Method for improving degradation efficiency of quinone-based catalyst in wastewater treatment based on electrochemical pulse

Abstract

The application discloses a sewage treatment method for improving degradation efficiency of quinone-based catalyst based on electrochemical pulse, and relates to the technical field of water treatment, and comprises the following steps: S1, determining CO2 capture potential and CO2 release potential x of a working electrode modified with a quinone-based catalyst; S2, performing electrochemical catalytic degradation, and applying a constant voltage to the generated CO2 and the quinone-based catalyst to combine; S3, then applying a weak electric field pulse voltage, until the quinone-based catalyst and the CO2 are completely dissociated; and S4, circulating S2 and S3 until the organic sewage is completely degraded. The method of the application realizes catalytic degradation of the quinone-based catalyst on the organic sewage and dissociation of the CO2 by applying a constant voltage and a pulse voltage capable of forming a weak electric field, significantly improves the efficiency and stability of the quinone-based catalyst in treating sewage, and reduces the time cost of catalytic degradation.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, specifically to a wastewater treatment method based on electrochemical pulses to improve the degradation efficiency of quinone-based catalysts. Background Technology

[0002] Water security is a persistent and profound global crisis, urgently requiring stable and efficient technologies to reduce emerging organic pollutants in water. Electrocatalytic processes based on the oxygen reduction reaction to generate reactive oxygen species have become a highly promising environmental remediation technology due to their efficient mineralization capabilities (degrading organic pollutants to CO2 and H2O). However, this technology currently faces two major challenges: First, the catalysts rely on metal active sites. Most high-efficiency catalysts depend on precious or transition metals as catalytic active sites, resulting in high costs, resource scarcity, and the risk of secondary pollution due to potential metal ion leaching. Second, the applicable pH range is narrow. The activity and stability of the catalysts are highly dependent on the solution pH, typically performing well only under neutral or weakly acidic conditions, while performance significantly declines in strongly acidic / alkaline environments, limiting their application in practical wastewater treatment (where pH fluctuations are large).

[0003] Quinone groups, as highly efficient non-metallic catalytic centers, can stably generate oxygen-containing free radicals (·OH) over a wide pH range (3-13), covering the typical pH range of wastewater, and pose no risk of metal leakage, making them a green and efficient catalytic site. However, the quinone anion (Q) generated in the reduced state of quinone... - ) and semiquinone anion radical (Q ·- Quinone-based catalysts can combine with CO2, and after combining with CO2, they lose their original catalytic activity (i.e., catalyst poisoning), which in turn leads to a decrease in wastewater treatment efficiency.

[0004] Current wastewater treatment technologies based on quinone-based electrocatalysis employ constant-potential catalysis, which cannot avoid a series of problems caused by CO2 binding, such as quinone catalytic center poisoning, decreased catalytic efficiency, and reduced cycle stability, resulting in poor pollutant removal. Existing technologies for catalytic center detoxification mainly employ two methods: heating and acid / alkali cleaning. Heating detoxification requires additional equipment (heating furnace, separation tower, etc.), involves high reaction temperatures (80-1200℃), requires inert gas protection, and is time-consuming (2 hours), making in-situ detoxification impossible. Existing acid / alkali treatment detoxification methods require additional reagents (acids, alkalis, redox agents, etc.), necessitate additional cleaning steps, are costly and complex, and also cannot achieve in-situ detoxification. Summary of the Invention

[0005] To address the aforementioned issues, the method of this invention enables in-situ and rapid detoxification of quinone-based catalysts, which can significantly improve the efficiency of quinone-based materials in electrocatalytic degradation of organic pollutants in wastewater and reduce costs.

[0006] This invention provides a wastewater treatment method based on electrochemical pulses to improve the degradation efficiency of quinone-based catalysts.

