Sewage purification and recovery device based on ferroelectric flocculation and purification method thereof

Abstract

The invention relates to the technical field of purification devices, in particular to a ferroelectric flocculation-based sewage purification and recovery device and a purification method thereof.The ferroelectric flocculation-based sewage purification and recovery device comprises a barrel, a reaction zone, an alkalization zone, a mixing zone and an aeration zone which are mutually separated are sequentially arranged in the barrel from top to bottom, and the reaction zone and the alkalization zone communicate with each other; during use, cuprous oxide and ferric hydroxide floc precipitates are generated during complex breaking in an anoxic environment and an alkaline environment constructed in the reaction zone by filling the first electrode group and sodium sulfate, the alkalinity is enhanced by the second electrode group and sodium sulfate in the alkalization zone, and thus, the cuprous oxide and ferric hydroxide floc precipitates are separated from the reaction zone. Free cuprous in water is completely combined into cuprous oxide precipitates, then free copper ions and precipitates are generated in the aeration area, the electromagnet attracts ferromagnetic precipitates, finally, the free copper ions are adsorbed by an electrode in the electro-adsorption box, the precipitates obtained after reaction in all the areas are transferred by dead weight and are independently treated, the consumption cost is low, and the efficiency is high.

Description

Technical Field

[0001] The invention relates to the technical field of purification devices, and in particular to a purification and recovery device based on ferroelectric flocculation sewage and a purification method thereof. Background Art

[0002] Heavy metal ions are one of the main pollutants in the environment. They can be enriched in aquatic organisms and endanger human health through the food chain. Therefore, wastewater containing heavy metals, such as copper in wastewater, must be treated. However, the treatment and reuse of heavy metals has always been a difficult problem, and the complexed state is even more difficult to treat, such as organic complexed copper-containing wastewater, such as the common ethylenediaminetetraacetic acid (EDTA) complexed copper (Cu(Ⅱ)-EDTA).

[0003] Organically complexed copper-containing wastewater refers to wastewater that contains both heavy metal ions copper and ethylenediaminetetraacetic acid (EDTA) organic complexing agent, which causes the copper in the wastewater to not exist in a single free state, but to form a complex compound with the organic complexing agent EDTA. The chemical properties of this compound are stable, which increases the difficulty of removal. Cu(Ⅱ)-EDTA organic complexed heavy metals are mainly produced by the electroplating industry, printed circuit boards, and printing and dyeing industries. Since Cu(Ⅱ)-EDTA organic complexed heavy metal wastewater has a wide range of sources and is difficult to remove by traditional precipitation methods, the treatment of this type of wastewater has always been a difficult and hot issue in water management. Summary of the invention

[0004] The technical problem to be solved by the present invention is: in order to solve the problem of removing and recovering copper in complex form in wastewater which is difficult to treat, a ferroelectric flocculation wastewater purification and recovery device and a purification method thereof are provided.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a purification and recovery device based on ferroelectric flocculation sewage, comprising a cylinder, wherein the cylinder is provided with a reaction zone, an alkalization zone, a mixing zone and an aeration zone separated from each other in sequence from top to bottom, the reaction zone and the alkalization zone are connected to each other, a first valve is provided at the connection between the reaction zone and the alkalization zone, the alkalization zone and the mixing zone are connected to each other, a second valve is provided at the connection between the alkalization zone and the mixing zone, the mixing zone and the aeration zone are connected to each other, and a third valve is provided at the connection between the mixing zone and the aeration zone;

[0006] The cylinder is provided with a water inlet and a drain port connected to the reaction zone, and a dosing pipe is provided on the cylinder, and the dosing pipe can be used to add sodium sulfate solution to the reaction zone or the alkalization zone respectively, and a first electrode group is provided in the reaction zone;

[0007] A second electrode group is arranged in the alkalization zone;

[0008] A second stirring mechanism is provided in the mixing zone;

[0009] An aeration head is provided in the aeration zone, a sewage outlet is provided on the cylinder in the aeration zone, and an electromagnet for adsorbing ferromagnetic substances is provided at the bottom of the aeration zone;

[0010] The bottom of the cylinder is provided with an adsorption box, and an adsorption electrode group is provided in the adsorption box. The adsorption box is connected to the aeration zone. The upper end of the alkalization zone, the upper end of the mixing zone and the upper end of the aeration zone are respectively connected to an overflow pipe, and the overflow pipes are all connected to the vertical pipe. The bottom of the vertical pipe is connected to the top of the adsorption box. The cylinder is provided with a clean water port connected to the adsorption box. Compared with the prior art, this scheme utilizes the Fe generated by the electrode plate anode to 2 + has strong reducing property. When the pH value is between 3 and 7, Cu(II) in Cu(II)-EDTA is reduced to Cu(I), and then Cu(I) is replaced to break the complex. The copper recovery process is green and efficient. The replaced Cu(I) is aerated, and the free Cu ions are released and will not be complexed again. Then, Cu can be recycled through electrosorption. Other substances in the water can be precipitated. This solution can break the complex, recover relatively pure copper and remove organic matter. The equipment does not need manual control, the treatment process is simple, and the energy consumption is low.

