A method for degrading levofloxacin in wastewater based on a visible light-driven CMP photocatalytic system.

Abstract

A method for degrading levofloxacin in wastewater based on a visible light-driven CMP (Chemical Molecular Polymer) photocatalytic system is disclosed. This invention aims to address the problems of most existing photocatalysts being only responsive to ultraviolet light, having limited solar energy utilization efficiency, being highly susceptible to the influence of wastewater turbidity and color, and exhibiting low degradation efficiency for norfloxacin. The method comprises: 1. Synthesizing a conjugated microporous polymer; 2. Performing photocatalytic degradation under visible light irradiation. This invention aims to achieve efficient solar energy utilization by utilizing the excellent photogenerated charge generation and transport efficiency of conjugated microporous polymers for the efficient degradation of levofloxacin. This provides a mild, efficient, and environmentally friendly green method for degrading the novel pollutant levofloxacin, offering a new option for treating complex industrial wastewater.

Description

Technical Field

[0001] This invention relates to a method for degrading levofloxacin in wastewater. Background Technology

[0002] With the acceleration of industrialization and urbanization, wastewater discharge continues to rise, leading to increasingly serious water pollution problems and posing significant pressure on ecosystem stability and water environment safety. Traditional methods for treating organic pollutants (such as chemical oxidation, adsorption, coagulation sedimentation, and membrane filtration) are still effective in removing conventional pollutants, but their limitations become increasingly apparent when dealing with complex, difficult-to-degrade organic matter and emerging new pollutants. While these methods have advantages such as mature operation, controllable cost, or fast processing speed, they generally suffer from problems such as difficulty in completely degrading pollutants, easy generation of secondary pollution, sensitivity to water quality conditions, or only achieving phase transfer. For example, adsorption methods often only transfer pollutants from the aqueous phase to the solid phase; membrane separation technology is easily affected by fouling and clogging, impacting operational stability; and traditional oxidants have limited efficiency in treating recalcitrant organic matter and may even generate potentially harmful byproducts. Therefore, traditional processes are insufficient to meet the demands for deep purification and efficient removal of emerging pollutants.

[0003] Advanced oxidation processes (AOPs) have attracted widespread attention due to their ability to deeply mineralize pollutants and reduce secondary pollution; however, their high energy consumption and operating costs limit their large-scale application. Therefore, developing water treatment technologies that are efficient, economical, and environmentally friendly has become a key research focus. Against this backdrop, photo-assisted advanced oxidation processes (PAOPs) have gradually become a research hotspot. These technologies introduce light energy as a driving force to promote the generation of reactive oxygen species (ROS), thereby accelerating the oxidative degradation of pollutants and reducing dependence on external energy sources. Compared with traditional AOPs, photo-assisted systems have significant advantages in improving reaction efficiency, reducing chemical reagent usage, and lowering operating costs. By optimizing the light source configuration and the design of photoactive materials, the system can obtain additional energy input, lower the reaction activation energy, and regulate the reaction pathway, thereby enhancing its ability to treat complex organic pollutants.

[0004] Photo-assisted advanced oxidation technologies mainly include three systems: photo-excited oxidation, photo-Fenton oxidation, and photocatalysis. Photo-excited oxidation involves the activation of an external oxidant (such as persulfate PMS, perdisulfate PDS, or ozone) under light irradiation, generating sulfate radicals (…). ), hydroxyl radicals ( ) or superoxide anion ( Highly reactive species such as α and β are suitable for the removal of micropollutants and recalcitrant organic compounds such as antibiotics. The photo-Fenton system utilizes light to promote the removal of Fe... 3+ / Fe 2+ The cycle with H2O2 continuously produces And accelerate Fe 3+ Photocatalysis improves iron recycling efficiency and enhances degradation capacity through photoreduction. The photocatalytic system, centered on semiconductor materials, generates electron-hole pairs through photoexcitation, driving the generation of various reactive oxygen species (ROS) and achieving the oxidative decomposition of pollutants. In recent years, through bandgap engineering and visible light-responsive modification, the performance of photocatalysts such as TiO2, g-C3N4, BiVO4, and ZnIn2S4 has been continuously improved, broadening their application prospects in complex wastewater treatment.

