Photocatalytic microalgae coupling-based full-cycle aquaculture water treatment device and method

Abstract

This invention provides a fully recirculating aquaculture water treatment device and method based on photocatalytic microalgae coupling. The device mainly includes a photocatalytic treatment tank, an adult culture tank, a seedling culture tank, and a microalgae feed culture tank. Each tank is equipped with an anode, cathode, photocatalytic film, sediment, ultraviolet lamp, CO2 aeration disc, gate valve, water pump, LED light source, and water quality sensor. In this fully recirculating aquaculture water treatment device, the anode, cathode, water body, and external circuitry together form a microbial-algae biofuel cell, powering the ultraviolet lamp in the photocatalytic treatment tank, the LED light source in each culture tank, and the water pump. A water quality sensor network is also formed within the fully recirculating water treatment device to control water replenishment, feed replenishment, and other processes in a timely and efficient manner. This invention synergistically purifies aquaculture wastewater through photocatalytic oxidation and a biofuel cell, uses microalgae as feed to reduce costs and enhance immunity, and generates electricity from the microbial fuel cell to power the microalgae light source for oxygenation, achieving zero emissions, full recirculation, and water conservation.

Description

Technical Field

[0001] This application belongs to the field of water treatment technology and relates to a whole-cycle aquaculture water treatment device and method based on photocatalytic microalgae coupling. Background Technology

[0002] The scale of aquaculture continues to grow, becoming an important pillar of food supply and economic growth. However, while high-density aquaculture increases production, it also leads to a series of environmental problems: eutrophication of water bodies caused by aquaculture wastewater leads to explosive algal growth; the use of microbial methods for water treatment carries the risk of uncontrolled microbial outbreaks leading to pond collapse; and the blind pursuit of aquaculture output results in antibiotic overuse and pollution.

[0003] High-density aquaculture refers to increasing the stocking density per unit of water through technological means. Traditional high-density aquaculture models include recirculating aquaculture systems, high-level pond intensive aquaculture, and biofloc technology. The key to these models lies in the control of the water body, the precise feeding of feed, and the prevention and control of diseases.

[0004] Although existing high-density aquaculture technologies have increased yields through enhanced water control and mechanized feeding, their over-reliance on energy consumption and passive pollution control makes it difficult to fundamentally balance environmental and economic benefits.

[0005] Chinese patent CN105961303B discloses a fish-bacteria-algae symbiotic ecological aquaculture system and its operation method. By establishing a photobioreactor connected to the aquaculture pond, it utilizes the synergistic purification of bacteria and algae to improve nitrogen utilization, reducing wastewater discharge, but still not achieving full recycling. Chinese patent CN211910169U discloses a recirculating aquaculture system with zero wastewater discharge. It uses a combination of inclined tube sedimentation and anaerobic membrane biofilters to remove suspended particles from the aquaculture water instead of microfilters. Ammonia nitrogen is then degraded by an aerobic fluidized bed, and pathogens are killed by an ultraviolet sterilizer, thus achieving zero wastewater discharge. However, it still requires the discharge of filtered solid waste, not achieving "full recycling." Patent CN118749484A discloses a system and method for zero wastewater discharge from aquaculture based on a pond and canal model. This requires the construction of ecological ditches and lotus ponds / wetlands, utilizing aquatic plants and microorganisms to achieve multi-stage treatment of pollutants such as COD, ammonia nitrogen, total nitrogen, and total phosphorus in the wastewater. It requires a large area and cannot achieve factory-style aquaculture. Patent CN212687850U ​​discloses a fishpond aquaculture water treatment device based on MBBR technology. Through multi-stage treatment including aerobic tanks, anoxic tanks, sedimentation tanks, ammonia nitrogen treatment and purification tanks, biofilm purification tanks, and denitrification filters, combined with MBBR packing material, suspended carriers, submerged plants, and a backwashing system, it achieves efficient removal of ammonia nitrogen, organic matter, and inorganic salts from the water, improving water purification efficiency, reducing aeration costs, and simultaneously enabling the recycling and compliant discharge of aquaculture wastewater. The entire process is similar to existing wastewater treatment plants, with a complex process flow, requiring the introduction of chemical agents, and cannot achieve zero discharge.

[0006] Therefore, there is a need for a sustainable development device / method that can balance efficient production with environmental protection. This device / method should have the characteristics of low energy consumption, reducing pollution at the source, achieving full recycling of the aquaculture system (including zero discharge of wastewater and solid waste), and simple and low-cost process flow, so as to solve the problems existing in the current high-density aquaculture model and related technologies. Summary of the Invention

[0007] The purpose of this invention is to provide a fully circular aquaculture water treatment device and method based on photocatalytic microalgae coupling, which recycles the wastewater generated during the aquaculture process to achieve multiple goals such as green, low-carbon, and zero emissions.

