Method for removing organic pollutants from water bodies using copper ion-activated percarbonate

Abstract

The application discloses a method for removing organic pollutants in water bodies by using copper ion activated percarbonate, and comprises the following steps: mixing divalent copper ions, percarbonate and water bodies containing organic pollutants to perform a degradation reaction, and completing degradation of the organic pollutants in the water bodies. According to the method, the divalent copper ions, the percarbonate and the water bodies containing the organic pollutants are directly mixed, the initial concentration of the divalent copper ions in the system is controlled to be 15-120 muM, and the initial concentration of the percarbonate is greater than or equal to 0.2 mM, so that the divalent copper ions can efficiently activate the percarbonate and form more trivalent copper and carbonate radicals, and then the trivalent copper and the carbonate radicals can be used to efficiently degrade the organic pollutants in the water bodies. The method has the advantages of simple process, convenient operation, low cost, strong practicability, wide adaptability, high treatment efficiency, good degradation effect, environmental protection and the like, and has high use value and good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of advanced oxidation treatment of organic pollutants, and specifically relates to a method for removing organic pollutants from water by activating percarbonate with copper ions. Background Technology

[0002] Organic pollutants are common, fundamental, and difficult-to-treat pollutants in industrial wastewater, exhibiting a wide variety and complexity, such as dyes and antibiotics. Dye wastewater accounts for 17%-20% of total industrial wastewater and is among the most difficult to decompose, characterized by high chroma, high biochemical oxygen demand (BOD), and high dissolved solids content. In practical applications, due to the need to maintain the color and structural integrity of dyes, most dyes exhibit strong resistance to biodegradation and low biodegradability. Dyes in dye wastewater often possess certain toxicity, even causing mutagenicity and carcinogenicity, which can seriously harm humans and aquatic organisms. Azo dyes, such as Acid Orange (AO7), are the most commonly used dyes in textiles, paper, food, and printing, characterized by low biodegradability and high ecotoxicity. In particular, they readily transform into dangerous aromatic amines under anaerobic conditions. Therefore, finding an efficient method for removing organic pollutants from water bodies, especially an effective method for degrading dyes and antibiotics, is of paramount importance.

[0003] Currently, the main treatment methods for removing organic pollutants from water bodies include physical treatment, chemical treatment, and biological treatment. Among these, biological treatment has significant shortcomings in decolorization, while physical treatment only achieves the transfer of dyes between different phases, posing a risk of secondary pollution. Compared with these, chemical treatment has more advantages. Among them, advanced oxidation technologies (AOPs) can use active free radicals to degrade organic pollutants into non-toxic or low-toxic small molecules, making it one of the most effective methods for treating organic pollutant wastewater. In existing advanced oxidation technologies (AOPs), hydrogen peroxide and persulfate are mainly used as oxidants. Under the activation of a catalyst, hydrogen peroxide is first activated into hydroxyl radicals, or persulfate is converted into sulfate radicals. These hydroxyl radicals or sulfate radicals are then used to degrade organic pollutants in water. However, AOPs processes based on hydrogen peroxide and persulfate still have the following drawbacks: (1) The formation rate of active groups is slow and the amount generated is small, making it difficult to remove organic pollutants quickly and thoroughly; (2) The oxidants are unstable. For example, hydrogen peroxide is easy to decompose, which is not conducive to transportation and storage, and is extremely inconvenient to use; (3) The treatment cost is high. For example, the price of persulfate is high, which leads to a high cost of wastewater treatment. Furthermore, existing percarbonate-based AOPs processes use a composite material of percarbonate and persulfate as an oxidant. This oxidant, activated by divalent copper ions in the wastewater, forms hydroxyl and sulfate radicals in situ. These radicals are then used to degrade organic pollutants in the wastewater. However, this method still struggles to rapidly and thoroughly remove organic pollutants. This is because persulfate has an acidifying effect, resulting in an acidic degradation system. In particular, the high concentration of persulfate hinders the increase of the pH value in the degradation system, leading to the formation of trivalent copper ions, or at least a low yield. This makes it difficult to rapidly and thoroughly remove organic pollutants from the wastewater. Simultaneously, an acidic degradation system also discourages the formation of carbonate radicals. To date, there are no reports on using divalent copper ions to activate percarbonate to form carbonate radicals and then utilizing these radicals to degrade organic pollutants. Meanwhile, in the inventors' previous research, it was discovered that when using divalent copper ions to activate percarbonate, the concentrations of divalent copper ions and percarbonate have a significant impact on the formation of trivalent copper ions and carbonate free radicals. Both excessively high and low concentrations of divalent copper ions and percarbonate are detrimental to the generation of trivalent copper and carbonate free radicals, thus hindering the efficient removal of organic pollutants from water using these free radicals. Therefore, obtaining a suitable and efficient activation method for percarbonate to rapidly form more trivalent copper and carbonate free radicals is of great significance for the efficient removal of organic pollutants from water and is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method for removing organic pollutants from water by activating percarbonate with copper ions, which is simple, easy to operate, low in cost, highly practical, widely applicable, highly efficient, effective in degradation, and environmentally friendly.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.

