Breeding tail water treatment device for freshwater fishery breeding

Abstract

The invention relates to an aquaculture tail water treatment device for freshwater fishery aquaculture. The aquaculture tail water treatment device comprises a water tank, a rotary drum, a driving mechanism, a conductive filter screen, a cathode assembly, a conductive slip ring and a power supply. According to the invention, electrochemical sterilization and mechanical filtration are integrated, and electroporation inactivation of environmental microorganisms and degradation of drug-resistant factors by reactive oxygen substances generated on the surface of the conductive filter screen are synchronously realized in the solid-liquid separation process. Furthermore, the cathode assembly can adopt a rotary brush roll cathode to realize self-cleaning, the conductive filter screen can be divided into independent conductive sections to realize zoned electric field regulation and control, and a coating regeneration system can be arranged to restore the activity of the electrocatalytic coating. The problem that drug-resistant factors are enriched and spread due to biofilm breeding on the surface of the electrode is fundamentally solved, and the device is compact in structure, low in operation cost and suitable for freshwater fishery breeding.

Description

Technical Field

[0001] This invention relates to the field of aquaculture wastewater technology, and in particular to an aquaculture wastewater treatment device for freshwater aquaculture. Background Technology

[0002] As freshwater aquaculture develops towards high-density and intensive practices, the environmental pollution caused by aquaculture wastewater discharge is becoming increasingly prominent. Aquaculture wastewater contains organic pollutants such as uneaten feed and feces, as well as nutrients such as nitrogen and phosphorus. It also contains a large number of environmental microorganisms, including opportunistic pathogens and antibiotic-resistant bacteria. More seriously, the antibiotics and disinfectants used in the aquaculture process, while killing some microorganisms, also induce the accumulation and spread of drug-resistant genes in the microbial community. These resistance factors can spread between different bacterial species through horizontal gene transfer and even be transmitted to humans through the food chain, posing a potential threat to public health and safety.

[0003] Electrochemical water treatment technology has gained widespread attention in recent years due to its advantages, such as eliminating the need for chemical additives, preventing secondary pollution, and achieving high sterilization efficiency, in response to the microbial risks in aquaculture wastewater. Such devices typically include a water tank, an electrode assembly housed within the tank, and a power source electrically connected to the electrode assembly. The basic structure is as follows: the water tank serves as a container for the wastewater, and the electrode assembly comprises an anode and a cathode, which are spaced apart and positioned relative to each other within the tank. However, existing electrochemical treatment devices exhibit the following problems when practically applied to freshwater aquaculture wastewater treatment: biofilms easily form on the electrode surfaces, creating a breeding ground for drug-resistant bacteria and thus exacerbating the risk of drug resistance transmission.

[0004] Specifically, aquaculture effluent contains abundant organic matter and microorganisms. Microorganisms irreversibly attach to electrode surfaces through physical adsorption and secretion of extracellular polymeric substances (EPS), gradually forming biofilms. Dissolved organic matter in the water (such as humus, proteins, and polysaccharides) can be adsorbed onto the electrode surface, providing a nutrient substrate for microorganisms and promoting biofilm growth. The biofilm provides a sanctuary for microorganisms, allowing them to escape the killing effect of the electric field. More seriously, drug-resistant bacteria within the biofilm multiply rapidly when the electrode is de-energized or at low potential, releasing high concentrations of intracellular and extracellular drug-resistant genes into the water upon disintegration. These resistance factors are discharged with the effluent or enter the environment through backwash sludge, causing drug-resistant genes to spread in the aquaculture water and surrounding environment, posing a threat to public health and safety. Summary of the Invention

