Filtrate fenton treatment process based on water pollution prevention and control agent

Abstract

The present application relates to the technical field of water treatment, and discloses a leachate Fenton treatment process based on a water pollution prevention and control agent, which comprises the following steps: adding a composite catalytic agent composed of an iron-based component and a copper graphite component to leachate, adding an oxidizing agent in a pulse mode and monitoring an oxidation-reduction potential response curve, calculating an instantaneous reaction factor according to the integral area of the curve, adjusting a dosing delay interval and a pump output frequency according to the comparison result of the instantaneous reaction factor and a preset limit value, controlling a fluid shear force generated by a reaction circulating pump in the delay interval, and washing and peeling a passivation layer on the surface of the agent, the present application realizes physical synchronization of agent injection and organic load degradation by dynamically adjusting the dosing frequency, inhibits free radical self-quenching and reduces chemical sludge generation, simultaneously identifies and compensates for the alkalinity of the leachate by using the potential signal characteristics, maintains the stability of the catalytic environment, and improves the leachate treatment efficiency.

Description

Technical Field

[0001] This invention relates to a Fenton process for leachate treatment based on water pollution control agents, belonging to the field of water treatment technology. Background Technology

[0002] The current Fenton-like process generates hydroxyl radicals with strong oxidizing properties through the synergistic effect of reagents, thereby achieving chain breaking of recalcitrant macromolecular organic matter. This is the mainstream method to ensure that the discharge indicators meet the standards. However, leachate has high salt content and strong buffering properties, which leads to nonlinear degradation kinetics. The density of free radicals when the oxidizing agent is injected can easily exceed the system's capacity, inducing a self-quenching reaction that converts chemical energy into chemical sludge and heat energy. Existing online chemical oxygen demand (COD) analyzers or constant ratio dosing methods are limited by physical fouling at the sampling end and the response lag of monitoring data, making it impossible to achieve physical synchronization between the supply intensity of the oxidizing agent and the degradation rate.

[0003] Linear improvements such as increasing the number of sensors or increasing the total dosage not only fail to improve removal efficiency due to reagent self-consumption, but also increase operating costs and solid waste disposal burden. Relying solely on steady-state feedback signals makes it difficult to identify pseudo-steady states caused by strong buffering systems, and it cannot solve the problem of multiphase interface passivation on the catalytic carrier surface. For example, Chinese invention patent CN102849839A discloses a method for determining the dosage of reagents for treating restaurant grease wastewater using a Fenton-like process. Laboratory single-factor experiments are used to plot removal rate curves and calibrate the reagent dosage ratio. However, in leachate treatment practice, this static calibration method reveals significant shortcomings: it is essentially an offline empirical model, unable to perceive instantaneous fluctuations in leachate organic load, resulting in a phase difference between the dosing command and actual reaction requirements; the empirical ratio is difficult to identify pseudo-steady states under strong buffering systems, and injection can induce excessively high local concentrations, leading to free radical self-quenching and the generation of excessive chemical sludge; ignoring the passivation and embedding of multiphase catalytic interfaces during operation causes the optimal values ​​obtained in experiments to drift rapidly during continuous operation, making it difficult for the system to maintain stable high catalytic activity.

[0004] Therefore, how to construct a control mechanism that can identify the degradation rate and dynamically adjust the supply energy level so that the redox reaction is maintained within the optimal chemical potential energy gradient is the technical problem to be solved by this invention. Summary of the Invention

[0005] To address the problems mentioned in the background art, the technical solution of the present invention is as follows: A Fenton-type leachate treatment process based on water pollution control agents, comprising the following steps:

[0006] Step S1: Add a composite catalyst to the leachate to be treated. The composite catalyst includes an iron-based catalyst component and a copper-graphite co-catalyst component to form a heterogeneous catalytic oxidation system in the leachate to be treated.

[0007] Step S2 involves pulse-dosing of hydrogen peroxide into the leachate to be treated. During each pulse dosing, a redox potential sensor is used to maintain a concentration of at least [value missing]. The sampling frequency was used to monitor the redox potential response curve of the reaction system;

[0008] Step S3: Using the redox potential value before the start of a single pulse injection as a baseline, calculate the integral area of ​​the redox potential response curve relative to the baseline during the duration of the single pulse injection and the subsequent reaction lag period. The reaction lag period continues until the slope of the redox potential response curve returns to the slope of the baseline. Calculate the ratio of the integral area to the duration of the single pulse injection to obtain the instantaneous reaction factor.

