a, and the sludge is guided to flow towards the sedimentation hopper by a slope of 0.01. The 60° design of the hopper wall ensures that the sludge naturally concentrates at the bottom of the hopper. The treated sewage then flows into the biological treatment tank 130 for further treatment after pretreatment.

[0119] Through the hierarchical sedimentation design of the horizontal flow grit chamber 121 and the primary sedimentation tank, large particles and small particles in the sewage can be effectively removed separately, greatly improving the efficiency of sewage treatment. The grit chamber specifically treats heavy substances such as sand grains, while the primary sedimentation tank removes lighter suspended solids, reducing the burden on subsequent treatment units.

[0120] The 60° angle design of the sludge sedimentation hopper 122b ensures the natural sliding of the sludge, reducing the retention time of sediment in the sedimentation area for too long and preventing the negative impact of sludge accumulation on the treatment efficiency.

[0121] The 0.01 bottom slope design effectively guides the sludge towards the sedimentation hopper, facilitating the centralized treatment of sludge, reducing the frequency of manual intervention required, and improving the automated operation ability of the primary sedimentation tank.

[0122] The 60° design of the grit hopper 121b optimizes the natural sedimentation process of the grit, making it easier for the sand grains to concentrate in the grit hopper 121b, reducing the need for manual cleaning, and improving the grit removal efficiency.

[0123] The bottom inclination of the chamber is designed to be 6°, which can effectively promote the flow of grit towards the grit hopper 121b, preventing the long-term accumulation of sand grains at the bottom of the chamber and affecting the treatment capacity and efficiency of the grit chamber.

[0124] Through the setting of a sand discharge pump (not marked in the figure), the system can automatically discharge the deposited sand grains, reducing manual intervention, improving the automation level of system operation, and ensuring the continuity of the sewage treatment process.

[0125] It should be noted that a traveling scraper is used for the horizontal primary sedimentation tank.

[0126] The sludge at the bottom of the horizontal primary sedimentation tank 122 is discharged using hydrostatic pressure.

[0127] In at least one embodiment of the present application, the biological treatment tank 130 includes:

[0128] The anaerobic tank 131 is connected to one end of the horizontal flow sedimentation assembly 120;

[0129] The first anoxic tank 132 is connected to one end of the anaerobic tank 131;

[0130] The second anoxic tank 133 is connected to the first anoxic tank 132;

[0131] The aerobic tank 134 is connected to the second anoxic tank 133, and the first anoxic tank 132 and the second anoxic tank 133 are located between the anaerobic tank 131 and the aerobic tank 134;

[0132] The aerobic tank 134 is connected to the membrane bioreactor.

[0133] Please refer to Figure 1 - Figure 11 , in this embodiment, the sewage enters the anaerobic tank 131, and the microorganisms decompose the organic matter and release phosphorus preliminarily in an anaerobic environment. Subsequently, the sewage enters the first anoxic tank 132, and the nitrate nitrogen in the water is removed through denitrification to further remove nitrogen. Then, the sewage flows into the second anoxic tank 133, and the denitrification reaction continues to further remove the residual nitrate to ensure the thoroughness of nitrogen removal. The sewage then enters the aerobic tank 134, and the organic matter is further degraded under the condition of sufficient oxygen, and at the same time, ammonia nitrogen is oxidized to nitrate. Finally, the sewage enters the membrane bioreactor through a pipeline, and efficient solid-liquid separation and further removal of organic pollutants are achieved through membrane filtration technology to ensure that the effluent meets the high-standard discharge requirements.

[0134] Through the multi-stage biological reaction design of anaerobic, anoxic and aerobic, pollutants such as nitrogen and phosphorus in the sewage can be efficiently removed, avoiding the occurrence of water eutrophication.

[0135] By setting up the anaerobic tank 131, two anoxic tanks and the aerobic tank 134, the biological treatment process is more efficient, making full use of the metabolic functions of different microorganisms to achieve the decomposition of organic matter and the removal of nitrogen and phosphorus.

