A riverway surrounding sewage collection and treatment system

Abstract

The application provides a river surrounding sewage collecting and treating system, which comprises a river surrounding sewage collecting device, a sewage treating device and a communication between the river surrounding sewage collecting device and the sewage device; the river surrounding sewage collecting device comprises a floating overflow intercepting plate, an upper layer sewage assembly, a lower layer sewage assembly, a sedimentation tank, a first filtering assembly and a second filtering assembly; the floating overflow intercepting plate is arranged at the bank of the river, the upper layer sewage assembly is arranged corresponding to the water surface of the river, the lower layer sewage assembly is arranged on the river, and the first filtering assembly is arranged on one side of the river; the river is communicated with the sedimentation tank through the upper layer sewage assembly and the lower layer sewage assembly; the sedimentation tank is communicated with the first filtering assembly, the first filtering assembly is communicated with the second filtering assembly, and the second filtering assembly is communicated with the sewage treating device. The A / O+BAF biological treatment process is adopted, so that the river surrounding sewage treatment can reach the discharge standard, and the treatment will not cause secondary pollution to the environment.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment, and in particular relates to a wastewater collection and treatment system for riverbanks. Background Technology

[0002] In recent years, with economic development and urbanization, the discharge of industrial and domestic sewage has increased year by year. Many residential areas are generally located around rivers, especially in older urban areas. These scattered settlements make sewage collection difficult, and the integrated domestic sewage pipe network is inadequate. Domestic sewage is discharged into rivers indiscriminately, severely impacting the self-purification capacity of the water bodies. Furthermore, the sewage around rivers contains many floating objects, including household garbage and duckweed, further complicating sewage collection and treatment. Invention Content

[0003] In view of this, the present invention aims to provide a sewage collection and treatment system for riverbanks to solve at least one of the technical problems in the prior art.

[0004] To achieve the above objectives, the technical solution created by this invention is implemented as follows:

[0005] A sewage collection and treatment system for riverbanks includes a sewage collection device and a sewage treatment device, wherein the sewage collection device and the sewage treatment device are connected.

[0006] The sewage collection device around the river includes a floating debris overflow interception plate, an upper sewage component, a lower sewage component, a sedimentation tank, a first filter component, and a second filter component;

[0007] The floating debris overflow interception plate is set on the bank of the river, the upper sewage component is set to correspond to the water surface of the river; the lower sewage component is set on the river, and the first filter component is set on one side of the river.

[0008] The river channel is connected to the sedimentation tank via an upper wastewater treatment module and a lower wastewater treatment module.

[0009] The sedimentation tank is connected to the first filter assembly, the first filter assembly is connected to the second filter assembly, and the second filter assembly is connected to the wastewater treatment device.

[0010] Furthermore, the aperture of the floating debris overflow interceptor plate is 70-80mm; it can block floating debris, impurities and gravel larger than 80mm in the river.

[0011] The upper sewage system includes a cylinder, an auger, and an output motor. The auger is installed inside the cylinder, and one end of the auger is connected to the output motor.

[0012] The cylinder has a sewage inlet on the upper part of one side and a sewage outlet on the lower part of the other side; the cylinder is set on the riverbank and the position of the cylinder corresponds to the position of the river water in the river channel.

[0013] This application enables floating debris and water on the river to be transported to the first filtration component via an auger through the upper sewage component;

[0014] The lower-level sewage system includes a sewage pipe and a first water pump. The first water pump is installed on the sewage pipe, one end of which is connected to the river and the other end is connected to the first filter component.

[0015] The sewage pipes are located below the upper sewage components and in the middle of the river channel.

[0016] This application combines a floating debris overflow interception plate, an upper sewage component, and a lower sewage component. The floating debris overflow interception plate initially intercepts impurities, the upper sewage is transported by a auger in the upper sewage component, and the lower sewage is transported by a first water pump. This allows for the separate transport of floating debris from the upper layer, extends the service life of the first water pump, and achieves stratification.

[0017] Furthermore, a first filter screen is horizontally installed inside the sedimentation tank;

[0018] A riverbank trough is provided on the riverbank, the first filter box is located in the riverbank trough, and the first filter screen is located between the upper sewage component and the lower sewage component.

[0019] The diameter of the first filter screen is 50-70mm.

[0020] The first filter screen filters the liquid transported by the screw conveyor, and the sedimentation tank settles the sewage around the riverbank.

[0021] Furthermore, the first filter assembly includes a first filter box, a second filter screen, and a third filter screen;

[0022] The second and third filters are arranged at an angle inside the first filter box.

