grassed swale drop energy dissipation tank

Abstract

The application provides a grassed swale drop energy dissipation tank, and relates to the technical field of environmental protection. The grassed swale drop energy dissipation tank comprises a tank body, an energy dissipation module and a purification module. The tank body has a first opening cavity and a second opening cavity with openings facing upwards. The bottom of the first opening cavity is in communication with the bottom of the second opening cavity, and the opening end of the first opening cavity is higher than the opening end of the second opening cavity. The energy dissipation module is installed in the first opening cavity. The purification module comprises a grid frame, porous biochar filling and a counterweight. The porous biochar filling is filled in the grid frame, the grid frame is installed in the second opening cavity, and there is a gap between the grid frame and the bottom wall of the second opening cavity. The counterweight is installed at the bottom of the grid frame. The grassed swale drop energy dissipation tank provided by the application solves the technical problems of soil erosion of the grassed swale and the threat of pollutants in runoff to the safety of river and reservoir water quality in the prior art.

Description

Technical Field

[0001] This application relates to the field of environmental protection technology, and more specifically, to a grass-planted ditch cascade energy dissipation trough. Background Technology

[0002] With the deepening of urbanization, more and more riverside and reservoir roads are being incorporated into local municipal road networks, becoming urban traffic arteries or tourist routes, playing an increasingly important role in transportation and public services. Along with the influx of vehicles and people, river and reservoir waters, especially those near water sources, face a serious threat of initial runoff pollution: large amounts of surface pollutants accumulated during the dry season are washed away and discharged into the reservoirs by rainwater, severely affecting water quality during the rainy season and causing the accumulation of pollutants such as heavy metals, polycyclic aromatic hydrocarbons (PAHs), and microplastics, potentially triggering water pollution incidents.

[0003] Grassed swales are ecological drainage facilities used in sponge city construction to collect and transfer excess runoff, and are widely used in ecological protection around river and reservoir water sources. However, when the longitudinal slope of the road is large, the runoff velocity in the grassed swales is too fast, which not only easily causes erosion of the swale body and soil loss, but also leads to the rapid inflow of pollutants such as heavy metals carried by the runoff into the river and reservoir, threatening the safety of the river and reservoir water quality. Utility Model Content

[0004] The purpose of this application is to provide a grassed swale cascade energy dissipation channel to alleviate the technical problems of soil erosion in grassed swales and the threat of pollutants in runoff to the safety of river and reservoir water quality in the prior art.

[0005] To solve the above-mentioned technical problems, the technical solution provided in this application is as follows:

[0006] The grassed swale cascade energy dissipation trough provided in this application includes a trough body, an energy dissipation module, and a purification module;

[0007] The groove has a first opening and a second opening, both of which face upwards. The bottom of the first opening is connected to the bottom of the second opening, and the opening end of the first opening is higher than the opening end of the second opening.

[0008] The energy dissipation module is installed inside the first oral cavity;

[0009] The purification module includes a grid frame, porous biochar filler, and a counterweight. The porous biochar filler is filled inside the grid frame. The grid frame is installed inside the second opening, and there is a gap between the grid frame and the bottom wall of the second opening. The counterweight is installed at the bottom of the grid frame.

[0010] Furthermore, the porous biochar packing material has a filling degree of less than or equal to 60% within the grid frame.

[0011] Furthermore, the porous biochar packing material comprises porous biochar with a specific surface area greater than or equal to 800 m². 2 / g, with the pore size of the internal pores set to 1-50nm.

[0012] Furthermore, the porous biochar is spherical or ellipsoidal in shape.

[0013] Furthermore, the volume ratio of the first oral cavity to the second oral cavity is set to 1:1-1:6.

[0014] Furthermore, the grid frame is connected to the inner wall of the second opening via a support member.

[0015] Furthermore, one end of the support member is inserted into the inner wall of the second opening, and the other end extends out of the inner wall of the second opening and is connected to the grid frame.

[0016] Furthermore, the counterweight is connected to the bottom of the grid frame via a suspension cable.

[0017] Furthermore, the grassed swale cascade energy dissipation trough includes a partition wall, which is installed inside the trough and has at least two water distribution holes at the bottom;

[0018] The partition wall divides the tank into a first opening and a second opening.

