Aquaculture wastewater treatment system

Abstract

This invention belongs to the field of aquaculture equipment, specifically relating to an aquaculture wastewater treatment system. The aquaculture wastewater treatment system includes a sedimentation device, a filtration device, a nitrification device, a sterilization device, and a control system. The control system controls the operation or shutdown of the entire aquaculture wastewater treatment system. The sedimentation device is used to settle the wastewater discharged from the aquaculture equipment. The filtration device filters the settled wastewater and then transports it to the nitrification device. The nitrification device nitrifies the filtered wastewater and then transports it to the sterilization device. The sterilization device sterilizes the nitrified wastewater and then returns it to the aquaculture equipment. By using two different modes of nitrification devices, the system effectively removes nitrogen and phosphorus ions from the wastewater, improving the denitrification effect of the aquaculture wastewater treatment system.

Description

Technical Field

[0001] This invention relates to the field of aquaculture equipment, and more specifically to an aquaculture wastewater treatment system. Background Technology

[0002] Aquaculture is the practice of raising aquatic economic animals and plants using aquatic waters suitable for cultivation (including planting) and according to the ecological habits and environmental requirements of the aquatic organisms. Currently, excessive feeding in aquaculture easily leads to eutrophication, resulting in high nitrogen and phosphorus levels and a significant amount of suspended particulate matter. As aquaculture progresses, feed and animal waste accumulate and dissolve in the water, increasing organic pollutants and promoting the growth of microorganisms and bacteria. Therefore, regular water exchange is necessary in aquaculture. Direct discharge of wastewater not only pollutes the environment but also wastes water resources. This has led to the development of a new aquaculture model: recirculating aquaculture. Recirculating aquaculture utilizes water treatment technology to purify and reuse aquaculture water, offering advantages such as water conservation, land conservation, energy saving, and emission reduction, making it a future direction for aquaculture development. Existing recirculating aquaculture systems (RAS) suffer from high equipment costs and require highly skilled personnel to operate the equipment when treating aquaculture wastewater, thus demanding a high level of expertise from the operators. Furthermore, existing RAS systems are not very efficient at removing ammonia nitrogen pollutants from the wastewater, resulting in persistently high ammonia nitrogen levels even after treatment. Directly recycling this wastewater back into the aquaculture system would be detrimental to the growth of aquatic animals. Summary of the Invention

[0003] To address the technical problem of low treatment efficiency of ammonia nitrogen pollutants in the wastewater of existing recirculating aquaculture systems, this invention provides an aquaculture wastewater treatment system.

[0004] This invention is achieved using the following technical solution: an aquaculture wastewater treatment system, comprising a sedimentation device, a filtration device, a nitrification device, a sterilization device, and a control system; the control system is used to control the operation or shutdown of the entire aquaculture wastewater treatment system; the sedimentation device is used to settle the wastewater discharged from the aquaculture device; the filtration device is used to filter the wastewater after sedimentation in the sedimentation device and transport the filtered wastewater to the nitrification device, the nitrification device is used to nitrify the wastewater after filtration in the filtration device and transport the nitrified wastewater to the sterilization device; the sterilization device is used to sterilize the nitrified wastewater and transport the sterilized wastewater back to the aquaculture device.

[0005] The nitrification device includes a first nitrification device and a second nitrification device. The outlet of the filtration device is connected to the inlet of the first nitrification device and the inlet of the second nitrification device, respectively. The inlet of the sterilization device is connected to the outlet of the first nitrification device and the outlet of the second nitrification device, respectively. The first nitrification device and the second nitrification device are interconnected, allowing them to form multiple nitrification paths, each corresponding to a different nitrification capacity. The filtration device can be connected to any one of the multiple nitrification paths and perform nitrification treatment on the filtered effluent through that path.

[0006] The first nitrification device includes a shell, a water spraying device, and multiple packing grids. The water spraying device is installed inside the shell and above the packing grids. The multiple packing grids are installed sequentially from top to bottom inside the shell. The water spraying device is used to connect to the filtration device. The upper surface of the packing grids is used to fill biological packing material, which is used to denitrify the water sprayed by the water spraying device. The packing grid installed at the bottom of the shell forms a biological nitrification tank with the shell. The biological nitrification tank is used to perform secondary denitrification treatment on the effluent after denitrification by the packing grids.

[0007] The second nitrification device includes a cathode electrode chamber, an anode electrode chamber, and an ion exchange membrane. The ion exchange membrane is disposed between the cathode electrode chamber and the anode electrode chamber and separates the cathode electrode chamber and the anode electrode chamber. The anode electrode chamber is used to introduce tailwater to be denitrified, and the cathode electrode chamber is used to introduce a liquid magnetic flow electrode. The magnetic flow electrode is used to adsorb nitrogen ions and phosphorus ions in the tailwater in the anode electrode chamber.

[0008] As a further improvement of the present invention, the second nitration apparatus further includes a magnetic flow electrode tank, wherein there are two sets of magnetic flow electrodes, one set located in the cathode electrode chamber and the other set located in the magnetic flow electrode tank, and the two sets of magnetic flow electrodes can be alternately placed in the cathode electrode chamber and the magnetic flow electrode tank; a regeneration device is also installed between the magnetic flow electrode tank and the cathode electrode chamber, the regeneration device being used to recycle and regenerate the magnetic flow electrodes flowing from the cathode electrode chamber to the magnetic flow electrode tank and to transport the recycled and regenerated magnetic flow electrodes back to the magnetic flow electrode tank.

[0009] As a further improvement of the present invention, the regeneration device includes a housing second, and a cavity second is provided inside the housing second. An aeration pipe, a power supply first, and at least a pair of electromagnetic rods are installed in the cavity second. The power supply first is used to energize the pair of electromagnetic rods. After being energized, one of the pair of electromagnetic rods carries a positive charge and the other carries a negative charge. The negatively charged electromagnetic rod is used to adsorb the solid material in the magnetic flow electrode located in the cavity. The aeration pipe is installed at the bottom of the cavity second and is used to introduce gas into the cavity second. The introduced gas can aerate the solid material in the magnetic flow electrode.

[0010] As a further improvement of the present invention, the filtration device includes a negative pressure bend-flow separation pipe and a microfilter; the negative pressure bend-flow separation pipe is installed at the front end of the inlet of the microfilter, and the negative pressure bend-flow separation pipe is used to filter the tailwater entering the microfilter; the negative pressure bend-flow separation pipe includes a separation pipe body, a return pipe, and multiple bends, the separation pipe body has a spiral structure, the spiral structure makes the separation pipe body itself form a cylindrical cavity, and the inner diameter of the separation pipe body gradually decreases from bottom to top; the return pipe is installed in the cylindrical cavity, the central axis of the return pipe coincides with the central axis of the cylindrical cavity, one end of the bend is connected to the bend of the separation pipe body, and the other end of the bend bends downward and connects to the return pipe.

[0011] As a further improvement of the present invention, the sterilization device includes a booster pump, an ozone generator, an ejector, and a sterilization reactor. The booster pump is connected to the ejector and is used to pressurize the wastewater to be treated and deliver it into the ejector. The ozone generator is connected to the ejector and is used to deliver the generated ozone into the ejector. The wastewater and ozone entering the ejector are mixed, and the mixed wastewater and ozone are delivered into the sterilization reactor, which is used to sterilize the incoming wastewater.

[0012] As a further improvement of the present invention, the sterilization reactor includes an inlet pipe, a shell three, a pipe one, a drain pipe one, and a gas return pipe two. The inlet pipe is installed on one side of the shell three and connected to the jet injector. The shell three has a cavity three. A baffle one and a baffle two are installed in the cavity three. The baffle one and the baffle two are arranged parallel to each other in the cavity three, and the baffle one is located on the side close to the inlet pipe. The baffle one is integrally formed extending upward from the bottom end face of the cavity three and does not contact the top end face of the cavity three. The baffle two is integrally formed extending downward from the top end face of the cavity three and does not contact the bottom end face of the cavity three. The baffle one divides the cavity three into a cavity four and a cavity five, and the baffle two divides the cavity three into a cavity six and a cavity seven. Cavity 6 and cavity 7 are vertically located above cavity 4 and cavity 5. Cavity 6 is connected to cavity 4 and cavity 5, and cavity 5 is connected to cavity 6 and cavity 7. The ozone and tailwater mixed by the jet injector enter cavity 4 and cavity 5 sequentially through the inlet pipe, and the tailwater is sterilized in the areas of cavity 4 and cavity 5. The ozone generated during the sterilization process accumulates in cavity 6. Pipe 1 is installed on the upper end face of shell 3 and is connected to cavity 7. Drain pipe 1 is horizontally arranged and is connected to pipe 1. One end of gas return pipe 2 is connected to pipe 1, and the other end is connected to the ozone generator. The vertical height of the outlet of gas return pipe 2 is higher than the vertical height of the outlet of drain pipe 1.

