A circulating water aquaculture system and method integrating ai decision and tail water reuse optimization

Abstract

The application relates to the technical field of aquaculture, and discloses a circulating water aquaculture system and method integrating AI decision and tail water recycling optimization. The system comprises a main aquaculture circulating loop, a biochemical and gas regulation loop, a deep oxygenation loop, a tail water treatment unit and a PLC controller. The main aquaculture circulating loop is provided with a carbon source bypass connected to a biological pool, and the deep oxygenation loop is provided with a gas backflow pipe connected to an ozone generator. According to water quality data, the PLC adjusts the shunt ratio of the carbon source bypass to supplement the denitrification carbon source, the oxygen-rich tail gas is recycled for ozone preparation, and the tail water recycling and new water supply are cooperatively adjusted according to liquid level feedback. Through intelligent deployment of the carbon source, step-by-step utilization of the gas and dynamic balance control of the water quantity, the effective utilization of the internal source carbon source and the efficient recovery of the oxygen are realized, which helps to improve the denitrification efficiency, reduce the operation energy consumption and save the water resources.

Description

Technical Field

[0001] This invention relates to the field of aquaculture technology, specifically to a recirculating aquaculture system and method that integrates AI decision-making and wastewater reuse optimization. Background Technology

[0002] Recirculating aquaculture systems are a type of industrialized aquaculture that uses a series of water treatment units, including physical filtration, biological purification, degassing, and sterilization, to remove uneaten feed, feces, and ammonia nitrogen metabolites from the aquaculture water. The purified water can then be recycled back to the aquaculture ponds. This system enables high-density aquaculture in a relatively enclosed space and features water conservation, strong environmental controllability, and minimal impact from natural climate. It represents the future direction of modern aquaculture facilities.

[0003] Existing factory-scale recirculating aquaculture systems typically follow standardized water treatment processes. The returned water first passes through a microfilter or drum filter to remove suspended solids, then enters a biofilter where microorganisms convert ammonia nitrogen and nitrite. Finally, after deaeration, oxygenation, and temperature control, it is returned to the aquaculture pond. In actual operation, to reduce the load on the subsequent biofilter and maintain water transparency, the physical filtration stage is usually designed to efficiently intercept and remove particulate organic matter from the water. Meanwhile, the oxygenation and disinfection units in the system are mostly configured and operated independently, respectively responsible for increasing dissolved oxygen content and controlling pathogenic microorganisms. The effluent generated during the aquaculture process is usually discharged directly after simple sedimentation or transported to independent external treatment facilities.

[0004] However, because existing technologies thoroughly remove organic suspended particulate matter during the physical filtration stage, the amount of usable dissolved organic carbon sources in the water entering the subsequent denitrification biological treatment unit is low. This results in insufficient carbon-to-nitrogen ratios for denitrifying bacteria during the nitrogen removal reaction, reducing nitrate removal efficiency. During production, it becomes necessary to artificially add exogenous carbon sources such as methanol or glucose to maintain the performance of the biological system, increasing operating costs and the complexity of water quality management. Furthermore, due to the lack of gas path connection between aeration and disinfection equipment, the undissolved oxygen-enriched tail gas generated during high-pressure gas-liquid mass transfer in the oxygen cone is usually directly discharged into the atmosphere, resulting in waste. Ozone generators also require additional oxygen sources for preparation, leading to low overall gas energy utilization efficiency in the recirculating aquaculture system. Simultaneously, the lack of a dynamic water volume linkage mechanism between the current system and the main circulation loop in tailwater treatment makes it difficult to automatically balance the reuse volume of deeply purified tailwater and the replenishment volume of new water based on the real-time system liquid level, hindering the deep conservation and utilization of water resources. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a recirculating aquaculture system and method that integrates AI decision-making and wastewater reuse optimization. It aims to solve the problems in existing recirculating aquaculture systems, such as the lack of endogenous carbon sources in the denitrification process due to physical filtration, reliance on manual addition, low gas energy utilization due to the independent operation of aeration and disinfection units, and the lack of dynamic water balance control for deep wastewater purification and reuse and fresh water replenishment.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] The first aspect of this invention provides a recirculating aquaculture system integrating AI decision-making and wastewater reuse optimization, comprising:

[0008] The system includes a main aquaculture circulation loop, a biochemical and gas regulation loop, a deep oxygenation loop, a tailwater treatment unit, a source water treatment unit, and a PLC controller.

[0009] The main aquaculture circulation loop is used for water circulation and primary filtration, including an aquaculture pond, a vertical flow separator and a filter pond connected in sequence by pipes. A microfilter is installed inside the filter pond. The outlet of the filter pond is equipped with a diversion structure. The first branch is connected to the suction end of the circulating water pump through the main pipe, and the second branch is connected to the carbon source bypass pipe.

[0010] The biochemical and gas control loop is configured after the circulating water pump and includes a protein separator, a decarbonizer, and a biological tank connected in sequence by pipelines. The outlet of the circulating water pump is connected to the inlet of the protein separator, the protein separator is equipped with an ozone generator, and the decarbonizer is equipped with a low-noise fan. The end of the carbon source bypass pipeline is directly connected to the inlet of the biological tank, and a controlled electric regulating valve is installed on the carbon source bypass pipeline. The inlet of the biological tank is provided with a confluence interface for combining the main water flow from the decarbonizer and the bypass water flow from the carbon source bypass pipeline.

[0011] The deep oxygenation circuit is connected between the biological tank and the aquaculture tank, and includes a clear water tank, a water quality conditioning device, an oxygen cone pump, and an oxygen cone connected in sequence by pipes; the outlet of the biological tank is connected to the clear water tank, and the bottom outlet of the oxygen cone is connected to the inlet of the aquaculture tank through a return pipe; the oxygen cone is connected to an oxygen generator, and the top exhaust port of the oxygen cone is provided with a gas return pipe, which is connected to the air inlet of the ozone generator through a one-way valve to realize the reuse of exhaust gas.

