Electroplating wastewater recycling system and method

Abstract

This invention discloses an electroplating wastewater recovery system and method, belonging to the field of electroplating wastewater treatment. It includes a resin adsorption device, a membrane concentration device, an electrolytic cell, a mixing tank, a submerged ultrafiltration membrane tank, an electrodialysis device, a reverse osmosis device, and a bipolar membrane electrodialysis device. The eluent outlet of the resin adsorption device is connected to the membrane concentration device; the concentrated liquid outlet of the membrane concentration device is connected to the electrolytic cell; the dialysis liquid outlet of the resin adsorption device, the permeate outlet of the membrane concentration device, and the residual liquid outlet of the electrolytic cell are all connected to the mixing tank; the outlet of the mixing tank is connected to the submerged ultrafiltration membrane tank; the filtrate outlet of the submerged ultrafiltration membrane tank is connected to the electrodialysis device; the desalination liquid outlet of the electrodialysis device is connected to the reverse osmosis device; the concentrated liquid outlet of the electrodialysis device is connected to the bipolar membrane electrodialysis device; and the alkali outlet of the bipolar membrane electrodialysis device is connected to the submerged ultrafiltration membrane tank. This invention not only yields valuable metals but also provides acid and alkali solutions.

Description

Technical Field

[0001] This invention belongs to the field of electroplating wastewater treatment, and particularly relates to an electroplating wastewater recycling system and method. Background Technology

[0002] With the rapid development of modern industry, the wastewater problem generated during the electroplating industry, as an important part of the manufacturing industry, has become increasingly prominent. Electroplating wastewater is a complex industrial wastewater containing heavy metal ions and other harmful substances. If not treated properly, it will not only cause serious pollution to the natural environment, but also accumulate through the food chain and ultimately threaten human health.

[0003] An integrated electroplating wastewater treatment device, application number CN202411025804.7, includes a main control box, a pretreatment cylinder, a centrifugal outer cylinder, and a recovery cylinder. The pretreatment cylinder, centrifugal outer cylinder, and recovery cylinder are all located at the top of the main control box. The pretreatment cylinder contains a pretreatment mechanism with a filtration and slag removal system. The centrifugal outer cylinder contains a deep purification mechanism with a microprocessor system. The recovery cylinder contains an electrolytic recovery mechanism with a ventilation system. While it recovers heavy metal ions through electrolysis, it does not provide subsequent treatment for the electrolytic residue and other treated liquids, resulting in insufficient resource utilization of the electroplating wastewater. Summary of the Invention

[0004] The purpose of this invention is to provide an electroplating wastewater recycling system and method to overcome at least one of the above-mentioned defects in the prior art.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] The electroplating wastewater recovery system provided by this invention includes a resin adsorption device, a membrane concentration device, an electrolytic cell, a mixing tank, a submerged ultrafiltration membrane tank, an electrodialysis device, a reverse osmosis device, and a bipolar membrane electrodialysis device. The eluent outlet of the resin adsorption device is connected to the membrane concentration device, the concentrate outlet of the membrane concentration device is connected to the electrolytic cell, the dialysis fluid outlet of the resin adsorption device, the permeate outlet of the membrane concentration device, and the residual liquid outlet of the electrolytic cell are all connected to the mixing tank, the outlet of the mixing tank is connected to the submerged ultrafiltration membrane tank, the filtrate outlet of the submerged ultrafiltration membrane tank is connected to the electrodialysis device, the desalination liquid outlet of the electrodialysis device is connected to the reverse osmosis device, and the concentrate outlet of the electrodialysis device is connected to the reverse osmosis device. The liquid outlet is connected to the bipolar membrane electrodialysis equipment, and the alkaline liquid outlet of the bipolar membrane electrodialysis equipment is connected to the submerged ultrafiltration membrane tank. The mixing tank includes a tank body, a liquid collection component, a stirring component, and a first cylinder. The liquid collection component and the stirring component are fixed on the top of the tank body. The first cylinder is fixed inside the tank body. The stirring component has a first spiral blade that passes through the first cylinder. The first cylinder has a chamber inside. The inner wall of the first cylinder has several first spray holes that communicate with the chamber. The stirring component has a second spray hole that is located inside the first cylinder. The liquid collection component has two outlets, one of which communicates with the chamber and the other of which communicates with the second spray hole.

