Copper sulfate wastewater treatment method and system

Abstract

The invention relates to a copper sulfate wastewater treatment method and system.The method comprises the steps that copper sulfate wastewater is pretreated, and a target treatment object with the molecular weight within a preset range is obtained; a catalyst is added into the target treatment object for a reaction, and the molar ratio of the target treatment object to the catalyst is 100: (0.5-1); carrying out reduced pressure distillation on a reactant of the catalytic reaction to obtain a distillate; checking the content of copper sulfate water and the content of hydrochloric acid in the distillate, and performing centrifugal separation when the content of the hydrochloric acid in the distillate is smaller than a first preset content and the content of the copper sulfate water is smaller than a second preset content to obtain copper sulfate crystals; wherein the catalyst is prepared from the following components in parts by mass: 0.05 to 0.1 part of N, N-dimethylformamide, 0.15 to 0.2 part of cationic polyacrylamide and 0.15 to 0.2 part of Al2 (OH) m (SO4) 3] n.

Description

Technical Field

[0001] This invention relates to the field of copper sulfate wastewater treatment technology, and in particular to a method and system for treating copper sulfate wastewater. Background Technology

[0002] The production of sodium saccharin generates wastewater containing copper sulfate and organic matter (such as toluene derivatives), which requires careful treatment. In the high-purity copper industry, wastewater containing copper nitrate and copper sulfate is a common pollutant. Direct discharge of this wastewater without treatment will severely pollute water bodies, impacting the ecological environment and human health. Therefore, developing effective treatment methods is of paramount importance.

[0003] The related technology provides a method for treating copper sulfate wastewater, including: Step 1, Pretreatment: Filtering copper nitrate and copper sulfate wastewater separately, and collecting the filtrates into reaction tanks A and B respectively; Step 2, Adding flocculant: Adding flocculant to the reaction tanks for copper nitrate and copper sulfate; Step 3, Optimizing pH value of the reaction tank: Monitoring the pH value of the reaction tanks during the reaction process with online monitoring instruments and adjusting the pH value in real time; Step 4, Complex breaking: Adding hydrogen peroxide to reaction tank A to break the complexed copper, converting it into Cu2+, and using the supernatant as effluent; Step 5, Conversion: Treating the copper nitrate and copper sulfate wastewater from reaction tanks A and B separately using diffusion dialysis technology; Step 6, Advanced treatment: Using active... The process involves several steps: Step 7, Sludge Stabilization: Stabilizing the sludge produced from the advanced treatment; Step 8, Sludge Washing: Washing the sludge eight times with circulating water; Step 9, Sludge Composting: Converting the stabilized sludge into organic fertilizer through composting technology; Step 10, Heavy Metal Recovery: Leaching technology utilizes the interaction between microorganisms or their metabolites and metals in the sludge to leach valuable metals; Step 11, Final Treatment: Neutralizing the treated wastewater before discharging it into a comprehensive wastewater pond; Step 12, Recycling: Electrolyzing the recovered copper to produce 98% pure copper products.

[0004] However, the above methods have low resource recovery rates, high impurities in hydrochloric acid recovery, low purity, complex processes, are environmentally unfriendly, and have high technical costs.

[0005] In view of the shortcomings of existing copper sulfate wastewater treatment methods, the inventor, based on years of practical experience and professional knowledge in the design and manufacture of such products, and in conjunction with theoretical application, actively researched and innovated to create a new copper sulfate wastewater treatment method that can improve upon existing methods and make them more practical. Through continuous research, design, and repeated trials and improvements, this invention, with proven practical value, was finally created. Summary of the Invention

[0006] The main objective of this invention is to overcome the shortcomings of existing copper sulfate wastewater treatment methods and provide a new method for treating copper sulfate wastewater. The technical problem to be solved is that it can address the issues of low resource recovery rate, high impurities in hydrochloric acid recovery rate, low purity, complex process flow, environmental unfriendliness, and high technical cost, thus making it more practical and industrially valuable.

[0007] On the one hand, a method for treating copper sulfate wastewater is provided, the method comprising:

[0008] Copper sulfate wastewater is pretreated to obtain the target analyte with a molecular weight within a preset range;

[0009] A catalyst is added to the target material for reaction, wherein the molar ratio of the target material to the catalyst is 100:0.5 to 1;

[0010] The reactants of the catalytic reaction were subjected to vacuum distillation to obtain the distillate.