[0011] In some preferred embodiments, the first electrode group and the second electrode group include an anode plate and a cathode plate spaced apart from each other, the anode plate is an iron plate, the cathode plate is a graphite plate, and both the anode plate and the cathode plate are provided with sieve holes, which facilitate water flow and increase hydraulic agitation.

[0012] In some preferred embodiments, the dosing tube is located between the anode plate and the cathode plate of the first electrode group. The dosing tube is arranged between the anode plate and the cathode plate of the first electrode group to enhance the conductivity of the anode plate and the cathode plate.

[0013] In some preferred embodiments, both electrodes of the adsorption electrode group are carbon felt electrodes. The carbon in the carbon felt electrode is conductive, and other materials can be mixed between the carbon felts to improve their conductive properties.

[0014] In order to realize the dosing tube, some preferred embodiments are that the dosing tube includes an outer sleeve and an inner sleeve arranged in the outer sleeve, one end of the outer sleeve is located in the reaction zone and are interconnected, one end of the inner sleeve is located in the alkalization zone and are interconnected, and the inner circumferential wall of the outer sleeve is penetrated outwardly with a plurality of flow holes.

[0015] In order to facilitate sufficient mixing and reaction of sewage and reagents in the reaction zone, in some preferred embodiments, a first stirring mechanism is provided in the reaction zone.

[0016] In order to facilitate the precipitate in the reaction zone to enter the alkalization zone, in some preferred embodiments, the lower bottom surface of the first reaction zone is a first inclined surface, and the first valve is located at the lower end of the first inclined surface.

[0017] In some preferred embodiments, the lower bottom surface of the mixing zone is a second slope, the third valve is located at the lower end of the second slope, the lower bottom surface of the aeration zone is a third slope, the electromagnet is located at the lower end of the third slope, and the sewage outlet is located at the lower end of the third slope. The sewage outlet is located at the lower end of the third slope to facilitate the discharge of sediment in the aeration zone, and the electromagnet is located at the lower end of the third slope to facilitate the adsorption of ferromagnetic substances in the sediment in the aeration zone.

[0018] In order to prevent sewage entering the reaction zone from being discharged from the drain port, in some preferred embodiments, the drain port is higher than the water inlet.

[0019] A purification method using a ferroelectric flocculation wastewater purification and recovery device as described above, the specific operating steps are as follows:

[0020] S1, the copper-containing wastewater to be treated enters the reaction zone from the water inlet, the first stirring mechanism is started, and sodium sulfate is injected into the reaction zone and the alkalization zone from the dosing pipe at the same time. After the copper-containing wastewater is injected and under the action of the first electrode group, ferrous ions are electrolyzed at the anode and hydroxide is generated at the cathode. A part of the ferrous ions reacts with oxygen in the water to consume the oxygen in the water, and another part of the ferrous ions reacts with copper ions complexed with EDTA to reduce Cu(II)-EDTA to Cu(I)-EDTA, and then replaces the Cu(I) therein, thereby breaking the complex and generating EDTA complexed iron precipitate. Then, as the alkalinity in the solution increases, Cu(I) combines with hydroxide and immediately generates cuprous oxide precipitate, and the remaining iron ions combine with hydroxide to generate iron hydroxide flocculent precipitate;

[0021] S2, the first valve is started at a fixed time to discharge the precipitate into the alkalization zone. Under the action of the second electrode group in the alkalization zone, the alkalinity is enhanced, and the free monovalent copper in the water is completely combined into cuprous oxide precipitation;

[0022] S3, the second valve is started at a fixed time, enters the mixing zone, starts the second stirring mechanism and stirs the precipitate discharged from the alkalization zone, so that the alkalinity and monovalent copper can fully react and react completely;

[0023] S4. Open the third valve and enter the aeration zone. In the aeration zone, cuprous oxide in the sediment is oxidized into free copper ions under the action of oxygen, and the residual ferrous ions are completely oxidized into iron ions. Under alkaline conditions, they combine to form precipitation, and some iron ions form green rust and magnetite nanoparticles. The electromagnet below the aeration zone is turned on to absorb these magnetic precipitations, and the magnetic precipitation and other precipitations can be discharged from the sewage outlet regularly. The free copper ions enter the electric adsorption box connected to the drain pipe, are adsorbed by the electrodes in the electric adsorption box, and the supernatant is discharged.

