An integrated device for treating and recovering electroplating wastewater

Abstract

The present invention relates to an integrated device for treating and recovering electroplating wastewater, comprising a pretreatment tank, a membrane concentration tank and an electrolytic cell connected in sequence, wherein the pretreatment tank comprises a filtration zone on the upstream side and a chemical reaction zone on the downstream side, a water distributor and a drug distributor are arranged on the top of the chemical reaction zone, and an agitator is arranged inside the chemical reaction zone, the filtration zone is connected to the water distributor through a pipeline, and the filtered wastewater is uniformly input into the chemical reaction zone through the water distributor; the drug distributor is connected to a drug adding device outside the chemical reaction zone; a plurality of mixed matrix membrane components are arranged in the membrane concentration tank for treating the wastewater treated in the chemical reaction zone; and at least one pair of electrodes are arranged in the electrolytic cell for electrolytically treating the wastewater treated in the membrane concentration tank.

Description

Technical Field

[0001] The invention belongs to the technical field of electroplating wastewater treatment, and in particular relates to an integrated device for treating and recovering electroplating wastewater. Background Art

[0002] Electroplating is the process of plating various metals on metals or other materials using chemical and electrochemical methods. Electroplating technology is widely used in machinery manufacturing, light industry, electronics and other industries. The composition of wastewater generated during the electroplating process is relatively complex, containing heavy metal ions such as chromium, zinc, copper, nickel, cadmium, and highly toxic pollutants such as acids, alkalis, and cyanides. Therefore, electroplating wastewater is a type of wastewater with great potential hazards. At present, the traditional treatment method for electroplating wastewater is to add chemical agents to precipitate and remove heavy metals. The sludge containing heavy metals is generally landfilled, and the remaining wastewater is regenerated. The traditional process has a long treatment cycle and high cost. Improper treatment will also cause secondary pollution, and the valuable metals cannot be effectively recovered, resulting in a waste of resources. Summary of the invention

[0003] In view of the above problems, the present invention provides an integrated device for treating and recovering electroplating wastewater, comprising a pretreatment tank, a membrane concentration tank and an electrolytic cell connected in sequence, wherein the pretreatment tank comprises a filtration zone on the upstream side and a chemical reaction zone on the downstream side, a water distributor and a drug distributor are arranged on the top of the chemical reaction zone, and an agitator is arranged inside the chemical reaction zone, the filtration zone is connected to the water distributor through a pipeline, and the filtered wastewater is uniformly input into the chemical reaction zone through the water distributor; the drug distributor is connected to a drug adding device outside the chemical reaction zone;

[0004] A plurality of mixed matrix membrane components are arranged in the membrane concentration tank for treating the wastewater treated in the chemical reaction zone; and at least one pair of electrodes are arranged in the electrolytic cell for electrolytically treating the wastewater treated in the membrane concentration tank.

[0005] Optionally, the pretreatment tank is cylindrical, and a partition is provided in the center to divide the pretreatment tank into two equal parts, and the cross-sections of the filtration area and the chemical reaction area are both semicircular, saving space;

[0006] A water inlet is provided at the bottom of the filter area, and a filter screen is provided at the lower part. Electroplating wastewater is input into the filter area from the water inlet, and then filtered from bottom to top through the filter screen. A water outlet is provided at the upper part or top of the partition, and the water outlet is connected to the water distributor through a water pipe to input the wastewater from the filter area into the chemical reaction area.

[0007] A first delivery pipe is provided at the top or bottom of the chemical reaction zone for connecting to a membrane concentration tank.

[0008] Optionally, a dosing device is provided above the chemical reaction zone, the dosing device comprises a reagent tank, a dosing pipe and a rotating device, the inlet of the dosing pipe is connected to the outlet of the reagent tank, and the outlet of the dosing pipe is located at the top of the drug distributor, for adding the treatment agent to the drug distributor;

[0009] The rotating device includes a first motor, a turntable and a connecting rod. The rotating shaft of the first motor is connected to the center of the turntable. One end of the connecting rod is connected to the vertical hanging rod on the edge of the turntable through a bearing, and the other end is connected to the dosing tube. The first motor drives the connecting rod to rotate through the turntable, thereby driving the dosing tube to rotate.