[0008] This invention provides the following technical solutions: One of the technical solutions of this invention provides a fully recirculating aquaculture water treatment device based on photocatalytic microalgae coupling, comprising a photocatalytic treatment tank, an adult culture tank, a seedling culture tank, and a microalgae feed culture tank, and further comprising: Anode, cathode, sediment, Gate valves, including a first gate valve, a second gate valve, a third gate valve, and a fourth gate valve; Water pumps, including a first water pump and a second water pump; The water quality sensor includes a first water quality sensor, a second water quality sensor, a third water quality sensor, and a fourth water quality sensor; The photocatalytic treatment tank is equipped with a fourth water quality sensor; the adult culture tank is equipped with an anode, a cathode, and a third water quality sensor; the seedling culture tank is equipped with an anode, a cathode, and a first water quality sensor; and the microalgae feed culture tank is equipped with an anode, a cathode, and a second water quality sensor. The sediment is laid at the bottom of the adult culture pond, the seedling culture pond, and the microalgae feed culture pond; the anodes are all laid in the sediment, and the cathode, the first water quality sensor, the second water quality sensor, the third water quality sensor, and the fourth water quality sensor are all suspended in the water against the wall.

[0009] The photocatalytic treatment tank, adult culture tank, seedling culture tank, and microalgae feed culture tank are all equipped with an inlet, an outlet, and a level gauge; the photocatalytic treatment tank is equipped with a circulating water inlet.

[0010] The photocatalytic treatment tank is connected to an external water source via a first gate valve; it is connected to a microalgae feed culture tank via a pipeline, on which a first water pump is installed to output treated water that meets the quality standards; it is connected to an adult culture tank via a fourth gate valve; it receives water to be treated from the adult culture tank and the seedling culture tank via a pipeline, on which a second water pump is installed; the seedling culture tank receives replenishment water from the microalgae feed culture tank via a pipeline, on which a second gate valve is installed; and it is connected to the adult culture tank via a pipeline, on which a third gate valve is installed.

[0011] Furthermore, the microalgae feed culture pond is equipped with CO2 aeration discs. CO2 aeration discs are devices used in aquaculture, wastewater treatment, and other fields to uniformly release CO2 gas into water bodies. Their core function is to optimize the ecological environment or promote specific biological processes by regulating the CO2 concentration in the water.

[0012] Furthermore, microalgae are cultivated in the microalgae feed culture pond; the microalgae species are selected from any one of Chlorella, Spirulina, Chaetoceros, Skeletalella, and Platycladus, with Spirulina or Chlorella being more preferred. The microalgae feed culture pond can provide a high-nutrient algae feed supply. The influent to the seedling pond contains high-nutrient microalgae feed, meeting the high protein requirements of the seedlings. The protein requirements of the grown adults are reduced, and the remaining microalgae feed from the seedling pond is reused in combination with formulated feed. Feeding with microalgae feed improves the immunity of the cultured organisms and prevents the overuse of antibiotics.

[0013] Furthermore, the microalgae feed culture pond is equipped with several first LED light sources; the adult culture pond is equipped with second LED light sources; and the photocatalytic treatment pond is equipped with several ultraviolet lamps. In the photocatalytic treatment pond, the ultraviolet lamps catalyze the thin film to cause an electron-hole separation reaction. The photogenerated holes and photogenerated electrons directly or indirectly degrade and oxidize pollutants, kill pathogenic bacteria, and ensure clean and safe culture.

[0014] Furthermore, a photocatalytic thin film, which is TiO2, is provided in the photocatalytic treatment pool.

[0015] Furthermore, in this device, all the anodes are connected in parallel, and all the cathodes are connected in parallel, together with the electrolyte solution in the photocatalytic treatment tank, adult culture tank, seedling culture tank, and microalgae feed culture tank, as well as the external circuit, to form a complete circuit, thereby forming a bacterial-algae biofuel cell for power generation; the microorganisms in the sediment generate electrons in the process of degrading fish and shrimp feces, apoptotic algal cells, and residual feed. The electrons flow out from the anode through the external circuit (electrical appliances or energy storage devices) and then to the cathode, continuously generating electrical energy to power the light source equipment in the system.

[0016] Furthermore, the water quality sensors (first water quality sensor, second water quality sensor, third water quality sensor and fourth water quality sensor) monitor the water quality indicators in each aquaculture pond in real time, and activate different processes in the device according to the water quality requirements to carry out aquaculture water circulation treatment.

