Photocatalyst and microorganism coupling material as well as preparation method and application thereof

Abstract

The invention provides a photocatalyst and microorganism coupling material as well as a preparation method and application thereof, and belongs to the field of sewage treatment. The photocatalyst and microorganism 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 calcium alginate hydrogel and a photocatalyst dispersed in the calcium alginate hydrogel; the biofilm carrier core material comprises a biofilm and a biofilm carrier. The calcium alginate hydrogel is used for coupling the photocatalyst and the microbial carrier at the same time, the problems existing in a traditional ICPB system are avoided, the calcium alginate hydrogel has the high fixing effect on the photocatalyst and is not prone to falling off, and microorganisms cannot cover and shield the photocatalyst. The prepared photocatalyst and microorganism coupling material has a good degradation effect on refractory antibiotics in a water body, has high practicability and can be widely applied to the field of sewage treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a photocatalyst and microorganism coupling material, a preparation method and application thereof. Background Art

[0002] Antibiotics refer to secondary metabolites or synthetic analogs produced by microorganisms with antibacterial activity, which can kill or hinder the growth and reproduction of bacteria. They have become one of the new pollutants that have attracted widespread international attention. The abuse of antibiotics and the lack of management measures have made antibiotics increasingly threatening water resources. They can spread through the food chain and food web, thus endangering human health. Therefore, it is urgent to find an effective and environmentally friendly method to remove antibiotics from sewage. At present, advanced oxidation technology (AOPs) is considered to be an effective means of treating antibiotics. It can effectively destroy the structure of pollutants by producing reactive oxygen species (ROS), but its high cost and the possibility of producing toxic byproducts limit its widespread application. On the other hand, biological treatment technology is a treatment method commonly adopted by sewage treatment plants in my country. It removes pollutants through microbial metabolism without causing secondary pollution. However, most antibiotics are toxic and stubborn 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 closely coupled photocatalytic and biodegradation technology (ICPB) is considered to be a very promising wastewater treatment technology because of its high degradation rate and high mineralization rate for most antibiotics.

[0003] The construction process of traditional ICPB systems is mostly to load the photocatalyst on a blank carrier first, and then enrich and culture the microorganisms. Currently, the widely used photocatalyst loading methods, such as sol-gel method, low-temperature sintering method and powder spraying method, all have the waste of photocatalysts and the following limitations: some loading methods may cause the adhesion strength of the photocatalyst to decrease under long-term water flow due to weak intermolecular forces, causing the photocatalyst to separate and fall off from the carrier, reducing the stability of the ICPB system; some loading processes may introduce organic substances that are toxic to microorganisms, thereby inhibiting the enrichment and growth of microorganisms. In addition, the growth of microorganisms is non-selective. This growth occurs not only inside the carrier, but also on the surface of the loaded photocatalyst, resulting in the photocatalyst being covered and blocked, thereby affecting the degradation efficiency of the ICPB system. Therefore, the development of a new ICPB system with high degradation efficiency and good stability is of great research significance for sewage treatment. Summary of the invention

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

[0005] In the first aspect, the embodiments of the present application provide a photocatalyst and microorganism coupling material, including 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 includes calcium alginate hydrogel and a photocatalyst dispersed in the calcium alginate hydrogel; the biofilm carrier core material includes a biofilm and a biofilm carrier.

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

[0007] In a second aspect, the present application provides a method for preparing a photocatalyst and microbial coupling material, comprising the following steps: S1, soaking the biofilm carrier in a mixture of activated sludge and synthetic wastewater, and then culturing it until a stable biofilm is formed inside the biofilm carrier, thereby obtaining a biofilm carrier core material; S2. Dispersing the photocatalyst in the sodium alginate solution to obtain a first mixed solution; mixing the biofilm carrier core material with the first mixed solution to obtain a second mixed solution; mixing the second mixed solution with the calcium chloride solution, and curing for 12 to 24 hours to obtain a photocatalyst and microbial coupling material.

[0008] Preferably, in step S1, the biofilm carrier is immersed 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 is formed inside the biofilm carrier, the sludge is discharged. After continuing to culture for more than one month, a stable biofilm is formed inside the biofilm carrier.

[0009] Preferably, the filling rate of the biofilm carrier in the moving bed biofilm reactor is 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 sewage treatment plant.

[0012] Preferably, the synthetic wastewater contains 0.15-0.5 g·L anhydrous glucose -1 、NaHCO30.15~0.5 g·L-1 、NH4HCO30.1~0.4 g·L -1 、K2HPO40.05~0.08 g·L -1 、KH2PO40.05~0.08 g·L -1 , micro-concentrate 1.5~2.5 mL·L -1 .

