Electro-active ecological floating bed, restoration breeding system and application and method of restoration breeding system

Abstract

The invention provides an electroactive ecological floating bed, a restoration breeding system and application and a method thereof. In the system, a conductive material is loaded on part of a floating bed material to form an electroactive ecological floating bed, emergent aquatic plants are planted on the electroactive ecological floating bed, and the nitrogen and phosphorus removal effect of the electroactive floating bed is remarkably improved through root system oxygen secretion and root system exudates of the plants. The anode material is buried in the bottom mud, so that the organic matters in the bottom mud can be removed. A weak electric field formed between the cathode and the anode has a sedimentation effect on suspended particles, and the turbidity of a culture system can be reduced. Submerged plants are planted in the bottom mud, oxygen is provided for repairing of the aquaculture system, and the submerged plants can also strengthen absorption of pollutants nitrogen and phosphorus. The electroactive floating bed can maintain long-term stability of water quality, and the early-stage investment and the later-stage operation and maintenance cost are low.

Description

Technical Field

[0001] The present invention relates to the technical field of aquaculture, and in particular to an electroactive ecological floating bed, a repair aquaculture system and an application and method thereof. Background Art

[0002] Since 2006, my country’s aquaculture production has increased by 50%, making it the country with the largest aquaculture production in the world. In 2018, the pollution area of ​​my country’s aquaculture areas reached 218km 2 , the loss of aquatic products caused by pollution is 4.6×10 7 kg, causing direct economic losses of 820 million yuan. In 2020, the chemical oxygen demand, total nitrogen and total phosphorus emissions of China's aquaculture were 6.7 million tons, 9.9 million tons and 1.6 million tons per year, respectively. The problem of nitrogen and phosphorus pollution released from aquaculture tailwater into aquatic ecosystems has increasingly attracted people's attention. The main input nutrients into aquaculture water bodies are fish feed. According to research, less than 30% of the fish feed added to the breeding system is assimilated by fish predation, and the remaining 70% is released into the water body as dissolved nitrogen, phosphorus and other nutrients or deposited in the bottom mud in the form of organic solids, causing double pollution of water bodies and bottom muds. Green remediation of aquaculture pollution is imminent.

[0003] At present, a large number of technologies have been applied to the restoration of aquaculture systems. The existing aquaculture system restoration technologies mainly include the addition of microbial agents, planting of aquatic plants, facility treatment, artificial wetlands, three pools and two dams, etc. The addition of microbial agents is mainly to decompose organic matter, ammonia nitrogen and nitrite accumulated in the aquaculture environment by increasing the proportion of beneficial bacteria. However, the application dosage of microbial agents is large, the maintenance time is short, the application cost is high, and the technical requirements for application personnel are high, which limits the application of microbial agents in the restoration of aquaculture systems. Planting submerged plants absorbs pollutants through the roots of plants, which is difficult to achieve the purpose of efficiently removing pollutants from the water. At the same time, aquatic plants occupy a large area, are greatly affected by the seasons, and the water quality of the effluent is unstable, which is restricted in various aspects during use. The area of ​​facility treatment is 5 to 10m 2, it occupies a small area and has a relatively high treatment efficiency. However, there are problems such as high construction cost, high operating energy consumption, and high maintenance cost during use. For aquaculture systems with less serious pollution, these high costs often constitute an unbearable economic burden. The removal of pollutants by artificial wetlands is mainly through plant absorption and the denitrification and phosphorus removal of functional fillers. When treating aquaculture tailwater, artificial wetlands generally account for 10% to 15% of the total aquaculture area. They occupy a large area, have low hydraulic load, and are prone to blockage and reduced efficiency after long-term use. Three pools and two dams is a commonly used aquaculture tailwater treatment model in aquaculture. It consists of a sedimentation tank, an aeration tank, an ecological purification tank and two filter dams, which generally account for 8% to 10% of the total aquaculture area, occupy a large area, and the initial construction cost is about 6,500 yuan / mu, and the engineering construction is difficult.