[0010] Optionally, the drug distributor includes a drug inlet barrel and a conical drug distribution barrel from top to bottom, the drug inlet barrel is cylindrical, and the conical drug distribution barrel is a cone that is small at the top and large at the bottom; the drug inlet barrel passes through the top surface of the chemical reaction zone and connects to the top of the conical drug distribution barrel, the drug adding tube extends into the interior of the drug inlet barrel and fits tightly against the inner wall of the drug inlet barrel, and the drug adding tube, driven by the rotating device, makes a circular motion along the inner wall of the drug inlet barrel, so that the treatment agent is evenly input along the drug inlet barrel and then flows down along the conical drug distribution barrel.

[0011] Optionally, the water distributor is arranged inside the conical distribution cylinder, including a water distribution cone plate and a plurality of water distribution guide plates, the water distribution cone plate is provided with a water inlet hole, and includes an upper vertical arc plate and a lower flat side plate, the vertical arc plate is conical and its own conical surface has a downward concave curvature; the side plate is connected to the bottom edge of the vertical arc plate and extends to the outside of the water distributor; a plurality of water distribution guide plates are distributed on the water distribution cone plate, and each water distribution guide plate vertically passes through the water distribution cone plate; the water pipe passes through the side wall of the conical distribution cylinder, so that the water outlet of the water pipe is above the center of the water distribution cone plate.

[0012] Optionally, the top center of the vertical curved plate is a closed conical pointed top structure, the upper surface of the vertical curved plate is a smooth surface with a curvature and concave downward, the lower surface is a smooth surface with a curvature corresponding to the upper surface and convex downward, and the bottom of the vertical curved plate is empty, that is, the cone of the vertical curved plate is hollow inside;

[0013] The bottom edge of the vertical curved plate is circular or elliptical; the inner edge of the side plate is connected to the bottom edge of the vertical curved plate, and the outer edge is elliptical or oblong to adapt to the chemical reaction zone with a semicircular cross-section, so that the wastewater flowing outward through the side plate is distributed as evenly as possible in the chemical reaction zone.

[0014] Optionally, the water-dividing guide plate is vertically arranged and includes an upper guide plate and a lower guide plate, the upper guide plate is located above the water distribution cone plate, and the lower guide plate is located below the water distribution cone plate; the water-dividing guide plate is radially distributed with the top center of the water distribution cone plate as the center.

[0015] Optionally, the agitator is arranged in the middle of the chemical reaction zone, and its agitator shaft vertically passes through the water distribution cone plate and the top surface of the pretreatment tank, and is connected to an external second motor. The upper surface of the second motor is connected to a lifting device for controlling the height of the second motor and the agitator.

[0016] Optionally, several mixed matrix membrane modules in the membrane concentration tank are connected in series, the wastewater treated in the chemical reaction zone is input into the first mixed matrix membrane module, the last mixed matrix membrane module is connected to the electrolytic cell through a second delivery pipe, and the retentate after membrane separation and concentration is input into the electrolytic cell for further treatment.

[0017] Optionally, the electrolytic cell includes several pairs of electrodes, namely several anodes and cathodes, and two opposite sides of the electrolytic cell are respectively provided with several pairs of corresponding grooves, and the two sides of the anode or cathode are respectively clamped in the corresponding grooves and perpendicular to the water flow direction in the electrolytic cell.

[0018] Optionally, a collecting port is provided on the side of the electrolytic cell opposite to the second delivery pipe, and a drain port is provided on the other side. The drain port is connected to a water production pipe and a return pipe in parallel through a pipeline, and the return pipe is connected to the water inlet of the filtration area. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of the integrated device for treating and recovering electroplating wastewater (the water distributor and the drug distributor are omitted);

[0020] Figure 2 It is a schematic diagram of the coordination between the water distributor and the medicine distributor;

[0021] Figure 3 is a schematic diagram of a water distributor;

[0022] Figure 4 is a schematic diagram of the bottom surface of the water distributor;

[0023] Figure 5 It is a structural schematic diagram of a stirrer;

[0024] Figure 6 A schematic diagram of a stirring paddle of another type of agitator.