[0007] Preferably, the liquid collection assembly includes a liquid collection tank, partitions, a first pipe, a second pipe, a first valve, a pressurizing pump, and a venturi tube. The liquid collection tank has two fixed partitions inside, dividing the internal space into three liquid collection chambers. The tops of the three liquid collection chambers are respectively connected to the dialysis fluid outlet of the resin adsorption device, the permeate outlet of the membrane concentration device, and the residual liquid outlet of the electrolytic cell. The bottom of each liquid collection chamber is fixedly connected to a first pipe, which is equipped with a first valve. The outlet end of the first pipe in the leftmost liquid collection chamber is connected to the inlet end of the venturi tube. The outlet end of the first pipe in the middle liquid collection chamber is connected to the throat of the venturi tube. The outlet end of the venturi tube is connected to a second nozzle via a second pipe. The outlet end of the first pipe in the rightmost liquid collection chamber is connected to the chamber. Pressurizing pumps are installed in the first pipes of the leftmost and rightmost liquid collection chambers.

[0008] Preferably, the mixing tank further includes a second valve, a third valve, a first air inlet pipe, and a second air inlet pipe. The first pipe in the rightmost liquid collection chamber is fixedly connected to the first air inlet pipe. The first air inlet pipe is equipped with a second valve. The first air inlet pipe is located below the pressurizing pump and is connected to an external air source. The second pipe is fixedly connected to the second air inlet pipe. The second air inlet pipe is equipped with a third valve. The second air inlet pipe is located below the pressurizing pump and is connected to an external air source.

[0009] Preferably, the chamber is an annular chamber, and the plurality of first nozzles include a plurality of nozzle groups that are spaced apart along the circumference of the chamber. Each nozzle group includes a plurality of first nozzles that are spaced apart along the height direction of the first cylinder. The first nozzles are inclined upward.

[0010] Preferably, the stirring assembly further includes a motor, a transmission assembly, a first bearing housing, a hollow shaft, an L-shaped stirring frame, and a first stirring plate. The motor and the first bearing housing are fixed to the top of the tank. The hollow shaft passes through the first bearing housing, the top wall of the tank, and the first cylinder, and is fixed to the L-shaped stirring frame. Several first stirring plates are fixed to the outside of the L-shaped stirring frame. The motor is connected to the hollow shaft through the transmission assembly. The bottom end of the second pipe extends into the hollow shaft. Several second spray holes are spaced apart along the length of the hollow shaft.

[0011] Preferably, the inner wall of the tank is fixed with several baffles that are spaced apart vertically, and several first stirring plates are spaced apart vertically and staggered with the baffles.

[0012] Preferably, the first cylinder is fixed to the tank body by a horizontal plate.

[0013] Preferably, the mixing tank further includes a sealed box, a second bearing seat, a first bevel gear, a third bearing seat, a second bevel gear, a rotating shaft, and a second stirring plate. The sealed box is fixed to the bottom wall of the tank body, and the second bearing seat is fixed to the bottom wall of the sealed box. The bottom end of the hollow shaft passes through the top wall of the sealed box and is inserted into the second bearing seat. The lower part of the hollow shaft is fixed with the first bevel gear, which is located inside the sealed box. The hollow shaft and the sealed box are sealed together. The left and right side walls of the sealed box are both fixed with third bearing seats. The inner end of the rotating shaft passes through the side wall of the sealed box and extends into the sealed box where the second bevel gear is fixed. The first bevel gear and the second bevel gear mesh. The rotating shaft and the sealed box are sealed together. The outer end of the rotating shaft is fixed with the second stirring plate, which is located below the first stirring plate and perpendicular to it.

[0014] Preferably, the mixing tank further includes a second spiral blade and a second cylinder. The second cylinder is fixed on both the left and right sides of the bottom wall of the tank. The second cylinder is located between the sealing box and the second stirring plate. The second spiral blade is fixed to the rotating shaft and passes through the second cylinder.

[0015] This invention also provides a method for recycling electroplating wastewater, using the aforementioned electroplating wastewater recycling system, comprising the following steps: feeding the electroplating wastewater into a resin adsorption device for resin adsorption treatment; feeding the resulting eluent into a membrane concentration device for membrane concentration treatment; feeding the resulting concentrate into an electrolytic cell for electrolysis treatment to obtain valuable metals; collecting the dialysis solution obtained from resin adsorption treatment, the permeate obtained from membrane concentration treatment, and the residual liquid obtained from electrolysis treatment into a collection component of a mixing tank; feeding the dialysis solution obtained from resin adsorption treatment, the permeate obtained from membrane concentration treatment, and the residual liquid obtained from electrolysis treatment into the tank body through the collection component, and mixing them through a stirring component; feeding the mixed solution into a submerged ultrafiltration membrane tank for ultrafiltration treatment; feeding the filtrate obtained from ultrafiltration treatment into an electrodialysis device for electrodialysis treatment; feeding the resulting desalinated solution into a reverse osmosis device for reverse osmosis treatment to obtain permeate; feeding the resulting concentrate into a bipolar membrane electrodialysis device for further electrodialysis treatment to obtain acid and alkali solutions; and reusing the alkali solution back into the submerged ultrafiltration membrane tank.