[0011] The copper sulfate water content and hydrochloric acid content of the distillate are tested. When the hydrochloric acid content in the distillate is less than a first preset content and the copper sulfate water content is less than a second preset content, centrifugation is performed to obtain copper sulfate crystals.

[0012] The catalyst comprises 0.05-0.1 parts by weight of N,N-dimethylformamide, 0.15-0.2 parts by weight of cationic polyacrylamide, and 0.15-0.2 parts by weight of Al2(OH). m [(SO4)3]n.

[0013] In one optional embodiment, the copper sulfate wastewater is pretreated, including:

[0014] Copper sulfate wastewater was filtered using an aluminum membrane with a diameter of 0.5μm to 1μm to retain organic matter with a molecular weight greater than 500Da, resulting in a target treated product with a molecular weight less than 500Da and a molecular particle size of 100μm > 10μm.

[0015] In one optional embodiment, the reactants of the catalytic reaction are distilled for 10 to 20 minutes under a vacuum of 0.15 MPa to 0.35 MPa and a vacuum of -0.086 MPa or higher, so that the temperature rises to 85° to 90°, and then cooled with water at -15° to 17°.

[0016] Adjust the steam pressure to 0.18 MPa and perform vacuum distillation for 1.5 to 2 hours to obtain the distillate.

[0017] In one optional implementation, the first preset content is 15% to 18%, and the second preset content is 30% to 35%.

[0018] In one alternative embodiment, the step of adding a catalyst to the target processed material includes:

[0019] N,N-dimethylformamide was added to the target material to degrade organic matter. The reaction was carried out for 20-30 minutes. When the pH value of the reaction reached 4-5, cationic polyacrylamide was added.

[0020] A composite system of polyaluminum sulfate and cationic polyacrylamide was added to catalyze the reaction.

[0021] In one optional embodiment, the molecular weight of the cationic polyacrylamide includes a first molecular weight gradient and a second molecular weight gradient, wherein the molecular weight of the first molecular weight gradient is less than the molecular weight of the second molecular weight gradient.

[0022] When the pH value of the reaction reaches 4-5, cationic polyacrylamide with a first molecular weight gradient is added;

[0023] The composite system of added polyaluminum sulfate and cationic polyacrylamide with a second molecular weight gradient is used for catalytic reaction.

[0024] In one alternative embodiment, the molecular weight of the first molecular weight gradient is 3-5 million, and the molecular weight of the second molecular weight gradient is 12-15 million.

[0025] In one alternative implementation, the Al2(OH) m The particle size of (SO4)3]n is 10 nm to 50 nm.

[0026] In one optional embodiment, the catalyst further includes mesoporous silica with a pore size of 3 nm to 5 nm.

[0027] On the other hand, a copper sulfate wastewater treatment system is provided, wherein the copper sulfate wastewater treatment system is used to treat the copper sulfate wastewater using any of the methods described above.

[0028] Compared with the prior art, the present invention has significant advantages and beneficial effects. As can be seen from the above technical solution, in order to achieve the aforementioned objectives, the main technical contents of the present invention are as follows:

[0029] By employing the above technical solution, the copper sulfate wastewater treatment method of the present invention has at least the following advantages:

[0030] The copper sulfate wastewater treatment method provided in this invention can retain large molecular organic matter through a pretreatment step to obtain the target copper sulfate wastewater to be treated; and promotes the copper sulfate treatment through a catalytic reaction of DFM (N,N-dimethylformamide) to enhance the copper sulfate content. 2+ Upon coordination dissociation with organic matter, polyaluminum sulfate (PAS) and CPAM form a three-dimensional network structure, adsorbing Cu(OH)₂ colloidal particles. Furthermore, N,N-dimethylformamide in the catalyst acts as an organic solvent to promote the decomposition of macromolecular organic matter, while also serving as a carrier to enhance the dispersibility of other catalytic components. Cationic polyacrylamide, through its cationic properties, adsorbs negatively charged colloidal particles, forming a "bridging" effect to accelerate flocculation. [Al₂(OH)₂] m [SO4)3]n (polyaluminum sulfate): Hydrolysis generates [Al(OH)3]+ colloids, which neutralize the surface charge of particles, achieving coagulation and precipitation. Hydrochloric acid is generated through vacuum distillation, and copper sulfate crystals are separated by centrifugation, thus treating copper sulfate wastewater.

