Wastewater recycling treatment process and system

Abstract

The invention relates to the technical field of water pollution treatment, in particular to a wastewater recycling treatment process and system, and the method comprises a primary oxidation step, a premixing and secondary oxidation step, an aeration and neutralization step, a complexation reaction step and a secondary neutralization and flocculation step. The system comprises a primary oxidation module, a premixing and secondary oxidation module, an aeration and neutralization module, a complex reaction module and a secondary neutralization and flocculation module. The method has the effect of improving the utilization rate of the oxidant.

Description

Technical Field

[0001] The present application relates to the technical field of water pollution treatment, and in particular to a wastewater recycling and reuse treatment process and system. Background Art

[0002] At present, with the rapid development of industrialization, the types and concentrations of organic pollutants in wastewater are becoming increasingly complex, especially the refractory organic matter (such as dyes, pesticides, drug residues, etc.) have posed a severe challenge to traditional treatment methods. Advanced oxidation technology (AOPs) has become a research hotspot due to its high efficiency in degradation. Among them, the Fenton reaction is a 2+ Catalyzing H₂O₂ to generate highly oxidizing hydroxyl radicals (·OH) can indiscriminately decompose organic matter. However, improving reaction efficiency, reducing reagent waste, and inhibiting by-product formation remain key challenges hindering the large-scale application of this technology.

[0003] The existing Fenton wastewater treatment method includes acidification, premixing, secondary oxidation, neutralization, and flocculation. The specific process involves mechanically agitating the addition of a ferrous salt solution and H₂O₂, using a magnetic field to assist the reaction, and finally precipitating and separating the purified water. This multi-step, phased treatment method significantly improves COD removal rates.

[0004] However, it is difficult to achieve uniform dispersion of ferrous salt solution by mechanical stirring. 2+ Too high a concentration will cause Fe 3+ Premature precipitation reduces catalytic activity, while insufficient H2O2 spray coverage leads to low oxidant utilization. Summary of the Invention

[0005] In order to improve the utilization rate of oxidants, the present application provides a wastewater recycling and reuse treatment process and system.

[0006] In the first aspect, the present application provides a wastewater recycling and treatment process, which adopts the following technical solutions: A wastewater recycling and treatment process comprises the following steps: Primary oxidation: add acid solution in counterclockwise rotation and start clockwise stirring simultaneously to adjust the pH of the wastewater to acidic, then introduce ozone and react for 15 to 30 minutes to generate primary oxidized wastewater; Premixing and secondary oxidation: including the first dosing step, the second dosing step, the secondary oxidation step and the detection step; First dosing: add ferrous salt solution to the primary oxidation wastewater through reverse stirring, and control the droplet size to 1~3mm; Second dosing: spray hydrogen peroxide solution in atomized form according to the delay setting time; Secondary oxidation: Apply an alternating magnetic field simultaneously and react for 30 to 45 minutes to obtain secondary oxidation wastewater; Detection: Real-time monitor the pH value of the reaction solution. If pH > 3.5, trigger the acid solution supplementary addition mechanism; Aeration and neutralization: Conduct ozone aeration on the secondary oxidation wastewater, add carbonate to adjust the pH to 5 - 6, and generate pre-neutralized wastewater; Complexation reaction: Synchronously spray the complexing defluorinating agent by atomization and rotate to add magnetic powder into the pre-neutralized wastewater, and stir and react for 10 to 20 minutes to obtain complexation reaction wastewater; Secondary neutralization and flocculation: Add alkali solution to the complexation reaction wastewater to adjust the pH to 6 - 7, add a coagulant aid, then conduct laminar flow stirring for 10 to 15 minutes, and let it stand to separate the supernatant.

[0007] The traditional process uses unidirectional stirring and direct addition of acid solution, with low mixing efficiency, pH adjustment taking 10 to 15 minutes, and ozone utilization rate less than 60%.

[0008] By adopting the above technical solution, adding acid in reverse rotation + clockwise stirring forms a shear flow field, the pH adjustment time is shortened to 5 - 8 minutes, and the ozone utilization rate is increased to 85%; droplet size control (1 - 3 mm): the dispersion uniformity of the ferrous salt solution is improved, avoiding too high local Fe 2+ concentration, reducing the risk of Fe 3+ precipitation, and through the delayed addition of hydrogen peroxide, reducing the premature reaction with Fe 2+ to improve the reaction effect, and through the spraying method, the waste of oxidant can be reduced, while the coverage area of hydrogen peroxide is increased, and through reverse stirring and adding ferrous salt solution, Fe²⁺ is dispersed evenly, reducing the premature precipitation caused by too high, thereby reducing the waste of oxidant, improving the oxidant utilization rate, and improving the oxidation efficiency.

[0009] Optionally, the premixing and secondary oxidation steps further include: a proportion monitoring step; Proportion monitoring: Monitor the Fe 2+ / Fe 3+ proportion, if the proportion of Fe 3+ is greater than 20%, then reduce the hydrogen peroxide spraying pressure and increase the magnetic field frequency to the upper limit value.

[0010] By adopting the above technical solution, the Fe 2+ / Fe 3+ proportion is monitored in real time, and the H2O2 spraying pressure and magnetic field frequency are dynamically adjusted; the catalytic activity is stabilized, the proportion of Fe 3+ is controlled below 15%, and the H2O2 utilization rate is increased from 60% to 85%; magnetic field dynamic response: when the magnetic field frequency is increased to 50 Hz, the Fe 2+ regeneration rate is increased and the reaction efficiency is improved.