[0023] The diameter of the second filter screen is 40-45mm.

[0024] The diameter of the third filter screen is 30-40mm.

[0025] The sedimentation tank is connected to the first filter box via a first connecting pipe. One end of the first connecting pipe is connected to the upper part of the first filter box and is located below the first filter screen.

[0026] The other end of the first connecting pipe is connected to the upper part of the first filter box;

[0027] A second water pump is installed on the first connecting pipe.

[0028] Furthermore, the first filter assembly and the second filter assembly are connected by a second connecting pipe; a third water pump is provided on the second connecting pipe;

[0029] One end of the second connecting pipe is connected to the upper part of the first filter assembly, and the other end is connected to the lower part of the second filter assembly.

[0030] The second filter assembly includes a second filter box, a first filter stone layer, and a second filter stone layer;

[0031] The first filter stone layer and the second filter stone layer are arranged sequentially from top to bottom in the second filter box;

[0032] The first filter stone layer consists of several uniformly arranged first filter stones;

[0033] The second filter stone layer consists of several uniformly arranged second filter stones.

[0034] The diameter of the first filter stone is smaller than the diameter of the second filter stone.

[0035] Wastewater passes through the second filter stone and the first filter stone before entering the wastewater treatment device.

[0036] Furthermore, the wastewater treatment device includes an equalization tank, an anaerobic hydrolysis tank, a two-stage A2O tank, a secondary sedimentation tank, an ozone contact tank, an aerated biological filter, a fiber disc filter, a coagulation tank, and a disinfection tank; the equalization tank, anaerobic hydrolysis tank, two-stage A2O tank, secondary sedimentation tank, ozone contact tank, aerated biological filter, fiber disc filter, coagulation tank, and disinfection tank are arranged in sequence.

[0037] After pretreatment, the wastewater is regulated in the equalization tank and then enters the anaerobic hydrolysis tank. It then enters the two-stage A2O tank and the secondary sedimentation tank in sequence. The sludge in the secondary sedimentation tank is returned to the two-stage A2O tank. After passing through the ozone contact tank and the aerated biological filter, it enters the fiber disc filter. After passing through the coagulation tank and the disinfection tank, it enters the effluent discharge tank.

[0038] Furthermore, the equalization tank adjusts the pH of the wastewater to 6-9.

[0039] Furthermore, the carbon, nitrogen, and phosphorus ratio in the anaerobic hydrolysis tank should be maintained at (200-300):5:1.

[0040] In the anaerobic hydrolysis tank, the hydraulic retention time (HRT) is controlled at 2h, and DO < 0.2mg / l to suppress the aerobic microorganisms in the activated sludge, causing polyphosphate-accumulating bacteria to release the phosphorus stored in their bodies.

[0041] In the anaerobic hydrolysis tank, wastewater undergoes hydrolysis and acid-producing bacteria reactions to break down insoluble organic matter into soluble organic matter, reducing the load on subsequent treatment structures. The hydrolysis stage is an essential process for the degradation of large organic molecules; for large organic molecules to be utilized by microorganisms, they must first be hydrolyzed into smaller molecules so they can enter bacterial cells for further degradation. The acidification stage accelerates the degradation of organic matter because it further transforms the hydrolyzed smaller organic molecules into simpler compounds that are secreted extracellularly.

[0042] Furthermore, the two-stage A2O tank includes a first anoxic zone, a first aerobic zone, a second anoxic zone, and a second aerobic zone, which are arranged sequentially. The sludge in the secondary sedimentation tank is returned to the first anoxic zone, the first aerobic zone, the second anoxic zone, and the second aerobic zone, respectively.

[0043] In the first anoxic zone of the two-stage A2O tank, DO < 0.5 mg / L. Due to the action of facultative denitrifying bacteria, the BOD in the influent is used as a hydrogen supplier (organic carbon source) to reduce the nitrate nitrogen and nitrite nitrogen produced by nitrification in the previous cycle into nitrogen gas, thereby achieving the purpose of denitrification. At the same time, organic matter is decomposed, which is also called the denitrification process.

[0044] DO in the first aerobic zone > 2 mg / L; DO in the second hypoxic zone < 0.5 mg / L; DO in the second aerobic zone > 2 mg / L.

[0045] The carbon, nitrogen, and phosphorus ratio in the first and second aerobic zones is 100:5:1.