[0005] Photocatalysis technology boasts advantages such as mild reaction conditions, high catalytic efficiency, and economic and environmental friendliness, making it a feasible and promising technology for the degradation of organic pollutants. However, most current photocatalysts only respond to ultraviolet light, exhibiting limited efficiency in utilizing solar energy, and their treatment effectiveness is significantly affected by the turbidity and color of wastewater. Therefore, catalyst regeneration and the utilization of light energy will be the main challenges for future development. Summary of the Invention

[0006] The purpose of this invention is to address the problems that most existing photocatalysts only respond to ultraviolet light, have limited efficiency in utilizing solar energy, are greatly affected by the turbidity and color of wastewater, and have low degradation efficiency for norfloxacin. The invention provides a method for degrading levofloxacin in wastewater based on a visible light-driven CMPs photocatalytic system.

[0007] In order to achieve efficient utilization of solar energy, this invention utilizes the excellent photogenerated charge generation and transport efficiency of conjugated microporous polymers to efficiently degrade levofloxacin, providing a mild, efficient, and environmentally friendly green method for the degradation of the new pollutant levofloxacin, and offering a new option for treating complex industrial wastewater.

[0008] A method for degrading levofloxacin in wastewater based on a visible light-driven CMPs photocatalytic system is specifically carried out according to the following steps:

[0009] I. Synthesis of conjugated microporous polymers:

[0010] ① Add 1,4-diacetylenebenzene, 2,6-dibromonaphthalene-1,5-diol, and tetratriphenylphosphine palladium to N,N-dimethylformamide, then add triethylamine, mix well to obtain a mixture;

[0011] ② Transfer the mixture to the lining of a hydrothermal reactor, evacuate the vacuum, and then fill it with nitrogen. Carry out a solvothermal reaction under nitrogen atmosphere protection. After the reaction is completed, cool to room temperature to obtain the reaction product. Wash and dry the reaction product to obtain a conjugated microporous polymer.

[0012] 2. Add the conjugated microporous polymer and persulfate to a quartz reaction tube, then add wastewater containing levofloxacin, turn on the LED, and perform photocatalytic degradation under visible light irradiation to obtain water with levofloxacin removed.

[0013] The beneficial effects of this invention are:

[0014] I. The conjugated microporous polymer CMP12-141 prepared in this invention exhibits excellent visible light response properties. Under the conditions of CMP12-141 dosage of 0.2 g / L, initial levofloxacin concentration of 10 mg / L, and irradiation with 36 W LED visible light, the degradation rate can reach 97.3% within 60 min, with a degradation rate constant of 0.0446 min. -1 It exhibits highly efficient photocatalytic activity.

[0015] Second, the system of this invention exhibits good compatibility with changes in solution pH and low concentrations of coexisting ions, and the catalyst demonstrates excellent stability. After five cycles, the degradation rate of 20 mL of 10 mg / L levofloxacin solution remains above 88%, indicating that the material has good reusability and is beneficial for reducing treatment costs.

[0016] Thirdly, and more importantly, the system of this invention maintains highly efficient and stable degradation performance even under large-volume, low-concentration, and low-power conditions. When treating 1 L of levofloxacin wastewater with an initial concentration of 1 mg / L, the dosage of CMP12-141 is only 0.02 g / L (1 / 10 of the small-scale test dosage), the PDS concentration is 1 mM, and under 12 W LED visible light irradiation (1 / 3 of the power of the small-scale test), the degradation rate can reach 90% within 300 min. Compared to existing technologies, this invention achieves the same excellent treatment effect under a 50-fold increase in treatment volume by reducing the catalyst dosage and light source power, significantly reducing reagent consumption and operating energy consumption, demonstrating good engineering scale-up potential and practical application value. Attached Figure Description

[0017] Figure 1 SEM image of the conjugated microporous polymer prepared in step 1, ② of Example 1;

[0018] Figure 2 The FTIR spectra of 1,4-diacetylenebenzene, 2,6-dibromonaphthalene-1,5-diol and CMP12-141 are shown.

[0019] Figure 3 Thermogravimetric curve of the conjugated microporous polymer prepared in step 1, ② of Example 1;

[0020] Figure 4 The specific surface area and pore size distribution of the conjugated microporous polymer prepared in step 1, ② of Example 1 are shown.

