A comprehensive river and lake management system and method based on in-situ solidification of silt and solid waste

Abstract

This application discloses a comprehensive river and lake management system and method based on in-situ solidification of silt, belonging to the field of river and lake ecological management technology. The system, from bottom to top along the riverbank, includes: a silt in-situ solidification base layer, a retaining wall, a slope protection layer, a sewage interception system, and a water-land alternating ecological zone. This system enables in-situ treatment and effective resource utilization of silt, avoiding the huge costs and secondary pollution associated with traditional off-site transportation methods. Furthermore, the composite structure of "gabion mesh + solidified soil + vegetation" achieves a balance between mechanical stability and ecological function. Additionally, filling the gabion filter cages with dephosphorization and water purification coupled filter media effectively removes total phosphorus and ammonia nitrogen from road runoff and agricultural non-point source pollution, achieving precise pollution control. Moreover, creating a water-land alternating ecological zone provides habitats for aquatic organisms, birds, and other species, contributing to increased biodiversity.

Description

Technical Field

[0001] This application relates to the field of river and lake ecological governance technology, and in particular to a comprehensive river and lake governance system and method based on in-situ solidification of silt and solid waste. Background Technology

[0002] Currently, river and lake ecosystems generally face multiple complex challenges, including endogenous pollution (sediment deposition and release), bank instability, non-point source pollution input, and habitat degradation. The main challenges in their management are: fluid silt with high organic matter content (8%~15%) and high water content (>60%) is difficult to directly solidify and utilize; traditional concrete revetments, while stable, cause ecological disruption; and non-point source pollution from agriculture and road runoff is dispersed and difficult to control.

[0003] Traditional dredging and transportation methods are costly, prone to secondary pollution during transportation and storage, and damage the benthic ecosystem. Therefore, it is necessary to develop a comprehensive management system and method that can achieve "waste treatment and systemic restoration" and seamlessly integrate endogenous pollution control, bank slope stabilization, pollution control and habitat creation. Summary of the Invention

[0004] This application provides a comprehensive river and lake management system and method based on in-situ solidification of silt and solid waste. The system can "treat pollution with waste and restore the system," seamlessly integrating endogenous pollution control, bank stabilization, pollution prevention and control, and habitat creation. The technical solution is as follows: On the one hand, a comprehensive river and lake management system based on in-situ solidification of silt and solid waste is provided. The system includes, from bottom to top along the riverbank: a silt in-situ solidification base layer, a retaining wall, a slope protection layer, a sewage interception system, and a water-land alternating ecological zone. The in-situ solidified silt base layer is formed by adding a silt polymerization stabilizer to the riverbed and then stirring and curing it in situ. The silt polymerization stabilizer includes a multi-element solid waste base material and a functional activator. The mass ratio of the multi-element solid waste base material to the functional activator is (2~5):1. The functional activator includes calcium hydroxide, hemihydrate gypsum, sodium sulfate and sodium carbonate in a mass ratio of 1:(1~1.5):(1~1.5):(1~1.5). The retaining wall is formed by layering gabion mesh cages filled with solidified silt. The slope protection layer is located on the water-facing slope of the retaining wall. A reinforcement layer is laid on the slope, which is formed by filling solidified silt with gabion mesh. The reinforcement layer is covered with planting soil, which is used to plant native plants. The interception system includes a gabion filter cage installed on the top of the dike. The gabion filter cage is filled with dephosphorization and water purification coupled filter media, which is used to remove phosphorus from non-point source pollution and purify water quality. The water-land alternating ecological zone is a habitat created by preserving the original silt within a predetermined range from the waterline on both banks, planting emergent plants, and providing a habitat for aquatic organisms and birds.

[0005] In one possible implementation, the multi-component solid waste-based material comprises the following components by mass fraction: 20%~35% ultrafine steel slag powder, 20%~35% ultrafine modified fly ash, 20%~35% ultrafine slag powder, and 20%~35% autoclaved aerated concrete powder.

[0006] In another possible implementation, the dephosphorization and water purification coupling filter media is composed of 45 to 65 parts by weight of fly ash, 3 to 10 parts by weight of desulfurization gypsum, 15 to 25 parts by weight of lime, 0.02 to 0.08 parts by weight of aluminum powder paste, and 0.03 to 0.06 parts by weight of polyaluminum chloride. After pre-curing and molding, the media is mechanically crushed into particles after autoclaving in an autoclave.