[0006] A method for removing organic pollutants from water by activating percarbonate with copper ions includes the following steps: mixing divalent copper ions, percarbonate, and water containing organic pollutants to carry out a degradation reaction, thereby completing the degradation of organic pollutants in the water; the initial concentration of divalent copper ions in the degradation reaction system is 15 μM to 120 μM, and the initial concentration of percarbonate is ≥0.2 mM.

[0007] In a further improvement to the above-mentioned method of removing organic pollutants from water by activating percarbonate with copper ions, the initial concentration of divalent copper ions in the degradation reaction system is 15 μM to 100 μM; and the initial concentration of percarbonate in the degradation reaction system is 0.2 mM to 10 mM.

[0008] In a further improvement to the above-mentioned method of removing organic pollutants from water by activating percarbonate with copper ions, the initial concentration of divalent copper ions in the degradation reaction system is 18 μM to 80 μM; and the initial concentration of percarbonate in the degradation reaction system is 0.4 mM to 8 mM.

[0009] In a further improvement to the above-mentioned method of removing organic pollutants from water by activating percarbonate with copper ions, the initial concentration of divalent copper ions in the degradation reaction system is 20 μM to 40 μM; and the initial concentration of percarbonate in the degradation reaction system is 0.4 mM to 4 mM.

[0010] In a further improvement to the above-mentioned method of using copper ions to activate percarbonate for removing organic pollutants from water, the initial pH value of the degradation reaction system is ≥5.5.

[0011] In a further improvement to the above-mentioned method of removing organic pollutants from water by activating percarbonate with copper ions, the initial concentration of percarbonate in the degradation reaction system is 0.4 mM to 4 mM; and the initial pH value of the degradation reaction system is 5.5 to 10.

[0012] In a further improvement to the above-mentioned method of using copper ions to activate percarbonate for removing organic pollutants from water, the initial pH value of the degradation reaction system is 5.8–9.

[0013] The above-described method for removing organic pollutants from water by activating percarbonate with copper ions is further improved in that the divalent copper ions are at least one of copper chloride and copper sulfate; the percarbonate is at least one of sodium percarbonate and potassium percarbonate; the divalent copper ions are added to the water containing organic pollutants in the form of a solution; and the divalent copper ion solution is wastewater containing divalent copper ions. The method of this invention, when the wastewater contains sufficient divalent copper ions, can directly add sufficient percarbonate to effectively remove organic pollutants from the wastewater without the need for additional catalysts, which is beneficial for further cost reduction.

[0014] The above-described method for removing organic pollutants from water by activating percarbonate with copper ions is further improved in that the organic pollutants in the water containing organic pollutants are antibiotics and / or dyes; the antibiotic is oxytetracycline; the dye is an azo dye; the azo dye is Acid Orange; and the initial concentration of organic pollutants in the water containing organic pollutants is ≤30 mg / L.

[0015] The above-mentioned method for removing organic pollutants from water by activating percarbonate with copper ions is further improved in that the degradation reaction is carried out under shaking conditions, the shaking speed is 160 rpm to 200 rpm, the degradation reaction temperature is 25℃ to 30℃, and the degradation reaction time is 0.5 min to 60 min.

