Self-cleaning electro-catalytic composite membrane reinforced treatment device and wastewater treatment method thereof

Abstract

This invention discloses a self-cleaning electrocatalytic composite membrane enhanced treatment device and its wastewater treatment method. The device includes a shell and an oil recovery system, an effluent system, and multiple electrocatalytic membrane systems disposed inside the shell. The oil recovery system is coaxially arranged with the shell. The multiple electrocatalytic membrane systems are evenly distributed circumferentially around the oil recovery system. The effluent system is located below the multiple electrocatalytic membrane systems and is connected to the outlet of the electrocatalytic membrane systems. A tail gas emission system is disposed above the shell. This invention organically combines electrocatalytic oxidation with membrane filtration, achieving synergistic effects of high-efficiency degradation, deep filtration, and self-cleaning anti-fouling. It is particularly suitable for treating recalcitrant industrial wastewater such as produced fluids from oil and gas fields and return fluids from enhanced production operations.

Description

Technical Field

[0001] This invention belongs to the field of industrial wastewater treatment and membrane separation technology, specifically relating to a self-cleaning electrocatalytic composite membrane enhanced treatment device that couples electrocatalytic advanced oxidation with membrane filtration technology and its wastewater treatment method. Background Technology

[0002] With the acceleration of industrialization and increasingly stringent environmental standards, the treatment and resource utilization of industrial wastewater, especially the refined and advanced treatment of recalcitrant organic wastewater such as oily production water, has become an urgent technical challenge. Among existing advanced treatment technologies, electrocatalytic advanced oxidation and membrane separation technologies each have their advantages, but both have significant limitations. Electrocatalysis can effectively degrade dissolved organic matter by generating active species such as hydroxyl radicals, but it has almost no effect on suspended solids and emulsified oils, requiring complex pretreatment. Moreover, when treating low-concentration wastewater, it suffers from low current efficiency and high energy consumption due to mass transfer limitations and side reactions, restricting its economic viability in engineering applications. Membrane separation technology can efficiently retain suspended solids and oils, but it is ineffective at removing dissolved small molecule organic matter. More seriously, membrane fouling leads to decreased flux, frequent cleaning, and shortened lifespan, increasing operation and maintenance costs. Therefore, a single technology is insufficient to meet the requirements of advanced treatment of complex wastewater. Coupled with electrocatalysis and membrane separation to construct catalytically functional filtration membranes has become an important direction for overcoming existing technological bottlenecks. Electrocatalytic membranes can generate oxide species in situ using an electric field while filtering, thereby achieving pollutant degradation and membrane surface self-cleaning. This is expected to solve the two major problems of removing dissolved organic matter and controlling membrane fouling simultaneously.

[0003] However, existing electrocatalytic membrane technologies still face many challenges: catalytic activity and filtration flux are difficult to balance; membrane materials lack sufficient mechanical strength and chemical stability; and reactor structures do not adequately enhance mass transfer and reaction processes. Porous titanium membranes, due to their excellent conductivity, mechanical strength, and chemical stability, are ideal substrates for constructing composite catalytic membranes. Catalytic functionality can be imparted by loading active components such as ruthenium and iridium. However, how to fully leverage the advantages of such composite membranes through optimized device design to achieve efficient, stable, and low-energy-consumption deep wastewater treatment remains a key technical problem that needs to be solved. Summary of the Invention

[0004] This invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a self-cleaning electrocatalytic composite membrane enhanced treatment device and a method for treating wastewater.

[0005] This invention is achieved through the following technical solution: A self-cleaning electrocatalytic composite membrane enhanced treatment device includes a device housing and an oil recovery system, a water discharge system, and multiple electrocatalytic membrane systems disposed inside the device housing; the oil recovery system is arranged coaxially with the device housing; the multiple electrocatalytic membrane systems are evenly distributed around the oil recovery system along the circumference; the water discharge system is disposed below the multiple electrocatalytic membrane systems; and an exhaust gas emission system is disposed above the device housing.

[0006] In the above technical solution, the lower side wall of the device housing is provided with an inlet and an outlet, and the inlet and outlet are located on opposite sides; the outlet is connected to the water discharge system; and a slag discharge port is provided at the lowest point of the bottom of the device housing.

