A method for degrading a sulfonamide antibiotic
By using an electrochemical method to activate persulfate with copper ions, persulfate and reactive oxygen species are generated, solving the problem of efficient degradation of sulfamethoxazole in water and achieving an economical and green water treatment effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WUHAN UNIV OF TECH
- Filing Date
- 2024-07-19
- Publication Date
- 2026-07-21
AI Technical Summary
Existing technologies are insufficient for efficiently removing sulfamethoxazole from water, and traditional methods are costly or pose a risk of secondary pollution. Furthermore, the problem of sulfate pollution treatment in water bodies has not been effectively solved.
An electrochemical method is used to activate persulfate with copper ions. The electrolyte containing sulfate and copper salt is treated through the cathode and anode under an external power supply to generate persulfate and reactive oxygen species. Sulfate antibiotics are then degraded directly using sulfate and copper ions in the water.
It achieves highly efficient degradation of sulfamethoxazole, with a degradation rate of up to 93.3%, while saving the cost of oxidants and catalysts. It is simple to operate, green and economical, and suitable for the field of water treatment.
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Figure CN118684314B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of electrochemical advanced oxidation and water treatment technology, specifically to a method and apparatus for electrochemically accelerating the activation of persulfate by copper ions. Background Technology
[0002] Sulfamethoxazole, as a sulfonamide antibiotic, is widely used in the medical field due to its significant therapeutic effect and affordability. However, sulfamethoxazole cannot be completely metabolized and absorbed by organisms; approximately 50%-80% of it is excreted in its original form along with metabolic products. Existing traditional urban wastewater treatment technologies are inefficient at removing sulfamethoxazole, leading to its entry into natural aquatic environments. Currently, varying levels of antibiotics, including sulfamethoxazole, have been detected in rivers. Although the concentration of sulfamethoxazole in the environment is low, its long half-life and hydrophilic nature make it prone to bioaccumulation and migration, posing a serious threat to ecosystems and human health. Long-term exposure to low concentrations of antibiotics may exacerbate the development of antibiotic-resistant pathogens, reduce the effectiveness of antibiotic treatment, and pose a potential threat to human health. Therefore, there is an urgent need to develop an economical and efficient method for removing sulfamethoxazole from water.
[0003] Currently, new technologies for removing sulfamethoxazole mainly include microbial treatment, adsorption, and advanced oxidation methods. Microbial treatment is time-consuming, requires harsh and difficult microbial cultivation environments, and may lead to drug resistance. While adsorption is simple to operate and low-cost, it cannot achieve complete degradation of pollutants, and the regeneration and subsequent disposal of adsorption materials remain unresolved. Advanced oxidation technologies utilize reactive oxygen species (ROS) generated by oxidants under the action of energy or catalysts to degrade antibiotics into small molecule intermediates or completely mineralize them into carbon dioxide (CO2), water (H2O), and inorganic salts, achieving complete removal of pollutants from water and thus considered a more promising technology. However, existing advanced oxidation technologies typically require the addition of exogenous oxidants and catalysts, increasing material and transportation costs. Furthermore, unreasonable mining, indiscriminate discharge of industrial and domestic wastewater, and excessive application of agricultural fertilizers have led to sulfate pollution in aquatic environments, making sulfate treatment a significant challenge in water treatment. Persulfate can be activated in various ways, among which transition metals can effectively activate persulfate to form reactive oxygen species. Transition metal copper is frequently used in advanced oxidation technologies due to its relatively low toxicity, wide effective pH range, and cost-effectiveness. Furthermore, copper, being widely used and inexpensive, has been found in various types of man-made wastewater. Surveys show that copper ion concentrations in municipal wastewater range from 0.2 to 8.0 mg / L, while concentrations in man-made mining wastewater can reach as high as 100 mg / L.
[0004] Therefore, there is an urgent need for a new technology to remove sulfonamide antibiotics, which can not only achieve efficient degradation of sulfonamide antibiotics, but also make full use of sulfate ions and copper ions in water to achieve the goal of economic and green development. Summary of the Invention
[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a method and apparatus for electrochemically accelerating the activation of persulfate by copper ions, thereby solving the technical problems of high difficulty and high cost in removing sulfonamide antibiotics from water in the prior art.
