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

Abstract

The invention belongs to the technical field of environmental engineering, and particularly relates to a method for enhancing the reaction efficiency of a Fenton-like fluidized bed through intelligent magnetic control. Specifically, customized composite magnetic particles are placed in a columnar Fenton-like fluidized bed reactor with an electromagnetic coil array distributed on the periphery, percarbonate activated by iron and aluminum phosphate is used as an oxidizing agent, and magnetic fields with different directions and intensities are applied to the magnetic particles by utilizing the electromagnetic coil array; the magnetic particles guide the fluid to form a required flowing form, and the fluid flowing path and the mixing process are highly accurately controlled, so that the aims of fully mixing the composite magnetic particles with the percarbonate ions, efficiently generating secondary oxidants such as hydroxyl free radicals, carbonate free radicals and superoxide anion free radicals and efficiently degrading pollutants are fulfilled.

Description

1. Technical Field

[0001] The present invention belongs to the field of environmental engineering technology, and in particular, relates to a method for enhancing the efficiency of Fenton-like fluidized bed reactions by intelligent magnetic control. In view of the problems that the existing Fenton-like fluidized bed reactors have complex and fixed structures, poor adjustability, and little improvement compared with traditional Fenton technology, a customized method for enhancing the efficiency of Fenton-like fluidized bed reactions by intelligent magnetic control is designed to achieve the purpose of energy saving and carbon reduction, and efficient degradation of pollutants. 2. Background Technology

[0002] Fenton fluidized bed technology has shown significant application value in the field of environmental pollution control, especially in the treatment of high-concentration and highly toxic organic industrial wastewater. By combining fluidized bed technology with Fenton reaction, Fenton fluidized bed can efficiently degrade difficult-to-degrade organic matter, such as coking wastewater, printing and dyeing wastewater, and pharmaceutical wastewater. Studies have shown that the COD removal rate of Fenton fluidized bed for coking wastewater can reach 55%-65%, which is better than the 40% of the traditional Fenton method. In the treatment of printing and dyeing wastewater, Fenton fluidized bed can reduce COD from 953mg / L to 290mg / L, while significantly improving the biodegradability of wastewater. In addition, Fenton fluidized bed also performs well in the treatment of landfill leachate, phenol-containing wastewater and electroplating wastewater. The hydroxyl radical (·OH) it produces has a redox potential of up to 2.8V, second only to fluorine, and can quickly degrade a variety of toxic organic matter.

[0003] Although the Fenton fluidized bed has significant advantages in wastewater treatment, its structural complexity and efficiency issues limit its further promotion. Existing Fenton fluidized beds usually adopt a fixed structure design, such as a tower reactor, and its design layout, filler distribution and reaction chamber shape are often not adjustable, resulting in limited optimization of reaction conditions. In addition, the multi-field coupling effect inside the reactor is difficult to accurately control. For example, uneven flow field distribution will lead to low local reaction efficiency, and excessive chemical reaction field intensity may induce side reactions. These problems make it difficult to break through the overall efficiency of the reactor. For example, the iron sludge generation of some Fenton fluidized beds is still as high as 70% of the traditional Fenton method, and the H2O2 utilization rate is low. At the same time, the scalability of existing reactors is poor, and it is difficult to adapt to the reaction requirements of different scales and types. In scale-up experiments, the reaction efficiency often decreases significantly. These shortcomings show that the existing Fenton fluidized bed has significant defects in structure and performance, and it is urgent to improve it through technological innovation.

[0004] In order to improve the defects of the Fenton fluidized bed, many 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 the reaction uniformity and stability by optimizing the filler distribution and flow pattern, and the COD removal rate is increased by 10% to 20%. Guangxi Bosch Environmental Protection Technology Co., Ltd. has developed a Fenton oxidation tower equipment, which forms a fluidized bed through hydraulic conditions and reacts with the catalyst to increase the wastewater purification efficiency by more than 30%. Shandong Huanke Environmental Protection Technology Co., Ltd. has developed a combination technology of Fenton fluidized bed and intelligent control automatic dosing system, which automatically adjusts the pH value, H2O2 and Fe by real-time monitoring of changes in redox potential. 2+ The dosage of H2O2 can be reduced by 10%-20%, and Fe 2+ The dosage is reduced by 50%-70%, the overall sludge volume is reduced by 40%-50%, and the COD removal rate is increased by 20%-30%, and the operating cost is saved by 30%-50%. However, the current design and improvement do not involve the essential innovation of the Fenton system. The main problems are reflected in the following three aspects:

[0005] 1) For the Fenton system, the traditional H2O2 and Fe 2+ The operation mode has large sludge production, low efficiency and poor adjustability;

[0006] 2) The pH value of the influent is required to be high, and more sulfuric acid and sodium hydroxide are consumed as pH regulators;

[0007] 3) There is a lack of intelligent control over the reaction process, and it is difficult to achieve optimal material and energy consumption. III. Summary of the invention

[0008] The present invention is made in view of the problems existing in the prior art, and aims to significantly improve the performance of the traditional Fenton fluidized bed reaction system through innovative design and technology integration. First, the present invention uses magnetic particles with a regular hexagonal structure as a catalyst, the core of which is an iron-nickel-tungsten alloy, tricyclopentadienyl samarium is added as a stabilizer, and a layer of nano-cerium dioxide is coated on the surface, which not only improves the mechanical strength but also improves the catalytic performance. Experimental data show that when treating the same volume of wastewater, the amount of iron sludge produced by the traditional Fenton system is about 3kg / m 3 , while the system of the present invention only produces about 0.005kg / m 3 , greatly reducing the cost of sludge treatment. In addition, the magnetic particles can be precisely controlled by the magnetic field generated by the external electromagnetic coil, ensuring efficient gas-liquid-solid three-phase contact, thereby enhancing the catalytic effect.

[0009] Secondly, the present invention uses percarbonate activated by aluminum iron phosphate as a Fenton-like oxidant to replace the traditional H2O2. This change not only reduces the consumption of H2O2, but also makes the reaction conditions milder. Under the action of the activator, percarbonate can gradually release peroxide groups to form hydroxyl radicals (·OH), carbonate radicals (CO3-·) and superoxide anion radicals (O2-·). These free radicals are strong oxidants that 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 be carried out in a wider pH range, greatly reducing the consumption of sulfuric acid and sodium hydroxide. In contrast, the traditional Fenton system usually requires strict control of pH between 2.5 and 4.5, which means that the present invention not only broadens the operating window, but also significantly reduces the input of chemicals.

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

[0014] In order to achieve the above object, the technical solution of the present invention is a method for enhancing the efficiency of Fenton-like fluidized bed reaction by intelligent magnetic control, characterized in that the method specifically comprises the following steps:

[0015] Step 1: construct a closed Fenton-like fluidized bed reactor with an inner 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 type is cylindrical with an arc-shaped bottom structure, which is conducive to the collection and discharge of solid particles; a liquid flow distribution plate is set at the bottom of the reactor, which is made of porous ceramic material with an opening rate of 10% to 30% and a pore size of 0.5 to 2 mm to promote the full mixing of liquid and solid particles; an overflow port is set at the top to discharge the treated liquid and prevent foam overflow; the reactor wall is made of 316L stainless steel, lined with polytetrafluoroethylene coating, and has a thickness of 0.5 mm; the reaction volume is designed to be 1 to 20 m according to the processing volume 3The main feed port is located at the lower part of the reactor side near the bottom, for the feed liquid to enter the reactor, 10 cm from the bottom, with a diameter of 80 mm; the auxiliary feed port is located next to the main feed port, for the percarbonate oxidant to be fed; the discharge port is located below the top overflow port and connected to it, and continuous discharge is achieved through overflow; the heat exchange system is integrated in the outer shell jacket, and the circulating cooling water or hot water flow rate is 1 to 5 m 3 / h, heat exchange area is 0.5 to 2m 2 , ensuring that the reaction temperature is stable within the set value ±1℃; the exhaust hole is located at the top of the reactor, with a diameter of 50mm and a regulating valve to control the pressure balance; the discharge port is located at the lowest point of the arc bottom, with a diameter of 100mm, which is convenient for regular cleaning of solid residues; the electrical system includes a frequency converter and a PLC controller to realize automatic control of the heating system; the operation mode under the feeding and discharging conditions is continuous feeding and intermittent discharging to ensure the stability of the material concentration in the reactor; multiple layers of spiral electromagnetic coils are evenly arranged on the periphery of the reactor, with a spacing of 10 to 20cm between each layer; the coil is wound with copper wire, with 100 to 500 turns per layer, and the wire The diameter is 0.5 to 1 mm; the electromagnetic coil is connected to a controllable power supply, supporting DC or AC power supply mode, and the voltage range is 0 to 50 V; the coil array can generate a magnetic field with a strength between 0.1 and 1 T, and the direction can be controlled by adjusting the current phase; the reactor's exclusive fluidization method is based on intelligent magnetic control technology, and an external electromagnetic coil generates a controllable magnetic field with a magnetic field strength of 0.1 to 1 T to act on the system containing a 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 the catalytic performance; the feeding method uses a metering pump to accurately control the raw material input to ensure a constant ratio of reactants;

