Electro-fenton water treatment system based on micro-bubble aeration

Abstract

The utility model relates to an electric fenton water treatment system based on micro -bubble aeration belongs to sewage treatment technical field, the utility model discloses including the pre -oxidation chamber, electrode reaction chamber and sludge sedimentation separation chamber that set up in proper order to the reaction procedure, be equipped with the screen board between pre -oxidation chamber and electrode reaction chamber, be equipped with the screen board between electrode reaction chamber and sludge sedimentation separation chamber, the pre -oxidation chamber is opened with the water inlet, be equipped with cathode plate and anode plate in the electrode reaction chamber, and cathode plate and anode plate are connected with pulse power supply, the sludge sedimentation separation chamber is opened with sewage outlet on, the bottom of pre -oxidation chamber and electrode reaction chamber is equipped with aeration device, the utility model discloses whole system through the synergic effect of pulse electric field - micro -bubble mass transfer has realized the efficient mineralization of organic pollutant, especially applicable to the advanced treatment of refractory organic wastewater of pharmaceutical, printing and dyeing etc.

Description

Technical Field

[0001] This utility model belongs to the field of wastewater treatment technology, specifically, it relates to an electro-Fenton water treatment system based on microbubble aeration. Background Technology

[0002] Compared with the traditional Fenton process, the electro-Fenton process has many advantages, such as no need or only need to add a small amount of chemical reagents, a clean treatment process, relatively simple equipment, easy to achieve automatic control, more complete oxidation of organic matter, less sludge, high treatment efficiency, small footprint, and easy to combine with other methods. However, in the practical application of traditional electro-Fenton technology for treating organic wastewater, there are still several key technical bottlenecks that restrict its large-scale engineering promotion.

[0003] Electrochemical Fenton technology, as an advanced oxidation process, has attracted much attention in the treatment of recalcitrant organic wastewater, but its industrial application has long been constrained by multiple technical bottlenecks. Traditional electro-Fenton systems generally employ batch reactors and DC power supply, resulting in significant hydrogen evolution side reactions at the cathode (accounting for 35%-45% of energy consumption), and the Fe²⁺ on the two-dimensional flat electrode surface... + The H2O2 mass transfer efficiency is low (the actual utilization rate of ·OH is less than 40%), especially when treating high-concentration and complex wastewater. 3+ The rapid accumulation of iron sludge can lead to catalyst deactivation and the generation of large amounts of iron sludge (8-12 kg per ton of water), causing a surge in subsequent sludge disposal costs. Existing aeration technologies mostly rely on millimeter-level bubbles for oxygen supply, resulting in limited gas-liquid contact area (<50 m² / m³) and oxygen utilization rates below 30%, severely restricting H₂O₂ generation kinetics. Furthermore, when treating chloride-containing wastewater, the continuous action of a DC electric field easily triggers excessive oxidation of Cl⁻, generating chlorinated byproducts (such as chloroform at concentrations reaching μg / L), posing a risk of secondary pollution. More significantly, during the operation of traditional electro-Fenton systems, iron sludge easily deposits on the electrode surface, forming an insulating layer (current efficiency decreases by more than 60% after 100 hours of operation), forcing frequent process shutdowns for cleaning and hindering continuous operation. Although recent studies have attempted to improve mass transfer through fluidized bed structures or three-dimensional electrodes, problems such as uneven bubble distribution and poor spatial matching between electrodes and catalysts remain unresolved. In particular, in the treatment of industrial wastewater with high chlorine (Cl⁻>5000mg / L) and high organic load (COD>8000mg / L), there are still drawbacks such as large fluctuations in treatment efficiency (TOC removal rate deviation ±15%) and high operating costs (energy consumption per ton of water>8kWh).