[0021] Figure 5 The XRD pattern of the conjugated microporous polymer prepared in step 1, ② of Example 1;

[0022] Figure 6 The solid-state NMR spectrum of the conjugated microporous polymer prepared in step 1② of Example 1;

[0023] Figure 7 The UV-Vis absorption spectrum of the conjugated microporous polymer prepared in step 1, ② of Example 1 is shown.

[0024] Figure 8 The Mott-Schottky test pattern is shown for the conjugated microporous polymer prepared in step 1, ② of Example 1.

[0025] Figure 9 This is a degradation kinetic diagram of the photocatalytic degradation of levofloxacin by CMP12-141 in Example 1;

[0026] Figure 10 This is a degradation effect diagram of levofloxacin using CMP12-141 photocatalytic degradation in step two of Example 1;

[0027] Figure 11 The degradation effect of levofloxacin by synergistic degradation of TiO2, g-C3N4 and PDS is shown in the figure.

[0028] Figure 12 The graph shows the effect of pH value of levofloxacin solution on photocatalytic performance.

[0029] Figure 13 The effect of different concentrations of humic acid on the removal of levofloxacin by CMP12-141;

[0030] Figure 14 The effect of recycling CMP12-141 to eliminate levofloxacin is shown in the diagram.

[0031] Figure 15 The image shows the effect of using CMP12-141 to eliminate levofloxacin in a large-scale experiment. Detailed Implementation

[0032] Specific Implementation Method 1: This implementation method is a method for degrading levofloxacin in wastewater based on a visible light-driven CMPs photocatalytic system, specifically completed according to the following steps:

[0033] I. Synthesis of conjugated microporous polymers:

[0034] ① Add 1,4-diacetylenebenzene, 2,6-dibromonaphthalene-1,5-diol, and tetratriphenylphosphine palladium to N,N-dimethylformamide, then add triethylamine, mix well to obtain a mixture;

[0035] ② Transfer the mixture to the lining of a hydrothermal reactor, evacuate the vacuum, and then fill it with nitrogen. Carry out a solvothermal reaction under nitrogen atmosphere protection. After the reaction is completed, cool to room temperature to obtain the reaction product. Wash and dry the reaction product to obtain a conjugated microporous polymer.

[0036] 2. Add the conjugated microporous polymer and persulfate to a quartz reaction tube, then add wastewater containing levofloxacin, turn on the LED, and perform photocatalytic degradation under visible light irradiation to obtain water with levofloxacin removed.

[0037] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the molar ratio of 1,4-diaethynylbenzene to 2,6-dibromonaphthalene-1,5-diol in step one ① is 1:1. The other steps are the same as in Specific Implementation Method One.

[0038] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that the molar ratio of 1,4-diethynylbenzene to tetratriphenylphosphine palladium in step one ① is 2:1. The other steps are the same as in Specific Implementation Method One or Two.

[0039] Specific Implementation Method Four: The difference between this implementation method and Specific Implementation Methods One to Three is that the mass ratio of 1,4-diacetylenebenzene to N,N-dimethylformamide in step one ① is (125mg~130mg):2mL. The other steps are the same as in Specific Implementation Methods One to Three.

[0040] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the volume ratio of N,N-dimethylformamide to triethylamine in step one ① is 2:1. The other steps are the same as in Specific Implementation Methods One to Four.

[0041] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that: the vacuuming time in step one ② is 1 min to 2 min; the temperature of the solvothermal reaction in step one ② is 115℃ to 125℃, and the time is 20 h to 24 h. Other steps are the same as in Specific Implementation Methods One to Five.

[0042] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that: the cleaning described in step one ② involves first washing with distilled water 2 to 3 times, followed by washing with methanol 2 to 3 times; the drying temperature described in step one ② is 60℃ to 80℃, and the drying time is 5 hours to 7 hours. Other steps are the same as in Specific Implementation Methods One to Six.

[0043] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that: the amount of conjugated microporous polymer added in step two is 0.01 g / L to 0.2 g / L; the amount of persulfate added in step two is 0.05 mmol / L to 1 mmol / L. Other steps are the same as in Specific Implementation Methods One to Seven.

