A photocatalyst coupled with microorganism material, and a preparation method and application thereof

Abstract

The application provides a photocatalyst and microbial coupling material, a preparation method and application thereof, and belongs to the field of wastewater treatment. The photocatalyst and microbial coupling material comprises a hydrogel wall material and a biofilm carrier core material; the biofilm carrier core material is embedded in the hydrogel wall material; the hydrogel wall material comprises a calcium alginate hydrogel and a photocatalyst dispersed in the calcium alginate hydrogel; and the biofilm carrier core material comprises a biofilm and a biofilm carrier. The application utilizes the calcium alginate hydrogel to simultaneously couple the photocatalyst and the microbial carrier, avoids the problems existing in the traditional ICPB system, has a strong fixing effect on the photocatalyst, is not easy to fall off, and the photocatalyst is not covered and shielded by the microorganism. The prepared photocatalyst and microbial coupling material has a good degradation effect on the refractory antibiotic in water, has strong practicability, and can be widely applied to the field of wastewater treatment.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a photocatalyst-microorganism coupling material, its preparation method, and its application. Background Technology

[0002] Antibiotics are secondary metabolites produced by microorganisms with antibacterial activity or synthetic analogues. They can kill or inhibit the growth and reproduction of bacteria and have become one of the emerging pollutants of widespread international concern. The overuse of antibiotics and inadequate management measures have made them an increasingly serious threat to water resources. They can spread through the food chain and food web, thus endangering human health. Therefore, there is an urgent need to find an effective and environmentally friendly method to remove antibiotics from wastewater. Currently, advanced oxidation processes (AOPs) are considered an effective means of treating antibiotics, as they can effectively destroy the structure of pollutants by generating reactive oxygen species (ROS). However, their high cost and potential for producing toxic byproducts limit their widespread application. On the other hand, biological treatment technology, a common treatment method adopted in my country's wastewater treatment plants, removes pollutants through microbial metabolism without causing secondary pollution. However, most antibiotics are toxic and persistent, and cannot be effectively removed by a single biological treatment system. Therefore, in order to improve the removal efficiency of antibiotics in wastewater, various hybrid systems based on biological treatment have been developed. Among them, the tightly coupled photocatalysis and biodegradation (ICPB) technology is considered a very promising wastewater treatment technology due to its high degradation rate and high mineralization rate for most antibiotics.

[0003] Traditional ICPB systems are typically constructed by first loading a photocatalyst onto a blank support, followed by microbial enrichment and cultivation. Currently widely used photocatalyst loading methods, such as sol-gel methods, low-temperature sintering, and powder coating, all suffer from photocatalyst waste and the following limitations: some loading methods may experience weakened intermolecular forces, leading to decreased adhesion to the photocatalyst under prolonged water flow, causing separation and detachment from the support, thus reducing the stability of the ICPB system; some loading processes may introduce organic substances toxic to microorganisms, inhibiting their enrichment and growth. Furthermore, microbial growth is non-selective, occurring not only within the support but also on the surface of the loaded photocatalyst, resulting in photocatalyst coverage and obstruction, thereby affecting the degradation efficiency of the ICPB system. Therefore, developing novel ICPB systems with high degradation efficiency and good stability is of great research significance for wastewater treatment. Summary of the Invention

[0004] In view of the technical problems existing in the background technology, this application provides a photocatalyst-microorganism coupling material, its preparation method and application, aiming to solve the technical problems of poor degradation efficiency of ICPB system caused by easy detachment of photocatalyst and inactivation of microorganisms due to poisoning in existing close coupling technologies of photocatalysis and biodegradation.

[0005] In a first aspect, embodiments of this application provide a photocatalyst-microorganism coupling material, comprising a hydrogel wall material and a biofilm carrier core material; the biofilm carrier core material is embedded within the hydrogel wall material; the hydrogel wall material comprises calcium alginate hydrogel and a photocatalyst dispersed in the calcium alginate hydrogel; the biofilm carrier core material comprises a biofilm and a biofilm carrier.

