Long-flowing water body ecological restoration permeable weir

Abstract

The present application belongs to the field of ecological restoration technology, and particularly relates to a long-flowing water body ecological restoration permeable weir. The permeable weir structure is filled by a segmented structure, oxygen is supplied by a solar oxygen supply system, and the structure integrates microbial intensification treatment, composite filter adsorption fixation and plant absorption extraction, so that pollutants are removed in all climates, at low cost and with high efficiency. The long-flowing water flow is controlled, the traffic function of the permeable weir is increased, and the ecological environment benefit of the watershed is significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of ecological restoration technology, specifically relating to a permeable weir for ecological restoration of long-flowing water bodies. Background Technology

[0002] Permeable weir technology is applied to non-point source pollution control, eutrophication, and water environment management and improvement. It improves upon the traditional weir's barrier effect on water bodies, restoring water connectivity to a certain extent and maintaining the balance of the aquatic ecosystem. Permeable weirs reduce pollutants through the adsorption and degradation by microorganisms attached to their construction materials and the absorption by plants. The remediation effect of permeable weir technology on the water environment shows a clear seasonality, with summer showing better results than spring and autumn. It is significantly effective in reducing total suspended solids (TSS), and has a certain reduction effect on nutrient pollutants such as nitrogen and phosphorus, but its effect on reducing organic matter is limited. Traditional permeable weirs are mostly constructed with inexpensive and readily available gravel and crushed stone, which are less effective at removing nutrient pollutants. Summary of the Invention

[0003] The purpose of this invention is to provide a permeable weir for ecological restoration of long-flowing water bodies. The permeable weir for ecological restoration of long-flowing water bodies provided by this 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 into one, which not only has a higher purification efficiency for polluted water bodies, but also provides a water-crossing traffic access road with better ecological and environmental effects.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

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

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

[0007] The weir 1 is filled with carboxylated biochar modified polyurethane composite filter media 5 and calcium-magnesium based composite filter media 7, which are separated by porous permeable walls 6.

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

[0009] A second weir top plate is placed on the upper part of 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 inlet pipe 2 passes through the water-facing weir, with its front end located inside the permeable gabion and its 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 back-water weir, two side weirs, 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 macroporous polyurethane biocarrier and carboxylated biochar modified polyurethane biocarrier.

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

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

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

[0016] The present invention also provides a permeable weir for ecological restoration of long-flowing water bodies 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 its front end located inside the calcium-magnesium-based composite filter material and its rear end extending outside the permeable gabion.

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

[0019] This invention provides a permeable weir for ecological restoration of long-flowing water bodies, comprising a solar reoxygenation system 10, an inlet pipe 2, a weir body 1, and an outlet pipe 9; the cutting aeration disc of the solar reoxygenation system 10 is located in a carboxylated biochar modified polyurethane composite filter media; the weir body 1 is filled with carboxylated biochar modified polyurethane composite filter media 5 and calcium-magnesium-based composite filter media 7 separated by a porous permeable wall 6; 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 media 5; a second weir top plate is placed on the upper part of the weir body of the calcium-magnesium-based composite filter media 7, and the second weir top plates are spaced apart; wetland plants 8 are planted in the gaps between the second weir top plates. The permeable weir structure adopted in this invention uses segmented structures for filling and oxygen is supplied by a solar reoxygenation system. It integrates microbial enhanced treatment, composite filter media adsorption and fixation, and plant absorption and extraction, achieving all-weather, low-cost, and high-efficiency removal of pollutants. It not only realizes the control of continuous water flow and increases the traffic 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 media used in this invention possesses excellent physical interception and filtration functions and water permeability. In addition, it exhibits superior compatibility with indigenous specific microorganisms, significantly increasing the microbial abundance per unit volume of the permeable weir construction material, increasing the volumetric load of the permeable weir, and thus reducing the weir's volume and footprint. The calcium-magnesium-based composite filter media is derived from crushed stone, ceramsite, and volcanic rock, with readily available and economical raw materials. Through modification of these raw materials, their adsorption capacity is greatly enhanced, exhibiting a strong interception capability for pollutants such as heavy metals, nitrogen, phosphorus, and microplastics in the water. Simultaneously, the calcium-magnesium-based composite filter media also significantly improves the ability to fix functional microorganisms on the surface of the construction material, enhancing the purification efficiency for nutrient pollutants. The solar-powered reoxygenation system employed in this invention uses solar energy as the system's power source, creating simultaneous nitrification and denitrification conditions for the carboxylated biochar-modified polyurethane composite filter media within the weir. This achieves simultaneous and efficient removal of organic matter, ammonia nitrogen, and total nitrogen, not only avoiding the consumption of traditional energy sources but also effectively increasing dissolved oxygen in the water.