[0019] Furthermore, the energy dissipation module includes at least two energy dissipation sills, and the plurality of energy dissipation sills are arranged in a stepped manner from the side of the first opening away from the second opening, with the height of each sill decreasing progressively.

[0020] Based on the above technical solutions, the technical effects achievable by this application can be analyzed as follows:

[0021] The grassed swale energy dissipation trough provided in this application includes a trough body, an energy dissipation module, and a purification module. The trough body has a first opening and a second opening, both with their openings facing upwards. The bottom of the first opening is connected to the bottom of the second opening, and the opening end of the first opening is higher than the opening end of the second opening. The energy dissipation module is installed inside the first opening. The purification module includes a grid frame, porous biochar filler, and a counterweight. The porous biochar filler is filled inside the grid frame, and the grid frame is installed inside the second opening, with a gap between the grid frame and the bottom wall of the second opening. The counterweight is installed at the bottom of the grid frame.

[0022] The trough has a first opening and a second opening, both facing upwards and connected at the bottom. The opening of the first opening is higher than the opening of the second opening. Surface runoff first enters the first opening, undergoes energy dissipation through the energy-dissipating modules, and then flows into the second opening through the bottom of the first opening, forming an upward flow that passes through the suspended purification modules. The purified runoff then flows into the downstream of the vegetated swale from the opening of the second opening. Energy-dissipating modules are installed inside the first opening to achieve graded energy dissipation of runoff and prevent erosion of the swale body. The second opening houses a purification module with a suspended grid frame. This ensures that the runoff, after energy dissipation, enters the second opening from the first and flows upward through the porous biochar packing within the grid frame. This increases the contact area and time between the runoff and the purification module, achieving efficient adsorption. A counterweight is installed at the bottom of the grid frame, ensuring the purification module does not float under the impact of the rising water flow. Based on the purification principle of upflow fluidized beds, the porous structure of the biochar packing efficiently adsorbs heavy metal pollutants in the runoff. The modular design of the purification module, with the biochar packing filling the grid frame, facilitates replacement and maintenance.

[0023] This grassed swale cascade energy dissipation trough is suitable for grassed swales around Binjiang Road and Binku Road. It combines the functions of cascading energy dissipation and adsorption of surface runoff pollutants, ensuring the overall water environment quality of the river and reservoir areas, especially the water source areas. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A plan view of the grassed swale waterfall energy dissipation trough provided in the embodiments of this application;

[0026] Figure 2 for Figure 1 Cross-sectional view at point AA;

[0027] Figure 3 for Figure 1 Cross-sectional view at point BB.

[0028] icon:

[0029] 1-Tank body; 2-Separation wall; 3-First opening; 4-Second opening; 5-Water distribution hole; 6-Energy dissipation sill; 7-Purification module; 8-Grid frame; 9-Porous biochar packing; 10-Suspension cable; 11-Counterweight; 12-Support component. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0031] In the description of this application, it should be noted that the terms "inner" and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application 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 this application. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0032] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "setup" and "connection" 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 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 application based on the specific circumstances.

[0033] Grassed swales are ecological drainage facilities used in sponge city construction for collecting and transferring excess runoff, and are widely used in ecological protection around river and reservoir water sources. However, when the longitudinal slope of the road is large, the runoff velocity in the grassed swales is too fast, which not only easily causes erosion of the swale body and soil loss, but also leads to the rapid inflow of pollutants such as heavy metals carried by the runoff into the river and reservoir, threatening the safety of the water quality. Runoff energy dissipation and runoff pollution control are key points and challenges in the current design of grassed swales. In existing technologies, most designs separate the runoff energy dissipation and pollution control functions of grassed swales, lacking overall consideration. For example, patent CN208650236U mitigates the impact of rainwater runoff on grassed swales by setting up a simple overflow trough and a pebble energy dissipation zone in the grassed swale. Patent CN207185366U controls pollutants such as nitrogen and phosphorus in the runoff by setting up a double-layer new filler at the bottom of the grassed swale and setting up a bark covering layer and a vegetation layer on the surface. Simple weirs and energy dissipation channels only address runoff issues and lack pollutant treatment capabilities. While vegetated swales with composite structures primarily control nutrients like nitrogen and phosphorus, they lack efficient and stable control over more biotoxic heavy metals and PAHs in runoff. Furthermore, the filler layer at the bottom of the swale is difficult to replace and has high management costs. Recent studies have shown that porous biochar, obtained by activating and pore-forming waste biomass, has a rapid and stable adsorption effect on heavy metals and PAHs in runoff and can be continuously recycled. However, currently, there is no integrated structural design that combines porous biochar modules with vegetated swale cascades to achieve integrated energy dissipation and pollutant adsorption.

