Urban surface runoff pollution purification system and purification method

Abstract

The application provides a kind of urban surface runoff pollution purification system and purification method, belongs to water environment treatment technical field, and purification system includes water seepage layer, water baffle, filter area and purification area, water seepage layer is inclined to set, and water baffle is set in the end of water seepage layer and protrudes upward;Filter area is set below water seepage layer, and purification area is set in the end of filter area along the direction of surface runoff, and the top of purification area is provided with vegetation layer, and surface runoff enters vegetation layer after passing over the water baffle in the end of water seepage layer, and then is discharged into river and lake.The urban surface runoff pollution purification system provided by the application, the water baffle intercepts the initial rainwater, the initial rainwater enters the filter area through the water seepage layer, and is discharged into river and lake after filtration and purification, the middle and later stage rainwater enters the vegetation layer after passing over the water baffle and is purified, and is finally discharged into river and lake, which realizes accurate interception and targeted purification of runoff pollution, and realizes efficient removal of runoff pollution.

Description

Technical Field

[0001] This invention relates to the field of water environment management technology, specifically to an urban surface runoff pollution purification system and method. Background Technology

[0002] Urban surface runoff pollution is caused by rainfall forming surface runoff. Rainwater carries pollutants from the air and those washed away from the ground, resulting in surface runoff pollution, which is a significant source of urban non-point source pollution. Initial rainfall runoff, generally referring to the surface runoff formed during the first 6-15 mm of rainfall, is the most polluting, sometimes exceeding the pollution levels of urban sewage. This runoff is discharged into rivers and lakes through pipes, causing considerable pollution to the aquatic environment.

[0003] In engineering practice, the treatment of urban surface runoff pollution typically involves purifying initial rainwater at its source by constructing urban sponge facilities (such as sunken green spaces and vegetated swales). However, these facilities require a large area and are often difficult to implement in urban built-up areas due to a lack of land. Alternatively, at the end of the runoff pollution process, measures such as the construction of stormwater storage tanks and sewage treatment facilities can be used to treat the pollution. This approach requires significant urban land space and purifies both initial and subsequent rainwater runoff, increasing the burden on the purification system. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is how to treat urban initial rainwater, thereby providing an urban surface runoff pollution purification system and purification method.

[0005] To address the aforementioned technical problems, this invention provides an urban surface runoff pollution purification system, comprising:

[0006] The inclined permeable layer is used for the downstream flow and infiltration of surface runoff;

[0007] A water-blocking plate protrudes upward and is disposed at the end of the permeable layer;

[0008] A filtration zone is located below the permeable layer, through which surface runoff enters the filtration zone for filtration.

[0009] The purification zone is located at the end of the filtration zone along the direction of surface runoff. The purification zone purifies the filtered surface runoff, which is then discharged into rivers and lakes. A vegetation layer is provided on top of the purification zone. The surface runoff passes over the water-retaining plate at the end of the permeable layer and enters the vegetation layer before being discharged into rivers and lakes.

[0010] Optionally, it also includes:

[0011] A water collection area is connected to the outlet end of the filtration area, and the filtered surface runoff is stored in the water collection area. The water collection area is connected to the beginning end of the purification area.

[0012] Optionally, the baffle plate also blocks the area between the filtration zone and the purification zone, which are connected by a connecting pipe;

[0013] The first end of the connecting pipe is connected to the water collection area, the second end of the connecting pipe is connected to the purification area, and at least a portion of the connecting pipe is higher than the top of the water collection area.

[0014] Optionally, the water collection area is filled with a first filter element, the filter particle size of the first filter element being larger than the filter particle size in the filtration area.

[0015] Optionally, the first end of the connecting pipe is away from the water inlet end of the water collection area.

[0016] Optionally, it also includes:

[0017] A connecting pipe, one end of which is connected to the connecting pipe, and the other end of which extends upward out of the seepage layer, wherein there are multiple sets of connecting pipes, and a control valve is provided on the connecting pipe.

[0018] Optionally, the purification zone is divided into multiple interconnected filling zones by partitions, with at least one filling zone at the beginning being a biological purification zone and at least one filling zone at the end being a phosphorus removal purification zone.

[0019] Optionally, the biological purification zone is filled with a biofilm carrier packing material, and the phosphorus removal purification zone is filled with a phosphorus removal matrix packing material.

