Controllable dynamic magnetic field micro-eddy current enhanced water treatment method and device

Abstract

This invention discloses a controllable dynamic magnetic field micro-eddy current enhanced water treatment method and apparatus, comprising the following steps: adding magnetic functional particles to the water to be treated in a non-magnetic reaction vessel; arranging a controllable dynamic magnetic field generating component on the outer wall of the non-magnetic reaction vessel; generating a lateral magnetic field whose direction and intensity change with time through the controllable dynamic magnetic field generating component; using a horizontal magnetic gradient force to keep the magnetic functional particles in a laterally suspended state in the water to be treated; and recovering the magnetic functional particles through a magnetic separation module located at the water outlet after the reaction is completed. This invention, through the horizontal magnetic force provided by the lateral magnetic field, breaks the limitation of gravity and magnetic force being superimposed in the same direction in traditional bottom-driven stirring methods, fundamentally changing the force state of the particles.

Description

Technical Field

[0001] This invention belongs to the technical field of water environment treatment and chemical process intensification equipment, and in particular relates to a controllable dynamic magnetic field micro eddy current enhanced water treatment method and device. Background Technology

[0002] In water treatment processes utilizing magnetic functional materials (such as magnetic biochar, magnetic resin, or nano-zero-valent iron composites), maintaining the uniform suspension of the magnetic materials in water and enhancing solid-liquid mass transfer over a long period are crucial to determining pollutant treatment efficiency. Existing technologies mostly employ contact mechanical stirring and bottom magnetic stirring, which have the following limitations: 1. In traditional mechanical stirring processes, the strong fluid shear force and mechanical impact force generated by the high-speed rotation of the paddle agitator can easily cause porous and brittle adsorbent materials (such as biochar) to break down. This not only produces a large amount of fine powder that is difficult to settle, causing material loss, but also leads to an increase in the suspended solids concentration (TSS) in the effluent, causing secondary pollution.

[0003] 2. The rate-limiting step of the adsorption reaction is usually the diffusion of pollutants from the bulk solution through the static liquid film layer (boundary layer) on the particle surface into the particle interior. Mechanical stirring mainly generates macroscopic fluid convection circulation, which can ensure macroscopic mixing, but its effect on reducing the thickness of the liquid film on the surface of microscopic particles is limited. Therefore, reaching adsorption equilibrium often requires a long time (usually 6-12 hours), limiting the treatment efficiency and load of water treatment equipment.

[0004] 3. Commonly used bottom magnetic stirring is difficult to directly apply to large-scale engineering water treatment devices (such as rectangular horizontal flow reaction tanks). In large horizontal flow tanks, the water flows slowly horizontally, and magnetic particles easily settle to the bottom and accumulate under gravity, resulting in insufficient contact between the bottom particles and the wastewater, forming a reaction dead zone. Existing stirring technology is unable to generate a uniform and sufficiently strong driving force at the bottom of large horizontal tanks to prevent settling.

[0005] Therefore, existing technologies cannot effectively solve the problems of sedimentation and caking of magnetic particles in engineered reactors, especially in horizontal flow channels, while avoiding mechanical damage. This limits the treatment efficiency and large-scale application. There is an urgent need to develop a magnetic drive method and device that can be driven non-contactly, efficiently enhance micro-mass transfer, and is easy to scale up in engineering, so as to solve the bottleneck of magnetic materials in water treatment applications. Summary of the Invention

[0006] In view of this, the present invention aims to provide a controllable dynamic magnetic field micro-eddy current enhanced water treatment method and apparatus to solve at least one technical problem in the background art.

[0007] This application describes a method and apparatus for rapidly separating solids and liquids by utilizing an externally controllable moving magnetic field to non-contactly drive the micro-vortex motion of magnetic functional particles (such as magnetic adsorbents and catalysts) inside the reaction device, thereby enhancing the efficiency of mass transfer and mixing between the solid and liquid phases. This invention is particularly applicable to the continuous flow deep treatment of recalcitrant organic wastewater containing macromolecular antibiotics such as maduramycin.