[0007] In another possible implementation, the autoclave temperature is 190℃~210℃, the pressure is 1MPa~1.4MPa, and the autoclaving time is 6h~10h.

[0008] In another possible implementation, the particle size of the dephosphorization water purification coupling filter media is 2cm to 8cm.

[0009] In another possible implementation, the in-situ solidified sludge base layer is a hard shell layer with a thickness of 1m to 1.2m and a width of not less than 1.5m.

[0010] In another possible implementation, the sewage interception system also includes an ecological isolation dike and a supporting interception ditch located on the farmland side, constructed of solidified silt.

[0011] In another possible implementation, the thickness of the reinforcing layer is 10cm to 50cm, and the thickness of the planting soil is 10cm to 20cm.

[0012] On the other hand, a comprehensive river and lake management method based on in-situ solidification of silt and solid waste is provided, the method being applied to any of the systems described above, the method comprising: The moisture content, organic matter content, and heavy metal background values ​​of the sludge were determined. Based on the test results, a sludge polymerization stabilizer was prepared. The prepared sludge polymerization stabilizer was delivered to the mixing head through an intelligent operating platform and a mixing device to carry out in-situ mixing and curing of the sludge, forming an in-situ solidified base layer of sludge. Gabion mesh boxes are filled with solidified silt and stacked in layers to form a retaining wall; A gabion mesh filled with solidified silt is laid on the water-facing slope of the retaining wall to form a reinforcement layer, and planting soil is covered on the reinforcement layer to form a slope protection layer. Gabion filter cages filled with dephosphorization and water purification coupling filter media are installed on the top of the dike to form a pollution interception system. Delineate the alternating water and land ecological zone and introduce local emergent plants.

[0013] In one possible implementation, the installation of gabion filter cages filled with dephosphorization and water purification coupling filter media on the top of the dike to form a pollution interception system includes: The gabion filter cages filled with the dephosphorization and water purification coupling filter media are installed on the top of the dike, and an ecological isolation dike and a matching interception ditch formed by solidified silt are constructed on the farmland side to form the sewage interception system.

[0014] This application provides a comprehensive river and lake management system based on in-situ solidification of silt. The system, from bottom to top along the riverbank, includes: a silt in-situ solidification base layer, a retaining wall, a slope protection layer, a sewage interception system, and a water-land alternating ecological zone. The silt in-situ solidification base layer is formed by adding a silt polymer stabilizer to the riverbed and then mixing and curing it in situ. The retaining wall is formed by layering gabion mesh cages filled with solidified silt. The slope protection layer is a reinforcement layer formed by filling gabion mesh with solidified silt. Therefore, this system can achieve in-situ treatment and effective resource utilization of silt, avoiding the huge costs and secondary pollution associated with traditional transportation methods. Furthermore, the composite structure of "gabion mesh + solidified soil + vegetation" achieves a balance between mechanical stability and ecological function. Additionally, filling the gabion filter cages with dephosphorization and water purification coupled filter media can effectively remove total phosphorus and ammonia nitrogen from road runoff and agricultural non-point source pollution, achieving precise pollution control. Furthermore, creating alternating water and land ecosystems provides habitats for aquatic organisms, birds, and other species, thus contributing to increased biodiversity. Therefore, this system is a comprehensive governance system that seamlessly integrates endogenous pollution control, bank stabilization, pollution prevention and control, and habitat creation, based on the principle of "treating pollution with waste and restoring the system."

[0015] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this disclosure. Attached Figure Description

[0016] Figure 1 This is a cross-sectional schematic diagram of a river and lake integrated management system provided in this application embodiment on the riverbank. Detailed Implementation

[0017] To make the technical solution and advantages of this application clearer, the embodiments of this application will be described in further detail below.