[0025] In the attached drawings, 1-pretreatment tank, 2-membrane concentration tank, 3-electrolyzer, 4-filtration zone, 5-chemical reaction zone, 6-water distributor, 7-drug distributor, 8-agitator, 9-mixed matrix membrane module, 10-filter screen, 11-water outlet, 12-water pipe, 13-first delivery pipe, 14-second delivery pipe, 15-drug adding pipe, 16-first motor, 17-turntable, 18-connecting rod, 19-inlet Cartridge, 20-conical distribution cartridge, 21-water distribution cone plate, 22-water distribution guide plate, 23-water inlet hole, 24-vertical arc plate, 25-side plate, 26-top center, 27-upper guide plate, 28-lower guide plate, 29-upper independent water channel, 30-lower independent water channel, 31-second motor, 32-lifting device, 33-electrode, 34-collection port, 35-drainage port, 36-reflux pipe. DETAILED DESCRIPTION

[0026] This embodiment provides an integrated device for treating and recovering electroplating wastewater, such as Figure 1-Figure 6 As shown, it includes a pretreatment tank 1, a membrane concentration tank 2 and an electrolytic cell 3 connected in sequence, the pretreatment tank 1 includes a filtration area 4 on the upstream side and a chemical reaction area 5 on the downstream side, a water distributor 6 and a drug distributor 7 are provided on the top of the chemical reaction area 5, and an agitator 8 is provided inside, the filtration area 4 is connected to the water distributor 6 through a pipeline, and the filtered wastewater is uniformly input into the chemical reaction area 5 through the water distributor 6; the drug distributor 7 is connected to the dosing device outside the chemical reaction area 5;

[0027] A plurality of mixed matrix membrane modules 9 are arranged in the membrane concentration tank 2 for treating the wastewater treated in the chemical reaction zone 5 ; at least one pair of electrodes are arranged in the electrolytic cell 3 for electrolytically treating the wastewater treated in the membrane concentration tank 2 .

[0028] Optionally, the pretreatment tank 1 is cylindrical, and a partition is provided in the center to divide the pretreatment tank 1 into two equal parts, and the cross-sections of the filtration area 4 and the chemical reaction area 5 are both semicircular, saving space;

[0029] The bottom of the filter area 4 is provided with a water inlet, and the lower part is provided with a filter screen 10. The electroplating wastewater is input into the filter area 4 from the water inlet, and then filtered from bottom to top through the filter screen 10; the upper part or top of the partition is provided with a water outlet 11, and the water outlet 11 is connected to the water distributor 6 through a water pipe 12, so that the wastewater from the filter area 4 is input into the chemical reaction area 5;

[0030] A first delivery pipe 13 is provided at the top or bottom of the chemical reaction zone 5 for connecting to the membrane concentration tank 2 .

[0031] Further optionally, the filter screen 10 is connected to a vibrator. When there are too many intercepted sediments on the filter screen 10, the vibrator vibrates the filter screen 10 to make the solid waste fall down and then be discharged from the slag discharge port at the bottom of the filter area 4.

[0032] Optionally, a dosing device is provided above the chemical reaction zone 5, the dosing device comprising a reagent tank, a dosing tube 15 and a rotating device, the inlet of the dosing tube 15 is connected to the outlet of the reagent tank, and the outlet of the dosing tube 15 is located at the top of the drug distributor 7, for adding the treatment agent to the drug distributor 7;

[0033] The rotating device includes a first motor 16, a turntable 17 and a connecting rod 18. The rotating shaft of the first motor 16 is connected to the center of the turntable 17. One end of the connecting rod 18 is connected to the vertical hanging rod at the edge of the turntable 17 through a bearing, and the other end is connected to the dosing tube 15. The first motor 16 drives the connecting rod 18 to rotate through the turntable 17, thereby driving the dosing tube 15 to rotate.