[0006] Preferably, the photocatalyst includes at least one of g-C3N4, g-C3N4 / BiOBr, and WO3 / BiOBr; the biofilm carrier includes a high-density polyethylene suspension carrier packing.

[0007] Secondly, embodiments of this application provide a method for preparing a photocatalyst-microorganism coupling material, comprising the following steps: S1. The biofilm carrier is immersed in a mixture of activated sludge and synthetic wastewater, and then cultured until a stable biofilm is formed inside the biofilm carrier to obtain the biofilm carrier core material. S2. The photocatalyst is dispersed in a sodium alginate solution to obtain a first mixed solution; the biofilm carrier core material is mixed with the first mixed solution to obtain a second mixed solution; the second mixed solution is mixed with a calcium chloride solution and cured for 12-24 hours to obtain a photocatalyst-microorganism coupling material.

[0008] Preferably, in step S1, the biofilm carrier is soaked in a mixture of activated sludge and synthetic wastewater, and then cultured. Specifically, the biofilm carrier, activated sludge and synthetic wastewater are added to a moving bed biofilm reactor for culture. After a biofilm forms inside the biofilm carrier, the sludge is discharged. After more than one month of continued culture, a stable biofilm is formed inside the biofilm carrier.

[0009] Preferably, the biofilm carrier in the moving bed biofilm reactor has a filling rate of 20% v / v to 60% v / v.

[0010] Preferably, the volume ratio of activated sludge to synthetic wastewater is 1:(6~10).

[0011] Preferably, the activated sludge is aerobic activated sludge from the oxidation ditch process section of a wastewater treatment plant.

[0012] Preferably, the synthetic wastewater includes 0.15~0.5 g·L of anhydrous glucose. -1 NaHCO3 0.15~0.5 g·L-1 NH4HCO3 0.1~0.4 g·L -1 K₂HPO₄ 0.05~0.08 g·L -1 KH₂PO₄ 0.05~0.08 g·L -1 1.5~2.5 mL·L of micro-concentrate -1 .

[0013] Preferably, the micro-concentrate comprises 0.8~1.2 g·L⁻¹ FeCl₃·6H₂O. -1 H3BO3 0.1~0.3 g·L -1 CuSO4·5H2O 0.01~0.05 g·L -1 KI 0.01~0.05 g·L -1 MnCl2·4H2O 0.1~0.15 g·L -1 (NH4)6Mo7O 24 ·4H₂O 0.05~0.08 g·L -1 ZnSO4·7H2O 0.1~0.15 g·L -1 CoCl2·6H2O 0.1~0.3 g·L -1 .

[0014] Preferably, the operating conditions in the moving bed biofilm reactor are as follows: aeration rate of 1~5 L·min -1 The hydraulic retention time is 4–20 h, and the influent flow rate is 0.01–1 L·min. -1 The outflow velocity is 0.01~1 L·min -1 The magnetic stirring speed was 200–450 rpm, and the initial MLVSS was 3.0–6.0 g·L⁻¹. -1 .

[0015] Preferably, the sodium alginate solution is a sterile sodium alginate solution.

[0016] In some embodiments of the present invention, the method for preparing sterilized sodium alginate solution is to transfer sodium alginate solution to a high-pressure steam sterilizer, set the sterilization temperature to 121°C, and the sterilization time to 30 min.

[0017] Thirdly, the present invention provides an application of a photocatalyst-microorganism coupling material in the degradation of antibiotics in water, including sulfonamide antibiotics.

[0018] Preferably, the filling ratio of the photocatalyst and microbial coupling material in the water to be degraded is 5% v / v to 40% v / v.

[0019] Preferably, the filling ratio of the photocatalyst and microbial coupling material in the water to be degraded is 10%v / v to 20%v / v.

[0020] Preferably, the filling ratio of the photocatalyst and microbial coupling material in the water to be degraded is 10% v / v.