[0005] This invention provides a freshwater aquaculture wastewater treatment device that can solve the problem in the prior art where biofilms grow on the electrode surface, leading to the accumulation and spread of drug resistance factors.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a freshwater aquaculture wastewater treatment device, comprising a water tank, a rotating drum, a drive mechanism, a conductive filter screen, a cathode assembly, a conductive slip ring, and a power supply. The rotating drum is rotatably supported on the water tank, and the output end of the drive mechanism is connected to the rotating drum. The conductive filter screen forms the cylindrical wall of the rotating drum and is used to filter suspended solids in the wastewater; the surface of the conductive filter screen has an electrocatalytic coating. The cathode assembly is located inside the rotating drum, contacting or maintaining a gap with the inner wall of the conductive filter screen, forming an electric field space between the cathode assembly and the conductive filter screen. The conductive slip ring is disposed on the rotating shaft of the rotating drum and is electrically connected to the conductive filter screen. The power supply is electrically connected to the conductive slip ring and the cathode assembly, and is used to apply voltage between the conductive filter screen and the cathode assembly, causing environmental microorganisms in the wastewater flowing through the electric field space to undergo electroporation and inactivation, and causing reactive oxygen species to be generated on the surface of the conductive filter screen to degrade drug resistance factors released by microorganisms.

[0007] Preferably, the cathode assembly is a rotary brush roller cathode, comprising: a brush roller body, parallel to the axis of the rotating drum and rotatably connected to the water tank; conductive bristles, disposed on the outer circumferential surface of the brush roller body, contacting or maintaining a gap with the inner wall of the conductive filter screen; a brush roller drive motor, disposed outside the rotating drum, with its output end connected to the brush roller body; and a second conductive slip ring, electrically connected to both the negative terminal of the power supply and the brush roller body.

[0008] Preferably, the conductive bristles are made of conductive nylon or stainless steel fiber material and are spirally distributed on the brush roller body; the rotation direction of the brush roller drive motor is opposite to the rotation direction of the drum, and the rotation speed is 5-10 times that of the drum.

[0009] Preferably, the conductive filter is divided into multiple independent conductive sections along the axis of the drum, and an insulating ring is provided between two adjacent conductive sections; the conductive slip ring is a multi-channel conductive slip ring, the number of its channels corresponding to the number of conductive sections, and each conductive section is electrically connected to the corresponding channel of the multi-channel conductive slip ring through an independent wire; the power supply is a multi-channel independently adjustable power supply, each of its output channels being electrically connected to the corresponding channel of the multi-channel conductive slip ring, for independently adjusting the voltage or current applied to each conductive section.

[0010] Preferably, both ends of the drum are open structures, with one end being a water inlet and the other end being a water outlet. Water quality sensors for detecting the water quality parameters of the tailwater are installed at the water inlet and the water outlet of the drum. The water quality sensors and a multi-channel independent adjustable power supply are electrically connected to a controller. The controller is used to adjust the voltage or current applied to each conductive section according to the water quality parameters, so that the electric field strength of the conductive section on the water inlet side is higher than that on the conductive section on the water outlet side.

[0011] Preferably, the outside of the drum is provided with a coating regeneration system, including: a regeneration liquid storage tank for storing regeneration liquid; a regeneration liquid pump connected to the regeneration liquid storage tank; a spray pipe disposed above the outside of the drum, extending along the axis of the drum and connected to the regeneration liquid pump; multiple nozzles connected to the spray pipe and facing the outer surface of the drum; the power supply has a regeneration mode, in which the power supply outputs a reverse voltage or a high-frequency pulse voltage.

[0012] Preferably, the drum is rotatably supported on the water tank by an insulated bearing housing, the insulated bearing housing including a bearing body and an insulating layer disposed between the inner and outer rings of the bearing.

[0013] Preferably, the conductive filter includes a titanium substrate and a shape-stabilized anode coating loaded on the surface of the titanium substrate, wherein the shape-stabilized anode coating is selected from one of IrO / TaO coating, RuO / IrO coating or Pt coating; the power supply is a pulsed DC power supply with an output voltage of 3-12V and a pulse frequency of 1-1000 Hz.