[0018] On the one hand, the embodiments of this application provide a comprehensive river and lake management system based on in-situ solidification of silt and solid waste. The system includes, from bottom to top, the following components along the riverbank: a silt in-situ solidification base layer, a retaining wall, a slope protection layer, a sewage interception system, and a water-land alternating ecological zone. The in-situ solidification base layer of silt is formed by adding silt polymer stabilizer to the riverbed and then mixing and curing it in situ. The silt polymer stabilizer includes multi-component solid waste-based materials and functional activators. The mass ratio of multi-component solid waste-based materials to functional activators is (2~5):1. The functional activators include calcium hydroxide, hemihydrate gypsum, sodium sulfate and sodium carbonate in a mass ratio of 1:(1~1.5):(1~1.5):(1~1.5). The retaining wall is formed by stacking layers of gabion mesh cages filled with solidified silt; The slope protection layer is located on the water-facing slope of the retaining wall. A reinforcement layer is laid, which is formed by filling solidified silt with gabion mesh. The reinforcement layer is covered with planting soil, which is used to plant native plants. The interception system includes gabion filter cages installed on the top of the dike. The gabion filter cages are filled with dephosphorization and water purification coupled filter media, which is used to remove phosphorus from non-point source pollution and purify the water. The alternating water and land ecological zone is a habitat created by preserving the original silt within a predetermined range from the waterline on both banks, planting emergent plants, and building a habitat for aquatic organisms and birds.

[0019] The mass ratio of the multi-component solid waste-based material to the functional activator can be 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, etc. The mass ratio of calcium hydroxide, hemihydrate gypsum, sodium sulfate, and sodium carbonate can be 1:1:1:1, 1:1.1:1:1, 1:1.2:1:1, 1:1.3:1:1, 1:1.4:1:1, 1:1.5:1:1, 1:1:1.1:1, 1:1:1.2:1, 1:1:1.3:1, 1:1:1.4:1, 1:1:1. 1.5:1, 1:1:1:1.1, 1:1:1:1.2, 1:1:1:1.3, 1:1:1:1.4, 1:1:1:1.5, 1:1.1:1.1:1.1, 1:1.2:1.2:1.2, 1:1.3:1.3:1.3, 1:1.4:1.4:1.4, 1:1.5:1.5:1.5, etc.

[0020] This application provides a comprehensive river and lake management system based on in-situ solidification of silt. The system, from bottom to top along the riverbank, includes: a silt in-situ solidification base layer, a retaining wall, a slope protection layer, a sewage interception system, and a water-land alternating ecological zone. The silt in-situ solidification base layer is formed by adding a silt polymer stabilizer to the riverbed and then mixing and curing it in situ. The retaining wall is formed by layering gabion mesh cages filled with solidified silt. The slope protection layer is a reinforcement layer formed by filling gabion mesh with solidified silt. Therefore, this system can achieve in-situ treatment and effective resource utilization of silt, avoiding the huge costs and secondary pollution associated with traditional transportation methods. Furthermore, the composite structure of "gabion mesh + solidified soil + vegetation" achieves a balance between mechanical stability and ecological function. Additionally, filling the gabion filter cages with dephosphorization and water purification coupled filter media can effectively remove total phosphorus and ammonia nitrogen from road runoff and agricultural non-point source pollution, achieving precise pollution control. Furthermore, creating alternating water and land ecosystems provides habitats for aquatic organisms, birds, and other species, thus contributing to increased biodiversity. Therefore, this system is a comprehensive governance system that seamlessly integrates endogenous pollution control, bank stabilization, pollution prevention and control, and habitat creation, based on the principle of "treating pollution with waste and restoring the system."

[0021] In one possible implementation, the multi-component solid waste-based material comprises the following components by mass fraction: 20%~35% ultrafine steel slag powder, 20%~35% ultrafine modified fly ash, 20%~35% ultrafine slag powder, and 20%~35% autoclaved aerated concrete powder.

[0022] For example, the mass fraction of ultrafine steel slag powder can be 20%, 22%, 25%, 28%, 30%, 32%, 35%, etc. The mass fraction of ultrafine modified fly ash can be 20%, 22%, 25%, 28%, 30%, 32%, 35%, etc. The mass fraction of ultrafine slag powder can be 20%, 22%, 25%, 28%, 30%, 32%, 35%, etc. The mass fraction of autoclaved aerated concrete powder can be 20%, 22%, 25%, 28%, 30%, 32%, 35%, etc.

[0023] Among them, ultrafine steel slag powder, ultrafine modified fly ash, and ultrafine slag powder can be steel slag, modified fly ash, and slag respectively, after being ground to a specific surface area ≥700m². 2 It was obtained at / kg (approximately 800-1000 mesh).