[0044] Specific Implementation Method Nine: The difference between this implementation method and Specific Implementation Methods One to Eight is that: the persulfate mentioned in step two is sodium persulfate; the concentration of levofloxacin in the wastewater containing levofloxacin mentioned in step two is 1 mg / L to 20 mg / L; and the pH value of the wastewater containing levofloxacin is 7.5 to 8.0.

[0045] The other steps are the same as those in Specific Implementation Methods 1 to 8.

[0046] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods One to Nine in that the power of the LED lamp mentioned in step two is 12W~36W, and the photocatalytic degradation time mentioned in step two is 30min~300min. Other steps are the same as in Specific Implementation Methods One to Nine.

[0047] The beneficial effects of the present invention are verified using the following embodiments:

[0048] Example 1: A method for degrading levofloxacin in wastewater based on a visible light-driven CMPs photocatalytic system, specifically completed according to the following steps:

[0049] I. Synthesis of conjugated microporous polymers:

[0050] ① Add 1,4-diacetylenebenzene, 2,6-dibromonaphthalene-1,5-diol, and tetratriphenylphosphine palladium to N,N-dimethylformamide, then add triethylamine, mix well to obtain a mixture;

[0051] The molar ratio of 1,4-diacetylenebenzene to 2,6-dibromonaphthalene-1,5-diol mentioned in step 1① is 1:1;

[0052] The molar ratio of 1,4-diacetylenebenzene to tetratriphenylphosphine palladium mentioned in step 1① is 2:1;

[0053] The mass ratio of 1,4-diacetylenebenzene to N,N-dimethylformamide in step 1① is 127.6 mg: 2 mL;

[0054] The volume ratio of N,N-dimethylformamide to triethylamine mentioned in step 1① is 2:1;

[0055] ② Transfer the mixture to the lining of a hydrothermal reactor, evacuate for 1 minute, then fill with nitrogen and carry out a solvothermal reaction under nitrogen atmosphere protection. After the reaction is completed, cool to room temperature to obtain the reaction product. Wash the reaction product and dry it at 80°C for 6 hours to obtain the conjugated microporous polymer (CMP12-141).

[0056] The solvothermal reaction described in step 1② is carried out at a temperature of 120℃ for 24 hours.

[0057] The cleaning described in step 1② is to first wash twice with distilled water, and then wash twice with methanol;

[0058] 2. Add 4 mg of conjugated microporous polymer (CMP12-141) and 20 μL of sodium persulfate (PDS) solution with a concentration of 1 mol / L to a 75 mL quartz reaction tube, then add 20 mL of levofloxacin solution with a concentration of 10 mg / L (pH 7.9), turn on the LED, and carry out photocatalytic degradation under visible light irradiation for 0 min to 60 min to obtain water with levofloxacin removed;

[0059] The LED light mentioned in step two has a power of 36W.

[0060] The structural formula of 1,4-diacetylenebenzene described in step 1① of Example 1 is: The structural formula of 2,6-dibromonaphthalene-1,5-diol is: ;

[0061] The structural formula of the conjugated microporous polymer described in step 1② of Example 1 is as follows: ;

[0062] The synthetic route for step one of Example 1 is as follows: .

[0063] The morphology of the conjugated microporous polymer (CMP12-141) prepared in step 1, ② of Example 1 was characterized using scanning electron microscopy (SEM), see below. Figure 1 As shown;

[0064] Figure 1 SEM image of the conjugated microporous polymer prepared in step 1, ② of Example 1;

[0065] from Figure 1 It can be seen that conjugated microporous polymers exhibit typical pore structures.

[0066] Figure 2 The FTIR spectra of 1,4-diacetylenebenzene, 2,6-dibromonaphthalene-1,5-diol and CMP12-141 are shown.

[0067] from Figure 2It can be determined that: 3274.3 cm of 1,4-diacetylenebenzene -1 and 625.8cm -1 The absorption peak is caused by the stretching vibration and in-plane bending vibration of -C≡CH, and is 878.8 cm⁻¹ in 2,6-dibromonaphthalene-1,5-diol. -1 The absorption peaks are caused by C-Br stretching vibrations. These peaks do not show obvious absorption peaks in the CMP12-141 infrared spectrum, indicating that the material was successfully synthesized.