[0034] In view of this, see Figures 1 to 3 The arrows in the figure indicate the direction of water flow. The grassed swale cascading energy dissipation trough provided in this embodiment includes a trough body 1, an energy dissipation module, and a purification module 7. The trough body 1 has a first opening 3 and a second opening 4 with both openings facing upwards. The bottom of the first opening 3 is connected to the bottom of the second opening 4, and the opening end of the first opening 3 is higher than the opening end of the second opening 4. The energy dissipation module is installed in the first opening 3. The purification module 7 includes a grid frame 8, a porous biochar filler 9, and a counterweight 11. The porous biochar filler 9 is filled in the grid frame 8, the grid frame 8 is installed in the second opening 4, and there is a gap between the grid frame 8 and the bottom wall of the second opening 4. The counterweight 11 is installed at the bottom of the grid frame 8.

[0035] Specifically, the porous biochar filler 9 has a macroscopic particle size not smaller than the structural pores of the mesh frame 8 to prevent the porous biochar filler 9 from being lost with the water flow. In this embodiment, the trough 1 has a double-compartment rectangular groove structure, and the inlet end of the trough 1 is higher than the outlet end. One compartment is the first opening 3, and the other compartment is the second opening 4. The opening end of the first opening 3 is the inlet end, and the opening end of the second opening 4 is the outlet end. At least one of these troughs 1 is set at intervals of 40-70m along the runoff direction in the grassed swale, and the trough 1 is adapted to the overall slope of the grassed swale. Multiple troughs 1 are combined to realize the staged cascading energy dissipation of runoff. Furthermore, the depth of trough 1 is set at 0.3-0.8m, and its width is consistent with the width of the vegetated swale. The inlet end of trough 1 is 0.1-0.15m higher than the outlet end; the outer wall of the inlet end of trough 1 should be about 10-15cm higher than the bottom of the swale to ensure a certain sediment settling effect; the four side walls should be smoothly connected to the side walls of the vegetated swale to ensure the landscape effect. Trough 1 should be inspected before the rainy season each year, removing debris and silt from the bottom and replacing the porous biochar filler 9. The porous biochar filler 9 should be replaced in batches, and the pollutants should be desorbed by the adsorbent material and then reused.

[0036] The trough 1 has a first opening 3 and a second opening 4 with their openings facing upwards and connected at the bottom. The opening end of the first opening 3 is higher than the opening end of the second opening 4. Surface runoff first enters the first opening 3 from its opening end, and after being graded and energy-dissipated by the energy dissipation module, it flows into the second opening 4 through the bottom of the first opening 3, forming an upward flow that passes through the suspended purification module 7. The purified runoff is discharged into the downstream of the vegetated swale from the opening end of the second opening 4. The energy dissipation module is installed inside the first opening 3 to achieve graded energy dissipation of runoff and prevent erosion of the swale body. The second opening 4 houses the purification module 7, with the grid frame 8 suspended in the air. This ensures that the runoff, after energy dissipation, enters the second opening 4 from the first opening 3 and passes through the porous biochar packing 9 filled in the grid frame 8 from bottom to top, increasing the contact area and contact time between the runoff and the purification module 7 for efficient adsorption. A counterweight 11 is installed at the bottom of the grid frame 8, and the gravity of the counterweight 11 ensures that the purification module 7 does not float under the impact of the rising water flow. Based on the purification principle of upflow fluidized bed, the porous structure of the porous biochar packing 9 efficiently adsorbs heavy metal pollutants in the runoff. The porous biochar packing 9 is filled in the grid frame 8, making the purification module 7 modular and easy to replace and maintain.