[0014] Compared to existing technologies, this invention, through the coordinated arrangement of a water tank, a rotating drum, a drive mechanism, a conductive filter, an electrocatalytic coating, a cathode assembly, a conductive slip ring, and a power supply, creates an electric field space between the conductive filter and the cathode assembly. During the filtration process, voltage is applied synchronously, causing microorganisms flowing through the electric field space to undergo electroporation and inactivation. At the same time, active oxygen substances are generated on the surface of the conductive filter to degrade drug resistance factors released by microorganisms, killing microorganisms at the source and eliminating drug resistance genes, thus avoiding the formation of biofilms and the secondary release of drug resistance factors. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the main structure of the present invention; Figure 2 This is a schematic diagram of the main cross-sectional structure of the present invention; Figure 3 This is a schematic diagram of the main structure of the conductive filter screen of the present invention; Figure 4 This is a schematic diagram of the main structure of the cathode assembly of the present invention; Figure 5 This is a block diagram of the coating regeneration system of the present invention; Figure 6 This is a schematic diagram of the control system of the present invention.

[0016] In the diagram: 100, water tank; 210, rotating shaft; 230, water inlet; 240, water outlet; 250, sludge collection tank; 300, drive mechanism; 310, drive motor; 320, transmission chain; 400, backwashing mechanism; 410, high-pressure water pump; 420, media switching valve; 430, differential pressure sensor; 500, conductive filter screen; 510, inlet section; 520, intermediate section; 530, outlet section; 540, insulating ring; 600, cathode assembly. ; 610, Brush roller body; 620, Conductive bristles; 630, Brush roller drive motor; 650, Second conductive slip ring; 700, Conductive slip ring; 800, Power supply; 820, Controller; 830, Water quality sensor; 831, Inlet turbidity sensor; 832, Outlet turbidity sensor; 833, Conductivity sensor; 900, Coating regeneration system; 910, Regeneration liquid storage tank; 920, Regeneration liquid pump; 930, Spray pipe; 940, Nozzle. Detailed Implementation

[0017] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the technical solution of this 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. Therefore, they should not be construed as limitations on this invention.

[0018] Example 1: Basic Scheme like Figures 1 to 2 As shown, this embodiment provides a freshwater aquaculture wastewater treatment device, including a water tank 100, a rotating drum, a drive mechanism 300, a conductive filter screen 500, a cathode assembly 600, a conductive slip ring 700, a power supply 800, and a backwashing mechanism 400.

[0019] The water tank 100 is welded from carbon steel and its surface is treated with anti-corrosion coating. The rotating drum has a cylindrical structure and is supported on the water tank 100 by a rotating shaft 210, which is a hollow structure. The rotating shaft 210 is connected to the water tank 100 by an insulated bearing housing. The insulated bearing housing includes a bearing body and a ceramic-coated insulating layer between the inner and outer rings of the bearing to prevent current loss, avoid creating conditions for biofilm growth due to local weakening of the electric field, ensure that all electric field energy is applied to the water, and improve the sterilization effect.

[0020] The drive mechanism 300 includes a drive motor 310 and a transmission chain 320. The drive motor 310 is mounted on the water tank 100 and connected to the rotating shaft 210 through the transmission chain 320. It drives the drum to rotate slowly at a speed of 1-3 rpm. In this embodiment, the transmission chain 320 includes a gear and a gear ring that mesh with each other. The gear is fixedly connected to the output end of the drive motor 310, and the gear ring is fixed to the outer surface of the rotating shaft 210.

[0021] The backwashing mechanism 400 includes a high-pressure water pump 410, a media switching valve 420, and a differential pressure sensor 430. The inlet of the media switching valve 420 is connected to both the high-pressure water pump 410 and the regenerated liquid pump 920, and the outlet is connected to the spray pipe 930. The spray pipe 930 is located above the outside of the drum and extends along the axis of the drum, with nozzles 940 facing the outer surface of the drum. The start and stop of the high-pressure water pump 410 are controlled by the differential pressure sensor 430, which detects the pressure difference inside and outside the conductive filter 500. The controller 820 controls the start and stop of the backwashing mechanism 400 and the brush roller drive motor 310 based on the pressure difference.

[0022] Both ends of the drum are open, with an inlet 230 at one end and an outlet 240 at the other. A sludge collection trough 250 is arranged axially inside the drum, and a drain pipe is connected to one end of the sludge collection trough 250, which leads out of the drum. Wastewater from backwashing is discharged from the drum through the drain pipe.

