An ecological revetment system for purifying non-point source runoff pollution

Abstract

This invention relates to an ecological revetment system for purifying non-point source runoff pollution, comprising a gabion-type revetment toe and a stepped ecological revetment slope. The ecological revetment slope, from bottom to top, consists of a compacted soil layer, a non-woven fabric layer, a non-woven fabric coarse sand protective layer, and a decommissioned wind turbine blade layer. The decommissioned wind turbine blade layer is formed by step-shaped anchoring of selected sections of decommissioned wind turbine blades. A first filler layer is filled in the selected sections of decommissioned wind turbine blades above the normal water level, and a second filler layer is filled in the selected sections of decommissioned wind turbine blades below the normal water level. Drainage outlets are provided on the outer side of the selected sections of decommissioned wind turbine blades, and filter bags are provided on the inner side of the drainage outlets. This invention combines the characteristics of glass fiber reinforced plastic in decommissioned wind turbine blades, filling their interiors with filter media according to experimental proportions. This maintains the safety of the revetment while improving its permeability to non-point source polluted water, and also significantly improves its water retention capacity.

Description

Technical Field

[0001] This invention relates to the field of ecological revetment in water conservancy, and in particular to an ecological revetment system that can intercept and control non-point source pollution of river water bodies caused by agriculture and initial rainwater runoff. Background Technology

[0002] In water conservancy slope protection and bank protection projects, ecological engineering composite bank protection is a very important type of project, while traditional forms of bank protection such as ecological grass pavers and ecological grass frames are widely used in practice. This type of bank protection mainly uses concrete bricks as a framework, with plain fill soil inside. The brickwork is constructed according to the slope requirements of the river channel, and finally, ground cover, aquatic (wet) plants, shrubs, and other plants are planted in the fill soil to create the effect of an ecological bank protection.

[0003] As the vegetation grows, this type of ecological revetment can effectively intercept pollutants carried by surface runoff. However, the overall effect will decrease with increased rainfall, especially in northern regions where less rainfall in early spring leads to slower revegetation of the revetment vegetation, and the effect on intercepting pollutants carried by the runoff from occasional heavy rainfall in the early stages is even more minimal.

[0004] Meanwhile, the wind turbine blades that were put into construction in the early stages are also nearing the end of their service life. A large number of retired blades will be scrapped and dismantled. How to dispose of and utilize these retired wind turbine blades, turning waste into treasure and making them harmless and resource-based, is an urgent problem that needs to be solved. Summary of the Invention

[0005] The purpose of this invention is to propose an ecological revetment system for purifying non-point source runoff pollution. Combining the high strength, high toughness, light weight, long life and corrosion resistance of decommissioned wind turbine blade glass fiber reinforced plastic (GRP), the interior of which is filled with filter media according to the experimental ratio. This not only maintains the safety of the revetment, but also improves the permeability of the revetment to non-point source polluted water bodies, and also greatly improves its water retention capacity.

[0006] To achieve the above objectives, this invention provides an ecological revetment system for purifying non-point source runoff pollution, mainly comprising gabion-type toe protection and stepped ecological revetment slope protection. The ecological revetment slope protection, from bottom to top, consists of a compacted soil layer, an impermeable non-woven fabric layer, a non-woven fabric coarse sand protective layer, and a decommissioned wind turbine blade layer. The decommissioned wind turbine blade layer is formed by stepped installation and anchoring of selected sections of decommissioned wind turbine blades. A first filler layer is filled in the selected sections above the normal water level, and a second filler layer is filled in the selected sections below the normal water level. The first filler layer, from bottom to top, consists of a gravel layer, a volcanic rock and sponge particle-graded water-bearing layer, a sponge particle-graded crushed stone layer, and a planting soil layer; the second filler layer consists of a bottom layer of plain backfill soil and an upper layer of planting soil. Drainage outlets are provided on the outer side of each selected section of decommissioned wind turbine blades, and filter bags are provided on the inner side of the drainage outlets. The ecological revetment constructed from the section cut by the decommissioned wind turbine blades is divided into three zones: a wetland plant planting area 400mm above and below the normal water level, an aquatic plant planting area below the normal water level, and a ground cover and shrub planting area above the normal water level.

[0007] Preferably, the slope of the ecological revetment is 15° to 35°.

[0008] Preferably, the gravel layer has a thickness of 10 cm, the volcanic rock and sponge particle-graded water-bearing layer has a thickness of 18-20 cm, and the sponge particle-graded crushed stone layer has a thickness of 12-15 cm.

[0009] Preferably, the thickness of the plain fill layer is 35cm, and the compaction degree is not less than 0.85.

[0010] Preferably, a non-woven fabric anchoring trench is provided on the inner side of the top of the ecological revetment slope.