[0006] In a first aspect, the present invention provides a method for electrochemically accelerating the activation of persulfate by copper ions, comprising the following steps: The cathode and anode are placed in an electrolyte, and electrochemical treatment is carried out under an external power supply. The electrolyte consists of sulfate, copper salt, and solvent.
[0007] Secondly, the present invention provides an apparatus for electrochemically accelerating the activation of persulfate by copper ions, comprising: a power source, a cathode, an anode, an electrolyte, an electrolytic cell, and a stirring mechanism; wherein, Electrolytic cells are used to hold electrolytes; The anode and cathode are placed in the electrolytic cell and immersed in the electrolyte; The anode and cathode are connected to the positive and negative terminals of the power supply, respectively. The apparatus for electrochemically accelerating the activation of persulfate by copper ions provided in the second aspect of the present invention is used to perform the method for electrochemically accelerating the activation of persulfate by copper ions provided in the first aspect of the present invention.
[0008] Thirdly, the present invention provides a method for degrading sulfonamide antibiotics, comprising the following steps: The electrochemically accelerated copper ion activation persulfate method provided in the first aspect of the present invention is used to degrade sulfonamide antibiotics; wherein the electrolyte also includes sulfonamide antibiotics.
[0009] Compared with the prior art, the beneficial effects of the present invention include: This invention uses a solution containing copper and sulfate as the electrolyte, directly utilizing sulfate ions in the solution to generate persulfate. Simultaneously, monovalent copper generated during the copper ion redox cycle activates the persulfate. This efficiently degrades sulfonamide antibiotics while fully utilizing sulfate and copper ions in the wastewater. No additional oxidants or catalysts are required, saving raw material costs. The operation and use are simple, achieving the goal of being economical and environmentally friendly. The electrochemical device of this invention is simple and can be widely promoted. Attached Figure Description
[0010] Figure 1This is a schematic diagram of an embodiment of the electrochemically accelerated copper ion activation persulfate device provided by the present invention; wherein, 1 is the power source, 2 is the electrolytic cell cover, 3 is the cathode, 4 is the electrolyte, 5 is the anode, 6 is the magnetic rotor, 7 is the magnetic stirrer, and 8 is the electrolytic cell; Figure 2 The graph shows the removal rates of 5 mg / L sulfamethoxazole in the 0-90 min range for a single electrochemical oxidation (EO) system, a binary combination system of electrochemical oxidation combined with sodium sulfate or copper chloride (EO / Na2SO4 or EO / CuCl2), and a ternary system of the three combined (EO / Na2SO4 / CuCl2). Figure 3 The graph shows the removal rate of 5 mg / L sulfamethoxazole in the ternary system at different voltage values (10-30 V) from 0 to 90 min. Figure 4 The graph shows the removal rate of 5 mg / L sulfamethoxazole in a ternary system with different copper chloride concentrations (0.1-2 mmol / L) from 0 to 90 min. Figure 5 The graph shows the removal rate of 5 mg / L sulfamethoxazole in a ternary system with different sodium sulfate concentrations (0.1-20 mmol / L) from 0 to 90 min. Figure 6 The graph shows the removal rate of sulfamethoxazole at a concentration of 5 mg / L in a ternary system after adjusting the initial pH (3-11) for 0-90 min. Figure 7 The graph shows the removal rate of sulfamethoxazole at a concentration of 5 mg / L by adding humic acid (0-10 mg / L) to the ternary system over 0-90 min. Figure 8 The graph shows the removal rate of sulfamethoxazole at a concentration of 5 mg / L by adding sodium chloride (NaCl) in the ternary system at a concentration range of 0-10 mmol / L for 0-90 min. Figure 9 The graph shows the removal rate of sulfamethoxazole at a concentration of 5 mg / L by adding sodium nitrate (NaNO3) to a ternary system at a concentration range of 0-10 mmol / L for 0-90 min. Figure 10 The graph shows the removal rate of sulfamethoxazole at a concentration of 5 mg / L by adding sodium carbonate (Na2CO3) to a ternary system at a concentration range of 0-10 mmol / L over a period of 0-90 min. Figure 11 The graph shows the removal rate of sulfamethoxazole at a concentration of 5 mg / L by adding sodium bicarbonate (NaHCO3) in a ternary system at a concentration range of 0-10 mmol / L for 0-90 min. Figure 12 The diagram shows the sustained degradation capacity of the ternary system for sulfamethoxazole. Figure 13 The graph shows the removal rates of three sulfonamide antibiotics in the ternary system. Detailed Implementation
[0011] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0012] In a first aspect, the present invention provides a method for electrochemically accelerating the activation of persulfate by copper ions, comprising the following steps: The cathode and anode are placed in an electrolyte, and electrochemical treatment is carried out under an external power supply. The electrolyte consists of sulfate, copper salt, and solvent.