[0016] The beneficial effects of this invention are as follows:

[0017] 1. Not only can valuable metals be obtained, but also acid and alkali solutions are produced, and the wastewater is discharged in compliance with standards.

[0018] 2. Zero pollution discharge is achieved by treating the liquids in each step.

[0019] 3. The dialysis solution obtained from resin adsorption treatment, the permeate obtained from membrane concentration treatment, and the residual liquid obtained from electrolysis treatment are mixed in a mixing tank and then sent to the submerged ultrafiltration membrane tank. This makes the water quality of the mixed solution more uniform and stable, providing more favorable water quality conditions for subsequent treatment steps.

[0020] 4. Before stirring, use a collision mixing method for preliminary mixing to greatly improve mixing efficiency.

[0021] 5. By setting up the first cylinder and the first spiral blades, the upper and lower layers can circulate and flow, thereby achieving a uniform mixing effect.

[0022] 6. During the rotation of the first helical blade, it not only promotes the flow of the mixture, but also cuts and flips the mixture, so that the mixture is more fully mixed during the stirring process.

[0023] 7. By using a venturi tube, the residual liquid obtained from electrolysis and the dialysis solution obtained from resin adsorption are mixed together during transportation to form a homogeneous mixture.

[0024] 8. First, the residual liquid obtained from electrolysis and the dialysis liquid obtained from resin adsorption are initially mixed to form a mixture. Then, the mixture is sprayed out through the first and second nozzles respectively to collide and initially mix the three liquids. Finally, mechanical stirring is used to achieve uniform mixing. The mixing effect is good and the efficiency is high.

[0025] 9. The airflow ejected through the first and second nozzles propels the mixture, causing it to mix more thoroughly, thereby improving mixing efficiency. The synergistic effect of aeration and stirring can enhance the stirring effect, making the mixture more uniform and delicate.

[0026] 10. The liquid inlet and air inlet share a single conveying structure, reducing space occupation and demonstrating ingenious design.

[0027] 11. During liquid spraying, this allows droplets to cover a higher area, increasing the vertical coverage of the droplets and making the sprayed droplets more uniform and fine, thus improving the collision and mixing effect. During jet spraying, the angled gas exit allows the gas to form more complex and intense flow patterns in the liquid. When the gas is sprayed at an angle, it propels the liquid along the angle, while also generating radial and tangential components, which contribute to the mixing and uniform distribution of the liquid.

[0028] 12. By setting up baffles, the flow direction of the mixture in the tank is changed. When the mixture encounters a baffle during the stirring process, it is forced to change its original flow path, thereby reducing the occurrence of circular motion (i.e., "swirl").

[0029] 13. The horizontal plate is not only used to fix the first cylinder, but also serves the same anti-spinning function as the baffle.

[0030] 14. The arrangement of the first and second stirring plates ensures that the mixture is subjected to shear and impact forces from different directions during the stirring process, thereby achieving more thorough mixing. The vertically distributed first and second stirring plates can cover a larger space within the tank, ensuring that the mixture is effectively stirred at all locations within the tank.

[0031] 15. The second spiral blade, combined with the second cylinder, achieves the effect of stirring and pushing the mixture at the same time. In conjunction with the pushing action of the first spiral blade, it is more conducive to the circulation of the mixture between the upper and lower layers.

[0032] 16. Through structural design, the first stirring plate rotates while simultaneously driving the second stirring plates on the left and right sides to rotate synchronously in opposite directions. This, in turn, drives the first and second spiral blades to rotate, causing the mixture to circulate within the tank and achieve uniform mixing. Attached Figure Description

[0033] Figure 1 This is a system block diagram of the present invention.

[0034] Figure 2 This is a schematic diagram of the main structure of the mixing tank of the present invention.

[0035] Figure 3 This is a schematic diagram of the internal structure of the tank body of the present invention.

[0036] Figure 4 This is a cross-sectional structural schematic diagram of the first cylindrical body of the present invention.

[0037] Figure 5 This is a schematic diagram of the internal structure of the sealing box of the present invention.