[0017] The second technical solution of this invention provides a whole-cycle aquaculture water treatment method based on photocatalytic microalgae coupling. This invention employs the following corresponding process schemes to address different states of the aquaculture water: S1-1: Device startup procedure, such as Figure 1 (a): Open the first gate valve to replenish water to the photocatalytic treatment tank. At the same time, the fourth water quality sensor monitors the indicators in the tank. If the water quality indicators deviate from the safe operating range, turn on the ultraviolet lamp to irradiate the photocatalytic film to generate photogenerated holes and electrons, which oxidize and reduce the H2O and O2 molecules adsorbed on the surface of the photocatalyst to generate ·OH and O. 2-This process further degrades organic pollutants (including pathogenic bacteria or residual microalgae) in the pond water. The fourth water quality sensor dynamically monitors the water quality in real time. Once the water quality meets the set standards, the first water pump starts, supplying (replenishing) water to the microalgae feed culture pond to the set level. The second water quality sensor monitors chlorophyll levels and, upon reaching the set standard value, opens the second gate valve, supplying (replenishing) water to the seedling culture pond to the set level. This process continues cyclically. The first water quality sensor monitors the seedling culture pond water in real time to ensure it operates within the set safety index range. If the water quality index is abnormal, the following S1-2 procedure is executed. This process continues cyclically until the seedlings reach a sub-adult state. Then, the third gate valve opens, transferring all sub-adults to the adult culture pond, while the fourth gate valve opens to replenish water to the adult culture pond to the set level. Afterward, the regular culture process begins. The third water quality sensor monitors the culture pond water in real time to ensure it operates within the set safety index range. If the water quality index is abnormal, the following S1-3 procedure is executed.

[0018] S1-2: Procedure for handling abnormal water quality in seedling rearing ponds: as follows Figure 1 (b): The first water quality sensor monitors and analyzes the total organic carbon, total nitrogen, total phosphorus, dissolved oxygen, pH, etc. in the seedling culture pond in real time. When the above indicators deviate from the set standard range, the third gate valve opens, and the water carrying the remaining microalgae feed flows into the adult culture pond under the action of gravity, while the seedlings are intercepted in the seedling culture pond through the filter screen. The second water pump pumps the water in the adult culture pond into the photocatalytic treatment pond. At the same time, the second gate valve opens to allow the water in the microalgae feed culture pond to flow into the seedling culture pond. The fresh replenishment water contains feed algae, which not only provides the seedlings with high-nutritional-value feed, rich in vitamins, minerals and amino acids, which can improve the seedlings' immunity, but also produces oxygen through the photosynthesis of microalgae, which increases the dissolved oxygen content in the water and helps to ensure the survival rate of seedlings under high-density culture.

[0019] S1-3: Procedure for handling abnormal water quality in adult aquaculture ponds: as follows Figure 1 (c): When only the third water quality sensor detects that the water quality index in the adult breeding pond deviates from the set standard range, and the first water quality sensor is monitoring normally, the fourth gate valve opens to replenish water to the adult breeding pond to the set liquid level. At the same time, the second water pump is turned on to pump water into the photocatalytic treatment tank. The filter screen retains the adults in the adult breeding pond. This process continues until the breeding water quality monitoring reaches the set safe operating range.

[0020] S2: Water quality control process for microalgae feed culture pond: When the water level in the microalgae feed culture pond is lower than the set minimum standard value, the first water pump is turned on. When the water level reaches the set maximum standard value, the first water pump is turned off. This process continues throughout the entire culture cycle as an auxiliary control for S1-1.

[0021] S3: Water quality control process of photocatalytic treatment tank: Once the liquid level of the photocatalytic treatment tank 19 is lower than the set value, the first gate valve connected to the water source will automatically open to replenish new water to the set liquid level. This process continues throughout the entire breeding cycle as an auxiliary control of S1-1.

[0022] Throughout the entire technical solution process described above, only water replenishment is needed due to water loss through evaporation during the aquaculture period, with no polluted water discharge, making it a fully cyclical zero-emission system.

[0023] This patent constructs an integrated system for factory-scale aquaculture using photocatalysis combined with microalgae biofuel cell technology. It enables the degradation of organic matter, conversion of ammonia nitrogen, and elimination of bacteria and pathogens in aquaculture water. Compared to patent (CN105961303B), this patent's photocatalytic effect can cyclically sterilize the aquaculture water, preventing bacterial outbreaks that could lead to pond turnover. Compared to patent (CN211910169U), this patent lays electrodes in the aquaculture pond, creating a natural microbial fuel cell with self-generating power. Compared to patent (CN118749484A), this patent requires less land area, and the water treatment process is unaffected by seasons. Compared to patent (CN212687850U), it achieves nitrification of hydroxyl radicals without the need for additional chemical agents, truly realizing full recycling and zero discharge of aquaculture water. At the same time, it can produce highly nutritious bait microalgae, improve the intestinal probiotics of aquatic animals, and increase feed utilization. The phycocyanin contained in bait algae can also enhance the immunity of aquatic animals and reduce the use of antibiotics in high-density aquaculture. Live bait algae can also fix nitrogen and phosphorus, purify aquaculture water quality, and increase dissolved oxygen content in water bodies, among many other advantages.

