Algae control method for landscape water bodies based on plant-microorganism electrochemical system

Abstract

The present invention relates to the technical field of algae control in landscape lake water bodies, and specifically to a method for controlling algae in landscape water bodies based on a plant-microorganism electrochemical system, which is composed of aquatic plants and a microbial electrochemical system. The aquatic plants include submerged plants (potaeros, foxtail algae, vallisneria, and hornwort) and floating plants (water lilies, water spinach, and water hyacinth). The main body of the microbial electrochemical system is composed of an anode electrode and a cathode electrode. The anode electrode is made of nickel-plated carbon felt, and the cathode electrode is made of a vanadium-based hybrid material. The anode electrode and the cathode electrode are connected by a stainless steel rod, and an anaerobic biofilm is attached to the surface of the anode. The present invention achieves the purpose of controlling algae in urban landscape water bodies by coupling plants and microbial electrochemical systems. At the same time, it can also simultaneously remove pollutants such as nitrogen, phosphorus, and organic matter in water bodies and sediments. It has the characteristics of simple operation, low cost, and excellent treatment effect.

Description

Technical Field

[0001] The present invention relates to the technical field of landscape lake water body algae control, and in particular to a landscape water body algae control method based on a plant-microorganism electrochemical system. Background Art

[0002] The discharge of large amounts of nitrogen and phosphorus-rich wastewater into lakes can lead to eutrophication and, consequently, algal blooms. The dominant toxic algae is Microcystis, which produces microcystin. Therefore, managing algal blooms caused by eutrophication is a critical issue in lake ecological management worldwide.

[0003] In order to solve the problems existing in algae removal technology, such as low removal efficiency, secondary pollution, long reaction time, low water conductivity leading to low algae removal efficiency, and the inability to completely remove nutrients in the water, resulting in a vicious cycle, and to make up for the shortcomings of algae removal technology, it is particularly necessary to design a new system and method that can simultaneously remove algae and nitrogen and phosphorus.

[0004] In view of the above-mentioned defects, the inventors of the present invention finally obtained the present invention after a long period of research and practice. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems existing in algae removal technology, such as low removal efficiency, secondary pollution, long reaction time, low water conductivity leading to low algae removal efficiency, and the inability to completely remove nutrients in the water, resulting in a vicious cycle, to make up for the shortcomings of algae removal technology, and to provide a method for controlling algae in landscape water bodies based on a plant-microorganism electrochemical system.

[0006] To achieve the above objectives, the present invention discloses a method for controlling algae in landscape water bodies based on a plant-microorganism electrochemical system, comprising the following steps:

[0007] S1, arrange anode electrodes in the bottom mud at a depth of 10-15 cm;

[0008] S2, planting submerged plants at the location where the anode electrode is arranged;

[0009] S3, cathode electrodes are arranged on the water surface, and the anode and cathode are connected with stainless steel rods;

[0010] S4, planting floating plants at the location where the cathode electrode is arranged.

[0011] In step S1, the anode electrode is made of nickel-plated carbon felt, which is treated before use so that pores are evenly distributed on its surface to facilitate the passage of plant roots, with a pore diameter of 2-4 mm.

[0012] In step S1, an anaerobic biofilm is attached to the surface of the anode. The preparation method of the anaerobic biofilm is as follows: the anaerobic sludge obtained by inoculating the anode electrode with the anaerobic reactor of the landscape water body sediment suspension is the anaerobic biofilm.

[0013] The landscape water body sediment suspension is prepared by mixing sediment and deionized water in a mass ratio of 1:1 to 1:5.

[0014] In step S2, the submerged plants include Potamogeton, Myriophyllum, Vallisneria and Ceratophyllum, and the planting ratio of Potamogeton, Myriophyllum, Vallisneria and Ceratophyllum is 1:1-3:1-2:2-3.