[0013] As a further improvement of the present invention, let the height of the side wall connected to the liquid inlet pipe on the sterilization separator be h, the length of the first baffle be a, the length of the second baffle be b, the distance from the first baffle to the side wall connected to the liquid inlet pipe be c, and the distance from the second baffle to the side wall connected to the liquid inlet pipe be d; wherein a, b, and h satisfy: a + b < h; c and d satisfy: d > 4c; b and c satisfy: 0.75c < b < c.

[0014] As a further improvement of the present invention, a photocatalytic ozonation reaction device is also installed on the side of the baffle two near the cavity seven. The photocatalytic ozonation reaction device includes a housing four, multiple ultraviolet lamps and multiple titanium dioxide films. The multiple ultraviolet lamps are arranged sequentially along the width direction of the housing four, and the multiple titanium dioxide films are arranged sequentially along the length direction of the housing four. The titanium dioxide films are located outside the ultraviolet lamps, so that the light source of the ultraviolet lamps can irradiate the titanium dioxide films and excite the titanium dioxide films to adsorb ozone molecules to generate reactive oxygen free radicals. The generated reactive oxygen free radicals are used to sterilize the effluent.

[0015] As a further improvement of the present invention, the sedimentation device is a sedimentation tank.

[0016] The technical solution provided by this invention has the following beneficial effects:

[0017] (1) The aquaculture wastewater treatment system of the present invention, by setting up two different modes of nitrification devices—a first nitrification device and a second nitrification device—can effectively remove nitrogen and phosphorus ions from the wastewater, thereby improving the denitrification effect of the entire aquaculture wastewater treatment system. Furthermore, the first and second nitrification devices can form multiple nitrification paths, each corresponding to a different nitrification capacity. During nitrification, the filtration device can be connected to any one of the multiple nitrification paths, and the filtered wastewater can be nitrified through that path. By setting different nitrification paths, the system can be selected according to requirements in practical applications, ensuring nitrification efficiency while accelerating the overall wastewater treatment speed.

[0018] (2) The aquaculture wastewater treatment system of the present invention includes a second nitrification device comprising a cathode electrode chamber, an anode electrode chamber, and an ion exchange membrane. A flowing magnetic electrode is selected in the cathode electrode chamber, and the anode electrode chamber is used to introduce wastewater to be treated. Through the above treatment, the magnetic flowing electrode in the cathode electrode chamber can effectively adsorb nitrogen and phosphorus ions in the wastewater located in the anode electrode chamber, thereby achieving denitrification and dephosphorization of the wastewater. Furthermore, the denitrification and dephosphorization operation in this solution is unaffected by the external environment, allowing for effective denitrification and dephosphorization of the wastewater at any temperature. This ensures that the nitrification efficiency of the entire nitrification device is unaffected by external temperature, improving the overall practicality of the nitrification device.

[0019] (3) The aquaculture wastewater treatment system of the present invention allows the wastewater after nitrification to enter the sterilization device, which is used to sterilize the nitrified wastewater and can then transport the sterilized wastewater back to the aquaculture device, thereby realizing the recycling of water in aquaculture and improving the utilization rate of water resources while saving water resources. Attached Figure Description

[0020] Figure 1 A schematic diagram of the framework structure of the aquaculture wastewater treatment system provided by the present invention.

[0021] Figure 2 This is a perspective view of the aquaculture wastewater treatment system provided by the present invention.

[0022] Figure 3 This is a schematic diagram of the internal structure of the first nitration device provided by the present invention.

[0023] Figure 4This is a partial structural schematic diagram of the second nitration device provided by the present invention.

[0024] Figure 5 This is a schematic diagram of the regeneration device in the second nitration unit provided by the present invention.

[0025] Figure 6 This is a schematic diagram of the negative pressure separation tube in the filtration device provided by the present invention.

[0026] Figure 7 This is a schematic diagram of the sterilization device provided by the present invention.

[0027] Figure 8 This is a schematic diagram of the internal structure of the sterilization reactor provided by the present invention.

[0028] Figure 9 This is a schematic diagram of the sterilization reactor with dimensions marked according to the present invention.

[0029] Figure 10 This is a schematic diagram of the photocatalytic ozonation reactor provided by the present invention.

[0030] Figure 11 The image shows a comparison of tilapia before and after being deodorized by rinsing in water, when the aquaculture wastewater treatment system of the present invention is applied to scenario one.

[0031] Figure 12 When the aquaculture wastewater treatment system of the present invention is applied to scenario three, the bass fry hatched by the facility-based all-season seedling breeding system.

[0032] The following are labeled in the diagram: 1. Sedimentation device; 2. Filtration device; 21. Negative pressure diversion pipe; 211. Separation pipe body; 212. Return pipe one; 213. Bend; 22. Microfilter; 31. First nitrification device; 311. Shell one; 312. Water spray device; 313. Packing grid; 315. Gap; 316. Biological nitrification tank; 317. Filter screen; 318. Nitrification zone; 319. Filtration zone; 32. Second nitrification device; 321. Cathode electrode chamber; 322. Anode electrode chamber; 323. Ion exchange membrane; 324. Magnetic flow electrode tank; 325. Regeneration device; 326. Chamber II; 327. Aeration pipe; 328. Electromagnetic rod; 4. Sterilization device; 41. Booster pump; 42. Ozone generator; 43. Ejector; 44. Sterilization reactor; 441. Liquid inlet pipe; 442. Shell III; 443. Pipe I; 444. Drain pipe I; 445. Gas return pipe II; 446. Baffle I; 447. Baffle II; 448. Chamber IV; 449. Chamber V; 450. Chamber VI; 451. Chamber VII; 452. Shell IV; 453. Ultraviolet lamp; 454. Titanium dioxide film. Detailed Implementation

[0033] The present invention will now be further described in conjunction with specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0034] In the description of this invention, it should be noted that directional terms such as "center," "lateral," "longitudinal," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These are used only for the convenience of describing the invention and 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. They should not be construed as limiting the specific scope of protection of this invention. The terms "first," "second," etc., in the specification and claims of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. The terms "comprising" and "having," and any variations thereof, in the specification and claims of this invention, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or devices.

[0035] This embodiment provides an aquaculture wastewater treatment system. Please refer to [link / reference]. Figure 1 and Figure 2The system includes a sedimentation device 1, a filtration device 2, a nitrification device, a sterilization device 4, and a control system. The control system controls the operation or shutdown of the entire aquaculture wastewater treatment system and can be a PLC control system commonly used in existing technologies. The sedimentation device 1 can be one or more sedimentation tanks. Wastewater from the aquaculture system can be directly discharged into the sedimentation device 1, which performs sedimentation to remove sludge and large suspended solids. One end of the filtration device 2 is connected to the sedimentation device 1, and the other end is connected to the nitrification device. The filtration device 2 filters the wastewater after sedimentation in the sedimentation device 1 and transports the filtered wastewater to the nitrification device. The nitrification device includes a first nitrification device 31 and a second nitrification device 32. The outlet of the filtration device 2 is connected to the inlet of the first nitrification device 31 and the inlet of the second nitrification device 32, respectively. The inlet of the sterilization device 4 is connected to the outlet of the first nitrification device 31 and the outlet of the second nitrification device 32, respectively. The first nitrification unit 31 and the second nitrification unit 32 are interconnected, allowing them to form multiple nitrification paths, each with a different nitrification capacity. During nitrification, the filtration unit 2 can connect to any one of these multiple nitrification paths to treat the filtered wastewater. The treated wastewater then enters the sterilization unit 4, which sterilizes the treated wastewater and can then return it to the aquaculture system, thus recycling water and improving water utilization efficiency.

