Electrochemical device and extraction method for extracting copper from copper-containing wastewater

Abstract

The present invention relates to the technical field of heavy metal wastewater treatment, in particular to an electrochemical device and an extraction method for extracting copper from copper-containing wastewater, wherein the electrochemical device comprises an anode material consisting of activated carbon, graphite, lead dioxide, BDD and Cu m X 1-a-b Y a Z b and a cathode material made of Cu n X 1-c-d Y c Z dand a carbon-selenium complex, and the cathode and anode are connected to a power supply for the treatment of copper-containing wastewater; wherein 1 < m ≤ 2, 1 ≤ n < 2 and m > n; 0 ≤ a ≤ 1, 0 ≤ b ≤ 1 and 0 ≤ a + b ≤ 1; 0 ≤ c ≤ 1, 0 ≤ d ≤ 1 and 0 ≤ c + d ≤ 1; and X, Y and Z are selected from one of S, Se and Te. The present invention uses copper-based sulfur compounds as electrode material and forms an electrochemical device with other electrodes, wherein the device is an electrocatalytically coupled deionization system with electrochemical oxidation and complexation breaking properties and exhibits good selective removal of Cu. 2+in organic, complex copper-containing wastewater, highly acidic wastewater, and wastewater contaminated by high concentrations of salt ions and heavy metal ions; this device can effectively break down the complexation of the organic pollutant complex Cu-EDTA, thus facilitating the extraction of Cu 2+ complete.

Description

Technical area

[0001] The present invention relates to the technical field of the treatment of heavy metal wastewater, in particular to an electrochemical device and an extraction method for extracting copper from copper-containing wastewater. Background technology

[0002] Copper resources play a vital role in modern industrial technology, encompassing key sectors such as communications, infrastructure, electrical and electronic equipment, and transportation. Consequently, the importance of copper applications will continue to grow, with demand increasing rapidly throughout the 20th century, accompanied by a growing scarcity and depletion of copper resources. Simultaneously, copper is a common heavy metal pollutant in wastewater generated by industrial processes such as copper mining and smelting, printed circuit board printing, and metal plating, and is characterized by high concentrations. In typical electroplating wastewater, the copper concentration can reach up to 1500 mg / L. Etching copper with ammonia solution is a common method in printed circuit board manufacturing; reportedly, the copper concentration in the waste solution can reach up to 150 g / L.Standards for copper emissions are very strict, ranging from 3.0 mg / L in India to 0.1 mg / L in Italy. If copper-containing wastewater is released into the environment untreated and of low quality, copper binds to other substances. 2+ with sediments, it is absorbed by plants and animals and eventually enters the human body via the food chain, where it accumulates and poses a potential health risk.

[0003] The discharge of heavy metal wastewater not only poses a serious threat to environmental safety and human health, but also causes an enormous waste of heavy metal resources, contradicting the concept of green development. Recovering copper while simultaneously and effectively removing copper pollution from the wastewater to regenerate copper resources is a crucial method for addressing current heavy metal pollution and the depletion of copper resources.On the one hand, copper-containing wastewater from smelting, electroplating, and other industries is characterized by harsh environmental conditions and a high acidity (sulfuric acid content of 5-10%), and the strong corrosiveness and high toxicity of the acidic wastewater make it hazardous waste, which makes efficient copper recovery difficult; on the other hand, some organic pollutants from industry are released as complexing agents, for example, ethylenediaminetetraacetic acid, etc., and these complexing agents form stable complexes with heavy metals that are difficult to biodegrade and bioaccumulate, exhibit high toxicity and stability, and are difficult to treat using general water treatment methods.

[0004] To meet emission standards, researchers in different countries have developed various treatment methods to remove copper. 2+developed from industrial wastewater, including chemical precipitation, adsorption, membrane separation, electrodialysis and other treatment technologies.

[0005] The conventional treatment method for copper and most heavy metals is precipitation, i.e., under alkaline pH conditions to induce the formation of insoluble hydroxides or sulfides. However, this method is cumbersome and requires adjusting the pH in two steps to destroy the copper complex. It also relies on iron ions to reduce divalent copper to copper, preventing it from recombining into a complex.

[0006] The mechanism of action of the adsorption method consists of utilizing the aggregation of aqueous pollutants at the solid-liquid interface with the adsorbent and adsorbing them to the adsorbent point through physical or chemical action, thus achieving the goal of aqueous pollutant removal. Due to its simple design and low operating costs, the adsorption method is one of the most frequently used processes for treating copper-containing wastewater. However, the operating range of Cu 2+ -Concentration is often limited, which hinders rapid metal uptake and frequent regeneration.

[0007] Membrane technology has evolved incrementally from microfiltration (MF) and ultrafiltration (UF) to nanofiltration (NF) and reverse osmosis (RO), and improving membrane selectivity for copper ions requires a deeper understanding of the fundamentals of solute transport in porous membrane media. Furthermore, membrane separation faces challenges such as high membrane costs, membrane fouling, and the complex real-world water environment in industrial applications.

[0008] The classic electrodialysis process is used to treat wastewater from the metal deposition and electroplating industries, and this strategy is suitable for the non-selective removal and recovery of copper. However, residual wastewater from copper ore processing is highly acidic and contains high concentrations of various heavy metals such as iron, zinc, and copper, which complicates effective treatment.

[0009] Therefore, there is an urgent need to develop a cost-effective and efficient method for treating copper-containing wastewater in order to recover copper from the wastewater. Content of the invention

[0010] To solve the aforementioned problems, the present invention provides an electrochemical device and an extraction method for extracting copper from copper-containing wastewater, thereby achieving highly selective adsorption and efficient extraction and recovery of copper ions in copper-containing wastewater.

[0011] A first aspect of the present invention provides an electrochemical device for extracting copper from copper-containing wastewater, wherein the anode material of the electrochemical device comprises activated carbon, graphite, lead dioxide, BDD and Cu m X 1-a-b Y a Z b is; the cathode material of a Cu n X1- c-d Y c Z d and a carbon and selenium complex material, and the cathode and the anode are connected to a power supply for the treatment of copper-containing wastewater; in particular, the cathode material is an active cathode material and the anode material is an active anode material, where 1 < m ≤ 2, 1 ≤ n < 2 and m > n; 0 ≤ a ≤ 1, 0 ≤ b ≤ 1 and 0 ≤ a+b ≤ 1; 0 ≤ c ≤ 1, 0 ≤ d ≤ 1 and 0 ≤ c + d ≤ 1; and X, Y and Z are selected from one of S, Se and Te.

[0012] In particular, Cu m X 1-a-b Y a Z b and Cu n X 1-c-a Y c Z d copper-based sulfur compounds, which can be listed as follows: CuS, CuSe, CuTe, CuS@CuSe, CuS 0,3 See 0,7 , CuS 0.5 See 0,5 , CuS 0.7 See 0,3 , CuS 0,3 See 0,7 , Cu2S, Cu2Se, Cu2Te, Cu2S 0,3 See0,7 , Cu2S 0.7 See 0,3 , Cu2Se 0,7 Te 0,3 etc.

[0013] In some of the embodiments, the anode material of the electrochemical device is one of activated carbon, graphite, lead dioxide and BDD material; and the cathode material is one of copper selenide, copper selenide sulfide and carbon-selenium complex material, and the anode and the cathode are connected to a power supply and subjected to a direct current of 0.6-4.0 V, and the device is used for the treatment of acidic, Cu-EDTA-containing organic wastewater as well as electroplating wastewater.

[0014] In some preferred embodiments, the electrochemical apparatus uses an activated carbon electrode as the anode and a copper selenide electrode produced by a hydrothermal process as the cathode. The anode and cathode are connected by wires and powered by a DC voltage of 0.6–4.0 V. The apparatus is used for the treatment of Cu-EDTA-containing organic wastewater and acidic electroplating wastewater. This apparatus system has been used for the electrochemical oxidative complex cleavage of Cu-EDTA and the selective adsorption of the Cu(II) ions released after complex cleavage onto the copper selenide cathode.

[0015] In some of the embodiments, the manufacturing steps of copper selenide are as follows: Dissolving selenium powder in hydrazine hydrate with stirring to obtain mixture A; mixing ethanol and water in equal proportions and adding anhydrous copper chloride with stirring to obtain mixture B; mixing A and B with stirring to obtain the mixture, and placing the mixture in an oven and increasing the temperature to 150-200°C and carrying out the reaction for 20-30 hours to obtain a crude copper selenide product.

[0016] In some of the embodiments, the molar ratio of selenium powder to anhydrous copper chloride is 1:1.

