Rotary reverse electrode electrochemical water treatment device and method

Abstract

The application discloses a rotating reverse electrode electrochemical water treatment device and method, which comprises a shell, an anode electrode group, an induction electrode group and a cathode electrode group. The anode electrode group and the cathode electrode group each comprise a plurality of single electrode plates which are arranged in the shell in parallel at a certain interval through limiting connecting rods penetrating the electrode plates. The limiting connecting rods are connected with positive and negative poles of a direct current electrolysis power supply. The induction electrode group is composed of disc electrodes, the two ends of the disc induction electrode are respectively arranged in the gap between adjacent two anode and cathode electrode plates, the center of the disc electrode is fixed to a center rotating limiting connecting rod, a rotating motor drives the center rotating limiting connecting rod through a center rotating shaft connecting rod to drive the induction electrode group to rotate, and the continuous alternating reverse electrode change of the induction electrode area is realized. The application is mainly used for electrochemical treatment of high-hardness wastewater, the continuous alternating reverse electrode change of the area is realized through the rotation of the induction electrode group, the defects of scaling and frequent descaling after long-term operation of the electrode are avoided, and the efficient and stable operation of the electrochemical treatment system is ensured.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electrochemical treatment of wastewater, and particularly relates to a rotating reverse electrode electrochemical water treatment device and method. BACKGROUND

[0002] In recent years, electrochemical water treatment technology has attracted widespread attention. It mainly uses potential difference to regulate electron flow, so that pollutants are degraded or converted in the electrode interface or solution to achieve water purification. It is considered as a green water treatment technology. Compared with traditional water treatment technology, the electrode potential of electrochemical technology is controllable, which can directly and efficiently oxidize and reduce pollutants. It does not need to add chemical reagents and does not produce sludge. The reaction kinetics of electrochemical water treatment is efficient and adjustable, the device can be designed in a compact modular form, and it can be operated in a highly automated manner.

[0003] In the electrochemical water treatment device, strong oxidizing hydroxyl radicals or other oxidizing species are generated to promote the oxidation of organic matter, while water decomposition and hydrogen evolution reactions occur near the cathode, producing a large amount of alkaline environment of hydroxyl ions. Stable operation of the electrochemical water treatment system is of great practical significance to ensure the safe and stable production of enterprises, such as circulating water treatment, fine wastewater treatment, tail water treatment, etc. With the operation of the water treatment system, when the salt content, alkalinity, calcium and magnesium ions and other dissolved substances exceed their solubility, they will precipitate on the electrode surface, causing serious scaling in the system, hindering electron transfer on the electrode surface, and reducing the overall efficiency of the electrochemical reaction, which also increases the energy consumption of the treatment. Therefore, after the electrochemical water treatment reactor has been operated for a period of time, it usually needs to be shut down for electrode surface scaling removal treatment, which seriously affects the treatment efficiency. Electrode passivation is a problem that all electrochemical wastewater treatment devices face, and how to ensure long-term activity of the electrode has become a difficult problem that needs to be solved in actual operation.

[0004] Currently, the methods to solve the electrode scaling of electrochemical systems mainly include chemical dosing method, mechanical scraper method, and electrochemical reverse electrode method. The chemical dosing method is relatively simple to operate and can effectively stabilize the water quality to achieve descaling effect, but it also exposes problems such as secondary pollution, limitations of reagent selection and use, etc. The mechanical scraper method realizes descaling through the relative movement of the scraper and the electrode plate, which is simple to operate and has good economy, but the existence of the mechanical scraper limits the adjustability of the electrode spacing, the scale layer is difficult to remove completely, and the electrode plate is easily damaged during the movement of the scraper. The electrochemical reverse electrode method is to change the wiring polarity of the electrode, intermittently exchange the anode and the cathode, use the local acidity and bubbles generated by the anode (original cathode) under high current to strip the scale layer on the electrode surface, and complete the cleaning of the electrode surface. This method does not need to add additional chemical reagents, is simple and easy to integrate and control, and has good application prospects in the field of electrochemical water treatment.

