A solid catalyst for treating residual antibiotics or pesticides in drinking water, and its preparation method and application

Abstract

The present invention relates to the technical field of drinking water treatment, specifically a solid catalyst, preparation method and application for treating residual antibiotics or pesticides in drinking water. The preparation method comprises the following steps: soaking foamed iron in dilute hydrochloric acid and ultrasonically soaking it, then placing it in ethanol and ultrasonically soaking it, and rinsing to obtain solid one; dissolving terephthalic acid in deionized water to obtain solution one; transferring solution one to a reactor, and placing solid one in the reactor, and heating the reactor; cooling the reactor to room temperature after the reaction, washing and drying to obtain solid two; preparing Ce(NO3)3·6H2O and Cu(NO3)2·3H2O solutions, adding ammonium fluoride and urea and mixing them evenly to obtain solution two, transferring solution two to a reactor, and placing solid two on the inner wall of the reactor; placing the reactor in a drying oven and heating it at a constant temperature, and then cleaning and drying it to obtain solid three; calcining solid three to obtain solid four, i.e., CuO‑CeO2 / Fe2O3 / FF catalyst.

Description

Technical Field

[0001] The present invention relates to the technical field of drinking water treatment, and in particular to a solid catalyst for treating residual antibiotics or pesticides in drinking water, a preparation method and use thereof. Background Art

[0002] In recent years, with the widespread use of antibiotics in healthcare, animal husbandry, agriculture, and the food industry, antibiotic residues have become a global environmental concern. Tetracycline, a widely used antibiotic, is widely used due to its high efficacy, low cost, and easy availability. Its widespread use poses a serious threat to aquatic ecosystems and drinking water safety. Traditional water treatment technologies struggle to effectively remove new contaminants like tetracycline from water. Therefore, developing drinking water treatment technologies that can efficiently remove these new contaminants is crucial to ensure a safe drinking water supply.

[0003] Currently, the main methods for removing tetracycline from drinking water include biodegradation, conventional chemical oxidation, adsorption, and membrane filtration. Although these methods can reduce the concentration of tetracycline in water to a certain extent, they all have problems such as low target removal efficiency, high treatment costs, and complex operation and management. For example, biodegradation is limited by microbial activity, has poor removal effects on new pollutants, and may promote the development of resistance genes; conventional chemical oxidation has a low mineralization rate and produces harmful byproducts; adsorption requires frequent replacement of adsorbent materials or regeneration, which is a complex procedure and relatively costly; membrane filtration requires regular chemical cleaning and physical regeneration of the membrane, which is complex to operate, increases chemical consumption, and produces concentrated water that is difficult to treat. Therefore, finding an efficient, economical, and environmentally friendly method to remove new pollutants (such as residual tetracycline) from drinking water has become one of the research focuses in this field.

[0004] To solve the problem of antibiotic contamination in drinking water, heterogeneous electro-Fenton technology, as an efficient advanced oxidation technology, shows great application potential. This technology generates strong oxidizing hydroxyl radicals ( · OH), effectively oxidizing and degrading new contaminants such as antibiotics in water. Compared to traditional treatment methods, heterogeneous electro-Fenton technology offers advantages such as ease of operation, high oxidation efficiency, and reduced risk of secondary pollution. Therefore, developing and optimizing heterogeneous electro-Fenton catalysts, and improving their stability and reusability, will be one of the key technical approaches to addressing antibiotic contamination in drinking water.

[0005] In recent years, many researchers have studied a number of novel heterogeneous electro-Fenton catalysts for removing organic pollutants from water, achieving good removal results. However, existing catalysts still have many problems, including: poor reusability, with significant decreases in catalytic activity after repeated recycling; unstable catalytic effects, which are easily affected by catalyst composition, structure, and reaction conditions; and difficulties in recovery and regeneration, with traditional methods struggling to efficiently separate and recover catalysts, and the regeneration process being complex and costly. These issues have severely limited the large-scale application of heterogeneous electro-Fenton technology in drinking water treatment.

[0006] CN117654635A discloses an iron-zinc bimetallic organic framework electro-Fenton catalyst. Sodium acetate trihydrate, ferric nitrate nonahydrate, and zinc nitrate hexahydrate are dissolved in deionized water, stirred at room temperature, centrifuged, washed, and dried to obtain Fe / Zn bimetallic clusters. The Fe / Zn bimetallic clusters are dispersed in an organic solvent, a PTA solution is added and stirred, and a 2-methylimidazole solution is added and stirred to obtain an iron-zinc bimetallic organic framework electro-Fenton catalyst. The catalyst is dispersed in a sodium sulfate electrolyte containing organic pollutants (a mixture of one or more of methylene blue, ciprofloxacin, tetracycline, and phenol), connected to a cathode and an aerator, and connected to an aeration device to construct a reaction system to remove the target pollutants. However, the Fe-Zn BOM electro-Fenton catalyst prepared by this method is in powder form, making it difficult to recover after the reaction. Improper handling can leave material residue in the treated water, affecting effluent quality and resulting in material waste. Furthermore, the recovered material requires chemical cleaning or high-temperature treatment before reuse, increasing the cost of reuse. Furthermore, during the reaction, the large number of bubbles generated by the aeration system can affect the catalyst's suspension, interfering with its catalytic performance and even disrupting the Fe-Zn BOM structure, significantly impacting its stability.