[0008] To achieve the above objectives, the technical solution of the present invention is implemented as follows: A controllable dynamic magnetic field micro-eddy current enhanced water treatment method includes the following steps: adding magnetic functional particles to the water to be treated in a non-magnetic reaction vessel; setting a controllable dynamic magnetic field generating component on the outer wall of the non-magnetic reaction vessel; generating a lateral magnetic field whose direction and intensity change with time through the controllable dynamic magnetic field generating component, so that the magnetic functional particles are simultaneously subjected to a horizontal magnetic gradient force and a magnetic torque under the action of the lateral magnetic field; the horizontal magnetic gradient force keeps the magnetic functional particles in a laterally suspended state in the water to be treated, and the magnetic torque drives the magnetic functional particles to spin, inducing micro-eddy currents on the particle surface, thereby enhancing mass transfer and mixing between the solid and liquid phases; after the reaction is completed, recovering the magnetic functional particles through a magnetic separation module set at the water outlet.

[0009] The controllable dynamic magnetic field generator acts on the outer wall of the reactor, producing a lateral magnetic field whose direction and intensity change over time. Magnetic particles suspended in the liquid are simultaneously subjected to two magnetic forces: a horizontal magnetic gradient force and a magnetic torque. The horizontal magnetic gradient force is orthogonal to the downward force of gravity. This combined force keeps the magnetic particles in a laterally suspended state in the fluid, effectively avoiding the bottom compaction effect caused by the superposition of gravity and magnetic force in traditional bottom-driven modes. Simultaneously, the magnetic torque drives the particles to spin at high speed around their own axis. This high-frequency spin disrupts the laminar boundary layer on their surface and induces micro-eddies, thereby transforming the mass transfer process of pollutants to the particle surface from slow film diffusion to rapid intraparticle diffusion.

[0010] Furthermore, the controllable dynamic magnetic field generating component is a surround-type external drive device; the surround-type external drive device is suitable for cylindrical reaction devices; The surrounding external drive device includes a rotatable annular support coaxially sleeved outside the cylindrical non-magnetic reactor. At least one pair of permanent magnets are symmetrically installed on the inner sidewall of the rotatable annular support, with the magnetic poles arranged such that the N pole and the S pole are opposite each other. During operation, the drive motor drives the annular support to rotate around the central axis of the reactor, generating a lateral dynamic magnetic field.

[0011] Furthermore, the controllable dynamic magnetic field generating component is a sidewall array type drive device, which is suitable for cuboid horizontal flow reaction tanks. The sidewall array drive device includes several sets of lateral magnetic drive units linearly arranged and installed on one or both outer walls of the reaction tank along the water flow direction. Each drive unit contains a vertically installed disk that can rotate around a horizontal axis. The permanent magnets on the disk surface are arranged with alternating N and S poles. During operation, the disk rotation generates a high-frequency alternating magnetic field in the horizontal direction, forming a spiral suspended fluidization zone above the bottom of the reaction tank.

[0012] Furthermore, the installation height of the disk is 1 / 10 to 1 / 3 of the height of the reaction tank from the bottom. Preferably, the installation height of the disk is set to 2 to 5 cm from the bottom of the reaction tank.

[0013] Furthermore, the disk rotation speed is 100~200 r / min.

[0014] Furthermore, the preparation method of the magnetic functional particles includes the following steps: The sludge biochar matrix was ball-milled with nano Fe3O4 magnetic powder, sealed and filled with nitrogen for protection, and then removed and cured by low-temperature heat treatment in a tube furnace under nitrogen protection to obtain magnetic functional particles.

[0015] Furthermore, the preparation method of the sludge biochar matrix includes the following steps: the dewatered sludge is dried to constant weight at 100~110℃, ground and passed through a 150~250 mesh sieve, pyrolyzed at 750~850℃ for 1.5~2.5h under nitrogen protection at a temperature of 8~12℃ / min, cooled and acid-washed to remove inorganic ash, then washed with deionized water until neutral, and dried to obtain a porous sludge biochar matrix.

[0016] Furthermore, the sludge biochar matrix and nano Fe3O4 magnetic powder are mixed at a mass ratio of 15~25:1.

[0017] The ball milling process involves placing the sludge biochar matrix and nano-Fe3O4 magnetic powder into a planetary ball mill jar, adding agate balls, and milling under nitrogen protection at a ball-to-material ratio of 15-25:1 and a rotation speed of 250-350 r / min for 0.5-1.5 h. Then, the mixture is subjected to low-temperature heat treatment at 100-200 ℃ for 0.5-1.5 h under nitrogen protection.

