Numerical simulation method for degrading metal-organic complex through dielectric barrier discharge

Abstract

The invention relates to the technical field of pollutant treatment, in particular to a numerical simulation method for degrading a metal-organic complex through dielectric barrier discharge. According to the method, a high-fidelity numerical model which is equivalent to a dielectric barrier discharge degradation metal-organic complex system is constructed, virtual deduction is carried out on experimental parameters, the response rule of main control parameters is disclosed, high-efficiency proceeding of subsequent experiments is guided, repeatability and blindness of parameter screening in an experimental method are overcome, and the method has the advantages of being high in repeatability and high in repeatability. The parameter optimization period is shortened; and by combining an optimized parameter change rule and a dielectric barrier discharge technology, efficient removal of the metal-organic complex is realized, more efficient mine wastewater treatment is facilitated, living environment pollution is reduced, and sustainable development is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of pollutant treatment, and in particular to a numerical simulation method for degradation of metal-organic complexes by dielectric barrier discharge. Background Art

[0002] Hydroxamic acid collectors often remain in tailings ponds due to differences in ore deposit characteristics and flotation processes. This type of organic matter easily forms a strong complex system in a mining environment containing metal ions, which significantly increases the difficulty of pollutant removal. Hydroxamic acid collectors represented by salicylic acid (SHA) occupy an important position in the mineral processing industry due to their efficient collection performance for rare earth minerals, lead oxide ores, cassiterite ores, etc. The highly electronegative hydroxamic acid group and the spatial site of the lone pair electron in its molecule give it the ability to form a stable coordination structure with a variety of metal ions, especially with Fe 3+ It should be noted that metal organic complexes not only interfere with heavy metal concentration monitoring, but also cause compound harm to mining area ecology and human health by changing toxicity thresholds and bioavailability.

[0003] Dielectric Barrier Discharge (DBD) technology has been used to treat wastewater containing hydroxamic acid collectors. For example, patent documents with publication numbers CN116573724A and CN118976347A both disclose this technology.

[0004] Extensive research has been conducted on the removal of complexed heavy metals, but existing technologies still have limitations. For example, experimental studies, constrained by the multidimensional nature of parameter space and nonlinear response characteristics, require researchers to conduct multi-parameter combination experiments and approach the optimal solution through trial and error. This empirical trial-and-error approach has the inherent drawback of low computational efficiency. Summary of the Invention

[0005] Based on this, the present invention provides a numerical simulation method for degradation of metal-organic complexes by dielectric barrier discharge, which at least solves one problem in the prior art.

[0006] In a first aspect, the present invention provides a numerical simulation method for the degradation of metal-organic complexes by dielectric barrier discharge, comprising the following steps: Acquire a data set of dielectric barrier discharge degradation of metal-organic complexes, wherein the data set includes active species data, physical and chemical process data of the active species, and time and reduced field strength data of the dielectric barrier discharge degradation of metal-organic complexes experimental process; Based on the electron impact reaction data in the physical and chemical process data of active species, the species particle data of BOLSIG+ is calculated; A numerical model was established based on the above dataset and the species particle data of BOLSIG+; The time and reduced field intensity parameters to be simulated and the discharge atmosphere parameters to be simulated are input into the numerical model, and the numerical model outputs simulation result data.

[0007] In some optional embodiments, the physical and chemical process data of the above-mentioned active species include reaction types and reaction rate data, wherein the reaction types include electron impact reactions (electron impact excitation, electron impact ionization, electron impact attachment, electron impact dissociation), vibrational energy level conversion, ion / neutral reactions (electron-ion recombination, ion-neutral collision, ion-ion recombination, ion-ion recombination, unimolecular reaction, bimolecular reaction, trimolecular reaction), solution reaction of gas-phase active particles and surface reaction.

[0008] In some optional embodiments, the discharge atmosphere parameters to be simulated may be parameters of dry air, humid air, pure nitrogen, pure oxygen or argon.

[0009] In some optional embodiments, the parameters of the humid air include the ratio of components of the humid air. For example, the parameters of the humid air may be that the volume ratio of nitrogen, oxygen, and water vapor is 79:20:1.

[0010] In some optional embodiments, a numerical model is established by ZDPlaskin software, and the BOLSIG+ species particle data is calculated by the BOLSIG+ solver.

