Permeable weir for ecological restoration of long-flowing water body

Abstract

The invention belongs to the technical field of ecological restoration, and particularly relates to a permeable weir for ecological restoration of a long-flowing water body. According to the permeable weir structure, sectional structure filling is adopted, oxygen is supplied through a solar reoxygenation system, microbial enhanced treatment, composite filter material adsorption and fixation and plant absorption and extraction are integrated, all-weather, low-cost and high-efficiency pollutant removal is achieved, long-flowing water flow control is achieved, the traffic function of the permeable weir is increased, and the service life of the permeable weir is prolonged. The ecological environment benefits of the watershed are also obviously improved.

Description

Technical Field

[0001] The invention belongs to the technical field of ecological restoration, and in particular relates to a permeable weir for ecological restoration of a long-flowing water body. Background Art

[0002] Permeable weir technology is a technology used in non-point source pollution control, water eutrophication, and water environment management and improvement. It improves the barrier of traditional weirs to water substances and energy, restores water connectivity to a certain extent, and maintains the balance of the water ecosystem. Permeable weirs can reduce pollutants through the adsorption and degradation of construction materials and microorganisms attached to their surfaces, and plant absorption. The remediation effect of permeable weir technology on the water environment shows obvious seasonality, with summer being better than spring and autumn; it has a significant effect on the reduction of total suspended solids (TSS), has a certain reduction effect on nutrient pollutants such as nitrogen and phosphorus, and has limited effect on the reduction of organic matter; the construction materials of traditional permeable weirs are mostly cheap and easily available gravel, crushed stone, etc., which have poor removal effects on nutrient salt pollutants. Summary of the Invention

[0003] The purpose of the present invention is to provide a permeable weir for the ecological restoration of long-flowing water bodies. The permeable weir for the ecological restoration of long-flowing water bodies provided by the present invention overcomes the shortcomings of existing permeable weirs that only have physical interception and low treatment efficiency. It integrates physical interception, biological purification and plant absorption, not only has a higher purification efficiency for polluted water bodies, but also provides a water-related traffic path with better ecological and environmental effects.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] The present invention provides a permeable weir for ecological restoration of long-flowing water bodies, comprising a solar reoxygenation system 10, a water inlet pipe 2, a weir body 1 and a water outlet pipe 9;

[0006] The cutting aeration disk of the solar reoxygenation system 10 is located in the carboxylated biochar modified polyurethane composite filter material 5;

[0007] The weir body 1 is filled with a carboxylated biochar-modified polyurethane composite filter material 5 and a calcium-magnesium-based composite filter material 7 separated by a porous permeable wall 6;

[0008] A grid 3 and a first weir top plate 4 are placed on the upper part of the weir body of the carboxylated biochar modified polyurethane composite filter material 5;

[0009] A second weir top plate is placed on the weir body of the calcium-magnesium-based composite filter material 7 , and the second weir top plates are placed at intervals; wetland plants 8 are planted in the gaps between the second weir top plates.

[0010] Preferably, the water inlet pipe 2 passes through the water-incoming weir, with the front end located in the permeable gabion and the rear end extending into the carboxylated biochar-modified polyurethane composite filter material 5 .

[0011] Preferably, the weir body 1 is composed of a permeable gabion, a water-facing weir, a water-facing overflow weir, a water-receiving weir, weirs on both sides and a base; the permeable gabion is located at the front end of the water-facing weir.

[0012] Preferably, the carboxylated biochar-modified polyurethane composite filter material 5 is composed of a macroporous polyurethane bio-carrier and a carboxylated biochar-modified polyurethane bio-carrier.

[0013] Preferably, the volume ratio of the macroporous polyurethane bio-carrier to the carboxylated biochar-modified polyurethane bio-carrier in the carboxylated biochar-modified polyurethane composite filter material 5 is 2-4:1-2.

[0014] Preferably, the calcium-magnesium-based composite filter material 7 is composed of 20-40 mm crushed stone or gravel, 10-20 mm calcium-based modified ceramsite and 5-10 mm magnesium-based modified volcanic rock.