[0007] A wastewater treatment method based on electrochemical pulses to enhance the degradation efficiency of quinone-based catalysts includes the following steps:

[0008] S1. Take the working electrode modified with quinone-based catalyst, the counter electrode used to form a circuit with the working electrode, and the reference electrode used for the reference potential, and place them in a gas-saturated electrolyte solution. Connect the working electrode and the counter electrode to form a circuit through a power supply, and perform a cyclic voltammetry scan to determine the CO2 release potential x of the working electrode modified with quinone-based catalyst; where -0.1≤x<0.2.

[0009] S2. Then, the working electrode, the counter electrode used to form a circuit with the working electrode, and the reference electrode used for the reference potential are placed in the organic wastewater for electrochemical catalytic degradation. The constant voltage applied during the electrochemical catalytic degradation is -1.0 to -0.6V until the CO2 generated by the electrochemical catalytic degradation combines with the quinone-based catalyst.

[0010] S3. Then electrochemical dissociation is carried out. During the electrochemical dissociation process, a weak electric field pulse voltage of x ~ 0.3V is applied until the quinone catalyst and CO2 are completely dissociated.

[0011] S4. Repeat steps S2 to S3 until the organic wastewater is completely degraded.

[0012] Explanation: The above method achieves catalytic degradation of organic wastewater and CO2 dissociation through potential setting using quinone-based catalysts, significantly improving the degradation efficiency of organic pollutants. Specifically, by applying voltage to the electrodes, the quinone-based catalyst generates hydroquinone / semiquinone groups in a reduced state. Organic matter is oxidized to form CO2. CO2 and the reduced quinone groups (hydroquinone / semiquinone groups) form carbonates, causing the quinone-based catalyst to be unable to continue degrading organic pollutants in the water (i.e., poisoning occurs). The above method uses pulsed voltage to re-oxidize the hydroquinone / semiquinone structure, releasing CO2 and restarting the catalytic process. The degradation effect; therefore, the above method can set a rapid detoxification step in the process of degrading organic pollutants by innovatively setting the pulse voltage, and achieve in-situ detoxification of the catalyst in the wastewater solution. Conventional pulse voltage is usually considered to be able to play its role in a strong electric field. The above content reveals for the first time that the quinone-CO2 bond can be dissociated through a weak electric field (0~0.3V), and subverts the traditional concept that "electrochemical regeneration requires a high redox potential". Through the temporal coupling of electrochemical catalysis and detoxification pulse, the industry problem of poisoning accumulation of quinone groups in continuous operation is solved.

[0013] Furthermore, the quinone-based catalyst is a quinone-based thiophene polymer.

[0014] Note: The above-mentioned quinone-based thiophene polymers have advantages such as high active site density, good electronic conductivity and mechanical stability as quinone-based catalysts.

[0015] Furthermore, when treating 100 mL of organic wastewater, the coverage area of ​​the quinone-based catalyst in the working electrode modified with the quinone-based catalyst is 16 cm². 2 .

[0016] Note: The above settings allow for precise control of catalyst dosage, avoiding increased costs or active site agglomeration and deactivation due to excessive loading. This ensures a dynamic balance between contaminant adsorption and electron transfer on the electrode surface, improving reaction efficiency. It provides a reference benchmark for the scale-up design of wastewater treatment systems of different scales.

[0017] Furthermore, the reference electrode mentioned in S1 is a silver / silver chloride electrode or a saturated calomel electrode.

[0018] Note: The wide applicability and mature technology of the two reference electrodes mentioned above facilitate cross-study verification and process scale-up. When evaluating the redox activity of quinone-based catalysts, a stable reference potential can accurately distinguish between the catalyst's electron transfer capability and background current interference, avoiding misjudgments of degradation efficiency due to potential drift, and ultimately improving the development efficiency and industrial feasibility of wastewater treatment technologies.

[0019] Furthermore, the organic wastewater mentioned in S1 includes one or more of sulfamethoxazole wastewater, azithromycin wastewater, and diclofenac wastewater.

