A microporous membrane electrode and its preparation method and application

Abstract

The application discloses a kind of microporous membrane electrode and its preparation method and application, the microporous membrane electrode includes porous conductive substrate and the electrocatalytic active layer supported on its surface, electrocatalytic active layer is doped with noble metal particles, the microporous membrane electrode is configured as anode and is applied electric field and is placed under ultraviolet irradiation, can activate persulfate with three kinds of mechanism of electrocatalysis, noble metal catalysis and ultraviolet light cooperation.This application also discloses a kind of reactor comprising the microporous membrane electrode, wherein anode, cathode and ultraviolet lamp tube are arranged alternately, so that ultraviolet light can be directly irradiated to the surface of membrane electrode, realize the space coupling of light, electricity, catalysis, so that ultraviolet light can not only activate persulfate cooperation, more can directly act on the pollutants and electrode active site intercepted on membrane surface, produce the unique effect of surface enhanced degradation and electrode in-situ regeneration.Therefore, the application can greatly improve the efficiency of pollutant removal, and effectively reduce energy consumption.

Description

Technical Field

[0001] This invention belongs to the field of water pollution control technology, specifically relating to a microporous membrane electrode, its preparation method, and its application. Background Technology

[0002] With the acceleration of industrialization, wastewater discharged from industries such as dyeing, printing, chemicals, and pharmaceuticals contains a large amount of structurally stable and highly biotoxic recalcitrant organic pollutants, posing a serious threat to the ecological environment and human health. Traditional biological and physicochemical methods are often insufficient to effectively remove these pollutants. Advanced oxidation technologies, which generate highly reactive free radicals (such as sulfate and hydroxyl radicals), are considered an effective means of treating such wastewater due to their advantages of strong oxidation capacity, fast reaction speed, and non-selectivity.

[0003] Persulfate (PS) or peroxymonosulfate (PMS) are commonly used oxidant precursors that can be activated by heat, ultraviolet light, transition metal ions, or electrochemistry to generate highly oxidizing sulfate radicals. However, single activation methods generally suffer from low efficiency, high energy consumption, or the potential to introduce secondary pollution.

[0004] Electrocatalytic membrane technology couples membrane separation with electrochemical oxidation processes. By applying an electric field to a conductive membrane, it significantly improves reaction rates and energy efficiency through the confinement effect of membrane pores and the enhancement of convective mass transfer. For example, prior art document 1 (CN114984949A) discloses a palladium metal composite bifacial electrocatalytic membrane that achieves efficient removal of micropollutants through electroactivation of peroxymonosulfate. However, this technology is still limited to a single "electroactivation" pathway, and its activation efficiency and energy utilization efficiency still have room for further improvement.

[0005] Ultraviolet light activation is another effective persulfate activation method, but it has poor penetration into high-turbidity wastewater and is difficult to directly act on pollutants that have been trapped and accumulated on the membrane surface, resulting in low light energy utilization.

[0006] Therefore, how to optimally couple electrocatalytic membrane technology with ultraviolet light activation technology to overcome their respective limitations and generate synergistic effects is a technical problem that urgently needs to be solved. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of existing single or simple combination activation technologies with insufficient efficiency, and to provide a microporous membrane electrode and reactor that achieves triple synergy of electrocatalytic oxidation, noble metal catalytic activation and ultraviolet light activation through structural innovation.

[0008] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a microporous membrane electrode, the microporous membrane electrode comprising: Porous conductive substrate: serving as the skeleton of electrodes and a filter medium, providing mechanical strength and conductive pathways; Electrocatalytic active layer: loaded on the surface of the porous conductive substrate, exhibiting excellent electrocatalytic performance; Noble metal particles: doped into the electrocatalytic active layer, serving as a chemical catalyst capable of efficiently activating persulfate; The microporous membrane electrode is configured to use a porous conductive substrate, which increases the surface contact area of ​​the substrate. At the same time, an electrocatalytic active layer is loaded on the porous conductive substrate. When it is set as an anode and opposite to the cathode, an electric field is applied, and it is alternately arranged with ultraviolet lamps and placed under ultraviolet irradiation, it can achieve the synergistic effect of three mechanisms: high specific surface area electrocatalytic activation, noble metal catalytic activation and ultraviolet light activation, which significantly improves the electrochemical oxidation effect.