[0034] Optionally, the drug distributor 7 includes a drug feed barrel 19 and a conical drug distribution barrel 20 from top to bottom, the drug feed barrel 19 is cylindrical, and the conical drug distribution barrel 20 is a cone that is small at the top and large at the bottom; the drug feed barrel passes through the top surface of the chemical reaction zone and connects to the top of the conical drug distribution barrel, the drug adding tube 15 extends into the interior of the drug feed barrel 19 and is close to the inner wall of the drug feed barrel 19, and the drug adding tube 15 is driven by the rotating device to make a circular motion along the inner wall of the drug feed barrel 19, so that the treatment agent is evenly input along the drug feed barrel 19 and then flows down along the conical drug distribution barrel 20.

[0035] The present invention designs the above-mentioned rotatable dosing tube 15, and cooperates with the dosing device 7, so that the treatment agent is evenly added to the periphery of the chemical reaction zone 5, and then evenly enters the interior of the chemical reactor under the action of the stirrer 8. Specifically, the first motor 16 drives the turntable 17 to rotate horizontally, and one end of the connecting rod 18 rotates with the turntable 17. The connecting rod 18 is connected to the hanging rod fixed at the edge of the turntable 17 through a bearing, so as to be more flexible during rotation and avoid jamming. Since the connecting rod 18 always remains horizontal, one end of it draws a circle with the turntable 17, and the other end also moves in a circle. The diameter of the turntable 17 is equal to the inner diameter of the medicine inlet barrel 19, so that the connecting rod 18 drives the dosing tube 15 to move in a circle, that is, the dosing tube 15 rotates along the inner wall of the medicine inlet barrel 19, so that the treatment agent flows evenly along the medicine inlet barrel 19, and then flows down along the inner wall of the conical medicine distribution barrel 20, so that the treatment agent is evenly added to the periphery of the chemical reaction zone 5, and then under the stirring of the agitator 8, the surrounding agents are introduced into the interior of the chemical reaction zone 5 and fully contacted with the wastewater.

[0036] The traditional dosing device considers how to achieve uniform dosing of the entire reactor, while the present invention starts from another perspective, tries to achieve uniform dosing around the reaction zone, and then uses the stirrer 8 in the middle of the reaction zone to roll the reagents at the edge of the reaction zone into the inside of the reaction zone by stirring. Those skilled in the art know that the stirring effect of the stirrer 8 is relatively uniform for the liquid in the container. In this way, under the multiple effects of the dosing device, the distributor 7 and the stirrer 8, a relatively uniform distribution of the reagents in the chemical reaction zone 5 can be achieved.

[0037] Optionally, the treatment agent is selected from one or more of lime, sodium hydroxide, and sodium sulfide, so as to convert heavy metal ions in the electroplating wastewater into ions with larger particle sizes, generate precipitates or colloids, and meet the retention requirements of the membrane pore size for subsequent membrane treatment.

[0038] Optionally, the water distributor 6 is arranged inside the conical distribution barrel 20, including a water distribution cone plate 21 and a plurality of water distribution guide plates 22. The water distribution cone plate 21 is provided with a water inlet hole 23, and includes an upper vertical arc plate 24 and a lower flat side plate 25. The vertical arc plate 24 is conical and its own conical surface has a downward concave curvature; the side plate 25 is connected to the bottom edge of the vertical arc plate 24 and extends to the outside of the water distributor 6; a plurality of water distribution guide plates 22 are distributed on the water distribution cone plate 21, and each water distribution guide plate 22 vertically passes through the water distribution cone plate 21; the water pipe 12 passes through the side wall of the conical distribution barrel 20, so that the water outlet of the water pipe 12 is above the center of the water distribution cone plate 21.