[0018] A controllable dynamic magnetic field micro-eddy current enhanced water treatment device, using the above-mentioned controllable dynamic magnetic field micro-eddy current enhanced water treatment method, includes: The first non-magnetic reaction vessel has a cover on its upper part; A rotatable annular support is coaxially sleeved outside a cylindrical non-magnetic reactor. At least one pair of permanent magnets are symmetrically installed on the inner sidewall of the annular support, with the magnetic poles arranged such that the N pole and the S pole are opposite each other. The first drive motor, whose output end drives the rotatable annular support to rotate along the first non-magnetic reaction vessel via the first conveyor belt.

[0019] The device employs a lateral, encircling drive configuration. This configuration includes a cylindrical, non-magnetic reactor body and a rotatable annular support coaxially fitted around the reactor. At least one pair of neodymium iron boron permanent magnets are symmetrically mounted on the inner wall of the annular support, with the magnetic poles arranged in an attraction configuration where the N and S poles face each other. During operation, the drive motor rotates the annular support around the reactor's central axis. Magnetic force from the side pulls the internal magnetic particles close to the inner wall, causing them to revolve and spin. Under the influence of the horizontal magnetic force, the particles remain suspended in the lower part of the solution, preventing them from settling to the bottom, thus achieving uniform mixing of the reaction system.

[0020] A controllable dynamic magnetic field micro-eddy current enhanced water treatment device, employing the aforementioned controllable dynamic magnetic field micro-eddy current enhanced water treatment method, includes a horizontal flow reaction tank. Several sets of lateral magnetic drive units are linearly arranged along the water flow direction within the horizontal flow reaction tank. These lateral magnetic drive units are installed on one or both outer walls of the horizontal flow reaction tank. Each drive unit includes a vertically mounted disk that can rotate around a horizontal axis. The permanent magnets on the disk surface are arranged with alternating N and S poles. The center of the disk is mounted on the side wall via a rotating shaft. The disks are connected by a belt, and a second drive motor drives the belt to rotate. Several embedded magnets are arranged along the circumference of the disk. A magnetic separation module is provided on one side of the horizontal flow reaction tank. The magnetic separation module is a pluggable neodymium iron boron permanent magnet array magnetic grid or a high-gradient magnetic separator.

[0021] This application specifically addresses the need for continuous flow deep treatment of wastewater containing large-molecule antibiotics such as maduramycin. Due to the large molecular weight and complex structure of maduramycin, its adsorption and purification process is greatly affected by liquid film diffusion resistance. Furthermore, in traditional horizontal flow reaction tanks, the magnetic adsorbent easily deposits and cakes at the bottom of the tank under gravity, forming dead zones with poor contact with the wastewater, severely limiting the removal efficiency of maduramycin. Therefore, this invention designs a sidewall array-type drive configuration specifically for this type of wastewater.

[0022] This configuration includes a cuboid horizontal flow non-magnetic reaction tank. Several sets of lateral magnetic drive units are linearly arranged along the water flow direction on one or both outer walls of the reaction tank. Each drive unit contains a vertically mounted disk that can rotate about a horizontal axis. To precisely match the settling trajectory and suspension requirements of magnetic biochar in maduramycin-containing wastewater, the disk is installed at a height slightly above the bottom of the reaction tank (e.g., 2-5 cm from the bottom), and the neodymium iron boron permanent magnets on the disk surface are strictly arranged in an alternating N-pole and S-pole configuration (NSNS).

[0023] During operation, the rotating disks on the sidewalls generate a high-frequency alternating magnetic field in the horizontal direction. This magnetic force not only effectively overcomes gravity, attracting bottom particles to the suspended area on the sidewalls, but also induces them to tumble and spin, causing the particles to form a dynamic "spiral suspended fluidization zone" along the magnetic field area on the sidewalls under the horizontal propulsion of the water flow. This special flow pattern not only completely eliminates the sedimentation dead zone at the bottom of the advection channel, but more importantly, the strong micro-eddies induced by the high-frequency spin greatly reduce the liquid film diffusion resistance of maduramycin molecules on the biochar surface, achieving rapid interception of large molecular pollutants, thereby ensuring the efficient removal of specific antibiotics under continuous flow conditions.