[0015] Preferably, the volume ratio of the 20-40 mm crushed stone or gravel, the 10-20 mm calcium-based modified ceramsite and the 5-10 mm magnesium-based modified volcanic rock is 3-5:1-3:1-3.

[0016] The present invention also provides a long-flow water body ecological restoration permeable weir as described in the above technical solution, wherein the length ratio of the carboxylated biochar-modified polyurethane composite filter material 5 and the calcium-magnesium-based composite filter material 7 is 3-5:1-3.

[0017] Preferably, the outlet pipe passes through the backwater weir, with the front end located in the calcium-magnesium-based composite filter material and the rear end extending to the outside of the permeable gabion.

[0018] Preferably, the water-facing overflow weir and the water-facing weir are arranged side by side, the height of the water-facing overflow weir is lower than that of the water-facing weir, and there is no permeable gabion at the front end.

[0019] The present invention provides a permeable weir for ecological restoration of long-flow water bodies, comprising a solar reoxygenation system 10, an inlet pipe 2, a weir body 1 and an outlet pipe 9; the cut aeration disk of the solar reoxygenation system 10 is located in a carboxylated biochar-modified polyurethane composite filter material; the weir body 1 is filled with a carboxylated biochar-modified polyurethane composite filter material 5 and a calcium-magnesium-based composite filter material 7 separated by a porous permeable wall 6; a grid and a first weir top plate 4 are placed on the weir body of the carboxylated biochar-modified polyurethane composite filter material 5; a second weir top plate is placed on the weir body of the calcium-magnesium-based composite filter material 7, and the second weir top plates are placed at intervals; wetland plants 8 are planted in the gaps between the second weir top plates. The permeable weir structure adopted in the present invention is filled with a segmented structure and supplied with oxygen through a solar reoxygenation system. It integrates microbial enhanced treatment, composite filter material adsorption and fixation, and plant absorption and extraction, achieving all-weather, low-cost, and high-efficiency pollutant removal. It not only realizes long-term water flow control, increases the transportation function of the permeable weir, but also significantly improves the ecological and environmental benefits of the watershed.

[0020] Furthermore, the carboxylated biochar modified polyurethane composite filter material used in the present invention has good physical interception and filtration functions and water permeability. In addition, it also has more excellent indigenous specific microbial compatibility, which can significantly improve the microbial abundance per unit volume of the permeable weir construction material, increase the volume load of the permeable weir, and thus reduce the weir volume and floor space of the permeable weir; the calcium-magnesium-based composite filter material is based on crushed stone, ceramsite and volcanic rock, and the raw materials are economical and easy to obtain. Through the modification of the raw materials, the adsorption capacity of the raw materials is greatly improved, and it has a strong interception ability for pollutants such as heavy metals, nitrogen and phosphorus, and microplastics in the water body; at the same time, the calcium-magnesium-based composite filter material also greatly improves the ability of functional microorganisms to be fixed on the surface of the construction material, thereby improving the purification efficiency of nutrient salt pollutants. The solar reoxygenation system used in the present invention uses solar energy as the power source of the system, creating conditions for simultaneous nitrification and denitrification of the carboxylated biochar modified polyurethane composite filter material in the weir body, achieving simultaneous and efficient removal of organic matter, ammonia nitrogen and total nitrogen, not only avoiding the consumption of traditional energy, but also effectively increasing the dissolved oxygen in the water body.