[0020] Optionally, the inlet and outlet of the filling area are respectively located at the upper and lower ends of the filling area; the inlet of the filling area at the beginning is at the lower end, and the outlet of the filling area at the end is at the upper end.

[0021] Optionally, the filling area is provided with a vent pipe that communicates with the outside.

[0022] Optionally, the filtration zone is provided with a coarse filtration layer and a fine filtration layer from top to bottom. The coarse filtration layer is filled with a second filter element, and the fine filtration layer is filled with a third filter element. The filter particle size of the second filter element is larger than that of the third filter element.

[0023] Optionally, the second filter element and the third filter element are gravel.

[0024] Optionally, a support layer is provided below the permeable layer to support the permeable layer, and the support layer is a permeable structure.

[0025] Optionally, an impermeable component is provided between the vegetation layer and the purification zone.

[0026] Optionally, the roots of the vegetation in the vegetation layer extend through the impermeable element into the purification zone.

[0027] The present invention also provides a method for purifying urban surface runoff pollution, employing the urban surface runoff pollution purification system described in any of the above claims, comprising the following steps:

[0028] Rainfall runoff flows into the purification system, is intercepted by baffles, and then infiltrates through the permeable layer into the filtration area.

[0029] Filtered surface runoff enters the purification zone after being filtered in the filtration zone.

[0030] The purified surface runoff in the purification zone is discharged into rivers and lakes.

[0031] Optionally, when the rainfall exceeds the initial rainfall set value, the initial rainwater exceeding the baffle plate is discharged into rivers and lakes after passing through the vegetation layer.

[0032] Optionally, the height of the water barrier is set according to the initial rainfall amount.

[0033] Optionally, the outlet of the filtration zone is connected to a water collection zone, and the water collection zone and the purification zone are connected by a connecting pipe. At least a portion of the connecting pipe is higher than the top of the water collection zone. A connecting pipe for communication with the outside is provided on the connecting pipe.

[0034] The connecting pipe is equipped with a control valve, and the initial rainfall amount is adjusted by the opening and closing or the opening degree ratio of the control valve.

[0035] The technical solution of this invention has the following advantages:

[0036] 1. This invention provides an urban surface runoff pollution purification system, comprising an inclined infiltration layer. Surface runoff flows along the infiltration layer and infiltrates into a filtration zone below it. A baffle intercepts the initial rainwater collected on the purification system, allowing it to pass through the infiltration layer into the filtration zone, where it is further purified before being discharged into rivers and lakes. Later-stage rainwater bypasses the baffle and enters a vegetation layer for purification before finally being discharged into rivers and lakes. This process avoids mixing with the initial rainwater, preventing the impact of non-initial runoff on the purification system and thus reducing its processing load. Only the initial rainwater undergoes deep purification. The purification system is located on the banks of rivers and lakes, blending seamlessly with the natural shoreline. The filtration and purification zones are located below the infiltration and vegetation layers, respectively, without occupying additional ground space. During non-purification phases, the infiltration and vegetation layers function as a relatively natural ecological environment, without affecting the ecological landscape of the riverbanks.

[0037] 2. The urban surface runoff pollution purification system provided by this invention further includes a water collection area connected to the outlet end of the filtration area. The filtered surface runoff is stored in the water collection area, which is connected to the beginning of the purification area. The water collection area is used to regulate and store the filtered initial rainwater, providing a relatively uniform and continuous water volume for subsequent deep purification, ensuring the stability of its treatment effect.

[0038] 3. The present invention provides an urban surface runoff pollution purification system, wherein a baffle plate also blocks the flow between the filtration zone and the purification zone. The filtration zone and the purification zone are connected by a connecting pipe. The first end of the connecting pipe is connected to the water collection zone, and the second end of the connecting pipe is connected to the purification zone. At least a part of the connecting pipe is higher than the top of the water collection zone. The connecting pipe is designed to use static pressure and siphon effect to allow the initial rainwater to flow into the subsequent purification zone, preventing residual suspended solids and floating matter from entering the purification zone and affecting the purification quality of the purification zone.

[0039] 4. The present invention provides an urban surface runoff pollution purification system, wherein a first filter element is filled in the water catchment area. The filter particle size of the first filter element is larger than that of the filter particle size in the filtration area. It can not only store rainwater, but also further remove larger suspended pollutants.