[0036] in, Figure 1 and Figure 2 The arrow on the connecting line indicates the direction of the tailrace flow. Figure 2 The two components connected by a connecting line indicate that there is a connection between them.

[0037] It is understood that, in this embodiment, please refer to Figure 1The nitrification pathway can be any one of the following four paths: Path 1: Filter device 2 - First nitrification device 31 - Sterilization device 4; Path 2: Filter device 2 - Second nitrification device 32 - Sterilization device 4; Path 3: Filter device 2 - First nitrification device 31 - Second nitrification device 32 - Sterilization device 4; Path 4: Filter device 2 - Second nitrification device 32 - First nitrification device 31 - Sterilization device 4. In the actual nitrification process, different nitrification pathways can be selected to nitrify the effluent filtered by filter device 2 according to the actual nitrification requirements. This multi-path nitrification setup allows the entire nitrification unit to select a suitable nitrification path based on the amount of effluent requiring nitrification, the ammonia nitrogen content in the effluent, or other factors. Furthermore, if one of the first nitrification devices 31 or the second nitrification device 32 fails, nitrification can be performed using the other nitrification device, ensuring the normal operation of the aquaculture effluent treatment system is not affected. Furthermore, in actual operation, by setting up a first nitrification device 31 and a second nitrification device 32, it is possible to alternately maintain the first nitrification device 31 and the second nitrification device 32, so that while one nitrification device is being maintained, the other nitrification device can continue to perform nitrification operation, enabling the entire nitrification device to work uninterruptedly, thereby improving the working efficiency of the entire aquaculture wastewater treatment system.

[0038] Please refer to Figure 3 , Figure 3 This is a diagram of the internal structure of the first nitrification unit. The first nitrification unit 31 includes a shell 311, a water spraying device 312, and multiple packing grids 313. The length direction of the shell 311 is defined as the X-axis, the height direction as the Y-axis, and the width direction as the Z-axis. The water spraying device 312 is installed inside the shell 311 along the X-axis and above the packing grids 313. Multiple packing grids 313 are installed sequentially from top to bottom inside the shell 311 along the Y-axis. One end of each packing grid 313 is fixed to the side wall of the shell 311, and a gap is provided between the other end of each packing grid 313 and the corresponding side wall of the shell 311. Each packing grid 313 has a through hole, and the upper surface and gaps of each packing grid 313 are filled with biological packing material. The water spraying device 312 is used to connect to the filter device 2. The water spraying device 312 can spray the water filtered by the filter device 2 onto the biological packing material on the packing grid 313. The water will flow downward along the packing grid 313. During the flow, the tailwater will come into full contact with the biological packing material, thereby achieving denitrification treatment of the tailwater through the biological packing material.

[0039] The two sidewalls of the shell 311 along the X-axis are referred to as the left side wall and the right side wall. Along the Y-axis, two adjacent packing grids 313 are alternately fixed to the left side wall and the right side wall of the shell 311. That is, in the Y-axis direction, when one packing grid 313 is fixed to the left side wall of the shell 311, the next packing grid 313 is fixed to the right side wall. A gap is provided at the end of the packing grid 313 that does not contact the side wall of the shell 311. This arrangement extends the residence time of the effluent sprayed by the spray device 312 on the multiple packing grids 313, thereby improving the treatment efficiency of the effluent by the biological packing material on the packing grids 313. The packing grid 313 installed at the bottom inside the shell 311 forms a biological nitrification tank with the shell 311. Biological packing material is also placed in the biological nitrification tank, and it is used for secondary denitrification treatment of the effluent after denitrification by the packing grids 313.

[0040] The water spraying device 312 includes a water spray pipe and multiple nozzles. The water spray pipe is connected to the outlet of the filter device 2 and is used to transport the effluent filtered by the filter device 2 to the nozzles, which then spray it onto the biological packing material on the packing grid 313. In this embodiment, the water flow rate of the nozzles can be set very slowly, so that the water from the nozzles drips into the biological packing material in droplet form. This ensures that the effluent is effectively dispersed within the biological packing material as it passes through, allowing for sufficient contact between the effluent and the biological packing material, increasing the contact area between the effluent and the biological packing material, and thus improving the denitrification efficiency of the biological packing material for the effluent. Furthermore, in this invention, the packing grid 313 is alternately installed along the Y-axis direction on the left or right side wall of the housing. This installation method can extend the path of the effluent through the biological packing material and the time the effluent remains in the biological packing material on the packing grid 313 within a limited space. Under the synergistic effect of both, the denitrification efficiency of the effluent can be further improved.

[0041] At least one filter screen may also be installed in the first nitrification unit 31. The filter screen is installed in the biological nitrification tank, which divides the biological nitrification tank into a nitrification zone and a filtration zone. Biological packing material is placed in the nitrification zone to perform secondary denitrification treatment on the effluent entering the nitrification zone. The effluent after secondary denitrification treatment can enter the filtration zone through the filter screen. The filter screen can filter the effluent after secondary denitrification treatment. The effluent after filtration in the filtration zone can be transported to the sterilization device 4 through a pipeline. The sterilization device 4 can sterilize the effluent after filtration by the filter screen.

[0042] It is understandable that the biological packing material filled in the first nitration unit 31 can be biological ceramic granules.

[0043] Please refer to Figure 4The second nitrification device 32 includes a cathode electrode chamber 321, an anode electrode chamber 322, and an ion exchange membrane 323, which is disposed between the cathode electrode chamber 321 and the anode electrode chamber 322. The anode electrode chamber 322 is used to introduce the wastewater to be treated, while the cathode electrode chamber 321 is used to introduce a liquid magnetic flow electrode. The ion exchange membrane 323 separates the cathode electrode chamber 321 and the anode electrode chamber 322, allowing ion exchange between them while preventing direct contact between the wastewater to be treated and the magnetic flow electrode. The magnetic flow electrode can effectively adsorb nitrogen and phosphorus ions in the wastewater. It is understood that the second nitrification device 32 also includes a power source, which applies a stable voltage or current to the second nitrification device 32 to drive ions to migrate between the magnetic flow electrode and the wastewater, thereby achieving the purpose of adsorbing nitrogen and phosphorus ions in the wastewater through the magnetic flow electrode, and thus removing nitrogen and phosphorus ions from the wastewater.

[0044] The magnetic flow electrode comprises a solid material and an electrode liquid, with the solid material mixed in the electrode liquid to form a liquid magnetic flow electrode. The solid material includes magnetic carbon particles and conductive materials, with a mass ratio of magnetic carbon particles to conductive materials of 6:1 to 4:1. The mass fraction of the solid material in the magnetic flow electrode is 1.5% to 5%.

[0045] The conductive material can be either graphene or copper nanoparticles. By adding an appropriate amount of conductive material to the magnetic flow electrode, the conductivity of the prepared magnetic flow electrode can be improved, thereby enhancing the electrochemical reaction efficiency between the magnetic flow electrode and pollutants in the effluent.

[0046] The electrode solution can be a NaCl solution. In this embodiment, a NaCl solution is selected as the electrode solution because it can provide the necessary ionic environment for the electrochemical reaction to maintain the flow of current.

[0047] In this embodiment, the magnetic carbon particles can be prepared as follows: 20g of 100-mesh DARCO activated carbon is mixed with a 0.259mol / L Fe(NO3)3 solution of 100mL to obtain mixture one. HNO3 is added to mixture one to adjust its pH to 2. The pH-adjusted mixture one is stirred at 100°C for 8 hours to form Fe(OH)3 precipitate on the surface of the activated carbon. Then, the activated carbon with Fe(OH)3 precipitate on its surface is calcined at 600°C under a nitrogen atmosphere for a period of time, allowing some of the Fe(OH)3 to be converted into Fe... 3+ Reduced to Fe 2+This process generates Fe3O4 on the surface of activated carbon. Finally, the calcined activated carbon with Fe3O4 on its surface is cooled, washed, and dried to obtain magnetic carbon particles.