[0046] In the biological treatment tank, activated sludge microorganisms adsorb and degrade organic pollutants in the influent. Nitrifying and denitrifying bacteria are used for nitrogen removal, and phosphorus-absorbing bacteria are used for phosphorus removal. The effluent from the biological treatment tank enters a secondary sedimentation tank for sludge-water separation. Since this application requires an effluent COD of less than 30 g / L, conventional biological treatment alone is insufficient to meet discharge requirements. Therefore, an ozone contact tank is installed after the secondary sedimentation tank. Ozone is added to the contact tank to oxidize recalcitrant organic matter in the wastewater, while also acting as a ring-breaking mechanism. The effluent then enters a biofilm filter (BAF) tank, where microorganisms in the biofilm on the filter media further degrade organic matter, ensuring that the effluent organic matter meets standards. A fiber disc filter is installed after the BAF tank. The filtered wastewater meets SS standards. To ensure TP standards are met, a backup dosing point for chemicals is set at the inlet of the fiber disc filter. Phosphorus removal chemicals are added when total phosphorus in the effluent fluctuates. Finally, sodium hypochlorite is added to disinfect the wastewater and kill E. coli.

[0047] Furthermore, part of the sludge in the secondary sedimentation tank enters the two-stage A2O tank, and the other part is pumped into the sludge storage tank, and then discharged after passing through the dewatering room.

[0048] This method is a biological wastewater treatment process consisting of anaerobic and aerobic phases. After entering the anaerobic zone, wastewater is mixed with returned sludge. During this process, polyphosphate-accumulating bacteria (PABs) in the activated sludge absorb large amounts of BOD from the wastewater and release phosphorus from the sludge into the mixed liquor as orthophosphate. After entering the aerobic tank, the organic matter is oxidized and decomposed, while PABs simultaneously absorb large amounts of orthophosphate from the mixed liquor into the sludge. Because PABs absorb more phosphorus than they release under aerobic conditions, the wastewater, through alternating anaerobic-aerobic action and sludge separation in the secondary sedimentation tank, ultimately achieves phosphorus removal.

[0049] The molecular formula of ozone in an ozone contact tank is O3, an allotrope of oxygen (O2). Ozone in an ozone contact tank is chemically extremely unstable, slowly decomposing into oxygen in both air and water. The reaction is: 2O3 → 3O2 + 285kJ. For ozone in an ozone contact tank with a concentration below 1%, the decomposition half-life in air at normal temperature and pressure is approximately 16 hours.

[0050] Ozone contact tank oxidation of inorganic substances: Ozone contact tank can react with ferrous iron and manganese ions in water, turning soluble iron and manganese into solid substances, which can then be removed through sedimentation and filtration. Ozone contact tank causes a series of reactions such as decomposition, fission, and polymerization of suspended solids, colloidal impurities, microparticles, and macromolecular organic matter in water, forming flocs that are released from the water. This has a significant effect on reducing COD and BOD in water.

[0051] Aerated biological filters remove suspended solids (SS), COD, BOD, and promote nitrification, denitrification, phosphorus removal, and other harmful substances. The filter is filled with a certain amount of small-diameter granular filter media (8mm in diameter). A highly active biofilm grows on the surface of the filter media, and the filter is aerated. When wastewater flows through, the high specific surface area of ​​the filter media leads to a high concentration of biofilm, which rapidly purifies the wastewater through oxidation and degradation—this is the biological oxidation and degradation process. Simultaneously, as the wastewater flows through, the filter media is compacted. Utilizing the small particle size of the filter media and the bioflocculation effect of the biofilm, suspended solids in the wastewater are trapped, and detached biofilm is prevented from floating away—this is the trapping effect. After a certain period of operation, due to increased head loss, the filter needs to be backwashed to release the trapped suspended solids and renew the biofilm—this is the backwashing process. Aerated biological filters integrate biological oxidation and suspended solids retention, featuring high volumetric and hydraulic loads, short hydraulic retention time, low energy consumption, and low operating costs.

[0052] BAF (Biological Aerated Filter) principle: A certain amount of small-diameter granular filter media is filled into the filter tank. A highly active biofilm grows on the surface of the filter media, and the filter tank is aerated. When sewage flows through, the high concentration of biofilm due to the high specific surface area of ​​the filter media rapidly purifies the sewage through oxidation and degradation; this is the biological oxidation and degradation process. At the same time, as the sewage flows through, the filter media is compacted. Utilizing the small particle size of the filter media and the bioflocculation effect of the biofilm, suspended solids in the sewage are trapped, and it is ensured that detached biofilm does not float away with the water; this is the trapping effect. After a certain period of operation, due to the increase in head loss, the filter tank needs to be backwashed to release the trapped suspended solids and renew the biofilm; this is the backwashing process.

