A biological retention pond with integrated collection-filtration-purification functions and its application

Abstract

The present invention provides a biological retention pond with integrated collection-filtration-purification functions and its application, belonging to the field of environmental and ecological restoration technology. The environmentally adaptable biological retention pond with integrated collection-filtration-purification functions described in the present invention includes, from top to bottom, an embedded composite microbial purification layer, a clay adsorption layer, a filler layer, and a gravel drainage layer. The unique design of the layers in the biological retention pond described in the present invention, through the optimization of structure and function, not only solves the problems of traditional systems in terms of processing efficiency, maintenance cost, environmental adaptability and sustainability, but also improves the overall performance and environmental friendliness of the system, and adapts to the environmental requirements for efficient water treatment technology in the process of modern urban and industrial development.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental and ecological restoration, and in particular to a biological retention pond with integrated collection, filtration and purification functions and application thereof. Background Art

[0002] The schematic diagram of the traditional bioretention pond structure is as follows Figure 1 As shown in the figure, from top to bottom, it includes aquifer, vegetation and cover layer, fill layer and drainage layer. The aquifer is located at the top and directly collects rainwater through surface runoff and rainfall; the vegetation and cover layer is used to plant various plants and provide preliminary mechanical filtration. The fill layer is used to treat pollutants in the water; the drainage layer is located at the bottom and is used for drainage and supporting the upper structure.

[0003] However, the above-mentioned traditional bioretention ponds have the following problems: 1. The filtering effect of a single vegetation layer is extremely limited, and the ecological diversity is low, which affects the purification effect and cannot remove complex pollutants; 2. The vegetation and filler layers are easily clogged and need to be replaced in a short period of time, which makes long-term maintenance difficult and costly; 3. For anti-seepage bioretention ponds, geotextile liners are very likely to fail during use, resulting in leakage of pollutants; 4. The hydraulic load is unevenly distributed, and some areas may experience waterlogging or drying up; 5. The ability to purify organic matter and heavy metal ions is extremely low. Summary of the invention

[0004] The object of the present invention is to provide a biological retention pond with integrated collection-filtration-purification functions and its application. The biological retention pond of the present invention can improve the efficiency of sewage and rainwater treatment and enhance environmental adaptability and ecological resilience.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a biological retention pond with integrated collection-filtration-purification functions, comprising an embedded composite microbial purification layer, a clay adsorption layer, a filler layer and a gravel drainage layer arranged in sequence from top to bottom;

[0007] The embedded composite microbial purification layer includes a first module layer and a second module layer; the first module layer and the second module layer form a corresponding upper and lower layer structure in space; the first module layer and the second module layer are connected by an embedded unit column; the first module layer includes a first microbial colony area, a second microbial colony area and a third microbial colony area arranged in parallel; the second module layer is a fourth microbial colony area; the types of microbial strains in the first microbial colony area, the second microbial colony area, the third microbial colony area and the fourth microbial colony area are different;

[0008] The packing layer comprises a first packing layer and a second packing layer which are stacked; the types of packing in the first packing layer and the second packing layer are different.

[0009] Preferably, it also includes an aquifer and a vegetation cover layer, and the vegetation cover layer and the aquifer are sequentially stacked on the embedded composite microbial purification layer.

[0010] Preferably, when the bioretention pond is an impermeable bioretention pond, a geotextile liner layer is further stacked on the gravel drainage layer.

[0011] Preferably, the thickness of the embedded composite microbial purification layer is ≥40 mm;

[0012] The first and second modules of the module are both provided with support plates for carrying microbial strains; and an activated carbon particle layer is laid on the support plate of the first module.

[0013] Preferably, the clay used in the clay adsorption layer is clay based on attapulgite and bentonite.

[0014] Preferably, the fillers used in the first filler layer and the second filler layer independently include gravel, bark sawdust, biochar or bentonite.

[0015] Preferably, the geosynthetic liner used in the geoliner layer is a bentonite-based geoliner.

[0016] The present invention provides the application of the biological retention pond with integrated collection-filtration-purification functions described in the above technical solution in sewage treatment and new generation urban stormwater management.

