A recirculating aquaculture system

Abstract

This application provides a recirculating aquaculture system, relating to the field of aquaculture technology. By setting up a main water circulation loop, wastewater discharged from the aquaculture ponds is treated by a water circulation treatment module and then returned to the ponds for reuse, reducing water consumption and pollution caused by direct discharge of aquaculture wastewater, thus conforming to the concept of green aquaculture. The water circulation treatment module adopts a multi-stage treatment structure of "microfilter + primary biological treatment tank + secondary biological treatment tank + disinfection chamber." The microfilter removes solid particles from the water, the primary biological treatment tank specifically degrades ammonia nitrogen, and the secondary biological treatment tank specifically degrades nitrite, solving the problem of harmful nitrogen accumulation in the aquaculture water. The disinfection chamber kills harmful microorganisms in the water, reducing the spread of aquaculture diseases.

Description

Technical Field

[0001] This invention relates to the field of aquaculture technology, and more specifically, to a recirculating aquaculture system. Background Technology

[0002] Traditional flow-through or still-water aquaculture systems primarily use water for single-use, requiring frequent water changes and consuming large amounts of water. Furthermore, nitrogenous waste (such as ammonia nitrogen and nitrite) and potential pathogens generated during the aquaculture process, including uneaten feed and feces, are directly discharged into the external environment with the wastewater, causing water pollution. This not only fails to meet the requirements of sustainable development but also poses a high risk of cross-infection of diseases. Therefore, we propose an improvement: a recirculating aquaculture system. Summary of the Invention

[0003] This invention provides a recirculating aquaculture system, including a water circulation treatment module and several parallel aquaculture ponds; The water circulation treatment module includes a microfilter, a pump tank, a primary biological treatment tank, a secondary biological treatment tank, and a disinfection chamber connected in sequence; the outlet of the microfilter is connected to the pump tank; the outlet of the disinfection chamber is connected to the aquaculture tank, and the outlet of the aquaculture tank is connected to the microfilter, forming the main water circulation loop.

[0004] As a preferred technical solution of this application, the microfilter is used to perform preliminary filtration of solid particles in the water discharged from the aquaculture pond; The primary biochemical tank is used to degrade ammonia nitrogen in the water. The secondary biological treatment tank is used to degrade nitrite in the water. The disinfection chamber is equipped with an ultraviolet sterilization device and an ozone sterilization device to disinfect the water after it has been treated in the secondary biological treatment tank.

[0005] As a preferred technical solution of this application, the aquaculture pond is also connected to a tailwater treatment end. When the aquaculture organisms in a certain aquaculture pond suffer from disease, the drainage of the aquaculture pond is switched to the tailwater treatment end, and after treatment, it is discharged into the microfilter or directly discharged to the outside of the system. The wastewater treatment end includes a sedimentation tank, a filter, and an enhanced disinfection tank in sequence, wherein the disinfection intensity of the enhanced disinfection tank is not less than twice the disinfection intensity of the disinfection chamber.

[0006] As a preferred technical solution of this application, the ratio R of the water treatment flow rate Qh (unit: m³ / h) of the water circulation treatment module to the total aquaculture water volume Vt (unit: m³) of all aquaculture ponds, i.e. the system circulation rate, satisfies: 1≤R≤3, where R=Qh / Vt.

[0007] As a preferred technical solution of this application, the total effective volume Vb (unit: m³) of the primary and secondary biological treatment tanks satisfies the following relationship with the total nitrogen input T (unit: kg / d / day) of the system through feed per day: Vb≥(T*SRT) / (C*1000), where SRT (sludge age) is 10-30 days, and C is the average biofilm concentration of the biological packing material in the biological tank, with a value range of 5-15 kg / m³.

[0008] As a preferred technical solution of this application, it also includes an online water quality monitoring module, which includes a water quality sensor installed at least one of the pump pool, the outlet of the primary biological treatment tank, the outlet of the secondary biological treatment tank, and the outlet of the disinfection chamber, for real-time monitoring of one or more parameters among dissolved oxygen, pH value, ammonia nitrogen, nitrite, nitrate, and turbidity in the water.