[0037] This grassed swale cascade energy dissipation channel is suitable for grassed swales around riverside roads and reservoir roads, and is also applicable to the construction and renovation of grassed swales around other natural water bodies, especially water sources. This grassed swale cascade energy dissipation channel combines the functions of cascading energy dissipation and surface runoff pollutant adsorption, ensuring the overall water environment quality of river and reservoir waters, especially water sources; it also achieves integrated drainage energy dissipation and runoff pollution control, with an adsorption rate of over 85% for heavy metals and PAHs, and is convenient to construct and maintain. This grassed swale cascade energy dissipation channel solves the problems of existing grassed swales' separation of runoff energy dissipation and pollution control, low purification efficiency of specific pollutants, and difficult operation and maintenance of the filler layer.

[0038] The following is a detailed description of the structure of the grass swale cascade energy dissipation trough:

[0039] In the optional embodiment provided in this application, the filling degree of the porous biochar packing 9 within the grid frame 8 is less than or equal to 60%.

[0040] Specifically, the grid frame 8 is made of corrosion-resistant materials, including but not limited to galvanized steel wire gabion mesh and steel-plastic geogrid mesh.

[0041] The porous biochar packing material 9 has a filling degree of no more than 60% within the grid frame 8, and its actual density is slightly greater than that of water. This ensures that the runoff after energy dissipation enters the second opening 4 from the bottom of the first opening 3 and then passes through the purification module 7 from bottom to top. The packing material with low filling degree becomes fluidized under the action of the rising water flow, which greatly increases the contact area and contact time with the runoff, thereby achieving efficient adsorption.

[0042] In the optional embodiments provided in this application, the porous biochar packing 9 includes porous biochar with a specific surface area greater than or equal to 800 m². 2 / g, with the pore size of the internal pores set to 1-50nm.

[0043] Specifically, the porous biochar packing material 9 has a macroscopic structure of spherical honeycomb with numerous internal pores to ensure good suspension and hydraulic contact under runoff conditions. The density of the porous biochar packing material 9 is between 1.00 and 1.20 g / cm³. 3 The core component of porous biochar filler 9 is porous biochar, with a particle size between 10-40 mm and a specific surface area of ​​not less than 800 m². 2 / g, whose microstructure is mainly micropores or mesopores with pore sizes of 1-52nm, is suitable for the adsorption of heavy metal ions and runoff pollutants such as PAHs.

[0044] In the optional solutions provided in the embodiments of this application, the porous biochar is spherical or ellipsoidal.

[0045] Specifically, porous biochar is made by activating waste biomass and then binding it with a binder to form spherical or ellipsoidal shapes. The waste biomass includes, but is not limited to, agricultural and forestry waste such as fallen leaves, straw, fruit shells, and sawdust. The binder includes, but is not limited to, bentonite and clay.

[0046] In the optional scheme provided in the embodiments of this application, the volume ratio of the first oral cavity 3 to the second oral cavity 4 is set to 1:1-1:6.

[0047] Specifically, the bottom and sidewalls of tank 1 are formed by casting reinforced concrete with a wall thickness of 100-300mm; or, tank 1 is prefabricated into modules by HDPE (high-density polyethylene) material with a module wall thickness of not less than 80mm.

[0048] In the optional solution provided in the embodiments of this application, the grid frame 8 is connected to the inner wall of the second opening 4 through the support member 12.

[0049] Specifically, the support member 12 is made of stainless steel. Furthermore, the bottom of the grid frame 8 is 15-50cm away from the bottom of the groove 1.

[0050] The support member 12 is used to support the fixed grid frame 8 so that the grid frame 8 is suspended in the second opening 4.

[0051] In the optional solution provided in the embodiments of this application, one end of the support member 12 is inserted into the inner wall of the second opening 4, and the other end extends out of the inner wall of the second opening 4 and is connected to the grid frame 8.

[0052] Specifically, the support member 12 is embedded in the inner wall of the second opening 4. The grid frame 8 is rectangular in shape, and its overall size is adapted to the size of the second opening 4.

[0053] The support member 12 is embedded in the inner wall of the second opening 4 to increase the connection strength between the support member 12 and the second opening 4.

[0054] In the optional solution provided in the embodiments of this application, the counterweight 11 is connected to the bottom of the grid frame 8 via the suspension cable 10.

[0055] Specifically, one end of the suspension cable 10 is connected to the bottom of the grid frame 8, and the other end is connected to the counterweight 11.