[0020] Note: The above-mentioned pollutants are all trace pollutants that are widely present in the aquatic environment and are difficult to remove by traditional biological treatment processes. Their residues may lead to environmental risks such as ecotoxicity and the spread of drug resistance genes. This invention can degrade a variety of organic pollutants, not limited to the above-mentioned ones.

[0021] Furthermore, the electrolyte solution in S1 is a Na2SO4 solution with a concentration of 0.1–1 M or a KCl solution with a concentration of 0.1–3 M, and the gas in the electrolyte solution is CO2, which is saturated by aeration.

[0022] Note: By designing this electrolyte and gas environment, the redox peak that can capture CO2 can be measured.

[0023] Furthermore, the constant voltage applied in S2 is applied for a period of 0.5 to 15 minutes.

[0024] Note: Experiments have shown that the above-mentioned application time can achieve efficient degradation of organic wastewater using quinone catalysts. If the application time is too long, the catalytic efficiency will decrease. This is because CO2 binds to the surface of the quinone catalyst, reducing the catalytic activity potential. If the application time is too short, the catalytic effect may not reach the optimal level.

[0025] Furthermore, the application time of the pulse voltage in S3 is 5 to 300 seconds.

[0026] Note: The above-mentioned application time is sufficient to complete the dissociation of quinone catalyst and carbon dioxide, releasing carbon dioxide from the surface of the quinone catalyst so that its active potential can be used normally. However, exceeding this range may lead to a decrease in the overall degradation efficiency of pollutants.

[0027] Furthermore, the ratio of the application time of the constant voltage to the application time of the pulse voltage is 11 to 1:1.

[0028] Note: The above-mentioned alternating application time settings can improve the temporal coupling effect of electrochemical catalysis and detoxification pulse.

[0029] Furthermore, the constant voltage applied during the electrochemical catalytic degradation process described in S2 is -0.7V.

[0030] Note: Experiments have shown that the catalytic degradation effect is better under the above parameters.

[0031] The beneficial effects of this invention are:

[0032] This invention achieves catalytic degradation of organic wastewater and CO2 dissociation using quinone-based catalysts by alternately applying constant voltage and pulsed voltages that create a weak electric field, significantly improving the efficiency and stability of quinone-based catalysts in wastewater treatment. This invention innovatively sets the pulse voltage magnitude to detoxify the catalyst, revealing for the first time that the quinone-CO2 bond can be dissociated through a weak electric field of less than 0.3V, overturning the conventional understanding that "electrochemical regeneration requires a strong reduction potential." Furthermore, by temporally coupling electrochemical catalysis with the detoxification pulse, it solves the industry problem of poisoning accumulation during continuous operation of quinone-based catalysts. In addition, this invention significantly reduces the cost of catalyst dissociation and continuous utilization, eliminating the need for chemical reagents such as acids, alkalis, and redox agents, as well as additional equipment such as tube furnaces and drying ovens; it also eliminates the need for additional operating steps such as heating, ultrasound, and cleaning. Moreover, the quinone-based catalyst exhibits high detoxification efficiency, a rapid detoxification process (as short as 5 seconds), and a long activity retention time, reducing the time cost of wastewater catalytic degradation. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the reversible CO2 binding reaction pathway during the redox process of the quinone-based catalyst of the present invention;

[0034] Figure 2 A schematic diagram illustrating the in-situ detoxification of quinone-based catalysts by applying a potential in this embodiment of the invention;

[0035] Figure 3 Catalytic current-time data of typical quinone-based catalysts in Example 1 and Comparative Example 1 after poisoning and in-situ detoxification;

[0036] Figure 4 The data graphs show the removal efficiency of azithromycin by the quinone-based catalytic electrode in Example 2 and Comparative Example 4 under constant potential and electrochemical pulse in-situ detoxification electrocatalysis.

[0037] Figure 5 CO2 and NO2 response data of a typical quinone-based catalyst surface in pulsed electrocatalysis in Example 3 of this invention;

[0038] Figure 6 Graph showing the effect of the quinone-based catalyst in Example 4 of this invention on the catalytic degradation of organic pollutants under different proportions of pulse-programmed detoxification;

[0039] Figure 7 The CO2 and NO2 response data of the graphite electrode surface in the pulsed electrocatalysis of Comparative Example 3 of this invention are shown in the figure.