[0007] CN114618554A discloses a porous iron-nitrogen-doped carbon composite electro-Fenton catalytic material derived from iron porphyrin. The material is calcined by mixing iron porphyrin, a metal oxide (at least one of magnesium oxide, zinc oxide, and copper oxide), and a carbonate (at least one of potassium carbonate, potassium bicarbonate, sodium carbonate, and sodium bicarbonate). The mixture is then mixed with a hydrochloric acid solution, sonicated, and allowed to stand to obtain the porous iron-nitrogen-doped carbon composite electro-Fenton catalytic material. When used as an electro-Fenton catalyst for degrading organic pollutants (ciprofloxacin) in water or preparing hydrogen peroxide, the material not only effectively degrades the organic pollutants but also significantly increases hydrogen peroxide production. When the porous iron-nitrogen-doped carbon composite electro-Fenton catalytic material is used in an electro-Fenton reaction for 90 minutes, the removal rate of ciprofloxacin reaches 99.5%, achieving efficient removal of ciprofloxacin. However, the catalyst's catalytic performance and structural stability are still affected by the presence of aeration in the electro-Fenton process. Furthermore, some material remains in the treated water during catalyst recovery, contaminating the effluent and causing catalyst loss. Furthermore, the proposed catalyst still achieves a 76% removal efficiency after four cycles. While this represents a significant improvement over traditional catalyst solutions, the catalytic performance remains significantly reduced, and the material's recyclability is suboptimal.

[0008] Therefore, it is of great practical significance to develop a heterogeneous electro-Fenton catalyst with high catalytic efficiency, easy recovery, and high reusability, and use it to remove antibiotic or pesticide pollution in drinking water. Summary of the Invention

[0009] In order to overcome the high consumption of reagents, poor pH applicability, · Problems such as low OH generation, as well as problems such as difficulty in recovering or reusing new heterogeneous catalysts, poor catalytic effect, poor reusability and insufficient stability, the present invention provides a solid catalyst for treating residual antibiotics or pesticides in drinking water, as well as a preparation method and application.

[0010] The present invention prepares a CuO-CeO2 / Fe2O3 / FF heterogeneous electro-Fenton catalyst, in which Fe-MOF is in situ grown on iron foam (FF) by a hydrothermal reaction to form a stable Fe-MOF / FF structure, which provides a more stable substrate for loading CuCe-LDH. Then, CuCe-LDH is loaded onto the Fe-MOF / FF substrate to form a stable catalyst structure. By bridging the Fe-MOF in situ grown on the FF with the CuCe-LDH, problems such as weak loading, easy falling off, and poor stability of the layered hydroxide are improved, and the catalytic performance of the material is significantly improved by the composite of multiple metals such as Fe, Cu, and Ce. Finally, by calcination, the CuO-CeO2 / Fe2O3 / FF heterogeneous electro-Fenton catalyst is formed, which has high specific surface area, high catalytic activity, simple recycling and regeneration, and extremely high reusability. Experiments have shown that the recovered catalyst can be reused after a simple deionized water wash, and the tetracycline removal rate can still reach 86% after 8 cycles. This invention provides a new catalyst preparation method and idea for heterogeneous electro-Fenton technology.

[0011] Specifically, this application provides the following technical solutions:

[0012] A method for preparing a solid catalyst for treating residual antibiotics or pesticides in drinking water comprises soaking FF in dilute hydrochloric acid and ultrasonically soaking it, then soaking it in ethanol and ultrasonically soaking it, and then rinsing it with deionized water to obtain a solid 1; dissolving PTA in deionized water to obtain a solution 1; transferring the solution 1 to a reactor, and then placing the solid 1 in the reactor and heating it for reaction; after the reaction is completed, cooling it to room temperature, repeatedly washing the obtained solid, and drying it to obtain a solid 2, named Fe-MOF / FF;

[0013] At room temperature, Ce(NO3)3·6H2O and Cu(NO3)2·3H2O solutions are prepared, ammonium fluoride and urea are added, and the mixture is evenly mixed to obtain solution 2, which is then transferred to a reactor, and solid 2 is placed on the inner wall of the reactor; the reactor is placed in a drying oven, and after constant temperature heating treatment, the obtained solid is washed and dried to obtain solid 3; solid 3 is then placed in a muffle furnace and calcined to obtain solid 4, which is the CuO-CeO2 / Fe2O3 / FF catalyst.

[0014] Furthermore, the specific preparation method of the solid one is to soak a 2 cm × 2 cm FF in 3 mol / L dilute hydrochloric acid and ultrasonicate for 30 minutes, then soak it in ethanol and ultrasonicate for 30 minutes, and then rinse it with deionized water to obtain the solid one. The specific preparation method of the solution one is to add 2 mmol of PTA to 60 mL of deionized water and continuously stir until it is completely dissolved to obtain the solution one.

[0015] Furthermore, the specific preparation method of the solid two is to transfer the solution one to a polytetrafluoroethylene-lined reactor with a volume of 100 mL, place the solid one in the reactor, and heat it to 150°C for 12 hours; when the reaction is completed and cooled to room temperature, repeatedly wash the obtained solid with ethanol and deionized water, and dry it at 80°C to obtain solid two, named Fe-MOF / FF.

[0016] 4 mmol Ce(NO3)3·6H2O, 12 mmol Cu(NO3)2·3H2O, 20 mmol ammonium fluoride, and 80 mmol urea were added to 20 mL of deionized water, mixed and dissolved, and then the pH was adjusted to a neutral range (7.4-7.5) using a mixed solution of Na2CO3 (0.6 mol / L) and NaOH (0.3 mol / L). The molar ratio of Cu:Ce in the second solution was 3:1. The total molar number of Cu and Ce in the second solution was controlled to 16 mmol (12 mmol copper, 4 mmol Ce).