[0017] In some of the embodiments, the cathode electrode is obtained by the following method: Uniform mixing of conductive carbon black and copper selenide material, then addition to a solvent for stirring, addition of a binder and further stirring until a uniform mixture is obtained; use of the resulting mixture, which is coated onto graphite paper, and drying of the coated graphite paper at a specific temperature overnight to finally obtain a cathode electrode with copper selenide as the active substance; in particular, the solvent is absolute ethanol; the drying temperature is 60°C.

[0018] By replacing the aforementioned copper selenide powder with activated carbon powder and using the same method, a specific anode electrode for the system can be produced; in particular, the anode electrode is obtained by the following procedure: Uniform mixing of conductive carbon black and activated carbon material, then addition to a solvent for stirring, addition of a binder and then further stirring until a uniform mixture is obtained; use of the resulting mixture to coat a graphite paper and drying of the coated graphite paper overnight at 60°C to finally obtain an anode electrode for electrocatalysis using activated carbon as the active material.

[0019] The electrodes mentioned above are incorporated into a device system for treating acidic wastewater containing Cu-EDTA pollutants. Specifically, the copper selenide cathode, activated carbon anode, power supply, and 50 ml of copper-containing wastewater were combined to construct an electrochemical apparatus. In this apparatus, charged ions in the wastewater were attracted to the electrodes with opposite charges under a specific voltage. The acidic pH conditions were adjusted using concentrated sulfuric acid, resulting in an anodic oxidation-breaking complexation and a cathodic selective adsorption reaction of Cu. 2+ Furthermore, the concentrations of Cu were 2+ Cu-EDTA was measured in the waste solution and analyzed as a component to determine the effect of copper extraction. The electrochemical oxidation complex breaker system with the copper selenide electrode as the cathode can selectively extract Cu2+ Extraction is achieved through anodic complex breaking under conditions such as strong acidity and complex ionic composition, thereby serving the purpose of copper resource recovery. Specifically, the supply voltage is 0.6-4.0 V and the pH value is 0.1-5.

[0020] In some of the preferred embodiments, the electrochemical device further comprises an anion exchange membrane.

[0021] A second aspect of the present invention provides a method for extracting copper from copper-containing wastewater, wherein the method uses one of the electrochemical devices described above to extract copper from copper-containing wastewater by electrochemical processes.

[0022] In some of the embodiments, the procedure comprises the following steps: (1) synchronous execution of the copper embedding and copper removal process: application of an electrodialysis reactor mode using a Cu m X 1-a-b Y a Z b -electrode as anode and a Cu n X 1-c-d Y c Z d - Electrode as cathode and separation of the anode and the cathode with an anion exchange membrane, wherein the anode chamber is added to a conducting salt solution and the cathode chamber is added to the copper-containing wastewater to be processed; after the current is applied, a copper-rich electrode forms at the cathode and simultaneously a copper-poor electrode forms at the anode; a highly concentrated copper-containing solution is obtained in the anode chamber, and the copper ions (II) of the copper-containing wastewater in the cathode chamber are selectively adsorbed onto the cathode material; (2) Regeneration process: after completion of the reaction in step (1), the positive and negative electrodes of the power supply are reversed, and the electrode exchange is carried out; the solution in the anode chamber after the electrode exchange is replaced with fresh conducting salt solution, and the solution in the cathode chamber after the electrode exchange is replaced with the copper-containing wastewater, and then the power supply is switched on again to carry out the anodic copper removal and cathodic embedding to realize the extraction of copper in the copper-containing wastewater, and in the meantime to complete the cyclic regeneration of the electrodes; where 1 < m ≤ 2, 1 ≤ n < 2 and m > n; 0 ≤ a ≤ 1, 0 ≤ b ≤ 1 and 0 ≤ a + b ≤ 1; 0 ≤ c ≤ 1, 0 ≤ d ≤ 1 and 0 ≤ c + d ≤ 1; and X, Y and Z are selected from one of S, Se and Te.

[0023] In some of the preferred embodiments, the method comprises the following steps: (1) Synchronous execution of the copper embedding and copper removal process: Application of an electrodialysis reactor mode using a Cu2Se electrode as the anode and a CuSe electrode as the cathode, and separation of the anode and cathode with an anion exchange membrane, wherein the anode chamber is added to a conducting salt solution and the cathode chamber is added to a copper-containing wastewater solution to be processed; after the current is applied, the copper-containing wastewater is introduced into the cathode chamber; copper(II) ions are embedded in the cathode material to form a copper-rich Cu2Se electrode; simultaneously, Cu2Se, as the active anode material, loses copper(I) ions and becomes a copper-rich CuSe electrode; a highly concentrated copper-containing solution is obtained in the anode chamber, and the copper(II) ions of the copper-containing wastewater in the cathode chamber are selectively adsorbed onto the cathode material. (2) Regeneration process: After completion of the reaction in step (1), the positive and negative electrodes of the power supply are exchanged, with the copper-rich Cu2Se electrode produced in step (1) serving as the anode and the copper-poor CuSe electrode produced in step (1) serving as the cathode, and the solution in the anode chamber containing the copper-rich Cu2Se electrode is replaced by a fresh conducting salt solution, and the solution in the cathode chamber containing the copper-poor CuSe electrode is replaced by the copper-containing wastewater, and then the power supply is switched on again to carry out the anodic copper removal and cathodic embedding to realize the extraction of copper in the copper-containing wastewater, and in the meantime the cyclic regeneration of the electrodes is completed.

[0024] Step (1) Construction of the system “Cu2Se electrode | conductive electrolyte | anion exchange membrane | copper-containing wastewater | CuSe electrode” for simultaneous copper extraction and removal; Step (2) Construction of the system “CuSe electrode | copper-containing wastewater | anion exchange membrane | conductive electrolyte | Cu2Se electrode” for electrode regeneration and obtaining a copper-rich solution by swapping the positive and negative electrodes of the cell and adjusting the solution in the cathode and anode chambers to regenerate the electrode and obtain a copper-rich solution to achieve highly selective extraction and recovery of copper from copper-containing wastewater and to regenerate the electrode during wastewater treatment to further improve treatment efficiency and reduce the cost of the electrode material.

[0025] In some of the embodiments, after completion of step (1) or (2), the highly concentrated copper-containing solution is collected in the anode chamber, decontaminated and used for the electrolytic refining of crude copper.

[0026] In some of the embodiments, the concentration of copper(II) ions in the highly concentrated copper-containing solution is above 10,000 mg / L, and the method for removing impurities is electrolysis.It should be noted that when a copper-based sulfur compound is used simultaneously as the active cathode and anode material to form a counter electrode, and an anion exchange membrane and power supply are assembled to form an electrodialysis reaction device for treating copper-containing wastewater, the concentration of Cu(II) ions in the final highly concentrated copper-containing solution obtained is normally compatible with that of the copper-containing wastewater. To carry out the enrichment of copper(II) ions in the treatment of wastewater with lower copper content, the anode chamber solution collected in the previous treatment (i.e., the solution collected in the previous treatment) can be used in subsequent treatments, except when using fresh conductive electrolyte solution for the first time.highly concentrated copper-containing wastewater) is used to replace the conductive electrolyte solution until the concentration of copper(II) ions in the highly concentrated copper-containing solution reaches a higher enrichment concentration, such as 10,000 mg / L, which is required for electrolysis to extract copper and complete the enrichment of copper(II) ions, and at this point the concentration of copper(II) ions in the highly concentrated copper-containing solution is the cumulative concentration of the treatment process.

[0027] At the same time, in practical application, the electrochemical device of the present invention typically connects several sets of cathodes and anodes in series and builds them with several anion exchange membranes and power supply to form an integrated device, wherein the integrated device comprises several treatment modules to increase the treatment capacity of copper-containing wastewater per unit volume of the device;If the concentration of copper(II) ions in the copper-containing wastewater does not meet the requirement for the discharge of copper-containing wastewater downstream of the device, or if the concentration of enriched copper ions does not reach the desired concentration, the wastewater treated in the cathode chamber only needs to be replaced with fresh copper-containing wastewater after treatment. It is not necessary to replace the solution in the anode chamber to maintain its electrical charge, and the process can be repeated until the cathode reaches saturation of adsorption to reach the copper(II) ions enriched in the anode chamber. If the cathode is already adsorbed and saturated, it can be regenerated by the anode for further treatment. In some embodiments, the excitation voltage in steps (1) and (2) is 0.1–1.4 V and the excitation time is 60–180 min.

[0028] In some of the embodiments, in step (1) the Cu2Se electrode is produced by mixing Cu2Se, conductive carbon material and binder PVDF in a mass ratio of 7-9: 2-0.5: 1-0.5.

[0029] In some of the embodiments, in step (1) the CuSe electrode is produced by mixing CuSe, conductive carbon material and binder PVDF in a mass ratio of 7-9: 2-0.5: 1-0.5.

[0030] In some of the embodiments, the conductive carbon material is selected from one or more of the substances acetylene carbon black, carbon nanotubes, graphene, graphite and carbon fibers.