[0068] Figure 3 Thermogravimetric curve of the conjugated microporous polymer prepared in step 1, ② of Example 1;

[0069] from Figure 3 It can be seen that CMP12-141 exhibits the smallest thermal weight loss (3%) below 300℃, less than 14% at 500℃, and a final thermal weight loss of 68.13% at 800℃. It maintains a high residual carbon rate of 68.1% even at 1000℃, which is attributed to the high-temperature carbonization capability of its naphthalene-aromatic ring framework structure. The multi-stage weight loss behavior indicates differentiated thermal stability of the material components and confirms its application potential in high-temperature environments.

[0070] The specific surface area and pore size distribution of CMP12-141 were characterized using a nitrogen-adsorption-desorption experiment at 298.15 K. (See figure...) Figure 4 As shown;

[0071] Figure 4 The specific surface area and pore size distribution of the conjugated microporous polymer prepared in step 1, ② of Example 1 are shown.

[0072] from Figure 4 It is evident that CMP12-141 exhibits typical Type IV adsorption-desorption isotherm characteristics. At relatively low pressures (P / P0 ≤ 0.1), the significant increase in nitrogen adsorption corresponds to the presence of micropores in the structure. A distinct hysteresis loop is observed in the desorption branch at moderate pressures, which is typically associated with mesoporous structures. In the high-pressure range of P / P0 = 0.9–1.0, the nitrogen adsorption / desorption isotherm rises sharply, indicating the presence of macroporous structures. The pore size distribution curves further confirm that the material possesses a continuous hierarchical porous structure.

[0073] Figure 5 The XRD pattern of the conjugated microporous polymer prepared in step 1, ② of Example 1;

[0074] Figure 5 The display shows a sharp and broad diffraction peak centered at 20°, confirming that CMP12-141 is formed in a kinetically controlled manner and has amorphous characteristics.

[0075] Figure 6 The solid-state NMR spectrum of the conjugated microporous polymer prepared in step 1② of Example 1;

[0076] like Figure 6 As shown, the resonance at 121.3 ppm is attributed to the aromatic carbon (-CAR-H) adjacent to the alkynyl group. The peak at 132.6 ppm can be attributed to the bending vibration of the aromatic carbon (-CAR-H) on the para-substituted benzene ring. The peak at 83.5 ppm corresponds to the hybridized CAR-C≡C-. The peak at 77.6 ppm belongs to the bending vibration of the alkynyl carbon attached to and close to the naphthalene ring, indicating successful synthesis of the material.

[0077] Figure 7 The UV-Vis absorption spectrum of the conjugated microporous polymer prepared in step 1, ② of Example 1 is shown.

[0078] from Figure 7 It can be seen that CMP12-141 exhibits a wide light absorption range across the entire visible light spectrum. It also shows good photochemical absorption in both the near-ultraviolet and visible light regions. The optical bandgap of CMP12-141 is calculated to be 1.74 eV based on the Tauc equation.

[0079] Figure 8 The Mott-Schottky test pattern is shown for the conjugated microporous polymer prepared in step 1, ② of Example 1.

[0080] from Figure 8 It can be seen that the Mott-Schottky curve of CMP12-141 shows a positive slope, revealing that the material has p-type semiconductor characteristics and holes are the main charge carriers. By fitting the Mott-Schottky curve, the conduction band position of CMPs12-141 is found to be -0.89V (vs. Ag / AgCl). Using the equation E(vs. NHE) = E(vs. Ag / AgCl) + 0.2V = -0.69V (vs. NHE, pH=7), the valence band position can be calculated to be 1.05eV.

[0081] To investigate the degradation rate of levofloxacin by the CMPs / PDS system, zero-order, first-order, and second-order kinetic models were used to fit the experimental data, as shown in the figure. Figure 9 As shown;

[0082] Figure 9 This is a degradation kinetic diagram of the photocatalytic degradation of levofloxacin by CMP12-141 in Example 1;

[0083] from Figure 9 It can be seen that the photocatalytic degradation of LEV by the CMP12-141 / PDS synergistic system follows a pseudo-first-order reaction, with a degradation rate of approximately 0.0446 min. -1 .