[0039] Optionally, the top center 26 of the vertical curved plate 24 is a closed conical pointed top structure, the upper surface of the vertical curved plate 24 is a smooth surface with a curvature and concave downward, the lower surface is a smooth surface with a curvature corresponding to the upper surface and convex downward, and the bottom of the vertical curved plate 24 is empty, that is, the cone of the vertical curved plate 24 is hollow;

[0040] The bottom edge of the vertical curved plate 24 is circular or elliptical; the inner side edge of the side plate 25 is connected to the bottom edge of the vertical curved plate 24, and the outer side edge is elliptical or oblong to adapt to the chemical reaction zone 5 with a semicircular cross-section, so that the wastewater flowing outward through the side plate 25 is distributed as evenly as possible in the chemical reaction zone 5.

[0041] Further optionally, on the water distribution cone plate 21, the aperture of the water inlet hole 23 gradually increases along the direction from the top center 26 to the surrounding of the bottom, and the opening rate gradually increases, so that the water distribution cone plate 21 at the projection of the water pipe 12 allows a smaller amount of wastewater to pass through the water distribution cone plate 21, and other parts of the water distribution cone plate 21 allow more wastewater to pass through the water distribution cone plate 21.

[0042] Optionally, the water-dividing guide plate 22 is vertically arranged and includes an upper guide plate 27 and a lower guide plate 28, the upper guide plate 27 is located above the water distribution cone plate 21, and the lower guide plate 28 is located below the water distribution cone plate 21; the water-dividing guide plates 22 are radially distributed with the top center 26 of the water distribution cone plate 21 as the center.

[0043] Further optionally, the height of the upper guide plate 27 is 2 / 3-5 / 6 of the height of the water distribution cone plate 21, and the side away from the top center 26 of the water distribution cone plate 21 has an arc convex outward and upward, and the outer edge of the upper guide plate 27 is not longer than the outer edge of the water distribution cone plate 21; the upper guide plate 27 divides the upper surface of the water distribution cone plate 21 and the space above it into several blocks, and each space forms an upper independent water channel 29, so that the wastewater that does not pass through the water inlet hole 23 flows along each upper independent water channel 29.

[0044] Further optionally, the lower guide plate 28 protrudes from the lower surface of the vertical curved plate 24, and the shape of the lower guide plate 28 is approximately triangular, the top angle is rounded and corresponds to the position where the curvature of the vertical curved plate 24 is the largest, the corner on one side coincides with the bottom edge of the vertical curved plate 24, and the corner on the other side is on the lower surface of the vertical curved plate 24 and corresponds to the highest point where the upper guide plate 27 and the vertical curved plate 24 are connected;

[0045] The lower guide plate 28 divides the lower surface of the vertical curved plate 24 and the space below into several blocks, each of which forms a lower independent waterway 30 , so that the wastewater after passing through the water inlet hole 23 flows along each lower independent waterway 30 .

[0046] The present invention designs the water distributor 6, and the water pipe 12 is directly opposite to the top center 26 of the vertical curved plate 24 and a small peripheral area, and the size of the peripheral area depends on the size of the diameter of the water pipe 12. The water inlet hole 23 in the area close to the top center 26 has a smaller aperture and a lower opening rate. Therefore, the amount of water that vertically passes through the vertical curved plate 24 through the water inlet hole 23 at the projection of the water pipe 12 will become smaller, and most of the wastewater will flow along the upper surface (curved surface) of the water distribution cone plate 21. The direction of wastewater flow gradually changes from vertical to horizontal (i.e. horizontal), and is discharged from each upper independent water channel 29, which is conducive to guiding the wastewater to each corner of the side plate 25, thereby making the water distribution uniform. While the wastewater flows outward along the upper surface of the water distribution cone plate 21, wastewater continues to pass through the water distribution cone plate 21 from the water inlet hole 23, and the closer to the outer edge of the water distribution cone plate 21, the greater the amount of water passing through the water inlet hole 23.