[0004] In summary, the existing in-situ remediation technology for aquaculture systems has problems such as substandard total nitrogen in effluent, large fluctuations in water quality, high turbidity, high construction costs, and lacks simultaneous remediation technology for water bodies and bottom sediments. Therefore, the key to solving the above problems is to invent an economical, efficient, low-carbon, modularly produced aquaculture system remediation technology. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides an electroactive ecological floating bed, a restoration aquaculture system and applications and methods thereof.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] The present invention provides an electroactive ecological floating bed, which comprises a floating material layer, an electroactive floating bed layer, an anode material and an electron conductive material, wherein the floating material layer is stacked on the electroactive floating bed layer, and the electroactive floating bed layer is provided with a plurality of planting holes, wherein the planting holes penetrate the floating material layer and the electroactive floating bed layer in a vertical direction, and the planting holes are used to arrange emergent plants; and further comprises an anode material for burying in the bottom mud of a polluted freshwater aquaculture fish pond, wherein the anode material is connected to the electroactive floating bed layer through an electron conductive material ; Wherein, the floating material layer is used to support the electroactive floating bed to float in the water to adapt to the requirements of different water depths; the electroactive floating bed layer is used to provide attachment points for functional microorganisms, and form synchronous nitrification and denitrification inside to achieve efficient removal of pollutants; it should be noted that different denitrification functional zones are formed inside the electroactive floating bed layer due to the difference in dissolved oxygen, the aerobic zone can undergo nitrification, and the anoxic zone can undergo autotrophic denitrification, thereby forming synchronous nitrification and denitrification inside the electroactive floating bed to achieve efficient removal of pollutants. The anode material is used to enrich functional microorganisms in the anaerobic environment of the sediment to degrade organic pollutants to generate electrons and transfer them to the electroactive floating bed layer through the electron conductive material; the electron conductive material is used to connect the electroactive floating bed layer and the anode material to construct a complete external circuit, and to compensate the electrons in the sediment to the electroactive floating bed layer to remove pollutants.

[0008] Furthermore, the floating material layer includes one or more foamed boards made of polyurethane, polystyrene, polyvinyl chloride, polyethylene, and phenolic resin.

[0009] Furthermore, the electroactive floating bed layer is prepared from the base material by the following method: washing the organic impurities on the surface of the base material with deionized water and drying to constant weight to obtain substance A; diluting the silane coupling agent to a mass fraction of 2% to 5%, placing the substance A in the diluted silane coupling agent for 2 hours, taking it out and drying it at 60°C to obtain substance B; soaking the substance B in a solution containing 0.15M pyrrole for 20 to 40 minutes, and after ultrasonic treatment for 20 minutes, adding 0.35M ferric chloride hexahydrate and 0.15M p-toluenesulfonic acid, placed for 1 to 3 hours, reaction temperature 20°C, to obtain substance C; 1mg / mL multi-walled carbon nanotubes and 1mg / mL dioctyl phosphate are mixed in deionized water to obtain a uniform and stable carbon nanotube dispersion; the substance C is placed in the carbon nanotube dispersion and ultrasonicated for 10 to 30 minutes, taken out and dried at room temperature overnight to obtain an electrically active floating bed layer with conductive properties; wherein the matrix material includes one or more of polyester fiber material, polyamide fiber material, vinylon material, and inorganic silicate material.

[0010] Furthermore, the length of the floating material layer is 20-50 cm, the width is 10-40 cm, and the thickness is 2-5 cm; the length of the electroactive floating bed layer is 30-50 cm, the width is 20-40 cm, the thickness is 5-20 cm, and the coverage is 10%-40%.

[0011] Furthermore, the anode material includes one or more of carbon brush, carbon cloth and carbon felt.

[0012] Furthermore, the electron conducting material includes one or more of copper wire, aluminum wire, titanium wire, stainless steel wire, copper alloy wire, titanium alloy wire, and carbon fiber.

[0013] The present invention also provides an electroactive ecological restoration breeding system, which is formed by connecting a number of the above-mentioned electroactive ecological floating beds; and also includes submerged plants buried in the bottom mud of a polluted freshwater fish pond; wherein the emergent plants are plants with strong nitrogen and phosphorus absorption capabilities and strong root oxygen secretion and root secretion capabilities, including one or more of purple taro, canna, wild taro, rush, sea longevity flower, arrowhead, cattail, variegated cattail, water moss, loosestrife, Alisma, giant arrowhead, wild rice stem, variegated reed, calamus, iris, Cyperus, reed, water lily, and water plantain; the submerged plants are plants that can adapt to various water depths and have strong oxygen secretion capabilities, including one or more of foxtail algae, Vallisneria, Ceratophyllum, and Hydrilla verticillata.