[0021] Preferably, the mass ratio of the photocatalyst to the initial sulfonamide antibiotic in the water is (50~500):1.

[0022] The principle of this invention is as follows: High-density polyethylene (HDPE) suspension carrier filler is used as the site for microbial enrichment and growth. HDPE carrier has the characteristics of large specific surface area, good hydrophilicity, long service life, and strong load resistance, which facilitates rapid microbial enrichment and growth. After the microorganisms grow and form a biofilm, the microbial carrier is encapsulated by calcium alginate (CA) hydrogel containing a quantitative photocatalyst to obtain the ICPB-CA carrier. The photocatalyst g-C3N4 can generate strong reactive oxygen species (ROS). After sulfonamide antibiotics are attacked by ROS, they generate some biodegradable intermediate products. These intermediate products are subsequently consumed and degraded by microorganisms as carbon sources. This step can reduce the competition for ROS between sulfonamide antibiotics and these intermediate products, making it easier for ROS to attack sulfonamide antibiotics. In the ICPB-CA carrier, the calcium alginate hydrogel has a strong fixation effect on the photocatalyst and is not easy to fall off. Moreover, the microorganisms are encapsulated inside and will not cover or block the photocatalyst. Therefore, the ICPB-CA carrier can maintain its high efficiency and stability in the process of degrading sulfonamide antibiotics.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention provides a method for preparing a photocatalyst-microorganism coupling material, which utilizes calcium alginate hydrogel to simultaneously couple the photocatalyst and the microbial carrier, avoiding the problems existing in the traditional ICPB system, such as the introduction of organic substances that are toxic to microorganisms, and the waste caused by the photocatalyst separating and falling off from the carrier due to poor fixation during long-term microbial enrichment and growth. In the photocatalyst-microorganism coupling material (i.e., ICPB-CA carrier) provided by this invention, the calcium alginate hydrogel has a strong fixation effect on the photocatalyst, is not easy to fall off, and the microorganisms will not cover or block the photocatalyst, which has certain application prospects.

[0024] (2) The photocatalyst-microorganism coupling material (ICPB-CA carrier) prepared in this invention has a good degradation effect on the recalcitrant antibiotics in water, has strong practicality, can be widely used in the field of sewage treatment, provides more possibilities for ICPB technology, provides an efficient and stable solution for the environmental protection industry, and has good commercial prospects and market size.

[0025] (3) The preparation method of the photocatalyst-microorganism coupling material (ICPB-CA carrier) provided by the present invention is simple. The materials required for preparation, such as urea, sodium alginate, anhydrous calcium chloride and other drugs, are non-toxic and will not cause pollution to the environment. Moreover, the cost is low.

[0026] (4) The calcium alginate hydrogel used in the photocatalyst and microbial coupling material (ICPB-CA carrier) provided by the present invention will not break under mechanical stirring and aeration, and will not decompose under visible light irradiation. It has high stability and is easy to recycle. Attached Figure Description

[0027] Figure 1 This is a diagram showing the operating performance of the MBBR reactor in the embodiments of this application; Figure 2 This is a schematic diagram of the ICPB-CA carrier preparation process in the embodiments of this application; Figure 3 Scanning electron microscope (SEM) images of g-C3N4 powder, calcium alginate hydrogel, and calcium alginate hydrogel material containing g-C3N4 powder in the embodiments of this application. Figure 4 The graph shows the degradation effect of ICPB-CA carrier on SMM under different filling ratios in the embodiments of this application. Figure 5 This is a graph showing the stability test effect of the ICPB-CA carrier on the degradation of SMM in the embodiments of this application. Detailed Implementation

[0028] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0029] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0030] The biofilm carrier used in the following embodiments of the present invention is a commercially available K1 type high-density polyethylene (HDPE) suspension carrier packing. This packing is a 4-pore hollow cylindrical structure with a diameter of approximately 1 cm and a height of approximately 1.2 cm, and a volume of approximately 1 cm³. 3 It has the characteristics of large specific surface area, good hydrophilicity, long service life and strong load resistance, which facilitates the rapid enrichment and growth of microorganisms.