[0047] For the wastewater passing through the water distribution cone plate 21 (i.e., the wastewater under the water distribution cone plate 21), a portion of it can be discharged along each lower independent water channel 30, further dispersing the wastewater outward. The rounded arc design of the upper guide plate 27 and the lower guide plate 28 of the present invention reduces the water flow resistance. The outer edge of the side plate 25 of the water distribution cone plate 21 and the inner wall of the conical drug distribution cylinder 20 leave a gap so that the wastewater flows down, and the gap is as small as 5-10 cm.

[0048] Traditional water distribution devices generally use multiple uniformly distributed nozzles to improve the uniformity of water distribution. The present invention completely abandons this idea and designs the water distributor 6. It uses the perforated water distribution cone plate 21 to allow part of the wastewater to pass through the water inlet hole 23 and part of the wastewater to flow along the upper surface of the water distribution cone plate 21. When flowing, it is respectively discharged from each upper independent water channel 29, that is, it flows down from the edge of the side plate 25 from all directions. In addition to falling directly into the chemical reaction zone 5, the wastewater passing through the water inlet hole 23 can also flow along the lower surface of the water distribution cone plate 21. When flowing, it is respectively discharged from each lower independent water channel 30, that is, it flows down from the edge of the side plate 25 from all directions. Since the treatment agent of the present invention flows down along the inner wall of the drug distributor 7, the water distributor 6 also cooperates with the treatment agent to divert part of the wastewater to the surroundings of the side plate 25 and then flows down, which is conducive to the priority mixing of this part of the water body and the agent, so that the overall mixing efficiency of the water body and the agent is improved.

[0049] Optionally, the agitator 8 is arranged in the middle of the chemical reaction zone 5, and its agitator shaft vertically passes through the water distribution cone plate 21 and the top surface of the pretreatment tank 1, and is connected to the external second motor 31, and the upper surface of the second motor 31 is connected to the lifting device 32, which is used to control the height of the second motor 31 and the agitator 8. The lifting device 32 can be a vertical hydraulic device, which drives the second motor 31 to move up and down by telescoping the hydraulic rod. Two forms of agitator paddles are provided below.

[0050] Optionally, the stirrer 8 includes a plurality of horizontal stirring paddles and a plurality of inclined stirring paddles, the inclined stirring paddles are inclined downward and have an angle of 20-70° with the stirring shaft; the same stirring paddles are symmetrically arranged at the same height on both sides of the stirring shaft, an inclined stirring paddle is arranged between two vertically adjacent horizontal stirring paddles, and the horizontal stirring paddles and the inclined stirring paddles are evenly arranged along the length direction of the stirring shaft. The horizontal stirring paddles and the inclined stirring paddles are arranged at intervals, which is conducive to improving the stirring efficiency.

[0051] Optionally, the agitator 8 includes a spiral plate agitator, which is connected to the agitator shaft through a plurality of connecting rods. The inner diameter of the spiral plate agitator is slightly smaller than the outer diameter of the water distribution cone plate 21. Each solid plate of the spiral plate agitator has a certain height in the vertical direction, and the ratio of the height to the inner diameter of the spiral plate agitator is (0.01-0.1):1.

[0052] The horizontal stirring paddle and the inclined stirring paddle have relatively large resistance during the rotation and up-and-down movement, resulting in relatively large power consumption of the second motor 31. In contrast, the spiral plate stirring paddle has relatively small resistance during the rotation and up-and-down movement, which is conducive to cooperating with the semicircular chemical reaction zone 5, and spirally rolling the treatment reagents and water inlet at the edge of the reaction zone into the interior of the reaction zone. In addition, the stirrer 8 can move up and down to form an inclined or oblique spiral water flow, which is conducive to providing a stirring and mixing effect.

[0053] Optionally, several mixed matrix membrane modules 9 in the membrane concentration tank 2 are connected in series, the wastewater treated in the chemical reaction zone 5 is input into the first mixed matrix membrane module 9, the last mixed matrix membrane module 9 is connected to the electrolytic cell 3 through the second delivery pipe 14, the retained liquid after membrane separation and concentration is input into the electrolytic cell 3 for further treatment, and the permeate of the mixed matrix membrane module is discharged and can be used as recycled water.

