A method for treating antibiotic wastewater based on modified hematite hybrid sludge biochar

Abstract

The application discloses an antibiotic wastewater treatment method based on modified hematite hybrid sludge biochar, and the method is used for degrading and treating antibiotic wastewater by using acid modified hematite hybrid sludge biochar, wherein the acid modified hematite hybrid sludge biochar is obtained by drying activated sludge recovered from a sewage treatment plant, adding hematite hybrid, pyrolyzing, and then modifying by microwave-assisted hydrochloric acid. The method has the advantages of simple process, low preparation cost, good degradation effect, high treatment efficiency, good stability, good recyclability and the like, and is a green and environment-friendly method for removing antibiotics in water which can be widely used.

Description

Technical Field

[0001] This invention belongs to the field of advanced oxidation catalyst preparation technology, and relates to the treatment of antibiotic wastewater, specifically to a method for treating antibiotic wastewater based on modified hematite hybrid sludge biochar. Background Technology

[0002] The potential negative impacts of emerging pollutants like antibiotics on human health and the risk of generating antibiotic resistance genes in ecosystems have attracted widespread attention. Due to the low concentrations and high toxicity of antibiotics, traditional wastewater treatment methods such as physical adsorption and chemical oxidation are insufficient for their effective removal. Advanced oxidation processes (AOS) have been applied to the treatment of organic pollutant wastewater due to their high efficiency and speed, and have garnered significant attention from researchers. Currently, the catalysts required for AOS are often difficult to mass-produce and have high synthesis costs. Therefore, there is an urgent need to develop novel, low-cost, and high-efficiency catalysts to effectively and rapidly degrade antibiotics in water. Since sewage sludge contains abundant organic matter, pyrolysis to obtain sludge biochar is a common method for sludge resource utilization. Biochar is a highly attractive environmental remediation material, attracting considerable attention from researchers due to its excellent physical properties and economic practicality. Combining AOS with modified sludge biochar shows great promise in the current environment. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an antibiotic wastewater treatment method based on modified hematite hybrid sludge biochar, which is highly recyclable, has high removal efficiency, low preparation cost, and strong practical application.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A method for treating antibiotic wastewater based on modified hematite hybrid sludge biochar is characterized by mixing acid-modified hematite hybrid sludge biochar with antibiotic wastewater, thereby achieving efficient degradation of antibiotics in the wastewater through its catalytic action on persulfate. The preparation method of the acid-modified hematite hybrid sludge biochar includes the following steps:

[0006] S1. The activated sludge recovered from the wastewater treatment plant is dried to obtain dry sludge;

[0007] S2. After grinding the dry sludge evenly, mix it with hematite and calcine it to obtain hematite hybrid sludge biochar.

[0008] S3. The hematite hybrid sludge biochar obtained in step S2 is mixed with hydrochloric acid solution and subjected to microwave hydrothermal reaction to obtain acid-modified hematite hybrid sludge biochar.

[0009] In a further improvement to the above method, in step S3, the mass-to-volume ratio of the hematite hybrid sludge biochar to the hydrochloric acid solution is 0.3 g~0.5 g : 30 ml~50 ml, and the concentration of the hydrochloric acid solution is 0.2 mol·L⁻¹. -1 .

[0010] In a further improvement to the above method, in step S2, the dried sludge and hematite are both ground and sieved through a 100-mesh sieve, and the mass ratio of the dried sludge to hematite is 3 g~4 g : 0.2 g~0.6 g.

[0011] In a further improvement to the above method, in step S3, the heating rate during the microwave hydrothermal reaction is 8°C·min. -1 ~10℃·min -1 The microwave hydrothermal reaction temperature is 80℃~160℃, the microwave hydrothermal reaction time is 40 min, the equipment used for the microwave hydrothermal reaction is a microwave hydrothermal synthesizer, and the power of the microwave hydrothermal synthesizer is 750 W; after the microwave hydrothermal reaction, the following treatment is also included: the microwave hydrothermal reaction product is washed with deionized water and ethanol in sequence, and then vacuum dried at a temperature of 60℃~80℃ for 8 h~12 h.