[0048] Activated carbon is an adsorbent with a high surface area and porous structure, exhibiting excellent adsorption effects on both organic and inorganic substances, such as ammonia nitrogen (NH3-N) and total phosphorus (TP). This embodiment utilizes magnetic activated carbon particles, which have a short adsorption reaction time for nitrogen and phosphorus, effectively removing nitrogen and phosphorus from water bodies and reducing eutrophication. Furthermore, their magnetic properties allow for rapid separation of the adsorbed magnetic activated carbon particles from the water body via magnetic separation, enabling their recycling.

[0049] The magnetic flow electrode is assembled as follows: Prepared magnetic carbon particles are mixed with conductive material at a ratio of 5:1 to form a solid material. This solid material is then immersed in a 1 mol / L NaCl solution, thus assembling the magnetic flow electrode. In this embodiment, by flexibly combining the high adsorption efficiency of magnetic carbon particles with the flowing electrode liquid, a novel water treatment technology is created. This technology improves nitrogen and phosphorus removal efficiency and adapts to different environmental conditions, providing a new wastewater treatment solution for recirculating aquaculture systems.

[0050] Please refer to Figure 2 and Figure 5 The second nitration device 32 also includes a magnetic flow electrode tank 324 and a regeneration device 325. In this embodiment, there are two sets of magnetic flow electrodes, one set located in the cathode electrode chamber 321 and the other set located in the magnetic flow electrode tank 324. The magnetic flow electrodes in the magnetic flow electrode tank 324 can be used as backup electrodes. The two sets of magnetic flow electrodes can be alternately placed in the cathode electrode chamber 321 and the magnetic flow electrode tank 324. In actual use, when the conductivity of the magnetic flow electrodes in the cathode electrode chamber 321 is lower than a set threshold, the connecting pipe between the cathode electrode chamber 321 and the regeneration device 325 can be opened, allowing all the magnetic flow electrodes in the cathode electrode chamber to enter the regeneration device 325. Then, the pipe between the cathode electrode chamber 321 and the regeneration device 325 is closed, while the pipe between the cathode electrode chamber 321 and the magnetic flow electrode tank 324 is opened, allowing the backup magnetic flow electrodes in the magnetic flow electrode tank 324 to enter the cathode electrode chamber 321 for use. The magnetic flow electrode that enters the regeneration device 325 can be recycled and reused.

[0051] Please refer to Figure 5The regeneration device 325 includes a housing second, and a cavity second 326 is provided inside the housing second. An aeration pipe 327, a power supply first, and at least a pair of electromagnetic rods 328 are installed in the cavity second 326. The power supply first is used to energize the pair of electromagnetic rods 328. After being energized, one of the pair of electromagnetic rods 328 carries a positive charge and the other carries a negative charge. The negatively charged electromagnetic rod 328 is used to adsorb solid material in the magnetic flow electrode located in the cavity. The aeration pipe 327 is installed at the bottom of the cavity second 326 and is used to introduce gas into the cavity second 326. The introduced gas can aerate the solid material in the magnetic flow electrode. The regeneration method of the magnetic flow electrode in the regeneration device 325 includes the following steps: The magnetic flow electrode after treating the effluent is transported to the second cavity 326 of the regeneration device 325, and power is turned on to energize a pair of electromagnetic rods 328, causing one electromagnetic rod 328 to carry a positive charge and the other a negative charge. The solid material in the magnetic flow electrode within the second cavity 326 is then completely adsorbed onto the negatively charged electromagnetic rod 328. Once all the solid material in the magnetic flow electrode within the second cavity 326 has been adsorbed onto the negatively charged electromagnetic rod 328, the outlet of the regeneration device 325 is opened to discharge all the electrode liquid from the magnetic flow electrode. Subsequently, NaOH solution is introduced into the regeneration device 325, and power is turned off. The solid material adsorbed onto the negatively charged electromagnetic rod 328 falls into the second cavity 326 of the regeneration device 325, where it is aerated, stirred, and cleaned. After cleaning, power is switched on to energize the pair of electromagnetic rods 328, allowing the cleaned solid material to be completely adsorbed onto the negatively charged electromagnetic rods 328. Then, the NaOH solution in the regeneration device 325 is drained and replaced with new electrode liquid. Once the electrode liquid in the regeneration device 325 is full, power is switched off. The regenerated solid material then enters the new electrode liquid, and the electrode liquid mixed with the solid material becomes the regenerated magnetic flow electrode.

[0052] This embodiment achieves the recycling and reuse of solid materials in the magnetic flow electrode by setting up a regeneration device 325. It can effectively adsorb nitrogen and phosphorus ions in the effluent by utilizing the high adsorption capacity of magnetic carbon particles. At the same time, it can also achieve adsorption and recycling regeneration by electromagnetic rod 328, realizing the recycling of solid materials and greatly reducing its processing cost.

[0053] Understandably, during the processing, the magnetic flow electrode can be monitored by a conductivity sensor to determine whether the magnetic flow electrode in the regeneration device 325 has been processed. If the control system displays that the conductivity in the regeneration device 325 exceeds the set threshold, it indicates that the solid material in the magnetic flow electrode has been processed. Then, by supplying electrode liquid to the regeneration device 325, the electrode liquid can be mixed with the solid material to form a recycled magnetic flow electrode.

[0054] In this embodiment, threshold one and threshold two can be set according to the values ​​required in the actual processing.

[0055] The filtration device 2 includes a negative pressure bend-flow separator and a microfilter 22. The negative pressure bend-flow separator is installed at the front end of the inlet of the microfilter 22 and is used to filter the effluent entering the microfilter 22. By setting up the negative pressure bend-flow separator, the effluent after sedimentation in the sedimentation device 1 can be pre-filtered, resulting in a lower content of suspended solids in the effluent entering the microfilter 22, thereby preventing clogging and extending the service life of the microfilter 22. Please refer to... Figure 6 The negative pressure bend-flow separator includes a separator body 211, a return pipe 212, and multiple bends 213. The separator body 211 has a spiral structure, which forms a cylindrical cavity within itself. The inner diameter of the separator body 211 gradually decreases from bottom to top. The return pipe 212 is installed inside the cylindrical cavity, with its central axis coinciding with the central axis of the cylindrical cavity. One end of each bend 213 connects to the bend of the separator body 211, and the other end bends downward and connects to the return pipe 212. The lower end of the separator body 211 is connected to the outlet of the sedimentation device 1 via a pipe, and the upper end of the separator body 211 is connected to the microfilter 22 via a pipe. The tailwater entering the separator body 211 utilizes the principle of the difference in solid and liquid distribution during the bend of the water flow. This design causes solid particles in the effluent to accumulate near the bend 213, while liquid particles accumulate on the side of the separator body 211 away from the bend 213. Therefore, under the influence of inertia and gravity, the solid particles flow along the bend 213 to the return pipe 212, while the liquid flows upwards along the separator body 211 in a rotating motion until it enters the microfilter 22. This removes solid particles from the effluent, solving the problem of clogging the microfilter 22 caused by solid particles in the effluent in existing technologies. This structure effectively performs preliminary filtration of the effluent entering the microfilter 22, significantly reducing the number of solid particles, thereby improving the filtration stability of the microfilter 22 and extending its service life.

[0056] In this embodiment, the plane containing the bottom surface of the return pipe 212 is set as the reference plane. The center of the bend 213 at the connection point with the separation pipe body 211 is designated as point one, and the center of the return pipe 212 is designated as point two. The straight line connecting the vertical projections of point one and point two on the reference plane is designated as line one. The angle between the vertical projection of the bend 213 on the reference plane and line one is smaller than the angle between the vertical projection of the bend 213 on the reference plane and line one.