[0021] Furthermore, during the start-up and commissioning phase of the permeable weir of the present invention, the addition of indigenous specific functional microorganisms and activators to directionally activate and enrich fixed functional microorganisms can achieve a rapid increase in functional microorganisms in the construction materials in a relatively short period of time, thereby achieving the water purification effect. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 The main view of the permeable weir for ecological restoration of long-flowing water bodies provided by the present invention includes: 1-weir body, 2-inlet pipe, 3-grid, 4-first weir top plate, 5-carboxylated biochar modified polyurethane composite filter media, 6-porous permeable wall, 7-calcium magnesium-based composite filter media, 8-wetland plants, 9-outlet pipe, and 10-solar reoxygenation system.

[0024] Figure 2 A top view of the permeable weir for ecological restoration of long-flowing water bodies provided by the present invention. Detailed Implementation

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

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

[0027] The weir 1 is filled with carboxylated biochar modified polyurethane composite filter media 5 and calcium-magnesium based composite filter media 7, which are separated by porous permeable walls 6.

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

[0029] A second weir top plate is placed on the upper part of 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 includes an inlet pipe 2.

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

[0032] In one embodiment of the present invention, the inlet pipe 2 is disposed at the bottom of the weir body 1; the inlet pipe 2 passes through the water-facing weir dam, with its front end located inside the permeable gabion and its rear end extending into the carboxylated biochar modified polyurethane composite filter material; in one embodiment of the present invention, the nominal diameter of the inlet pipe 2 is preferably 300 mm.

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

[0034] In one embodiment of the present invention, the weir body 1 is preferably composed of a permeable gabion, a water-facing weir, a water-facing overflow weir, a backwater weir, two side weirs, and a base. In another embodiment of the present invention, the water-facing weir, the water-facing overflow weir, the backwater weir, the two side weirs, and the base are preferably made of concrete.

[0035] In one embodiment of the present invention, the permeable gabion is preferably located at the front end of the water-facing weir. In this invention, the front end specifically refers to the water-facing end. In another 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] In one embodiment of the present invention, the weir body is filled with carboxylated biochar modified polyurethane composite filter media 5 and calcium-magnesium based composite filter media 7 separated by a porous permeable wall 6.

[0037] In one embodiment of the present invention, the carboxylated biochar modified polyurethane composite filter material 5 is preferably composed of macroporous polyurethane biocarrier and carboxylated biochar modified polyurethane biocarrier; the volume ratio of macroporous polyurethane biocarrier and carboxylated biochar modified polyurethane biocarrier in the carboxylated biochar modified polyurethane composite filter material can be 2~4:1~2, specifically 3:1.

[0038] As one embodiment of the present invention, the preparation method of the carboxylated biochar modified polyurethane biocarrier includes the following steps:

[0039] Biochar is obtained by calcining biomass under a protective atmosphere.

[0040] The biochar was immersed in acid for carboxylation to obtain carboxylated biochar;

[0041] Carboxylated biochar was dispersed in KH-550 ethanol solution and silane-coupled to obtain silane-coupled carboxylated biochar.

[0042] Prepare an ethanol solution with pH=9 using NaOH, add silane-coupled carboxyl biochar to the ethanol solution with pH=9, and sonicate for 20-30 min to obtain a silane-coupled carboxyl biochar dispersion; place the polyurethane biocarrier in Ar / O2 plasma for ultraviolet treatment to activate the polyurethane biocarrier.

[0043] The activated polyurethane carrier was placed in a silane-coupled carboxyl biochar dispersion and stirred at 60°C for 24-36 hours. After ultrasonic cleaning and drying, the carboxyl-modified polyurethane biocarrier was obtained.