[0009] Step S4: The instantaneous reaction factor is compared with the preset free radical self-quenching limit to identify the local accumulation state of the oxidizing agent in the leachate to be treated.

[0010] Step S5: Adjust the delay interval of the dosing pulse and the frequency of the dosing pump according to the comparison results so that the dosing frequency matches the consumption rate of the organic load of the leachate. Within the delay interval, control the reaction circulation pump to increase its operating power to generate fluid shear force, and use the fluid shear force to flush and peel off the passivation layer generated on the surface of the composite catalyst.

[0011] Preferably, in step S3, the transient response factor The calculation formula is: ,in, For the integral area, This refers to the duration of a single pulse application.

[0012] Preferably, in step S5, if the instantaneous reaction factor If the self-quenching limit of free radicals is exceeded, the diffusion time of the reagent in the reaction system is prolonged by increasing the delay interval and reducing the frequency of the dosing pump, thereby inhibiting the self-consumption side reaction of the oxidizing agent.

[0013] Preferably, in step S3, the monitoring time of the redox potential response curve is... to With a single pulse application time that is times longer than that of the standard, the sampling accuracy of the redox potential sensor is no less than [a certain value]. .

[0014] Preferably, the method further includes a step of neutralizing the alkalinity of the leachate using a delay interval, specifically: extracting the time constant of the redox potential response curve from the peak to the baseline slope; if the time constant is greater than a preset buffer release threshold, then extending the delay interval to allow the reaction system to recover to the preset potential reaction window using its own acid-base reaction environment.

[0015] Preferably, in step S1, the mass fraction of the copper-graphite co-catalyst component is: to The graphite component consists of multilayer flexible graphite sheets, which are used to perform interlayer micro-exfoliation under the action of fluid shear force to expose the electron conduction interface and promote the reduction conversion of ferric iron to ferrous iron.

[0016] Preferably, in step S2, the duration of a single pulse application is... to In step S5, the adjustment step size of the delay interval is... Satisfy the following formula: ,in, This is the proportionality coefficient. This is the limit for free radical self-quenching.

[0017] Preferably, the particle size of the composite catalyst is [missing value]. to In step S5, the local turbulence intensity within the reactor is increased by utilizing fluid shear force. above.

[0018] Preferably, it also includes an online self-cleaning step for the sensor probe, that is, within a delay interval, the reaction circulation pump is controlled to generate tangential flushing fluid to act on the probe surface of the redox potential sensor in order to remove the scale layer on the probe surface.

[0019] Preferably, in step S4, if the continuous Instantaneous response factor within each pulse cycle If all values ​​are below the preset minimum reaction threshold, the system will automatically reduce the influent flow rate of the leachate to be treated.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. In the Fenton process for leachate treatment, the dosing delay interval is dynamically adjusted by collecting the rate of change of the redox potential signal. This allows the injection frequency of the oxidant to be physically synchronized with the real-time degradation rate of organic components in the leachate. By feeding back the slope of the redox potential signal, the kinetic plateau period of the reaction system is captured, effectively suppressing the free radical self-quenching reaction induced by the instantaneous local high concentration of the oxidant in the complex matrix, reducing the amount of ineffective iron sludge generated, and improving oxidation efficiency.

[0022] 2. The time constant of the redox potential signal returning from the impulse point to the baseline slope is extracted and used to identify and neutralize the strong buffering capacity of the leachate itself. This acidity self-repair mechanism based on signal characteristics enables the reaction system to maintain a stable acid-base catalytic environment without the addition of new physical sensors, eliminates the corrosive effect of the inherent alkalinity of the leachate on the Fenton-like reaction environment, avoids the failure of catalytic centers due to acidity drift, and ensures that the redox reaction continues within the optimal potential window.

[0023] 3. By using the delay interval of pulse dosing as a functional switching point, the reaction circulation pump is guided to generate instantaneous hydraulic impact, which, together with the interfacial pulse of the catalytic component, strips the adsorption film on the surface of the support. By utilizing the fragmented time of the process sequence, the microscopic impact force generated by physical shearing and interfacial micro-reactions is used to achieve in-situ regeneration of the active sites on the surface of the catalytic agent, eliminate the entrapment effect of complex matrix on the catalyst, significantly extend the service life of the composite agent and maintain the stability of the multiphase catalytic efficiency. Attached Figure Description

[0024] Figure 1 This is a flow chart of the Fenton treatment process for leachate based on the instantaneous response factor feedback of this invention;

[0025] Figure 2 This is a schematic diagram illustrating the interaction between the adaptive adjustment strategy for process parameters and system components of the present invention. Detailed Implementation

[0026] The present invention will be described below through specific embodiments. It should be understood that the following embodiments are intended to explain the present invention and not to limit the scope of protection of the present invention.