[0011] Preferably, the drain outlet is located 15-20cm from the bottom of the decommissioned wind turbine blade cutting selection section and 8cm from the top of the next row of decommissioned wind turbine blade cutting selection sections. The diameter of the drain outlet is 10-15mm, and the number of drain outlets is 5-8 holes.

[0012] Preferably, the sponge particle graded crushed stone layer consists of crushed stone with a particle size of 5-15 mm accounting for 85% of the volume and sponge particles with a particle size of 5-10 mm accounting for 15% of the volume.

[0013] Preferably, the volcanic rock and sponge particle graded aquifer consists of volcanic rock with an average block diameter of 25-40 mm and a volume percentage of 70-80%, and sponge particles with a particle size of 5-12 mm and a volume percentage of 20-30%.

[0014] Preferably, the natural degradation time of the sponge particles is 15 to 20 years.

[0015] Preferably, the sections of the decommissioned wind turbine blades are fixed together by anchor bolts.

[0016] Based on the above technical solution, the advantages of the present invention are:

[0017] The ecological revetment system of this invention can be laid in different ways to combine different slopes and landscape effects. Its main function is to improve the water filtration capacity of the bank slope for surface runoff, reduce the amount of pollutants such as suspended particulate matter, organic matter, and ammonia nitrogen carried by non-point source pollution before it flows into the river, and at the same time improve the water storage capacity of the revetment, promote the growth of slope vegetation, and enhance the stability and soil and water conservation capacity of the riverbank.

[0018] This invention provides more growth conditions and living space for riverbank plants and microorganisms, enhances the buffering effect of ecological revetments, greatly reduces the impact of non-point source pollution on the river water environment and aquatic ecology, improves the ecological resilience of river water bodies, and also highlights the feasibility, economy and practicality of discarded wind turbine blades in water conservancy projects, and has broad promotion significance. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0020] Figure 1 This is a schematic diagram of the cross-section of the ecological revetment system;

[0021] Figure 2 This is a schematic diagram of the ecological revetment system;

[0022] Figure 3 A typical cross-sectional view of a decommissioned wind turbine blade. Detailed Implementation

[0023] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0024] This invention provides an ecological revetment system for purifying non-point source runoff pollution, such as... Figure 1 , Figure 2 As shown, a preferred embodiment of the present invention is illustrated.

[0025] Specifically, the ecological revetment system includes a gabion-shaped revetment footing 12 and a stepped ecological revetment slope. The ecological revetment slope is laid from bottom to top as follows: a compacted soil layer (existing revetment soil layer), an impermeable non-woven fabric layer 10, a non-woven coarse sand protective layer 9, and a decommissioned wind turbine blade laying layer. The decommissioned wind turbine blade laying layer is formed by cutting and selecting sections 1 of decommissioned wind turbine blades and anchoring them in a stepped shape.

[0026] like Figure 3As shown, the decommissioned wind turbine blades are cut according to the actual construction length, generally 60cm to 80cm in length. Sections with similar shapes and curvatures are grouped and managed. Finally, sections with relatively regular outlines, such as near-quadrilaterals or circles, that are easy to assemble into a single slope are selected as the supporting framework for the riverbank protection.

[0027] The slope of the ecological revetment is 15° to 35°. For example... Figure 2 As shown, the entire revetment retains the traditional gabion structure. The burial depth and width will be determined later based on the actual river conditions. The upper revetment is anchored using categorized wind turbine blade sections spliced ​​together. In this embodiment, the thickness of the sections is designed to be 60cm. Preferably, the selected sections 1 of the decommissioned wind turbine blades are fixed together using anchor bolts 2. This approach makes the revetment a unified whole, improving its resistance to flood impact and stability. Preferably, a non-woven fabric anchoring trench 13 is provided on the inner side of the top of the ecological revetment slope to fix the non-woven fabric.

[0028] After the retired wind turbine blades are cut and selected, section 1 is anchored. At a distance of 15cm to 20cm from the bottom of the wind turbine blades and 8cm from the top of the next row of wind turbine blades, multiple drainage holes 4 with a diameter of φ10mm to 15mm are drilled (the specific number depends on the actual situation, generally 5 to 8 holes). When filling the drainage holes, filter bags 3 are placed at the upper drainage holes.

[0029] like Figure 1 As shown, the decommissioned wind turbine blade cutting section 1 above the normal water level is filled with a first filler layer, and the decommissioned wind turbine blade cutting section 1 below the normal water level is filled with a second filler layer. The first filler layer includes, from bottom to top, a gravel layer 5, a volcanic rock and sponge particle-graded water-bearing layer 6, a sponge particle-graded crushed stone layer 7, and a planting soil layer 8. The second filler layer includes, from bottom to top, a plain soil backfill layer 11 and a planting soil layer 8. The decommissioned wind turbine blade cutting section 1 is provided with a drainage outlet 4 on the outside and a filter bag 3 on the inside of the drainage outlet 4. The decommissioned wind turbine blade cutting section 1 is a decommissioned wind turbine blade cutting section with a length of 60-80cm, similar curvature, and regular outline, which is nearly quadrilateral or circular.