[0007] In the above technical solution, the electrocatalytic membrane system includes an electrocatalytic composite membrane assembly and a DC regulated power supply; the electrocatalytic composite membrane assembly consists of an inner and outer catalytic composite membrane anode and a mesh cathode; the positive terminal of the DC regulated power supply is electrically connected to the catalytic composite membrane anode, the negative terminal of the DC regulated power supply is electrically connected to the mesh cathode, and the lower outlet of the catalytic composite membrane anode is connected to the water effluent system.

[0008] In the above technical solution, the catalytic composite membrane anode has a cylindrical structure, the substrate is a porous titanium-based membrane, and the surface is modified with active transition metals such as ruthenium, iridium, nickel, or manganese. The pore size of the catalytic composite membrane anode is between 0.03 μm and 5 μm, the porosity is between 15% and 40%, and the specific surface area is 5 m². 2 / g~80m 2 Between / g; the mesh cathode has a tubular structure; the catalytic composite membrane anode and the mesh cathode are arranged coaxially.

[0009] In the above technical solution, the vertical distance between the outer wall of the catalytic composite membrane anode and the inner wall of the mesh cathode is 4cm to 8cm; the gap between the outer wall of the catalytic composite membrane anode and the inner wall of the mesh cathode forms a gas stripping zone; the gap between the outer side of the mesh cathode and the outer wall of the oil recovery system, as well as the gap between the outer side of the mesh cathode and the inner wall of the device housing, both form flow guiding zones.

[0010] In the above technical solution, the oil recovery system includes a funnel-shaped oil receiving section, a tubular oil guiding pipe, and a conical oil collecting section connected sequentially from top to bottom; an oil discharge pipe is provided at the lowest point of the bottom of the oil recovery system, and the oil discharge pipe extends out of the device housing.

[0011] In the above technical solution, the water outlet system is a ring-shaped water collection pipe, and the water outlet system is connected to the lower outlet of the catalytic composite membrane anode through a connecting pipe; the water outlet system is sleeved on the lower part of the oil recovery system, and the two are fixed together by connecting rods evenly distributed along the circumference.

[0012] In the above technical solution, the exhaust gas emission system is provided with an air inlet and an air outlet. The throat of the exhaust gas emission system is connected to the top of the device housing. The air inlet is connected to a gas source, and the air outlet is connected to an exhaust gas collection system. The gas source of the exhaust gas emission system is compressed nitrogen or inert gas, and the volume ratio of exhaust gas drawn in at the air inlet and the throat is controlled at 50~100:1.

[0013] A method for treating wastewater using a self-cleaning electrocatalytic composite membrane enhanced treatment device, specifically comprising: Wastewater enters the device through the inlet and rises from the air-lift zone. A DC regulated power supply applies voltage to the catalytic composite membrane anode and mesh cathode; Driven by pressure, the wastewater is purified by catalytic degradation and then passes through the catalytic composite membrane anode and enters the effluent system through the connecting pipe, and is then discharged from the outlet. Pollutants float to the top of the unit under air lift, enter the oil recovery system, and are discharged through the oil drain pipe. The sludge produced during the reaction settles at the bottom and is periodically discharged through the sludge discharge port; The exhaust gas produced by the reaction is drawn in and diluted by the negative pressure generated by the exhaust gas emission system before being safely discharged.

[0014] In the above technical solution, the DC regulated power supply applies a voltage of 0~40V and a current of 0~500A; the hydraulic retention time of wastewater in the self-cleaning electrocatalytic composite membrane enhanced treatment device is 10min~30min.

[0015] The beneficial effects of this invention are: This invention provides a self-cleaning electrocatalytic composite membrane enhanced treatment device and its wastewater treatment method. By coupling electrocatalytic oxidation and membrane filtration processes in the same reaction unit, the device achieves deep degradation of pollutants and self-cleaning of the membrane surface simultaneously through electrochemical action, effectively solving the problems of severe pollution in traditional membrane technology and poor filtration effect of single electrocatalytic technology.