[0009] As a preferred technical solution of this application, it also includes a central controller. The circulation of aquaculture water is powered by a water pump. The central controller is communicatively connected to the online water quality monitoring module, the water pump, the sterilization device in the disinfection chamber, and the control valve connecting the aquaculture pond and the effluent treatment end. The central controller is configured as follows: Based on the data fed back by the online water quality monitoring module, the water pump flow rate and the sterilization intensity of the disinfection chamber are automatically adjusted. When the water quality parameters of a certain aquaculture pond are detected to be continuously abnormal, the corresponding control valve is automatically controlled to switch the drainage of the aquaculture pond to the tailwater treatment end.

[0010] As a preferred technical solution of this application, the water in the disinfection chamber is injected into the aquaculture pond in the form of a jet, so as to entrain air during the injection process to achieve air-water mixing and oxygenation; The jet direction forms an angle of 0 to 45 degrees with the horizontal plane, and the jet of water is directed towards the wall of the aquaculture pond.

[0011] As a preferred technical solution of this application, the microfilter is also connected to a water supply end for receiving external water supply; The water supply end is equipped with a flow control valve and a water pretreatment device. The water pretreatment device includes a quartz sand filter and an activated carbon filter arranged in sequence to remove suspended solids, odors and organic matter from the external water supply. The flow control valve is connected to the central controller, which automatically adjusts the water supply according to the water level in the system.

[0012] As a preferred technical solution of this application, the pump pool is equipped with a submersible sewage pump and a liquid level sensor. The liquid level sensor is used to monitor the water level in the pump pool in real time. When the water level is higher than the preset upper limit, the submersible sewage pump is started to discharge the excess water. When the water level is lower than the preset lower limit, the central controller controls the water supply end to start water supply to ensure that the water level in the pump pool is stable within the preset range.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This application sets up a main water circulation loop, which treats the wastewater discharged from the aquaculture pond through a water circulation treatment module and then re-transports it to the aquaculture pond for reuse, thereby reducing the consumption of water resources and reducing the pollution caused by the direct discharge of aquaculture wastewater to the environment, which is in line with the concept of green aquaculture. 2. The water circulation treatment module adopts a multi-stage treatment structure of "microfilter + primary biological tank + secondary biological tank + disinfection chamber". The microfilter can remove solid particles in the water, the primary biological tank specifically degrades ammonia nitrogen, and the secondary biological tank specifically degrades nitrite, which solves the problem of harmful nitrogen accumulation in aquaculture water. The disinfection chamber can kill harmful microorganisms in the water and reduce the spread of aquaculture diseases. 3. Several breeding ponds are set up in parallel, and the number of breeding ponds can be flexibly adjusted according to the breeding scale. Moreover, the inspection and maintenance of a single breeding pond will not affect the normal operation of the entire system. Attached Figure Description

[0014] Figure 1 A schematic diagram of the recirculating aquaculture system provided in this application; Figure 2 Diagram of water treatment for diseased aquaculture ponds provided in this application. Detailed Implementation

[0015] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0016] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0017] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0018] For an example, please refer to... Figures 1-2 A recirculating aquaculture system, comprising a water circulation and treatment module and several parallel aquaculture ponds; The water circulation treatment module includes a microfilter, a pump tank, a primary biological treatment tank, a secondary biological treatment tank, and a disinfection chamber connected in sequence. The outlet of the microfilter is connected to the pump tank; the outlet of the disinfection chamber is connected to the aquaculture pond, and the outlet of the aquaculture pond is connected to the microfilter, forming the main water circulation loop. The closed loop ensures that the aquaculture water does not need to be discharged in large quantities, and only a small amount of water loss needs to be added to maintain the system operation, reducing water waste. The parallel structure reduces the impact of a single aquaculture pond failure on the overall system and disperses operational risks.