[0013] This invention utilizes an electrochemical method to cause sulfate ions in the electrolyte to lose electrons in situ at the anode to generate persulfate. Simultaneously, the electrochemical action accelerates the redox cycle (i.e., valence state cycle) of copper ions. The monovalent copper ions generated in the redox cycle can effectively activate persulfate to produce reactive oxygen species, such as hydroxyl radicals and sulfate radicals, which degrade sulfonamide antibiotics. At the same time, the copper redox cycle also produces trivalent copper, which has a certain oxidizing ability and can directly oxidize some sulfonamide antibiotics.
[0014] In this embodiment, the sulfate is at least one of sodium sulfate, potassium sulfate, and copper sulfate.
[0015] In this embodiment, the copper salt is at least one of copper chloride and copper sulfate.
[0016] In this embodiment, the solvent is water.
[0017] In this embodiment, the concentration of sulfate ions in the electrolyte is 0.1-20 mmol / L, including but not limited to 0.1 mmol / L, 1 mmol / L, 5 mmol / L, 10 mmol / L, 20 mmol / L, etc.; the concentration of copper ions is 0.1-2 mmol / L, including but not limited to 0.1 mmol / L, 0.2 mmol / L, 0.5 mmol / L, 1 mmol / L, 2 mmol / L, etc.
[0018] In this embodiment, the concentration of humic acid in the electrolyte is 0-20 mg / L, including but not limited to 0 mg / L, 0.1 mg / L, 1 mg / L, 5 mg / L, 10 mg / L, 15 mg / L, 20 mg / L, etc.; the concentration of sodium nitrate is 0-15 mmol / L, including but not limited to 0 mmol / L, 0.1 mmol / L, 1 mmol / L, 5 mmol / L, 10 mmol / L, 15 mmol / L, etc.; the concentration of sodium carbonate is 0-30 mmol / L, including but not limited to 0 mmol / L, 0.1 mmol / L, 1 mmol / L, 5 mmol / L, 10 mmol / L, 15 mmol / L, 20 mmol / L, 25 mmol / L, 30 mmol / L, etc.; and the concentration of sodium bicarbonate is 0-20 mmol / L, including but not limited to 0 mmol / L, 0.1 mmol / L, 1 mmol / L, 5 mmol / L, 10 mmol / L, 15 mmol / L, 20 mmol / L, 25 mmol / L, 30 mmol / L, etc. mmol / L, 15 mmol / L, 20 mmol / L, etc.
[0019] In this embodiment, the pH of the electrolyte is 3-11, including but not limited to 3, 5, 7, 9, 11, etc.
[0020] In this embodiment, the cathode is platinum metal and the anode is titanium metal.
[0021] In some specific embodiments of the present invention, the cathode is a platinum wire with a diameter of 0.7-1.2 mm and a length of 35-40 mm; the anode is a titanium sheet with a thickness of 1.0-1.5 mm and an area of 500-550 mm². 2 .
[0022] In some more specific embodiments of the present invention, before using the titanium sheet, it is first ultrasonically soaked in concentrated nitric acid, then ultrasonically soaked in acetone, then cleaned with ultrapure water, and finally dried.
[0023] Furthermore, the concentration of concentrated nitric acid is 15-16 mol / L, and the ultrasonic soaking time is 10-20 min; the concentration of acetone is 97%-99%, and the ultrasonic soaking time is 10-20 min.
[0024] In this embodiment, the distance between the cathode and the anode is 1.5-2.5 cm.
[0025] In this embodiment, the power supply voltage is 10-30 V, including but not limited to 10 V, 15 V, 20 V, 25 V, 30 V, etc.; the electrochemical treatment time is 0.1-90 min, including but not limited to 0.1 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, etc.