[0136] The membrane bioreactor (not marked in the figure) combines with the biological treatment process to achieve efficient solid-liquid separation, making the effluent water quality stable and clear, meeting the high-standard discharge or reuse requirements.

[0137] It should be noted that the design of the anaerobic tank 131 enables the phosphorus-accumulating bacteria to release phosphorus in an anaerobic environment, laying a foundation for the subsequent phosphorus removal steps and effectively preventing water eutrophication.

[0138] In an anaerobic environment, the nitrogen and organic matter in the sewage are decomposed preliminarily, providing effective prerequisite conditions for subsequent biological nitrogen and phosphorus removal.

[0139] The sewage first enters the anaerobic tank 131 from the horizontal flow sedimentation component 120. Under anaerobic conditions, anaerobic microorganisms (such as phosphorus-accumulating bacteria, sulfate-reducing bacteria, etc.) begin to decompose the organic matter in the sewage, especially phosphorus-containing compounds, and this process releases phosphorus into the water body. At this time, the organic pollutants in the sewage are initially degraded.

[0140] The design of the first anoxic tank 132 effectively removes nitrate nitrogen in the water through denitrification, preventing water eutrophication and excessive nitrogen emissions.

[0141] In the subsequent treatment step of the anaerobic tank 131, the first anoxic tank 132 further improves the nitrogen removal effect, which helps to reduce the treatment pressure of the subsequent aerobic tank 134.

[0142] The sewage enters the first anoxic tank 132 from the anaerobic tank 131. Under anoxic conditions, denitrifying bacteria use the organic carbon source in the sewage to reduce nitrate to nitrogen gas, thereby removing nitrogen from the sewage.

[0143] The denitrification reaction reduces the nitrate nitrogen in the sewage through a biological transformation process under anoxic conditions, achieving the purpose of nitrogen removal.

[0144] By setting up the second anoxic tank 133 after the first anoxic tank 132, the system realizes multi-stage denitrification, further improves the nitrogen removal efficiency, and ensures that the nitrogen content of the effluent meets strict discharge standards.

[0145] The setting of the second anoxic tank 133 effectively supplements the treatment of the previous anoxic tank, avoids nitrogen residues, and improves the stability and treatment efficiency of the system operation.

[0146] The sewage flows from the first anoxic tank 132 into the second anoxic tank 133, and under similar anoxic conditions, denitrification continues to convert the residual nitrate into nitrogen gas and escape from the water body.

[0147] The second anoxic tank 133 serves as a supplementary denitrification tank to ensure that the denitrification process is more complete and effectively removes the residual nitrate nitrogen in the water.

[0148] The aerobic tank 134 provides an ideal growth environment for aerobic microorganisms, enabling the organic matter in the sewage to be fully degraded, effectively reducing the chemical oxygen demand (COD) and biochemical oxygen demand (BOD), and improving the effluent quality.

[0149] The aerobic tank 134 converts ammonia nitrogen in the sewage into nitrate through nitrification, providing a nitrate source for the subsequent denitrification and nitrogen removal steps.

[0150] The sewage enters the aerobic tank 134. Under sufficient oxygen supply, aerobic microorganisms (such as nitrifying bacteria) thoroughly decompose the organic matter in the sewage and simultaneously oxidize ammonia nitrogen to nitrate.

[0151] Through the air-blowing aeration system, the sewage contains sufficient dissolved oxygen to support the biodegradation and nitrification of aerobic microorganisms.

[0152] It should be further noted that the hydraulic retention time ratio of each section is anaerobic: anoxic: aerobic = 1:1:3.

[0153] In at least one embodiment of the present application, the sewage treatment system 100 further includes:

[0154] A membrane bioreactor tank 140, and the membrane bioreactor is disposed within the membrane bioreactor tank 140.

[0155] Please refer to Figure 1 - Figure 11 , in this embodiment, after passing through the anaerobic, anoxic and aerobic treatment units, the sewage enters the membrane bioreactor tank 140. In this tank, the sewage continues to undergo biodegradation to further reduce the concentration of organic pollutants.