[0024] Steel slag is a byproduct of the steelmaking process. It consists of various oxides formed by the oxidation of impurities such as silicon, manganese, phosphorus, and sulfur in pig iron during smelting, as well as salts formed by the reaction of these oxides with solvents. Its main chemical components include 40%–60% calcium oxide (CaO), 3%–10% magnesium oxide (MgO), and iron oxide, etc. The mineral composition is mainly tricalcium silicate, followed by dicalcium silicate, RO phase, etc.

[0025] Fly ash is a fine fly ash collected from the flue gas of coal combustion in thermal power plants, exhibiting excellent pozzolanic activity. Its main chemical components are Al2O3 (approximately 40%) and SiO2 (approximately 35%), with mineral phases including glass (50%–80%), quartz, and mullite. Modified fly ash is obtained by compounding 0.02%–0.1% triethanolamine, ethylene glycol, sodium silicate, sodium sulfite, glycerol, stearic acid, and sodium hexametaphosphate in a mass ratio of 6:5:2:1:1:1:0.5, followed by a mixing and grinding process to modify the fly ash.

[0026] Blast furnace slag, also known as blast furnace slag, is a byproduct of the blast furnace ironmaking process. During ironmaking, impurities such as silica and alumina in iron ore react with lime and other materials to form a molten substance mainly composed of silicates and aluminosilicates. After quenching, it becomes a loose, porous granular material. Its main chemical components include CaO, SiO2, Al2O3, and MgO.

[0027] Autoclaved aerated concrete (AAC) powder originates from scraps, defective products, or waste materials from the production process of AAC blocks / slabs. AAC itself is made primarily from slag waste stone powder (70-75%), gypsum, lime, cement, and other raw materials. Therefore, the main components of its powder are SiO2, CaO, etc., which have a certain degree of hydraulic activity.

[0028] In this embodiment of the application, various industrial solid wastes are ultrafinely ground to the micro-nano scale (specific surface area 700m²). 2 / kg), significantly improving particle activity and reaction interface. The complementary chemical compositions of different solid wastes, under the action of functional activators, undergo synergistic hydration reactions to form a dense microstructure. Furthermore, using ultrafine industrial solid waste as the main raw material, high-value utilization of waste can also be achieved.

[0029] In this embodiment, a high-performance silt polymer stabilizer is added to the riverbed silt using a special engineering machinery mixing device. After in-situ mixing and curing, a hard shell layer with a thickness of 1m to 1.2m and a width of not less than 1.5m is formed, which is the in-situ solidified silt base layer. The unconfined compressive strength after 7 days is ≥0.6MPa, the strength after 28 days is ≥2.0MPa, and the permeability coefficient is ≤1×10⁻⁶. -7 cm / s, providing a solid foundation for subsequent construction.

[0030] The retaining wall is formed by stacking layers of gabion mesh cages filled with solidified silt. The solidified silt refers to the silt that has been solidified in the in-situ solidified foundation layer.

[0031] In this embodiment, gabion mesh cages filled with solidified silt are stacked in layers to form a gravity retaining wall, which constitutes the core support structure of the bank slope.

[0032] For the slope protection layer, located on the water-facing slope of the retaining wall, a reinforcement layer is laid, which is formed by filling solidified silt with gabion mesh. The reinforcement layer is covered with planting soil, which is used to plant native plants.

[0033] The thickness of the reinforcement layer can be 10cm to 50cm, and the thickness of the planting soil can be 10cm to 20cm.

[0034] For example, the thickness of the reinforcement layer can be 10cm, 15cm, 20cm, 25cm, 30cm, 35cm, 40cm, 45cm, 50cm, etc. The thickness of the planting soil can be 10cm, 12cm, 15cm, 18cm, 20cm, etc.

[0035] Native plant seeds, such as reeds and bermudagrass, can be sown on the planting soil; there are no specific restrictions.

[0036] In this embodiment, the reinforcement layer is formed by filling solidified silt with gabion mesh, providing structural protection against erosion and scouring of the bank slope, preventing slope damage caused by water erosion. Topsoil is then placed on the reinforcement layer, and native plants are planted on top. The plant roots can penetrate the reinforcement layer, forming a composite ecological reinforcement system of roots, solidified soil, and gabion mesh, increasing overall stability as the vegetation grows. Furthermore, the plant growth creates a natural ecological landscape, enhancing biodiversity in the water-land transition zone.