[0024] Furthermore, to achieve efficient recovery and recycling of the magnetic functional particles adsorbed with maduramycin and prevent their loss with the effluent, a magnetic separation module is installed at the effluent end of the reaction tank. The magnetic separation module preferably employs a pluggable neodymium iron boron permanent magnet array or a high-gradient magnetic separator. When water carrying magnetic particles passes through this module, under the action of a strong magnetic field, the magnetic particles are rapidly adsorbed and retained on the surface of the magnetic grid, while the purified water flows through smoothly. After a certain amount of particles accumulates on the surface of the magnetic grid, the entire assembly can be removed and unloaded and cleaned by mechanical scraping or high-pressure water washing, thus achieving particle recovery.

[0025] Compared with existing technologies, the controllable dynamic magnetic field micro-eddy current enhanced water treatment method and device described in this invention have the following advantages: 1. Solving the problems of particle deposition and caking: This invention utilizes a lateral magnetic field to provide horizontal magnetic force, breaking the limitation of gravity and magnetic force being superimposed in the same direction in traditional bottom-driven stirring methods, fundamentally changing the force state of the particles. Experiments have shown that in the sidewall-driven mode, there is no obvious particle accumulation at the bottom of the horizontal flow channel, the effective adsorption area utilization rate is increased by more than 20%, and the dead zone problem commonly found in continuous flow experiments is solved.

[0026] 2. Significantly improves microscopic mass transfer efficiency. This invention utilizes the micro-eddy current effect induced by the spin of magnetic particles to effectively reduce liquid film diffusion resistance. Under the same operating conditions, the device of this invention reaches adsorption equilibrium in 30-50% less time than traditional mechanical stirring, and the apparent adsorption rate constant can be increased by 1.5-2.5 times, significantly improving reaction space-time efficiency.

[0027] 3. Protecting the integrity of particle structure: This invention employs non-contact magnetic drive, completely avoiding the mechanical shearing force exerted by mechanical blades on magnetic functional materials. It is particularly suitable for porous and brittle adsorbent materials (such as biochar and resin). After 24 hours of continuous operation, the suspended solids concentration (TSS) in the effluent of the reaction system using this device showed no significant increase (change rate <5%), and the particle morphology remained intact. In contrast, in comparative experiments with high-speed mechanical stirring, particle breakage typically led to an increase of over 20% in effluent TSS. This characteristic effectively ensures the long-term cycle life of valuable functional materials and prevents secondary pollution of the effluent caused by particle breakage.

[0028] 4. Enhanced engineering applicability: The bottom array drive configuration of Option 2 is specifically designed for horizontal flow reactors. By modularly adding or removing drive units, it can be flexibly adapted to industrial reactors of different sizes, fundamentally solving the industry pain point of magnetic particles settling and accumulating in large tanks. By adjusting the magnetic field speed or replacing it with a stronger permanent magnet, it can flexibly handle complex water qualities such as high viscosity and high turbidity, ensuring that the particles are always in an effectively activated state, with wide process adaptability. Attached Figure Description

[0029] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the circumferential cylindrical device proposed in this invention; Figure 2 This is a three-dimensional structural diagram of the horizontal flow channel device driven by the sidewall array proposed in this invention. Figure 3 This is a schematic diagram of the microscopic mechanism of enhanced mass transfer by micro eddy currents proposed in this invention (a is the traditional static state, b is the micro eddy current enhanced state). Figure 4 This is a comparative data graph showing the processing efficiency and particle breakage degree (TSS variation) between the device proposed in this invention and a traditional mechanical stirring device.

[0030] Explanation of reference numerals in the attached figures; 1. Rotatable ring support; 2. Permanent magnet; 3. First non-magnetic reaction vessel; 4. First transmission belt; 5. First drive motor; 6. Horizontal flow reaction tank; 7. Disk; 8. Fluid motion; 9. Embedded magnet; 10. Magnetic separation module. Detailed Implementation

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0032] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] To perfectly adapt to the high-frequency dynamic lateral magnetic field and strong shear micro-eddy current characteristics of the device of this invention, this embodiment preferably uses a low-leaching, high-stability magnetic sludge biochar prepared based on high-energy ball milling deep embedding technology. Three materials (denoted as MBC-1, MBC-2, and MBC-3 as a comparison) were prepared to evaluate their synergistic treatment effect with this device.

[0034] Preparation method: Preparation of sludge biochar matrix (SBC): Dewatered sludge from a municipal wastewater treatment plant was dried to constant weight at 105℃, ground, and passed through a 200-mesh sieve. Under nitrogen protection (flow rate 200 mL / min), the sludge was pyrolyzed at 800℃ for 2 hours at a rate of 10℃ / min. After cooling, inorganic ash was removed by acid washing with 1 mol / L HCl, followed by washing with deionized water until neutral, and then dried for later use to obtain a porous sludge biochar matrix.