[0011] In some optional embodiments, the above simulation result data include time, gas temperature, electron temperature, electron density, current density, power density, reduced field strength, density of all species, and reaction rate data.

[0012] In a second aspect, the present invention provides an electronic device comprising: at least one processor; and a memory communicatively coupled to the at least one processor; The memory stores instructions, which, when executed by at least one processor, implement the numerical simulation method for dielectric barrier discharge degradation of metal-organic complexes.

[0013] In a third aspect, the present invention provides a computer-readable storage medium storing instructions, which, when executed by a processor, implement the above-mentioned numerical simulation method for dielectric barrier discharge degradation of metal-organic complexes.

[0014] In a fourth aspect, the present invention provides a method for degrading a metal-organic complex by dielectric barrier discharge, comprising the following steps: According to the numerical simulation method of dielectric barrier discharge degradation of metal-organic complex, simulation result data is obtained; Determine the condition parameters for degradation of metal-organic complexes by dielectric barrier discharge based on simulation results; Degradation of wastewater containing metal-organic complexes according to condition parameters.

[0015] In some optional embodiments, the metal-organic complex is a SHA-Fe complex. Preferably, the molar ratio of SHA to Fe in the SHA-Fe complex is 1:1.

[0016] In some optional embodiments, the above-mentioned condition parameters include: the discharge atmosphere is humid air, wherein the volume ratio of H2O in the humid air is 30%; the discharge voltage is 24kV; and the pH value of the wastewater containing the metal-organic complex is 4.

[0017] Due to the adoption of the above technical solution, the embodiments of the present invention have at least the following beneficial effects: By constructing a high-fidelity numerical model that is equivalent to the dielectric barrier discharge degradation system of metal-organic complexes, the experimental parameters are virtually deduced, the response laws of the main control parameters are revealed, and the efficient conduct of subsequent experiments is guided. This overcomes the repetitiveness and blindness of parameter screening in the experimental method and shortens the parameter optimization cycle. Combining the optimization parameter change law with dielectric barrier discharge technology, the efficient removal of metal-organic complexes is achieved, which helps to more efficiently treat mine wastewater, reduce residential environmental pollution, and promote sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The graph shows the change in the concentration of active species over time in an embodiment of the present invention, where (a) is the gas phase and (b) is the liquid phase.

[0019] Figure 2 The graph shows the time-dependent changes in the concentration of active species in different discharge atmospheres according to the embodiments of the present invention, where (a) is the gas phase and (b) is the liquid phase.

[0020] Figure 3 The reaction pathways of different active species in the examples of the present invention are shown, including (a) O3, (b) H2O2, and (c) OH.

[0021] Figure 4 The free radical quenching conditions in the embodiments of the present invention are shown. Among them, (a) TBA quenches •OH; (b) BQ quenches O2 - ; (c) CAT quenches H2O2.

[0022] Figure 5Figure 3 shows the effect of discharge voltage on the degradation performance of metal-organic complexes in embodiments of the present invention. These include: (a) SHA-Fe decomplexation efficiency; (b) change in kinetic constant during SHA-Fe decomplexation; (c) change in power during SHA-Fe decomplexation; (d) energy efficiency; (e) change in ·OH concentration; and (f) SHA degradation efficiency in solution.

[0023] Figure 6 Figure 3 shows the effect of pH on the degradation performance of metal-organic complexes in the examples of the present invention. These include: (a) the hydrolysis equilibrium of a single iron species; (b) the pH dependence of the solution after SHA-Fe complexation; (c) the protonation equilibrium of SHA; (d) the pH change of different SHA-Fe solutions before and after complexation; (e) the change in kinetic constants; and (f) the degradation efficiency.

[0024] Figure 7 The effect of the molar ratio of metal to organic ligand on the degradation performance of metal-organic complexes in the embodiments of the present invention is shown. Among them, (a) the change of SHA-Fe decomplexation efficiency over time; (b) the change of kinetic constant; (c) the change of Fe at different concentrations 3+ Changes in decomplexation efficiency under complexation; (d) Different Fe 3+ The change of hydroxyl concentration after decomplexation for 10 minutes at the same concentration.

