Sewage treatment system

Abstract

This application relates to the field of wastewater treatment technology and proposes a wastewater treatment system comprising a biological filter, a collection area, and an constructed wetland arranged sequentially from the inside out. The biological filter includes a water distribution device, a filter media layer, and a drainage system. Wastewater is sprayed onto the surface of the filter media layer through the water distribution device, flows through the filter media layer under gravity for biodegradation, and then enters the collection area through the drainage system. The collection area is located around the periphery of the biological filter and is connected to the drainage system. The collection area is used to collect the effluent from the biological filter and distribute it to the constructed wetland. The constructed wetland includes a plant layer and a packing layer arranged from top to bottom. Wastewater enters the constructed wetland from the collection area and flows through the plant layer and packing layer for purification treatment before being discharged after meeting standards. Through the cooperation of the biological filter and the vertical subsurface flow constructed wetland, the clogging problem of the constructed wetland is effectively improved. Through the purification effect of the packing layer and the plant layer, deep treatment of pollutants is achieved, ensuring that the effluent quality meets standards.

Description

Technical Field

[0001] This application relates to the field of wastewater treatment technology, and more specifically, to a wastewater treatment system. Background Technology

[0002] With continuous social development, large-scale wastewater treatment plants are difficult to build in some relatively underdeveloped small and medium-sized towns and communities due to limitations in funding, technology, and scale. However, the importance of domestic wastewater treatment and water quality improvement in these areas is increasing day by day.

[0003] As a comprehensive ecological engineering project, constructed wetlands can cleverly simulate the physical, chemical, and biological effects in the natural environment, thereby achieving effective wastewater treatment and providing a feasible solution to the wastewater treatment problems in the aforementioned regions.

[0004] However, traditional constructed wetlands still have some shortcomings in practical engineering applications that need improvement. In the process of wastewater treatment using constructed wetlands, the influent usually requires pretreatment, typically using screens and simple sedimentation to remove suspended particulate matter and some biochemical oxygen demand (BOD). However, when the concentration of pollutants in the influent exceeds a certain limit, the wetland system is prone to clogging and hardening due to high load operation. Furthermore, constructed wetlands face many other problems in actual operation, such as excessively high influent suspended solids concentration, difficulty in consistently controlling the treated water volume, and uneven water distribution. These problems further increase the risk of system clogging. Therefore, relying solely on the wetland structure to complete the water purification task often falls short of ideal treatment efficiency.

[0005] Therefore, how to utilize constructed wetlands to achieve deep purification of wastewater has become a key issue that urgently needs to be addressed. Utility Model Content

[0006] To address at least one of the aforementioned technical problems, this application proposes a wastewater treatment system.

[0007] In view of this, this application proposes a wastewater treatment system, comprising a biological filter, a collection area, and an constructed wetland arranged sequentially from the inside out; the biological filter includes a water distribution device, a filter media layer, and a drainage system, whereby wastewater is sprayed onto the surface of the filter media layer by the water distribution device, flows through the filter media layer under gravity for biodegradation, and then enters the collection area through the drainage system; the collection area is located around the periphery of the biological filter and is connected to the drainage system, and is used to collect the effluent from the biological filter and distribute it to the constructed wetland; the constructed wetland includes a plant layer and a packing layer arranged from top to bottom, whereby wastewater enters the constructed wetland from the collection area and flows through the plant layer and packing layer for purification treatment, and is discharged after meeting the standards.

[0008] In some feasible ways, biological filters are circular, catchment areas are circular, and constructed wetlands are circular.

[0009] In some feasible implementations, the water distribution device includes: an inlet pipe for conveying pretreated wastewater; a main distribution pipe connected to the inlet pipe and arranged circumferentially along the top of the biofilter; multiple branch distribution pipes spaced apart from the main distribution pipe, each branch distribution pipe having multiple distribution holes; and a flow monitoring device installed on the inlet pipe for monitoring wastewater flow.

[0010] In some feasible implementations, the water distribution device also includes a nozzle, detachably mounted to the water distribution hole, for spraying wastewater.

[0011] In some feasible implementations, the filter media layer is a biological ceramsite layer, and the wastewater treatment system also includes a pebble support layer disposed below the biological ceramsite layer.

[0012] In some feasible methods, the bio-ceramic particles in the bio-ceramic layer have a particle size of 30 mm to 50 mm, and the pebble support layer has a pebble particle size of 50 mm to 60 mm.

[0013] In some feasible implementations, the filler layer includes: a soil layer for plant growth fixation; a volcanic rock layer disposed below the soil layer, the volcanic rock layer having a porous structure to provide a surface for microbial attachment; and a zeolite layer disposed below the volcanic rock layer.

[0014] In some feasible ways, constructed wetlands also include an impermeable layer, placed below the zeolite layer, to prevent water infiltration.

[0015] In some feasible methods, the impermeable layer is one of bentonite, clay, or polyethylene resin geomembrane.