[0035] MBC-1 (Ball-milled embedded Fe3O4 sludge biochar, optimal choice): Prepared SBC was mixed with nano-Fe3O4 magnetic powder with an average particle size of 50 nm at a mass ratio of 20:1 and placed in a planetary ball mill jar. Agate balls were added (ball-to-material ratio 20:1). The jar was sealed and filled with nitrogen for protection, and the mill was run at 300 r / min for 1 hour. After removal, the mixture was heat-treated at 150℃ for 1 hour in a tube furnace under nitrogen protection to solidify it, thereby releasing internal stress and enhancing interfacial bonding, ultimately yielding MBC-1.

[0036] MBC-2 (ball-milled nZVI sludge biochar): 5 wt% nano-zero valent iron (nZVI) was mixed with SBC in an anaerobic glove box environment and prepared using the same ball milling parameters (300 r / min, 1 h) and low-temperature curing (150 °C) process as MBC-1.

[0037] MBC-3 (conventional chemical impregnation type - control group): SBC was impregnated in 0.2 mol / L FeCl3 solution and shaken for 12 h, then dried and pyrolyzed at 800℃ for 2 h to obtain MBC-3.

[0038] The high-frequency spin and micro-eddy currents induced by this device during operation generate extremely strong fluid shear forces. In traditional chemical impregnation methods, the iron oxides in magnetic biochar (such as MBC-3) are loosely attached to the carbon skeleton surface mainly through weak chemical bonds. Under this strong shear micro-eddy current environment, the magnetic particles on the surface are easily washed away and peeled off by the water flow, leading to severe iron ion dissolution (causing secondary pollution) and a sharp drop in magnetic recovery rate.

[0039] Conversely, the preferred MBC-1 and MBC-2 materials in this embodiment utilize the strong mechanical force of high-energy ball milling to forcibly push and deeply embed the nano-magnetic powder into the mesoporous channels and surface defect sites of the sludge biochar, forming an extremely robust mechanical interlocking structure through low-temperature thermosetting. This deeply embedded structure perfectly resists the strong fluid scouring and shearing forces of this device, maintaining the effective reduction of liquid film resistance by micro-vortexes and enhancing the high-speed mass transfer of macromolecular maduramycin, while achieving extremely low iron ion dissolution and excellent cycle stability.

[0040] Unless otherwise stated, the simulated wastewater in the following examples is a maduramycin solution with an initial concentration of 20.0 mg / L.

[0041] Example 1: Screening of Operating Efficiency and Material Compatibility of Cylindrical Reactor This embodiment uses a standard 100 mL transparent glass conical flask as the reaction unit. A controllable dynamic magnetic field micro-eddy current enhanced water treatment device, using the above-mentioned controllable dynamic magnetic field micro-eddy current enhanced water treatment method, includes: a first non-magnetic reaction container 3, the upper part of which is provided with a cover; a rotatable annular support 1 coaxially sleeved on the outside of the cylindrical non-magnetic reactor, the inner sidewall of which is symmetrically equipped with at least one pair of permanent magnets 2, the magnetic poles of which are arranged with the N pole and S pole facing each other; the output end of a first drive motor 5 drives the rotatable annular support 1 to rotate along the first non-magnetic reaction container 3 through a first transmission belt.

[0042] A rotatable ring bracket is installed on the outside of the conical flask. Two neodymium iron boron magnets with dimensions of 50mm×30mm×5mm (the length of which is about 0.8 times the maximum inner diameter of the bottom of the conical flask) are horizontally and symmetrically fixed on the magnetic frame. The two magnets are installed opposite each other with the N pole facing the S pole.

[0043] During the experiment, 50 mL of simulated maduramycin wastewater with an initial concentration of 20.0 mg / L was added to an Erlenmeyer flask, and 0.5 g / L of the three types of magnetic biochar particles (MBC-1, MBC-2, and MBC-3) were added respectively. The magnetic rack rotation speed was set to 120 r / min. It was observed that all three types of magnetic particles were suspended in a ribbon-like shape in the lower part of the solution and rotated at high speed. After 12 hours of reaction, samples were taken and various indicators were measured. The results are compared below: MBC-1 treatment group (optimal): Maduromycin removal rate reached 90±3% (concentration reduced to approximately 2.0 mg / L after treatment). The effluent iron ion concentration was extremely low (≤0.05 mg / L, close to the detection limit). Magnetic recovery rate was ≥90% after shutdown, and no demagnetization or particle breakage was observed under a microscope. This demonstrates that the ball mill embedded structure is perfectly matched to the high-shear environment of this device.