[0023] A conductive filter 500 forms the drum wall. The conductive filter 500 has a mesh size of 120 and is used to filter suspended solids in the effluent. In this embodiment, the conductive filter 500 uses a titanium substrate as the base. An IrO2 / Ta2O5 stable anode coating is coated onto the substrate using a thermal decomposition method. Combined with a pulsed DC power supply, this not only improves electrocatalytic activity but also reduces the tendency of organic matter and microorganisms to adhere to the electrode surface, thus inhibiting biofilm formation at the material level.

[0024] The cathode assembly 600 is located inside the rotating drum and is in contact with or maintains a gap of 0.5-2mm with the inner wall of the conductive filter 500, forming an electric field space between the cathode assembly 600 and the conductive filter 500.

[0025] A conductive slip ring 700 is mounted on the rotating shaft 210 of the drum. The rotor of the conductive slip ring 700 is fixedly connected to the rotating shaft 210 and rotates together with the drum. The stator of the conductive slip ring 700 is fixed to the water tank 100. The conductive filter screen 500 is electrically connected to the rotor of the conductive slip ring 700 via a wire.

[0026] Power supply 800 uses a pulsed DC power supply. The positive terminal of power supply 800 is electrically connected to the stator of the conductive slip ring 700, and the negative terminal is electrically connected to the cathode assembly 600. The output voltage of power supply 800 is adjustable from 3-12V, and the current density is 10-100 A / m.2 The pulse frequency is 100 Hz.

[0027] The working principle of this embodiment is as follows: The aquaculture wastewater to be treated enters the drum through inlet 230 and flows from the inside to the outside through conductive filter 500 under the action of gravity. Suspended particles in the wastewater are trapped on the inner surface of conductive filter 500, and the filtered clean water is discharged through outlet 240.

[0028] During filtration, the power supply 800 applies a pulsed voltage between the conductive filter 500 (anode) and the cathode assembly 600 (cathode), creating an electric field in the space between them. Since the current density is highest at the mesh openings of the conductive filter 500, a localized strong electric field is formed. When microorganisms (including drug-resistant bacteria) in the effluent flow through the mesh, their cell membranes undergo electroporation under the influence of the strong electric field, resulting in cell membrane structure disruption and microbial inactivation.

[0029] Simultaneously, the IrO2 / Ta2O5 electrocatalytic coating on the surface of the conductive filter 500 activates water molecules or dissolved oxygen under the action of an electric field, generating reactive oxygen species (such as hydroxyl radicals ·OH, hydrogen peroxide H2O2, etc.). These reactive oxygen species have strong oxidizing properties and can oxidize and degrade intracellular drug resistance genes released into the water after microbial rupture, as well as free extracellular drug resistance genes in the water, breaking them down into harmless small molecules.

[0030] When the solids trapped on the inner surface of the conductive filter screen 500 accumulate to a certain level, the pressure difference between the inside and outside of the filter screen increases. After the differential pressure sensor 430 detects the set threshold, the control system initiates the backwashing procedure. At this time, the drum rotates at low speed. When the clogged area reaches the top, the high-pressure water pump 410 starts, and high-pressure water is sprayed through the nozzle 930 onto the outer surface of the drum, flushing down the solids trapped on the inner surface of the conductive filter screen 500, which then fall into the sludge collection tank 250 and are discharged. During the backwashing process, the power supply 800 is automatically cut off to ensure safety.

[0031] Example 2: Rotary brush roller cathode solution like Figure 4 As shown, this embodiment is an improvement on embodiment 1, in which the cathode assembly 600 is set as a rotary brush roller cathode.

[0032] The rotary brush roller cathode includes a brush roller body 610, conductive bristles 620, and a brush roller drive motor 630.

[0033] The brush roller body 610 is arranged parallel to the axis of the drum and is rotatably connected to the water tank 100 via a bearing.

