Water body ecological restoration system and method based on three-dimensional planting of submerged plants

Abstract

The present invention relates to a water ecological restoration system and method based on three-dimensional planting of submerged plants. The system comprises a modular support structure that can be assembled and spliced. The modular support structure is vertically layered with multiple layers of planting units, which serve as planting areas for submerged plants. These plants are layered within each layer of the planting units. Compared to existing technologies, this invention overcomes the limitations of traditional planar planting, improving the purification efficiency per unit area of ​​water. It is suitable for ecological restoration of urban rivers, landscape water bodies, and hardened substrates.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental protection water ecological restoration (C02F), and in particular to a water ecological restoration system and method based on three-dimensional planting of submerged plants. Background Art

[0002] In recent years, with the rapid development and expansion of cities, urban environmental infrastructure has become increasingly inadequate, leading to increasing urban sewage discharge. This has resulted in a large amount of pollutants entering water bodies through sewage, garbage, precipitation, and runoff, leading to a deterioration in environmental quality. Chemical oxygen demand (COD), nitrogen (N), and phosphorus (P) in urban water bodies have exceeded standards, and rivers are severely polluted, with water bodies showing seasonal or year-round black and smelly water. The treatment of polluted urban water bodies is urgent.

[0003] Submerged plants play a crucial role in maintaining the balance of aquatic ecosystems. They are not only the most important primary producers in water bodies but also experts in water purification. Their roots, stems, and leaves purify water by absorbing nutrients, immobilizing sediments, and releasing allelopathic substances. Currently, traditional submerged plant plantings mostly employ flat layouts, which present problems such as low space utilization, a single landscape layer, and limited ecological effectiveness. With the acceleration of urbanization and the increasing demand for water environment management, traditional flat-planar water ecological restoration technologies are no longer able to meet the dual requirements of intensive water space utilization and landscape creation in modern cities. How to construct a stable and efficient ecosystem within limited space while simultaneously enhancing both landscape aesthetics and ecological service functions has become a key issue in the field of water environment management.

[0004] Patent CN111320284A discloses a system and method for ecological restoration of river / lake / reservoir water bodies. By combining micro-nano aeration contact oxidation equipment with composite ecological floating islands, it addresses the pollution and ecological degradation issues of urban river and lake water bodies. Patent CN115504580A discloses an ecological restoration system for closed landscape water bodies. By installing a rainwater and sewage pipe network, a bottom solidification layer, and a live water circulation system in closed urban landscape water bodies, combined with aquatic plants and floating wetlands, it addresses the fragile water ecology caused by pollution, achieves water purification and increases oxygen content, and restores the water's self-purification capacity and ecological service functions. However, further research is needed to further improve the ecological restoration of polluted urban water bodies. Summary of the Invention

[0005] The purpose of the present invention is to solve the above problems and provide a water ecological restoration system and method based on the three-dimensional planting of submerged plants. The present invention reconstructs the ecological layout through spatial dimensions, opening up a new technical path for water ecological restoration.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A water body ecological restoration system based on the three-dimensional planting of submerged plants, the system includes a modular support body that can be spliced ​​and assembled, and the modular support body is layered with multi-layered planting bearing units in the vertical direction as the planting area of ​​the submerged plants. The submerged plants are planted in layers in each layer of the planting bearing units.

[0008] As a preferred technical solution of the present invention, the submerged plants are arranged in at least three layers along the vertical direction of the modular support body, with the bottom layer being planted with weak-light-resistant submerged plants, the middle layer being planted with medium-light-resistant submerged plants, and the upper layer being planted with strong-light-resistant submerged plants.

[0009] As a preferred technical solution of the present invention, the weak-light-tolerant submerged plant includes Vallisneria;

[0010] The medium light tolerant submerged plants include Hydrilla and / or Potamogeton crispus;

[0011] The strong light-resistant submerged plants include hornwort and / or foxtail algae.

[0012] As a preferred technical solution of the present invention, the planting density of the submerged plants is 10-100 plants / m2, preferably 30-50 plants / m2.

[0013] As a preferred technical solution of the present invention, the weak-light-tolerant submerged plants are planted 0-0.5m away from the bottom of the water body by cutting method with a plant spacing of 15-20cm;

[0014] The medium light tolerant submerged plant is 0.5-1.5 m away from the bottom of the water body and is inserted into the pores of the modular support using a root fixing clip;

[0015] The strong light-resistant submerged plants are arranged on the upper layer and are arranged on the modular support body by hanging, with 3-5 plants in each cluster being tied.

[0016] As a preferred technical solution of the present invention, the modular support body is provided with an adjustment device for adjusting the position, and an anchoring system.