[0017] The specific preparation method of the solid three is as follows: first, the solution two is transferred to a polytetrafluoroethylene-lined reactor, and then the solid two is placed on the inner wall of the polytetrafluoroethylene-lined reactor; the reactor is placed in a blast drying oven, and heated at a constant temperature of 120°C for 12 hours, and then the obtained solid is rinsed with ethanol and deionized water, and then dried in an oven at 80°C to obtain the solid three;

[0018] Among them, the specific preparation method of the solid four is to place the solid three in a muffle furnace and calcine it at 400°C for 1 hour to obtain solid four.

[0019] The solid catalyst prepared by the present invention can be used to treat residual antibiotics and pesticides in drinking water, wherein the antibiotics are ciprofloxacin, tetracycline, and sulfasalazine; and the pesticides are atrazine and imidacloprid. The solid catalyst is used to treat residual antibiotics in drinking water through a heterogeneous electro-Fenton reaction, and the current density of the electro-Fenton reaction is 9 mA / cm 2 , the aeration rate was 0.6 L / min, and the pH value of the solution was 7.2.

[0020] This solid catalyst not only has a high efficiency in the treatment of tetracycline, but also has a good removal effect on other typical antibiotics (ciprofloxacin, sulfasalazine) and pesticides (atrazine, imidacloprid), proving that this solid catalyst has good catalytic oxidation removal efficiency for typical drugs, and the prepared catalyst has good applicability.

[0021] Compared with the prior art, the solid catalyst for treating residual antibiotics or pesticides in drinking water, its preparation method, and its application of the present invention have at least the following beneficial effects:

[0022] (1) The preparation method of the present invention involves first using cleaned FF, adding PTA and deionized water to conduct a hydrothermal reaction, thereby forming a well-formed Fe-MOF on the FF surface, providing a more stable matrix for the loading of copper-cerium hydroxide. Furthermore, the Fe-MOF / FF not only provides better structural support, but also improves the material's conductivity through the Fe-MOF, facilitating electron transport and thus enhancing its catalytic ability.

[0023] (2) The CuO-CeO2 / Fe2O3 / FF electro-Fenton catalyst prepared by the present invention has significant advantages in removing antibiotics from drinking water. By optimizing the composition and structure of the catalyst, not only the catalytic activity and stability of the catalyst are significantly improved, but also the problems existing in the traditional electro-Fenton technology are solved. The catalyst can significantly improve the · The OH generation efficiency was significantly improved, thereby achieving efficient tetracycline removal. Experimental results showed that under optimal conditions, the catalyst could achieve 100% tetracycline removal within 75 minutes, significantly outperforming existing electro-Fenton catalysts.

[0024] (3) High stability and long life: The catalyst has good stability and corrosion resistance, and can maintain high catalytic activity during long-term operation. Even after multiple cycles, the catalyst performance remains stable and efficient. Experimental results show that after eight cycles, the catalyst can still achieve a tetracycline removal rate of 86% or more, significantly reducing the frequency of catalyst replacement and operating costs in actual electro-Fenton process applications.

[0025] (4) Easy recovery and reuse: The CuO-CeO2 / Fe2O3 / FF composite catalyst is in solid form and can be easily separated and recovered from the reaction system. The recovered catalyst can be reused after simple cleaning without the need for complex chemical treatment or high-temperature regeneration. This simplifies the catalyst regeneration process, reduces its processing cost, and has better application prospects.

[0026] (5) This catalyst is not only suitable for removing tetracycline from water, but can also effectively remove other types of pollutants, such as ciprofloxacin, sulfasalazine, atrazine, and imidacloprid. By adjusting and optimizing the reaction conditions (such as current density, aeration volume, pH value, etc.), its removal efficiency for different pollutants can be further improved, broadening its application range.

[0027] (6) The composite material prepared by the two-step hydrothermal method of the present invention not only strengthens the basic support function of the foamed iron, but also gives full play to the advantages of the copper-cerium bimetallic oxide, thereby having better catalytic performance and application effect. The preparation method of the catalyst is simple, the raw materials used are low-cost, and it is environmentally friendly throughout its preparation and use process, and no harmful by-products are produced. This makes the catalyst highly economical and environmentally sustainable in practical applications, providing a new and effective method for ensuring drinking water safety.

[0028] The solid catalyst for treating residual antibiotics or pesticides in drinking water, its preparation method and application of the present invention will be further described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1-Figure 2 This is the SEM image of FF.

[0030] Figure 3-Figure 4 This is the SEM image of Fe-MOF / FF.

[0031] Figure 5-Figure 6 This is the SEM image of CuO-CeO2 / Fe2O3 / FF.

[0032] Figure 7 This is the XRD pattern of CuO-CeO2 / Fe2O3 / FF.

[0033] Figure 8 The efficiency of tetracycline removal from drinking water by CuO-CeO2 / Fe2O3 / FF catalyst in heterogeneous electro-Fenton system under optimal conditions.

[0034] Figure 9 Effect of metal ratio on the removal efficiency of tetracycline in drinking water over CuO-CeO2 / Fe2O3 / FF catalyst in heterogeneous electro-Fenton system.

[0035] Figure 10 The effect of hydrothermal temperature on the removal efficiency of tetracycline in drinking water over CuO-CeO2 / Fe2O3 / FF catalyst in a heterogeneous electro-Fenton system.

[0036] Figure 11 The effect of hydrothermal time on the efficiency of CuO-CeO2 / Fe2O3 / FF catalyst in removing tetracycline from drinking water in a heterogeneous electro-Fenton system.