[0084] Figure 10 This is a degradation effect diagram of levofloxacin using CMP12-141 photocatalytic degradation in step two of Example 1;

[0085] from Figure 10 It was found that after 1 hour of light exposure, the concentration of levofloxacin rapidly decreased from 10.0 mg / L to 0.37 mg / L, with an elimination rate of 97.3%. The degradation of levofloxacin by CMP12-141 was a first-order reaction, with a degradation rate of 0.0446 min. -1 .

[0086] Comparative Example 1: The conjugated microporous polymer (CMP12-141) in step two of Example 1 was replaced with TiO2 and g-C3N4, respectively; all other steps and parameters were the same as in step two of Example 1. The degradation effects of the TiO2 / PDS system and the g-C3N4 / PDS system on levofloxacin solution are shown in [reference needed]. Figure 11 As shown;

[0087] Figure 11 The degradation effect of levofloxacin by synergistic degradation of TiO2, g-C3N4 and PDS is shown in the figure.

[0088] from Figure 11 It can be seen that the total elimination rates of photocatalysts TiO2 and g-C3N4 are 70.0% and 26.0%, respectively, indicating that the CMP12-141 prepared in this invention has better photocatalytic performance.

[0089] Example 2: The difference between this example and Example 1 is that the pH value of the levofloxacin solution in step two is 1, 3, 5, 9, 11, or 13. All other steps and parameters are the same as in Example 1.

[0090] Figure 12 The graph shows the effect of pH value of levofloxacin solution on photocatalytic performance.

[0091] from Figure 12It can be seen that the effect of solution pH on photocatalytic performance has two mechanisms: (1) adjusting the concentration of hydroxyl groups on the catalyst surface, causing changes in the positions of its valence band and conduction band; (2) preferential adsorption, the catalyst tends to adsorb cationic pollutants under alkaline conditions and anionic species under acidic conditions. The photocatalytic degradation efficiency of levofloxacin by CMPs / PDS varies under different pH values. Under the condition of pH 7.9 (stock solution), the elimination rate of levofloxacin by the system can reach 97.3% after 60 min, which is better than that under alkaline conditions. Under acidic conditions, the elimination rates of CMPs / PDS at pH=1, pH=3 and pH=5 are 91.1%, 98.2% and 96.3%, respectively; under alkaline conditions, the elimination rates at pH=13, pH=11 and pH=9 are 29.6%, 55.6% and 88.2%, respectively.

[0092] Example 3: The difference between this example and Example 1 is that humic acid was added to the system in step two, so that the concentrations of humic acid in the system were 1 mg / L, 5 mg / L, 10 mg / L, and 20 mg / L, respectively. All other steps and parameters were the same as in Example 1.

[0093] Figure 13 The effect of different concentrations of humic acid on the removal of levofloxacin by CMP12-141;

[0094] Figure 13 The stock solution in this example is from Example 1; Figure 13 It can be seen that different concentrations of humic acid (HA) have no significant effect on the removal of levofloxacin by CMP12-141, demonstrating the applicability of the CMP12-141 photocatalytic system.

[0095] Example 4: The cyclic test was carried out according to the following steps:

[0096] The conjugated microporous polymer (CMP12-141) after levofloxacin removal in step two of Example 1 was washed with water and methanol, filtered, and then dried. The levofloxacin solution was then degraded again following the process in step two of Example 1, i.e., CMP12-141 was repeatedly used to eliminate levofloxacin. (See...) Figure 14 As shown;

[0097] Figure 14 The effect of recycling CMP12-141 to eliminate levofloxacin is shown in the diagram.

[0098] from Figure 14 It can be seen that after five cycles, the photocatalytic degradation of levofloxacin by CMP12-141 decreased from 97.3% to 88.0%, indicating that CMP12-141 has good reusability.

[0099] Example 5: Large-volume experiment, specifically carried out according to the following steps.

[0100] 0.02g of the conjugated microporous polymer (CMP12-141) prepared in step one of Example 1 and 20μL of sodium persulfate (PDS) solution with a concentration of 1mol / L were added to a glass beaker, followed by 1L of levofloxacin solution with a concentration of 1mg / L (pH 7.9). A 12W circular LED lamp was turned on, and photocatalytic degradation was carried out under visible light irradiation for 0min~300min to obtain water with levofloxacin removed.

[0101] The LED light mentioned in step two has a power of 12W.

[0102] Figure 15 The effect of using CMP12-141 to eliminate levofloxacin in a large-volume experiment is shown in the figure.