[0044] MBC-2 treatment group: It combines adsorption and nZVI reduction, achieving a removal rate of 92±3%. The iron ion leaching concentration is 0.45±0.12 mg / L (meets emission standards), and the magnetic recovery rate is ≥90%.

[0045] MBC-3 treatment group (comparative example): Although the initial removal rate can reach 85%, under the strong shearing and scouring of the high-frequency micro eddy current of this device, a large number of iron particles attached to the surface are detached, resulting in an iron ion concentration in the effluent as high as 0.85 mg / L (posing a serious risk of secondary pollution). Moreover, the water body was found to be black during magnetic separation, and the magnetic recovery rate dropped sharply to below 75%.

[0046] It is evident that MBC-1 exhibits excellent synergy with this device, therefore, MBC-1, with its superior overall performance and lack of secondary pollution, was selected as the material for subsequent continuous flow experiments.

[0047] Example 2: Sidewall Array Driven Flow Tank Reactor and Engineering Scale-up Basis Construct a small laboratory-grade acrylic flow channel measuring 60 cm long, 10 cm wide, and 15 cm high. Evenly arrange three rotating disks (8 cm in diameter) along the water flow direction on one side of the channel's outer wall (the disk diameter to channel width ratio is 0.8:1, providing a dimensional basis for dead-zone-free coverage in industrial scale-up). The center axis of each disk is 3 cm from the bottom of the channel. Each disk surface is inlaid with four neodymium iron boron magnets (alternating N and S magnets).

[0048] The system includes a horizontal flow reaction tank 6, with several sets of lateral magnetic drive units linearly arranged on one or both outer walls of the horizontal flow reaction tank 6 along the water flow direction. Each drive unit contains a vertically mounted disk 7 that can rotate around a horizontal axis. The permanent magnets on the disk surface are arranged with alternating N and S poles. The center of the disk 7 is mounted on the side wall via a pivot, and the disks 7 are connected by a belt. A second drive motor drives the belt to rotate. Several embedded magnets 9 are provided around the circumference of the disk 7. A magnetic separation module 10 is provided on one side of the horizontal flow reaction tank 6. The magnetic separation module 10 is a pluggable neodymium iron boron permanent magnet array magnetic grid or a high gradient magnetic separator.

[0049] A continuous flow mode was adopted, with the influent (maduramycin 20.0 mg / L) flow rate set at 200 mL / min (retention time approximately 20 min), and MBC-1 particles were continuously added. The sidewall magnetic disk rotation speed was 150 r / min. The particles were attracted by the sidewall magnetic field to form a tumbling spiral fluidized zone, with no bottom sediment deposition. The effluent stable residual maduramycin concentration was between 2.0 and 2.4 mg / L (average removal rate stable at 88-90%), and the effluent iron ion concentration was consistently maintained at ≤0.05 mg / L. The magnetic separation module successfully intercepted and recovered >95% of the MBC-1 particles.

[0050] Example 3: Verification of Complex Water Quality Using the device and MBC-1 particles described in Example 1, actual wastewater containing suspended colloids (initial maduramycin concentration 20.0 mg / L) was treated. In the experiment, the rotation speed was increased to 180 r / min to enhance the micro-vortex shear force, successfully preventing the colloids from clogging and encapsulating the porous carbon channels. After the reaction, the effluent concentration decreased to 3.8 mg / L (removal rate remained at 81%), demonstrating that this coupled system has good adaptability to complex actual water quality.

[0051] Example 4: Key Parameters of Dynamic Magnetic Field This embodiment uses the device and MBC-1 particles described in Example 1, and selects the same pollutant conditions (initial concentration of maduramycin 20 mg / L, water temperature 30℃, pH=7.0). By modifying the magnet spacing and disk rotation speed respectively, the influence of key physical parameters of dynamic magnetic field on treatment efficiency is obtained.

