Method for strengthening fluidized bed reaction efficiency of intelligent magnetic control Fenton-like

Abstract

The present application belongs to the technical field of environmental engineering, and particularly relates to a method for enhancing the reaction efficiency of a fluidized bed by using intelligent magnetic control. Specifically, the present application places customized composite magnetic particles in a columnar Fenton-like fluidized bed reactor with an array of electromagnetic coils arranged around the reactor, uses iron aluminum phosphate-activated percarbonate as an oxidizing agent, and applies magnetic fields of different directions and strengths to the magnetic particles by using the array of electromagnetic coils, so that the magnetic particles guide the fluid to form a desired flow pattern, thereby achieving highly precise control over the fluid flow path and mixing process, and achieving the purpose of fully mixing the composite magnetic particles with percarbonate ions, efficiently generating secondary oxidizing agents such as hydroxyl radicals, carbonate radicals and superoxide anion radicals, and efficiently degrading pollutants.

Description

I. Technical Field

[0001] This invention belongs to the field of environmental engineering technology, and specifically relates to a method for enhancing the efficiency of Fenton-like fluidized bed reactions using intelligent magnetic control. Addressing the challenges of existing Fenton-like fluidized bed reactors, such as complex and fixed structures, poor adjustability, and limited improvement compared to traditional Fenton technology, this invention provides a customized method for enhancing the efficiency of Fenton-like fluidized bed reactions using intelligent magnetic control, aiming to achieve energy conservation, carbon reduction, and efficient degradation of pollutants. II. Background Technology

[0002] Fenton fluidized bed technology has demonstrated significant application value in environmental pollution control, particularly in the treatment of high-concentration, highly toxic organic industrial wastewater. By combining fluidized bed technology with the Fenton reaction, the Fenton fluidized bed can efficiently degrade recalcitrant organic compounds, such as coking wastewater, dyeing and printing wastewater, and pharmaceutical wastewater. Studies have shown that the COD removal rate of the Fenton fluidized bed for coking wastewater can reach 55%-65%, superior to the 40% of the traditional Fenton process. In dyeing and printing wastewater treatment, the Fenton fluidized bed can reduce COD from 953 mg / L to 290 mg / L, while significantly improving the biodegradability of the wastewater. Furthermore, the Fenton fluidized bed also performs excellently in treating landfill leachate, phenol-containing wastewater, and electroplating wastewater. Its generated hydroxyl radicals (·OH) have a redox potential as high as 2.8V, second only to fluorine, enabling rapid degradation of various toxic organic compounds.

[0003] Despite the significant advantages of Fenton fluidized beds in wastewater treatment, their structural complexity and efficiency issues limit their further widespread adoption. Existing Fenton fluidized beds typically employ fixed structural designs, such as tower-type reactors, where the design layout, packing distribution, and reaction chamber shape are often non-adjustable, limiting the optimization of reaction conditions. Furthermore, the multi-field coupling effects within the reactor are difficult to control precisely; for example, uneven flow field distribution can lead to localized low reaction efficiency, while excessively high chemical reaction field intensity may trigger side reactions. These problems make it difficult to improve the overall efficiency of the reactor; for instance, some Fenton fluidized beds still generate iron sludge at levels as high as 70% of the traditional Fenton process, and H2O2 utilization is low. Simultaneously, existing reactors have poor scalability, making it difficult to adapt to different scales and types of reactions; in scale-up experiments, reaction efficiency often drops significantly. These shortcomings indicate that existing Fenton fluidized beds have significant structural and performance deficiencies, urgently requiring improvement through technological innovation.

[0004] To address the shortcomings of Fenton fluidized beds, numerous research teams have actively explored structural design and performance optimization. For example, Chinese patent CN202139138U discloses an improved Fenton fluidized bed wastewater treatment device, which significantly improves reaction uniformity and stability by optimizing packing distribution and flow patterns, increasing COD removal rate by 10%–20%. Guangxi Bosch Environmental Protection Technology Co., Ltd. has developed a Fenton oxidation tower device that forms a fluidized bed under hydraulic conditions, reacting with a catalyst to improve wastewater purification efficiency by over 30%. Shandong Huanke Environmental Protection Technology Co., Ltd. has developed a technology combining a Fenton fluidized bed with an intelligent automatic dosing system, which automatically adjusts pH, H2O2, and Fe by real-time monitoring of oxidation-reduction potential changes. 2+ The dosage of Fe was reduced by 10%-20%, thus decreasing the amount of H2O2 used. 2+ The dosage is reduced by 50%-70%, the overall sludge volume is reduced by 40%-50%, while the COD removal rate is increased by 20%-30%, and operating costs are reduced by 30%-50%. However, the current design and improvements do not involve a fundamental innovation to the Fenton system, and the main problems are reflected in the following three aspects:

[0005] 1) For the Fenton system, the traditional H2O2 and Fe are still used. 2+ The operating mode has a large mud production, low efficiency, and poor adjustability;

[0006] 2) It requires a high pH value for the influent, consuming a large amount of sulfuric acid and sodium hydroxide as pH adjusters;

[0007] 3) The reaction process lacks intelligent control, making it difficult to achieve optimal material and energy consumption. III. Summary of the Invention

[0008] This invention addresses the problems existing in the prior art, aiming to significantly improve the performance of traditional Fenton fluidized bed reaction systems through innovative design and technological integration. Firstly, this invention employs magnetic particles with a regular hexagonal prism structure as catalysts, with an iron-nickel-tungsten alloy core, incorporating tricyclopentadiene samarium as a stabilizer, and coating the surface with a layer of nano-cerium dioxide. This not only improves mechanical strength but also enhances catalytic performance. Experimental data shows that when treating the same volume of wastewater, the traditional Fenton system produces approximately 3 kg / m³ of iron sludge. 3 The system of this invention produces only about 0.005 kg / m³. 3 This significantly reduces sludge treatment costs. Furthermore, the magnetic particles can be precisely controlled by the magnetic field generated by an external electromagnetic coil, ensuring efficient gas-liquid-solid three-phase contact, thereby enhancing the catalytic effect.

[0009] Secondly, this invention selects aluminum iron phosphate activated percarbonate as a Fenton-like oxidant, replacing traditional H2O2. This change not only reduces H2O2 consumption but also makes the reaction conditions milder. Under the action of the activator, percarbonate can gradually release peroxy groups, forming hydroxyl radicals (·OH), carbonate radicals (CO3-·), and superoxide anion radicals (O2-·). These radicals are strong oxidants and can efficiently degrade organic pollutants, as shown in the following formula:

[0010] CO3 2- +H + →·HCO3 -

[0011] HCO3 - →CO2+·OH

[0012] This process allows the reaction to proceed over a wider pH range, significantly reducing the consumption of sulfuric acid and sodium hydroxide. In contrast, traditional Fenton systems typically require strict pH control between 2.5 and 4.5, meaning this invention not only broadens the operating window but also significantly reduces the amount of chemicals required.

[0013] Finally, to achieve intelligent control, this invention introduces machine learning algorithms such as recurrent neural networks (RNNs) to predict the optimal trajectory of magnetic particles and optimize multi-field coupling conditions. The RNN model, trained based on historical experimental data, can identify complex time-series relationships, improving control accuracy. Through this intelligent control system, material consumption is reduced by approximately 20%, energy consumption is reduced by 15%, achieving optimal configuration.

[0014] To achieve the above objectives, the present invention provides a method for enhancing the efficiency of a Fenton-like fluidized bed reaction using intelligent magnetic control, characterized by the following steps:

[0015] Step 1: Construct a closed-loop Fenton-like fluidized bed reactor with an internal diameter of 0.5 to 2 m and a height of 3 to 6 m to ensure sufficient reaction space and material residence time. The reactor is cylindrical with an arc-shaped bottom to facilitate the collection and discharge of solid particles. A liquid distribution plate made of porous ceramic material with an opening ratio of 10% to 30% and a pore size of 0.5 to 2 mm is installed at the bottom of the reactor to promote thorough mixing of liquid and solid particles. An overflow port is provided at the top to discharge the treated liquid and prevent foam overflow. The reactor wall is made of 316L stainless steel with a 0.5 mm thick polytetrafluoroethylene (PTFE) coating. The reaction volume is designed to be 1 to 20 m³ / h depending on the throughput. 3The reactor is located between the main inlet and the auxiliary inlet. The main inlet is located on the lower side of the reactor, near the bottom, and is 10 cm from the bottom, with a diameter of 80 mm. The auxiliary inlet is located next to the main inlet and is used for feeding the percarbonate oxidant. The outlet is located below the top overflow outlet and is connected to it, allowing for continuous discharge via overflow. The heat exchange system is integrated into the outer jacket, with a circulating cooling water or hot water flow rate of 1 to 5 m³ / h. 3 / h, heat exchange area is 0.5 to 2m² 2 The reactor is designed to ensure a stable reaction temperature within ±1℃ of the set value. An exhaust vent, 50mm in diameter, is located at the top of the reactor and equipped with a regulating valve to control pressure balance. A 100mm diameter discharge port, located at the lowest point of the arc bottom, facilitates regular cleaning of solid residue. The electrical system includes a frequency converter and a PLC controller for automated control of the heating system. The reactor operates with continuous feeding and intermittent discharge to ensure stable material concentration. Multiple layers of spiral electromagnetic coils are evenly arranged around the reactor's outer perimeter, with a spacing of 10 to 20cm between each layer. The coils are made of copper wire, with 100 to 500 turns per layer. The diameter is 0.5 to 1 mm; the electromagnetic coil is connected to a controllable power supply, supporting DC or AC power supply modes, with a voltage range of 0 to 50V; the coil array can generate a magnetic field with an intensity between 0.1 and 1T, and the direction can be controlled by adjusting the current phase; the reactor's exclusive fluidization method is based on intelligent magnetic control technology, which generates a controllable magnetic field with an intensity of 0.1 to 1T through an external electromagnetic coil, acting on the system containing the magnetic catalyst. When the magnetic field direction is perpendicular to the rising path of the bubbles, it can significantly enhance the gas-liquid-solid three-phase contact efficiency and regulate the catalytic performance; the feeding method uses a metering pump to precisely control the raw material input amount, ensuring a constant reactant ratio;

[0016] Step 2: Prepare regular hexagonal prism-shaped magnetic particles as catalysts, with particle sizes ranging from 1 to 5 mm. The magnetic core is an iron-nickel-tungsten alloy, wherein the mass ratio of iron:nickel:tungsten is 7:1:0.02 to 9:1:0.02. Tricyclopentadiene samarium is incorporated as a stabilizer, and tianqing powder is used as a binder. The catalyst is prepared by rolling. Finally, a layer of nano-cerium dioxide with a thickness of 10 to 100 nm is coated on its surface by flame spraying to improve mechanical strength, enhance catalytic performance, and provide a certain slow-release effect.

[0017] Step 3: Select percarbonate as a Fenton-like oxidant. The initial addition amount is 1:100 to 1:1000 (percarbonate: feed liquid) by mass ratio. At the same time, add aluminum iron phosphate (aluminum iron phosphate: feed liquid) by mass ratio of 1:10000 to 1:100000 as an activator. It is quantitatively mixed with the feed liquid by metering pump. The addition frequency is adjusted in real time according to the reaction process to ensure that the percarbonate ion concentration is maintained at the optimal level.

[0018] Step 4: Before starting the Fenton-like fluidized bed reactor, first set the reactor operating conditions to a temperature of 20–60°C. Fill the reactor with magnetic particles, which make up 10% of the reactor's volume, as a catalyst. First, pass a certain flow rate of tap water through the main feed inlet to maintain the magnetic particle suspension layer at 1 / 3 below the reactor liquid surface, forming a stable fluidized state. Set the feed liquid pH to 3–11 and gradually switch to feed liquid to replace tap water. At the same time, introduce percarbonate from the auxiliary feed inlet. Simultaneously, closely monitor the height of the magnetic particle suspension layer to ensure it does not exceed 1 / 3 below the liquid surface, and prevent abnormal phenomena such as flooding, overpressure, and aggregation.

[0019] Step 5: The position and velocity of the magnetic particles are monitored by the built-in sensors. The control system dynamically adjusts the current intensity and phase of the electromagnetic coil according to the preset algorithm to achieve precise control of the movement path of the magnetic particles. When it is necessary to enhance the mixing effect, a rotating magnetic field can be applied to make the particles move along a specific trajectory; when it is necessary to reduce local turbulence, a stationary magnetic field is applied to fix the position of the particles.