[0011] Optionally, in the first additive step, stirring is carried out in a turbulent flow manner.

[0012] By adopting the above technical solution, through the turbulent stirring method, the position of the ferrous salt solution is advanced and its fluidity is enhanced, so that the mixing with the wastewater is more uniform, the dispersion time of the ferrous salt is shortened to 1.5 minutes, and the uniformity is improved; at the same time, the stirring energy consumption can be reduced, the COD degradation rate can be increased, and the utilization rate of the oxidant can be further improved.

[0013] Optionally, in the secondary oxidation step, the frequency of the alternating magnetic field is adjusted based on the results of electrochemical impedance spectroscopy analysis, specifically as follows: the impedance spectrum of the wastewater is collected in real time, and the electron transfer rate between Fe 2+ and H2O2 is calculated; if the electron transfer rate is less than the first threshold, the magnetic field frequency is increased and the magnetic field intensity is synchronously increased; if the electron transfer rate is greater than the second threshold, the magnetic field frequency is decreased to inhibit side reactions.

[0014] By adopting the above technical solution, impedance spectrum data is collected through the electrode array, and the electron transfer rate between Fe 2+ and H2O2 is calculated. When the rate < 0.5 mol / (m²·s), the magnetic field frequency is increased to 50 Hz and the intensity is increased to 200 mT, and the free radical generation rate is increased by 45%; by-product inhibition: when the rate > 1.2 mol / (m²·s), the magnetic field frequency is decreased to 10 Hz, reducing the over-oxidation side reaction, and the by-product generation rate is reduced from 20% to 8%; through electrochemical impedance spectroscopy analysis, the redox efficiency is visualized, the magnetic field is adjusted according to the actual efficiency, the oxidation effect is maintained, the purification efficiency of the wastewater is improved, and at the same time, resource waste can be reduced.

[0015] Optionally, in the complexation reaction step, the magnetic powder is added in a rotating manner, and a local magnetic field is applied to the initial addition of the magnetic powder during the rotating addition; according to the dispersion degree of the magnetic powder, the local magnetic field intensity is adjusted; and the sedimentation rate of the magnetic powder is obtained. If the sedimentation rate of the magnetic powder is greater than the third threshold, an acoustic oscillator is used to assist in dispersion.

[0016] By adopting the above technical solution, the magnetic powder is adsorbed by the local magnetic field and added in a rotating manner, so that it is uniformly dispersed throughout the wastewater, the magnetic powder adsorption rate is increased, and the dispersion effect is improved; the cavitation effect destroys the magnetic powder aggregates, delays the aggregation of the magnetic powder, and thus delays the sedimentation rate. The sludge volume is reduced by 35%, and the magnetic powder recycling utilization rate is increased by 60%, improving the purification efficiency of the wastewater.

[0017] Optionally, in the second additive step, the set delay duration is dynamically adjusted through electrochemical noise analysis: a reference electrode and a working electrode are set in the wastewater obtained after the first additive step, and the current noise signal is collected; if the noise amplitude is greater than the fourth threshold, the first adjustment step is executed; First adjustment: extend the set delay duration, and then execute the second additive step according to the extended set delay duration; After the second additive step, a feedback judgment step is further included; Feedback judgment: after the second additive step is completed, for the noise frequency of the wastewater, if the noise frequency is greater than the fifth threshold, the feedback step is executed; Feedback: shorten the set delay duration, update it to the new set delay duration, and increase the atomization pressure.

[0018] By adopting the above technical solution, the current noise amplitude reflects the aggregation degree of Fe²⁺. The delay time is extended to 30 seconds to ensure that Fe 2+ is fully dispersed, and the dispersion uniformity is increased from 90% to 98%; noise frequency feedback (>100 Hz): the high-frequency noise signal indicates out-of-control decomposition of H2O2. The delay is shortened to 10 seconds and the atomization pressure is increased to 0.5 MPa. The effective utilization rate of H2O2 is increased from 60% to 85%; by means of the noise amplitude and the noise frequency, the set delay duration is adjusted, which can truly feedback the actual reaction situation, and can also keep Fe 2+ fully dispersed, determine the input timing of hydrogen peroxide, and further reduce the premature precipitation of Fe 2+ while being able to maintain the full mixing of hydrogen peroxide and Fe 2+ Both work together to treat the wastewater, improve the utilization rate of the oxidant, and improve the treatment efficiency of the wastewater.

[0019] Optionally, in the first adjustment step, the calculation formula for the set delay duration is: ; In the formula, is the initial set delay duration, is the fourth threshold, is the maximum allowable noise amplitude, is the actually measured noise amplitude; , and increases as the treatment volume of the wastewater increases or increases according to the increase in the complexity of the wastewater.

[0020] By adopting the above technical solution, by non-linearly adjusting the set delay time, it can truly fit the dispersion efficiency of Fe 2+ and promote the mixing of Fe 2+ and hydrogen peroxide through dynamic adjustment, thereby improving the subsequent treatment efficiency of the wastewater.

[0021] Optionally, in the secondary oxidation step, it further includes dynamically adjusting the intensity of the alternating magnetic field and the atomization spray pressure, and the intensity of the alternating magnetic field and the atomization spray pressure are cooperatively regulated by the edge computing module: Real-time collect the data of the COD degradation rate, H2O2 residual concentration and magnetic field frequency of the wastewater, and input them into the pre-trained neural network model; If the predicted reaction efficiency output by the model is less than 85%, the magnetic field intensity is simultaneously increased to the maximum value, the atomization pressure is increased to the maximum value, and the stirring speed is reduced by 10% - 20%; If the predicted by-product generation rate output by the model is greater than 15%, the reverse adjustment of the magnetic field frequency and the atomization pressure is triggered.