[0103] from Figure 15 It can be seen that the degradation experiment of 1L of 1mg / L levofloxacin solution using 0.02g / L CMP12-141 can achieve an elimination rate of 90% within 300min.

[0104] In the large-volume experiment, although the treatment time was 300 min, which is longer than the 60 min treatment time in the smaller experiment, a 90% degradation rate was still achieved under the conditions of 50-fold volume scaling up, catalyst (CMP12-141) reduced to 1 / 10, and light source power reduced to 1 / 3. This demonstrates the engineering potential of CMP12-141 prepared in this invention.

Claims

1. A method for degrading levofloxacin in wastewater based on a visible light-driven CMPs photocatalytic system, characterized in that... The method is specifically implemented according to the following steps: I. Synthesis of conjugated microporous polymers: ① Add 1,4-diacetylenebenzene, 2,6-dibromonaphthalene-1,5-diol, and tetratriphenylphosphine palladium to N,N-dimethylformamide, then add triethylamine, mix well to obtain a mixture; ② Transfer the mixture to the lining of a hydrothermal reactor, evacuate the vacuum, and then fill it with nitrogen. Carry out a solvothermal reaction under nitrogen atmosphere protection. After the reaction is completed, cool to room temperature to obtain the reaction product. Wash and dry the reaction product to obtain a conjugated microporous polymer.

2. Add the conjugated microporous polymer and persulfate to a quartz reaction tube, then add wastewater containing levofloxacin, turn on the LED, and perform photocatalytic degradation under visible light irradiation to obtain water with levofloxacin removed.

2. The method for degrading levofloxacin in wastewater based on a visible light-driven CMPs photocatalytic system according to claim 1, characterized in that... The molar ratio of 1,4-diacetylenebenzene to 2,6-dibromonaphthalene-1,5-diol mentioned in step 1① is 1:

1.

3. The method for degrading levofloxacin in wastewater based on a visible light-driven CMPs photocatalytic system according to claim 1, characterized in that... The molar ratio of 1,4-diacetylenebenzene to tetratriphenylphosphine palladium mentioned in step 1① is 2:

1.

4. The method for degrading levofloxacin in wastewater based on a visible light-driven CMPs photocatalytic system according to claim 1, characterized in that... The mass ratio of 1,4-diacetylenebenzene to N,N-dimethylformamide in step 1① is (125mg~130mg):2mL.

5. The method for degrading levofloxacin in wastewater based on a visible light-driven CMPs photocatalytic system according to claim 1, characterized in that... The volume ratio of N,N-dimethylformamide to triethylamine mentioned in step 1① is 2:

1.

6. The method for degrading levofloxacin in wastewater based on a visible light-driven CMPs photocatalytic system according to claim 1, characterized in that... The vacuuming time mentioned in step 1② is 1 min to 2 min; the temperature of the solvothermal reaction mentioned in step 1② is 115℃ to 125℃, and the time is 20 h to 24 h.

7. The method for degrading levofloxacin in wastewater based on a visible light-driven CMPs photocatalytic system according to claim 1, characterized in that... The cleaning described in step 1② involves washing with distilled water 2 to 3 times, followed by washing with methanol 2 to 3 times; the drying temperature described in step 1② is 60℃ to 80℃, and the drying time is 5h to 7h.

8. The method for degrading levofloxacin in wastewater based on a visible light-driven CMPs photocatalytic system according to claim 1, characterized in that... The dosage of the conjugated microporous polymer in step two is 0.01 g / L to 0.2 g / L; the dosage of the persulfate in step two is 0.05 mmol / L to 1 mmol / L.

9. The method for degrading levofloxacin in wastewater based on a visible light-driven CMPs photocatalytic system according to claim 1, characterized in that... The persulfate mentioned in step two is sodium persulfate; the concentration of levofloxacin in the wastewater containing levofloxacin in step two is 1 mg / L to 20 mg / L; the pH value of the wastewater containing levofloxacin is 7.5 to 8.

0.

10. The method for degrading levofloxacin in wastewater based on a visible light-driven CMPs photocatalytic system according to claim 1, characterized in that... The power of the LED lamp mentioned in step two is 12W~36W, and the photocatalytic degradation time mentioned in step two is 30min~300min.

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