[0037] The interception system includes gabion filter cages installed on the top of the dike. The gabion filter cages are filled with dephosphorization and water purification coupled filter media, which is used to remove phosphorus from non-point source pollution and purify the water.

[0038] In one possible implementation, the dephosphorization and water purification coupling filter media is composed of 45 to 65 parts by weight of fly ash, 3 to 10 parts by weight of desulfurization gypsum, 15 to 25 parts by weight of lime, 0.02 to 0.08 parts by weight of aluminum powder paste, and 0.03 to 0.06 parts by weight of polyaluminum chloride. After pre-curing and molding, the media is autoclaved in an autoclave and then mechanically crushed into particles.

[0039] The autoclave temperature is 190℃~210℃, the pressure is 1MPa~1.4MPa, and the autoclaving time is 6h~10h.

[0040] In addition, the particle size of the dephosphorization and water purification coupling filter media is 2cm~8cm.

[0041] For example, the mass fractions of fly ash can be 45, 48, 50, 52, 55, 58, 60, 62, or 65 parts by mass. The mass fractions of desulfurized gypsum can be 3, 4, 5, 6, 7, 8, 9, or 10 parts by mass. The mass fractions of lime can be 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 parts by mass. The mass fractions of aluminum powder paste can be 0.02, 0.03, 0.035, 0.04, 0.05, 0.06, 0.07, or 0.08 parts by mass. The mass fractions of polyaluminum chloride can be 0.03 parts by mass, 0.035 parts by mass, 0.04 parts by mass, 0.05 parts by mass, 0.06 parts by mass, etc.

[0042] The autoclave temperature can be 190℃, 195℃, 200℃, 205℃, 210℃, etc. The autoclave pressure can be 1MPa, 1.1MPa, 1.2MPa, 1.3MPa, 1.4MPa, etc. The autoclaving time can be 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, 9.5h, 10h, etc.

[0043] The particle size of the dephosphorization and water purification coupling filter media can be 2cm, 3cm, 4cm, 5cm, 6cm, 7cm, 8cm, etc.

[0044] In this embodiment, gabion filter cages are installed on the top of the dike to intercept non-point source pollution runoff from farmland, roads, and other land areas. The gabion filter cages have high permeability, effectively supporting and fixing the dephosphorization and water purification coupled filter media, preventing it from being lost with the water flow. Through the synergistic effect of its components, the dephosphorization and water purification coupled filter media can chemically adsorb, precipitate, and flocculate total phosphorus in the runoff, achieving efficient phosphorus removal while simultaneously removing ammonia nitrogen, suspended solids, and some organic pollutants, thus improving overall water quality. Furthermore, the 2cm~8cm particle size distribution forms a porous structure, ensuring hydraulic retention time while preventing clogging.

[0045] It should be noted that the sewage interception system may also include: an ecological isolation dike located on the side of farmland, constructed of solidified silt, and a supporting interception ditch.

[0046] Among them, the ecological isolation dike can be formed directly by compacting solidified silt, or it can be formed by stacking gabion mesh cages filled with solidified silt, without specific limitations.

[0047] In this embodiment, the ecological dike can form a barrier between farmland and the river, preventing surface runoff from directly entering the river. The intercepting ditch can collect scattered non-point source pollution runoff generated on the farmland side, preventing it from directly entering the river.

[0048] The alternating water and land ecosystem involves preserving native silt within a predetermined range from the waterline on both banks, planting emergent plants, and creating habitats for aquatic organisms and birds.

[0049] Emergent plants are aquatic plants whose roots grow in underwater silt, but whose main parts, such as stems and leaves, grow above the water surface. Examples include reeds and bermudagrass.

[0050] The preset range can be set and changed as needed, without any specific limitations. For example, the preset range can be 2m, 2.5m, 3m, etc.

[0051] In this embodiment of the application, the alternating water and land ecosystem can provide habitats for fish, amphibians and birds, which helps to enhance biodiversity.

[0052] See Figure 1 , Figure 1 This is a cross-sectional schematic diagram of a river and lake integrated management system provided in an embodiment of this application on a riverbank.