[0013] Preferably, the trace amount of concentrated solution includes FeCl3·6H2O 0.8~1.2 g·L -1 、H3BO30.1~0.3 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: the aeration rate is 1-5 L·min -1 , hydraulic retention time is 4~20 h, and inlet flow rate is 0.01~1 L·min -1 , water flow rate is 0.01~1 L·min -1 , magnetic stirring rate was 200-450 rpm, and initial MLVSS was 3.0-6.0 g·L -1 .

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

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

[0017] In a third aspect, the present invention provides an application of a photocatalyst and a microbial coupling material in degrading antibiotics in water, wherein the antibiotics include sulfonamide antibiotics.

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

[0019] Preferably, the filling ratio of the photocatalyst and the 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 the 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 degradation water is (50~500):1.

[0022] The principle of the technical solution of the present invention is as follows: a high-density polyethylene (HDPE) suspension carrier filler is used as a place for microbial enrichment and growth. The HDPE carrier has the characteristics of large specific surface area, good hydrophilicity, long service life, strong load resistance, etc., which is convenient for rapid enrichment and growth of microorganisms. After the microorganisms grow and form a biofilm, the microbial carrier is encapsulated by using a calcium alginate (CA) hydrogel containing a quantitative photocatalyst to obtain an ICPB-CA carrier. The photocatalyst g-C3N4 can produce strong reactive oxidative substances (ROS). After sulfonamide antibiotics are attacked by ROS, some biodegradable intermediates will be generated. These intermediates will then be consumed and degraded by microorganisms as carbon sources. This step can reduce the competition between sulfonamide antibiotics and these intermediates for ROS, 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, is not easy to fall off, and the microorganisms are wrapped inside, which will not cover and block the photocatalyst, so the ICPB-CA carrier can maintain its high efficiency and stability during the degradation of sulfonamide antibiotics.

[0023] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides a method for preparing a photocatalyst and microorganism coupling material, which uses calcium alginate hydrogel to simultaneously couple the photocatalyst and the microorganism carrier, thereby avoiding the problems existing in the traditional ICPB system, such as the introduction of organic substances that are toxic to microorganisms, and the waste of photocatalysts due to separation and shedding from the carrier during the long-term microbial enrichment and growth process due to loose fixation. In the photocatalyst and microorganism coupling material (i.e., ICPB-CA carrier) provided by the present invention, 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 and microbial coupling material (ICPB-CA carrier) prepared by the present invention has a good degradation effect on difficult-to-degrade antibiotics in water bodies, has strong practicality, can be widely used in the field of sewage treatment, provides more possibilities for ICPB technology, and provides an efficient and stable solution for the environmental protection industry, with good commercial prospects and market scale.

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

[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, will not decompose under visible light irradiation, has high stability, and is easy to recycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is an operating performance diagram of the MBBR reactor in the embodiment of this application; Figure 2 This is a schematic diagram of the preparation process of the ICPB-CA carrier in the examples of this application; Figure 3 The scanning electron microscope images of g-C3N4 powder, calcium alginate hydrogel and calcium alginate hydrogel material containing g-C3N4 powder in the examples of the present application; Figure 4 This is a diagram showing the degradation effect of the ICPB-CA carrier on SMM at different filling ratios in the examples of this application; Figure 5 This is a diagram showing the stability test effect of the ICPB-CA carrier on the degradation of SMM in the examples of the present application. DETAILED DESCRIPTION

[0028] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0029] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0030] The biofilm carrier used in the following examples of the present invention is a commercially available k1 type high-density polyethylene (HDPE) suspension carrier filler. The filler is a 4-hole hollow cylindrical structure with a diameter of about 1 cm and a height of about 1.2 cm, and a volume of about 1 cm 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 synthetic wastewater used for biofilm culture in the following examples of the present invention are shown in Table 1.

[0032] Table 1 Components of biofilm culture wastewater

[0033] Among them, 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 examples of the present invention are shown in Table 3.

[0036] Table 3 MBBR reactor operating parameters

[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 a photocatalyst, and carbon nitride is prepared by the following steps: (1) Dissolve 10 g urea in 15 ml water and adjust the pH to 4.5 using 1 M HCl solution; (2) The mixed solution was placed in an oven at 60°C for 12 h to obtain a white crystalline solid; (3) Place the solid in a programmable temperature muffle furnace and heat it at 10°C min -1 The temperature was raised to 550°C at a heating rate and kept at that temperature for 2 h to obtain a honeycomb yellow solid. After cooling to room temperature, the solid was ground into powder using a mortar and labeled as carbon nitride.