[0031] The method provided in this invention achieves a copper ion recovery rate of up to 99.5% through the synergistic effect of catalysts (DFM promotes organic matter decomposition, CPAM adsorbs colloidal particles, and polyaluminum sulfate enhances coagulation). By catalytically decomposing organic matter such as o-benzenesulfinyl chloride using DFM, the COD removal rate is increased to 35%, while the decomposition products (such as benzenesulfonic acid derivatives) are reused as chemical intermediates, solving the problem of ash residue generated from organic matter incineration in existing technologies. The copper salt concentration and separation are completed in three stages: catalysis, distillation, and centrifugation, eliminating complex processes such as neutralization precipitation, electrodeposition, or multiple crystallization in traditional processes. This reduces equipment investment, is environmentally friendly, and has low processing costs.

[0032] In summary, the unique copper sulfate wastewater treatment method of this invention can solve the technical problems of low resource recovery rate, high impurity and low purity in hydrochloric acid recovery, complex process flow, environmental unfriendliness, and high technical cost, thus making it more suitable for practical application and possessing industrial utilization value. It possesses numerous advantages and practical value, and is truly innovative as no similar design has been publicly disclosed or used in similar copper sulfate wastewater treatment methods. It represents a significant improvement in both the method and function of copper sulfate wastewater treatment, demonstrating substantial technological progress and producing user-friendly and practical effects. Furthermore, it offers several enhanced functions compared to existing copper sulfate wastewater treatment methods, making it more suitable for practical application and possessing broad industrial utilization value. It is indeed a novel, progressive, and practical new design.

[0033] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0034] The specific copper sulfate wastewater treatment method of the present invention is given in detail in the following embodiments and accompanying drawings. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the copper sulfate wastewater treatment method provided in an embodiment of the present invention. Detailed Implementation

[0036] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description of the specific implementation method and effects of the copper sulfate wastewater treatment method proposed according to the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0037] The copper sulfate wastewater to be treated in this embodiment of the invention can be copper sulfate wastewater generated during the production of sodium saccharin.

[0038] Please see Figure 1 The preferred embodiment of the copper sulfate wastewater treatment method of the present invention mainly includes the following steps: step S101, step S102, step S103 and step S104.

[0039] Step S101: Pre-treat the copper sulfate wastewater to obtain the target analyte with a molecular weight within a preset range.

[0040] Step S102: Add a catalyst to the target material for reaction, wherein the molar ratio of the target material to the catalyst is 100:0.5-1.

[0041] Step S103: Perform vacuum distillation on the reactants of the catalytic reaction to obtain the distillate.

[0042] Step S104: Test the copper sulfate water content and hydrochloric acid content of the distillate. When the hydrochloric acid content in the distillate is less than the first preset content and the copper sulfate water content is less than the second preset content, centrifuge to obtain copper sulfate crystals.

[0043] The catalyst comprises 0.05-0.1 parts by weight of N,N-dimethylformamide, 0.15-0.2 parts by weight of cationic polyacrylamide, and 0.15-0.2 parts by weight of Al2(OH). m [(SO4)3]n.

[0044] By employing the above technical solution, the copper sulfate wastewater treatment method of the present invention has at least the following advantages:

[0045] The copper sulfate wastewater treatment method provided in this invention can retain large molecular organic matter through a pretreatment step to obtain the target copper sulfate wastewater to be treated; and promotes the copper sulfate treatment through a catalytic reaction of DFM (N,N-dimethylformamide) to enhance the copper sulfate content.2+ Upon coordination dissociation with organic matter, polyaluminum sulfate (PAS) and CPAM form a three-dimensional network structure, adsorbing Cu(OH)₂ colloidal particles. Furthermore, N,N-dimethylformamide in the catalyst acts as an organic solvent to promote the decomposition of macromolecular organic matter, while also serving as a carrier to enhance the dispersibility of other catalytic components. Cationic polyacrylamide, through its cationic properties, adsorbs negatively charged colloidal particles, forming a "bridging" effect to accelerate flocculation. [Al₂(OH)₂] m [SO4)3]n (polyaluminum sulfate): Hydrolysis generates [Al(OH)3]+ colloids, which neutralize the surface charge of particles, achieving coagulation and precipitation. Hydrochloric acid is generated through vacuum distillation, and copper sulfate crystals are separated by centrifugation, thus treating copper sulfate wastewater.