[0056] The counterweight 11 ensures that the grid frame 8 does not float under the impact of the rising water flow.

[0057] In the optional solution provided in the embodiments of this application, the grassed swale cascade energy dissipation trough includes a partition wall 2, which is installed inside the trough body 1 and has at least two water distribution holes 5 at the bottom; the partition wall 2 divides the trough body 1 into a first opening 3 and a second opening 4.

[0058] Specifically, the partition wall 2 is flush with the opening end of the first opening 3. The water distribution hole 5 is located at the bottom of the partition wall 2, and its dimensions are length × width = 200 × 100 ~ 300 × 200 mm.

[0059] The interior of the tank 1 is divided into a first opening 3 and a second opening 4 by a partition wall 2, and at least two water distribution holes 5 are reserved at the bottom of the partition wall 2 to ensure that the runoff after energy dissipation flows into the second opening 4.

[0060] In the optional solution provided in the embodiments of this application, the energy dissipation module includes at least two energy dissipation sills 6, and the multiple energy dissipation sills 6 are arranged in a stepped manner from the side of the first opening 3 away from the second opening 4, and the height of each one decreases.

[0061] Specifically, the energy dissipation module includes stepped energy dissipation sills 6, which reduce runoff velocity and prevent erosion of the ditch.

[0062] The following explains the research objectives and effects of grassed swale cascade energy dissipation troughs:

[0063] To address the problems of existing vegetated swales, such as the separation of runoff energy dissipation and pollution control functions, poor control of heavy metals and PAHs pollutants, and difficulties in operation and maintenance, a new type of vegetated swale cascade energy dissipation channel is proposed. This cascade energy dissipation channel combines energy dissipation sills 6 with porous biochar filler 9, which can reduce runoff velocity and prevent scouring of the swale body while efficiently adsorbing pollutants such as heavy metals and PAHs in the runoff. After adsorption saturation, it can be quickly replaced, desorbed, and recycled, in order to reduce surface runoff pollution and improve the overall water environment quality of rivers and reservoirs. Grass ditch cascades are installed at intervals along the runoff direction in the grassed swales. Surface runoff first enters the first opening 3 of the grassed switch cascade, and after being dissipated in stages by the stepped energy dissipation platform 6, it enters the bottom of the second opening 4 through the water distribution hole 5 at the bottom of the partition wall 2, forming an upward flow that passes through the suspended purification module 7, causing the porous biochar packing 9 to become fluidized and adsorb pollutants in the runoff. The purified runoff is discharged into the downstream of the grassed swales from the outlet of the second opening 4.

[0064] Integrated functionality, simultaneous energy dissipation and pollution control: Combining the energy dissipation module and purification module 7, it achieves graded cascading energy dissipation within the vegetated swale, reducing runoff velocity by 60%~80% and preventing swale erosion and soil loss. Utilizing the highly efficient and stable adsorption of pollutants such as heavy metals and PAHs by porous biochar, the removal rate of heavy metals and PAHs can reach over 85%; compared to existing vegetated swales, the adsorption efficiency is improved by over 60%, achieving the dual effect of drainage energy dissipation and water quality protection.

[0065] High adsorption efficiency, suitable for water source requirements: The porous biochar packing material 9 has a macroscopic spherical honeycomb porous structure with through-pores on the surface. Its actual density is slightly greater than that of water, and the module packing has a filling density of less than 60%. Under the action of vertically rising turbulent water flow, the packing material becomes fluidized, greatly increasing the contact area and contact time with the runoff. The porous biochar packing material 9 is mainly composed of micropores and mesopores, with a BET specific surface area exceeding 800 m². 2 / g, which can achieve rapid and stable control of pollutants such as heavy metals and PAHs;

[0066] Convenient construction and maintenance: The purification module 7 is a prefabricated structure that can be directly installed in the cascading energy dissipation trough. Construction is simple. When the adsorption is saturated, it can be removed and replaced for regeneration. There is no need to completely renovate the grassed swale. The maintenance cost in the later stage of the project is reduced by more than 40%.

[0067] Highly adaptable and easy to promote: The overall structure of the grassed swale cascade energy dissipation trough is well connected with the existing grassed swale project. It can be directly modified and constructed within the existing grassed swale without affecting the overall structure and layout of the grassed swale. It is particularly suitable for runoff pollution control in river and reservoir waters and around water sources.