[0014] Furthermore, the planting density of the emergent plants is 10 to 30 plants / m 2 The planting density of submerged plants is 30 to 60 plants / m 2 .

[0015] The present invention also provides the application of the electroactive ecological restoration aquaculture system as described above in the field of aquaculture system restoration.

[0016] The present invention further provides an electroactive ecological restoration aquaculture method, which is applied to the electroactive ecological restoration aquaculture system as described above; the method comprises: selecting a polluted freshwater aquaculture fish pond, and constructing the electroactive ecological restoration aquaculture system in the polluted freshwater aquaculture fish pond; the electroactive floating bed layer provides attachment points for functional microorganisms, and forms synchronous nitrification and denitrification inside to achieve efficient removal of pollutants; the anode material enriches functional microorganisms in the anaerobic environment of the sediment to degrade organic pollutants to generate electrons and transfer them to the electroactive floating bed layer through the electron conductive material; the electron conductive material compensates the electrons in the sediment to the electroactive floating bed layer to remove pollutants.

[0017] Compared with the prior art, the technical solution provided by the present invention has at least the following advantages:

[0018] 1. Emergent plants planted in planting baskets can efficiently absorb pollutants such as nitrogen and phosphorus, and the oxygen secreted by the roots of emergent plants can provide electron acceptors for the electroactive floating bed layer. The roots of emergent plants penetrate the electroactive floating bed layer, and functional microorganisms can be enriched on the root surface.

[0019] 2. The electroactive floating bed layer provides good attachment points for microorganisms due to its large porosity, hydrophilicity, good biocompatibility and good electrical conductivity. The electroactive floating bed can obtain sufficient electron acceptors through atmospheric oxygen enrichment, oxygen secretion from the roots of emergent plants and nitrate pollutants in the water. In the present invention, the electroactive floating bed layer can undergo nitrification reaction and also serve as a cathode to receive electrons and carry out an autotrophic denitrification process (ordinary floating beds can only undergo heterotrophic denitrification and cannot undergo autotrophic denitrification). The electroactive floating bed in the present invention is a cheap and readily available organic polymer material, and functional microorganisms such as electroactive bacteria and nitrogen-converting bacteria attached to the surface can replace traditional catalysts and can effectively remove pollutants such as carbon, nitrogen and phosphorus in the water. There is a dissolved oxygen gradient inside the electroactive floating bed, and there is a simultaneous nitrification and denitrification effect.

[0020] 3. The anode material is placed in the sediment, which can enrich functional microorganisms in the anaerobic environment of the sediment. The electroactive bacteria can degrade organic pollutants to produce electrons and transfer them to the electroactive floating bed through an external circuit, where oxygen reduction and nitrate reduction are carried out to achieve energy recovery and conversion.

[0021] 4. Submerged plants are planted in the bottom mud. Their leaves can provide dissolved oxygen to the water, promoting the oxidative decomposition of organic pollutants on the electroactive floating bed. At the same time, the roots of submerged plants secrete oxygen to increase the redox potential of the rhizosphere bottom mud, inhibit the formation of sulfides, and reduce sediment resuspension through physical fixation, comprehensively alleviating the black and smelly phenomenon of the water.

[0022] 5. The micro-electric field formed between the electroactive floating bed and the anode material in the present invention has a directional migration effect on charged particles in the water body, which can reduce suspended matter in the water and improve water transparency.

[0023] 6. The ammonia nitrogen removal rate of the electroactive floating bed of the present invention is always stable at more than 90.2%, and can reach up to 97.9%. The nitrate nitrogen removal rate is always maintained at more than 59.8%, and the total phosphorus removal rate can be stably reached more than 68.2%. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplifications do not constitute limitations on the embodiments. Unless otherwise stated, the pictures in the drawings do not constitute proportional limitations.

[0025] Figure 1 is a schematic diagram of the electroactive floating bed of Example 1;

[0026] Figure 2 This is a diagram showing the effect of removing ammonia nitrogen from the effluent after the system of Example 1 runs stably;

[0027] Figure 3 This is a diagram showing the effect of nitric nitrogen removal from the effluent after the system in Example 1 runs stably;

[0028] Figure 4 This is a diagram showing the effect of total phosphorus removal in the effluent after the system in Example 1 has stabilized;

[0029] Figure 5 This is a diagram showing the turbidity effect of the system after the system in Example 1 has stabilized;

[0030] Figure 6 This is a diagram showing the total carbon removal effect of the sediment after the system of Example 1 has stabilized.

