Cyclone electrochemical reactor for organic wastewater

Abstract

The invention discloses a rotational flow electrochemical reactor for organic wastewater, which belongs to the field of electrochemical reaction devices, and comprises a reactor shell, a second cathode, an anode and a first cathode are vertically arranged in the shell from inside to outside in sequence and are distributed at intervals, the first cathode and the anode are both annular bodies, and the second cathode and the anode are both annular bodies. The space between the first cathode and the anode is partitioned into a first cavity, the anode and the middle of the reactor shell are partitioned into a second cavity, a water inlet pipe and a water outlet pipe are arranged on the opposite side faces of the reactor shell respectively, and the top end of the first cathode is detachably connected with the reactor shell. And in combination with the action of the cathode and anode electric fields, pollutants are directly oxidized or a strong oxidant is indirectly generated, so that efficient mineralization is realized, the mass transfer effect is improved on the basis of reducing the organic wastewater treatment cost, and the organic wastewater treatment efficiency is further improved.

Description

Technical Field

[0001] This invention belongs to the field of electrochemical reactions, specifically referring to a vortex electrochemical reactor for organic wastewater. Background Technology

[0002] Electrochemical advanced oxidation degrades recalcitrant organic matter in wastewater through direct oxidation and indirect oxidation that generates strong oxidants. It is characterized by high automation, no secondary pollution, no need to add other agents, easy mobility, and low site requirements. However, the reactors currently suffer from low mass transfer and high energy consumption. Optimization of electrode materials, reactor design, and system control is necessary to achieve market success.

[0003] The swirling electrochemical reactor utilizes its design to generate swirling shear force, significantly improving mass transfer between pollutants and electrodes, and enhancing the efficiency of direct oxidation on the electrode surface. Furthermore, the conductivity of organic wastewater treated electrochemically generally meets treatment requirements, while the wastewater commonly contains abundant chloride ions (Cl). - The generated active chlorine (·Cl, ·OCl, HOCl, OCl) - Strong oxidants such as Cl2 and hydroxyl radicals indirectly oxidize and degrade organic matter, achieving the mineralization effect of recalcitrant organic matter.

[0004] However, current cyclone reactors are characterized by low mass transfer and high energy consumption, and optimization of electrode materials and reactor design is required to achieve market success. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a vortex electrochemical reactor for organic wastewater, thereby improving reaction efficiency and achieving full treatment of high-salt, recalcitrant organic wastewater.

[0006] To solve the above problems, the technical solution adopted by the present invention is as follows: A swirling electrochemical reactor for organic wastewater includes a reactor shell. Inside the shell, a second cathode, an anode, and a first cathode are vertically arranged sequentially from the inside out, spaced apart. Both the first cathode and the anode are annular. A first cavity separates the first cathode and the anode. A second cavity separates the anode and the reactor shell at the middle. A horizontally arranged inlet pipe and outlet pipe are respectively provided on opposite sides of the reactor shell. One end of each inlet pipe and outlet pipe is inserted into the shell, with the opening inside the shell tangential to the inner wall of the shell, allowing water to enter tangentially and collide with the inner wall to form a swirling flow. The top of the first cathode is detachably connected to the reactor shell, and its bottom is spaced apart from the reactor shell to form a first opening. The bottom of the anode is detachably connected to the inner side of the reactor shell, and its top is spaced apart from the inner side of the reactor shell to form a second opening. The inlet pipe, the first cavity, the first opening, the second opening, the second cavity, and the outlet pipe form a complete fluid channel.

[0007] Furthermore, both the inner and outer sides of the anode are coated with a highly active Ti4O7 coating that produces ·OH and has low chlorine evolution.

[0008] Furthermore, the reactor shell has a cylindrical structure, and both the inlet pipe and the outlet pipe are perpendicular to the outer wall of the shell.

[0009] Furthermore, the distances between the first cathode and the anode, and between the anode and the second cathode, are equal.

[0010] Furthermore, the housing includes a cylindrical body, with an upper cover and a lower cover detachably connected to the upper and lower ends of the cylindrical body, respectively. The upper end of the first cathode is threadedly connected to the upper cover, and the lower end of the anode is threadedly connected to the lower cover.

[0011] Furthermore, an exhaust valve is connected to the upper end of the housing; the upper and lower ends of the second cathode are detachably connected to the upper cover and the lower cover, respectively.

[0012] Furthermore, both the first cathode and the anode are hollow tubular electrodes, while the second cathode is a solid cylindrical electrode.