[0034] Conductive bristles 620 are disposed on the outer peripheral surface of the brush roller body 610 in a spiral pattern. The conductive bristles 620 are made of conductive nylon material and contain carbon fibers to improve conductivity. The length of the bristles is precisely calculated to maintain a gap of about 1 mm between them and the inner wall of the conductive filter screen 500, which ensures effective establishment of the electric field while avoiding excessive friction that could damage the filter screen.

[0035] The brush roller drive motor 630 is located outside the drum and is connected to the end of the brush roller body 610 near the water inlet 230.

[0036] The brush roller drive motor 630 rotates in the opposite direction to the drum, and its speed is 8 times that of the drum (approximately 16-24 rpm).

[0037] In terms of electrical connection, the brush roller body 610, acting as the cathode, needs to be electrically connected to the negative terminal of the power supply 800 via the second conductive slip ring 650. The second conductive slip ring 650 is installed on the shaft end of the brush roller body 610 near the water outlet 240, with its rotor connected to the brush roller body 610 and its stator connected to the negative terminal of the power supply 800 via a wire.

[0038] In this embodiment, a rotating brush roller cathode achieves the dual functions of cathode self-cleaning and online cleaning of the anode filter. During rotation, the conductive bristles 620 continuously scrape the inner wall of the conductive filter 500, effectively preventing biofilm growth and clogging. Simultaneously, the movement of the brush roller body 610 disrupts the crystallization conditions of scale on the cathode surface, preventing cathode passivation and secondary release of drug resistance factors, significantly improving the long-term operational stability and reliability of the device. The conductive bristles 620 are spirally distributed on the brush roller body 610 and rotate in the opposite direction to the rotating drum, achieving full-coverage cleaning without dead angles. Furthermore, the disturbance effect of the conductive bristles 620 disrupts the crystallization conditions of scale on the cathode surface, preventing cathode passivation and ensuring long-term stable operation of the electric field.

[0039] Example 3: Segmented Electric Field Control Scheme like Figures 2 to 3 as well as Figure 5 As shown, this embodiment is an improvement on embodiment 2. The conductive filter 500 is divided into multiple independent conductive sections along the axis of the drum, and a multi-channel independent adjustable power supply and control system are used to achieve zoned electric field control.

[0040] The conductive filter 500 is divided into three sections along the axial direction: the inlet section 510, the middle section 520, and the outlet section 530. Adjacent conductive sections are isolated from each other by an insulating ring 540. The insulating ring 540 is made of high-strength engineering plastic to ensure electrical insulation between the sections.

[0041] The conductive slip ring 700 is a multi-channel conductive slip ring, and the number of its channels corresponds to the number of the conductive sections.

[0042] Each conductive section is connected to a wire. The wires leading from each section converge at the multi-channel conductive slip ring at the end of the rotating shaft 210. The multi-channel conductive slip ring has four channels (three anode channels + one cathode channel for backup).

[0043] The power supply 800 uses a multi-channel independently adjustable pulsed DC power supply with three independent output channels, each connected to one of the three anode channels of the multi-channel conductive slip ring. The voltage and current of each anode channel can be adjusted independently.

[0044] The control system includes a controller 820 and a water quality sensor 830. The water quality sensor 830 includes an inlet turbidity sensor 831 installed at the inlet of the drum and an outlet turbidity sensor 832 installed at the outlet 240. The controller 820 is a PLC controller, which is electrically connected to the water quality sensor 830 and a multi-channel independently adjustable pulse DC power supply.

[0045] The controller 820 calculates the pollution load distribution of each section based on the influent turbidity T_in and the effluent turbidity T_calculation, and outputs control signals to the multi-channel independently adjustable pulsed DC power supply to set the output voltage of each anode channel. A higher voltage (e.g., 10V) is applied to the influent section 510, a medium voltage (e.g., 6V) is applied to the intermediate section 520, and a lower voltage (e.g., 3V) is applied to the effluent section 530, achieving on-demand power supply.

[0046] In this embodiment, the controller 820 independently adjusts the voltage of each section according to the water quality parameters, so that a higher intensity electric field is applied to the water inlet side (the area where biofilm is prone to grow), which enhances the sterilization effect, inhibits the formation of biofilm, and significantly reduces energy consumption while ensuring the sterilization effect.