[0024] Compared with the prior art, this application has at least the following improvements and beneficial effects: 1) The unique synergistic effect of photocatalytic oxidation and biofuel cells can thoroughly purify humic acid organic pollutants in aquaculture wastewater, reduce ammonia nitrogen and total phosphorus, and achieve zero discharge and full recycling of aquaculture water, resulting in significant water-saving benefits; at the same time, photocatalysis has a broad-spectrum sterilization effect, which can prevent the pond from being overturned due to bacterial outbreaks in the aquaculture system. 2) High-nutrient microalgae serve as a supplement to feed, reducing the need for artificial feed, lowering costs, and reducing excessive water pollution caused by feed overload and decay; the fully circulating water treatment system operates simultaneously to purify and reuse aquaculture wastewater, forming an ecological closed loop of "microalgae feed supply - water purification - resource reuse", thereby improving the economic efficiency and environmental friendliness of aquaculture. 3) High-nutrient microalgae can be used as feed to supplement the energy required for life activities, while improving the immunity of cultured organisms, reducing the risk of antibiotic abuse, and in conjunction with ecological farming models, building a healthy farming system and promoting the upgrading of green aquaculture technology. 4) The electricity generated by the microbial fuel cell can provide a light source for the growth of microalgae, enabling microalgae to photosynthesize 24 hours a day and continuously oxygenate the water, reducing the mortality rate of aquaculture and increasing the aquaculture density. This invention couples bio-electricity generation with algal oxygenation to form a sustainable conversion chain, which optimizes the aquaculture environment and reduces energy consumption, providing a new technical path for high-density ecological aquaculture. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating the operation of the present invention. Figure 2 This is a schematic diagram of the structure of the present invention; Figure label: 1 Anode, 2 Cathode, 3 Photocatalytic film, 4 Sediment, 5 Ultraviolet lamp, 6 First gate valve, 7 Second gate valve, 8 First water pump, 9 Third gate valve, 10 Second water pump, 11 First water quality sensor, 12 Second water quality sensor, 13 Third water quality sensor, 14 First LED light source, 15 Microalgae, 16 Second LED light source, 17 Fourth gate valve, 18 CO2 aeration disc, 19 Photocatalytic treatment tank, 20 Seedling culture tank, 21 Adult culture tank, 22 Microalgae feed culture tank, 23 Fourth water quality sensor. Detailed Implementation

[0026] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be described in detail below with reference to specific embodiments. It should be noted that the following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0027] Unless otherwise specified, all raw materials used in this invention are not subject to any particular restriction on their source; they may be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0028] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of the invention, it should be noted that unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. The terms "connected via gate valve" and "connected via water pump" in this invention refer to connections via pipelines, and the pipelines are equipped with corresponding valves or water pumps.

[0029] Example 1: Freshwater Macrobrachium rosenbergii farming like Figure 1 The process shown and Figure 2 The apparatus shown in this embodiment provides a fully circulating water treatment method suitable for freshwater weakly alkaline aquaculture. The method uses a fully circulating water treatment device, which includes a photocatalytic treatment tank 19, a seedling culture tank 20, an adult culture tank 21, and a microalgae feed culture tank 22.

[0030] The fully circulating water treatment device also includes an anode 1, a cathode 2, a photocatalytic film 3, sediment 4, an ultraviolet lamp 5, a CO2 aeration disc 18, gate valves, water pumps, LED light sources, and water quality sensors. The gate valves include a first gate valve 6, a second gate valve 7, a third gate valve 9, and a fourth gate valve 17; the water pumps include a first water pump 8 and a second water pump 10; the LED light sources include a first LED light source 14 and a second LED light source 16; and the water quality sensors include a first water quality sensor 11, a second water quality sensor 12, a third water quality sensor 13, and a fourth water quality sensor 23. Microalgae 15 are cultivated in the microalgae feed culture pond 22.

[0031] The inlet of the photocatalytic treatment tank 19 is connected to an external water source through the first gate valve 6 for water replenishment; the first outlet is connected to the microalgae feed culture tank 22 through the first water pump 8 to output water that meets the water quality standards after treatment; the second outlet is connected to the adult culture tank 21 through the fourth gate valve 17; and the circulating inlet receives the water to be treated from the adult culture tank 21 and the seedling culture tank 20 through the second water pump 10.

[0032] The inlet of the microalgae feed culture pond 22 receives the treated water input from the photocatalytic treatment pond 19 via the first water pump 8; the outlet is connected to the seedling culture pond 20 via the second gate valve 7 to output replenished water containing feed algae.

[0033] The inlet of the seedling culture pond 20 receives replenishment water from the microalgae feed culture pond 22 through the second gate valve 7; and receives return water from the adult culture pond 21 through the third gate valve 9 when the water quality is abnormal; the outlet of the seedling culture pond 20 transfers sub-adults to the adult culture pond 21 through the third gate valve 9; and when the water quality is abnormal, the water is discharged into the photocatalytic treatment pond 19 through the second water pump 10.

[0034] The inlet of the adult breeding pond 21 is connected to the photocatalytic treatment pond 19 for water replenishment through the fourth gate valve 17; the sub-adults are transferred from the seedling breeding pond 20 through the third gate valve 9; when the water quality at the outlet of the adult breeding pond 21 is abnormal, the water is discharged into the photocatalytic treatment pond 19 through the second water pump 10; during normal operation, the water forms a circulation with the photocatalytic treatment pond 19 through the pipeline.