[0016] In some feasible ways, the aquatic plants in the plant layer are one or more of the following: reeds, calamus, water lilies, cattails, canna lilies, water lilyturf, windmill grass, rush pith, water bamboo, and water celery.

[0017] Compared with related technologies, this application has the following technical advantages: The wastewater treatment system provided by this application includes a biological filter, a water collection area, and an artificial wetland arranged sequentially from the inside out. The overall structure is simple, highly operable, and easy to maintain and manage, making it very suitable for small-volume wastewater treatment in rural areas. The biological filter, water collection area, and artificial wetland bed are all designed in a ring shape, which is beneficial for uniform water distribution and reducing the land area occupied, while also providing a better landscape effect.

[0018] The biofilter is a downflow filter, which is simple in structure, easy to operate and maintain, stable in performance, and low in energy consumption. The constructed wetland is a vertical subsurface flow constructed wetland. The biofilter and the vertical subsurface flow constructed wetland work together to effectively prevent and delay clogging of the constructed wetland. Through the purification effect of the packing layer, pollutants are treated efficiently.

[0019] The catchment area not only has the functions of water storage and distribution, but also enables suspended solids in the water body to settle further after treatment by the biological filter.

[0020] In constructed wetlands, aquatic plants remove organic matter through metabolism, and their roots also intercept and adsorb solid particles. A significant amount of nitrogen, phosphorus, heavy metals, and recalcitrant organic matter can be absorbed and adsorbed by plant roots. Furthermore, plants provide a larger adsorption surface area for microbial growth and can also transport oxygen to the water. Through the combined use of biological filters and vertical subsurface flow constructed wetlands, clogging problems are effectively improved. The purification effect of the packing layer and plant layer achieves deep treatment of pollutants, ensuring that the effluent meets standards.

[0021] Additional aspects and advantages of this application will become apparent in the following description or may be learned by practice of this application. Attached Figure Description

[0022] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0023] Figure 1 A schematic diagram of the wastewater treatment system in one embodiment of this application is shown;

[0024] Figure 2 It shows Figure 1 A cross-sectional structural diagram of the wastewater treatment system in the embodiment.

[0025] in, Figure 1 and Figure 2 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0026] 100 Wetland inlet pipe, 102 Water collection area, 103 Filter inlet pipe, 104 Main water distribution pipe, 105 Branch water distribution pipe, 106 Biological filter, 107 Biological ceramsite layer, 108 Pebble support layer, 109 Filter outlet pipe, 110 Constructed wetland, 111 Plant layer, 112 Soil layer, 113 Volcanic rock layer, 114 Zeolite layer, 115 Impermeable layer, 116 Wetland outlet pipe. Detailed Implementation

[0027] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0028] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0029] The following reference Figure 1 and Figure 2 Describes a wastewater treatment system according to some embodiments of this application.

[0030] like Figure 1 and Figure 2 As shown, this application provides a wastewater treatment system, including a biological filter 106, a water collection area 102, and an artificial wetland 110 arranged sequentially from the inside out. The biological filter 106 includes a water distribution device, a filter media layer, and a drainage system. Wastewater is sprayed onto the surface of the filter media layer through the water distribution device, flows through the filter media layer under gravity for biodegradation, and then enters the water collection area 102 through the drainage system. The water collection area 102 is located around the outer periphery of the biological filter 106 and is connected to the drainage system. The water collection area 102 is used to collect the effluent from the biological filter 106 and distribute it to the artificial wetland 110. The artificial wetland 110 includes a plant layer 111 and a packing layer arranged from top to bottom. Wastewater enters the artificial wetland 110 from the water collection area 102 and flows through the plant layer 111 and the packing layer for purification treatment, and is discharged after meeting the standards.

[0031] The wastewater treatment system provided in this application includes a biological filter 106, a collection area 102, and an constructed wetland 110. The biological filter 106 is a downflow filter, and the constructed wetland 110 is a vertical subsurface flow constructed wetland 110. Wastewater is first evenly sprayed onto the surface of the filter media layer by a water distribution device, and then flows through the filter media layer under gravity for biodegradation, thus initially purifying the wastewater. Afterwards, it enters the collection area 102 through a drainage system, where it collects the effluent from the biological filter 106 and provides stable water distribution to the constructed wetland 110. Finally, the wastewater flows into the constructed wetland 110, where it undergoes further purification treatment through a plant layer 111 and a packing layer, and is discharged after meeting standards. The entire wastewater treatment process is continuous and efficient, effectively improving the wastewater treatment effect.

[0032] The biological filter 106 uses a water distribution device to evenly distribute the sewage, ensuring full contact between the sewage and the filter media layer. This provides a good environment for the attachment and growth of microorganisms, promoting the effective degradation of pollutants such as organic matter in the sewage by microorganisms as they flow through the filter media layer, thus achieving a highly efficient biological purification effect.

[0033] The water collection area 102 is located around the biological filter 106 and connected to the drainage system. It can effectively collect the effluent from the biological filter 106 to prevent sewage overflow, and can also stably distribute water to the constructed wetland 110 to ensure the uniformity and stability of the water intake of the constructed wetland 110 and ensure the normal operation of the subsequent treatment process.