[0046] The method provided in this invention achieves a copper ion recovery rate of up to 99.5% through the synergistic effect of catalysts (DFM promotes organic matter decomposition, CPAM adsorbs colloidal particles, and polyaluminum sulfate enhances coagulation). By catalytically decomposing organic matter such as o-benzenesulfinyl chloride using DFM, the COD removal rate is increased to 35%, while the decomposition products (such as benzenesulfonic acid derivatives) are reused as chemical intermediates, solving the problem of ash residue generated from organic matter incineration in existing technologies. The copper salt concentration and separation are completed in three stages: catalysis, distillation, and centrifugation, eliminating complex processes such as neutralization precipitation, electrodeposition, or multiple crystallization in traditional processes. This reduces equipment investment, is environmentally friendly, and has low processing costs.

[0047] The method provided by the present invention will be further explained and described below through optional embodiments.

[0048] In step S101, the copper sulfate wastewater is pretreated to obtain the target analyte with a molecular weight within a preset range.

[0049] In one optional embodiment, the copper sulfate wastewater is pretreated by: filtering the copper sulfate wastewater with an aluminum membrane with a diameter of 0.5 μm to 1 μm to retain organic matter with a molecular weight greater than 500 Da, thereby obtaining a target treated material with a molecular weight less than 500 Da and a molecular particle size of 100 μm > 10 μm.

[0050] For example, copper sulfate wastewater is filtered using aluminum membranes with diameters of 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, or 1 μm, etc., to retain organic matter with a molecular weight greater than 500 Da, resulting in a product with a molecular weight less than 500 Da and a particle size of 100 μm > 10 μm. For example, target treated products with molecular particle sizes of 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, or 65 μm.

[0051] Step S102: Add a catalyst to the target material for reaction, wherein the molar ratio of the target material to the catalyst is 100:0.5 to 1. For example, the molar ratio of the target material to the catalyst can be 100:0.5, 100:0.6, 100:0.7, 100:0.8, 100:0.9, or 100:1.0, etc.

[0052] In step S103, the reactants of the catalytic reaction are subjected to vacuum distillation to obtain the distillate.

[0053] In one optional embodiment, the reactants of the catalytic reaction are distilled for 10 to 20 minutes under a vacuum of 0.15 MPa to 0.35 MPa and a vacuum of -0.086 MPa or higher, so that the temperature rises to 85° to 90°, and then cooled with water at -15° to 17°.

[0054] Furthermore, the reactants in the catalytic reaction can be distilled for 10, 15, or 20 minutes at steam pressures of 0.15 MPa, 0.16 MPa, 0.17 MPa, 0.18 MPa, 0.19 MPa, 0.20 MPa, 0.21 MPa, 0.22 MPa, 0.23 MPa, 0.24 MPa, 0.3 MPa, 0.32 MPa, 0.33 MPa, and 0.35 MPa, with a vacuum degree of -0.086 MPa, to raise the temperature to 85°C, 86°C, 87°C, 88°C, 89°C, and 90°C, and then cooled with water at temperatures of -15°C, -14°C, -13°C, -12°C, -11°C, -10°C, -7°C, -5°C, -1°C, 1°C, 5°C, 8°C, 9°C, 10°C, 14°C, 16°C, and 17°C.

[0055] Adjust the steam pressure to 0.18 MPa and perform vacuum distillation for 1.5 to 2 hours to obtain the distillate. For example, adjust the steam pressure to 0.18 MPa and perform vacuum distillation for 1.5 or 2 hours to obtain the distillate.

[0056] In step S104, the copper sulfate water content and hydrochloric acid content of the distillate are tested. When the hydrochloric acid content in the distillate is less than the first preset content and the copper sulfate water content is less than the second preset content, centrifugation is performed to obtain copper sulfate crystals.

