Preparation method and application of photocatalytic microorganism-nano material heterozygote

Abstract

The invention provides a preparation method and application of a photocatalytic microorganism-nano material heterozygote. The heterozygote is formed by compounding electroactive bacteria Shewanella oneidensis MR-1 and a nano material CNx with a photoelectric effect, degradation of antibiotics such as tetracycline and the like is accelerated by utilizing photo-induced electrons and holes generated by excitation of the CNx under a natural illumination condition, inhibition of the antibiotics on microbial activity is relieved, the microbial metabolism efficiency is improved, and the degradation rate of antibiotics such as tetracycline and the like is increased. Therefore, nitrogen and phosphorus elements in the wastewater are rapidly induced to form magnesium ammonium phosphate crystals, and synchronous antibiotic degradation and nitrogen and phosphorus resource recovery are realized. The method is easy and convenient to operate, environmentally friendly and high in phosphorus recovery efficiency, the obtained magnesium ammonium phosphate crystals are controllable in grain size and excellent in quality, and the method is suitable for resourceful treatment scenes of antibiotic-containing organic pollutants such as breeding wastewater and has good application and popularization prospects.

Description

Technical Field

[0001] The present invention belongs to the field of water pollution control and resource recovery, and particularly relates to a preparation method of a microorganism-nanomaterial hybrid and its application in nitrogen and phosphorus recovery and antibiotic degradation in antibiotic-polluted aquaculture wastewater. Background Art

[0002] Among various phosphorus recovery methods, magnesium ammonium phosphate (struvite) has been widely used in agricultural fertilizers and sewage resource utilization due to its good slow-release property and high phosphorus content. Traditional magnesium ammonium phosphate precipitation methods mainly rely on chemical pH regulation (such as adding NaOH, MgCl2). Although the recovery rate is high, there are problems such as high cost, cumbersome operation, and secondary pollution. The microbial method uses the metabolic activities of bacteria to promote the formation of magnesium ammonium phosphate by producing alkali and transforming phosphorus and nitrogen sources, and has advantages such as environmental friendliness and low cost, and has become a research hotspot in recent years.

[0003] Shewanella oneidensis MR-1 is a widely studied electroactive bacterium with strong extracellular electron transfer ability. It can carry out metabolic activities through a complex electron transfer chain in anaerobic or hypoxic environments, and shows excellent potential in environmental pollution control and resource recovery. However, in complex systems such as aquaculture wastewater, the presence of broad-spectrum antibiotics such as tetracycline severely inhibits the growth of microorganisms and affects their ability to induce the mineralization of magnesium ammonium phosphate. Tetracycline can bind to the 30S subunit of ribosomes to inhibit protein synthesis. At the same time, its molecular structure contains multiple complexing groups, which easily compete with extracellular metal ions and hinder the mineral nucleation process.

[0004] In recent years, photocatalytic technology has attracted attention because it can generate reactive oxygen species (ROS) by exciting photosensitive materials under mild conditions for the degradation of organic pollutants. Polymeric carbon nitride (CN x ) is a metal-free, highly photo-stable, and excellent photocatalytic nanosemiconductor material, which is commonly used for visible-light-driven pollutant degradation and resource conversion. Existing studies have shown that constructing a hybrid system of nanomaterials and microorganisms can not only enhance the electron transfer activity of microorganisms, but also improve the efficiency of pollutant degradation and resource recovery through synergy.

[0005] However, current research on the combined application of photocatalytic nanomaterials and microorganisms in the recovery of magnesium ammonium phosphate and antibiotic degradation in aquaculture wastewater is still scarce, and related technologies still have bottlenecks such as low stability, inactivation of bacteria, and slow reaction.

[0006] Therefore, there is an urgent need to develop a composite system that can grow stably in the presence of antibiotics, has good electron transfer ability, and can generate reactive oxygen species in cooperation with nanomaterials to improve the phosphorus recovery efficiency and solve the technical problems of resource treatment in aquaculture wastewater. Summary of the Invention

[0007] The main object of the present invention is to overcome the bottleneck problems existing in the above-mentioned background technology, and to provide a preparation method of a microorganism-nanomaterial hybrid, a photocatalytic microorganism-nanomaterial hybrid, and their applications in nitrogen and phosphorus recovery and antibiotic degradation in antibiotic-polluted aquaculture wastewater.

[0008] A preparation method of a photocatalytic microorganism-nanomaterial hybrid, comprising the following steps: (1) Synthesize and activate the polymeric carbon nitride CN x nanomaterial by thermal polymerization. (2) Culture the bacterium Shewanella oneidensis MR-1 in a modified LB medium until the logarithmic growth phase. (3) Mix the bacterium and the CN x nanomaterial under anaerobic conditions to form a bio-nanohybrid.