[0012] In a further improvement to the above method, in step S2, the calcination is carried out under a nitrogen atmosphere, and the heating rate during the calcination process is 8°C·min. -1 ~10℃·min -1 The calcination temperature is 780℃~820℃, and the calcination time is 2 h~2.5 h.

[0013] In a further improvement to the above method, in step S1, the drying process is carried out in an oven, the drying temperature is 80℃~120℃, and the drying time is 24 h~36 h.

[0014] A further improvement to the above method is that the degradation treatment involves mixing acid-modified hematite hybrid sludge biochar with antibiotic wastewater, pre-adsorbing it, adding persulfate, and carrying out an advanced oxidation reaction to degrade the antibiotics in the wastewater.

[0015] A further improvement to the above method is that the initial concentration of antibiotics in the antibiotic wastewater is 10 mg·L⁻¹. -1 ~20 mg·L -1 The antibiotics in the antibiotic wastewater include sulfadiazine, tetracycline, and enflufloxacin, and the pH value of the antibiotic wastewater is 2-10.

[0016] A further improvement to the above method is that, after adding persulfate during the advanced oxidation reaction process, the concentration of persulfate in the antibiotic wastewater is increased to 1 mmol·L⁻¹. -1 The time for the advanced oxidation reaction is 15-20 min.

[0017] Compared with the prior art, the advantages of the present invention are as follows:

[0018] This invention discloses a method for treating antibiotic wastewater based on modified hematite hybrid sludge biochar. The method utilizes acid-modified hematite hybrid sludge biochar to degrade antibiotic wastewater. The acid-modified hematite hybrid sludge biochar is obtained by drying activated sludge recovered from a wastewater treatment plant, adding hematite hybrid biochar, pyrolyzing, and then modifying with microwave-assisted hydrochloric acid. The acid-modified hematite hybrid sludge biochar used in this invention benefits from the fact that activated sludge is a globally produced, renewable, carbon-neutral biological waste. Pyrolysis offers advantages such as rapid reaction speed, elimination of harmful organic components, and significant reduction in waste volume. Thanks to the rich organic components and elemental composition of the sludge, the biochar produced by pyrolysis has abundant surface functional groups, a large specific surface area, and high porosity. After acid modification, the specific surface area and surface active sites are further increased, increasing the contact area with persulfate. The numerous active sites can rapidly and efficiently catalyze the production of singlet oxygen (…). 1 The active substances, primarily O2, accelerate degradation efficiency. Furthermore, the addition of hematite creates a protective iron oxide layer on the surface of the biochar produced by pyrolysis, effectively protecting the material from erosion during acid modification and improving its stability and recyclability. It also introduces a small number of iron active sites, enhancing catalytic efficiency. This method offers advantages such as low preparation cost, excellent degradation effect, high treatment efficiency, good stability, and good recyclability. It maintains high catalytic activity across a wide range of pH values, antibiotic concentrations, and different antibiotic types, and exhibits high adaptability in various aquatic environments. Attached Figure Description

[0019] Figure 1 Scanning electron microscope images of sludge biochar treated with different methods in Example 1 of this invention.

[0020] Figure 2 The images show the Raman spectra of acid-modified hematite hybrid sludge biochar (HFDBC), acid-modified sludge biochar (HSDBC), hematite hybrid sludge biochar (FDBC), and sludge biochar (SDBC) in Example 1 of this invention.

[0021] Figure 3The X-ray photoelectron scanning full spectrum and the O spectrum in the X-ray photoelectron energy spectrum of acid-modified hematite hybrid sludge biochar (HFDBC), hematite hybrid sludge biochar (FDBC), and sludge biochar (SDBC) in Example 1 of this invention are shown.

[0022] Figure 4 The graph shows the degradation effect of sulfadiazine on sludge biochar treated with different methods in Example 1 of this invention.

[0023] Figure 5 This is a graph showing the removal rate of sulfadiazine by acid-modified hematite hybrid sludge biochar (HFDBC) after 20 minutes of reaction following different cycles of use in Example 2 of this invention.