[0016] Compared with the prior art, the advantages of the present invention are as follows:

[0017] To address the shortcomings of existing AOPs processes, such as difficulty in efficiently removing organic pollutants from water and high costs, this invention creatively proposes a method for removing organic pollutants from water by activating percarbonate with copper ions. This method involves directly mixing divalent copper ions, percarbonate, and water containing organic pollutants, while controlling the initial concentration of divalent copper ions to 15 μM–120 μM and the initial concentration of percarbonate to ≥0.2 mM. This ensures the degradation system contains sufficient catalyst and oxidant. Under these conditions, the percarbonate and its decomposition products can rapidly raise the pH of the reaction system to above 5.5. At this point, a large amount of divalent copper ions can be converted into monovalent copper ions. Copper ions can be used to react with hydrogen peroxide to form a large number of hydroxyl radicals and trivalent copper ions. At the same time, due to the formation of a large number of hydroxide ions during the reaction, the pH value of the reaction system can be further increased to near neutral or alkaline. Under this pH condition, the hydroxyl radicals formed in the reaction system preferentially react with carbonate and bicarbonate ions and can form a large number of carbonate radicals. This allows the reaction system to quickly form more trivalent copper and carbonate radicals, which can then be used to efficiently degrade organic pollutants in water. The degradation principle is shown in formulas (1) to (12). Taking Acid Orange 7 as an example, the method of the present invention can remove more than 90% of Acid Orange 7 within 2 minutes and can achieve basic removal of Acid Orange 7 within 15 minutes. The degradation effect is very significant. At the same time, it can degrade Acid Orange 7 into non-toxic or low-toxic small molecule substances, realizing the harmless treatment of Acid Orange 7. Furthermore, compared to liquid H2O2, the percarbonate used in this invention has significant advantages in terms of storage and transportation, is more convenient to use, and its reaction products, such as CO2, H2O, and CO3, are also more readily available. 2- and HCO 3- Percarbonate and its derivatives are commonly found in the natural environment. Percarbonate and its derivatives act as buffers, and the reaction process generates hydroxide ions, thus preventing water acidification. This invention utilizes copper ion activation of percarbonate to remove organic pollutants from water. This method is simple, easy to operate, low-cost, highly practical, widely adaptable, highly efficient, effectively degrades pollutants, and is environmentally friendly. It can effectively degrade high concentrations of organic pollutants in water, especially those with concentrations ≤30 mg / L, demonstrating high practical value and promising application prospects.

[0018] 2M2CO3·3H2O2=4M + +2CO3 2- +3H₂O₂ (1)

[0019]

[0020] HO2 · →H+ +O2 ·- (3)

[0021]

[0022] Cu(I) + H₂O₂ → Cu(II) + · OH+OH - (5)

[0023] Cu(I) + H₂O₂ → Cu(III) + 2OH⁻ - (6)

[0024] CO3 2- +H₂O₂→HO₂ - +HCO3 - (7)

[0025] CO3 2- +H₂O→HCO₃ - +OH - (8)

[0026] HO2 - +H₂O₂→HO₂ · +HO · +OH - (9)

[0027] HO · +H₂O₂→HO₂ · +H2O(10)

[0028] · OH + CO3 2- →OH - +CO3 ·- (11)

[0029] · OH + HCO3 - →H2O+CO3 ·- (12) Attached Figure Description

[0030] Figure 1 This is a comparison chart of the removal effects of different copper ion concentrations on Acid Orange 7 in Example 1 of the present invention.

[0031] Figure 2 This is a comparison chart of the removal effects of different sodium percarbonate concentrations on Acid Orange 7 in Example 2 of the present invention.

[0032] Figure 3 This is a comparison chart showing the removal effect of copper ion-activated percarbonate on different concentrations of Acid Orange 7 in Example 4 of the present invention.

[0033] Figure 4This is a comparison chart of the removal effects of Acid Orange 7 under different reaction systems in Example 5 of the present invention.

[0034] Figure 5 This is a comparison chart of the removal effects of different free radical scavengers on Acid Orange 7 in Example 6 of the present invention.

[0035] Figure 6 This is a comparison chart of the removal effects of acid orange 7 under different oxidant conditions in Example 7 of the present invention.

[0036] Figure 7 This is a comparison chart of the removal effects of oxytetracycline under different reaction systems in Example 8 of the present invention. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention. All materials and instruments used in the following embodiments are commercially available.

[0038] Example 1:

[0039] A method for removing organic pollutants from water by activating percarbonate with copper ions according to the present invention specifically involves activating sodium percarbonate (SPC) with divalent copper ions to remove Acid Orange 7 (AO7) from water, comprising the following steps:

[0040] (1) Prepare 5 groups of 100 mL Acid Orange 7 aqueous solutions with a concentration of 30 mg / L (the original pH value of the aqueous solution is 5.8), with three parallel samples in each group.

[0041] (2) Add different amounts of copper sulfate to each group of solutions to make the concentration of copper ions in the solution 10μM, 20μM, 40μM, 80μM and 160μM respectively; then add sodium percarbonate to make the concentration of sodium percarbonate in the solution 0.4mM; shake the reaction at 30℃ and 200rpm for 15min to complete the removal of Acid Orange 7 from the water.