[0009] Further, in step (1), the activation treatment includes subjecting the CN x nanomaterial to a modification treatment to obtain a g-C3N4 material modified with potassium thiocyanate (KSCN).

[0010] Further, in step (1), heat melamine at a high temperature in an air atmosphere to obtain an intermediate product, grind it after cooling and mix it evenly with a thiocyanate, then perform two-step heat treatment under a protective atmosphere, wash and remove impurities after cooling, and finally freeze-dry to obtain the polymeric carbon nitride CN x nanomaterial.

[0011] Further, in step (3), the compounding ratio of the bacterium and the nanomaterial is configured such that the OD 600 value of the bacterial cells is 2.0 - 3.0, and the added mass concentration of CN x is 0.5 - 1.0 g / L.

[0012] Further, in step (3), culture the bacterium and the CN x nanomaterial at 28 - 32 °C and 140 - 180 rpm under oscillating conditions for 24 hours.

[0013] Further, the preparation of the polymeric carbon nitride CN x nanomaterial includes: heating melamine at a high temperature in an air atmosphere to obtain an intermediate product, grinding it after cooling and mixing it evenly with a thiocyanate, then performing two-step heat treatment under a protective atmosphere, washing and removing impurities after cooling, and finally freeze-drying to obtain the polymeric carbon nitride CN x nanomaterial.

[0014] A photocatalytic microorganism-nanomaterial hybrid, which is composed of polymeric carbon nitride CN xNanomaterials and bacteria Shewanella oneidensis Combined with MR-1, with the synergistic effect of photoinduced electron transfer and biocatalysis.

[0015] The application of the photocatalytic microorganism-nanomaterial hybrid in the treatment of antibiotic wastewater can simultaneously achieve the degradation of tetracycline antibiotics in the wastewater and the rapid mineralization of magnesium ammonium phosphate under natural light conditions.

[0016] Furthermore, the hybrid can degrade organic pollutants by photocatalysis and induce phosphorus recovery without the addition of external alkali or oxidant.

[0017] Furthermore, the initial concentration of tetracycline in the treated wastewater is 5–20 mg / L.

[0018] The beneficial effects of the present invention are: The present invention provides a photocatalytic microorganism-nanomaterial hybrid system, which synergistically realizes the removal of antibiotics and the rapid mineralization of magnesium ammonium phosphate, and improves the nitrogen and phosphorus recovery efficiency in aquaculture wastewater. This system Shewanella oneidensis Constructs a complex with MR-1 and CN x materials, and uses the photo-generated holes generated by CN x to form reactive oxygen species to scavenge the inhibitory effect of tetracycline, while its photo-generated electrons are captured by the bacterial outer membrane, improving the metabolic flux and promoting pH increase and magnesium ammonium phosphate precipitation.

[0019] The present invention provides a preparation method of a photocatalytic microorganism-nanomaterial hybrid and its application in the treatment of aquaculture wastewater, and innovatively constructs a Shewanella oneidensis MR-1-CN x hybrid system with both photocatalytic function and bioelectron transfer ability, successfully solving the technical bottlenecks such as low efficiency of magnesium ammonium phosphate precipitation under the interference of antibiotics, complex operation and poor stability of the microbial method in traditional chemical methods.

[0020] The main advantages of the present invention are: the constructed hybrid can achieve the efficient degradation of broad-spectrum antibiotics such as tetracycline under natural light conditions, while promoting the extracellular electron transfer process, inducing the formation of a local alkalized environment for magnesium ammonium phosphate crystallization, and realizing the coordinated progress of antibiotic degradation and phosphorus recovery. This system does not rely on external alkali or oxidant, has mild reaction conditions, simple operation and strong adaptability. In addition, the hybrid material prepared by the present invention has a wide source, good biocompatibility, simple construction process, low cost, good chemical stability and reusability, and is particularly suitable for the resource treatment of antibiotic and phosphorus pollution coexistence systems such as aquaculture wastewater, with significant environmental benefits and industrial application prospects. Brief Description of the Drawings

[0021] Figure 1It is the SEM result of the microorganism-nanomaterial hybrid in the embodiment of the present invention; Figure 2 It is the SEM result of the magnesium ammonium phosphate crystal recovery product in the embodiment of the present invention; Figure 3 It is the XRD result of the magnesium ammonium phosphate crystal recovery product in the embodiment of the present invention; Figure 4 It is the FTIR result of the magnesium ammonium phosphate crystal recovery product in the embodiment of the present invention. Detailed implementation manners

[0022] In order to make the invention purpose, technical solution and technical effect of the present invention clearer, the present invention will be further described in detail below in conjunction with specific implementation manners. It should be understood that the specific implementation manners described in this specification are only for explaining the present invention and not for limiting the present invention.