[0053] On the other hand, embodiments of this application provide a comprehensive river and lake management method based on in-situ solidification of silt and solid waste, applied to the aforementioned comprehensive river and lake management system. This method includes: Step 101: Determine the moisture content, organic matter content, and heavy metal background value of the sludge.

[0054] Among them, the background value of heavy metals refers to the original concentration value of heavy metal elements (such as cadmium, mercury, lead, arsenic, etc.) that already existed in the sludge before treatment.

[0055] In the embodiments of this application, the water content, organic matter content and heavy metal background value of the silt can be determined by on-site investigation and silt sampling.

[0056] The moisture content of silt can be measured using a drying method. For example, weigh the silt before and after drying, determine the ratio of the mass difference before and after drying to the mass of the silt after drying, and then obtain the moisture content of the silt.

[0057] The organic matter content can be measured using either the potassium dichromate oxidation-volume method or the ignition method. The potassium dichromate oxidation-volume method involves heating the sludge sample with a potassium dichromate-sulfuric acid solution for oxidation, titrating the remaining oxidant with ferrous sulfate, calculating the organic carbon content, and then converting it to organic matter content. The ignition method involves igniting the dried sludge at high temperature in a muffle furnace for a certain time, and calculating the organic matter content based on the mass loss.

[0058] Background values ​​for heavy metals can be determined using methods such as inductively coupled plasma mass spectrometry or atomic absorption spectrometry.

[0059] In the embodiments of this application, the water content of the sludge mainly affects the amount of sludge polymerization stabilizer added, the organic matter content mainly affects the formulation of the sludge polymerization stabilizer, and the background value of heavy metals is mainly used to verify whether the leaching toxicity after solidification meets the standard, so as to ensure environmental safety.

[0060] Step 102: Based on the test results, prepare a sludge polymerization stabilizer. The prepared sludge polymerization stabilizer is delivered to the mixing head through an intelligent operating platform and a mixing device to carry out in-situ mixing and curing of the sludge, forming an in-situ solidified base layer of sludge.

[0061] Based on the measurement results of step 101, the content of each component in the sludge polymerization stabilizer is determined, and the sludge polymerization stabilizer is prepared. Then, using an intelligent operating platform and a special stirring device, the prepared sludge polymerization stabilizer is quantitatively delivered to the stirring head through a conveying pipeline for in-situ stirring and curing of the sludge, forming an in-situ solidified base layer of sludge.

[0062] Step 103: Fill the gabion mesh boxes with solidified silt and stack them in layers to form a retaining wall.

[0063] The gabion mesh is filled with the solidified silt from step 102 and then stacked in layers to form a retaining wall.

[0064] Step 104: Lay gabion mesh filled with solidified silt on the water-facing slope of the retaining wall to form a reinforcement layer, and cover the reinforcement layer with planting soil to form a slope protection layer.

[0065] Step 105: Install gabion filter cages filled with dephosphorization and water purification coupling filter media on the top of the dike to form a pollution interception system.

[0066] In one possible implementation, gabion filter cages filled with dephosphorization and water purification coupling filter media are directly installed on the top of the dike to form a pollution interception system.

[0067] In another possible implementation, if there is farmland nearby, in addition to installing gabion filter cages filled with dephosphorization and water purification coupling filter media on the top of the dike, an ecological isolation dike formed by solidified silt and a supporting interception ditch are also constructed on the farmland side to form a sewage interception system.

[0068] Step 106: Delineate the alternating water and land ecological zone and introduce local emergent plants.

[0069] In summary, the solution provided in this application has the following beneficial effects: (1) Resource recycling and cost saving: It realizes the in-situ treatment and effective resource utilization of sludge, avoiding the huge costs and secondary pollution caused by traditional transportation methods.

[0070] (2) Ecological synergy and performance improvement: Through the composite structure of "gabion net + solidified soil + vegetation", the mechanical stability and ecological function are unified. Compared with traditional masonry retaining walls, the ecological benefits (vegetation coverage) of the bank slope in this application are increased by more than 80%, while the engineering cost is reduced by about 30%.

[0071] (3) Precise pollution control: The average removal rate of total phosphorus (TP) and ammonia nitrogen (NH3-N) in road runoff and agricultural non-point source pollution by the interception system reaches more than 65% and 50%, respectively.