[0016] Step 2, preparing regular hexagonal magnetic particles as a catalyst, the particle size range is 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, tricyclopentadienyl samarium is added as a stabilizer, and tianqing powder is used as a binder, and the preparation is carried out by a roller pressing method; finally, a layer of nano-cerium dioxide is coated on its surface by flame spraying, and the thickness is 10 to 100 nm, so as to improve the mechanical strength, improve the catalytic performance and have a certain slow release effect;

[0017] Step 3, selecting percarbonate as a Fenton-like oxidant, with an initial dosage of 1:100 to 1:1000 (percarbonate: feed solution) by mass ratio, and simultaneously adding aluminum ferric phosphate (aluminum ferric phosphate: feed solution) with a mass ratio of 1:10000 to 1:100000 as an activator, quantitatively mixing with the feed solution by a metering pump, and adjusting the dosage frequency in real time according to the reaction progress to ensure that the percarbonate ion concentration is maintained at an optimal level;

[0018] Step 4, before starting the Fenton-like fluidized bed reactor, first set the reactor operating conditions to a temperature of 20 to 60° C., fill the reactor with 10% of the reactor volume of magnetic particles as a catalyst, first pass a certain flow of tap water through the main feed port, keep the magnetic particle suspension layer 1 / 3 below the reactor liquid surface, and form a stable fluidized state; set the feed liquid pH value to 3 to 11, gradually switch to the feed liquid to replace the tap water feed, and introduce percarbonate to feed from the auxiliary feed port, and closely monitor the height of the magnetic particle suspension layer so that it does not exceed 1 / 3 below the liquid surface, and no abnormal phenomena such as flooding, overpressure, and aggregation occur;

[0019] Step 5: The position and speed 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 the preset algorithm to achieve precise control of the movement path of the magnetic particles. When the mixing effect needs to be enhanced, a rotating magnetic field can be applied to move the particles along a specific trajectory; when local turbulence needs to be reduced, a static magnetic field is applied to fix the particle position;

[0020] Step 6, under the action of the magnetic field, the magnetic particles are fully in contact with the percarbonate ions to generate hydroxyl radicals (·OH), carbonate radicals (CO3-·) and superoxide anion radicals (O2-·); these radicals are quantitatively analyzed using the fluorescence probe method and electron paramagnetic resonance (EPR) technology to ensure that their concentrations achieve the best catalytic degradation effect; the detection range of the fluorescence probe method is 10 -9 Up to 10 -6 mol / L, the resolution of EPR technology is better than 10- 12 mol / L;

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

[0022] Step 8, with the help of various types of sensors, such as temperature sensors, pH sensors, dissolved oxygen sensors, etc., the environmental parameters in the reactor are collected in real time; all sensor data are transmitted to the central controller, and the working parameters of the electromagnetic coil are automatically adjusted after data analysis to form a closed-loop feedback system; the system has a fault diagnosis function and can automatically alarm and take protective measures under abnormal conditions.

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

[0024] It is further defined that the surface coating of the regular hexagonal magnetic particles described in step 2 can also be polytetrafluoroethylene (PTFE) with a thickness of 5 to 20 nm to further improve the corrosion resistance and lubrication performance of the particles and extend the service life.