[0038] The labels in the attached diagram are as follows: 100-resin adsorption device, 200-membrane concentration device, 300-electrolytic cell, 400-mixing tank, 500-submerged ultrafiltration membrane tank, 600-electrodialysis equipment, 700-reverse osmosis equipment, 800-bipolar membrane electrodialysis equipment, 1-tank body, 2-collection assembly, 3-stirring assembly, 4-first cylinder, 41-chamber, 42-first nozzle, 21-collection tank, 22-partition plate, 23-first pipe, 24-second pipe, 25-first valve, 26-pressurization pump, 27-Venturi tube, 2 8-Liquid collection chamber, 5-Second valve, 6-Third valve, 7-First air inlet pipe, 8-Second air inlet pipe, 31-Motor, 32-Transmission assembly, 33-First bearing seat, 34-Hollow shaft, 35-L-shaped stirring frame, 36-First stirring plate, 37-Second nozzle, 38-First spiral blade, 9-Horizontal plate, 10-Sealed box, 11-Second bearing seat, 12-First bevel gear, 13-Third bearing seat, 14-Second bevel gear, 15-Rotating shaft, 16-Second stirring plate, 17-Second spiral blade, 18-Second cylinder. Detailed Implementation

[0039] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0040] Contents not described in detail in this specification are prior art known to those skilled in the art. In the description of this invention, it should be understood that terms such as "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and 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, terms such as "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0041] like Figures 1 to 5 As shown, the electroplating wastewater recovery system provided in this embodiment includes a resin adsorption device 100, a membrane concentration device 200, an electrolytic cell 300, a mixing tank 400, a submerged ultrafiltration membrane tank 500, an electrodialysis device 600, a reverse osmosis device 700, and a bipolar membrane electrodialysis device 800. The eluent outlet of the resin adsorption device 100 is connected to the membrane concentration device 200, the concentrate outlet of the membrane concentration device 200 is connected to the electrolytic cell 300, the dialysis fluid outlet of the resin adsorption device 100, the permeate outlet of the membrane concentration device 200, and the residual liquid outlet of the electrolytic cell 300 are all connected to the mixing tank 400, the outlet of the mixing tank 400 is connected to the submerged ultrafiltration membrane tank 500, the filtrate outlet of the submerged ultrafiltration membrane tank 500 is connected to the electrodialysis device 600, and the desalination liquid outlet of the electrodialysis device 600 is connected to the reverse osmosis device 700. The concentrated liquid outlet of the electrodialysis device 600 is connected to the bipolar membrane electrodialysis device 800, and the alkaline liquid outlet of the bipolar membrane electrodialysis device 800 is connected to the submerged ultrafiltration membrane tank 500. The mixing tank 400 includes a tank body 1, a liquid collection assembly 2, a stirring assembly 3, and a first cylinder 4. The liquid collection assembly 2 and the stirring assembly 3 are fixed on the top of the tank body 1. The first cylinder 4 is fixed inside the tank body 1. The stirring assembly 3 has a first spiral blade 38 that passes through the first cylinder 4. The first cylinder 4 has a chamber 41 inside. The inner wall of the first cylinder 4 has several first spray holes 42 that communicate with the chamber 41. The stirring assembly 3 has a second spray hole 37 located inside the first cylinder 4. The liquid collection assembly 2 has two outlets, one of which communicates with the chamber 41 and the other of which communicates with the second spray hole 37.

[0042] This embodiment also provides a method for recycling electroplating wastewater, which uses the above-mentioned electroplating wastewater recycling system for recycling, including the following steps:

[0043] Electroplating wastewater is fed into a resin adsorption device 100 for resin adsorption treatment. The resulting eluent is then fed into a membrane concentration device 200 for membrane concentration treatment. The concentrated solution is then fed into an electrolytic cell 300 for electrolysis treatment to obtain valuable metals. The dialysis solution obtained from the resin adsorption treatment, the permeate obtained from the membrane concentration treatment, and the residual liquid obtained from the electrolysis treatment are collected in a mixing tank 400 by a collection assembly 2. The collection assembly 2 separates the dialysis solution obtained from the resin adsorption treatment, the permeate obtained from the membrane concentration treatment, and the residual liquid obtained from the electrolysis treatment. The residual liquid obtained from the treatment is sent into tank 1 and mixed by stirring component 3. The mixed liquid is then sent to submerged ultrafiltration membrane tank 500 for ultrafiltration treatment. The filtrate obtained from ultrafiltration treatment is sent to electrodialysis equipment 600 for electrodialysis treatment. The desalinated liquid obtained from the treatment is sent to reverse osmosis equipment 700 for reverse osmosis treatment to obtain permeate water. The concentrated liquid obtained from the treatment is sent to bipolar membrane electrodialysis equipment 800 for electrodialysis treatment again to obtain acid solution and alkali solution. The alkali solution is recycled back to submerged ultrafiltration membrane tank 500.