[0024] The beneficial effects of the present invention are as follows: when the ferroelectric flocculation sewage purification and recovery device and the purification method thereof are used, the first electrode group and the sodium sulfate solution are used to construct an anoxic environment and an alkaline environment in the reaction zone, so that the anode plate of the first electrode group is electrolyzed to produce ferrous ions, a part of the ferrous ions reacts with oxygen in water to consume the oxygen in the water, and another part of the ferrous ions reacts with copper ions complexed with EDTA to break the complex, and more importantly, when the first electrode group is electrolyzed, hydroxide is generated on the cathode plate, and cuprous oxide precipitates can be generated by using Cu(I) and hydroxide, and the remaining ferrous ions can be eliminated, so that the ferrous ions and the hydroxide are combined to generate iron hydroxide flocculent precipitates, and finally the cuprous oxide precipitates and the iron hydroxide flocculent precipitates are separated from the reaction zone by their own weight. Then it reaches the alkalization zone through the first valve. By configuring the second electrode group and adding sodium sulfate in the alkalization zone, the alkalinity of the alkalization zone can be further enhanced, and the free monovalent copper in the water can be completely combined into cuprous oxide precipitates. Then it reaches the mixing zone through the second valve. The precipitates discharged from the alkalization zone are stirred by the second stirring mechanism, so that the alkalinity and monovalent copper can fully react and completely combine to form cuprous oxide precipitates. Then it reaches the aeration zone through the third valve. The cuprous oxide in the precipitate is oxidized into free copper ions under the action of oxygen, and the residual ferrous ions are completely oxidized into iron ions, which are combined into precipitates under alkaline conditions. At the same time, some iron ions form green rust and magnetite nanoparticles. The electromagnet below the aeration zone can absorb the ferromagnetic precipitates, and can regularly discharge the ferromagnetic precipitates and other precipitates from the sewage outlet. Copper ions It enters the electrosorption box, is adsorbed by the electrode in the electrosorption box, and generates elemental copper on the electrode, and the supernatant is discharged. The overflowed supernatant in the alkalization zone, mixing zone and aeration zone flows into the electrosorption box 17 from the overflow pipe and the vertical pipe to electrolyze and remove organic matter such as EDTA. The precipitate after the reaction is gradually transferred from the reaction zone, alkalization zone, mixing zone and aeration zone by its own weight. There is no additional power, the consumption cost is low, and the reaction zone, alkalization zone, mixing zone and aeration zone can be processed independently, with high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0026] Figure 1 It is a schematic diagram of the structure of the present invention;

[0027] Figure 2 yes Figure 1 A partial enlarged view of middle A.

[0028] In the figure: 1, cylinder, 2, reaction zone, 3, alkalization zone, 4, mixing zone, 5, aeration zone, 6, first valve, 7, second valve, 8, third valve, 9, water inlet, 10, drain outlet, 11, dosing pipe, 12, first electrode group, 13, second electrode group, 14, aeration head, 15, sewage outlet, 16, electromagnet, 17, adsorption box, 18, adsorption electrode group, 19, overflow pipe, 20, water purification outlet, 21, outer sleeve, 22, inner sleeve, 23, first stirring mechanism, 24, second stirring mechanism. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with embodiments:

[0030] The present invention is not limited to the following specific embodiments. A person skilled in the art can implement the present invention in various other specific embodiments according to the contents disclosed in the present invention, or any simple changes or modifications made to the design structure and ideas of the present invention fall within the protection scope of the present invention. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0031] Example 1

[0032] like Figure 1-2 As shown, a purification and recovery device based on ferroelectric flocculation sewage comprises a cylinder 1, in which a reaction zone 2, an alkalization zone 3, a mixing zone 4 and an aeration zone 5 separated from each other are sequentially arranged from top to bottom, the reaction zone 2 and the alkalization zone 3 are interconnected, a first valve 6 is arranged at the connection point between the reaction zone 2 and the alkalization zone 3, the alkalization zone 3 and the mixing zone 4 are interconnected, a second valve 7 is arranged at the connection point between the alkalization zone 3 and the mixing zone 4, the connection between the alkalization zone 3 and the mixing zone 4 is mainly used for mud discharge, the mixing zone 4 and the aeration zone 5 are interconnected, a third valve 8 is arranged at the connection point between the mixing zone 4 and the aeration zone 5;