[0012] The wastewater treatment unit is connected to the discharge outlet of the vertical flow separator and the microfilter, and includes a wastewater pretreatment module, a wastewater biological treatment module, a second clear water tank and a recycling module connected in sequence; the reuse tank at the end of the recycling module is connected to the source water treatment unit or the filter tank through a reuse pipeline equipped with a flow regulating valve.

[0013] The PLC controller is connected to the water quality monitor in the system via signal lines to collect data on pH, dissolved oxygen, ammonia nitrogen, chemical oxygen demand, and temperature. It is also connected to the electric regulating valve, pump, and fan via control lines. The PLC controller stores carbon source control logic and water balance logic internally.

[0014] A second aspect of this invention provides a recirculating aquaculture method integrating AI decision-making and wastewater reuse optimization, applied to the aforementioned system, comprising the following steps:

[0015] S1, start the physical filtration process, use the PLC controller to monitor water quality parameters in real time and calculate the carbon-nitrogen ratio requirement according to the preset model, and adjust the opening of the electric regulating valve on the carbon source bypass pipeline accordingly, and divide the water that has been physically filtered into two paths according to the ratio: one path is used as bypass water to retain some dissolved organic carbon source, and the other path is used as main water to enter the deep purification process.

[0016] S2, the main water body is subjected to ozone oxidation and decarbonization treatment, and then the treated main water body is introduced into the biological tank to merge with the bypass water body. The organic carbon source carried by the bypass water body is used to assist the biofilm in denitrification and denitrification reaction to obtain biochemical purified water.

[0017] S3, the biochemically purified water is pumped into the oxygen cone for oxygenation, and the undissolved oxygen-enriched tail gas discharged from the top of the oxygen cone is transported to the ozone generator through the gas return pipeline for recycling as raw material gas for ozone preparation. The oxygenated water is returned to the aquaculture pond.

[0018] S4 collects the wastewater generated from physical filtration and biochemical treatment and performs multi-stage purification. The PLC controller coordinates the amount of purified effluent reused and the amount of fresh water supplied to the source water treatment unit based on the feedback from the liquid level sensors in the aquaculture pond and the filtration pond, so as to maintain the dynamic balance of the total water volume of the system.

[0019] This invention provides a recirculating aquaculture system and method that integrates AI decision-making and wastewater reuse optimization. It offers the following advantages:

[0020] 1. This invention, through the cooperation of a PLC controller and a carbon source bypass pipeline, helps to improve the situation of insufficient carbon source in the denitrification process of the aquaculture system. The system can calculate the carbon-nitrogen ratio requirement based on real-time water quality monitoring data, adjust the diversion ratio of water filtered by the microfilter, and introduce water with some dissolved organic carbon into the biological tank through the bypass. This design uses the organic matter of the aquaculture water itself as an electron donor, which reduces the dependence on external carbon source addition to a certain extent, helps to improve the denitrification efficiency of the biological tank, and helps to maintain the stable operation of the biochemical system.

[0021] 2. This invention constructs a gas cascade utilization structure between the deep oxygenation circuit and the biochemical regulation circuit, which is beneficial to improving the comprehensive utilization efficiency of oxygen. The oxygen-enriched tail gas discharged by the oxygen cone during operation is guided to the ozone generator through the gas return pipeline and used as raw material gas for the protein separator. This structural design reduces the direct emission of high-concentration oxygen, and at the same time, the recovered oxygen source assists in the ozone preparation and oxidation treatment process of the protein separator, which helps to optimize the overall energy consumption performance of the recirculating aquaculture system.

[0022] 3. This invention combines the coordinated control of the wastewater treatment unit and the source water treatment unit, promoting the resource-based reuse of aquaculture wastewater and the balance of system water volume. After multiple stages of treatment, including pretreatment, biochemical degradation, and membrane filtration, the wastewater, in conjunction with the water balance module of the PLC controller, adjusts the reuse amount and the amount of fresh water replenishment based on the liquid level feedback. This operating mode helps to reduce the consumption of fresh water while maintaining the dynamic balance of the total system water volume, which is of positive significance for realizing water conservation and emission reduction in recirculating aquaculture. Attached Figure Description

[0023] Figure 1 This is a system framework diagram in an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the method flow in an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the main aquaculture circulation loop and gas control loop in an embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the connection and process flow of the wastewater treatment unit in an embodiment of the present invention.

[0027] The components include: 1. Aquaculture pond; 2. Vertical flow separator; 3. Filtration pond; 4. Microfilter; 5. Temperature control device; 6. Disinfection device; 7. Circulating water pump; 8. Protein skimmer; 9. Ozone generator; 10. Decarbonizer; 11. Low-noise fan; 12. Biological pond; 13. Clear water pond; 14. Water quality adjustment device; 15. Water quality monitor; 16. Oxygen cone pump; 17. Oxygen cone; 18. Oxygen generator; 19. Wastewater treatment unit; 191. Wastewater pretreatment module; 1911. Wastewater collection well; 1912. Bar screen well; 1913. Equalization pond. 192. Wastewater biological treatment module; 1921. Sedimentation tank; 1922. Air flotation tank; 1923. Acidification tank; 1924. Denitrification tank; 1925. Contact oxidation tank; 1926. Secondary sedimentation tank; 1927. Second biological tank; 1928. High-speed blower; 193. Second clear water tank; 194. Recycling module; 1941. Activated carbon tank; 1942. Ultrafiltration tank; 1943. MBR membrane tank; 1944. Reuse tank; 195. Sludge tank; 196. Sludge dewatering machine; 20. Raw water treatment unit; 21. PLC controller. Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] See attached document Figure 1 This invention provides a recirculating aquaculture system integrating AI decision-making and wastewater reuse optimization, comprising:

[0030] The system comprises a main aquaculture circulation loop, a biochemical and gas regulation loop, a deep aeration loop, a wastewater treatment unit 19, a raw water treatment unit 20, and a PLC controller 21. All modules are connected via pipelines and signal lines, forming a closed-loop control architecture.