[0027] The Fenton-like treatment process for leachate based on water pollution control agents provided by this invention consists of a composite catalyst dosing stage, a potential signal monitoring stage, an instantaneous reaction factor calculation stage, and a coordinated adjustment link between the output frequency of the dosing pump and the power of the circulating pump. During system operation, the integral area characterizing the utilization efficiency of free radicals is calculated by collecting the redox potential response curve of the reaction system, and then the instantaneous reaction factor is determined based on the ratio of the integral area to the pulse time. The control unit dynamically adjusts the delay interval between oxidant injection actions according to the deviation of the instantaneous reaction factor from the preset value, and performs in-situ cleaning of the catalytic center using the fluid shear force generated by the circulating pump within the delay interval. In the engineering site of leachate treatment, since the leachate to be treated contains a high concentration of carbonate and bicarbonate buffer system, the traditional constant dosing method is prone to causing local accumulation of oxidant, resulting in self-quenching reaction and the generation of a large amount of chemical sludge.

[0028] To address this challenge, the present invention employs the following procedure: Step S1 involves adding a composite catalytic agent to the leachate to be treated; the composite catalytic agent comprises an iron-based catalytic component and a copper-graphite co-catalytic component, forming a heterogeneous catalytic oxidation system within the leachate; wherein the mass fraction of the copper-graphite co-catalytic component is... to The graphite component consists of multilayer flexible graphite sheets, which undergo interlayer micro-exfoliation under the fluid shear force generated in subsequent steps to expose the electron conduction interface and promote the reduction conversion of ferric iron to ferrous iron. To improve the electron transfer efficiency of the composite catalyst in the ferric iron reduction process, the multilayer flexible graphite sheets in the copper-graphite co-catalyst component form a heterogeneous interface with a micro-battery effect with copper. The degree of interlayer exfoliation of the multilayer flexible graphite sheets is adjusted by regulating the tangential velocity of the impeller of the reaction circulation pump. When the fluid shear force overcomes the van der Waals forces between the graphite layers, the interlayer spacing changes from the initial... Expansion to The above exposes electron conduction sites with high specific surface area, thereby reducing the energy barrier in the electron transfer process and accelerating the process. Towards In-situ regeneration maintains the active centers within the system at a high kinetic energy level, establishing the variable frequency output frequency of the circulating pump. With impeller tangential velocity Mapping function Calculate fluid shear stress The critical shear strength was determined based on the graphite interlayer exfoliation energy level gradient experiment. Maintain at to The control unit compares the current turbulence intensity with the target value in real time. ,trigger The regulating circuit dynamically compensates for the pump output power to ensure the local Reynolds number. In the forced convection region, microscopic impact loads are used to disable the van der Waals forces between the layers of multilayer flexible graphite sheets, and the fluid dynamic viscosity is monitored online. With shearing time Attenuation rate, and fitting calculation of graphite component interface exposure rate ,when Below the rated value It automatically increases the output frequency of the circulating pump to an overclocking condition to perform in-situ regeneration.

[0029] Step S2 involves pulse-dosing of hydrogen peroxide into the leachate to be treated; during each pulse dosing, a redox potential sensor is used to maintain a concentration of at least [value missing]. The sampling frequency is used to monitor the redox potential response curve of the reaction system; then, step S3 is executed to calculate the energy efficiency parameters within a single pulse cycle; using the redox potential value before the start of the single pulse injection as a baseline, the integral area of ​​the redox potential response curve relative to the baseline is calculated during the single pulse injection duration and the subsequent reaction lag period; the reaction lag period continues until the slope of the redox potential response curve returns to the slope of the baseline; the ratio of the integral area to the single pulse injection duration is calculated to obtain the instantaneous reaction factor. The specific algorithm path is as follows: instantaneous response factor The calculation formula is: ,in: The instantaneous response factor is expressed in units of 1000 kJ / m². ; The integral area is expressed in units of 1000 ppm. ; The duration of a single pulse application is expressed in units of... In this step, the monitoring time for the redox potential response curve is set to... to Double the duration of a single pulse injection The sampling accuracy of the redox potential sensor needs to reach [a certain level]. ; Perform step S4 to convert the transient response factor With respect to the preset free radical self-quenching limit A comparison is performed; the local accumulation state of the oxidizing agent in the leachate to be treated is determined in advance through Fenton-like reaction kinetic tests on specific water quality.