[0021] Furthermore, during the startup and debugging phase of the permeable weir of the present invention, indigenous specific functional microorganisms and activators are added to activate and enrich the fixed functional microorganisms in a targeted manner, which can achieve a rapid increase in the functional microorganisms in the construction materials in a relatively short period of time and achieve a water purification effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a front view of the long-flow water body ecological restoration permeable weir provided by the present invention, wherein 1-weir body, 2-water inlet pipe, 3-grid, 4-first weir top plate, 5-carboxylated biochar-modified polyurethane composite filter material, 6-porous permeable wall, 7-calcium-magnesium-based composite filter material, 8-wetland plants, 9-outlet pipe, 10-solar reoxygenation system;

[0024] Figure 2 This is a top view of the permeable weir for ecological restoration of long-flowing water bodies provided by the present invention. DETAILED DESCRIPTION

[0025] The present invention provides a permeable weir for ecological restoration of long-flowing water bodies, comprising a solar reoxygenation system 10, a water inlet pipe 2, a weir body 1 and a water outlet pipe 9;

[0026] The cutting aeration disk of the solar reoxygenation system 10 is located in the carboxylated biochar modified polyurethane composite filter material;

[0027] The weir body 1 is filled with a carboxylated biochar-modified polyurethane composite filter material 5 and a calcium-magnesium-based composite filter material 7 separated by a porous permeable wall 6;

[0028] A grid and a first weir top plate 4 are placed on the upper part of the weir body of the carboxylated biochar modified polyurethane composite filter material 5;

[0029] A second weir top plate is placed on the weir body of the calcium-magnesium-based composite filter material 7 , and the second weir top plates are placed at intervals; wetland plants 8 are planted in the gaps between the second weir top plates.

[0030] The permeable weir for ecological restoration of long-flowing water bodies provided by the present invention comprises a water inlet pipe 2 .

[0031] As an embodiment of the present invention, the water inlet pipe 2 may also be a water inlet hole.

[0032] As an embodiment of the present invention, the water inlet pipe 2 is arranged at the bottom of the weir body 1; the water inlet pipe 2 passes through the water-facing weir, the front end is located in the permeable gabion, and the rear end extends into the carboxylated biochar modified polyurethane composite filter material; as an embodiment of the present invention, the nominal diameter of the water inlet pipe 2 is preferably 300 mm.

[0033] The permeable weir for ecological restoration of a long-flowing water body provided by the present invention comprises a weir body 1.

[0034] As an embodiment of the present invention, the weir body 1 is preferably composed of a permeable gabion, a water-inflow weir, a water-inflow overflow weir, a water-return weir, weirs on both sides, and a base. As an embodiment of the present invention, the water-inflow weir, water-inflow overflow weir, water-return weir, weirs on both sides, and a base are preferably made of concrete.

[0035] As an embodiment of the present invention, the permeable gabion is preferably located at the front end of the water-facing weir. In the present invention, the front end specifically refers to the water-facing end. As an embodiment of the present invention, the water-facing overflow weir and the water-facing weir are arranged side by side, the height of the water-facing overflow weir is lower than that of the water-facing weir, and there is no permeable gabion at the front end.

[0036] As an embodiment of the present invention, the weir body is filled with a carboxylated biochar-modified polyurethane composite filter material 5 and a calcium-magnesium-based composite filter material 7 separated by a porous permeable wall 6 .

[0037] As an embodiment of the present invention, the carboxylated biochar modified polyurethane composite filter material 5 is preferably composed of a macroporous polyurethane bio-carrier and a carboxylated biochar modified polyurethane bio-carrier; the volume ratio of the macroporous polyurethane bio-carrier and the carboxylated biochar modified polyurethane bio-carrier in the carboxylated biochar modified polyurethane composite filter material can be 2 to 4:1 to 2, specifically 3:1.

[0038] As an embodiment of the present invention, the preparation method of the carboxylated biochar-modified polyurethane bio-carrier comprises the following steps:

[0039] calcining the biomass under a protective atmosphere to obtain biochar;

[0040] immersing the biochar in acid for carboxylation to obtain carboxylated biochar;

[0041] The carboxylated biochar was dispersed in a KH-550 ethanol solution and subjected to silane coupling to obtain silane-coupled carboxylated biochar.

[0042] An ethanol solution with a pH of 9 was prepared using NaOH, and the silane-coupled carboxyl biochar was added to the ethanol solution with a pH of 9, and ultrasonic stirring was performed for 20 to 30 minutes to obtain a silane-coupled carboxyl biochar dispersion. The polyurethane biocarrier was placed in Ar / O2 plasma and treated with ultraviolet light to activate the polyurethane biocarrier.