[0053] Furthermore, the fiber disc filter has a hopper-shaped bottom beneath the filter disc, which facilitates the collection of sludge from the bottom. Sludge deposition at the bottom reduces the amount of sludge on the filter cloth, extending the filtration time and reducing backwash water consumption. After a set time period, the controller (PLC) starts the sludge discharge pump, returning the sludge to the plant's drainage system through the perforated sludge discharge pipe at the bottom of the tank.

[0054] Furthermore, the filter cloth in the fiber disc filter has a filtration accuracy of less than 10μm, which can intercept and filter hydrophobic pollutants.

[0055] Furthermore, the coagulants used in the coagulation disinfection were polyaluminum chloride (PAC) (positive) and polystyrene amide (PAM) (negative);

[0056] Wastewater coagulation is a water treatment method in which colloids and fine suspended solids in the wastewater are coagulated into flocs by coagulants, and then separated and removed. Coagulation clarification is widely used in water treatment; it can reduce the turbidity, color, and other sensory indicators of water quality, and remove various toxic and harmful pollutants.

[0057] Furthermore, hypochlorous acid is used as the disinfectant in coagulation disinfection.

[0058] Wastewater disinfection is a water treatment process that kills harmful pathogenic microorganisms in domestic sewage and industrial wastewater treatment systems. Domestic sewage not only contains a large number of bacteria, but also often contains viruses. These cannot be eradicated through ordinary wastewater treatment processes. To prevent the spread of diseases, sodium hypochlorite is used for disinfection.

[0059] Compared with existing technologies, the wastewater collection and treatment system for riverbanks described in this invention has the following advantages:

[0060] 1. This application combines a floating debris overflow interception plate, an upper sewage component, and a lower sewage component. The floating debris overflow interception plate initially intercepts impurities, the upper sewage is transported by the auger of the upper sewage component, and the lower sewage is transported by the first water pump. This allows for the separate transport of floating debris from the upper layer, extends the service life of the first water pump, and enables the treatment of sewage around the river through stratification.

[0061] 2. This application treats riverbank sewage by combining a sedimentation tank, a first filter component, and a second filter component. The treatment effect is good, and it can remove most of the impurities in the riverbank sewage.

[0062] 2. This application adopts the A / O+BAF biological treatment process, which can effectively solve the problem of sewage treatment and discharge in compliance with standards around the river, and the treatment will not cause secondary pollution to the environment.

[0063] 2. The two-stage A / O process system of this application can effectively remove COD while also resolving the sludge age conflict in simultaneous nitrogen and phosphorus removal. In the various operating conditions implemented so far, the COD, ammonia nitrogen, and phosphorus levels in the effluent from the system have met national discharge standards.

[0064] 3. The two A / O units in this application are connected in series, with each having its own reflux and operating independently. The two A / O systems perform different functions: the first-stage A / O removes phosphorus, and the second-stage A / O removes nitrogen. Attached Figure Description

[0065] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0066] Figure 1 A schematic diagram of a sewage collection and treatment system around a river as described in an embodiment of the present invention;

[0067] Figure 2 A schematic diagram of a sewage collection device for a riverbank sewage collection and treatment system according to an embodiment of the present invention;

[0068] Figure 3 A schematic diagram of a two-stage A2O tank for a sewage collection and treatment system around a river, as described in an embodiment of the present invention;

[0069] Explanation of reference numerals in the attached figures:

[0070] 1. Floating debris overflow interception plate; 2. Cylinder body; 3. Screw conveyor; 4. Output motor; 5. Sewage inlet; 6. Sewage outlet; 7. Sewage pipe; 8. First water pump; 9. First filter screen; 10. Sedimentation tank; 11. Riverbank channel; 12. First filter box; 13. First connecting pipe; 14. Second water pump; 15. Second filter screen; 16. Third filter screen; 17. Second connecting pipe; 18. Third water pump; 19. Second filter box; 20. First filter stone layer; 21. Second filter stone layer. Detailed Implementation

[0071] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0072] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0073] like Figure 1 As shown, a sewage collection and treatment system for a riverbank includes a sewage collection device and a sewage treatment device, with the sewage collection device connected to the sewage treatment device. The sewage collection device includes a floating debris overflow interception plate 1, an upper sewage component, a lower sewage component, a sedimentation tank 10, a first filter component, and a second filter component. The floating debris overflow interception plate 1 is located on the bank of the river, and the upper sewage component is positioned corresponding to the water surface of the river. The lower sewage component is located on the river, and the first filter component is located on one side of the river. The river is connected to the sedimentation tank 10 through the upper and lower sewage components. The sedimentation tank 10 is connected to the first filter component, the first filter component is connected to the second filter component, and the second filter component is connected to the sewage treatment device.