[0030] Finally, step S5 is executed to adjust the delay interval of the dosing pulse based on the comparison results. And the variable frequency output frequency of the dosing pump; if the instantaneous reaction factor Exceeding the free radical self-quenching limit This indicates that the oxidant supply rate exceeds the degradation rate of organic matter; the system increases the delay interval. This also reduces the frequency of the dosing pump's variable frequency output, prolongs the diffusion time of the reagent in the reaction system, and suppresses the self-consumption side reaction of the oxidizing agent; the adjustment step size of the delay interval... Satisfy the following formula: ,in: The adjustment increment for the delay interval, in units of ; This is a proportionality coefficient, which is calibrated based on the ratio of the reactor's effective volume to the processing flow rate; This represents the limit for free radical self-quenching, in units of... The system calibration procedure was initiated, and the total mixing time of the reactor was determined using the conductivity tracer method. Record the physical lag time between the dosing pump command being issued and the sensor response. Combined with effective volume With rated circulating flow Calculate the hydraulic cycle period According to the linear weighting formula Determine the proportionality coefficient, including the correlation coefficient. Range of values to During the calibration process, the change in the slope of the redox potential was monitored through a hydrogen peroxide step response experiment. Once the region is determined to be in the saturation zone, the corresponding instantaneous response factor is extracted and calculated. Initial value, established based on Inlet load gradient Dynamic lookup tables compensate for differences in the background reducibility of leachate at different landfill ages; during delay intervals Inside, the system controls the reaction circulation pump to increase operating power, generating fluid shear force; this fluid shear force is used to flush away and peel off the iron sludge passivation layer formed on the surface of the composite catalyst, thereby increasing the intensity of local turbulence within the reactor. The above describes the process of extracting the time constant from the peak to the baseline slope of the redox potential response curve. If the time constant is greater than the preset buffer release threshold, it indicates that the acidity of the system is being consumed too quickly. This can be addressed by extending the delay interval. The reaction system utilizes its own acid production process to restore the potential to a preset reaction window; the composite catalyst used in this invention has a particle size range set within... to During the delay interval, the control reaction circulation pump generates tangential flushing fluid, which acts on the probe surface of the redox potential sensor to remove the surface scale layer; if continuous Instantaneous response factor within each pulse cycle If all values ​​are below the preset minimum reaction threshold, the system determines that the organic matter concentration has dropped to the deep treatment endpoint and automatically reduces the influent flow rate of the leachate to be treated or stops the dosing action.

[0031] Example 1: In a deep treatment engineering scenario for leachate with high salt and high organic loading characteristics, when the carbonate alkalinity of the leachate to be treated is... to When the organic load in the influent fluctuates instantaneously within a certain range, the system's strong buffering capacity can cause localized damage from the instantaneous addition of oxidant. The ripple effect causes the hydrogen peroxide agent to undergo a free radical self-quenching reaction before reacting with the target organic matter, resulting in excessive chemical sludge. The degradation kinetics are stabilized by executing the heterogeneous catalytic oxidation procedure described in the aforementioned specific implementation method. The system is fed with an iron-based catalytic component and a mass fraction of... The composite catalyst, premixed with copper-graphite co-catalyst components, utilizes the momentum provided by a reaction circulation pump to form a uniform fluidized bed within the reactor, and controls the dosing pump to deliver the catalyst in single-pulse dosing. Inject hydrogen peroxide reagent, and use a sampling frequency of The redox potential sensor collects potential response data, and the control unit determines the duration of each pulse application. and the area of ​​the redox potential response curve during the subsequent reaction lag period. According to the formula The current instantaneous response factor is calculated. This factor is used to quantitatively characterize the degree of matching between the current oxidant supply level and the leachate's organic load accepting capacity. When the calculated... Greater than the preset free radical self-quenching limit When this is determined, it indicates that the oxidant has accumulated locally within the reactor, and the control unit determines the situation according to the formula. Determine the adjustment increment for the delay interval. And correspondingly extend the delay interval between subsequent drug administration actions. Synchronously, commands are sent to the dosing pump to reduce the frequency of the variable frequency output, so that the release pace of the oxidation energy level is physically aligned with the consumption rate of reducing substances in the leachate. This feedback-based asynchronous pulse dosing logic changes the traditional total balance thinking and solves the technical contradiction between improving treatment efficiency and self-consumption of reagents through time-series energy level adjustment.