[0043] The activated polyurethane carrier was placed in a silane-coupled carboxyl biochar dispersion, stirred at 60° C. for 24 to 36 hours, and ultrasonically cleaned and dried to obtain a carboxylated biochar-modified polyurethane biocarrier.

[0044] The present invention calcines biomass under a protective atmosphere to obtain biochar.

[0045] As an embodiment of the present invention, the biomass is preferably rice husk or straw; and the calcination temperature is preferably 300-500°C.

[0046] After obtaining the biochar, the present invention immerses the biochar in acid for carboxylation to obtain carboxylated biochar.

[0047] As an embodiment of the present invention, the acid includes concentrated nitric acid and concentrated sulfuric acid; the volume ratio of the concentrated nitric acid and concentrated sulfuric acid is 3:1; the carboxylation is preferably carried out under ultrasonic conditions; the temperature of the hydroxylation is preferably 60°C, and the time is preferably 2 hours; as an embodiment of the present invention, after the hydroxylation, the hydroxylated material is further washed to neutrality to obtain carboxylated biochar.

[0048] After obtaining the carboxylated biochar, the present invention disperses the carboxylated biochar in a KH-550 ethanol solution and performs silane coupling to obtain silane-coupled carboxylated biochar.

[0049] In one embodiment of the present invention, the mass concentration of KH-550 in the KH-550 ethanol solution is preferably 2%. In one embodiment of the present invention, the silane coupling is preferably performed by refluxing the reaction system at 60° C. for 2 hours; after the silane coupling, the reaction system is centrifuged, washed, and then dried to obtain silane-coupled carboxyl biochar.

[0050] Use NaOH to prepare an ethanol solution with a pH of 9, add the silane-coupled carboxyl biochar to the ethanol solution with a pH of 9, and stir ultrasonically for 20 to 30 minutes to obtain a silane-coupled carboxyl biochar dispersion; place the polyurethane biocarrier in Ar / O2 plasma and treat it with ultraviolet light to activate the polyurethane biocarrier; place the activated polyurethane carrier in the silane-coupled carboxyl biochar dispersion, stir at 60°C for 24 to 36 hours, and then ultrasonically clean and dry to obtain a carboxylated biochar-modified polyurethane biocarrier.

[0051] As an embodiment of the present invention, the volume ratio of Ar and O2 in the Ar / O2 plasma is preferably 4:1; the power of the ultraviolet treatment is preferably 100 W, and the time is preferably 5 minutes.

[0052] As an embodiment of the present invention, a grid 3 and a first weir top plate 4 are placed on the upper part of the weir body of the carboxylated biochar modified polyurethane composite filter material.

[0053] As an embodiment of the present invention, the calcium-magnesium-based composite filter material 7 is preferably composed of 20-40 mm crushed stone or gravel, 10-20 mm calcium-based modified ceramsite and 5-10 mm magnesium-based modified volcanic rock. The volume ratio of the 20-40 mm crushed stone or gravel, 10-20 mm calcium-based modified ceramsite and 5-10 mm magnesium-based modified volcanic rock is preferably 3-5:1-3:1-3, specifically 4:2:1. As an embodiment of the present invention, a second weir top plate is placed on the weir body of the calcium-magnesium-based composite filter material, and the second weir top plates are placed at intervals; wetland plants 8 are planted in the gaps between the second weir top plates; the wetland plants 8 are preferably native wetland plants that have high absorption of pollutants such as nitrogen and phosphorus and good landscape effects. In the embodiment of the present invention, Iris fulva is taken as an example.

[0054] As one embodiment of the present invention, the method for preparing the calcium-based modified ceramsite preferably comprises the following steps: adding water to clay and calcium carbonate and stirring them into a uniform slurry, allowing the mixture to stand for 24 to 48 hours, producing raw balls with a particle size of 10 to 20 mm by extrusion or rolling into a ball mill, drying and oven-drying at 105°C, and then sintering at 900 to 1100°C for 1 to 2 hours to obtain the calcium-based modified ceramsite. As one embodiment of the present invention, the mass ratio of the clay to calcium carbonate is preferably (6 to 9): (4 to 1).