[0044] In this way, the electroplating wastewater recycling process not only yields valuable metals but also provides acid and alkali solutions, and the treated water meets discharge standards. Zero-pollution discharge is achieved through the treatment of liquids from each step. A mixing tank 400 is used to mix the dialysis solution obtained from resin adsorption treatment, the permeate obtained from membrane concentration treatment, and the residual liquid obtained from electrolysis treatment before sending them to the submerged ultrafiltration membrane tank 500. This results in a more uniform and stable water quality in the mixed solution, providing more favorable water quality conditions for subsequent treatment steps. During mixing, the dialysis solution obtained from resin adsorption treatment and the residual liquid obtained from electrolysis treatment are transported to the stirring assembly 3 through the liquid collection component 2 and sprayed out through the second nozzle 37. Simultaneously, the permeate obtained from membrane concentration treatment is sent into the chamber 41 and sprayed out through the first nozzle 42. The droplets sprayed from the second nozzle 37 and the droplets sprayed from the first nozzle 42 collide and mix before falling to the bottom of the tank 1. Thus, preliminary mixing is performed by collision mixing before agitation, greatly improving mixing efficiency. Based on this, the combination of the first cylinder 4 and the first spiral blade 38 enables circulating flow between the upper and lower layers, thereby achieving a uniform mixing effect. During rotation, the first spiral blade 38 not only propels the mixture to flow but also cuts and tumbles it, ensuring more thorough mixing during the stirring process.

[0045] The liquid collection assembly 2 includes a liquid collection tank 21, partitions 22, a first pipe 23, a second pipe 24, a first valve 25, a pressure pump 26, and a venturi tube 27. Two partitions 22 are fixed inside the liquid collection tank 21, dividing the internal space of the tank into three liquid collection chambers 28. The tops of the three collection chambers 28 are respectively connected to the dialysis fluid outlet of the resin adsorption device 100, the permeate outlet of the membrane concentration device 200, and the residual liquid outlet of the electrolytic cell 300. The bottom of each collection chamber 28 is fixedly connected to a first pipe 23. The first pipe 23 is configured with… The system includes a first valve 25. The outlet of the first pipe 23 in the leftmost collecting chamber 28 is connected to the inlet of the venturi tube 27. The outlet of the first pipe 23 in the middle collecting chamber 28 is connected to the throat of the venturi tube 27. The outlet of the venturi tube 27 is connected to the second nozzle 37 via a second pipe 24. The outlet of the first pipe 23 in the rightmost collecting chamber 28 is connected to the chamber 41. Each of the three collecting chambers 28, including the leftmost and rightmost collecting chambers, is equipped with a pressure pump 26. The three collecting chambers 28, from left to right, store the dialysis fluid obtained from resin adsorption treatment, the residual liquid obtained from electrolysis treatment, and the permeate obtained from membrane concentration treatment. Integrating the three collecting chambers 28 into a single collecting tank 21 reduces space requirements. The transport of the dialysate obtained from resin adsorption treatment, the permeate obtained from membrane concentration treatment, and the residual liquid obtained from electrolysis treatment are controlled by the three first pipes 23 and the first valve 25 to meet different operational needs. The liquid is pressurized by the pressure pump 26, which facilitates subsequent liquid ejection collision and dispersion. The dialysate obtained from resin adsorption treatment is pressurized and sent to the Venturi tube 27 through the first pipe 23. When the dialysate passes through the throat of the Venturi tube 27, the flow rate increases and the pressure decreases, forming a negative pressure zone that draws in the residual liquid obtained from electrolysis treatment. This causes the residual liquid obtained from electrolysis treatment and the dialysate obtained from resin adsorption treatment to mix during transport, forming a homogeneous mixture. During this process, the fluid generates strong shear force and turbulence effect, thereby achieving effective mixing between different fluids. The mixed liquid is pressurized and sent to the stirring assembly 3 through the second pipe 24, and finally ejected through the second nozzle 37. The permeate obtained from membrane concentration treatment, after pressurization, is sent to the chamber 41 through the first pipe 23 and finally ejected through the first nozzle 42. First, the residual liquid obtained from electrolysis and the dialysis liquid obtained from resin adsorption are initially mixed to form a mixture. Then, the mixture is sprayed out through the first nozzle 42 and the second nozzle 37 respectively to collide and initially mix the three liquids. Finally, the mixture is mechanically stirred to achieve uniform mixing. The mixing effect is good and the efficiency is high.