[0005] Patent CN106115858 A discloses a kind of high-efficiency electrochemical wastewater treatment device automatic frequent control method of reverse pole, the reverse pole regeneration / activation electrode power polarity reversal is completed by PLC control, surge current is generated by using electric pile reverse pole, so that electrode can be quickly regenerated, but this method requires higher for electrical connection, waterway arrangement and reverse pole control;Patent CN114804457 A discloses a kind of electrochemical intermittent reverse pole composite electric adsorption device, copper on the surface of copper-clad stainless steel plate is corroded, which makes scale easy to fall off from the surface of cathode, and a vibration generator is provided on the cathode, which is beneficial to vibrate and fall off most of the scale, however, this method is intermittent reverse pole treatment, which needs to be manually set according to the operation condition;Patent CN115745090 A discloses a kind of circulating water electrochemical continuous reverse pole descaling system, which connects working circuit and reverse pole circuit in parallel mode respectively, and uses electric control switch to control descaling and descaling state switching, but parallel connection of multiple single devices increases control complexity, floor area and equipment investment. SUMMARY

[0006] To solve the above problems, the present application provides a kind of rotating reverse pole electrochemical water treatment device and method.The device of the present application mainly utilizes the technical features of inductive electrode rotation to generate continuous and regular reverse pole, thereby achieving the effects of quickly regenerating the surface of the electrode in the device, long-term ensuring the activity of the electrode, and improving the processing efficiency, etc., and applying the device to a circulating water treatment system can greatly improve the concentration ratio and prolong the operation and maintenance period.

[0007] To solve the above technical problems, according to one aspect of the present application, the present application provides the following technical solutions:

[0008] A kind of rotating reverse pole electrochemical water treatment device, comprising a shell, an anode electrode group, an inductive electrode group, a cathode electrode group, an electrolysis power supply and a rotating motor;The inside of the shell is provided with a limit connecting rod, including a center rotating limit connecting rod and a fixed electrode limit connecting rod;The center rotating limit connecting rod crosses the center of the inductive electrode group, and the center rotating shaft connecting rod of the rotating motor is connected through the shell;The fixed electrode limit connecting rod crosses the two ends of the anode electrode group and the cathode electrode group respectively, and the positive and negative electrodes of the direct current electrolysis power supply are connected through the shell;The inductive electrode group is cross-positioned with the anode electrode group and the cathode electrode group on both sides.

[0009] Further, the outside of the shell is provided with a water inlet, a water outlet and a sewage outlet, the water inlet, the water outlet and the sewage outlet are connected with a water inlet valve, a water outlet valve and a sewage valve outside, and an electromagnetic flowmeter is arranged between the water inlet and the water inlet valve.

[0010] Further, the water inlet and the water outlet are respectively provided with meters, which can monitor the water quality in real time, and the meters include COD, ammonia nitrogen, chloride, conductivity, pH and ORP meters, and the meters and the valves are connected to a remote control system.

[0011] Further, the anode electrode group and the cathode electrode group are both composed of the same number of single electrode sheets, the single electrode sheets are arranged in parallel at a certain interval through fixed electrode limiting connecting rods, and the single electrode sheets are spaced from each other through PTFE sleeves; after the fixed electrode limiting connecting rods of the cathode electrode group and the anode electrode group are connected to a direct current electrolysis power supply, a cathode region and an anode region are formed near the electrode sheets, respectively.

[0012] Further, the single electrode sheet of the anode electrode group is one of DSA, BDD, PbO2 and Ti4O7 electrodes; and the single electrode sheet of the cathode electrode group is one of stainless steel plate, titanium plate, carbon plate, aluminum plate and metal plated electrode.