[0015] In step S3, the cathode electrode is a vanadium-based hybrid cathode material. The cathode electrode is subjected to a multi-layer grid treatment before use so that pores (pore diameter is 2-4 mm) are evenly distributed on its surface to facilitate the roots of floating plants to pass through and entangle. The multi-layer treatment makes the cathode and the roots of floating plants more tightly combined.

[0016] The preparation method of the vanadium-based hybrid cathode material comprises the following steps:

[0017] S31, stirring and mixing Ti3AlC2 and hydrofluoric acid, reacting at 40-60°C for 6-10 hours, and repeatedly rinsing with deionized water after the reaction to remove residual hydrofluoric acid;

[0018] S32, adding the material obtained in step S31 and 1-propyl-3-methylimidazolium brominating agent to deionized water, treating with ultrasound and stirring uniformly;

[0019] S33, adding NH4VO3 to the mixture obtained in step S32, and stirring for 6-8 hours to obtain a composite material;

[0020] S34, immersing the three-dimensional porous carbon nanoplate into the composite material obtained in step S33, the treatment time is 30-60s, after drying and washing, thermally reducing it at 200-300°C for 2-3 hours to obtain a vanadium-based hybrid cathode electrode.

[0021] In step S31, the mass ratio of Ti3AlC2 to hydrofluoric acid is 1:2-1:5.

[0022] In step S32, the amount of the material obtained in step S31 is 3 mg, the amount of 1-propyl-3-methylimidazole brominating agent is 150 mg, and the amount of deionized water is 100 mL.

[0023] In the step S33, the amount of NH4VO3 used is 2-3 g.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. The present invention plants submerged plants at the anode. The roots of submerged plants can secrete a variety of organic substances, which not only provide a readily available carbon source for microorganisms but also enhance the reactivity of the anode electrode. The organic acids and other metabolites in the root secretions can promote electrochemical reactions, improve electron transfer efficiency, and thus increase the current output of the anode. In addition, submerged plants can absorb and utilize nitrogen, phosphorus, and organic pollutants in the sediment, thereby reducing pollutant emissions from the sediment.

[0026] 2. The present invention plants floating plants at the cathode. Floating plants also have important ecological functions. Their root secretions can improve the electrochemical reaction of the cathode electrode. The microenvironment formed by the roots of floating plants in the water can promote the growth and reproduction of microorganisms, increase the thickness of the biofilm on the cathode surface, and thus improve the conductivity and reaction rate of the cathode, thereby better removing algae from the water and reducing organic pollutants in the upper water. In addition, the floating plants themselves can also absorb and utilize nitrogen, phosphorus, and organic pollutants in the water.

[0027] 3. The vanadium-based hybrid cathode material of the present invention has excellent electrochemical performance and stability. Its high conductivity and good electrochemical activity enable it to perform well in the cathode reaction and effectively promote electron transfer. In addition, the corrosion resistance and thermal stability of the vanadium-based material give it a longer service life in complex water environments, reducing maintenance costs.

[0028] 4. This method utilizes sediment from urban landscape water bodies to acclimate anaerobic sludge, enabling the system to quickly adapt to the actual environment. The rich microbial communities and organic matter in the sediment can accelerate the formation of anaerobic biofilms, improving the system's startup speed and stability. This method not only improves the system's adaptability, but also effectively utilizes local resources, reduces external investment, and enhances the system's eco-friendliness.

[0029] 5. The plant-microorganism electrochemical system of the present invention combines the advantages of plants and microorganisms, and can effectively remove algae from water bodies while controlling the concentration of pollutants such as nitrogen and phosphorus. The growth of plants can absorb nutrients in the water body and enhance the functions of the anode and cathode of the microbial electrochemical system through root secretions. The microbial electrochemical reaction can produce oxidizing substances such as chlorine, hydrogen peroxide and free radicals. These substances can directly oxidize and destroy the structure and function of algae cells, leading to their death. In addition, the microbial electrochemical reaction can also reduce organic matter in the water body. Through the synergistic effect of these two mechanisms, the system can not only remove algae from the water body, but also improve the water quality as a whole, and enhance the stability and sustainability of the water ecological environment. DETAILED DESCRIPTION

[0030] The above and other technical features and advantages of the present invention are described in more detail below in conjunction with embodiments.