[0025] It is further defined that the adaptive feedback control system described in step 5 also integrates a machine learning algorithm, particularly a recursive neural network (RNN), for predicting the optimal motion trajectory of the magnetic particles. The RNN model is trained based on historical experimental data and is capable of identifying complex time series relationships and improving control accuracy.

[0026] It is further defined that the free radical quantitative measurement method described in step 6 also includes the use of an online ultraviolet visible spectrophotometer (UV-Vis), which has a detection wavelength range of 200 to 800 nm and 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.

[0027] The present invention is beneficial in that:

[0028] 1) Regular hexagonal magnetic particles are used as catalysts to significantly reduce the amount of iron sludge produced during the reaction, greatly reducing secondary pollution and sludge treatment costs;

[0029] 2) Using percarbonate activated by aluminum iron phosphate as a Fenton-like oxidant, the reaction can be carried out efficiently in the range of pH 3 to 11, significantly reducing the consumption of acid-base regulators and reducing chemical input;

[0030] 3) The introduction of machine learning algorithms such as recursive neural networks (RNNs) enables precise control of the motion trajectory of magnetic particles and multi-field coupling conditions, reducing material consumption by about 20%, energy consumption by 15%, and improving the overall reaction efficiency and system stability. IV. Description of the drawings

[0031] In order to more clearly illustrate the specific embodiments of the present invention, the drawings used in the description of the specific embodiments are briefly described below.

[0032] Figure 1 This is a schematic diagram of the structure of a closed Fenton-like fluidized bed reactor, and the reference numerals are explained as follows:

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

[0034] Figure 2 is a structural schematic diagram (cross-sectional view) of a closed 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. Specific implementation methods

[0035] The present invention is described in detail below with reference to the accompanying drawings and embodiments:

[0036] Embodiment 1:

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

[0038] Step 1: Build a closed Fenton-like fluidized bed reactor with an inner 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 type is cylindrical with an arc-shaped bottom structure, which is conducive to the collection and discharge of solid particles. A liquid flow distribution plate is set at the bottom of the reactor, which is made of porous ceramic material with an opening rate of 10% to 30% and a pore size of 0.5 to 2 mm to promote the full mixing of liquid and solid particles. An overflow port is set at the top to discharge the treated liquid and prevent foam overflow. The reactor wall is made of 316L stainless steel, lined with polytetrafluoroethylene coating, and has a thickness of 0.5 mm. The reaction volume is designed to be 1 to 20 m according to the processing volume. 3 The main feed port is located at the lower part of the reactor side near the bottom, for the feed liquid to enter the reactor, 10 cm from the bottom, with a diameter of 80 mm; the auxiliary feed port is located next to the main feed port, for the percarbonate oxidant to be fed; the discharge port is located below the top overflow port and connected to it, and continuous discharge is achieved through overflow; the heat exchange system is integrated in the outer shell jacket, and the circulating cooling water or hot water flow rate is 1 to 5 m 3 / h, heat exchange area is 0.5 to 2m 2, ensuring that the reaction temperature is stable within the set value ±1℃; the exhaust hole is located at the top of the reactor, with a diameter of 50mm and is equipped with a regulating valve to control the pressure balance; the discharge port is located at the lowest point of the arc bottom, with a diameter of 100mm, which is convenient for regular cleaning of solid residues; the electrical system includes a frequency converter and a PLC controller to realize automatic control of the heating system; the operation mode under the feeding and discharging conditions is continuous feeding and intermittent discharging to ensure the stability of the material concentration in the reactor; multiple layers of spiral electromagnetic coils are evenly arranged on the periphery of the reactor, with a spacing of 10 to 20cm between each layer; the coil is wound with copper wire, with a single layer of 100 to 500 turns and a wire diameter of 0.5 to 1mm; the electromagnetic coil is connected to a controllable power supply, supports DC or AC power supply mode, and the voltage range is 0 to 50V; the coil array can generate strong The magnetic field strength is between 0.1 and 1T, and the 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 to enhance the effect of the dynamic magnetic field. The permanent magnet material is neodymium iron boron (NdFeB), and the magnetic energy product (BHmax) is greater than 40MGOe. The operating temperature range is -40℃ to +150℃, ensuring stable operation under different environments; the reactor's exclusive fluidization method is based on intelligent magnetron technology, and an external electromagnetic coil generates a controllable magnetic field with a magnetic field strength of 0.1 to 1T to act on the system containing a 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 the catalytic performance; the feeding method uses a metering pump to accurately control the input amount of raw materials to ensure a constant ratio of reactants;