[0042] Control group: No Cu(II) added, all other conditions are the same.

[0043] In this embodiment, 2 mL of sample solution was taken at 0 min, 0.5 min, 1 min, 1.5 min, 2 min, 3 min, 5 min, 7 min, 10 min, and 15 min of the shaking reaction, respectively. The solution was filtered through a 0.45 μm filter, and the filtered solution was added to a sample vial containing excess Na₂S₂O₃ solution (2.5 mM) to terminate the reaction. The concentration of Acid Orange 7 was measured at an absorption wavelength of 484 nm using a UV2600 spectrophotometer. The corresponding concentration of Acid Orange 7 was obtained, and the change curve of Acid Orange 7 concentration under different copper ion concentrations was plotted. The results are shown below. Figure 1 As shown.

[0044] Figure 1 This is a comparison chart showing the removal effect of different copper ion concentrations on Acid Orange 7 in Example 1 of the present invention. Figure 1 It is observed that as the concentration of Cu(II) increases from 10 μM to 20 μM, the removal rate of AO7 increases from 25.4% to 97.5%. The accelerated reaction rate may be due to the fact that higher concentrations of divalent copper ions promote the generation of more active species in the SPC reaction, while lower concentrations result in fewer active species. Furthermore, when the concentration of divalent copper ions reaches 160 μM, the degradation rate of AO7 decreases. This is because a large number of divalent copper ions may interact with AO7 to produce intermediate products, such as metal-complexed azo dyes, which alter the color of the reaction solution and increase the absorbance of the sample. Therefore, an initial concentration of divalent copper ions of 15 μM to 80 μM in the degradation reaction system of this invention is beneficial for the efficient and thorough removal of Acid Orange 7 from water. In particular, the optimal removal effect is achieved when the concentration of divalent copper ions in the degradation reaction system is 20 μM to 40 μM.

[0045] Example 2:

[0046] A method for removing organic pollutants from water by activating percarbonate with copper ions according to the present invention specifically involves removing Acid Orange 7 (AO7) from water by activating sodium percarbonate (SPC) with copper ions, comprising the following steps:

[0047] (1) Prepare 6 groups of 100 mL Acid Orange 7 aqueous solutions with a concentration of 30 mg / L (the original pH value of the aqueous solution is 5.8), with three parallel samples in each group.

[0048] (2) Add copper sulfate to each group of solutions to make the concentration of copper ions in the solution 20 μM; then add different amounts of sodium percarbonate to make the concentration of sodium percarbonate in the solution 0, 0.1 mM, 0.2 mM, 0.4 mM, 0.8 mM and 1.6 mM respectively; shake the reaction at 30℃ and 200 rpm for 15 min to complete the removal of Acid Orange 7 from the water.

[0049] Control group: No sodium percarbonate added, all other conditions are the same.

[0050] In this embodiment, 2 mL of sample solution was taken at 0 min, 0.5 min, 1 min, 1.5 min, 2 min, 3 min, 5 min, 7 min, 10 min, and 15 min of the shaking reaction, respectively. The solution was filtered through a 0.45 μm filter, and the filtered solution was added to a sample vial containing excess Na₂S₂O₃ solution (2.5 mM) to terminate the reaction. The concentration of Acid Orange 7 was measured at an absorption wavelength of 484 nm using a UV2600 spectrophotometer. The corresponding concentration of Acid Orange 7 was obtained, and the change curve of Acid Orange 7 concentration under different sodium percarbonate concentrations was plotted. The results are shown below. Figure 2 As shown.

[0051] Figure 2 This is a comparison chart showing the removal effect of different sodium percarbonate concentrations on Acid Orange 7 in Example 2 of the present invention. Figure 2 It is observed that as the concentration of SPC increases from 0.1 mM to 1.6 mM, the degradation efficiency of AO7 increases from 14.6% to 99.6% within 15 minutes. This may be because SPC acts as a buffer; when the SPC concentration is too low, the pH of the system does not increase significantly, and trivalent copper is only generated in an alkaline environment. Therefore, a low SPC concentration is not conducive to the formation of trivalent copper. As the SPC concentration increases, more carbonate free radicals with oxidizing effects are generated, which is more conducive to the formation of trivalent copper, thereby degrading the target organic pollutant. Therefore, in this invention, when using copper ions to activate percarbonate to degrade Acid Orange 7 in water, the initial concentration of SPC in the degradation reaction system can be controlled between 0.2 mM and 1.6 mM to achieve efficient degradation of Acid Orange 7 in water, with higher economic benefits. In particular, when the initial concentration of SPC in the degradation reaction system is 0.4 mM, the optimal degradation effect and economic benefits can be obtained.