[0017] The adjustment device includes a buoyancy balancing device, a water-level linkage lifting mechanism, and a multi-directional connector. The buoyancy balancing device can be configured to integrate three independent air chambers (capacity 0.5-2L) within each modular support, with solenoid valves controlling the inflation and deflation of the air to achieve water level adjustment. The water-level linkage lifting mechanism can be configured as a worm gear transmission system. The multi-directional connector features XYZ three-axis adjustment to accommodate complex terrain. The anchoring system includes clips, bolts, elastic cables, and more.

[0018] Furthermore, the modular support body is provided with a water quality sensor and an underwater fill light unit, and the sensor data is transmitted to the control terminal via the LoRa module.

[0019] The supplementary light unit is set in an area with a water depth greater than 2m, and includes an underwater LED supplementary light (light intensity 2000-3000 lux, wavelength 450-660nm), which provides supplementary light for 4-6 hours per day.

[0020] As a preferred technical solution of the present invention, the modular support body is made of a bio-based modified resin porous material, including the following raw materials in parts by weight: 50-60 parts of bio-based resin, 10-15 parts of polylactic acid, 5-8 parts of carbon fiber chopped strands, 0.1-10 parts of nano-titanium dioxide, 5-10 parts of humic acid / amino acid complex, 5-8 parts of biochar particles, 4-7 parts of epoxy resin, and 1-2 parts of polytetrafluoroethylene powder.

[0021] As a preferred technical solution, the bio-based modified resin porous material includes the following raw materials in parts by weight: 55 parts of bio-based resin, 12 parts of polylactic acid, 6 parts of carbon fiber chopped strands, 5 parts of nano-titanium dioxide, 6 parts of humic acid / amino acid complex, 5 parts of biochar particles, 5 parts of epoxy resin, and 1 part of polytetrafluoroethylene powder.

[0022] Furthermore, the preparation method of the bio-based modified resin porous material comprises the following steps:

[0023] (1) Synthesis of bio-based resin: starch is dispersed in deionized water, an initiator is added, styrene monomer is added under nitrogen protection for graft copolymerization reaction, the reaction temperature is 65-75°C, the reaction time is 3-5 hours, and the graft copolymer is generated. The graft copolymer is immersed in a 1,2-dichloroethane solution containing an external crosslinking agent glutaraldehyde and a catalyst FeCl3, and a Friedel-Crafts alkylation crosslinking reaction is carried out at 75-85°C for 5-10 hours to form a three-dimensional porous network structure. After the reaction is completed, the unreacted reagent is washed to remove the unreacted reagent to obtain a bio-based resin with a porous structure;

[0024] (2) Porous material molding: the bio-based resin obtained in step (1) is mixed with polylactic acid, carbon fiber chopped strands, nano-titanium dioxide, and a pore-forming agent, and melt-blended at 170-190° C. using a twin-screw extruder at a screw speed of 120-180 r / min. The molten mixture is injected into a mold and rapidly cooled to 0-5° C. to form directional pores by solvent volatilization, and then freeze-dried to remove the pore-forming agent to obtain a porous material;

[0025] (3) Slow-release nutrient layer loading: The porous material is immersed in a humic acid / amino acid / biochar particle solution, adsorbed under a vacuum of -0.1 to -0.05 MPa for 1-3 hours, and then UV-cured to form a microcapsule slow-release layer;

[0026] (4) Surface treatment: The material surface is treated with plasma at a power of 80-120 W for 3-8 minutes, followed by spraying of an epoxy resin-polytetrafluoroethylene composite coating with a coating thickness of 30-150 μm. The finished product is obtained after curing at room temperature.

[0027] As a preferred technical solution of the present invention, in step (1), the initiator is potassium persulfate, and the addition amount is 4-6% of the mass of starch; the mass ratio of the styrene monomer to starch is 1:3 to 1:2; the addition amount of glutaraldehyde in the cross-linking reaction is 3-8% of the mass of the graft copolymer;

[0028] In step (2), the length of the carbon fiber chopped strands is 3-6 mm, and the addition amount is 8-12% of the mass of the bio-based resin; the pore-forming agent is ammonium bicarbonate, and the addition amount is 8-12% of the mass of the bio-based resin;

[0029] The freeze-drying conditions in step (2) are: temperature of -50 to -30°C, drying time of 20 to 28 hours, and the porosity of the directional pores is synergistically controlled by the cooling rate and the pore-forming agent content;

[0030] In step (3), the mass fraction of the humic acid / amino acid solution is 15-25%, and the UV curing conditions are a wavelength of 350-380 nm and an irradiation time of 20-40 minutes;

[0031] In step (4), the plasma treatment uses argon or nitrogen with a gas flow rate of 15-25 sccm.