[0024] Figure 6 The graph shows the degradation effect of acid-modified hematite hybrid sludge biochar (HFDBC) on sulfadiazine under different pH conditions in Example 3 of this invention.

[0025] Figure 7 This is a graph showing the degradation effect of acid-modified hematite hybrid sludge biochar (HFDBC) on sulfadiazine under different anion coexistence conditions in Example 4 of the present invention.

[0026] Figure 8 The graph shows the degradation effect of acid-modified hematite hybrid sludge biochar (HFDBC) on sulfadiazine under different water quality conditions in Example 5 of this invention. Detailed Implementation

[0027] 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.

[0028] Example 1

[0029] An antibiotic wastewater treatment method based on modified hematite hybrid sludge biochar of the present invention specifically involves using acid-modified hematite hybrid sludge biochar to degrade sulfadiazine wastewater, including the following steps:

[0030] Using 10 mg of acid-modified hematite hybrid sludge biochar (HFDBC) as a catalyst, 50 mL of a solution with a pH of 5.8 and an initial concentration of 10 mg·L⁻¹ was added. -1 The sulfadiazine wastewater was pre-adsorbed for 10 min, and then persulfate (PMS) was added to make the concentration of persulfate in the system 1 mmol·L⁻¹. -1 The degradation reaction was carried out for 20 minutes to treat sulfadiazine wastewater. All reactions were conducted in a shaking chamber at a rotation speed of 150 r / min.

[0031] Control group 1: No catalyst added, all other conditions are the same.

[0032] Control group 2: Hematite hybrid sludge biochar (FDBC) was used as a catalyst, and other conditions were the same.

[0033] Control group 3: Acid-modified sludge biochar (HSDBC) was used as the catalyst, and all other conditions were the same.

[0034] During the degradation reaction, 1 mL of sample was taken at regular intervals (0 min, 2 min, 5 min, 10 min, 15 min, 20 min) and filtered through a 0.22 μm filter membrane. The peak area change of sulfadiazine at different degradation times was then measured by high performance liquid chromatography to determine the concentration of sulfadiazine after degradation, thereby obtaining the degradation effect of sludge biochar on sulfadiazine under different treatments.

[0035] In this embodiment, the preparation method of acid-modified hematite hybrid sludge biochar (HFDBC) includes the following steps:

[0036] (1) The activated sludge recovered from the sewage treatment plant was dried in an oven at 105°C for 24 h. The resulting solid was ground evenly and sieved through a 100-mesh sieve to obtain dry sludge.

[0037] (2) Mix 3 g of dry sludge and 0.4 g of hematite, grind them evenly, and then heat them in a nitrogen atmosphere at 10 °C·min. -1 The temperature was increased to 800℃ and calcined for 2 h to obtain hematite hybrid sludge biochar, which was named FDBC.

[0038] (3) Take 0.3 g of the FDBC obtained in step (2) and add it to 30 mL of hydrochloric acid solution with a concentration of 0.2 mol·L⁻¹. -1 After sonication for 5 minutes, the sample was placed in a microwave hydrothermal reactor with a power of 750 W. The microwave hydrothermal reaction was carried out at 160℃ for 40 minutes. After the reaction was completed, the sample was rinsed repeatedly with ultrapure water and ethanol, twice each. The sample was then dried in a vacuum oven at 80℃ for 12 hours to obtain acid-modified hematite hybrid sludge biochar, which was named HFDBC.

[0039] In control group 2, the hematite hybrid sludge biochar used was prepared by steps (1) and (2) of the preparation method of acid-modified hematite hybrid sludge biochar (HFDBC), and was named FDBC.

[0040] In control group three, the method for preparing acid-modified sludge biochar (HSDBC) included the following steps:

[0041] (1) is consistent with step (1) of the preparation method of acid-modified hematite hybrid sludge biochar (HFDBC).

[0042] (2) After grinding 3.4 g of dry sludge evenly, it was heated in a nitrogen atmosphere at 10 °C·min. -1 The temperature was increased to 800℃ and calcined for 2 h to obtain sludge biochar, which was named SDBC.

