Double pulse internal aeration type electro-fenton device

Abstract

The application discloses a double-pulse internal aeration type electro-Fenton device, and relates to the technical field of sewage treatment equipment.The device comprises an electrolytic cell, a plurality of cathode plates and anode plates are arranged in the electrolytic cell at intervals, a water inlet and a water outlet are arranged at two diagonal positions of the electrolytic cell, the cathode plates comprise a plurality of small cathode plates, the small cathode plates are spliced on the same plane, and the small cathode plates are hollow honeycomb plate structures; a power supply system, the positive electrode is connected with the anode plates, the negative electrode of the power supply system is connected with each small cathode plate through pulse switches; an aeration system, the aeration system is connected with each small cathode plate; and a control system, the control system is connected with the power supply system and the aeration system for control. The electro-Fenton device solves the problems of low hydrogen peroxide yield, decomposition of hydrogen peroxide at the electrode plate, poor mass transfer of hydroxyl radicals, low utilization rate and high treatment cost in the traditional electro-Fenton.

Description

Technical Field

[0001] This invention belongs to the technical field of wastewater treatment equipment, and more specifically, relates to a dual-pulse internal aeration type electro-Fenton device. Background Technology

[0002] In the field of wastewater treatment, industrial wastewater is extremely difficult to treat due to its complex pollutant composition, high pollutant concentration, and poor biodegradability. High-salinity industrial wastewater, in particular, causes changes in osmotic pressure in microbial cells due to its high salinity, leading to microbial death; therefore, traditional biological treatment methods are ineffective. Currently, advanced oxidation processes are mainly used to treat high-salinity industrial wastewater.

[0003] Mainstream advanced oxidation methods include ozone catalytic oxidation, photocatalytic oxidation, Fenton oxidation, and electro-Fenton oxidation. Ozone catalytic oxidation primarily utilizes ozone to decompose into hydroxyl radicals via a catalyst, thereby breaking down and degrading long-chain, ring-linked macromolecular pollutants in water or directly mineralizing them. However, in treating high-salinity wastewater, various anions and cations in the wastewater adhere to the catalyst surface and react with the active sites, leading to catalyst passivation and deactivation. Therefore, the ozone catalyst needs to be replaced periodically. The cost of the ozone catalyst accounts for a significant portion of the ozone catalytic oxidation process, and regular catalyst replacement increases the time and economic cost per ton of water treated. Photocatalytic oxidation requires high water color, has generally low treatment efficiency, and high operating costs, limiting its engineering applications. Fenton oxidation, in an acidic environment, uses ferrous ions to oxidize hydrogen peroxide, generating a large number of hydroxyl radicals, which then degrade pollutants in the water. However, Fenton oxidation uses hydrogen peroxide, which poses certain risks during transportation and storage. Furthermore, pH adjustment and iron sludge treatment increase processing costs, making traditional Fenton oxidation an undesirable option. Electro-Fenton oxidation is similar to traditional Fenton oxidation, the difference being the source of the hydrogen peroxide. Traditional electro-Fenton oxidation generates hydrogen peroxide at the cathode through electrolysis to drive the Fenton reaction. While electro-Fenton oxidation solves the problems of hydrogen peroxide transportation and storage, its high energy consumption, low hydrogen peroxide production, and low hydroxyl radical utilization rate still need to be addressed.

[0004] Traditional advanced oxidation methods face numerous limitations in treating high-salinity industrial wastewater, and the problem of high-salinity wastewater treatment urgently needs to be solved. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a dual-pulse internal aeration type electro-Fenton device. This electro-Fenton device solves the problems of low hydrogen peroxide production, side reaction decomposition of hydrogen peroxide at the electrode plate, poor mass transfer of hydroxyl radicals, low utilization rate, and high processing cost in traditional electro-Fenton devices.

[0006] To achieve the above objectives, the present invention provides a dual-pulse internal aeration type electro-Fenton device, comprising:

[0007] An electrolytic cell is provided, wherein multiple cathode plates and anode plates are arranged at intervals within the electrolytic cell, and an inlet and an outlet are respectively provided at two diagonal positions of the electrolytic cell. The cathode plate includes multiple small cathode plates, which are spliced ​​together on the same plane and have a hollow honeycomb structure.

[0008] The power supply system has its positive terminal connected to the anode plate, and its negative terminal connected to each of the small cathode plates via pulse switches.