[0031] Figure 1 In the figure, 1-emergent plants, 2-floating material layer, 3-electroactive floating bed layer, 4-anode material, 5-submerged plants, 6-electron conducting material;

[0032] Figures 2 to 6 In the figure, a is a system reactor constructed for a comparative blank experiment, b is a system reactor for a traditional floating bed, and c is a system reactor for an electroactive floating bed coupled with submerged plants constructed in Example 1. DETAILED DESCRIPTION

[0033] The present invention proposes a restoration technology for an electroactive ecological floating bed aquaculture system based on the simultaneous restoration of aquaculture water bodies and bottom mud. Conductive materials are loaded on part of the floating bed materials to form an electroactive ecological floating bed, and emergent plants are planted on the electroactive ecological floating bed. The oxygen secretion and root secretions of the plants have a significant effect on improving the denitrification and phosphorus removal of the electroactive floating bed. Anode materials are buried in the bottom mud to achieve the removal of organic matter in the bottom mud. The weak electric field formed between the cathode and anode has a sedimentation effect on suspended particles, which can reduce the turbidity of the aquaculture system. Submerged plants are planted in the bottom mud to provide oxygen for the restoration of the aquaculture system, and the submerged plants can also enhance the absorption of pollutants such as nitrogen and phosphorus. The electroactive floating bed can maintain the long-term stability of water quality, and the initial investment and later operation and maintenance costs are low.

[0034] The present invention is described in detail below in conjunction with specific implementation modes.

[0035] The present invention provides an electroactive ecological floating bed, a restoration aquaculture system and its application and method. The electroactive ecological restoration aquaculture method is a method for synchronously restoring water bodies and bottom mud by using an electroactive floating bed coupled with submerged plants, which is carried out according to the following steps:

[0036] 1. Select polluted freshwater fish ponds;

[0037] 2. Construct electroactive floating beds and plant submerged plants in polluted freshwater fish ponds;

[0038] 1. The electroactive ecological restoration aquaculture system adopted by the present invention is composed of a plurality of electroactive floating beds connected together, and the electroactive floating beds are composed of a floating material layer, an electroactive floating bed layer, an anode material, emergent plants, submerged plants and an electron conductive material. An electroactive floating bed layer is arranged below the floating material layer, and a plurality of emergent plant planting holes are arranged vertically along the electroactive floating bed layer, and the planting holes penetrate the floating material layer and the electroactive floating bed layer. Plant planting baskets are arranged in the planting holes and plants are planted;

[0039] 2. The floating material layer constructed according to the method in 1 has a monomer length of 20 to 50 cm, a width of 10 to 40 cm, and a thickness of 2 to 5 cm. The floating material layer includes but is not limited to one or more foamed boards made of polyurethane, polystyrene, polyvinyl chloride, polyethylene, phenolic resin, etc.;

[0040] 3. The electroactive ecological floating bed constructed according to the method in 1 has a single electroactive floating bed layer length of 30 to 50 cm, a width of 20 to 40 cm, a thickness of 5 to 20 cm, and a coverage rate of 10% to 40% which can be determined according to the water pollution situation. The electroactive floating bed matrix material includes but is not limited to one or more of polyester fiber material, polyamide fiber material, vinylon material, inorganic silicate material, etc.;

[0041] 1) Washing the organic impurities on the surface of the base material with deionized water and drying to constant weight to obtain substance A;

[0042] 2) diluting the silane coupling agent KH550 to 2% (mass fraction), placing substance A in the silane coupling agent for 2 hours, taking it out and drying it at 60° C. to obtain substance B;

[0043] 3) Substance B was placed in 100 mL of a solution containing 0.15 M pyrrole and soaked for 40 min. After ultrasonic treatment for 20 min, 100 mL of 0.35 M ferric chloride hexahydrate and 100 mL of 0.15 M p-toluenesulfonic acid were added at room temperature and allowed to stand for 3 h. The reaction temperature was 20° C. to obtain substance C.

