A circular sewage treatment tank

Abstract

This utility model discloses a ring-shaped wastewater treatment tank, belonging to the technical field of wastewater treatment. The tank includes an anaerobic tank, a contact oxidation tank, and an constructed wetland arranged concentrically from the inside out. The anaerobic tank consists of a fixed outer wall and a movable inner sleeve. The movable inner sleeve can be moved up and down via an electric jack at the bottom to adjust the volume and hydraulic retention time of the anaerobic tank. An overflow weir and an outwardly extending overflow plate are provided at the top of the movable inner sleeve. By adjusting the height of the inner sleeve, this utility model can create a dynamic environment of anaerobic, anoxic, and aerobic conditions within the system, effectively improving nitrogen and phosphorus removal capabilities. The overflow plate creates a "spread-fall" process for wastewater, enhancing natural oxygenation and reducing energy consumption. This system is compact, flexible in operation, and suitable for small to medium-scale wastewater treatment.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, specifically to a ring-shaped wastewater treatment tank. Background Technology

[0002] Constructed wetland wastewater treatment systems are particularly suitable for wastewater treatment in small and medium-sized towns and rural areas due to their advantages such as low construction and operating costs, simple maintenance, and stable treatment effects. While the traditional combination of anaerobic ponds and constructed wetlands effectively removes organic pollutants from wastewater to a certain extent, significant technical bottlenecks still exist.

[0003] For example, in the prior art (Patent No.: CN205616719U, Title: Integrated Circular Constructed Wetland Wastewater Treatment System with Anaerobic Pond), a concentric circular wastewater treatment system comprising an anaerobic pond, a contact oxidation pond, and a constructed wetland is disclosed. This technology reduces the footprint through integrated design and improves treatment efficiency to a certain extent by utilizing the contact oxidation pond.

[0004] However, after in-depth analysis and practical verification, the existing technical solution still has the following inherent defects: Limited nitrogen and phosphorus removal efficiency: Although the system includes a contact oxidation tank, its operation mode is fixed and monotonous. Wastewater enters the aerobic contact oxidation tank directly after passing through the anaerobic tank, primarily undergoing organic matter degradation and nitrification. The lack of an efficient anaerobic / anoxic environment for denitrification results in insufficient total nitrogen removal. Simultaneously, an effective "anaerobic phosphorus release-aerobic phosphorus uptake" environment is also not established for phosphorus removal, leading to unsatisfactory phosphorus removal.

[0005] The system operates in a rigid manner and has weak resistance to shock loads: its water flow path and the biochemical environment of the treatment unit are fixed. When the quality and quantity of influent water fluctuate, the system cannot self-regulate to adapt to the changes, resulting in unstable treatment effects and easy deterioration of effluent water quality due to pollutant load shocks.

[0006] Poor functional scalability: The processing potential of this system is limited by its fixed structure, and it cannot be upgraded to a more advanced processing technology (such as A / O process) without changing the core structure.

[0007] Therefore, existing circular wastewater treatment ponds have shown their limitations in the pursuit of higher effluent standards (such as meeting the Class A standard of the "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants"). There is an urgent need for a new type of wastewater treatment system that can significantly improve nitrogen and phosphorus removal efficiency, enhance operational flexibility, and have the ability to withstand shock loads while retaining the advantages of its integrated, circular layout. Utility Model Content

[0008] The purpose of this utility model is to overcome the aforementioned technical difficulties. This utility model provides a ring-shaped sewage treatment tank, which, while retaining its advantages of integration and ring layout, can significantly improve nitrogen and phosphorus removal efficiency, enhance operational flexibility, and has the ability to resist shock loads.

[0009] To achieve the above objectives, the technical solution adopted is as follows: a ring-shaped sewage treatment pond, comprising an anaerobic pond, a contact oxidation pond, and an artificial wetland arranged concentrically from the inside to the outside, characterized in that: the bottom of the anaerobic pond is provided with an inlet, and the heights of the anaerobic pond, the contact oxidation pond, and the artificial wetland are arranged sequentially from high to low; The anaerobic tank consists of a fixed outer wall and a movable inner sleeve. The movable inner sleeve is fitted onto the fixed outer wall and can move up and down relative to it. The bottom of the movable inner sleeve is provided with an electric support component that drives its lifting and lowering. An overflow weir is provided at the top of the movable inner sleeve.

[0010] Furthermore, the electric jacking component is one of an electric push rod, a spiral lifting mechanism, or a hydraulic cylinder, and the water inlet is located on one side of the electric jacking component at the bottom of the anaerobic tank.

[0011] Furthermore, the inner wall of the fixed outer wall is provided with a groove in the vertical direction, and the outer wall of the movable inner sleeve is slidably connected with a protrusion in the groove.

[0012] Furthermore, the contact oxidation tank is filled with suspended biological packing material, and the filling rate of the suspended biological packing material is 20% to 40%.

[0013] Furthermore, it also includes a control system, which is electrically connected to the electric jack.