[0034] The constructed wetland 110 consists of a plant layer 111 and a packing layer from top to bottom. When sewage flows through it, the plant layer 111 removes some pollutants through absorption, adsorption, and degradation by root microorganisms. At the same time, the physiological activities of plants, such as photosynthesis, provide oxygen to the wetland ecosystem and promote the growth and metabolism of aerobic microorganisms. The packing layer further filters, adsorbs, and settles impurities and pollutants in the sewage, achieving deep purification of the sewage and ensuring that the effluent meets discharge standards.

[0035] The wastewater treatment system provided in this application includes a water collection area 102 located inside an constructed wetland 110, and a biological filter 106 located inside the water collection area 102. The biological filter 106 is a downflow filter, and the water collection area 102 serves as the effluent storage area for the biological filter 106, and also as the water distribution area for the constructed wetland 110. The constructed wetland 110 is a vertical subsurface flow constructed wetland 110, and the water collection area 102 is connected to the constructed wetland 110 via a perforated flower wall. Through the cooperation of the biological filter 106 and the vertical subsurface flow constructed wetland 110, the clogging problem of the constructed wetland 110 is effectively improved. Through the purification effect of the packing layer and the plant layer 111, deep treatment of pollutants is achieved, ensuring that the effluent quality meets standards.

[0036] like Figure 2 As shown, in some embodiments provided in this application, the biological filter 106 is annular, the water collection area 102 is annular, and the constructed wetland 110 is annular.

[0037] In this embodiment, the ring-shaped structural layout makes the entire wastewater treatment system more compact in its planar arrangement, making full use of limited space resources while also providing a better aesthetic appeal. Compared to other irregular or linear layouts, the ring design allows for the construction of larger-scale treatment facilities within the same land area, or reserves more space for other supporting equipment, green areas, etc., thereby improving land use efficiency.

[0038] The ring structure provides a natural and smooth circulation path for wastewater. Wastewater is treated starting from the biological filter 106, passing sequentially through the collection area 102 and the constructed wetland 110. The water flow transition between each treatment unit is smoother, reducing water flow resistance and energy consumption. It also helps maintain a stable water flow velocity, ensuring the uniformity of treatment effect.

[0039] The annular biological filter 106 has a larger filtration area and a longer wastewater retention time. At the same time, the annular structure facilitates natural air circulation, providing ample oxygen for aerobic microorganisms in the filter media, promoting their metabolic activity, and further improving biological treatment efficiency.

[0040] The annular water collection zone 102 is arranged around the biological filter 106, which can evenly collect the effluent from the biological filter 106 and avoid problems such as local water accumulation or poor drainage. When distributing water to the constructed wetland 110, the annular water collection zone 102 can distribute the sewage evenly to various areas of the constructed wetland 110 through multiple water inlets or water distribution pipes, ensuring that the water quality and quantity of the influent to the constructed wetland 110 are uniform. This is conducive to the uniform removal of pollutants by plants and microorganisms in the constructed wetland 110 and improves the overall purification effect.

[0041] The annular constructed wetland 110 provides a larger treatment area and a longer purification path for wastewater. As wastewater flows through the annular plant layer 111 and the packing layer, it can fully contact the plant roots and packing material, achieving deep purification of suspended solids, organic matter, heavy metals, and other pollutants through physical filtration, chemical adsorption, and biodegradation. Furthermore, the annular structure facilitates favorable hydraulic conditions, preventing short-circuiting and dead zones, thus ensuring the wastewater's retention time and treatment effectiveness within the constructed wetland 110.

[0042] like Figure 1 As shown, in some embodiments provided in this application, the water distribution device includes: an inlet pipe for conveying pretreated wastewater; a main water distribution pipe 104 connected to the inlet pipe and arranged circumferentially along the top of the biological filter 106; a plurality of branch water distribution pipes 105 spaced apart from the main water distribution pipe 104, each branch water distribution pipe 105 having a plurality of water distribution holes; and a flow monitoring device installed on the inlet pipe for monitoring wastewater flow.

[0043] In this embodiment, the water distribution device includes an inlet pipe, a main water distribution pipe 104, multiple branch water distribution pipes 105, and a flow monitoring device. The main water distribution pipe 104 is arranged circumferentially around the top of the biological filter 106, which can uniformly introduce sewage from all sides of the biological filter 106, avoiding the problem of excessive or insufficient local water flow caused by sewage entering from a single point.

[0044] Multiple branch pipes 105 are spaced apart on the main branch pipe 104, and each branch pipe 105 has multiple water distribution holes. This allows wastewater to be sprayed relatively evenly onto the surface of the filter media layer of the biological filter 106 in a "surface" manner through numerous water distribution holes. The wastewater and filter media can fully contact each other, allowing the microorganisms in the filter media layer to react more extensively and effectively with pollutants in the wastewater. This improves the degradation efficiency of organic matter, nitrogen, phosphorus, and other pollutants in the wastewater by the biological filter 106, enhancing the overall treatment effect.