[0031] The main aquaculture circulation loop is used for the physical purification and circulation of the aquaculture water. The main aquaculture circulation loop begins at aquaculture pond 1, and the outlet of aquaculture pond 1 is connected to the inlet of vertical flow separator 2 via a gravity pipe. Vertical flow separator 2 is used to settle large suspended solids. The supernatant outlet of vertical flow separator 2 is connected to filter pond 3, which is equipped with a microfilter 4. Microfilter 4 is used to further intercept fine suspended particles in the water. A diversion structure is installed at the outlet of filter pond 3, connecting to the suction end of circulating water pump 7 and a carbon source bypass pipe, respectively.

[0032] The biochemical and gas control loop is used for the removal of dissolved pollutants in the water and the balancing of gas components. The outlet of the circulating water pump 7 is connected to the inlet of the protein skimmer 8. The protein skimmer 8 is equipped with an ozone generator 9, which injects ozone-containing gas into the protein skimmer 8. The outlet of the protein skimmer 8 is connected to the top water distribution device of the decarbonator 10. The decarbonator 10 is equipped with a low-noise fan 11, which blows air into the decarbonator 10 to remove carbon dioxide from the water. The bottom outlet of the decarbonator 10 is connected to the inlet of the biological tank 12.

[0033] In addition, one end of the carbon source bypass pipe is connected to the filter tank 3, and the other end is directly connected to the inlet of the biological tank 12. The carbon source bypass pipe is equipped with a controlled electric regulating valve to allow part of the water flow to bypass the protein separator 8 and the decarbonizer 10. The biological tank 12 is filled with biological packing material for nitrifying bacteria to attach.

[0034] A deep oxygenation circuit is used to regulate the dissolved oxygen content of the water ultimately returned to aquaculture pond 1. The outlet of biological pond 12 is connected to clear water pond 13. A water quality regulating device 14 is installed on the outlet path of clear water pond 13, and the water quality regulating device 14 is connected to the suction end of oxygen cone pump 16. The output end of oxygen cone pump 16 is connected to the tangential inlet of oxygen cone 17. Oxygen cone 17 is connected to oxygen generator 18, which provides high-purity oxygen to oxygen cone 17. The bottom outlet of oxygen cone 17 returns to the inlet of aquaculture pond 1 through a pipe. The top exhaust port of oxygen cone 17 is equipped with a gas return pipe, which is connected to the air inlet of ozone generator 9, delivering undissolved oxygen-enriched exhaust gas to ozone generator 9.

[0035] The wastewater treatment unit 19 is connected to the wastewater discharge node of the main aquaculture circulation loop. The bottom discharge port of the vertical flow separator 2 and the backwash discharge port of the microfilter 4 are respectively connected to the inlet of the wastewater treatment unit 19 through pipes. The outlet of the wastewater treatment unit 19 is connected to a recycling pipeline, which can be selectively connected to the source water treatment unit 20 or directly reused in the main aquaculture circulation loop.

[0036] The source water treatment unit 20 is used to pretreat the supplementary water source. The outlet of the source water treatment unit 20 is connected to the filter tank 3 or the clear water tank 13 through a water supply pipe to replenish the water lost by the system due to evaporation or sewage discharge.

[0037] The PLC controller 21 serves as the system's control center. Its signal input terminals are connected to water quality monitoring instruments 15 distributed within the aquaculture pond 1, biological pond 12, and clear water pond 13. These instruments collect real-time data on pH, dissolved oxygen, ammonia nitrogen, chemical oxygen demand (COD), and temperature. The PLC controller 21's control output terminals are connected via electrical circuits to the microfilter 4, temperature control device 5, disinfection device 6, circulating water pump 7, protein skimmer 8, ozone generator 9, low-noise fan 11, water quality control device 14, oxygen cone pump 16, oxygen generator 18, and electric valves on various pipelines. The PLC controller 21 stores preset control logic, dynamically adjusting the operating status and water flow path of each actuator based on the data collected by the water quality monitoring instruments 15 and the feeding signals.

[0038] The workflow of a recirculating aquaculture system integrating AI decision-making and wastewater reuse optimization mainly includes:

[0039] The water discharged from the aquaculture pond 1 undergoes physical solid-liquid separation through the vertical flow separator 2 and the microfilter 4. Depending on the water quality, the separated water is either entirely treated by the protein separator 8 and the decarbonizer 10 for oxidation and decarbonization, or partially bypassed and directly enters the biological pond 12 for nitrification. The treated water undergoes high-pressure oxygenation in the oxygen cone 17 and is then returned to the aquaculture pond 1. At the same time, the oxygen-enriched tail gas at the top of the oxygen cone 17 is returned to the ozone generator 9 for reuse. Waste generated during the aquaculture process is transported to the wastewater treatment unit 19 for treatment to meet standards or for resource recovery.

[0040] Main aquaculture cycle and physical separation subsystem structure:

[0041] The physical foundation of this system is built on the main aquaculture circulation loop, which is responsible for water collection, primary solid-liquid separation and transportation.

[0042] The main aquaculture circulation loop starts at aquaculture pond 1, which is connected to the inlet of vertical flow separator 2 via a gravity flow pipe at the bottom. Vertical flow separator 2 is used to remove heavier uneaten feed and fish feces particles from the aquaculture water through sedimentation.

[0043] The upper outlet pipe of the vertical flow separator 2 is connected to the filter tank 3. A microfilter 4 is installed inside the filter tank 3. The microfilter 4 is used to intercept fine particulate matter suspended in the water. The microfilter 4 is equipped with a backwashing mechanism, and its drain outlet merges with the bottom drain outlet of the vertical flow separator 2, and both are connected to the inlet of the tailwater treatment unit 19.

[0044] At the outlet of filter tank 3, the system is equipped with a dual-flow diversion structure:

[0045] The first path serves as the main processing path, connected to the suction end of the circulating water pump 7 via a pipeline, and is used to transport the physically filtered water to the subsequent biochemical and gas control loop.

[0046] The second path is a carbon source bypass, consisting of an independent pipe. Its inlet end is connected to the outlet tank of filter tank 3, and its outlet end is directly connected to the inlet end of biological tank 12. An electric regulating valve is installed on this bypass pipe, which is electrically connected to PLC controller 21 to control whether the water flow bypasses the subsequent oxidation and decarbonization stages.