[0016] This invention innovatively combines a catalytic composite membrane anode with a filter membrane, simultaneously completing two core processes—confined catalytic oxidation and precision filtration—within a single processing unit. This achieves functional coupling and synergistic effect, resulting in a compact structure and high processing efficiency. Crucially, the catalytic composite membrane anode used in this invention possesses a unique microporous structure and specific porosity, resulting in a huge specific surface area (up to 5m²). 2 / g~80m 2 / g); compared with traditional electrocatalytic electrodes (specific surface area is generally geometric area or <0.01m²). 2Compared to / g), the catalytic composite membrane anode of the present invention expands the reaction area by several orders of magnitude, significantly increasing the electrode discharge area, thereby greatly improving the electron transfer efficiency and current efficiency of the electrode surface, thus accelerating the efficient removal of recalcitrant organic pollutants, reducing energy consumption, and at the same time achieving the removal of oil and insoluble suspended particulate matter in wastewater, further improving the quality of effluent. This invention utilizes the "airlift" and "tearing" effects of microbubbles (such as O2, H2, Cl2, etc.) generated on the electrode surface and inside the pores (especially on the anode surface and inside the pores of the catalytic composite membrane) during the electrochemical reaction process. Combined with the direct decomposition of pollutants by electrochemical oxidation, it achieves in-situ physicochemical cleaning and efficient self-cleaning and anti-fouling of the membrane surface, fundamentally alleviating membrane fouling and significantly extending the chemical cleaning cycle and membrane lifespan. This invention utilizes the air-lift effect caused by microbubbles generated by an electrochemical reaction to create a strong internal circulation flow within the device. This significantly enhances the mass transfer process of pollutants from the liquid phase to the electrode surface, improving current utilization and reaction rate. It eliminates the need for an external circulation pump, reducing operating energy consumption. Furthermore, the adhesion effect of microbubbles enables multiple cycles of removal of oil and insoluble particulate matter from wastewater, substantially improving effluent quality while ensuring long-term stable operation of the membrane filtration system.

[0017] This invention can flexibly adapt to the treatment needs of various complex water qualities, from oily wastewater to high-salinity, high-organic wastewater, by adjusting power supply parameters (voltage, current), membrane parameters (pore size) and operating conditions (pressure difference, HRT). It is highly flexible in operation and extremely versatile. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the self-cleaning electrocatalytic composite membrane enhancement treatment device of the present invention.

[0019] in: 1. Electrocatalytic membrane system; 2. DC regulated power supply; 3. Oil recovery system; 4. Water outlet system; 5. Exhaust gas emission system; 6. Unit shell; 7. Oil discharge pipeline; 8. Water inlet; 9. Slag discharge port; 10. Water outlet; 101. Electrocatalytic composite membrane module; 102. Catalytic composite membrane anode; 103. Mesh cathode; 104. Gas stripping zone; 105. Flow guiding zone; 401. Connecting pipe; 501. Air inlet; 502. Air outlet.

[0020] For those skilled in the art, other related figures can be obtained from the above figures without any creative effort. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0022] Example 1

[0023] like Figure 1 As shown, a self-cleaning electrocatalytic composite membrane enhanced treatment device includes a device housing 6 and an oil recovery system 3, a water outlet system 4, and multiple electrocatalytic membrane systems 1 disposed inside the device housing 6; the oil recovery system 3 is arranged coaxially with the device housing 6; the multiple electrocatalytic membrane systems 1 are evenly distributed around the oil recovery system 3 along the circumference; the water outlet system 4 is disposed below the electrocatalytic membrane systems 1; and an exhaust gas emission system 5 is disposed above the device housing 6.

[0024] The lower side wall of the device housing 6 is provided with an inlet 8 and an outlet 10, and the inlet 8 and outlet 10 are located on opposite sides; the outlet 10 is connected to the water outlet system 4; the lowest point of the bottom of the device housing 6 is provided with a slag discharge port 9; the device housing 6 is made of stainless steel or duplex steel and has corrosion resistance, high temperature resistance and pressure resistance.