[0031] In particular, the manufacturing methods are similar to those of Cu. m X 1-a-b Y a Z b -electrode and the Cu n X 1-c-d Y c Z d -Electrode those of Cu2Se and CuSe and they are made by mixing Cu m X 1-a-b Y a Z b / Cun X 1-c-d Y e Z d , conductive carbon material and binder PVDF in a mass ratio of 7-9: 2 -0.5: 1-0.5.

[0032] In some of the embodiments, in step (1) and step (2) the conducting salt solution is a sulfate solution or a chloride salt solution, and the sulfate concentration in the sulfate solution is 0.1-2 mol / L and the chloride ion concentration in the chloride salt solution is 0.1-2 mol / L.

[0033] For example, the sulfate solution can be listed as follows: sodium sulfate solution, potassium sulfate solution, magnesium sulfate solution, ammonium sulfate solution, zinc sulfate solution, etc.; the chloride salt solution can be listed as follows: sodium chloride solution, potassium chloride solution, ammonium chloride solution, etc.

[0034] In some of the embodiments, step (2) is repeated 10-20 times.

[0035] In some of the embodiments, the copper-containing wastewater is one of the following: acidic wastewater from electroplating, integrated wastewater from printed circuit board printing, copper-containing wastewater from copper smelting, and copper-containing wastewater after network interruption.

[0036] In some of the embodiments, the concentration of copper(II) ions in the copper-containing wastewater is 0.5-10000 mg / L; the pH of the copper-containing wastewater is 0.1-5.0; in particular, if the pH of copper-containing wastewater is greater than 5.0, sulfuric acid or hydrochloric acid must be used to adjust the pH to 0.1-5.0.

[0037] In comparison to the prior art, the advantageous effects of the present invention are as follows: (1) The present invention uses copper-based sulfur compounds as electrode materials and other electrodes such as carbon materials and BDD to form an electrochemical device, wherein the device is an electrocatalytically coupled deionization system with electrochemical oxidation complex breaking performance and is effective in the selective removal of copper(II) ions from organic, complex copper-containing wastewaters, strongly acidic wastewaters and wastewaters disturbed by a high concentration of salt ions and heavy metal ions; the device can effectively achieve the decomplexation of organically complex pollutants Cu-EDTA, so that it is degraded into lower-order complex forms or even completely degraded and copper(II) ions are released, thereby completing the extraction of copper(II) ions;More importantly, CuSe still exhibits a higher electrosorption capacity compared to CuS electrodes in an acidic environment (1 mol / L hydrochloric acid). (2) The present invention furthermore uses copper-based sulfur compounds as active cathode and anode materials to form a counter electrode, which is assembled with an anion exchange membrane and a power supply to form an electrodialysis reaction device. It can simultaneously carry out copper removal and copper embedding reactions at a lower voltage and a wider pH range. In combination with the electrode regeneration step, the copper extraction process can be carried out continuously, thereby significantly improving the copper extraction efficiency and resulting in high removal efficiency and selectivity of copper(II) ions in copper-containing wastewater. (3) The copper-based sulfur compound electrode material of the present invention has the advantages of high adsorption capacity and high selectivity in the treatment of copper-containing electroplating wastewater and is capable of achieving selective extraction of copper(II) ions under conditions of interference by a high concentration of salt ions and heavy metal ions and a high acid content; the present invention uses bicopper-based sulfur compounds as the two electrodes of the electrochemical reactor and utilizes the excellent copper(II) ion extraction performance of the bicopper-based sulfur compound electrode to achieve a high copper ion adsorption capacity under low-voltage conditions; furthermore, the electrode pair showed good selective adsorption capacity (removal efficiency of more than 90%) for copper(II) ions at high concentrations of the coexistence system with polymetallic ions;Furthermore, the electrode pair with sulfur compounds based on bicopper of the present invention is also suitable for the treatment of copper-containing wastewater in a wide pH range, thus overcoming the limitation that conventional adsorption materials can only extract copper in a narrow pH range; the present invention verifies the feasibility of the dual CuSiS electrode pair system for the effective extraction of copper ions in the treatment of actual wastewater and can be applied for the selective extraction of copper(II) ions from strongly acidic copper-containing wastewater with complex components, thereby opening up a new avenue for wastewater extraction for the recycling of copper resources and other areas; (4) The excellent removal performance of the bicupper-based sulfur compound electrode pair of the present invention for copper(II) ions results from the reversible conversion between different copper-based sulfur compound electrodes in the bicupper-based sulfur compound electrode pair. The reversible conversion of the electrodes, i.e., the electrode regeneration, is carried out by interchanging the positive and negative electrodes of the power supply and adjusting the solution in the cathode and anode chambers. The electrode regeneration is performed synchronously with the copper lifting process to achieve continuous treatment of copper-containing wastewater, thereby significantly improving the efficiency of copper extraction, extending the service life of the electrodes, and reducing treatment costs. Brief description of the drawings

[0038] To clarify the embodiments of the present invention or the prior art technical solutions, the figures that must be used in describing these embodiments or the prior art are briefly presented below. It is obvious that the figures in the following description represent only some embodiments of the invention. General technical personnel can easily create other figures based on these without any creative effort. Fig. Figure 1 shows an X-ray diffraction spectrum of the copper selenide electrode material produced in embodiment 1; Fig. Figure 2 shows a scanning electron microscope image of the copper selenide electrode material produced in embodiment 1; Fig. Figure 3 shows a schematic representation of the device of the combination device of embodiment 3; Fig. Figure 4 shows the curve of the concentration of Cu-EDTA over time for embodiment 3 during the treatment of Cu-EDTA-containing wastewater; Fig. Figure 5 shows a diagram of the adsorption of copper and other ions by the copper selenide cathode electrode of embodiment 4 during the treatment of acidic electroplating wastewater; Fig. Figure 6 shows a diagram of the adsorption of copper and other heavy metals by the copper selenide cathode electrode in embodiment 5 during the treatment of wastewater containing a complex system of multi-component heavy metals; Fig. Figure 7 shows a schematic structure of the electrochemical device built in embodiment 6, wherein: 1-Cu2Se anode, 2-CuSe cathode, 3-anion exchange membrane, 4-DC power supply, 5-carrier electrolyte and 6-copper-containing wastewater; Fig. Figure 8 shows a schematic structure of the electrochemical device for the regeneration process of embodiment 6, wherein: 11-Cu2Se anode (obtained from CuSe after copper embedding), 21-CuSe cathode (obtained from Cu2Se after copper removal), 3-anion exchange membrane, 4-DC power supply, 5-carrier electrolyte, 6-copper-containing wastewater; Fig. Figure 9 shows a diagram of the adsorption of copper and other ions by embodiment 6 during the treatment of copper mine water from a copper mine. Specific embodiments

[0039] The technical solution of the present invention is described clearly and completely below in conjunction with specific embodiments. Obviously, the described embodiments represent only a portion and not all embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by general technical personnel without creative work fall within the scope of protection of the present invention. Example 1

[0040] 0.316 g of selenium powder were removed and dissolved in 10 mL of hydrazine hydrate at 70°C with vigorous stirring to form mixture A. 0.523 g of anhydrous copper chloride were removed and dissolved in an ethanol-water mixture (ethanol to water volume ratio 3:2), mixed and stirred to form mixture B. Mixture A was added dropwise to mixture B and stirred for 30 minutes at room temperature. The reactants were then transferred to a reaction vessel and placed in an oven at 180°C for 24 hours. After cooling to room temperature, the solid product was washed several times with anhydrous ethanol and deionized water. Finally, it was placed in the oven and dried overnight at 60°C to obtain copper selenide electrode materials.

[0041] The X-ray diffraction spectrum of the copper selenide electrode material produced in embodiment 1 is shown in Fig. Figure 1 shows that the main diffraction peak of the sample completely coincides with the characteristic peak corresponding to the hexagonal crystal phase of copper selenide (CuSePDF#34-0171). No other impurity peaks were observed. This result demonstrates that the copper selenide material was successfully produced and that the obtained sample exhibited high purity.

[0042] Fig. Figure 2 shows a scanning electron microscope image of the fabricated copper selenide electrode material; the figure shows that the copper selenide nanomaterial has an irregular hexagonal nanosheet shape with a size of about 200 nm to 500 nm and is relatively dispersed without any stacking. Example 2

[0043] The copper selenide electrode material produced in embodiment 1 was used as the active material, mixed with conductive carbon black in a mass ratio of 8:1, anhydrous ethanol was added, the mixture was stirred uniformly, a binder was added (the ratio of active material to binder was 8:1), and the mixture was stirred uniformly. The resulting mixture was then applied to graphite paper with a coating thickness of 100–600 µm. The coated graphite paper was dried overnight at 60 °C to obtain a cathode electrode for deionization using copper selenide as the active material.