[0057] The wastewater to be filtered enters through the inlet pipe at the lower end of the separator tube body 211, and flows upward along the separator tube body 211 in a rotating manner until it enters the microfilter 22 through the outlet pipe. At the connection between the separator tube body 211 and the bend 213, solid particles in the wastewater flow along the bend 213 inside the separator tube body 211 to the return pipe 212, while liquid in the wastewater flows upward along the separator tube body 211 in a rotating manner. This design allows for solid-liquid separation by utilizing the difference in solid and liquid distribution during the bend of the water flow after the wastewater enters the separator tube body 211. When the wastewater enters the separator body 211 from the inlet pipe, the separator body 211 has a spiral structure with its inner diameter gradually decreasing from bottom to top. The high velocity of the wastewater entering the separator body 211 easily generates negative pressure. Under this negative pressure, solid particles in the wastewater tend to move towards the inner wall of the separator body 211, while liquid particles tend to move towards the outer wall of the bend 213. At the connection between the separator body 211 and the bend 213, because the solid particles in the wastewater are closer to the bend 213, the upward force of the wastewater and the inertia and gravity of the flowing solid particles cause them to enter the return pipe 212 along the bend 213. Meanwhile, the liquid particles in the wastewater continue to rotate and flow upwards along the separator body 211, finally entering the microfilter 22 through the outlet pipe. This achieves preliminary filtration of the wastewater before it enters the microfilter 22.

[0058] Understandably, in this embodiment, the lower end of the return pipe 212 can be connected to a filter tank via a pipe. The filter tank is used to collect solid particles and mixed liquids entering the return pipe 212, and can also separate the collected solid particles and liquids again. The separated wastewater can be transported to the microfilter 22 through the outlet of the filter tank.

[0059] Please refer to Figure 7The sterilization device 4 includes a booster pump 41, an ozone generator 42, an ejector 43, and a sterilization reactor 44. One end of the booster pump 41 is connected to the outlet of the nitrification unit, and the other end is connected to the ejector 43. The booster pump 41 is used to pressurize the nitrified effluent and deliver it to the ejector 43. The ozone generator 42 is connected to the ejector 43 and is used to deliver the generated ozone to the ejector 43. The effluent and ozone entering the ejector 43 are mixed, and the ejector 43 delivers the mixed effluent and ozone to the sterilization reactor 44, which is used to sterilize the incoming effluent.

[0060] Please refer to Figure 8 The sterilization reactor 44 includes an inlet pipe 441, a shell 442, a pipe 443, a drain pipe 444, and a gas return pipe 445. The shell 442 has a cavity. The inlet pipe 441 is installed on one side of the shell 442 and connected to an ejector 43. Ozone and wastewater mixed in the ejector 43 are allowed to enter the cavity through the inlet pipe 441. The pipe 443 is vertically installed on the upper surface of the sterilization reactor 44 and connects to the cavity. The outlet of the pipe 443 is connected to both the drain pipe 444 and the gas return pipe 445. The gas return pipe 445 is vertically positioned, while the drain pipe 444 is horizontally positioned. The vertical height of the outlet of the gas return pipe 445 is higher than the height of the outlet of the drain pipe 444. The gas return pipe 445 and the drain pipe 444 form an L-shaped structure, allowing liquid in pipe 443 to be discharged through the drain pipe 444, and gas entering pipe 443 to be discharged through the gas return pipe 445. The outlet pipe of the gas return pipe 445 is connected to the ozone generator 42, allowing ozone discharged through the gas return pipe 445 to re-enter the ozone generator 42, thereby improving ozone utilization. Furthermore, the gas return pipe 445 also prevents ozone from directly leaking into the air, thus reducing ozone diffusion pollution.

[0061] Please refer to Figure 8The cavity three contains a first baffle 446 and a second baffle 447, which are arranged parallel to each other within the cavity three. The first baffle 446 is located near the inlet pipe 441 and extends integrally upwards from the bottom end face of the cavity three without contacting the top end face. The second baffle 447 extends integrally downwards from the top end face of the cavity three without contacting the bottom end face. The first baffle 446 divides the cavity three into a fourth cavity 448 and a fifth cavity 449. The second baffle 447 divides the cavity three into a sixth cavity 450 and a seventh cavity 451. The sixth cavity 450 and the seventh cavity 451 are vertically positioned above the fourth cavity 448 and the fifth cavity 449. Cavity 6 450 is connected to Cavity 4 448 and Cavity 5 449, respectively. Cavity 5 449 is connected to Cavity 6 450 and Cavity 7 451, respectively. The ozone and tailwater mixed by the jet injector 43 enter Cavity 4 448 and Cavity 5 449 sequentially through the inlet pipe 441, where the tailwater is sterilized. During the sterilization process, the ozone accumulates in Cavity 6 450. Pipe 1 443 is installed on the upper end face of shell 3 442 and connects to Cavity 7 451. This arrangement increases the movement path of the mixed ozone and tailwater within the sterilization reactor 44, providing more time for ozone treatment of the tailwater and thus improving ozone treatment efficiency. Furthermore, the tailwater entering the sterilization reactor 44 is pressurized, allowing it to dissolve more ozone, ensuring sufficient contact between the ozone and tailwater for sterilization. The disinfection method within the sterilization reactor 44 is as follows: The ozone and tailwater mixed in the jet injector 43 enter chamber four 448 through the inlet pipe 441. The ozone entering chamber four 448 sterilizes the tailwater, and the ozone treated in chamber four 448 overflows and accumulates in chamber six 450. When the water level in chamber four 448 is higher than the height of baffle one 446, the liquid overflows from baffle one 446 and enters chamber five 449. At this time, the ozone in the mixture in chambers four 448 and five 449 continues to overflow and accumulate in chamber six 450. When the height of the mixture in chamber five 449 rises to be level with the bottom of baffle two 447, the amount of ozone in chamber six 450 is already substantial, and the pressure on both sides of baffle two 447 is balanced. If liquid is supplied to cavity three, the ozone overflowing from the liquid will enter cavity six 450, putting cavity six 450 under pressure. Under the pressure of cavity six 450, the liquid levels on both sides of baffle two 447 rise at different rates, with the liquid level on the right side of baffle two 447 being higher than that on the left side. Therefore, the ozone-separated tailwater in cavity five 449 can enter pipe one 443 along the right side of baffle two 447.As the pressure inside chamber 6 (450) increases, the liquid to the right of baffle 2 (447) rises along pipe 1 (443) until it reaches drain pipe 1 (444) and is discharged through drain pipe 1 (444). Once the liquid to the right of baffle 2 (447) is discharged through drain pipe 1 (444), the pressure to the right of baffle 2 (447) stabilizes. Meanwhile, as the liquid inlet pipe 441 continuously introduces the mixed liquid, the ozone inside chamber 6 (450) continues to increase. When the amount of ozone in chamber 6 (450) reaches its maximum capacity, the ozone, under high pressure, passes through baffle 2 (447) and flows back along the right side of baffle 2 (447) through pipe 1 (443) and gas return pipe 2 (445) to the ozone generator 42, thus achieving ozone collection and treatment. When ozone passes through baffle 2 447, the pressure in chamber 6 450 is released. At this time, the liquid in chamber 7 451 and pipe 1 443 falls back due to gravity. The volume of the falling water column fills the volume of the ozone diffused in chamber 6 450, causing the reactor to re-enter a pressurized state, thus repeating the series of operations after pressurization.

[0062] The sterilization separator can be a cuboid structure; please refer to [reference needed]. Figure 9 Let the height of the side wall connected to the inlet pipe 441 be h, the length of baffle 1 446 be a, the length of baffle 2 447 be b, the distance between baffle 1 446 and the side wall connected to the inlet pipe 441 be c, and the distance between baffle 2 447 and the side wall connected to the inlet pipe 441 be d. Among these, a, b, and h must satisfy: a + b < h; c and d must satisfy: d > 4c; and b and c must satisfy: 0.75c < b < c.

[0063] Understandably, please refer to Figure 9In this embodiment, by setting baffle 446, the cavity can be divided into cavity 448 and cavity 449. Cavity 448 is connected to the liquid inlet pipe 441, and the distance from baffle 446 to the side wall connected to the liquid inlet pipe 441 is c, and the distance from baffle 447 to the liquid inlet pipe 441 is d. The relationship between d and c needs to satisfy d > 4c. This shows that the volume of cavity 448 is much smaller than the volume of cavity 449. By setting such a small-volume cavity 448, the mixing effect between ozone and effluent can be effectively improved, thereby improving the ozone treatment efficiency of effluent. In addition, by setting baffle 446, when the liquid level in cavity 448 rises to be flush with the upper end face of baffle 446, the mass transfer rate is improved under the strong turbulent dynamics of this small volume and high water level, which is conducive to enhancing the hybrid mixing of ozone and effluent, thereby improving the ozone treatment efficiency of effluent. Furthermore, in this embodiment, by setting cavity six 450 to be connected to cavity four 448 and cavity five 449 respectively, ozone overflowing from either cavity four 448 or cavity five 449 can be gathered into cavity six 450, thereby achieving unified collection of ozone overflowing during the disinfection process.