[0055] As an embodiment of the present invention, the method for preparing magnesium-based modified volcanic rock preferably includes the following steps: screening 5-10 mm volcanic rock and soaking it in 1 M HCl for 2 hours, rinsing it until it is neutral, and drying it; immersing the dried volcanic rock in a 0.5-2 M MgCl2·6H2O solution, ultrasonicating it for 30 minutes, stirring and evaporating it to dryness at 80°C, and then calcining it at 350-500°C for 2 hours to obtain calcium-based modified volcanic rock.

[0056] As an embodiment of the present invention, the porous permeable wall 6 is preferably a porous precast concrete slab partition. The length ratio of the carboxylated biochar modified polyurethane composite filter material to the calcium magnesium based composite filter material can be 3 to 5:1 to 3, specifically 3:1. In the specific embodiment, 9:4.9 is used as an example for illustration.

[0057] The permeable weir for ecological restoration of long-flowing water bodies provided by the present invention includes a water outlet pipe 9.

[0058] As an embodiment of the present invention, the water outlet pipe 9 may also be a water outlet hole.

[0059] As an embodiment of the present invention, the outlet pipe passes through the backwater weir, with the front end located in the calcium-magnesium-based composite filter material 7 and the rear end extending to the outside of the permeable gabion. As an embodiment of the present invention, the nominal diameter of the outlet pipe is preferably 300 mm.

[0060] The present invention provides a permeable weir for ecological restoration of long-flowing water bodies, comprising a solar reoxygenation system 10 comprising a solar panel, an aerator, piping, and a cutting aeration disk; the cutting aeration disk is located within a carboxylated biochar-modified polyurethane composite filter material. In the present invention, the solar reoxygenation system primarily provides oxygen within the carboxylated biochar-modified polyurethane composite filter material.

[0061] As an embodiment of the present invention, the carboxylated biochar modified polyurethane composite filter material 5 and the calcium magnesium based composite filter material 7 also include indigenous specific functional microorganisms and functional microorganism activators; the indigenous specific functional microorganisms are derived from the rivers, wetland sediments and soil in the area, and are screened and enriched, specifically, include indigenous nitrification and denitrification functional bacteria obtained by screening and enrichment from the rivers, wetland sediments and soil in the area; the activator can promote the rapid growth and enrichment of indigenous functional microorganisms on the filter material. As an embodiment of the present invention, the specific functional microorganisms and functional microorganism activators are preferably added during the commissioning stage of the permeable weir for ecological restoration of long-flowing water bodies, and then the solar reoxygenation system, water level and water volume are controlled to activate and directional enrich the indigenous specific functional microorganisms to obtain a dominant bacterial community.

[0062] In the present invention, a certain range of water surface will be formed at the front end of the permeable weir. The permeable weir can be used as a river traffic shortcut in non-flood season. In case of smaller floods, the water can overflow through the overflow weir dam. In case of larger floods, the water will overflow the weir top plate and flow without affecting the safety of river flow.

[0063] River water forms a pool of water at a certain height in front of the weir, where larger suspended matter such as silt settles. Permeable gabions further intercept large pollutants before the water enters the weir through an inlet pipe, where it comes into contact with the biofilm immobilized on the carboxylated biochar-modified polyurethane composite filter media for purification. Oxygen provided by a solar reoxygenation system within the carboxylated biochar-modified polyurethane composite filter media creates conditions for simultaneous nitrification and denitrification. The calcium-magnesium-based high-efficiency composite filter media has high adsorption properties, effectively removing pollutants such as nitrogen, phosphorus, and heavy metals from the water. Pollutants adsorbed on the calcium-magnesium-based high-efficiency composite filter media are then absorbed by wetland plants, removing organic matter, nitrogen, phosphorus, and heavy metals from the water, thereby improving water quality in the basin. The purified water then flows back into the river through an outlet (pipe). The permeable weir can serve as a traffic path, facilitating access on both sides of the wading section. During flood season, overflow can be channeled through the upstream overflow weir and the weir itself, ensuring the safety of long-term flood flow.