[0040] 5. The present invention provides an urban surface runoff pollution purification system in which the first end of the connecting pipe is far away from the inlet end of the water collection area, so that the rainwater entering the water collection area is filtered by the first filter element before being sent into the purification area through the connecting pipe, thereby preventing suspended solids from entering the purification area through the connecting pipe and causing blockage.

[0041] 6. The present invention provides an urban surface runoff pollution purification system, which further includes a connecting pipe, one end of which is connected to a connecting pipe, and the other end extending upwards into the permeable layer. A control valve is installed on the connecting pipe, and multiple sets of connecting pipes are provided. The number of connecting pipes connected is controlled by opening and closing the control valve, or the amount of treated water flowing from the filtration zone into the purification zone is controlled by the opening degree of the control valve, thereby controlling the amount of initial rainwater intercepted. The control valve can also serve as a cleaning interface when the connecting pipe is blocked; after disassembling the control valve, high-pressure air or water is blown into the connecting pipe for cleaning.

[0042] 7. The present invention provides an urban surface runoff pollution purification system, wherein the purification zone is divided into multiple interconnected filling zones by partitions. At least one filling zone at the beginning is a biological purification zone, and at least one filling zone at the end is a phosphorus removal purification zone. The filtered initial rainwater first passes through the biological purification zone to remove dissolved pollutants from the runoff pollution, and then passes through the phosphorus removal purification zone to remove dissolved phosphorus, thereby achieving efficient removal of dissolved pollutants from the runoff pollution.

[0043] 8. The present invention provides an urban surface runoff pollution purification system, wherein the biological purification zone is filled with biofilm carrier packing and the phosphorus removal purification zone is filled with phosphorus removal matrix packing. The biofilm carrier packing is used to attach a sufficient amount of biofilm, thereby improving the pollutant purification efficiency. The dissolved pollutants in the runoff pollution undergo carbonization reaction to remove COD through the action of biofilm microorganisms, and nitrification and denitrification reactions to remove ammonia nitrogen and total nitrogen. Some of the dissolved total phosphorus is removed through adsorption and interception. The phosphorus removal matrix packing reacts chemically with and physically intercepts the dissolved orthophosphate to remove it.

[0044] 9. The present invention provides an urban surface runoff pollution purification system in which the inlet and outlet ends of the filling zone are respectively located at the upper and lower ends of the filling zone. The inlet end of the filling zone at the beginning is at the lower end, and the outlet end of the filling zone at the end is at the upper end. This increases the residence time of the initial rainwater in the purification zone and improves the mass transfer efficiency between dissolved pollutants and biofilm, thereby improving the purification efficiency.

[0045] 10. The present invention provides an urban surface runoff pollution purification system, wherein a ventilation pipe connected to the outside is provided in the filling area to replenish dissolved oxygen in the purification area, which facilitates microbial reaction.

[0046] 11. The present invention provides an urban surface runoff pollution purification system, wherein a coarse filter layer and a fine filter layer are arranged sequentially from top to bottom in the filtration zone. The coarse filter layer is filled with a second filter element, and the fine filter layer is filled with a third filter element. The filter particle size of the second filter element is larger than that of the third filter element. The coarse filter layer and the fine filter layer sequentially filter suspended solids of different sizes in the initial rainwater. After multi-stage interception and filtration, the rainwater flows into the collection area. After two stages of filtration, most of the suspended solids, particulate matter, colloids, etc. in the initial rainwater are intercepted and removed. The removal rates of SS and COD can reach more than 80% and 50%, respectively.

[0047] 12. The present invention provides an urban surface runoff pollution purification system, wherein the second and third filter elements are gravel, which can not only filter impurities and pollutants, but also have good load-bearing capacity and improve the stability of the filtration zone.

[0048] 13. The present invention provides an urban surface runoff pollution purification system, wherein a support layer is provided below the permeable layer. The support layer is a permeable structure and is used to support the permeable layer, thereby improving the stability of the permeable layer and giving it good load-bearing capacity when used as a road.

[0049] 14. The present invention provides an urban surface runoff pollution purification system, wherein an impermeable component is provided between the vegetation layer and the purification zone to prevent rainwater that has passed through the water barrier from directly entering the purification zone and causing a large burden on the purification zone. The roots of the vegetation in the vegetation layer extend into the purification zone through the impermeable component, and the vegetation can provide a certain amount of dissolved oxygen to the purification zone through its roots, which facilitates microbial reactions.