[0031] The components of the synthetic wastewater used for biofilm culture in the following embodiments of the present invention are shown in Table 1.

[0032] Table 1. Components of wastewater from biofilm culture synthesis

[0033] The components of the trace concentrate in Table 1 are shown in Table 2.

[0034] Table 2 Trace Components

[0035] The operating parameters of the moving bed biofilm reactor (MBBR) used for biofilm culture in the following embodiments of the present invention are shown in Table 3.

[0036] Table 3 Operating parameters of the MBBR reactor

[0037] Example 1 1. Preparation of photocatalyst carbon nitride (g-C3N4) In this embodiment, carbon nitride, a covalent compound with good biocompatibility, is selected as the photocatalyst. Carbon nitride is prepared through the following steps: (1) Dissolve 10g of urea in 15ml of water and adjust the pH to 4.5 using 1M HCl solution; (2) The mixed solution was placed in a 60℃ oven for 12 hours to obtain a white crystalline solid; (3) Place the solid into a programmable muffle furnace and heat at 10°C for 1 minute. -1 The temperature was increased to 550℃ at a heating rate and held for 2 hours to obtain a honeycomb-shaped yellow solid. After cooling to room temperature, the solid was ground into powder using a mortar and pestle and labeled as carbon nitride.

[0038] 2. Microbial culture In this embodiment, the activated sludge used for inoculation was aerobic activated sludge from the oxidation ditch process of a wastewater treatment plant, and it was cultured using a moving bed biofilm reactor (MBBR). The carrier used was commercially available K1 type high-density polyethylene (HDPE) packing, also known as MBBR packing. This packing is a 4-pore hollow cylindrical structure with a diameter of approximately 1 cm and a height of approximately 1.2 cm, and a volume of approximately 1 cm³. 3 It has the characteristics of large specific surface area, good hydrophilicity, long service life and strong load resistance, which facilitates the rapid enrichment and growth of microorganisms.

[0039] 200 mL of activated sludge was added to a 1.8 L reactor, along with 1.6 L of synthetic wastewater. Simultaneously, 720 K1 carriers were added at a filling ratio of 40% v / v. The composition of the synthetic wastewater is shown in Tables 1 and 2, and the specific parameters of the MBBR reactor are shown in Table 3.

[0040] After observing biofilm formation within the K1 carrier, the sludge was discharged. The concentrations of ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, and COD in the discharge were continuously monitored. Once the effluent stabilized, the influent load was gradually increased. Approximately one month after the start of biofilm formation, the mixed liquor suspended solids (MLSS) concentration reached 1.49 g·L⁻¹. -1 COD and NH4 + The removal rates reached 92% and 100%, respectively. The operating performance of the MBBR reactor is as follows: Figure 1 As shown.

[0041] 3. Preparation of ICPB-CA vector (1) Preparation of sterile sodium alginate solution: Weigh 6 g of sodium alginate and dissolve it in 200 mL of ultrapure water. Transfer the prepared solution to a high-pressure steam sterilizer, set the sterilization temperature to 121 °C and the sterilization time to 30 min. After sterilization, cool it to room temperature on a sterile operating table for later use.

[0042] (2) Dissolve 90 mg of g-C3N4 photocatalyst powder in 8 mL of ultrapure water and stir at high speed for 2 min using a vortex mixer to obtain an aqueous solution of photocatalyst. Mix it with 12 mL of sodium alginate solution and stir at high speed using a vortex mixer until the mixture is uniform.

[0043] (3) Dissolve 6g of anhydrous calcium chloride in 300 mL of ultrapure water, keep the magnetic stirring speed at 150 rpm, and stir until the solution is clear and transparent to obtain calcium chloride solution.