[0044] This invention involves calcining biomass under a protective atmosphere to obtain biochar.

[0045] In one embodiment of the present invention, the biomass is preferably rice husk or straw; the calcination temperature is preferably 300~500℃.

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

[0047] In one embodiment of the present invention, the acid includes concentrated nitric acid and concentrated sulfuric acid; the volume ratio of the concentrated nitric acid to the 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; in another embodiment of the present invention, after the hydroxylation, the hydroxylated material is washed to neutral to obtain carboxylated biochar.

[0048] After obtaining carboxylated biochar, the present invention disperses the carboxylated biochar in 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 another embodiment of the present invention, the silane coupling is preferably performed by refluxing the reaction system at 60°C for 2 hours; after silane coupling, the reaction system is further further subjected to centrifugation, washing, and drying to obtain silane-coupled carboxyl biochar.

[0050] Prepare an ethanol solution with pH=9 using NaOH. Add silane-coupled carboxyl biochar to the ethanol solution with pH=9 and stir ultrasonically for 20-30 min to obtain a silane-coupled carboxyl biochar dispersion. Place the polyurethane biocarrier in Ar / O2 plasma for UV treatment to activate the polyurethane biocarrier. Place the activated polyurethane carrier in the silane-coupled carboxyl biochar dispersion and stir at 60℃ for 24-36 h. After ultrasonic cleaning and drying, obtain the carboxylated biochar-modified polyurethane biocarrier.

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

[0052] In one 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] In one embodiment of the present invention, the calcium-magnesium-based composite filter material 7 is preferably composed of 20-40mm crushed stone or gravel, 10-20mm calcium-based modified ceramsite, and 5-10mm magnesium-based modified volcanic rock. The volume ratio of the 20-40mm crushed stone or gravel, the 10-20mm calcium-based modified ceramsite, and the 5-10mm magnesium-based modified volcanic rock is preferably 3-5:1-3:1-3, specifically 4:2:1. In another embodiment of the present invention, a second weir top plate is placed on the upper part of 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 with high absorption capacity for pollutants such as nitrogen and phosphorus and good landscape effect. In this embodiment of the present invention, yellow iris is used as an example.

[0054] In one embodiment of the present invention, the method for preparing the calcium-based modified ceramsite preferably includes the following steps: mixing clay and calcium carbonate with water to form a uniform slurry, allowing it to stand for 24-48 hours, preparing raw material balls with a particle size of 10-20 mm by extrusion or rolling pelletizing machine, drying at 105℃, and then sintering at 900-1100℃ for 1-2 hours to obtain calcium-based modified ceramsite. In another embodiment of the present invention, the preferred mass ratio of clay to calcium carbonate is (6-9):(4-1).

[0055] As one embodiment of the present invention, the method for preparing magnesium-based modified volcanic rock preferably includes the following steps: screening volcanic rocks of 5-10 mm in size, soaking them in 1 M HCl for 2 h, rinsing them until neutral and drying them; immersing the dried volcanic rocks in 0.5-2 M mgCl2·6H2O solution, sonicating them for 30 min, stirring and evaporating them at 80 °C until dry, and then calcining them at 350~500 °C for 2 h to obtain magnesium-based modified volcanic rock.

[0056] In one embodiment of the present invention, the porous permeable wall 6 is preferably a perforated 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 3~5:1~3, specifically 3:1, and a specific embodiment is illustrated by 9:4.9.

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

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

[0059] In one embodiment of the present invention, the outlet pipe passes through the backwater weir, with its front end located inside the calcium-magnesium-based composite filter media 7 and its rear end extending outside the permeable gabion. In another embodiment of the present invention, the nominal diameter of the outlet pipe is preferably 300 mm.

[0060] The permeable weir for ecological restoration of long-flowing water bodies provided by this invention includes a solar-powered reoxygenation system 10. The solar-powered reoxygenation system 10 includes a solar panel, an aerator, pipes, and a cutting aeration disc; the cutting aeration disc is located within a carboxylated biochar-modified polyurethane composite filter media. In this invention, the solar-powered reoxygenation system primarily provides oxygen to the carboxylated biochar-modified polyurethane composite filter media.

