A device for purifying sewage from urban river outlets

Abstract

This utility model relates to the field of wastewater treatment technology, specifically a device for purifying wastewater from urban river outlets. It includes a main body, a water distributor, micro-nano aeration discs, a fixed biofilm carrier, and a PLC control cabinet. The main body is equipped with upper and lower limiting perforated plates to restrict the movement range of the porous, nest-like biofilm carrier, and micro-nano aeration enhances oxygen transfer efficiency. The device adopts a compact, bank-side design, integrating an influent pump, an aeration pump, and an automated control system to achieve uniform wastewater distribution, efficient aeration, and automatic sludge discharge. The fixed biofilm carrier has pre-fixed functional microbial communities on its surface, eliminating the need for inoculation with native microorganisms, shortening the biofilm formation cycle, and improving the removal efficiency of pollutants (COD, ammonia nitrogen, TP, TN). This device also has advantages such as small footprint, low operating costs, and strong resistance to shock loads, making it suitable for the efficient treatment of wastewater from urban river outlets.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, specifically to a device for purifying wastewater from urban river outlets. Background Technology

[0002] As urban economies develop rapidly, wastewater production also increases. Although wastewater treatment is now receiving sufficient attention, the direct discharge of wastewater into rivers remains widespread due to factors such as low coverage of existing urban sewage pipe networks and high treatment costs. Furthermore, once wastewater spreads into waterways, the polluted area and volume expand rapidly, making remediation difficult and severely impacting the social, economic, and cultural value of urban waterways. With the increasing national emphasis on environmental protection and rising public demand for a better living environment, how to economically and efficiently solve the problem of wastewater discharge into rivers has become a hot topic.

[0003] To address the problems of high concentration, easy diffusion, large volume, and difficult treatment of urban sewage from outfalls, researchers have proposed biofilm purification technology. This method involves forming a biofilm on a biological carrier and utilizing functional bacteria within the biofilm that target carbon, nitrogen, and phosphorus pollutants to purify the sewage. Compared to traditional sewage purification technologies, biofilm technology offers advantages such as low investment cost, high resistance to shock loads, no secondary pollution, simple operation and management, and small footprint, making it suitable for urban river outfall sewage treatment. However, current domestic biofilm equipment generally relies on indigenous microbial inoculation, which presents challenges such as difficulty in biofilm formation, long start-up cycles, and low purification efficiency. Furthermore, mainstream biofilm equipment currently used for urban river water purification also suffers from large footprints and low pollution loads, severely limiting the large-scale application of biofilm technology in river outfall sewage purification.

[0004] Therefore, it is necessary to design a set of efficient and stable biofilm purification equipment that does not rely on native bacterial strains for inoculation of microorganisms, and can achieve stable and low-cost operation while effectively removing pollutants from wastewater. Utility Model Content

[0005] The problem to be solved is to provide equipment for urban river outlets that can effectively remove pollutants from sewage without relying on native bacteria, while also being able to start up quickly and operate stably and at low cost.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a device for purifying sewage from urban river outlets, comprising a main body, an inlet, an outlet, and an air inlet. The inlet and outlet are arranged from bottom to top, with a water distributor, a micro-nano aeration disc, a lower limit perforated plate, a fixed biofilm carrier, and an upper limit perforated plate arranged sequentially between them. The water distributor is connected to the river outlet via an inlet pump. The micro-nano aeration disc is located between the water distributor and the lower limit perforated plate and connected to an aeration pump. The upper limit perforated plate is located at the outlet. The fixed biofilm carrier is located between the lower limit perforated plate and the upper limit perforated plate. The inlet pump and the aeration pump are both located outside the main body and controlled by a PLC control cabinet. The apertures of the lower limit perforated plate and the upper limit perforated plate are smaller than the outer diameter of the fixed biofilm carrier. The surface of the fixed biofilm carrier's skeletal structure is pre-fixed with functional bacteria.

[0007] Preferably, the main body of the equipment is placed on the bank of the river outlet, and the inlet of the main body of the equipment is connected to the outlet enclosure through an inlet pump. The outlet enclosure receives the sewage discharged from the river outlet, and the outlet is connected to the river.

[0008] Preferably, the upper limit orifice plate is inclinedly disposed on the inner wall of the equipment body and forms an upward angle with the inner wall of the equipment body, the angle ranging from 20 to 30°.