[0009] An aeration system is connected to each of the small cathode plates;

[0010] The control system is connected to the power supply system and the aeration system.

[0011] Optionally, the bottom of the electrolytic cell is provided with multiple quick-release slots, which are detachably connected to the cathode plate and the anode plate.

[0012] Optionally, the distance between the outermost cathode plate or anode plate and the wall of the electrolytic cell is not less than 200 mm, and the distance between adjacent cathode plates and anode plates is 20 mm to 50 mm.

[0013] Optionally, the edge of the small cathode plate is provided with an insulating frame.

[0014] Optionally, the small cathode plate is made of titanium, the anode plate is made of iron, the porosity of the small cathode plate is 40%-50%, and the micropore diameter of the small cathode plate is less than 10 micrometers.

[0015] Optionally, the aeration system includes an air compressor and an air storage tank, which are connected by pipelines. The outlet of the air storage tank is connected to a solenoid valve group, which is controlled by a pulse controller. The solenoid valve group consists of multiple solenoid valves, and each solenoid valve is connected one-to-one with the small cathode plate.

[0016] Optionally, the system also includes a dosing system comprising multiple reagent tanks connected to the electrolytic cell via a dosing pump.

[0017] Optionally, the dosing system includes a reagent tank containing 98% sulfuric acid and a reagent tank containing 30% hydrogen peroxide.

[0018] Optionally, the electrolytic cell is equipped with an online monitoring system, which includes a pH probe and a COD probe connected to the control system.

[0019] Optionally, the side wall of the electrolytic cell is provided with a slag discharge port.

[0020] This invention provides a dual-pulse internal aeration type electro-Fenton device, which has the following advantages: the electro-Fenton device solves the problems of low oxygen mass transfer efficiency, low hydrogen peroxide production at the cathode plate, hydrogen peroxide being reduced and consumed again, and short existence time and low utilization rate of hydroxyl radicals under low power consumption. At the same time, it also has the advantages of low reagent consumption, high degree of automation, and strong economy.

[0021] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0022] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the invention.

[0023] Figure 1 A schematic diagram of a dual-pulse internal aeration type electro-Fenton device according to an embodiment of the present invention is shown.

[0024] Figure 2 A schematic diagram of the structure of a cathode plate according to an embodiment of the present invention is shown.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1. Electrolytic cell; 2. Cathode plate; 3. Anode plate; 4. Inlet; 5. Outlet; 6. Small cathode plate; 7. Power supply system; 8. Pulse switch; 9. Aeration connector; 10. Aeration system; 11. Control system; 12. Quick-release slot; 13. Insulating frame; 14. Air compressor; 15. Air tank; 16. Solenoid valve assembly; 17. Dosing system; 18. Chemical tank; 19. Dosing pump; 20. Online monitoring system; 21. pH probe; 22. COD probe; 23. Sludge discharge port. Detailed Implementation

[0027] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0028] This invention provides a dual-pulse internal aeration type electro-Fenton device, comprising:

[0029] An electrolytic cell is provided with multiple cathode plates and anode plates spaced apart inside. An inlet and an outlet are located at two opposite corners of the electrolytic cell. The cathode plate consists of multiple small cathode plates spliced ​​together on the same plane. The small cathode plates have a hollow honeycomb structure.

[0030] The power supply system has its positive terminal connected to the anode plate and its negative terminal connected to each small cathode plate via a pulse switch.

[0031] The aeration system is connected to each small cathode plate;

[0032] The control system is connected to the power supply system and the aeration system.

[0033] Specifically, the electro-Fenton device includes an electrolytic cell, a power supply system, and an aeration system. Cathode and anode plates are spaced apart within the electrolytic cell. When wastewater enters the electrolytic cell, the control system activates the power supply and aeration systems based on real-time wastewater monitoring data. The aeration system delivers gas to small cathode plates, which then uniformly aerate the electrolytic cell through micropores. The power supply system controls the sequential start and stop of the small cathode plates, achieving cyclic electrolysis. Within a short time, a gas-liquid-solid interface is formed within the gaps of the cathode plates, creating a working environment for the gas diffusion electrode. Because the internal structure of the small cathode plates is honeycomb-like, this gas-liquid-solid interface forms not only on the surface of the cathode plates but also within the honeycomb pores inside, significantly increasing the reaction area. Since the solubility of oxygen in air is approximately 45 mmol, while the solubility of dissolved oxygen in water is only about 1 mmol, and hydrogen peroxide is produced by reducing oxygen atoms at the cathode plate to generate hydrogen peroxide with a two-electron structure, the amount of oxygen introduced from the air is far greater than the amount of dissolved oxygen in water. This means more oxygen can be utilized around the cathode plate, thus greatly increasing the yield of hydrogen peroxide around it. Furthermore, because the cathode plate is composed of multiple small cathode plates with a hollow honeycomb structure, the interior of the cathode plate is continuously impacted by gas, effectively preventing passivation of the cathode plate structure.