[0033] The cylinder 1 is provided with a water inlet 9 and a drain port 10 connected with the reaction zone 2, and the drain port 10 is higher than the water inlet 9. The cylinder 1 is provided with a dosing pipe 11, which can be used to add the required reagents to the reaction zone 2 or the alkalization zone 3 respectively. The reagent added in this embodiment is sodium sulfate, wherein the amount of sodium sulfate added is: for every cubic meter of wastewater treated, the amount of sodium sulfate added is 100g, and the amount of sodium sulfate distributed between the reaction zone 2 and the alkalization zone 3 is 7:3. A first electrode group 12 is provided in the reaction zone 2, and the dosing pipe 11 includes an outer sleeve 21 and an inner sleeve 22 provided in the outer sleeve 21, one end of the outer sleeve 21 is located in the reaction zone 2 and is connected to each other, one end of the inner sleeve 22 is located in the alkalization zone 3 and is connected to each other, and a plurality of through-holes are penetrated outwardly through the inner peripheral wall of the outer sleeve 21, and a first stirring mechanism 23 is provided in the reaction zone 2, and the lower bottom surface of the first reaction zone 2 is a first inclined surface, and the first valve 6 is located at the lower end of the first inclined surface;

[0034] A second electrode group 13 is provided in the alkalization zone 3, wherein the electrode plate materials of the first electrode group 12 and the second electrode group 13 are the same, the anode plates of both are iron plates with sieve holes, the cathode plates of both are graphite plates with sieve holes, the distance between the cathode plates is 2cm-5cm, the voltage is 20V-36V, and the dosing tube 11 is located between the anode plate and the cathode plate of the first electrode group 12;

[0035] A second stirring mechanism 24 is provided in the mixing zone 4, the lower bottom surface of the mixing zone 4 is a second inclined surface, and the third valve 8 is located at the lower end of the first inclined surface;

[0036] An aeration head 14 is provided in the aeration zone 5, a sewage outlet 15 is provided on the cylinder 1 in the aeration zone 5, an electromagnet 16 for adsorbing ferromagnetic substances is provided at the bottom of the aeration zone 5, the lower bottom surface of the aeration zone 5 is a third inclined surface, the electromagnet 16 is located at the lower end of the third inclined surface, and the sewage outlet 15 is located at the lower end of the third inclined surface;

[0037] An adsorption box 17 is arranged at the bottom of the cylinder 1, and an adsorption electrode group 18 is arranged in the adsorption box 17. The two electrodes of the adsorption electrode group 18 are carbon felt electrodes. The distance between the two electrodes is 1cm-3cm, and the electrode voltage is 1V-3V. The adsorption box 17 is connected with the aeration zone 5. The upper end in the alkalization zone 3, the upper end in the mixing zone 4 and the upper end in the aeration zone 5 are respectively connected with an overflow pipe 19. The overflow pipe 19 is connected with the vertical pipe. The bottom of the vertical pipe is connected with the top of the adsorption box 17. A clean water outlet 20 connected with the adsorption box 17 is arranged on the cylinder 1. The treated clean water is discharged from the clean water outlet 20. The supernatant overflowing from the alkalization zone 3, the mixing zone 4 and the aeration zone 5 can also flow into the electric adsorption box 17 from the overflow pipe 19 and be removed after electric adsorption.

[0038] Example 2

[0039] Embodiment 2 is a purification method of the device in Embodiment 1, specifically: a purification method using a purification and recovery device based on ferroelectric flocculation wastewater as described above, and the specific operation steps are as follows:

[0040] S1, connect the first electrode group 12 and the second electrode group 13, close the first valve 6, the second valve 7 and the third valve 8, then let the copper-containing wastewater to be treated enter the reaction zone 2 from the water inlet 9, start the first stirring mechanism 23, and inject sodium sulfate into the reaction zone 2 and the alkalization zone 3 from the dosing pipe 11 at the same time. After the copper-containing wastewater is injected and under the action of the first electrode group 12, ferrous ions are generated at the anode and hydroxide ions are generated at the cathode. A part of the ferrous ions reacts with oxygen in the water to consume all the oxygen in the water and form an oxygen-deficient environment , another part of the ferrous ions reacts with the copper ions complexed with EDTA to reduce Cu(II)-EDTA to Cu(I)-EDTA, and then displaces the Cu(I) therein, thereby breaking the complex and generating an EDTA-complexed iron precipitate. Then, as the alkalinity in the solution increases, the anoxic environment and the increase in alkalinity both promote the decomplexation of Cu(II)-EDTA and the generation of Cu(I). Cu(I) combines with hydroxide and then generates cuprous oxide precipitate. The remaining iron ions combine with hydroxide to generate an iron hydroxide flocculent precipitate.