[0009] Preferably, the outer diameter of the fixed biofilm carrier is 20-30 mm; the pore diameter of the lower limiting plate and the upper limiting plate is 10-15 mm.

[0010] Preferably, a mud discharge hopper is provided below the water distributor.

[0011] Preferably, the water distributor is cylindrical, with several 10-15mm water distribution holes on the upper side.

[0012] Preferably, the diameter of the micro / nano aeration disc is 300 mm.

[0013] Preferably, the fixed biofilm carrier is a porous nest-like cubic structure with a length of 20-30 mm.

[0014] Preferably, the top of the device body is provided with an inspection port.

[0015] Compared with existing technologies, this utility model provides a device for purifying sewage from urban river outlets, which has the following beneficial effects: Micro-nano aeration discs enhance oxygen transfer efficiency, and combined with a biofilm carrier pre-fixed with functional bacteria, significantly improve the removal rates of COD, ammonia nitrogen, TP, and TN, adapting to water quality fluctuations; the pre-fixed functional bacteria on the carrier surface shortens the biofilm formation cycle by more than 50%, eliminating the need for indigenous microbial inoculation; PLC automated control reduces manual intervention, and timed sludge discharge and precise aeration reduce power consumption, resulting in a 30% reduction in overall operating costs compared to traditional processes; the bank-side design occupies an area of ​​1m². 2It is suitable for urban river channels with limited space, and the equipment manufacturing and installation costs are low; the biofilm process does not require the addition of chemical agents, avoiding secondary pollution; precise sludge discharge reduces the amount of sludge to be treated. Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating the usage scenario of the device of this utility model;

[0017] Figure 2 This is a schematic diagram of the structure of the device of this utility model;

[0018] Figure 3 This is a schematic diagram of the water distributor structure involved in this utility model;

[0019] Figure 4 This is a schematic diagram of the lower limit orifice plate and the upper limit orifice plate involved in this utility model.

[0020] Explanation of reference numerals in the attached drawings: 1. Outlet enclosure; 2. Main body of equipment; 3. Inlet pipe; 4. Water distributor; 41. Water distribution hole; 5. Aeration pipe; 6. Micro-nano aeration disc; 7. Lower limit orifice plate; 8. Upper limit orifice plate; 9. Fixed biofilm carrier; 10. Inspection port; 11. Inlet pump; 12. Aeration pump; 13. PLC control cabinet; 14. Outlet; 15. Sludge hopper; 16. Support structure; 17. Inlet; 18. Air inlet; 19. Flange interface; 20. Solenoid valve. Detailed Implementation

[0021] The technical solutions of the present utility model will now be described with reference to the accompanying drawings in the embodiments of the present utility model:

[0022] To address the problems in the background technology, reduce the reliance of urban river outlet sewage purification equipment on indigenous microorganisms, and shorten the biofilm formation time, as shown in the figure, this utility model provides a device for purifying urban river outlet sewage. The device includes a main body 2, with its bottom supported by a support structure 16 on the riverbank. The main body 2 serves as the core container, integrating water distribution, aeration, biofilm reaction, and sludge discharge functions, providing the physical space for sewage treatment. The structural layout of the main body 2 optimizes the sewage flow path, ensuring coordinated operation of all components and improving treatment efficiency. The main body 2 is connected to an outlet enclosure 1, which is installed at the river outlet to intercept sewage, preventing untreated sewage from directly entering the river and achieving preliminary collection and centralized treatment of sewage. The main body 2 of the equipment is equipped with an inlet 17, an outlet 14, and an air inlet 18. The inlet 17 is located at the bottom of the main body 2 and is connected to the sewage in the discharge enclosure 1 via an inlet pipe 3 and an inlet pump 11. The inlet pipe 3 delivers the sewage to the water distributor 4 inside the main body 2. The air inlet 18 is located above the inlet 17 and is connected to the aeration pump 12 via an aeration pipe 5. The aeration pipe 5 delivers gas to the micro-nano aeration disc 6 inside the main body 2. The outlet 14 is located at the top of the main body 2 and is responsible for discharging the purified water into the river. The inlet 17 is located at the bottom of the main body 2 and is connected to the discharge outlet 18. The equipment consists of a water distributor 4, a micro-nano aeration disc 6, a lower limit orifice plate 7, a fixed biofilm carrier 9, and an upper limit orifice plate 8, arranged sequentially from bottom to top between the outlet 7 and outlet 14. The water distributor 4 evenly distributes the wastewater into the equipment, avoiding localized overload and ensuring full contact between the wastewater and the fixed biofilm carrier 9, preventing short-circuiting or dead zones, and improving the uniformity of pollutant degradation. Specifically, the water distributor 4 is connected to the river outlet via an inlet pump 11. The micro-nano aeration disc 6 is located between the water distributor 4 and the lower limit orifice plate 7 and is connected to an aeration pump 12 via an aeration pipe 5. The lower limit orifice plate 7 is horizontally positioned above the micro-nano aeration disc 6 to prevent the fixed biofilm carrier 9 from sinking into the aeration zone and to ensure the suspended circulation of the fixed biofilm carrier 9. The upper limit orifice plate 8 forms an angle α with the equipment, where α is 20-30°, and restricts the fixed biofilm carrier 9 from being lost with the water flow. The double-layer limiting design ensures the uniform distribution of the fixed biofilm carrier 9, maintaining biofilm activity while preventing it from flowing out of the outlet 14. The micro-nano aeration disc 6 generates micro-nano-scale bubbles to enhance oxygen dissolution efficiency, providing sufficient dissolved oxygen for the functional bacteria in the biofilm. Compared to traditional aeration, the oxygen mass transfer efficiency of micro-nano bubbles is increased by 30%-50%, significantly accelerating microbial metabolic reactions. The upper limiting orifice plate 8 is located at the outlet 14. The fixed biofilm carrier 9 is situated between the lower limiting orifice plate 7 and the upper limiting orifice plate 8, providing an attachment surface for the functional bacteria. Pre-fixed functional bacteria can directly participate in pollutant degradation.The inlet pump 11 and the aeration pump 12 are both located outside the main body 2 of the equipment and controlled by the PLC control cabinet 13; the apertures of the lower limit orifice plate 7 and the upper limit orifice plate 8 are both smaller than the outer diameter of the fixed biofilm carrier 9, and the surface of the skeleton structure of the fixed biofilm carrier 9 is pre-fixed with functional bacteria.

[0023] The main body of the equipment 2 is placed on the bank of the river outlet. The inlet 17 of the main body of the equipment 2 is connected to the outlet enclosure 1 through the inlet pump 11. The outlet enclosure 1 receives the sewage discharged from the river outlet. The outlet 14 is connected to the river.

[0024] The upper limit orifice plate 8 is inclinedly set on the inner wall of the main body 2, forming an upward angle with the inner wall of the main body 2, with an angle ranging from 20° to 30°; the outer diameter of the fixed biofilm carrier 9 is 20–30 mm, and the fixed biofilm carrier 9 is a porous nest-like cubic structure with a length of 20–30 mm; the pore diameter of the lower limit orifice plate 7 and the upper limit orifice plate 8 is 10–15 mm. The micro-nano aeration disc 6 has a diameter of 300 mm.

[0025] Water distributor 4 has a hollow columnar structure, such as Figure 3 The water distributor 4 is a hollow pipe. Its left end connects to the inlet 17, and its right end is sealed. Several water distribution holes 41, each with a diameter of 10-15 mm, are provided on the hollow pipe. A sludge discharge hopper 15 is located below the water distributor 4. The bottom of the sludge discharge hopper 15 is connected to a pipe via a flange interface 19. A solenoid valve 20 is located at the pipe outlet and is connected to the PLC control cabinet 13. The sludge discharge hopper 15 collects the sludge that settles at the bottom of the equipment and discharges it periodically via the PLC control cabinet 13 to prevent sludge accumulation from affecting treatment efficiency. The PLC control cabinet 13 also controls the start and stop of the inlet pump 11 and the aeration pump 12, and adjusts the aeration rate and inlet water flow to achieve fully automated management of the entire process. Flow meters can also be installed on the inlet pipe 3 and the aeration pipe 5 to monitor the inlet flow and aeration volume in real time, provide data feedback to the PLC control cabinet 13, and optimize operating parameters; the aeration intensity and hydraulic retention time can be dynamically adjusted according to the flow meter readings to ensure a balance between treatment efficiency and energy consumption.

[0026] The top of the main body 2 of the equipment is provided with an inspection port 10; the inspection port 10 provides an internal inspection channel for the equipment, which facilitates the replacement of the fixed biofilm carrier 9, the cleaning of the micro-nano aeration disc 6 and the troubleshooting.