[0045] The flow monitoring device can be a flow meter. By installing a flow monitoring device on the inlet pipe, the flow rate of sewage entering the biological filter 106 can be monitored in real time and accurately. With precise control of the sewage flow rate, operators can adjust the inlet flow rate in a timely manner according to the treatment capacity of the biological filter 106 and the actual operating conditions, ensuring that the biological filter 106 is always in the optimal operating state.

[0046] In some embodiments provided in this application, the water distribution device further includes a nozzle, which is detachably mounted on the water distribution hole for spraying wastewater.

[0047] In this embodiment, the water distribution device also includes nozzles. The nozzles can spray wastewater into the surface of the filter media layer of the biological filter 106 in the form of finer, more uniform water droplets or mist. This uniform spraying method makes the distribution of wastewater on the filter media layer more consistent, avoiding localized water accumulation or dryness, providing a more suitable living environment for microorganisms in the filter media layer, and facilitating the uniform degradation of pollutants in the wastewater by microorganisms, thereby improving the treatment efficiency and stability of the biological filter 106.

[0048] The sprinkler heads are detachable, allowing for easy and quick disassembly and installation when they become clogged, damaged, or require replacement to meet different treatment needs. This reduces maintenance time, minimizes the impact of equipment malfunctions on the normal operation of the wastewater treatment system, and improves system maintainability and reliability.

[0049] like Figure 1 As shown, in some embodiments provided in this application, the filter media layer is a biological ceramsite layer 107, and the wastewater treatment system further includes a pebble support layer 108, which is disposed below the biological ceramsite layer 107.

[0050] In this embodiment, the filter media layer is a bio-ceramic granule layer 107, with a pebble support layer 108 located below it. The bio-ceramic granule layer 107 is porous and coarse, capable of trapping suspended solids and particulate pollutants, reducing wastewater turbidity. It provides an attachment carrier for microorganisms, forming a biofilm that degrades organic matter, achieving nitrogen and phosphorus removal through nitrification, denitrification, and polyphosphate accumulation. The bio-ceramic granules themselves possess adsorption properties, adsorbing dissolved pollutants, improving the taste and odor of the water, and buffering fluctuations in wastewater quality and quantity, maintaining stable water flow and uniform hydraulic conditions within the biological filter 106, creating a stable living environment for microorganisms, and ensuring the stable operation of the treatment system.

[0051] The pebble support layer 108, composed of pebbles of varying sizes, possesses high strength and stability, providing solid support for the biological ceramsite layer 107 and preventing its subsidence and collapse. This ensures the structural integrity and stability of the biological ceramsite layer 107, enabling the biological filter 106 to operate stably for extended periods. The porous structure of the pebble support layer 108 facilitates the exchange and transfer of dissolved oxygen, nutrients, and metabolic products between the biological ceramsite layer 107 and the support layer. Sufficient dissolved oxygen ensures the normal metabolic activities of aerobic microorganisms, while favorable material exchange conditions help microorganisms acquire necessary nutrients and promptly remove metabolic waste, maintaining their activity and growth, thereby further improving the treatment efficiency of the biological filter 106.

[0052] In some embodiments provided in this application, the particle size of the bioceramsite layer 107 is 30mm to 50mm, and the particle size of the pebbles in the pebble support layer 108 is 50mm to 60mm.

[0053] In this embodiment, the bio-ceramic particles have a particle size of 30mm to 50mm, are porous and have a large specific surface area, which can provide sufficient attachment space for microorganisms, facilitate the formation of biofilm, efficiently degrade organic matter in wastewater, achieve nitrogen and phosphorus removal, and have good filtration effect within this particle size range, which can retain more suspended solids.

[0054] The pebble support layer 108 has pebbles with a particle size of 50mm to 60mm. These pebbles are larger than the bio-ceramic particles, providing stable support for the bio-ceramic particle layer 107, preventing it from settling, collapsing, or being lost, thus ensuring structural stability. Simultaneously, the pores between the pebbles evenly distribute water flow, slowing the flow velocity and allowing for sufficient contact and reaction between the wastewater and the bio-ceramic particles, extending the wastewater retention time and improving treatment efficiency. The combination of these two elements ensures both effective biological treatment and stable system operation, effectively improving the quality of wastewater treatment.

[0055] like Figure 1 As shown, in some embodiments provided in this application, the filler layer includes: a soil layer 112 for plant growth fixation; a volcanic rock layer 113 disposed below the soil layer 112, the volcanic rock layer 113 having a porous structure to provide a surface for microbial attachment; and a zeolite layer 114 disposed below the volcanic rock layer 113.