[0074] The floating debris overflow interceptor plate 1 has an aperture of 75mm, which can block floating debris, impurities, and gravel larger than 80mm in the river. The upper sewage assembly includes a cylinder 2, an auger 3, and an output motor 4. The auger 3 is installed inside the cylinder 2, and one end of the auger 3 is connected to the output motor 4. A sewage inlet 5 is provided on the upper part of one side of the cylinder 2, and a sewage outlet 6 is provided on the lower part of the other side. The cylinder 2 is installed on the riverbank, and the position of the cylinder 2 corresponds to the position of the river water in the river channel. This application enables floating debris and water on the river to be transported to the first filter assembly through the auger 3 via the upper sewage assembly. The lower sewage assembly includes a sewage pipe 7 and a first water pump 8. The first water pump 8 is installed on the sewage pipe 7. One end of the sewage pipe 7 is connected to the river channel, and the other end is connected to the first filter assembly. The sewage pipe 7 is located below the upper sewage assembly and in the middle of the river channel. This application combines a floating debris overflow interception plate 1, an upper sewage component, and a lower sewage component. The floating debris overflow interception plate 1 initially intercepts impurities, the upper sewage is transported by the auger of the upper sewage component, and the lower sewage is transported by the first water pump 8. This allows for the separate transport of floating debris from the upper layer, extends the service life of the first water pump 8, and achieves stratification.

[0075] A first filter screen 9 is horizontally installed inside the sedimentation tank 10; a riverbank trough 11 is provided on the riverbank, and a first filter box 12 is installed in the riverbank trough 11. The first filter screen 9 is installed between the upper and lower sewage components; the diameter of the first filter screen 9 is 60mm. The first filter screen 9 can filter the liquid transported by the screw conveyor 3, and the sedimentation tank 10 can settle the sewage around the riverbank.

[0076] The first filter assembly includes a first filter box 12, a second filter screen 15, and a third filter screen 16; the second filter screen 15 and the third filter screen 16 are sequentially and obliquely arranged inside the first filter box 12. The diameter of the second filter screen 15 is 40 mm. The diameter of the third filter screen 16 is 35 mm.

[0077] The sedimentation tank 10 is connected to the first filter box 12 via a first connecting pipe 13. One end of the first connecting pipe 13 is connected to the upper part of the first filter box 12 and is located below the first filter screen 9. The other end of the first connecting pipe 13 is connected to the upper part of the body of the first filter box 12. A second water pump 14 is provided on the first connecting pipe 13.

[0078] The first filter assembly and the second filter assembly are connected by a second connecting pipe 17; a third water pump 18 is provided on the second connecting pipe 17; one end of the second connecting pipe 17 is connected to the upper part of the first filter assembly, and the other end is connected to the lower part of the second filter assembly.

[0079] The second filtration assembly includes a second filter box 19, a first filter stone layer 20, and a second filter stone layer 21. The first filter stone layer 20 and the second filter stone layer 21 are arranged sequentially from top to bottom within the second filter box 19. The first filter stone layer 20 consists of several uniformly arranged first filter stones. The second filter stone layer 21 consists of several uniformly arranged second filter stones. The diameter of the first filter stones is smaller than the diameter of the second filter stones. Wastewater passes through the second filter stones and the first filter stones before entering the wastewater treatment device.

[0080] The wastewater treatment unit includes an equalization tank, an anaerobic hydrolysis tank, a two-stage A2O tank, a secondary sedimentation tank, an ozone contact tank, an aerated biological filter, a fiber disc filter, a coagulation tank, and a disinfection tank; the equalization tank, anaerobic hydrolysis tank, two-stage A2O tank, secondary sedimentation tank, ozone contact tank, aerated biological filter, fiber disc filter, coagulation tank, and disinfection tank are arranged in sequence.

[0081] After pretreatment, the wastewater is regulated in the equalization tank and then enters the anaerobic hydrolysis tank. It then enters the two-stage A2O tank and the secondary sedimentation tank in sequence. The sludge in the secondary sedimentation tank is returned to the two-stage A2O tank. After passing through the ozone contact tank and the aerated biological filter, it enters the fiber disc filter. After passing through the coagulation tank and the disinfection tank, it enters the effluent discharge tank.