[0014] Furthermore, the contact oxidation tank is equipped with an oxidation-reduction potential sensor, and the control system performs control based on the feedback signal from the oxidation-reduction potential sensor.

[0015] Furthermore, the overflow weir is one of a sawtooth weir, a continuous weir, or a perforated pipe weir.

[0016] Furthermore, an overflow plate is provided on the top of the overflow weir, extending outward and parallel to the ground, with the outer edge of the overflow plate located above the inner side of the contact oxidation tank wall.

[0017] The beneficial effects of adopting the above solution are as follows: Addressing the problem of "limited nitrogen and phosphorus removal efficiency," this invention achieves flexible adjustment of the effective volume of the anaerobic tank through a liftable inner sleeve structure. By controlling the lifting of the inner sleeve, anaerobic, anoxic, and aerobic environments can be actively created and switched within the system, providing the necessary anoxic conditions for denitrification and creating an ideal environment for the "anaerobic phosphorus release" and "aerobic phosphorus uptake" of polyphosphate-accumulating bacteria. This significantly improves the system's removal efficiency for total nitrogen and total phosphorus, making it easier for the effluent to meet higher discharge standards (such as Class A standards).

[0018] To address the issues of "rigid system operation mode and weak resistance to shock loads," the movable inner sleeve, combined with the electric jacking component, control system, and oxidation-reduction potential sensor, forms an intelligent response unit. When the influent water quality and quantity fluctuate, the system can automatically adjust the height of the inner sleeve through sensor feedback, changing the hydraulic residence time and flow state of each treatment unit. This achieves dynamic optimization of operating parameters, greatly enhancing the system's resistance to shock loads and operational stability, ensuring excellent effluent water quality even under fluctuating conditions.

[0019] Addressing the issue of "poor functional scalability," the core adjustment component (movable inner sleeve) of this invention is ingeniously designed, requiring no alteration to the basic annular structure of the tank. By adjusting the height and residence time of the inner sleeve, more advanced process flow patterns such as A / O (anaerobic-aerobic) and A² / O (anaerobic-anoxic-aerobic) can be easily simulated, endowing the system with powerful functional scalability and process upgrade potential, overcoming the limitations of the original system's fixed structure and single function.

[0020] Inheriting and optimizing the advantages of integrated layout: While solving the aforementioned technical challenges, this utility model fully retains the traditional advantages of the ring structure, such as small footprint, continuous process, and convenient construction and maintenance. Furthermore, the optimized overflow weir structure (such as a sawtooth weir combined with an overflow plate) ensures uniform water distribution to the contact oxidation tank, avoiding short-circuiting and further improving overall treatment efficiency and reliability. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the annular sewage treatment tank of this utility model.

[0022] Figure 2 for Figure 1 Side view.

[0023] Figure 3 This is a schematic diagram of the annular sewage treatment tank in Example 2.

[0024] In the diagram, 1 is a chute; 2 is an anaerobic tank; 3 is an overflow weir; 4 is a contact oxidation tank; 5 is a wetland; 6 is an electric jack; 7 is a protrusion; and 8 is an overflow plate. Detailed Implementation

[0025] The technical solution of this utility model will be clearly and completely described below with reference to specific embodiments. The described embodiments are merely some, not all, of these embodiments. 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.

[0026] Example 1 like Figure 1 and Figure 2 As shown, this utility model provides a ring-shaped wastewater treatment tank, comprising an anaerobic tank 2, a contact oxidation tank 4, and an constructed wetland 5 arranged concentrically from the inside out. The anaerobic tank 2 has an inlet at its bottom for receiving wastewater to be treated. The anaerobic tank 2, contact oxidation tank 4, and constructed wetland 5 are arranged in descending order of height to ensure that water flows sequentially through each treatment unit by gravity.

[0027] The anaerobic tank 2 consists of a fixed concrete outer wall and a movable inner sleeve. A vertical groove 1 is formed on the inner side of the fixed outer wall. A protrusion 7, which mates with the groove 1, is fixedly connected to the outer wall of the movable inner sleeve, allowing the inner sleeve to move smoothly up and down along the groove 1 and preventing horizontal deflection. An electric lifting device 6, preferably a waterproof electric push rod, is provided at the bottom of the movable inner sleeve to drive its lifting and lowering. An overflow weir 3, preferably a sawtooth weir, is provided at the top of the movable inner sleeve to ensure uniform overflow.

[0028] The contact oxidation tank 4 is filled with suspended biological packing material, with a filling rate of 30%. In practice, the suspended biological packing material is spherical or multi-faceted hollow spheres made of polyethylene or polypropylene, with a filling rate of 30%. This type of packing material has the characteristics of large specific surface area, easy biofilm formation, and good fluidization performance. Specifically, the constructed wetland 5 is filled with gravel and sand and planted with wetland plants (such as reeds and cattails).

[0029] In a specific implementation, it also includes a control system, which is electrically connected to the electric support member 6.