[0056] In this embodiment, the filler layer includes a soil layer 112, a volcanic rock layer 113, and a zeolite layer 114. The soil layer 112 provides a stable growth substrate for plant roots, facilitating root establishment and fixation. Plants grow by absorbing nutrients such as nitrogen and phosphorus from wastewater, while root secretions promote microbial activity, forming a synergistic purification system of plants and microorganisms. This enhances the system's ability to remove pollutants, beautifies the environment, and maintains ecological balance.

[0057] The volcanic rock layer 113, located below the soil layer 112, has a porous structure that significantly increases the specific surface area, providing abundant attachment sites for microorganisms and promoting the formation of diverse microbial communities. Microorganisms attach to and grow on the volcanic rock surface, forming a biofilm that efficiently degrades organic matter in wastewater, converting it into carbon dioxide and water, thus reducing the chemical oxygen demand (COD) and biochemical oxygen demand (BOD) of the wastewater.

[0058] The zeolite layer 114 is located below the volcanic rock layer 113. Zeolite possesses unique ion exchange and adsorption properties, enabling it to further adsorb pollutants such as ammonia nitrogen and heavy metal ions in wastewater, achieving deep purification. Simultaneously, the zeolite layer 114 buffers and stabilizes the treated water from the upper layers, resulting in more uniform and stable effluent quality, meeting higher discharge standards or reuse requirements. The entire packing layer is rationally layered and functionally complementary, effectively improving the performance and stability of the wastewater treatment system.

[0059] like Figure 1 As shown, in some embodiments provided in this application, the constructed wetland 110 further includes an impermeable layer 115, disposed below the zeolite layer 114, for preventing water penetration.

[0060] In this embodiment, an anti-permeability layer 115 is also provided below the zeolite layer 114, which can effectively prevent sewage and harmful substances generated during the treatment process from seeping downwards, avoid polluting the surrounding soil and groundwater, ensure the safety of groundwater resources and the stability of the ecological environment, prevent soil salinization, heavy metal pollution and other problems caused by sewage leakage, and maintain the regional ecological balance.

[0061] The impermeable layer 115 can reduce water leakage and maintain a stable water level and hydraulic conditions within the constructed wetland 110, providing a relatively stable environment for plant growth and microbial activity. This is conducive to the development of plant roots and the stability of the microbial community, thereby ensuring the continuous and efficient removal of pollutants by the constructed wetland 110.

[0062] The impermeable layer 115 can also prevent unnecessary water loss, allowing sewage to be fully treated and utilized within the constructed wetland 110, thus improving the efficiency of water resource recycling. Especially in water-scarce areas, it can better realize the resource utilization of sewage and alleviate water shortages.

[0063] In some embodiments provided in this application, the impermeable layer 115 is one of bentonite, clay, or polyethylene resin geomembrane.

[0064] In this embodiment, bentonite expands upon contact with water to form a dense colloid, which effectively fills gaps and prevents water penetration. Its low impermeability coefficient significantly reduces the risk of wastewater infiltration, protecting surrounding soil and groundwater from pollution and maintaining ecological stability.

[0065] The clay is natural clay, with fine particles and low porosity after compaction, forming a low-permeability impermeable layer 115. In the constructed wetland 110, it can effectively intercept harmful substances in sewage and prevent them from spreading into the underground environment.

[0066] Polyethylene resin geomembranes have extremely low permeability, good chemical stability, and can withstand long-term corrosion from wastewater. They can form reliable seepage barriers, providing long-lasting protection for groundwater.

[0067] In some embodiments provided in this application, the aquatic plants in the plant layer 111 are one or more of the following: reed, calamus, water lily, cattail, canna, water lily, windmill grass, rush, water bamboo, and water celery.

[0068] In this embodiment, multiple aquatic plants work synergistically to efficiently remove pollutants. Reeds and cattails have extensive root systems that can absorb large amounts of nitrogen and phosphorus, reducing eutrophication; calamus has the ability to accumulate heavy metals, resulting in more comprehensive water purification. Plants provide attachment sites for microorganisms, promoting the decomposition of organic matter and forming a stable ecological chain; they also provide habitats for aquatic animals, increasing biodiversity and enhancing system stability. The vibrant flowers of water lilies and the bright colors of canna lilies, combined with emergent plants such as reeds, create a richly layered wetland landscape with beauty throughout the four seasons, offering both aesthetic and recreational value.

[0069] Some plants have economic value; water bamboo and water celery are edible, and reeds can be used for papermaking and weaving. While purifying wastewater, resources can be recycled and reused, reducing the operating costs of artificial wetlands and achieving a balance of ecological, economic, and social benefits.