[0044] 4) mixing 1 mg / mL multi-walled carbon nanotubes and 1 mg / mL dioctyl phosphate in deionized water to obtain a uniform and stable carbon nanotube dispersion;

[0045] 5) placing substance C in the carbon nanotube dispersion and ultrasonicating for 20 minutes, taking it out and drying it at room temperature overnight, and the obtained substance is an electroactive ecological floating bed with conductive properties;

[0046] 4. The anode material of the electroactive ecological floating bed constructed according to the method in 1 is buried in the bottom mud, and the anode material includes but is not limited to one or more of carbon brushes, carbon cloth, and carbon felt. The anode material can enrich electroactive bacteria in the bottom mud, degrade the refractory organic matter in the bottom mud to generate electrons, and provide electrons for the electroactive floating bed to reduce oxygen and nitrates.

[0047] 5. The emergent plants planted on the electroactive ecological floating bed constructed according to the method in 1 are plants with strong nitrogen and phosphorus absorption capacity and strong root oxygen secretion and root secretion capacity, including but not limited to purple taro, canna, wild taro, rush, sea longevity flower, arrowhead, cattail, variegated cattail, water moss, loosestrife, oriental water chestnut, big arrowhead, wild rice stem, variegated reed, calamus, iris, Cyperus, reed, lily flower, water plantain, one or more of the following. The planting density of emergent plants is generally 10 to 30 plants / m 2 The plants planted in the bottom mud are submerged plants that can adapt to various water depths and have strong oxygen secretion capacity, including but not limited to one or more of foxtail algae, Vallisneria, Ceratophyllum, and Hydrilla verticillata. The planting density of submerged plants is generally 30 to 60 plants / m 2 .

[0048] 6. The electronic conductive material of the electroactive ecological floating bed constructed according to the method in 1 is used to connect the electroactive floating bed and the anode material, including but not limited to one or more of copper wire, aluminum wire, titanium wire, stainless steel wire, copper alloy wire, titanium alloy wire, and carbon fiber.

[0049] The following examples are used to verify the beneficial effects of the present invention:

[0050] Embodiment 1:

[0051] An embodiment of the present invention provides an electroactive ecological floating bed, which includes a floating material layer 2, an electroactive floating bed layer 3, an anode material 4 and an electron conductive material 6, wherein the floating material layer 2 is stacked on the electroactive floating bed layer 3, and a plurality of planting holes are arranged on the electroactive floating bed layer 3, wherein the planting holes vertically penetrate the floating material layer 2 and the electroactive floating bed layer 3, and the planting holes are used to arrange emergent plants 1; the anode material 4 is also included for burying in the bottom mud of polluted freshwater aquaculture fish ponds, wherein the anode material 4 is connected to the electroactive floating bed layer 3 through the electron conductive material 6. This embodiment proposes a method for synchronously repairing water bodies and bottom mud by coupling submerged plants 5 with an electroactive ecological floating bed, which is applied to the in-situ repair of aquaculture systems. The floating material is a polystyrene foam board, the matrix of the electroactive floating bed material is polyester fiber, the anode material 4 is a carbon brush, the emergent plant 1 is calamus, and the submerged plant 5 is Vallisneria. Specifically, Figure 1 shown.

[0052] A method for synchronously repairing water bodies and bottom mud by using an electroactive floating bed coupled with submerged plants is carried out according to the following steps:

[0053] 1. Select polluted freshwater fish ponds;

[0054] 2. Construct electroactive floating beds and plant submerged plants in polluted freshwater fish ponds5;

[0055] The electroactive ecological restoration aquaculture system is formed by connecting a plurality of electroactive floating beds, and the electroactive floating beds are composed of a floating material layer 2, an electroactive floating bed layer 3, an anode material 4, an emergent plant 1, a submerged plant 5, and an electron conductive material 6. An electroactive floating bed layer 3 is arranged below the floating material layer 2, and a plurality of planting holes for emergent plants 1 are arranged in the vertical direction of the electroactive floating bed layer 3, and the planting holes penetrate the floating material layer 2 and the electroactive floating bed layer 3, and a plant planting basket is arranged in the planting holes and plants are planted;

[0056] The floating material layer 2 described in step 2 has a length of 20 cm, a width of 15 cm, and a thickness of 5 cm. The floating material layer 2 is a foam board made of polystyrene;

[0057] The electroactive floating bed layer 3 described in step 2 has a length of 20 cm, a width of 15 cm, a thickness of 5 cm, a coverage rate of 30%, and a matrix material of the electroactive floating bed is composed of a polyester fiber material;

[0058] 1) Washing the organic impurities on the surface of the base material with deionized water and drying to constant weight to obtain substance A;

[0059] 2) diluting the silane coupling agent KH550 to 2% (mass fraction), placing substance A in the silane coupling agent for 2 hours, taking it out and drying it at 60° C. to obtain substance B;

[0060] 3) Substance B was placed in 100 mL of a solution containing 0.15 M pyrrole and soaked for 40 min. After ultrasonic treatment for 20 min, 100 mL of 0.35 M ferric chloride hexahydrate and 100 mL of 0.15 M p-toluenesulfonic acid were added at room temperature and allowed to stand for 3 h. The reaction temperature was 20° C. to obtain substance C.

