Electrochemistry-based high-oil-content emulsified wastewater treatment process

Abstract

The invention belongs to the technical field of recycling of oily wastewater in water treatment, and provides a high-oil-content emulsified wastewater treatment process based on electrochemistry. Oil-containing wastewater enters the pretreatment unit, oil slick and suspended substances in water are removed through the pretreatment processes of filtration, air floatation, pH adjustment and the like, and the pH is adjusted to a proper range; the reacted oily wastewater enters an electrochemical device, and proper voltage is applied to an electrode, so that emulsified oil in the water is destabilized, and the purpose of demulsification is achieved; the oily wastewater enters an oil-water separation device, demulsified oil drops are coalesced, grow and float upwards, and recoverable oil is obtained on the upper layer of the device; after long-time operation, the water enters the regeneration unit, so that the electrochemical demulsification unit recovers good demulsification and oil removal effects. According to the invention, the treatment of various high-oil-content emulsified wastewater and the recovery of oil can be realized by regulating and controlling the voltage, and the method is suitable for electro-desalting wastewater, machining wastewater, cold rolling wastewater and the like.

Description

Technical Field

[0001] This invention belongs to the field of water treatment and resource recovery technology, and relates to an electrochemical process for treating high-oil-content emulsified wastewater. Background Technology

[0002] Existing oily wastewater treatment processes suffer from problems such as high reagent dosage, low demulsification efficiency, high energy consumption, difficulty in treating byproducts, and complex maintenance and operation of some units. For example, the core treatment process of "oil separation-air flotation-biological treatment" requires the addition of large amounts of chemical reagents and complex process flows, which increases construction costs and subsequent operating costs such as sludge treatment due to the addition of chemical reagents. For example, Thyara Campos Martins Nonato (Combination of electroflotation process and down-flow granular filtration to treat wastewater contaminated with oil) uses an "electroflotation + filtration" process to treat oily wastewater. Electroflotation uses a titanium cathode and DSA anode, and the application of electricity generates hydrogen and chlorine microbubbles to make oil droplets float and separate; the filter bed consists of a 0.4m sand layer (0.58mm particle size) and a 0.25m gravel layer to further remove residual oil. This method in the paper requires the addition of reagents: NaCl (7900 mg / L) is required. -1 To improve conductivity, treatment costs increase, and high-salinity wastewater may require subsequent desalination; high energy consumption: high current density (80 A / m -2 ); Filter unit maintenance is complex: the filter bed requires regular backwashing (every 720 minutes), increasing operational complexity. For example, the Kubra Ulucan (Comparative study of electrochemical wastewater treatment processes for bilge water as oily wastewater: A kinetic approach) employs two processes: electrocoagulation and electro-Fenton. One is electrocoagulation, which uses aluminum / iron electrodes, where anodic dissolution produces Al. 3+ / Fe 2+ Hydroxide flocs are formed to adsorb oil stains, and H2 bubbles generated at the cathode rise to the surface and separate the pollutants. This method has insufficient treatment depth: electrocoagulation has limited removal of emulsified oil, requiring further purification through subsequent processes; secondary pollution: Al 3+ or Fe 2+ Oxidized to Fe 3+ The formation of aluminum hydroxide or iron hydroxide precipitates with hydroxide ions leads to secondary pollution; secondly, the electro-Fenton reaction at pH=3 and current density of 6.8 mA / cm² results in secondary pollution. 2The reaction occurs under conditions where H2O2 dosage is 5000 mg / L, and electrolysis produces Fe. 2+ The reaction with added H2O2 generates ·OH free radicals, which oxidize the target wastewater. This method requires a large amount of reagents: electro-Fenton requires a large amount of H2O2 (5000 mg / L), increasing operating costs and reagent management complexity; it is sensitive to operating conditions: electro-Fenton requires strict pH control at 3 (efficiency decreases after deviation); temperatures above 40°C easily cause H2O2 decomposition; byproduct interference: residual H2O2 interferes with COD detection, requiring additional removal steps; and the electro-Fenton process itself is energy-intensive. For example, Mohammad Vahid Sarfaraz (Experimental investigation and modeling hybrid nano-porous membrane process for industrial oily wastewater treatment) uses a "hybrid nanoporous membrane + powdered activated carbon" process. The core principle of this method is synergistic effect, that is, combining the physical adsorption / coagulation of powdered activated carbon with the separation of the hybrid nanoporous membrane. Higher operating costs: The addition and subsequent treatment of powdered activated carbon (such as disposal of waste powdered activated carbon) increase operating costs; increased system complexity: Additional equipment is required for the addition and mixing of powdered activated carbon, making operation and maintenance more complex; introduction of secondary pollution: If the powdered activated carbon is not completely removed or regenerated, it will cause solid waste problems. For example, the process used in Sun Sen's patent (CN115636521A) to treat high-temperature heavy oil produced water involves: conditioning and homogenization: High-temperature heavy oil produced water first enters a conditioning tank for water quality homogenization; electrochemical oil removal: The electrochemical oil removal reactor uses fiber-reinforced graphite plate electrodes (current density 10–20 mA / cm²). 2 Oil is removed via electrodemulsification. Electrochemical desiliconization: combined with electrocoagulation reaction (current intensity 10–26 mA / cm). 2A special silica removal agent (such as sodium aluminate, 100–300 mg / L) is added to further remove silica. Sedimentation separation: Solid-liquid separation is performed using inclined tube / plate sedimentation tanks with a surface rise velocity of 1–5 m / h. Ceramic membrane filtration: Fine filtration is performed using ceramic membranes with a pore size ≤100 nm to further remove suspended solids and residual oil. This method has a high initial investment: ceramic membrane system equipment costs are high; membrane fouling and cleaning: although ceramic membranes are resistant to fouling, they still require regular cleaning to maintain flux; sensitivity to influent water quality: in the example, the influent oil content is only 64 mg / L; if the oil content is too high, it will affect the efficiency of the electrochemical unit. For example, a process method used in Dai Min's patent (CN116969620A) for treating refinery sulfur-containing emulsified wastewater is described. Electrochemical flocculation-enhanced demulsification: Sulfur-containing emulsified wastewater undergoes demulsification treatment in an electrochemical flocculation tank using iron electrodes (Fe > 99%), operating under specific voltage, temperature, and time conditions to achieve oil-water separation and obtain low-oil wastewater; Electrochemical oxidation catalytic treatment: The low-oil wastewater enters an electrochemical oxidation catalytic tank equipped with metal oxide catalysts (such as Al2O3, TiO2, MnO2), while ozone or an ozone / oxygen mixture is simultaneously introduced for aeration, further degrading organic matter and emulsified oil; Solid-liquid separation: The treated wastewater is centrifuged to remove solid particles, yielding purified water that can enter a subsequent sulfur-containing wastewater stripping unit. This method has high energy consumption: Electroflocculation alone has limited removal of emulsified oil, so an electro-oxidation process is added. The energy consumption generated by the electrochemical unit during the reaction and the energy consumption generated by ozone production lead to the high energy consumption of this method; Strict operating conditions are required: Multiple parameters such as voltage, electrode spacing, gas flow rate, and pH need to be controlled, resulting in high operational complexity.