[0031] Example 1

[0032] (1) A method for preparing a cathode electrode, comprising the following steps:

[0033] (a) Ti3AlC2 and hydrofluoric acid were stirred and mixed in a mass ratio of 1:2, and reacted at 40°C for 8 hours. After the reaction, the mixture was repeatedly rinsed with deionized water to remove residual hydrofluoric acid.

[0034] (b) 3 mg of the material obtained in step (a) and 150 mg of 1-propyl-3-methylimidazolium brominating agent were added to 100 mL of deionized water, treated with ultrasound, and stirred until uniform;

[0035] (c) adding 2 g of NH4VO3 to the mixture of step (b) and stirring at high speed for 6 hours to obtain a composite material;

[0036] (d) The three-dimensional porous carbon nanosheet was immersed in the mixed solution from step (c) for 30 seconds. During this process, the vanadium-based hybrid material self-assembled on the carbon nanosheet to form an interlaced network. After drying and washing, the material was thermally reduced at 200°C for 2 hours to obtain a vanadium-based hybrid cathode electrode.

[0037] (2) Anaerobic biofilm attached to the anode surface: Take the bottom mud (0-20 cm) of the urban landscape water body, mix the bottom mud with deionized water at a mass ratio of 1:2, and use the anaerobic sludge after acclimation in the anaerobic reactor for anode electrode inoculation.

[0038] (3) Arrange anode electrodes in the bottom mud at a depth of 10 cm.

[0039] (4) Submerged plants are planted at the location where the anode electrode is arranged. The planting ratio of duckweed, foxtail algae, Vallisneria, and hornwort is 1:2:1:3.

[0040] (5) A cathode electrode is placed on the water surface, and the anode and cathode are connected with a stainless steel rod.

[0041] (6) Floating plants are planted at the location where the cathode electrode is arranged. The planting ratio of water lilies, water lilies, and water hyacinths is 1:3:2. The cathode electrode is subjected to multi-layer grid treatment before use so that pores are evenly distributed on its surface (pore size is 2-4mm) to facilitate the roots of floating plants to pass through and entangle. The multi-layer treatment makes the cathode and the roots of floating plants more closely integrated.

[0042] Example 2

[0043] (1) A method for preparing a cathode electrode, comprising the following steps:

[0044] (a) Ti3AlC2 and hydrofluoric acid were stirred and mixed in a mass ratio of 1:3, and reacted at 50°C for 8 hours. After the reaction, the mixture was repeatedly rinsed with deionized water to remove residual hydrofluoric acid.

[0045] (b) 3 mg of the material obtained in step (a) and 150 mg of 1-propyl-3-methylimidazolium brominating agent were added to 100 mL of deionized water, treated with ultrasound, and stirred until uniform;

[0046] (c) adding 2 g of NH4VO3 to the mixture of step (b) and stirring at high speed for 8 hours to obtain a composite material;

[0047] (d) The three-dimensional porous carbon nanosheet was immersed in the mixed solution from step (c) for 50 seconds. During this process, the vanadium-based hybrid material self-assembled on the carbon nanosheet to form an interlaced network. After drying and washing, the material was thermally reduced at 200°C for 3 hours to obtain a vanadium-based hybrid cathode electrode.

[0048] (2) Anaerobic biofilm attached to the anode surface: Take the bottom mud (0-20 cm) of the urban landscape water body, mix the bottom mud with deionized water at a mass ratio of 1:2, and use the anaerobic sludge after acclimation in the anaerobic reactor for anode electrode inoculation.