[0050] 15. The present invention provides a method for purifying urban surface runoff pollution, wherein surface runoff generated by rainfall flows into a purification system, is intercepted by a baffle plate, and then infiltrates into a filtration zone through a permeable layer; the filtered surface runoff in the filtration zone enters the purification zone; and the purified surface runoff in the purification zone is discharged into rivers and lakes, thereby achieving precise interception and effective purification of runoff pollution.

[0051] 16. The present invention provides a method for purifying urban surface runoff pollution. When the rainfall exceeds the initial rainwater volume set value, the initial rainwater exceeding the water barrier passes through the vegetation layer and is discharged into rivers and lakes, thus avoiding the impact of non-initial runoff on the purification system and causing a decrease in purification efficiency. Attached Figure Description

[0052] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0053] Figure 1 This is a schematic diagram of a specific embodiment of the urban surface runoff pollution purification system provided in the embodiments of the present invention;

[0054] Figure 2 for Figure 1 A schematic diagram of the internal structure of the filter area.

[0055] Explanation of reference numerals in the attached figures:

[0056] 1. Permeable layer; 2. Water baffle; 3. Filtration zone; 4. Purification zone; 5. Vegetation layer; 6. Water collection zone; 7. Connecting pipe; 8. First filter element; 9. Connecting pipe; 10. Control valve; 11. Partition; 12. Filling zone; 13. Ventilation pipe; 14. Coarse filter layer; 15. Fine filter layer; 16. Second filter element; 17. Third filter element; 18. Support layer; 19. Impermeable component. Detailed Implementation

[0057] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0059] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0060] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0061] The urban surface runoff pollution purification system provided in this embodiment filters and purifies urban surface runoff sequentially, achieving efficient removal of pollutants from surface runoff. Runoff pollution in densely built-up urban areas has the following characteristics: (1) high concentration of runoff pollution, containing dissolved pollutants; (2) strong initial pollution effect, with a high proportion of initial rainwater (typically 6-15 mm) pollution load; (3) large runoff volume, small buffer zone ecological space, and short buffer zone retention time. In response to the characteristics of the initial pollution effect of urban runoff, semi-permeable and impermeable surfaces and areas are constructed along the runoff direction, achieving interception of initial runoff volume, precise interception and targeted purification of runoff pollution, significantly reducing the amount of purified water, and providing a prerequisite for achieving the purification capacity of the buffer zone.

[0062] like Figure 1The diagram illustrates a specific implementation of the urban surface runoff pollution purification system provided in this embodiment. It includes an infiltration layer 1, a baffle plate 2, a filtration zone 3, and a purification zone 4. The infiltration layer 1 is inclined and used for the downstream flow and infiltration of surface runoff. The baffle plate 2 protrudes upwards from the end of the infiltration layer 1. The filtration zone 3 is located below the infiltration layer 1, allowing initial rainwater from the surface runoff to pass through the infiltration layer 1 and enter the filtration zone 3 for filtration. The purification zone 4 is located at the end of the filtration zone 3 along the surface runoff direction, purifying the filtered surface runoff, which is then discharged into rivers and lakes. A vegetation layer 5 is installed on top of the purification zone 4, allowing mid-to-late-stage rainwater from the surface runoff to pass over the baffle plate 2 at the end of the infiltration layer 1 and enter the vegetation layer 5 before being discharged into rivers and lakes. The purification system is designed with a slope to create conditions for rainwater runoff. The permeable layer 1 can be laid using semi-permeable bricks or perforated bricks to collect a certain thickness of initial rainwater. Its length is related to the slope of the purification system and the intercepted runoff volume. The slope is consistent with the slope of the purification system, generally set at 10-20% to facilitate smooth runoff. Taking an initial rainwater interception volume of 12mm as an example, with a permeability of 3mm / s for the permeable bricks, a 20% slope for the purification system, and a runoff velocity of 0.3m / s, the interception zone length is 1.2m. Under certain rainfall intensity, when the rainfall exceeds 12mm, only a portion of the initial rainwater (12mm) passes through the permeable bricks and enters the filtration zone 3. Rainwater exceeding 12mm bypasses the baffle 2 and enters the vegetation layer 5. The baffle 2 extends 3-5mm above the top slope to intercept runoff under normal intensity.