[0039] Step 2, preparing regular hexagonal magnetic particles as a catalyst, the particle size range is 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 added as a stabilizer, and tianqing powder is used as a binder, and prepared by a roller pressing method; finally, a layer of nano cerium dioxide is coated on its surface by flame spraying, with a thickness of 10 to 100 nm, so as to improve the mechanical strength, improve the catalytic performance and have a certain slow release effect; the surface coating can also be polytetrafluoroethylene (PTFE) with a thickness of 5 to 20 nm, so as to further improve the corrosion resistance and lubrication performance of the particles and extend the service life;

[0040] Step 3, selecting percarbonate as a Fenton-like oxidant, with an initial dosage of 1:100 to 1:1000 (percarbonate: feed solution) by mass ratio, and simultaneously adding aluminum ferric phosphate (aluminum ferric phosphate: feed solution) with a mass ratio of 1:10000 to 1:100000 as an activator, quantitatively mixing with the feed solution by a metering pump, and adjusting the dosage frequency in real time according to the reaction progress to ensure that the percarbonate ion concentration is maintained at an optimal level;

[0041] Step 4, before starting the Fenton-like fluidized bed reactor, first set the reactor operating conditions to a temperature of 20 to 60° C., fill the reactor with 10% of the reactor volume of magnetic particles as a catalyst, first pass a certain flow of tap water through the main feed port, keep the magnetic particle suspension layer 1 / 3 below the reactor liquid surface, and form a stable fluidized state; set the feed liquid pH value to 3 to 11, gradually switch to the feed liquid to replace the tap water feed, and introduce percarbonate to feed from the auxiliary feed port, and closely monitor the height of the magnetic particle suspension layer so that it does not exceed 1 / 3 below the liquid surface, and no abnormal phenomena such as flooding, overpressure, and aggregation occur;

[0042] Step 5, the position and speed of the magnetic particles are monitored by built-in sensors, and 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; the machine learning algorithm includes a recursive neural network (RNN) to predict the optimal movement 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 move the particles along a specific trajectory; when it is necessary to reduce local turbulence, a static magnetic field is applied to fix the position of the particles;

[0043] Step 6, under the action of the magnetic field, the magnetic particles are fully in contact with the percarbonate ions to generate hydroxyl radicals (·OH), carbonate radicals (CO3-·) and superoxide anion radicals (O2-·); these radicals are quantitatively analyzed using the fluorescence probe method and electron paramagnetic resonance (EPR) technology to ensure that their concentrations achieve the best catalytic degradation effect; the detection range of the fluorescence probe method is 10 -9 Up to 10 -6 mol / L, the resolution of EPR technology is better than 10- 12 mol / L; In addition, the free radical quantitative measurement method also includes the use of an online ultraviolet-visible spectrophotometer (UV-Vis), which has a detection wavelength range of 200 to 800 nm and 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 and change the liquid flow pattern by adjusting the magnetic field strength and direction; apply a gradient magnetic field to aggregate particles to form a "micro-vortex" to promote local mixing; apply a uniform magnetic field to maintain overall fluidity; combine ultrasonic flowmeter and laser Doppler anemometry (LDA) to monitor flow field changes to ensure the optimal mixing state;

[0045] Step 8, with the help of various types of sensors, such as temperature sensors, pH sensors, dissolved oxygen sensors, etc., the environmental parameters in the reactor are collected in real time; all sensor data are transmitted to the central controller, and the working parameters of the electromagnetic coil are automatically adjusted after data analysis to form a closed-loop feedback system; the system has a fault diagnosis function and can automatically alarm and take protective measures under abnormal conditions.

[0046] The structural diagram of the closed Fenton-type fluidized bed reactor is shown in the attached figure. Figure 1 and attached Figure 2 shown.

[0047] Embodiment 2:

[0048] The concentrated leachate from a landfill in Beijing was treated with the closed Fenton-like fluidized bed reactor constructed in Example 1, and the results are as follows.