[0043] (3) Take 0.3 g of the SDBC obtained in step (2) and add it to 30 mL of hydrochloric acid solution with a concentration of 0.2 mol·L⁻¹. -1 After sonication for 5 minutes, the sample was placed in a microwave hydrothermal reactor with a power of 750 W. The microwave hydrothermal reaction was carried out at 160℃ for 40 minutes. After the reaction was completed, the sample was rinsed repeatedly with ultrapure water and ethanol, twice each. The sample was then dried in a vacuum oven at 80℃ for 12 hours to obtain acid-modified hematite hybrid sludge biochar, named HSDBC.

[0044] Figure 1 The images are scanning electron microscope images of sludge biochar that have undergone different treatments in Example 1 of this invention. Figure 1 In the figures (a) and (d), the surface morphologies of sludge biochar and hematite hybrid sludge biochar are shown, respectively. (b) and (c) show the surface morphologies of acid-modified sludge biochar at different magnifications, and (e) and (f) show the surface morphologies of acid-modified hematite hybrid sludge biochar at different magnifications. Figure 1 It can be observed that after hematite hybridization, the surface of the sludge biochar is uniformly covered with a layer of granular metal oxides ((a), (d)), indicating that iron elements have successfully adhered to the surface of the biochar. Meanwhile, the structural morphology of the acid-modified sludge biochar differs significantly from that of the hematite hybridized sludge biochar. The acid-modified sludge biochar ((b), (c)) is severely corroded by hydrochloric acid, exhibiting a loose and porous morphology. The acid-modified hematite hybridized sludge biochar ((e), (f)) shows less internal corrosion from hydrochloric acid due to the buffering protection of iron oxides, exhibiting a coral-like surface. This indicates that the acid-modified hematite hybridized sludge biochar, while possessing a high specific surface area, has a more stable structure compared to the acid-modified sludge biochar, making it less prone to collapse during catalytic reactions and thus less likely to affect catalytic efficiency.

[0045] Figure 2 These are Raman spectra of acid-modified hematite hybrid sludge biochar (HFDBC), acid-modified sludge biochar (HSDBC), hematite hybrid sludge biochar (FDBC), and sludge biochar (SDBC) from Example 1 of this invention. Raman spectroscopy is commonly used to represent defects and the degree of graphitization in carbon materials. Figure 2It can be seen that after hematite hybridization, the area ratio of the D peak to the G peak of the sludge biochar decreased, indicating that the addition of iron oxide reduced the degree of defects in the biochar. The area ratio of the D peak to the G peak of the acid-modified sludge biochar and the hematite hybridized sludge biochar both increased, indicating that the erosion of hydrochloric acid increased the degree of defects in the sludge biochar, which is beneficial to the catalytic performance of the material.

[0046] Figure 3 The X-ray photoelectron scanning full spectrum and the O spectrum in the X-ray photoelectron energy spectrum of acid-modified hematite hybrid sludge biochar (HFDBC), hematite hybrid sludge biochar (FDBC), and sludge biochar (SDBC) in Example 1 of this invention are shown. Figure 3 (a) It can be seen that the elemental composition of sludge biochar remained almost unchanged after modification with hydrochloric acid. Figure 3 (b) It can be seen that the binding energy of the oxygen peak shifted to a higher position after the hematite hybrid sludge biochar was modified with hydrochloric acid, indicating that some carbon-oxygen double bonds were broken and the silica structure was damaged by hydrogen ions, resulting in a large number of oxygen defects, thereby improving the catalytic activity of sludge biochar for persulfate.

[0047] Figure 4 This image shows the degradation effect of sulfadiazine on sludge biochar treated with different methods in Example 1 of this invention. Figure 4 It can be seen that the degradation effect of sulfadiazine by using persulfate alone is limited. The acid-modified hematite hybrid sludge biochar (HFDBC) used in this invention can not only effectively remove sulfadiazine from wastewater, but also has a higher removal rate.