[0035] The sediment 4 is present in the seedling culture pond 20, the adult culture pond 21, and the microalgae feed culture pond 22. The anode 1 is placed in the sediment 4, and the cathode 2 is attached to the wall and placed in the water. In the fully circulating water treatment device, the anode 1, cathode 2, water body, and external circuit are connected in parallel to form a bacterial-algae biofuel cell. The power supply of the bacterial-algae biofuel cell is provided by the ultraviolet lamp 5 of the photocatalytic treatment pond 19, the LED light sources 14 and 16 of each culture pond, and the water pumps 8 and 10. The energy generation end utilizes the electrons generated by the microbial degradation of organic matter in the sediment 4 of each culture pond to form an electric current through the external circuit.

[0036] The fully circulating water treatment device forms a water quality sensor network: In the photocatalytic treatment tank 19, the fourth water quality sensor 23 monitors the water quality and controls the start and stop of the ultraviolet lamp 5. In the microalgae feeding tank 22, the second water quality sensor 12 monitors the chlorophyll concentration and controls water replenishment and feed output. In the seedling breeding tank 20, the first water quality sensor 11 monitors total organic carbon, dissolved oxygen, etc., and triggers a water quality anomaly treatment process. In the adult breeding tank 21, the third water quality sensor 13 monitors the water quality and triggers a water replenishment or treated water discharge process.

[0037] In this embodiment, the above-mentioned device is applied to a giant freshwater prawn (Macrobrachium rosenbergii) farming base in Shanghai. Two 14 m × 7 m × 1.7 m farming ponds are arranged one above the other; the upper pond (20) is for larvae, and the lower pond (21) is for adults. Along the longer sides are a photocatalytic treatment pond (19) and a Chlorella microalgae feed pond (22), measuring 2 m × 7 m × 6 m and 0.5 m × 7 m × 6 m respectively. Water quality sensors are installed in each of the four ponds to monitor salinity, pH, ammonia nitrogen, and nitrite in real time. Except for the photocatalytic treatment pond (19), the inner walls of the other ponds are insulated. Graphite plate anodes (1) are buried in the sediment (4), and graphite plate cathodes (2) are suspended high above the sediment (4) and laid against the walls, connected to an energy storage device by wires. A CO2 aeration disc 18 is installed below the side wall of the Chlorella feed tank to provide CO2 for Chlorella; LED light sources for lighting are evenly distributed inside to provide light for Chlorella photosynthesis; a water inlet is provided on the upper right side of the microalgae feed culture tank 22, and a pipe is installed to connect to the first water pump 8, and further connected to the opening at the bottom of the photocatalytic treatment tank 19. The purified water from the photocatalytic treatment tank can be supplied to the microalgae feed culture tank as makeup water through the control of the first water pump 8. The inner wall of the photocatalytic treatment tank 19 is covered with a TiO2 photocatalytic film 3. Four sets of titanium plates, each 12 m × 4 m × 0.005 m in size, loaded with the TiO2 photocatalytic film 3 are evenly suspended inside the tank. Ultraviolet lamps 5 are suspended between the TiO2 films. A fourth gate valve 17 is installed above the tank connected to the adult culture tank 21. A first gate valve 6 is installed above the side wall for the raw water inlet. An outlet is installed at the bottom and connected to the Chlorella microalgae feed culture tank 22 via a pipe. An inlet is installed below the raw water inlet and connected to the lower part of the adult culture tank 21 via a pipe. Aquatic plants are planted at the bottom of the larval culture tank 20, and a third gate valve 9 is installed. The outlet can drain water to the adult culture tank 21 below through a connecting pipe. The drain pipe is higher than the silt layer inside the tank. Giant freshwater prawn larvae are cultured in the larval culture tank 20. Aquatic plants are planted at the bottom of the adult culture pond 21, and the bottom is connected to the photocatalytic treatment pond 19 via pipes and water pumps; sub-adult giant freshwater prawns are cultured in the adult culture pond 21.

[0038] The water quality sensor monitoring indicators in the seedling rearing pond within 20 minutes deviated from the following safe ranges: pH value deviated from 7.5-8.2, DO <5mg / L, NH4+ + -N>0.02 mg / L, NO2 - When the concentration is >0.1 mg / L, the gate valve installed in the seedling rearing pond 20 is opened to discharge the rearing water into the adult pond. At the same time, the water pump on the pipeline connecting the adult pond and the photocatalytic treatment pond 19 pumps the original water from the adult pond into the photocatalytic treatment pond 19. Ultraviolet lamps are turned on for photocatalytic purification, degrading ammonia nitrogen, organic matter, and killing pathogens, residual feed, and microalgae. The water quality is controlled at pH 7.5-8.2, DO >4 mg / L, and NH4+. + -N<0.02 mg / L, NO2 -<0.1 mg / L. The water in the Chlorella microalgae feed culture pond 22 comes from the photocatalytic treatment pond 19. Chlorella photosynthesis supplements the dissolved oxygen content, and the chlorophyll concentration is controlled at 5-50 μg / L. It is used as makeup water when changing the water in the seedling culture pond 20.