[0044] The activated carbon anode electrode was prepared in the same way: The activated carbon material was used as the active material, mixed with the conductive carbon black in a mass ratio of 8:1, and anhydrous ethanol was added, stirred thoroughly, and then the binder was added, again in an 8:1 ratio, and stirred thoroughly. The resulting mixture was then applied to graphite paper with a coating thickness of 100–600 µm. The coated graphite paper was dried overnight at 60°C to obtain an anode electrode for electrocatalysis using activated carbon as the active material. Example 3

[0045] A combined device for electrochemical oxidation complex breaking and cathodic selective copper extraction, constructed with the copper selenide cathode electrode and activated carbon anode electrode obtained in Example 2, is used for the treatment of wastewater and acidic electroplating wastewater containing Cu-EDTA pollutants, i.e., for the extraction of copper. The specific process is as follows: The copper selenide cathode electrode and the activated carbon anode electrode, the power supply, and 50 ml of copper-containing waste liquid were combined to construct a unified system. At 1 V, the charged ions in the waste liquid were attracted to the electrodes with opposite charges, and anodic oxidation complex breaking and cathodic selective adsorption of Cu occurred. 2+took place by adjusting the pH to 1 using concentrated sulfuric acid, and the schematic diagram of the device is in Fig. 3 shown. In addition, the concentration of Cu was 2+ and Cu-EDTA was measured in the wastewater liquid and the component analysis of Cu-EDTA was carried out, as described in Fig. Figure 4 shows that, according to the high-performance liquid chromatography test, the concentration of Cu-EDTA in the wastewater was significantly reduced from an initial 400 mg / L to 0.2 mg / L after 300 minutes of electrochemical treatment, indicating that the capacitive deionization system has a significant effect on the removal of Cu-EDTA from the wastewater. Under normal conditions, Cu-EDTA exists in the wastewater as a negative charge. Under voltage, Cu-EDTA is attracted to the activated carbon anode. Through anodic oxidation of the activated carbon anode, the generated hydroxyl radicals and other substances disrupt the complex structure of Cu-EDTA. 2+ and -EDTA-, produce lower-order copper complex species or set Cu 2+ directly free, forming the broken Cu-EDTA complex. The released Cu 2+was attracted to the cathode under voltage and finally recovered by the copper selenide electrode. Example 4

[0046] A copper selenide electrode was used to perform selective copper extraction in strongly acidic electroplating wastewater. The specific procedure is as follows: The electroplating wastewater from the electroplating company was adjusted to a strongly acidic pH of 1. The wastewater was treated with a combination device of electrochemical oxidation complex breaking and cathodic selective copper extraction, and the specific experiments were carried out in the same manner as in embodiment 3. As in Fig. 5 shown, Cu dropped 2+ -Concentration after adsorption from 417.12 mg / L to 1.92 mg / L, and under the condition of interference by other ions (Na+: 553.97 mg / L, Ca2+: 672.91 mg / L) the removal rate of Cu reached 2+99.52%. In contrast, the removal rates of Na+ and Ca2+ were only 3.21% and 1.95%, respectively. The results showed that the copper selenide electrode still exhibited excellent adsorption performance and selectivity for Cu even under the actual conditions of strong acid and high concentrations of interfering ions. 2+ can exhibit. Example 5

[0047] A copper selenide electrode was used for selective copper extraction under the influence of heavy metals. The specific procedure is as follows: The copper selenide electrode was electrosorbed into a mixed solution system with a copper concentration of 10 mg / L and a heavy metal concentration of 1:10, and the specific experiments were carried out in the same manner as in embodiment 3. As in Fig. Figure 6 shows that the results demonstrate that the copper selenide electrode still achieves a Cu removal rate of 99.02% even at a concentration ratio of 1:10. 2+ exhibits a high removal rate, while the removal rate of other ions is low. The removal rate was calculated using the following formula: RE=C0−CtC0×100% RE: Removal efficiency; C0: Initial concentration; Ct: Equilibrium concentration.

[0048] In embodiment 1, a copper selenide material of higher purity was produced by a hydrothermal process. In embodiment 2, a copper selenide electrode was produced as the cathode using the copper selenide material produced in embodiment 1, while an activated carbon electrode was produced as the anode using activated carbon.In embodiments 3-5, the cathode and anode produced in embodiment 2 are used to construct an electrochemical arrangement “activated carbon electrode copper-containing wastewater|CuSe electrode” for the treatment of copper-containing wastewater, of which embodiment 3 is used for the treatment of Cu-EDTA-containing wastewater, and the results show that the electrochemical device system of the present invention has the performance of electrochemical oxidation complex breaking and can effectively realize the treatment of organically complexed pollutants, whereby it decomposes into complex forms of lower order or even completely breaks down Cu. 2+ is released. At the same time, the electrochemical system of the present invention can also process the released Cu. 2+ adsorb and thus enable the extraction and recovery of Cu 2+realise; embodiment 4 was used for the treatment of acidic electroplating wastewater and the results showed that the electrochemical device system of the present invention still exhibits excellent adsorption performance and selectivity for Cu under the conditions of strong acid and high concentration of interfering ions. 2+ Exemplary embodiment 5 was used to treat copper-containing wastewater with various heavy metals, and the results showed that the electrochemical device system of the present invention still exhibits a good removal rate and selectivity for Cu under the influence of heavy metals. 2+ exhibits. Example 6 (1) Synchronous execution of the copper embedding and copper removal process: Construction of an electrochemical apparatus. The schematic diagram of the apparatus structure is shown in Fig. Figure 7 illustrates the process. An electrodialysis reactor was used, employing a Cu₂Se electrode as the anode and a CuSe electrode as the cathode. An anion exchange membrane was used to separate the anode and cathode. 100 ml of sodium sulfate solution was added to the anode chamber (sulfate ion concentration was 0.5 mol / L) as the conducting electrolyte solution, and 100 ml of the copper-containing wastewater to be treated was added to the cathode chamber (copper(II) ion concentration was 200 mg / L). After connecting to a power supply and applying a direct current of 1 V, the copper(II) ions in the copper-containing wastewater were incorporated into the cathode material in the cathode chamber, forming a copper-rich Cu₂Se electrode. The following reaction took place: CuSe + 2e⁻ + Cu 2+ Cu₂Se₂, while simultaneously Cu₂Se₂ as the anode loses copper(I) ions and becomes a copper-deficient CuSe electrode. The following reaction took place: Cu₂Se⁻ 2e⁻ = CuSe⁺ Cu 2+; after 60 minutes of excitation, a highly concentrated copper-containing solution with 199.36 mg / L was obtained in the anode chamber, the copper(II) ions in the copper-containing wastewater flowing into the cathode chamber were selectively adsorbed onto the cathode material, and the copper ion concentration of the treated copper-containing wastewater was 0.89 mg / L. (2) Regeneration process: After completion of the reaction, the positive and negative electrodes of the power supply were exchanged and an electrode exchange was carried out. Using the copper-rich Cu2Se electrode produced in step (1) as the anode and the copper-poor CuSe electrode produced in step (1) as the cathode, the solution in the anode chamber containing the copper-rich Cu2Se electrode was replaced by 100 ml of fresh sodium sulfate solution as the conducting electrolyte solution (the concentration of sulfate ions was 0.5 mol / L) and the solution in the cathode chamber containing the copper-poor CuSe electrode was replaced by 100 ml of copper-containing wastewater (the concentration of copper(II) ions was 200 mg / L); Fig. Figure 8 shows a schematic structure diagram of the electrochemical device. It was reconnected to the power supply, and the process of step (1) was repeated, with a switch-on voltage of 1 V and an excitation duration of 60 minutes. Copper removal at the anode and copper deposition at the cathode were performed, with the anode chamber receiving a highly concentrated copper solution of 198.44 mg / L. The copper(II) ions in the copper-containing wastewater flowing into the cathode chamber are selectively adsorbed onto the cathode material, thereby extracting copper from the copper-containing wastewater. Simultaneously, the electrode regeneration cycle is completed.

[0049] In step (1) the Cu2Se electrode was produced by mixing Cu2Se, acetylene black and PVDF binder in a mass ratio of 7:0.5:1, and the specific manufacturing process is the same as in embodiment 2.