[0017] The present invention provides an environmentally adaptable bioretention pond with integrated collection-filtration-purification functions, which includes, from top to bottom, an aquifer, a vegetation cover layer, an embedded composite microbial purification layer, a clay adsorption layer, a filler layer, a gravel drainage layer, and a modified geotextile liner (for anti-seepage type). The unique design of the layers in the bioretention pond of the present invention not only solves the problems of traditional systems in terms of treatment efficiency, maintenance cost, environmental adaptability and sustainability through structural and functional optimization, but also improves the overall performance and environmental friendliness of the system, and adapts to the needs of modern urban and industrialized environments for efficient water treatment technology.

[0018] Compared with the existing traditional biological retention pond, the biological retention pond provided by the present invention has the following advantages:

[0019] The bioretention pond of the present invention can improve the efficiency of pollutant removal, improve the efficiency of sewage treatment, and comprehensively treat multiple pollutants: Traditional bioretention ponds may be inefficient in treating certain types of pollutants (such as heavy metals or persistent organic pollutants); the present invention enhances the removal ability of these difficult-to-treat pollutants by introducing an embedded composite microbial purification layer and a clay adsorption layer, combined with the unique hierarchical structure of the microbial purification layer. By setting up a unique layered treatment strategy and using targeted microbial flora and clay materials in specific layers, more effective pollutant decomposition and adsorption are ensured. The bioretention pond of the present invention shows higher efficiency than traditional bioretention ponds in removing organic matter (COD and BOD), nitrogen (N), phosphorus (P) and heavy metals (lead and cadmium). By combining different levels, the treatment process of traditional bioretention ponds is optimized to achieve higher pollutant removal efficiency.

[0020] The modular design of the embedded composite microbial purification layer in the bioretention tank of the present invention allows the expansion or reduction of treatment units according to actual needs, provides greater flexibility and system scalability, and solves the problem that traditional systems are difficult to adjust according to treatment needs or environmental changes.

[0021] The present invention reduces the negative impact on the environment, promotes ecological balance, improves the environmental sustainability and ecological resilience of the system by using environmentally friendly materials (such as natural clay), increasing the vegetation layer and optimizing the use of microorganisms. It combines natural ecological processes and engineering technology, reduces the use of chemical synthetic materials and energy, promotes environmental protection and resource recycling, and can provide the dual functions of ecological restoration and landscaping.

[0022] The bioretention system of the present invention can operate stably under different environmental conditions, such as temperature changes and pH fluctuations, and can adapt to environmental changes by adjusting the microbial combination and operating conditions in the composite biological layer, thereby avoiding the limitation of environmental conditions on the treatment effect.

[0023] The present invention is easy to maintain and replace parts through modular and layered design, reducing the possibility of system blockage and the complexity of long-term maintenance. In addition, the modular and flexible design allows the system to be quickly adjusted according to different water treatment requirements and environmental conditions, providing customized solutions, such as increasing the flexibility and adaptability of the system by changing the microbial population or adjusting the operating parameters, and improving the stability and adaptability of the system operation. For example, under conditions of temperature changes (5°C to 35°C) and pH fluctuations (pH 5-9), the system shows stronger processing capabilities and stability than traditional systems.

[0024] The replaceable layers and modular design of the bioretention pond of the present invention simplify the maintenance process, reduce the labor and time required for system shutdown or overhaul, reduce maintenance costs, and improve economic benefits; by using readily available organisms and modified materials, it reduces dependence on expensive chemicals, further reducing operating costs. The bioretention pond is not only suitable for industrial wastewater treatment, but also can be used for urban rainwater management and agricultural drainage systems, and has a wide range of market applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the structure of a traditional bioretention pond;

[0026] Figure 2 This is a schematic diagram of the cross-sectional structure of a biological retention tank in an embodiment of the present invention;

[0027] Figure 3 It is a schematic diagram of the structure of the packing layer in the biological retention pond of the present invention;

[0028] Figure 4 Schematic diagram of the structure of the embedded composite microbial purification layer of the present invention, wherein (a) is a cross-sectional view and (b) is a top view. DETAILED DESCRIPTION

[0029] like Figure 2 As shown, the present invention provides a biological retention pond with integrated collection-filtration-purification functions, including an embedded composite microbial purification layer, a clay adsorption layer, a filler layer and a gravel drainage layer arranged in sequence from top to bottom;

[0030] The embedded composite microbial purification layer includes a first module layer and a second module layer; the first module layer and the second module layer form a corresponding upper and lower layer structure in space; the first module layer and the second module layer are connected by an embedded unit column; the first module layer includes a first microbial colony area, a second microbial colony area and a third microbial colony area arranged in parallel; the second module layer is a fourth microbial colony area; the types of microbial strains in the first microbial colony area, the second microbial colony area, the third microbial colony area and the fourth microbial colony area are different;

[0031] The packing layer comprises a first packing layer and a second packing layer which are stacked; the types of packing in the first packing layer and the second packing layer are different.