[0020] Step 6: Under the influence of a magnetic field, the magnetic particles come into full contact with percarbonate ions, generating hydroxyl radicals (·OH), carbonate radicals (CO3-·), and superoxide anion radicals (O2-·). These radicals are quantitatively analyzed using a fluorescent probe method and electron paramagnetic resonance (EPR) technology to ensure optimal catalytic degradation. The detection range of the fluorescent probe method is 10... -9 Up to 10 -6 mol / L, EPR technology has a resolution better than 10⁻⁶. 12 mol / L;

[0021] Step 7: Optimize the fluid flow path and mixing process; control the movement of magnetic particles by adjusting the magnetic field strength and direction to change the liquid flow pattern; apply a gradient magnetic field to cause particles to aggregate and form "micro-vortices" to promote local mixing; apply a uniform magnetic field to maintain overall fluidity; combine ultrasonic flow meters and laser Doppler velocimeters (LDA) to monitor flow field changes and ensure optimal mixing state;

[0022] Step 8: Using various types of sensors, such as temperature sensors, pH sensors, and dissolved oxygen sensors, environmental parameters inside the reactor are collected in real time. All sensor data are transmitted to the central controller, and after data analysis, the operating parameters of the electromagnetic coil are automatically adjusted to form a closed-loop feedback system. The system has a fault diagnosis function and can automatically alarm and take protective measures in abnormal situations.

[0023] Furthermore, the electromagnetic coil array described in step 1 also includes an embedded permanent magnet to provide a static background magnetic field and enhance the effect of the dynamic magnetic field. The permanent magnet material is neodymium iron boron (NdFeB), with a magnetic energy product (BHmax) greater than 40 MGOe and an operating temperature range of -40℃ to +150℃, ensuring stable operation in different environments.

[0024] Furthermore, the surface coating of the regular hexagonal prism magnetic particles mentioned in step 2 can also be polytetrafluoroethylene (PTFE) with a thickness of 5 to 20 nm, in order to further improve the corrosion resistance and lubrication performance of the particles and extend their service life.

[0025] Furthermore, the adaptive feedback control system described in step 5 also integrates machine learning algorithms, especially recurrent neural networks (RNNs), to predict the optimal motion trajectory of magnetic particles. The RNN model is trained based on historical experimental data and can identify complex time series relationships, thereby improving control accuracy.

[0026] Furthermore, the free radical quantitative measurement method described in step 6 also includes the application of an online ultraviolet-visible spectrophotometer (UV-Vis), with a detection wavelength range of 200 to 800 nm and a sensitivity better than 0.001 Abs. This allows for rapid response to changes in free radical concentration, providing real-time monitoring data and assisting in optimizing reaction conditions.

[0027] The advantages of this invention are:

[0028] 1) The use of regular hexagonal prism-shaped magnetic particles as catalysts significantly reduces the amount of iron sludge generated during the reaction, greatly reducing secondary pollution and sludge treatment costs.

[0029] 2) Using aluminum iron phosphate activated percarbonate as a Fenton-like oxidant allows the reaction to proceed efficiently in the pH range of 3 to 11, significantly reducing the consumption of acid-base regulators and lowering the input of chemicals;

[0030] 3) By introducing machine learning algorithms such as recurrent neural networks (RNN), precise control of the trajectory of magnetic particles and multi-field coupling conditions is achieved, reducing material consumption by about 20% and energy consumption by 15%, thereby improving overall reaction efficiency and system stability. IV. Description of the attached drawings

[0031] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the following description of the specific embodiments are briefly explained.

[0032] Figure 1 This is a schematic diagram of a closed-loop Fenton-type fluidized bed reactor. The reference numerals are explained below:

[0033] Housing (1), spiral electromagnetic coil array (2), main feed port (3), discharge port (4), return pipe (5), exhaust port (6), discharge port (7), auxiliary feed port (8), liquid flow distribution plate (9), pump controller (10), magnetic controller (11).

[0034] Figure 2 This is a schematic diagram (cross-sectional view) of a closed-loop Fenton-like fluidized bed reactor. Except for the fluidized magnetic particles and liquid mixture (12), the reference numerals in the figure are the same as those in the appendix. Figure 1 . V. Detailed Implementation Methods

[0035] The present invention will now be described in detail with reference to the accompanying drawings and embodiments:

[0036] Example 1:

[0037] A method for enhancing the efficiency of a Fenton-like fluidized bed reaction using intelligent magnetic control, characterized by the following steps:

[0038] Step 1: Construct a closed-loop Fenton-like fluidized bed reactor with an internal diameter of 0.5 to 2 m and a height of 3 to 6 m to ensure sufficient reaction space and material residence time. The reactor is cylindrical with an arc-shaped bottom to facilitate the collection and discharge of solid particles. A liquid distribution plate made of porous ceramic material is installed at the bottom of the reactor, with an opening ratio of 10% to 30% and a pore size of 0.5 to 2 mm to promote thorough mixing of liquid and solid particles. An overflow port is provided at the top to discharge the treated liquid and prevent foam overflow. The reactor wall is made of 316L stainless steel with a 0.5 mm thick polytetrafluoroethylene (PTFE) coating. The reaction volume is designed to be 1 to 20 m³ / h depending on the throughput. 3 The reactor is located between the main inlet and the auxiliary inlet. The main inlet is located on the lower side of the reactor, near the bottom, and is 10 cm from the bottom, with a diameter of 80 mm. The auxiliary inlet is located next to the main inlet and is used for feeding the percarbonate oxidant. The outlet is located below the top overflow outlet and is connected to it, allowing for continuous discharge via overflow. The heat exchange system is integrated into the outer jacket, with a circulating cooling water or hot water flow rate of 1 to 5 m³ / h. 3 / h, heat exchange area is 0.5 to 2m² 2The reactor is designed to ensure a stable reaction temperature within ±1℃ of the set value. A vent, 50mm in diameter, is located at the top of the reactor and equipped with a regulating valve to control pressure balance. A 100mm diameter discharge port, located at the lowest point of the arc bottom, facilitates regular cleaning of solid residue. The electrical system includes a frequency converter and a PLC controller for automated control of the heating system. The reactor operates with continuous feeding and intermittent discharge to ensure stable material concentration. Multiple layers of spiral electromagnetic coils are evenly arranged around the reactor's perimeter, with a spacing of 10 to 20cm between each layer. The coils are made of copper wire, with 100 to 500 turns per layer and a wire diameter of 0.5 to 1mm. The electromagnetic coils are connected to a controllable power supply, supporting DC or AC power supply modes with a voltage range of 0 to 50V. The coil array can generate strong... The magnetic field ranges from 0.1 to 1 T, and its direction can be controlled by adjusting the current phase. The electromagnetic coil array also includes embedded permanent magnets to provide a static background magnetic field and enhance the effect of the dynamic magnetic field. The permanent magnet material is neodymium iron boron (NdFeB), with a magnetic energy product (BHmax) greater than 40 MGOe. The operating temperature range is -40℃ to +150℃, ensuring stable operation in different environments. The reactor's dedicated fluidization method is based on intelligent magnetic control technology. An external electromagnetic coil generates a controllable magnetic field with a strength of 0.1 to 1 T, which acts on the system containing the magnetic catalyst. When the magnetic field direction is perpendicular to the bubble rising path, it can significantly enhance the gas-liquid-solid three-phase contact efficiency and regulate catalytic performance. The feeding method uses a metering pump to precisely control the raw material input, ensuring a constant reactant ratio.

[0039] Step 2: Prepare regular hexagonal prism-shaped magnetic particles as catalysts, with particle sizes ranging from 1 to 5 mm. The magnetic core is an iron-nickel-tungsten alloy, wherein the mass ratio of iron:nickel:tungsten is 7:1:0.02 to 9:1:0.02. Tricyclopentadiene samarium is incorporated as a stabilizer, and chlorine powder is used as a binder. The catalyst is prepared by a rolling method. Finally, a layer of nano-cerium dioxide with a thickness of 10 to 100 nm is coated on its surface by flame spraying to improve mechanical strength, enhance catalytic performance, and provide a certain slow-release effect. This surface coating can also be polytetrafluoroethylene (PTFE) with a thickness of 5 to 20 nm to further improve the corrosion resistance and lubrication properties of the particles and extend their service life.

[0040] Step 3: Select percarbonate as a Fenton-like oxidant. The initial addition amount is 1:100 to 1:1000 (percarbonate: feed liquid) by mass ratio. At the same time, add aluminum iron phosphate (aluminum iron phosphate: feed liquid) by mass ratio of 1:10000 to 1:100000 as an activator. It is quantitatively mixed with the feed liquid by metering pump. The addition frequency is adjusted in real time according to the reaction process to ensure that the percarbonate ion concentration is maintained at the optimal level.