[0025] The number of electrocatalytic membrane systems 1 is determined according to the processing capacity; the electrocatalytic membrane systems 1 are fixed inside the device housing 6 by an insulating support plate located at their lower part; The electrocatalytic membrane system 1 includes an electrocatalytic composite membrane assembly 101 and a DC regulated power supply 2. The electrocatalytic composite membrane assembly 101 consists of an inner and outer catalytic composite membrane anode 102 and a mesh cathode 103. The positive terminal of the DC regulated power supply 2 is electrically connected to the catalytic composite membrane anode 102, and the negative terminal of the DC regulated power supply 2 is electrically connected to the mesh cathode 103. The catalytic composite membrane anode 102 and the mesh cathode 103 are arranged coaxially. Multiple electrocatalytic membrane systems 1 can share the same DC regulated power supply 2, and can be selected according to actual needs. The catalytic composite membrane anode 102 has a cylindrical structure; The mesh cathode 103 has a tubular structure; The vertical distance between the outer wall of the catalytic composite membrane anode 102 and the inner wall of the mesh cathode 103 is 4cm to 8cm; the gap between the outer wall of the catalytic composite membrane anode 102 and the inner wall of the mesh cathode 103 forms a gas lift-off zone 104; The lower outlet of the catalytic composite membrane anode 102 is connected to the water outlet system 4; The gap between the outer side of the mesh cathode 103 and the outer wall of the oil recovery system 3, and the gap between the outer side of the mesh cathode 103 and the inner wall of the device housing 6, both form the flow guiding area 105; Under the condition of applying a DC regulated power supply 2, the catalytic composite membrane anode 102 and the mesh cathode 103 simultaneously undergo confined electrocatalytic oxidation and filtration processes on the surface of the catalytic composite membrane anode 102 and in the membrane channels, thereby achieving the degradation, destabilization and aggregation of pollutants in wastewater and fine filtration. The applied voltage and current are adjustable according to the treatment requirements. The catalytic composite membrane anode 102 is a surface-modified substrate, which is a commercially available porous titanium-based membrane; the surface modification is performed using an active material; the active material is a transition metal or a transition metal oxide; the transition metal is ruthenium, iridium, nickel, or manganese; The surface modification method involves acid washing, cleaning, and drying of a porous titanium-based substrate, followed by vacuum impregnation in a soluble salt solution containing ruthenium, iridium, nickel, or manganese at a concentration of 0.1 mol / L to 2.0 mol / L under a vacuum of 10 Pa to 1000 Pa, allowing the soluble salt solution to fully penetrate deep into the pores of the substrate. The substrate is then removed, dried at 105°C, and subsequently heat-treated at 300°C to 500°C for 10 to 60 minutes to convert the precursor into an active substance. This process of vacuum impregnation and heat treatment is repeated 2 to 10 times until the desired loading amount is achieved. This invention achieves uniform loading of the active substance within the pores through a vacuum-assisted impregnation method.

[0026] The pore size of the catalytic composite membrane anode 102 is between 0.03 μm and 5 μm, and the porosity is between 15% and 40%. The catalytic composite membrane anode 102 adopts external pressure or negative pressure suction filtration, and the filtration pressure difference is controlled between 0.05MPa and 0.2MPa. The mesh cathode 103 is made of titanium, which has acid and alkali resistance and corrosion resistance; the mesh size of the mesh cathode 103 is 1mm~6mm. The DC regulated power supply 2 applies a voltage of 0~40V and a current of 0~500A, which can be adjusted according to the wastewater treatment requirements. The oil recovery system 3 includes a funnel-shaped oil receiving section, a tubular oil guiding pipe, and a conical oil collecting section connected sequentially from top to bottom; an oil discharge pipe 7 is provided at the lowest point of the bottom of the oil recovery system 3, and the oil discharge pipe 7 extends out of the device housing 6; the top surface of the oil recovery system 3 is higher than the top surface of the electrocatalytic membrane system 1. The water outlet system 4 is a ring-shaped water collection pipe, which is connected to the lower outlet of the catalytic composite membrane anode 102 through a connecting pipe 401. The water outlet system 4 is sleeved on the lower part of the oil recovery system 3, and the two are fixed together by connecting rods evenly distributed along the circumference. The water outlet system 4 realizes the unified collection of water after oxidation and filtration and discharges it through the water outlet 10. The exhaust gas emission system 5 is provided with an air inlet 501 and an air outlet 502. The throat of the exhaust gas emission system 5 is connected to the top of the device housing 6. The air inlet 501 is connected to the air source, and the air outlet 502 is connected to the exhaust gas collection system. Under the condition of air intake, the exhaust gas emission system 5 generates a negative pressure suction effect at the throat to realize the collection and dilution of exhaust gas from the self-cleaning electrocatalytic composite membrane separation device. The exhaust gas emission system 5 adopts a Venturi tube structure; The exhaust gas emission system 5 uses compressed nitrogen or inert gas as its gas source. The volume ratio of the exhaust gas drawn in at the inlet 501 to the throat is controlled at 50~100:1, which can be adjusted according to the wastewater treatment volume and the power applied by the power supply.