[0037] Figure 12 The effect of calcination temperature on the efficiency of CuO-CeO2 / Fe2O3 / FF catalyst in removing tetracycline from drinking water in a heterogeneous electro-Fenton system.

[0038] Figure 13The effect of calcination time on the efficiency of CuO-CeO2 / Fe2O3 / FF catalyst in removing tetracycline from drinking water in a heterogeneous electro-Fenton system.

[0039] Figure 14 Effect of current density on the removal efficiency of tetracycline in drinking water over CuO-CeO2 / Fe2O3 / FF catalyst in a heterogeneous electro-Fenton system.

[0040] Figure 15 The effect of aeration rate on the removal efficiency of tetracycline in drinking water over CuO-CeO2 / Fe2O3 / FF catalyst in a heterogeneous electro-Fenton system.

[0041] Figure 16 The effect of solution pH on the efficiency of CuO-CeO2 / Fe2O3 / FF catalyst in removing tetracycline from drinking water in a heterogeneous electro-Fenton system.

[0042] Figure 17 The effect of electrolyte type on the efficiency of CuO-CeO2 / Fe2O3 / FF catalyst in removing tetracycline from drinking water in a heterogeneous electro-Fenton system.

[0043] Figure 18 The effect of initial tetracycline concentration on the efficiency of CuO-CeO2 / Fe2O3 / FF catalyst in removing tetracycline from drinking water in a heterogeneous electro-Fenton system.

[0044] Figure 19 The effect of drinking water matrix type on the efficiency of CuO-CeO2 / Fe2O3 / FF catalyst in the removal of tetracycline from drinking water in a heterogeneous electro-Fenton system.

[0045] Figure 20 The removal efficiency of tetracycline in drinking water when the CuO-CeO2 / Fe2O3 / FF catalyst was reused 8 times in a heterogeneous electro-Fenton system.

[0046] Figure 21 The removal efficiency of different types of organic matter by CuO-CeO2 / Fe2O3 / FF catalyst in the heterogeneous electro-Fenton system. DETAILED DESCRIPTION

[0047] A method for preparing a CuO-CeO2 / Fe2O3 / FF catalyst for treating residual antibiotics in drinking water, specifically comprising:

[0048] A 2cm×2cm sheet of FF was soaked in 3mol / L dilute hydrochloric acid and ultrasonically treated for 30 minutes, then placed in ethanol and ultrasonically treated for 30 minutes. The sheet was then rinsed with deionized water to obtain solid 1. 2mmol of PTA was added to 60mL of deionized water and stirred continuously until completely dissolved, yielding solution 1. Solution 1 was transferred to a 100mL polytetrafluoroethylene-lined reactor. Solid 1 was placed in the reactor, heated to 150°C, and reacted for 12 hours. After the reaction was complete, the reaction was cooled to room temperature and the resulting solid was repeatedly washed with ethanol and deionized water. The solid was then dried in an oven at 80°C to obtain solid 2. Because the Fe-MOF grown on solid 2 formed a composite material with solid 1 after the reaction, solid 2 was named Fe-MOF / FF.

[0049] At room temperature, the method for preparing solution 2 is as follows: 4 mmol Ce(NO3)3·6H2O, 12 mmol Cu(NO3)2·3H2O, 20 mmol ammonium fluoride and 80 mmol urea are weighed, added to 20 mL deionized water, mixed thoroughly and evenly until they are completely dissolved, and then the pH is adjusted to the neutral range (7.4-7.5) using a mixed solution of Na2CO3 (0.6 mol / L) and NaOH (0.3 mol / L). Then, solution 2 is transferred to a polytetrafluoroethylene-lined reactor, and solid solution 2 (Fe-MOF / FF) is placed on the inner wall of the polytetrafluoroethylene-lined reactor. The reactor was placed in a forced air drying oven and heated at a constant temperature of 120°C for 12 hours. The obtained solid was then washed with ethanol and deionized water, and then dried in an oven at 80°C to obtain solid three. Solid three was then placed in a muffle furnace and calcined at 400°C for 1 hour to obtain solid four, named CuO-CeO2 / Fe2O3 / FF catalyst.

[0050] The total molar number of metals (Cu and Ce) in solution 2 is controlled at 16 mmol, wherein the molar ratio of Cu:Ce is 3:1, i.e., 12 mmol of copper and 4 mmol of Ce.

[0051] Figures 1-4 The SEM images of FF and Fe-MOF / FF at 500 times and 10000 times respectively. Figure 1-2 It can be seen that the surface of FF is relatively smooth and flat, and its three-dimensional structure is obvious, with a unique reticular macroporous structure. Figure 4 It can be seen that after the first hydrothermal reaction, a uniform Fe-MOF was generated on the FF. Figure 3-Figure 4 The corresponding material is named Fe-MOF / FF.

[0052] Figure 5-Figure 6SEM images of the CuO-CeO2 / Fe2O3 / FF material at 150x and 10,000x magnifications are shown. As can be seen, under optimal preparation conditions, CuCe-LDH transforms into metal (Cu, Ce) oxides after calcination, uniformly adhering to the substrate. The aforementioned Fe-MOF / FF also transforms into a Fe2O3 / FF structure after calcination. This unique structure provides a larger specific surface area and more active catalytic sites for the catalytic oxidation and degradation of tetracycline in the electro-Fenton system.