[0003] Therefore, there is an urgent need in this field to develop an efficient and green process for treating high-oil-content emulsified wastewater. By inputting oily wastewater and adjusting the process parameters, the emulsified oil in the wastewater can be destabilized, the oil content can be reduced, and some recyclable oil can be generated.

[0004] This invention is based on the use of microchannel electrodes. After applying a low-voltage electric field, the negative charge on the inner surface of the cathode microchannel repels the negative charge on the surface of the oil droplet, causing the oil droplet to change from a spherical shape to a rod shape and the surface charge to accumulate at both ends of the rod. The areas of multiple oil droplets lacking charge come into contact with each other, promoting the coalescence of small oil droplets. At the same time, the low-voltage electric field generates reactive oxygen free radicals in the microchannel, which can oxidize and decompose the oil-water interface film, causing the oil-water interface to become unstable. Summary of the Invention

[0005] This invention addresses the lack of a corresponding efficient and environmentally friendly process for treating high-oil-content emulsified wastewater. It proposes and designs an electrochemical-based process for treating such wastewater. This process is applicable to various practical applications generating high-oil-content emulsified wastewater, particularly: machining wastewater from the equipment manufacturing industry, electro-desalination wastewater from the petrochemical industry, and cold rolling wastewater from the metallurgical industry. It provides efficient and clean technical support for the green and sustainable development of related industries.