[0027] Example 2

[0028] A method for treating wastewater using the self-cleaning electrocatalytic composite membrane enhanced treatment device described in Example 1 is as follows: Wastewater enters the device from inlet 8 and rises in the annular cavity air-lift zone 104 formed between the catalytic composite membrane anode 102 and the mesh cathode 103 of the electrocatalytic membrane system 1. A DC regulated power supply 2 applies voltage to the catalytic composite membrane anode 102 and the mesh cathode 103. Under the action of the current applied by the DC regulated power supply 2, the catalytic composite membrane anode 102 and the mesh cathode 103 undergo confined electrocatalytic oxidation reaction and filtration process on the surface and in the membrane pores of the catalytic composite membrane anode 102. The DC regulated power supply 2 applies a voltage of 0~40V and a current of 0~500A, which can be adjusted according to the wastewater treatment requirements. The electrocatalytic reaction generates highly oxidizing active groups such as ·OH, oxygen free radicals, and chlorine free radicals, which rapidly mineralize recalcitrant organic pollutants in wastewater, degrading them into CO2 and H2O. Simultaneously, the microbubble gases O2 and H2 generated during the reaction promote a strong air-lifting effect in the air-lift zone 104, driving internal circulation between the air-lift zone 104 and the guide zone 105, thus promoting internal circulation oxidation and enhancing the mass transfer process. The number of internal circulation cycles depends on the current and voltage applied by the DC regulated power supply 2. Due to confined oxidation reactions and bubble precipitation effects on the surface of the catalytic composite membrane anode 102 and within the membrane pores, pollutants on the membrane surface and within the pores are rapidly degraded and torn apart, achieving the membrane's self-cleaning and anti-fouling functions. Driven by pressure, the wastewater is purified by catalytic degradation and passes through the catalytic composite membrane anode 102 to filter out suspended particulate matter, oil and other pollutants. After being filtered, it flows into the effluent system 4 through the connecting pipe 401 and is finally collected and discharged from the outlet 10. The trapped oil and light suspended solids and other pollutants float to the top of the device under the action of air lifting, enter the oil recovery system 3 and are discharged through the oil discharge pipe 7; The small amount of sludge produced during the reaction settles at the bottom and is periodically discharged through the sludge discharge port 9; The exhaust gas produced by the reaction is drawn in by the negative pressure generated by the exhaust gas emission system 5 and diluted before being safely discharged.

[0029] The hydraulic retention time of wastewater in the self-cleaning electrocatalytic composite membrane enhanced treatment device is 10 min to 30 min, depending on the wastewater quality.

[0030] Application Example 1 An offshore platform has an oil-containing production water treatment capacity of approximately 300 m³. 3 / d. The wastewater has a complex composition, containing a large amount of emulsified oil, dissolved oil, and various oilfield chemical additives (such as corrosion inhibitors and demulsifiers), resulting in severe emulsification. The oil content of the production water ranges from 250 mg / L to 600 mg / L, and the suspended solids content ranges from 180 mg / L to 300 mg / L. The existing treatment process on the platform is "air flotation combined with precision filtration," but the oil content in the effluent fluctuates between 30 mg / L and 80 mg / L, which cannot reliably meet the increasingly stringent reuse and discharge standards (oil content <45 mg / L). Furthermore, the filter unit requires frequent backwashing, resulting in a heavy operational and maintenance burden.

[0031] The self-cleaning electrocatalytic composite membrane separation device of this invention is used for advanced treatment of the effluent from the original process. It comprises eight electrocatalytic composite membrane modules 101; the anode of the catalytic composite membrane uses a porous titanium-based membrane as the substrate, modified with a ruthenium-iridium coating, with an average pore size of 0.08 μm; the mesh cathode is made of titanium-based material, with a coaxial distance of 5 cm from the anode. A DC regulated power supply with a applied voltage of 10V and a current density of 15 mA / cm² is used. 2 The catalytic composite membrane anode uses external pressure filtration, with the operating pressure difference controlled between 0.07 MPa and 0.10 MPa. The total hydraulic retention time of wastewater within the device is 25 minutes. Nitrogen gas is introduced into the tail gas emission system, with a gas-liquid volume ratio set at 75:1. After treatment by this device, the oil content in the effluent is stable at 12 mg / L to 28 mg / L, and the suspended solids content is below 5 mg / L, all indicators exceeding the platform's emission standards. Furthermore, the device exhibits excellent anti-fouling performance; after continuous operation for over 200 hours, the membrane flux decay rate is less than 8%, far superior to traditional ultrafiltration membranes, significantly reducing operational and maintenance pressure. The separated oil phase is effectively collected in the oil recovery system, realizing the resource utilization of waste oil.