[0022] By adopting the above technical solutions, through prediction and comparison, the magnetic field intensity and the atomization spray pressure can be finely adjusted, the comprehensive energy consumption can be reduced, and the COD removal rate can be improved.

[0023] Optionally, the set delay duration and the magnetic field frequency are cooperatively optimized through a coupling algorithm: Establish the empirical formula, where is the proportionality coefficient that is positively correlated with the wastewater ; if the deviation between the actual COD removal rate and the predicted value of the formula is greater than 10%, the adaptive learning module is triggered to update the value and redistribute the weights of the magnetic field energy and the delay time.

[0024] This solution is used to provide a reference delay time, combined with and the magnetic field frequency ( ) to determine the initial parameters and adapt to the wastewater with different pollution loads; the previous solution is calculated through the noise amplitude to dynamically correct the delay time on the basis of the reference value, realizing real-time fine-tuning, and is applicable to short-term rapid response to solve instantaneous problems such as uneven dispersion of Fe 2+ or out-of-control decomposition of H2O2.

[0025] By adopting the above technical solutions, by dynamically adjusting the intensity of the alternating magnetic field and the atomization spray pressure, it can effectively promote the mixing of Fe 2+ and hydrogen peroxide, and can promote the generation of free radicals, improve the wastewater treatment efficiency, and at the same time can provide the utilization rate of the oxidant.

[0026] In the second aspect, a wastewater recycling treatment system provided by the present application adopts the following technical solutions: A wastewater recycling treatment system includes the following modules: Primary oxidation module: Adjust the acidity of the wastewater and introduce ozone for primary oxidation; Premixing and secondary oxidation module: Used to receive the primary oxidation wastewater produced by the primary oxidation module, add and mix the ferrous salt solution, then add hydrogen peroxide, apply an alternating magnetic field for secondary oxidation, monitor the pH during the oxidation process, and add acid solution for supplementation; Aeration and neutralization module: Used to receive the secondary oxidation wastewater produced by the premixing and secondary oxidation module, perform ozone aeration on the secondary oxidation wastewater, add carbonate to adjust the pH to 5 - 6, and generate pre-neutralized wastewater; Complexation reaction module: Used to receive the pre-neutralized wastewater produced by the aeration and neutralization module, simultaneously atomize and spray the complexing defluorinating agent into the pre-neutralized wastewater and rotate to add magnetic powder, stir and react to produce complexation reaction wastewater; Secondary neutralization and flocculation module: Used to receive the complexation reaction wastewater, add alkali solution to the complexation reaction wastewater to adjust the pH to 6 - 7, add a coagulant aid, then perform laminar flow stirring, and let it stand to separate the supernatant.

[0027] By adopting the above technical solutions, first, the acidity is adjusted and primary oxidation is carried out through the primary oxidation module, then the addition of ferrous salt solution is carried out through the premixing and secondary oxidation module, and after the mixing is completed, hydrogen peroxide is added, and an alternating magnetic field is applied for secondary oxidation. Then, aeration treatment and pH value adjustment are carried out through the aeration and neutralization module; then complexation and flocculation are carried out successively through the complexation reaction module and the secondary neutralization and flocculation module to obtain the supernatant; integrating modules such as ozone oxidation, magnetic field-enhanced Fenton, and magnetic powder complexation, combined with intelligent control (such as edge computing, electrochemical feedback), a full-process closed-loop treatment system is formed; compared with the traditional system where each unit operates independently and lacks linkage regulation, the system realizes efficient, stable, and low-consumption wastewater treatment through modular design and intelligent algorithms.

[0028] In summary, the present application includes at least one of the following beneficial technical effects: 1. Reverse rotation for adding acid + clockwise stirring to form a shear flow field, shortening the pH adjustment time to 5 - 8 minutes and increasing the ozone utilization rate to 85%; Droplet size control (1 - 3 mm): improving the dispersion uniformity of the ferrous salt solution, avoiding too high local Fe 2+ concentration, reducing the risk of Fe 3+ precipitation, and through the delayed addition of hydrogen peroxide, reducing the premature reaction with Fe 2+ , improving the reaction effect, and through the spraying method, reducing the waste of oxidants, while increasing the coverage area of hydrogen peroxide, and through reverse stirring and adding the ferrous salt solution, making Fe 2+ dispersed evenly, reducing the premature precipitation caused by too high, thereby reducing the waste of oxidants, increasing the oxidant utilization rate, and increasing the oxidation efficiency; 2. By non-linearly adjusting the delay setting time, a true fit can be achieved, and the dispersion efficiency of Fe 2+ can be improved. Through dynamic adjustment, the mixing of Fe 2+ with hydrogen peroxide can be promoted, and the treatment efficiency of subsequent wastewater can be improved; 3. By dynamically adjusting the alternating magnetic field intensity and the atomizing spray pressure, the mixing of Fe 2+ with hydrogen peroxide can be effectively promoted, the generation of free radicals can be promoted, the wastewater treatment efficiency can be improved, and at the same time, the utilization rate of the oxidant can be provided. Description of the Drawings

[0029] Figure 1 is a flow chart of the process for recycling and treating wastewater in an embodiment of the present application. Detailed Embodiments

[0030] The following is a further detailed description of the present application in conjunction with Figure 1 This will be further described in detail below.

[0031] This embodiment discloses a process for recycling and treating wastewater.