[0063] The baffle plate 2 intercepts the initial rainwater collected on the purification system, allowing it to pass through the infiltration layer 1 into the filtration zone 3. After filtration, it continues into the purification zone 4 for further purification. The purified initial rainwater is then discharged into the river or lake. Later-stage rainwater bypasses the baffle plate 2 and enters the vegetation layer 5 for further purification before finally being discharged into the river or lake. This process avoids mixing with the initial rainwater, preventing the impact of non-initial runoff on the purification system and minimizing its processing load. The purification system focuses on deep purification of the initial rainwater. Located on the river or lake shore, the system blends seamlessly with the natural riverbanks. The filtration zone 3 and purification zone 4 are situated below the infiltration layer 1 and vegetation layer 5, respectively, without occupying additional ground space. During non-purification phases, the infiltration layer 1 and vegetation layer 5 function as a relatively natural ecological environment, without affecting the ecological landscape of the river or lake banks. The vegetation layer 5 consists of various trees, shrubs, and flowers.

[0064] like Figure 1As shown, the urban surface runoff pollution purification system provided in this embodiment also includes a water collection area 6, which is connected to the outlet end of the filtration area 3. The filtered surface runoff is stored in the water collection area 6, which is connected to the beginning end of the purification area 4. The water collection area 6 is used to regulate and store the initial rainwater after filtration, preventing excessive accumulation of rainwater in the filtration area 3 from affecting subsequent filtration. This provides a relatively uniform and continuous water volume for subsequent deep purification, ensuring the stability of its treatment effect. Specifically, the water collection area 6 is separated by an impermeable plate, with multiple permeable holes on only one side, connected to the filtration area 3. This allows filtered rainwater to enter the water collection area 6 through the permeable holes. The length of the water collection area 6 is greater than 0.5m, and its height is 400-600mm. The top elevation of the water collection area 6 is higher than the outlet elevation at the end, allowing for higher regulation and storage of the filtered water.

[0065] like Figure 1 As shown, in the urban surface runoff pollution purification system provided in this embodiment, the baffle plate 2 also blocks the area between the filtration zone 3 and the purification zone 4, which are connected by a connecting pipe 7. The first end of the connecting pipe 7 is connected to the water collection zone 6, and the second end is connected to the purification zone 4. At least a portion of the connecting pipe 7 is higher than the top of the water collection zone 6. The connecting pipe 7 utilizes static pressure and siphon effect to direct initial rainwater into the subsequent purification zone 4, preventing residual suspended and floating matter from entering the purification zone and affecting its purification quality. Specifically, the connecting pipe 7 can be an inverted U-shaped pipe, and generally 2-4 sets of connecting pipes 7 are installed. The diameter of the connecting pipe 7 is DN100-150mm, and both ends of the connecting pipe 7 can be fixed to the baffle plate 2 with retaining rings.

[0066] The urban surface runoff pollution purification system provided in this embodiment includes a first filter element 8 filling the catchment area 6. The filter particle size of the first filter element 8 is larger than that of the filter particle size in the filtration area 3. This system not only stores rainwater but also further removes larger suspended pollutants. The first filter element 8 can be large-diameter gravel with a particle size of 16-32 mm and a porosity > 50%.

[0067] like Figure 1 As shown, in the urban surface runoff pollution purification system provided in this embodiment, the first end of the connecting pipe 7 is far from the inlet end of the water collection area 6. This allows rainwater entering the water collection area 6 to be filtered by the first filter element 8 before being sent into the purification area 4 through the connecting pipe 7, preventing suspended solids from entering the purification area 4 through the connecting pipe 7 and causing blockage.

[0068] like Figure 1As shown, the urban surface runoff pollution purification system provided in this embodiment also includes a connecting pipe 9. One end of the connecting pipe 9 is connected to the connecting pipe 7, and the other end of the connecting pipe 9 extends upwards out of the permeable layer 1. Multiple sets of connecting pipes 9 are provided, and control valves 10 are installed on each connecting pipe 9. The number of connecting pipes 9 connected is controlled by opening and closing the control valves 10, or the opening degree of the control valves 10 is controlled to regulate the amount of treated water flowing from the filtration zone 3 into the purification zone 4, thereby controlling the amount of initial rainwater intercepted. The control valves 10 can also serve as a cleaning interface when the connecting pipe 7 is blocked. After disassembling the control valves 10, high-pressure air and water are blown into the connecting pipe for cleaning. The control valves 10 are shut-off valves.