[0052] 1. The effect of magnet spacing on processing efficiency The disk rotation speed was set to 120 rpm. The removal rate of maduramycin was measured after 12 hours by varying the magnet spacing between the lateral magnetic drive units on both sides of the horizontal flow reaction tank. The results showed that a magnet spacing of 20 cm resulted in a maduramycin removal rate of approximately 90%, indicating the best treatment effect. When the spacing was shortened to 15 cm, the removal rate decreased by about 3%, due to excessively strong local magnetic fields causing some particles to adhere to the tank walls, reducing the effective reaction space. When the spacing increased to 25 cm, the magnetic field gradient in the central region weakened, reducing the induction ability of particles and decreasing the removal rate by about 8%.

[0053] 2. The impact of disk rotation speed on processing efficiency With a fixed magnet spacing of 20 cm and a magnetic functional particle dosage of 0.5 g / L, the disk rotation speed of the lateral magnetic drive unit was adjusted, and the removal rate of maduramycin was measured after 12 hours. The results showed that the maduramycin removal rate increased with increasing disk rotation speed. Within the 60–120 rpm range, the increased magnetic pole reversal frequency enhanced the micro-eddy currents, significantly increasing the removal rate from 82% to 90%. After the rotation speed reached 120 rpm, the removal rate remained relatively stable, with changes within 1%. This indicates that the dynamic magnetic field described in this invention can achieve excellent enhanced treatment effects at a relatively low rotation speed (120 rpm), effectively eliminating liquid film mass transfer resistance. This characteristic helps reduce operating energy consumption in practical engineering and effectively avoids damage to the physical structure of the magnetic functional particles caused by high-speed shear force, maintaining their structural integrity.

[0054] Comparative Example 1: Static magnetic field combined with mechanical stirring Using the same apparatus as in Example 1, with both disks fixed and not rotating, MBC-1 was added to a conical flask of the same size and stirred at 200 r / min using a mechanical stirrer. After 12 hours of operation, the removal rate was only 62%, and the solution became significantly turbid, with the TSS increasing by 35% compared to the initial value. Under a microscope, numerous fine carbon fragments caused by the impact of the mechanical impeller were visible, indicating that contact mechanical stirring severely damages the overall framework of brittle biochar materials, while the flexible non-contact magnetic drive of the present invention effectively avoids this problem.

[0055] Comparative Example 2: Bottom magnetic drive leads to sedimentation dead zone Using a horizontal flow channel with the exact same dimensions as in Example 2, three rotating disks were installed directly below the bottom of the channel. After continuous flow operation with MBC-1 for 10 minutes, a large number of particles were adsorbed and agglomerated at the bottom of the channel. The water flow mainly passed over the sediment layer (short-flow phenomenon), resulting in a residual maduramycin concentration in the effluent as high as 11.0 mg / L (removal rate plummeted to 45%), which fully demonstrates the necessity of the lateral drive configuration in engineering horizontal flow channel applications.

[0056] Table 1. Effects of Examples 1-3 and Comparative Examples 1-2; The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A controllable dynamic magnetic field micro-eddy current enhanced water treatment method, characterized in that: The process includes the following steps: adding magnetic functional particles to the water to be treated in a non-magnetic reaction vessel; installing a controllable dynamic magnetic field generating component on the outer wall of the non-magnetic reaction vessel; generating a lateral magnetic field whose direction and intensity change with time through the controllable dynamic magnetic field generating component, so that the magnetic functional particles are simultaneously subjected to horizontal magnetic gradient force and magnetic torque under the action of the lateral magnetic field; the horizontal magnetic gradient force keeps the magnetic functional particles in a laterally suspended state in the water to be treated, so as to at least avoid the particles from settling under the action of gravity, and the magnetic torque drives the magnetic functional particles to spin, inducing micro-eddies on the particle surface, enhancing the mass transfer and mixing between the solid and liquid phases; after the reaction is completed, recovering the magnetic functional particles through a magnetic separation module installed at the water outlet.

2. The controllable dynamic magnetic field micro-eddy current enhanced water treatment method according to claim 1, characterized in that: The controllable dynamic magnetic field generating component is a surround-type external drive device; the surround-type external drive device is suitable for cylindrical reaction devices; The surrounding external drive device includes a rotatable annular support coaxially sleeved around the outside of the cylindrical non-magnetic reactor. At least one pair of permanent magnets are symmetrically installed on the inner sidewall of the annular support, with the magnetic poles arranged such that the N pole and the S pole are opposite each other. During operation, the drive motor drives the annular support to rotate around the central axis of the reactor, generating a lateral dynamic magnetic field.