[0061] In one embodiment of the present invention, the carboxylated biochar-modified polyurethane composite filter media 5 and the calcium-magnesium-based composite filter media 7 further include indigenous specific functional microorganisms and functional microbial activators. The indigenous specific functional microorganisms originate from river and wetland sediments and soils in the region, and are obtained through screening and enrichment. Specifically, they include indigenous nitrifying and denitrifying functional microbial communities screened and enriched from river and wetland sediments and soils in the region. The activator can promote the rapid growth and enrichment of indigenous functional microorganisms on the filter media. In another embodiment of the present invention, the specific functional microorganisms and functional microbial activators are preferably added during the commissioning stage of the permeable weir for ecological restoration of long-flowing water bodies. Then, the solar reoxygenation system, water level, and water volume are controlled to activate and directionally enrich the indigenous specific functional microorganisms, thereby obtaining the dominant microbial community.

[0062] In this invention, the front end of the permeable weir will form a certain range of water surface. During non-flood seasons, the permeable weir can be used as a temporary passage for river crossing. During minor floods, the water can overflow through the overflow weir dam. During major floods, the water can overflow the top plate of the weir to allow flooding, without affecting the safety of flood discharge in the river channel.

[0063] The river water forms a water accumulation zone of a certain height in front of the weir, where larger suspended solids such as silt settle. After further interception of large particulate pollutants by permeable gabions, the river water enters the weir through the inlet pipe, where it comes into contact with the biofilm fixed on the carboxylated biochar modified polyurethane composite filter media for purification. Because the carboxylated biochar modified polyurethane composite filter media contains oxygen provided by a solar-powered reoxygenation system, it creates conditions for simultaneous nitrification and denitrification in the area. The calcium-magnesium-based high-efficiency composite filter media has high adsorption capacity, effectively removing pollutants such as nitrogen, phosphorus, and heavy metals from the water. Wetland plants absorb the pollutants adsorbed on the calcium-magnesium-based high-efficiency composite filter media, removing organic matter, nitrogen, phosphorus, heavy metals, and other pollutants from the water, thus achieving the goal of improving the water quality of the basin. The purified water flows back into the river through the outlet (pipe). The permeable weir can serve as a temporary traffic path, facilitating passage on both sides of the water-crossing section. During flood season, the overflow weir and the overflowing of the weir body can ensure the safety of the continuous flow of water.

[0064] In this invention, multiple permeable weirs for ecological restoration of flowing water bodies can be used, such as... Figure 2 This is a top view of two permeable weirs for ecological restoration of two long-flowing water bodies.

[0065] To further illustrate the present invention, the following detailed description of the invention's solutions, in conjunction with the accompanying drawings and embodiments, is provided, but should not be construed as limiting the scope of protection of the present invention.

[0066] Example 1

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

[0068] Biochar was obtained by calcining biomass at 400°C under nitrogen atmosphere.

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

[0070] 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] Prepare an ethanol solution with pH=9 using NaOH. Add silane-coupled carboxylated biochar to the ethanol solution with pH=9 and sonicate for 30 min to obtain a silane-coupled carboxylated biochar dispersion. Place the polyurethane biocarrier in an Ar / O2 plasma (Ar to O2 volume ratio of 4:1) and treat with 100W UV for 5 min to activate the polyurethane biocarrier. Place the activated polyurethane carrier in the silane-coupled carboxylated biochar dispersion and stir at 60℃ for 36 h. After ultrasonic cleaning and drying, obtain the carboxylated biochar-modified polyurethane biocarrier.

[0072] The preparation method of calcium-based modified ceramsite includes the following steps: clay and calcium carbonate are mixed with water to form a uniform slurry, allowed to stand for 48 hours, raw material balls with a particle size of 10-20 mm are prepared by a rolling pelletizing machine, dried at 105℃, and then sintered at 1000℃ for 2 hours to obtain calcium-based modified ceramsite. The mass ratio of clay to calcium carbonate is 6:2.

[0073] A method for preparing magnesium-based modified volcanic rock includes the following steps: screening volcanic rocks of 5-10 mm size, soaking them in 1M HCl for 2 hours, rinsing them until neutral and drying them; immersing the dried volcanic rocks in 1M MgCl2·6H2O solution, sonicating them for 30 minutes, stirring and evaporating them at 80℃ until dry, and then calcining them at 400℃ for 2 hours to obtain magnesium-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 the weir body, inlet pipe, bar screen, weir top plate, carboxylated biochar modified polyurethane composite filter media, porous permeable wall, calcium-magnesium based composite filter media, wetland plants, outlet pipe and solar reoxygenation system.