[0004] Furthermore, existing electro-Fenton reactors suffer from turbulent internal flow fields, low micro-interface contact efficiency between oxidants and contaminants, and the coupling effect of iron sludge accumulation and electrode passivation makes long-term stable operation difficult. These problems essentially stem from the disconnect between reactor structural design and process mass transfer enhancement, as well as the mismatch between electrochemical parameters and hydrodynamic characteristics. A technological breakthrough is urgently needed through deep integration of reactor-specific innovation and multiphase synergistic mechanisms. Summary of the Invention

[0005] To overcome the problems existing in the background technology, this utility model provides an electro-Fenton water treatment system based on microbubble aeration. The whole system achieves efficient mineralization of organic pollutants through the synergistic effect of pulsed electric field and microbubble mass transfer, and is particularly suitable for the deep treatment of recalcitrant organic wastewater in the pharmaceutical, printing and dyeing industries.

[0006] To achieve the above objectives, this utility model is implemented through the following technical solution: The microbubble aeration-based electro-Fenton water treatment system includes a pre-oxidation chamber, an electrode reaction chamber, and a sludge sedimentation separation chamber arranged sequentially according to the reaction process. A partition plate is provided between the pre-oxidation chamber and the electrode reaction chamber. A partition is provided between the electrode reaction chamber and the sludge sedimentation separation chamber. The pre-oxidation chamber has an inlet. The electrode reaction chamber has a cathode plate and an anode plate, which are connected to a pulse power supply. The sludge sedimentation separation chamber has a wastewater outlet. An aeration device is provided at the bottom of the pre-oxidation chamber and the electrode reaction chamber.

[0007] Preferably, the cathode plate is made of cathode copper; the anode plate is made of titanium plate with SnO2-Sb2O3 coating; and the space between the anode plate and the cathode plate is filled with a biochar matrix loaded with Fe3O4.

[0008] Preferably, the partition plate is a plate-shaped structure or a mesh-shaped structure with sewage channels.

[0009] Preferably, the aeration device is a titanium micro-nano aeration disc with a pore size of 1-5 μm and a porosity of 60%.

[0010] Preferably, the titanium-based micro / nano aeration disc is equipped with an oxygen supply pipe and an ozone supply pipe; each of the oxygen supply pipe and the ozone supply pipe is equipped with a flow meter.

[0011] Preferably, the cathode plate is a corrugated plate.

[0012] Preferably, the pulse power supply is equipped with an H-bridge power module.

[0013] Preferably, the top of the electrode reaction chamber is equipped with a hydraulic scraper; the partition between the electrode reaction chamber and the sludge sedimentation and separation chamber is equipped with a sludge discharge channel at the top.

[0014] The beneficial effects of this utility model are: This invention, by separately setting up a pre-oxidation chamber, an electrode reaction chamber, and a sludge sedimentation and separation chamber, and by installing micro-nano aeration discs at the bottom of the pre-oxidation chamber and the electrode reaction chamber, enables the gradient addition of ozone. This gradient ozone addition effectively decomposes macromolecular organic precursors while inhibiting bromate formation. It is specifically designed for high-chlorine wastewater (Cl... - The effective chlorine concentration was controlled below 0.2 mg / L by controlling the ozone dosage ratio to preferentially oxidize chloride ions, combined with pulsed electric field modulation (>8000 mg / L).

[0015] This invention employs a copper cathode as the cathode plate and a titanium plate coated with a SnO2-Sb2O3 layer as the anode plate. Fe3O4-loaded biochar is filled between the cathode and anode plates. Combined with the effect of a pulsed electric field, under acidic conditions, the Fe3O4-loaded biochar achieves Fe... 2+ The continuous slow release, configured with a titanium-based SnO2-Sb2O3 anode, selectively activates the hydroxyl radical generation pathway by controlling the pulse frequency and duty cycle through pulse power supply. This effectively suppresses side reactions while controlling the dynamic matching between the ·OH generation rate and oxidation demand, thereby improving the Fenton reaction activity.

[0016] This invention achieves efficient mineralization of organic pollutants through the synergistic effect of pulsed electric field, three-dimensional electrode, and microbubble mass transfer, and is particularly suitable for the deep treatment of recalcitrant organic wastewater from industries such as pharmaceuticals and dyeing. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model; In the diagram, 1-inlet, 2-micro-nano aeration disc, 3-pre-oxidation chamber, 4-partition screen, 5-hydraulic scraper, 6-electrode reaction chamber, 7-pulse power supply, 8-partition, 9-sludge sedimentation and separation chamber, 10-outlet, 11-sludge collection hopper, 12-cathode plate, 13-loaded Fe3O4 biochar, 14-anode plate. Detailed Implementation

[0018] To make the objectives, technical solutions, and beneficial effects of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, so as to facilitate the understanding of those skilled in the art.