[0070] In specific embodiments, such as Figure 1 and Figure 2As shown, this application provides a wastewater treatment system, which is a high-efficiency wastewater treatment system combining a biological filter 106 and an constructed wetland 110 in a ring. The wastewater treatment system consists of, from the inside out, the biological filter 106, a collection area 102, and the constructed wetland 110. Pre-treated wastewater enters the biological filter 106 and is continuously and evenly sprayed onto its surface by a water distribution device. The wastewater falls under gravity, with some adsorbed onto the filter media surface and the rest permeating through the filter media layer to form a flowing water layer. The biofilm helps degrade organic matter, and the wastewater finally flows into the collection area 102 through the drainage system, and then into the constructed wetland 110 through the wetland inlet pipe 100. Wastewater flows vertically through the bed layer, where it is further decomposed by the interception and adsorption of pollutants by plant roots and microorganisms on the surface of the packing material. The effluent meets the discharge standards. The biological filter 106, the water collection area 102, and the constructed wetland 110 are all annular. The water collection area 102 is located inside the constructed wetland 110, and the biological filter 106 is located inside the water collection area 102. The biological filter 106 is a downflow filter. The water collection area 102 serves as the effluent storage area for the biological filter 106 and also as the water distribution area for the constructed wetland 110. The constructed wetland 110 is a vertical subsurface flow constructed wetland. The water collection area 102 and the constructed wetland 110 are connected by a perforated flower wall. The structure of the biological filter 106 includes a water distribution device, a filter bed, and a drainage system. The constructed wetland 110 includes a plant layer 111, a packing layer, and an impermeable layer 115.

[0071] The water collection area 102 is equipped with a water distribution pipe connected to the water pump, and a flow meter is installed on the water distribution pipe. The water collection pipe, water distribution pipe, and outlet pipe are all made of PVC-U pipe. The water distribution device of the biological filter 106 is a spray-type water distribution device. The filter bed of the biological filter 106 consists of biological ceramic particles and a support layer. The filter media layer of the biological filter 106 is biological ceramic particles with a particle size of 30mm–50mm, and the support layer is pebbles with a particle size of 50mm–60mm. The thicknesses of the biological ceramic particle layer 107 and the pebble support layer 108 are 1.5m and 0.2m, respectively.

[0072] The filler layer consists of, from bottom to top, a zeolite layer 114 (particle size 3mm-5mm), a volcanic rock layer 113 (particle size 3mm-5mm), and a soil layer 112 (particle size 1mm-4mm), with heights of 20cm-30cm, 30cm-60cm, and 15cm-20cm, respectively.

[0073] The impermeable layer 115 is made of polyethylene resin geomembrane, natural clay, bentonite, etc., with a thickness of 1.0 mm, thereby preventing water infiltration, maintaining the moisture balance of the wetland, and enhancing the stability of the wetland.

[0074] The aquatic plants in plant layer 111 include one or more of the following: reed, calamus, water lily, cattail, canna, water lily, windmill grass, rush, water bamboo, and water celery. Specific Implementation Example 1:

[0076] A circular combined high-efficiency wastewater treatment system consisting of a biological filter 106 and an constructed wetland 110 includes a biological filter 106 and an constructed wetland 110. The biological filter 106 utilizes microorganisms attached to a solid surface to remove suspended solids from the water and degrade some organic matter and ammonia nitrogen. The constructed wetland 110 is a vertical subsurface flow constructed wetland 110, which further purifies pollutants such as organic matter, nitrogen, and phosphorus in wastewater through adsorption, sedimentation, filtration, oxidation-reduction, and microbial decomposition. It also includes a circular water collection area 102 located inside the constructed wetland 110 and outside the biological filter 106. The biological filter 106 and the water collection area 102 are connected by a filter outlet pipe 109. The biological filter 106 is a downflow filter, and the filter outlet pipe 109 is located at the bottom of the biological filter 106. The water distribution device above the biological filter 106 includes a filter inlet pipe 103, a main water distribution pipe 104, and branch water distribution pipes 105. Wastewater is continuously and evenly sprayed onto the surface of the filter through the water distribution device. The biological filter 106 consists of a biological ceramsite layer 107 and a pebble support layer 108 arranged sequentially from top to bottom. The ceramsite layer 107 has a particle size of 30 mm and a filling thickness of 1.5 m, while the pebble support layer 108 has a pebble particle size of 50 mm and a filling thickness of 0.2 m. The water collection area 102 and the constructed wetland 110 are connected by a wetland inlet pipe 100. Wastewater treated by the biological filter 106 in the water collection area 102 flows into the constructed wetland 110 through the wetland inlet pipe 100. The constructed wetland 110 consists of a layer of aquatic plants, a layer of packing material, and a seepage-proof layer 115 arranged sequentially from top to bottom. The aquatic plant layer is planted with reeds. The filler layer consists of a soil layer 112, a volcanic rock layer 113, and a zeolite layer 114. The soil layer 112 has sand particles with a diameter of 1 mm and a filling height of 15 cm. The volcanic rock layer 113 has rock particles with a diameter of 3 mm and a filling height of 30 cm. The zeolite layer 114 has zeolite particles with a diameter of 3 mm and a filling height of 20 cm. The impermeable layer 115 is a polyethylene resin geomembrane with a thickness of 1.0 mm. Wastewater is purified by the constructed wetland 110 and then discharged through the wetland outlet pipe 116 at the bottom, meeting discharge standards. Specific Implementation Example 2:

[0078] A circular combined high-efficiency wastewater treatment system consisting of a biological filter 106 and an constructed wetland 110 includes a biological filter 106 and an constructed wetland 110. The biological filter 106 utilizes microorganisms attached to a solid surface to remove suspended solids from the water and degrade some organic matter and ammonia nitrogen. The constructed wetland 110 is a vertical subsurface flow constructed wetland 110, which further purifies pollutants such as organic matter, nitrogen, and phosphorus in wastewater through adsorption, sedimentation, filtration, oxidation-reduction, and microbial decomposition. It also includes a circular water collection area 102 located inside the constructed wetland 110 and outside the biological filter 106. The biological filter 106 and the water collection area 102 are connected by a filter outlet pipe 109. The biological filter 106 is a downflow filter, and the filter outlet pipe 109 is located at the bottom of the biological filter 106. The water distribution device above the biological filter 106 includes a filter inlet pipe 103, a main water distribution pipe 104, and branch water distribution pipes 105. Wastewater is continuously and evenly sprayed onto the surface of the filter through the water distribution device. The biological filter 106 consists of a biological ceramsite layer 107 and a pebble support layer 108 arranged sequentially from top to bottom. The ceramsite layer 107 has a particle size of 35 mm and a filling thickness of 1.5 m, while the pebble support layer 108 has a pebble particle size of 55 mm and a filling thickness of 0.2 m. The water collection area 102 and the constructed wetland 110 are connected by a wetland inlet pipe 100. Wastewater treated by the biological filter 106 in the water collection area 102 flows into the constructed wetland 110 through the wetland inlet pipe 100. The constructed wetland 110 consists of a layer of aquatic plants, a layer of packing material, and a seepage-proof layer 115 arranged sequentially from top to bottom. The aquatic plant layer is planted with calamus, water lilies, and cattails. The filler layer consists of a soil layer 112, a volcanic rock layer 113, and a zeolite layer 114. The soil layer 112 has a sand particle size of 2mm and a filling height of 15cm. The volcanic rock layer 113 has a rock particle size of 4mm and a filling height of 40cm. The zeolite layer 114 has a zeolite particle size of 4mm and a filling height of 25cm. The impermeable layer 115 is made of natural clay and is 1.0mm thick. Wastewater is purified by the constructed wetland 110 and then discharged through the wetland outlet pipe 116 at the bottom, meeting discharge standards. Specific Implementation Example 3:

[0080] A circular combined high-efficiency wastewater treatment system consisting of a biological filter 106 and an constructed wetland 110 includes a biological filter 106 and an constructed wetland 110. The biological filter 106 utilizes microorganisms attached to a solid surface to remove suspended solids from the water and degrade some organic matter and ammonia nitrogen. The constructed wetland 110 is a vertical subsurface flow constructed wetland 110, which further purifies pollutants such as organic matter, nitrogen, and phosphorus in wastewater through adsorption, sedimentation, filtration, oxidation-reduction, and microbial decomposition. It also includes a circular water collection area 102 located inside the constructed wetland 110 and outside the biological filter 106. The biological filter 106 and the water collection area 102 are connected by a filter outlet pipe 109. The biological filter 106 is a downflow filter, and the filter outlet pipe 109 is located at the bottom of the biological filter 106. The water distribution device above the biological filter 106 includes a filter inlet pipe 103, a main water distribution pipe 104, and branch water distribution pipes 105. Wastewater is continuously and evenly sprayed onto the surface of the filter through the water distribution device. The biological filter 106 consists of a biological ceramsite layer 107 and a pebble support layer 108 arranged sequentially from top to bottom. The ceramsite layer 107 has a particle size of 40 mm and a filling thickness of 1.5 m, while the pebble support layer 108 has a pebble particle size of 60 mm and a filling thickness of 0.2 m. The water collection area 102 and the constructed wetland 110 are connected by a wetland inlet pipe 100. Wastewater treated by the biological filter 106 in the water collection area 102 flows into the constructed wetland 110 through the wetland inlet pipe 100. The constructed wetland 110 consists of a layer of aquatic plants, a layer of packing material, and a seepage-proof layer 115 arranged sequentially from top to bottom. The aquatic plant layer is planted with canna lilies, water lilies, and windmill grass. The filler layer consists of a soil layer 112, a volcanic rock layer 113, and a zeolite layer 114. The soil layer 112 has a sand particle size of 3mm and a filling height of 20cm. The volcanic rock layer 113 has a rock particle size of 5mm and a filling height of 50cm. The zeolite layer 114 has a zeolite particle size of 5mm and a filling height of 25cm. The impermeable layer 115 is made of bentonite and has a thickness of 1.0mm. Wastewater is purified by the constructed wetland 110 and then discharged through the wetland outlet pipe 116 at the bottom, meeting discharge standards. Specific Implementation Example 4:

[0082] A circular combined high-efficiency wastewater treatment system consisting of a biological filter 106 and an constructed wetland 110 includes a biological filter 106 and an constructed wetland 110. The biological filter 106 utilizes microorganisms attached to a solid surface to remove suspended solids from the water and degrade some organic matter and ammonia nitrogen. The constructed wetland 110 is a vertical subsurface flow constructed wetland 110, which further purifies pollutants such as organic matter, nitrogen, and phosphorus in wastewater through adsorption, sedimentation, filtration, oxidation-reduction, and microbial decomposition. It also includes a circular water collection area 102 located inside the constructed wetland 110 and outside the biological filter 106. The biological filter 106 and the water collection area 102 are connected by a filter outlet pipe 109. The biological filter 106 is a downflow filter, and the filter outlet pipe 109 is located at the bottom of the biological filter 106. The water distribution device above the biological filter 106 includes a filter inlet pipe 103, a main water distribution pipe 104, and branch water distribution pipes 105. Wastewater is continuously and evenly sprayed onto the surface of the filter through the water distribution device. The biological filter 106 consists of a biological ceramsite layer 107 and a pebble support layer 108 arranged sequentially from top to bottom. The ceramsite layer 107 has a particle size of 45 mm and a filling thickness of 1.5 m, while the pebble support layer 108 has a pebble particle size of 55 mm and a filling thickness of 0.2 m. The water collection area 102 and the constructed wetland 110 are connected by a wetland inlet pipe 100. Wastewater treated by the biological filter 106 in the water collection area 102 flows into the constructed wetland 110 through the wetland inlet pipe 100. The constructed wetland 110 consists of a layer of aquatic plants, a layer of packing material, and a seepage-proof layer 115 arranged sequentially from top to bottom. The aquatic plant layer is planted with rush pith, water chestnut, and water celery. The filler layer consists of a soil layer 112, a volcanic rock layer 113, and a zeolite layer 114. The soil layer 112 has a sand particle size of 4mm and a filling height of 20cm. The volcanic rock layer 113 has a rock particle size of 5mm and a filling height of 55cm. The zeolite layer 114 has a zeolite particle size of 5mm and a filling height of 30cm. The impermeable layer 115 is a polyethylene resin geomembrane with a thickness of 1.0mm. Wastewater is purified by the constructed wetland 110 and then discharged through the wetland outlet pipe 116 at the bottom, meeting discharge standards.

[0083] In this application, the term "multiple" refers to two or more unless otherwise expressly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0084] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0085] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A sewage treatment system characterised in that, It includes a biological filter, a water collection area, and an artificial wetland arranged sequentially from the inside out; The biological filter includes a water distribution device, a filter media layer, and a drainage system. Wastewater is sprayed onto the surface of the filter media layer through the water distribution device, flows through the filter media layer under gravity for biodegradation, and then enters the water collection area through the drainage system. The water collection area is located around the outer periphery of the biological filter and is connected to the drainage system. The water collection area is used to collect the effluent from the biological filter and distribute water to the constructed wetland. The constructed wetland includes a plant layer and a filler layer arranged from top to bottom. Wastewater enters the constructed wetland from the catchment area and flows through the plant layer and the filler layer for purification treatment before being discharged after meeting the standards.

2. The sewage treatment system of claim 1, wherein, The biological filter is circular, the water collection area is circular, and the constructed wetland is circular.

3. The sewage treatment system of claim 1, wherein, The water distribution device includes: The inlet pipe is used to transport pretreated wastewater; A main water distribution pipe is connected to the inlet pipe and is arranged circumferentially along the top of the biological filter. Multiple water distribution branch pipes are spaced apart from the main water distribution pipe, and each water distribution branch pipe is provided with multiple water distribution holes; A flow monitoring device is installed on the inlet pipe to monitor the sewage flow rate.

4. The sewage treatment system of claim 3, wherein, The water distribution device also includes: The nozzle is detachably mounted on the water distribution hole for spraying wastewater.

5. The sewage treatment system of claim 1, wherein, The filter media layer is a biological ceramic particle layer, and the wastewater treatment system further includes: A pebble support layer is disposed below the bio-ceramic granule layer.

6. The sewage treatment system of claim 5, wherein, The bio-ceramsite in the bio-ceramsite layer has a particle size of 30mm to 50mm, and the pebble in the pebble support layer has a particle size of 50mm to 60mm.

7. The sewage treatment system according to any one of claims 1 to 6, characterized in that, The filler layer includes: The soil layer is used for plant growth and fixation. A volcanic rock layer, disposed below the soil layer, has a porous structure to provide a surface for microbial attachment; A zeolite layer is located below the volcanic rock layer.

8. The sewage treatment system of claim 7, wherein, The constructed wetland also includes: An anti-permeability layer is disposed below the zeolite layer to prevent water penetration.

9. The sewage treatment system of claim 8, wherein, The impermeable layer is one of bentonite, clay, or polyethylene resin geomembrane.

10. The sewage treatment system of any one of claims 1 to 6, wherein, The aquatic plants in the plant layer are one or more of the following: reed, calamus, water lily, cattail, canna, water lilyturf, windmill grass, rush, water bamboo, and water celery.

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