[0006] The technical solution of the present invention:

[0007] An electrochemical-based process for treating high-oil-content emulsified wastewater involves the wastewater sequentially passing through a pretreatment unit, an electrochemical demulsification unit, and an oil-water separation unit. The pretreatment unit, depending on the influent water quality, includes at least one of the following: a filtration unit I, a flotation unit, a filtration unit II, and a pH adjustment unit. The pretreated wastewater meets the operational requirements of the electrochemical demulsification unit. The electrochemical demulsification unit destabilizes the emulsified oil in the wastewater under an electric field by applying an appropriate voltage and controlling the residence time. The destabilized wastewater then enters the oil-water separation unit, where the destabilized oil droplets coalesce and float to the surface, yielding recoverable oil. When the efficiency of the electrochemical demulsification unit significantly decreases, the inlet and outlet water switches are shut off to regenerate the unit. This process has two operating modes: First, during normal operation, oily wastewater flows sequentially through the pretreatment unit, the electrochemical demulsification unit, and the oil-water separation unit. Second, when the efficiency of the electrochemical demulsification unit decreases significantly, the inlet and outlet water switches for the electrochemical demulsification unit are closed, and the regeneration operation switch is opened. Unlike normal operation, where water enters from the anode and exits from the cathode, the regeneration operation uses a cathode-in, anode-out method. Regeneration methods include, but are not limited to, acid washing, alkaline washing, oxidant cleaning, applying reverse voltage, cathode effluent backwashing, and high-purity water backwashing.

[0008] The pretreatment unit for oily wastewater is configured as follows: If the oil content of the high-oil-content emulsified wastewater is ≥1000 mg / L and the ZETA potential is ≥-40 eV, the wastewater will sequentially pass through filtration unit I (intercepting solid impurities and floating oil with a particle size greater than 50 μm), flotation unit, filtration unit II (intercepting solid impurities with a particle size greater than 50 μm after flotation), and pH adjustment unit for pretreatment to remove organic matter and suspended solids. If the oil content of the high-oil-content emulsified wastewater is <1000 mg / L, the wastewater will only pass through filtration unit I and pH adjustment unit to remove suspended solids.

[0009] The electrochemical demulsification unit uses microchannel electrodes for both the cathode and anode. The diameter of the microchannel is 10~50μm. The materials used for the cathode include, but are not limited to, carbon, titanium, copper, and titanium with mixed oxide coating. The materials used for the anode include, but are not limited to, titanium with mixed oxide coating, titanium, and carbon.

[0010] The oil-water separation unit employs, but is not limited to, inclined plate / corrugated plate separators, hydrocyclones, coalescing plate separators, API separators, ultrafiltration / microfiltration membranes, and dissolved air flotation equipment. It separates oil and water in a solution using different separation forces, including gravity and centrifugal force. The collected oil after separation can be recycled and reused. Specifically, the pressure difference between the plates in the inclined plate / corrugated plate separator is less than 0.05 MPa; the hydrocyclone separator applies a pressure between 0.2 and 0.8 MPa with a split ratio between 5 and 20%; the empty column velocity in the coalescing plate separator is between 4 and 8 m / h; the horizontal velocity in the API separator is between 0.3 and 0.9 m / min; and the ultrafiltration / microfiltration membrane operates at a pressure of 0.1 to 0.3 MPa with a flux of 30 to 50 L / (m³). 2 •h); The dissolved air flotation equipment has a dissolved air pressure of 0.35~0.50MPa and a reflux ratio of 20%~40%.

[0011] The high-oil-content emulsified wastewater to be treated includes, but is not limited to, electro-desalination wastewater, machining wastewater, and cold rolling wastewater. Preferably, the oil content in the oily wastewater is 1000~10000 mg / L, and the ZETA potential is ≥-40eV.

[0012] The electrochemical demulsification unit uses a microchannel cathode and anode in combination. The distance between the cathode reactor and the anode reactor is 1~10mm, the residence time is 0.08~1h, the influent flow rate is 0.1~100L / h, and the applied voltage is 0.5~5V.

[0013] The inlet flow rate of the oil-water separation unit is 0.02~200 L / h, the hydraulic residence time is 0.1~4h, and the oil content of the aqueous phase after separation is below 50mg / L.

[0014] When the efficiency of the electrochemical demulsification unit is ≤65%, it is regenerated by backwashing with cathode effluent. Preferably, backwashing is performed using a pump at a flow rate between 0.02 and 10 L / h, with a hydraulic retention time of 0.05 to 1 h. After backwashing, the oil removal rate of the electrochemical demulsification unit can be restored to over 95%, thereby achieving the rational utilization of water resources and the long-term use of the electrochemical demulsification unit.