[0052] Example 3:

[0053] A method for removing organic pollutants from water by activating percarbonate with copper ions according to the present invention specifically involves activating sodium percarbonate (SPC) with divalent copper ions to remove Acid Orange 7 (AO7) from water, comprising the following steps:

[0054] (1) Prepare 4 groups of 100 mL Acid Orange 7 aqueous solution with a concentration of 30 mg / L (the original pH value of the aqueous solution is 5.8), and set up three parallel samples for each group.

[0055] (2) Add copper sulfate to each group of solutions to make the concentration of copper ions in the solution 20 μM; then add sodium percarbonate to make the concentration of sodium percarbonate in the solution 0.4 mM; adjust the pH of the three groups of solutions to 3, 6 and 9 using 0.1 mol / L HCl or 0.1 mol / L NaOH, and shake the reaction at 30℃ and 200 rpm for 15 min to complete the removal of Acid Orange 7 from the water.

[0056] In this embodiment, 2 mL of sample solution was taken at 0 min, 0.5 min, 1 min, 1.5 min, 2 min, 3 min, 5 min, 7 min, 10 min, and 15 min of the shaking reaction, respectively. The solution was filtered through a 0.45 μm filter, and the filtered solution was added to a sample bottle containing an excess of Na2S2O3 solution (2.5 mM) to terminate the reaction. The concentration of Acid Orange 7 was measured at an absorption wavelength of 484 nm using a UV2600 ultraviolet spectrophotometer, and the removal effect of Acid Orange 7 was obtained. The results are shown in Table 1.

[0057] Table 1. Removal effect of divalent copper ions on Acid Orange 7 under different pH conditions.

[0058]

[0059]

[0060] As shown in Table 1, an initial pH of 5.8-9 is more conducive to the activation of sodium percarbonate by divalent copper ions, thus facilitating the efficient removal of AO7 from water. In particular, the pH of AO7 wastewater is typically 5.8, close to neutral, so no pH adjustment is required during actual treatment, thereby reducing treatment costs.

[0061] Example 4:

[0062] A method for removing organic pollutants from water by activating percarbonate with copper ions according to the present invention specifically involves activating sodium percarbonate (SPC) with divalent copper ions to remove Acid Orange 7 (AO7) from water, comprising the following steps:

[0063] (1) Prepare 5 groups of 100mL Acid Orange 7 aqueous solutions (the original pH value of the aqueous solution is 5.8). The concentrations of Acid Orange 7 aqueous solutions are 10mg / L, 30mg / L, 50mg / L, 70mg / L and 100mg / L, respectively. Each group has three parallel samples.

[0064] (2) Add copper sulfate to each group of solutions to make the concentration of copper ions in the solution 20 μM; then add sodium percarbonate to make the concentration of sodium percarbonate in the solution 0.4 mM; shake the reaction at 30℃ and 200 rpm for 15 min to complete the removal of Acid Orange 7 from the water.

[0065] In this embodiment, 2 mL of sample solution was taken at 0 min, 0.5 min, 1 min, 1.5 min, 2 min, 3 min, 5 min, 7 min, 10 min, and 15 min of the shaking reaction, respectively. The solution was filtered through a 0.45 μm filter, and the filtered solution was added to a sample vial containing excess Na₂S₂O₃ solution (2.5 mM) to terminate the reaction. The concentration of Acid Orange 7 was measured at an absorption wavelength of 484 nm using a UV2600 spectrophotometer. The corresponding concentration of Acid Orange 7 was obtained, and the change curve of Acid Orange 7 concentration under different initial concentrations was plotted. The results are shown below. Figure 3 As shown.

[0066] Figure 3 This is a comparison chart showing the removal effect of copper ion-activated percarbonate on different concentrations of Acid Orange 7 in Example 4 of the present invention. Figure 3 It is evident that the degradation effect of divalent copper ions on AO7 significantly decreases with increasing initial AO7 concentration. This is because, with a fixed dosage of sodium percarbonate, the number of active species produced is limited. Therefore, as the initial AO7 concentration increases, it becomes difficult to generate more active species in the system, resulting in only partial degradation of AO7 and a significant decrease in removal rate. Consequently, when treating wastewater with high concentrations of organic pollutants, increasing the dosage of percarbonate and divalent copper ions can achieve efficient removal of organic pollutants from the wastewater.