[0025] Figure 8 The active sites for decomplexation and degradation of the SHA-Fe complex in an embodiment of the present invention are shown. (a) SHA-Fe molecular orbital; (b) SHA-Fe decomplexation pathway; (c) SHA molecular orbital; (d) SHA electrostatic potential diagram. Red areas represent electron-rich regions with electrophilic activity; blue areas represent electron-deficient regions with nucleophilic activity. DETAILED DESCRIPTION

[0026] The following is a clear and complete description of the concept of the present invention and the technical effects produced, so as to fully explain the purpose, scheme and effects of the present invention.

[0027] In the study of metal-organic complex degradation using dielectric barrier discharge (DBD), traditional discharge experimental methods suffer from repetitive and blind parameter screening. Therefore, embodiments of the present invention provide a numerical simulation method for DBD degradation of metal-organic complexes. According to embodiments of the present invention, a zero-dimensional numerical model is developed to reveal the response patterns of key control parameters and provide guidance for optimizing subsequent experimental parameters. This can conserve experimental resources, efficiently degrade heavy metal-organic complexes, and promote sustainable, green development in the mining industry.

[0028] In order to construct a numerical model, a data set of dielectric barrier discharge degradation of metal-organic complexes is first obtained. In one embodiment, the data set includes data of 97 gas-liquid mixed active species and 920 physical and chemical process data of these active species, as well as time and reduced field strength data of the dielectric barrier discharge degradation of metal-organic complexes experimental process (derived from multiple dielectric barrier discharge degradation of metal-organic complexes in mine wastewater experiments). Among them, the 97 gas-liquid mixed active species are: E, N2, N2 (v = 1, 2, 3, 4, 5, 6, 7, 8), N2 (A3), N2 (B3), N2 (a`1), N2 (C3), N, N ( 2 D)、N( 2 P), N + 、N2 + 、N3 + 、N4 + , O2, O2(v=1, 2, 3, 4), O2(a1), O2(b1), O2(4.5eV), O, O( 1 D), O( 1 S), O3, O + 、O2 + 、O4 + , O - 、O2 - 、O3 - 、NO、N2O、NO2、NO3、NO + 、N2O + 、NO2 + 、NO - 、N2O - 、NO2 - 、NO3 - ,H2O,H2O(v=1,2,3),H2O + 、H3O + 、H2O2、OH、OH + OH - ,H,H + 、H - 、H2 + , H2, H3 + , HO2, HNO3, HNO2, HNO, E aq , O aq , O aq - , O 2aq , O 3aq , O 3aq - 、O(1D) aq OH aq 、H2O aq , HO 2aq 、H2O2aq 、H3O aq + 、H2O aq - 、H2O aq + 、H aq + OH aq - , O 2aq - , HO 2aq - 、H aq 、H 2aq 、NO aq 、NO 2aq 、NO 3aq 、NO 2aq - 、NO 3aq - 、HNO 3aq 、HNO 2aq Active species with parentheses indicate their vibrational energy levels and states. Active species with the aq subscript are liquid-phase species. The 920 physical and chemical processes include electron impact reactions (electron impact excitation, electron impact ionization, electron impact attachment, and electron impact dissociation), vibrational energy level conversions, ion / neutral reactions (electron-ion recombination, ion-neutral collisions, ion-ion recombination, ion-ion recombination, unimolecular reactions, bimolecular reactions, and trimolecular reactions), solubilization reactions of gas-phase active particles, and surface reactions, along with corresponding reaction rate data.

[0029] Based on the data set, a gas-liquid interface numerical model that meets the experimental conditions is established. In one embodiment, the numerical model is implemented using ZDPlaskin software. Specifically, the data set is converted into a ZDPlaskin file using a preprocessor, and the electron collision reaction data is calculated by the BOLSIG+ solver to obtain the species particle data of BOLSIG+. Edit the user code file that can realize the plasma gas-liquid interface reaction of the dielectric barrier discharge degradation of metal-organic complexes in mining wastewater, and call the ZDPlaskin library in the user code file; set the initial parameters of the numerical model, where the initial parameters include gas pressure, gas temperature, gas density, liquid density, electron density, discharge atmosphere ratio, etc.; write the data set and BOLSIG+ species particle data; perform initialization; specify the calculation condition parameters (gas temperature, reduced electric field, electron temperature, reduced electron mobility, etc.); specify the species density (N2, O2, H2O, E, O2 + 、H2O aq); Set the time integral of the DVODE_F90 solver and set the calculation duration; set the output parameters, which include time, gas temperature, electron temperature, electron density, current density, power density, reduced field strength, density of all species, and reaction rate; call the ZDPlaskin file, user code file, and DVODE_F90 solver in the ZDPlaskin software at the same time to compile and obtain the output parameter data.