[0064] In this embodiment, by limiting the relationship between c and d, the volume of cavity 5449 can be increased, so that the ozone located in cavity 5449 can fully react with water, thereby improving the ozone's treatment effect on the wastewater.

[0065] In this embodiment, please refer to Figure 9 The relationship between b and c is defined as 0.75c < b < c. The purpose is to ensure that the length of baffle 2 447 is not too short; that is, the minimum length of baffle 2 447 needs to be greater than 0.75 times the distance c between baffle 1 446 and the side wall connected to the inlet pipe 441. This ensures that the space of cavity 6 450 formed between baffle 2 447 and the sterilization reactor 44 is large enough to accommodate sufficient ozone. Sufficient ozone will create high pressure in cavity 6 450. Under high pressure, the solubility of ozone in water increases, thereby improving the sterilization effect of ozone on the effluent. Furthermore, the length of b is limited to a maximum of c. This is because if the length b of baffle 2 447 is too long, excessive ozone will accumulate in cavity 6 450 and cannot quickly pass through baffle 2 447 to exit through pipe 1 443 and gas return pipe 2 445. This would easily lead to water hammer, which can cause serious damage to the entire device, thus affecting the normal operation of the circulating water disinfection system. Therefore, in the actual design process, a, b, and h must satisfy the condition: a + b < h.

[0066] Furthermore, since this equipment is used to treat the wastewater from a recirculating aquaculture system, its working environment is generally humid and contains a lot of moisture. This makes the electronic components in the equipment susceptible to moisture damage and short circuits. In this embodiment, however, the pressure changes within the sterilization reactor 44 are not controlled by automatic exhaust valves or other equipment, minimizing the number of air-related components and reducing the possibility of equipment operation being affected by component damage, thus greatly improving the overall stability of the device.

[0067] In this embodiment, a photocatalytic ozonation reactor can also be installed on the right side of baffle 447. This reactor utilizes the principle of photocatalytic ozonation to oxidize and degrade harmful substances in the effluent. Specifically, the photocatalyst is brought into contact with ozone. The photocatalyst absorbs light energy to excite electrons, forming active species, which then react with ozone to generate an oxidant, thereby oxidizing and degrading the harmful substances.

[0068] Please refer to Figure 10 The photocatalytic ozonation reactor includes a housing 452, multiple ultraviolet lamps 453, and multiple titanium dioxide films 454. The ultraviolet lamps 453 are arranged sequentially along the width of the housing 452, and the titanium dioxide films 454 are arranged sequentially along the length of the housing 452, with the titanium dioxide films 454 positioned outside the ultraviolet lamps 453, allowing the light source of the ultraviolet lamps 453 to illuminate the titanium dioxide films 454. In this embodiment, the ultraviolet light emitted by the ultraviolet lamps 453 can excite the surface of the titanium dioxide films 454, generating photoexcited electron-hole pairs. Ozone molecules can be adsorbed on the surface of the titanium dioxide films 454, generating reactive oxygen free radicals. These free radicals can react with organic pollutants, microorganisms, and harmful chemicals in the water, thereby achieving degradation, sterilization, disinfection, and toxicity reduction.

[0069] By setting up a photocatalytic ozonation reactor, the ozone entering the cavity 451 can be converted into reactive oxygen free radicals, thus utilizing this portion of ozone and preventing it from being released into the environment and causing pollution. At the same time, it can also treat the tailwater in the pipe 443 again, improving the treatment efficiency and effect of the tailwater.

[0070] Understandably, in this embodiment, by designing the structure of the sterilization reactor 44 and installing a photocatalytic ozonation reactor on the side of the baffle 447 connected to the pipe 443, it is possible to ensure that ozone and effluent are fully mixed and treated, while also collecting the treated ozone through the cavity 450. This ozone, combined with the photocatalytic ozonation reactor, further treats any remaining ozone in the treated effluent, resulting in effluent that is essentially ozone-free, or at least extremely low in concentration. If further treatment of this low concentration of ozone in the effluent is required, the ozone generator 42 can use either liquid oxygen or air as the gas source.

[0071] The aquaculture wastewater treatment system described in this embodiment can be used in the following application scenarios.

[0072] Scenario 1: Deodorizing wastewater in a water tank.

[0073] When treating the wastewater in a suspended pond, an aquaculture wastewater treatment system may include a filtration device, a nitrification device, a sterilization device, a recirculating aquaculture system, and a control system.

[0074] The filtration device can be a negative pressure bend-flow separator or a microfilter. Its specific structure can be found in the description above. The negative pressure bend-flow separator can treat the effluent in the sump by separating solids and liquids, thus reducing the load on the microfilter. The microfilter can be used to remove suspended solids from the effluent, improving water cleanliness.

[0075] The nitrification unit can be a first nitrification unit or a second nitrification unit. The specific structures of the first and second nitrification units can be found in the description above. Both the first and second nitrification units remove nitrogen and phosphorus from the effluent, enabling the recycling of effluent resources.

[0076] The specific structure of the sterilization device can also be found in the description above. The sterilization device can use ozone to deodorize the effluent.

[0077] A recirculating aquaculture system is used to dynamically regulate the water in the entire recirculating aquaculture system. It can dynamically regulate the water according to the different water requirements of fish under different growth conditions.

[0078] In this scenario, the fish farmed in the suspended pond are typically largemouth bass and sturgeon.

[0079] The aquaculture wastewater treatment system of the present invention can deodorize the fish pond, remove the fishy smell from the fish, and improve the product quality of farmed fish.

[0080] The specific implementation of the aquaculture wastewater treatment system of the present invention in this scenario is as follows:

[0081] Operating procedures:

[0082] (1) Purchased commercial fish are placed in the hanging water tank;

[0083] (2) The microfiltration equipment is used in conjunction with the negative pressure bend flow separator to remove suspended solids from the water;

[0084] (3) Ammonia nitrogen is controlled by a gas-liquid two-phase biological denitrification device to ensure water quality stability;

[0085] (4) The circulating water disinfection device removes fishy and odorous substances from the water through ozone treatment;

[0086] (5) Dynamic monitoring of water quality to ensure the effectiveness of deodorization by water immersion.

[0087] Key data and results

[0088] The deodorization process for fish in the aquaculture wastewater treatment system takes 7-10 days. The removal rate of fishy odor substances in the water can reach over 90%, and the system's circulating water utilization rate reaches over 95%.

[0089] The following test results were obtained from the water quality testing of the aquaculture water: no ammonia nitrogen or nitrite was detected in the aquaculture water.

[0090] After being drained, the fishy smell is significantly reduced, and the market price increases by 35-45%. For example, the purchase price of sea bass is 9.9 yuan, and after draining to remove the fishy smell, the supply price in fresh food supermarkets is 14.5 yuan.

[0091] After the above treatment, tilapia that have been deodorized by immersion in water are obtained. Please refer to the attached instruction manual. Figure 11 .

[0092] The instruction manual is attached. Figure 11 These are before-and-after photos of tilapia before and after being soaked in water to remove the fishy smell. (The photos are included with the instruction manual.) Figure 11 It can be seen that the body color of fish changes significantly before and after being treated in the hanging pond with an aquaculture wastewater treatment system to remove fishy odors.

[0093] Scenario 2: Application in facility-based off-season aquaculture of mandarin fish

[0094] The aquaculture wastewater treatment system of this invention, when applied to the facility-based off-season farming of mandarin fish, has the following functions for each device: The second nitrification device enables deep purification of wastewater under low-temperature conditions, ensuring the safety of circulating water quality in winter. The sterilization device utilizes ozone to sterilize and disinfect the water, preventing the outbreak of diseases in the aquaculture water.

[0095] The negative pressure bend separator in the filtration device can perform preliminary solid-liquid separation of aquaculture wastewater, reducing the burden on the microfilter. The microfilter can remove tiny suspended solids from the wastewater, reducing the burden on subsequent treatment systems.