[0053] Figure 7 Characterization results show that the characteristic peaks at 28.55°, 47.48°, 56.33°, 59.08°, 79.07°, and 88.41° correspond to the (111), (220), (311), (222), (420), and (422) crystal planes of CeO2, respectively. The diffraction peaks at 38.71°, 48.72°, 61.52°, and 68.12° correspond to the (111), (20-2), (11-3), and (220) crystal planes of CuO, respectively. The diffraction peaks at 33.15° and 35.61° correspond to the (104) and (110) crystal planes of Fe2O3, respectively, and the diffraction peak at 76.58° corresponds to the (222) crystal plane of FeO. The characterization results indicate that copper-cerium hydroxide and Fe-MOF generate their corresponding metal oxides after calcination.

[0054] Experimental Example 1

[0055] The prepared CuO-CeO2 / Fe2O3 / FF catalyst was added to an electro-Fenton reaction tank, and the cathode and anode were inserted, connected to a power source, and aeration was introduced to form a reaction apparatus. The apparatus was placed on a magnetic stirrer at 300 rpm at room temperature (25°C). Samples were taken at reaction times of 0, 1, 2.5, 5, 10, 15, 30, 45, and 75 minutes, and the tetracycline concentration in the water samples was determined using ultra-performance liquid chromatography-tandem triple quadrupole mass spectrometry.

[0056] The power supply current density is 9 mA / cm, the solution tank contains 300 mL of 0.05 mol / L Na2SO4 electrolyte and 10 mg / L tetracycline, and the initial solution pH is 7.2.

[0057] Among them, the aeration volume of the aeration device is 0.6L / min.

[0058] Among them, the cathode is preferably a 2cm×5cm graphite felt (GF) cathode modified with carbon black and polytetrafluoroethylene (PTFE), and other cathodes can also be used.

[0059] The anode is a 2cm×5cm titanium-based ruthenium iridium oxide (DSA) anode, and other anodes may also be used.

[0060] Experimental Example 2

[0061] Unlike Experimental Example 1, the Cu:Ce molar ratios of 0:1, 1:7, 1:3, 1:1, 3:1, 7:1, and 1:0 (total molar ratio 16 mmol) were used in the preparation of the CuO-CeO2 / Fe2O3 / FF catalyst in Experimental Example 2. Samples were taken at 75 minutes of reaction to determine the tetracycline concentration. The remaining steps were the same as in Experimental Example 1. The experiment determined the effect of the Cu:Ce ratio in the catalyst on the efficiency of the CuO-CeO2 / Fe2O3 / FF catalyst in removing tetracycline in an electro-Fenton system.

[0062] Experimental Example 3

[0063] Unlike Experimental Example 1, in Experimental Example 3, during the process of preparing the CuO-CeO2 / Fe2O3 / FF catalyst from Solid 2 to Solid 3, the reaction temperatures were set at 30°C, 60°C, 90°C, 120°C, 150°C, and 180°C, respectively. Samples were taken at 75 minutes to measure the tetracycline concentration. The remaining steps were the same as in Experimental Example 1. This experiment determined the effect of hydrothermal temperature on the tetracycline removal efficiency of the prepared CuO-CeO2 / Fe2O3 / FF catalyst in an electro-Fenton system.

[0064] Experimental Example 4

[0065] Unlike Experimental Example 1, in Experimental Example 3, during the process of preparing the CuO-CeO2 / Fe2O3 / FF catalyst from Solid 2 to Solid 3, the hydrothermal time was set to 4 hours, 8 hours, 12 hours, 16 hours, and 20 hours, respectively. Samples were taken at 75 minutes of reaction to determine the tetracycline concentration. The remaining steps were the same as in Experimental Example 1. This experiment determined the effect of the hydrothermal time on the tetracycline removal efficiency of the prepared CuO-CeO2 / Fe2O3 / FF catalyst in an electro-Fenton system.

[0066] Experimental Example 5

[0067] Unlike Experimental Example 1, in Experimental Example 5, during the process of preparing the CuO-CeO2 / Fe2O3 / FF catalyst from Solid 3 to Solid 4, the muffle furnace calcination temperatures were set to uncalcined, 200°C, 300°C, 400°C, and 500°C, respectively. Samples were taken at 75 minutes of reaction to determine the tetracycline concentration. The remaining steps were the same as in Experimental Example 1. This experiment determined the effect of the calcination temperature during the process of Solid 3 to Solid 4 on the tetracycline removal efficiency of the prepared CuO-CeO2 / Fe2O3 / FF catalyst in an electro-Fenton system.

[0068] Experimental Example 6

[0069] Unlike Experimental Example 1, in Experimental Example 6, during the preparation of the CuO-CeO2 / Fe2O3 / FF catalyst from Solid 3 to Solid 4, the muffle furnace calcination times were set to 0 min, 30 min, 60 min, and 120 min, respectively. Samples were taken at 75 minutes to measure the tetracycline concentration. The remaining steps were identical to Experimental Example 1. This experiment determined the effect of calcination time during the conversion from Solid 3 to Solid 4 on the tetracycline removal efficiency of the prepared CuO-CeO2 / Fe2O3 / FF catalyst in an electro-Fenton system.

[0070] Experimental Example 7

[0071] Different from the experimental example 1, the current density of the power supply in the experimental example 7 is 1mA / cm 2 , 3mA / cm 2 , 6mA / cm 2 , 9mA / cm 2 , 12mA / cm 2 and 15mA / cm 2 The remaining steps are the same as those in Experimental Example 1. The effect of current density on the removal efficiency of tetracycline over CuO-CeO2 / Fe2O3 / FF catalyst in an electro-Fenton system was determined by experiments.