[0038] 2. Cultivation of microorganisms The activated sludge inoculated in this example is aerobic activated sludge from the oxidation ditch process section of a sewage treatment plant, and is cultured using a moving bed biofilm reactor (MBBR). The carrier used is a commercially available k1 type high-density polyethylene (HDPE) filler, also known as MBBR filler. The filler is a 4-hole hollow cylindrical structure with a diameter of about 1 cm and a height of about 1.2 cm, and a volume of about 1 cm 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, and 1.6 L of synthetic wastewater was added, and 720 k1 carriers were added at a filling ratio of 40% v / v. The components of the synthetic wastewater are shown in Tables 1 and 2, and the specific parameters of the MBBR reactor are shown in Table 3.

[0040] After observing the formation of biofilm in the inner circle of the k1 carrier, the sludge was discharged. The discharge concentrations of ammonia nitrogen, nitrite nitrogen, nitrate nitrogen and COD were continuously monitored. After the effluent stabilized, the influent load was gradually increased. About one month after the biofilm formation began, the mixed liquor suspended solids (MLSS) concentration reached 1.49 g·L -1 , COD and NH4 + The removal rates of 2,4-dioxide and 2,4-dioxide were 92% and 100% respectively. The operating performance of the MBBR reactor is shown in Figure 2. Figure 1 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 and set the sterilization temperature to 121 °C for 30 min. After sterilization, cool it to room temperature on a sterile operating table for use.

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

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

[0044] (4) 30 biofilm carriers were placed in a sodium alginate solution containing a photocatalyst, and a vortexer was used to stir at high speed until the inside and outside of each biofilm carrier were coated. Tweezers were used to quickly transfer the carrier to a calcium chloride solution, and a rubber-tipped dropper was used to drop the remaining mixed solution into the calcium chloride solution drop by drop. After curing in the calcium chloride solution for 12 h, a system in which the microbial carrier was coated with a calcium alginate (CA) hydrogel containing a quantitative photocatalyst was obtained, which was recorded as ICPB-CA carrier. The specific preparation process is as follows: Figure 2 shown.

[0045] The prepared g-C3N4 powder and calcium alginate hydrogel were characterized by scanning electron microscopy (SEM). Figure 3 shown. Figure 3 (a) is the SEM image of g-C3N4 powder, showing its hierarchical structure with tiny crystals 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 the calcium alginate hydrogel, resulting in a rougher and denser surface of the calcium alginate hydrogel and narrower polymer chains.

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

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

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

[0049] Test Example 1 Test on the degradation performance of ICPB-CA carrier on antibiotics In order to study the application of the ICPB-CA carrier prepared by the present invention in the field of degradation of antibiotics in sewage, the difficult-to-degrade antibiotic sulfamethoxazole (SMM) was selected as the target pollutant, and the photocatalytic-biodegradation experiment of the ICPB-CA carrier was carried out under LED light at different filling ratios (i.e., adding different numbers of ICPB-CA carriers) to evaluate the degradation performance of the ICPB-CA carrier. The test method is 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 The experiment was composed of sulfamethoxazole (SMM) and synthetic wastewater without COD, and a double-sided LED lamp (40W) was used as the light source. The experiment was divided into 4 groups, and the ICPB-CA carriers prepared in Examples 1 to 4 were added to the reaction solution respectively. The reactor was shaded with tin foil, and the dark reaction was carried out in the dark for 30 min to reach adsorption equilibrium. Taking the time of starting illumination and aeration as the initial point, 2 mL was sampled every 1 h, and the total experimental time was set to 10 h. During the whole experiment, a magnetic stirrer was used to stir at a speed of 250 rpm, and the aeration pump was used at 100 mL·min -1 The sample was aerated with an aeration rate of 100 μm. After being filtered through a 0.22 μm water filter membrane, the concentration of SMM was determined using a high performance liquid chromatograph, the degradation rate of SMM by the ICPB-CA carrier was calculated, and a degradation curve was drawn. The content of the photocatalyst in the reaction system corresponding to Examples 1 to 4 was 300 mg·L -1The filling ratios of the ICPB-CA carrier in the corresponding reaction systems of Examples 1 to 4 were 10% v / v, 5% v / v, 20% v / v, and 40% v / v, respectively. Figure 4 shown.

[0050] Figure 4 The results show that the SMM degradation rates corresponding to the filling ratios of 5% v / v, 10% v / v, 20% v / v, and 40% v / v are 86.2%, 100%, 100%, and 93.1%, respectively. It can be seen that the SMM degradation rate is not positively correlated with the carrier filling ratio. When the filling ratio is too high, the carriers will block each other, making it impossible for the photocatalyst on the surface of some carriers to receive light, thereby affecting the degradation rate. Based on the above experimental results, when the filling ratio of the ICPB-CA carrier in the reaction system is 10% v / v, the degradation effect of SMM is the best.