[0047] Example 4: Coating Regeneration System like Figure 5 and Figure 6 As shown, this embodiment is an improvement on embodiment 3, by adding a coating regeneration system 900, which is used to periodically restore the activity of the electrocatalytic coating on the surface of the conductive filter 500.

[0048] The coating regeneration system 900 includes a regeneration liquid storage tank 910, a regeneration liquid pump 920, a spray pipe 930 shared with the backwashing mechanism 400, and multiple nozzles 940.

[0049] The regenerated liquid storage tank 910 is used to store the regenerated liquid. In this embodiment, a 1% citric acid solution is used as the regenerated liquid. The inlet of the regenerated liquid pump 920 is connected to the regenerated liquid storage tank 910, and the outlet is connected to the second inlet of the medium switching valve 420.

[0050] The media switching valve 420 is a three-way valve. Its first inlet is connected to the outlet of the high-pressure water pump 410 of the backwashing mechanism 400, its second inlet is connected to the outlet of the regenerated liquid pump 920, and its outlet is connected to the spray pipe 930. The media switching valve 420 is electrically connected to the controller 820 and controls the switching of the media channel.

[0051] The controller 820 has a pre-set regeneration cleaning program that is automatically triggered based on the cumulative running time (e.g., every 7 days) or based on changes in power output parameters (e.g., a 10% decrease in current efficiency).

[0052] The regeneration and cleaning process is as follows: The first step is to stop the machine and drain the water: the controller 820 stops the water intake, and the drum rotates at low speed to drain the water inside.

[0053] The second step is circuit switching: Controller 820 controls the multi-channel independently adjustable pulsed DC power supply to switch to regeneration mode. In regeneration mode, the multi-channel independently adjustable pulsed DC power supply outputs a reverse voltage (i.e., conductive filter 500 is connected to the negative terminal, and cathode assembly 600 is connected to the positive terminal), and superimposed a high-frequency pulse (frequency 1000 Hz). The reverse voltage helps loosen the deposits on the coating surface, and the high-frequency pulse can generate a micro-vibration effect, enhancing the cleaning effect.

[0054] The third step is to spray the regenerant: The controller 820 switches the media switching valve 420 to the second inlet (connecting to the regenerant pump 920), starts the regenerant pump 920, and evenly sprays the regenerant onto the rotating conductive filter screen 500 through the spray pipe 930 and nozzle 940. The spraying time lasts for 5-10 minutes to allow the regenerant to fully wet the surface of the conductive filter screen 500.

[0055] Step 4, Immersion reaction: Stop spraying and continue to rotate the drum at a low speed to allow the regeneration solution to fully react with the coating surface for 10-15 minutes.

[0056] Step 5, rinse with clean water: Controller 820 shuts off regenerated liquid pump 920, switches media switching valve 420 back to the first inlet (connecting to high-pressure water pump 410), starts high-pressure water pump 410, and rinses the spray pipe 930, nozzle 940, and conductive filter screen 500 surface with clean water. Rinse for 3-5 minutes.

[0057] Step 6, Resume Operation: The controller 820 switches the power supply back to normal operating mode, resumes water intake, and resumes normal operation.

[0058] The beneficial effects of this embodiment are as follows: During long-term use, the electrocatalytic activity of the DSA coating decreases due to the adsorption of organic matter on its surface and the formation of a passivation film. This embodiment, through a combination of in-situ electrochemical regeneration and chemical cleaning, can restore the coating activity without disassembling the conductive filter 500, maintaining its continuous ability to kill microorganisms and biofilms, and extending the service life of the conductive filter 500 from 1 year to 3-5 years. Simultaneously, the media switching valve 420 allows the regeneration solution and backwash to share the same spray pipe 930 and nozzle 940, eliminating the need for additional spray piping, resulting in a more compact structure and lower cost.

[0059] Example 5: Complete Implementation of the Control System like Figure 6 As shown, the control system is based on the PLC controller 820 and connects to the following modules: Input modules: water quality sensor 830 (including inlet turbidity sensor 831, outlet turbidity sensor 832, conductivity sensor 833), differential pressure sensor 430, manual / automatic switch and parameter setting touch screen.