[0032] Application Example 2 The backflow fluid and production water generated after fracturing operations in a block of Qinghai Oilfield have a treatment capacity of approximately 320m³. 3 / d. This wastewater contains a large amount of fracturing fluid residue, fine formation particles, and crude oil. The petroleum content ranges from 180 mg / L to 450 mg / L, and the suspended solids content ranges from 300 mg / L to 600 mg / L. The median suspended solids particle size is D.50 The particle size ranges from 5μm to 15μm. The existing treatment process uses "inclined plate sedimentation plus air flotation plus walnut shell filtration," which results in large fluctuations in effluent quality, with petroleum content ranging from 15mg / L to 40mg / L and suspended solids from 10mg / L to 25mg / L. This fails to consistently meet the oilfield reinjection water standards (petroleum < 5mg / L, suspended solids ≤ 1mg / L, median particle size ≤ 1μm), severely restricting the resource utilization of water.

[0033] The self-cleaning electrocatalytic composite membrane separation device of this invention is used as the core processing unit for deep treatment of fracturing flowback fluid. Twelve sets of electrocatalytic composite membrane modules 101 are configured; the catalytic composite membrane anode uses a porous titanium-based membrane as the substrate, modified with a ruthenium-iridium-tin multi-element coating, with an average pore size of 0.05 μm; the mesh cathode is made of titanium, with a coaxial distance of 6 cm from the anode; the device housing is made of 2205 duplex steel. A DC regulated power supply with a applied voltage of 8V and a current density of 12 mA / cm² is used. 2 The catalytic composite membrane anode adopts external pressure filtration, and the operating pressure difference is precisely controlled at 0.06MPa~0.09MPa; the total hydraulic retention time of wastewater in the device is 18min; nitrogen is introduced into the tail gas emission system, and the gas-liquid volume ratio is set at 70:1.

[0034] After treatment by the device of this invention, the petroleum content is stabilized at 2 mg / L~4 mg / L, the suspended solids content is ≤1 mg / L, and the median particle size of the suspended solids is D. 50 Between 0.8μm and 1.0μm, the effluent quality fully meets and exceeds the highest standards for oilfield reinjection water. Furthermore, after 180 hours of continuous treatment, the membrane flux decline rate is less than 10%, significantly better than traditional ceramic or polymer ultrafiltration membranes, enabling the resource-based reuse of wastewater and effectively addressing the environmental pressures faced by oilfields.

[0035] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A self-cleaning electrocatalytic composite membrane enhancement treatment device, characterized in that: The device includes a housing (6) and an oil recovery system (3), a water outlet system (4), and multiple electrocatalytic membrane systems (1) disposed inside the housing (6); the oil recovery system (3) is arranged coaxially with the housing (6); the multiple electrocatalytic membrane systems (1) are evenly distributed around the oil recovery system (3) along the circumference; the water outlet system (4) is disposed below the multiple electrocatalytic membrane systems (1); and a tail gas emission system (5) is disposed above the housing (6). The lower side wall of the device housing (6) is provided with an inlet (8) and an outlet (10), and the outlet (10) is connected to the water outlet system (4); the bottom of the device housing (6) is provided with a slag discharge port (9). The electrocatalytic membrane system (1) includes an electrocatalytic composite membrane module (101) and a DC regulated power supply (2); the electrocatalytic composite membrane module (101) consists of an inner and outer catalytic composite membrane anode (102) and a mesh cathode (103); the positive terminal of the DC regulated power supply (2) is electrically connected to the catalytic composite membrane anode (102), the negative terminal of the DC regulated power supply (2) is electrically connected to the mesh cathode (103), and the lower outlet of the catalytic composite membrane anode (102) is connected to the water outlet system (4); the gap between the outer wall of the catalytic composite membrane anode (102) and the inner wall of the mesh cathode (103) forms a gas stripping zone (104); the gap between the outer side of the mesh cathode (103) and the outer wall of the oil recovery system (3) and the gap between the outer side of the mesh cathode (103) and the inner wall of the device housing (6) both form flow guiding zones (105). The oil recovery system (3) is provided with an oil drain pipe (7) at the bottom, and the oil drain pipe (7) extends out of the device housing (6). The water outlet system (4) is a ring-shaped water collection pipe; The exhaust gas emission system (5) is provided with an air inlet (501) and an air outlet (502). The throat of the exhaust gas emission system (5) is connected to the top of the device housing (6). The air inlet (501) is connected to the air source, and the air outlet (502) is connected to the exhaust gas collection system.

