Composite ecological ditch system for coastal rural high-nitrogen domestic sewage treatment

Abstract

The utility model relates to a composite ecological ditch system for coastal rural high-nitrogen domestic sewage treatment, which comprises an integrated anaerobic jar and an ecological ditch treatment unit, the ecological ditch treatment unit comprises a ditch side wall and a ditch bottom, the top of the ditch side wall is provided with a coping, and the bottom is provided with a base; water-permeable grass planting bricks for planting emergent aquatic plants are laid on the side walls of the ditch; the ditch bottom comprises a planting layer, a permeable layer and a drainage layer, the planting layer is used for planting submerged plants, zeolite is filled in the permeable layer, a water distribution pipe is arranged in the center of the permeable layer, and gravels and gravels with large particle sizes are filled in the drainage layer. And an efficient system integrating sewage collection, pretreatment and ecological treatment is formed. Compared with a traditional decentralized treatment facility, complementary advantages of the two technologies can be brought into full play, the sewage treatment efficiency can be improved, the treatment period can be shortened, the energy consumption and the operation cost can be reduced, and cyclic utilization of water resources and sustainable development of the ecological environment are promoted.

Description

Technical Field

[0001] This application relates to the field of water purification technology, and in particular to a composite ecological ditch system for treating high-nitrogen domestic sewage in coastal rural areas. Background Technology

[0002] With the rapid economic development of coastal areas, rural sewage discharge has increased significantly. Compared to urban sewage, rural sewage is characterized by higher nitrogen content, greater seasonal variation in concentration, and better biodegradability. In coastal rural areas, especially in densely populated areas, domestic sewage typically contains large amounts of organic matter and nitrogen compounds. The continuous increase in nitrogen content in water bodies not only leads to eutrophication, causing oxygen deficiency and producing toxins, thus endangering aquatic life; the nitrogen-containing nitrosamines formed during the slow conversion of nitrate nitrogen are potential carcinogens. These problems not only affect water quality but also threaten human health and ecological balance. However, in coastal rural areas, due to limited land resources and insufficient infrastructure, traditional sewage treatment methods face significant challenges. Therefore, finding an economical, effective, and adaptable sewage treatment system is particularly important.

[0003] Currently, common methods for wastewater treatment include anaerobic digesters or ecological ditches. While both have significant advantages, relying on a single technology has limitations. The treatment efficiency of anaerobic reactors is highly sensitive to the organic matter concentration in the wastewater. If the organic matter concentration in the raw water is too low, insufficient microbial degradation may occur, affecting nitrogen removal. In high-nitrogen wastewater treatment, ammonia nitrogen produced in anaerobic digesters may require further treatment through subsequent denitrification processes (such as nitrification-denitrification), increasing system complexity and operating costs. Ecological ditches often suffer from uneven water flow, wastewater accumulation, and low removal efficiency. Especially when dealing with the rapid removal of high-nitrogen wastewater, relying solely on ecological ditches often falls short of expectations, particularly under high water load conditions, where treatment capacity may be insufficient. Utility Model Content

[0004] To address or partially address the problems existing in related technologies, this application provides a composite ecological ditch system for treating high-nitrogen domestic sewage in coastal rural areas. This composite ecological ditch system combines the advantages of anaerobic tanks and ecological ditches, overcomes the limitations of single technologies, and is suitable for treating high-nitrogen domestic sewage in coastal rural areas.

[0005] The first aspect of this application provides a composite ecological ditch system for treating high-nitrogen domestic sewage in coastal rural areas, comprising:

[0006] An integrated anaerobic tank includes an inlet pipe on one side, a vortex distributor at the end of the inlet pipe, a suspended sludge reaction zone and a three-phase separator above the vortex distributor, an outlet weir above the three-phase separator, an outlet pipe connected to the outlet weir, an overflow pipe for adjusting the water level, and an exhaust pipe installed inside the three-phase separator that is connected to a gas treatment device.

[0007] The ecological ditch treatment unit includes ditch sidewalls and ditch bottom. The top of the ditch sidewalls is equipped with a capping, and the bottom is equipped with a base. The ditch sidewalls are paved with permeable grass bricks for planting emergent plants. The ditch bottom includes a planting layer, a permeable layer and a drainage layer. The planting layer is used to plant submerged plants. The permeable layer is filled with zeolite and has a water distribution pipe in the center. The drainage layer is filled with large-diameter gravel and pebbles.