[0040] Figure 8 CV scan data of the typical quinone catalyst polybenzo[1,2-B:4,5-B']dithiophene-4,8-dione (PBth-BQ) in N2-saturated and CO2-saturated solutions in embodiments of the present invention. Detailed Implementation

[0041] To further illustrate the methods and effects of this invention, the technical solution of this invention will be clearly and completely described below in conjunction with experiments.

[0042] Quinone-based materials, due to their unique redox properties, can promote water electrolysis during electrocatalysis, generating strong oxidizing agents such as hydroxyl radicals (·OH). These strong oxidizing agents can efficiently react with organic pollutants in water (such as new pollutants, dyes, antibiotics, etc.), gradually oxidizing and decomposing them into smaller molecules, mineralizing them into carbon dioxide and water. However, during negative potential catalysis, quinone-based catalysts generate ·OH in situ on the electrode surface to mineralize organic pollutants. Since the lifetime of ·OH is <10 μs and the migration distance is only 90 nm, most of the mineralization occurs at the electrode surface, resulting in a relatively high local CO2 concentration on the electrode surface. This leads to a relatively low binding rate between CO2 and quinone groups. - / Q ·- Protonation is more likely to occur, and the reversible CO2 binding reaction pathway during the redox process of quinone-based catalysts is as follows: Figure 1 As shown;

[0043] To address the problem of catalytic poisoning caused by the capture of CO2 generated during pollutant mineralization in the hydroquinone structure during the negative potential catalytic degradation of organic pollutants by quinone-based catalysts, thus affecting wastewater treatment efficiency, this invention attempts to achieve rapid release of quinone and CO2 by applying a reverse pulsed weak electric field. Figure 2 As shown, this enables in-situ detoxification of quinone-based catalysts, thereby improving their catalytic efficiency and recycling stability;

[0044] Pulsed electric field (PEF) is a technique that uses high-intensity (kV / cm to MV / cm) and short-duration electric field pulses to induce physical, chemical, or biological effects. It is used for microbial inactivation, sludge reduction and dewatering, heavy metal removal, and degradation of organic pollutants. However, it has some drawbacks, as follows:

[0045] ① Regarding the degradation of organic pollutants, there are some drawbacks to using high-voltage pulses to break down the organic molecular structure. For example, high-voltage pulses often require a large amount of power and need to overcome the energy loss caused by the conductivity of water. In addition, some energy may be converted into heat energy instead of being directly used for pollutant degradation, which may significantly increase energy consumption and increase the operating (wear and tear) cost of the equipment. Furthermore, when high-voltage pulse electric fields are used to degrade wastewater polluted with hydrophobic organics such as polycyclic aromatic hydrocarbons (PAHs) and petroleum hydrocarbons, the hydrophobic nature of these organic pollutants makes them difficult to be efficiently degraded through free radical oxidation or electroporation. At the same time, high-voltage pulses can accelerate electrode corrosion, requiring regular replacement and increasing operation and maintenance costs.

[0046] ② Material Synthesis: Medium-intensity electric fields (1–100 kV) are used to regulate particle morphology or lattice reconstruction. By controlling the surface charge distribution of particles, inducing ion migration, or triggering local electrochemical reactions, particle morphology reconstruction (such as the formation of nanostructures) or lattice defect control (such as changing the exposure ratio of crystal faces) can be promoted, thereby optimizing material properties (such as catalytic activity and adsorption capacity). However, high voltage can easily cause particle agglomeration or phase transition runaway, requires high equipment insulation and consumes a lot of energy, and long-term electric field action may destroy the intrinsic structure of the material. However, when the voltage is reduced (e.g., less than 1–5 V), the morphology of the material surface cannot be modified or changed, and thus the desired particle morphology or lattice reconstruction effect cannot be achieved. The above-mentioned disadvantages limit its efficiency and stability in large-scale synthesis.