[0048] Example 2

[0049] An antibiotic wastewater treatment method based on modified hematite hybrid sludge biochar of the present invention specifically comprises a method for treating sulfadiazine wastewater using acid-modified hematite hybrid sludge biochar that has undergone different cycles of use, including the following steps:

[0050] Using acid-modified hematite hybrid sludge biochar recycled 1, 2, 3, and 4 times respectively as catalysts, four 50 mL portions of the product with a pH of 5.8 and an initial concentration of 10 mg·L⁻¹ were added. -1 The sulfadiazine wastewater was pre-adsorbed for 10 min, and then persulfate (PMS) was added to make the concentration of persulfate in the system 1 mmol·L⁻¹. -1 The degradation reaction was carried out for 20 minutes to treat sulfadiazine wastewater. All reactions were conducted in a shaking chamber at a speed of 150 r / min.

[0051] Control group: Acid-modified sludge biochar was used as a catalyst in cycles 1, 2, 3, and 4, with other conditions being the same.

[0052] The sampling method is the same as in Example 1.

[0053] In this embodiment, the method for preparing acid-modified hematite hybrid sludge biochar through 1, 2, 3, and 4 cycles includes the following steps:

[0054] (1) The sulfadiazine wastewater containing acid-modified hematite hybrid sludge biochar after the reaction in Example 1 was filtered using a glass filter with a 0.22 μm filter membrane. The solid obtained by filtration was washed repeatedly with ultrapure water and ethanol twice each, and dried in a vacuum oven at 80°C for 12 h to obtain acid-modified hematite hybrid sludge biochar after one cycle.

[0055] (2) After the acid-modified hematite hybrid sludge biochar obtained in step (1) is used once, the reaction in Example 1 is repeated, and step (1) is repeated to obtain acid-modified hematite hybrid sludge biochar that is used twice. This step is repeated in turn to obtain acid-modified hematite hybrid sludge biochar that is used three or four times.

[0056] In control group 2, the acid-modified sludge biochar used in cycles 1, 2, 3, and 4 was prepared using a method that was basically the same as that used in cycles 1, 2, 3, and 4 for acid-modified hematite hybrid sludge biochar.

[0057] Figure 5 This is a graph showing the removal rate of sulfadiazine by acid-modified hematite hybrid sludge biochar (HFDBC) after 20 minutes of reaction following different cycles in Example 2 of this invention. Figure 5 It can be seen that, in the fourth cycle, the removal rate of sulfadiazine by acid-modified hematite hybrid sludge biochar can still reach 86%, while the removal rate of sulfadiazine by acid-modified sludge biochar decreases to 64.3%. This further demonstrates that, while possessing high catalytic performance, acid-modified hematite hybrid sludge biochar has a more stable structure than acid-modified sludge biochar, and still exhibits good degradation effects on sulfadiazine even after multiple cycles.

[0058] Example 3

[0059] An antibiotic wastewater treatment method based on modified hematite hybrid sludge biochar of the present invention specifically comprises a method for treating sulfadiazine wastewater using acid-modified hematite hybrid sludge biochar under different pH conditions, including the following steps:

[0060] Using acid-modified hematite hybrid sludge biochar (HFDBC) from Example 1 as a catalyst, five 50 mL portions of the product with an initial concentration of 10 mg·L⁻¹ were added respectively. -1 The sulfadiazine wastewater was pre-adsorbed for 10 min after pH adjustments to 2, 4, 5.8, 8, and 10, and then permonosulfate (PMS) was added to achieve a PMS concentration of 1 mmol·L⁻¹. -1 The degradation reaction was carried out for 20 minutes to treat the sulfadiazine wastewater. All reactions were conducted in a shaking chamber at a rotation speed of 150 r / min. The sampling method was the same as in Example 1.

[0061] Figure 6 This image shows the degradation effect of acid-modified hematite hybrid sludge biochar (HFDBC) on sulfadiazine under different pH conditions in Example 3 of this invention. Figure 6 It can be seen that when the pH values ​​are 2, 4, 5.8, 8, and 10, the advanced oxidation system constructed from acid-modified hematite hybrid sludge biochar and persulfate achieves removal rates of sulfadiazine of 100%, 100%, 100%, 96.5%, and 92.3%, respectively. This demonstrates that the advanced oxidation system of this invention, using acid-modified hematite hybrid sludge biochar as a catalyst, exhibits good removal effects on sulfadiazine wastewater over a wide pH range. The system achieves optimal removal efficiency at an initial pH of 5.8, proving that the advanced oxidation system constructed in this invention does not require further pH adjustment and is easy to operate.