[0032] The present invention uses bio-based modified resin porous materials to prepare modular supports, which has the following technical advantages: (1) Renewable starch and polylactic acid are blended, and the proportion of bio-based raw materials is ≥70%, which is in line with the development trend of green water treatment technology. (2) The porous structure with high porosity provides sufficient attachment space for the roots of submerged plants. Combined with the humic acid / amino acid microcapsule slow-release nutrient layer, the root coverage rate of plants such as Vallisneria and Hydrilla is greatly increased, and the biomass is significantly increased compared with traditional carriers, which significantly enhances the ecological restoration effect of water bodies. (3) The long-term stability and corrosion resistance of carbon fiber chopped strands and epoxy resin-PTFE composite coating work synergistically to improve the compressive strength of the material, overcoming the problem of low mechanical properties caused by the use of too high a bio-based raw material. (4) Nano-TiO2 photocatalytic antibacterial and biochar pollutant adsorption realize the integration of plant fixation and water purification. (5) Through the replacement of bio-based raw materials and process optimization, the material cost is reduced compared with traditional engineering plastics. Under the same mechanical and anti-corrosion properties, the technical economy and market promotion value are significantly improved.

[0033] A water body ecological restoration method based on three-dimensional planting of submerged plants, using the above-mentioned water body ecological restoration system, includes the following steps:

[0034] S1. Conduct on-site survey and match the type of modular support;

[0035] S2. Install the modular support and anchor it;

[0036] S3. Plant submerged plants in layers according to vertical gradients.

[0037] Furthermore, the method further comprises the following steps:

[0038] S4, water quality pretreatment, including sediment improvement and water flocculation;

[0039] S5. Introduce aquatic animals to build a symbiotic system, carrying benthic organisms and fish, to create an underwater micro-landscape with both ecological functions and ornamental value;

[0040] S6. Configure intelligent control parameters and debug to achieve intelligent control.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] This invention introduces a groundbreaking three-dimensional planting concept, achieving a scientific vertical arrangement of submerged plants through a modular support system. This technology not only increases plant coverage per unit of water space by 2-3 times compared to traditional methods, but also creates a gradient underwater forest system through the three-dimensional combination of plants from different ecological niches.

[0043] This invention integrates the multidisciplinary expertise of ecological engineering, materials science, and landscape design. The support system utilizes eco-friendly composite materials, and its porous structure ensures plant root anchorage while allowing water to flow freely. By adapting to varying light intensities and water flow characteristics at varying depths, a combination of submerged plants, such as Vallisneria, Ceratophyllum, and Hydrilla, is strategically placed to form a self-sustaining, three-dimensional ecological community. Furthermore, benthic organisms and fish can be accommodated, creating an underwater micro-landscape with both ecological function and ornamental value.

[0044] This invention can effectively alleviate the plight of insufficient ecological space in urban waters and is particularly suitable for use in landscape water creation and ecological park construction. Its modular design facilitates rapid repair and subsequent maintenance, meeting the needs of large-scale water ecological restoration projects as well as smaller spaces such as courtyard waterscapes. It will provide strong technical support for the high-quality development of urban water spaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Schematic diagram of the vertical wall section of the water ecological restoration system of the present invention;

[0046] Figure 2 This is a schematic plan view of the wall facade of the water ecological restoration system of the present invention. DETAILED DESCRIPTION

[0047] The present invention will be described in detail below with reference to specific embodiments, but this is by no means intended to limit the present invention. Anything not described in detail in the embodiments is a common technical means in the art.

[0048] [Prefabrication of modular support bodies]

[0049] The modular support is made of bio-based modified resin porous material. The main raw materials are shown in Table 1. The specific preparation method is as follows (taking 100 kg as an example):

[0050] (1) Synthesis of bio-based resin: Through graft copolymerization, 55 kg of starch was dispersed in 100 L of deionized water, and 2.75 kg of potassium persulfate initiator was added. The temperature was raised to 70 °C in a reactor equipped with a stirring device. Under nitrogen protection, 16.5 kg of styrene monomer was added dropwise at a rate of 50 mL / min. The reaction was allowed to proceed for 4 hours. During the reaction, the stirring speed was adjusted to 300 r / min to ensure uniform reaction and generate a graft copolymer.

[0051] The resulting graft copolymer was crosslinked via Friedel-Crafts alkylation. The copolymer was immersed in 200 L of 1,2-dichloroethane (CAS No. 107-06-2, purchased from Tianjin Kermiou Chemical Reagent Co., Ltd.). 5 kg of an external crosslinker, glutaraldehyde (CAS No. 111-30-8, 50% by mass, purchased from Shanghai MacLean Biochemical Technology Co., Ltd.) and 3 kg of a catalyst, FeCl3 (CAS No. 7705-08-0, analytical grade, purchased from Sinopharm Chemical Reagent Co., Ltd.), were added. The mixture was stirred at 80°C for 8 hours at a stirring speed of 200 rpm to form a three-dimensional porous network structure. After the reaction, the product was washed several times with ethanol (CAS No. 64-17-5) to remove any unreacted reagents.