[0047] ③ Application scenarios: Generally speaking, wastewater treatment requires >5kV / cm to effectively break down microbial cell membranes and organic molecular structures; catalyst regeneration usually requires >1~1kV / cm to overcome the reaction energy barrier and regulate particle morphology or lattice reconstruction. Voltages below 1~2V are difficult to initiate electrochemical reactions; and low voltages are difficult to drive high current densities, while pulse effects are closely related to instantaneous current: 1V voltage cannot meet this requirement in conventional electrolytes.

[0048] Based on the above description of pulsed electric fields, it can be seen that the electrochemical pulses in the prior art mainly have two effects: high-voltage breakdown of organic molecules and alteration of particle morphology and lattice reconstruction. Both of these effects are based on high voltage and are instantaneous, and cannot play their role in low-voltage weak electric fields.

[0049] In comparison with the above, the quinone catalyst of this invention firstly enriches and catalytically degrades organic compounds such as polycyclic aromatic hydrocarbons and petroleum hydrocarbons that are difficult to break down under high-voltage pulsed electric fields through the catalyst itself and electrochemical π-π interactions, redox-mediated surface adsorption, etc., thereby improving degradation efficiency; secondly, as... Figure 2 As shown, this invention is the first to utilize a low-voltage (<1V) pulsed electric field to act on a molecular-level weakly interacting system (such as quinone-CO2) to achieve the detoxification of quinone catalysts. Moreover, through estimation and comparison, the energy consumption of achieving the detoxification of quinone catalysts using a weak electric field (<1V) pulse is only 1 / 100 of that of the thermal regeneration method, and the time consumption is very short. No separate regeneration process is required during the degradation process, which has a significant effect.

[0050] Based on the above, the following are specific solutions of embodiments of the present invention:

[0051] Example 1: A wastewater treatment method based on electrochemical pulses to improve the degradation efficiency of quinone-based catalysts, comprising the following steps:

[0052] S1. The working electrode modified with the quinone-based catalyst, the counter electrode used to form a circuit with the working electrode, and the reference electrode used for the reference potential are placed in a gas-saturated electrolyte solution. The working electrode and counter electrode are connected to form a circuit using an electrochemical workstation (an instrument used in electrochemical experiments in the prior art, capable of precisely applying and adjusting voltage and current, such as the instrument used to apply constant voltage and pulse voltage as described later). Cyclic voltammetry scans are performed to determine the CO2 capture potential and CO2 release potential x of the working electrode modified with the quinone-based catalyst; where -0.1 ≤ x < 0.2; the results are as follows: Figure 8 As shown, from Figure 8 It can be deduced that an oxidation peak exists at a potential of -0.1V. This potential is the CO2 release potential x of the working electrode modified with the quinone-based catalyst, where x takes the value of -0.1V.

[0053] This embodiment treats wastewater with a concentration of 10 mg / L sulfamethoxazole; the quinone-based catalyst mentioned above is a quinone-based thiophene polymer;

[0054] When treating 100 mL of organic wastewater, the coverage area of ​​the quinone-based catalyst in the above-mentioned modified quinone-based working electrode is 16 cm². 2The reference electrode in this embodiment is a silver / silver chloride electrode. It should be understood that the reference electrode is an electrode that provides a stable and known potential for the electrochemical reaction. The potential difference between the working electrode and the counter electrode is measured with reference to the known potential of the reference electrode. This potential difference is equal to the measured applied voltage.

[0055] The electrolyte solution in this embodiment is a 0.5M Na2SO4 solution; the gas in the electrolyte solution is CO2, and the CO2 is saturated through aeration.