[0026] In this embodiment, the volume of the electrolyte is 45-55 mL.
[0027] In this embodiment, the electrochemical treatment is carried out at room temperature and pressure.
[0028] In this embodiment, the electrochemical treatment is carried out under stirring.
[0029] Furthermore, the stirring rate is 450-550 r / min.
[0030] Please see Figure 1 Secondly, the present invention provides an apparatus for electrochemically accelerating the activation of persulfate by copper ions, comprising: a power source 1, a cathode 3, an anode 5, an electrolyte 4, an electrolytic cell 8, and a stirring mechanism; wherein, Electrolytic cell 8 is used to hold electrolyte 4; The anode 5 and cathode 3 are placed in the electrolytic cell 8 and immersed in the electrolyte 4; Anode 5 and cathode 3 are connected to the positive and negative terminals of power supply 1, respectively; The apparatus for electrochemically accelerating the activation of persulfate by copper ions provided in the second aspect of the present invention is used to perform the method for electrochemically accelerating the activation of persulfate by copper ions provided in the first aspect of the present invention.
[0031] In this embodiment, the electrolytic cell 8 is a single-chamber electrolytic cell.
[0032] In this embodiment, an electrolytic cell cover 2 is provided on the top of the electrolytic cell 8; the electrolytic cell cover 2 is a three-hole electrolytic cell cover, in which two holes are used to fix the anode 5 and the cathode 3 respectively, and the other hole is used to extract samples and ventilate.
[0033] In this embodiment, power supply 1 is a regulated DC power supply.
[0034] In this embodiment, the stirring mechanism includes a magnetic rotor 6 and a magnetic stirrer 7.
[0035] Thirdly, the present invention provides a method for degrading sulfonamide antibiotics, comprising the following steps: The electrochemically accelerated copper ion activation persulfate method provided in the first aspect of the present invention is used to degrade sulfonamide antibiotics; wherein the electrolyte also includes sulfonamide antibiotics.
[0036] This invention utilizes the redox cycle of copper in different valence states under electrochemical action to activate persulfate generated in situ from sulfate ions to degrade sulfonamide antibiotics. This not only achieves the full utilization of sulfate and copper ions in wastewater by using local materials, but also achieves the efficient degradation of sulfonamide antibiotics in water.
[0037] In this embodiment, the sulfonamide antibiotic is at least one of sulfamethoxazole (SMX), sulfamethoxazine (SMP), and sulfadiazine (SDZ).
[0038] In this embodiment, the concentration of sulfonamide antibiotics in the electrolyte is 4-6 mg / L.
[0039] In the following embodiments of the present invention, the device for electrochemically accelerating the activation of persulfate by copper ions includes a power source 1, an electrolytic cell cover 2, a cathode 3, an electrolyte 4, an anode 5, a magnetic rotor 6, a magnetic stirrer 7, and an electrolytic cell 8: wherein, Power supply 1 is a regulated DC power supply; The electrolytic cell cover 2 is located on top of the electrolytic cell 8, and the electrolytic cell cover 2 is a three-hole electrolytic cell cover, in which two small holes are used to fix the electrodes and the other small hole is used to extract samples and ventilate. The cathode 3 and anode 5 are placed in the electrolytic cell 8 and immersed in the electrolyte 4; The cathode is a platinum wire with a diameter of 1 mm and a length of 37 mm; The anode is a titanium sheet with a thickness of 1.5 mm and an area of 525 mm². 2 Before using the titanium sheet, it should be ultrasonically soaked in concentrated nitric acid with a concentration of 15 mol / L for 15 min, then ultrasonically soaked in acetone with a concentration of 99% for 15 min, and finally washed with ultrapure water and dried. The cathode and anode are connected to the positive and negative terminals of power supply 1, respectively, with the titanium sheet facing the platinum wire and maintaining a distance of 2 cm. Electrolytic cell 8 is a single-chamber electrolytic cell, used to hold electrolyte 4 containing sodium sulfate, copper chloride and sulfamethoxazole.