[0027] In this embodiment of the invention, the upper limit orifice plate 8 and the lower limit orifice plate 7 inside the main body 2 have a hole diameter of 15mm. The lower limit orifice plate 7 is horizontally placed above the micro-nano aeration disc 6, and the upper limit orifice plate 8 is located at the outlet 14 at a 20° angle to the inner wall of the main body 2. Flow meters are installed in the water inlet pipe 3 and the aeration pipe 5 of the main body 2. The water distributor 4 is designed as a columnar structure, such as... Figure 3The water distributor 4 shown has several water distribution holes 41 on its upper side, each with a diameter of 10mm. The main body 2 is connected to the inlet pipe 3. The micro-nano aeration disc 6, with a diameter of 300mm, is located above the water distributor 4 and is connected to the external aeration pump 12 via the aeration pipe 5. The fixed biofilm carrier 9 is filled between the lower limit orifice plate 7 and the upper limit orifice plate 8. The fixed biofilm carrier 9 is a 20mm porous nest-shaped cube with pre-fixed functional bacteria on its surface. The outer diameter of the fixed biofilm carrier 9 is larger than the pore diameter on the lower limit orifice plate 7 and the upper limit orifice plate 8, and it circulates in suspension between the lower limit orifice plate 7 and the upper limit orifice plate 8. The PLC control cabinet 13 controls the inlet pump 11, the aeration pump 12, and the solenoid valve 20. The fixed biofilm carrier 9 is made of hydrophilic polyurethane sponge with a density close to that of water, allowing it to circulate under aeration and hydraulic action.

[0028] In operation, wastewater is first collected, and the wastewater at the river mouth is intercepted by the discharge outlet enclosure 1. The wastewater is then pumped to the water distributor 4 by the inlet pump 11. The water distributor 4 then distributes the water evenly, dispersing the wastewater evenly into the main body 2 of the equipment through the distribution holes 41. After that, the purified water is discharged through aeration and oxygenation. The micro-nano aeration disc 6 releases highly dissolved oxygen bubbles, providing the functional bacteria with the oxygen required for metabolism. The wastewater flows through the fixed biofilm carrier 9, where pre-fixed functional bacteria degrade pollutants such as COD and ammonia nitrogen. The purified water is then discharged into the river after passing through the lower limit orifice plate 7 and the outlet 14, meeting the discharge standards.

[0029] This invention features a small footprint, which is crucial for urban water treatment equipment where space requirements are high, and large equipment is often prohibited on riverbanks. The small footprint and simple structure of this invention reduce manufacturing and on-site construction costs. It utilizes a biofilm process instead of traditional physicochemical methods that can cause secondary pollution. The biofilm process eliminates the need for chemical or microbial additives, achieving long-term purification with high stability and resistance to shock loads. Furthermore, the design incorporates a PLC system for scheduled sludge removal, eliminating the need for personnel intervention during operation. Compared to in-situ river biofilm systems, this small-scale riverside device offers controllable operating parameters, including influent water quality (ammonia nitrogen, COD, TP, TN, etc.), influent flow rate, hydraulic retention time (HRT), temperature, and aeration rate. The compact design enhances oxygen utilization, reduces power consumption, and lowers operating costs.

[0030] The immobilized biofilm carrier 9 in this invention has significant advantages, as the pre-immobilized functional microbial community does not rely on indigenous strains. Specific advantages are as follows:

[0031] (1) Structural advantages: The fixed biofilm carrier 9 is a porous nested cubic structure with a length of 20-30mm. The porous nested cubic structure has sufficient surface area for biofilm attachment. Secondly, the biofilm near the inside of the cubic structure is not easily lost, which is conducive to the long-term effectiveness of the system's purification effect.

[0032] (2) Material advantages: The fixed biofilm carrier 9 is made of hydrophilic polyurethane sponge with a density close to that of water. It can be suspended inside the equipment and form a circulation under hydraulic shear force and aeration, which can promote the replacement of old and new biofilms and keep the equipment highly efficient in purification. In addition, the fixed biofilm carrier 9 circulates inside the equipment, and its contact with sewage is more sufficient, which is conducive to further improving the purification efficiency.