[0056] S2. Next, the working electrode modified with the quinone-based catalyst, the counter electrode used to form a circuit with the working electrode, and the reference electrode used for the reference potential are placed in organic wastewater. The working electrode and the counter electrode are connected to form a circuit through an electrochemical workstation to carry out electrochemical catalytic degradation. During the electrochemical catalytic degradation, a constant voltage of -1.0V relative to the reference electrode is applied until the CO2 generated by the electrochemical catalytic degradation combines with the quinone-based catalyst. The constant voltage is applied for 10 minutes.

[0057] S3. Then, electrochemical dissociation is performed. During the electrochemical dissociation process, a weak electric field pulse voltage of -0.1V is applied using an electrochemical workstation until the quinone catalyst and CO2 are completely dissociated. The application time of the pulse voltage is 120s. The ratio of the application time of the constant voltage to the application time of the pulse voltage is 5:1.

[0058] S4. Repeat steps S2 to S3 until the organic wastewater is completely degraded; in this embodiment, S2-S3 are repeated a total of 10 times.

[0059] To further illustrate the technical effects of the present invention, comparative examples 1 and 2 were set up under the same wastewater conditions as in Example 1;

[0060] Comparative Example 1: This example is largely the same as Example 1, except that operations S3 and S4 were not performed; the degradation process was completed after S2. The results obtained are as follows: Figure 3 As shown, the catalytic current of the poisoned quinone-based catalytic electrode is significantly lower than that of the quinone-based catalytic electrode after in-situ detoxification, indicating that the core quinone structure of the quinone-based catalyst is preserved after electrochemical pulse detoxification, resulting in improved electrocatalytic activity and enhanced wastewater treatment effect.

[0061] Comparative Example 2: This example is largely the same as Example 1, except that the gas in the electrolyte solution in S1 above is replaced with N2, and the measured potential is as follows. Figure 8 , Figure 8 The results show that polybenzo[1,2-B:4,5-B']dithiophene-4,8-dione (PBth-BQ) exhibits a distinct reversible redox peak in the presence of CO2, with the reduction peak corresponding to the reduction of PBth-BQ to PBth-BQ.2- / PBth-BQ 2·- It also captures CO2 to form [PBth-BQ-(CO2)2] 2- The oxidation peak corresponds to [PBth-BQ-(CO2)2]. 2- The CO2 molecules are oxidized and restored to PBth-BQ and CO2 molecules, but this redox peak is not obvious under N2 conditions. This result demonstrates that PBth-BQ has a strong ability to reversibly capture and release CO2 when the CO2 concentration near the electrode is high, and this reaction may affect the electrocatalytic process.

[0062] The comparison results of Example 1 with Comparative Example 1 and Comparative Example 2 are shown in Table 1 below;

[0063] Table 1. Sulfamethoxazole removal rate

[0064] Example 1 98.5％ Comparative Example 1 61.2％ Comparative Example 2 87.8％

[0065] By comparing Comparative Example 1 with Example 1 of the present invention, it was found that S3 and S4 set in the present invention can significantly improve the catalytic effect of quinone catalyst, thereby improving the removal rate of sulfamethoxazole in wastewater. By comparing Comparative Example 2 with Example 1, it was found that the pulse voltage limit obtained by using saturated carbon dioxide gas in Example 1 is more suitable for the present invention. Using N2 redox peak reaction is not obvious and it is difficult to determine the appropriate working electrode modified with quinone catalyst for CO2 capture potential and CO2 release potential.

[0066] Example 2: This example is largely the same as Example 1, except that the organic wastewater is wastewater with a concentration of 5 mg / L azithromycin; a constant voltage of -0.7V is applied for 54 seconds in S2; and a pulse voltage of 0.3V is applied for 6 seconds in S3.

[0067] Comparative Example 3: This example is largely the same as Example 2, except that the working electrode modified with the quinone-based catalyst was replaced with a graphite sheet working electrode for electrocatalysis; the results are as follows. Figure 7 As shown, the removal rate of azithromycin by the graphite electrode decreased by more than 10% within 4 hours under the same pulse voltage method, which is the opposite of the effect of the quinone-based catalytic electrode. This indicates that the pulse voltage method only has a beneficial effect on quinone-based catalysts.