[0057] In one optional embodiment, the first preset content is 15% to 18%, and the second preset content is 30% to 35%. For example, the first preset content can be 15%, 16%, 17%, or 18%, and the second preset content can be 30%, 31%, 32%, 33%, 34%, or 35%.

[0058] For example, the catalyst may include 0.05 parts, 0.06 parts, 0.07 parts, 0.08 parts, 0.09 parts, or 0.1 parts by weight of N,N-dimethylformamide; 0.15 parts, 0.16 parts, 0.17 parts, 0.18 parts, 0.19 parts, or 0.2 parts by weight of cationic polyacrylamide; and 0.15 parts, 0.16 parts, 0.17 parts, 0.18 parts, 0.19 parts, or 0.2 parts by weight of Al2(OH). m [(SO4)3]n.

[0059] Preferably, the composition is N,N-dimethylformamide: cationic polyacrylamide: polyaluminum sulfate (Al2(OH)2) m (SO4)3]n)=1:3:4 (by mass ratio), and the total addition amount can be adjusted to 0.05:0.15:0.3 (by mass ratio) when the baseline of 100:0.5 is maintained.

[0060] In one optional embodiment, the step of adding a catalyst to the target material includes: adding N,N-dimethylformamide to the target material to degrade organic matter, reacting for 20-30 minutes, and adding cationic polyacrylamide when the reaction pH reaches 4-5; and adding a composite system of polyaluminum sulfate and cationic polyacrylamide to carry out a catalytic reaction.

[0061] First, N,N-dimethylformamide (DFM) (0.05%) is added to decompose organic matter, preferentially degrading macromolecular pollutants such as o-phenylenesulfinyl chloride through the π-π action of DFM. Then, a composite system of polyaluminum sulfate (0.2%) and CPAM (0.15%) is added, utilizing Al... 3+ The charge neutralization effect of Cu(OH)2 and the bridging effect of CPAM (with a molecular weight of 8-12 million) form flocs with a particle size of 50-200 nm, thereby improving the capture efficiency of Cu(OH)2 colloids.

[0062] In one optional embodiment, the molecular weight of the cationic polyacrylamide includes a first molecular weight gradient and a second molecular weight gradient, wherein the molecular weight of the first molecular weight gradient is smaller than that of the second molecular weight gradient; when the reaction pH reaches 4-5, the cationic polyacrylamide of the first molecular weight gradient is added; and a composite system of polyaluminum sulfate and cationic polyacrylamide of the second molecular weight gradient is added to carry out a catalytic reaction.

[0063] In one optional embodiment, the molecular weight of the first molecular weight gradient is 3-5 million, and the molecular weight of the second molecular weight gradient is 12-15 million. Exemplarily, the molecular weight of the first molecular weight gradient can be 3 million, 3.3 million, 3.6 million, 3.8 million, 4 million, 4.5 million, 4.8 million, or 5 million, etc., and the molecular weight of the second molecular weight gradient can be 12 million, 12.4 million, 13 million, 13.6 million, 14.4 million, 14.7 million, 14.8 million, or 15 million, etc.

[0064] In one alternative implementation, Al2(OH) m The particle size of [(SO4)3]n is 10nm to 50nm. For example, it can be 10nm, 20nm, 25nm, 30nm, 36nm, 40nm, 45nm or 50nm, etc.

[0065] In an optional embodiment, the catalyst further includes mesoporous silica with a pore size of 3 nm to 5 nm. By using mesoporous silica to support DFM, the molecular sieve effect is controlled, ensuring that the molecular weight of DFM (73.09 g / mol) matches the pore size of the support, thus preventing large organic molecules from clogging the active sites.

[0066] On the other hand, a copper sulfate wastewater treatment system is provided, wherein the copper sulfate wastewater treatment system uses any of the copper sulfate wastewater treatment methods described above for treatment.

[0067] The method provided by the present invention will be further explained and described below through specific embodiments.

[0068] Example 1

[0069] First, the copper sulfate wastewater generated during the sodium saccharin production process is collected into a 100 cubic meter PVC tank, and then pumped in for precision filtration.