[0032] Referring to Figure 1 , the process for recycling and treating wastewater includes the following steps: Primary oxidation: Add acid solution while rotating counterclockwise, and simultaneously start clockwise stirring to adjust the pH of the wastewater to acidic. Then, introduce ozone and react for 15 - 30 minutes to generate primary oxidation wastewater; Specifically, four stainless - steel reaction tanks (volume 2 m³) connected in series, made of 316L material, with the inner wall polished (Ra ≤ 0.8 μm); each reaction tank is equipped with a two - way stirring system (clockwise stirring paddle + counterclockwise rotating feeding tray), motor power 5.5 kW; rotating feeding tray (liquid droplet size control module, accuracy ±0.5 mm); annular tube atomizing spray system (spray head pressure 0.2 - 0.5 MPa, atomizing particle size 20 - 50 μm); magnetic field device: electromagnet group (magnetic field intensity 50 - 200 mT, frequency 10 - 50 Hz), externally placed in the reaction tank for secondary oxidation; pH sensor, ORP sensor, turbidity sensor, and magnetic flux sensor are arranged in the reaction tank.

[0033] Wastewater (initial COD = 1500 mg / L, pH = 7.2) is injected into the first reaction tank; sulfuric acid solution (concentration 10%) is added at a rate of 5 L / min while rotating counterclockwise, and simultaneously clockwise stirring (rotation speed 120 rpm) is started; the pH of the wastewater is adjusted to 2.8, and then ozone (concentration 50 mg / L) is introduced through the bottom aeration head and reacts for 25 minutes; where the stirring Reynolds number Re = 4500 (turbulent flow mode), and the ozone feeding rate is 0.8 L / min.

[0034] Premixing and secondary oxidation: including a first additive step, a second additive step, a secondary oxidation step, and a detection step; First additive: Add a ferrous salt solution to the primary oxidation wastewater by reverse stirring, control the droplet size to be 1 - 3 mm, and stir in a turbulent flow manner; Second additive: According to the set delay time , atomize and spray a hydrogen peroxide solution; Secondary oxidation: Apply an alternating magnetic field simultaneously and react for 30 - 45 minutes to obtain secondary oxidation wastewater; Ratio monitoring: Monitor the Fe 2+ / Fe 3+ ratio. If the proportion of Fe 3+ is greater than 20%, then reduce the hydrogen peroxide spray pressure and increase the magnetic field frequency to the upper limit value; Specifically, pump the primary oxidation wastewater into the second reaction tank. Under reverse stirring (rotation speed 100 rpm), add FeSO4 solution (concentration 0.1 mol / L) through a rotating feeding disk, and control the droplet size to be 1.5 ± 0.3 mm; maintain turbulent stirring (Re = 4200) for 2 minutes to ensure that the Fe 2+ dispersion uniformity ≥ 95%.

[0035] Second additive (H2O2 spray): Delay time (initially set), start the annular pipe atomizing spray of 30% H2O2 solution; the spray pressure is 0.3 MPa to form a conical mist curtain covering the reaction area.

[0036] Secondary oxidation: Start the electromagnet group, apply an alternating magnetic field (initial intensity 100 mT, frequency 30 Hz); react for 35 minutes and monitor the Fe 2+ / Fe 3+ ratio in real time; when the ORP sensor detects that the proportion of Fe 3+ is > 20%: Reduce the H2O2 spray pressure to 0.2 MPa; increase the magnetic field frequency to 50 Hz and the intensity to 150 mT.

[0037] Detection: Monitor the pH value of the reaction solution in real time. If pH > 3.5, then trigger the acid solution supplementary addition mechanism; Specifically, monitor the pH of the reaction solution in real time. When pH > 3.5, trigger the acid solution supplementary addition mechanism; add sulfuric acid solution (rate 2 L / min) through a rotating feeding disk until the pH returns to 3.0 ± 0.2.

[0038] Aeration and neutralization: Conduct ozone aeration on the secondary oxidation wastewater, add carbonate to adjust the pH to 5 - 6 to generate pre-neutralized wastewater; Specifically, the secondary oxidation wastewater is transferred to the third reaction tank, and ozone (concentration 30 mg / L, rate 1.0 L / min) is introduced through the bottom aeration head for 15 minutes; a sodium carbonate solution (concentration 5%) is added to adjust the pH to 5.5; Complexation reaction: The complexing defluorination agent is atomized and sprayed into the pre-neutralized wastewater synchronously, and magnetic powder is added while rotating, and the reaction is stirred for 10 - 20 minutes to obtain the complexation reaction wastewater; Specifically, the pre-neutralized wastewater is pumped into the fourth reaction tank, and the complexing defluorination agent (polyacrylamide, concentration 0.05%) is atomized and sprayed synchronously and magnetic powder (Fe3O4, particle size ≤ 50 μm) is added while rotating; When adding magnetic powder, a local magnetic field (intensity 5 mT) is applied to guide the dispersion of magnetic powder, and an acoustic oscillator (frequency 30 kHz) is used to inhibit sedimentation; the reaction is stirred for 15 minutes (rotation speed 80 rpm); Secondary neutralization and flocculation: An alkali solution is added to the complexation reaction wastewater to adjust the pH to 6 - 7, and after adding a coagulant aid, it is stirred in laminar flow for 10 - 15 minutes, and then the supernatant is separated by standing.

[0039] Specifically, an NaOH solution (concentration 10%) is added to adjust the pH to 6.8; polyaluminum chloride (PAC, dosage 30 mg / L) is added, and it is stirred in laminar flow (flow rate 0.15 m / s) for 12 minutes; it is allowed to stand and precipitate for 45 minutes, and the supernatant is separated (COD = 85 mg / L, pH = 6.9).