[0013] The beneficial effects achieved by the present invention using the above structure are as follows: Wastewater enters the shell at a tangential velocity, forming a stable rotating flow field within the cavity. This generates centrifugal force, promoting the migration of organic matter to the electrode surface and compressing the double layer thickness. This reduces diffusion resistance, increases the reaction rate, and significantly improves the mass transfer efficiency between pollutants and the electrode surface. Traditional electrochemical reactors suffer from high energy consumption and poor treatment efficiency due to slow mass transfer. In contrast, this invention uses swirling shear force to rapidly diffuse organic matter to the electrode interface. Combined with the electric fields of the anode and cathode, it directly oxidizes pollutants or indirectly generates strong oxidants, achieving efficient mineralization. This not only reduces the cost of organic wastewater treatment but also improves the mass transfer effect, thereby increasing the treatment efficiency of organic wastewater. The tangentially entering water flow generates a swirling flow in the first and second chambers, which washes over the outer surfaces of the first cathode, anode, and second cathode, preventing substances generated during wastewater treatment from adhering to the electrode surfaces and thus further improving the mass transfer efficiency of the electrode surfaces. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 The figure shows the results of a mineralization experiment on organic wastewater treated using the present invention.

[0015] Explanation of reference numerals in the attached drawings: 1. Shell; 2. First cathode; 3. Anode; 4. Second cathode; 5. Inlet pipe; 6. Outlet pipe; 7. Air vent valve; 8. Valve. Detailed Implementation

[0016] The following is in conjunction with the appendix Figures 1-2 To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art.

[0017] The terms "first," "second," and similar words used in the patent application specification and claims of this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "inner," "outer," "upper," "lower," "far," "near," "front," and "rear" are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. The drawings in this invention are not strictly drawn to scale; the specific dimensions and quantity of each structure can be determined according to actual needs. The drawings described in this invention are merely structural schematic diagrams.

[0018] A cyclone electrochemical reactor for organic wastewater, such as Figures 1-2 As shown, the reactor includes a reactor shell 1. Inside the shell 1, from the inside out, there are vertically arranged a second cathode 4, an anode 3, and a first cathode 2, spaced apart. The first cathode 2 and the anode 3 are both annular. The space between the first cathode 2 and the anode 3 forms a first cavity. The space between the anode 3 and the middle of the reactor shell 1 forms a second cavity. On opposite sides of the reactor shell 1, there are horizontally arranged inlet pipes 5 and 6. One end of each inlet pipe 5 and outlet pipe 6 is inserted into the shell 1, and the opening of the pipe inside the shell 1 is tangential to the inner wall of the shell 1, so that the water flows tangentially into the shell 1 and collides with the inner wall of the shell 1 to form a swirling flow. The top of the first cathode 2 is detachably connected to the reactor shell 1, and the bottom is spaced from the reactor shell 1 to form a first opening. The bottom of the anode 3 is detachably connected to the inner side of the reactor shell 1, and the top is spaced from the inner side of the reactor shell 1 to form a second opening. The inlet pipe 5, the first cavity, the first opening, the second opening, the second cavity, and the outlet pipe 6 form a complete fluid channel.

[0019] In this embodiment, organic wastewater is first pumped into the housing 1 through the inlet using a peristaltic pump. A DC power supply is then turned on to power the first cathode 2, anode 3, and second cathode 4, thus initiating the electrochemical treatment process. Since the influent flows into the housing 1 via the peristaltic pump, it has a certain influent velocity. The water flows tangentially into the housing 1 through the inlet, causing its trajectory to change and exhibit a swirling effect upon contact with the first cathode 2, thereby improving mass transfer. Furthermore, because the influent head is pressurized and delivered by the peristaltic pump, the swirling effect is continuously achieved during the flow into the housing 1 and towards the outlet, due to the collision with the anode 3 and the second cathode 4. This swirling characteristic further enhances mass transfer during the reaction process. After the reaction, the wastewater is discharged through the outlet.

[0020] The tangential inlet allows wastewater to enter the shell 1 at a tangential velocity, forming a stable rotating flow field within the cavity. This generates centrifugal force, promoting the migration of organic matter to the electrode surface and compressing the double-layer thickness, thereby reducing diffusion resistance, increasing the reaction rate, and significantly improving the mass transfer efficiency between pollutants and the electrode surface. Traditional electrochemical reactors suffer from high energy consumption and poor treatment efficiency due to slow mass transfer. In contrast, this invention uses swirling shear force to rapidly diffuse organic matter to the electrode interface. Combined with the electric field of the anode and cathode 3, it directly oxidizes pollutants or indirectly generates strong oxidants, achieving highly efficient mineralization. This not only reduces the cost of organic wastewater treatment but also improves the mass transfer effect, thus increasing the treatment efficiency of organic wastewater.