[0082] The equalization tank adjusts the pH of the wastewater to 6-9. The carbon, nitrogen, and phosphorus ratio in the anaerobic hydrolysis tank should be maintained at (200-300):5:1. The hydraulic retention time (HRT) in the anaerobic hydrolysis tank is controlled at 2 hours, and DO < 0.2 mg / L to suppress aerobic microorganisms in the activated sludge, allowing polyphosphate-accumulating bacteria to release phosphorus stored within them.

[0083] In the anaerobic hydrolysis tank, wastewater undergoes hydrolysis and acid-producing bacteria reactions to break down insoluble organic matter into soluble organic matter, reducing the load on subsequent treatment structures. The hydrolysis stage is an essential process for the degradation of large organic molecules; for large organic molecules to be utilized by microorganisms, they must first be hydrolyzed into smaller molecules so they can enter bacterial cells for further degradation. The acidification stage accelerates the degradation of organic matter because it further transforms the hydrolyzed smaller organic molecules into simpler compounds that are secreted extracellularly.

[0084] The two-stage A2O tank comprises a first anoxic zone, a first aerobic zone, a second anoxic zone, and a second aerobic zone, arranged sequentially. Sludge from the secondary sedimentation tank is recycled to each of these zones. In the first anoxic zone, the dissolved oxygen (DO) is <0.5 mg / L. Due to the action of facultative denitrifying bacteria, the BOD in the influent is used as a hydrogen donor (organic carbon source), reducing nitrate nitrogen and nitrite nitrogen produced in the previous nitrification cycle to nitrogen gas, thus achieving denitrification. Simultaneously, organic matter decomposes, also known as the denitrification process. In the first aerobic zone, the DO is >2 mg / L; in the second anoxic zone, the DO is <0.5 mg / L; and in the second aerobic zone, the DO is >2 mg / L. The carbon, nitrogen, and phosphorus ratio in the first and second aerobic zones is 100:5:1.

[0085] In the biological treatment tank, activated sludge microorganisms adsorb and degrade organic pollutants in the influent. Nitrifying and denitrifying bacteria are used for nitrogen removal, and phosphorus-absorbing bacteria are used for phosphorus removal. The effluent from the biological treatment tank enters a secondary sedimentation tank for sludge-water separation. Since this application requires an effluent COD of less than 30 g / L, conventional biological treatment alone is insufficient to meet discharge requirements. Therefore, an ozone contact tank is installed after the secondary sedimentation tank. Ozone is added to the contact tank to oxidize recalcitrant organic matter in the wastewater, while also acting as a ring-breaking mechanism. The effluent then enters a biofilm filter (BAF) tank, where microorganisms in the biofilm on the filter media further degrade organic matter, ensuring that the effluent organic matter meets standards. A fiber disc filter is installed after the BAF tank. The filtered wastewater meets SS standards. To ensure TP standards are met, a backup dosing point for chemicals is set at the inlet of the fiber disc filter. Phosphorus removal chemicals are added when total phosphorus in the effluent fluctuates. Finally, sodium hypochlorite is added to disinfect the wastewater and kill E. coli.

[0086] Part of the sludge in the secondary sedimentation tank enters the two-stage A2O tank, and the other part is pumped into the sludge storage tank and discharged after passing through the dewatering room.

[0087] Ozone contact tank oxidation of inorganic substances: Ozone contact tank can react with ferrous iron and manganese ions in water, turning soluble iron and manganese into solid substances, which can then be removed through sedimentation and filtration. Ozone contact tank causes a series of reactions such as decomposition, fission, and polymerization of suspended solids, colloidal impurities, microparticles, and macromolecular organic matter in water, forming flocs that are released from the water. This has a significant effect on reducing COD and BOD in water.

[0088] Aerated biological filters remove suspended solids (SS), COD, BOD, and promote nitrification, denitrification, phosphorus removal, and other harmful substances. The filter is filled with a certain amount of small-diameter granular filter media (8mm in diameter). A highly active biofilm grows on the surface of the filter media, and the filter is aerated. When wastewater flows through, the high specific surface area of ​​the filter media leads to a high concentration of biofilm, which rapidly purifies the wastewater through oxidation and degradation—this is the biological oxidation and degradation process. Simultaneously, as the wastewater flows through, the filter media is compacted. Utilizing the small particle size of the filter media and the bioflocculation effect of the biofilm, suspended solids in the wastewater are trapped, and detached biofilm is prevented from floating away—this is the trapping effect. After a certain period of operation, due to increased head loss, the filter needs to be backwashed to release the trapped suspended solids and renew the biofilm—this is the backwashing process. Aerated biological filters integrate biological oxidation and suspended solids retention, featuring high volumetric and hydraulic loads, short hydraulic retention time, low energy consumption, and low operating costs.