[0009] Preferably, the porous conductive substrate is one of porous Al2O3, porous TiO2, Ti4O7 or porous SiC.

[0010] Preferably, the pore size of the porous conductive substrate is 50μm-200μm.

[0011] Preferably, the electrocatalytic active layer is one of boron-doped diamond, ruthenium-iridium oxide, iridium-tantalum oxide, tin-antimony oxide, or lead dioxide. Preferably, the noble metal particles are one or more of ruthenium, rhodium, palladium, platinum, and gold.

[0012] Secondly, the present invention provides a method for preparing the microporous membrane electrode described above, the method comprising the following steps: S10. Provide a porous conductive substrate and perform necessary cleaning pretreatment on it; S20. Construct an electrocatalytic active layer on the surface of the porous conductive substrate and introduce noble metal particles into the electrocatalytic active layer. This step is performed by one of magnetron sputtering, sol-gel method or powder sintering method.

[0013] Preferably, in step S20, noble metal particles are loaded onto the electrocatalytic active layer or its surface simultaneously with or after the construction of the electrocatalytic active layer by one of magnetron sputtering, sol-gel method or powder sintering method.

[0014] Preferably, the magnetron sputtering method involves using a transition metal target, controlling the sputtering power to be 50-100W, the vacuum degree to be 0.3-0.8Pa, the sputtering time to be 20-120s, and the argon flow rate to be 10-30sccm to load noble metal particles in the electrocatalytic active layer.

[0015] Thirdly, the present invention provides a reactor for the synergistic activation of persulfate, the reactor comprising: At least one microporous membrane electrode as described above serves as the anode; At least one cathode is positioned opposite the anode to form an electric field; At least one ultraviolet lamp is used to provide ultraviolet irradiation; The anode, cathode, and ultraviolet lamp are arranged alternately inside the reactor, so that the ultraviolet light emitted by the ultraviolet lamp can directly irradiate the surface of the microporous membrane electrode, thereby achieving photoactivation and photoregeneration of pollutants trapped on the membrane surface and electrode active sites, and rapidly oxidizing and degrading the pollutants trapped on the membrane surface. Through synergistic effect, the degradation efficiency is greatly improved and the reaction energy consumption is reduced.

[0016] Preferably, the electrode spacing between the anode and cathode is 5-20 cm to ensure a uniform electric field and excellent energy efficiency. This reactor brings about technical effects that existing technologies could not anticipate: (1) In conventional “electro-optical” reactors, ultraviolet lamps are usually placed on one side or in the center of the reactor. The light needs to pass through a thick solution layer to reach the electrode surface, resulting in severe light intensity attenuation and difficulty in effectively acting on the membrane surface. In the reactor of the present invention, the anode, cathode and ultraviolet lamps are arranged in an alternating structure, so that there are ultraviolet lamps near each membrane electrode, the light path is short, and the membrane electrode surface can be directly and efficiently irradiated.

[0017] (2) In the flow-through filtration mode, pollutants are intercepted by the membrane pores and enriched on the membrane surface, forming a local high-concentration area. Alternating ultraviolet lamps directly irradiate the membrane surface, and the light energy is precisely applied to the high-concentration pollutant area. In turn, photoactivation and electroactivation are simultaneously activated at this high-concentration pollutant area on the membrane surface, achieving in-situ and rapid degradation of the intercepted pollutants. This effectively solves the problem that traditional photoactivation has poor penetration of high-turbidity wastewater and is difficult to act on the membrane surface to enrich pollutants.

[0018] (3) By irradiating the surface of the membrane electrode with ultraviolet light, organic matter or intermediate products that may be deposited on the surface of the electrode during the reaction can be effectively decomposed, playing a "photo-cleaning" role, thereby maintaining the long-term stability and high catalytic activity of the electrode active sites and extending the life of the membrane electrode.

[0019] Therefore, through the structural innovation of "alternating arrangement", the reactor highly couples the three mechanisms of light, electricity and catalysis in space, so that ultraviolet light is upgraded from simple "bulk activation" to have the dual functions of "bulk activation" and "surface strengthening", thus producing a synergistic effect of 1+1+1>3.