[0039] When the water quality in the juvenile rearing pond is normal, and the water quality sensor readings in the adult rearing pond fall within any of the following ranges: pH < 7.0 or pH > 8.5, DO < 4 mg / L, NH4+ + -N>0.2 mg / L, NO2 - When the concentration is >0.5 mg / L, the water pump on the pipeline connecting the adult culture pond 21 and the photocatalytic treatment pond 19 is started, pumping the water from the adult culture pond 21 into the photocatalytic culture pond. The ultraviolet lamp 5 is then turned on for photocatalytic treatment, degrading ammonia nitrogen, residual organic matter, and killing pathogens and residual feed algae. When the water quality is 7.5 < pH < 8.2, DO > 4 mg / L, and NH4+ < 0.5 mg / L, the water quality is further improved. + -N<0.02 mg / L, NO2 - When the concentration is <0.1 mg / L, the valve connecting the photocatalytic treatment tank 19 to the adult rearing tank 21 is opened to replenish the water volume in the adult rearing tank 21. The system operated for 12 months, with only water replenishment and no drainage, yielding two harvests of giant freshwater prawns, with the average adult prawn weight reaching 32.5g.

[0040] Example 2: Marine Black-spotted Mantis Shrimp Farming The device structure used in this embodiment is the same as that provided in Embodiment 1, and is used in a black-spotted mantis shrimp farming base in Shanghai. Two farming ponds, each 18 m × 9 m × 1.6 m in size, are arranged one above the other; the upper pond is the juvenile farming pond 20, and the lower pond is the adult farming pond 21. On either side are a photocatalytic treatment pond 19 and a spirulina microalgae feed farming pond 22, measuring 2.5 m × 9 m × 6 m and 0.5 m × 9 m × 6 m respectively. Water quality sensors are installed in each of the four ponds to monitor salinity, pH, ammonia nitrogen, and nitrite in real time. Except for the photocatalytic treatment pond 19, the inner walls of the other ponds are insulated, and graphite plate anodes 1 are buried in the sediment 4. Titanium electrode cathodes 2 are suspended high above the sediment 4 and laid against the wall, connected to an energy storage device by wires. A CO2 aeration disc 18 is installed below the side wall of the Spirulina microalgae feed culture tank 22 to provide CO2 for the Spirulina. A hollow suspended LED light source is used for illumination to supplement the photosynthesis of Spirulina. A water inlet is located on the upper right side of the microalgae feed culture tank 22, and a pipe is installed to connect to the first water pump 8, which is further connected to the opening at the bottom of the photocatalytic treatment tank. The purified water from the photocatalytic treatment tank can be supplied to the microalgae feed culture tank as makeup water through the control of the first water pump 8. The inner wall of the photocatalytic treatment tank 19 is covered with a TiO2 photocatalytic film 3, and titanium plates loaded with TiO2 photocatalytic film 3 are evenly suspended in the tank. Ultraviolet lamps are arranged between the TiO2 films. A fourth gate valve 17 is installed above the side connected to the adult culture tank 21. A first gate valve 6 is installed above the side wall as the raw water inlet. An outlet is installed at the bottom and connected to the Spirulina microalgae feed culture tank 22 through a pipe. An inlet is installed below the raw water inlet and connected to the lower part of the adult culture tank 21 through a pipe. The bottom of the juvenile rearing pond 20 is planted with aquatic plants and equipped with a third gate valve 9. A drain pipe connects to the adult rearing pond 21 below, with the drain pipe extending above the silt layer. Juvenile black-spotted mantis shrimp are raised in this pond. The bottom of the adult rearing pond 21 is also planted with aquatic plants and has an outlet at the bottom connected to the photocatalytic treatment pond 19 via a pipe and pump. Sub-adult black-spotted mantis shrimp are raised in this pond.

[0041] Water quality sensors in the seedling rearing pond showed pH values ​​deviating from 7.8-8.8, DO <5 mg / L, and NH4+ levels below normal. + -N>0.1 mg / L, NO2 - When the concentration is >0.01 mg / L, the valve at the bottom of the seedling rearing pond 20 is opened, discharging the rearing water from the seedling pond into the adult pond. Simultaneously, a pump on the connecting pipe between the adult pond and the photocatalytic treatment pond 19 pumps the original water from the adult pond into the photocatalytic treatment pond 19. Ultraviolet lamps are then turned on for photocatalytic oxidation water purification, degrading ammonia nitrogen, residual organic matter, and killing pathogens and residual feed spirulina. The water quality is controlled at pH 7.8-8.8, DO >4 mg / L, and NH4+. + -N<0.1 mg / L, NO2 -<0.01 mg / L. The water replenishment for Spirulina microalgae feed culture pond 22 comes from photocatalytic treatment pond 19. Spirulina photosynthesis replenishes dissolved oxygen content, and chlorophyll concentration is controlled at 5-50 μg / L. It is used as fresh water replenishment when changing the water in seedling culture pond 20.