[0044] (4) Thirty biofilm carriers were placed in a sodium alginate solution containing a photocatalyst. The mixture was stirred at high speed using a vortex mixer until each biofilm carrier was completely coated both internally and externally. The carriers were then quickly transferred to a calcium chloride solution using tweezers. The remaining mixture was then added dropwise to the calcium chloride solution using a dropper. After solidification in the calcium chloride solution for 12 hours, a system was obtained in which a calcium alginate (CA) hydrogel containing a quantitative amount of photocatalyst encapsulated the microbial carriers. This system was designated as ICPB-CA carrier. The specific preparation process is as follows: Figure 2 As shown.

[0045] The prepared g-C3N4 powder and calcium alginate hydrogel were characterized by scanning electron microscopy (SEM), and the results are as follows: Figure 3 As shown. Figure 3 (a) is a SEM image of g-C3N4 powder, showing its hierarchical structure with microcrystals and aggregated particles. Figure 3 (b) and Figure 3 (c) SEM images of calcium alginate hydrogel and calcium alginate hydrogel containing g-C3N4, respectively. Comparative observation shows that g-C3N4 is uniformly dispersed in calcium alginate hydrogel, resulting in a rougher and denser surface and narrower polymer chains in calcium alginate hydrogel.

[0046] Example 2 The difference between this embodiment and Example 1 is that in the preparation of the ICPB-CA carrier, 15 biofilm carriers were put into a sodium alginate solution containing a photocatalyst. All other steps and parameters are the same as in Example 1.

[0047] Example 3 The difference between this embodiment and Example 1 is that in the preparation of the ICPB-CA carrier, 60 biofilm carriers were put into a sodium alginate solution containing a photocatalyst. All other steps and parameters are the same as in Example 1.

[0048] Example 4 The difference between this embodiment and Example 1 is that in the preparation of the ICPB-CA carrier, 120 biofilm carriers were put into a sodium alginate solution containing a photocatalyst. All other steps and parameters are the same as in Example 1.

[0049] Test Example 1: Degradation Performance of ICPB-CA Carrier for Antibiotics To investigate the application of the ICPB-CA carrier prepared in this invention in the degradation of antibiotics in wastewater, the recalcitrant antibiotic sulfamethoxypyrimidine (SMM) was selected as the target pollutant. Photocatalytic-biodegradation experiments of the ICPB-CA carrier were conducted under LED illumination at different filling ratios (i.e., different numbers of ICPB-CA carriers) to evaluate its degradation performance. The test methods are as follows: A 500 mL quartz beaker was used as the reactor, with an effective volume of 300 mL. The reaction solution contained 1 mg·L⁻¹ -1 The reaction mixture consisted of sulfamethoxypyrimidine (SMM) and COD-free synthetic wastewater, and a dual-sided LED lamp (40W) was used as the light source. The experiment was divided into four groups. The ICPB-CA carriers prepared in Examples 1-4 were added to the reaction solution, and the reactors were shielded from light using aluminum foil. A dark reaction was carried out for 30 minutes to reach adsorption equilibrium. Starting from the time of initial illumination and aeration, 2 mL samples were taken every 1 hour, with a total experimental duration of 10 hours. Throughout the experiment, a magnetic stirrer was used at 250 rpm, and an aeration pump was used at 100 mL / min. -1 Aeration was performed at a certain aeration rate. After filtration through a 0.22 μm aqueous filter membrane, the concentration of SMM was determined using high-performance liquid chromatography (HPLC). The degradation rate of SMM by the ICPB-CA carrier was calculated, and degradation curves were plotted. In Examples 1-4, the photocatalyst content in the reaction systems was 300 mg·L⁻¹. -1The filling ratios of the ICPB-CA support in the reaction systems of Examples 1-4 were 10% v / v, 5% v / v, 20% v / v, and 40% v / v, respectively. The test results are as follows: Figure 4 As shown.