[0070] The filtered copper sulfate solution was stored in a 150 cubic meter PVC tank, and the filtered solid o-phenylenesulfinyl chloride was injected into the production reactor. Then, a catalyst was added to the filtered copper sulfate solution at a ratio of 100:0.5 (catalyst: DFM (N,N-dimethylformamide) + CPAM (cationic polyacrylamide) + [Al2(OH)m(SO4)3]n). The amounts of DFM, CPAM, and [Al2(OH)m(SO4)3]n were 0.05 parts, CPAM, and [Al2(OH)m(SO4)3]n were 0.2 parts. N,N-dimethylformamide was added to the target material to degrade organic matter, and the reaction was allowed to proceed for 20-30 minutes. When the pH reached 4-5, cationic polyacrylamide was added; a composite system of polyaluminum sulfate and cationic polyacrylamide was then added to catalyze the reaction.

[0071] The copper sulfate solution with added catalyst is pumped into the resin circulation tower for circulation. After ten minutes, the bypass valve is opened, and the copper sulfate solution is pumped into the preheater, and then enters the vacuum distillation tower through the preheater.

[0072] Open the automatic steam regulating valve to maintain the steam pressure at 0.15 MPa, then turn on the vacuum pump to maintain the vacuum degree above -0.086 MPa. After ten minutes, the temperature will rise to 90°C. Then turn on the cooler to cool the inlet and outlet automatic regulating valve (cooling water temperature -15°C).

[0073] Open the automatic regulating valve of the hydrochloric acid receiving tank, and adjust the automatic steam valve to reach a pressure of 0.18 MPa for vacuum distillation. Distill for 1.5 hours, then take a sample of the hydrochloric acid from the receiving tube for analysis. Also, take a sample of the single-effect evaporated copper sulfate solution for analysis.

[0074] If the hydrochloric acid content is greater than or equal to 18% and the copper sulfate solution content is greater than or equal to 35%, close the automatic steam regulating valve and prepare to open the bypass valve for automatic discharge. If the copper sulfate solution content is less than 35%, continue evaporation.

[0075] An automatic centrifuge was used for centrifugation. The centrifuged mother liquor passed through a suspension device and entered a copper sulfate storage tank, while the centrifuged solids entered an automatic packaging system for packaging and warehousing. The copper sulfate crystal recovery rate was determined to be 98.7%.

[0076] Example 2

[0077] First, the copper sulfate wastewater generated during the sodium saccharin production process is collected into a 100 cubic meter PVC tank, and then pumped in for precision filtration.

[0078] The filtered copper sulfate solution was stored in a 150 cubic meter PVC tank, and the filtered solid o-phenylenesulfinyl chloride was injected into the production reactor. Then, a catalyst was added to the filtered copper sulfate solution at a ratio of 100:0.8 (catalyst: DFM (N,N-dimethylformamide) + CPAM (cationic polyacrylamide) + [Al2(OH)m(SO4)3]n). Specifically, DFM was 0.06 parts, CPAM was 0.2 parts, and [Al2(OH)m(SO4)3]n was 0.15 parts. N,N-dimethylformamide was added to the target material to degrade organic matter, and the reaction was allowed to proceed for 20-30 minutes. When the pH reached 4-5, cationic polyacrylamide was added; a composite system of polyaluminum sulfate and cationic polyacrylamide was then added to catalyze the reaction.

[0079] The copper sulfate solution with added catalyst is pumped into the resin circulation tower for circulation. After ten minutes, the bypass valve is opened, and the copper sulfate solution is pumped into the preheater, and then enters the vacuum distillation tower through the preheater.

[0080] Open the automatic steam regulating valve to maintain the steam pressure at 0.15 MPa, then turn on the vacuum pump to maintain the vacuum degree above -0.086 MPa. After ten minutes, the temperature will rise to 90°C. Then turn on the cooler to cool the inlet and outlet automatic regulating valve (cooling water temperature -10°C).

[0081] Open the automatic regulating valve of the hydrochloric acid receiving tank, and adjust the automatic steam valve to reach a pressure of 0.18 MPa for vacuum distillation. Distill for 1.5 hours, then take a sample of the hydrochloric acid from the receiving tube for analysis. Also, take a sample of the single-effect evaporated copper sulfate solution for analysis.