[0072] (4) Enhanced biodiversity: The created alternating water and land ecosystem provides habitats for fish, amphibians and birds. After the treatment, the number and species of benthic animals surveyed in the area can increase by about 40%.

[0073] (5) Convenience of construction and environmental friendliness: The main materials are all taken from the site, the construction period is short, and no construction waste is generated. The curing technology can effectively solidify / stabilize heavy metals and other harmful substances, and the leaching toxicity is lower than the national standard limit.

[0074] To make the technical solution and advantages of this application clearer, they will be described in detail below through specific embodiments.

[0075] In the following specific embodiments, operations without specified conditions are performed under standard conditions or conditions recommended by the manufacturer. Raw materials without specified manufacturers and specifications are all commercially available products.

[0076] Example 1 Example 1 provides a sludge polymerization stabilizer in which the mass ratio of multi-component solid waste-based material to functional activator is 3:1.

[0077] The multi-component solid waste-based material comprises the following components by mass fraction: 25% ultrafine steel slag powder, 25% ultrafine modified fly ash, 25% ultrafine slag powder, and 25% autoclaved aerated concrete powder.

[0078] The mass ratio of calcium hydroxide, gypsum hemihydrate, sodium sulfate, and sodium carbonate in the functional activator is 1:1:1:1.

[0079] Performance testing: Experimental materials: The silt used in the experiment was taken from a typical eutrophic river channel, with a water content of 65%~70% and an organic matter content of 10%~12%.

[0080] Test materials: Sample A: sludge polymer stabilizer provided in Example 1; Sample B: 42.5 grade ordinary silicate cement; Sample C: commercially available roadbed curing agent.

[0081] Test method: Each sample was mixed with silt at a dosage of 12% (percentage of wet mud mass), the samples were prepared and cured according to standard, and the unconfined compressive strength (UCS) and permeability coefficient were tested.

[0082] The test results are shown in Table 1.

[0083] Table 1. Test results of unconfined compressive strength and permeability coefficient

[0084] As can be seen from Table 1, the sludge polymer stabilizer provided in this application is significantly superior to the materials of sample B and sample C in terms of early strength, later strength development and impermeability, and is especially suitable for the solidification of high organic matter sludge.

[0085] Example 2 A pilot test was conducted on a 150m long section of a riverbank with an average silt thickness of 1.2m.

[0086] Construction Implementation: Strictly follow the methods provided in this application to construct the in-situ solidified silt foundation layer, retaining wall, slope protection layer, sewage interception system, and alternating water and land ecological zone.

[0087] The interception system includes gabion filter cages installed on the top of the dike, an ecological isolation dike constructed of solidified silt located on the farmland side, and a supporting interception ditch.

[0088] The test results are shown in Table 2.

[0089] Table 2. Results of the pilot-scale test in the field

[0090] As can be seen from Table 2, the pilot project verified the comprehensive feasibility of the system provided in this application in terms of material performance, structural stability and ecological restoration effect, and the synergistic effect of each subsystem was obvious.

[0091] Example 3 This embodiment is based on a hypothetical but data-rich full-scale treatment project of a 500m river section, and makes a quantitative comparison of the proposed solution with traditional solutions throughout the entire life cycle.

[0092] Solution settings: Option A: Use the system provided in this application for comprehensive governance.

[0093] Option B (traditional option): adopts a combination of "sludge off-site disposal (transport distance 30km) + precast concrete block revetment + end-of-pipe artificial wetland".

[0094] The results of the comparative analysis are shown in Table 3.

[0095] Table 3 Comparison and Analysis Results of Scheme A and Scheme B

[0096] As can be seen from Table 3, the advantages of the system provided in this application are revealed using quantitative data from four dimensions: economic, environmental, engineering, and social. It is not only more cost-effective during the construction phase, but also creates significant application value throughout its entire life cycle due to its low maintenance, self-sustaining, and self-repairing characteristics, effectively improving the predicament of traditional governance models characterized by "high investment, high emissions, low efficiency, and difficulty in sustainability."