[0050] The copper-containing wastewater was obtained from the copper mine water at a pH of 2, and its chemical composition is shown in Table 1. The adsorption situation of copper and other ions in the copper mine water using the electrochemical device and method of the present invention is shown in Fig. 9 shown. Table 1 Chemical composition of copper mine water (unit: mg / L) Element Cu Fe Ca Zn Pb SO4 2- Inhalt 200 2000 180 96 1,8 15000

[0051] As from Fig. As can be seen in Figure 9, embodiment 6 uses a CuSe|Cu2Se electrode pair to construct an electrochemical device for treating copper mine water and can simultaneously perform the copper embedding and copper removal processes. At the same time, by interchanging the positive and negative electrodes of the power supply and adjusting the solutions in the cathode and anode chambers, the electrode regeneration and copper extraction processes are synchronized, which significantly improves the efficiency of copper-containing wastewater treatment, extends electrode life, and reduces costs.In embodiment 6, the removal rate of copper(II) ions in step (1) reached 99.55%, and the ion removal rates of Fe, Ca, Mg, and Pb were all below 5%, indicating that this device system has good selectivity for copper(II) ions; during the electrode regeneration process of step (2), the anode chamber received a highly concentrated copper-containing solution of 198.44 mg / L with a desorption rate of 99.22% and a good desorption effect; step (2) was repeated 15 times, i.e., the 17th processing was carried out. After 16 regenerations of the electrode, the concentration of copper(II) ions in the copper-containing wastewater in the cathode chamber decreased from 200 mg / L to 12 mg / L, the removal rate of copper(II) ions was 94%, and the removal rate of copper(II) ions in the copper-containing wastewater could still be achieved.Simultaneously, after 16 regeneration cycles, the anode chamber still received a highly concentrated copper solution of 186 mg / L, and the desorption rate reached 93%, indicating a good regeneration effect of the electrode cycle. The formula for calculating the desorption rate is as follows: DE=CtC0×100%

[0052] DE: Desorption efficiency; C0: Initial concentration; Ct: Concentration after desorption. Example 7

[0053] The difference between this embodiment and embodiment 6 is that an integrated device for treating copper-containing wastewater is used, and there are differences in the corresponding processes. The specific operating steps are as follows: (1) Synchronous realization of the copper embedding and decoppering process: An electrochemical apparatus was constructed, and several sets of cathodes and anodes were connected in series and assembled with several anion exchange membranes and a power supply to form an integrated device, the integrated device containing several treatment modules, and an electrodialysis reactor mode was adopted to separate the anode and the cathode by means of anion exchange membranes, using Cu2Se electrodes as the anode and CuSe electrodes as the cathode, 100 mL of sodium sulfate solution as the conducting electrolyte solution (concentration of copper(II) ions 0.5 mol / L) was added to the anode chamber, and the cathode chamber was filled with 100 mL of copper-containing wastewater to be treated (the concentration of copper(II) ions was 200 mg / L);The power supply was switched on and a DC voltage of 1 V was applied, and copper(II) ions in the copper-containing wastewater in the cathode chamber were incorporated into the cathode material to form a Cu2-rich Cu2Se electrode, and a reaction took place: Cu2Se+2e-+Cu; 2+ Cu2Se, at the same time Cu2Se as the anode lost copper(I) ions and became a copper-poor CuSe electrode, with the reaction taking place as follows: Cu2Se-2e-=CuSe+ Cu 2+ After 60 minutes of excitation, a highly concentrated copper-containing solution with 199.36 mg / L was obtained in the anode chamber; the copper(II) ions in the copper-containing wastewater flowing into the cathode chamber were selectively adsorbed onto the cathode material, and the copper ion concentration of the treated copper-containing wastewater was 0.89 mg / L. (2) The first enrichment process: The treated wastewater in the cathode chamber was replaced by fresh copper-containing wastewater, step (1) was repeated 50 times to enrich copper(II) ions, and a highly concentrated copper-containing solution of 10100mg / L was obtained in the anode chamber after enrichment. (3) Regeneration process: After completion of the reaction, the positive and negative electrodes of the power supply were exchanged and an electrode exchange was performed. Using the copper-rich Cu₂Se electrode produced in step (2) as the anode and the copper-poor CuSe electrode produced in step (2) as the cathode, the solution in the anode chamber containing the copper-rich Cu₂Se electrode was replaced by 100 ml of fresh sodium sulfate solution as the conducting electrolyte solution (the concentration of sulfate ions was 0.5 mol / L), and the solution in the cathode chamber containing the copper-poor CuSe electrode was replaced by 100 ml of copper-containing wastewater (the concentration of copper(II) ions was 200 mg / L). The power supply was reconnected and the process of step (1) was repeated, with the switch-on voltage being 1 V and the excitation duration 60 minutes.Copper removal at the anode and copper embedding at the cathode were performed, with the anode chamber containing a highly concentrated copper solution. The copper(II) ions in the copper-containing wastewater flowing into the cathode chamber were selectively adsorbed onto the cathode material, thereby extracting copper from the wastewater. Simultaneously, the electrode regeneration cycle was completed. (4) The first enrichment process: The treated wastewater in the cathode chamber was replaced by fresh copper-containing wastewater, step (3) was repeated 50 times to enrich copper(II) ions, and a highly concentrated copper-containing solution of 10000mg / L was obtained in the anode chamber after enrichment. (5) After completion of step (2) or (4), the highly concentrated copper-containing solution in the anode chamber is collected after enrichment and used for the electrolytic refining of crude copper after removal of impurities, resulting in high-purity electrolytic copper with a purity of over 99%.

[0054] Exemplary embodiment 7 further integrates several treatment units, so that copper enrichment can also be carried out when the concentration of copper(II) ions in the copper-containing wastewater is low, in order to further use the extracted copper for the electrolytic refining of crude copper and to realize a comprehensive copper processing system for copper-containing wastewater treatment and waste copper recovery applications, which has high application value and is worth promoting for industrialization. Example 8 (1) Synchronous execution of the copper embedding and copper removal process: Construction of an electrochemical apparatus. The electrodialysis reactor mode was used with a Cu₂S electrode as the anode and a CuS electrode as the cathode, and an anion exchange membrane was used to separate the anode and cathode. 100 ml of sodium sulfate solution was added to the anode chamber (the concentration of sulfate ions was 1.0 mol / L) as the conducting electrolyte solution, and 100 ml of the copper-containing wastewater to be treated was added to the cathode chamber (the concentration of copper(II) ions was 1000 mg / L). After connection to a power supply and application of a direct current of 0.1 V, the copper(II) ions in the copper-containing wastewater were embedded in the cathode material in the cathode chamber, forming a copper-rich Cu₂S electrode. The following reaction took place: CuS + 2e⁻ + Cu 2+Cu₂S, acting as the anode, simultaneously lost copper(I) ions and became a copper-deficient CuS electrode. The following reaction took place: Cu₂S ⇌ 2e⁻ = CuS + Cu 2+ ; after 180 minutes of excitation, a highly concentrated copper-containing solution with 996 mg / L was obtained in the anode chamber; the copper(II) ions in the copper-containing wastewater flowing into the cathode chamber were selectively adsorbed onto the cathode material, and the copper ion concentration of the treated copper-containing wastewater was 9.8 mg / L. (2) Regeneration process: After completion of the reaction, the positive and negative electrodes of the power supply were exchanged, and an electrode exchange was performed. Using the copper-rich Cu₂S electrode produced in step (1) as the anode and the copper-poor CuS electrode produced in step (1) as the cathode, the solution in the anode chamber containing the copper-rich Cu₂S electrode was replaced with 100 ml of fresh sodium sulfate solution as the conducting electrolyte solution (the concentration of sulfate ions was 1.0 mol / L), and the solution in the cathode chamber containing the copper-poor CuS electrode was replaced with 100 ml of copper-containing wastewater (the concentration of copper(II) ions was 1000 mg / L). The power supply was reconnected, and the process of step (1) was repeated, with a switch-on voltage of 0.1 V and an excitation duration of 180 minutes.Copper removal at the anode and copper embedding at the cathode were performed, with the anode chamber containing a highly concentrated copper solution of 978 mg / L. The copper(II) ions in the copper-containing wastewater flowing into the cathode chamber were selectively adsorbed onto the cathode material, thereby extracting copper from the wastewater. Simultaneously, the electrode regeneration cycle was completed.

[0055] In step (1) the Cu2S electrode was produced by mixing Cu2S, carbon nanotubes and PVDF binder in a mass ratio of 8:1:1, and the CuS electrode was produced by mixing CuS, carbon nanotubes and PVDF binder in a mass ratio of 8:1:1, and the specific manufacturing process is the same as in Example 2.