[0032] During the delay interval During the cycle, the system increases the operating power of the reaction circulation pump to ensure that the increase in local turbulence intensity inside the reactor is not less than [amount missing]. By utilizing fluid shear force applied to the surface of a fluidized composite catalyst, the flexible graphite layer undergoes micro-exfoliation to expose the electron conduction interface, and the passivation coating layer adhering to the catalyst surface due to strong buffering effect is washed away. This achieves in-situ regeneration of catalytic active sites, ultimately enabling the same... Under the removal load, the reduction in chemical sludge production reached The above, and the increase in the utilization rate of the oxidizing agent is not less than .

[0033] Example 2: In the engineering verification phase of leachate deep treatment, the carbonate alkalinity of the leachate to be treated reached... Furthermore, in operating conditions containing high concentrations of recalcitrant organic matter, a volume of [missing information] is used. A physical experimental platform was built using a fluidized bed reactor, equipped with a measurement range of... to Sampling frequency is And the resolution is better than A redox potential sensor is used to acquire electrochemical signals in the reaction system in real time. To simulate signal fluctuations under real industrial electromagnetic environments, a signal-to-noise ratio of [value missing] is actively superimposed at the signal input end of the redox potential sensor. Gaussian white noise; the preparation process of the composite catalyst is as follows, selecting a purity of not less than Ferrous sulfate, as an iron-based catalytic component, is present in the following mass percentages: The iron-based catalytic component and its mass percentage are as follows: The copper-graphite co-catalyst components were formulated in a specific ratio, wherein the copper-graphite co-catalyst components comprised multilayer flexible graphite sheets. The above components were then placed in a rotation speed set to... Dry blending is performed in a ball mill for a duration of [duration missing]. Particles with a size distribution of [missing information] were selected through grading and screening. to The particles within the specified range are used as the final product. This particle size setting aims to balance the suspension stability of the agent in the fluid with the active surface area per unit mass. The experiment included an experimental group, control group 1, control group 2, and control group 3. The experimental group followed the adaptive pulse dosing procedure described in the aforementioned specific implementation method. Control group 1 used a constant ratio dosing method. Control group 2 removed the copper-graphite co-catalyst component from the composite catalyst. Control group 3 used the instantaneous reaction factor... Set at the upper limit of the preset limit Overload injection is performed; the duration of a single pulse injection is [number missing]. In terms of its design, the decision-making logic is based on the relationship between system viscosity and mass transfer rate. When the internal circulation flow rate of the reactor is detected to be lower than the preset calibration value, the duration of a single pulse injection is adjusted. The value should be set closer to the lower limit of its range to prevent free radicals from undergoing self-quenching reactions in local areas.

[0034] Table 1: Comparison of performance of different experimental groups in treating high-alkalinity leachate

[0035]

[0036] Referring to Table 1, under the same initial water quality conditions, the experimental group The removal rate was improved compared to control group 1. Furthermore, the production of iron sludge decreased. By comparing the data of the experimental group and the control group 2, it can be seen that without the copper-graphite co-catalyst component, the transient reaction factor is reduced due to the lack of an electron conduction interface to promote iron ion cycling. Descending to This resulted in the inability to effectively release degradation efficiency, confirming the synergistic effect of iron-based components and copper-graphite components in improving the utilization rate of hydroxyl radicals; the data of control group 3 showed a clear performance inflection point, when the transient reaction factor achieve In a supersaturated state, The removal rate did not increase linearly with the dosage of the reagent; instead, due to the ineffective decomposition of hydrogen peroxide in a strong buffer system, the amount of chemical sludge increased sharply. During the experiment, the control unit followed the formula... Real-time calculation of instantaneous response factors, among which The instantaneous response factor is expressed in units of 1000 kJ / m². , The integral area of ​​the redox potential response curve relative to the reference potential is given in units of 1000 m² / m². , The duration of a single pulse application is expressed in units of... When measured When the preset limit is exceeded, the system uses a formula to... Calculate the adjustment amount for the delay interval, where To adjust the increment, the unit is... , This is a proportionality coefficient, which is calibrated based on the effective volume of the reactor. , The preset free radical self-quenching limit was set; monitoring data showed that the dynamic stretching delay interval... The potential fluctuation curve inside the reaction system gradually converges to the preset stable range, proving the stability of the process under conditions of severe load fluctuations.