[0015] The beneficial effects of this invention are as follows: 1. This invention proposes an electrochemical-based process for treating high-oil-content emulsified wastewater, applicable to various types of oil-containing emulsified wastewater, including electro-desalination wastewater, machining wastewater, and cold rolling wastewater. It can adapt to different water qualities by simply changing operating parameters in different application scenarios, demonstrating broad application prospects; 2. Compared with traditional oil-containing emulsified wastewater treatment technologies, such as membrane separation and the addition of chemical demulsifiers, this invention does not require the addition of chemicals, does not generate additional solid waste during production, and significantly reduces carbon emissions compared to traditional methods, making it a green and environmentally friendly technology; 3. Compared with existing technologies, conventional electrochemical demulsification technology uses flat plates, resulting in excessively long migration distances of oil droplets between the two plates and low demulsification efficiency. The method of this invention can achieve an oil removal efficiency of over 95% while shortening the residence time. 4. The cathode effluent treated by the method of this invention can be used to backwash and regenerate the electrodes, thereby reducing electrode regeneration costs while recycling water resources, and ensuring good oil removal performance even after long-term operation. 5. The method of this invention can recover the oil after oil-water separation and use it as fuel, achieving both resource recycling and reducing environmental pollution. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the process of the present invention;

[0017] Figure 2 This is the piping and instrumentation flow diagram of the present invention;

[0018] Figure 3 Schematic diagram of the microchannel cathode and anode combined structure described in this invention;

[0019] In the diagram, 1. Inlet tank; 2. Filter unit I; 3. Inlet pump; 4. Check valve; 5. Flow meter; 6. Air flotation unit; 7. Filter unit II; 8. pH adjustment unit; 9. Electrochemical demulsification unit; 10. Oil-water separation unit; 11. Regeneration operation; 12. Outlet tank; 13. Central control and power supply; 14. Switch I; 15. Switch II; 16. Microchannel cathode; 17. Microchannel anode; 18. Inlet; 19. Outlet. Detailed Implementation

[0020] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0021] like Figure 1 As shown, an electrochemical-based process for treating high-oil-content emulsified wastewater includes a pretreatment unit, an electrochemical demulsification unit, and an oil-water separation unit.

[0022] Specifically, such as Figure 2As shown, an electrochemical-based high-oil-content emulsified wastewater treatment process includes an inlet tank 1, a pretreatment unit, an electrochemical demulsification unit 9, an oil-water separation unit 10, a regeneration operation unit 11, an outlet tank 12, a central control and power supply unit 13, a switch I 14, and a switch II 15. The pretreatment unit includes a filtration unit I 2, an air flotation unit 6, a filtration unit II 7, and a regulating unit 8. An inlet pump 3, a check valve 4, and a flow meter 5 are connected between the filtration unit I 2 and the air flotation unit 6. The electrochemical demulsification unit 9 includes a microchannel cathode 16, a microchannel anode 17, an inlet 18, and an outlet 19. The high-oil-content emulsified wastewater is stored in the inlet tank 1 and first undergoes pretreatment through the filtration unit I 2. The inlet pump 3 is installed after the filtration unit I 2 to prevent solid impurities in the raw water from clogging the inlet pump 3. Its function is to pump the raw water into the subsequent treatment unit. A check valve 4 is installed after the inlet pump 3 to prevent water from the subsequent treatment unit from flowing back to the inlet pump. 3. This causes damage to the inlet pump 3. Then, a flow meter 5 is installed to monitor the inlet flow rate. Based on the detected flow rate, the opening of the inlet pump 3 is adjusted to adjust the inlet flow rate to meet the requirements of the subsequent reaction unit. Then, it enters the flotation unit 6 to perform flotation on the filtered raw water to blow out and scrape off the soluble organic matter. Then, it enters the filtration unit II 7 to filter the raw water again after flotation to prevent the sediment generated by flotation from entering the electrochemical demulsification unit 9 and clogging the microchannel electrode. Then, it enters the pH adjustment unit 8 to adjust the pH to a suitable value to meet the working requirements of the subsequent electrochemical demulsification unit 9. Then, it enters the electrochemical demulsification unit 9 through the inlet pump 3. Under the action of the microchannel electrode, the emulsified oil is destabilized and the oil removal purpose is achieved, and the oil removal efficiency can reach more than 95%. Then, it enters the oil-water separation unit 10 through the inlet pump 3. After a certain residence time, the oil phase and water phase are separated and the oil phase is recovered. The water phase enters the outlet tank 12 through the inlet pump 3.