[0061] 4) mixing 1 mg / mL multi-walled carbon nanotubes and 1 mg / mL dioctyl phosphate in deionized water to obtain a uniform and stable carbon nanotube dispersion;

[0062] 5) placing substance C in the carbon nanotube dispersion and ultrasonicating for 20 minutes, taking it out and drying it at room temperature overnight, and the obtained substance is an electroactive ecological floating bed with conductive properties;

[0063] The anode material 4 of the electroactive ecological floating bed described in step 2 is buried in the bottom mud, and a carbon brush is used for the anode material 4. The anode material 4 can enrich the electroactive bacteria in the bottom mud, degrade the refractory organic matter in the bottom mud to generate electrons, and provide electrons for the electroactive floating bed to reduce oxygen and nitrates.

[0064] The emergent plant 1 planted on the electroactive ecological floating bed in step 2 is a calamus having strong nitrogen and phosphorus absorption capacity and strong root oxygen secretion and root secretion capacity. The planting density of the emergent plant 1 is generally 30 plants / m 2 The plants planted in the bottom mud are submerged plants 5 Vallisneria, which can adapt to various water depths and have strong oxygen secretion capacity. The planting density of submerged plants 5 is generally 60 plants / m 2 .

[0065] In step 2, the electron conductive material 6 of the electroactive ecological floating bed uses titanium wire to connect the electroactive floating bed and the anode material 4, and the resistance connected to the electron conductive material 6 is 1000Ω.

[0066] This embodiment uses a small test reactor of an electroactive ecological floating bed coupled with submerged plants. Only one electroactive ecological floating bed is used in the small test reactor, and two planting holes are set in the electroactive ecological floating bed. The other parameters are the same as above, and the test of the synchronous repair and removal effect of water bodies and bottom mud by coupling submerged plants using the electroactive ecological floating bed in this embodiment is specifically completed according to the following steps:

[0067] The small test reactor of the electroactive ecological floating bed coupled with submerged plants is constructed as a cuboid with a length × width × height of 400mm × 240mm × 600mm, made of plexiglass, and the effective volume in the reactor is 40L. Two comparative reactors are set up, a is a reactor constructed for the comparative blank experiment, with only 10cm thick bottom mud laid on the bottom; b is a traditional ecological floating bed reactor, the size of the ecological floating bed is 20cm × 15cm × 10cm; c is an electroactive ecological floating bed coupled with submerged plants reactor constructed in this embodiment, and 10cm bottom mud is laid on the bottom of the three reactors, the inlet water is 40L of water distribution, and the hydraulic retention time is 3 days.

[0068] Figure 2 This is a diagram showing the effect of removing ammonia nitrogen from the effluent after the system of Example 1 runs stably; Figure 3 This is a diagram showing the effect of nitric nitrogen removal from the effluent after the system in Example 1 runs stably; Figure 4 This is a diagram showing the effect of total phosphorus removal in the effluent after the system in Example 1 has stabilized; Figure 5 This is a diagram showing the turbidity effect of the system after the system in Example 1 has stabilized; Figure 6 This is a diagram showing the total carbon removal effect of the sediment after the system of Example 1 has stabilized;

[0069] Figures 2 to 6 In the figure, a is a system reactor constructed for a comparative blank experiment, b is a system reactor for a traditional floating bed, and c is a system reactor for an electroactive floating bed coupled with submerged plants constructed in Example 1.

[0070] The ammonia nitrogen concentration of the influent is 2.1±0.1mg / L. Figure 2It can be seen that the blank experimental group lacks microbial carriers, nitrifying bacteria are difficult to enrich, and the average ammonia nitrogen removal rate is only 22.6%. The floating bed of the traditional floating bed group can provide attachment sites for nitrifying bacteria, and the ammonia nitrogen removal rate is always stable at more than 82.0%. The ammonia nitrogen removal rate of the electroactive floating bed group is always stable at more than 90.2%, and can reach up to 97.9%.