[0040] Example 1 Under electrochemical oxidation, the removal capacity of mono- (EO), binary (EO / Na2SO4, EO / CuCl2), and ternary (EO / Na2SO4 / CuCl2) systems for 5 mg / L (total volume 50 mL) sulfamethoxazole solution was compared within a reaction time of 0-90 min. The constant voltage was 25 V, the sodium sulfate concentration was 1 mmol / L, and the copper chloride concentration was 1 mmol / L. The beaker was placed on a magnetic stirrer at 500 r / min and stirred thoroughly. Samples were taken at preset time points (0-90 min), and the residual concentration of sulfamethoxazole was determined by high performance liquid chromatography-mass spectrometry. The removal rate of sulfamethoxazole at different time points was also determined.
[0041] Depend on Figure 2 It can be seen that the removal rate of sulfamethoxazole by the ternary system is significantly higher than that of the mono- and binary systems, and the removal rate of sulfamethoxazole can reach 93.3% after 90 min of reaction.
[0042] Example 2 In a ternary system, the concentrations of sodium sulfate and copper chloride were set at 1 mmol / L, and the voltage values were set at 10, 15, 20, 25, and 30 V, respectively. The concentration of sulfamethoxazole was 5 mg / L, and the total volume was 50 mL. The beaker was placed on a magnetic stirrer at 500 r / min and stirred thoroughly. Samples were taken at preset time points (0-90 min), and the residual concentration of sulfamethoxazole was determined by high performance liquid chromatography-mass spectrometry. The removal rate of sulfamethoxazole at different time points was measured to investigate the effect of voltage on the removal capacity of sulfamethoxazole in the ternary system.
[0043] Depend on Figure 3 It can be seen that the removal rate of sulfamethoxazole by the ternary system increases with the increase of voltage value. When the voltage reaches 25 V and the reaction time is 90 min, the removal rate of sulfamethoxazole by the ternary system is about 93.3%.
[0044] Example 3 In the ternary system, the voltage was set to 25 V, the sodium sulfate concentration was 1 mmol / L, the copper chloride concentrations were 0.1, 0.2, 0.5, 1.0, and 2.0 mmol / L, and the sulfamethoxazole concentration was 5 mg / L. The total volume was 50 mL. The beaker was placed on a magnetic stirrer at 500 r / min and stirred thoroughly. Samples were taken at preset time points (0-90 min), and the residual concentration of sulfamethoxazole was determined by high performance liquid chromatography-mass spectrometry. The removal rate of sulfamethoxazole at different time points was determined to investigate the effect of copper chloride concentration on the removal capacity of sulfamethoxazole in the ternary system.
[0045] Depend on Figure 4It can be seen that the removal rate of sulfamethoxazole by the ternary system increases with the increase of copper chloride concentration. When the copper chloride concentration is 1 mmol / L, the removal rate of sulfamethoxazole by the ternary system is about 93.3% after 90 min of reaction.
[0046] Example 4 The ternary system was set with a voltage of 25 V, a copper chloride concentration of 1 mmol / L, sodium sulfate concentrations of 0.1, 1, 5, 10, and 20 mmol / L, and a sulfamethoxazole concentration of 5 mg / L. The total volume was 50 mL, and the system was thoroughly stirred on a magnetic stirrer at 500 r / min. Samples were taken at preset time points (0-90 min), and the residual concentration of sulfamethoxazole was determined by high performance liquid chromatography-mass spectrometry. The removal rate of sulfamethoxazole at different time points was measured to investigate the effect of sodium sulfate concentration on the removal capacity of sulfamethoxazole in the ternary system.
[0047] Depend on Figure 5 It can be seen that the removal rate of sulfamethoxazole by the ternary system increases with the increase of sodium sulfate concentration. When the sodium sulfate concentration is 1 mmol / L, after a reaction of 90 min, the removal rate of sulfamethoxazole by the ternary system is approximately 93.3%.
[0048] Example 5 In a ternary system, a constant voltage of 25 V was set, the concentration of copper chloride was 1 mmol / L, the concentration of sodium sulfate was 1 mmol / L, the initial pH of the solution was adjusted to 3, 5, 7, 9 and 11, the concentration of sulfamethoxazole was 5 mg / L, and the total volume was 50 mL. The system was stirred thoroughly on a magnetic stirrer at 500 r / min. Samples were taken at preset time points (0-90 min), and the residual concentration of sulfamethoxazole was determined by high performance liquid chromatography-mass spectrometry. The removal rate of sulfamethoxazole at different time points was determined to investigate the effect of the initial pH of the solution on the removal capacity of sulfamethoxazole in the ternary system.