[0019] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "equipped with" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0020] like Figure 1 As shown, the electro-Fenton water treatment system based on microbubble aeration includes a pre-oxidation chamber 3, an electrode reaction chamber 6, and a sludge sedimentation separation chamber 9 arranged sequentially according to the reaction process. A partition plate 4 is provided between the pre-oxidation chamber 3 and the electrode reaction chamber 6, and a partition plate 8 is provided between the electrode reaction chamber 6 and the sludge sedimentation separation chamber 9. The pre-oxidation chamber 3 has an inlet 1. The electrode reaction chamber 6 has a cathode plate 12 and an anode plate 14, which are connected to a pulse power supply 7. The sludge sedimentation separation chamber 9 has a wastewater outlet. Micro-nano aeration discs 2 are provided at the bottom of the pre-oxidation chamber 3 and the electrode reaction chamber 6.

[0021] The micro-nano aeration disc 2 has a pore size of 1-5μm and a porosity of 60%. It is equipped with oxygen supply pipes and ozone supply pipes, each with a flow meter. The flow meters are used to control the amount of oxygen and ozone entering the micro-nano aeration disc 2. Through multiple experiments, it has been verified that for wastewater with a chlorine content greater than 3000mg / L, an ozone content of 5-8% (ozone accounting for 5-8% of the total volume of ozone and oxygen) yields the optimal oxidation effect. By controlling the air inlet pressure of the micro-nano aeration disc 2 at 0.3-0.45MPa, a bubble cluster with an average diameter of approximately 15μm is formed in the pre-oxidation chamber 3. The wastewater mixes with ozone and oxygen, and the gas-liquid contact time reaches 40 seconds.

[0022] Wastewater enters the pre-oxidation chamber 3 through inlet 1 and is premixed with oxygen and ozone delivered by micro-nano aeration disc 2. During the premixing process, chloride ions in the wastewater are oxidized. According to sampling analysis, taking wastewater with an influent chloride content of 3000 mg / L as an example, the chloride ions oxidized after passing through the pre-oxidation chamber 3 are approximately 2000 mg / L.

[0023] The cathode plate is made of cathode copper; the anode plate is made of titanium-based SnO2-Sb2O3; and Fe3O4-loaded biochar is filled between the anode and cathode plates. Under acidic conditions, the Fe3O4-loaded biochar achieves Fe... 2+ The continuous slow release, configured with a titanium-based SnO2-Sb2O3 anode, selectively activates the hydroxyl radical generation pathway by adjusting the pulse frequency (0.1-10kHz) and duty cycle (10-90%) through pulse power supply 7. This effectively suppresses side reactions while controlling the dynamic matching between the ·OH generation rate and oxidation demand, thereby improving the Fenton reaction activity.

[0024] As a preferred option, the cathode plate is designed as an S-shaped corrugated plate with a wave height of 30mm, a wavelength of 150mm, and a specific surface area of ​​1500m². 2 / m 3 The curved structure of the corrugated plate can increase the H2O2 yield to 3.2 mmol / (h·cm). 2 ).

[0025] It should be further explained that the partition plate 4 is a plate-shaped structure or a mesh-shaped structure with a sewage channel. Its main function is to allow sewage to enter the electrode reaction chamber from the pre-oxidation chamber, and to reduce the water flow rate, prolong the residence time of sewage in the pre-oxidation chamber 3, and thus prolong the oxidation time.

[0026] The pulse power supply 7 is equipped with an H-bridge power module, which can be set to forward and reverse pulses (this technology is known). By setting a reverse pulse, the passivation layer on the electrode surface can be self-cleaned using the reverse pulse (applying a reverse voltage for 30 seconds every 15 minutes), preventing sludge from depositing on the electrode plate.