[0064] In the present invention, when in use, the long-flow water body ecological restoration permeable weir can be used in multiple ways, such as Figure 2 An overhead view of two permeable weirs for ecological restoration of long-flowing water bodies.

[0065] In order to further illustrate the present invention, the scheme of the present invention is described in detail below with reference to the accompanying drawings and embodiments, but they should not be understood as limiting the scope of protection of the present invention.

[0066] Example 1

[0067] Preparation of carboxylated biochar-modified polyurethane biocarrier:

[0068] The biomass was calcined at 400 °C under nitrogen to obtain biochar;

[0069] The biochar was immersed in acid (concentrated nitric acid and concentrated sulfuric acid, with a volume ratio of 3:1) for carboxylation (temperature of 60° C., time of 2 h), and then the hydroxylated material was washed to neutrality to obtain carboxylated biochar;

[0070] The carboxylated biochar was dispersed in a 2 wt% KH-550 ethanol solution and refluxed at 60°C for 2 h to obtain silane-coupled carboxylated biochar.

[0071] An ethanol solution with a pH of 9 was prepared with NaOH, and the silane-coupled carboxyl biochar was added to the ethanol solution with a pH of 9, and ultrasonic stirring was performed for 30 minutes to obtain a silane-coupled carboxyl biochar dispersion. The polyurethane biocarrier was placed in Ar / O2 plasma (the volume ratio of Ar and O2 was 4:1) and treated with 100W ultraviolet light for 5 minutes to activate the polyurethane biocarrier. The activated polyurethane carrier was placed in the silane-coupled carboxyl biochar dispersion, stirred at 60°C for 36 hours, and ultrasonically cleaned and dried to obtain a carboxylated biochar-modified polyurethane biocarrier.

[0072] The preparation method of calcium-based modified ceramsite includes the following steps: adding clay and calcium carbonate to water and stirring them into a uniform slurry. The mixture is allowed to stand for 48 hours, and then a rolling ball mill is used to produce raw balls with a particle size of 10-20 mm. The raw balls are then dried at 105°C and sintered at 1000°C for 2 hours to obtain the calcium-based modified ceramsite. The mass ratio of clay to calcium carbonate is 6:2.

[0073] The preparation method of magnesium-based modified volcanic rock comprises the following steps: screening 5-10 mm thick volcanic rock, soaking it in 1M HCl for 2 hours, rinsing it until it is neutral, and drying it; immersing the dried volcanic rock in a 1M MgCl2·6H2O solution, ultrasonicating it for 30 minutes, stirring and evaporating it to dryness at 80°C, and then calcining it at 400°C for 2 hours to obtain calcium-based modified volcanic rock.

[0074] like Figure 1 and Figure 2 As shown, the permeable weir for ecological restoration of long-flowing water bodies includes a weir body, an inlet pipe, a grille, a weir top plate, a carboxylated biochar-modified polyurethane composite filter material, a porous permeable wall, a calcium-magnesium-based composite filter material, wetland plants, an outlet pipe, and a solar reoxygenation system;

[0075] The weir body consists of permeable gabions, a water-facing weir, a water-facing overflow weir, a water-facing weir, weirs on both sides and a base. The permeable gabions are filled with gravel, pebbles or crushed stones, and the water-facing weir, a water-facing overflow weir, a water-facing weir, weirs on both sides and a base are made of concrete.