[0096] A recirculating aquaculture system is used to dynamically regulate the water in the entire recirculating aquaculture system. It can dynamically regulate the water according to the different water requirements of fish under different growth conditions.

[0097] In this scenario, palatable and nutritionally balanced floating aquatic feeds can be selected. Floating aquatic feeds can float on the water surface for up to 1 hour, avoiding waste and reducing the risk of eutrophication.

[0098] The specific implementation of the aquaculture wastewater treatment system of the present invention in this scenario is as follows:

[0099] 1. Aquaculture target: Mandarin fish (also known as mandarin perch)

[0100] 2. Aquaculture Objectives: To achieve off-season aquaculture of mandarin fish using existing facility-based recirculating aquaculture systems, filling the winter market supply gap and improving economic benefits. The aquaculture wastewater treatment system described in this application will treat the wastewater from the facility-based recirculating aquaculture system.

[0101] 3. Size: The water volume of a single pool is 40m³. 3 The system is equipped with four aquaculture ponds, with a total aquaculture water volume of 160m³. 3 .

[0102] 4. The technical process is as follows:

[0103] 4.1 Wastewater purification and reuse

[0104] (1) The wastewater from mandarin fish farming first passes through a negative pressure bend separation pipe and a microfilter in the filtration device to remove solid particles, with a filtration accuracy of 50 microns;

[0105] (2) Then, it is further purified under low temperature conditions through the first nitration unit.

[0106] (3) The water treated by the first nitrification device is then treated by a sterilization device, sterilized and disinfected, and then returned to the aquaculture pond to achieve a water recycling rate of more than 80%.

[0107] 4.2 Feeding and Management

[0108] (1) Using floating aquatic feed, the feed can float on the water surface for up to 1 hour, avoiding waste and reducing the risk of eutrophication of the water body;

[0109] (2) The flow rate is adjusted by controlling the flow rate through the control system to simulate the feeding environment of mandarin fish and improve feed utilization.

[0110] 4.3 System Monitoring and Flow Control

[0111] (1) The recirculating aquaculture system can dynamically monitor the flow rate of the entire aquaculture water body, maintain stable water flow, and promote the growth of mandarin fish;

[0112] (2) Monitor water indicators in real time, such as dissolved oxygen, ammonia nitrogen, pH value, etc., to ensure water quality stability.

[0113] 4.4 Key Data and Results

[0114] The following results were obtained from the water quality tests in the aquaculture water: the ammonia nitrogen content was less than 0.5 mg / L; the nitrite nitrogen content was less than 0.1 mg / L; and the dissolved oxygen content was maintained at 6-8 mg / L.

[0115] Statistical analysis of the growth data of farmed mandarin fish shows that:

[0116] 1. Average farming cycle for mandarin fish: 7 months (September to March or April of the following year), with a harvest size of 500g / fish;

[0117] 2. Survival rate of mandarin fish: increased to over 80%.

[0118] 4.5 Economic Benefits:

[0119] 1. Off-season fish harvesting can increase profits by 20-30%.

[0120] 2. The annual yield per pond reaches 2,000 jin, with a total output value of approximately 65,000 yuan per pond.

[0121] Scenario 3: Application in largemouth bass facility-based all-season seedling production system

[0122] When the aquaculture wastewater treatment system in this embodiment is applied to the largemouth bass facility-based all-season breeding system, the negative pressure bend separator in its filtration device can perform preliminary solid-liquid separation on the wastewater to be treated. Then, a microfilter removes suspended particles from the water, improving water transparency and purification efficiency. The first nitrification device can remove nitrogen and phosphorus from the wastewater year-round, achieving deep purification. The second nitrification device can effectively remove ammonia nitrogen and nitrate nitrogen from the wastewater. The recirculating aquaculture system can be used to dynamically regulate the aquaculture water in the facility-based all-season breeding system. By controlling the flow rate and volume of the aquaculture water, it simulates the natural environment, which is beneficial to the breeding and growth of largemouth bass.

[0123] The specific implementation of the aquaculture wastewater treatment system of the present invention in this scenario is as follows:

[0124] Breeding target: Largemouth bass

[0125] Breeding objective: To achieve year-round breeding of largemouth bass by implementing facility-based water environment regulation and tailwater resource treatment, thus overcoming seasonal limitations.

[0126] Scale of the facility-based all-season seedling system:

[0127] (1) Breeding ponds: 20 parent fish ponds, each with a water volume of 30m³.

[0128] (2) Seedling cultivation ponds: 10 small ponds with a water volume of 20m³ for seedling cultivation.

[0129] Understandably, in this scenario, each set of facility-based all-season seedling raising system can be equipped with four aquaculture wastewater treatment systems.

[0130] The technical process is as follows:

[0131] (I) Seedling incubation and cultivation stage (all seasons)

[0132] 1. Hatching conditions control: Adjust the water temperature to 22-25℃ and maintain dissolved oxygen at 6-8mg / L.

[0133] The temperature of the aquaculture water can be regulated through heating equipment and dynamic water flow control, thereby stabilizing the hatching environment in the facility-based all-season seedling raising system. Maintaining dissolved oxygen at 6-8 mg / L ensures a high hatching rate.

[0134] 2. Water quality management: The wastewater from the incubation process can be initially filtered through a filtration device; then it can be further purified by passing through the first nitrification device and the second nitrification device.

[0135] 3. Flow control: By regulating the flow rate, the natural flowing water environment of the fry is simulated, enhancing the adaptability of the fry.

[0136] (II) Seasonal circulation and wastewater reuse

[0137] 1. Wastewater Management: The wastewater can be deeply purified through the first and second nitrification units, so that the ammonia nitrogen content in the wastewater is less than 0.5 mg / L. The treated wastewater can be recycled back to the aquaculture pond for reuse.

[0138] 2. System Automation: Water quality parameters (pH, ammonia nitrogen, dissolved oxygen, etc.) are monitored in real time using sensors and other monitoring devices. Automated water flow control ensures stable water quality throughout the year in the facility-based, all-season seedling system.

[0139] (III) Key Data and Results

[0140] The following test results were obtained from the water quality testing of the aquaculture water body:

[0141] Water quality indicators: Ammonia nitrogen and nitrite were not detected. Dissolved oxygen: Stable at 6-8 mg / L. Water recycling rate: Reached 90%.

[0142] Calculations of the hatching rate of fertilized eggs and the survival rate of seedlings during seedling cultivation show that after the aquaculture wastewater treatment system of this invention treats the wastewater of the facility-based all-season seedling cultivation system, the hatching rate of fertilized eggs in the facility-based all-season seedling cultivation system is stabilized at over 90%, and the survival rate of seedlings is increased to 72%.

[0143] The aquaculture wastewater treatment system and the facility-based all-season seedling raising system of the present invention are combined to raise sea bass seedlings, resulting in the seedlings shown in the appendix to the specification. Figure 12 The image is shown in the picture. (Instruction manual included.) Figure 12 These are bass fry hatched in a facility-based, all-season seedling breeding system equipped with an aquaculture wastewater treatment system.

[0144] The basic principles, main features, and advantages of this invention have been described above. Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made without departing from the spirit and scope of the invention, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection claimed by this invention is defined by the appended claims and their equivalents.