[0068] The following is an example illustrating the use of vegetated swales and cascading energy dissipation channels:

[0069] Example 1:

[0070] The grassed swale cascade energy dissipation trough is applied to the runoff grassed swale of the newly built ring road around a reservoir water source. The grassed swale has a ground slope of 6.2% and dimensions of width × height = 1200 × 300 mm.

[0071] Along the runoff direction of the vegetated swales, a cascading energy dissipation trough is installed every 60m, for a total of 4 troughs. The trough body 1 is a double-compartment rectangular groove structure. The water inlet of trough body 1 is 0.10m above the bottom surface of the vegetated swales. The overall dimensions are length × width × height = 1020 × 500 × 500mm. The width of trough body 1 is consistent with the width of the flow section at the bottom of the vegetated swales. The four side walls are smoothly connected to the swales. The side walls and base of trough body 1 are made of 120mm thick reinforced concrete. The interior is divided into a first opening 3 and a second opening 4 by a partition wall 2. The dimensions of the first opening 3 are length × width × height = 300 × 500 × 500 mm, and a stepped energy dissipation platform 6 is arranged inside. The dimensions of the second opening 4 are length × width × height = 600 × 500 × 500 mm. mm, four galvanized square steel support pieces 12 are reserved on the side wall; two water distribution holes 5 with a length × width = 150 × 200 mm are reserved at the bottom of the partition wall 2 to ensure that the runoff after energy dissipation can be smoothly guided into the second opening 4; a purification module 7 is suspended in the second opening 4 of the grassed swale water dissipation trough. The purification module 7 has a rectangular macrostructure, and the outer frame material is galvanized stainless steel gabion mesh with a length × width × height = 600 × 500 × 350 mm. The interior is filled with porous biochar filler 9 with a spherical honeycomb structure, with a filling density of 50% and a macroscopic particle size of 20~40 mm. The porous biochar is made from activated straw and has a BET specific surface area of ​​900 m². 2 / g, made of bentonite bonded and sintered into a spherical honeycomb structure, with an actual density of 1.05g / cm³. 3 The cascading energy dissipation troughs in the vegetated swales are maintained quarterly. The main maintenance includes removing accumulated silt and replacing saturated purification modules 7. The replaced porous biochar is regenerated with 0.1 mol / L dilute hydrochloric acid solution, washed with deionized water, and then dried. The adsorption and removal rate of heavy metals remains above 85% of the initial value, and it can be recycled back into the cascading energy dissipation troughs. In this embodiment, when the runoff flows through the steep slope section of the vegetated swales, it undergoes graded energy dissipation through the four-stage cascading energy dissipation troughs, reducing the flow velocity from the initial 0.82 m / s to 0.28 m / s, effectively preventing erosion of the swales. After adsorption by purification modules 7, the removal rates of heavy metals such as lead and cadmium in the runoff reach 92.8% and 88.5%, respectively, preventing heavy metal deposition in the reservoir and reducing the risk of water pollution at the source.

[0072] Example 2:

[0073] The grassed swale cascade energy dissipation trough was applied to the runoff grassed swale of a municipal road. The grassed swale ground slope is 5.5%, and the dimensions are width × height = 1000 × 300 mm.