[0041] S2, the first valve 6 is started regularly, and the precipitate is discharged into the alkalization zone 3 for 30s to 50s. Under the action of the second electrode group 13 in the alkalization zone 3, the alkalinity is enhanced, and the free monovalent copper in the water is completely combined into cuprous oxide precipitation;

[0042] S3, the second valve 7 is started at a fixed time, enters the mixing zone 4, starts the second stirring mechanism 24 and stirs the precipitate discharged from the alkalization zone 3, so that the alkalinity and monovalent copper can fully react and react completely;

[0043] S4, open the third valve 8, enter the aeration zone 5, in the aeration zone 5, cuprous oxide in the precipitate is oxidized into free copper ions under the action of oxygen, the copper ion content gradually increases during the aeration process, mainly in the form of Cu(I), the residual ferrous ions are completely oxidized into iron ions, under alkaline conditions, they combine to form precipitation, and part of the iron ions form green rust and magnetite nanoparticles, the electromagnet 16 below the aeration zone 5 is turned on, these magnetic precipitates can be absorbed, and the magnetic precipitates and other precipitates can be regularly discharged from the sewage outlet 15, the free copper ions enter the electric adsorption box 17 connected to the drain pipe, are adsorbed by the electrodes in the electric adsorption box 17, and the supernatant is discharged.

[0044] The opening and closing of the first valve 6, the second valve 7 and the third valve 8 are automatically controlled by the program. The first valve 6 is started for 30s-50s every 30 minutes, and then the second valve 7 is started for 30s-50s 20 minutes after the first valve 6 is closed. After the second valve 7 is closed for 20 minutes, the third valve 8 is started again for 20 minutes, so that each area is interconnected and independent of each other.

[0045] The above-mentioned ideal embodiments of the present invention are for inspiration. Through the above-mentioned description, relevant staff can make various changes and modifications without departing from the technical idea of ​​the present invention. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A sewage purification and recovery device based on ferroelectric flocculation, characterized in that: The invention comprises a cylinder (1), wherein the cylinder (1) is provided with a reaction zone (2), an alkalization zone (3), a mixing zone (4) and an aeration zone (5) which are separated from each other in sequence from top to bottom, the reaction zone (2) and the alkalization zone (3) are connected to each other, a first valve (6) is provided at the connection point between the reaction zone (2) and the alkalization zone (3), the alkalization zone (3) and the mixing zone (4) are connected to each other, a second valve (7) is provided at the connection point between the alkalization zone (3) and the mixing zone (4), the mixing zone (4) and the aeration zone (5) are connected to each other, and a third valve (8) is provided at the connection point between the mixing zone (4) and the aeration zone (5); The cylinder (1) is provided with a water inlet (9) and a water outlet (10) which are connected to the reaction zone (2); the cylinder (1) is provided with a dosing pipe (11), and the dosing pipe (11) can be used to add sodium sulfate solution to the reaction zone (2) or the alkalization zone (3), respectively; and a first electrode group (12) is provided in the reaction zone (2); A second electrode group (13) is arranged in the alkalization zone (3); A second stirring mechanism (24) is provided in the mixing zone (4); An aeration head (14) is provided in the aeration zone (5), a sewage outlet (15) is provided on the cylinder (1) and located in the aeration zone (5), and an electromagnet (16) for adsorbing ferromagnetic substances is provided at the bottom of the aeration zone (5); An adsorption box (17) is arranged at the bottom of the cylinder (1), an adsorption electrode group (18) is arranged in the adsorption box (17), the adsorption box (17) is connected to the aeration zone (5), the upper end of the alkalization zone (3), the upper end of the mixing zone (4) and the upper end of the aeration zone (5) are respectively connected to an overflow pipe (19), the overflow pipe (19) is connected to a vertical pipe, the bottom of the vertical pipe is connected to the top of the adsorption box (17), and the cylinder (1) is provided with a clean water outlet (20) connected to the adsorption box (17).