[0071] The nitrate nitrogen concentration of the influent is 3.2±0.1mg / L. Figure 3 It can be seen that the average nitrate nitrogen removal rate of the blank experimental group is 46.5%, while the average nitrate nitrogen removal rate of the traditional floating bed group is 33.5%. The nitrification of the traditional floating bed group promotes the conversion of ammonia nitrogen into nitrate nitrogen in the system. The average nitrate nitrogen removal rate of the electroactive floating bed group is 64.23%, and the effluent concentration is 1.13 mg / L. The electroactive floating bed can receive electrons generated by the anode to reduce nitrates, so synchronous nitrification and denitrification can be achieved inside the electroactive floating bed, improving the nitrogen removal effect.

[0072] The total phosphorus concentration of the influent is 1.0±0.1mg / L. Figure 4 It can be seen that the blank experimental group mainly reduced the total phosphorus concentration through the adsorption of sediment, with an average removal rate of 19.0%. The emergent plants in the traditional floating bed group can absorb the total phosphorus in the system, and the average removal rate of total phosphorus is 39.0%. Under the joint absorption of emergent plants and submerged plants, the total phosphorus removal rate of the electroactive floating bed group has always been stable at more than 68.2%, and can reach up to 84.7%.

[0073] from Figure 5 It can be seen that the average turbidity of the blank experimental group is 34.1NTU, and the system is turbid, while the average turbidity of the traditional floating bed group is 14.8NTU. The roots of emergent plants can act as a suspended matter trap to promote the sedimentation of suspended particles. The electroactive floating bed group can not only fix sediments through the roots of submerged plants and inhibit the resuspension of particles, but the micro-electric field between the electroactive ecological floating bed and the anode can also promote the sedimentation of suspended particles carrying negative charges to the bottom mud, further improving the transparency of the system. The average turbidity of the electroactive floating bed group is 8.2NTU.

[0074] The total carbon content of the electroactive floating bed group was 12.5% ​​before the test. Figure 6 It can be seen that after the experiment, the total carbon content of the electroactive floating bed group was 10.8%, and the total carbon content decreased by 13.6%. The anode material enriched the electroactive bacteria and organic matter degrading bacteria in the sediment. At the same time, the roots of submerged plants increased the redox potential of the sediment and promoted the degradation of organic matter in the sediment.

[0075] The test results show that the electroactive floating bed in this embodiment can not only provide a carrier for the attachment of microorganisms, but also enrich more denitrifying bacteria and improve the denitrification capacity. The electroactive microorganisms are also enriched on the anode material to reduce the total carbon content of the bottom mud. The system operation effect is very stable, and the micro-electric field effect between the electroactive floating bed and the anode material reduces the turbidity of the system and improves the transparency of the water body.

[0076] Those skilled in the art will appreciate that the above embodiments are specific examples of the present invention, and in practical applications, various changes may be made to the embodiments in form and detail without departing from the spirit and scope of the present invention. Any person skilled in the art may make changes and modifications without departing from the spirit and scope of the present invention, and therefore the scope of protection of the present invention shall be subject to the scope defined in the claims.

Claims

1. An electroactive ecological floating bed, characterized in that: The electroactive ecological floating bed comprises a floating material layer, an electroactive floating bed layer, an anode material and an electron conductive material, wherein the floating material layer is stacked on the electroactive floating bed layer, and the electroactive floating bed layer is provided with a plurality of planting holes, wherein the planting holes vertically penetrate the floating material layer and the electroactive floating bed layer, and the planting holes are used to plant emergent plants; Also included is an anode material for burying in the bottom mud of a polluted freshwater fish pond, wherein the anode material is connected to the electroactive floating bed layer via an electronic conductive material; Wherein, the floating material layer is used to support the electroactive floating bed to float in the water to adapt to the requirements of different water depths; The electroactive floating bed layer is used to provide attachment points for functional microorganisms and form synchronous nitrification and denitrification inside to achieve efficient removal of pollutants; The anode material is used to enrich functional microorganisms in the anaerobic environment of the bottom mud to degrade organic pollutants to generate electrons and transfer them to the electroactive floating bed layer through the electron conductive material; The electron conductive material is used to connect the electroactive floating bed layer and the anode material to construct a complete external circuit, and to compensate the electrons in the bottom mud to the electroactive floating bed layer to remove pollutants.