[0054] The plurality of mixed matrix membrane modules 9 are modularly designed to enable the concentration and separation, gas-water backwashing, and membrane regeneration of the membrane modules to be operated dynamically and continuously. This is prior art and is not limited here.

[0055] Optionally, the electrolytic cell 3 includes several pairs of electrodes 33, i.e., several anodes and cathodes. Two opposite sides of the electrolytic cell 3 are respectively provided with several pairs of corresponding grooves, and the two sides of the anode or cathode are respectively clamped in the corresponding grooves and perpendicular to the water flow direction in the electrolytic cell 3.

[0056] Optionally, a collecting port 34 is provided on the side of the electrolytic cell 3 opposite to the second delivery pipe 14, and a drain port 35 is provided on the other side. The drain port 35 is connected to a water production pipe and a return pipe 36 in parallel through a pipeline. A heavy metal ion detection instrument is provided on the pipeline. The return pipe 36 is connected to the upstream side of the electrolytic cell 3. The heavy metal ion detection instrument is linked to an electric diverter regulating valve. When it is detected that the heavy metal ions in the produced water exceed the emission index, the electric diverter regulating valve opens the return pipe 36, and the produced water returns to the electrolytic cell 3 for treatment; when the heavy metal ions do not exceed the emission index, the electric diverter regulating valve opens the water production pipe, and the produced water is discharged and can be used again as recycled water.

[0057] The electrode pairs in the electrolytic cell 3 can be increased or decreased according to actual needs to improve the practicality of the electrolytic cell 3. The anode and the cathode are electrically connected to an external power supply, and the heavy metals in the electroplating wastewater are deposited at the cathode, and the reducing ions in the wastewater are precipitated at the anode. After treatment, the deposited heavy metals are discharged and collected through the collection port 34 to realize the resource utilization of heavy metals, and the produced water after electrolysis is discharged from the drain port 35.

Claims

1. An integrated device for treating and recovering electroplating wastewater, characterized in that: It includes a pretreatment tank, a membrane concentration tank and an electrolytic cell connected in sequence. The pretreatment tank includes a filtration zone on the upstream side and a chemical reaction zone on the downstream side. A water distributor and a drug distributor are provided on the top of the chemical reaction zone, and an agitator is provided inside. The filtration zone is connected to the water distributor through a pipeline, and the filtered wastewater is uniformly input into the chemical reaction zone through the water distributor; the drug distributor is connected to a drug adding device outside the chemical reaction zone; A plurality of mixed matrix membrane modules are arranged in the membrane concentration tank for treating the wastewater after treatment in the chemical reaction zone; at least one pair of electrodes are arranged in the electrolytic cell for electrolytically treating the wastewater after treatment in the membrane concentration tank; A dosing device is provided above the chemical reaction zone, and the dosing device includes a reagent tank, a dosing pipe and a rotating device, the inlet of the dosing pipe is connected to the outlet of the reagent tank, and the outlet of the dosing pipe is located at the top of the drug distributor, and is used to add the treatment agent to the drug distributor; The rotating device comprises a first motor, a rotating disk and a connecting rod, wherein the rotating shaft of the first motor is connected to the center of the rotating disk, one end of the connecting rod is connected to the vertical hanging rod at the edge of the rotating disk through a bearing, and the other end is connected to the dosing tube, and the first motor drives the connecting rod to rotate through the rotating disk, thereby driving the dosing tube to rotate; The drug distributor comprises a drug inlet cylinder and a conical drug distributing cylinder from top to bottom, the drug inlet cylinder is cylindrical, and the conical drug distributing cylinder is a cone with a small top and a large bottom; the drug inlet cylinder passes through the top surface of the chemical reaction zone and connects to the top of the conical drug distributing cylinder, the drug adding tube extends into the inside of the drug inlet cylinder and is closely attached to the inner wall of the drug inlet cylinder, and the drug adding tube, driven by the rotating device, moves in a circle along the inner wall of the drug inlet cylinder, so that the treatment agent is evenly input along the drug inlet cylinder and then flows down along the conical drug distributing cylinder; The water distributor is arranged inside the conical medicine distribution cylinder, and includes a water distribution cone plate and a plurality of water distribution guide plates. The water distribution cone plate is provided with a water inlet hole, and includes an upper vertical arc plate and a lower flat side plate. The vertical arc plate is conical and its own conical surface has a downward concave arc; the side plate is connected to the bottom edge of the vertical arc plate and extends to the outside of the water distributor; a plurality of water distribution guide plates are distributed on the water distribution cone plate, and each water distribution guide plate vertically passes through the water distribution cone plate.