[0020] Fourthly, the present invention provides a method for treating wastewater based on the above-mentioned reactor, comprising the following steps: S30. Mix the wastewater to be treated with persulfate to obtain pretreated wastewater; S40. The pretreated wastewater is fed into the reactor and, under circulating flow conditions, an electric field and ultraviolet irradiation are applied simultaneously for synergistic oxidation treatment.

[0021] Preferably, in step S30, the pH value of the wastewater to be treated is adjusted to 4-6, and the mass ratio of persulfate dosage to COD of the wastewater to be treated is controlled at 1:0.8-1.2.

[0022] Preferably, in step S40, the current density of the applied electric field is 100-1000 A / m. 2 The intensity of ultraviolet radiation is 100-300 W / m. 2 .

[0023] Compared with the prior art, the present invention has the following beneficial technical effects: (1) The microporous membrane electrode effectively increases the electrochemical active area and improves the mass transfer efficiency. By arranging the anode, cathode and ultraviolet lamp of the microporous membrane electrode in an alternating manner, the surface of the membrane electrode can achieve self-cleaning of pollutants through oxidation. On the other hand, it realizes direct and efficient irradiation of the surface of the microporous membrane electrode by ultraviolet light, extending photoactivation from traditional bulk activation to surface-enhanced degradation and in-situ photoregeneration of the electrode, which is something that existing technologies cannot anticipate.

[0024] (2) This invention integrates three mechanisms—microporous membrane electrode electrocatalysis, noble metal catalysis, and ultraviolet light activation—in a highly synergistic manner in space and time, which significantly improves the yield of active species and the degradation efficiency of pollutants.

[0025] (3) In this invention, due to the alternating arrangement of ultraviolet lamps, anodes and cathodes, the utilization of light energy is more precise and the electrode activity is more durable. Under the premise of achieving the same treatment effect, the current density and ultraviolet light intensity can be reduced, effectively saving energy. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a cross-sectional view of the microporous membrane electrode in Embodiment 1 of the present invention.

[0028] Figure 2 This is a schematic diagram of the structure of the persulfate reactor used for synergistic activation in Embodiment 1 of the present invention.

[0029] Figure 3for Figure 2 The diagram shows a top view of the internal structure of the reactor.

[0030] In the diagram: 1. DC power supply; 2. Reactor; 3. Anode; 4. Cathode; 5. UV lamp; 6. Circulation pipe; 7. Circulation pump; 8. Circulation valve; 9. Drain valve; 10. Drain pipe; 11. Inlet pipe; 12. Conductive substrate; 13. Electrocatalytic active layer; 14. Noble metal particles. Detailed Implementation

[0031] To make the objectives, technical solutions, and technical effects of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings, multiple embodiments, and comparative examples. In the following description, the same components are referred to by the same reference numerals.

[0032] Example 1 (1) Preparation of microporous membrane electrode A porous SiC ceramic film was selected as the conductive substrate 12 (average pore size 100±10μm, thickness 1-3mm), and the conductive substrate 12 was ultrasonically cleaned in acetone, ethanol and deionized water for 15±2 minutes each, and then dried for later use. A boron-doped diamond (BDD) electrocatalytic active layer 13 was deposited on the surface and inside the pores of a SiC conductive substrate 12 using hot-wire chemical vapor deposition for 2 hours. Using high-purity palladium (Pd) as the target material, Pd nano-noble metal particles 14 were sputtered onto the surface of the BDD electrocatalytic active layer 13 using a magnetron sputtering instrument at a sputtering power of 30W for 5 minutes to obtain a Pd-BDD / SiC microporous membrane electrode. The structure of the microporous membrane electrode is as follows. Figure 1 As shown, from Figure 1 As can be seen, Pd nano-noble metal particles 13 are distributed in the BDD electrocatalytic active layer 13 and on its surface.

[0033] (2) Constructing the reactor The prepared microporous membrane electrode is used as the anode 3, and a stainless steel mesh of equal area is used as the cathode 4. Anodes 3 and cathodes 4 are alternately arranged with UV lamps 5 (each UV lamp has a power of 25W) to assemble a closed reactor 2 with an effective volume of 10L. The distance between the plates of anodes 3 and cathodes 4 is set to 10cm. The constructed reactor structure is as follows. Figure 2 and Figure 3 As shown, this alternating arrangement structure ensures that the surface of each membrane electrode can be directly irradiated by the ultraviolet lamp.