[0033] (3) Advantages of microbial strains: The strains used in the fixed biofilm carrier 9 are screened functional strains rather than relying on native strains for coating. After the functional strains proliferate to form a biofilm, the purification efficiency of the biofilm equipment is greatly improved compared with that of native strains.

[0034] (4) Advantages of the start-up method: The fixed biofilm carrier 9 uses microbial immobilization technology to fix functional bacteria onto the polyurethane sponge carrier in advance, which reduces the process of inoculating microorganisms in the equipment, which is conducive to the rapid formation of biofilm and shortens the start-up time of the equipment.

[0035] This invention provides a device for purifying sewage from urban river outfalls. By integrating a water distributor 4, micro-nano aeration discs 6, a fixed biofilm carrier 9 with pre-fixed functional bacteria, and an automated control system, it achieves efficient sewage treatment and stable operation. The fixed biofilm carrier 9 adopts a porous, nested cubic structure, combined with a lower limiting perforated plate 7 and an upper limiting perforated plate 8, ensuring uniform distribution of the biofilm and preventing long-term loss of its activity. Its miniaturized structure on the riverbank adapts to the space constraints of urban river channels, and PLC intelligent control reduces the difficulty of operation and maintenance. In practical applications, this device can rapidly degrade pollutants (COD removal rate ≥85%, ammonia nitrogen removal rate ≥90%) and has strong resistance to shock loads.

[0036] The above embodiments are merely some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

Claims

1. A device for purifying urban river mouth sewage, comprising a device main body (2), the device main body (2) is provided with a water inlet (17), a water outlet (14) and an air inlet (18), characterized in that: The water inlet (17) and the water outlet (14) are arranged from bottom to top, and a water distributor (4), a micro-nano aerator (6), a lower limiting hole plate (7), a fixed biofilm carrier (9), and an upper limiting hole plate (8) are sequentially arranged between the water inlet (17) and the water outlet (14); the water distributor (4) is connected with a river channel outlet through a water inlet pump (11), the micro-nano aerator (6) is located between the water distributor (4) and the lower limiting hole plate (7) and is connected with an aeration pump (12), and the upper limiting hole plate (8) is arranged at the water outlet (14); the fixed biofilm carrier (9) is located between the lower limiting hole plate (7) and the upper limiting hole plate (8); the water inlet pump (11) and the aeration pump (12) are arranged outside the equipment main body (2) and are controlled through a PLC control cabinet (13); the pore diameter of the lower limiting hole plate (7) and the upper limiting hole plate (8) is smaller than the outer diameter of the fixed biofilm carrier (9), and the surface of the skeleton structure of the fixed biofilm carrier (9) is pre-fixed with functional bacteria.

2. The device for purifying urban river mouth sewage according to claim 1, characterized in that: The equipment main body (2) is arranged at the river channel outlet bank, the water inlet (17) of the equipment main body (2) is connected with the outlet enclosure (1) through the water inlet pump (11), the outlet enclosure (1) receives sewage discharged from the river channel outlet, and the water outlet (14) is connected with the river channel.

3. The device for purifying urban river mouth sewage according to claim 1, characterized in that: The upper limiting hole plate (8) is arranged on the inner wall of the equipment main body (2) in an inclined manner and forms an upward included angle with the inner wall of the equipment main body (2), and the included angle ranges from 20 to 30 degrees.

4. The device for purifying urban river mouth sewage according to claim 1, characterized in that: The outer diameter of the fixed biofilm carrier (9) is 20-30 mm; the pore diameter of the lower limiting hole plate (7) and the upper limiting hole plate (8) is 10-15 mm.

5. The device for purifying urban river mouth sewage according to claim 1, characterized in that: A sludge discharge hopper (15) is arranged below the water distributor (4).

6. The device for purifying urban river mouth sewage according to claim 1, characterized in that: The water distributor (4) is a column, and a plurality of water distribution holes (41) with a diameter of 10-15 mm are arranged on the upper side of the water distributor (4).

7. The device for purifying urban river mouth sewage according to claim 1, characterized in that: The micro-nano aerator (6) has a diameter of 300 mm.

8. The device for purifying urban river mouth sewage according to claim 1, characterized in that: The fixed biofilm carrier (9) is a porous nest-shaped cubic structure with a length of 20-30 mm.

9. The device for purifying urban river mouth sewage according to claim 1, characterized in that: The equipment main body (2) is provided with an inspection port (10) at the top.

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