[0030] Working principle: Wastewater enters from the inlet at the bottom of anaerobic tank 2 and undergoes hydrolysis and acidification. Based on a preset program or sensor feedback, the control system activates the electric jacking component 6 to raise or lower the movable inner sleeve, thereby adjusting the effective water depth and hydraulic retention time of anaerobic tank 2. The treated wastewater overflows evenly through the sawtooth weir at the top to the contact oxidation tank 4, where organic matter is further degraded and nitrification occurs in an aerobic environment. Subsequently, the wastewater enters the outermost constructed wetland 5, where it undergoes deep purification through the combined action of plants, microorganisms, and substrates, ultimately meeting discharge standards.

[0031] Example 2 like Figure 3 As shown, based on Embodiment 1, this embodiment has been optimized as follows: the top of the overflow weir 3 extends outward and is provided with an overflow plate 8 parallel to the ground, and the outer edge of the overflow plate 8 is precisely positioned above the inner side of the contact oxidation tank 4.

[0032] In practice, the contact oxidation tank 4 is equipped with an oxidation-reduction potential sensor, and the control system performs control based on the feedback signal from the oxidation-reduction potential sensor.

[0033] The significant advantage of this embodiment is that: Optimized flow pattern and significantly improved oxygenation: After overflowing from the overflow weir 3, wastewater does not fall directly into the contact oxidation tank. Instead, it first spreads gently across the entire surface of the overflow plate 8, forming a thin water film, and then falls evenly from its outer edge into the contact oxidation tank 4 below. This process of "overflow from the weir → spread on the plate → evenly falling from the edge" greatly increases the contact area and contact time between the water flow and air compared to the traditional single fall, thus significantly enhancing the natural aeration and oxygenation effect. This efficient oxygenation method provides a richer supply of dissolved oxygen for aerobic microorganisms in the contact oxidation tank, effectively enhancing the degradation and nitrification efficiency of organic matter, while avoiding the energy consumption associated with relying on external power aeration.

[0034] Achieving uniform water distribution: Overflow plate 8 allows water to spread and distribute evenly before entering the biological packing area, effectively preventing concentrated water flow from impacting local areas of the packing, eliminating short-circuiting, and ensuring that the packing in the entire contact oxidation tank is fully utilized, resulting in a uniform treatment load and improved overall treatment efficiency and stability.

[0035] Intelligent linkage control: Similarly, in this embodiment, an oxidation-reduction potential (ORP) sensor or dissolved oxygen (DO) sensor can also be added to the contact oxidation tank 4, which is linked with the control system and the electric top support 6. When the sensor detects insufficient dissolved oxygen, the system can adjust the overflow flow and drop height by adjusting the height of the inner sleeve, thereby assisting in the adjustment of the natural oxygenation intensity.

[0036] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention.

[0037] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A circular sewage treatment tank, characterized in that: It includes an anaerobic tank (2), a contact oxidation tank (4) and an artificial wetland (5) arranged concentrically from the inside to the outside, characterized in that: the bottom of the anaerobic tank (2) is provided with an inlet, and the heights of the anaerobic tank (2), the contact oxidation tank (4) and the artificial wetland (5) are arranged from high to low; The anaerobic tank (2) consists of a fixed outer wall and a movable inner sleeve. The movable inner sleeve is fitted with the fixed outer wall and can move up and down relative to it. The bottom of the movable inner sleeve is provided with an electric top support (6) that drives its lifting and lowering. An overflow weir (3) is provided at the top of the movable inner sleeve.

2. The annular sewage treatment tank according to claim 1, characterized in that: The electric top support (6) is one of an electric push rod, a spiral lifting mechanism or a hydraulic cylinder, and the water inlet is located on one side of the electric top support (6) at the bottom of the anaerobic tank (2).

3. The annular sewage treatment tank according to claim 1, characterized in that: The inner wall of the fixed outer wall is provided with a groove (1) in the vertical direction, and the outer wall of the movable inner sleeve is slidably connected with a protrusion (7) in the groove (1).

4. The annular sewage treatment tank according to claim 1, characterized in that: The contact oxidation tank (4) is filled with suspended biological packing material, and the filling rate of the suspended biological packing material is 20%~40%.

5. The annular sewage treatment tank according to claim 2, characterized in that: It also includes a control system, which is electrically connected to the electric top support (6).

6. The annular sewage treatment tank according to claim 5, characterized in that: The contact oxidation tank (4) is equipped with an oxidation-reduction potential sensor, and the control system is controlled based on the feedback signal of the oxidation-reduction potential sensor.

7. The annular sewage treatment tank according to claim 1, characterized in that: The overflow weir (3) is one of a sawtooth weir, a continuous weir, or a perforated pipe weir.

8. The annular sewage treatment tank according to claim 7, characterized in that: The overflow weir (3) extends outward from the top and is provided with an overflow plate (8) parallel to the ground. The outer edge of the overflow plate (8) is located above the inner side of the contact oxidation tank (4).

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