[0034] (3) Wastewater treatment A 10L sample of wastewater from the equalization tank of a dyeing and printing factory was taken. The test results showed that the COD of the wastewater was 1025mg / L and the pH was 7.8. The pH of the wastewater was adjusted to 4.0 with dilute sulfuric acid, and 10.25g of sodium persulfate was added (i.e., the mass ratio of sodium persulfate to COD in the wastewater was 1:1). The mixture was stirred until it was completely dissolved to obtain pretreated wastewater. The pretreated wastewater is injected into the reactor 2 through the inlet pipe 11, the drain valve 9 is closed, the circulation valve 8 is opened, and the circulation pump 7 is started so that the pretreated wastewater circulates between the reactor 2 and the circulation pipe 6 at a flow rate of 5L / min. Connect DC power supply 1 and set the current density to 100A / m. 2 Simultaneously, all ultraviolet lamps 5 are turned on for light irradiation, and the cycle reaction time is 2 hours. After the cycle reaction is completed, the power supply and ultraviolet lamps are turned off, the drain valve 9 is opened to discharge the treated water sample, and the discharged treated water sample is sampled and tested.

[0035] Example 2 The same microporous membrane electrode preparation method and reactor structure as in Example 1 are used, with the difference being: In Example 2, Ti4O7 was selected as the porous conductive substrate 12, tin antimony oxide was selected as the material of the electrocatalytic active layer 13, and platinum was selected as the noble metal particle 14. In the reactor of Example 2, the distance between the plates of anode 3 and cathode 4 is set to 5 cm; Example 2 treats a chemical plant's wastewater with a COD of 12500 mg / L. In Example 2, during the pretreatment of wastewater, the pH value of the wastewater was adjusted to 5.0, and 105g of sodium persulfate was added (i.e., the mass ratio of sodium persulfate to COD in the wastewater was 1:1.2). The processing conditions in Example 2 were: current density of 500 A / m 2 The UV lamp power remains at 30W, the total power is 120W, the cycle reaction time is 10 hours, and after the cycle reaction is completed, the treated water sample is taken for testing.

[0036] Example 3 Compared with Example 1, Example 3 differs in that: Step (1) is different. The specific steps (1) of Example 3 are as follows: A porous Al2O3 ceramic membrane was selected as the conductive substrate 12 (average pore size 200 μm, thickness 2 mm). The conductive substrate 12 was ultrasonically cleaned in acetone, ethanol and deionized water for 15 minutes each, and then dried for later use. A ruthenium-iridium oxide (RuO2-IrO2 / Ti) electrocatalytic active layer 13 was prepared on the surface and inside the pores of the conductive substrate 12 using the sol-gel method. The treatment time was 2 hours. Specifically, the precursor salt containing Ru and Ir was dissolved in an alcohol solvent, and an appropriate amount of the precursor salt of noble metal Rh (RhCl2) was added and stirred evenly to form a sol. The porous Al2O3 conductive substrate 12 was immersed in the formed sol, removed and dried, and then sintered at 500℃ for 2 hours. This process was repeated three times to obtain the Rh-doped RuO2-IrO2 / Al2O3 microporous membrane electrode.

[0037] In reactor 2 of Example 3, the distance between the anode 3 and the cathode 4 is set to 20cm.

[0038] Example 3 treated wastewater from a pharmaceutical factory. The wastewater had a COD of 5500 mg / L, and its pH was adjusted to 6.0. 68.75 g of sodium persulfate was added (i.e., the mass ratio of sodium persulfate to COD in the wastewater was 1:0.8). The reaction time was 5 hours, and the current density was 1000 A / m³. 2 The ultraviolet lamp has a power of 70W, the total power is 280W, the cycle reaction time is 4 hours, and after the cycle reaction is completed, the treated water sample is taken for testing.

[0039] Example 4 The difference from Example 1 is that porous TiO2 is selected as the conductive substrate 12, the electrocatalytic active layer 13 is made of iridium tantalum oxide, and the noble metal particles 14 are made of ruthenium.

