A system for electroplating wastewater treatment and nickel recovery

Abstract

The utility model provides a system for electroplating wastewater treatment and nickel recovery, its characterized in that, including ion exchange unit, regeneration unit, adjusting pool and electrodeposition device. The system through ion exchange unit selective adsorption and enrichment nickel ion, adsorbed saturation after obtaining high concentration nickel containing eluent by sulfuric acid regeneration, after the eluent in adjusting pool control pH and add reagent, enter electrodeposition device electrolysis, in cathode precipitate high purity metal nickel product, realize the utilization of resources. System is equipped with automatic control and cycle unit, effectively improved nickel recovery efficiency and product quality, reduced energy consumption and cost simultaneously. The system can effectively realize the efficient recovery of nickel resources, maintain the stable operation of the system, and also consider the integrated treatment of low energy consumption and economy.

Description

Technical Field

[0001] This utility model relates to a wastewater treatment and recycling system, and more specifically, a system for treating electroplating wastewater and recovering nickel. Background Technology

[0002] Current mainstream technologies for treating nickel-containing wastewater include chemical precipitation, ion exchange, and membrane separation, each with its own significant drawbacks. Chemical precipitation involves adding alkali or sulfides to form nickel precipitate, but it generates large amounts of hazardous sludge, has high disposal costs, and cannot recover nickel resources. Ion exchange is complex to operate, generates secondary pollution during regeneration, and is economically unviable. Membrane technologies such as reverse osmosis and nanofiltration produce high-quality effluent, but membranes are prone to fouling, require high investment, and the concentrate is difficult to treat, making them unsuitable for high-concentration or fluctuating nickel-containing wastewater. In contrast, electrodeposition technology, with its electrochemical reduction mechanism, can directly convert nickel ions into elemental metal for recovery, offering advantages such as high resource recovery, high reaction efficiency, and low sludge production. It is particularly suitable for high-concentration wastewater such as electroless nickel plating solutions and nickel plating rinse water. However, in practical applications, this technology is still limited by issues such as electrode surface fouling, current efficiency decay, and high energy consumption, requiring further optimization and promotion.

[0003] To address the aforementioned technical bottlenecks, there is an urgent need to develop an integrated treatment system that can effectively achieve efficient nickel resource recovery, maintain stable system operation, and simultaneously achieve low energy consumption and economic efficiency. Based on this, this invention proposes a system for electroplating wastewater treatment and nickel recovery. This system innovatively combines an ion exchange enrichment unit with an electrodeposition recovery unit, constructing a synergistic resource recovery process of "adsorption-elution-deposition." Specifically, the system first selectively adsorbs nickel ions from the wastewater through an ion exchange unit, achieving initial nickel enrichment. After adsorption saturation, sulfuric acid is used for regeneration to obtain a high-concentration nickel-containing eluent. The eluent undergoes precise pH adjustment in an equalization tank and the addition of functional agents before entering the electrodeposition device for electrolytic recovery. High-purity metallic nickel is deposited at the cathode, enabling resource utilization. The system is also equipped with an automatic control and circulation unit, significantly improving nickel recovery efficiency and deposition quality while reducing energy consumption and operating costs. The entire system is suitable for the deep treatment and valuable metal recovery of nickel-containing wastewater such as rinsing water from electroplating lines and electroless nickel plating solutions, providing an efficient, stable, and economical solution for the resource-based treatment of industrial wastewater. Summary of the Invention

[0004] To solve the above-mentioned technical problems, this utility model provides a system for electroplating wastewater treatment and nickel recovery, adopting the following technical solution: The system includes: The ion exchange unit is used to adsorb nickel ions in the wastewater to be treated, and can also be used as a regeneration container to elute the saturated resin by injecting sulfuric acid regeneration solution to produce nickel-containing eluent. A regeneration unit, connected to the ion exchange unit, is used to provide sulfuric acid regeneration solution and perform regeneration operations on the ion exchange unit; An equalization tank, connected to the eluent outlet of the ion exchange unit, is used to receive and store the nickel-containing eluent. The equalization tank is equipped with an online pH detection device, an automatic dosing device, a first dosing unit, and a second dosing unit. An electrodeposition apparatus, connected to the conditioning cell and forming a circulation loop, is used to perform electrodeposition treatment on the conditioned electrolyte to deposit metallic nickel on the cathode. In this process, wastewater flows sequentially through the ion exchange unit for nickel adsorption. The nickel-containing eluent generated during the regeneration stage of the ion exchange unit is input into the conditioning tank for physicochemical conditioning. The conditioned electrolyte circulates between the electrodeposition device and the conditioning tank through a circulation loop until electrolysis is completed.

[0005] Furthermore, the ion exchange unit includes at least two ion exchange devices, which are connected in series to achieve complete adsorption of nickel ions.