[0082] If the hydrochloric acid content is greater than or equal to 18% and the copper sulfate solution content is greater than or equal to 35%, close the automatic steam regulating valve and prepare to open the bypass valve for automatic discharge. If the copper sulfate solution content is less than 35%, continue evaporation.

[0083] An automatic centrifuge was used for centrifugation. The centrifuged mother liquor passed through a suspension unit and entered a copper sulfate storage tank, while the centrifuged solids entered an automatic packaging system for packaging and warehousing. The copper sulfate crystal recovery rate was determined to be 98.8%.

[0084] Example 3

[0085] First, the copper sulfate wastewater generated during the sodium saccharin production process is collected into a 100 cubic meter PVC tank, and then pumped in for precision filtration.

[0086] The filtered copper sulfate solution was stored in a 150 cubic meter PVC tank, and the filtered solid o-phenylenesulfinyl chloride was injected into the production reactor. Then, a catalyst was added to the filtered copper sulfate solution at a ratio of 100:1 (catalyst: DFM (N,N-dimethylformamide) + CPAM (cationic polyacrylamide) + [Al2(OH)m(SO4)3]n). The amounts of DFM, CPAM, and [Al2(OH)m(SO4)3]n were 0.08 parts, CPAM, and [Al2(OH)m(SO4)3]n were 0.2 parts. N,N-dimethylformamide was added to the target material to degrade organic matter, and the reaction was allowed to proceed for 20-30 minutes. When the pH reached 4-5, cationic polyacrylamide was added; a composite system of polyaluminum sulfate and cationic polyacrylamide was then added to catalyze the reaction.

[0087] The copper sulfate solution with added catalyst is pumped into the resin circulation tower for circulation. After ten minutes, the bypass valve is opened, and the copper sulfate solution is pumped into the preheater, and then enters the vacuum distillation tower through the preheater.

[0088] Open the automatic steam regulating valve to maintain the steam pressure at 0.15 MPa, then turn on the vacuum pump to maintain the vacuum degree above -0.086 MPa. After ten minutes, the temperature will rise to 90°C. Then turn on the cooler to cool the inlet and outlet automatic regulating valve (cooling water temperature -15°C).

[0089] Open the automatic regulating valve of the hydrochloric acid receiving tank, and adjust the automatic steam valve to reach a pressure of 0.18 MPa for vacuum distillation. Distill for 1.5 hours, then take a sample of the hydrochloric acid from the receiving tube for analysis. Also, take a sample of the single-effect evaporated copper sulfate solution for analysis.

[0090] If the hydrochloric acid content is greater than or equal to 18% and the copper sulfate solution content is greater than or equal to 35%, close the automatic steam regulating valve and prepare to open the bypass valve for automatic discharge. If the copper sulfate solution content is less than 35%, continue evaporation.

[0091] An automatic centrifuge was used for centrifugation. The centrifuged mother liquor passed through a suspension unit and entered a copper sulfate storage tank, while the centrifuged solids entered an automatic packaging system for packaging and warehousing. The copper sulfate crystal recovery rate was determined to be 98.3%.

[0092] Comparative Example

[0093] Step 1: Filter the copper nitrate and copper sulfate wastewater separately and collect the filtrates into reaction tanks A and B respectively. Step 2: Add flocculant: Add flocculant to the reaction tanks containing copper nitrate and copper sulfate. Step 3: Optimize the pH value of the reaction tanks: Monitor the pH value of the reaction tanks online and adjust the pH value in real time. Step 4: Break the complex: Add hydrogen peroxide to reaction tank A to break the complexed copper and convert it into Cu2+. The supernatant is used as the effluent. Step 5: Conversion: Treat the copper nitrate and copper sulfate wastewater from reaction tanks A and B respectively using diffusion dialysis technology. Step 6: Advanced treatment: Use activated carbon adsorption and reverse osmosis separation technology. The process further removes residual copper ions; Step 7, sludge stabilization treatment: The sludge produced from the deep treatment is stabilized; Step 8, sludge washing: The sludge is washed 8 times with circulating water; Step 9, sludge composting: Based on sludge stabilization, the sludge is converted into organic fertilizer through composting technology; Step 10, heavy metal recovery: Bioleaching technology uses microorganisms or their metabolites to leach valuable metals from the sludge through interaction with them; Step 11, final treatment: The treated wastewater is neutralized and then discharged into a comprehensive wastewater pond; Step 12, recycling: The recovered copper is electrolyzed to produce copper products with 98% purity.