[0056] The copper-containing wastewater originates from the integrated copper-containing wastewater of printed circuit board production at pH=4, and its chemical composition is shown in Table 2. Table 2 Chemical composition of the integrated copper-containing wastewater (unit: mg / L) Element Cu COD Gesamtphosphor Zn Pb SO4 2- Inhalt 1000 200 180 96 1,8 15000

[0057] Embodiment 8 uses a CuS|Cu2S electrode pair to construct an electrochemical device for treating integrated copper-containing wastewater from printed circuit board production, simultaneously performing copper embedding and copper removal processes. By interchanging the positive and negative electrodes of the power supply and adjusting the solutions in the cathode and anode chambers, the electrode regeneration and copper extraction processes are synchronized, significantly improving the efficiency of copper-containing wastewater treatment. In Embodiment 8, the removal rate of copper(II) ions in step (1) reached 99.02%, and the desorption rate of the electrode regeneration process in the second treatment in step (2) reached 97.8%, demonstrating a good electrode cycle regeneration effect. Step (2) was repeated 15 times, i.e., the 17th processing cycle was performed.After 16 electrode regenerations, the concentration of copper(II) ions in the copper-containing wastewater in the cathode chamber decreased from 1000 mg / L to 30 mg / L, the copper(II) ion removal rate was 97%, and the desired copper(II) ion removal rate in the copper-containing wastewater was still achieved. Simultaneously, after 16 regenerations, the anode chamber still received a highly concentrated copper solution of 950 mg / L, and the desorption rate reached 95%, indicating a good electrode cycle regeneration effect. Example 9 (1) Synchronous execution of the copper embedding and copper removal process: Construction of an electrochemical device. The electrodialysis reactor mode was used with a Cu2S 0,3 See 0,7 -electrode as anode and a CuS 0,3 See 0,7An electrode was used as the cathode, and an anion exchange membrane was used to separate the anode and cathode. 100 ml of sodium sulfate solution was added to the anode chamber (sulfate ion concentration was 2.0 mol / L) as the conducting electrolyte solution, and 100 ml of the copper-containing wastewater to be treated was added to the cathode chamber (copper(II) ion concentration was 1000 mg / L). After connecting to a power supply and applying a direct current of 1.4 V, the copper(II) ions in the copper-containing wastewater were incorporated into the cathode material in the cathode chamber, forming a copper-rich Cu₂S solution. 0,3 See 0,7 -electrode. The following reaction took place: CuS 0,3 See 0,7 +2e-+Cu 2+ =Cu2S 0,3 See 0,7 . At the same time, Cu2S lost 0,3 Se0.7 as an anode copper (I) ions and became a CuS 0,3 See 0,7 -Electrode with copper deficiency. The following reaction took place: Cu2S 0,3 See0,7 -2e-=CuS 0,3 See 0,7 + Cu 2+ ; after 120 minutes of excitation, a highly concentrated copper-containing solution with 988 mg / L was obtained in the anode chamber; the copper(II) ions in the copper-containing wastewater flowing into the cathode chamber were selectively adsorbed onto the cathode material, and the copper ion concentration of the treated copper-containing wastewater was 6.3 mg / L. (2) Regeneration process: After completion of the reaction, the positive and negative electrodes of the power supply were exchanged and an electrode exchange was performed. Using the copper-rich Cu₂S produced in step (1) 0,3 See 0,7 -electrode as anode and the copper-poor CuS produced in step (1) 0,3 See 0,7 The solution in the anode chamber, containing the copper-rich Cu2S, was used as the cathode electrode. 0,3 See 0,7-Electrode is located, replaced by 100 ml of fresh sodium sulfate solution as the conducting electrolyte salt solution (the concentration of sulfate ions was 2.0 mol / L) and the solution is placed in the cathode chamber, in which the copper-poor CuS 0,3 See 0,7 The electrode was replaced with 100 ml of copper-containing wastewater (the copper(II) ion concentration was 1000 mg / L); it was reconnected to the power supply, and the process of step (1) was repeated, with a switch-on voltage of 1.4 V and an excitation duration of 120 minutes. Copper removal from the anode and copper deposition at the cathode were performed, with the anode chamber receiving a highly concentrated copper solution of 966 mg / L. The copper(II) ions in the copper-containing wastewater flowing into the cathode chamber were selectively adsorbed onto the cathode material, thereby extracting copper from the copper-containing wastewater. Simultaneously, the electrode regeneration cycle was completed.

[0058] In step (1) the Cu2S 0,3 See 0,7 -Electrode by mixing Cu2S 0,3 See 0,7 , graphite and PVDF binder, produced in a mass ratio of 9:2:1, and the CuS 0,3 See 0,7 -Electrode was created by mixing CuS 0,3 See 0,7 , graphite and PVDF binder in a mass ratio of 9:2:1, and the specific manufacturing process is the same as in embodiment 2.

[0059] The copper-containing wastewater has the same origin and composition as the copper-containing wastewater in embodiment 8.

[0060] Example 9 uses a “CuS 0,3 See 0,7 |Cu2S 0,3 See 0,7“-Electrode pair to construct an electrochemical device for treating the integrated copper-containing wastewater from printed circuit board production and can simultaneously perform the copper embedding and copper removal processes. At the same time, by swapping the positive and negative electrodes of the power supply and adjusting the solutions in the cathode and anode chambers, the electrode regeneration and copper extraction processes are synchronized, which significantly improves the efficiency of treating copper-containing wastewater. In embodiment 9, the removal rate of copper(II) ions in step (1) reached 99.17%, and the desorption rate of the electrode regeneration process of the second treatment in step (2) reached 96.6%, with a good regeneration effect of the electrode cycle. Step (2) was repeated 15 times, i.e., the 17th processing cycle was performed.”After 16 electrode regenerations, the concentration of copper(II) ions in the copper-containing wastewater in the cathode chamber decreased from 1000 mg / L to 46 mg / L, the copper(II) ion removal rate was 95.4%, and the target removal rate for copper(II) ions in the copper-containing wastewater was still achieved. Simultaneously, after 16 regenerations, the anode chamber still contained a highly concentrated copper solution of 948 mg / L, and the desorption rate reached 94.8%, indicating a good regeneration effect of the electrode cycle. Example 10 (1) Synchronous execution of the copper embedding and copper removal process: Construction of an electrochemical apparatus. Several sets of cathodes and anodes are connected in series and assembled with several anion exchange membranes and power supplies to form an integrated apparatus, the integrated apparatus comprising several processing modules. The electrodialysis reactor mode was used with a Cu₂S@Cu₂Se electrode as the anode and a CuS@CuSe electrode as the cathode, and an anion exchange membrane was used to separate the anode and cathode. 100 ml of sodium sulfate solution was added as the conducting electrolyte solution to the anode chamber (the concentration of sulfate ions was 2.0 mol / L) and 100 ml of the copper-containing wastewater to be treated was added to the cathode chamber (the concentration of copper (II.The concentration of copper(II) ions (10 mg / L) was introduced; after connection to a power supply and application of a direct current of 1 V, the copper(II) ions in the copper-containing wastewater were incorporated into the cathode material in the cathode chamber, forming a copper-rich Cu₂S@Cu₂Se electrode. The following reaction took place: CuS@CuSe + 4e⁻ + 2Cu. 2+ =Cu₂S@Cu₂Se. Simultaneously, Cu₂S@Cu₂Se, acting as the anode, lost copper(I) ions and became a copper-deficient CuS@CuSe electrode. The following reaction took place: Cu₂S@Cu₂Se - 4e⁻ = CuS@CuSe + 2Cu 2+The treated wastewater in the cathode chamber was continuously replaced with fresh copper-containing wastewater to enrich it with copper(II) ions. After enrichment, the anode chamber received a highly concentrated copper solution with a copper(II) concentration of 10,000 mg / L. The copper(II) ions in the copper-containing wastewater flowing into the cathode chamber were selectively adsorbed onto the cathode material, and the copper ion concentration of the treated copper-containing wastewater was 0.05 mg / L. (2) Regeneration process: After completion of the reaction, the positive and negative electrodes of the power supply were exchanged, and an electrode exchange was performed. Using the copper-rich Cu₂S@Cu₂Se electrode produced in step (1) as the anode and the copper-poor CuS@CuSe electrode produced in step (1) as the cathode, the solution in the anode chamber containing the copper-rich Cu₂S@Cu₂Se electrode was replaced with 100 ml of fresh sodium sulfate solution as the conducting electrolyte solution (the concentration of sulfate ions was 2.0 mol / L), and the solution in the cathode chamber containing the copper-poor CuS@CuSe electrode was replaced with 100 ml of copper-containing wastewater (the concentration of copper(II) ions was 10 mg / L). The power supply was reconnected, and the process of step (1) was repeated, with the switch-on voltage being 1 V. The anode copper was removed, and the cathode was embedded in copper.The treated wastewater in the cathode chamber was continuously replaced with fresh copper-containing wastewater to enrich it with copper(II) ions. After enrichment, a highly concentrated copper solution (10,000 mg / L) was obtained in the anode chamber. The copper(II) ions in the copper-containing wastewater flowing into the cathode chamber were selectively adsorbed onto the cathode material, thereby extracting copper from the wastewater. Simultaneously, the electrode regeneration cycle was completed. (3) After completion of step (1) or (2), the highly concentrated copper-containing solution in the anode chamber is collected after enrichment, purified of impurities and used in the electrolytic refining of crude copper to obtain high-purity electrolytic copper with a purity of more than 99%.