[0040] Example 5 The difference from Example 4 is that the precious metal particles 14 are gold.

[0041] Comparative Example 1 The same microporous membrane electrode, reactor 2, and dyeing wastewater as in Example 1 were used, but sodium persulfate was not added in the pretreatment step. Other operating conditions were the same as in Example 1. After the cyclic reaction treatment was completed, the treated water sample was taken for testing.

[0042] Comparative Example 2 Using the same microporous membrane electrode, reactor 2, and dyeing wastewater as in Example 1, sodium persulfate was added during pretreatment, but no electricity was applied during the reaction; only the ultraviolet lamp 5 (total power 100W) was turned on.

[0043] Comparative Example 3 The reactor 2 and pharmaceutical wastewater were exactly the same as in Example 1. The difference was that no noble metal Pd precursor was added in the sol-gel step when preparing the microporous membrane electrode. That is, the electrocatalytic active layer 13 was only RuO2-IrO2 and did not contain noble metal particles 14. Other treatment conditions were the same as in Example 1. After the cyclic reaction was completed, the treated water sample was taken for testing.

[0044] Comparative Example 4 The reactor structure was the same as in Example 1, but the microporous membrane electrode was replaced with a double-sided palladium metal composite electrocatalytic membrane (PdCM, Pd sputtering thickness 30nm). The same dyeing wastewater (sodium persulfate added) was treated as in Example 1, but the ultraviolet lamp 5 was not turned on during the reaction, and only electroactivation (current density 200A / m²) was used. After the cycle reaction was completed, the treated water sample was taken for testing.

[0045] Comparative Example 5 The same microporous membrane electrode (Pd-BDD / SiC) and dyeing wastewater as in Example 1 were used, but the internal structure of the reactor was changed. Specifically, four UV lamps 5 were centrally installed in the center of reactor 2, while the anode 3 and cathode 4 were installed around the UV lamps 5. In this structure, the UV light needs to penetrate a thicker solution layer to reach the membrane electrode surface, and the irradiation is uneven. Other conditions in Comparative Example 5 (PMS dosage, current density, total UV lamp power, reaction time, etc.) were the same as in Example 1. After the cyclic reaction was completed, the treated water sample was taken for testing.

[0046] The wastewater treatment equipment, treatment conditions, and test results of Examples 1-3 and Comparative Examples 1-5 were compared and analyzed, as shown in Table 1.

[0047]

[0048] As can be seen from Table 1, the COD removal rates of Comparative Examples 1-3 are all less than 90%, while the COD removal rate of Example 1 is as high as 98.36%. This is because no persulfate was added in Comparative Example 1, no electroactivation was performed in Comparative Example 2, and no precious metals were added in Comparative Example 3. Based on the test results of Examples 1-6 and Comparative Examples 1-3, it can be concluded that persulfate, electroactivation, precious metal activation, and ultraviolet light activation are all indispensable in the process of COD removal from wastewater. Compared to Example 1, the UV lamp 5 was not turned on in Comparative Example 4, and the COD removal rate in Comparative Example 4 was only 74.32%, which was much lower than 98.36% in Example 1, further proving the importance of UV activation. Compared to Example 1, Comparative Example 5 changed the relative positions of the UV lamp 5 and the membrane electrode (from alternating arrangement to central irradiation). The COD removal rate in Comparative Example 5 was 76.45%, which was still lower than 98.36% in Example 1. This shows that not every combination of "electricity + UV light" can produce excellent synergistic effects. Only by adopting an "alternating arrangement" structure can UV light be directly irradiated onto the surface of the membrane electrode, thereby achieving surface-enhanced degradation of pollutants trapped on the surface of the membrane electrode and in-situ photoregeneration of the membrane electrode, resulting in significant synergistic effects.

[0049] In summary, this invention achieves direct and efficient irradiation of the membrane electrode surface by arranging the anode 3, cathode 4, and ultraviolet lamp 5 in an alternating manner. This expands photoactivation from traditional bulk activation to surface-enhanced degradation and in-situ photoregeneration of the electrode, making light energy utilization more precise and electrode activity more durable. Under the premise of achieving the same treatment effect, the current density and ultraviolet light intensity can be reduced, effectively saving energy. At the same time, this invention highly synergizes the three mechanisms of electrocatalysis, noble metal catalysis, and ultraviolet photoactivation in space and time, thereby significantly improving the yield of active species and the degradation efficiency of pollutants.