[0075] The weir body consists of permeable gabions, a water-facing weir, a water-facing overflow weir, a back-water weir, two side weirs, and a base. The permeable gabions are filled with gravel, pebbles, or crushed stone, while the water-facing weir, the water-facing overflow weir, the back-water weir, the two side weirs, and the base are made of cast concrete.

[0076] Along the water flow direction, the weir body is filled with carboxylated biochar-modified polyurethane composite filter media and calcium-magnesium-based high-efficiency composite filter media. The two types of composite filter media are separated by a precast concrete porous permeable wall. A grid and a weir crest plate are placed on top of the weir body containing the carboxylated biochar-modified polyurethane composite filter media. The weir body containing the calcium-magnesium-based composite filter media has spaced-apart weir crest plates, with wetland plants planted between the spaced-apart plates. The carboxylated biochar-modified polyurethane composite filter media consists of macroporous polyurethane biocarriers and carboxylated biochar-modified polyurethane biocarriers, with a volume ratio of 2:1. The calcium-magnesium-based high-efficiency composite filter media consists of 20-40mm crushed stone, 10-20mm calcium-based modified ceramsite, and 5-10mm magnesium-based modified volcanic rock, with a volume ratio of 5:3:2. Native wetland plants are planted at intervals on the calcium-magnesium-based composite filter media. The top of the weir is covered with a weir top plate, which is made of precast concrete. The bottom of the carboxylated biochar modified polyurethane composite filter media is equipped with a cutting aeration disc of a solar reoxygenation system, which provides the oxygen required for the system to operate. The inlet and outlet pipes of the permeable weir are made of precast concrete.

[0077] Example 2

[0078] The structure of the permeable weir is as shown 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, 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 inlet weir (1.5m high), an inlet overflow weir (1.3m high), a base, a backwater weir (1.5m high), and two side weirs (1.5m high). The length of the inlet overflow weir is 0.50m. The inlet and outlet pipes are each made of two DN300 corrugated pipes.

[0080] The carboxylated biochar-modified polyurethane composite filter media consists of macroporous polyurethane biocarriers in a 3:2 ratio and a filling depth of 1.2m. The calcium-magnesium-based high-efficiency composite filter media is composed of 20-40mm gravel, 10-20mm calcium-based modified ceramsite, and 5-10mm magnesium-based modified volcanic rock in a 4:2:1 ratio. The two types of composite filter media are separated by a perforated precast concrete slab, and their filling lengths are 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 crest is a precast concrete cover. The solar-powered reoxygenation system is powered by four solar panels. Indigenous specific microorganisms, originating from the local river wetlands, are enriched and added to the composite filter media after screening. The influent (water temperature 19℃) contained COD, NH3-N, and TP of 45 mg / L, 1.46 mg / L, and 0.21 mg / L, respectively. After one month of operation, the effluent concentrations were 28 mg / L, 0.43 mg / L, and 0.09 mg / L, respectively, representing an improvement in water quality. The permeable weir not only improved the watershed's water quality but also served as a convenient passageway for local residents to cross the river.

[0081] Example 3

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

[0083] The permeable weir is located in a long-flowing river channel, perpendicular to the channel. The weir is 1.5m high, 15m long, and 5.0m wide. It consists of a 50cm wide permeable gabion, a 20cm wide concrete upstream weir, an upstream overflow weir, a base, a downstream weir, and two side weirs. The upstream overflow weir is 20cm lower than the upstream weir and is 0.50m long. Two DN300 corrugated pipes are used for both inlet and outlet. The carboxylated biochar-modified polyurethane composite filter media has a macroporous polyurethane biocarrier and carboxylated biochar-modified polyurethane biocarrier composition ratio of 3:2, with a filling depth of 1.2m. 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 ratio of 4:2:1.