[0023] The experimental materials and reagents used, unless otherwise specified, are all conventional consumables and reagents that can be obtained from commercial channels.

[0024] In some embodiments, a preparation method of a photocatalytic microorganism-nanomaterial hybrid includes the following steps: Step (1): Thermally polymerize and activate the polymeric carbon nitride CN x nanomaterial; Step (2): Culture the bacterium Shewanella oneidensis MR-1 in a modified LB medium until the logarithmic growth phase; Step (3): Mix the bacterium and the CN x nanomaterial under anaerobic conditions to form a bio-nano hybrid.

[0025] In some embodiments, in step (1), the activation treatment includes subjecting the CN x nanomaterial to a modification treatment to obtain a g-C3N4 material modified with potassium thiocyanate (KSCN).

[0026] In some embodiments, in step (1), melamine is heated at a high temperature in an air atmosphere to obtain an intermediate product, which is ground and mixed evenly with a thiocyanate after cooling, and then subjected to two-step heat treatment under a protective atmosphere, washed to remove impurities after cooling, and finally freeze-dried to obtain the polymeric carbon nitride CN x nanomaterial.

[0027] In some embodiments, in step (3), the compounding ratio of the bacterium and the nanomaterial is configured such that the OD 600 value of the bacterial cells is 2.0 - 3.0, and the added mass concentration of CN x is 0.5 - 1.0 g / L.

[0028] In some embodiments, in step (3), the bacteria and CN x nanomaterials are cultured for 24 hours under the oscillation conditions of 28 - 32 °C and 140 - 180 rpm.

[0029] In some embodiments, a photocatalytic microorganism-nanomaterial hybrid is formed by the combination of polymeric carbon nitride CN x nanomaterials and bacteria Shewanella oneidensis MR-1, and has the synergistic effect of photogenerated electron transfer and biocatalysis.

[0030] In some embodiments, the application of the photocatalytic microorganism-nanomaterial hybrid in the treatment of antibiotic wastewater can simultaneously achieve the degradation of tetracycline antibiotics in the wastewater and the rapid mineralization of magnesium ammonium phosphate under natural light conditions.

[0031] In some embodiments, the hybrid can photocatalytically degrade organic pollutants and induce phosphorus recovery without the addition of external alkali or oxidant.

[0032] In some embodiments, the initial concentration of tetracycline in the treated wastewater is 5–20 mg / L.

[0033] In one embodiment, in the preparation method of the photocatalytic microorganism-nanomaterial hybrid, the liquid LB medium used has the following composition: in each liter of liquid LB medium, there are 10 g of tryptone, 5 g of yeast extract, 10 g of sodium chloride, and pH 7.0. The preparation method is: after mixing the above components, add 1000 mL of distilled water, fully dissolve, and it can be used after autoclaving at 121 °C.

[0034] In one experimental example, the specific composition of the simulated sewage used is: in each liter of simulated sewage, there are 10 g of tryptone, 5 g of yeast extract, 10 g of sodium chloride, 0.399 g of magnesium chloride, 0.408 g of potassium dihydrogen phosphate, and pH 7.0. The preparation method is: after mixing the above components, add 1000 mL of distilled water, fully dissolve, and after autoclaving at 121 °C, add tetracycline through a 0.22 μm sterile filter head to make its concentration 8 mM, and then it can be used.

[0035] In view of the deficiencies of the existing chemical and microbial methods for recovering phosphorus from aquaculture wastewater, the present invention provides a preparation method of a microorganism-nanomaterial hybrid and its applications in antibiotic degradation and phosphorus recovery. The hybrid can simultaneously achieve the degradation of antibiotics and the recovery of phosphorus in aquaculture wastewater under light.

[0036] The embodiments of the present invention provide a preparation method of a microorganism-nanomaterial hybrid, including the following steps: Step S1: Place melamine in a crucible, heat it at high temperature in an air atmosphere to obtain an intermediate product. After cooling, grind it and mix it evenly with thiocyanate. Then, perform two-step heat treatment under a protective atmosphere. After cooling, wash it with water multiple times to remove impurities, and finally freeze-dry it to obtain modified polymeric carbon nitride (CN x ) nanomaterials.

[0037] Step S2: Inoculate the strain into a liquid medium and culture it at an appropriate temperature and oscillation conditions until the cell concentration reaches the late logarithmic growth phase for subsequent experiments.

[0038] Step S3: Disperse the CN x nanomaterials in sterile water, ultrasonically treat it to make it evenly dispersed, and then sterilize it for standby. Centrifuge and wash the active bacterial solution and resuspend it in a buffer solution. After mixing it with the treated polymeric carbon nitride (CN x ) nanomaterials, co-culture them for a certain period of time under light-shielded and appropriate temperature conditions. After the culture is completed, obtain a microorganism-nanomaterial hybrid system by centrifugation and washing.