[0050] Figure 4 The results showed that the degradation rates of SMM were 86.2%, 100%, 100%, and 93.1% for filling ratios of 5% v / v, 10% v / v, 20% v / v, and 40% v / v, respectively. This indicates that the SMM degradation rate is not directly correlated with the carrier filling ratio. When the filling ratio is too high, the carriers block each other, preventing some of the photocatalyst on the carrier surface from receiving light, thus affecting the degradation rate. Based on these experimental results, a filling ratio of 10% v / v for the ICPB-CA carrier in the reaction system resulted in the best degradation effect on SMM.

[0051] Test Example 2: Stability test of ICPB-CA vector against antibiotic degradation The ICPB-CA carrier prepared in Example 1 (corresponding to a filling ratio of 10% v / v) was used to prepare 1 mg·L⁻¹ -1 The SMM was subjected to three cycles of photocatalytic-biodegradation (detection method same as in Test Example 1) to evaluate the stability of its degradation performance. The results are as follows: Figure 5 As shown.

[0052] Figure 5 The results showed that the removal efficiency of SMM reached a maximum of 99.3 ± 0.7% within 10 h, demonstrating the excellent degradation ability of the ICPB-CA support for SMM. This is mainly attributed to the strong reactive oxygen species (ROS) generated by the photocatalyst g-C3N4. After SMM is attacked by ROS, it generates some biodegradable intermediates. These intermediates are subsequently consumed and degraded by microorganisms as carbon sources. This step reduces the competition between SMM and these intermediates for ROS, making it easier for ROS to attack SMM. After three cycles, the weight of the ICPB-CA support decreased by only 1.6%, proving that the calcium alginate hydrogel firmly fixes the photocatalyst and does not cause a large amount of photocatalyst to fall off due to water erosion, effectively enhancing the adhesion strength between the photocatalyst and the microbial support. At the same time, the SMM degradation rate decreased by only 6.8%, indicating that the system maintained high efficiency and stability during continuous operation.

[0053] Comparative Example 1 The traditional ICPB carrier preparation process using the sol-gel method was as follows: 1 g of carbon nitride powder was dissolved in 20 ml of ethanol and stirred to obtain a homogeneous suspension. Then, 2 ml of nitric acid was added, followed by sonication at 60 °C for 30 min. Thirty K1 carriers were added to the sonicated solution and stirred using a heated magnetic stirrer, maintaining the temperature at 100 °C until the solution was completely evaporated. The carriers were removed, rinsed with pure water, and dried in a 60 °C oven for 12 h to obtain the photocatalytic carrier. Subsequently, the photocatalytic carrier was cultured in the dark for biofilm enrichment, under the same conditions as the microbial culture in Example 1.

[0054] Under the same testing conditions, the ICPB carrier (10% v / v filling ratio) prepared in Comparative Example 1 was used to treat 1 mg·L⁻¹ of ... -1 Three cycles of photocatalytic-biodegradation experiments were conducted on SMM. The results showed that the removal efficiency of SMM was only 64% within 10 h. After three cycles, the degradation rate of SMM decreased by 12%. During the microbial culture process, a large amount of photocatalyst was detached, which seriously affected the degradation effect.

[0055] Example 5 The difference between this embodiment and Example 1 is that the photocatalyst in this embodiment is g-C3N4 / BiOBr, as described in the literature. Growth of BiOBr nanosheets on C 3 N 4 nanosheets to construct two-dimensional nanojunctions with enhanced photoreactivity for NO removal Prepared by the method described in (DOI: 10.1016 / j.jcis.2013.12.037).

[0056] The steps for culturing the microorganisms and preparing the ICPB-CA vector in this embodiment are the same as in Example 1.

[0057] Under the same test conditions, the ICPB-CA carrier (10% v / v filling ratio) prepared in Example 5 was used to test 1 mg·L⁻¹. -1 The SMM was subjected to a three-cycle photocatalytic-biodegradation experiment. The results showed that the removal efficiency of SMM reached 87% within 10 h. After three cycles, the SMM degradation rate decreased by 7%, and the weight of the ICPB-CA carrier decreased by 2.5%.