[0047] In addition, the temperature regulating device 5 and the disinfection device 6 are connected in series on the outlet pipe of the circulating water pump 7 and connected to the PLC controller 21 to regulate the water temperature of the system and perform sterilization treatment.

[0048] Structure of the Biochemical and Gas Regulation Subsystem:

[0049] The biochemical and gas regulation loop is located after the physical separation unit of the main aquaculture cycle loop.

[0050] The outlet of the circulating water pump 7 is connected to the inlet of the protein separator 8 via a pipe. The top of the protein separator 8 has a drain outlet, which is connected to the inlet of the wastewater treatment unit 19 via a pipe for discharging the separated foam waste liquid. The air inlet of the protein separator 8 is connected to an ozone generator 9, which is used to inject ozone-containing gas into the protein separator 8.

[0051] The outlet of the protein separator 8 is connected to the top water distributor of the decarbonizer 10. The interior of the decarbonizer 10 is filled with gas-liquid contact packing, and a low-noise fan 11 is connected externally. The outlet of the low-noise fan 11 is connected to the air inlet at the bottom of the decarbonizer 10 to blow air into the decarbonizer 10.

[0052] The bottom outlet of the decarbonizer 10 is connected to the inlet of the biological tank 12 via a pipe. The biological tank 12 is filled with biological carriers. The inlet of the biological tank 12 is equipped with a manifold interface, which connects both the outlet pipe of the decarbonizer 10 and the carbon source bypass pipe from the filter tank 3, so that the main flow and the bypass flow are combined before or during entry into the biological tank 12.

[0053] In addition, the system is equipped with a gas return pipeline. The input end of this gas return pipeline is connected to the top exhaust port of the oxygen cone 17 in the subsequent deep oxygenation circuit, and the output end is connected to the air inlet port of the ozone generator 9. This structure delivers the undissolved oxygen-enriched gas discharged from the oxygen cone 17 to the ozone generator 9 as the source of raw gas.

[0054] The ozone generator 9 and the low-noise fan 11 are connected to the PLC controller 21 through electrical circuits, and the PLC controller 21 controls their start-up, shutdown and operating power.

[0055] Structure of the deep oxygenation and reflux subsystem:

[0056] The deep oxygenation circuit is connected between biological pond 12 and aquaculture pond 1.

[0057] The outlet of the biological tank 12 is connected to the clear water tank 13. A water quality conditioning device 14 is connected to the outlet pipe of the clear water tank 13. The water quality conditioning device 14 includes a pipe mixer connected in series on the pipe and a dosing pump connected to the pipe mixer, which is electrically connected to the PLC controller 21. The outlet of the water quality conditioning device 14 is connected to the suction end of the oxygen cone pump 16.

[0058] The output end of the oxygen cone pump 16 is connected to the tangential inlet at the top of the oxygen cone 17 via a pipe. The top air inlet of the oxygen cone 17 is connected to an oxygen generator 18 via a gas pipe. The bottom outlet of the oxygen cone 17 is connected to the inlet of the aquaculture pond 1 via a pipe. A back pressure regulating valve is installed on the outlet pipe at the bottom of the oxygen cone 17 to regulate the internal working pressure of the oxygen cone 17.

[0059] An automatic exhaust valve is connected to the top exhaust port of the oxygen cone 17, and the outlet of the automatic exhaust valve is connected to the input end of the gas return pipeline. A one-way valve is installed on the gas return pipeline, and its output end is connected to the air inlet of the ozone generator 9.

[0060] The clear water tank 13 is equipped with a water quality monitor 15, which is used to collect dissolved oxygen and pH data of the water. Its signal output terminal is connected to the PLC controller 21. The oxygen cone pump 16 and the oxygen generator 18 are both electrically connected to the PLC controller 21.

[0061] Tailwater cascade treatment and resource recovery subsystem structure:

[0062] The wastewater treatment unit 19 is connected to the end of the main aquaculture circulation loop. The bottom drain of the vertical flow separator 2 and the backwash drain of the microfilter 4 are both connected to the inlet of the wastewater treatment unit 19 through pipes.

[0063] The wastewater treatment unit 19 includes a wastewater pretreatment module 191, a wastewater biological treatment module 192, a second clear water tank 193, and a recycling module 194 connected in sequence.

[0064] The effluent pretreatment module 191 includes an effluent collection well 1911, a bar screen well 1912, and a regulating tank 1913, which are connected in sequence by pipelines. The effluent collection well 1911 is connected to the sewage discharge pipe. A mechanical bar screen is installed inside the bar screen well 1912. A submersible mixer and a booster pump are installed inside the regulating tank 1913.

[0065] The booster pump in equalization tank 1913 is connected to the effluent biological treatment module 192 via pipeline. The effluent biological treatment module 192 includes a sedimentation tank 1921, a dissolved air flotation (DAF) tank 1922, an acidification tank 1923, a denitrification tank 1924, a contact oxidation tank 1925, a secondary sedimentation tank 1926, and a second biological treatment tank 1927, all connected sequentially via waterways. Sedimentation tank 1921 is equipped with a central guide tube and an overflow weir, which is connected to the DAF tank 1922. The outlet of the DAF tank 1922 is connected to the acidification tank 1923. Acidification tank 1923, denitrification tank 1924, and contact oxidation tank 1925 are connected in series. Contact oxidation tank 1925 is connected to the secondary sedimentation tank 1926. The supernatant outlet of the secondary sedimentation tank 1926 is connected to the second biological treatment tank 1927.

[0066] The effluent biological treatment module 192 also includes a high-speed blower 1928. The air outlet pipe of the high-speed blower 1928 is branched to the bottom aeration head of the contact oxidation tank 1925 and the second biological tank 1927.

[0067] The outlet of the second biological treatment tank 1927 is connected to the second clear water tank 193. The outlet of the second clear water tank 193 is connected to the recovery module 194. The recovery module 194 includes an activated carbon tank 1941, an ultrafiltration tank 1942, an MBR membrane tank 1943, and a reuse tank 1944 connected in series. The MBR membrane tank 1943 is equipped with a membrane module and a suction pump. The reuse tank 1944 is connected to the source water treatment unit 20 or the filter tank 3 through a reuse pipeline. This reuse pipeline is equipped with a flow regulating valve, which is electrically connected to the PLC controller 21.