[0072] Experimental Example 8

[0073] Unlike Experimental Example 1, the aeration rates in Experimental Example 8 were 0 L / min, 0.1 L / min, 0.3 L / min, 0.6 L / min, and 0.9 L / min, respectively. The remaining steps were the same as in Experimental Example 1. The experiment determined the effect of aeration rate on the efficiency of tetracycline removal over the CuO-CeO2 / Fe2O3 / FF catalyst in an electro-Fenton system.

[0074] Experimental Example 9

[0075] Unlike Experimental Example 1, the pH of the reaction solution in Experimental Example 9 was adjusted to 3.0, 5.0, 7.2, and 9.0, respectively. The remaining steps were the same as Experimental Example 1. The experiment determined the effect of solution pH on the efficiency of tetracycline removal over the CuO-CeO2 / Fe2O3 / FF catalyst in an electro-Fenton system.

[0076] Experimental Example 10

[0077] Unlike Experimental Example 1, the electrolyte solutions in Experimental Example 10 were replaced with 0.05 mol / L NaCl, 0.05 mol / L NaNO₃, and 0.05 mol / L Na₂SO₄, respectively. The remaining steps were the same as in Experimental Example 1. The experiment determined the effect of electrolyte type on the efficiency of tetracycline removal over the CuO-CeO₂ / Fe₂O₃ / FF catalyst in an electro-Fenton system.

[0078] Experimental Example 11

[0079] Unlike Experimental Example 1, the initial concentrations of tetracycline in Experimental Example 11 were set at 2.5 mg / L, 5 mg / L, 10 mg / L, 15 mg / L, and 20 mg / L, respectively. The remaining steps were the same as in Experimental Example 1. The experiment determined the effect of the initial tetracycline concentration on the tetracycline removal efficiency of the CuO-CeO2 / Fe2O3 / FF catalyst in an electro-Fenton system.

[0080] Experimental Example 12

[0081] Unlike Experimental Example 1, Experimental Example 12 used tap water, ultrapure water, pure water, lake water, and river water to prepare a 0.05 mol / L Na₂SO₄ solution. The remaining steps were the same as in Experimental Example 1. This experiment determined the effect of drinking water matrix type on the tetracycline removal efficiency of the CuO-CeO₂ / Fe₂O₃ / FF catalyst in an electro-Fenton system.

[0082] Experimental Example 13

[0083] Different from Experimental Example 1, in Experimental Example 13, the catalyst was rinsed with deionized water and dried after the reaction in Experimental Example 1, and the dried catalyst was reused. The other experimental parameters and steps were the same as those in Experimental Example 1. This operation was repeated 8 times, and the catalyst reuse experiment was used to determine the reuse performance of the prepared CuO-CeO2 / Fe2O3 / FF catalyst for removing tetracycline in the electro-Fenton system.

[0084] Experimental Example 14

[0085] Unlike Experimental Example 1, the target pollutants in Experimental Example 14 were replaced with ciprofloxacin, sulfasalazine, atrazine, and imidacloprid at the same concentrations as the tetracycline in Experimental Example 1. The remaining steps were the same as in Experimental Example 1. The removal efficiency of different types of pollutants in the electro-Fenton system using CuO-CeO2 / Fe2O3 / FF as the catalyst was determined through experiments.

[0086] The experimental results are as follows:

[0087] Figure 8 The results of Experiment 1 demonstrate the efficiency of tetracycline removal from drinking water using the CuO-CeO2 / Fe2O3 / FF catalyst in a heterogeneous electro-Fenton system under optimal conditions. The results of Experiment 1 demonstrate that the CuO-CeO2 / Fe2O3 / FF catalyst is highly effective in removing tetracycline from drinking water in a heterogeneous electro-Fenton system, achieving a 100% tetracycline removal rate after just 75 minutes of reaction.

[0088] Figure 9This study examines the effect of metal ratio on the tetracycline removal efficiency of the CuO-CeO2 / Fe2O3 / FF catalyst in a heterogeneous electro-Fenton system. The results of Experimental Example 2 demonstrate that varying Cu:Ce ratios affect the efficiency of the prepared catalyst in removing tetracycline from drinking water in a heterogeneous electro-Fenton system. By comparing the tetracycline removal efficiencies at different ratios, the optimal Cu:Ce molar ratio was determined to be 3:1.

[0089] Figure 10 The results of Experimental Example 3 show the effect of hydrothermal temperature on the efficiency of CuO-CeO2 / Fe2O3 / FF catalyst in removing tetracycline in a heterogeneous electro-Fenton system. The results of Experimental Example 3 demonstrate that a hydrothermal temperature of 120°C stabilizes the catalyst structure and enables efficient tetracycline removal from drinking water in a heterogeneous electro-Fenton system. However, temperatures too high or too low affect catalytic activity.

[0090] Figure 11 The results of Experimental Example 4 show the effect of hydrothermal time on the efficiency of CuO-CeO2 / Fe2O3 / FF catalyst in removing tetracycline in a heterogeneous electro-Fenton system. The results of Experimental Example 4 indicate that a 12-hour hydrothermal time stabilizes the catalyst structure and effectively removes tetracycline from drinking water in a heterogeneous electro-Fenton system. However, either a shorter or longer hydrothermal time can negatively impact catalytic activity.

[0091] Figure 12 This study examined the effect of calcination temperature on the tetracycline removal efficiency of a CuO-CeO2 / Fe2O3 / FF catalyst in a heterogeneous electro-Fenton system. The results of Experimental Example 5 indicate that a calcination temperature of 400°C stabilizes the catalyst structure and reduces metal shedding. While calcination at too high a temperature can destabilize the structure, calcination at too low a temperature can easily cause metal shedding, compromising catalytic performance.