[0023] When the efficiency of the electrochemical demulsification unit drops significantly, the inlet and outlet water switches I14 before and after the electrochemical demulsification unit 9 are closed, and switch II15 is opened. The system then enters regeneration operation 11 via the inlet water pump 3. After a certain residence time, the oil removal efficiency of the electrochemical demulsification unit 9 is restored to over 95%. The effluent from the regeneration operation enters the outlet water tank 12 via the inlet water pump 3. The entire process, including the inlet water pump 3, flow meter 5, electrolysis unit power supply, and motor drive, is integrated into an operation control center equipped with an automated control system. Parameters are adjusted according to changes in inlet water quality and process requirements to ensure stable operation of the entire process system.

[0024] The pretreatment unit includes different treatment units depending on the quality of the influent. For high-oil-content emulsified wastewater with an oil content ≥1000mg / L and a ZETA potential greater than or equal to -40eV, the high-oil-content emulsified wastewater is first pumped into filtration unit I to remove large particulate suspended solids. Then it enters the air flotation unit to blow out and scrape off soluble organic matter in the oil by adhering to fine air bubbles. Then it is pumped into filtration unit II to remove the precipitate generated by air flotation to avoid clogging the microchannel electrodes. It is further pumped into the pH adjustment unit to adjust the pH value to between 2 and 9. The particle size of the substances in the oily water entering the electrochemical demulsification unit 9 is <50μm. If the oil content of the high-oil-content emulsified wastewater is <1000mg / L, the pretreatment unit only includes filtration unit I and pH adjustment unit to remove suspended solids in the water, with the pH between 2 and 9. The particle size of the substances in the oily water entering the electrochemical demulsification unit is <50μm.

[0025] The pretreated oily water enters the electrochemical demulsification unit 9. The reactor of the electrochemical demulsification unit 9 is a microchannel cathode and anode combined reactor, such as... Figure 3 As shown, the combined reactor consists of a microchannel cathode 16 and a microchannel anode 17, with a spacing of 1~10mm between them. Oily water enters the microchannel anode 17 through the inlet 18. The microchannel cathode 16 is connected to the negative terminal of the power supply, and the microchannel anode 17 is connected to the positive terminal. The applied voltage is 0.5~5V. The oily water first passes through the microchannel anode 17 and then through the microchannel cathode 16. The inlet flow rate is 0.1~100L / h. After a residence time of 0.08~1h, the water is extracted from the outlet 19 and pumped into the oil-water separation unit 10 by the inlet pump 3 for oil-water separation and recovery of the oil phase.

[0026] When the treatment efficiency of the electrochemical demulsification unit 9 is ≤65%, close its front and rear switches I14 and open switch II15. The inlet water pump 3 pumps the cathode water from the cathode into the anode for regeneration operation 11. The inlet water flow rate is 0.02~10L / h and the hydraulic residence time is 0.05~1h, so that the oil removal efficiency of the electrochemical demulsification unit is restored to more than 95%.

[0027] This invention centers on an electrochemical demulsification unit with microchannel cathodes and anodes. Due to its adsorption, polarization, and oxidation functions, it achieves extremely high demulsification and oil removal efficiency. Therefore, the pretreatment unit is designed to ensure that oily wastewater meets the operational requirements of the electrochemical demulsification unit, eliminating the need for coagulation and flocculation with added chemicals. This reduces subsequent sludge treatment costs and prevents secondary pollution. For high emulsified oil removal rates, the residence time required for the flat plate electrode is 25 times that of the microchannel electrode. When the efficiency of the electrochemical demulsification unit decreases, regeneration is performed using the cathode effluent, making efficient use of water resources and reducing electrode regeneration costs. Ultimately, recyclable oil can be obtained, enabling the reuse of oil resources.

Claims

1. A high-oil-content emulsified wastewater treatment process based on electrochemistry, characterized in that, High-oil-content emulsified wastewater sequentially passes through a pretreatment unit, an electrochemical demulsification unit, and an oil-water separation unit; The pretreatment unit is equipped with at least one of the following according to the influent water quality: filtration unit I, flotation unit, filtration unit II, and pH adjustment unit. The wastewater treated by the pretreatment unit meets the operating requirements of the electrochemical demulsification unit. The electrochemical demulsification unit destabilizes the emulsified oil in the oily wastewater under the action of an electric field by applying an appropriate voltage and controlling the residence time. The destabilized oily wastewater enters the oil-water separation unit, where the destabilized oil droplets coalesce and float to the surface to obtain recoverable oil.