[0021] The tangentially entering water flow generates a swirling flow in the first and second chambers, which washes the outer surfaces of the first cathode 2, anode 3, and second cathode 4, preventing substances generated during wastewater treatment from adhering to the electrode surfaces and thus further improving the mass transfer efficiency of the electrode surfaces.

[0022] The electrochemical reaction process will be explained in detail below using chemical reaction equations.

[0023] By utilizing the electric field between anode 3 and cathode to create an electron-gain / loss system in the water, pollutants in the water can be directly oxidized at anode 3, or through the generated ·OH and active chlorine (·Cl, ·OCl, HClO, ClO). - It indirectly oxidizes pollutants (using Cl2) and achieves a degradation effect.

[0024] The following chemical reactions mainly occur around the first cathode 22 and the second cathode 44 in the reactor shell 11 of the present invention: 2H2O+2e - →H2+2OH - ① The following reactions mainly occur near anode 33: 4OH - →O2 + 2H2O + 4e - ② 2Cl-→Cl2+2e - ③ H₂O→·OH + H₂ + +e - ④ When Cl2 dissolves in water, the following reaction occurs: Cl₂ + H₂O → HClO + H₂ + +Cl - ⑤ According to the above chemical reaction formula ③, chlorine gas is generated during the reaction process. Chlorine gas can not only oxidize organic matter, but also kill bacteria and pathogenic microorganisms, so that this reactor also has a disinfection function.

[0025] Furthermore, in order to further improve the swirling effect, the gas generated by the reaction can be discharged from the shell 11 to the outside in a timely manner, thereby expanding the reaction area of ​​the anode 33.

[0026] Preferred, such as Figure 1 As shown, both the inner and outer sides of anode 3 are coated with a highly active Ti4O7 coating that produces ·OH and has low chlorine evolution.

[0027] In this embodiment, the inner and outer sides of the anode 3 are coated with a Ti4O7 highly active coating electrode that produces ·OH and has low chlorine evolution as a shape-stable anode 3. It has low chlorine evolution performance and corrosion resistance, and can effectively generate hydroxyl radicals and active chlorine to indirectly oxidize refractory organic matter.

[0028] Preferred, such as Figure 1 As shown, the reactor shell 1 has a cylindrical structure, and both the inlet pipe 5 and the outlet pipe 6 are perpendicular to the outer wall of the shell 1.

[0029] In this embodiment, the uniformity of the flow field and the compactness of the device are optimized. The cylindrical shell 1 provides a smooth inner wall, reducing flow resistance and promoting swirl formation; the vertical pipe layout facilitates installation and maintenance, and the cylindrical structure promotes uniform distribution of water flow between the anode and cathode 3, avoiding dead zones and improving treatment consistency.

[0030] Preferred, such as Figure 1 As shown, the distances between the first cathode 2 and the anode 3 and between the anode 3 and the second cathode 4 are equal.

[0031] In this embodiment, uniform electric field distribution and maximized reaction efficiency are ensured. The spacing is controlled within 5mm-20mm to reduce ohmic losses and improve current efficiency; the equidistant layout ensures sufficient contact between contaminants and avoids localized overload or insufficient reaction.

[0032] Preferred, such as Figure 1 As shown, the housing 1 includes a cylindrical body, with an upper cover and a lower cover detachably connected to the upper and lower ends of the cylindrical body, respectively. The upper end of the first cathode 2 is threadedly connected to the upper cover, and the lower end of the anode 3 is threadedly connected to the lower cover.

[0033] This embodiment improves the flexibility and ease of maintenance of the device. Threaded connections facilitate electrode replacement or cleaning, reducing downtime; the upper and lower cover designs, combined with sealing rings, ensure reactor sealing and prevent leakage. It also facilitates adjustment of water head and gas accumulation.

[0034] Preferred, such as Figure 1 As shown, an exhaust valve 7 is connected to the upper end of the housing 1; the upper and lower ends of the second cathode 4 are detachably connected to the upper cover and the lower cover, respectively.

[0035] In this embodiment, efficient management of reaction gases and improved safety are achieved. The exhaust valve 7 promptly discharges gases such as H2, O2, and Cl2 to prevent pressure buildup from affecting the reaction area. Gas discharge maintains the effective contact area between the anode 3 and the wastewater. Automatic venting, achieved by ensuring the water head at the outlet is higher than that at the anode 3, enhances the stability of the main project and the continuity of treatment.

[0036] Preferred, such as Figure 1 As shown, the first cathode 2 and anode 3 are both hollow tubular electrodes, while the second cathode 4 is a solid cylindrical electrode.

[0037] In this embodiment, the first cathode 2, the anode 3, and the second cathode 4 are made of titanium metal substrate material, and are combined with a Ti4O7 high-activity coating surface coating, so that the device can achieve good ·OH production and low chlorine evolution performance, and extend the service life of the device. The principle analysis is as follows.