[0092] Figure 13 This study examined the effect of calcination time on the efficiency of a CuO-CeO2 / Fe2O3 / FF catalyst for tetracycline removal from drinking water in a heterogeneous electro-Fenton system. The results of Experimental Example 6 showed that a calcination time of 60 minutes stabilized the catalyst structure and reduced the shedding of the supported metal. Longer calcinations compromised the material's structural stability, while shorter calcinations increased the likelihood of supported metal shedding, impairing catalytic performance.

[0093] Figure 14 The effect of current density on the tetracycline removal efficiency of the CuO-CeO2 / Fe2O3 / FF catalyst in a heterogeneous electro-Fenton system is shown. The results of Experimental Example 7 show that the tetracycline removal efficiency increases with increasing current density. At current densities of 0.09A and 0.12A, the tetracycline removal rate reaches 100% after 75 minutes of reaction. Considering the operating costs of the process, 0.09A is selected as the optimal current density.

[0094] Figure 15 The effect of aeration rate on tetracycline removal efficiency using a CuO-CeO2 / Fe2O3 / FF catalyst in a heterogeneous electro-Fenton system was investigated. The results of Experimental Example 8 show that higher aeration rates increase tetracycline removal efficiency. At both 0.6 L / min and 0.9 L / min, tetracycline removal rates reached 100% after 75 minutes of reaction. Considering process operating costs, 0.6 L / min was selected as the optimal aeration rate.

[0095] Figure 16 The effect of solution pH on the tetracycline removal efficiency of the CuO-CeO2 / Fe2O3 / FF catalyst in a heterogeneous electro-Fenton system was studied. The results of Experimental Example 9 show that when the solution pH is less than 7.2, the tetracycline removal rate reaches 100% after 75 minutes of reaction. When the solution is weakly alkaline (pH = 9.0), the tetracycline removal rate still reaches a high removal rate of 91%. This demonstrates that the prepared catalyst has extremely strong stability in the heterogeneous electro-Fenton system, effectively overcoming the narrow pH range of application of traditional Fenton and electro-Fenton systems.

[0096] Figure 17 The effect of electrolyte type on the removal efficiency of tetracycline by CuO-CeO2 / Fe2O3 / FF catalyst in heterogeneous electro-Fenton system. The results of Experimental Example 10 show that Na2SO4 and NaCl have little effect on the removal of tetracycline by the catalyst in the heterogeneous electro-Fenton system. The removal rate of tetracycline reaches more than 90%, indicating that the prepared catalyst has good applicability. When NaNO3 is used as the electrolyte in this system, the NO3 - This affects the conductivity of the solution, thereby reducing the current efficiency of the system and the reaction rate of the target substance.

[0097] Figure 18 The results of Experimental Example 11 show the effect of initial tetracycline concentration on tetracycline removal efficiency using a CuO-CeO2 / Fe2O3 / FF catalyst in a heterogeneous electro-Fenton system. The results of Experimental Example 11 show that while the removal rate gradually decreases with increasing initial tetracycline concentration, it still maintains a high level of removal. When the initial tetracycline concentration is 20 mg / L, the removal rate reaches 82% after 75 minutes of reaction. When the initial tetracycline concentration is below 10 mg / L, the removal rate reaches 100% after 75 minutes of reaction.

[0098] Figure 19The effect of drinking water matrix type on the tetracycline removal efficiency of the CuO-CeO2 / Fe2O3 / FF catalyst in a heterogeneous electro-Fenton system was investigated. The results of Experimental Example 12 show that when CuO-CeO2 / Fe2O3 / FF is used as the catalyst, the efficiency of tetracycline removal from drinking water using the heterogeneous electro-Fenton system is somewhat affected by the drinking water matrix, but still maintains a high tetracycline removal rate. For lake water, the tetracycline removal rate was 82% after 75 minutes of reaction; for municipal tap water, the tetracycline removal rate was 89% after 75 minutes of reaction; and for river water, the tetracycline removal rate was 92% after 75 minutes of reaction. This indicates that the prepared catalyst is minimally affected by the actual drinking water matrix and has good potential for engineering applications.

[0099] Figure 20 The tetracycline removal efficiency of the CuO-CeO2 / Fe2O3 / FF catalyst in drinking water was measured when the catalyst was reused eight times in a heterogeneous electro-Fenton system. The results of Experimental Example 13 show that the CuO-CeO2 / Fe2O3 / FF catalyst achieved a high tetracycline removal efficiency of 86% in the heterogeneous electro-Fenton system after eight cycles (a total usage time of 600 minutes). This indicates that the prepared catalyst has extremely high stability in application and can be reused after only rinsing with deionized water before reuse. This catalyst has high potential for engineering applications and significantly reduces the cost of catalyst regeneration.

[0100] Figure 21 The removal efficiency of different target pollutants in the heterogeneous electro-Fenton system using CuO-CeO2 / Fe2O3 / FF as the catalyst is shown in Experimental Example 14. The results show that the CuO-CeO2 / Fe2O3 / FF catalyst has good removal effects on ciprofloxacin, tetracycline, sulfasalazine, atrazine, and imidacloprid, indicating that the system has good applicability for the removal of different types of pollutants.

[0101] The experimental results above demonstrate that the present invention stabilizes the structure by loading copper-cerium layered double hydroxide (CuCe-LDH) onto a FF substrate grown on a Fe-MOF / FF substrate, creating a composite material (CuO-CeO2 / Fe2O3 / FF) with a high specific surface area and a porous structure. This design not only enhances the catalyst's physical adsorption capacity and catalytic activity, but also improves its stability and facilitates its recycling.