[0094] Experiments have shown that the copper sulfate wastewater treated by the methods provided in Examples 1-3 of this invention has a lower cost and a copper sulfate crystal recovery rate of over 98%, which is far higher than the accuracy of the methods provided in the comparative examples.

[0095] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the methods and techniques disclosed above without departing from the scope of the present invention to create equivalent embodiments. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for treating copper sulfate wastewater, characterized in that, The method includes: Copper sulfate wastewater is pretreated to obtain the target analyte with a molecular weight within a preset range; A catalyst is added to the target material for reaction, wherein the molar ratio of the target material to the catalyst is 100:0.5 to 1; The reactants of the catalytic reaction were subjected to vacuum distillation to obtain the distillate. The copper sulfate water content and hydrochloric acid content of the distillate are tested. When the hydrochloric acid content in the distillate is less than a first preset content and the copper sulfate water content is less than a second preset content, centrifugation is performed to obtain copper sulfate crystals. The catalyst comprises 0.05-0.1 parts by weight of N,N-dimethylformamide, 0.15-0.2 parts by weight of cationic polyacrylamide, and 0.15-0.2 parts by weight of Al2(OH). m (SO4)3] n .

2. The method for treating copper sulfate wastewater according to claim 1, characterized in that, Pretreatment of copper sulfate wastewater includes: Copper sulfate wastewater was filtered using an aluminum membrane with a diameter of 0.5μm to 1μm to retain organic matter with a molecular weight greater than 500Da, resulting in a target treated product with a molecular weight less than 500Da and a molecular particle size of 100μm > 10μm.

3. The method for treating copper sulfate wastewater according to claim 1, characterized in that, The reactants of the catalytic reaction were distilled for 10 to 20 minutes under a vacuum of 0.15 MPa to 0.35 MPa and a vacuum of -0.086 MPa or higher, so that the temperature rose to 85° to 90° and then cooled with water at -15° to 17°. Adjust the steam pressure to 0.18 MPa and perform vacuum distillation for 1.5 to 2 hours to obtain the distillate.

4. The method for treating copper sulfate wastewater according to claim 1, characterized in that, The first preset content is 15% to 18%, and the second preset content is 30% to 35%.

5. The method for treating copper sulfate wastewater according to claim 1, characterized in that, The step of adding a catalyst to the target material for reaction includes: N,N-dimethylformamide was added to the target material to degrade organic matter. The reaction was carried out for 20-30 minutes. When the pH value of the reaction reached 4-5, cationic polyacrylamide was added. A composite system of polyaluminum sulfate and cationic polyacrylamide was added to catalyze the reaction.

6. The method for treating copper sulfate wastewater according to claim 5, characterized in that, The molecular weight of the cationic polyacrylamide includes a first molecular weight gradient and a second molecular weight gradient, wherein the molecular weight of the first molecular weight gradient is less than the molecular weight of the second molecular weight gradient. When the pH value of the reaction reaches 4-5, cationic polyacrylamide with a first molecular weight gradient is added; The composite system of added polyaluminum sulfate and cationic polyacrylamide with a second molecular weight gradient is used for catalytic reaction.

7. The method for treating copper sulfate wastewater according to claim 6, characterized in that, The molecular weight of the first molecular weight gradient is 3-5 million, and the molecular weight of the second molecular weight gradient is 12-15 million.

8. The method for treating copper sulfate wastewater according to claim 1, characterized in that, The Al2(OH) m The particle size of (SO4)3]n is 10 nm to 50 nm.

9. The method for treating copper sulfate wastewater according to claim 1, characterized in that, The catalyst also includes mesoporous silica, the pore size of which is 3 nm to 5 nm.

10. A copper sulfate wastewater treatment system, characterized in that, The copper sulfate wastewater treatment system uses the copper sulfate wastewater treatment method according to any one of claims 1 to 9 for treatment.

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