[0067] Example 5:

[0068] A method for removing organic pollutants from water by activating percarbonate with copper ions according to the present invention specifically involves activating sodium percarbonate (SPC) with divalent copper ions to remove Acid Orange 7 (AO7) from water, comprising the following steps:

[0069] (1) Prepare one group of 100 mL of Acid Orange 7 aqueous solution with a concentration of 30 mg / L (the original pH value of the aqueous solution is 5.8), and set three parallel samples for each group.

[0070] (2) Add copper sulfate to each group of solutions to make the concentration of copper ions in the solution 20 μM; then add sodium percarbonate to make the concentration of sodium percarbonate in the solution 0.4 mM; shake the reaction at 30℃ and 200 rpm for 15 min to complete the removal of Acid Orange 7 from the water.

[0071] Control group 1: No copper sulfate was added, and all other conditions were the same.

[0072] Control group 2: No sodium percarbonate was added, and all other conditions were the same.

[0073] Control group 3: No copper sulfate was added, sodium carbonate was used instead of sodium percarbonate, and all other conditions were the same.

[0074] In this embodiment, 2 mL of sample solution was taken at 0 min, 0.5 min, 1 min, 1.5 min, 2 min, 3 min, 5 min, 7 min, 10 min, and 15 min of the shaking reaction, respectively. The solution was filtered through a 0.45 μm filter, and the filtered solution was added to a sample vial containing excess Na₂S₂O₃ solution (2.5 mM) to terminate the reaction. The concentration of Acid Orange 7 was measured at an absorption wavelength of 484 nm using a UV2600 spectrophotometer. The corresponding concentration of Acid Orange 7 was obtained, and the change curve of Acid Orange 7 concentration under different reaction systems was plotted. The results are shown below. Figure 4 As shown.

[0075] Figure 4 This is a comparison chart showing the removal effect of Acid Orange 7 under different reaction systems in Example 5 of the present invention. Figure 4 It is evident that adding sodium percarbonate and Cu(II) alone can hardly degrade AO7, indicating that the ability of Cu(II) or SPC to decompose AO7 is weak. This is because adding Cu(II) or SPC alone produces fewer active species, resulting in an insignificant degradation effect on AO7. When Cu(II) and SPC are present simultaneously in the reaction system, AO7 decolorizes relatively quickly, with approximately 90% of AO7 removed within the first 2 minutes, and a removal rate of 97.5% within 15 minutes. This demonstrates that Cu(II) can effectively activate SPC to produce active species that degrade AO7. Furthermore, the degradation of AO7 exhibits a two-stage reaction. Approximately 90% of AO7 is removed in the first stage, with a very rapid reaction rate. However, the decolorization rate is slower in the second stage. This may be because the concentration of copper ions is relatively high at the beginning of the reaction, resulting in a better activation effect on SPC and a faster degradation rate of AO7. As the reaction progresses, the active species are consumed by the pollutants, and the degradation rate of AO7 gradually slows down.

[0076] Example 6:

[0077] A method for removing organic pollutants from water by activating percarbonate with copper ions according to the present invention specifically involves activating sodium percarbonate (SPC) with divalent copper ions to remove Acid Orange 7 (AO7) from water, comprising the following steps:

[0078] (1) Prepare 5 groups of 100 mL Acid Orange 7 aqueous solutions with a concentration of 30 mg / L (the original pH value of the aqueous solution is 5.8), with three parallel samples in each group.

[0079] (2) Copper sulfate was added to each group of solutions to make the concentration of copper ions in the solution 20 μM; sodium percarbonate was then added to make the concentration of sodium percarbonate in the solution 0.4 mM; tert-butanol (TBA), phenol (PhOH), sugar alcohol (FFA), and chloroform (CF) were added to the four groups of solutions as free radical scavengers to make the concentrations of tert-butanol 100 mM, phenol 5 mM, sugar alcohol 20 mM, and chloroform 20 mM in the solution, respectively; the reaction was shaken at 30℃ and 200 rpm for 15 min to complete the removal of Acid Orange 7 from the water.

[0080] In this embodiment, 2 mL of sample solution was taken during the reaction and filtered through a 0.45 μm filter. The filtered solution was then added to a sample vial containing excess Na2S2O3 solution to terminate the reaction. The concentration of Na2S2O3 was 2.5 mM. The concentration of Acid Orange 7 was measured using a UV2600 ultraviolet spectrophotometer at an absorption wavelength of 484 nm. The corresponding concentration of Acid Orange 7 was obtained, and the change curves of Acid Orange 7 concentration under the addition of different types of free radical scavengers were plotted. The results are as follows. Figure 5 As shown.