[0041] Step 4: Before starting the Fenton-like fluidized bed reactor, first set the reactor operating conditions to a temperature of 20–60°C. Fill the reactor with magnetic particles, which make up 10% of the reactor's volume, as a catalyst. First, pass a certain flow rate of tap water through the main feed inlet to maintain the magnetic particle suspension layer at 1 / 3 below the reactor liquid surface, forming a stable fluidized state. Set the feed liquid pH to 3–11 and gradually switch to feed liquid to replace tap water. At the same time, introduce percarbonate from the auxiliary feed inlet. Simultaneously, closely monitor the height of the magnetic particle suspension layer to ensure it does not exceed 1 / 3 below the liquid surface, and prevent abnormal phenomena such as flooding, overpressure, and aggregation.

[0042] Step 5: The position and velocity of the magnetic particles are monitored by built-in sensors. The control system dynamically adjusts the current intensity and phase of the electromagnetic coil according to a preset algorithm to achieve precise control of the magnetic particle's movement path. The machine learning algorithm, including a recurrent neural network (RNN), is used to predict the optimal trajectory of the magnetic particles. The RNN model is trained based on historical experimental data and can identify complex time series relationships to improve control accuracy. When it is necessary to enhance the mixing effect, a rotating magnetic field can be applied to make the particles move along a specific trajectory. When it is necessary to reduce local turbulence, a stationary magnetic field is applied to fix the particle position.

[0043] Step 6: Under the influence of a magnetic field, the magnetic particles come into full contact with percarbonate ions, generating hydroxyl radicals (·OH), carbonate radicals (CO3-·), and superoxide anion radicals (O2-·). These radicals are quantitatively analyzed using a fluorescent probe method and electron paramagnetic resonance (EPR) technology to ensure optimal catalytic degradation. The detection range of the fluorescent probe method is 10... -9 Up to 10 -6 mol / L, EPR technology has a resolution better than 10⁻⁶. 12 mol / L; In addition, the quantitative measurement method of free radicals also includes the application of an online ultraviolet-visible spectrophotometer (UV-Vis), which has a detection wavelength range of 200 to 800 nm, a sensitivity better than 0.001 Abs, and can quickly respond to changes in free radical concentration, provide real-time monitoring data, and assist in optimizing reaction conditions;

[0044] Step 7: Optimize the fluid flow path and mixing process; control the movement of magnetic particles by adjusting the magnetic field strength and direction to change the liquid flow pattern; apply a gradient magnetic field to cause particles to aggregate and form "micro-vortices" to promote local mixing; apply a uniform magnetic field to maintain overall fluidity; combine ultrasonic flow meters and laser Doppler velocimeters (LDA) to monitor flow field changes and ensure optimal mixing state;

[0045] Step 8: Using various types of sensors, such as temperature sensors, pH sensors, and dissolved oxygen sensors, environmental parameters inside the reactor are collected in real time. All sensor data are transmitted to the central controller, and after data analysis, the operating parameters of the electromagnetic coil are automatically adjusted to form a closed-loop feedback system. The system has a fault diagnosis function and can automatically alarm and take protective measures in abnormal situations.

[0046] A schematic diagram of a closed-loop Fenton-like fluidized bed reactor is attached. Figure 1 and attached Figure 2 As shown.

[0047] Example 2:

[0048] The closed-loop Fenton-like fluidized bed reactor constructed in Example 1 was used to treat concentrated leachate from a landfill in Beijing. The results are as follows.

[0049]

[0050] As can be seen from the table above, for concentrated leachate from recalcitrant organic wastewater, the COD removal rate is only 67% and the ammonia nitrogen removal rate is only 50% when using the traditional Fenton process. However, by using the closed-loop Fenton-like fluidized bed reactor of this invention and optimizing the feeding conditions with an intelligent algorithm, the COD removal rate can reach 98.4% and the ammonia nitrogen removal rate can reach nearly 90%, while the corresponding unit cost is reduced by 60.9%, demonstrating significant technical advantages.

[0051] Example 3:

[0052] The closed-loop Fenton-like fluidized bed reactor constructed in Example 1 was used to treat the fracturing flowback fluid waste liquid from an oilfield in Shandong Province. The results are as follows.

[0053]

[0054] As can be seen from the table above, for recalcitrant organic wastewater fracturing flowback fluid, the COD removal rate is only 51% and the viscosity removal rate is only 50% when using the traditional Fenton process. However, when the closed-loop Fenton-like fluidized bed reactor of this invention is used for treatment, and the feeding conditions are optimized by intelligent algorithm, the COD removal rate can reach 91% and the viscosity removal rate can reach as high as 99%, while the corresponding unit cost is reduced by 75%, showing significant technical advantages.