[0156] The membrane bioreactor is disposed in the tank, and solid-liquid separation is carried out through its membrane module. Suspended solids and microorganisms are intercepted outside the membrane, and clean water flows out through the membrane pores.

[0157] The activated sludge and microorganisms in the membrane bioreactor tank 140 continue to decompose the residual organic matter in the sewage and clean the membrane surface through biological action to reduce membrane pore blockage.

[0158] By integrating the membrane bioreactor with the membrane bioreactor tank 140, this design not only improves the sewage treatment efficiency, but also enables solid-liquid separation and biodegradation to be carried out simultaneously, significantly improving the quality of the effluent.

[0159] Reduces the space requirement of the sewage treatment system 100. By directly installing the membrane bioreactor in the reaction tank, the layout of the treatment equipment is optimized, reducing the need to construct a separate membrane tank.

[0160] Since the sewage in the membrane bioreactor tank 140 has undergone biodegradation before membrane filtration, the suspended solid content is low, reducing the possibility of membrane blockage, extending the service life of the membrane bioreactor, and reducing the cost of frequent cleaning.

[0161] The microporous structure of the membrane bioreactor can effectively remove suspended solids and microorganisms in the water, enabling the transparency and quality of the effluent to reach high standards, meeting the requirements for industrial water use, urban sewage reuse and high-standard discharge.

[0162] The ultrafiltration membrane adopts the working mode of "continuous aeration and intermittent suction".

[0163] There are 12 groups of membrane boxes, with 12 membrane boxes in each column, located in the membrane bioreactor 140. A water production pump is set separately for each column. When operating normally, 6 blowers are provided, with 4 in use and 2 in standby, 1 backwash pump in use and 1 in standby, and 1 pump for maintenance cleaning. When performing restorative cleaning, 2 pumps are turned on simultaneously.

[0164] The designed distance between the membrane boxes and the outer wall of the membrane box is 0.3m, and the designed distance between the outer wall of the membrane box and the pool wall, as well as between the outer walls of the membrane boxes, is 300 - 350cm. The width between the outer wall of the membrane box and the pool wall is 0.35m.

[0165] In at least one embodiment of the present application, the sewage treatment system 100 further includes:

[0166] A sludge storage tank 180, one end of the output pipe of the membrane bioreactor 140 is connected to the sludge storage tank 180 and the anaerobic tank 131.

[0167] In at least one embodiment of the present application, the sewage treatment system 100 further includes:

[0168] A sludge thickening and dewatering room 190, connected to the output pipe of the sludge storage tank 180.

[0169] Please refer to Figure 1 - Figure 11 , in this embodiment, after the sewage is treated by the membrane bioreactor 140, the generated sludge is intercepted by the membrane module and transported to the sludge storage tank 180. The sludge storage tank 180 serves as an intermediate sludge storage and regulation facility, storing the sludge and partially returning it to the anaerobic tank 131 to further promote biodegradation and improve the treatment capacity of the system. The remaining sludge that is not returned in the sludge storage tank 180 is transported to the sludge thickening and dewatering room 190 through a pipeline. Here, the sludge undergoes thickening and dewatering treatment, and finally its volume is greatly reduced and the moisture content is decreased, facilitating subsequent treatment or external transportation and disposal.

[0170] Through the design of the sludge storage tank 180, the sludge can be temporarily stored and returned to the anaerobic tank 131 according to needs, improving the efficiency of biological treatment and reducing the burden of sludge accumulation on the system.

[0171] The sludge flowing back from the sludge storage tank 180 to the anaerobic tank 131 can maintain the activity of microorganisms, help the anaerobic tank 131 continuously remove organic matter and phosphorus, and improve the treatment efficiency of the entire sewage treatment system 100.

[0172] The sludge thickening and dewatering room 190 reduces the moisture content in the sludge, decreases the sludge volume, and reduces the cost and energy consumption of subsequent treatment. The thickened and dewatered sludge is more efficiently treated, and at the same time, the transportation and treatment burden are reduced.

[0173] Through the combination of the sludge storage tank 180 and the sludge thickening and dewatering room 190, the sludge treatment process can be automated, reducing manual intervention and making the operation of the entire system more stable and reliable, ensuring the synchronous and efficient operation of the sludge treatment link and the sewage treatment system 100.