[0032] In the present invention, the biological retention pond with integrated collection-filtration-purification functions further comprises an aquifer and a vegetation cover layer, and the vegetation cover layer and the aquifer are sequentially stacked on the embedded composite microbial purification layer.

[0033] The present invention has no special limitation on the depth of the aquifer, and the water level depth in the aquifer is designed according to the application environment and geographical factors. In the present invention, the depth below the overflow port in the aquifer is 200 mm, and the depth above the overflow port can be extended accordingly. In an embodiment of the present invention, the water level depth in the aquifer is 20 cm.

[0034] The present invention has no special limitation on the aquifer, which can be set up in the manner of a detention pond well known in the art to temporarily store rainwater runoff, especially to reduce the direct entry of rainwater into the municipal drainage system during heavy rainfall events.

[0035] The present invention has no special limitation on the plant species used in the vegetation cover layer, and the plant species well known in the art may be used.

[0036] The present invention has no particular limitation on the specific thickness of the vegetation cover layer, which can be designed according to the application environment and geographical factors. In an embodiment of the present invention, 20 mm of the vegetation cover layer is used for planting, and the upper height varies according to the local vegetation characteristics as a ground landscape.

[0037] The vegetation cover layer in the present invention not only provides beauty and a natural feel, but also increases the ecological functions of the system: natural filtration, plants can absorb soluble pollutants through their root systems, while their roots can promote the growth of microorganisms and enhance biodegradation; ecological restoration: this layer helps to restore ecosystem functions, provides habitats for insects and birds, and increases biodiversity.

[0038] In the present invention, the thickness of the embedded composite microorganism purification layer is preferably ≥40 mm.

[0039] In the present invention, if Figure 4 As shown, in the embedded composite microbial purification layer, the first module layer and the second module layer form a corresponding upper and lower structure in space; the first module layer and the second module layer of the present invention preferably adjust the peripheral structure according to different application scenarios. When the embedded series-parallel unit microbial purification module is used alone, it is necessary to set a peripheral plate to form an overall structure; when the embedded series-parallel unit microbial purification module is placed in other systems for use, there is no need to set a peripheral plate.

[0040] The present invention preferably adjusts the sizes of the first module layer and the second module layer according to actual needs, and the sizes of the two layers do not need to be exactly the same.

[0041] The first module layer and the second module layer are connected by an embedded unit column; the present invention has no special limitation on the material of the embedded unit column, as long as it can support the weight of the first module layer and the second module layer; in the embodiment of the present invention, the embedded unit column is preferably PVC. The present invention uses the embedded unit column as a support to separate the first module layer and the second module layer.

[0042] In the present invention, the first and second modules of the module are both equipped with support plates to carry microbial strains. The support plates are preferably PVC plates, PLA plates or PHA plates; the present invention preferably customizes the support plates according to the usage scenarios and costs. The support plates used in the present invention are porous and degradable, which not only facilitates the growth and spread of microorganisms, but also complies with the principles of environmental protection and sustainability, reducing environmental pollution and waste disposal problems.

[0043] In the present invention, an activated carbon particle layer is preferably laid on the support plate of one layer of the module; the thickness of the activated carbon particle layer is preferably 30 to 50 mm; the particle size of the activated carbon in the activated carbon particle layer is preferably 2 to 4 mm. The activated carbon particle layer in the present invention is used for the adsorption of organic matter and heavy metals on the one hand, and can help to evenly distribute the water flow on the other hand, ensuring that the laying density and thickness of the activated carbon particles are uniform to optimize the adsorption effect. The present invention regularly monitors the adsorption saturation state of the activated carbon particles and determines the replacement frequency according to the actual treatment situation. When replacing, keep the new and old particles evenly mixed to maintain the stable operation of the system.