[0030] Preferably, the gravel layer 5 has a thickness of 10 cm, the volcanic rock and sponge particle-graded aquifer 6 has a thickness of 18–20 cm, and the sponge particle-graded crushed stone layer 7 has a thickness of 12–15 cm. The plain fill layer 11 has a thickness of 35 cm and a compaction degree of not less than 0.85.

[0031] Preferably, the sponge particle-graded crushed stone layer 7 consists of crushed stone with a particle size of 5-15 mm accounting for 85% of the volume and sponge particles with a particle size of 5-10 mm accounting for 15% of the volume. The volcanic rock and sponge particle-graded aquifer layer 6 consists of volcanic rock with an average block size of 25-40 mm accounting for 70-80% of the volume and sponge particles with a particle size of 5-12 mm accounting for 20%-30% of the volume.

[0032] The bottom of the cutting section is a non-woven fabric and coarse sand protective layer 9. This layer not only protects the non-woven fabric layer 10, but also utilizes the gaps in the coarse sand to quickly drain excess filter water from the cutting section filler.

[0033] The four layers of filling above the normal water level in the cut section mainly increase the infiltration of non-point source pollution runoff, and have a certain interception and reduction effect on suspended particles, organic matter, nitrogen, phosphorus and other pollutants in the water flowing into the river. The top layer of planting soil mainly plays a preliminary role in filtering the water. The thickness of this layer should not be too thick, generally 20cm to 25cm is appropriate, to avoid reducing the permeability of the soil layer and being detrimental to soil and water conservation. The middle upper layer is a 12cm to 15cm layer of sponge-graded crushed stone. This layer is composed of 85% crushed stone with a φ5mm to 15mm diameter and 15% sponge particles with a φ5mm to 10mm diameter. The main function of this layer is to quickly introduce the permeable water from the upper layer into the lower space, while using a small amount of water-absorbing sponge particles to retain a small amount of water, providing shallow-rooted plants with a small amount of water to promote their rapid growth. The middle lower layer is a 18cm-20cm thick volcanic rock and sponge particle grade aquifer 6. This layer is the core layer of the ecological revetment purification non-point source runoff pollution system. It is composed of volcanic rock with an average block diameter of 25mm-40mm accounting for 70%-80% and sponge particles with a diameter of 5mm-12mm accounting for 20%-30%.

[0034] Preferably, the natural degradation time of the sponge particles is 15 to 20 years. The sponge particles in the aquifer are pulverized particles obtained by recycling waste sponges from daily life and industry without pollution, and their lifespan is basically consistent with the service life of ordinary riverbank protection and also matches the service life of retired wind turbine blades.

[0035] Furthermore, the volcanic rock and sponge particle-graded aquifer 6 has two important functions. First, it enhances the water-holding capacity of the revetment. The internal volcanic rock has a water content of over 85%, and the sponge particles have a water content of over 98%. Such an aquifer can provide a long-term water supply to the upper ground cover plants in seasonal river channels or relatively arid areas, ensuring their healthy growth and allowing the plants' extensive root systems to better stabilize the slope and intercept pollution. The second important function is to effectively prevent non-point source pollution runoff from directly flowing into the river channel.

[0036] The pores in the sponge and volcanic rock absorb a large amount of pollutants carried by runoff. These pores also provide a habitat for numerous microorganisms, effectively purifying the water while simultaneously adsorbing pollutants. With the next rainfall, the microbially purified pore water, under pressure from the upper water layer, seeps through the underlying gravel layer 5 and the impermeable non-woven coarse sand protective layer 9 into the river, indirectly enhancing the river's self-purification capacity.

[0037] like Figure 1 As shown, the planting soil layer 8 400mm above and below the normal water level is the wetland plant planting area B, the planting soil layer 8 400mm below the normal water level is the aquatic plant planting area A, and the planting soil layer 8 400mm above the normal water level is the ground cover plant planting area C.