[0052] (2) Porous structure molding: 55 kg of bio-based resin, 12 kg of polylactic acid, 6 kg of carbon fiber chopped strands, and 5 kg of nano-titanium dioxide were added to a twin-screw extruder (Model: TE-35, Nanjing Jieente Electromechanical Co., Ltd.) through a phase separation method. The mixture was melt-blended at 180°C with the screw speed set at 150 r / min to completely melt and evenly disperse. The molten mixture was then injected into a custom mold and immediately placed in 0°C cooling water for rapid cooling. Directed pores were formed by solvent evaporation, with a controlled porosity of ≥65% and a pore size of 10-100 μm.

[0053] During the above-mentioned twin-screw extruder blending process, about 6.5 kg of pore-forming agent ammonium bicarbonate (CAS No.: 1066-33-7, purchased from Xilong Science Co., Ltd.) was added. After mixing evenly, the material was taken out and placed in a freeze dryer (model: FD-1A-50, Beijing Boyikang Laboratory Instrument Co., Ltd.) and freeze-dried at -40°C for 24 hours. After removing the pore-forming agent, the pore distribution was further controlled.

[0054] (3) Slow-release nutrient layer loading: 3 kg of humic acid, 3 kg of amino acids, and 5 kg of biochar particles were prepared into a humic acid / amino acid / biochar particle solution with a mass fraction of 20%, and the solution was placed in a vacuum impregnation tank. The formed porous material was placed in the tank and adsorbed for 2 hours under a vacuum degree of -0.08 MPa to allow the solution to fully penetrate the pores of the material. The material was then taken out and placed in a UV curing box (model UV-1000, Shenzhen Instrument Equipment Co., Ltd.), and irradiated with ultraviolet light of a wavelength of 365 nm for 30 minutes to form a microcapsule slow-release layer.

[0055] (4) Surface treatment: The surface of the material was treated using a plasma treatment device (model: PDC-002, Beijing Chuangshi Weina Technology Co., Ltd.) with a treatment power of 100 W and a treatment time of 5 minutes. Argon gas (flow rate 20 sccm) was used to enhance the surface hydrophilicity and promote the attachment of plant roots. 5 kg of epoxy resin E-51 and 1 kg of polytetrafluoroethylene powder were added to a high-speed disperser (model: SDF-400, Shanghai Modern Environmental Engineering Technology Co., Ltd.) and dispersed at a speed of 1500 r / min for 30 minutes to prepare a composite coating material. The composite coating material was evenly sprayed on the surface of the material using an air spray device (model: W-71, Iwata Corporation) with a spray pressure of 0.3 MPa and a coating thickness controlled at 50-100 μm. After spraying, the material was placed in an environment at room temperature (25°C) and a relative humidity of 60% for 24 hours to cure.

[0056] Table 1 Main raw materials of bio-based modified resin porous materials

[0057]

[0058]

[0059]

Material performance test

[0060] Pore ​​structure determination: A mercury intrusion meter (model: AutoPore IV 9500, Micromeritics Instruments, USA) was used to determine the porosity, pore size distribution, and connectivity. The test pressure range was 0.003–60,000 psi, and the porosity was 76% (≥60%), indicating that the material had uniform pore size distribution and good connectivity.

[0061] Mechanical properties test: A compressive strength test was conducted to simulate water flow impact conditions. A universal material testing machine (Model: Instron 5982, Instron Corporation, USA) was used to cut the prepared specimens into 50 mm × 50 mm × 50 mm cubes. The loading rate was set to 10 mm / min. The test results showed that the compressive strength was ≥ 2 MPa, which meets the requirements for water flow impact resistance in practical applications.

[0062] Plant colonization experiment: submerged plants Vallisneria and Hydrilla were selected and planted in an indoor recirculating aquaculture system (water tank size: 1m×1m×1m, effective water depth 0.8m). The prepared materials were cut into appropriate sizes and evenly placed on the bottom of the water tank, with 20 material units placed in each water tank. The planting density was 20 plants per square meter. The growth of plant roots was observed regularly, and the root coverage was calculated using ImageJ software. The biomass changes were calculated by weighing the fresh weight of the plants. The experimental period was 60 days. The results showed that the root coverage rate was ≥90% and the biomass increased by 30%, indicating that the material has good ecological compatibility and excellent plant root fixation effect.

[0063] The prepared bio-based modified resin porous material is cut and assembled to form a modular support body. The individual units are spliced ​​together through a snap-fit ​​structure, and the combination and quantity of the modules can be flexibly adjusted according to specific needs.