[0069] like Figure 1 As shown, the urban surface runoff pollution purification system provided in this embodiment divides the purification zone 4 into multiple interconnected filling zones 12 by partitions 11. At least one filling zone 12 at the beginning is a biological purification zone, and at least one filling zone 12 at the end is a phosphorus removal purification zone. The filtered initial rainwater first passes through the biological purification zone to remove dissolved pollutants from the runoff, and then passes through the phosphorus removal purification zone to remove dissolved phosphorus, achieving efficient removal of dissolved pollutants from the runoff. The partitions 11 are impermeable. The biological purification zone is filled with biofilm carrier packing, and the phosphorus removal purification zone is filled with phosphorus removal matrix packing. The biofilm carrier packing can be ceramsite or fiber balls, with a particle size of 2-4 mm and a specific surface area >10×10⁻⁶. 4 The biofilm carrier packing material has a particle size of 2-4 mm and an aluminum content of >75%, with a porosity >80%. It is used to attach a sufficient amount of biofilm to improve pollutant purification efficiency. The phosphorus removal matrix packing material (such as bauxite) has a particle size of 2-4 mm and an aluminum content >75%. It removes soluble orthophosphate through chemical reaction and physical interception. After rainwater enters purification zone 4, it undergoes an aerobic biological reaction under the action of the biofilm carrier packing material, removing soluble pollutants (such as NH3-N, COD, and TP) from the runoff. The dissolved pollutants (such as NH3-N, COD, and TP) in the runoff are removed through carbonization by biofilm microorganisms, nitrification and denitrification to remove NH3-N and total nitrogen, and adsorption and interception to remove some of the soluble total phosphorus.

[0070] like Figure 1As shown, in this embodiment of the urban surface runoff pollution purification system, the inlet and outlet of the filling zone 12 are respectively located at the upper and lower ends of the filling zone 12; the inlet of the filling zone 12 located at the first end is at the lower end, and the outlet of the filling zone 12 located at the last end is at the upper end. This increases the residence time of initial rainwater in the purification zone 4, improving the mass transfer efficiency between dissolved pollutants and the biofilm, thus improving the purification efficiency. Specifically, the cooperation between the inlet and outlet of the filling zone 12 and the baffle 11 creates a baffled channel after rainwater enters the purification zone 4, improving the mass transfer efficiency between pollutants and the biofilm.

[0071] like Figure 1 As shown, the urban surface runoff pollution purification system provided in this embodiment has a ventilation pipe 13 connected to the outside in the filling area 12 to replenish the dissolved oxygen in the purification area 4, providing the necessary conditions for efficient biochemical reactions. The ventilation pipe 13 is generally a pipe with a diameter of DN32.

[0072] like Figure 2 As shown, the urban surface runoff pollution purification system provided in this embodiment has a coarse filter layer 14 and a fine filter layer 15 arranged sequentially from top to bottom in the filtration zone 3. The coarse filter layer 14 is filled with a second filter element 16, and the fine filter layer 15 is filled with a third filter element 17. The filter particle size of the second filter element 16 is larger than that of the third filter element 17. The coarse filter layer 14 and the fine filter layer 15 sequentially filter suspended solids of different sizes in the initial rainwater. After multi-stage interception and filtration, the rainwater flows into the collection zone 6. After two stages of filtration, most of the suspended solids, particulate matter, colloids, etc. in the initial rainwater are intercepted and removed. The removal rates of SS and COD can reach more than 80% and 50%, respectively. The second filter element 16 and the third filter element 17 are made of gravel. The coarse filter layer 14 contains larger gravel particles (8-16 mm in diameter) and a thickness of 300-500 mm. The fine filter layer 15 contains gravel particles (4-8 mm in diameter) and a thickness of 300-500 mm. The gravel not only filters impurities and contaminants but also has good load-bearing capacity, improving the stability of the filtration zone 3.

[0073] like Figure 2 As shown, the urban surface runoff pollution purification system provided in this embodiment has a support layer 18 below the permeable layer 1 to support it. The support layer 18 is a permeable structure with a thickness of 150mm. The support layer 18 improves the stability of the permeable layer 1 and provides better load-bearing capacity when used as a road.