[0076] The weir is filled with carboxylated biochar-modified polyurethane composite filter media and calcium-magnesium-based high-efficiency composite filter media along the water flow direction. A precast concrete porous permeable wall separates the two composite filter media. A grid and a weir top plate are placed above the weir for the carboxylated biochar-modified polyurethane composite filter media. The calcium-magnesium-based composite filter media is separated by weir top plates, with wetland plants planted between the plates. The carboxylated biochar-modified polyurethane composite filter media consists of a macroporous polyurethane biocarrier and a carboxylated biochar-modified polyurethane biocarrier in a volumetric filling ratio of 2:1. The calcium-magnesium-based high-efficiency composite filter media consists of 20-40mm gravel, 10-20mm calcium-modified ceramsite, and 5-10mm magnesium-modified volcanic rock in a volumetric filling ratio of 5:3:2. Native wetland plants are planted on the calcium-magnesium-based composite filter media. The top of the weir body is covered with a weir top plate, which is a precast concrete plate; the bottom of the carboxylated biochar modified polyurethane composite filter material is installed with a cutting aeration disk of the solar reoxygenation system, which provides the oxygen required for the system operation; the inlet and outlet pipes of the permeable weir are precast concrete pipes.

[0077] Example 2

[0078] The structure of the permeable weir is the same as that in Example 1, and the specific parameters are as follows:

[0079] The permeable weir is located in the long-flowing river channel. The weir body is perpendicular to the river channel. The weir body is 1.5m high, 15m long and 5.0m wide. It includes a 50cm wide permeable gabion, a 20cm wide concrete incoming weir (1.5m high), an incoming overflow weir (1.3m high), a base, a backwater weir (1.5m high) and weirs on both sides (1.5m high). The incoming overflow weir is 0.50m long. The inlet and outlet pipes use two DN300 corrugated pipes respectively.

[0080] The carboxylated biochar-modified polyurethane composite filter media consists of a macroporous polyurethane biosupport and a carboxylated biochar-modified polyurethane biosupport in a ratio of 3:2, with a filling depth of 1.2 m. The calcium-magnesium-based high-efficiency composite filter media consists of 20-40 mm gravel, 10-20 mm calcium-modified ceramsite, and 5-10 mm magnesium-modified volcanic rock in a ratio of 4:2:1. The two composite filter media are separated by a perforated precast concrete slab, with filling lengths of 9.0 m and 4.9 m, respectively. Three rows of yellow irises are planted on the calcium-magnesium-based high-efficiency composite filter media, and the weir top plate is a precast concrete cover. The solar reoxygenation system is powered by four solar panels. Indigenous specific microorganisms are sourced from the local river wetlands and are screened and enriched before being added to the composite filter media. The COD, NH3-N, and TP levels in the influent (at 19°C) were 45 mg / L, 1.46 mg / L, and 0.21 mg / L, respectively. After one month of operation, the effluent levels were 28 mg / L, 0.43 mg / L, and 0.09 mg / L, respectively. This represents a significant improvement in effluent quality. While improving water quality in the basin, the permeable weir has also become a convenient cross-river transportation route for local residents.

[0081] Example 3

[0082] The structure of the permeable weir is the same as that in Example 1, and the specific parameters are as follows:

[0083] The permeable weir is located in a long-flowing river channel. The weir body is perpendicular to the river channel, with a height of 1.5m, a length of 15m and a width of 5.0m. It consists of a 50cm wide permeable gabion, a 20cm wide concrete incoming weir, an incoming overflow weir, a base, a backwater weir and weirs on both sides. The incoming overflow weir is 20cm lower than the incoming weir, and the incoming overflow weir is 0.50m long. Two DN300 corrugated pipes are used for water inlet and outlet respectively. The composition ratio of the macroporous polyurethane bio-carrier and the carboxylated biochar modified polyurethane bio-carrier in the carboxylated biochar modified polyurethane composite filter material is 3:2, and the filling depth is 1.2m; the calcium-magnesium-based high-efficiency composite filter material is composed of 20-40mm gravel, 10-20mm calcium-based modified ceramsite and 5-10mm magnesium-based modified volcanic rock, and the ratio is 4:2:1;