Claims

1. An aquaculture wastewater treatment system, characterized in that, It includes: a sedimentation device (1), a filtration device (2), a nitrification device, a sterilization device (4), and a control system; the control system is used to control the operation or shutdown of the entire aquaculture wastewater treatment system; the sedimentation device (1) is used to settle the wastewater discharged from the aquaculture device; the filtration device (2) is used to filter the wastewater after sedimentation in the sedimentation device (1) and transport the filtered wastewater to the nitrification device, the nitrification device is used to nitrify the wastewater after filtration in the filtration device (2) and transport the nitrified wastewater to the sterilization device (4); the sterilization device (4) is used to sterilize the nitrified wastewater and transport the sterilized wastewater back to the aquaculture device; The nitrification device includes a first nitrification device (31) and a second nitrification device (32). The outlet of the filter device (2) is connected to the inlet of the first nitrification device (31) and the inlet of the second nitrification device (32), respectively. The inlet of the sterilization device (4) is connected to the outlet of the first nitrification device (31) and the outlet of the second nitrification device (32), respectively. The first nitrification device (31) and the second nitrification device (32) are interconnected, so that the first nitrification device (31) and the second nitrification device (32) can form multiple nitrification paths, each of which corresponds to a different nitrification capacity. The filter device (2) can be connected to any one of the multiple nitrification paths, and the filtered tailwater can be nitrified through the nitrification path. The first nitrification device (31) includes a shell (311), a water spraying device (312), and a plurality of packing grids (313). The water spraying device (312) is installed inside the shell (311) and located above the packing grids (313). The plurality of packing grids (313) are installed in the shell (311) from top to bottom. The water spraying device (312) is used to connect to the filter device (2). The upper end face of the packing grids (313) is used to fill biological packing material. The biological packing material is used to denitrify the water sprayed by the water spraying device (312). The packing grids (313) installed at the bottom of the shell (311) and the shell (311) form a biological nitrification tank (316). The biological nitrification tank (316) is used to perform secondary denitrification treatment on the effluent after denitrification treatment by the packing grids (313). The second nitrification device (32) includes a cathode electrode chamber (321), an anode electrode chamber (322), a magnetic flow electrode tank (324), and an ion exchange membrane (323). The ion exchange membrane (323) is disposed between the cathode electrode chamber (321) and the anode electrode chamber (322) and separates the cathode electrode chamber (321) and the anode electrode chamber (322). The anode electrode chamber (322) is used to introduce tailwater to be denitrified, and the cathode electrode chamber (321) is used to introduce liquid magnetic flow electrodes. The magnetic flow electrodes are used to adsorb nitrogen and phosphorus ions in the tailwater in the anode electrode chamber (322). There are two sets of magnetic flow electrodes, one set located in the cathode electrode chamber (321) and the other set located in the magnetic flow electrode tank (324). The two sets of magnetic flow electrodes can be alternately placed in the cathode electrode chamber (321) and the magnetic flow electrode tank (324). The magnetic flow electrode tank (324) and the cathode electrode chamber... A regeneration device (325) is also installed between (321). The regeneration device (325) is used to recycle and regenerate the magnetic flow electrode that flows from the cathode electrode chamber (321) to the magnetic flow electrode tank (324) and transport the recycled magnetic flow electrode to the magnetic flow electrode tank (324). The regeneration device (325) includes a housing second, and a cavity second (326) is provided inside the housing second. An aeration pipe (327), a power supply first, and at least one pair of electromagnetic devices are installed in the cavity second (326). The first power source is used to energize a pair of electromagnetic rods (328). After being energized, one of the electromagnetic rods (328) carries a positive charge and the other carries a negative charge. The electromagnetic rod (328) with a negative charge is used to adsorb the solid material in the magnetic flow electrode located in the cavity. The aeration pipe (327) is installed at the bottom of the second cavity (326) and is used to introduce gas into the second cavity (326). The introduced gas can aerate the solid material in the magnetic flow electrode.

2. The aquaculture wastewater treatment system as described in claim 1, characterized in that, The water spraying device (312) includes a water spraying pipe and multiple nozzles. The water spraying pipe is connected to the outlet of the filter device (2). The water spraying pipe is used to transport the tailwater filtered by the filter device (2) to the nozzles and spray it onto the packing grid (313) through the nozzles.

3. The aquaculture wastewater treatment system as described in claim 1, characterized in that, The filtration device (2) includes a negative pressure bend-flow separation pipe and a microfilter (22); the negative pressure bend-flow separation pipe is installed at the front end of the inlet of the microfilter (22), and is used to filter the tailwater entering the microfilter (22); the negative pressure bend-flow separation pipe includes a separation pipe body (211), a return pipe (212), and multiple bends (213), the separation pipe body (211) has a spiral structure, and the spiral structure makes the... The separation tube body (211) itself forms a cylindrical cavity, and the inner diameter of the separation tube body (211) gradually decreases from bottom to top; the return tube (212) is installed in the cylindrical cavity, and the central axis of the return tube (212) coincides with the central axis of the cylindrical cavity; one end of the bend (213) is connected to the bend of the separation tube body (211), and the other end of the bend (213) bends downward and connects to the return tube (212).

4. The aquaculture wastewater treatment system as described in claim 1, characterized in that, The sterilization device (4) includes a booster pump (41), an ozone generator (42), an ejector (43), and a sterilization reactor (44). The booster pump (41) is connected to the ejector (43) and is used to pressurize the wastewater to be treated and then transport it into the ejector (43). The ozone generator (42) is connected to the ejector (43) and is used to transport the generated ozone into the ejector (43). The wastewater and ozone entering the ejector (43) are mixed, and the mixed wastewater and ozone are transported into the sterilization reactor (44). The sterilization reactor (44) is used to sterilize the incoming wastewater.

5. The aquaculture wastewater treatment system as described in claim 4, characterized in that, The sterilization reactor (44) includes an inlet pipe (441), a shell three (442), a pipe one (443), a drain pipe one (444), and a gas return pipe two (445). The inlet pipe (441) is installed on one side of the shell three (442) and connected to the jet injector (43). The shell three (442) is provided with a cavity three. A baffle one (446) and a baffle two (447) are installed in the cavity three. The baffle one (446) and the baffle two (447) are arranged parallel to each other in the cavity three, and the baffle one (446) is located close to the... On one side of the inlet pipe (441), the first baffle (446) is integrally formed extending upward from the bottom end face of the third cavity and does not contact the top end face of the third cavity; the second baffle (447) is integrally formed extending downward from the top end face of the third cavity and does not contact the bottom end face of the third cavity; the first baffle (446) divides the third cavity into a fourth cavity (448) and a fifth cavity (449), and the second baffle (447) divides the third cavity into a sixth cavity (450) and a seventh cavity (451). 451) Vertically located above the fourth cavity (448) and the fifth cavity (449), the sixth cavity (450) is connected to the fourth cavity (448) and the fifth cavity (449), and the fifth cavity (449) is connected to the sixth cavity (450) and the seventh cavity (451); the ozone and tailwater mixed by the jet injector (43) enter the fourth cavity (448) and the fifth cavity (449) sequentially through the inlet pipe (441), and sterilize the tailwater in the areas of the fourth cavity (448) and the fifth cavity (449). During the treatment and sterilization process, ozone accumulates in the sixth cavity (450); the first pipe (443) is installed on the upper end face of the third shell (442) and connects to the seventh cavity (451); the first drain pipe (444) is horizontally arranged and connects to the first pipe (443); one end of the second gas return pipe (445) is connected to the first pipe (443), and the other end is connected to the ozone generator (42). The vertical height of the gas outlet of the second gas return pipe (445) is higher than the vertical height of the water outlet of the first drain pipe (444).

6. The aquaculture wastewater treatment system as described in claim 5, characterized in that it includes: The height of the side wall of the sterilizing separator connected to the liquid inlet pipe (441) is h, the length of the first baffle (446) is a, the length of the second baffle (447) is b, the distance from the first baffle (446) to the side wall connected to the liquid inlet pipe (441) is c, and the distance from the second baffle (447) to the side wall connected to the liquid inlet pipe (441) is d; where a, b, and h satisfy: a + b < h; c and d satisfy: d > 4c; b and c satisfy: 0.75c < b < c.

7. The aquaculture wastewater treatment system as described in claim 5, characterized in that, A photocatalytic ozonation reaction device is also installed on the side of the baffle two (447) near the cavity seven (451). The photocatalytic ozonation reaction device includes a housing four (452), multiple ultraviolet lamps (453) and multiple titanium dioxide films (454). The multiple ultraviolet lamps (453) are arranged sequentially along the width direction of the housing four (452), and the multiple titanium dioxide films (454) are arranged sequentially along the length direction of the housing four (452). The titanium dioxide films (454) are located outside the ultraviolet lamps (453), and the light source of the ultraviolet lamps (453) can irradiate the titanium dioxide films (454) and excite the titanium dioxide films (454) to adsorb ozone molecules to generate active oxygen free radicals. The generated active oxygen free radicals are used to sterilize the effluent.

8. The aquaculture wastewater treatment system as described in claim 1, characterized in that, The sedimentation device (1) is a sedimentation tank.

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