[0034] Optionally, the bottom of the electrolytic cell is provided with multiple quick-release slots, which are detachably connected to the cathode plate and the anode plate.

[0035] Optionally, the distance between the outermost cathode plate or anode plate and the wall of the electrolytic cell shall not be less than 200 mm, and the distance between adjacent cathode plates and anode plates shall be 20 mm to 50 mm.

[0036] Specifically, the electrolytic cell adopts a tumbling electrolytic cell, and the installation direction of the cathode plate and anode plate is parallel to the water flow direction. This can avoid mechanical damage to the cathode plate and anode plate caused by water flow impact. In addition, a detachable quick-release slot is set inside the electrolytic cell to facilitate the installation and removal of the plates, thus enabling the adjustment of the distance between the plates.

[0037] Optionally, the edges of the small cathode plate are provided with an insulating frame.

[0038] Specifically, each cathode plate is composed of four smaller cathode plates spliced ​​together. Each smaller cathode plate is individually connected to a pulse switch, and each smaller cathode plate is connected to the aeration system through an aeration connector. The smaller cathode plates are sealed with an insulating frame around their perimeter, which facilitates the installation of the smaller cathode plates by a pull-in method.

[0039] Optionally, the small cathode plate is made of titanium, the anode plate is made of iron, the porosity of the small cathode plate is 40%-50%, and the micropore diameter of the small cathode plate is less than 10 micrometers.

[0040] Specifically, when the electro-Fenton device is powered on, ferrous ions are deposited on the anode plate, hydrogen peroxide is generated by a reduction reaction on the cathode plate, and Fenton oxidation occurs in the electrolytic cell, thereby removing pollutants.

[0041] Optionally, the aeration system includes an air compressor and an air storage tank, which are connected by pipelines. The outlet of the air storage tank is connected to a solenoid valve assembly, which is controlled by a pulse controller. The solenoid valve assembly consists of multiple solenoid valves, each of which is connected one-to-one to a small cathode plate.

[0042] Specifically, the solenoid valves in the aeration system are solenoid valves with pulse controllers. The controllers use a time-reciprocating cyclic control method, which can control the start and stop times of each independent solenoid valve in a coordinated manner. The pulse switches that power the small cathode plates are electromagnetic time relays, operating in a time-reciprocating cyclic mode, and the switching time can be adjusted arbitrarily. In this way, the pulse switches of each small cathode plate and the solenoid valves with pulse controllers can start and stop synchronously.

[0043] Optionally, it also includes a dosing system, which includes multiple reagent tanks connected to the electrolytic cell via a dosing pump.

[0044] Optionally, the dosing system includes a tank containing 98% sulfuric acid and a tank containing 30% hydrogen peroxide.

[0045] Specifically, the dosing system can add pH adjusters and enhancers to the electrolytic cell. After the dosing pump is started, it is connected to the dosing port on the electrolytic cell through the dosing pipeline. In this way, based on the feedback data from the online monitoring system, the control system can control the dosing amount of the dosing system.

[0046] Optionally, an online monitoring system is installed in the electrolytic cell, which includes a pH probe and a COD probe connected to the control system.

[0047] Specifically, when the online monitoring system detects that the COD level in the wastewater is higher than the set value, the control system will start the dosing pump to add an enhancer into the electrolytic cell, ensuring that the COD of the effluent meets the standard.

[0048] Optionally, the side wall of the electrolytic cell is provided with a slag discharge port. When the electro-Fenton unit stops operating, the sludge inside the unit can be discharged through the slag discharge port.