[0068] In addition, the effluent treatment unit 19 is also equipped with sludge treatment pipelines. The bottom sludge discharge ports of the sedimentation tank 1921, the dissolved air flotation tank 1922, the secondary sedimentation tank 1926, and the MBR membrane tank 1943 are all connected to the sludge tank 195. The sludge tank 195 is connected to the sludge dewatering machine 196.

[0069] The water pumps, fans, dewatering machines, and electric valves in the system are all electrically connected to the PLC controller 21.

[0070] Structure of the raw water treatment and replenishment subsystem:

[0071] The inlet of the raw water treatment unit 20 is connected to an external water source via a pipe. The raw water treatment unit 20 includes a raw water pump, a sedimentation tank, a multi-media filter, and a precision filter connected sequentially along the water flow direction. The outlet pipe of the raw water pump is connected to the inlet of the sedimentation tank, the outlet of the sedimentation tank is connected to the top inlet of the multi-media filter, and the outlet of the multi-media filter is connected to the inlet of the precision filter.

[0072] The inlet pipe of the raw water treatment unit 20 is also equipped with a reuse interface, which is connected to the outlet pipe of the reuse tank 1944 in the tailwater treatment unit 19, so that the reused water and the raw water are combined and enter the treatment process.

[0073] The outlet of the precision filter is connected to a water supply pipe, the end of which is connected to filter tank 3 in the main aquaculture circulation loop. A water supply flow meter and a water supply electric valve are installed in series on the water supply pipe.

[0074] The source water pump and the water supply electric valve are both connected to the PLC controller 21 via control lines.

[0075] Control and decision subsystem structure:

[0076] The PLC controller 21 is installed in the electrical control cabinet and includes a central processing unit, memory, input / output modules, and communication interface connected via an internal bus. The PLC controller 21 is connected to a human-machine interface (HMI) via the communication interface.

[0077] The signal input terminals of the PLC controller 21 are connected to sensors throughout the system via shielded cables, specifically including:

[0078] Water quality monitoring instrument 15 located in clear water tank 13; liquid level sensor located in aquaculture tank 1 and filter tank 3; gas flow meter located on gas return pipeline; flow meter located on water supply pipeline of source water treatment unit 20.

[0079] The control output terminals of the PLC controller 21 are connected to the actuators in various parts of the system via relays, contactors, or frequency converters, specifically including:

[0080] The inverters connect to the circulating water pump 7, oxygen cone pump 16, source water pump, and lift pump in the equalization tank 1913; the start / stop control terminals connect to the temperature control device 5, disinfection device 6, ozone generator 9, low-noise fan 11, oxygen generator 18, high-speed fan 1928, MBR suction pump, and sludge dewatering machine 196; and the control terminals connect to the electric regulating valve on the carbon source bypass, the flow regulating valve on the reuse pipeline of the tailwater treatment unit 19, and the water replenishment electric valve of the source water treatment unit 20.

[0081] The PLC controller 21 has a pre-stored control logic program in its memory. This program includes: a dissolved oxygen control module, used to adjust the operating parameters of the oxygen cone pump 16 and the oxygen generator 18 according to the data from the water quality monitor 15; a carbon source regulation module, used to adjust the opening of the electric regulating valve on the carbon source bypass; and a water balance module, used to coordinate the operation of the flow regulating valve and the water replenishment electric valve according to the data from the liquid level sensor and the flow meter.

[0082] See attached document Figure 2This invention provides a recirculating aquaculture method integrating AI decision-making and wastewater reuse optimization, comprising the following steps:

[0083] S1, start the system to perform physical filtration, use PLC controller 21 to monitor water quality in real time and calculate carbon-nitrogen ratio requirements, adjust the diversion ratio of carbon source bypass accordingly, and divide the water body after physical filtration into two paths: one path is used as bypass water body to directly retain carbon source, and the other path is used as main water body to enter the deep purification process.

[0084] S2, the main water body is subjected to ozone oxidation and decarbonization treatment in sequence, and then introduced into biological pond 12 to merge with the bypass water body. The organic carbon source carried by the bypass water body is used to complete the biochemical denitrification reaction in synergy, and biochemical purified water is produced.

[0085] S3, the biochemically purified water is pumped into the oxygen cone 17 for high-pressure supersaturation oxygenation. At the same time, the oxygen-enriched tail gas discharged from the oxygen cone 17 is returned to the ozone generator 9 in step S2 through the gas return pipeline as raw material gas for recycling. The oxygenated water is returned to the aquaculture pond 1.

[0086] S4. Collect the wastewater generated in steps S1 and S2 for deep purification. The PLC controller 21 adjusts the amount of purified tailwater reused and the amount of fresh water supplied to the source water treatment unit 20 in coordination with the system liquid level feedback to maintain the dynamic balance of the total water volume of the system.

[0087] The implementation details of the above steps will be explained in detail below, taking into account specific operating data and control logic.

[0088] Step S1 involves physical filtration of the aquaculture water and control of the distribution of organic carbon sources.

[0089] During system operation, the PLC controller 21 reads the liquid level data of the aquaculture tank 1 and the filter tank 3, and controls the operation of the circulating water pump 7 and the microfilter 4. Water in the aquaculture tank 1 enters the vertical flow separator 2 through a pipe, where large suspended solids are removed by gravity sedimentation. The supernatant after sedimentation enters the microfilter 4 through a pipe. The filter screen of the microfilter 4 intercepts fine suspended particles, and the filtered water flows into the filter tank 3 for temporary storage, forming mechanically filtered water. During this process, the separated solid waste is discharged into the wastewater treatment unit 19 through a sewage pipe.

[0090] Meanwhile, the PLC controller 21 performs carbon source allocation control. The PLC controller 21 calls the internally stored carbon-nitrogen ratio calculation model, which uses the system's preset daily feeding parameters and the real-time pH value and ammonia nitrogen data fed back by the water quality monitor 15 as input variables to estimate the current ammonia nitrogen production rate of the water body and the theoretical amount of carbon source required for denitrification.