[0081] Figure 5 This is a comparison chart showing the removal effect of different free radical scavengers on Acid Orange 7 in Example 6 of the present invention. Figure 5 It is known that tert-butanol (TBA) is a typical hydroxyl radical scavenger. After the addition of TBA, the oxidation activity in the Cu(II) / SPC system hardly decreased, indicating that there were no hydroxyl radicals in the degradation system. Phenol (PhOH) is commonly used as a scavenger of hydroxyl and carbonate radicals. When phenol was added, the degradation rate of AO7 decreased from 97.5% to 68.9%, confirming that a large number of carbonate radicals were generated during the degradation reaction, and that carbonate radicals played an important role in the degradation of AO7. Sugar alcohols (FFA) are selective... 1 O2 scavenger, chloroform (CF), is used as an O2· – The scavenging agent, after the addition of sugar alcohol and chloroform, showed almost no decrease in oxidation activity in the Cu(II) / SPC system, indicating that no scavenging agent was present in the degradation system. 1 O2 and O2· – .

[0082] Example 7:

[0083] A method for removing organic pollutants from water by activating percarbonate with copper ions according to the present invention specifically involves activating sodium percarbonate (SPC) with divalent copper ions to remove Acid Orange 7 (AO7) from water, comprising the following steps:

[0084] (1) Prepare 6 groups of 100 mL Acid Orange 7 aqueous solutions with a concentration of 30 mg / L (the original pH value of the aqueous solution is 5.8), with three parallel samples in each group.

[0085] (2) Copper sulfate was added to each group of solutions to make the concentration of copper ions in the solution 20 μM; among them, sodium percarbonate (SPC), hydrogen peroxide, peroxymonosulfate (PMS), persulfate (PS) and periodate (PI) were added as oxidants to 5 groups respectively, so that their concentrations in the solution were all 0.4 mM; sodium carbonate and hydrogen peroxide were added as oxidants to another group, so that the concentrations of sodium carbonate and hydrogen peroxide in the solution were both 0.4 mM. The reaction was shaken for 15 min at 30℃ and 200 rpm to complete the removal of Acid Orange 7 from the water.

[0086] In this embodiment, 2 mL of sample solution was taken at 0 min, 0.5 min, 1 min, 1.5 min, 2 min, 3 min, 5 min, 7 min, 10 min, and 15 min of the shaking reaction, respectively. The solution was filtered through a 0.45 μm filter, and the filtered solution was added to a sample vial containing excess Na₂S₂O₃ solution (2.5 mM) to terminate the reaction. The concentration of Acid Orange 7 was measured at an absorption wavelength of 484 nm using a UV2600 spectrophotometer. The corresponding concentration of Acid Orange 7 was obtained, and the change curves of Acid Orange 7 concentration with the addition of different types of oxidants were plotted. The results are shown below. Figure 6 As shown.

[0087] Figure 6 This is a comparison chart showing the removal effect of Acid Orange 7 under different oxidant conditions in Example 7 of the present invention. Figure 6It was observed that in reaction systems where the oxidants were peroxymonosulfate, persulfate, and periodate, no significant degradation of AO7 was observed. This indicates that under the current conditions, copper ions may not be able to effectively activate hydrogen peroxide, peroxymonosulfate, persulfate, and periodate to generate effective active species for the removal of AO7. When hydrogen peroxide was used as the oxidant, only about 7% of AO7 was degraded, indicating that under the current conditions, only a small amount of H2O2 was activated by Cu(II). However, when sodium carbonate and hydrogen peroxide were used as the oxidants, and copper ions, Na2CO3, and H2O2 coexisted, the degradation rate of AO7 was very rapid, with approximately 90% of AO7 removed in the first 2 minutes and over 97% decomposed at the end of the reaction. Notably, the degradation rate of AO7 was almost the same in the Cu(II) / SPC system and the Cu(II) / Na2CO3 / H2O2 system, indicating that carbonates play an important role in the generation of active species for AO7 decolorization. In summary, in Figure 6 Among all the Cu(II) / peroxidant systems shown, the Cu(II) / SPC system and the Cu(II) / Na2CO3 / H2O2 system performed the best in AO7 degradation. Due to the disadvantages of H2O2 liquid in transportation and storage, it can be concluded that the Cu(II) / SPC system has obvious advantages compared with other systems.