[0049] Depend on Figure 6 It can be seen that the removal rate of sulfamethoxazole by the ternary system decreases with increasing initial pH, indicating that acidic conditions are more favorable for the degradation of sulfamethoxazole by the ternary system than alkaline conditions. When the initial pH is 5, the removal rate of sulfamethoxazole by the ternary system is approximately 93.6%.
[0050] Example 6 In the ternary system, the voltage was set to 25V, the concentration of copper chloride was 1 mmol / L, the concentration of sodium sulfate was 1 mmol / L, the concentration of humic acid (HA) was set to 0, 1, 5 and 10 mg / L, the concentration of sulfamethoxazole was 5 mg / L, and the total volume was 50 mL. The system was stirred thoroughly on a magnetic stirrer at 500 r / min. Samples were taken at preset time points (0-90 min), and the residual concentration of sulfamethoxazole was determined by high performance liquid chromatography-mass spectrometry. The removal rate of sulfamethoxazole at different time points was determined to investigate the effect of humic acid on the removal capacity of sulfamethoxazole in the ternary system.
[0051] Depend on Figure 7 It can be seen that the removal rate of sulfamethoxazole by the ternary system decreases with increasing humic acid concentration. When the humic acid concentration is 10 mg / L, the removal rate of sulfamethoxazole is 51.8% after 60 min of reaction.
[0052] Example 7 In the ternary system, the voltage was set to 25 V, the concentration of copper chloride was 1 mmol / L, the concentration of sodium sulfate was 1 mmol / L, the concentration of sulfamethoxazole was 5 mg / L, and the total volume was 50 mL. Sodium chloride, sodium nitrate, sodium carbonate, and sodium bicarbonate with concentrations of 1, 5, and 10 mmol / L were added respectively. The system was stirred thoroughly on a magnetic stirrer at a speed of 500 r / min. Samples were taken at preset time points (0-90 min), and the residual concentration of sulfamethoxazole was determined by high performance liquid chromatography-mass spectrometry. The removal rate of sulfamethoxazole at different time points was determined to explore the effect of coexisting inorganic ions on the system's ability to remove sulfamethoxazole.
[0053] Depend on Figure 8-11 It can be seen that sodium chloride has a low inhibitory effect on the ability of the ternary system to degrade sulfamethoxazole, but the inhibitory effects of sodium nitrate, sodium carbonate and sodium bicarbonate on the ability of the ternary system to degrade sulfamethoxazole increase with increasing concentration, among which sodium nitrate has the strongest inhibitory effect.
[0054] Example 8 In the ternary system, the voltage was set to 25 V, the concentration of copper chloride was 1 mmol / L, the concentration of sodium sulfate was 1 mmol / L, the concentration of sulfamethoxazole was 5 mg / L, and the total volume was 50 mL. Samples were taken every 90 min. After each sampling, sulfamethoxazole and sodium sulfate were added back to the system to bring their concentrations back to 5 mg / L and 1 mmol / L, respectively. The system was then stirred and degraded on a magnetic stirrer at 500 r / min. After five samplings, the removal rate of sulfamethoxazole from the five samples was measured to investigate the continuous removal capacity of the ternary system for sulfamethoxazole.
[0055] Depend on Figure 12 It can be seen that supplementing with 1 mmol / L sodium sulfate each time can effectively maintain the ability of the ternary system to continuously degrade sulfamethoxazole. After the 4th cycle, the removal rate of sulfamethoxazole by the ternary system can still reach 77.8%.
[0056] Example 9 In the ternary system, the voltage was set to 25 V, the concentration of copper chloride was 1 mmol / L, the concentration of sodium sulfate was 1 mmol / L, and the pollutants were sulfamethoxazole, sulfamethoxazine, and sulfadiazine at a concentration of 5 mg / L, respectively. The total volume was 50 mL, and the system was thoroughly stirred on a magnetic stirrer at a speed of 500 r / min. Samples were taken at preset time points (0-90 min), and the residual concentration of sulfamethoxazole was determined by high performance liquid chromatography-mass spectrometry. The removal rate of sulfamethoxazole at different time points was measured to explore the ability of this ternary system to degrade different sulfonamide pollutants.