[0068] Comparative Example 4: This example is largely the same as Example 2, except that operations S3 and S4 were not performed; the degradation process was completed after S2. The results obtained are as follows: Figure 4 As shown, the first-order reaction kinetic constant k of the removal of azithromycin by the quinone catalytic electrode at a constant potential of -0.7V is 0.488 h. -1 The k-value for removing azithromycin using the electrocatalytic method based on pulsed electrochemical in-situ detoxification was 0.958 h.-1 That is, the in-situ detoxification quinone catalytic center increased the degradation rate constant by 96.6%.

[0069] The comparison results between Example 2 and Comparative Example 3 and Comparative Example 4 are shown in Table 2 below;

[0070] Table 2. Azithromycin degradation kinetic constants

[0071] Example 2 <![CDATA[0.958h -1 ]]> Comparative Example 3 <![CDATA[0.122h -1 ]]> Comparative Example 4 <![CDATA[0.488h -1 ]]>

[0072] By comparing Example 3 with Example 2, it can be found that the quinone catalyst used in Example 2 has a good catalytic effect. More importantly, graphite itself has the function of electrochemical catalytic degradation of wastewater. However, after applying a pulse voltage, its effect was not improved, but decreased instead. This indicates that the pulse electric field in this scheme does not act on other substances and react to improve the catalytic effect, but only acts on the quinone catalyst. This solves the problem of quinone catalyst poisoning in this invention and proves the principle and feasibility of this invention.

[0073] By comparing Example 4 with Example 2 of the present invention, it was found that S3 and S4 set in the present invention can significantly improve the catalytic effect of quinone catalyst, thereby improving the removal rate of sulfamethoxazole in wastewater.

[0074] Example 3: This example is largely the same as Example 1, except that the organic wastewater is wastewater with a concentration of 10 mg / L azithromycin; a constant voltage of -0.7 V is applied for 11 min in S2, causing an oxygen reduction reaction on the surface of the quinone catalyst to generate hydroxyl radicals that degrade azithromycin. Figure 5 The differential electrochemical mass spectrometry results shown verify the capture of CO2 by the quinone catalytic center; a pulse voltage of 0.3V for 300 s was applied in S3. Figure 5 The results shown confirm that the CO2 bound to the surface of the quinone catalyst is rapidly released, and the quinone catalyst is detoxified.

[0075] Example 4: This example is largely the same as Example 1, except that five electrodes modified with quinone-based catalysts were placed in wastewater containing 5 mg / L of the organic pollutant diclofenac. A counter electrode and a saturated calomel reference electrode were also placed in each electrode for electrocatalysis. A constant voltage of -0.7V was applied for 30s, 40s, 45s, 50s, and 55s, respectively. An oxygen reduction reaction occurred on the surface of the quinone-based catalyst, generating hydroxyl radicals to degrade diclofenac and simultaneously producing CO2. In step S2, a pulse voltage of 0.1V was applied for 30s, 20s, 15s, 10s, and 5s, respectively. The CO2 bound to the surface of the quinone-based catalyst was rapidly released, and the catalyst was detoxified. Steps S2-3 were repeated for a total of 240 times.

[0076] The results are as follows Figure 6 As shown, Figure 6 The degradation effect of the quinone catalyst on diclofenac was investigated under different pulse ratios. By applying a constant potential of -0.7V (in-situ detoxification without pulse), different pulse ratios could achieve detoxification of the quinone catalytic center. Among them, the combination of a constant potential of -0.7V for 55s and a pulse potential of 0.1V for 5s showed the best detoxification effect and the strongest catalytic degradation ability of organic pollutants by the quinone catalytic center.

[0077] Example 5: This example is largely the same as Example 1, except that the electrolyte solution in S1 is a 0.1M KCl solution; a constant voltage of -0.6V relative to the reference electrode is applied during the electrochemical catalytic degradation in S2; the application time of the constant voltage in S2 is 15min; and the application time of the pulse voltage in S3 is 5s.