[0091] If the calculated theoretical carbon source amount is greater than the estimated background carbon source amount of the current water body, it indicates that the carbon source needs to be supplemented. The PLC controller 21 outputs a signal to increase the opening of the electric regulating valve on the carbon source bypass. At this time, part of the mechanically filtered water containing dissolved organic matter in the filter tank 3 is used as bypass water under water pressure and is directly transported to the biological tank 12 through the carbon source bypass.

[0092] If the calculation results show that the ammonia nitrogen load is too high or no additional carbon source is needed, the PLC controller 21 reduces or closes the electric regulating valve, so that the mechanically filtered water mainly enters the protein separator 8 for subsequent treatment. By adjusting the opening of the electric regulating valve, the total amount of dissolved organic matter entering the subsequent biochemical reaction unit is controlled.

[0093] In this embodiment, the cascade physical filtration of the vertical flow separator 2 and the microfilter 4 effectively reduces the load of suspended solids in the water. Simultaneously, the PLC controller 21 intelligently adjusts the diversion ratio of the carbon source bypass based on feeding parameters, achieving on-demand retention of dissolved organic carbon sources in the water. This diversion mechanism ensures the treatment efficiency of subsequent oxidation units while helping to maintain the optimal carbon-to-nitrogen ratio of the influent to the biological tank 12, thereby improving the denitrification performance of the system without the need for external carbon sources.

[0094] Step S2 involves pre-treatment of the main water body after diversion in step S1 by oxidation and decarbonization, and then merging it with the bypass water body for biochemical degradation.

[0095] The main water in filter tank 3 enters protein skimmer 8 through a pipeline. PLC controller 21 controls ozone generator 9 to inject ozone gas into the reaction chamber of protein skimmer 8 and mix it with the water. The strong oxidizing properties of ozone decompose dissolved organic matter and color factors in the water, while air flotation is used to coagulate suspended particles and discharge them through the top foam outlet to effluent treatment unit 19.

[0096] After oxidation treatment, the water flows into the decarbonator 10. The PLC controller 21 starts the blower of the decarbonator 10 to aerate the water. This process removes the carbon dioxide accumulated in the water to maintain a stable pH value, and also removes and decomposes the residual ozone in the water, reducing the redox potential of the water and preventing residual ozone from inhibiting the subsequent biofilm activity.

[0097] The pretreated main channel water flows into biological tank 12 and mixes with the bypass water introduced via the carbon source bypass in step S1. The mixed water flows through the biological packing material in biological tank 12. Under aerobic conditions, nitrifying bacteria on the surface of the biofilm convert ammonia nitrogen into nitrate; simultaneously, utilizing the micro-anoxic environment inside the biofilm and the dissolved organic carbon source provided by the bypass water, denitrifying bacteria carry out simultaneous nitrification and denitrification reactions, reducing some nitrate into nitrogen gas which escapes. The treated biochemically purified water flows into clear water tank 13 for temporary storage.

[0098] In this embodiment, by setting a protein separator 8 and a decarbonizer 10 at the front end of the biological tank 12, not only are the organic load and carbon dioxide that inhibit the nitrification reaction removed, but the air lift effect of the decarbonizer is also used to eliminate the residual ozone toxicity. In addition, the bypass water is used to directionally supplement the carbon source in the anoxic zone inside the biofilm, so that aerobic nitrification and anoxic denitrification can be carried out in a single biological tank.

[0099] Step S3 involves oxygenating the biochemically purified water and recovering undissolved oxygen for ozone preparation.

[0100] PLC controller 21 starts the oxygen cone pump 16, pumping water from the clear water tank 13 into the oxygen cone 17. Simultaneously, high-purity oxygen generated by the oxygen generator 18 is injected into the inlet pipe or top inlet of the oxygen cone 17. Inside the oxygen cone 17, the water flow velocity decreases as the cone's cross-sectional area increases, and air bubbles, under buoyancy, remain in the upper part of the cone, contacting the water flow in a counter-current or turbulent manner. By adjusting the outlet pressure of the oxygen cone pump 16 and the opening of the outlet valve at the bottom of the oxygen cone 17, the working pressure inside the cone is maintained at 0.1-0.4 MPa, ensuring that the oxygen is supersaturated and dissolved in the water. The oxygenated water is then returned to the aquaculture tank 1.

[0101] During the oxygenation process, the undissolved oxygen-enriched gas accumulated at the top of the oxygen cone 17 is discharged through the exhaust port. This oxygen-enriched exhaust gas enters the gas-water separator (a conventional configuration in the art) through the gas return pipeline to remove entrained water vapor, and after the pressure is regulated by the pressure reducing and stabilizing valve, it is delivered to the air inlet of the ozone generator 9 in step S2. The PLC controller 21 coordinates the supply of oxygen-enriched exhaust gas according to the air inlet flow requirements of the ozone generator 9; if the exhaust gas volume is insufficient, the oxygen generator 18 directly supplements oxygen to the ozone generator 9.

[0102] In this embodiment, oxygen cone 17 is used to achieve high-concentration oxygenation of the aquaculture water; at the same time, the exhaust gas rich in high-purity oxygen is recovered as the raw material gas for ozone generator 9. Compared with air source ozone preparation, the ozone production rate and concentration are increased, and the total oxygen consumption of the system is reduced.

[0103] Step S4 involves treating the contaminated waste and maintaining the system's water level.

[0104] PLC controller 21 controls the opening of the drain valve, which transports the sediment from vertical flow separator 2, the backwash water from microfilter 4, and the discharge foam from protein separator 8 to the tailwater treatment unit 19 through the drain network.

[0105] In the effluent treatment unit 19, the wastewater first enters the sedimentation tank 1921 for gravity concentration and separation. The separated bottom sludge is periodically pumped out by a sludge pump for dewatering or transported off-site; the upper clarified liquid flows into the biological contact oxidation tank to further degrade dissolved organic matter and ammonia nitrogen in the water. The treated supernatant is temporarily stored in the reuse water tank.