[0037] Example 3: This example combines Figures 1 to 2 The Fenton process for leachate treatment based on water pollution control agents is described below. Figure 1 As shown, a composite catalyst containing iron-based catalytic components and copper-graphite co-catalytic components is added to the leachate to be treated, forming a heterogeneous catalytic oxidation system within the leachate. Hydrogen peroxide is then added to the leachate in a pulsed manner. During the duration of each pulse addition, the redox potential response curve is monitored using a redox potential sensor at a sampling frequency of at least 10 Hz. Immediately afterward, using the redox potential value before the start of the single pulse addition as a benchmark, the integral area of ​​the response curve during the single pulse addition duration and the reaction lag period, and its ratio to the addition duration, are calculated to obtain the instantaneous reaction factor. This instantaneous reaction factor is then compared with a preset free radical self-quenching limit to identify the local accumulation state of the oxidant in the leachate. Finally, based on the comparison results, the pulse delay interval and the frequency converter output frequency of the addition pump are adjusted. During the delay interval, the operating power of the reaction circulation pump is increased to generate fluid shear force, thereby flushing and stripping the passivation layer formed on the surface of the composite catalyst.

[0038] like Figure 2 As shown, the process operator sets the reaction threshold. With k, and control the pulsed addition of hydrogen peroxide, the system synchronously monitors the ORP response curve with a sampling frequency of 10Hz, and according to the formula Calculate the instantaneous response factor; when the judgment condition is... > Upon establishment, the system automatically adjusts including The dosing strategy, including pump frequency, includes performing a surface regeneration step, utilizing fluid shear force, and a sensor probe self-cleaning step. In addition, the system judges the time constant, and if the time constant is greater than the threshold, it uses a delay interval to neutralize the alkalinity of the leachate. The entire process involves signal interaction and control with sensors and actuators, including ORP, pumps, and valves.

[0039] Example 4: In a processing scale of At the leachate treatment project site, in response to the parameter initialization requirements during the initial startup of the reaction system, a system operation parameter calibration procedure is established to determine the logical criteria for subsequent adjustment processes. Specifically, this includes determining the free radical self-quenching limit. and proportionality coefficient After the leachate to be treated is injected into the system and reaches the design water level, the reaction circulation pump is started to adjust the fluid in the reactor to a steady-state circulation. At this time, the composite catalyst is added to the system in a single injection. The first stage of the calibration procedure is to perform a step response test, controlling the dosing pump to continuously inject a mass percentage of the catalyst at a constant flow rate. Hydrogen peroxide was injected, and the system's potential change trajectory was recorded using a redox potential sensor. As hydrogen peroxide was continuously injected, the rising slope of the redox potential response curve gradually decreased. When the redox potential response curve entered the saturation region and the instantaneous slope was observed to be below a certain value... At that time, the potential integral parameter corresponding to the starting point of the saturation interval is extracted, and the free radical self-quenching limit under the current operating condition is determined according to the instantaneous reaction factor calculation logic. for .

[0040] The second stage of the calibration procedure is to calculate the proportional coefficient. Used to define the timing compensation step size corresponding to a unit potential deviation; used to measure the effective volume of the reactor. for And the circulating flow rate of the reaction circulation pump at rated power. for ( The hydraulic circulation period is calculated, and then a weighted sum is made of the hydraulic circulation period and the physical lag time from receiving the command to the stable flow output of the dosing pump. The proportionality coefficient is then calibrated based on this sum. for After the system enters the operational phase, in response to potential anomalies caused by fluctuations in the influent organic load, the system executes feedback logic based on the aforementioned calibration parameters; when the redox potential sensor collects data, it calculates the instantaneous response factor. achieve At this time, the control unit determines that the oxidant is in a state of local supersaturation, and the system determines the appropriate action based on the calibrated proportional coefficient. Calculate the adjustment increment of the delay interval Specifically, the adjustment increment of the delay interval Satisfy the following formula: ,in: The adjustment increment for the delay interval, in units of ; The measured instantaneous response factor is expressed in units of [missing information]. ; The value here represents the limit for free radical self-quenching. In this running example, the calculation is as follows: for The system uses this to determine the delay interval for the current period. Add to the original By extending the timing step of reagent injection, excess hydroxyl radicals are brought into full contact with organic matter in the leachate under the influence of fluid. To maintain the activity of heterogeneous catalytic centers, during the delay interval... During the cycle, the frequency converter drives the reaction circulation pump to increase the operating frequency. When the local turbulence intensity inside the reactor increases to During this process, the surface of the composite catalyst in a fluidized state is subjected to fluid erosion. Electron microscopy revealed a microscopic expansion of the interlayer spacing of the multilayer flexible graphite sheets in the composite catalyst, exposing the electron conduction interface and removing the passivation layer on the catalyst surface. Under this operating mechanism, the instantaneous reaction factor in subsequent pulse dosing cycles... When the alkalinity of the influent falls back to the stable range of the calibrated value, the system faces fluctuations in influent alkalinity of [value missing]. When there is interference, the water output The standard deviation of the indicator's volatility remained at Within.