[0060] Output modules: control interface for multi-channel independent adjustable pulse DC power supply, frequency converter for drive motor 310, frequency converter for brush roller drive motor 630, contactor for backwash high-pressure water pump 410, contactor for regenerated liquid pump 920, control line for medium switching valve 420, and alarm device (audible and visual alarm).

[0061] The control program running in controller 820 includes the following main functional modules: (1) Basic operation module: controls the drive motor 310 to run at a constant speed and keep the drum rotating continuously.

[0062] (2) Backwash control module: Based on the signal from differential pressure sensor 430, the backwash program is started when the differential pressure reaches the set upper limit P_max; the backwash is stopped when the differential pressure drops to the lower limit P_min. At the same time, the backwash frequency and duration are recorded to determine the clogging trend of conductive filter 500.

[0063] (3) Electric field control module: Based on the influent turbidity T_in and effluent turbidity T_out, the required voltage / current values ​​for each conductive section are calculated according to the preset control curve, and the setting command is sent to the multi-channel independent adjustable pulse DC power supply via Modbus protocol. When the water quality changes abruptly, the PID algorithm is used for rapid adjustment.

[0064] (4) Brush Roller Control Module: Adjusts the speed of the brush roller drive motor 630 according to the running time and pressure difference. When the pressure difference rises rapidly, the speed of the brush roller body 610 is increased to enhance the cleaning effect; the speed can be reduced to save energy during low load at night.

[0065] (5) Regeneration control module: Based on the cumulative running time and power efficiency parameters, automatically trigger the regeneration cleaning program, execute the regeneration process according to the preset steps, and record the number of regenerations and the effect.

[0066] (6) Fault diagnosis and alarm module: Real-time monitoring of the status of each sensor and actuator. When an abnormality is detected (such as motor overload, power failure, pressure difference not dropping for a long time, etc.), the machine will automatically stop and issue an audible and visual alarm. At the same time, the fault code and possible handling suggestions will be displayed on the touch screen.

[0067] The touchscreen human-machine interface provides the following functions: real-time display of influent / outfluent turbidity, pressure difference, voltage / current of each section, cumulative running time, etc.; parameter setting of electric field control curve parameters, backwash threshold, regeneration cycle, etc.; historical data query; manual control and debugging.

[0068] Example 6: Experimental Verification of Treatment Effect To verify the technical effects of this invention, a comparative experiment was conducted at the aquaculture experimental base of Shanxi Agricultural University. Three treatment groups were set up: Control group A used a conventional stainless steel microfiltration machine (without an electric field); Control group B used a conventional microfiltration machine with terminal ultraviolet disinfection; the experimental group used the device described in Example 4 of this invention (conductive filter + rotating brush roller + segmented electric field + coating regeneration).

[0069] The experimental water was simulated high-density aquaculture wastewater, with the following main water quality indicators: COD 120 mg / L, ammonia nitrogen 15 mg / L, total phosphorus 3.5 mg / L, and suspended solids 180 mg / L. *E. coli* carrying tetracycline resistance genes (tetA) and sulfonamide resistance genes (sul1) were inoculated into the water to achieve a bacterial concentration of 10-1. 6 CFU / mL.

[0070] After 7 days of continuous operation, the experimental group showed a 99.7% removal rate of drug-resistant bacteria and a more than 90% removal rate of extracellular drug-resistant genes. The treated water quality was stable with no regrowth. The control group A showed a removal rate of only about 60% of drug-resistant bacteria and almost no removal of free genes. The control group B showed good bacterial killing effect (98.5%), but a removal rate of only about 35% of extracellular drug-resistant genes, and there was a risk of regrowth in the effluent.