[0038] The overall revetment planting area is roughly divided into three zones, which also serve as the final barrier for the river's ecological buffer zone. Using the design normal water level as a reference, the area 400mm above and below this level is designated for wetland plants. This zone serves as both the main landscape area of ​​the ecological river and an ecological buffer zone between the waterline and the hard shoreline. The height and width of this zone will be determined later based on the actual drawdown cycle of the river's water level. Above 400mm above the waterline, ground cover plants with well-developed root systems are preferred. Plants in this area should be native to the river, easy to manage, tolerant of extensive maintenance, and effective in slope protection and soil and water conservation. Other ornamental plants can be interplanted during actual construction to meet the revetment landscape requirements. Below the waterline, from 400mm to 800mm, is the aquatic plant planting area. The first choice should be local aquatic plants that are suitable for local growth, have strong water purification capabilities, high survival rates, and are tolerant of extensive maintenance. Ornamental aquatic plants will be appropriately added at key landscape nodes later to enrich the river's ecological landscape.

[0039] The ecological revetment system of this invention can be laid in different ways to combine different slopes and landscape effects. Its main function is to improve the water filtration capacity of the bank slope for surface runoff, reduce the amount of pollutants such as suspended particulate matter, organic matter, and ammonia nitrogen carried by non-point source pollution before it flows into the river, and at the same time improve the water storage capacity of the revetment, promote the growth of slope vegetation, and enhance the stability and soil and water conservation capacity of the riverbank.

[0040] This invention provides greater growth and survival space for riverbank plants and microorganisms, enhances the buffering effect of ecological revetments, greatly reduces the impact of non-point source pollution on the river water environment and aquatic ecology, improves the ecological resilience of river water bodies, and highlights the feasibility, economy, and practicality of discarded wind turbine blades in water conservancy projects, thus having broad promotional significance.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. An ecological revetment system for purifying non-point source runoff pollution, comprising gabion-type revetment toeing (12) and stepped ecological revetment slope protection, characterized in that: The ecological revetment slope protection is laid from bottom to top as follows: a compacted soil layer, a seepage-proof non-woven fabric layer (10), a non-woven fabric coarse sand protection layer (9), and a decommissioned wind turbine blade layer. The decommissioned wind turbine blade layer is formed by step-shaped masonry and anchoring of the decommissioned wind turbine blade cutting selection section (1). The decommissioned wind turbine blade cutting selection section (1) above the normal water level is filled with a first filler layer, and the decommissioned wind turbine blade cutting selection section (1) below the normal water level is filled with a second filler layer. The first filler layer includes, from bottom to top, a gravel layer (5), a volcanic rock and sponge particle graded aquifer layer (6), a sponge particle graded crushed stone layer (7), and a planting soil layer (8). The sponge particle graded crushed stone layer (7) is composed of crushed stone with a particle size of 5-15mm and a volume ratio of 85% and sponge particles with a particle size of 5-10mm and a volume ratio of 15%. The volcanic rock and sponge particle graded aquifer layer (6) is composed of average block The second filler layer consists of volcanic rock with a diameter of 25-40 mm and a volume ratio of 70-80%, and sponge particles with a diameter of 5-12 mm and a volume ratio of 20%-30%. The natural degradation time of the sponge particles is 15-20 years. The second filler layer includes a plain soil backfill layer (11) and a planting soil layer (8) laid from bottom to top. The outer side of the decommissioned wind turbine blade cutting section (1) is provided with a drainage outlet (4), and the inner side of the drainage outlet (4) is provided with a filter bag (3). The decommissioned wind turbine blade cutting section (1) is a near quadrilateral or circular decommissioned wind turbine blade cutting section with a length of 60-80 cm, similar curvature, and regular outline. The planting soil layer (8) 400 mm above and below the normal water level is the wetland plant planting area (B). The planting soil layer (8) below the normal water level 400 mm is the aquatic plant planting area (A). The planting soil layer (8) above the normal water level 400 mm is the ground cover plant planting area (C).

2. The ecological revetment system according to claim 1, characterized in that: The slope of the ecological revetment is 15° to 35°.

3. The ecological revetment system according to claim 1, characterized in that: The gravel layer (5) has a thickness of 10 cm, the volcanic rock and sponge particle graded aquifer (6) has a thickness of 18-20 cm, and the sponge particle graded crushed stone layer (7) has a thickness of 12-15 cm.

4. The ecological revetment system according to claim 1, characterized in that: The thickness of the plain soil backfill layer (11) is 35cm, and the compaction degree is not less than 0.

85.

5. The ecological revetment system according to claim 1, characterized in that: The ecological revetment slope is provided with a non-woven fabric anchoring trench (13) on the inner side of the top.

6. The ecological revetment system according to claim 1, characterized in that: The drain outlet (4) is located 15-20cm from the bottom of the decommissioned wind turbine blade cutting selection section (1) and 8cm from the top of the next row of decommissioned wind turbine blade cutting selection section (1). The diameter of the drain outlet (4) is 10-15mm and the number of drain outlets (4) is 5-8 holes.

7. The ecological revetment system according to claim 1, characterized in that: The decommissioned wind turbine blades are cut and selected from the segments (1) and fixed together by anchor bolts (2).

Images