[0049] Example

[0050] like Figures 1 to 2 As shown, the present invention provides a dual-pulse internal aeration type electro-Fenton device, comprising:

[0051] Electrolytic cell 1, with multiple cathode plates 2 and anode plates 3 spaced apart inside the electrolytic cell 1, and water inlet 4 and water outlet 5 respectively located at two opposite corners of the electrolytic cell 1; Cathode plate 2 includes four small cathode plates 6, which are spliced ​​together on the same plane and have a hollow honeycomb structure.

[0052] The positive terminal of the power supply system 7 is connected to the anode plate 3, and the negative terminal of the power supply system 7 is connected to each small cathode plate 6 through the pulse switch 8.

[0053] The aeration system 10 is connected to the aeration connector 9 of each small cathode plate 6;

[0054] The control system 11 is connected to the power supply system 7 and the aeration system 10.

[0055] In this embodiment, the bottom of the electrolytic cell 1 is provided with a plurality of quick-release slots 12, which are detachably connected to the cathode plate 2 and the anode plate 3.

[0056] In this embodiment, the distance between the outermost cathode plate 2 or anode plate 3 and the wall of the electrolytic cell 1 is not less than 200mm, and the distance between adjacent cathode plates 2 and anode plates 3 is 20mm-50mm.

[0057] In this embodiment, the edge of the small cathode plate 6 is provided with an insulating frame 13.

[0058] In this embodiment, the small cathode plate 6 is made of titanium, the anode plate 3 is made of iron, the porosity of the small cathode plate 6 is 40%-50%, and the micropore diameter of the small cathode plate 6 is less than 10 micrometers.

[0059] In this embodiment, the aeration system 10 includes an air compressor 14 and an air storage tank 15, which are connected by pipelines. The air storage tank 15 is equipped with a solenoid valve group 16, which includes multiple solenoid valves, each of which is connected one-to-one with a small cathode plate 6.

[0060] In this embodiment, a dosing system 17 is also included, which includes a plurality of reagent tanks 18, and the reagent tanks 18 are connected to the electrolytic cell 1 via a dosing pump 19.

[0061] In this embodiment, the dosing system 17 includes a reagent tank containing 98% sulfuric acid and a reagent tank containing 30% hydrogen peroxide.

[0062] In this embodiment, an online monitoring system 20 is provided in the electrolytic cell 1. The online monitoring system 20 includes a pH probe 21 and a COD probe 22 connected to the control system 10.

[0063] In this embodiment, a slag discharge port 23 is provided on the side of the electrolytic cell 1 near the water inlet 4.

[0064] In summary, in this dual-pulse internal aeration electro-Fenton device, each cathode plate 2 is composed of four small cathode plates 6. Each small cathode plate 6 is individually connected to a pulse switch 8 and an aeration connector 9. The small cathode plate 6 is connected to the pulse switch 8 via a power supply wire, and the pulse switch 8 is connected to the negative terminal of the DC power supply. The anode plate 3 is directly connected to the positive terminal of the DC power supply via a power supply wire. The air compressor 14 is connected to the air storage tank 15 via a pipeline. The air storage tank 15 is connected to the controllable pulse solenoid valve group 16. The air outlet of the solenoid valve group 16 is connected to the aeration connector 9, and the aeration connector 9 is directly connected to the hollow flat honeycomb titanium cathode plate 2. During the operation of this electro-Fenton device, the pH probe 21 and COD probe 22 are installed inside the electrolytic cell 1. Real-time monitoring data is obtained through the two probes and fed back to the PLC automatic control system. The PLC automatic control system compares the obtained feedback data with the set values. When the values ​​exceed or fall below the set values, the dosing system 17 is started or stopped for regulation.

[0065] When wastewater enters the electrolysis cell 1, the pH probe 21 is activated first, and real-time data is fed back to the PLC automatic control system. The PLC automatic control system will add chemicals by adjusting the dosing pump 19. After the added chemicals enter the electrolysis cell 1, they are evenly dissolved in the wastewater by the aeration inside the cathode plate 2, thereby adjusting the pH value of the wastewater to the set range.

[0066] Once the wastewater pH reaches the standard, the DC power supply is activated to electrolyze the wastewater in electrolysis cell 1. Each small cathode plate 6 is controlled by a pulse switch 8 to cycle and stop, achieving cyclic batch electrolysis. When the pulse switch 8 corresponding to one of the small cathode plates 6 is in the open state, its corresponding solenoid valve is activated simultaneously. At this time, the gas is evenly released through the internal honeycomb structure of the small cathode plate 6. Within a short time, a gas-liquid-solid interface is formed in the gaps of the cathode plate 2, creating a gas diffusion electrode working environment. The special honeycomb structure inside the cathode plate 2 ensures that the gas-liquid-solid interface is not only formed on the surface of the cathode plate but also in the honeycomb pores inside the cathode plate 2, greatly increasing the contact area.