[0008] The vortex water distributor includes a vortex water distributor assembly and water distribution main pipes evenly distributed around the vortex water distributor assembly. Each water distribution main pipe is connected to multiple water distribution nozzles at equal intervals.

[0009] The water distribution pipes are arranged in a "fishbone" shape in the middle of the permeable layer, including the main water distribution pipe and the branch water distribution pipes. The branch water distribution pipes are symmetrically distributed at equal intervals on both sides of the main water distribution pipe.

[0010] The anaerobic tank is equipped with a sludge discharge device at the bottom and a flow monitor and regulating valve on the inlet pipe.

[0011] A fence is installed above the top of the dam to prevent debris from falling into the ditch from both sides. The technical solution provided in this application can include the following beneficial effects:

[0012] This application provides a composite ecological ditch system for treating high-nitrogen domestic sewage in coastal rural areas. It combines the advantages of anaerobic digesters and ecological ditches, forming a highly efficient system integrating sewage collection, pretreatment, and ecological treatment. Compared to traditional decentralized treatment facilities, it fully leverages the complementary advantages of both technologies, not only improving sewage treatment efficiency and shortening the treatment cycle but also reducing energy consumption and operating costs. Simultaneously, the generated biogas is collected through a gas collection system and may be used for power generation, heating, or as fuel, demonstrating greater economic efficiency and practicality. This promotes the recycling of water resources and the sustainable development of the ecological environment.

[0013] The swirling water distribution device in the anaerobic tank can evenly distribute wastewater within the tank, ensuring uniform flow of wastewater in the reaction zone and enhancing treatment efficiency. The three-layer structure of the ecological ditch utilizes the synergistic effect of plants, soil, and microorganisms to further purify water quality. Simultaneously, by installing perforated water distribution pipes, the system can evenly distribute wastewater into the ecological ditch, effectively reducing localized wastewater accumulation. This design increases the contact area between wastewater and plant roots, improving plant absorption efficiency and significantly enhancing nitrogen removal rate.

[0014] The composite system is highly scalable and adaptable, and can be flexibly adjusted according to different water quality characteristics and needs to meet the wastewater treatment requirements of different regions.

[0015] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0016] The above and other objects, features and advantages of this application will become more apparent from the more detailed description of exemplary embodiments thereof in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments thereof.

[0017] Figure 1 This is a schematic diagram of the structure of the composite ecological ditch system shown in the embodiments of this application;

[0018] Figure 2 This is a schematic diagram of the integrated anaerobic tank structure of the composite ecological ditch system shown in the embodiments of this application;

[0019] Figure 3 This is a schematic cross-sectional view of the ecological ditch in the composite ecological ditch system shown in the embodiments of this application;

[0020] Figure 4 This is a schematic diagram of the water distribution pipe structure of the composite ecological ditch system shown in the embodiments of this application.

[0021] Figure label:

[0022] 1-Integrated anaerobic tank; 2-Ecological ditch treatment unit; 3-Receiving body; 4-Inlet pipe; 5-Outlet pipe; 6-Overflow pipe; 7-Distribution pipe; 71-Distribution main pipe; 72-Distribution branch pipe; 8-Ditch sidewall; 9-Ditch bottom; 11-Swirl distributor; 12-Suspended sludge reaction zone; 13-Three-phase separator; 14-Outlet weir; 15-Gas treatment device; 16-Exhaust pipe; 17-Sludge discharge device; 41-Flow monitor; 42-Regulating valve; 81-Coping; 82-Fence; 83-Base; 84-Permeable grass brick; 85-Emerging plants; 91-Planting layer; 92-Permeable layer; 93-Drainage layer; 94-Submerged plants. Detailed Implementation

[0023] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0024] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0025] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0026] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0027] The technical solutions of the embodiments of this application are described in detail below with reference to the accompanying drawings.