[0006] Furthermore, the first dosing unit is used to control the addition of alkaline agents by an automatic dosing device based on feedback from the online pH detection device to maintain the solution pH within a set range; the second dosing unit is used to add electrodeposition additives to the conditioning tank to improve the density, brightness, or deposition efficiency of the cathode nickel deposition layer.

[0007] Furthermore, the electrodeposition apparatus includes a cathode and an anode, wherein the cathode is made of either a stainless steel plate or a titanium plate, and the anode is made of a titanium plate coated with a noble metal oxide.

[0008] Furthermore, the system also includes an external power supply, with the anode connected to the positive terminal of the power supply and the cathode connected to the negative terminal of the power supply.

[0009] Furthermore, the circulation loop is equipped with a circulation pump to maintain the normal flow of electrolyte within the electrodeposition device, reduce concentration polarization within the electrodeposition device, and maintain the reaction pH value during electrodeposition.

[0010] Furthermore, the wastewater treated by the ion exchange unit is transported to the biochemical treatment process section.

[0011] Furthermore, the regulating tank is also equipped with a stirring device; the regulating tank and the electrodeposition device are connected by a pipeline, and a delivery pump is installed on the pipeline.

[0012] Compared with existing technologies, the advantages of this utility model are: (1) The system has a simple overall structure and a clear operation process, making it easy to operate and maintain daily.

[0013] (2) The system mainly uses conventional and simple materials, which not only makes it easy to manufacture and install, but also greatly reduces the cost of equipment materials and processing.

[0014] (3) This system can effectively reduce the nickel content in electroplating wastewater. The treated effluent does not need to rely on other complex deep nickel removal processes to meet strict discharge or reuse standards.

[0015] (4) This system can directly recover nickel ions in wastewater in the form of metallic element, and the product has high economic value, realizing an effective combination of pollution control and resource recovery. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model; The components are: 1-Ion exchange unit, 2-Regeneration unit, 3-Equalization tank, 4-Electrodeposition device, 5-Eluent outlet, 6-Online pH detection device, 7-Automatic dosing device, 8-Anode, 9-Cathode, 10-Ion exchange device, 11-Stirring device, 12-First dosing unit, 13-Second dosing unit, 14-Power supply, 15-Circulation loop, 16-Circulation pump, and 17-Transfer pump. Detailed Implementation

[0017] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments.

[0018] As shown in the figure, this utility model provides a system for treating electroplating wastewater and recovering nickel, characterized in that it includes: Ion exchange unit 1 is used to adsorb nickel ions in the wastewater to be treated, and can also be used as a regeneration treatment container to elute the saturated resin by injecting sulfuric acid regeneration solution to produce nickel-containing eluent. Regeneration unit 2, connected to ion exchange unit 1, is used to provide sulfuric acid regeneration solution and perform regeneration operation on ion exchange unit 1; The conditioning tank 3 is connected to the eluent outlet 5 of the ion exchange unit 1 and is used to receive and store the nickel-containing eluent. The conditioning tank 3 is equipped with an online pH detection device 6, an automatic dosing device 7, a first dosing unit 12 and a second dosing unit 13. The electrodeposition device 4 is connected to the conditioning cell 3 and forms a circulation loop 15 for electrodepositing the conditioned electrolyte to deposit metallic nickel on the cathode 9. In this process, wastewater flows sequentially through the ion exchange unit 1 for nickel adsorption. The nickel-containing eluent generated during the regeneration stage of the ion exchange unit 1 is input into the conditioning tank 3 for physicochemical conditioning. The conditioned electrolyte circulates between the electrodeposition device 4 and the conditioning tank 3 through the circulation loop 15 until electrolysis is completed.

[0019] The ion exchange unit 1 includes at least two ion exchange devices 10, which are connected in series to achieve complete adsorption of nickel ions.

[0020] The first dosing unit 12 is used to control the addition of alkaline agents by the automatic dosing device 7 to maintain the pH of the solution within a set range based on the feedback from the online pH detection device 6; the second dosing unit 13 is used to add electrodeposition additives to the conditioning tank 3 to improve the density, brightness or deposition efficiency of the cathode nickel deposition layer.

[0021] The electrodeposition apparatus 4 includes a cathode 9 and an anode 8. The cathode 9 is made of either a stainless steel plate or a titanium plate, and the anode 8 is made of a titanium plate coated with a noble metal oxide.

[0022] The system also includes an external power supply 14, with the anode 8 connected to the positive terminal of the power supply 14 and the cathode 9 connected to the negative terminal of the power supply 14.

[0023] The circulation loop 15 is equipped with a circulation pump 16, which is used to maintain the normal flow of electrolyte in the electrodeposition device 4, reduce the concentration polarization phenomenon in the electrodeposition device 4, and maintain the reaction pH value during electrodeposition.