[0106] Simultaneously, the PLC controller 21 monitors the liquid level signals of the aquaculture tank 1 and the filter tank 3, and performs water replenishment control: when the system liquid level is lower than the set lower limit, the PLC controller 21 prioritizes starting the return water pump of the tailwater treatment unit 19, pumping the temporarily stored purified tailwater into the filter tank 3, so that it re-enters the main circulation treatment process. If the liquid level in the return water tank is insufficient (low liquid level alarm), the PLC controller 21 opens the inlet valve of the source water treatment unit 20. External water is replenished into the system after being filtered by the source water treatment unit 20 until the monitored system liquid level returns to the normal range.

[0107] In this embodiment, solid waste and wastewater discharged from each stage are centrally settled and biochemically treated to separate solid sludge and recover supernatant. The priority water replenishment mechanism established by the PLC controller 21 prioritizes the use of purified tailwater to replenish system evaporation and sewage discharge losses, and only replenishes external source water when necessary, thereby maintaining the water balance of the aquaculture system and reducing the consumption of new water.

[0108] Working Principle: First, in the main aquaculture circulation loop, the polluted aquaculture water discharged from aquaculture pond 1 flows by gravity through vertical flow separator 2, pre-separating large particles of suspended solids using the principle of gravity sedimentation. The supernatant then enters filter pond 3, where it is further intercepted by the internally installed microfilter 4. At this stage, PLC controller 21 executes carbon source control logic based on real-time pH and ammonia nitrogen data collected by water quality monitoring instruments 15 distributed in each pond. By adjusting the opening of the electric regulating valve on the carbon source bypass pipeline, the water that has undergone physical filtration is divided into two paths: one part of the water serves as bypass water, retaining the dissolved organic carbon originally contained in the water, and is directly introduced into biological pond 12; the other part of the water serves as main water, which is drawn into the deep purification process by circulating water pump 7, utilizing the aquaculture water's own endogenous carbon source to provide the necessary electron donor for subsequent biochemical denitrification.

[0109] Secondly, the main water body flows through the temperature regulating device 5 and the disinfection device 6 under pressure to ensure a constant water temperature and kill pathogens. Then, the water body enters the protein separator 8, which uses the principle of air flotation to remove fine suspended solids and colloidal organic matter. The gas used in the protein separator 8 is not ordinary air, but oxygen-enriched return tail gas from the top of the oxygen cone 17 in the deep oxygenation circuit (which enters the ozone generator 9 through a one-way valve and is converted into ozone before use), realizing the cascade recycling of gas. The water body that has undergone strong oxidation treatment then enters the decarbonizer 10, where the carbon dioxide accumulated in the water body is blown off by the gas-liquid contact packing under the action of the low-noise fan 11, maintaining the stability of the water quality pH value.

[0110] Next, the main water, after decarbonization treatment, and the bypass water carrying the carbon source are fully mixed at the inlet of the biological tank 12. Inside the biological tank 12, the microbial community utilizes the organic carbon source supplemented by the bypass water to efficiently carry out nitrification and denitrification reactions, converting ammonia nitrogen and nitrite into harmless nitrogen gas. The purified water flows into the clear water tank 13, and after being finely adjusted by the water quality conditioning device 14, it is pumped into the oxygen cone 17 by the oxygen cone pump 16. The water flows tangentially at high speed into the oxygen cone 17, where it is mixed countercurrently with the pure oxygen generated by the oxygen generator 18 under a high pressure environment of 0.1-0.4 MPa, achieving efficient gas-liquid mass transfer and supersaturated dissolution. The oxygenated, highly dissolved oxygen water is finally returned to the aquaculture tank 1, completing the closed loop.

[0111] Finally, the wastewater generated during system operation (from vertical flow separator 2, microfilter 4, and protein separator 8) is collected in the tailwater treatment unit 19. After being filtered and regulated by the tailwater pretreatment module 191, it enters the tailwater biological treatment module 192 for multi-stage biochemical degradation, and is supplied with oxygen by the high-speed blower 1928. The generated residual sludge is discharged into the sludge tank 195 and treated by the sludge dewatering machine 196, while the supernatant enters the recovery module 194 and undergoes deep purification through the activated carbon tank 1941, ultrafiltration tank 1942, and MBR membrane tank 1943. The PLC controller 21 monitors the liquid level sensor data of the entire system in real time and, based on the water balance logic, coordinates the reuse rate of the tailwater treatment unit 19 through the flow regulating valve and the fresh water supply rate of the source water treatment unit 20, so as to maximize the utilization of water resources while maintaining the dynamic balance of the total water volume of the system.

Claims

1. A recirculating aquaculture system integrating AI decision-making and wastewater reuse optimization, characterized in that, include: The main aquaculture circulation loop is configured to perform physical filtration and solid-liquid separation on the aquaculture water, and a dual-path diversion architecture is constructed at the output end of the physical filtration. The dual-path diversion architecture includes a main passage connected to the deep purification process and a carbon source bypass pipe for conveying water flow that retains endogenous organic carbon. The biochemical and gas control loop is configured to receive the water flow from the main channel for oxidation and degassing, and to receive the water flow from the carbon source bypass pipe for synergistic denitrification using the carried organic carbon source. The biochemical and gas control loop is also configured with a gas cascade utilization architecture, which recovers undissolved oxygen-enriched tail gas through a gas return pipeline and transports it to an ozone generator for secondary utilization. The deep oxygenation circuit is configured to perform high-pressure oxygenation on the biochemically treated water and provide the generated oxygen-enriched tail gas to the gas cascade utilization architecture. The tailwater treatment unit (19) and the source water treatment unit (20) are respectively configured to perform multi-stage deep purification of system sewage to generate reclaimed water and to pre-treat external water sources; The PLC controller (21) is configured to communicate with the above-mentioned loops and units, execute carbon source control logic, adjust the flow ratio of the carbon source bypass pipeline based on water quality data, execute water balance logic, and coordinate the reuse amount of the tailwater treatment unit (19) and the replenishment amount of the source water treatment unit (20) based on liquid level data.