[0028] Taking the resource utilization of domestic sewage from a residential area with a permanent population of 200 as an example, the sewage generation is 20 m³ / d. For example... Figure 1As shown, this composite ecological ditch system includes an integrated anaerobic tank 1, an ecological ditch treatment unit 2, and a receiving body 3. The integrated anaerobic tank 1 collects wastewater for anaerobic pretreatment to remove most organic matter and nitrogen compounds. The effluent pipe 5 of the anaerobic tank is connected to the ecological ditch distribution pipe 7, through which the pretreated wastewater flows into the ecological ditch. The ecological ditch treatment unit 2 is located after the integrated anaerobic tank 1 to further purify the water. The ecological ditch treatment unit 2 includes ditch sidewalls 8 and a ditch bottom 9. The ditch has an inverted isosceles trapezoidal cross-section, a depth of 0.5m, a width of 1m, and a slope of 0.5%. The receiving body 3 is connected after the ecological ditch treatment unit 2 to receive the treated wastewater, enabling water resource recycling. It can be used for local woodlands, grasslands, vegetable gardens, farmland, etc.

[0029] like Figure 2 As shown, the integrated anaerobic tank 1 has an inlet pipe 4 on one side of its body. The inlet pipe 4 is equipped with a flow monitor 41 and a regulating valve 42 to monitor the wastewater flow rate entering the anaerobic tank in real time and adjust the inlet flow according to the flow requirements to ensure stable inlet flow. A vortex distributor 11 is installed at the end of the inlet pipe. The vortex distributor 11 includes a vortex distributor assembly, with four distribution main pipes evenly distributed around the assembly. Each distribution main pipe is connected to multiple equally spaced distribution nozzles. The vortex distributor system evenly distributes wastewater into the anaerobic tank, ensuring uniform flow of wastewater in the reaction zone and enhancing the reaction effect. Above the distribution device is the suspended sludge reaction zone 12. A three-phase separator 13 is also installed above the interior of the anaerobic tank, effectively separating the gas, liquid, and precipitated solid sludge generated during the anaerobic reaction, ensuring gas and liquid stratification and solid sedimentation to the bottom of the tank. The three-phase separator has an outlet weir 14 at the top, which connects to an outlet pipe 5. An overflow pipe 6 is installed above the outlet pipe 5 to regulate the water level. An exhaust pipe 16 is installed inside the three-phase separator 13, which connects to a gas treatment device 15 to collect and purify the gases (such as biogas) produced during the anaerobic reaction. A sludge removal device 17 is installed at the bottom of the anaerobic tank. Designed for a wastewater influent flow rate of 20 m³ / d, with a hydraulic retention time (HRT) of 1 day, the anaerobic tank volume should be 20 m³. The organic load per cubic meter of anaerobic tank should be controlled at 0.3 kg COD / m³·d. The suspended sludge concentration should be maintained at 3000 mg / L. The anaerobic tank pH should be controlled at 8.0, the operating temperature at 25℃, and the influent flow rate at 0.83 m³ / h. The vortex distributor has a vortex angle of 30° and a stirring speed of 40 rpm.

[0030] like Figure 3As shown, the ecological ditch treatment unit 2 includes ditch sidewalls 8 and ditch bottom 9, which can be modified according to existing local ditches. The cross-section of the ditch sidewall 8 is an inverted isosceles trapezoid, with a concrete capping 81 at the top, 100mm high and 150mm wide. A fence 82 is installed above the concrete capping 81 to prevent debris from falling into the ditch. The fence can be made of stone or wood, and the spacing can be adjusted according to local conditions. Its main purpose is to intercept debris, provide safety protection, and not affect subsequent ditch cleaning and maintenance. A concrete base 83, 150mm high and 200mm wide, is installed at the bottom of the ditch sidewall 8. The ditch sidewall 8 is paved with permeable grass pavers 84, and the permeable grass pavers are filled with soil for planting emergent plants 85, such as canna lilies, irises, and cattails.

[0031] The bottom of the ditch 9 consists of three layers from top to bottom, including a planting layer 91, a permeable layer 92, and a drainage layer 93. A water distribution pipe 7 is installed at the center of the permeable layer 92.

[0032] The planting layer 91 is 20cm high and includes natural soil and supplementary substrate materials. The supplementary substrate materials are new materials such as humus, compost, or rice husk biochar, added in a certain proportion according to local conditions to support plant root growth and provide some water purification. Submerged plants 94, such as Vallisneria natans and Typha orientalis, are planted above the planting layer. Local perennial aquatic plants with high biomass and nitrogen and phosphorus requirements can be selected to effectively intercept particulate matter in wastewater and absorb the intercepted nitrogen and phosphorus nutrients. Around the plant roots, aerobic, facultative, and anaerobic zones are created that promote nitrification, denitrification, and the excessive accumulation of phosphorus by microorganisms, achieving the effect of removing nitrogen, phosphorus, and other pollutants. A plant density of 10-15 plants per square meter is recommended.