[0102] The present invention ensures the close integration of CuCe-LDH and Fe-MOF / FF by optimizing the hydrothermal reaction conditions (such as hydrothermal temperature and time), calcination temperature and calcination time, thereby achieving the structural stability and high catalytic performance of the composite material, enabling it to maintain high catalytic activity and pollutant removal efficiency after multiple reuses or long-term reaction.

[0103] This catalyst is suitable for removing various new organic pollutants from drinking water, and can effectively remove a variety of antibiotic contaminants, particularly tetracycline, in a relatively short treatment time. By optimizing reaction conditions (such as current density, aeration rate, and solution pH), the removal efficiency of target substances in drinking water can be further improved, ensuring the catalyst's high efficiency and stability in practical engineering applications.

[0104] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A method for preparing a solid catalyst for treating residual antibiotics or pesticides in drinking water, characterized in that: First, the foamed iron is soaked in dilute hydrochloric acid and ultrasonically treated, then placed in ethanol and ultrasonically treated, and then rinsed with deionized water to obtain a solid 1; terephthalic acid is dissolved in deionized water to obtain a solution 1; Solution 1 was transferred to a reactor, and solid 1 was placed in the reactor for hydrothermal reaction. After the reaction was completed and the temperature dropped to room temperature, the obtained solid was repeatedly washed with deionized water and dried in a drying oven at a constant temperature of 80°C to obtain solid 2, which was named Fe-MOF / FF. Solution 2 was prepared by dissolving weighed amounts of Ce(NO3)3·6H2O, Cu(NO3)2·3H2O, ammonium fluoride, and urea in deionized water at room temperature. The pH was then adjusted to a neutral range using a mixed solution of Na2CO3 and NaOH. Solution 2 was then transferred to a reactor, and solid 2 was placed on the inner wall of the reactor. The reactor was placed in a drying oven and heated at a constant temperature. The resulting solid was then washed and dried to obtain solid 3, named CuCe-LDH / Fe-MOF / FF. Finally, solid three is placed in a muffle furnace and calcined to obtain solid four, which is the CuO-CeO2 / Fe2O3 / FF catalyst.

2. The method for preparing a solid catalyst for treating residual antibiotics or pesticides in drinking water according to claim 1, wherein: The specific preparation method of the solid one is to soak a 2cm×2cm foam iron in 3mol / L dilute hydrochloric acid and ultrasonically treat it for 30 minutes, then soak it in ethanol and ultrasonically treat it for 30 minutes, and finally rinse it with deionized water to obtain the solid one.

3. The method for preparing a solid catalyst for treating residual antibiotics or pesticides in drinking water according to claim 1, wherein: The specific preparation method of the solution 1 is as follows: 2 mmol of terephthalic acid is added to 60 mL of deionized water and continuously stirred until it is completely dissolved to obtain solution 1.

4. The method for preparing a solid catalyst for treating residual antibiotics or pesticides in drinking water according to claim 1, wherein: The specific preparation method of the solid two is to transfer the solution one into a reactor with a volume of 100 mL and a polytetrafluoroethylene lining, place the solid one in the reactor, and react at 150° C. for 12 hours; after the reaction is completed, cool it to room temperature, repeatedly wash it with ethanol and deionized water in sequence, and then dry it at 80° C. to obtain the solid two, which is named Fe-MOF / FF.

5. The method for preparing a solid catalyst for treating residual antibiotics or pesticides in drinking water according to claim 1, wherein: The specific preparation method of the second solution is: 4 mmol of Ce(NO3)3·6H2O, 12 mmol of Cu(NO3)2·3H2O, 20 mmol of ammonium fluoride and 80 mmol of urea are dissolved in 20 mL of deionized water and mixed evenly with ice, and the pH is adjusted to 7.4-7.5 using a mixed solution of Na2CO3 and NaOH to obtain the second solution; wherein the concentration of the Na2CO3 is 0.6 mol / L, and the concentration of the NaOH is 0.3 mol / L.

6. The method for preparing a solid catalyst for treating residual antibiotics or pesticides in drinking water according to claim 1, wherein: The molar ratio of Cu:Ce in the second solution is 3:

1.

7. The method for preparing a solid catalyst for treating residual antibiotics or pesticides in drinking water according to claim 1, wherein: The total molar number of Cu and Ce in the second solution is controlled at 16 mmol.

8. The method for preparing a solid catalyst for treating residual antibiotics or pesticides in drinking water according to claim 1, wherein: The specific preparation method of the solid three is as follows: after transferring the solution two into a polytetrafluoroethylene-lined reactor, the solid two is placed on the inner wall of the reactor; the reactor is placed in a forced air drying oven, and heated at a constant temperature of 120° C. for 12 hours; then the obtained solid is repeatedly washed with ethanol and deionized water in sequence, and dried in an oven at 80° C. to obtain the solid three; The specific preparation method of the solid four is to place the solid three in a muffle furnace and calcine at 400° C. for 1 hour to obtain the solid four.

9. The solid catalyst prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the solid catalyst according to claim 9 in treating residual antibiotics or pesticides in drinking water, characterized in that: The antibiotics include tetracycline, ciprofloxacin and sulfasalazine, and the pesticides include atrazine and imidacloprid; The solid catalyst is used to treat residual antibiotics or pesticides in drinking water through a heterogeneous electro-Fenton reaction, and the current density of the electro-Fenton reaction is 9 mA / cm 2 , aeration volume was 0.6 L / min, and pH value was 7.2.

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