2. The recirculating aquaculture system integrating AI decision-making and wastewater reuse optimization according to claim 1, characterized in that, The main aquaculture circulation loop includes an aquaculture pond (1), a vertical flow separator (2) and a filter pond (3) connected in sequence by pipes. A microfilter (4) is installed in the filter pond (3). The dual-path diversion architecture is set at the outlet of the filter tank (3): the first path is connected to the suction end of the circulating water pump (7) through the main pipeline, the second path is connected to the carbon source bypass pipeline, and a controlled electric regulating valve is installed on the carbon source bypass pipeline. A temperature regulating device (5) and a disinfection device (6) are also connected in series on the outlet pipe of the circulating water pump (7); the bottom drain of the vertical flow separator (2) and the drain of the microfilter (4) are both connected to the inlet of the tailwater treatment unit (19).

3. The recirculating aquaculture system integrating AI decision-making and wastewater reuse optimization according to claim 2, characterized in that, The biochemical and gas regulation circuit includes a protein separator (8), a carbon remover (10), and a biological pool (12) connected in sequence by pipelines. The outlet of the circulating water pump (7) is connected to the protein separator (8), and the protein separator (8) is equipped with an ozone generator (9); the drain outlet of the protein separator (8) is connected to the wastewater treatment unit (19). The decarbonizer (10) is equipped with a low-noise blower (11) for aeration of the water flowing through it; the end of the carbon source bypass pipe is directly connected to the inlet of the biological tank (12) for merging the main water flow from the decarbonizer (10) and the bypass water flow from the carbon source bypass pipe.

4. The recirculating aquaculture system integrating AI decision-making and wastewater reuse optimization according to claim 3, characterized in that, The deep oxygenation circuit includes a clear water tank (13), a water quality adjustment device (14), an oxygen cone pump (16), and an oxygen cone (17) connected in sequence by pipes. The bottom outlet of the oxygen cone (17) is connected to the aquaculture pond (1), and the top exhaust port is connected to the gas return pipeline. The gas cascade utilization architecture is specifically manifested as follows: the gas return pipeline is connected to the air inlet port of the ozone generator (9) through a one-way valve, and the exhaust gas of the oxygen cone (17) is used as the gas source of the ozone generator (9). The oxygen cone (17) is also connected to an oxygen generator (18).

5. A recirculating aquaculture system integrating AI decision-making and wastewater reuse optimization according to claim 2, characterized in that, The tailwater treatment unit (19) includes a tailwater pretreatment module (191), a tailwater biological treatment module (192), a second clear water tank (193), and a recycling module (194) connected in sequence. The recycling tank (1944) at the end of the recycling module (194) is connected to the source water treatment unit (20) or the filter tank (3) through a recycling pipeline equipped with a flow regulating valve. The flow regulating valve is electrically connected to the PLC controller (21).

6. The recirculating aquaculture system integrating AI decision-making and wastewater reuse optimization according to claim 5, characterized in that, The tailwater pretreatment module (191) includes a tailwater collection well (1911), a bar screen well (1912), and a regulating tank (1913) connected in sequence. The tailwater biological treatment module (192) includes a sedimentation tank (1921), an air flotation tank (1922), an acidification tank (1923), a denitrification tank (1924), a contact oxidation tank (1925), a secondary sedimentation tank (1926), and a second biological tank (1927) that are connected in sequence by waterways. The tailwater biological treatment module (192) is also connected to a high-speed blower (1928), and the outlet pipe of the high-speed blower (1928) is branched to the bottom of the contact oxidation tank (1925) and the second biological tank (1927); The recovery module (194) includes an activated carbon tank (1941), an ultrafiltration tank (1942), and an MBR membrane tank (1943) connected in series.

7. A recirculating aquaculture system integrating AI decision-making and wastewater reuse optimization as described in claim 6, characterized in that, The tailwater treatment unit (19) also includes a sludge tank (195) and a sludge dewatering machine (196). The sludge tank (195) is connected to the bottom sludge discharge port of the sedimentation tank (1921), the flotation tank (1922), the secondary sedimentation tank (1926), and the MBR membrane tank (1943) through pipelines.

8. A recirculating aquaculture system integrating AI decision-making and wastewater reuse optimization according to claim 4, characterized in that, The system also includes a water quality monitor (15) distributed in the aquaculture pond (1), the biological pond (12) and the clear water pond (13), and a liquid level sensor located in the aquaculture pond (1) and the filtration pond (3); The signal output terminals of the water quality monitor (15) and the liquid level sensor are both connected to the PLC controller (21).

9. A recirculating aquaculture system integrating AI decision-making and wastewater reuse optimization according to claim 5, characterized in that, The source water treatment unit (20) includes a source water pump, a sedimentation tank, a multi-media filter and a precision filter connected in sequence along the water flow direction; the outlet of the precision filter is connected to the main aquaculture circulation loop.

10. A recirculating aquaculture system integrating AI decision-making and wastewater reuse optimization, applied to a recirculating aquaculture system integrating AI decision-making and wastewater reuse optimization according to any one of claims 1-9, characterized in that, include: S1. Start the system for physical filtration. Use the PLC controller (21) to monitor the water quality in real time and calculate the carbon-nitrogen ratio requirement. Adjust the diversion ratio of the carbon source bypass pipe accordingly. Divide the water body after physical filtration into two paths: one path is used as bypass water body to directly retain the carbon source, and the other path is used as main water body to enter the deep purification process. S2. The main water body is subjected to ozone oxidation and decarbonization treatment in sequence. Then the treated main water body is introduced into the biological pool (12) and merged with the bypass water body. The organic carbon source carried by the bypass water body is used to complete the biochemical denitrification reaction in synergy, and biochemical purified water is obtained. S3. The biochemically purified water is pumped into the oxygen cone (17) for high-pressure supersaturation oxygenation. At the same time, the oxygen-enriched tail gas discharged from the oxygen cone (17) is returned to the ozone generator (9) in step S2 through the gas return pipeline as raw material gas for circulation. The oxygenated water is returned to the aquaculture pond (1). S4. Collect the wastewater generated in steps S1 and S2 for deep purification. The PLC controller (21) adjusts the amount of purified tailwater reused and the amount of new water supplied to the source water treatment unit (20) in coordination with the system liquid level feedback to maintain the dynamic balance of the total water volume of the system.

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