[0040] In other embodiments, in the secondary oxidation step, the frequency of the alternating magnetic field is adjusted based on the results of electrochemical impedance spectroscopy analysis, specifically as follows: The impedance spectrum of the wastewater is collected in real time, and the electron transfer rate between Fe 2+ and H2O2 is calculated; if the electron transfer rate is less than the first threshold, the magnetic field frequency is increased, and the magnetic field intensity is increased synchronously; if the electron transfer rate is greater than the second threshold, the magnetic field frequency is decreased to inhibit side reactions.

[0041] In other embodiments, in the complexation reaction step, the magnetic powder is added in a rotating manner, and a local magnetic field is applied to the initial addition of magnetic powder during the rotating addition; according to the dispersion degree of the magnetic powder, the local magnetic field intensity is adjusted; and the sedimentation rate of the magnetic powder is obtained. If the sedimentation rate of the magnetic powder is greater than the third threshold, an acoustic oscillator is used to assist in dispersion.

[0042] Specifically, the rotation speed is set to 30 rpm, and the magnetic powder is evenly scattered into the reaction tank by rotation; before adding magnetic powder, screening is first carried out to ensure that the particle size of the magnetic powder ≤ 50 μm, and the feeding rate is 5 kg / h.

[0043] An annular electromagnet group is set at the rotary feeding position. The annular electromagnet group is turned on, and the initial magnetic field intensity is set to 10 mT, with the direction perpendicular to the rotation axis of the magnetic powder rotary addition; the magnetic field guides the magnetic powder to disperse radially in the reaction tank to avoid accumulation in the central area.

[0044] The dispersion degree is monitored in real time: the magnetic flux sensor collects data every 10 seconds to calculate the magnetic powder distribution density; the dispersion degree threshold is set to ≥95% (i.e., the deviation of the magnetic powder density per unit volume ≤5%). Magnetic field intensity adjustment: if the dispersion degree <95%, gradually increase the magnetic field intensity to 15 mT to improve the magnetic powder adsorption force; if the dispersion degree ≥95%, maintain the magnetic field intensity at 10 mT for energy conservation.

[0045] The sedimentation rate is detected in real time: the laser scattering instrument monitors the sedimentation rate of the magnetic powder, and the threshold is set to 0.1 mm / s; if the sedimentation rate >0.1 mm / s, it is determined that the magnetic powder agglomerates or the sedimentation is too fast. Start the acoustic oscillator: trigger 30 kHz ultrasonic waves, and the cavitation effect generates microbubbles to break the magnetic powder agglomerates; continuously oscillate for 5 minutes until the sedimentation rate drops below 0.05 mm / s.

[0046] At this time, the complexation reaction proceeds synchronously, and the polyacrylamide solution (concentration 0.05%) is added synchronously through the atomizing spray system, and the spray pressure is 0.3 MPa; the particle size of the complexing agent droplets is controlled to be 20 - 30 μm to cover the magnetic powder dispersion area. The two-way stirring system operates (the clockwise stirring paddle is 80 rpm, and the counterclockwise feeding tray is 30 rpm); the reaction time is 15 minutes to ensure sufficient contact between the magnetic powder - complexing agent - pollutant.

[0047] Through the rotation - magnetic field collaborative dispersion, the rotary feeding is combined with the local magnetic field to achieve the directional dispersion of the magnetic powder, avoiding the energy consumption waste of mechanical stirring; the magnetic field intensity is dynamically adjusted to accurately match the dispersion requirements. Acoustic - sedimentation feedback control: trigger the acoustic oscillation based on the sedimentation rate threshold to solve the problem of magnetic powder agglomeration; the cavitation effect improves the dispersion efficiency and reduces the dependence on chemical agents.

[0048] In other embodiments, in the second additive step, the set delay duration is dynamically adjusted through electrochemical noise analysis: a reference electrode and a working electrode are set in the wastewater obtained after the first additive step to collect the current noise signal; if the noise amplitude is greater than the fourth threshold, the first adjustment step is executed; First adjustment: extend the set delay duration, and the calculation formula for the set delay duration is: ; In the formula, is the initial set delay duration, is the fourth threshold, is the maximum allowable noise amplitude, is the actually measured noise amplitude; , and increases according to the increase in the treatment volume of the wastewater or according to the increase in the complexity of the wastewater; wherein, , where represents the current wastewater volume (or flow rate), represents the reference wastewater volume benchmark value (such as average load), is an adjustment coefficient to control the sensitivity of the base number to the wastewater volume, ; or , wherein, represents the current wastewater complexity (such as pollutant concentration), represents the reference complexity benchmark value, represents the non - linear adjustment coefficient ( and increases smoothly).

[0049] Then, perform the second additive step according to the extended delay setting duration; After the second additive step, a feedback judgment step is further included; Feedback judgment: After the second additive step is completed, for the noise frequency of the wastewater, if the noise frequency is greater than the fifth threshold value, then perform the feedback step; Feedback: Shorten the delay setting duration, update it to the new delay setting duration, and increase the atomization pressure.

[0050] Specifically, the reaction tank (volume 2m³) is equipped with a two - way stirring system and an electrochemical workstation; Electrode system: Reference electrode: Ag / AgCl electrode, installed on the side wall of the reaction tank; Working electrode: Platinum electrode (surface area 10cm²), with a distance of 5cm from the reference electrode.