[0030] In the numerical model, the discharge atmosphere ratio is matched with the reduced field intensity curve (plotted based on time and reduced field intensity data), thereby connecting the actual experiment and the numerical simulation in series, as shown in the following formula: Where I is the current value obtained under a specific discharge atmosphere ratio in the discharge experiment; μ is the reduced electron mobility; n e is the electron density; q is the elementary charge; E is the electric field strength; N is the number density of neutral particles; E / N is the reduced field strength.

[0031] Based on the established numerical model, a dielectric barrier discharge (DBD) experiment was conducted to simulate the degradation of metal-organic complexes, simulating the degradation of the SHA-Fe complex. The numerical model inputs included a dataset (including BOLSIG+ species particle data), initial parameters (gas pressure, gas temperature, gas density, liquid density, electron density, and discharge atmosphere ratio), and calculation parameters (gas temperature, reduced electric field, electron temperature, and reduced electron mobility). The model outputs time, gas temperature, electron temperature, electron density, current density, power density, reduced field strength, density of all species, and reaction rate. Based on the model outputs, the generation and consumption pathways of selected species were analyzed, and the motion pathways of active species in the gas and liquid phases were determined. The response patterns and motion pathways of the active species were summarized to prepare for experimental design.

[0032] In one embodiment, the electric field in the discharge degradation process is converted into a time-reduced field strength curve through the above formula and input into the numerical model. Wet air (N2:O2:H2O) is used as the discharge atmosphere, and the H2O ratio is adjusted to 30%, 40%, and 50% respectively for numerical simulation. The obtained output data (time, gas temperature, electron temperature, electron density, current density, power density, reduced field strength, density of all species, reaction rate) is imported into QtPlaskin / Tecplot / Origin for analysis and processing to obtain the production and consumption reactions, density evolution, weight ratio analysis and species path distribution of all species, so as to know the response rules of important active substances. Figure 1 As shown in , the evolution law of some active species in gas and liquid phases can be obtained. Figure 2As shown in the figure, the H2O ratio in the discharge atmosphere increases from 30% to 50%, and we can get the following: ① At the beginning of the discharge, the O3 density in the gas phase and liquid phase increases with the increase of the H2O ratio, and the density decreases with the increase of the H2O ratio as the discharge progresses; ② The O2 - , basically the whole process follows the rule that the smaller the H2O ratio, the higher the density; ③ The rule of H2O2 and OH in the gas phase is the opposite, and the larger the H2O ratio, the higher the density; H2O2 and OH in the liquid phase initially maintain the rule that the larger the H2O ratio, the higher the density, but as the reaction proceeds, the density difference under different H2O ratios becomes smaller and smaller. Figure 3 As shown, the generation and consumption pathways of different free radicals obtained by the numerical model.

[0033] Through free radical quenching experiments, the main controlling free radicals in the degradation process of the complex were obtained ( Figure 4 ), tert-butyl alcohol (TBA) quenches OH, and p-benzoquinone (BQ) quenches O2 - , catalase (CAT) quenches H2O2. The results show that hydroxyl is the main controlling free radical that dominates the degradation of SHA-Fe complex. Based on this conclusion, looking back at the results obtained in the numerical model, it is necessary to control the H2O ratio and increase the production of hydroxyl. Figure 3 The hydroxyl generation pathway can be inferred that O aq 、H2O 2aq Can generate OH aq , H2O 2aq HO 2aq Produced, HO 2aq By O 3aq Taking all factors into consideration, reducing the indoor H2O ratio can increase the hydroxyl production and promote the degradation of the complex.

[0034] The patterns derived from the numerical model were validated through laboratory experiments. A 0.4 mM SHA-Fe complex was prepared at a pH of 4 and a molar ratio of 1:1. The complex was subjected to discharge degradation at a discharge voltage of 24 kV, a power frequency of 7500 Hz, and an air flow rate of 20 L / min. The H₂O ratio was adjusted. The results showed that the degradation efficiency of the complex reached its highest level at a 30% H₂O ratio, reaching 61.36%. At a 40% H₂O ratio, the degradation efficiency reached 55.7%, while at a 50% H₂O ratio, the efficiency was only 47.14%. Increasing the H₂O ratio from 30% to 50% decreased the degradation efficiency by 14.22%, consistent with the results of the numerical model. This confirms that reducing the H₂O ratio indoors can increase hydroxyl yields and promote the degradation of the SHA-Fe complex.