2. The electroactive ecological floating bed according to claim 1, characterized in that: The floating material layer includes one or more foamed boards made of polyurethane, polystyrene, polyvinyl chloride, polyethylene, and phenolic resin.

3. The electroactive ecological floating bed according to claim 1, characterized in that: The electroactive floating bed layer is made of a base material by the following method: Washing the organic impurities on the surface of the base material with deionized water and drying to constant weight to obtain substance A; The silane coupling agent is diluted to a mass fraction of 2% to 5%, the substance A is placed in the diluted silane coupling agent for 2 hours, and then taken out and dried at 60° C. to obtain the substance B; The substance B is placed in a solution containing 0.15M pyrrole and soaked for 20 to 40 minutes. After ultrasonic treatment for 20 minutes, 0.35M ferric chloride hexahydrate and 0.15M p-toluenesulfonic acid are added at room temperature and allowed to stand for 1 to 3 hours at a reaction temperature of 20°C to obtain substance C; Mixing 1 mg / mL multi-walled carbon nanotubes and 1 mg / mL dioctyl phosphate in deionized water to obtain a uniform and stable carbon nanotube dispersion; The substance C is placed in a carbon nanotube dispersion and subjected to ultrasonic treatment for 10 to 30 minutes, and then taken out and dried overnight at room temperature to obtain an electrically active floating bed layer having conductive properties; Wherein, the matrix material includes one or more of polyester fiber material, polyamide fiber material, vinylon material, and inorganic silicate material.

4. The electroactive ecological floating bed according to claim 1, characterized in that: The length of the floating material layer is 20 to 50 cm, the width is 10 to 40 cm, and the thickness is 2 to 5 cm; The electroactive floating bed layer has a length of 30 to 50 cm, a width of 20 to 40 cm, a thickness of 5 to 20 cm, and a coverage rate of 10% to 40%. (This coverage rate is for the total area of ​​the polluted pond.

5. The electroactive ecological floating bed according to claim 1, characterized in that: The anode material includes one or more of carbon brush, carbon cloth and carbon felt.

6. The electroactive ecological floating bed according to claim 1, characterized in that: The electronic conductive material includes one or more of copper wire, aluminum wire, titanium wire, stainless steel wire, copper alloy wire, titanium alloy wire and carbon fiber.

7. An electroactive ecological restoration breeding system, characterized in that: The system is formed by connecting several electroactive ecological floating beds according to any one of claims 1 to 6; It also includes submerged plants buried in the mud of polluted freshwater fish ponds; The emergent plants are plants with strong nitrogen and phosphorus absorption capacity and strong root oxygen secretion and root secretion capacity, including one or more of purple taro, canna, wild taro, rush, sea longevity flower, arrowhead, cattail, variegated cattail, water moss, loosestrife, oriental water chestnut, large arrowhead, wild wild rice stem, variegated reed, calamus, iris, Cyperus, reed, lily, and water plantain; The submerged plants are plants that are adaptable to various water depths and have strong oxygen secretion capabilities, including one or more of foxtail algae, Vallisneria, hornwort, and Hydrilla verticillata.

8. The electroactive ecological restoration aquaculture system according to claim 7, characterized in that: The planting density of the emergent plants is 10 to 30 plants / m 2 The planting density of submerged plants is 30 to 60 plants / m 2 .

9. Application of the electroactive ecological restoration aquaculture system as claimed in claim 7 in the field of aquaculture system restoration.

10. An electroactive ecological restoration breeding method, characterized in that: Applied in the electroactive ecological restoration aquaculture system as claimed in claim 7; the method comprises: Selecting a polluted freshwater fish pond, and constructing the electroactive ecological restoration aquaculture system in the polluted freshwater fish pond; The electroactive floating bed layer provides attachment points for functional microorganisms and forms simultaneous nitrification and denitrification inside to achieve efficient removal of pollutants; The anode material is enriched with functional microorganisms in the anaerobic environment of the bottom mud to degrade organic pollutants to generate electrons and transfer them to the electroactive floating bed layer through the electron conductive material; The electron conductive material compensates the electrons in the bottom mud to the electroactive floating bed layer to remove pollutants.

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