[0051] Data acquisition module: Electrochemical noise analyzer (sampling frequency 1kHz, accuracy ±1nA); Noise amplitude ( ) and frequency ( ) are displayed and transmitted to the PLC control system in real - time.

[0052] Initial delay time: 15 seconds; Noise amplitude threshold: (the fourth threshold value), ; Noise frequency threshold: (the fifth threshold value).

[0053] Electrochemical noise signal acquisition and delay time calculation, electrode configuration and signal acquisition: After the first additive step (ferrous salt addition) is completed, start the reference electrode and the working electrode, and collect the current noise signal; The electrochemical noise analyzer records the noise amplitude every 5 seconds ( ) with frequency ( ).

[0054] Dynamic adjustment of delay time: Condition judgment: If , maintain the initial delay time ; If , calculate the adjustment coefficient J, and adjust the delay time according to the formula: ; Determination of the adjustment coefficient J (in two scenarios): Scenario A (based on wastewater volume): ; Parameter setting: (reference wastewater volume), ; Example: Current wastewater volume → .

[0055] Scenario B (based on complexity): ; Parameter setting: (reference COD baseline value), ; Example: Current wastewater → .

[0056] Example of delay time calculation: If , , , (Scenario A): ; Execute the second additive (H2O2 atomized spray) Delayed addition: Start the H2O2 spray according to the adjusted delay time seconds; Atomization parameter control: Spray pressure 0.3 MPa, forming a uniform mist curtain to cover the reaction zone.

[0057] Noise frequency monitoring: After the H2O2 spray is completed, monitor the noise frequency in real time ; If , it is determined that the H2O2 decomposition is too fast or the free radical generation is out of control.

[0058] Feedback adjustment: Shorten the delay time: Update to 80% of the original value ( ), for the second additive step of the same wastewater treatment next time; Increase atomization pressure: The spraying pressure is increased from 0.3 MPa to 0.4 MPa to refine the liquid droplets to below 30 μm; Record parameters: The adjusted are stored in the database for reference in the next batch.

[0059] Through the above settings, the dynamic range of the delay time is 15 - 30 seconds (the traditional fixed delay is 20 seconds, with an error of ±5 seconds); H2O2 utilization rate: In scenario A (J = 1.45), the utilization rate is increased from 70% to 85%; In scenario B (J = 1.22), the utilization rate is increased from 70% to 80%; COD removal rate: After dynamic adjustment, the COD removal rate is stable at 90% - 92% (the traditional process is 80% - 85%); By - product generation rate: The feedback control of the noise frequency reduces the by - product generation rate from 18% to 7%; Energy consumption comparison: The unit treatment energy consumption is reduced from 1.0 kWh / m³ to 0.7 kWh / m³.

[0060] In other embodiments, in the secondary oxidation step, it further includes dynamically adjusting the alternating magnetic field intensity and the atomization spraying pressure, and the intensity of the alternating magnetic field and the atomization spraying pressure are coordinately regulated by the edge computing module: Real - time collect the data of the COD degradation rate, the residual concentration of H2O2 and the magnetic field frequency of the wastewater, and input them into the pre - trained neural network model; If the predicted reaction efficiency output by the model is less than 85%, then simultaneously increase the magnetic field intensity to the maximum value, the atomization pressure to the maximum value, and reduce the stirring speed by 10% - 20%; If the predicted by - product generation rate output by the model is greater than 15%, then trigger the reverse adjustment of the magnetic field frequency and the atomization pressure.

[0061] Specifically, use hardware devices, online COD detector: ultraviolet - visible spectroscopy (UV - Vis), to real - time monitor the COD degradation rate (mg / (L·min)); H2O2 electrochemical sensor: to detect the residual concentration (mg / L), with an accuracy of ±5%; Magnetic field frequency monitoring module: Hall effect sensor, frequency range 10 - 50 Hz.

[0062] Edge computing module: Hardware: NVIDIA Jetson AGX Xavier, computing power 32 TOPS; Pre - trained neural network model: Based on the LSTM architecture, the input is the COD degradation rate, H2O2 concentration, and magnetic field frequency, and the output is the reaction efficiency (%) and the by - product generation rate (%).

[0063] Actuator: Alternating magnetic field generator: intensity 50 - 200 mT, frequency 10 - 50 Hz; Atomization spraying system: pressure 0.2 - 0.5 MPa, droplet diameter 20 - 50 μm; Variable-frequency stirring motor: The speed regulation range is 50~150 rpm.

[0064] The specific steps are as follows: Real-time data acquisition and model input, sensor data synchronization: The COD degradation rate (such as 0.8 mg / (L·min)), the residual concentration of H2O2 (such as 120 mg / L), and the magnetic field frequency (such as 30 Hz) are collected every 5 seconds; the data is transmitted to the edge computing module through the Modbus protocol.

[0065] Neural network prediction: After normalizing the input data, it is input into the pre-trained model, and the predicted value is output: Reaction efficiency: The model predicts that the current efficiency is 78% (<85% threshold); By-product generation rate: The model predicts it to be 18% (>15% threshold).

[0066] Implementation of dynamic regulation strategy: Scenario A (reaction efficiency <85%): Increase the magnetic field strength: from 100 mT to 200 mT (maximum value), keep the magnetic field frequency at 30 Hz; increase the atomization pressure: from 0.3 MPa to 0.5 MPa (maximum value), refine the droplet size to 20 μm; reduce the stirring speed: from 120 rpm to 96 rpm (reduce by 20%), reduce the turbulent energy consumption; regulation goal: accelerate the generation of free radicals and compensate for the insufficient reaction efficiency.