[0050] Those skilled in the art will understand that pure porous Al2O3 and porous TiO2 ceramics are inherently non-conductive or have extremely poor conductivity. Therefore, when Al2O3 or TiO2 is chosen as a porous conductive substrate, it needs to be conductively treated. Commonly used conductive treatment methods include, but are not limited to: high-temperature reduction (e.g., reducing TiO2 to Ti4O7 under an argon or hydrogen atmosphere, or further reducing it to lower-valence titanium oxides), metal ion doping (e.g., Nb-doped TiO2, Fe-doped Al2O3), and surface coating with a conductive layer (e.g., a carbon layer, a metal layer), etc. After the above treatments, Al2O3 and TiO2 substrates can obtain conductivity that meets the requirements of electrochemical applications. The porous Al2O3 and porous TiO2 described in this invention encompass materials that have undergone such conductive treatment.

[0051] The microporous membrane electrode, its preparation method, and its application provided by this invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A microporous membrane electrode, characterized in that, include: Porous conductive substrate; An electrocatalytic active layer supported on the surface of the porous conductive substrate; as well as Noble metal particles doped into the electrocatalytic active layer; The microporous membrane electrode is configured to, when used as an anode and positioned opposite to the cathode, with an applied electric field, and alternately arranged with ultraviolet lamps and placed under ultraviolet irradiation, synergistically activate persulfate through electrocatalytic activation, noble metal catalytic activation, and ultraviolet light activation to degrade pollutants.

2. The microporous membrane electrode according to claim 1, characterized in that, The porous conductive substrate is one of porous Al2O3, porous TiO2, Ti4O7 or porous SiC, and the pore size of the membrane channel of the porous conductive substrate is 50μm-200μm.

3. The microporous membrane electrode according to claim 1, characterized in that, The electrocatalytic active layer is one of boron-doped diamond, ruthenium-iridium oxide, iridium-tantalum oxide, tin-antimony oxide, or lead dioxide.

4. The microporous membrane electrode according to claim 1, characterized in that, The precious metal particles are one or more of ruthenium, rhodium, palladium, platinum, and gold.

5. A method for preparing a microporous membrane electrode as described in any one of claims 1 to 4, characterized in that, Includes the following steps: S10, Provides a porous conductive substrate; S20. Construct an electrocatalytic active layer on the surface of the porous conductive substrate, and introduce noble metal particles into the electrocatalytic active layer.

6. The preparation method according to claim 5, characterized in that, In step S20, noble metal particles are loaded onto the electrocatalytic active layer or its surface simultaneously with or after the construction of the electrocatalytic active layer by one of magnetron sputtering, sol-gel method or powder sintering method.

7. A reactor for the synergistic activation of persulfate, characterized in that, include: At least one microporous membrane electrode as described in any one of claims 1 to 4 is used as the anode; At least one cathode; as well as At least one ultraviolet lamp; The anode, cathode, and ultraviolet lamp are arranged alternately inside the reactor, so that the ultraviolet light emitted by the ultraviolet lamp can directly irradiate the surface of the microporous membrane electrode, thereby achieving photoactivation and photoregeneration of pollutants trapped on the membrane surface and electrode active sites.

8. A reactor as described in claim 7, characterized in that, The distance between the anode and cathode plates is 5-20 cm.

9. A method for treating wastewater based on the reactor of claim 7 or 8, characterized in that, Includes the following steps: S30. Mix the wastewater to be treated with persulfate to obtain pretreated wastewater; S40. The pretreated wastewater is introduced into the reactor, and an electric field and ultraviolet irradiation are applied simultaneously for synergistic oxidation treatment.

10. The method as described in claim 9, characterized in that, In step S30, the pH of the wastewater to be treated is adjusted to 4-6, and the mass ratio of persulfate dosage to COD of the wastewater to be treated is 1:0.8-1.

2. In step S40, the current density of the applied electric field is 100-1000 A / m. 2 The intensity of ultraviolet radiation is 100-300 W / m. 2 .

Images