2. The electrochemical-based high-oil-content emulsified wastewater treatment process according to claim 1, characterized in that, When the processing efficiency of the electrochemical demulsification unit decreases significantly, the inlet and outlet water valves of the electrochemical demulsification unit are closed to regenerate the electrochemical demulsification unit. The regeneration operation is carried out with the cathode inlet and the anode outlet outlet. The regeneration methods include acid washing, alkali washing, oxidant cleaning, applying reverse voltage, cathode outlet backwashing, and high-purity water backwashing.

3. The electrochemical-based high-oil-content emulsified wastewater treatment process according to claim 1, characterized in that, The pretreatment unit is set up as follows: If the oil content of the high oil content emulsified wastewater is ≥1000mg / L and the ZETA potential is ≥-40eV, the high oil content emulsified wastewater flows through the filtration unit I, the air flotation unit, the filtration unit II and the pH adjustment unit in sequence for pretreatment to remove organic matter and suspended matter from the high oil content emulsified wastewater. If the oil content of the high-oil-content emulsified wastewater is <1000mg / L, then the high-oil-content emulsified wastewater will only pass through filtration unit I and pH adjustment unit to remove suspended solids in the water.

4. The electrochemical-based high-oil-content emulsified wastewater treatment process according to claim 1, characterized in that, The electrochemical demulsification unit uses microchannel electrodes for both the cathode and anode. The diameter of the microchannel is 10~50μm. The materials used for the cathode include carbon, titanium, copper, and titanium with mixed oxide coating. The materials used for the anode include titanium with mixed oxide coating, titanium, and carbon.

5. The electrochemical-based high-oil-content emulsified wastewater treatment process according to claim 1, characterized in that, The oil-water separation unit includes inclined plate / corrugated plate separators, hydrocyclones, coalescing plate separators, API separators, ultrafiltration / microfiltration membranes, or dissolved air flotation equipment. The recoverable oil collected after oil-water separation is reused. Specifically, the inter-plate pressure difference in the inclined plate / corrugated plate separator is less than 0.05 MPa; the applied pressure of the hydrocyclone separator is between 0.2 and 0.8 MPa, and the split ratio is between 5 and 20%; the empty column velocity of the coalescing plate separator is between 4 and 8 m / h; the horizontal velocity of the API separator is between 0.3 and 0.9 m / min; and the operating pressure of the ultrafiltration / microfiltration membrane is 0.1 to 0.3 MPa, and the flux is 30 to 50 L / (m³). 2 •h); The dissolved air flotation equipment has a dissolved air pressure of 0.35~0.50MPa and a reflux ratio of 20%~40%.

6. The electrochemical-based high-oil-content emulsified wastewater treatment process according to claim 1, characterized in that, The high-oil-content emulsified wastewater to be treated includes electro-desalination wastewater, machining wastewater, and cold rolling wastewater, with an oil content of 1000~10000 mg / L and a ZETA potential ≥ -40 eV.

7. The electrochemical-based high-oil-content emulsified wastewater treatment process according to claim 1, characterized in that, The electrochemical demulsification unit uses a combination of microchannel cathode and microchannel anode. The distance between the cathode reactor and the anode reactor is 1~10mm, the residence time is 0.08~1h, the influent flow rate is 0.1~100L / h, and the applied voltage is 0.5~5V.

8. The electrochemical-based high-oil-content emulsified wastewater treatment process according to claim 1, characterized in that, The inlet flow rate of the oil-water separation unit is 0.02~200 L / h, the hydraulic residence time is 0.1~4h, and the oil content of the aqueous phase after separation is below 50mg / L.

9. The electrochemical-based high-oil-content emulsified wastewater treatment process according to claim 1, characterized in that, When the treatment efficiency of the electrochemical demulsification unit is ≤65%, it is regenerated by backwashing with cathode effluent. The backwashing is performed by pumping at a flow rate of 0.02~10L / h and a hydraulic retention time of 0.05~1h. After backwashing, the oil removal rate of the electrochemical demulsification unit is restored to over 95%.

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