[0044] In the present invention, the first microorganism colony area, the second microorganism colony area and the third microorganism colony area are carried on the activated carbon particle layer.

[0045] The particle size of the attapulgite used in the present invention is preferably 1 to 2 mm. The present invention utilizes the attapulgite layer to treat organic matter and heavy metals remaining in water.

[0046] In the present invention, the fourth microbial colony area is carried on the lower clay adsorption layer.

[0047] The present invention preferably sets the types and quantities of the microbial species in the first microbial colony area, the second microbial colony area, the third microbial colony area, and the fourth microbial colony area according to the actual application scenario and the water source to be treated. In an embodiment of the present invention, the number ratio of the microbial species in the first microbial colony area, the second microbial colony area, and the third microbial colony area is preferably 4:3:3; the laying amount of the fourth microbial colony area is 1×10 8 CFU.

[0048] The microbial agents used in the microbial colony area of ​​the present invention are harmless to animals and plants, are environmentally friendly, will not introduce foreign species, and are helpful to maintain or restore ecological balance.

[0049] In an embodiment of the present invention, the microbial species in the first microbial colony area is Pseudomonas putida (used to degrade aromatic hydrocarbon organic matter, such as benzene and toluene); the microbial species in the second microbial colony area is Nitrosomonas europaea (oxidizing ammonia nitrogen into nitrite); the microbial species in the third microbial colony area is Alcaligenes faecalis (used to treat nitrogen-containing organic matter and provide the system with adaptability to pH fluctuations); the microbial species in the fourth microbial colony area is Nitrobacter winogradskyi (configured in series with a layer of microorganisms to further oxidize nitrite into nitrate to complete the nitrogen oxidation process); wherein, Pseudomonas putida is responsible for the degradation of organic pollutants and creates a cleaner environment for subsequent nitrogen and phosphorus treatment; Nitrosomonas spp. and Nitrobacterspp. form an effective continuous action chain of ammonia oxidation and nitrite oxidation to ensure efficient conversion of nitrogen; Alcaligenes faecalis provides the system with adaptability to environmental fluctuations, especially maintaining the activity of other microorganisms when the pH value changes greatly. These four bacterial colonies can coexist, and the modular sewage treatment system constructed can not only efficiently remove a variety of pollutants, but also adapt to the complex and changeable urban rainwater environment, ensuring the stability and sustainability of the treatment system.

[0050] The present invention has no particular limitation on the source of the microbial agents used in different microbial colony areas, and any commercially available product known in the art may be used; in the embodiments of the present invention, the microbial agents used are specifically derived from ATCC.

[0051] In the present invention, in the embedded composite microbial purification layer, sewage first enters the first module layer, and after being treated by the microbial colony, the sewage treated by the first module layer flows into the second module layer.

[0052] The present invention has no special limitation on the manufacturing method of the embedded composite microbial purification layer, and it can be constructed using specific materials according to the required structure.

[0053] In the embedded composite microbial purification layer of the present invention, each layer uses a specific microbial community for specific pollutants. Using modular units, different microbial communities are combined and assembled in a "series-parallel" manner to achieve synergy: in "series", different microorganisms have different physiological characteristics and metabolic pathways. Combining them can achieve more comprehensive and efficient pollutant treatment; in "parallel", the redundant design enables the composite microorganisms to better adapt to different environmental conditions, such as pH value, temperature, oxygen content, etc., and have higher system ecological resilience, so that it can still maintain effectiveness in a variety of application scenarios. The bacterial agents used are harmless to animals and plants, environmentally friendly, and will not introduce alien species, which helps to maintain or restore ecological balance. The use of porous and degradable support plates not only helps the growth and spread of microorganisms, but also complies with the principles of environmental protection and sustainability, reducing environmental pollution and waste disposal problems. The use of embedded modules has a directional effect. By selecting specific types of microorganisms, specific types of pollutants can be treated, such as specific types of organic matter, heavy metals, nitrogen and phosphorus. In addition, the modular combination assembly technology is simple and flexible to build, and is easy to expand or modify as needed. The modular design also facilitates maintenance and upgrading, and can be customized according to specific application requirements, which improves treatment efficiency and environmental adaptability, and may reduce operation and maintenance costs in the long run, especially when dealing with large-scale or complex pollution problems. The modular design allows the system to be quickly adjusted or expanded for specific pollutant loads or treatment goals. Due to its high adaptability and efficiency, the embedded composite microbial module can be applied to a wide range of fields such as urban rainwater management, agricultural drainage treatment, and industrial wastewater treatment.