[0041] Example 5: In a leachate treatment scenario, when the organic load of the leachate shifts with the age of the landfill, the system uses an offline calibration method based on redox response kinetics to determine the core control parameters. The leachate sample to be treated is placed in a test container with a constant flow field intensity, and reagents are added in stages. A redox potential sensor monitors the potential response curve. The derivative of the potential response curve with respect to the addition time is used to determine the optimal parameters. When the temperature drops to the preset saturation threshold, the system is determined to have reached the upper limit of oxidation acceptance under the current water quality background. The instantaneous reaction factor calculated at this point is taken as the free radical self-quenching limit under this operating condition. ,in The instantaneous response factor is the rate of change with the addition time, in units of... , The unit is the time of application. , This represents the limit for free radical self-quenching, in units of... It is used to identify the buffer capacity of leachate at different treatment stages, so that the control unit can retrieve the pulse interval adjustment reference that matches the influent water quality.

[0042] When the morphology of the composite catalyst fluctuates due to batch variations, a catalyst activity verification method based on shear response characteristics is used to determine the exposure rate of catalytic sites. The composite catalyst batch to be verified is injected into the standard percolate test solution, and the operating frequency of the reaction circulation pump is adjusted to increase the local turbulence intensity inside the reactor to a certain level. The above describes the monitoring of fluid dynamic viscosity. With shearing time The decay curve, in which Fluid dynamic viscosity, in units of , Shearing time, in units of If the fluid dynamic viscosity If the interlayer ablation characteristics of the multilayer flexible graphite sheets exhibit a non-linear decreasing trend within the preset shearing period, then the interlayer ablation energy level of this batch of reagents is determined to meet the preset specifications, and the hydrodynamic viscosity is... The rate of change is used to characterize the causal relationship between reagent flow regime and interlayer active site exposure rate, compensate for deviations in the raw material preparation process, and ensure that the standard deviation of effluent chemical oxygen demand fluctuation remains within a certain range after the catalyst is replaced. Within.

[0043] Example 6: In the treatment of carbonates with an alkalinity of Under leachate conditions, the system determines the buffer release threshold characterizing acid-base balance fluctuations by executing a pre-calibration procedure. Specifically, this includes injecting a leachate sample into a container equipped with a potential monitoring unit, controlling the dosing pump to perform a single-pulse injection, and utilizing a sampling frequency of [missing information]. The redox potential sensor records the potential response curve from the peak potential. Return to initial reference potential The control unit extracts the recovery time constant based on the decay envelope of the potential response curve, according to the decay trajectory. The calculation formula is as follows: ,in: The potential recovery time constant is expressed in units of 1000 m / s. ; The peak potential after the pulse, in units of ; The reference potential before the pulse, in units of ; The average voltage change rate during the recovery phase, in units of The system will use the response time constant obtained from multiple repeated experiments. The arithmetic mean was set as the buffer release threshold; when the alkalinity of the influent to the leachate to be treated increased to a certain extent... When the measured response time constant of the current period is detected to reach a certain value, the system initiates timing compensation logic based on the response time constant. And exceeds the preset buffer release threshold. At that time, the system will adjust the delay interval of the drug delivery pulse. Extended based on the previous cycle The increased interval is used to neutralize excess alkalinity in situ using the acidity generated by the hydrolysis of iron ions during the Fenton-like reaction, until continuous... The measured response time constant for each cycle has fallen back to within the buffer release threshold.

[0044] Under the action of this regulatory mechanism, the local area inside the reactor... The fluctuation range is from Units converge to Within a few units, the carbonate precipitation adhesion rate on the surface of the composite catalyst decreased. The above, under the continuous alkalinity shock During operation, the chemical oxygen demand removal rate remained at The above; with a processing capacity of In pilot-scale application scenarios, the system executes actions targeting the duration of a single pulse application. The flow field adaptation procedure calculates the total mixing time of the reactor at the current rated circulation flow rate by injecting a conductivity tracer into the reactor and monitoring its conductivity response curve in the circulation loop. The duration of a single pulse injection is set based on the accepting capacity of the oxidation energy level. satisfy Proportional constraints, in handling mass concentration is When dealing with high-salt permeate, the total mixing time is increased. for Corresponding single pulse application duration Set as The detected transient response factor Stable at to Within the specified range, dynamic matching between the instantaneous energy level release rate of the agent and the mixing rate of the flow field was achieved.