[0078] Example 6: This example is largely the same as Example 5, except that the electrolyte solution in S1 is a 3M KCl solution.

[0079] Example 7: This example is largely the same as Example 5, except that the electrolyte solution in S1 is a 1M Na2SO4 solution; a constant voltage of -1.0V relative to the reference electrode is applied during the electrochemical catalytic degradation in S2; the application time of the constant voltage in S2 is 0.5min; and the application time of the pulse voltage in S3 is 300s.

Claims

1. A wastewater treatment method based on electrochemical pulses to improve the degradation efficiency of quinone-based catalysts, characterized in that, Includes the following steps: S1. Take a working electrode modified with a quinone-based catalyst, a counter electrode used to form a circuit with the working electrode, and a reference electrode used for reference potential, and place them in a gas-saturated electrolyte solution. Connect the working electrode and the counter electrode to form a circuit through a power supply, and perform a cyclic voltammetry scan to determine the CO2 release potential x of the working electrode; where -0.1≤x<0.

2. S2. Then, the working electrode, counter electrode, and reference electrode are placed in organic wastewater for electrochemical catalytic degradation. A constant voltage of -1.0 to -0.6V is applied during the electrochemical catalytic degradation until the CO2 generated by the electrochemical catalytic degradation combines with the quinone-based catalyst. S3. Then electrochemical dissociation is carried out. During the electrochemical dissociation process, a weak electric field pulse voltage of x ~ 0.3V is applied until the quinone catalyst and CO2 are completely dissociated. S4. Repeat steps S2 to S3 until the organic wastewater is completely degraded.

2. The wastewater treatment method based on electrochemical pulse to improve the degradation efficiency of quinone-based catalysts as described in claim 1, characterized in that, The quinone-based catalyst is a quinone-based thiophene polymer.

3. The wastewater treatment method based on electrochemical pulse to improve the degradation efficiency of quinone-based catalysts as described in claim 1, characterized in that, When treating 100 mL of organic wastewater, the coverage area of ​​the quinone-based catalyst in the modified working electrode is 16 cm². 2 .

4. The wastewater treatment method based on electrochemical pulse to improve the degradation efficiency of quinone-based catalysts as described in claim 1, characterized in that, The reference electrode mentioned in S1 is a silver / silver chloride electrode or a saturated calomel electrode.

5. The wastewater treatment method based on electrochemical pulse to improve the degradation efficiency of quinone-based catalysts as described in claim 1, characterized in that, Organic wastewater includes one or more of the following: sulfamethoxazole wastewater, azithromycin wastewater, and diclofenac wastewater.

6. The wastewater treatment method based on electrochemical pulse to improve the degradation efficiency of quinone-based catalysts as described in claim 1, characterized in that, The electrolyte solution in S1 is a Na2SO4 solution with a concentration of 0.1–1 M or a KCl solution with a concentration of 0.1–3 M. The gas in the electrolyte solution is CO2, and the CO2 is saturated through aeration.

7. The wastewater treatment method based on electrochemical pulse to improve the degradation efficiency of quinone-based catalysts as described in claim 1, characterized in that, The constant voltage applied in S2 is for a duration of 0.5 to 15 minutes.

8. The wastewater treatment method based on electrochemical pulse to improve the degradation efficiency of quinone-based catalysts as described in claim 7, characterized in that, The pulse voltage applied in S3 is for a duration of 5 to 300 seconds.

9. The wastewater treatment method based on electrochemical pulse to improve the degradation efficiency of quinone-based catalysts as described in claim 8, characterized in that, The ratio of the application time of the constant voltage to the application time of the pulse voltage is 11 to 1:

1.

10. The wastewater treatment method based on electrochemical pulse to improve the degradation efficiency of quinone-based catalysts as described in claim 7, characterized in that, The constant voltage applied during the electrochemical catalytic degradation process described in S2 is -0.7V.

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