[0013] Further, the inductive electrode group is composed of a plurality of disc-shaped inductive electrode sheets, the disc-shaped inductive electrode sheets are arranged in parallel at a certain interval through a center rotating limiting connecting rod, and the inductive electrode sheets are spaced from each other through PTFE sleeves, and the inductive electrode sheets are one of aluminum electrode, iron electrode and stainless steel electrode.

[0014] Further, the two semicircles on both sides of each disc-shaped inductive electrode sheet are respectively placed in the gap between two adjacent single electrode sheets of the anode electrode group and the cathode electrode group, and the disc-shaped inductive electrode sheets of the inductive electrode group are rotated around the center by rotating the center rotating connecting rod driven by a rotating motor.

[0015] Further, under the action of an electric field, the disc-shaped inductive electrode sheets correspond to form an inductive cathode and an anode in the disc-shaped parts placed in the anode region and the cathode region, and as the rotating motor drives the disc-shaped inductive electrode sheets to rotate, the rotating speed can be adjusted in the range of 0~200r / min, the area of the inductive anode and cathode generated on the disc-shaped anode changes, and the cathode region and the anode region are alternately changed.

[0016] The process method of the above-mentioned rotating reverse electrode electrochemical water treatment device includes an electrochemical water treatment process and a sewage cleaning process after long-term operation, and the process is as follows:

[0017] The electrolytic water treatment process: open the water inlet and outlet valves, close the sewage outlet valve, adjust the electromagnetic flowmeter to adjust the water inflow, and the wastewater enters the electrochemical treatment device through the water inlet; open the direct current electrolysis power supply to set a certain voltage and current, and at the same time, open the rotating motor power supply, electrolysis and continuous rotation of the inductive electrode group; detect the water quality change before and after electrolysis through the water inlet and outlet meters.

[0018] The process of cleaning and discharging after long-term operation is as follows: opening the water inlet valve, closing the water outlet valve, opening the discharge valve, adjusting the electromagnetic flow meter to adjust the water inlet flow, and cleaning water enters the electrochemical treatment device through the water inlet, and the long-term operation sediment in the device is discharged through the discharge port.

[0019] The beneficial effects of the present application are:

[0020] (1) Electrochemical reverse electrode treatment can be realized during the operation of the electrochemical device, and the electrode regeneration is realized continuously, avoiding the traditional intermittent reverse electrode shutdown adjustment;

[0021] (2) No complex logic control is needed for the electrolysis power supply, and the reverse electrode can be realized only by sensing the rotation of the electrode, without frequent polarity reversal of the power supply input end;

[0022] (3) Electrochemical reverse electrode treatment regenerates, avoiding the adverse environmental impact of chemical pickling and the damage to the electrode caused by mechanical scraper method, and the operation and maintenance are simpler, saving the daily operation cost and labor cost;

[0023] (4) According to different water quality characteristics and site conditions, the rotation speed of the driven electrode can be adjusted to change the reverse electrode frequency to avoid the influence of scale on the electrode surface on water treatment effect. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a side view of the rotating reverse electrode electrochemical water treatment device of the present application;

[0025] Figure 2 It is a top view of the rotating reverse electrode electrochemical water treatment device of the present application;

[0026] Figure 3 It is the running state 1 of the rotating disc induction electrode of the present application;

[0027] Figure 4 It is the running state 2 of the rotating disc induction electrode of the present application;

[0028] In the figure: 1, shell; 2, anode electrode group; 3, induction electrode group; 4, fixed electrode limit connecting rod; 5, center rotating connecting rod; 6, center rotating limit connecting rod; 7, cathode electrode group; 8, water outlet; 9, water inlet; 10, discharge port; 12, direct current electrolysis power supply; 13, rotating motor. DETAILED DESCRIPTION

[0029] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described in detail below. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present application.