[0074] The urban surface runoff pollution purification system provided in this embodiment includes an impermeable component 19 between the vegetation layer 5 and the purification zone 4. The roots of the vegetation in the vegetation layer 5 extend through the impermeable component 19 into the purification zone 4. The impermeable component 19 prevents rainwater that has passed over the baffle 2 from directly entering the purification zone 4, thus avoiding a significant burden on the purification zone 4. The roots of the vegetation in the vegetation layer 5 can provide dissolved oxygen to the purification zone 4 through the impermeable component 19, facilitating microbial reactions. The impermeable component 19 is made of impermeable geotextile, with a lawn or planted flowers, grasses, and trees laid on top, and a 100-150mm layer of planting soil. The partition 11 in the purification zone 4 must avoid the tree roots in the vegetation layer 5.

[0075] This embodiment also provides a method for purifying urban surface runoff pollution, using the urban surface runoff pollution purification system described in any of the above embodiments, including the following steps:

[0076] Rainfall runoff flows into the purification system, is intercepted by baffle 2, and then seeps into the filtration zone 3 through the infiltration layer 1.

[0077] The filtered surface runoff in filtration zone 3 enters purification zone 4;

[0078] The purified surface runoff in purification zone 4 is discharged into rivers and lakes.

[0079] The interception of water by the baffle plate 2 enables precise interception and targeted purification of runoff pollution, significantly reducing the amount of water required for purification and achieving effective purification of runoff pollution.

[0080] When the rainfall exceeds the initial rainfall set value, the initial rainwater exceeding the baffle 2 is discharged into the river and lake after passing through the vegetation layer 5, thus avoiding the impact of non-initial runoff on the purification system and causing a decrease in purification efficiency. The height of the baffle 2 is set according to the initial rainfall set value.

[0081] The urban surface runoff pollution purification method provided in this embodiment includes a water collection area 6 connected to the outlet of the filtration zone 3. The water collection area 6 and the purification zone 4 are connected by a connecting pipe 7, at least a portion of which is higher than the top of the water collection area 6. A connecting pipe 9 connected to the outside is provided on the connecting pipe 7. A control valve 10 is provided on the connecting pipe 9, and the initial rainwater volume setting value is adjusted by the opening and closing or opening degree ratio of the control valve 10.

[0082] Specifically, taking the interception of initial rainwater of 12mm as an example, if the rainfall does not exceed 12mm, the water barrier 2 intercepts the surface runoff and filters and purifies it in sequence after passing through the infiltration layer 1, and then discharges it into rivers and lakes. When the rainfall exceeds 12mm, only a portion of the initial rainwater (12mm) passes through the infiltration layer 1 and enters the filtration zone 3. Rainwater exceeding 12mm passes through the water barrier 2 and enters the vegetation layer 5, and is finally discharged into rivers and lakes.

[0083] In response to the water quality characteristics of urban runoff pollution, a purification system consisting of filtration and interception, microbial purification, and physicochemical phosphorus removal was constructed, achieving highly efficient removal of runoff pollution, especially dissolved pollutants. Furthermore, the system utilizes the slope and terrain of the purification area to create the hydraulic conditions for the runoff, requiring no power equipment or aeration. Facilities such as U-shaped pipes and ventilation pipes are installed, making operation, maintenance, and repair convenient.

[0084] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A system for purifying urban stormwater runoff, the system comprising: The utility model relates to a rainwater collection and purification system, comprising: a water infiltration layer (1) arranged obliquely to guide the flow of surface runoff and infiltration; a water baffle (2) arranged upwardly at the end of the water infiltration layer (1); a filtering area (3) arranged below the water infiltration layer (1) for filtering the surface runoff entering the filtering area (3) from the water infiltration layer (1); a purification area (4) arranged at the end of the filtering area (3) along the direction of the surface runoff, the purification area (4) purifying the filtered surface runoff, and the purified surface runoff being discharged into a river or lake, the top of the purification area (4) being provided with a vegetation layer (5), the surface runoff entering the vegetation layer (5) from the water baffle (2) at the end of the water infiltration layer (1) and then being discharged into a river or lake; a water collecting area (6) arranged in communication with the water outlet of the filtering area (3), the filtered surface runoff being stored in the water collecting area (6), the water collecting area (6) being in communication with the head of the purification area (4); the filtering area (3) and the purification area (4) being in communication through a communication pipe (7); the first end of the communication pipe (7) being in communication with the water collecting area (6), the second end of the communication pipe (7) being in communication with the purification area (4), and at least a part of the communication pipe (7) being higher in height than the top of the water collecting area (6); a connecting pipe (9) having one end connected with the communication pipe (7) and the other end extending upwardly beyond the water infiltration layer (1), the connecting pipe (9) having a plurality of groups, and the connecting pipe (9) being provided with a control valve (10); the height of the water baffle (2) being set according to the initial rainwater amount setting value; the connecting pipe (9) being provided with the control valve (10), the initial rainwater amount setting value being adjusted by the opening and closing or opening degree of the control valve (10).