[0024] The wastewater treated by the ion exchange unit 1 is then transported to the biochemical treatment process section.

[0025] The regulating tank 3 is also equipped with a stirring device 11; the regulating tank 3 and the electrodeposition device 4 are connected by a pipeline, and a delivery pump 17 is provided on the pipeline.

[0026] The system's processing flow is as follows: The workflow of this system begins with electroplating wastewater entering ion exchange unit 1, which consists of at least two ion exchange devices 10 connected in series. The wastewater flows through these devices sequentially, allowing nickel ions to be fully adsorbed. The treated wastewater, meeting the standards, is then transported to the subsequent biochemical process section. When the resin becomes saturated, the system switches to regeneration mode. Regeneration unit 2 injects sulfuric acid regeneration solution into ion exchange unit 1 for elution. The resulting nickel-containing eluent enters the equalization tank 3 through eluent outlet 5. In the equalization tank 3, online pH detection device 6 monitors the solution pH value in real time. The pH is automatically adjusted to the set range by adding alkaline reagent through the first dosing unit 12 of automatic dosing device 7, while the second dosing unit 13 adds electrodeposition additives to optimize the deposition effect. The mixture is uniformly mixed under the action of stirring device 11. The adjusted mixture enters electrodeposition device 4 under the action of transfer pump 17. Inside electrodeposition device 4, external power supply 14 supplies power to anode 8 and cathode 9, causing nickel ions in the electrolyte to be reduced and deposited on the surface of cathode 9 as metallic nickel products. The effluent from the electrodeposition device is driven by the circulation pump 16 and continuously circulates in the circulation loop 15 between the electrodeposition device 4 and the equalization tank 3. The circulation effectively reduces concentration polarization and maintains the stable pH environment required for the reaction until electrolysis is completed, thereby achieving the dual purpose of nickel resource recovery and wastewater treatment.

[0027] This invention organically combines an ion exchange enrichment unit with an electrodeposition recovery unit, constructing a synergistic resource recovery process of "adsorption-elution-deposition". The system selectively adsorbs and enriches nickel ions through the ion exchange unit. After adsorption saturation, the eluent is regenerated with sulfuric acid to obtain a high-concentration nickel-containing eluent. This eluent, after pH adjustment and reagent addition in an adjustment tank, enters the electrodeposition device for electrolysis, depositing high-purity metallic nickel at the cathode, thus achieving resource utilization. The system is equipped with an automatic control and circulation unit, effectively improving nickel recovery efficiency and product quality while reducing energy consumption and costs. This system effectively achieves efficient nickel resource recovery, maintains stable system operation, and integrates low-energy consumption and economic efficiency. Example

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0029] A fluoride-containing wastewater treatment system was trial-produced using the above technical solution, such as... Figure 1 .

[0030] The system includes an ion exchange unit 1, a regeneration unit 2, an equalization tank 3, an electrodeposition device 4, an eluent outlet 5, an online pH detection device 6, an automatic dosing device 7, an anode 8, a cathode 9, an ion exchange device 10, a stirring device 11, a first dosing unit 12, a second dosing unit 13, a power supply 14, a circulation loop 15, a circulation pump 16, and a transfer pump 17.

[0031] The system includes: Ion exchange unit 1 is used to adsorb nickel ions in the wastewater to be treated, and can also be used as a regeneration treatment container to elute the saturated resin by injecting sulfuric acid regeneration solution to produce nickel-containing eluent. Regeneration unit 2, connected to ion exchange unit 1, is used to provide sulfuric acid regeneration solution and perform regeneration operation on ion exchange unit 1; The conditioning tank 3 is connected to the eluent outlet 5 of the ion exchange unit 1 and is used to receive and store the nickel-containing eluent. The conditioning tank 3 is equipped with an online pH detection device 6 and an automatic dosing device 7. Electrodeposition device 4 is connected to the conditioning cell 3 and forms a circulation loop 15 for electrodepositing the conditioned electrolyte to deposit metallic nickel on the cathode 9. In this process, wastewater flows sequentially through the ion exchange unit 1 for nickel adsorption. The nickel-containing eluent generated during the regeneration stage of the ion exchange unit 1 is input into the conditioning tank 3 for physicochemical conditioning. The conditioned electrolyte circulates between the electrodeposition device 4 and the conditioning tank 3 through the circulation loop 15 until electrolysis is completed.

[0032] The ion exchange unit 1 includes at least two ion exchange devices 10, which are connected in series to achieve complete adsorption of nickel ions.

[0033] The first dosing unit 12 is used to control the addition of alkaline agents by the automatic dosing device 7 to maintain the pH of the solution within a set range based on the feedback from the online pH detection device 6; the second dosing unit 13 is used to add electrodeposition additives to the conditioning tank 3 to improve the density, brightness or deposition efficiency of the cathode nickel deposition layer.