[0061] In step (1) the CuS@CuSe electrode was produced by mixing CuS@CuSe, graphite and PVDF binder in a mass ratio of 9:2:1, and the Cu2S@Cu2Se electrode was produced by mixing Cu2S@Cu2Se, graphite and PVDF binder in a mass ratio of 9:2:1, and the specific manufacturing process is the same as in embodiment 2.

[0062] The copper-containing wastewater has a pH value of 5.

[0063] Embodiment 10 uses a CuS@CuSe|Cu2S@Cu2Se electrode pair to construct an electrochemical device for treating integrated copper-containing wastewater from printed circuit board production, simultaneously performing copper embedding and copper removal processes. By interchanging the positive and negative electrodes of the power supply and adjusting the solutions in the cathode and anode chambers, the electrode regeneration and copper extraction processes are synchronized, significantly improving the efficiency of copper-containing wastewater treatment. In Embodiment 10, the removal rate of copper(II) ions reached 99.5%, and the desorption rate of the electrode regeneration process before the enrichment of the second treatment in step (2) reached 99.1%, demonstrating a good regeneration effect of the electrode cycle. Step (2) was repeated 15 times, i.e., the 17th processing cycle was performed.After 16 electrode regenerations, the concentration of copper(II) ions in the copper-containing wastewater in the cathode chamber decreased from 10 mg / L to 0.24 mg / L, the copper(II) ion removal rate was 97.6%, and the target removal rate for copper(II) ions in the copper-containing wastewater was still achieved. Simultaneously, after 16 regenerations, the anode chamber still received a highly concentrated copper solution of 9.65 mg / L, and the desorption rate reached 96.5%, indicating a good regeneration effect of the electrode cycle. Example 11 (1) Synchronous execution of the copper embedding and copper removal process: Construction of an electrochemical apparatus. Several sets of cathodes and anodes are connected in series and assembled with several anion exchange membranes and power supplies to form an integrated apparatus, the integrated apparatus comprising several processing modules. The electrodialysis reactor mode was used with a Cu₂Te electrode as the anode and a CuTe electrode as the cathode, and an anion exchange membrane was used to separate the anode and cathode. 100 ml of sodium sulfate solution was added as the conducting electrolyte solution to the anode chamber (the concentration of sulfate ions was 2.0 mol / L), and 100 ml of the copper-containing wastewater to be treated was added to the cathode chamber (the concentration of copper (II.The concentration of copper(II) ions (10 mg / L) was introduced; after connection to a power supply and application of a direct current of 1 V, the copper(II) ions in the copper-containing wastewater were incorporated into the cathode material in the cathode chamber, forming a copper-rich Cu₂Te electrode. The following reaction took place: CuTe + ​​2e⁻ + Cu. 2+ =Cu₂Te. Simultaneously, Cu₂Te, acting as the anode, lost copper(I) ions and became a copper-deficient CuTe electrode. The following reaction took place: Cu₂Te - 2e⁻ = CuTe + ​​Cu 2+ The treated wastewater in the cathode chamber was continuously replaced with fresh copper-containing wastewater to enrich it with copper(II) ions. After enrichment, the anode chamber received a highly concentrated copper solution with a copper(II) concentration of 10,000 mg / L. The copper(II) ions in the copper-containing wastewater flowing into the cathode chamber were selectively adsorbed onto the cathode material, and the copper ion concentration of the treated copper-containing wastewater was 0.1 mg / L.(2) Regeneration process: After completion of the reaction, the positive and negative electrodes of the power supply were exchanged, and an electrode exchange was performed. Using the copper-rich Cu₂Te electrode produced in step (1) as the anode and the copper-poor CuTe electrode produced in step (1) as the cathode, the solution in the anode chamber containing the copper-rich Cu₂Te electrode was replaced with 100 ml of fresh sodium sulfate solution as the conducting electrolyte solution (the concentration of sulfate ions was 2.0 mol / L), and the solution in the cathode chamber containing the copper-poor CuTe electrode was replaced with 100 ml of copper-containing wastewater (the concentration of copper(II) ions was 10 mg / L). The power supply was reconnected, and the process of step (1) was repeated, with the switch-on voltage being 1 V. The anode copper was removed, and the cathode was embedded in copper.The treated wastewater in the cathode chamber was continuously replaced with fresh copper-containing wastewater to enrich it with copper(II) ions. After enrichment, a highly concentrated copper solution (10,000 mg / L) was obtained in the anode chamber. The copper(II) ions in the copper-containing wastewater flowing into the cathode chamber were selectively adsorbed onto the cathode material, thereby extracting copper from the copper-containing wastewater. Simultaneously, the electrode regeneration cycle was completed. (3) After completion of step (1) or (2), the highly concentrated copper solution in the anode chamber was collected after enrichment, purified, and used in the electrolytic refining of crude copper to obtain high-purity electrolytic copper with a purity of more than 99%.

[0064] In step (1) the CuTe electrode was produced by mixing CuTe, graphite and PVDF binder in a mass ratio of 9:2:1, and the Cu2Te electrode was produced by mixing Cu2Te, graphite and PVDF binder in a mass ratio of 9:2:1, and the specific manufacturing process is the same as in embodiment 2.

[0065] The copper-containing wastewater has a pH value of 5.

[0066] Embodiment 11 uses a CuTe|Cu2Te electrode pair to construct an electrochemical device for treating integrated copper-containing wastewater from printed circuit board production and can simultaneously perform the copper embedding and copper removal processes. At the same time, by interchanging the positive and negative electrodes of the power supply and adjusting the solutions in the cathode and anode chambers, the electrode regeneration and copper extraction processes are synchronized, significantly improving the efficiency of copper-containing wastewater treatment. In Embodiment 11, the removal rate of copper(II) ions reached 99%, and the desorption rate of the electrode regeneration process of the second treatment in step (2) reached 96.2%, with a good regeneration effect of the electrode cycle. Step (2) was repeated 15 times, i.e., the 17th processing cycle was performed.After 16 electrode regenerations, the concentration of copper(II) ions in the copper-containing wastewater in the cathode chamber decreased from 10 mg / L to 0.62 mg / L, the copper(II) ion removal rate was 93.8%, and the target removal rate for copper(II) ions in the copper-containing wastewater was still achieved. Simultaneously, after 16 regenerations, the anode chamber still contained a highly concentrated copper solution of 9.26 mg / L, and the desorption rate reached 92.6%, indicating a good regeneration effect of the electrode cycle.

[0067] In embodiments 6 to 11, a copper-based sulfur compound was used as the counter electrode and the electrodialysis reaction device was assembled with an anion exchange membrane and a power supply.The active materials of the cathode and anode of the reaction device are both copper-based sulfur compounds, so that the removal of the anode copper and the embedding of the cathode copper are carried out simultaneously to increase the processing speed; and by exchanging the positive and negative electrodes of the power supply and adjusting the solutions in the cathode and anode chambers, the electrode regeneration and copper extraction processes are synchronized to achieve continuous treatment of copper-containing wastewater, thereby significantly improving the efficiency of copper extraction; at the same time, the electrode regeneration process significantly extends the lifespan of the electrode and reduces costs.The electrodialysis reaction device and the method of embodiments 6-11 can be used for the treatment of actual wastewater, exhibit a high removal rate and selectivity for copper(II) ions in the wastewater, and show good application effects; in addition, by setting up an integrated device, copper(II) ions can be concentrated to a concentration of 10,000 mg / L during the treatment of copper-containing wastewater, which can then be used for roughening and refining to high-purity electrolytic copper.

[0068] In summary, the present invention uses copper-based sulfur compounds as electrode material and forms an electrochemical device with other electrodes, wherein the device is an electrocatalytically coupled deionization system with electrochemical oxidation and complexation breaking properties and has a good effect in the selective removal of copper(II) ions from organic, complex copper-containing wastewaters, strongly acidic wastewaters and wastewaters disturbed by a high concentration of salt ions and heavy metal ions;The present invention furthermore uses copper-based sulfur compounds as active cathode and anode materials to form a counter electrode, which is assembled with an anion exchange membrane and a power supply to form an electrodialysis reaction device. It can simultaneously perform copper removal and copper embedding reactions at a lower voltage and a wider pH range. In combination with the electrode regeneration step, the copper extraction process can be carried out continuously, thereby significantly improving the copper extraction efficiency and resulting in high removal efficiency and selectivity of copper(II) ions in copper-containing wastewater.

[0069] The present invention has been further described above with reference to specific embodiments. However, it should be clear that the specific description here should not be interpreted as limiting the nature and scope of the present invention. Various modifications that general technical personnel make to the above embodiments after reading this description fall within the scope of protection of the present invention.