[0030] Reference Figures 1-2 The rotating reverse electrode electrochemical water treatment device mainly comprises a shell 1, an anode electrode group 2, an induction electrode group 3, a cathode electrode group 7, a direct current electrolysis power supply 12 and a rotating motor 13. The shell 1 is internally provided with limiting connecting rods, including a central rotating limiting connecting rod 6 and a fixed electrode limiting connecting rod 4. The central rotating limiting connecting rod 6 crosses the center of the induction electrode group 3 and is connected with the central rotating shaft connecting rod 5 of the rotating motor 13. The fixed electrode limiting connecting rod 4 crosses the two ends of the anode electrode group 2 and the cathode electrode group 7 respectively and is connected with the positive and negative electrodes of the direct current electrolysis power supply 12. The induction electrode group 3 is crosswise and staggered with the anode electrode group 2 and the cathode electrode group 7 on both sides.

[0031] Reference Figure 2 The rotating reverse electrode electrochemical water treatment device is externally connected with the rotating motor 13 and the direct current electrolysis power supply 12.

[0032] The anode electrode group 2 and the cathode electrode group 7 are respectively fixedly arranged on both sides of the electrolytic tank and connected with the positive and negative electrodes of the direct current electrolysis power supply 12 through the fixed electrode limiting connecting rod 4 penetrating the shell 1 of the electrolytic tank. The anode electrode group 2 and the cathode electrode group 7 are respectively composed of 10 pieces of DSA electrode sheets and 10 pieces of titanium plate electrode sheets and fixed in the electrochemical device at intervals of 20 mm through the fixed electrode limiting connecting rod 4 crossing the three end points of the electrode sheets.

[0033] The induction electrode group 3 is composed of 9 pieces of disc induction iron alloy electrode sheets and fixed through the central rotating limiting connecting rod 6 penetrating the centers of the electrode sheets. The central rotating limiting connecting rod 6 is connected with the central rotating shaft connecting rod 5, and the central rotating shaft connecting rod 5 is provided with a PTFE limiting block to isolate the disc induction electrode sheets. The interval between two adjacent disc induction electrode sheets is 20 mm.

[0034] Each disc induction electrode sheet of the induction electrode group 3 is respectively arranged between the electrode sheet gaps of two adjacent anode electrode groups 2 and two adjacent cathode electrode groups 7 on both sides.

[0035] The fixed electrode limiting connecting rods 4 of the anode and the cathode are connected with the positive and negative electrodes of the direct current electrolysis power supply 12 after copper plates are collected, and the central rotating shaft connecting rod 5 of the induction electrode is connected with the rotating motor 13.

[0036] The device shell 1 is provided with water inlet 9 and water outlet 8 on the side, and sewage outlet 10 at the lower part, and the water inlet 9, water outlet 8 and sewage outlet 10 are respectively provided with valves;

[0037] When electrochemical water treatment is carried out, the water inlet 9 and water outlet 8 valves are opened, the sewage outlet 10 valve is closed, the raw water fills the electrochemical device shell 1 after passing through the water inlet 9; at the same time, the direct current electrolysis power supply 12 and the rotating motor 13 are opened, the electrolysis voltage is set to 0~24 V, the electrolysis current is set to 0~200 A, and the rotating speed of the rotating motor 13 is set to 0~10 r / min;

[0038] Reference Figure 3 For the running state 1 of the disc induction electrode, the anode electrode group 2 and the cathode electrode group 7 are electrified, and the areas where they are located form an anode reaction area (a) and a cathode reaction area (b) respectively, while the c and d areas on the induction electrode sheet which are placed in the corresponding areas form a cathode area and an anode area respectively under the induction of the electric field;

[0039] Reference Figure 4 For the running state 2 of the disc induction electrode, the rotating motor 13 drives the center shaft connecting rod 5 to rotate, and when the induction electrode group 3 disc electrode rotates, the c and d areas on the disc electrode gradually change into the cathode area and the anode area, and the c and d areas of the disc electrode form the anode and the cathode respectively under the induction of the electric field, thereby completing the electrode reversal of the disc electrode area;