[0057] Depend on Figure 13 It can be seen that the degradation rate of sulfamethoxazine by this ternary system is close to that of sulfamethoxazole, both exceeding 90%; the degradation rate of sulfadiazine by the system also exceeds 80%.
[0058] In summary, compared with the prior art, the present invention also has the following characteristics and beneficial effects: (1) This invention utilizes the redox cycle of copper under electrochemical action to activate persulfate generated in situ from sulfate ions to degrade sulfamethoxazole. It makes full use of sulfate ions and copper ions in wastewater and achieves efficient degradation of sulfonamide antibiotics in water, especially sulfamethoxazole, without the need to add other oxides and activators.
[0059] (2) In a single electrolytic cell, the present invention utilizes the redox cycle of generating persulfate and copper to generate multiple active oxygen species to degrade sulfonamide antibiotics. It is an efficient and economical electrochemical advanced oxidation method. The device and operation are simple. It uses sulfate ions and copper ions present in water as oxidant and catalyst, respectively, and can be widely used in the field of water treatment.
[0060] (3) The present invention can efficiently generate persulfate and activate it to achieve effective degradation of sulfamethoxazole. When the constant voltage is 25 V, the sodium sulfate concentration is 1 mmol / L, the copper chloride concentration is 1 mmol / L, and after a reaction time of 90 min, the removal rate of sulfamethoxazole with a concentration of 5 mg / L reaches 93.3%, and the removal rate of other sulfonamide antibiotics (sulfamethoxazine and sulfadiazine) is also over 80%.
[0061] (4) The present invention has the characteristics of low operating cost, simple operation, thorough degradation and strong continuous degradation ability. It also has a good degradation effect on a variety of sulfonamide antibiotics (such as sulfamethoxazole, sulfamethoxazine (SMP) and sulfadiazine (SDZ)), has a wide range of applications, and the method is green and sustainable.
[0062] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.
Claims
1. A method for degrading sulfonamide antibiotics, characterized in that, Includes the following steps: The cathode and anode are placed in an electrolyte, and electrochemical treatment is carried out under an external power supply; wherein the electrolyte comprises sulfate, copper salt and solvent. The sulfate is at least one of sodium sulfate, potassium sulfate, and copper sulfate; the copper salt is at least one of copper chloride and copper sulfate; and the solvent is water. The cathode is made of platinum, and the anode is made of titanium. The electrolyte contains sulfate ions at a concentration of 1-20 mmol / L, copper ions at a concentration of 1-2 mmol / L, humic acid at a concentration of 0-20 mg / L, sodium nitrate at a concentration of 0-15 mmol / L, sodium carbonate at a concentration of 0-30 mmol / L, and sodium bicarbonate at a concentration of 0-20 mmol / L; the pH of the electrolyte is 3-7. The electrolyte contains sulfonamide antibiotics.
2. The degradation method for sulfonamide antibiotics according to claim 1, characterized in that, The power supply voltage is 10-30V.
3. The degradation method for sulfonamide antibiotics according to any one of claims 1-2, characterized in that, The degradation of persulfate is carried out using an electrochemically accelerated copper ion activation device, which includes: a power source, a cathode, an anode, an electrolyte, an electrolytic cell, and a stirring mechanism; wherein, The electrolytic cell is used to hold the electrolyte; The anode and the cathode are placed in the electrolytic cell and immersed in the electrolyte; The anode and the cathode are respectively connected to the positive and negative terminals of the power supply.
4. The degradation method for sulfonamide antibiotics according to claim 3, characterized in that, The electrolytic cell is a single-chamber electrolytic cell; the power supply is a regulated DC power supply; the stirring mechanism includes a magnetic rotor and a magnetic stirrer.
5. The degradation method for sulfonamide antibiotics according to claim 4, characterized in that, The top of the electrolytic cell is provided with an electrolytic cell cover, which is a three-hole electrolytic cell cover.
6. The degradation method for sulfonamide antibiotics according to any one of claims 1-2, characterized in that, The sulfonamide antibiotic is at least one of sulfamethoxazole, sulfamethoxazine, and sulfadiazine; the concentration of the sulfonamide antibiotic is 4-6 mg / L.