[0049]

[0050] As can be seen from the above table, for the concentrated solution of landfill leachate from difficult-to-degrade organic wastewater, when the traditional Fenton method is adopted, the COD removal rate is only 67%, and the ammonia nitrogen removal rate is only 50%. When the closed Fenton-like fluidized bed reactor of the present invention is used for treatment and the feeding conditions are optimized by an intelligent algorithm, the COD removal rate can reach 98.4%, and the ammonia nitrogen removal rate can reach nearly 90%, but the corresponding unit cost is reduced by 60.9%, showing a significant technical advantage.

[0051] Embodiment 3:

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

[0053]

[0054] It can be seen from the above table that for the difficult-to-degrade organic wastewater fracturing flowback fluid, when the traditional Fenton method is adopted, the COD removal rate is only 51%, and the viscosity removal rate is only 50%. After the closed Fenton-like fluidized bed reactor of the present invention is used for treatment and the feeding conditions are optimized by the intelligent algorithm, the COD removal rate can reach 91%, and the viscosity removal rate is as high as 99%, but the corresponding unit cost is reduced by 75%, showing a significant technical advantage.

[0055] The specific implementation methods described above are only used to specifically illustrate the spirit of the present invention, and the protection scope of the present invention is not limited thereto. For those skilled in the art, other implementation methods can certainly be easily made by changing, replacing or modifying the technical contents disclosed in this specification, and these other implementation methods should all be covered within the protection scope of the present invention.