[0058] Example 6 The difference between this embodiment and Example 1 is that the photocatalyst in this embodiment is WO3 / BiOBr, as described in the reference. Visible-light-driven WO 3 / BiOBr heterojunction photocatalysts for oxidative coupling of amines to imines: Energy band alignment and mechanistic insight It was prepared by the method described in (DOI: 10.1016 / j.jcis.2019.10.057).

[0059] The steps for culturing the microorganisms and preparing the ICPB-CA vector in this embodiment are the same as in Example 1.

[0060] Under the same test conditions, the ICPB-CA carrier (10% v / v filling ratio) prepared in Example 6 was used to test 1 mg·L⁻¹. -1 The SMM was subjected to a three-cycle photocatalytic-biodegradation experiment. The results showed that the removal efficiency of the ICPB-CA carrier reached 54% within 10 h. After three cycles, the SMM degradation rate decreased by 3%, and the weight of the ICPB-CA carrier decreased by only 0.2%.

[0061] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A photocatalyst coupled with microorganisms, characterized in that, The device includes a hydrogel wall material and a biomembrane carrier core material; the biomembrane carrier core material is embedded within the hydrogel wall material; the hydrogel wall material includes calcium alginate hydrogel and a photocatalyst dispersed in the calcium alginate hydrogel; the biomembrane carrier core material includes a biomembrane and a biomembrane carrier. The preparation method of the photocatalyst-microorganism coupling material includes the following steps: S1. The biofilm carrier is immersed in a mixture of activated sludge and synthetic wastewater, and then cultured until a stable biofilm is formed inside the biofilm carrier to obtain the biofilm carrier core material. S2. The photocatalyst is dispersed in a sodium alginate solution to obtain a first mixed solution; the biofilm carrier core material is mixed with the first mixed solution to obtain a second mixed solution; the second mixed solution is mixed with a calcium chloride solution and cured for 12-24 hours to obtain the photocatalyst-microorganism coupling material.

2. The photocatalyst-microorganism coupling material according to claim 1, characterized in that, The photocatalyst includes at least one of g-C3N4, g-C3N4 / BiOBr, and WO3 / BiOBr; The biofilm carrier includes a high-density polyethylene suspension carrier packing material.

3. The photocatalyst-microorganism coupling material according to claim 1, characterized in that, Step S1 specifically involves adding a biofilm carrier, activated sludge, and synthetic wastewater into a moving bed biofilm reactor for cultivation. After a biofilm forms inside the biofilm carrier, the sludge is discharged, and the cultivation continues for more than one month until a stable biofilm forms inside the biofilm carrier.

4. The photocatalyst-microorganism coupling material according to claim 3, characterized in that, The biofilm carrier is filled at a rate of 20% v / v to 60% v / v in the moving bed biofilm reactor.

5. The photocatalyst-microorganism coupling material according to claim 3, characterized in that, The operating conditions in the moving bed biofilm reactor are as follows: aeration rate of 1~5 L·min -1 The hydraulic retention time is 4–20 h, and the influent flow rate is 0.01–1 L·min. -1 The outflow velocity is 0.01~1 L·min -1 The magnetic stirring speed was 200–450 rpm, and the initial MLVSS was 3.0–6.0 g·L⁻¹. -1 .

6. The photocatalyst-microorganism coupling material according to claim 1, characterized in that, The volume ratio of activated sludge to synthetic wastewater is 1:(6~10).

7. The application of the photocatalyst-microbial coupling material as described in any one of claims 1 to 6 in the degradation of antibiotics in water, characterized in that, The antibiotics include sulfonamide antibiotics.

8. The application according to claim 7, characterized in that, The filling ratio of the photocatalyst and microbial coupling material in the water to be degraded is 5% v / v to 40% v / v.

9. The application according to claim 8, characterized in that, The filling ratio of photocatalyst and microbial coupling material in the water body to be degraded is 10%v / v~20%v / v.

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