[0046] The mixing tank 400 also includes a second valve 5, a third valve 6, a first air inlet pipe 7, and a second air inlet pipe 8. The first pipe 23 of the rightmost liquid collection chamber 28 is fixedly connected to the first air inlet pipe 7, which is equipped with the second valve 5. The first air inlet pipe is located below the pressurizing pump 26 and is connected to an external air source. The second pipe 24 is fixedly connected to the second air inlet pipe 8, which is equipped with the third valve. The second air inlet pipe is located below the pressurizing pump 26 and is connected to an external air source. After the liquid delivery is complete, the first valve 25 and the pressurizing pump 26 are closed. The second valve 5 and the third valve 6 are opened as needed. After the second valve 5 is opened, the airflow enters the chamber 41 through the first air inlet pipe 7 and is ejected through the first nozzle 42. After the third valve 6 is opened, the airflow enters the stirring assembly 3 through the second air inlet pipe 8 and is ejected through the second nozzle 37. Combined with the rotation of the stirring assembly 3, the airflow is ejected in a rotating jet form. The airflow ejected through the first nozzle 42 and the second nozzle 37 propels the mixture, causing it to mix more thoroughly and thus improving mixing efficiency. The synergistic effect of airflow and stirring enhances the mixing effect, resulting in a more uniform and finer mixture. The liquid and air inlet share a single conveying structure, reducing space requirements and demonstrating ingenious design.

[0047] The chamber 41 is an annular cavity, and the plurality of first nozzles 42 include several groups of nozzles spaced apart circumferentially along the chamber 41. Each group of nozzles includes several first nozzles 42 spaced apart along the height direction of the first cylinder 4, and the first nozzles 42 are inclined upwards. During liquid spraying, this allows the droplets to cover a higher area, increasing the vertical coverage of the droplets and making the sprayed droplets more uniform and fine, thus improving the collision mixing effect. During gas spraying, the inclined gas outlet allows the gas to form a more complex and intense flow pattern in the liquid. When the gas is sprayed at an inclined angle, it propels the liquid along the inclined direction, while also generating certain radial and tangential components, which contribute to the mixing and uniform distribution of the liquid.

[0048] The stirring assembly 3 includes a motor 31, a transmission assembly 32, a first bearing seat 33, a hollow shaft 34, an L-shaped stirring frame 35, and first stirring plates 36. The motor 31 and the first bearing seat 33 are fixed to the top of the tank 1. The hollow shaft 34 passes through the first bearing seat 33, the top wall of the tank 1, and the first cylinder 4, and is fixed to the L-shaped stirring frame 35. Several first stirring plates 36 are fixed to the outer side of the L-shaped stirring frame 35. The motor 31 is connected to the hollow shaft 34 via the transmission assembly 32. The bottom end of the second pipe 24 extends into the hollow shaft 34. Several second spray holes 37 are spaced apart along the length of the hollow shaft 34. When the motor 31 rotates, it drives the hollow shaft 34 to rotate via the transmission assembly 32, causing the spiral blades to rotate, simultaneously pushing and stirring the mixture. Simultaneously, it drives the L-shaped stirring frame 35 and the first stirring plates 36 to rotate for stirring operations.

[0049] The inner wall of the tank 1 is fixed with several baffles spaced vertically, and several first stirring plates 36 are spaced vertically and staggered with the baffles. The baffles change the flow direction of the mixture in the tank 1. When the mixture encounters a baffle during stirring, it is forced to change its original flow path, thereby reducing the occurrence of circular motion (i.e., "spinning").

[0050] The first cylindrical body 4 is fixed inside the tank body 1 by a horizontal plate 9. The horizontal plate 9 is not only used to fix the first cylindrical body 4, but also serves the same anti-spinning function as the baffle.

[0051] The mixing tank 400 also includes a sealed box 10, a second bearing seat 11, a first bevel gear 12, a third bearing seat 13, a second bevel gear 14, a rotating shaft 15, and a second stirring plate 16. The sealed box 10 is fixed to the bottom wall of the tank body 1, and the second bearing seat 11 is fixed to the bottom wall of the sealed box 10. The bottom end of the hollow shaft 34 passes through the top wall of the sealed box 10 and is inserted into the second bearing seat 11. The lower part of the hollow shaft 34 is fixed with the first bevel gear 12, which is located inside the sealed box 10. The spindle 34 is sealed to the sealed box 10. Third bearing seats 13 are fixed to both the left and right side walls of the sealed box 10. The inner end of the rotating shaft 15 passes through the side wall of the sealed box 10 and extends into the sealed box 10 where a second bevel gear 14 is fixed. The first bevel gear 12 meshes with the second bevel gear 14. The rotating shaft 15 is sealed to the sealed box 10. A second stirring plate 16 is fixed to the outer end of the rotating shaft 15. The second stirring plate 16 is located below the first stirring plate 36 and is perpendicular to it. Rotation of the hollow shaft 34 drives the first bevel gear 12 to rotate, which in turn drives the second bevel gear 14 to rotate, causing the rotating shaft 15 to rotate, thus rotating the second stirring plate 16. This, in conjunction with the first stirring plate 36, ensures that the mixture is subjected to shear and impact forces from different directions during stirring, thereby achieving more thorough mixing. The vertically distributed first and second stirring plates 36 can cover a larger space within the tank 1, ensuring that the mixture is effectively stirred at all locations within the tank 1.