[0049] (3) Arrange anode electrodes in the bottom mud at a depth of 15 cm;

[0050] (4) Plant submerged plants at the location where the anode electrode is arranged, with the planting ratio of Potamogeton chinensis, Foxtail algae, Vallisneria truncatula, and Ceratophyllum truncatum being 1:1:2:2;

[0051] (5) Arrange cathode electrodes on the water surface, and connect the anode and cathode with stainless steel rods;

[0052] (6) Floating plants are planted at the location where the cathode electrode is arranged. The planting ratio of water lilies, water chestnuts, and water hyacinths is 1:2:3. The cathode electrode is subjected to multi-layer grid treatment before use so that pores are evenly distributed on its surface (pore size is 2-4mm) to facilitate the roots of floating plants to pass through and entangle. The multi-layer treatment makes the cathode and the roots of floating plants more closely integrated.

[0053] Example 3

[0054] (1) A method for preparing a cathode electrode, comprising the following steps:

[0055] (a) Ti3AlC2 and hydrofluoric acid were stirred and mixed in a mass ratio of 1:5, and reacted at 60°C for 10 hours. After the reaction, the mixture was repeatedly rinsed with deionized water to remove residual hydrofluoric acid.

[0056] (b) 3 mg of the material obtained in step (a) and 150 mg of 1-propyl-3-methylimidazolium brominating agent were added to 100 mL of deionized water, treated with ultrasound, and stirred until uniform;

[0057] (c) adding 3 g of NH4VO3 to the mixture of step (b) and stirring at high speed for 8 hours to obtain a composite material;

[0058] (d) The three-dimensional porous carbon nanosheet was immersed in the mixed solution from step (c) for 50 seconds. During this process, the vanadium-based hybrid material self-assembled on the carbon nanosheet to form an interlaced network. After drying and washing, the material was thermally reduced at 300°C for 2 hours to obtain a vanadium-based hybrid cathode electrode.

[0059] (2) Anaerobic biofilm attached to the anode surface: Take the bottom mud (0-20 cm) of urban landscape water bodies, mix the bottom mud with deionized water at a mass ratio of 1:2, and use the anaerobic sludge after acclimation in the anaerobic reactor to inoculate the anode electrode;

[0060] (3) Arrange anode electrodes in the bottom mud at a depth of 15 cm;

[0061] (4) Plant submerged plants at the location where the anode electrode is arranged, with the planting ratio of Potamogeton chinensis, Foxtail algae, Vallisneria truncatula, and Ceratophyllum truncatum being 1:3:1:2;

[0062] (5) Arrange cathode electrodes on the water surface, and connect the anode and cathode with stainless steel rods;

[0063] (6) Floating plants are planted at the location where the cathode electrode is arranged. The planting ratio of water lilies, water lilies, and water hyacinths is 1:3:1. The cathode electrode is subjected to multi-layer grid treatment before use so that pores are evenly distributed on its surface (pore size is 2-4mm) to facilitate the roots of floating plants to pass through and entangle. The multi-layer treatment makes the cathode and the roots of floating plants more closely integrated.

[0064] After 60 days of operation, the water bodies of Examples 1-3 were tested. The indicators of the river water samples before treatment were: chlorophyll content was 40.3 mg / m 3 ; Algae density is 3025×10 4 The test results are shown in Table 1.

[0065] Table 1 Water body detection results of Examples 1-3

[0066]

[0067] As shown in Table 1, the plant-microorganism electrochemical system developed by the present invention can effectively remove algae from water bodies and significantly improve water quality. This plant-microorganism electrochemical system is easy to construct and apply. While controlling algae in urban landscape waters, it can also simultaneously remove pollutants such as nitrogen, phosphorus, and organic matter from the water and sediment. It features simple operation, low cost, and excellent treatment results. Example 2 demonstrates significantly superior algae removal performance compared to other examples. Its core advantage stems from the precise synergistic optimization of electrode materials, plant functions, and system architecture. In cathode preparation, a 1:3 HF etching ratio and a 50°C reaction temperature were employed, potentially enhancing the material's electron mobility. In terms of plant configuration, the increased proportion of Vallisneria species, whose secreted citric acid acts as a highly efficient electron shuttle, increases the expression of extracellular electron transfer genes in the anode microorganisms. In terms of system architecture, a 15 cm anode burial depth creates a microaerobic-anaerobic transition zone, while rigid stainless steel connectors ensure a stable root-electrode interface. This multi-parameter synergy significantly improves algae density removal, demonstrating the irreplaceable nature of this process combination.