[0040] It should be noted that during the rotation of the induction disc electrode, the disc electrode area is periodically reversed, and for the convenience of illustration, only the running state 1 and the running state 2 are used for illustration, and the electrode reversal process in other cases is sequentially extended; Figure 3 and reference Figure 4 Two running states are used for illustration, and the electrode reversal process in other cases is sequentially extended;

[0041] When sewage is discharged after long-term operation, the water inlet 9 and sewage outlet 10 valves are opened, the water outlet 8 valve is closed, the direct current electrolysis power supply 12 and the rotating motor 13 are closed, and the cleaning water enters the electrochemical device shell 1, and then the deposited dirt flows out from the sewage outlet 10, thereby completing the cleaning of the electrochemical equipment and the electrode. Example 1

[0042] The raw water of the refined treatment wastewater of a power plant has a COD of 52 mg / L, an ammonia nitrogen concentration of 84 mg / L, a pH of 9, and a chlorine ion content of 2538 mg / L, under the conditions of a direct current electrolysis power supply voltage of 8V, a current of 150A, an anode electrode group of 10 pieces of DSA electrode, a cathode electrode group of 10 pieces of stainless steel electrode, a disc induction electrode group of 9 pieces of iron alloy induction electrode, an electrode spacing of 5 mm between the cathode electrode piece, the anode electrode piece and the disc induction electrode piece, and a raw wastewater flow of 1 t / h pumped into the electrochemical treatment device, after the wastewater is treated by the rotating reverse electrode electrochemical device, the effluent has a COD of 23 mg / L and an ammonia nitrogen concentration of 35 mg / L, after 100 days of operation, no hard scale layer is generated on the surface of the electrochemical reactor, and the electrochemical system can normally and stably operate, maintaining >90% ammonia nitrogen and COD degradation activity. Example 2

[0043] The raw water of the desulfurization zero discharge wastewater of a power plant has a COD of 345 mg / L, an ammonia nitrogen concentration of 120 mg / L, a chlorine ion content of 45300 mg / L, a calcium hardness of 750 mg / L, a magnesium hardness of 230 mg / L, a total salt content of 17000 mg / L, and a pH of 6.5, under the conditions of a direct current electrolysis power supply voltage of 8V, a current of 150A, an anode electrode group of 10 pieces of DSA electrode, a cathode electrode group of 10 pieces of stainless steel electrode, a disc induction electrode group of 9 pieces of DSA electrode, an electrode spacing of 5 mm between the cathode electrode piece, the anode electrode piece and the disc induction electrode piece, and a raw wastewater flow of 1 t / h pumped into the electrochemical treatment device, after the wastewater is treated by the rotating reverse electrode electrochemical device, the effluent has a COD of 22.1 mg / L and an ammonia nitrogen concentration of 10.4 mg / L, after 50 days of operation, no hard scale layer is generated on the surface of the electrochemical reactor, and the electrochemical system can normally and stably operate, maintaining >85% ammonia nitrogen and COD degradation activity.

[0044] It should be noted that, in the process of treating wastewater, the anode region of the anode electrode group and the induction anode region of the induction electrode group jointly act on the treated wastewater, the induction electrode group removes the electrode scale through the rotating reverse electrode mode, and a small amount of scale may appear on the anode electrode group and the cathode electrode group on both sides during the wastewater treatment process, which can be removed by periodically reversing the positive and negative polarities of the power supply to remove the surface scale of the two fixed electrode groups.

[0045] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit it. Although the present application has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the specific embodiments of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, and any modification or equivalent replacement without departing from the spirit and scope of the present application should be covered in the protection scope of the claims of the present application.