[0067] Scenario B (by-products >15%): Reverse the magnetic field frequency: from 30 Hz to 15 Hz, keep the magnetic field strength at 100 mT; reduce the atomization pressure: from 0.4 MPa to 0.25 MPa, reduce the excessive decomposition of H2O2; regulation goal: inhibit over-oxidation and reduce the generation of by-products.

[0068] Real-time feedback and parameter optimization: Data closed-loop update: After regulation, data is re-collected every 2 minutes to update the model input; if the reaction efficiency increases to more than 85% or the by-products decrease to less than 15%, maintain the current parameters; otherwise, trigger secondary adjustment (such as alternating execution of Scenario A and Scenario B).

[0069] In other embodiments, when the working conditions have high fluctuations, the above method of calculating the delay setting duration through the noise amplitude is adopted ; when the working conditions are stable, the delay setting duration and the magnetic field frequency are co-optimized through a coupling algorithm: Establish empirical formula, where is a proportionality coefficient positively correlated with the wastewater ; if the deviation between the actual COD removal rate and the predicted value of the formula is greater than 10%, the adaptive learning module is triggered to update value, and re - distribute the magnetic field energy and the delay time weight.

[0070] Specifically, for the initial parameter setting and formula application, the wastewater characteristics are input: the initial COD value of the wastewater ( ) = 1200 mg / L; Calculate the proportionality coefficient k: ; Delay time calculation: Set the initial magnetic field frequency ; Calculate the delay time according to the formula : ; Execute the secondary oxidation process, and start the cooperation of the magnetic field and the delay: Turn on the alternating magnetic field (frequency 30 Hz, intensity 100 mT); Start the H2O2 atomization spray (pressure 0.3 MPa) after the delay time .

[0071] Real - time data collection: Record the COD degradation rate, the residual concentration of H2O2, and the magnetic field frequency every 10 seconds.

[0072] Adaptive learning and parameter optimization, calculate the actual COD removal rate: Initial COD = 1200 mg / L, treated COD = 150 mg / L; Actual removal rate = (1200 - 150) / 1200×100% = 87.5%.

[0073] Predicted value and deviation analysis: Model - predicted removal rate = 82% (trained based on historical data); Deviation = (<10%, no adjustment is triggered).

[0074] Example of trigger condition: If the actual removal rate = 70%, the predicted value = 82%, and the deviation = 14.6% (>10%), then perform the following operations: Update the k value: Adjust k according to the deviation direction. If the actual removal rate is lower than the prediction, increase k to extend the delay time: , (γ = 0.1 is the learning rate); Re - distribute the magnetic field energy: Reduce the magnetic field frequency to 25 Hz, and at the same time increase the magnetic field intensity to 150 mT. The formula is updated to: ; Closed - loop feedback and process stability, continuous monitoring and iteration: Update the k value and the magnetic field parameters after each batch of wastewater treatment; The optimized parameters are recorded in the database for the initial setting of the next batch.

[0075] The embodiments of the present application also disclose a wastewater recycling and treatment system, including the following modules: Primary oxidation module: adjust the acidity of the wastewater and introduce ozone for primary oxidation; Premixing and secondary oxidation module: used to receive the primary oxidation wastewater prepared by the primary oxidation module, add and mix the ferrous salt solution, then add hydrogen peroxide, apply an alternating magnetic field for secondary oxidation, monitor the pH during the oxidation process, and add acid solution; and used to monitor the Fe 2+ / Fe 3+ ratio, adjust the magnetic field frequency and intensity; Aeration and neutralization module: used to receive the secondary oxidation wastewater prepared by the premixing and secondary oxidation module, perform ozone aeration on the secondary oxidation wastewater, add carbonate to adjust the pH to 5 - 6, and generate pre-neutralized wastewater; Complexation reaction module: used to receive the pre-neutralized wastewater prepared by the aeration and neutralization module, synchronously spray the complexing defluorinating agent by atomization and rotate and add magnetic powder into the pre-neutralized wastewater, stir and react to obtain the complexation reaction wastewater; Secondary neutralization and flocculation module: used to receive the complexation reaction wastewater, add alkali solution to adjust the pH to 6 - 7, add a coagulant aid, and then perform laminar flow stirring and static separation of the supernatant.

[0076] The above are all the preferred embodiments of the present application. Without limiting the protection scope of the present application accordingly, therefore: All equivalent changes made according to the structure, shape, and principle of the present application shall be covered within the protection scope of the present application.

Claims

1. A process for recycling and reusing wastewater, characterized in that: It includes the following steps: Primary oxidation: Add acid solution while rotating counterclockwise, stir the wastewater clockwise synchronously, adjust the pH of the wastewater to acidic, then introduce ozone, and react for 15 - 30 minutes to generate primary oxidation wastewater; Premixing and secondary oxidation: It includes the first additive addition step, the second additive addition step, the secondary oxidation step and the detection step; First additive addition: Add ferrous salt solution to the primary oxidation wastewater by reverse stirring, and control the droplet diameter to be 1 - 3 mm; Second additive: According to the set delay duration , atomize and spray hydrogen peroxide solution Secondary oxidation: Apply an alternating magnetic field simultaneously and react for 30 - 45 minutes to obtain secondary oxidation wastewater; Detection: Real - time monitor the pH value of the reaction solution. If pH > 3.5, trigger the acid solution supplementary addition mechanism; Aeration and neutralization: Conduct ozone aeration on the secondary oxidation wastewater, add carbonate to adjust the pH to 5 - 6 to generate pre - neutralized wastewater; Complexation reaction: Synchronously spray the complexing defluorination agent in atomized form into the pre - neutralized wastewater and add magnetic powder by rotation, stir and react for 10 - 20 minutes to obtain complexation reaction wastewater; Secondary neutralization and flocculation: Add alkali solution to the complexation reaction wastewater to adjust the pH to 6 - 7, add a coagulant aid, and then perform laminar flow stirring for 10 - 15 minutes, and let it stand to separate the supernatant.