[0064] The modular support is vertically layered with multiple layers of planting units, serving as planting areas for submerged plants. Submerged plants are layered within each layer of the planting units. Submerged plants are arranged in at least three layers vertically along the modular support, with the bottom layer being planted with submerged plants tolerant to low light, the middle layer being planted with submerged plants tolerant to medium light, and the top layer being planted with submerged plants tolerant to high light. Figure 1 This is a schematic diagram of a vertical wall section of a water ecological restoration system. Figure 2 This is a schematic diagram of the wall facade of a water ecological restoration system.

[0065] Among them, submerged plants that tolerate weak light include Vallisneria; submerged plants that tolerate medium light include Hydrilla and / or Potamogeton crispa; and submerged plants that tolerate strong light include Ceratophyllum and / or Myriophyllum. The planting density of submerged plants is 10-100 plants / ㎡, preferably 30-50 plants / ㎡. Submerged plants that tolerate weak light are planted 0-0.5m from the bottom of the water body using the cutting method with a spacing of 15-20cm. Submerged plants that tolerate medium light are planted 0.5-1.5m from the bottom of the water body using root clips inserted into the pores of the modular support. Submerged plants that tolerate strong light are arranged on the upper layer and are arranged on the modular support by hanging, with 3-5 plants tied in each cluster.

[0066] Furthermore, the modular support bodies are equipped with adjustment devices and anchoring systems for position adjustment. The adjustment devices can be buoyancy balancing devices, water-level linkage lifting mechanisms, or multi-directional connectors. The buoyancy balancing devices can be configured to integrate three independent air chambers (volume 0.5-2L) within each modular support body, with inflation and degassing controlled by solenoid valves to adjust the water level of the support body. The water-level linkage lifting mechanism can be configured as a worm gear transmission system. The multi-directional connector features X, Y, and Z axis adjustment to adapt to complex terrain. The support bodies are dynamically adjusted to ensure that the lifting and lowering amplitudes adapt to water level fluctuations. The anchoring system includes clips, bolts, and elastic cables for mounting and securing the support bodies. The modular support bodies are equipped with water quality sensors and underwater lighting units. Sensor data is transmitted to a control terminal via a LoRa module. The lighting unit is installed in areas with water depths greater than 2m and includes an underwater LED light (light intensity 2000-3000 lux, wavelength 450-660nm) that provides 4-6 hours of light daily to enhance plant growth.

[0067] The overall implementation process is: on-site investigation → scheme design → support body installation → water quality pretreatment → submerged plant planting → introduction of aquatic animals → intelligent system integration → commissioning and maintenance.

[0068] (1) Site investigation and scheme design

[0069] Water parameter determination: measuring water depth, flow rate, transparency, bottom sediment thickness (the base material needs to be recorded for hardened water bodies); testing water quality indicators (pH, dissolved oxygen, COD, ammonia nitrogen, total phosphorus, etc.).

[0070] Environmental conditions assessment: Analyze light intensity (underwater light compensation depth), seasonal water level fluctuation range, and surrounding pollution source types.

[0071] Customized plan: Based on the data, select the support type (floating island / frame / suspended), design the floor height (usually 0.5-1.2m per floor), determine the plant combination (Vallis ternatea + Black algae + Ceratophyllum), planting density (30-50 plants / ㎡), and animal ratio.

[0072] (2) Support body installation

[0073] Material inspection: Check the support material (tensile strength ≥10MPa, porosity ≥60%) to confirm corrosion resistance and ecological safety.

[0074] Module assembly: The support frame is pre-assembled on land and connected with snaps or bolts to ensure that the error between modules is ≤3mm.

[0075] Underwater positioning and anchoring: Still water area: Use a gravity base (concrete block or steel frame) for fixation. The base weight must be ≥ 1.5 times the buoyancy of the support.

[0076] Water flow area: add elastic cable anchorage (tensile strength ≥ 500kg), and the cable should form an angle of 30°-45° with the direction of water flow.

[0077] Height adjustment test: Dynamically adjust the liftable support to ensure that the lifting range adapts to the water level changes.

[0078] (3) Water quality pretreatment

[0079] Bottom mud treatment: After natural bottom mud is turned over and aerated, add microbial agents (such as Bacillus subtilis, dosage 2-5g / ㎡). Hard substrate: Lay a 3-5cm thick layer of ceramsite (particle size 10-20mm) as a transitional substrate.

[0080] Water Improvement: For highly turbid water, add a flocculant (e.g., PAC, 5-10 mg / L) to settle suspended solids. pH Adjustment: For acidic water, sprinkle quicklime (50-100 g / m2). For alkaline water, introduce CO2 to adjust the pH to 7-8.

[0081] (4) Submerged plant cultivation

[0082] Plant pretreatment: Remove rotten roots and soak in 0.1% potassium permanganate solution for 10 minutes for disinfection.

[0083] Three-dimensional planting: Bottom layer (0-0.5m from the bottom): Plant weak-light-tolerant plants (such as Vallisneria) and adopt the cutting method (plant spacing 15-20cm).