[0055] The specific embodiments described above are only used to illustrate the spirit of the present invention. The scope of protection of the present invention is not limited thereto. For those skilled in the art, other embodiments can be easily made by means of changes, substitutions or modifications based on the technical content disclosed in this specification. All such other embodiments should be covered within the scope of protection of the present invention.

Claims

1. A method for enhancing the efficiency of a Fenton-like fluidized bed reaction using intelligent magnetic control, characterized in that... The method specifically includes the following steps: Step 1: Construct a closed-loop Fenton-like fluidized bed reactor with an internal diameter of 0.5 to 2 m and a height of 3 to 6 m to ensure sufficient reaction space and material residence time. The reactor is cylindrical with an arc-shaped bottom to facilitate the collection and discharge of solid particles. A liquid distribution plate made of porous ceramic material with an opening ratio of 10% to 30% and a pore size of 0.5 to 2 mm is installed at the bottom of the reactor to promote thorough mixing of liquid and solid particles. An overflow port is provided at the top to discharge the treated liquid and prevent foam overflow. The reactor wall is made of 316L stainless steel with a 0.5 mm thick polytetrafluoroethylene (PTFE) coating. The reaction volume is designed to be 1 to 20 m³ depending on the throughput. 3 The reactor is located between the main inlet and the auxiliary inlet. The main inlet is located on the lower side of the reactor, near the bottom, and is used for the liquid feed into the reactor. It is 10 cm from the bottom and has a diameter of 80 mm. The auxiliary inlet is located next to the main inlet and is used for feeding the percarbonate oxidant. The outlet is located below the top overflow outlet and is connected to it, allowing for continuous discharge via overflow. The heat exchange system is integrated into the outer jacket, with a circulating cooling water or hot water flow rate of 1 to 5 m³ / h. 3 / h, heat exchange area is 0.5 to 2 m² 2 The reactor is designed to ensure a stable reaction temperature within ±1°C of the set value. A vent, 50 mm in diameter, is located at the top of the reactor and equipped with a regulating valve to control pressure balance. A 100 mm diameter discharge port, located at the lowest point of the arc bottom, facilitates regular cleaning of solid residue. The electrical system includes a frequency converter and a PLC controller for automated control of the heat exchange system. The reactor operates with continuous feeding and intermittent discharge to ensure stable material concentration. Multiple layers of spiral electromagnetic coils are evenly arranged around the reactor's perimeter, with a spacing of 10 to 20 cm between each layer. The coils are made of copper wire, with 100 to 500 turns per layer and a wire diameter of 0.5 to 1 mm. The electromagnetic coils are connected to a controllable power supply, supporting DC or AC power modes with a voltage range of 0 to 50 V. The coil array generates a magnetic field with an intensity between 0.1 and 1 T, the direction of which is controlled by adjusting the current phase. The reactor's proprietary fluidization method is based on intelligent magnetic control technology, using external electromagnetic coils to generate a magnetic field with an intensity of 0.1 to 1 T. The controllable magnetic field of T acts on the system containing the magnetic catalyst. When the direction of the magnetic field is perpendicular to the rising path of the bubbles, it can significantly enhance the gas-liquid-solid three-phase contact efficiency and regulate the catalytic performance. The feeding method uses a metering pump to precisely control the amount of raw materials input, ensuring a constant ratio of reactants. Step 2: Prepare magnetic particles with a regular hexagonal prism structure. These magnetic particles serve as a reaction catalyst. The particle size ranges from 1 to 5 mm, and the magnetic core is an iron-nickel-tungsten alloy with an iron:nickel:tungsten mass ratio of 7:1:0.02 to 9:1:0.