[0062] Example 4

[0063] An antibiotic wastewater treatment method based on modified hematite hybrid sludge biochar of the present invention specifically comprises a method for treating sulfadiazine wastewater using acid-modified hematite hybrid sludge biochar under different anion coexistence conditions, including the following steps:

[0064] Using the acid-modified hematite hybrid sludge biochar (HFDBC) from Example 1 as a catalyst, five 50 mL portions of the product with a pH of 5.8 and an initial concentration of 10 mg·L⁻¹ were added. -1 The sulfadiazine wastewater contained 5 mmol·L⁻¹. -1 Chloride ions, phosphate ions, bicarbonate ions, sulfate ions, and nitrate ions (i.e., sodium chloride, sodium phosphate, sodium carbonate, sodium sulfate, and sodium nitrate were added to the sulfadiazine wastewater, respectively) were pre-adsorbed for 10 min, and then permonosulfate (PMS) was added to make the concentration of permonosulfate in the system 1 mmol·L⁻¹. -1The degradation reaction was carried out for 20 minutes to treat the sulfadiazine wastewater. All reactions were conducted in a shaking chamber at a rotation speed of 150 r / min. The sampling method was the same as in Example 1.

[0065] Figure 7 This image shows the degradation effect of acid-modified hematite hybrid sludge biochar (HFDBC) on sulfadiazine under different anion coexistence conditions in Example 4 of this invention. Figure 7 As shown, chloride ions, phosphate ions, sulfate ions, and nitrate ions have little effect on the catalytic performance of acid-modified hematite hybrid sludge biochar. The addition of bicarbonate ions slows down the degradation process of activated persulfate by hematite hybrid sludge biochar. This is because bicarbonate ions can react with persulfate, which reduces the concentration of persulfate and thus affects the degradation effect on sulfadiazine.

[0066] Example 5

[0067] An antibiotic wastewater treatment method based on modified hematite hybrid sludge biochar of the present invention specifically comprises a method for treating sulfadiazine wastewater under different water quality conditions using acid-modified hematite hybrid sludge biochar, including the following steps:

[0068] Using the acid-modified hematite hybrid sludge biochar (HFDBC) from Example 1 as a catalyst, ultrapure water, tap water, river water (Xiangjiang River water), and medical wastewater containing sulfadiazine were added respectively. The volume of each wastewater was 50 mL, the pH value was 5.8, and the initial concentration of sulfadiazine was 10 mg·L⁻¹. -1 After pre-adsorption for 10 min, persulfate (PMS) was added to make the concentration of persulfate in the system 1 mmol·L⁻¹. -1 The degradation reaction was carried out for 20 minutes to treat the sulfadiazine wastewater. All reactions were conducted in a shaking chamber at a rotation speed of 150 r / min. The sampling method was the same as in Example 1.

[0069] Figure 8 This image shows the degradation effect of acid-modified hematite hybrid sludge biochar (HFDBC) on sulfadiazine under different water quality conditions in Example 5 of this invention. Figure 5As shown, in these four water bodies, the advanced oxidation system constructed from acid-modified hematite hybrid sludge biochar and persulfate achieved removal rates of 100%, 100%, 100%, and 86.3% for sulfadiazine, respectively. Due to the complex composition of anions in medical wastewater, particularly carbonate and bicarbonate ions, the catalytic efficiency of the acid-modified hematite hybrid sludge biochar was somewhat affected, leading to a slight decrease in removal rate, but it still remained above 85%. This indicates that the advanced oxidation system has good application potential in actual water bodies, and HFDBC maintains good stability and catalytic activity even in complex water environments.