Claims

[1] Electrochemical device for extracting copper from copper-containing wastewater, characterized by , that the anode material of the electrochemical device consists of activated carbon, graphite, lead dioxide, BDD and Cu m X 1-a-b Y a Z b is; the cathode material of a Cu n X 1-c-d Y c Z d and is a carbon and selenium complex material, and the cathode and anode are connected to a power supply for the treatment of copper-containing wastewater; where 1 < m ≤ 2, 1 ≤ n < 2 and m > n; 0 ≤ a ≤ 1, 0 ≤ b ≤ 1 and 0 ≤ a + b ≤ 1; 0 ≤ c ≤ 1, 0 ≤ d ≤ 1 and 0 ≤ c + d ≤ 1; and X, Y and Z are selected from one of S, Se and Te. [2] Electrochemical device for extracting copper from copper-containing wastewater according to claim 1, characterized by, that the anode material of the electrochemical device is one of activated carbon, graphite, lead dioxide and BDD material; and the cathode material is one of copper selenide, copper selenide sulfide and carbon-selenium complex material, and that the anode and the cathode are connected to a power supply and are subjected to a direct current of 0.6-4.0 V, and that the device is used for the treatment of acidic electroplating wastewater containing Cu-EDTA. [3] Electrochemical device for extracting copper from copper-containing wastewater according to claim 2, characterized by , that the copper selenide material is produced as follows: Dissolving selenium powder in hydrazine hydrate with stirring to obtain mixture A; mixing ethanol and water in equal proportions and adding anhydrous copper chloride with stirring to obtain mixture B; mixing A and B with stirring to obtain the mixture, and placing the mixture in an oven and increasing the temperature to 150-200°C and carrying out the reaction for 20-30 hours to obtain a crude copper selenide product. [4] Electrochemical device for extracting copper from copper-containing wastewater according to claim 3, characterized by , that the molar ratio of selenium powder and anhydrous copper chloride is 1:

1. [5] Electrochemical device for extracting copper from copper-containing wastewater according to claim 2, characterized by , that the cathode electrode is obtained by the following procedure: Uniform mixing of conductive carbon black and copper selenide material, then addition to a solvent for stirring, addition of a binder and further stirring until a uniform mixture is obtained; use of the resulting mixture, which is coated onto graphite paper, and drying of the coated graphite paper at 60°C overnight to finally obtain a cathode electrode with copper selenide as the active substance. [6] Electrochemical device for extracting copper from copper-containing wastewater according to claim 2, characterized by , that the anode electrode is obtained by the following procedure: Uniform mixing of conductive carbon black and activated carbon material, then addition to a solvent for stirring, addition of a binder and then further stirring until a uniform mixture is obtained; use of the resulting mixture to coat a graphite paper and drying of the coated graphite paper overnight at 60°C to finally obtain an anode electrode. [7] Electrochemical device for extracting copper from copper-containing wastewater according to claim 1, characterized by that the electrochemical device also includes an anion exchange membrane. [8] Methods for extracting copper from copper-containing wastewater, characterized by , that the electrochemical device according to one of claims 1 to 7 is used for the extraction of copper from copper-containing wastewater by an electrochemical process. [9] Method for extracting copper from copper-containing wastewater according to claim 8, characterized by that the procedure includes the following steps: (1) synchronous execution of the copper embedding and copper removal process: application of an electrodialysis reactor mode using a Cu m X 1-a-b Y a Z b -electrode as anode and a Cu n X 1-c-d YcZ d - Electrode as cathode and separation of the anode and the cathode with an anion exchange membrane, wherein the anode chamber is added to a conducting salt solution and the cathode chamber is added to the copper-containing wastewater to be processed; after the current is applied, a copper-rich electrode forms at the cathode and simultaneously a copper-poor electrode forms at the anode; a highly concentrated copper-containing solution is obtained in the anode chamber, and the copper ions (II) of the copper-containing wastewater in the cathode chamber are selectively adsorbed onto the cathode material; (2) Regeneration process: after completion of the reaction in step (1), the positive and negative electrodes of the power supply are reversed, and the electrode exchange is carried out; the solution in the anode chamber after the electrode exchange is replaced with fresh conducting salt solution, and the solution in the cathode chamber after the electrode exchange is replaced with the copper-containing wastewater, and then the power supply is switched on again to carry out the anodic copper removal and cathodic embedding to realize the extraction of copper in the copper-containing wastewater, and in the meantime to complete the cyclic regeneration of the electrodes; where 1 < m ≤ 2, 1 ≤ n < 2 and m > n; 0 ≤ a ≤ 1, 0 ≤ b ≤ 1 and 0 ≤ a + b ≤ 1; 0 ≤ c ≤ 1, 0 ≤ d ≤ 1 and 0 ≤ c + d ≤ 1; and X, Y and Z are selected from one of S, Se and Te. [10] Method for extracting copper from copper-containing wastewater according to claim 9, characterized bythat the procedure includes the following steps: (1) Synchronous execution of the copper embedding and copper removal process: application of an electrodialysis reactor mode using a Cu2Se electrode as the anode and a CuSe electrode as the cathode, and separation of the anode and cathode with an anion exchange membrane, wherein the anode chamber is added to a conducting salt solution and the cathode chamber is added to a copper-containing wastewater solution to be processed; after the current is applied, the copper-containing wastewater is introduced into the cathode chamber; copper(II) ions are embedded in the cathode material to form a copper-rich Cu2Se electrode; simultaneously, Cu2Se, as the active anode material, loses copper(I) ions and becomes a copper-rich CuSe electrode; a highly concentrated copper-containing solution is obtained in the anode chamber, and the copper(II) ions of the copper-containing wastewater in the cathode chamber are selectively adsorbed onto the cathode material. (2) Regeneration process: After completion of the reaction in step (1), the positive and negative electrodes of the power supply are exchanged, with the copper-rich Cu2Se electrode produced in step (1) serving as the anode and the copper-poor CuSe electrode produced in step (1) serving as the cathode, and the solution in the anode chamber containing the copper-rich Cu2Se electrode is replaced by a fresh conducting salt solution, and the solution in the cathode chamber containing the copper-poor CuSe electrode is replaced by the copper-containing wastewater, and then the power supply is switched on again to carry out the anodic copper removal and cathodic embedding to realize the extraction of copper in the copper-containing wastewater, and in the meantime the cyclic regeneration of the electrodes is completed. [11] Method for extracting copper from copper-containing wastewater according to claim 9 or 10, characterized by, that after completion of step (1) or (2) the highly concentrated copper-containing solution is collected in the anode chamber, decontaminated and then used for the electrolytic refining of crude copper. [12] Method for extracting copper from copper-containing wastewater according to claim 11, characterized by , that the concentration of copper(II) ions in the highly concentrated copper-containing solution is above 10,000 mg / L and that the method for removing impurities is electrolysis. [13] Method for extracting copper from copper-containing wastewater according to claim 9 or 10, characterized by , that in steps (1) and (2) the excitation voltage is 0.1-1.4 V and the excitation time is 60-180 min. [14] Method for extracting copper from copper-containing wastewater according to claim 10, characterized by, that in step (1) the Cu2Se electrode is produced by mixing Cu2Se, conductive carbon material and binder PVDF in a mass ratio of 7-9: 2-0.5: 1-0.

5. [15] Method for extracting copper from copper-containing wastewater according to claim 10, characterized by , that in step (1) the CuSe electrode is produced by mixing CuSe, conductive carbon material and binder PVDF in the mass ratio 7-9: 2-0.5: 1-0.

5. [16] Method for extracting copper from copper-containing wastewater according to claim 14 or 15, characterized by , that the conductive carbon material is selected from one or more of the substances acetylene carbon black, carbon nanotubes, graphene, graphite and carbon fibers. [17] Method for extracting copper from copper-containing wastewater according to claim 9 or 10, characterized by, that in step (1) and step (2) the conducting salt solution is a sulfate solution or a chloride salt solution and the sulfate concentration in the sulfate solution is 0.1-2 mol / L and the chloride ion concentration in the chloride salt solution is 0.1-2 mol / L. [18] Method for extracting copper from copper-containing wastewater according to claim 9 or 10, characterized by that step (2) is repeated 10-20 times. [19] Method for extracting copper from copper-containing wastewater according to any one of claims 8 to 10, characterized by , that the copper-containing wastewater is one of the following: acidic wastewater from electroplating, integrated wastewater from printed circuit board printing, copper-containing wastewater from copper smelting and copper-containing wastewater after network interruption. [20] Method for extracting copper from copper-containing wastewater according to claim 19, characterized by, that the concentration of copper(II) ions in the copper-containing wastewater is 0.5-10000 mg / L; the pH value of the copper-containing wastewater is 0.1-5.0.

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