[0084] Two types of composite filter media are separated by a perforated precast concrete slab, with filling lengths of 9.0m and 4.9m for the first two types, respectively. Three rows of yellow irises are planted on the calcium-magnesium-based high-efficiency composite filter media, and the weir crest is a precast concrete cover. The solar-powered reoxygenation system is powered by four solar panels. Indigenous specific microorganisms, sourced from the local river wetlands, are added to the composite filter media after screening and enrichment. During low-temperature operation, with an influent water temperature of 10.5℃, the influent COD, NH3-N, and TP concentrations are 36mg / L, 1.22mg / L, and 0.18mg / L, respectively, while the effluent concentrations are 27mg / L, 0.57mg / L, and 0.08mg / L, respectively. The removal rates of COD, NH3-N, and TP are 25.0%, 53.3%, and 55.6%, respectively, effectively ensuring the removal efficiency of pollutants during low-temperature periods.

[0085] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A long stream water body ecological restoration permeable weir, characterized in that, The solar reoxygenation system (10), the water inlet pipe (2), the weir body (1) and the water outlet pipe (9) are included. The cutting aeration disc 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 the carboxylated biochar modified polyurethane composite filter material (5) and the calcium-magnesium based composite filter material (7) separated by the porous water permeable wall (6). The weir body upper part of the carboxylated biochar modified polyurethane composite filter material (5) is provided with the grating (3) and the first weir top plate (4). The weir body upper part of the calcium-magnesium based composite filter material (7) is provided with the second weir top plate, and the second weir top plates are spaced apart. The second weir top plate is planted with wetland plants (8). The carboxylated biochar modified polyurethane composite filter material (5) is composed of macroporous polyurethane biological carriers and carboxylated biochar modified polyurethane biological carriers. The preparation method of the carboxylated biochar modified polyurethane biological carrier comprises the following steps. The biomass is calcined under a protective atmosphere to obtain biochar. The biochar is immersed in acid for carboxylation to obtain carboxylated biochar. The carboxylated biochar is dispersed in a KH-550 ethanol solution for silane coupling to obtain silane coupled carboxylated biochar. An ethanol solution with pH=9 is prepared by using NaOH, the silane coupled carboxylated biochar is added into the ethanol solution with pH=9, ultrasonic stirring is performed for 20-30 min to obtain a silane coupled carboxylated biochar dispersion liquid, the polyurethane biological carrier is placed in Ar / O2 plasma, ultraviolet treatment is performed to activate the polyurethane biological carrier.

2. The long-streamed water body ecological restoration and permeable weir according to claim 1, characterized in that, The activated polyurethane carrier is placed in the silane coupled carboxylated biochar dispersion liquid, stirring is performed at 60℃ for 24-36 h, ultrasonic cleaning and drying are performed to obtain the carboxylated biochar modified polyurethane biological carrier.

3. The long-streamed water body ecological restoration and permeable weir according to claim 1, characterized in that, The water inlet pipe (2) penetrates through the water-facing weir dam, the front end is located in the water-permeable stone cage, and the rear end extends into the carboxylated biochar modified polyurethane composite filter material (5).

4. The long-streamed water body ecological restoration and permeable weir according to claim 1, wherein, The weir body (1) is composed of a water-permeable stone cage, a water-facing weir dam, a water-facing overflow weir dam, a backwater weir dam, two side weir dams and a base; the water-permeable stone cage is located at the front end of the water-facing weir dam.

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

6. The long-streamed water body ecological restoration permeable weir of claim 5, wherein, The calcium-magnesium based composite filter material (7) is composed of 20-40 mm gravel or gravel, 10-20 mm calcium-based modified ceramsite and 5-10 mm magnesium-based modified volcanic rock.

7. The ecological restoration permeable weir for long and slow flowing water body according to any one of claims 3-6, characterized in that, The volume ratio of the 20-40 mm gravel 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.

8. The long-streamed water body ecological restoration and permeable weir of claim 1, 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.

9. The long-streamed water body ecological restoration permeable weir of claim 3, wherein, The water outlet pipe penetrates through the backwater weir dam, the front end is located in the calcium-magnesium based composite filter material, and the rear end extends to the outside of the water-permeable stone cage. The water-facing overflow weir dam and the water-facing weir dam are arranged side by side, the height of the water-facing overflow weir dam is lower than that of the water-facing weir dam, and the front end is without a water-permeable stone cage.

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