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

[0052] Figure 5 The results show that the removal efficiency of SMM reaches up to 99.3±0.7% within 10 h, which reflects the excellent degradation ability of ICPB-CA carrier for SMM. This is mainly attributed to the fact that the photocatalyst g-C3N4 can produce strong reactive oxidative species (ROS). After SMM is attacked by ROS, some biodegradable intermediates will be generated, which will then be consumed and degraded by microorganisms as carbon sources. This step can reduce the competition between SMM and these intermediates for ROS, making it easier for ROS to attack SMM. After three cycles, the weight of ICPB-CA carrier decreased by only 1.6%, proving that calcium alginate hydrogel has a relatively firm fixation on the photocatalyst, and will not cause a large amount of photocatalyst to fall off due to water scouring, effectively enhancing the adhesion strength between the photocatalyst and the microbial carrier. At the same time, the SMM degradation rate only decreased by 6.8%, indicating that the system still maintains high efficiency and stability during continuous operation.

[0053] Comparative Example 1 Preparation of traditional ICPB carrier by sol-gel method: 1g carbon nitride powder was dissolved in 20ml ethanol, stirred to obtain a uniform suspension, and then 2ml nitric acid was added, followed by ultrasound at 60°C for 30 min. 30 k1 carriers were added to the ultrasonic solution and stirred with a heated magnetic stirrer, and the temperature was controlled at 100°C until the solution was completely evaporated. The carrier was taken out and rinsed with pure water, placed in a 60°C oven and continued to dry for 12 h to obtain a photocatalytic carrier. The photocatalytic carrier was then cultured for biofilm enrichment in the dark, and the specific culture conditions were the same as those in the culture of the microorganisms in Example 1.

[0054] Under the same test conditions, the ICPB carrier prepared in Comparative Example 1 (10% v / v filling ratio) was used to test 1 mg·L -1 The photocatalytic-biodegradation experiment of SMM was carried out for three cycles. The test showed that its removal efficiency of SMM was only 64% within 10 h. After three cycles, the degradation rate of SMM decreased by 12%. A large amount of photocatalyst had fallen off during the microbial cultivation process, which seriously affected its degradation effect.

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

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

[0057] Under the same test conditions, the ICPB-CA carrier prepared in Example 5 (10% v / v filling ratio) was used to test 1 mg·L -1 The SMM was subjected to three cycles of photocatalytic-biodegradation experiments. The test showed that its 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 embodiment 1 is that the photocatalyst in this embodiment is WO3 / BiOBr. 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 of culturing the microorganisms and preparing the ICPB-CA vector in this example are the same as those in Example 1.

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

[0061] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A photocatalyst and microorganism coupling material, characterized in that: It 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; the biofilm carrier core material comprises a biofilm and a biofilm carrier.

2. A photocatalyst and 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 comprises a high-density polyethylene suspension carrier filler.

3. A method for preparing a photocatalyst and microorganism coupling material as claimed in any one of claims 1 to 2, characterized in that: The following steps are involved: S1, soaking the biofilm carrier in a mixture of activated sludge and synthetic wastewater, and then culturing it until a stable biofilm is formed inside the biofilm carrier, thereby obtaining a biofilm carrier core material; S2, dispersing the photocatalyst into the sodium alginate solution to obtain a first mixed solution; and mixing the biofilm carrier core material with the first mixed solution to obtain a second mixed solution; The second mixed solution is mixed with a calcium chloride solution, and the photocatalyst and microorganism coupling material is obtained after curing for 12 to 24 hours.

4. The method for preparing the photocatalyst and microorganism coupling material according to claim 3, characterized in that: The step S1 specifically comprises: adding a biofilm carrier, activated sludge and synthetic wastewater into a moving bed biofilm reactor for cultivation; after a biofilm is formed inside the biofilm carrier, the sludge is discharged; and after continuing to cultivate for more than one month, a stable biofilm is formed inside the biofilm carrier.

5. The method for preparing the photocatalyst and microorganism coupling material according to claim 4, characterized in that: The filling rate of the biofilm carrier in the moving bed biofilm reactor is 20% v / v to 60% v / v.

6. The method for preparing the photocatalyst and microorganism coupling material according to claim 4, characterized in that: The operating conditions in the moving bed biofilm reactor are as follows: the aeration rate is 1-5 L·min -1 , hydraulic retention time is 4~20 h, and inlet flow rate is 0.01~1 L·min -1 , water flow rate is 0.01~1 L·min -1 , magnetic stirring rate was 200-450 rpm, and initial MLVSS was 3.0-6.0 g·L -1 .

7. The method for preparing the photocatalyst and microorganism coupling material according to claim 3, characterized in that: The volume ratio of the activated sludge to the synthetic wastewater is 1:(6-10).

8. The use of the photocatalyst and microbial coupling material as claimed in any one of claims 1 to 2 in the degradation of antibiotics in water, characterized in that: The antibiotics include sulfonamide antibiotics.

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

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

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