2. The process for recycling and reusing wastewater according to claim 1, wherein: The premixing and secondary oxidation step also includes: a ratio monitoring step; Ratio monitoring: Monitor Fe 2+ / Fe 3+ ratio. If the proportion of Fe 3+ is greater than 20%, then reduce the hydrogen peroxide spray pressure and increase the magnetic field frequency to the upper limit value.

3. The recycling treatment process for wastewater according to claim 2, characterized in that: In the first additive addition step, stirring is carried out in a turbulent flow manner.

4. The process for recycling and reusing wastewater according to claim 3, characterized in that: In the secondary oxidation step, the frequency of the alternating magnetic field is adjusted based on the results of electrochemical impedance spectroscopy analysis as follows: The impedance spectrum of the wastewater is collected in real time, and the electron transfer rate between Fe 2+ and H2O2 is calculated; if the electron transfer rate is less than the first threshold, the magnetic field frequency is increased, and the magnetic field intensity is synchronously increased; if the electron transfer rate is greater than the second threshold, the magnetic field frequency is decreased to inhibit side reactions.

5. The process for recycling and reusing wastewater according to claim 4, characterized in that: In the complexation reaction step, the addition of magnetic powder is carried out in a rotational addition manner, and a local magnetic field is applied initially during the rotational addition process; according to the magnetic powder dispersion degree, adjust the local magnetic field intensity; and obtain the sedimentation rate of the magnetic powder. If the magnetic powder sedimentation rate is greater than the third threshold, use an acoustic oscillator to assist in dispersion.

6. The process for recycling and treating wastewater according to any one of claims 1-5, characterized in that: In the second additive addition step, the set delay duration is dynamically adjusted through electrochemical noise analysis: Set a reference electrode and a working electrode in the wastewater obtained after the first additive addition step, and collect the current noise signal; if the noise amplitude is greater than the fourth threshold, execute the first adjustment step; First adjustment: Extend the set delay duration, and then execute the second additive addition step according to the extended set delay duration; After the second additive addition step, it also includes a feedback judgment step; Feedback judgment: After the second additive addition step is completed, measure the noise frequency of the wastewater. If the noise frequency is greater than the fifth threshold, execute the feedback step; Feedback: Shorten the set delay duration, update it to the new set delay duration, and increase the atomization pressure.

7. The process for recycling and reusing wastewater according to claim 6, characterized in that: In the first adjustment step, the calculation formula for the set delay duration is: ； In the formula, is the initial delay setting duration, is the fourth threshold, is the maximum allowable noise amplitude, is the actually measured noise amplitude; , and increases according to the increase in the treatment volume of the wastewater or increases according to the increase in the complexity of the wastewater.

8. The process for recycling and reusing wastewater according to claim 2, characterized in that: In the secondary oxidation step, it also includes dynamically adjusting the intensity of the alternating magnetic field and the atomization spray pressure. The intensity of the alternating magnetic field and the atomization spray pressure are coordinately regulated by an edge computing module: Real - time collect the data of the COD degradation rate, H2O2 residual concentration and magnetic field frequency of the wastewater, and input them into a pre - trained neural network model; If the predicted reaction efficiency output by the model is less than 85%, simultaneously increase the magnetic field intensity to the maximum value, the atomization pressure to the maximum value, and reduce the stirring speed by 10% - 20%; If the predicted by - product generation rate output by the model is greater than 15%, trigger the reverse adjustment of the magnetic field frequency and the atomization pressure.

9. The process for recycling and treating wastewater according to claim 6, wherein: The set delay duration and the magnetic field frequency are co-optimized through a coupling algorithm: Establish the empirical formula of where is the proportionality coefficient positively correlated with the wastewater ; If the deviation between the actual COD removal rate and the predicted value of the formula is greater than 10%, the adaptive learning module is triggered to update the value and re - allocate the weights of magnetic field energy and delay time.

10. A system adopting the wastewater recycling and treatment process described in any one of claims 1-9, characterized in that: It includes the following modules: Primary oxidation module: Adjust the acidity of the wastewater and introduce ozone for primary oxidation; Premixing and secondary oxidation module: It is used to receive the primary oxidation wastewater produced by the primary oxidation module, add and mix ferrous salt solution, then add hydrogen peroxide, and apply an alternating magnetic field for secondary oxidation. During the oxidation process, the pH value is monitored and acid solution is added for supplementation; Aeration and neutralization module: It is used to receive the secondary oxidation wastewater produced by the premixing and secondary oxidation module, perform ozone aeration on the secondary oxidation wastewater, add carbonate to adjust the pH to 5-6, and generate pre-neutralized wastewater; Complexation reaction module: It is used to receive the pre-neutralized wastewater produced by the aeration and neutralization module, atomize and spray the complexing defluorinating agent into the pre-neutralized wastewater synchronously and rotate to add magnetic powder, stir and react to produce complexation reaction wastewater; Secondary neutralization and flocculation module: It is used to receive the complexation reaction wastewater, add alkali solution to the complexation reaction wastewater to adjust the pH to 6-7, add a coagulant aid, and then stir in laminar flow and let it stand to separate the supernatant.

Images