[0054] Features of the embedded composite microbial purification layer of the present invention include: Segmented specialization: different microbial communities are designed in different layers, such as separating microorganisms for degrading organic matter from microorganisms for nitrogen removal. This specialization allows each community to work in an environment that is most suitable for its metabolism, thereby improving purification efficiency. Enhanced synergy: By placing microorganisms with different metabolic pathways in consecutive layers, continuous treatment of pollutants during movement can be achieved, thereby increasing synergy and reducing the accumulation of intermediate products. Scalability: Additional modules can be added as needed to treat larger volumes of water or different types of wastewater. Easy maintenance and replacement: The modular design simplifies maintenance tasks because individual modules can be independently removed, repaired or replaced without stopping the entire system.

[0055] In the present invention, the thickness of the clay adsorption layer is 20 mm; the clay used in the clay adsorption layer is a mixture of attapulgite and bentonite; the present invention has no special restrictions on the mass ratio of attapulgite to bentonite, which can be adjusted according to actual needs. The present invention has no special restrictions on the source of the clay, and natural clays well known in the art can be used. Natural clay, as an environmentally friendly material, can reduce the negative impact on the ecosystem. Different clays can be customized according to specific water quality conditions and treatment requirements, improve the treatment capacity for diversified pollution sources, and adapt to water treatment needs of different scales and types. Not only can it reversely supply water to the microbial layer and the plant cover layer through capillary action during dry periods, but it also provides additional pollutant adsorption capacity: 1) Enhanced adsorption capacity: The clay adsorption layer has adsorption capacity for specific pollutants, such as heavy metals and organic pollutants, which helps to reduce pollutants that may be missed by traditional biological treatment; 2) Ion exchange function: further purify water quality, especially the removal of phosphorus and nitrogen.

[0056] The present invention sets the clay adsorption layer under the embedded composite microbial purification layer for adsorption and treatment of specific pollutants such as heavy metals and organic pollutants. Placing it between the composite microbial layer and the filler layer plays a "bridging" role: on the one hand, as a carrier of microorganisms, it provides a larger specific surface area for microorganisms to attach, enhancing the effect of biological treatment; on the other hand, it can effectively adsorb organic matter and heavy metal ions in water, which helps to remove pollutants in water, and has a certain ion exchange capacity, which can remove nutrients such as phosphorus and nitrogen in water to a certain extent.

[0057] The present invention has no special limitation on the thickness ratio between the first filler layer and the second filler layer, which can be adjusted according to actual needs. In an embodiment of the present invention, the thickness ratio is specifically 1:1.

[0058] The present invention has no special limitation on the thickness of the packing layer and the thickness of the first packing layer and the second packing layer in the packing layer, which can be adjusted according to actual needs. In an embodiment of the present invention, the thickness of the packing layer is specifically 30 cm.

[0059] In the present invention, the fillers used in the first filler layer and the second filler layer preferably independently include gravel, bark sawdust, biochar or bentonite.

[0060] The improved filler used in the present invention is preferably derived from industrial and agricultural waste, which reduces the carbon footprint, embodies resource recycling, and reduces production costs. The setting of the filler layer can effectively remove pollutants and improve the overall efficiency of the water treatment system. The double-layer filler combination optimizes the permeability, helps to evenly distribute water and effectively treat pollutants, helps to regulate the total amount of runoff, reduces surface water pollution and urban flood risks, and ensures the long-term stable operation of the bioretention pond.

[0061] The packing layer of the present invention adopts a two-layer "overlapping" design (such as Figure 3 As shown in the figure, different packing layers can be used to treat different types of pollutants, such as the upper layer for organic matter and the lower layer for soluble pollutants and nutrients, which improves the overall treatment and filtration efficiency. The "combination" mode packing layer optimizes the permeability, helps to evenly distribute water and effectively treat pollutants, helps to regulate the total amount of runoff, reduces surface water pollution and urban flood risks, and ensures the long-term stable operation of the bioretention system. For different working environments, the optimal packing combination is selected to achieve the highest pollutant removal efficiency and effectively reduce system blockage.