[0074] Along the runoff direction of the vegetated swales, a cascading energy dissipation trough is installed every 50m, for a total of 5 troughs. The trough body 1 is a double-compartment rectangular groove structure. The water inlet of trough body 1 is 0.10m above the bottom surface of the vegetated swales. Its overall dimensions are length × width × height = 815 × 450 × 500 mm, with the width matching the cross-sectional width of the bottom of the vegetated swales. The four side walls smoothly connect to the swales body. The entire cascading energy dissipation trough is prefabricated from HDPE, with 10cm thick walls and base. The interior is divided into a first opening 3 and a second opening 4. The dimensions of the first opening 3 are length × width × height = 250 × 450 × 500 mm, and it contains stepped energy dissipation sills 6. The dimensions of the second opening 4 are length × width × height = 550 × 450 × 500 mm. mm, four galvanized square steel support pieces 12 are reserved on the side wall; two water distribution holes 5 with a length × width = 150 × 200 mm are reserved at the bottom of the partition wall 2 to ensure that the runoff after energy dissipation can be smoothly guided into the second opening 4; the grassed swale cascade energy dissipation trough is filled with purification modules 7, the macro structure is rectangular, the outer frame material is galvanized stainless steel gabion mesh, the size is length × width × height = 550 × 450 × 350 mm, the inside is filled with spherical honeycomb structure porous biochar filler 9, the filling density is 50%, the particle size is 20~40 mm; the porous biochar is made from activated sycamore leaves, and the BET specific surface area is 820 m² 2 / g, actual density is 1.10 g / cm³ 3 The vegetated swale cascade energy dissipation trough is maintained quarterly. The main maintenance includes removing accumulated silt from the bottom and replacing saturated purification modules 7. The replaced porous biochar is regenerated with 0.1 mol / L dilute hydrochloric acid solution, washed with deionized water, and then dried. The adsorption and removal rate of PAHs remains above 88% of the initial value, allowing for recycling back into the vegetated swale cascade energy dissipation trough. In this embodiment, when the road flow passes through the steep slope section of the vegetated swale, the flow velocity is reduced from the initial 0.73 m / s to 0.21 m / s by the five-stage cascade energy dissipation trough, effectively preventing erosion of the swale body. After adsorption by purification module 7, the removal rate of PAHs in the runoff reaches 91.5%, preventing PAHs from depositing in the reservoir and reducing the risk of urban river water pollution.

[0075] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0076] 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 grass-planted ditch cascade energy dissipation trough, characterized in that, include: Tank (1), energy dissipation module and purification module (7); The groove (1) has a first opening (3) and a second opening (4) with both openings facing upwards. The bottom of the first opening (3) is connected to the bottom of the second opening (4), and the opening end of the first opening (3) is higher than the opening end of the second opening (4). The energy dissipation module is installed inside the first oral cavity (3); The purification module (7) includes a grid frame (8), a porous biochar filler (9), and a counterweight (11). The porous biochar filler (9) is filled in the grid frame (8). The grid frame (8) is installed in the second opening (4), and there is a gap between the grid frame (8) and the bottom wall of the second opening (4). The counterweight (11) is installed at the bottom of the grid frame (8).

2. The grass-covered swale cascade energy dissipation trough according to claim 1, characterized in that, The porous biochar packing material (9) has a filling degree of less than or equal to 60% within the grid frame (8).

3. The grassed swale cascade energy dissipation trough according to claim 2, characterized in that, The porous biochar packing material (9) comprises porous biochar with a specific surface area greater than or equal to 800 m². 2 / g, with the pore size of the internal pores set to 1-50nm.

4. The grassed swale cascade energy dissipation trough according to claim 3, characterized in that, The porous biochar is spherical or ellipsoidal in shape.

5. The grassed swale cascade energy dissipation trough according to any one of claims 1-4, characterized in that, The volume ratio of the first oral cavity (3) to the second oral cavity (4) is set to 1:1-1:

6.

6. The grass-covered swale cascade energy dissipation trough according to claim 1, characterized in that, The grid frame (8) is connected to the inner wall of the second opening (4) via a support member (12).

7. The grassed swale cascade energy dissipation trough according to claim 6, characterized in that, One end of the support member (12) is inserted into the inner wall of the second opening (4), and the other end extends out of the inner wall of the second opening (4) and is connected to the grid frame (8).

8. The grass-covered swale cascade energy dissipation trough according to claim 1, characterized in that, The counterweight (11) is connected to the bottom of the grid frame (8) via a suspension cable (10).

9. The grass-covered swale cascade energy dissipation trough according to claim 1, characterized in that, The grass-covered ditch water dissipation trough includes a partition wall (2), which is installed inside the trough body (1) and has at least two water distribution holes (5) at the bottom. The partition wall (2) divides the groove (1) into the first opening (3) and the second opening (4).

10. The grass-covered swale cascade energy dissipation trough according to claim 1, characterized in that, The energy dissipation module includes at least two energy dissipation sills (6), and the multiple energy dissipation sills (6) are arranged in a stepped manner from the side of the first opening (3) away from the second opening (4), with the height of each sill decreasing gradually.

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