[0027] As a preferred embodiment, the top of the electrode reaction chamber 6 is equipped with a hydraulic scraper 5; the partition 8 between the electrode reaction chamber 6 and the sludge sedimentation separation chamber 9 is equipped with a sludge discharge channel at the top. The intercepted iron sludge flocs are pushed into the sludge sedimentation separation chamber 9 by the hydraulic scraper 5, and a conical sludge collection hopper 11 is arranged at the bottom of the sludge sedimentation separation chamber 9, from which the sludge is discharged.

[0028] The working process and working principle of this utility model: Wastewater flows continuously through the electro-Fenton water treatment system at a flow rate of 0.8-1.2 m / s. After being fully mixed with micro-nano bubbles in the pre-oxidation chamber 3, it flows through the electrode reaction chamber 6 via the partition plate 4. Under the action of a pulsed electric field, the H2O2 generated at the cathode reacts with the released Fe²⁺. + The process involves thorough contact with wastewater, and the high mass transfer efficiency provided by the microbubbles in the micro-nano aeration discs enables the ·OH generation rate to reach 3.5 times that of traditional processes. During operation, this invention employs a gradient ozone dosing strategy: 70% of the total ozone consumption is used in the pre-oxidation chamber, and 30% in the electrode reaction chamber. Experimental verification shows that gradient ozone dosing effectively decomposes macromolecular organic precursors while inhibiting bromate formation. This method is particularly effective for high-chlorine wastewater (Cl... - The effective chlorine concentration is controlled below 0.2 mg / L by controlling the ozone dosage ratio to preferentially oxidize chloride ions, combined with pulsed electric field modulation (frequency > 4 kHz). The entire system achieves efficient mineralization of organic pollutants through the synergistic effect of pulsed electric field, three-dimensional electrode, and microbubble mass transfer, and is particularly suitable for the deep treatment of recalcitrant organic wastewater from industries such as pharmaceuticals and dyeing.

[0029] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although the utility model has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of this utility model.

Claims

1. An electro-Fenton water treatment system based on microbubble aeration, characterized in that, The system includes a pre-oxidation chamber, an electrode reaction chamber, and a sludge sedimentation and separation chamber arranged sequentially according to the reaction process. A partition plate is provided between the pre-oxidation chamber and the electrode reaction chamber. A partition is provided between the electrode reaction chamber and the sludge sedimentation and separation chamber. The pre-oxidation chamber has an inlet. The electrode reaction chamber has a cathode plate and an anode plate, which are connected to a pulse power supply. The sludge sedimentation and separation chamber has a wastewater outlet. An aeration device is provided at the bottom of the pre-oxidation chamber and the electrode reaction chamber.

2. The electro-Fenton water treatment system based on microbubble aeration according to claim 1, characterized in that, The cathode plate is made of cathode copper; the anode plate is made of titanium plate with SnO2-Sb2O3 coating; and the space between the anode plate and the cathode plate is filled with a biochar matrix loaded with Fe3O4.

3. The electro-Fenton water treatment system based on microbubble aeration according to claim 1 or 2, characterized in that, The partition plate is a plate-shaped structure or a mesh-shaped structure with sewage channels.

4. The electro-Fenton water treatment system based on microbubble aeration according to claim 3, characterized in that, The aeration device is a titanium micro-nano aeration disc with a pore size of 1-5μm and a porosity of 60%.

5. The electro-Fenton water treatment system based on microbubble aeration according to claim 4, characterized in that, The titanium-based micro / nano aeration disc is equipped with an oxygen supply pipe and an ozone supply pipe; each of the oxygen supply pipe and the ozone supply pipe is equipped with a flow meter.

6. The electro-Fenton water treatment system based on microbubble aeration according to claim 1 or 2, characterized in that, The cathode plate is a corrugated plate.

7. The electro-Fenton water treatment system based on microbubble aeration according to claim 1, characterized in that, The pulse power supply is equipped with an H-bridge power module.

8. The electro-Fenton water treatment system based on microbubble aeration according to claim 1, characterized in that, The top of the electrode reaction chamber is equipped with a hydraulic scraper; the partition between the electrode reaction chamber and the sludge sedimentation and separation chamber has a sludge discharge channel at the top.

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