[0084] Middle layer (0.5-1.5m): Plant Hydrilla and Potamogeton crispus, and use root fixing clips to insert them into the pores of the support.

[0085] Upper layer (above 1.5m): hang foxtail algae and duckweed, with 3-5 plants in each cluster tied to the horizontal bar of the support.

[0086] Installation of supplementary lighting system: In areas with water depth greater than 2m, underwater LED supplementary lights (light intensity 2000-3000 lux, wavelength 450-660nm) are added, and supplementary lighting is provided for 4-6 hours per day.

[0087] (5) Introduction of aquatic animals

[0088] Species selection: Fish: Crucian carp (5-10 fish / ㎡), minnow (control algae); benthic species: Ring-edged snail (20-30 pieces / ㎡), River clams.

[0089] Release time: Release submerged plants in batches one month after planting (after the root system is stable) to prevent animals from eating the seedlings.

[0090] Ecological balance control: monitor fish density and reduce the number of herbivorous fish when transparency is less than 50cm.

[0091] (6) Intelligent system integration

[0092] Sensor layout: Water quality sensors (monitoring pH, dissolved oxygen, and turbidity) are installed in the upper, middle, and lower layers of the water body, with a data sampling interval of ≤1 hour.

[0093] Control system debugging: set the threshold for automatic lifting of the support body (such as triggering lifting when the water level rises by more than 30cm), and link the fill light system with water quality data.

[0094] Remote monitoring configuration: Use LoRa or NB-IoT modules to transmit data to the management platform and set abnormal warnings (such as automatic alarm when dissolved oxygen is less than 3mg / L).

[0095] (7) Debugging and maintenance

[0096] Initial maintenance (1-3 months): Check plant survival rate weekly (target ≥90%), replant rotten plants in time, and clean attached algae (manually scrape or place algae control organisms).

[0097] Long-term maintenance (after 3 months): Trim overcrowded plants quarterly (maintain a coverage rate of 60-70%) and replace damaged support modules (replacement rate <5% / year). In low-temperature areas in winter, cover plants with poor cold tolerance (such as foxtail algae) with insulation film or move them to deeper water areas.

[0098] Application Example 1

[0099] Urban River Ecological Restoration Project. Due to long-term exposure to domestic sewage, the water quality of a city river has deteriorated to Class V (TN = 6.5 mg / L, TP = 0.8 mg / L). The bottom is hardened concrete, the river is 500 meters long, the water depth is 1.2-2.5 meters, and the flow rate is ≤ 0.2 m / s. Traditional flat planting is difficult to improve ecological efficiency within the limited space, so three-dimensional planting technology is needed for restoration. The solution is as follows:

[0100] (1) Site investigation and scheme design

[0101] Parameter determination: measuring the width of the river section, water depth distribution and bottom hardness; testing water quality indicators (pH = 6.8, dissolved oxygen = 2.5 mg / L, turbidity = 50 NTU).

[0102] Environmental assessment: Analyze the light intensity (underwater light compensation depth is 1.5m) to determine whether the support body needs to be equipped with an underwater lighting system; evaluate the water level fluctuation range during the rainy season (±0.5m) and design a liftable suspension support body.

[0103] Customized plan: 120 groups of hanging supports are selected, with a layer height interval of 0.8m (the bottom layer is 0.3m from the bottom, the middle layer is 1.1m, and the upper layer is 1.9m); the plant combination is Vallisneria ovata (resistant to weak light) at the bottom layer, Black algae at the middle layer, and Dermatophaga at the upper layer, with a planting density of 40 plants / ㎡.

[0104] (2) Support body installation

[0105] Material inspection: The support body is made of bio-based modified resin porous material (porosity 70%, pore diameter 10mm), with a tensile strength of 12MPa, and has passed the ecological safety test.

[0106] Module assembly: Pre-assembled three-dimensional frame units on land, each unit is 2m long and 0.8m wide, connected by snap-fits, with an error controlled within 2mm.

[0107] Underwater anchoring: Install gravity bases (concrete blocks, each weighing 300kg) on ​​the hardened riverbed and secure the support with stainless steel chains; arrange a group every 5m along the river channel, at a 40° angle to the direction of water flow, to enhance stability.

[0108] Fill light system integration: Install underwater LED fill lights (wavelength 450-660nm, light intensity 2500lux) in areas with water depth greater than 2m, and provide fill light for 5 hours per day.

[0109] (3) Water quality pretreatment

[0110] Bottom mud improvement: lay a 5 cm thick ceramsite layer (particle size 15 mm) as a transitional matrix, and add Bacillus subtilis (3 g / ㎡) to accelerate the decomposition of organic matter.

[0111] Water flocculation: Add polyaluminium chloride (PAC, concentration 8 mg / L) and remove surface suspended matter after standing for 48 hours.