[0045] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A Fenton-type leachate treatment process based on water pollution control agents, characterized in that, Includes the following steps: Step S1: Add a composite catalyst to the leachate to be treated. The composite catalyst includes an iron-based catalyst component and a copper-graphite co-catalyst component to form a heterogeneous catalytic oxidation system in the leachate to be treated. Step S2 involves pulse-dosing of hydrogen peroxide into the leachate to be treated. During each pulse dosing, a redox potential sensor is used to maintain a concentration of at least [value missing]. The sampling frequency was used to monitor the redox potential response curve of the reaction system; Step S3: Using the redox potential value before the start of a single pulse injection as a baseline, calculate the integral area of ​​the redox potential response curve relative to the baseline during the duration of the single pulse injection and the subsequent reaction lag period. The reaction lag period continues until the slope of the redox potential response curve returns to the slope of the baseline. Calculate the ratio of the integral area to the duration of the single pulse injection to obtain the instantaneous reaction factor. Step S4: The instantaneous reaction factor is compared with the preset free radical self-quenching limit to identify the local accumulation state of the oxidizing agent in the leachate to be treated. Step S5: Adjust the delay interval of the dosing pulse and the frequency of the dosing pump according to the comparison results so that the dosing frequency matches the consumption rate of the organic load of the leachate. Within the delay interval, control the reaction circulation pump to increase its operating power to generate fluid shear force, and use the fluid shear force to flush and peel off the passivation layer generated on the surface of the composite catalyst.

2. The Fenton process for leachate treatment based on water pollution control agents according to claim 1, characterized in that, In step S3, the instantaneous response factor The calculation formula is: ,in, For the integral area, This refers to the duration of a single pulse application.

3. The Fenton process for leachate treatment based on water pollution control agents according to claim 2, characterized in that, In step S5, if the instantaneous reaction factor If the free radical self-quenching limit is exceeded, the diffusion time of the reagent in the reaction system is extended by increasing the delay interval and reducing the frequency of the dosing pump.

4. The Fenton process for leachate treatment based on water pollution control agents according to claim 1, characterized in that, In step S3, the monitoring time for the redox potential response curve is... to With a single pulse application time that is times longer than that of the standard, the sampling accuracy of the redox potential sensor is no less than [a certain value]. .

5. The Fenton process for leachate treatment based on water pollution control agents according to claim 1, characterized in that, It also includes a step of neutralizing the alkalinity of the leachate by using a delay interval, specifically: extracting the time constant of the redox potential response curve from the peak to the baseline slope; if the time constant is greater than the preset buffer release threshold, then extending the delay interval allows the reaction system to recover to the preset potential reaction window by utilizing its own acid-base reaction environment.

6. The Fenton process for leachate treatment based on water pollution control agents according to claim 1, characterized in that, In step S1, the mass fraction of the copper-graphite co-catalyst component is: to The graphite component consists of multilayer flexible graphite sheets, which are used to perform interlayer micro-exfoliation under the action of fluid shear force to expose the electron conduction interface and promote the reduction conversion of ferric iron to ferrous iron.

7. The Fenton process for leachate treatment based on water pollution control agents according to claim 2, characterized in that, In step S2, the duration of a single pulse application is to ; In step S5, the adjustment step size of the delay interval Satisfy the following formula: ,in, This is the proportionality coefficient. This is the limit for free radical self-quenching.

8. The Fenton process for leachate treatment based on water pollution control agents according to claim 1, characterized in that, The particle size of the composite catalyst is to In step S5, the local turbulence intensity within the reactor is increased by utilizing fluid shear force. above.

9. The Fenton process for leachate treatment based on water pollution control agents according to claim 1, characterized in that, It also includes an online self-cleaning step for the sensor probe, which involves controlling the reaction circulation pump to generate tangential flushing fluid to act on the probe surface of the redox potential sensor during a delay interval, in order to remove the scale layer on the probe surface.

10. The Fenton process for leachate treatment based on water pollution control agents according to claim 2, characterized in that, In step S4, if continuous Instantaneous response factor within each pulse cycle If all values ​​are below the preset minimum reaction threshold, the system will automatically reduce the influent flow rate of the leachate to be treated.

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