[0070] In summary, compared with conventional catalysts, the acid-modified hematite hybrid sludge biochar used in this invention has advantages such as low preparation cost, large specific surface area, high catalytic efficiency, good structural stability, and good recyclability. The advanced oxidation system constructed from this system has advantages such as multiple active sites, high catalytic efficiency, rapid generation of active substances, strong anti-interference ability, and strong adaptability, enabling efficient removal of antibiotics from wastewater over a wide pH range (2-10). Taking sulfadiazine as an example, the advanced oxidation catalytic system constructed in this invention can achieve a removal rate of over 85% for sulfadiazine in three water matrices: tap water, river water, and medical wastewater. This invention's method for treating antibiotic wastewater based on modified hematite hybrid sludge biochar has advantages such as low material cost, good degradation effect, high treatment efficiency, good stability, good recyclability, and strong anti-interference ability. It is an advanced oxidation method that can be widely applied and has high practical value and application prospects.

[0071] 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 treating antibiotic wastewater based on modified hematite hybrid sludge biochar, characterized in that, The method utilizes acid-modified hematite hybrid sludge biochar to activate persulfate for the degradation of antibiotic wastewater; the preparation method of the acid-modified hematite hybrid sludge biochar includes the following steps: S1. The activated sludge recovered from the wastewater treatment plant is dried to obtain dry sludge; S2. After grinding the dry sludge evenly, mix it with hematite and calcine it to obtain hematite hybrid sludge biochar. S3. The hematite hybrid sludge biochar obtained in step S2 is mixed with hydrochloric acid solution and subjected to microwave hydrothermal reaction to obtain acid-modified hematite hybrid sludge biochar.

2. The method for treating antibiotic wastewater based on modified hematite hybrid sludge biochar according to claim 1, characterized in that, In step S3, the mass-to-volume ratio of the hematite hybrid sludge biochar to the hydrochloric acid solution is 0.3 g~0.5 g : 30 ml~50 ml, and the concentration of the hydrochloric acid solution is 0.2 mol·L⁻¹. -1 .

3. The method for treating antibiotic wastewater based on modified hematite hybrid sludge biochar according to claim 2, characterized in that, In step S2, the dry sludge and hematite are both ground and sieved through a 100-mesh sieve, and the mass ratio of the dry sludge to hematite is 3 g~4 g : 0.2 g~0.6 g.

4. The method for treating antibiotic wastewater based on modified hematite hybrid sludge biochar according to claim 3, characterized in that, The microwave hydrothermal reaction in step S3 is carried out at a temperature of 80℃~160℃ for 40 min. The equipment used for the microwave hydrothermal reaction is a microwave hydrothermal synthesizer with a power of 750 W. After the microwave hydrothermal reaction, the following treatment is also included: the microwave hydrothermal reaction product is washed with deionized water and ethanol in sequence, and then vacuum dried at a temperature of 60℃~80℃ for 8 h~12 h.

5. The method for treating antibiotic wastewater based on modified hematite hybrid sludge biochar according to claim 4, characterized in that, In step S2, the calcination is carried out under a nitrogen atmosphere, the calcination temperature is 780℃~820℃, and the calcination time is 2 h~3 h.

6. The method for treating antibiotic wastewater based on modified hematite hybrid sludge biochar according to claim 5, characterized in that, In step S1, the drying process is carried out in an oven, and the drying temperature is 80℃~120℃.

7. The method for treating antibiotic wastewater based on modified hematite hybrid sludge biochar according to any one of claims 1 to 6, characterized in that, The degradation process involves mixing acid-modified hematite hybrid sludge biochar with antibiotic wastewater, pre-adsorbing it, adding persulfate, and then conducting an advanced oxidation reaction to degrade the antibiotics in the wastewater.

8. The method for treating antibiotic wastewater based on modified hematite hybrid sludge biochar according to claim 7, characterized in that, The initial concentration of antibiotics in the antibiotic wastewater was 10 mg·L⁻¹. -1 ~20 mg·L -1 The antibiotics in the antibiotic wastewater include sulfadiazine, tetracycline, and enflufloxacin, and the pH value of the antibiotic wastewater is 2-10.

9. The method for treating antibiotic wastewater based on modified hematite hybrid sludge biochar according to claim 8, characterized in that, After the addition of persulfate in the advanced oxidation process, the concentration of persulfate in the antibiotic wastewater is 1 mmol·L⁻¹. -1 The time for the advanced oxidation reaction is 15-20 min.

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