[0052] The mixing tank 400 also includes a second helical blade 17 and a second cylinder 18. The second cylinder 18 is fixed to both the left and right sides of the bottom wall of the tank 1, located between the sealed box 10 and the second stirring plate 16. The second helical blade 17 is fixed to the rotating shaft 15 and passes through the second cylinder 18. Rotation of the rotating shaft 15 drives the second helical blade 17 to rotate. Combined with the arrangement of the second cylinder 18, this achieves the effect of simultaneously stirring and pushing the mixture. This, along with the pushing action of the first helical blade 38, further facilitates the circulation of the mixture between the upper and lower layers. Through structural design, the rotation of the first stirring plate 36 simultaneously drives the second stirring plates 16 on both sides to rotate synchronously in opposite directions, and also drives the first helical blade 38 and the second helical blade 17 to rotate, causing the mixture to circulate and flow uniformly within the tank 1.

[0053] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electroplating wastewater recycling system, characterized in that: This includes resin adsorption devices, membrane concentration devices, electrolytic cells, mixing tanks, submerged ultrafiltration membrane tanks, electrodialysis equipment, reverse osmosis equipment, and bipolar membrane electrodialysis equipment; The eluent outlet of the resin adsorption device is connected to the membrane concentration device. The concentrated liquid outlet of the membrane concentration device is connected to the electrolytic cell; The dialysis liquid outlet of the resin adsorption device, the permeate outlet of the membrane concentration device, and the residual liquid outlet of the electrolytic cell are all connected to the mixing tank. The outlet of the mixing tank is connected to the submerged ultrafiltration membrane tank, the filtrate outlet of the submerged ultrafiltration membrane tank is connected to the electrodialysis equipment, the desalination outlet of the electrodialysis equipment is connected to the reverse osmosis equipment, and the concentrate outlet of the electrodialysis equipment is connected to the bipolar membrane electrodialysis equipment. The alkaline solution outlet of the bipolar membrane electrodialysis equipment is connected to the submerged ultrafiltration membrane tank. The mixing tank includes a tank body, a liquid collection assembly, a stirring assembly, and a first cylindrical body; The top of the tank is fixed with a liquid collection assembly and a stirring assembly; The first cylindrical body is fixed inside the tank. The stirring assembly has a first helical blade that passes through the first cylinder; The first cylinder has a cavity inside, and the inner wall of the first cylinder has a plurality of first spray holes, which communicate with the cavity. The stirring assembly has a second spray hole, which is located inside the first cylinder. The liquid collection assembly has two outlets, one of which is connected to the chamber and the other is connected to the second spray hole; The liquid collection assembly includes a liquid collection tank, a partition, a first pipe, a second pipe, a first valve, a pressure pump, and a venturi tube; The liquid collection tank has two fixed partitions inside, which divide the internal space of the liquid collection tank into three liquid collection chambers. The tops of the three liquid collection chambers are respectively connected to the dialysis liquid outlet of the resin adsorption device, the permeate outlet of the membrane concentration device, and the residual liquid outlet of the electrolytic cell. Each of the liquid collection chambers is fixedly connected to a first pipe at its bottom end, and the first pipe is equipped with a first valve; The outlet end of the first pipe in the leftmost liquid collection chamber is connected to the inlet end of the Venturi tube; the outlet end of the first pipe in the middle liquid collection chamber is connected to the throat of the Venturi tube; the outlet end of the Venturi tube is connected to the second nozzle through the second pipe; and the outlet end of the first pipe in the rightmost liquid collection chamber is connected to the chamber. The first pipe in the leftmost liquid collection chamber, the first pipe in the rightmost liquid collection chamber, and the second pipe are all equipped with pressure pumps; The chamber is an annular cavity; The first nozzles include several groups of nozzles spaced apart circumferentially along the chamber. Each group of nozzles includes several first nozzles spaced apart along the height direction of the first cylinder.