2. The device for purifying and recovering wastewater based on ferroelectric flocculation according to claim 1, characterized in that: The first electrode group (12) and the second electrode group (13) both comprise an anode plate and a cathode plate which are spaced apart from each other, the anode plate is an iron plate, the cathode plate is a graphite plate, and both the anode plate and the cathode plate are provided with sieve holes.

3. The device for purifying and recovering wastewater based on ferroelectric flocculation according to claim 2, characterized in that: The drug adding tube (11) is located between the anode plate and the cathode plate of the first electrode group (12).

4. The device for purifying and recovering wastewater based on ferroelectric flocculation according to claim 1, characterized in that: Both electrodes of the adsorption electrode group (18) are carbon felt electrodes.

5. The device for purifying and recovering wastewater based on ferroelectric flocculation according to claim 1, characterized in that: The dosing tube (11) comprises an outer sleeve (21) and an inner sleeve (22) arranged inside the outer sleeve (21); one end of the outer sleeve (21) is located inside the reaction zone (2) and is interconnected; one end of the inner sleeve (22) is located inside the alkalization zone (3) and is interconnected; a plurality of through holes are penetrated through the inner peripheral wall of the outer sleeve (21) toward the outside.

6. The device for purifying and recovering wastewater based on ferroelectric flocculation according to claim 1, characterized in that: A first stirring mechanism (23) is provided in the reaction zone (2).

7. The device for purifying and recovering wastewater based on ferroelectric flocculation according to claim 1, characterized in that: The lower bottom surface of the first reaction zone (2) is a first inclined surface, and the first valve (6) is located at the lower end of the first inclined surface.

8. The device for purifying and recovering wastewater based on ferroelectric flocculation according to claim 1, characterized in that: The lower bottom surface of the mixing zone (4) is a second inclined surface, the third valve (8) is located at the lower end of the first inclined surface, the lower bottom surface of the aeration zone (5) is a third inclined surface, the electromagnet (16) is located at the lower end of the third inclined surface, and the sewage outlet (15) is located at the lower end of the third inclined surface.

9. The device for purifying and recovering wastewater based on ferroelectric flocculation according to claim 1, characterized in that: The water outlet (10) is higher than the water inlet (9).

10. A purification method using a ferroelectric flocculation wastewater purification and recovery device as claimed in any one of claims 1 to 9, characterized in that: The specific steps are as follows: S1, the copper-containing wastewater to be treated enters the reaction zone (2) from the water inlet (9), the first stirring mechanism (23) is started, and sodium sulfate is injected into the reaction zone (2) and the alkalization zone (3) from the dosing pipe (11). After the copper-containing wastewater is injected and under the action of the first electrode group (12), ferrous ions are generated at the anode by electrolysis, and hydroxide is generated at the cathode. A part of the ferrous ions reacts with oxygen in the water to consume the oxygen in the water, and another part of the ferrous ions reacts with copper ions complexed with EDTA to reduce Cu(II)-EDTA to Cu(I)-EDTA, and then replaces the Cu(I) therein, thereby breaking the complex and generating an EDTA-complexed iron precipitate. Then, as the alkalinity in the solution increases, Cu(I) combines with hydroxide to generate cuprous oxide precipitate, and the remaining iron ions combine with hydroxide to generate iron hydroxide flocculent precipitate; S2, the first valve (6) is started at a fixed time to discharge the precipitate into the alkalization zone (3). Under the action of the second electrode group (13) in the alkalization zone (3), the alkalinity is enhanced, and the free monovalent copper in the water is completely combined to form cuprous oxide precipitate; S3, the second valve (7) is started at a fixed time, entering the mixing zone (4), starting the second stirring mechanism (24) and stirring the precipitate discharged from the alkalization zone (3), so that the alkalinity and monovalent copper can fully react and react completely; S4, open the third valve (8), enter the aeration zone (5), in the aeration zone (5), cuprous oxide in the precipitate is oxidized into free copper ions under the action of oxygen, and the residual ferrous ions are completely oxidized into iron ions. Under alkaline conditions, they are combined to form precipitates, and at the same time, part of the iron ions form green rust and magnetite nanoparticles. The electromagnet (16) below the aeration zone (5) is turned on to absorb these magnetic precipitates, and the magnetic precipitates and other precipitates can be discharged from the sewage outlet (15) regularly. The free copper ions enter the electric adsorption box (17) connected to the drainage pipe, are adsorbed by the electrodes in the electric adsorption box (17), and the supernatant is discharged.

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