2. The urban stormwater runoff pollution abatement system of claim 1, wherein, The water baffle (2) also blocks the filtering area (3) and the purification area (4).

3. The urban stormwater runoff pollution abatement system of claim 2, wherein, The water collecting area (6) is filled with a first filter (8) having a filter particle size larger than that of the filtering area (3).

4. The urban stormwater runoff pollution abatement system of claim 3, wherein, The first end of the communication pipe (7) is away from the water inlet end of the water collecting area (6).

5. The urban stormwater runoff pollution abatement system of any one of claims 1-4, wherein The purification area (4) is divided into a plurality of groups of filling areas (12) in communication by a partition (11), at least one group of the filling areas (12) at the head being a biological purification area, and at least one group of the filling areas (12) at the tail being a phosphorus removal purification area.

6. The urban stormwater runoff pollution abatement system of claim 5, wherein, The biological purification area is filled with a biological membrane carrier filler, and the phosphorus removal purification area is filled with a phosphorus removal substrate filler.

7. The urban stormwater runoff pollution purification system of claim 5, wherein, The inlet end and the outlet end of the filling area (12) are arranged at the upper and lower ends of the filling area (12), respectively; the inlet end of the filling area (12) at the head is at the lower end, and the outlet end of the filling area (12) at the tail is at the upper end.

8. The urban stormwater runoff pollution abatement system of claim 5, wherein, The filling area (12) is provided with an air pipe (13) in communication with the outside.

9. The urban stormwater runoff pollution abatement system of any one of claims 1-4, wherein, The coarse filtering layer (14) is filled with second filtering members (16), and the fine filtering layer (15) is filled with third filtering members (17), the filtering particle size of the second filtering members (16) is larger than that of the third filtering members (17).

10. The urban stormwater runoff pollution abatement system of claim 9, wherein, The second filtering members (16) and the third filtering members (17) are gravels.

11. The urban stormwater runoff pollution abatement system of any one of claims 1-4, wherein, A supporting layer (18) is arranged below the water permeable layer (1) for supporting the water permeable layer (1), and the supporting layer (18) is a water permeable structure.

12. The urban stormwater runoff pollution abatement system of any one of claims 1-4, wherein, A water impermeable member (19) is arranged between the vegetation layer (5) and the purification zone (4).

13. The urban stormwater runoff pollution abatement system of claim 12, wherein, Roots of the vegetation in the vegetation layer (5) penetrate through the water impermeable member (19) and extend into the purification zone (4).

14. A method of purifying urban stormwater runoff, characterized by, The urban surface runoff pollution purification system according to any one of claims 1-13 comprises the following steps: Surface runoff generated by rainfall converges to the purification system, is intercepted by the water baffle (2), and then is infiltrated to the filtering zone (3) through the water permeable layer (1); The filtered surface runoff in the filtering zone (3) enters the purification zone (4); The purified surface runoff in the purification zone (4) is discharged into a river or a lake.

15. The method of claim 14, wherein, When the rainfall exceeds the initial rainwater setting value, the initial rainwater exceeding the water baffle (2) is discharged into the river or the lake after passing through the vegetation layer (5).

16. The method of claim 15, wherein, A water collecting zone (6) is arranged at the water outlet of the filtering zone (3), the water collecting zone (6) and the purification zone (4) are connected through a connecting pipe (7), at least a part of the connecting pipe (7) is higher than the top of the water collecting zone (6) in height, and a connecting pipe (9) connected with the outside is arranged on the connecting pipe (7).

Images