[0097] The above description is only for the purpose of enabling those skilled in the art to understand the technical solution of this application, and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A comprehensive river and lake management system based on in-situ solidification of silt and solid waste, characterized in that, The system, from bottom to top along the riverbank, includes: an in-situ solidification base layer for silt, a retaining wall, a slope protection layer, a sewage interception system, and a water-land alternating ecological zone; The in-situ solidified silt base layer is formed by adding a silt polymerization stabilizer to the riverbed and then stirring and curing it in situ. The silt polymerization stabilizer includes a multi-element solid waste base material and a functional activator. The mass ratio of the multi-element solid waste base material to the functional activator is (2~5):

1. The functional activator includes calcium hydroxide, hemihydrate gypsum, sodium sulfate and sodium carbonate in a mass ratio of 1:(1~1.5):(1~1.5):(1~1.5). The retaining wall is formed by layering gabion mesh cages filled with solidified silt. The slope protection layer is located on the water-facing slope of the retaining wall. A reinforcement layer is laid on the slope, which is formed by filling solidified silt with gabion mesh. The reinforcement layer is covered with planting soil, which is used to plant native plants. The interception system includes a gabion filter cage installed on the top of the dike. The gabion filter cage is filled with dephosphorization and water purification coupled filter media, which is used to remove phosphorus from non-point source pollution and purify water quality. The water-land alternating ecological zone is a habitat created by preserving the original silt within a predetermined range from the waterline on both banks, planting emergent plants, and providing a habitat for aquatic organisms and birds.

2. The system according to claim 1, characterized in that, The multi-component solid waste-based material comprises the following components by mass fraction: 20%~35% ultrafine steel slag powder, 20%~35% ultrafine modified fly ash, 20%~35% ultrafine slag powder, and 20%~35% autoclaved aerated concrete powder.

3. The system according to claim 1, characterized in that, The dephosphorization and water purification coupling filter media is composed of 45-65 parts by weight of fly ash, 3-10 parts by weight of desulfurization gypsum, 15-25 parts by weight of lime, 0.02-0.08 parts by weight of aluminum powder paste, and 0.03-0.06 parts by weight of polyaluminum chloride. After pre-curing and molding, the media is mechanically crushed into granules after autoclaving in an autoclave.

4. The system according to claim 3, characterized in that, The autoclave has a temperature of 190℃~210℃, a pressure of 1MPa~1.4MPa, and an autoclaving time of 6h~10h.

5. The system according to claim 3, characterized in that, The particle size of the dephosphorization and water purification coupling filter media is 2cm to 8cm.

6. The system according to claim 1, characterized in that, The in-situ solidified silt base layer is a hard shell layer with a thickness of 1m to 1.2m and a width of not less than 1.5m.

7. The system according to claim 1, characterized in that, The sewage interception system also includes an ecological isolation dike and a supporting interception ditch located on the farmland side, constructed from solidified silt.

8. The system according to claim 1, characterized in that, The thickness of the reinforcement layer is 10cm to 50cm, and the thickness of the planting soil is 10cm to 20cm.

9. A comprehensive river and lake management method based on in-situ solidification of silt and solid waste, characterized in that, The method is applied to the system according to any one of claims 1 to 8, and the method comprises: The moisture content, organic matter content, and heavy metal background values ​​of the sludge were determined. Based on the test results, a sludge polymerization stabilizer was prepared. The prepared sludge polymerization stabilizer was delivered to the mixing head through an intelligent operating platform and a mixing device to carry out in-situ mixing and curing of the sludge, forming an in-situ solidified base layer of sludge. Gabion mesh boxes are filled with solidified silt and stacked in layers to form a retaining wall; A gabion mesh filled with solidified silt is laid on the water-facing slope of the retaining wall to form a reinforcement layer, and planting soil is covered on the reinforcement layer to form a slope protection layer. Gabion filter cages filled with dephosphorization and water purification coupling filter media are installed on the top of the dike to form a pollution interception system. Delineate the alternating water and land ecological zone and introduce local emergent plants.

10. The method according to claim 9, characterized in that, The installation of gabion filter cages filled with dephosphorization and water purification coupling filter media on the top of the dike to form a pollution interception system includes: The gabion filter cages filled with the dephosphorization and water purification coupling filter media are installed on the top of the dike, and an ecological isolation dike and a matching interception ditch formed by solidified silt are constructed on the farmland side to form the sewage interception system.

Images