[0035] After determining the basic parameters, the discharge voltage ( Figure 5 ), pH value ( Figure 6 ), the molar ratio of metal to organic ligand ( Figure 7 ) on the degradation performance of metal-organic complexes. From these results, it can be seen that when other conditions remain unchanged, the degradation efficiency is highest when the discharge voltage is 24kV, pH=2, and the SHA:Fe molar ratio is 2:1. Combined with density functional theory, it is found that the active site of the SHA-Fe complex is located on the Fe atom, and the active site of SHA is located on the N atom and the side chain oxygen atom ( Figure 8 ), thus deducing the degradation pathway of SHA-Fe / SHA.

[0036] In summary, the numerical simulation method of the present invention can simplify experimental procedures and reduce repetitive experimental steps, thereby promoting faster in-depth research. Furthermore, the numerical simulation method can optimize the conditions and parameters for the degradation of metal-organic complexes by dielectric barrier discharge, thereby improving the degradation efficiency.

[0037] The above description is merely a preferred embodiment of the present invention. The present invention is not limited to the above-described embodiments. Any method that achieves the technical effects of the present invention by the same or equivalent means shall fall within the scope of protection of the present invention. Within the scope of protection of the present invention, various modifications and variations of the technical solutions and / or implementation methods are possible.

Claims

1. A numerical simulation method for the degradation of metal-organic complexes by dielectric barrier discharge, characterized in that: The following steps are involved: Acquiring a data set of dielectric barrier discharge degradation of metal-organic complexes, wherein the data set includes active species data, physical and chemical process data of the active species, and time and reduced field strength data of the dielectric barrier discharge degradation of the metal-organic complex experimental process; Based on the electron impact reaction data in the physical and chemical process data of active species, the species particle data of BOLSIG+ is calculated; A numerical model was established based on the dataset and the species particle data of BOLSIG+; The time and reduced field intensity parameters to be simulated and the discharge atmosphere parameters to be simulated are input into the numerical model, and the numerical model outputs simulation result data.

2. The method according to claim 1, characterized in that The physical and chemical process data of the active species include reaction types and reaction rate data, wherein the reaction types include electron impact reaction, vibrational energy level conversion, ion / neutral reaction, solution reaction of gas-phase active particles and surface reaction.

3. The method according to claim 1, characterized in that The discharge atmosphere parameters to be simulated may be parameters of dry air, humid air, pure nitrogen, pure oxygen or argon.

4. The method according to claim 1, wherein The numerical model was established using ZDPlaskin software, and the species particle data of BOLSIG+ was calculated using the BOLSIG+ solver.

5. The method according to claim 1, wherein The simulation result data include time, gas temperature, electron temperature, electron density, current density, power density, reduced field strength, density of all species, and reaction rate data.

6. An electronic device, characterized in that: include: at least one processor; and a memory communicatively coupled to the at least one processor; The memory stores instructions, which, when executed by at least one processor, implement the numerical simulation method for dielectric barrier discharge degradation of metal-organic complexes according to any one of claims 1 to 5.

7. A computer-readable storage medium, characterized in that Instructions are stored, and when the instructions are executed by the processor, the numerical simulation method for dielectric barrier discharge degradation of metal-organic complexes according to any one of claims 1 to 5 is realized.

8. A method for degrading metal-organic complexes by dielectric barrier discharge, characterized in that: The following steps are involved: According to the numerical simulation method for dielectric barrier discharge degradation of metal-organic complexes according to any one of claims 1 to 5, obtaining simulation result data; Determine the condition parameters for degradation of metal-organic complexes by dielectric barrier discharge based on simulation results; Degradation of wastewater containing metal-organic complexes according to condition parameters.

9. The method according to claim 8, characterized in that The metal-organic complex is a SHA-Fe complex.

10. The method according to claim 9, characterized in that The condition parameters include: the discharge atmosphere is humid air, wherein the volume ratio of H2O in the humid air is 30%; the initial discharge voltage is 24kV; and the initial pH value of the wastewater containing the metal-organic complex is 4.

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