2. The integrated device for treating and recovering electroplating wastewater according to claim 1, characterized in that: The pretreatment tank is cylindrical, and a partition is arranged in the center to divide the pretreatment tank into two equal parts, and the cross-sections of the filtration area and the chemical reaction area are both semicircular; A water inlet is provided at the bottom of the filter area, and a filter screen is provided at the lower part. Electroplating wastewater is input into the filter area from the water inlet, and then filtered from bottom to top through the filter screen. A water outlet is provided at the upper part or top of the partition, and the water outlet is connected to the water distributor through a water pipe to input the wastewater from the filter area into the chemical reaction area. A first delivery pipe is provided at the top or bottom of the chemical reaction zone for connecting to a membrane concentration tank.

3. The integrated device for treating and recovering electroplating wastewater according to claim 2, characterized in that: The water pipe passes through the side wall of the conical medicine distribution cylinder, so that the water outlet of the water pipe is located above the center of the water distribution cone plate.

4. The integrated device for treating and recovering electroplating wastewater according to claim 3 is characterized in that: The top center of the vertical curved plate is a closed conical pointed top structure, the upper surface of the vertical curved plate is a smooth surface with a curvature and concave downward, the lower surface is a smooth surface with a curvature corresponding to the upper surface and convex downward, the bottom of the vertical curved plate is empty, and the cone of the vertical curved plate is hollow inside; The bottom edge of the vertical curved plate is circular or elliptical; the inner side edge of the side plate is connected to the bottom edge of the vertical curved plate, and the outer side edge of the side plate is an oblong.

5. The integrated device for treating and recovering electroplating wastewater according to claim 4, characterized in that: The water diversion guide plate is vertically arranged and includes an upper guide plate and a lower guide plate. The upper guide plate is located above the water distribution cone plate, and the lower guide plate is located below the water distribution cone plate. The water diversion guide plates are radially distributed with the top center of the water distribution cone plate as the center.

6. The integrated device for treating and recovering electroplating wastewater according to claim 1, characterized in that: The agitator is arranged in the middle of the chemical reaction zone, and its agitator shaft vertically passes through the water distribution cone plate and the top surface of the pretreatment tank, and is connected to an external second motor. The upper surface of the second motor is connected to a lifting device for controlling the height of the second motor and the agitator.

7. The integrated device for treating and recovering electroplating wastewater according to claim 1, characterized in that: Several mixed matrix membrane modules in the membrane concentration tank are connected in series, the wastewater treated in the chemical reaction zone is input into the first mixed matrix membrane module, the last mixed matrix membrane module is connected to the electrolytic cell through the second delivery pipe, and the retentate concentrated by membrane separation is input into the electrolytic cell for further treatment.

8. The integrated device for treating and recovering electroplating wastewater according to claim 7, characterized in that: The electrolytic cell comprises a plurality of pairs of electrodes, and two opposite sides of the electrolytic cell are respectively provided with a plurality of pairs of corresponding grooves, and the two sides of the anode or cathode are respectively clamped in the corresponding grooves and perpendicular to the water flow direction in the electrolytic cell; The electrolytic cell has a collecting port on the side opposite to the second delivery pipe, and a drain port on the other side. The drain port is connected in parallel to a water production pipe and a return pipe through a pipeline, and the return pipe is connected to the water inlet of the filtration area.

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