[0019] Furthermore, microfilters are used for the preliminary filtration of solid particles in the water discharged from the aquaculture pond. If solid particles such as uneaten feed and feces enter the biological tank, they will cover the surface of the biological packing material, hindering the contact between microorganisms and the water, reducing the degradation efficiency of pollutants such as ammonia nitrogen and nitrite, and the long-term accumulation of solid impurities will breed harmful bacteria, leading to water quality deterioration. The preliminary filtration of microfilters can reduce such problems from the source. The primary biological treatment tank is used to degrade ammonia nitrogen in the water. Ammonia nitrogen is the main toxic substance produced by the metabolism of cultured organisms. Excessive ammonia nitrogen can lead to poisoning, slow growth, or even death of cultured organisms. Degrading ammonia nitrogen can significantly improve water quality, reduce stress response of cultured organisms, and improve survival rate and growth quality. The secondary biological treatment tank is used to degrade nitrite in the water. The disinfection chamber is equipped with ultraviolet sterilization and ozone sterilization devices to disinfect the water after it has been treated in the secondary biological treatment tank.

[0020] The primary biological treatment tank is specifically designed to degrade ammonia nitrogen (a major toxic substance produced by the metabolism of aquaculture organisms) in the aquaculture water, laying the foundation for subsequent secondary biological treatment. It contains biological packing material (as a microbial carrier) that utilizes the metabolic activity of microorganisms in the tank to convert ammonia nitrogen in the water into nitrite, reducing the accumulation of ammonia nitrogen in the water. The secondary biological treatment tank also contains biological packing material, which works in conjunction with the primary biological treatment tank to jointly undertake the task of degrading nitrogen pollutants. By utilizing the oxidative decomposition of nitrifying bacteria in the tank, nitrite is converted into non-toxic nitrate. Nitrate can serve as a nutrient for beneficial algae in the water, enhancing the water's self-purification capacity and achieving nutrient recycling.

[0021] Furthermore, the aquaculture ponds are also connected to a wastewater treatment end. When the aquaculture organisms in a certain aquaculture pond become diseased, the drainage of that aquaculture pond is switched to the wastewater treatment end, and after treatment, it is discharged into the microfilter or directly discharged to the outside of the system. The effluent treatment end includes a sedimentation tank, a filter, and an enhanced disinfection tank in sequence. The disinfection intensity of the enhanced disinfection tank is no less than twice that of the disinfection chamber. The enhanced disinfection tank uses chemical disinfection (such as ozone disinfection, sodium hypochlorite disinfection, and chlorine dioxide disinfection). When a disease occurs in a single aquaculture pond, its drainage contains a large number of pathogenic microorganisms. If it enters the main water circulation loop directly, it will cause the disease to spread rapidly. The sedimentation tank at the tailwater treatment end can remove suspended pathogen carriers in the water, the filter further intercepts fine impurities and pathogens, and the enhanced disinfection tank thoroughly kills pathogenic microorganisms through higher intensity disinfection, cutting off the transmission route from the source, and at the same time achieving the harmless treatment of diseased water. Furthermore, the ratio R of the water treatment flow rate Qh (unit: m³ / h) of the water circulation treatment module to the total aquaculture water volume Vt (unit: m³) of all aquaculture ponds, i.e., the system circulation rate, satisfies: 1≤R≤3, where R=Qh / Vt. When the circulation rate is too low, the aquaculture water purification speed cannot keep up with the pollutant generation speed, which will lead to the exceedance of indicators such as ammonia nitrogen and nitrite. When the circulation rate is too high, the water pump needs to operate at a high load continuously, increasing energy consumption, and excessive circulation may lead to the loss of beneficial microorganisms in the water, affecting the water's self-purification capacity. The range of 1-3 can balance the two, ensuring that the water quality meets the standards and the energy consumption is reasonable. Furthermore, the total effective volume Vb (unit: m³) of the primary and secondary biological treatment ponds satisfies the following relationship with the total nitrogen input T (unit: kg / d / day) of the system per day through feed: Vb≥(T*SRT) / (C*1000), where SRT (sludge age) is 10-30 days, and C is the average biofilm concentration of the biological packing material in the biological tank, with a value range of 5-15 kg / m³.

[0022] Furthermore, it also includes an online water quality monitoring module, which includes a water quality sensor installed at least at one of the following locations: the pump pool, the outlet of the primary biological treatment tank, the outlet of the secondary biological treatment tank, and the outlet of the disinfection chamber. This sensor is used to monitor one or more parameters in the water body in real time, such as dissolved oxygen, pH value, ammonia nitrogen, nitrite, nitrate, and turbidity. The online monitoring can provide real-time data feedback, allowing staff or the central controller to keep abreast of changes in water quality.