[0034] The electrodeposition apparatus 4 includes a cathode 9 and an anode 8. The cathode 9 is made of either a stainless steel plate or a titanium plate, and the anode 8 is made of a titanium plate coated with a noble metal oxide.

[0035] The system also includes an external power supply 14, with the anode 8 connected to the positive terminal of the power supply 14 and the cathode 9 connected to the negative terminal of the power supply 14.

[0036] The circulation loop 15 is equipped with a circulation pump 16, which is used to maintain the normal flow of electrolyte in the electrodeposition device 4, reduce the concentration polarization phenomenon in the electrodeposition device 4, and maintain the reaction pH value during electrodeposition.

[0037] The wastewater treated by the ion exchange unit 1 is then transported to the biochemical treatment process section.

[0038] The regulating tank 3 is also equipped with a stirring device 11; the regulating tank 3 and the electrodeposition device 4 are connected by a pipeline, and a delivery pump 17 is provided on the pipeline.

[0039] A wastewater treatment plant using this recycling system can reduce the nickel content in chemical nickel production wastewater from 500 mg / L to below 0.1 mg / L. The purity of the metallic nickel generated by electrodeposition cathode can reach over 99%. Compared with the traditional chemical precipitation process, this significantly improves the utilization rate and economic benefits of wastewater.

[0040] The above-described embodiments are merely illustrative of one implementation of this utility model and are not intended to limit it. It should be noted that those skilled in the art can modify the technical solutions described in the above embodiments or make equivalent substitutions for some or all of the technical features; however, these modifications or substitutions do not cause the essence of the corresponding technical solutions to depart from the protection scope of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the protection scope of this utility model.

Claims

1. A system for treating electroplating wastewater and recovering nickel, characterized in that, include: The ion exchange unit is used to adsorb nickel ions in the wastewater to be treated, and can also be used as a regeneration container to elute the saturated resin by injecting sulfuric acid regeneration solution to produce nickel-containing eluent. A regeneration unit, connected to the ion exchange unit, is used to provide sulfuric acid regeneration solution and perform regeneration operations on the ion exchange unit; An equalization tank, connected to the eluent outlet of the ion exchange unit, is used to receive and store the nickel-containing eluent. The equalization tank is equipped with an online pH detection device, an automatic dosing device, a first dosing unit, and a second dosing unit. An electrodeposition apparatus, connected to the conditioning cell and forming a circulation loop, is used to perform electrodeposition treatment on the conditioned electrolyte to deposit metallic nickel on the cathode. In this process, wastewater flows sequentially through the ion exchange unit for nickel adsorption. The nickel-containing eluent generated during the regeneration stage of the ion exchange unit is input into the conditioning tank for physicochemical conditioning. The conditioned electrolyte circulates between the electrodeposition device and the conditioning tank through a circulation loop until electrolysis is completed.

2. The system for treating electroplating wastewater and recovering nickel according to claim 1, characterized in that, The ion exchange unit includes at least two ion exchange devices, which are connected in series to achieve complete adsorption of nickel ions.

3. The system for treating electroplating wastewater and recovering nickel according to claim 1, characterized in that, The first dosing unit is used to control the addition of alkaline agents by an automatic dosing device based on feedback from the online pH detection device to maintain the solution pH within a set range; the second dosing unit is used to add electrodeposition additives to the conditioning tank to improve the density, brightness, or deposition efficiency of the cathode nickel deposition layer.

4. The system for treating electroplating wastewater and recovering nickel according to claim 1, characterized in that, The electrodeposition apparatus includes a cathode and an anode, wherein the cathode is made of either a stainless steel plate or a titanium plate, and the anode is made of a titanium plate coated with a noble metal oxide.

5. A system for treating electroplating wastewater and recovering nickel according to claim 1, characterized in that, The system also includes an external power supply, with the anode connected to the positive terminal of the power supply and the cathode connected to the negative terminal of the power supply.

6. The system for treating electroplating wastewater and recovering nickel according to claim 1, characterized in that, The circulation loop is equipped with a circulation pump to maintain the normal flow of electrolyte in the electrodeposition device, reduce concentration polarization in the electrodeposition device, and maintain the reaction pH value during electrodeposition.

7. The system for treating electroplating wastewater and recovering nickel according to claim 1, characterized in that, The wastewater treated by the ion exchange unit is then transported to the biochemical treatment process section.

8. A system for treating electroplating wastewater and recovering nickel according to claim 1, characterized in that, The regulating tank is also equipped with a stirring device; the regulating tank and the electrodeposition device are connected by a pipeline, and a delivery pump is installed on the pipeline.

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