[0112] (4) Submerged plant cultivation

[0113] Bottom planting: Vallisneria is planted using the cutting method, with a plant spacing of 18 cm, and the roots are inserted into the expanded clay layer for fixation.

[0114] Middle layer planting: Use root fixing clips to insert the black algae seedlings into the pores of the support, and plant 45 plants per square meter.

[0115] Upper layer planting: Tie 4 plants of hornwort to the horizontal bar of the support in each cluster, with a hanging height of 1.9m and a spacing of 20cm.

[0116] (5) Introduction of aquatic animals

[0117] Species release: One month after planting, introduce crucian carp (8 per m2) and ring-edge snails (25 per m2) to control algae growth.

[0118] Ecological balance monitoring: Check transparency weekly and maintain it at ≥50cm. If it is below the threshold, reduce the number of herbivorous fish.

[0119] (6) Intelligent system debugging

[0120] Sensor layout: pH, dissolved oxygen, and turbidity sensors are installed on the upper, middle, and lower layers of the support, and the data is uploaded to the management platform every hour.

[0121] Automatic control: When the water level rises by 30cm, the support body is triggered to rise by 0.3m to prevent plants from being submerged; the aerator is started when the dissolved oxygen is less than 3mg / L.

[0122] (7) Maintenance and management

[0123] Initial maintenance: Clean attached algae weekly and replant areas with survival rates less than 90%; monitor water quality changes and adjust the dosage of microbial agents.

[0124] Long-term maintenance: trim overcrowded plants every quarter to maintain a coverage rate of 65%; replace damaged support modules (<3%) every year.

[0125] After 180 days of operation, TN dropped to 2.1mg / L, TP to 0.2mg / L, and transparency increased to 1.2m, forming a stable "underwater forest." The richness of fish and benthic communities increased by 25%, significantly restoring the river's ecological functions.

[0126] Application Example 2

[0127] A three-dimensional water ecological landscape renovation project for an urban exterior wall. A city core area exterior wall (total area 2,000 m2, length 100 m, height 2 m) requires ecological renovation, with the goal of both purifying water quality and enhancing the landscape. The wall is adjacent to a pedestrian path, allowing visitors to view it up close. The proposed plan is as follows:

[0128] (1) Scheme design

[0129] Structural adaptation: 300 groups of suspended supports are used, each group is 1m long and 0.5m wide, designed in a wavy artistic shape, which is coordinated with the style of the building facade.

[0130] Plant configuration: Vallisneria (weak light resistant) is planted on the bottom layer, black algae in the middle layer, and duckweed on the upper layer, with a density of 40 plants / ㎡; transparent acrylic viewing windows are added (one group every 5 meters) to display the underwater ecological process.

[0131] (2) Support body installation

[0132] Wall fixing: Stainless steel brackets are embedded in the wall, and the supports are connected by bolts to ensure the load-bearing capacity is ≥50kg / ㎡.

[0133] Water flow simulation: Install a micro circulation pump (flow rate 0.1m / s) to simulate natural water flow and avoid algae accumulation in still water areas.

[0134] (3) Plant planting and maintenance

[0135] Three-dimensional planting: The roots of Vallisneria are embedded in the pores of the bottom layer of the support, the black algae are implanted in layers through fixing clips, and the hornwort is hung on the top horizontal bar.

[0136] Lighting optimization: Install side-emitting LED lights (light intensity 3000 lux) in the backlight area of ​​the wall, and provide supplementary lighting for 6 hours a day to ensure photosynthesis of upper-layer plants.

[0137] (4) Intelligent interaction design

[0138] Visualization system: An electronic screen is set up next to the viewing window to display water quality data (pH, dissolved oxygen) and ecological succession animation in real time.

[0139] Visitor interaction: Touch sensors are designed so that visitors can trigger the feeding device by touching the screen, attracting fish to gather and enhancing the experience.

[0140] (5) Ecological synergy

[0141] Biological introduction: Ornamental minnows (10 per m2) and colorful snails are released to form a dynamic landscape with the plants.

[0142] Water quality maintenance: integrated UV sterilization module to control pathogenic microorganisms and avoid ornamental fish diseases.

[0143] Upon completion, the project achieved a water transparency of 1.5 meters, creating a "three-dimensional underwater garden" landscape on the walls, attracting over 500 visitors daily. Water quality remained stable at Class III (TN = 1.2 mg / L, TP = 0.15 mg / L), making it a landmark ecological landmark in the city.