[0023] Furthermore, it also includes a central controller. The circulation of aquaculture water is powered by a water pump. The central controller is communicatively connected to the online water quality monitoring module, the water pump, the sterilization device in the disinfection chamber, and the control valves connecting the aquaculture pond and the wastewater treatment end. The central controller is configured as follows: Based on the data fed back from the online water quality monitoring module, the water pump flow rate and the sterilization intensity of the disinfection chamber are automatically adjusted. When the water quality parameters of a certain aquaculture pond are detected to be abnormal for an extended period, the corresponding control valve is automatically switched to switch the drainage of the aquaculture pond to the tailwater treatment end.

[0024] Furthermore, the water in the disinfection chamber is injected into the aquaculture pond in the form of a jet, so as to entrain air during the injection process to achieve air-water mixing and oxygenation; when injected in the form of a jet, the high-speed water flow will entrain a large amount of air, and the air and water will be fully mixed, which can effectively increase the dissolved oxygen content, replace traditional oxygenation equipment, and save energy. The jet direction forms an angle of 0 to 45 degrees with the horizontal plane, and the jet of water is directed towards the wall of the aquaculture pond.

[0025] Furthermore, the microfilter is also connected to a water supply end for receiving external water. The water supply end is equipped with a flow control valve and a water pretreatment device. The water pretreatment device includes a quartz sand filter and an activated carbon filter arranged in sequence to remove suspended solids, odors and organic matter from the external water supply. The flow control valve is connected to the central controller, which automatically adjusts the water supply according to the water level in the system.

[0026] Furthermore, the pump pool is equipped with a submersible sewage pump and a liquid level sensor. The liquid level sensor is used to monitor the water level in the pump pool in real time. When the water level is higher than the preset upper limit, the submersible sewage pump starts to discharge the excess water. When the water level is lower than the preset lower limit, the central controller controls the water supply end to start water supply to ensure that the water level in the pump pool is stable within the preset range.

[0027] The usage process of the recirculating aquaculture system provided by this invention is as follows: The water in the aquaculture pond is transported to a microfiltration machine for filtration. The water treated by the microfiltration machine enters the pump tank and is then transported to the primary biological treatment tank for ammonia nitrogen degradation. The water treated in the primary biological treatment tank is then transported to the secondary biological treatment tank for nitrite degradation. After that, it is disinfected in the disinfection chamber and then transported back to the aquaculture pond. When a disease is found in a culture pond, immediately observe the water quality parameters of the culture pond. If the water quality is confirmed to be abnormal, switch the drainage of the culture pond to the tailwater treatment end and treat it through the tailwater treatment end. The treated water can be discharged into the microfiltration machine to re-enter the main circulation or directly discharged to the outside of the system, depending on the water quality. Isolate the diseased aquaculture ponds. After the disease is controlled and the water quality meets the standards, reconnect the aquaculture ponds to the main water circulation loop and test the water quality of the main circulation water at the same time to ensure that there is no cross-contamination. If the central controller detects that the water quality parameters at a certain monitoring point (such as the outlet of the secondary biological treatment tank) are continuously abnormal (such as excessive nitrite), first check whether the biological packing material and SRT sludge age of the biological treatment tank meet the requirements. If the biofilm concentration is insufficient, replenish the biological packing material in time; if the sludge age is abnormal, adjust the sludge discharge frequency. If the water quality at the disinfection chamber outlet does not meet the standards, check whether the sterilization device is operating normally, replace the ultraviolet lamps in a timely manner, adjust the ozone generation, and clean the scale in the disinfection chamber.

[0028] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0029] Obviously, the embodiments described above are merely some embodiments of the present invention, not all embodiments. The accompanying drawings show preferred embodiments of the present invention, but do not limit the patent scope of the present invention. The present invention can be implemented in many different forms; rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of this invention.

Claims

1. A recirculating aquaculture system, characterized in that, It includes a water circulation and treatment module and several parallel aquaculture ponds; The water circulation treatment module includes a microfilter, a pump tank, a primary biological treatment tank, a secondary biological treatment tank, and a disinfection chamber connected in sequence; the outlet of the microfilter is connected to the pump tank; the outlet of the disinfection chamber is connected to the aquaculture tank, and the outlet of the aquaculture tank is connected to the microfilter, forming the main water circulation loop.