[0062] The present invention has no special limitation on the thickness of the gravel drainage layer, which can be adjusted according to the sewage treatment requirements. In an embodiment of the present invention, the thickness of the gravel drainage layer is specifically 20 cm.

[0063] In the present invention, the aquifer is provided with an overflow port; the gravel drainage layer is provided with a drainage port.

[0064] In the present invention, when the bioretention pond is an anti-seepage type bioretention pond, a geotextile liner layer is further stacked on the gravel drainage layer. When the bioretention pond is an infiltration type bioretention pond, a geotextile liner layer is not required.

[0065] In the present invention, the geosynthetic liner used in the geoliner layer is preferably a bentonite-based geoliner, more preferably an anti-seepage geoliner, and further preferably a polyacrylamide-modified bentonite geoliner; the thickness of the geoliner layer is preferably 10 to 20 mm.

[0066] The geotextile liner of the present invention is used to control and purify runoff, to prevent pollutants from penetrating into groundwater through surface runoff, and to provide high anti-seepage effect and durability. Under long-term erosion of polluted environment, the liner has excellent chemical stability, can maintain a low permeability coefficient, helps to continuously protect groundwater resources, and can effectively prevent surface runoff pollution. The use of polyacrylamide-modified bentonite geotextile liner increases its chemical corrosion resistance and physical stability, effectively preventing pollutants from penetrating into groundwater bodies.

[0067] The present invention has no special limitation on the construction method of the biological retention pond with integrated collection-filtration-purification functions, and each layer can be stacked and arranged according to actual needs in accordance with methods well known in the art.

[0068] Compared with the traditional biological retention pond, the biological retention pond with integrated collection-filtration-purification functions of the present invention has significant structural advantages, improves the treatment efficiency, increases the flexibility of the system, and improves the environmental adaptability.

[0069] In practical applications, the system design, operating performance and social and environmental impacts can be comprehensively evaluated according to actual needs, and the biological retention tank with integrated collection-filtration-purification functions can be upgraded or optimized (such as replacing microbial colonies and replacing fillers) to improve efficiency and adapt to new environmental requirements (such as seasonal temperature changes).

[0070] The present invention provides the application of the biological retention pond with integrated collection-filtration-purification functions described in the above technical solution in sewage treatment and new generation urban stormwater management. The present invention has no special limitation on the application method, and the application can be carried out according to methods well known in the art.

[0071] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0072] In the following examples, the microbial agents used are all from ATCC, and the specific numbers are:

[0073] Pseudomonas putida: ATCC 47054;

[0074] Nitrosomonas europaea: ATCC 19718;

[0075] Alcaligenes faecalis: ATCC 8750;

[0076] Nitrobacter winogradskyi (nitrifying bacteria): ATCC 25391.

[0077] Example 1

[0078] To treat the stormwater runoff from a certain urban community and its surrounding areas, synthetic rainwater was used. The specific components are shown in Table 1.

[0079] Based on the laboratory scale, a small bioretention pond model was constructed with a length, width and height of 2m, 1m and 1m respectively. Water quality tests and microbial activity monitoring were carried out regularly to ensure that the system operates effectively according to the design standards.

[0080] Set up each layer of material as follows:

[0081] Design of biological retention pond, specific dimensions of each layer are shown in Figure 2 :

[0082] First layer: Aquifer

[0083] Second layer: vegetation planting layer

[0084] Cattails, rushes, and native irises were selected to provide initial solid filtration and landscaping while the plant roots absorbed nutrients from the water.

[0085] The third layer: embedded composite microbial purification layer

[0086] The upper layer microorganisms are Pseudomonas putida, Nitrosomonas europaea and Alcaligenes faecalis, which are used to degrade organic pollutants from residential areas; the lower layer microorganisms are Nitrobacter winogradskyi, which oxidizes nitrite to nitrate.