[0084] The two composite filter media are separated by a perforated precast concrete slab, with the first two types of composite filter media being packed in lengths of 9.0m and 4.9m, respectively. Three rows of yellow irises are planted on the calcium-magnesium-based high-efficiency composite filter media, and the weir top plate is a precast concrete cover. The solar reoxygenation system is powered by four solar panels. Indigenous, specific microorganisms are sourced from the local river wetlands, screened and enriched, and then added to the composite filter media. During operation during the low-temperature period, the inlet water temperature was 10.5°C, and COD, NH3-N, and TP concentrations in the inlet water were 36mg / L, 1.22mg / L, and 0.18mg / L, respectively. These concentrations in the effluent were 27mg / L, 0.57mg / L, and 0.08mg / L, respectively. The removal rates for COD, NH3-N, and TP were 25.0%, 53.3%, and 55.6%, respectively, effectively ensuring efficient pollutant removal during the low-temperature period.

[0085] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A permeable weir for ecological restoration of long-flowing water bodies, characterized in that: It comprises a solar reoxygenation system (10), a water inlet pipe (2), a weir body (1) and a water outlet pipe (9); The cutting aeration disk of the solar reoxygenation system (10) is located in the carboxylated biochar modified polyurethane composite filter material (5); The weir body (1) is filled with a carboxylated biochar-modified polyurethane composite filter material (5) and a calcium-magnesium-based composite filter material (7) separated by a porous permeable wall (6); A grid (3) and a first weir top plate (4) are placed on the upper part of the weir body of the carboxylated biochar modified polyurethane composite filter material (5); A second weir top plate is placed on the weir body of the calcium-magnesium-based composite filter material (7), and the second weir top plates are placed at intervals; wetland plants (8) are planted in the gaps between the second weir top plates.

2. The permeable weir for ecological restoration of long-flowing water bodies according to claim 1, characterized in that: The water inlet pipe (2) passes through the water-incoming weir, with the front end located in the permeable gabion and the rear end extending into the carboxylated biochar-modified polyurethane composite filter material (5).

3. The permeable weir for ecological restoration of long-flowing water bodies according to claim 1, characterized in that: The weir body (1) is composed of a permeable gabion, a water-facing weir, a water-facing overflow weir, a water-receiving weir, weirs on both sides and a base; the permeable gabion is located at the front end of the water-facing weir.

4. The permeable weir for ecological restoration of long-flowing water bodies according to claim 1, characterized in that: The carboxylated biochar modified polyurethane composite filter material (5) consists of a macroporous polyurethane bio-carrier and a carboxylated biochar modified polyurethane bio-carrier.

5. The permeable weir for ecological restoration of long-flowing water bodies according to claim 4, characterized in that: The volume ratio of the macroporous polyurethane bio-carrier to the carboxylated biochar-modified polyurethane bio-carrier in the carboxylated biochar-modified polyurethane composite filter material (5) is 2-4:1-2.

6. The permeable weir for ecological restoration of long-flowing water bodies according to claim 1, characterized in that: The calcium-magnesium-based composite filter material (7) is composed of 20-40 mm crushed stone or gravel, 10-20 mm calcium-based modified ceramsite and 5-10 mm magnesium-based modified volcanic rock.

7. The permeable weir for ecological restoration of long-flowing water bodies according to claim 6, characterized in that: The volume ratio of the crushed stone or gravel of 20-40 mm, the calcium-based modified ceramsite of 10-20 mm and the magnesium-based modified volcanic rock of 5-10 mm is 3-5:1-3:1-3.

8. The permeable weir for ecological restoration of a long-flowing water body according to any one of claims 4 to 7, characterized in that: The length ratio of the carboxylated biochar modified polyurethane composite filter material (5) to the calcium-magnesium-based composite filter material (7) is 3-5:1-3.

9. The permeable weir for ecological restoration of long-flowing water bodies according to claim 1, characterized in that: The outlet pipe passes through the backwater weir, with the front end located in the calcium-magnesium-based composite filter material and the rear end extending to the outside of the permeable gabion.

10. The permeable weir for ecological restoration of long-flowing water bodies according to claim 3, characterized in that: The water-facing overflow weir and the water-facing weir are arranged side by side. The height of the water-facing overflow weir is lower than that of the water-facing weir, and there is no permeable gabion at the front end.

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