2. The recirculating aquaculture system according to claim 1, characterized in that, The microfilter is used for preliminary filtration of solid particles in the water discharged from the aquaculture pond. The primary biological treatment tank is used to degrade ammonia nitrogen in the water. The secondary biological treatment tank is used to degrade nitrite in the water. The disinfection chamber is equipped with an ultraviolet sterilization device and an ozone sterilization device to disinfect the water after it has been treated in the secondary biological treatment tank.

3. The recirculating aquaculture system according to claim 1, characterized in that, The aquaculture pond is also connected to a tailwater treatment end. When the aquaculture organisms in a certain aquaculture pond become diseased, the drainage of the aquaculture pond is switched to the tailwater treatment end, and after treatment, it is discharged into the microfilter or directly discharged to the outside of the system. The wastewater treatment end includes a sedimentation tank, a filter, and an enhanced disinfection tank in sequence, wherein the disinfection intensity of the enhanced disinfection tank is not less than twice the disinfection intensity of the disinfection chamber.

4. The recirculating aquaculture system according to claim 1, characterized in that, The ratio R of the water treatment flow rate Qh of the water circulation treatment module to the total aquaculture water volume Vt of all aquaculture ponds satisfies: 1≤R≤3, where R=Qh / Vt.

5. The recirculating aquaculture system according to claim 1, characterized in that, The total effective volume Vb of the primary and secondary biological treatment tanks and the total nitrogen input T of the system through feed per day satisfy the following relationship: Vb≥(T*SRT) / (C*1000), where SRT is 10-30 days and C is the average biofilm concentration of the biological packing material in the biological tank, with a value range of 5-15 kg / m³.

6. The recirculating aquaculture system according to claim 1, characterized in that, It also includes an online water quality monitoring module, which includes a water quality sensor installed at least at one of the following locations: the pump pool, the outlet of the primary biological treatment tank, the outlet of the secondary biological treatment tank, and the outlet of the disinfection chamber. The sensor is used to monitor one or more parameters in the water body in real time, including dissolved oxygen, pH value, ammonia nitrogen, nitrite, nitrate, and turbidity.

7. The recirculating aquaculture system according to claim 6, characterized in that, It also includes a central controller. The aquaculture water circulation is powered by a water pump. The central controller is communicatively connected to the online water quality monitoring module, the water pump, the sterilization device in the disinfection chamber, and the control valve connecting the aquaculture pond and the wastewater treatment terminal. The central controller is configured as follows: Based on the data fed back by the online water quality monitoring module, the water pump flow rate and the sterilization intensity of the disinfection chamber are automatically adjusted. When the water quality parameters of a certain aquaculture pond are detected to be continuously abnormal, the corresponding control valve is automatically controlled to switch the drainage of the aquaculture pond to the tailwater treatment end.

8. The recirculating aquaculture system according to claim 1, characterized in that, Water in the disinfection chamber is injected into the aquaculture pond in the form of a jet, so as to entrain air during the injection process to achieve air-water mixing and oxygenation; The jet direction forms an angle of 0 to 45 degrees with the horizontal plane, and the jet of water is directed towards the wall of the aquaculture pond.

9. The recirculating aquaculture system according to claim 7, characterized in that, The microfilter is also connected to a water supply end for receiving external water. The water supply end is equipped with a flow control valve and a water pretreatment device. The water pretreatment device includes a quartz sand filter and an activated carbon filter arranged in sequence to remove suspended solids, odors and organic matter from the external water supply. The flow control valve is connected to the central controller, which automatically adjusts the water supply according to the water level in the system.

10. The recirculating aquaculture system according to claim 9, characterized in that, The pump pool is equipped with a submersible sewage pump and a liquid level sensor. The liquid level sensor is used to monitor the water level in the pump pool in real time. When the water level is higher than the preset upper limit, the submersible sewage pump starts to discharge the excess water. When the water level is lower than the preset lower limit, the central controller controls the water supply end to start water supply.

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