Claims

1. A rotating reverse electrode electrochemical water treatment device, characterized in that, The shell (1) is internally provided with a limiting connecting rod, including a center rotating limiting connecting rod (6) and a fixed electrode limiting connecting rod (4); the center rotating limiting connecting rod (6) crosses the center of the induction electrode group (3) and is connected with the center rotating shaft connecting rod (5) of the rotating motor (13) through the shell (1); the fixed electrode limiting connecting rod (4) respectively crosses the two ends of the anode electrode group (2) and the cathode electrode group (7), and is connected with the positive and negative poles of the direct current electrolysis power supply (12) through the shell (1); the induction electrode group (3) and the anode electrode group (2) and the cathode electrode group (7) on both sides are cross-positioned; The anode electrode group (2) and the cathode electrode group (7) are both composed of the same number of multiple single electrode sheets, and the multiple single electrode sheets are arranged in parallel at a certain interval through the fixed electrode limiting connecting rod (4), and the single electrode sheets are spaced from each other through the PTFE sleeve; after the fixed electrode limiting connecting rod (4) of the cathode electrode group (7) and the anode electrode group (2) is connected with the direct current electrolysis power supply (12), a cathode region and an anode region are respectively formed near the electrode sheet; The induction electrode group (3) is composed of multiple disc-shaped induction electrode sheets, the disc-shaped induction electrode sheets are arranged in parallel at a certain interval through the center rotating limiting connecting rod (6), and the induction electrode sheets are spaced from each other through the PTFE sleeve, and the induction electrode sheets are one of aluminum electrode, iron electrode and stainless steel electrode; The two sides of each disc-shaped induction electrode sheet are respectively placed in the gap between two adjacent single electrode sheets of the anode electrode group (2) and the cathode electrode group (7), and the center rotating shaft connecting rod (5) is driven to rotate by the rotating motor (13), so that the disc-shaped induction electrode sheet of the induction electrode group (3) rotates around the center; The two sides of the disc-shaped induction electrode sheet respectively form an induced anode and a cathode in the cathode region and the anode region, and with the rotation of the disc-shaped induction electrode sheet driven by the rotating motor (13), the region of the induced anode and the cathode generated on the disc-shaped anode changes, so that the cathode region and the anode region are continuously and alternately changed.

2. A rotating reverse electrode electrochemical water treatment device according to claim 1, wherein The shell (1) is externally provided with a water inlet (9), a water outlet (8) and a sewage outlet (10), the water inlet (9), the water outlet (8) and the sewage outlet (10) are externally connected with a water inlet valve, a water outlet valve and a sewage valve, and an electromagnetic flowmeter is arranged between the water inlet (8) and the water inlet valve.

3. A rotating reverse electrode electrochemical water treatment device according to claim 2, wherein The water inlet (8) and the water outlet (9) are respectively provided with a meter, which can monitor the water quality in real time, and the meter includes COD, ammonia nitrogen, chloride, conductivity, pH and ORP meters, and the meter and the valve switch are connected to a remote control system.

4. A rotating reverse electrode electrochemical water treatment device according to claim 1, wherein The single electrode sheet of the anode electrode group (2) is one of DSA, BDD, PbO2 and Ti4O7 electrode, and the single electrode sheet of the cathode electrode group (7) is one of stainless steel plate, titanium plate, carbon plate, aluminum plate and metal plated electrode.

5. A process for the treatment of water by a rotating reverse electrode electrochemical device according to any one of claims 1 to 4, wherein The process includes the following steps: Electrolytic water treatment process: open the inlet (9) and outlet (8) valve, close the sewage (10) valve, adjust the electromagnetic flowmeter to adjust the water flow, wastewater through the inlet (9) into the electrochemical treatment device; open the DC electrolysis power supply (12) to set a certain voltage and current, while opening the rotary motor (13) power, electrolysis while the induction electrode group (3) continuous rotation; through the inlet (9) and outlet (8) meter to detect the change of water quality before and after electrolysis.

6. A process for the treatment of water by a rotating bipolar electrochemical device as claimed in claim 5, wherein After a long time running, the sewage treatment process is as follows: open the inlet (9) valve, close the outlet (8) valve, open the sewage (10) valve, adjust the electromagnetic flowmeter to adjust the water flow, clean water through the inlet (9) into the electrochemical treatment device, and the long-term running sediment in the device is discharged through the sewage outlet (10).

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