2. The electroplating wastewater recovery system according to claim 1, characterized in that: The mixing tank also includes a second valve, a third valve, a first air inlet pipe, and a second air inlet pipe; The first pipe of the liquid collection chamber located on the far right is fixedly connected to the first air inlet pipe. The first air inlet pipe is equipped with a second valve. The first air inlet pipe is located below the pressurizing pump and is connected to an external air source. The second pipeline is fixedly connected to a second air inlet pipe, the second air inlet pipe is equipped with a third valve, the second air inlet pipe is located below the pressurization pump, and the second air inlet pipe is connected to an external air source.

3. The electroplating wastewater recovery system according to claim 1, characterized in that: The first nozzle is tilted upwards.

4. The electroplating wastewater recovery system according to claim 1, characterized in that: The stirring assembly also includes a motor, a transmission assembly, a first bearing housing, a hollow shaft, an L-shaped stirring frame, and a first stirring plate; The top of the tank is fixed with a motor and a first bearing seat; The hollow shaft passes through the first bearing seat, the top wall of the tank and the first cylinder, and is fixed with an L-shaped stirring frame. Several first stirring plates are fixed on the outside of the L-shaped stirring frame. The motor is connected to the hollow shaft via a transmission assembly; The bottom end of the second pipe extends into the hollow shaft; The hollow shaft has a plurality of second spray holes spaced apart along its length.

5. The electroplating wastewater recovery system according to claim 4, characterized in that: The inner wall of the tank is fixed with several baffles that are spaced vertically apart. Several of the first stirring plates are distributed at intervals above and below, and are staggered from the baffle.

6. The electroplating wastewater recovery system according to claim 1, characterized in that: The first cylindrical body is fixed to the tank body by a horizontal plate.

7. The electroplating wastewater recovery system according to claim 4, characterized in that: The mixing tank also includes a sealed box, a second bearing housing, a first bevel gear, a third bearing housing, a second bevel gear, a rotating shaft, and a second stirring plate; A sealed box is fixed to the bottom wall of the tank body; A second bearing seat is fixed to the bottom wall of the sealed box. The bottom end of the hollow shaft passes through the top wall of the sealed box and is inserted into the second bearing seat. A first bevel gear is fixed to the lower part of the hollow shaft. The first bevel gear is located inside the sealed box. The hollow shaft and the sealed box are sealed together. The left and right side walls of the sealed box are each fixed with a third bearing seat. The inner end of the rotating shaft passes through the side wall of the sealed box and extends into the sealed box where a second bevel gear is fixed. The first bevel gear meshes with the second bevel gear. The rotating shaft and the sealed box are sealed together. The outer end of the rotating shaft is fixed with a second stirring plate. The second stirring plate is located below the first stirring plate and is perpendicular to the first stirring plate.

8. The electroplating wastewater recovery system according to claim 7, characterized in that: The mixing tank also includes a second spiral blade and a second cylindrical body; A second cylinder is fixed to both the left and right sides of the bottom wall of the tank, and the second cylinder is located between the sealing box and the second stirring plate. The second helical blade is fixed to the rotating shaft and passes through the second cylinder.

9. A method for recycling electroplating wastewater, characterized in that, The electroplating wastewater recycling system according to any one of claims 1-8 is used for recycling, comprising the following steps: Electroplating wastewater is sent to a resin adsorption device for resin adsorption treatment. The eluent obtained from the treatment is sent to a membrane concentration device for membrane concentration treatment. The concentrated solution obtained from the treatment is sent to an electrolytic cell for electrolysis treatment to obtain valuable metals. The dialysis solution obtained from resin adsorption treatment, the permeate obtained from membrane concentration treatment, and the residual liquid obtained from electrolysis treatment are collected by the liquid collection component of the mixing tank. The liquid collection component sends the dialysis solution obtained from resin adsorption treatment, the permeate obtained from membrane concentration treatment, and the residual liquid obtained from electrolysis treatment into the tank body, and the stirring component is used for stirring and mixing. The mixed solution after the mixing treatment is sent to a submerged ultrafiltration membrane tank for ultrafiltration treatment. The filtrate obtained from the ultrafiltration treatment is sent to an electrodialysis device for electrodialysis treatment. The desalinated solution obtained from the treatment is sent to a reverse osmosis device for reverse osmosis treatment to obtain permeate water. The concentrated solution obtained from the treatment is sent to a bipolar membrane electrodialysis device for electrodialysis treatment again to obtain acid solution and alkali solution. The alkaline solution is recycled to the submerged ultrafiltration membrane tank.

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