3. The controllable dynamic magnetic field micro-eddy current enhanced water treatment method according to claim 1, characterized in that: The controllable dynamic magnetic field generating component is a sidewall array type drive device, which is suitable for cuboid horizontal flow reaction tanks. The sidewall array drive device includes several sets of lateral magnetic drive units linearly arranged and installed on one or both outer walls of the reaction tank along the water flow direction. Each drive unit contains a vertically installed disk that can rotate around a horizontal axis. The permanent magnets on the disk surface are arranged with alternating N and S poles. During operation, the disk rotation generates a high-frequency alternating magnetic field in the horizontal direction, forming a spiral suspended fluidization zone above the bottom of the reaction tank.

4. The controllable dynamic magnetic field micro-eddy current enhanced water treatment method according to claim 3, characterized in that: The disk is installed at a height of 1 / 10 to 1 / 3 of the tank height from the bottom of the reaction tank.

5. The controllable dynamic magnetic field micro-eddy current enhanced water treatment method according to claim 3, characterized in that: The disk rotation speed is 100~200 r / min.

6. The controllable dynamic magnetic field micro-eddy current enhanced water treatment method according to claim 1, characterized in that: The preparation method of the magnetic functional particles includes the following steps: The sludge biochar matrix was ball-milled with nano Fe3O4 magnetic powder, sealed and filled with nitrogen for protection, and then removed and cured by low-temperature heat treatment in a tube furnace under nitrogen protection to obtain magnetic functional particles.

7. The controllable dynamic magnetic field micro-eddy current enhanced water treatment method according to claim 6, characterized in that: The preparation method of sludge biochar matrix includes the following steps: dewatered sludge is dried to constant weight at 100~110℃, ground and passed through a 150~250 mesh sieve, pyrolyzed at 750~850℃ for 1.5~2.5h under nitrogen protection at a temperature of 8~12℃ / min, cooled and acid-washed to remove inorganic ash, then washed with deionized water until neutral, and dried to obtain a porous sludge biochar matrix.

8. The controllable dynamic magnetic field micro-eddy current enhanced water treatment method according to claim 6, characterized in that: The sludge biochar matrix and nano Fe3O4 magnetic powder are mixed at a mass ratio of 15~25:1; The ball milling process involves placing the sludge biochar matrix and nano-Fe3O4 magnetic powder into a planetary ball mill jar, adding agate balls, and milling for 0.5 to 1.5 hours under nitrogen protection at a ball-to-material ratio of 15 to 25:1 and a rotation speed of 250 to 350 r / min. Then, the mixture is subjected to low-temperature heat treatment at 100 to 200°C for 0.5 to 1.5 hours under nitrogen protection.

9. A controllable dynamic magnetic field micro-eddy current enhanced water treatment device, using the controllable dynamic magnetic field micro-eddy current enhanced water treatment method according to any one of claims 1, 2, 4 to 8, characterized in that: include: The first non-magnetic reaction vessel has a cover on its upper part; A rotatable annular support is coaxially sleeved outside a cylindrical non-magnetic reactor. At least one pair of permanent magnets are symmetrically installed on the inner sidewall of the annular support, with the magnetic poles arranged such that the N pole and the S pole are opposite each other. The first drive motor, whose output end drives the rotatable annular support to rotate along the first non-magnetic reaction vessel via the first conveyor belt.

10. A controllable dynamic magnetic field micro-eddy current enhanced water treatment device, using the controllable dynamic magnetic field micro-eddy current enhanced water treatment method according to any one of claims 1, 3, 4 to 8, characterized in that: The system includes a horizontal flow reaction tank, in which several sets of lateral magnetic drive units are arranged linearly along the water flow direction. The lateral magnetic drive units are installed on one or both outer walls of the horizontal flow reaction tank. Each drive unit contains a vertically mounted disk that can rotate around a horizontal axis. The permanent magnets on the surface of the disk are arranged with alternating N and S poles. The middle part of the disk is mounted on the side wall via a rotating shaft. The disks are connected by a belt, and a second drive motor drives the belt to rotate. Several embedded magnets are provided around the circumference of the disk. A magnetic separation module is provided on one side of the horizontal flow reaction tank. The magnetic separation module is a pluggable neodymium iron boron permanent magnet array magnetic grid or a high gradient magnetic separator.

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