[0068] The above description is merely a preferred embodiment of the present invention and is intended to be illustrative rather than restrictive of the present invention. Those skilled in the art will appreciate that many changes, modifications, and even equivalents may be made to the present invention within the spirit and scope of the claims, all of which fall within the scope of protection of the present invention.

Claims

1. A method for controlling algae in landscape water bodies based on a plant-microorganism electrochemical system, characterized in that: The following steps are involved: S1, arrange anode electrodes in the bottom mud at a depth of 10-15 cm; S2, planting submerged plants at the location where the anode electrode is arranged; S3, cathode electrodes are arranged on the water surface, and the anode and cathode are connected with stainless steel rods; S4, planting floating plants at the location where the cathode electrode is arranged; In step S3, the cathode electrode is a vanadium-based hybrid cathode material; The preparation method of the vanadium-based hybrid cathode material comprises the following steps: S31, stirring and mixing Ti3AlC2 and hydrofluoric acid, reacting at 40-60°C for 6-10 hours, and repeatedly rinsing with deionized water after the reaction to remove residual hydrofluoric acid; S32, adding the material obtained in step S31 and 1-propyl-3-methylimidazolium brominating agent to deionized water, treating with ultrasound and stirring uniformly; S33, adding NH4VO3 to the mixture obtained in step S32, and stirring for 6-8 hours to obtain a composite material; S34, immersing the three-dimensional porous carbon nanoplate into the composite material obtained in step S33, the treatment time is 30-60s, after drying and washing, thermally reducing it at 200-300°C for 2-3 hours to obtain a vanadium-based hybrid cathode electrode.

2. The method for controlling algae in landscape water bodies based on a plant-microorganism electrochemical system according to claim 1, characterized in that: In step S1, the anode electrode is made of nickel-plated carbon felt, which is treated before use so that pores are evenly distributed on its surface to facilitate the passage of plant roots, with a pore diameter of 2-4 mm.

3. The method for controlling algae in landscape water bodies based on a plant-microorganism electrochemical system according to claim 1, wherein: In step S1, an anaerobic biofilm is attached to the surface of the anode. The preparation method of the anaerobic biofilm is as follows: the anaerobic sludge obtained by inoculating the anode electrode with the anaerobic reactor of the landscape water body sediment suspension is the anaerobic biofilm.

4. The method for controlling algae in landscape water bodies based on a plant-microorganism electrochemical system according to claim 3, characterized in that: The landscape water body sediment suspension is prepared by mixing sediment and deionized water in a mass ratio of 1:1 to 1:

5.

5. The method for controlling algae in landscape water bodies based on a plant-microorganism electrochemical system according to claim 1, wherein: In step S2, the submerged plants include Potamogeton, Myriophyllum, Vallisneria and Ceratophyllum, and the planting ratio of Potamogeton, Myriophyllum, Vallisneria and Ceratophyllum is 1:1-3:1-2:2-3.

6. The method for controlling algae in landscape water bodies based on a plant-microorganism electrochemical system according to claim 1, characterized in that: In step S31, the mass ratio of Ti3AlC2 to hydrofluoric acid is 1:2-1:

5.

7. The method for controlling algae in landscape water bodies based on a plant-microorganism electrochemical system according to claim 1, characterized in that: In step S32, the amount of the material obtained in step S31 is 3 mg, the amount of 1-propyl-3-methylimidazole brominating agent is 150 mg, and the amount of deionized water is 100 mL.

8. The method for controlling algae in landscape water bodies based on a plant-microorganism electrochemical system according to claim 1, wherein: In the step S33, the amount of NH4VO3 used is 2-3 g.

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