[0089] BAF (Biological Aerated Filter) principle: A certain amount of small-diameter granular filter media is filled into the filter tank. A highly active biofilm grows on the surface of the filter media, and the filter tank is aerated. When sewage flows through, the high concentration of biofilm due to the high specific surface area of ​​the filter media rapidly purifies the sewage through oxidation and degradation; this is the biological oxidation and degradation process. At the same time, as the sewage flows through, the filter media is compacted. Utilizing the small particle size of the filter media and the bioflocculation effect of the biofilm, suspended solids in the sewage are trapped, and it is ensured that detached biofilm does not float away with the water; this is the trapping effect. After a certain period of operation, due to the increase in head loss, the filter tank needs to be backwashed to release the trapped suspended solids and renew the biofilm; this is the backwashing process.

[0090] The fiber disc filter features a funnel-shaped bottom beneath the filter disc, facilitating sludge collection. Sludge deposition at the bottom reduces the amount of sludge on the filter cloth, extending filtration time and reducing backwash water volume. After a set time period, the controller (PLC) activates the sludge discharge pump, returning the sludge to the plant's drainage system through a perforated sludge discharge pipe at the bottom of the tank. The filter cloth in the fiber disc filter has a filtration precision of less than 10μm, effectively trapping and filtering hydrophobic pollutants.

[0091] The coagulants used in coagulation disinfection are polyaluminum chloride (PAC) (positive) and polystyrene amide (PAM) (negative). Wastewater is treated by coagulating colloids and fine suspended solids into flocs, which are then separated and removed. Coagulation clarification is widely used in water treatment; it can reduce the turbidity, color, and other sensory indicators of water quality, and remove various toxic and harmful pollutants. Hypochlorous acid is used as the disinfectant in coagulation disinfection. Wastewater disinfection is a water treatment process that kills harmful pathogenic microorganisms in domestic sewage and industrial wastewater treatment systems. Domestic sewage not only contains a large number of bacteria but also often contains viruses. These cannot be eradicated through general wastewater treatment processes; therefore, sodium hypochlorite is used for disinfection to prevent the spread of disease.

[0092] The device described in this application was used to treat a section of riverbank in Tianjin, and the effluent met the discharge standard B in Table 2 of the "Discharge Standard of Water Pollutants for Urban Wastewater Treatment Plants" (DB11 / 890-2012).

[0093] The two-stage A / O process system effectively removes COD while simultaneously resolving the sludge age conflict associated with simultaneous nitrogen and phosphorus removal. In all operational scenarios tested, the COD, ammonia nitrogen, and phosphorus levels in the effluent met national discharge standards. 2.0.2 The two-stage A / O process successfully resolves the sludge age conflict because the two A / O units are connected in series, each with its own reflux, operating independently. Aerobic heterotrophic bacteria, phosphorus-removing bacteria, denitrifying bacteria, and nitrifying bacteria grow in their respective systems or reactors with minimal interference, allowing for flexible adjustment of process operating parameters based on changes in influent water quality and quantity. By selecting different process parameters, the two-stage A / O systems perform different functions: the first stage removes phosphorus, and the second stage removes nitrogen and phosphorus.