2. The self-cleaning electrocatalytic composite membrane enhancement treatment device according to claim 1, characterized in that: The catalytic composite membrane anode (102) has a cylindrical structure; the mesh cathode (103) has a tubular structure; the catalytic composite membrane anode (102) and the mesh cathode (103) are arranged along the same axis; the vertical distance between the outer wall of the catalytic composite membrane anode (102) and the inner wall of the mesh cathode (103) is 4cm to 8cm.

3. The self-cleaning electrocatalytic composite membrane enhancement treatment device according to claim 1, characterized in that: The housing (6) of the device is made of stainless steel or duplex steel.

4. The self-cleaning electrocatalytic composite membrane enhancement treatment device according to claim 1, characterized in that: The pore size of the catalytic composite membrane anode (102) is between 0.03 μm and 5 μm, and the porosity is between 15% and 40%. The catalytic composite membrane anode (102) is a surface-modified substrate, which is a porous titanium-based membrane. The surface modification is carried out using an active material. The active material is a transition metal or a transition metal oxide. The transition metal is ruthenium, iridium, nickel, or manganese. The mesh cathode (103) is made of titanium, and the mesh size of the mesh cathode (103) is 1mm~6mm; The applied voltage of the DC regulated power supply (2) is 0~40V and the current is 0~500A.

5. The self-cleaning electrocatalytic composite membrane enhancement treatment device according to claim 1, characterized in that: The catalytic composite membrane anode (102) adopts external pressure or negative pressure suction filtration, and the filtration pressure difference is controlled between 0.05MPa and 0.2MPa.

6. The self-cleaning electrocatalytic composite membrane enhancement treatment device according to claim 1, characterized in that: The oil recovery system (3) includes a funnel-shaped oil collection section, a tubular oil guide pipe, and a conical oil collection section connected sequentially from top to bottom.

7. The self-cleaning electrocatalytic composite membrane enhancement treatment device according to claim 1, characterized in that: The water outlet system (4) is connected to the lower outlet of the catalytic composite membrane anode (102) through a connecting pipe (401); the water outlet system (4) is fitted under the oil recovery system (3), and the two are fixed together by connecting rods evenly distributed along the circumference.

8. The self-cleaning electrocatalytic composite membrane enhancement treatment device according to claim 1, characterized in that: The exhaust gas emission system (5) uses compressed nitrogen or inert gas as its gas source, and the volume ratio of the exhaust gas drawn in at the inlet (501) to the throat is controlled at 50~100:

1.

9. A method for treating wastewater using the self-cleaning electrocatalytic composite membrane enhanced treatment device according to any one of claims 1 to 8, characterized in that: Wastewater enters the device through the inlet (8) and rises from the air-lift zone (104); A DC regulated power supply (2) applies voltage to the catalytic composite membrane anode (102) and the mesh cathode (103); After catalytic degradation, the purified water passes through the catalytic composite membrane anode (102) and flows into the effluent system (4) via the connecting pipe (401), and is then discharged from the outlet (10). The pollutants float to the top of the self-cleaning electrocatalytic composite membrane enhanced treatment device under the action of air lifting, enter the oil recovery system (3) and are discharged through the oil discharge pipeline (7); The sludge generated during the reaction settles at the bottom of the self-cleaning electrocatalytic composite membrane enhanced treatment device and is periodically discharged through the sludge discharge port (9); The exhaust gas produced by the reaction is drawn in by the negative pressure generated by the exhaust gas emission system (5) and diluted before being safely discharged.

10. The method for treating wastewater using the self-cleaning electrocatalytic composite membrane enhanced treatment device according to claim 9, characterized in that: The DC regulated power supply (2) applies a voltage of 0~40V and a current of 0~500A; the hydraulic retention time of the wastewater in the self-cleaning electrocatalytic composite membrane enhanced treatment device is 10min~30min.

Images