Claims

1. A method for enhancing the efficiency of Fenton-like fluidized bed reaction by intelligent magnetic control, characterized in that The method specifically comprises the following steps: Step 1: construct a closed Fenton-like fluidized bed reactor with an inner 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 type is cylindrical with an arc-shaped bottom structure, which is conducive to the collection and discharge of solid particles; a liquid flow distribution plate is set at the bottom of the reactor, which is made of porous ceramic material with an opening rate of 10% to 30% and a pore size of 0.5 to 2 mm to promote the full mixing of liquid and solid particles; an overflow port is set at the top to discharge the treated liquid and prevent foam overflow; the reactor wall is made of 316L stainless steel, lined with polytetrafluoroethylene coating, and has a thickness of 0.5 mm; the reaction volume is designed to be 1 to 20 m according to the processing volume 3 The main feed port is located at the lower part of the reactor side near the bottom, for the feed liquid to enter the reactor, 10 cm from the bottom, with a diameter of 80 mm; the auxiliary feed port is located next to the main feed port, for the percarbonate oxidant to be fed; the discharge port is located below the top overflow port and connected to it, and continuous discharge is achieved through overflow; the heat exchange system is integrated in the outer shell jacket, and the circulating cooling water or hot water flow rate is 1 to 5 m 3 / h, heat exchange area is 0.5 to 2m 2 , ensuring that the reaction temperature is stable within the set value ±1℃; the exhaust hole is located at the top of the reactor, with a diameter of 50mm, and is equipped with a regulating valve to control the pressure balance; the discharge port is located at the lowest point of the arc bottom, with a diameter of 100mm, which is convenient for regular cleaning of solid residues; the electrical system includes a frequency converter and a PLC controller to realize the automatic control of the heating system; the operation mode under the feeding and discharging conditions is continuous feeding and intermittent discharging to ensure the stability of the material concentration in the reactor; multiple layers of spiral electromagnetic coils are evenly arranged on the periphery of the reactor, with a spacing of 10 to 20cm between each layer; the coil is wound with copper wire, with 100 to 500 turns per layer and a wire diameter of The electromagnetic coil is connected to a controllable power supply, supporting DC or AC power supply mode, with a voltage range of 0 to 50V; the coil array can generate a magnetic field with a strength 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, and an external electromagnetic coil generates a controllable magnetic field with a magnetic field strength of 0.1 to 1T to act on the system containing a 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 the catalytic performance; the feeding method uses a metering pump to accurately control the raw material input to ensure a constant ratio of reactants; Step 2, preparing regular hexagonal magnetic particles as a catalyst, the particle size range is 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, tricyclopentadienyl samarium is added as a stabilizer, and tianqing powder is used as a binder, and the preparation is carried out by a roller pressing method; finally, a layer of nano-cerium dioxide is coated on its surface by flame spraying, and the thickness is 10 to 100 nm, so as to improve the mechanical strength, improve the catalytic performance and have a certain slow release effect; Step 3, selecting percarbonate as a Fenton-like oxidant, with an initial dosage of 1:100 to 1:1000 (percarbonate: feed solution) by mass ratio, and simultaneously adding aluminum ferric phosphate (aluminum ferric phosphate: feed solution) with a mass ratio of 1:10000 to 1:100000 as an activator, quantitatively mixing with the feed solution by a metering pump, and adjusting the dosage frequency in real time according to the reaction progress to ensure that the percarbonate ion concentration is maintained at an optimal level; Step 4, before starting the Fenton-like fluidized bed reactor, first set the reactor operating conditions to a temperature of 20 to 60° C., fill the reactor with 10% of the reactor volume of magnetic particles as a catalyst, first pass a certain flow of tap water through the main feed port, keep the magnetic particle suspension layer 1 / 3 below the reactor liquid surface, and form a stable fluidized state; set the feed liquid pH value to 3 to 11, gradually switch to the feed liquid to replace the tap water feed, and introduce percarbonate to feed from the auxiliary feed port, and closely monitor the height of the magnetic particle suspension layer so that it does not exceed 1 / 3 below the liquid surface, and no abnormal phenomena such as flooding, overpressure, and aggregation occur; Step 5: The position and speed 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 the preset algorithm to achieve precise control of the movement path of the magnetic particles. When the mixing effect needs to be enhanced, a rotating magnetic field can be applied to move the particles along a specific trajectory; when local turbulence needs to be reduced, a static magnetic field is applied to fix the particle position; Step 6, under the action of the magnetic field, the magnetic particles are fully in contact with the percarbonate ions to generate hydroxyl radicals (·OH), carbonate radicals (CO3-·) and superoxide anion radicals (O2-·); these radicals are quantitatively analyzed using the fluorescence probe method and electron paramagnetic resonance (EPR) technology to ensure that their concentrations achieve the best catalytic degradation effect; the detection range of the fluorescence probe method is 10 -9 Up to 10 -6 mol / L, the resolution of EPR technology is better than 10- 12 mol / L; Step 7, optimize the fluid flow path and mixing process; control the movement of magnetic particles and change the liquid flow pattern by adjusting the magnetic field strength and direction; apply a gradient magnetic field to aggregate particles to form "micro-vortices" to promote local mixing; apply a uniform magnetic field to maintain overall fluidity; combine ultrasonic flowmeters and laser Doppler anemometry (LDA) to monitor flow field changes and ensure optimal mixing conditions; Step 8, with the help of various types of sensors, such as temperature sensors, pH sensors, dissolved oxygen sensors, etc., the environmental parameters in the reactor are collected in real time; all sensor data are transmitted to the central controller, and the working parameters of the electromagnetic coil are automatically adjusted after data analysis to form a closed-loop feedback system; the system has a fault diagnosis function and can automatically alarm and take protective measures under abnormal conditions.

2. According to the method of claim 1, wherein the method comprises: 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), the magnetic energy product (BHmax) is greater than 40MGOe, and the operating temperature range is -40°C to +150°C, ensuring stable operation in different environments.

3. According to the method of claim 1, wherein the method comprises: The surface coating of the regular hexagonal magnetic particles described in step 2 may also be polytetrafluoroethylene (PTFE) with a thickness of 5 to 20 nm to further improve the corrosion resistance and lubrication performance of the particles and extend the service life.

4. According to the method of claim 1, wherein the method comprises: The adaptive feedback control system described in step 5 also integrates a machine learning algorithm, particularly a recursive neural network (RNN), to predict the optimal motion 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.

5. The method for enhancing the efficiency of Fenton-like fluidized bed reaction by intelligent magnetic control according to claim 1, characterized in that: The free radical quantitative measurement method described in step 6 also includes the use of an online ultraviolet visible spectrophotometer (UV-Vis), which has a detection wavelength range of 200 to 800 nm and a sensitivity better than 0.001 Abs, can quickly respond to changes in free radical concentration, provide real-time monitoring data, and assist in optimizing reaction conditions.

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