[0071] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A freshwater aquaculture wastewater treatment device, comprising a water tank, characterized in that, Also includes: The drum is rotatably supported on the water tank. A conductive filter screen forms the cylinder wall of the drum and is used to filter suspended solids in the effluent. The surface of the conductive filter screen has an electrocatalytic coating. A drive mechanism, connected to the drum, is used to drive the drum to rotate; The cathode assembly is located inside the rotating drum and is in contact with or maintains a gap with the inner wall of the conductive filter. An electric field space is formed between the cathode assembly and the conductive filter. A conductive slip ring is disposed on the rotating shaft of the drum and is electrically connected to the conductive filter screen; A power source, electrically connected to the conductive slip ring and cathode assembly, is used to apply voltage between the conductive filter and the cathode assembly, causing environmental microorganisms in the tailwater flowing through the electric field space to undergo electroporation and inactivation, and causing reactive oxygen species to be generated on the surface of the conductive filter to degrade the drug resistance factors released by the microorganisms.

2. The aquaculture wastewater treatment device for freshwater aquaculture according to claim 1, characterized in that, The cathode assembly is a rotary brush roller cathode, comprising: a brush roller body, parallel to the axis of the rotating drum and rotatably connected to the water tank; conductive bristles, disposed on the outer circumferential surface of the brush roller body, contacting or maintaining a gap with the inner wall of the conductive filter screen; a brush roller drive motor, disposed outside the rotating drum, with its output end connected to the brush roller body; and a second conductive slip ring, electrically connected to both the negative terminal of the power supply and the brush roller body.

3. The aquaculture wastewater treatment device for freshwater aquaculture according to claim 2, characterized in that: The conductive bristles are made of conductive nylon or stainless steel fiber and are spirally distributed on the brush roller body; the rotation direction of the brush roller drive motor is opposite to the rotation direction of the drum, and the rotation speed is 5-10 times that of the drum.

4. The aquaculture wastewater treatment device for freshwater aquaculture according to claim 1, characterized in that: The conductive filter is divided into multiple independent conductive sections along the axis of the drum, and an insulating ring is provided between two adjacent conductive sections. The conductive slip ring is a multi-channel conductive slip ring, the number of which corresponds to the number of conductive segments. Each conductive segment is electrically connected to the corresponding channel of the multi-channel conductive slip ring through an independent wire. The power supply is a multi-channel independently adjustable power supply, with each output channel electrically connected to the corresponding channel of the multi-channel conductive slip ring, used to independently adjust the voltage or current applied to each conductive section.

5. The aquaculture wastewater treatment device for freshwater aquaculture according to claim 4, characterized in that: Both ends of the drum are open structures, with one end being a water inlet and the other end being a water outlet. Water quality sensors for detecting the water quality parameters of the tailwater are installed at the water inlet and the water outlet of the drum. The water quality sensors and a multi-channel independent adjustable power supply are electrically connected to a controller. The controller is used to adjust the voltage or current applied to each conductive section according to the water quality parameters, so that the electric field strength of the conductive section on the water inlet side is higher than that on the conductive section on the water outlet side.

6. The aquaculture wastewater treatment device for freshwater aquaculture according to claim 1, characterized in that: The outside of the drum is equipped with a coating regeneration system, including: a regeneration liquid storage tank for storing regeneration liquid; a regeneration liquid pump connected to the regeneration liquid storage tank; a spray pipe located above the outside of the drum, extending along the axis of the drum and connected to the regeneration liquid pump; and multiple nozzles connected to the spray pipe and facing the outer surface of the drum. The power supply has a regenerative mode, in which the power supply outputs a reverse voltage or a high-frequency pulse voltage.

7. The aquaculture wastewater treatment device for freshwater aquaculture according to claim 1, characterized in that: The drum is rotatably supported on the water tank by an insulated bearing housing, which includes a bearing body and an insulating layer disposed between the inner and outer rings of the bearing.

8. The aquaculture wastewater treatment device for freshwater aquaculture according to claim 1, characterized in that: The conductive filter includes a titanium substrate and a shape-stabilized anode coating loaded on the surface of the titanium substrate. The shape-stabilized anode coating is selected from one of IrO / TaO coating, RuO / IrO coating or Pt coating. The power supply is a pulsed DC power supply with an output voltage of 3-12V and a pulse frequency of 1-1000 Hz.

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