[0088] Example 8:

[0089] A method for removing organic pollutants from water by activating percarbonate with copper ions according to the present invention specifically involves removing oxytetracycline (OTC) from water by activating sodium percarbonate (SPC) with divalent copper ions, comprising the following steps:

[0090] (1) Prepare a group of 100 mL oxytetracycline aqueous solution with a concentration of 30 mg / L (the original pH value of the aqueous solution is 5.8), and set up three parallel samples for each group.

[0091] (2) Add copper sulfate to each group of solutions to make the concentration of copper ions in the solution 25 μM; then add sodium percarbonate to make the concentration of sodium percarbonate in the solution 4 mM; shake the reaction at 25℃ and 160 rpm for 1 h to complete the removal of oxytetracycline from the water.

[0092] Control group 1: No copper sulfate was added, and all other conditions were the same.

[0093] Control group 2: No sodium percarbonate was added, and all other conditions were the same.

[0094] In this embodiment, 2 mL of sample solution was taken at 0 min, 2 min, 5 min, 10 min, 15 min, 30 min, 45 min, and 60 min of the shaking reaction, filtered through a 0.45 μm filter, and the filtered solution was added to a sample bottle containing excess Na2S2O3 solution (2.5 mM) to terminate the reaction. The concentration of oxytetracycline was measured at an absorption wavelength of 357 nm using a UV2600 spectrophotometer. The corresponding concentration of oxytetracycline was obtained, and the change curve of oxytetracycline concentration under different reaction systems was plotted. The results are shown below. Figure 7 As shown.

[0095] Figure 7 This is a comparison chart showing the removal effect of oxytetracycline under different reaction systems in Example 8 of the present invention. Figure 7 It can be seen that adding Cu(II) alone and adding SPC alone have little effect on the removal of OTC, indicating that Cu(II) alone does not degrade OTC; while adding SPC alone only achieves a removal rate of 17.9% for OTC, which may be because SPC alone has a slight oxidizing effect on OTC, making the degradation process of OTC relatively slow. In the Cu(II) / SPC system, the degradation rate of OTC is significantly improved, reaching 81% after 60 min of reaction. The degradation efficiency of OTC in the Cu(II) / SPC system is much higher than that of adding Cu(II) or SPC alone. This can be attributed to the activating effect of Cu(II), which accelerates the decomposition of SPC and generates more active species, thereby improving the degradation efficiency of OTC.

[0096] 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 many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the spirit and technical essence of the present invention. Therefore, any simple modifications, equivalent substitutions, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall still fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method for removing organic pollutants from water by activating percarbonate with copper ions, characterized in that, Includes the following steps: A degradation reaction is carried out by mixing divalent copper ions, percarbonate, and water containing organic pollutants to complete the degradation of organic pollutants in the water. The initial concentration of divalent copper ions in the degradation reaction system is 20 μM to 40 μM, and the initial concentration of percarbonate is 0.4 mM to 1.6 mM. The organic pollutant in the water containing organic pollutants is a dye. The dye is an azo dye. The azo dye is Acid Orange. The initial concentration of organic pollutants in the water containing organic pollutants is ≤30 mg / L.

2. The method for removing organic pollutants from water by activating percarbonate with copper ions according to claim 1, characterized in that, The initial pH value of the degradation reaction system is ≥5.

5.

3. The method for removing organic pollutants from water by activating percarbonate with copper ions according to claim 2, characterized in that, The initial pH value of the degradation reaction system is 5.5-10.

4. The method for removing organic pollutants from water by activating percarbonate with copper ions according to claim 3, characterized in that, The initial pH value of the degradation reaction system is 5.8–9.

5. The method for removing organic pollutants from water by activating percarbonate with copper ions according to any one of claims 1 to 4, characterized in that, The divalent copper ion is at least one of copper chloride and copper sulfate; the percarbonate is at least one of sodium percarbonate and potassium percarbonate; the divalent copper ion is added to the water body containing organic pollutants in the form of a solution; The divalent copper ion solution is wastewater containing divalent copper ions.

6. The method for removing organic pollutants from water by activating percarbonate with copper ions according to any one of claims 1 to 4, characterized in that, The degradation reaction is carried out under oscillation conditions, with an oscillation speed of 160 rpm to 200 rpm, a degradation reaction temperature of 25°C to 30°C, and a degradation reaction time of 0.5 min to 60 min.

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