[0094] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A sewage collection and treatment system for riverbanks, characterized in that: This includes sewage collection devices and sewage treatment devices around the river, with the sewage collection devices and sewage treatment devices connected together. The sewage collection device around the river includes a floating debris overflow interception plate, an upper sewage component, a lower sewage component, a sedimentation tank, a first filter component, and a second filter component; The floating debris overflow interception plate is set on the bank of the river, the upper sewage component is set to correspond to the water surface of the river; the lower sewage component is set on the river, and the first filter component is set on one side of the river. The river channel is connected to the sedimentation tank via an upper wastewater treatment module and a lower wastewater treatment module. The sedimentation tank is connected to the first filter assembly, the first filter assembly is connected to the second filter assembly, and the second filter assembly is connected to the wastewater treatment device. The aperture of the floating debris overflow interceptor plate is 70-80mm; The upper sewage system includes a cylinder, an auger, and an output motor. The auger is installed inside the cylinder, and one end of the auger is connected to the output motor. The cylinder has a sewage inlet on the upper part of one side and a sewage outlet on the lower part of the other side; the cylinder is set on the riverbank and the position of the cylinder corresponds to the position of the river water in the river channel. The lower-level sewage system includes a sewage pipe and a first water pump. The first water pump is installed on the sewage pipe, one end of which is connected to the river and the other end is connected to the first filter component. The sewage pipes are located below the upper sewage components and in the middle of the river channel; A first filter screen is horizontally installed inside the sedimentation tank; A riverbank trough is provided on the riverbank, the first filter box is located in the riverbank trough, and the first filter screen is located between the upper sewage component and the lower sewage component. The diameter of the first filter screen is 50-70mm; The first filtration assembly includes a first filter box, a second filter screen, and a third filter screen; The second and third filters are arranged at an angle inside the first filter box in sequence. The diameter of the second filter screen is 40-45mm; The diameter of the third filter screen is 30-40mm; The sedimentation tank and the first filter box are connected by a first connecting pipe. One end of the first connecting pipe is connected to the upper part of the sedimentation tank and is located below the first filter screen. The other end of the first connecting pipe is connected to the upper part of the first filter box; A second water pump is installed on the first connecting pipe; The first filter assembly and the second filter assembly are connected by a second connecting pipe; a third water pump is installed on the second connecting pipe. One end of the second connecting pipe is connected to the upper part of the first filter assembly, and the other end is connected to the lower part of the second filter assembly. The second filter assembly includes a second filter box, a first filter stone layer, and a second filter stone layer; The first filter stone layer and the second filter stone layer are arranged sequentially from top to bottom in the second filter box; The first filter stone layer consists of several uniformly arranged first filter stones; The second filter stone layer consists of several uniformly arranged second filter stones. The diameter of the first filter stone is smaller than the diameter of the second filter stone; The wastewater passes through the second filter stone and the first filter stone before entering the wastewater treatment device. The wastewater treatment unit includes an equalization tank, an anaerobic hydrolysis tank, a two-stage A2O tank, a secondary sedimentation tank, an ozone contact tank, an aerated biological filter, a fiber disc filter, a coagulation tank, and a disinfection tank; the equalization tank, anaerobic hydrolysis tank, two-stage A2O tank, secondary sedimentation tank, ozone contact tank, aerated biological filter, fiber disc filter, coagulation tank, and disinfection tank are arranged in sequence. After pretreatment, the wastewater is regulated in the equalization tank and then enters the anaerobic hydrolysis tank. It then enters the two-stage A2O tank and the secondary sedimentation tank in sequence. The sludge in the secondary sedimentation tank is returned to the two-stage A2O tank. After passing through the ozone contact tank and the aerated biological filter, it enters the fiber disc filter. After passing through the coagulation tank and the disinfection tank, it enters the effluent discharge tank.

2. The sewage collection and treatment system for riverbanks according to claim 1, characterized in that: The equalization tank adjusts the pH of the wastewater to 6-9; The carbon, nitrogen, and phosphorus ratio in the anaerobic hydrolysis tank should be maintained at (200-300):5:1; The hydraulic retention time (HRT) in the anaerobic hydrolysis tank was controlled at 2 h, and the DO in the anaerobic hydrolysis tank was <0.2 mg / L.

3. The sewage collection and treatment system for riverbanks according to claim 1, characterized in that: The two-stage A2O tank includes a first anoxic zone, a first aerobic zone, a second anoxic zone, and a second aerobic zone, which are arranged sequentially. The sludge in the secondary sedimentation tank is returned to the first anoxic zone, the first aerobic zone, the second anoxic zone, and the second aerobic zone, respectively. In the first anoxic zone of the two-stage A2O tank, DO < 0.5 mg / L; DO in the first aerobic zone > 2 mg / L; DO in the second hypoxic zone < 0.5 mg / L; DO in the second aerobic zone > 2 mg / L; The carbon, nitrogen, and phosphorus ratio in the first and second aerobic zones is 100:5:

1.

4. A sewage collection and treatment system for riverbanks according to claim 3, characterized in that: Part of the sludge in the secondary sedimentation tank enters the two-stage A2O tank, and the other part is pumped into the sludge storage tank and discharged after passing through the dewatering room.

5. A sewage collection and treatment system for riverbanks according to claim 3, characterized in that: The filtration accuracy of the filter cloth in the fiber disc filter is less than 10μm; The coagulants used in coagulation disinfection are polyaluminum chloride (PAC) and polyacrylamide (PAM); PAC is cationic and PAM is anionic. Hypochlorous acid is used as the disinfectant in coagulation disinfection.

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