[0038] Titanium metal itself has low catalytic activity. When used directly as an electrode, reactions such as oxygen evolution and chlorine evolution require very high overpotentials, consuming a large amount of electrical energy. High-activity coatings, however, possess excellent conductivity and electrocatalytic properties. Titanium is an excellent electrode substrate material, characterized by corrosion resistance, light weight, and high mechanical strength. However, it has a fatal flaw in electrochemical systems: a dense insulating oxide film easily forms on the titanium surface. This film hinders electron transport, leading to a sharp increase in electrode resistance, ultimately resulting in high energy consumption and poor processing efficiency. High-activity coatings, as conductive and catalytically active outer layers, can completely cover the titanium substrate, isolating the electrolyte from direct contact with titanium and fundamentally inhibiting titanium passivation.

[0039] Meanwhile, the active anode, which produces ·OH and exhibits low chlorine evolution, is itself a good conductor, ensuring rapid electron transport between the electrode and the electrolyte and maintaining long-term high-efficiency conductivity. The cathode used in this invention is a pure titanium cathode with low hydrogen evolution.

[0040] The wastewater treatment device of the present invention is used as follows: Start-up and water intake phase. First, the high-salt, recalcitrant organic wastewater to be treated is injected into the reactor shell 1 through the inlet pipe 5 using a peristaltic pump, controlling the flow rate within the range of 0.1~0.5 L / min to ensure the wastewater fills the chamber and forms a swirling flow. Simultaneously, the position of the outlet pipe 6 is adjusted so that the water head is slightly higher than the upper side of the anode 3 to facilitate subsequent gas discharge. After the reactor is full, the sealing is checked and it is confirmed that the automatic air vent 7 is in the open position to prevent gas accumulation.

[0041] Connect the first cathode 2 and the second cathode 4 to the negative electrode, and the anode 3 to the positive electrode. Control the current density between 5-20 mA / cm², turn on the DC power supply, and begin wastewater treatment. During the reaction, the wastewater swirls within the chamber, and direct and indirect oxidation reactions occur near the anode and cathode 3. Continuous or circulating flow can be achieved by adjusting the flow rate via valve 8. Real-time monitoring of the exhaust valve 7 ensures timely discharge of gases such as H2, O2, and Cl2, maintaining reaction stability. This stage maximizes the organic matter mineralization efficiency by optimizing the current and flow rate.

[0042] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A cyclone electrochemical reactor for organic wastewater, characterized in that, The reactor includes a reactor shell, within which a second cathode, an anode, and a first cathode are vertically arranged sequentially from the inside out, spaced apart. Both the first cathode and the anode are annular, separated by a first cavity. A second cavity is formed between the anode and the reactor shell. A horizontally arranged inlet pipe and outlet pipe are respectively provided on opposite sides of the reactor shell. One end of each inlet and outlet pipe is inserted into the shell, with the opening tangential to the inner wall of the shell, allowing water to enter tangentially and collide with the inner wall to form a swirling flow. The top of the first cathode is detachably connected to the reactor shell, and its bottom is spaced apart to form a first opening. The bottom of the anode is detachably connected to the inner side of the reactor shell, and its top is spaced apart to form a second opening. The inlet pipe, the first cavity, the first opening, the second opening, the second cavity, and the outlet pipe form a complete fluid channel.

2. The cyclone electrochemical reactor for organic wastewater according to claim 1, characterized in that, Both the inner and outer sides of the anode 3 are coated with a highly active Ti4O7 coating that produces ·OH and has low chlorine evolution.

3. The cyclone electrochemical reactor for organic wastewater according to claim 1, characterized in that, The reactor shell has a cylindrical structure, and both the inlet pipe and the outlet pipe are perpendicular to the outer wall of the shell.

4. A cyclone electrochemical reactor for organic wastewater according to claim 1, characterized in that, The distances between the first cathode and the anode, and between the anode and the second cathode, are equal.

5. A cyclone electrochemical reactor for organic wastewater according to claim 1, characterized in that, The housing includes a cylindrical body, with an upper cover and a lower cover detachably connected to the upper and lower ends of the cylindrical body, respectively. The upper end of the first cathode is threadedly connected to the upper cover, and the lower end of the anode is threadedly connected to the lower cover.

6. A cyclone electrochemical reactor for organic wastewater according to claim 1, characterized in that, An exhaust valve is connected to the upper end of the housing; the upper and lower ends of the second cathode are detachably connected to the upper cover and the lower cover, respectively.

7. A cyclone electrochemical reactor for organic wastewater according to claim 1, characterized in that, Both the first cathode and the anode are hollow tubular electrodes, while the second cathode is a solid cylindrical electrode.

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