[0174] The above are only the implementation manners of the present application. It should be noted here that for those of ordinary skill in the art, improvements can be made without departing from the creative concept of the present application, but these all fall within the protection scope of the present application.

Claims

1. A sewage treatment system, characterized in that, Comprising: A preliminary filtration component, one end of which is connected to the inlet channel; A horizontal flow sedimentation component, one end of which is connected to the other end of the preliminary filtration component; A biological treatment tank, the input pipe of which is connected to the side of the horizontal flow sedimentation component away from the preliminary filtration component; A membrane bioreactor, one end of which is connected to the output pipe of the biological treatment tank, and the other end of which is connected to the input pipe of the biological treatment tank; A high-density sedimentation tank, the output pipe of the membrane bioreactor is connected to the input pipe of the high-density sedimentation tank; A denitrification filtration tank, which is connected to the output pipe of the high-density sedimentation tank; An ultraviolet disinfection tank, one end of which is connected to the output pipe of the denitrification filtration tank, and the other end of which is connected to the outlet channel.

2. The sewage treatment system according to claim 1, wherein, The preliminary filtration component includes: A coarse grid filter element, which is located in the input pipe of the inlet channel; A lift pump, one end of which is connected to the coarse grid filter element; A fine grid filter element, which is connected to the output pipe of the lift pump away from the coarse grid filter element.

3. The sewage treatment system according to claim 2, wherein The angle between the coarse grid filter element and the inlet channel is α, satisfying the relationship: 60° ≤ α ≤ 90°; The angle between the fine grid filter element and the inlet channel is β, satisfying the relationship: β = 35°.

4. The sewage treatment system according to claim 2, characterized in that, The preliminary filtration component further includes: A collecting tank, in which the lift pump is located.

5. The sewage treatment system according to claim 1, characterized in that, The horizontal flow sedimentation component includes: A horizontal flow grit chamber, which has two grit chambers and a grit hopper located between the two grit chambers. The inclination angle between the hopper wall of the grit hopper and the horizontal plane is denoted as γ, satisfying the relationship: γ = 60°; The inclination angle between the bottom of the grit chamber and the horizontal plane is denoted as i, satisfying the relationship: i = 6°, and the bottom of the grit chamber is inclined towards the hopper wall of the grit hopper; A sand discharge pump is provided at the bottom of the grit chamber, and one end of the sand discharge pump is connected to the outside.

6. The sewage treatment system according to claim 5, characterized in that, The horizontal flow sedimentation component further includes: A horizontal primary sedimentation tank, which has a sludge sedimentation area and a sludge sedimentation hopper. The sludge sedimentation area is connected to the sludge sedimentation hopper. The angle between the sludge sedimentation hopper and the horizontal plane is θ, satisfying the relationship: θ = 60°. The bottom slope of the sludge sedimentation area is b, satisfying the relationship: b = 0.01; The horizontal primary sedimentation tank is connected to the biological treatment tank.

7. The sewage treatment system according to claim 1, characterized in that The biological treatment tank includes: An anaerobic tank, one end of which is connected to the horizontal flow sedimentation component; A first anoxic tank, one end of which is connected to the anaerobic tank; A second anoxic tank, which is connected to the first anoxic tank; An aerobic tank, which is connected to the second anoxic tank. The first anoxic tank and the second anoxic tank are located between the anaerobic tank and the aerobic tank; The aerobic tank is connected to the membrane bioreactor.

8. The sewage treatment system according to claim 7, characterized in that, The sewage treatment system further includes: A membrane bioreaction tank, in which the membrane bioreactor is arranged.

9. The sewage treatment system according to claim 8, wherein, The sewage treatment system further includes: A sludge storage tank, one end of the output pipe of the membrane bioreaction tank is connected to the sludge storage tank and the anaerobic tank.

10. The sewage treatment system according to claim 9, characterized in that, The sewage treatment system further includes: A sludge thickening and dewatering room, which is connected to the output pipe of the sludge storage tank.

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