[0144] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A water ecological restoration system based on three-dimensional planting of submerged plants, characterized in that: The system includes a modular support body that can be assembled and spliced. The modular support body is layered with multi-layered planting bearing units in the vertical direction, which serve as the planting area for submerged plants. The submerged plants are layered and planted in each layer of the planting bearing units. The modular support is made of a bio-based modified resin porous material, including the following raw materials in parts by weight: 50-60 parts of bio-based resin, 10-15 parts of polylactic acid, 5-8 parts of carbon fiber chopped strands, 0.1-10 parts of nano-titanium dioxide, 5-10 parts of humic acid and amino acid complex, 5-8 parts of biochar particles, 4-7 parts of epoxy resin, and 1-2 parts of polytetrafluoroethylene powder; The preparation method of the bio-based modified resin porous material comprises the following steps: (1) Synthesis of bio-based resin: starch is dispersed in deionized water, an initiator is added, styrene monomer is added under nitrogen protection for graft copolymerization reaction, the reaction temperature is 65-75 ° C, the reaction time is 3-5 hours, the graft copolymer is generated, and the graft copolymer is immersed in a mixture containing an external crosslinking agent glutaraldehyde and a catalyst. A Friedel-Crafts alkylation cross-linking reaction is carried out in a 1,2-dichloroethane solution at 75-85° C. for 5-10 hours to form a three-dimensional porous network structure. After the reaction is completed, unreacted reagents are removed by washing to obtain a bio-based resin with a porous structure. (2) Porous material molding: The bio-based resin obtained in step (1) is mixed with polylactic acid, carbon fiber chopped strands, nano-titanium dioxide and a pore-forming agent, and melt-blended at 170-190°C through a twin-screw extruder with a screw speed of 120-180 r / min. The molten mixture is injected into a mold and rapidly cooled to 0-5°C. Directed pores are formed by solvent evaporation, and the pore-forming agent is subsequently removed by freeze drying to obtain a porous material; (3) Slow-release nutrient layer loading: The porous material is immersed in a solution of humic acid, amino acids and biochar particles, adsorbed for 1-3 hours under a vacuum degree of -0.1~-0.05MPa, and then UV-cured to form a microcapsule slow-release layer; (4) Surface treatment: The material surface is treated with plasma at a power of 80-120W for 3-8 minutes, followed by spraying of an epoxy resin-polytetrafluoroethylene composite coating with a coating thickness of 30-150 μm. The finished product is obtained after curing at room temperature.

2. The water ecological restoration system based on three-dimensional planting of submerged plants according to claim 1 is characterized in that: The submerged plants are arranged in at least three layers along the vertical direction of the modular support body, with the bottom layer being planted with weak-light-resistant submerged plants, the middle layer being planted with medium-light-resistant submerged plants, and the upper layer being planted with strong-light-resistant submerged plants.

3. The water ecological restoration system based on three-dimensional planting of submerged plants according to claim 2 is characterized in that: The low-light-tolerant submerged plants include Vallisneria; The medium light tolerant submerged plants include Hydrilla and / or Potamogeton crispus; The strong light-resistant submerged plants include hornwort and / or foxtail algae.

4. The water ecological restoration system based on three-dimensional planting of submerged plants according to claim 3 is characterized in that: The planting density of the submerged plants is 10-100 plants / ㎡.

5. The water ecological restoration system based on three-dimensional planting of submerged plants according to claim 4 is characterized in that: The planting density of the submerged plants is 30-50 plants / ㎡.

6. The water ecological restoration system based on three-dimensional planting of submerged plants according to claim 3 is characterized in that: The weak light tolerant submerged plants are planted 0-0.5m away from the bottom of the water body by cutting method with a plant spacing of 15-20cm; The medium light tolerant submerged plant is 0.5-1.5 m away from the bottom of the water body and is inserted into the pores of the modular support using a root fixing clip; The strong light-resistant submerged plants are arranged on the upper layer and are arranged on the modular support body by hanging, with 3-5 plants in each cluster being tied.

7. The water ecological restoration system based on three-dimensional planting of submerged plants according to claim 1 is characterized in that: The modular support body is provided with an adjustment device for adjusting the position, and an anchoring system.

8. The water ecological restoration system based on three-dimensional planting of submerged plants according to claim 1 is characterized in that: In step (1), the initiator is potassium persulfate, and the addition amount is 4-6% of the mass of starch; the mass ratio of the styrene monomer to starch is 1:3-1:2; the addition amount of glutaraldehyde in the cross-linking reaction is 3-8% of the mass of the graft copolymer; In step (2), the length of the carbon fiber chopped strands is 3-6 mm, and the addition amount is 8-12% of the mass of the bio-based resin; the pore-forming agent is ammonium bicarbonate, and the addition amount is 8-12% of the mass of the bio-based resin; The freeze-drying conditions in step (2) are: temperature -50 to -30°C, drying time 20 to 28 hours; In step (3), the mass fraction of the humic acid and amino acid solution is 15-25%, and the UV curing conditions are a wavelength of 350-380 nm and an irradiation time of 20-40 minutes; In step (4), the plasma treatment uses argon or nitrogen with a gas flow rate of 15-25 sccm.

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