[0042] When the water quality in the juvenile rearing pond is normal, and the water quality sensor in the adult rearing pond shows a pH value deviating from 7.5-9.0, DO <4mg / L, and NH4 <21, the water quality is within the range of 21. + -N>0.2 mg / L, NO2 - When the concentration is >0.05 mg / L, the water pump on the pipeline connecting the adult culture tank 21 and the photocatalytic treatment tank 19 is started, pumping the water from the adult culture tank 21 into the photocatalytic culture tank. The ultraviolet lamps are then turned on for photocatalytic treatment, degrading ammonia nitrogen, residual organic matter, and killing pathogens and residual spirulina. The water pH is controlled at 7.8-8.8, DO >4 mg / L, and NH4 <0.05 mg / L. + -N<0.1 mg / L, NO2 - <0.01 mg / L. The valve connecting the photocatalytic treatment tank 19 to the adult rearing tank 21 is opened to replenish the water volume of the adult rearing tank 21. The system has been running for 6 months, with only water replenishment and no drainage, and one season of black-spotted mantis shrimp has been harvested, with the average weight of the adult shrimp reaching 50.1g.

[0043] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any 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 invention should be within the protection scope of the present invention.

Claims

1. A fully cyclical aquaculture water treatment device based on photocatalytic microalgae coupling, characterized in that, It includes a photocatalytic treatment tank (19), an adult culture tank (21), a seedling culture tank (20), and a microalgae feed culture tank (22). It also includes an anode (1), a cathode (2), sediment (4), a first gate valve (6), a second gate valve (7), a third gate valve (9) and a fourth gate valve (17); a first water pump (8) and a second water pump (10); a first water quality sensor (11), a second water quality sensor (12), a third water quality sensor (13) and a fourth water quality sensor (23); The photocatalytic treatment tank (19) is equipped with a fourth water quality sensor (23); the adult culture tank (21) is equipped with an anode (1), a cathode (2), and a third water quality sensor (13); the seedling culture tank (20) is equipped with an anode (1), a cathode (2), and a first water quality sensor (11); the microalgae feed culture tank (22) is equipped with an anode (1), a cathode (2), and a second water quality sensor (12). The sediment (4) is laid at the bottom of the adult culture pond (21), the seedling culture pond (20), and the microalgae feed culture pond (22); the anode (1) is laid in the sediment (4); the cathode (2), the first water quality sensor (11), the second water quality sensor (12), the third water quality sensor (13), and the fourth water quality sensor (23) are all suspended in the water against the wall. The photocatalytic treatment tank (19) is connected to an external water source through a first gate valve (6); the photocatalytic treatment tank (19) is connected to a microalgae feed culture tank (22) through a pipeline, on which a first water pump (8) is installed to output water that meets the quality standards after being treated by the photocatalytic treatment tank (19); the photocatalytic treatment tank (19) is connected to an adult culture tank (21) through a fourth gate valve (17); the seedling culture tank (20) receives replenishment water from the microalgae feed culture tank (22) through a pipeline, on which a second gate valve (7) is installed; the seedling culture tank (20) is connected to the adult culture tank (21) through a pipeline, on which a third gate valve (9) is installed; the photocatalytic treatment tank (19) is connected to the adult culture tank (21) through a pipeline, on which a second water pump (10) is installed, and the photocatalytic treatment tank (19) receives the water to be treated input from the adult culture tank (21) and the seedling culture tank (20) through the pipeline where the second water pump (10) is located.

2. The whole-cycle aquaculture water treatment device based on photocatalytic microalgae coupling according to claim 1, characterized in that, The microalgae feed culture pond (22) is equipped with a CO2 aeration plate (18); microalgae (15) are cultured in the microalgae feed culture pond (22); the microalgae (15) are selected from any one of Chlorella, Spirulina, Chaetoceros, Skeletalella, and Flat Algae.

3. The whole-cycle aquaculture water treatment device based on photocatalytic microalgae coupling according to claim 1, characterized in that, The microalgae feed culture pond (22) is equipped with several first LED light sources (14); the adult culture pond (21) is equipped with second LED light sources (16); and the photocatalytic treatment pond (19) is equipped with several ultraviolet lamps (5).

4. The whole-cycle aquaculture water treatment device based on photocatalytic microalgae coupling according to claim 1, characterized in that, The photocatalytic treatment pool (19) is provided with a photocatalytic film (3), which is TiO2.

5. The whole-cycle aquaculture water treatment device based on photocatalytic microalgae coupling according to claim 1, characterized in that, All the anodes (1) are connected in parallel, all the cathodes (2) are connected in parallel, and together with the electrolyte solution in the photocatalytic treatment tank (19), adult culture tank (21), seedling culture tank (20), microalgae feed culture tank (22), and external circuit, they form a complete circuit in parallel, which together form a bacterial-algae biofuel cell and is used to generate electricity.