02. Tricyclopentadiene samarium is incorporated as a stabilizer, and guar gum powder is used as a binder. The particles are prepared by a rolling method. Finally, a layer of nano-cerium dioxide with a thickness of 10 to 100 nm is coated on the surface by flame spraying to improve mechanical strength, enhance catalytic performance, and provide a certain slow-release effect. Step 3: Select percarbonate as a Fenton-like oxidant. The initial dosage of percarbonate is 1:100 to 1:1000 by mass ratio to the feed liquid. At the same time, add aluminum iron phosphate as an activator at a mass ratio of 1:10000 to 1:100000 by mass ratio to the feed liquid. Mix it quantitatively with the feed liquid using a metering pump. The addition frequency is adjusted in real time according to the reaction progress to ensure that the percarbonate ion concentration is maintained at the optimal level. Step 4: Before starting the Fenton-like fluidized bed reactor, first set the reactor operating conditions to a temperature of 20~60°C. Fill the reactor with magnetic particles accounting for 10% of the reactor's internal volume as a reaction catalyst. First, pass a certain flow rate of tap water through the main feed inlet to keep the magnetic particle suspension layer within 1 / 3 of the total liquid depth of the reactor, forming a stable fluidized state. Set the feed liquid pH value to 3 to 11, and gradually switch to feed liquid to replace tap water. Simultaneously, introduce percarbonate feed from the auxiliary feed inlet. During the process, closely monitor the height of the magnetic particle suspension layer to ensure that the magnetic particle suspension layer is located in the lower half of the reactor, the upper interface of the suspension layer is kept within 1 / 3 of the total liquid depth and below the liquid surface, and no abnormal phenomena such as flooding, overpressure, or aggregation occur. Step 5: The position and velocity of the magnetic particles are monitored by the built-in sensors. The closed-loop feedback control system dynamically adjusts the current intensity and phase of the electromagnetic coil according to the preset algorithm to achieve precise control of the movement path of the magnetic particles. When it is necessary to enhance the mixing effect, a rotating magnetic field is applied to make the particles move along a specific trajectory; when it is necessary to reduce local turbulence, a stationary magnetic field is applied to fix the position of the particles. Step 6: Under the influence of a magnetic field, the magnetic particles come into full contact with percarbonate ions, generating hydroxyl radicals, carbonate radicals, and superoxide anion radicals. These radicals are quantitatively analyzed using a fluorescent probe method and electron paramagnetic resonance (EPR) technology. This quantitative analysis method ensures that the concentration reaches the optimal catalytic degradation effect. The detection range of the fluorescent probe method is 10... -9 Up to 10 -6 mol / L, EPR technology has a resolution better than 10⁻ 12 mol / L; Step 7: Optimize the fluid flow path and mixing process; control the movement of magnetic particles by adjusting the magnetic field strength and direction to change the liquid flow pattern; apply a gradient magnetic field to cause particles to aggregate and form "micro-vortices" to promote local mixing; apply a uniform magnetic field to maintain overall fluidity; combine ultrasonic flow meters and laser Doppler velocimeters to monitor flow field changes and ensure optimal mixing state. Step 8: Using various types of sensors, including temperature sensors, pH sensors, and dissolved oxygen sensors, environmental parameters inside the reactor are collected in real time. All sensor data is transmitted to the central controller, and after data analysis, the operating parameters of the electromagnetic coil are automatically adjusted to form the closed-loop feedback system. This system has a fault diagnosis function and can automatically alarm and take protective measures in abnormal situations.

2. The method for enhancing the efficiency of a Fenton-like fluidized bed reaction using intelligent magnetic control as described in claim 1, characterized in that, The electromagnetic coil described in step 1 also includes an embedded permanent magnet to provide a static background magnetic field and enhance the effect of the dynamic magnetic field. The permanent magnet material is neodymium iron boron with a magnetic energy product greater than 40 MGOe and an operating temperature range of -40℃ to +150℃, ensuring stable operation in different environments.

3. The method for enhancing the efficiency of a Fenton-like fluidized bed reaction using intelligent magnetic control as described in claim 1, characterized in that, The surface coating of the regular hexagonal prism-shaped magnetic particles described in step 2 is polytetrafluoroethylene with a thickness of 5 to 20 nm, in order to further improve the corrosion resistance and lubrication performance of the particles and extend their service life.

4. The method for enhancing the efficiency of a Fenton-like fluidized bed reaction using intelligent magnetic control as described in claim 1, characterized in that, The closed-loop feedback control system described in step 5 also integrates a recurrent neural network machine learning algorithm to predict the optimal motion trajectory of the magnetic particles. The recurrent neural network model is trained based on historical experimental data and can identify complex time series relationships, thereby improving control accuracy.

5. The method for enhancing the efficiency of a Fenton-like fluidized bed reaction using intelligent magnetic control as described in claim 1, characterized in that, The quantitative detection method for free radicals described in step 6 also includes the application of an online ultraviolet-visible spectrophotometer with a detection wavelength range of 200 to 800 nm and a sensitivity better than 0.001 Abs. This allows for rapid response to changes in free radical concentration, providing real-time monitoring data and assisting in optimizing reaction conditions.

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