[0033] The permeable layer 92 has a height of 20cm and is filled with zeolite (particle size 4-8mm) and slag (particle size 10-15mm) in a 2:1 ratio. This ensures sufficient permeability while utilizing sedimentation filtration and adsorption to remove nitrogen and phosphorus.

[0034] The drainage layer 93 is 20cm high and is filled with large-diameter crushed stone and gravel (15-25mm in diameter), which serves to drain and aerate the water and provide some support. It also promotes the formation of biofilm and the activity of microorganisms.

[0035] like Figure 4As shown, the water distribution pipe 7 is arranged in a "fishbone" shape in the middle of the permeable layer, including a water distribution main pipe 71 and water distribution branch pipes 72. The outer diameter of the water distribution main pipe 71 is 160mm. The water distribution branch pipes 72 are symmetrically distributed at equal intervals on both sides of the water distribution main pipe, with one water distribution branch pipe every 2m. One end of the water distribution branch pipe is connected to the water distribution main pipe 71, and the other end is closed. The ratio of the outer diameter of the water distribution branch pipe 72 to the outer diameter of the water distribution main pipe 71 is 1:2. A water outlet is set every 120° in the circumferential direction of the water distribution pipe 7, and water outlets are also set at equal intervals in the longitudinal direction of the water distribution pipe in the same manner. The diameter of the perforation is 25mm, and the perforation interval is 100mm, which is used to evenly distribute sewage. The water distribution pipe 7 is wrapped with permeable geotextile to prevent the soil above and below from intruding into the pipe, effectively preventing the water distribution pipe from being blocked and maintaining its stable permeability.

[0036] The treatment results are as follows: nitrogen removal efficiency reaches 90%; COD removal rate reaches 80%; and suspended solids removal efficiency reaches over 85% through physical filtration and biodegradation. Water treated in the ecological ditch can be used for agricultural irrigation or other non-potable water needs.

[0037] Finally, it should be noted that in this document, relationships such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "include," "contain," or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0038] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0039] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0040] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application.

[0041] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A composite ecological ditch system for treating high-nitrogen domestic sewage in coastal rural areas, characterized in that, The application relates to an integrated anaerobic tank and an ecological ditch treatment unit. The integrated anaerobic tank comprises a water inlet pipe arranged on one side, a rotational flow water distributor arranged at the end of the water inlet pipe, a suspended sludge reaction zone and a three-phase separator arranged above the rotational flow water distributor, a water outlet weir arranged above the three-phase separator, a water outlet pipe connected with the water outlet weir, an overflow pipe for adjusting the water level, and an exhaust pipe arranged in the three-phase separator and connected with a gas treatment device. The ecological ditch treatment unit comprises ditch side walls and a ditch bottom, the top of the ditch side walls is provided with a pressure top, the bottom is provided with a base, and water-permeable plant bricks for planting emergent plants are arranged on the ditch side walls; the ditch bottom comprises a planting layer, a permeation layer and a drainage layer, the planting layer is used for planting submerged plants, the permeation layer is filled with zeolite and is provided with a water distribution pipe at a central position, and the drainage layer is filled with large-diameter gravel and pebbles.

2. The composite ecological trench system for the treatment of high nitrogen domestic sewage in coastal rural areas according to claim 1, characterized in that, The rotational flow water distributor comprises a rotational flow water distributor assembly and water distribution main pipes which are uniformly and peripherally connected with the rotational flow water distributor assembly, and a plurality of equidistant water distribution nozzles are connected with each water distribution main pipe.

3. The composite ecological trench system for the treatment of high nitrogen domestic sewage in coastal rural areas according to claim 1, characterized in that, The water distribution pipe is arranged in the middle of the permeation layer in a "fish bone shape" and comprises a water distribution main pipe and water distribution branch pipes which are symmetrically and equidistantly arranged on both sides of the water distribution main pipe.

4. The composite ecological trench system for the treatment of high nitrogen domestic sewage in coastal rural areas according to claim 1, characterized in that, The anaerobic tank is provided with a sludge discharge device at the bottom, and a flow monitor and an adjusting valve are arranged on the water inlet pipe.

5. The composite ecological trench system for the treatment of high nitrogen domestic sewage in coastal rural areas according to claim 1, characterized in that, A fence is arranged above the pressure top and is used for preventing sundries on both sides from falling into the ditch.

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