6. The whole-cycle aquaculture water treatment device based on photocatalytic microalgae coupling according to claim 1, characterized in that, The first water quality sensor (11), the second water quality sensor (12), the third water quality sensor (13) and the fourth water quality sensor (23) monitor the water quality indicators in each aquaculture pond in real time, and start different processes according to the water quality requirements to carry out aquaculture water circulation treatment; the process includes: S1-1: device start-up process, S1-2: seedling aquaculture pond water quality abnormality treatment process, S1-3: adult aquaculture pond water quality abnormality treatment process.

7. A fully cyclical aquaculture water treatment method based on photocatalytic microalgae coupling, performed using the apparatus described in any one of claims 1-6, characterized in that... Under normal circumstances, the procedure is as follows: S1-1: Open the first gate valve (6) to replenish water to the photocatalytic treatment tank (19). At the same time, the fourth water quality sensor (23) monitors the indicators in the tank. If the water quality indicators deviate from the safe operating range, turn on several ultraviolet lamps (5) set in the photocatalytic treatment tank (19) to irradiate the photocatalytic film (3) set in the photocatalytic treatment tank (19). The fourth water quality sensor (23) monitors the water quality in real time. After meeting the set standard, the first water pump (8) is turned on to supply water to the microalgae feed culture tank (22) to the set liquid level. After the second water quality sensor (12) monitors that the chlorophyll reaches the set standard value, the second gate valve (7) is opened to supply water to the seedling culture tank (20) to the set liquid level. Set liquid level; The first water quality sensor (11) monitors the water in the seedling rearing pond in real time to ensure that it operates within the set safety index range. If the water quality index is abnormal, the seedling rearing pond (20) water quality abnormality treatment process is executed until the seedlings are reared to the sub-adult state. Then the third gate valve (9) is opened to transfer all the sub-adults to the adult rearing pond (21). At the same time, the fourth gate valve (17) is opened to replenish water to the adult rearing pond (21) to the set liquid level. After that, the regular rearing process begins. The third water quality sensor (13) monitors the water in the rearing pond in real time to ensure that it operates within the set safety index range. If the water quality index is abnormal, the adult rearing pond (21) water quality abnormality treatment process is executed. In the abnormal water quality treatment process of the seedling culture pond (20), the third gate valve (9) is opened, and the water carrying the remaining microalgae feed flows into the adult culture pond (21) under the action of gravity. The second water pump (10) pumps the water in the adult culture pond (21) into the photocatalytic treatment pond (19). In the process of handling abnormal water quality in the adult aquaculture pond (21), the fourth gate valve (17) is opened to replenish water to the adult aquaculture pond (21) to the set liquid level, and at the same time the second water pump (10) is turned on to pump water into the photocatalytic treatment pond (19).

8. The whole-cycle aquaculture water treatment method according to claim 7, characterized in that, The abnormal water quality treatment process for the seedling rearing pond (20) is as follows: S1-2: The first water quality sensor (11) monitors and analyzes the total organic carbon, total nitrogen, total phosphorus, dissolved oxygen and pH in the seedling culture pond (20) in real time. When the above indicators deviate from the set standard range, the third gate valve (9) opens, and the water carrying the remaining microalgae feed flows into the adult culture pond (21) under the action of gravity, while the seedlings are intercepted in the seedling culture pond (20) through the filter screen. The second water pump (10) pumps the water in the adult culture pond (21) into the photocatalytic treatment pond (19); at the same time, the second gate valve (7) opens to allow the water in the microalgae feed culture pond (22) to flow into the seedling culture pond (20).

9. The whole-cycle aquaculture water treatment method according to claim 7, characterized in that, The process for handling abnormal water quality in the adult aquaculture pond (21) is as follows: S1-3: When only the third water quality sensor (13) detects that the water quality index in the adult breeding pond (21) deviates from the set standard range, and the first water quality sensor (11) is monitoring normally, the fourth gate valve (17) is opened to replenish water to the adult breeding pond (21) to the set liquid level. At the same time, the second water pump (10) is turned on to pump water into the photocatalytic treatment pond (19). The filter screen retains the adults in the adult breeding pond (21). This process continues until the breeding water quality monitoring reaches the set safe operating range.

10. The whole-cycle aquaculture water treatment method according to claim 7, characterized in that, While the cyclic culture is carried out in step S1-1, the water quality control process of the microalgae feed culture pond (22) and the water quality control process of the photocatalytic treatment pond (19) are carried out as auxiliary control for S1-1. S2: Water quality control process of microalgae feed culture pond (22): When the water level in the microalgae feed culture pond (22) is lower than the set minimum standard value, the first water pump (8) is turned on. When the water level reaches the set maximum standard value, the first water pump (8) is turned off. This process continues throughout the entire culture cycle. S3: Photocatalytic treatment tank (19) water quality control process: When the liquid level of the photocatalytic treatment tank (19) is lower than the set value, the first gate valve (6) connected to the water source will automatically open to replenish new water to the set liquid level. This process continues throughout the entire breeding cycle.

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