[0087] like Figure 4 As shown, the support plate is a PVC plate, the thickness of the activated carbon particle layer is 50 mm; the particle size of the activated carbon in the activated carbon particle layer is 2 to 4 mm;

[0088] The microbial species in the microbial colony zone 1 is Pseudomonas putida (Pseudomonas putida); the microbial species in the microbial colony zone 2 is Nitrosomonas europaea (Nitrosomonas); the microbial species in the microbial colony zone 3 is Alcaligenes faecalis (Alcaligenes faecalis); the microbial species in the microbial colony zone 4 is Nitrobacter winogradskyi (Nitrifying bacteria); the laying amount of microbial species in the microbial colony zone 1, microbial colony zone 2, microbial colony zone 3 and microbial colony zone 4 is 4×10 8 CFU, 3 × 10 8 CFU, 3 × 10 8 CFU, 1×10 8 CFU.

[0089] The fourth layer: clay adsorption layer

[0090] A mixed clay of attapulgite and bentonite (attapulgite is from Gansu Rongwan Technology Co., Ltd., and bentonite is a commercially available nano-bentonite material (Tianjin Huasheng Chemical Reagent Co., Ltd.)) is used to adsorb heavy metals (such as lead and cadmium) and non-biodegradable organic pollutants.

[0091] Fifth layer: filler layer

[0092] The packing layer adopts a two-layer "superposition" design (such as Figure 3 As shown), the upper layer is a mixture of gravel and biochar, the weight ratio of gravel to biochar is 1:1, and the lower layer is a mixture of gravel and bentonite, the weight ratio of gravel to bentonite is 3:1; the biochar is 40-80 mesh straw biochar (purchased from Tanerno New Materials);

[0093] Sixth layer: Gravel drainage layer

[0094] Coarse gravel and drainage pipe network are used to provide an effective water flow channel to ensure water infiltration and control drainage to the municipal stormwater pipe network.

[0095] Seventh layer: geotextile liner anti-seepage layer

[0096] Polyacrylamide modified bentonite geoliner (BPC-GCL): It is made by dry mixing with 5% mass percentage of polyacrylamide relative to dry bentonite.

[0097] The short-term experiment simulated a rainfall event, with a total flow rate of 500L and a duration of 2h. Sampling points were set at the inlet and outlet, and water samples were collected every 30 minutes before, during, and after the experiment. The removal rate was calculated according to the following formula:

[0098]

[0099] The results are shown in Table 1.

[0100] Table 1 Data of synthetic rainwater treatment in Example 1

[0101]

[0102]

[0103] After 6 months of operation, the removal rates of COD and BOD stabilized at over 90%, the removal efficiencies of nitrogen and phosphorus exceeded 85%, and the removal rate of heavy metals reached 95%.

[0104] Experiments have shown that the application of this system can improve the ecological value and leisure quality of sponge communities or parks, reduce the processing burden of urban drainage systems, and reduce long-term environmental maintenance costs.

[0105] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Application of a biological retention pond with integrated collection-filtration-purification functions in sewage treatment and new generation urban stormwater management, characterized in that: It includes an embedded composite microbial purification layer, a clay adsorption layer, a filler layer and a gravel drainage layer arranged in sequence from top to bottom; it also includes an aquifer and a vegetation cover layer, wherein the vegetation cover layer and the aquifer are stacked in sequence on the embedded composite microbial purification layer; The embedded composite microbial purification layer includes a first module layer and a second module layer; the first module layer and the second module layer form a corresponding upper and lower layer structure in space; the first module layer and the second module layer are connected by an embedded unit column; the first module layer includes a first microbial colony area, a second microbial colony area and a third microbial colony area arranged in parallel; the second module layer is a fourth microbial colony area; the types of microbial strains in the first microbial colony area, the second microbial colony area, the third microbial colony area and the fourth microbial colony area are different; The packing layer comprises a first packing layer and a second packing layer which are stacked; the first packing layer and the second packing layer have different types of packing; The thickness of the embedded composite microbial purification layer is ≥40 mm; The first and second modules of the module are both equipped with support plates to carry microbial strains; the support plate of the first module is provided with an activated carbon particle layer; The clay used in the clay adsorption layer is clay based on attapulgite and bentonite.

2. The use according to claim 1, characterized in that: When the bioretention pond is an impermeable bioretention pond, a geotechnical liner layer is further stacked on the gravel drainage layer.

3. The use according to claim 1, characterized in that: The fillers used in the first filler layer and the second filler layer independently include gravel, bark sawdust, biochar or bentonite.

4. The use according to claim 2, characterized in that: The geosynthetic liner used in the geotextile liner layer is a bentonite-based geotextile liner.

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