[0067] During electrolysis, cathode plate 2 not only produces hydrogen peroxide but also undergoes a side reaction that reduces hydrogen peroxide to water. When pulse switch 8 is closed, small cathode plate 6 stops electrolysis, cutting off the side reaction that reduces hydrogen peroxide to water and avoiding waste. When the electro-Fenton device is working, each small cathode plate 6 cycles through being energized and de-energized sequentially, preventing the reduction of hydrogen peroxide during electrolysis and thus enhancing the Fenton reaction within the electrolytic cell. Furthermore, during electrolysis, anode plate 3 continuously electrolyzes and dissolves ferrous ions. These ferrous ions catalyze the hydrogen peroxide produced at cathode plate 2 to generate hydroxyl radicals, which then undergo a series of chain reactions. The hydroxyl radicals generated within electrolytic cell 1 oxidize pollutants in the water, and ferric ions form ferric hydroxide precipitate. The oxidized pollutant colloids are adsorbed by the ferric hydroxide precipitate, thereby achieving pollutant removal. Meanwhile, because the cathode plate 2 has an aeration function, it enhances the diffusion of hydrogen peroxide and strengthens the contact catalytic effect between ferrous iron and hydrogen peroxide in the electrolysis cell 1, thereby generating more hydroxyl radicals. The hydroxyl radicals are also affected by the aeration effect, and react quickly with pollutants in the water, reducing the decomposition and waste of hydroxyl radicals.

[0068] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A dual-pulse internal aeration type electro-Fenton device, characterized in that, include: An electrolytic cell is provided, wherein multiple cathode plates and anode plates are arranged at intervals within the electrolytic cell, and an inlet and an outlet are respectively provided at two diagonal positions of the electrolytic cell. The cathode plate includes multiple small cathode plates, which are spliced ​​together on the same plane and have a hollow honeycomb structure. The power supply system has its positive terminal connected to the anode plate and its negative terminal connected to each of the small cathode plates via pulse switches. An aeration system is connected to each of the small cathode plates; The control system is connected to the power supply system and the aeration system, and the pulse switch controls the sequential start and stop of each small cathode plate. The aeration system includes an air compressor and an air storage tank, which are connected by pipelines. The outlet of the air storage tank is connected to a solenoid valve group, which is controlled by a pulse controller. The solenoid valve group consists of multiple solenoid valves, and each solenoid valve is connected one-to-one with the small cathode plate. It also includes a dosing system, which comprises multiple reagent tanks connected to the electrolytic cell via a dosing pump; The electrolytic cell is equipped with an online monitoring system, which includes a pH probe and a COD probe connected to the control system. The pulse switch of each small cathode plate starts and stops synchronously with the solenoid valve corresponding to that small cathode plate. The anode plate is made of iron.

2. The dual-pulse internal aeration type electro-Fenton device according to claim 1, characterized in that, The bottom of the electrolytic cell is provided with multiple quick-release slots, which are detachably connected to the cathode plate and the anode plate.

3. The dual-pulse internal aeration type electro-Fenton device according to claim 2, characterized in that, The distance between the outermost cathode plate or anode plate and the wall of the electrolytic cell is not less than 200 mm, and the distance between adjacent cathode plates and anode plates is 20 mm to 50 mm.

4. The dual-pulse internal aeration type electro-Fenton device according to claim 1, characterized in that, The edge of the small cathode plate is provided with an insulating frame.

5. The dual-pulse internal aeration type electro-Fenton device according to claim 4, characterized in that, The small cathode plate is made of titanium, and the porosity of the small cathode plate is 40%-50%, with the micropore diameter of the small cathode plate being less than 10 micrometers.

6. The dual-pulse internal aeration type electro-Fenton device according to claim 1, characterized in that, The dosing system includes a reagent tank containing 98% sulfuric acid and a reagent tank containing 30% hydrogen peroxide.

7. The dual-pulse internal aeration type electro-Fenton device according to claim 1, characterized in that, The side wall of the electrolytic cell is provided with a slag discharge port.

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