[0039] The present invention provides a preparation method of a photocatalytic microorganism-nanomaterial hybrid and its application in the treatment of aquaculture wastewater. The hybrid is formed by combining electroactive bacteria S.oneidensis MR-1 with a nanomaterial CN x with a photoelectric effect. Utilize the photogenerated electrons and holes generated by the excitation of CN x under natural light conditions to accelerate the degradation of antibiotics such as tetracycline, relieve its inhibition of microbial activity, improve the microbial metabolic efficiency, thereby quickly inducing the formation of struvite crystals from nitrogen and phosphorus elements in the wastewater, and realizing the synchronous degradation of antibiotics and the recovery of nitrogen and phosphorus resources. This method is simple to operate, environmentally friendly, has a high phosphorus recovery efficiency, the obtained struvite crystals have controllable particle size and excellent quality, is suitable for the resource treatment scenarios of aquaculture wastewater and other antibiotic-containing organic pollutants, and has good application prospects for popularization.

[0040] The following further describes specific embodiments of the present invention.

[0041] In some embodiments, the microorganism-nanomaterial hybrid is formed by hybridizing a microorganism Shewanella with extracellular electron ability and a nanomaterial CN x with good biocompatibility. Its preparation method includes the following steps: Step S1: Weigh 4–6 g of melamine in a crucible and heat it in an air atmosphere at 500–600 °C for 3–5 hours to generate a yellow precursor. After cooling and grinding, mix it evenly with 1–3 g of KSCN, and then heat it successively at 380–420 °C for 0.5–1 hour and 480–520 °C for 20–40 minutes in an argon atmosphere. After cooling and grinding, resuspend it with ultrapure water, centrifuge it at 7000–9000 rpm for 8–12 minutes, discard the supernatant, repeat the washing 3–6 times to remove KSCN, and finally freeze-dry it for 20–30 hours to obtain modified CN x nanomaterials.

[0042] Step S2: Inoculate Shewanella into LB liquid medium and shake-culture it at 28–32 °C and 140–180 rpm until OD 600 reaches 2.0–3.0, indicating that the cells are in the late logarithmic growth phase and are suitable for subsequent experiments.

[0043] Step S3: Prepare a suspension of CN x nanomaterials at 0.5–2 mg / mL, then ultrasonicate it for 20–40 minutes for sufficient dispersion, sterilize it at 121 °C under high pressure for 15–25 minutes, and then cool it for standby. Take the bacterial liquid with OD 600 of 2.0–3.0, centrifuge it at 8000–9000 rpm for 4–6 minutes, wash it 1–3 times with sterile PBS, and then resuspend it. Mix the bacterial liquid and the CN x suspension in a volume ratio of 1:1–3:1, place it in a simulated wastewater system, and co-culture it at 28–32 °C and 140–180 rpm under dark conditions for 18–30 hours. After centrifugation and washing, a stable bacteria-material hybrid is obtained.

[0044] In some embodiments, for the application of a said microorganism-nanomaterial hybrid, add the prepared hybrid to simulated wastewater, place the simulated wastewater under a light source, and perform shake-culture at 30 °C and 160 rpm. Free radicals are generated by the photoelectric effect of the hybrid, and the efficient removal of antibiotics is achieved with the help of active free radicals, and phosphorus is recovered under the action of microorganisms. The light wavelength of the light source is 400 - 800 nm, and its intensity is 5 - 10 mW / cm2.

[0045] Step S1: First, 5 g of melamine (C3H6N6) was placed in a crucible and heated at 550°C for 4 hours in an air atmosphere in a muffle furnace to obtain a yellow block precursor. After it was cooled naturally, it was fully ground in a mortar and mixed evenly with 2 g of KSCN. The resulting mixture was then placed in a muffle furnace and heated at 400°C for 1 hour and then at 500°C for 30 minutes in an argon atmosphere. After cooling to room temperature, the product was fully ground, ultrapure water was added, and centrifuged at 8000 rpm for 10 minutes, the supernatant was discarded, and the washing step was repeated 5 times to remove residual KSCN. Finally, the washed precipitate was freeze-dried for 24 hours to obtain modified polymeric nitrogen carbide (CN x ) nanomaterials, namely, g-C3N4 (CN x ) nanomaterials.

[0046] Step S2: S.oneidensis The MR-1 strain was inoculated in LB liquid medium. The inoculated bacterial solution was placed in a constant temperature shaking incubator and cultured at 30°C and 160 rpm to ensure sufficient dissolved oxygen and uniform growth. During the culture process, the optical density (OD) of the bacterial solution was regularly monitored by a spectrophotometer at a wavelength of 600 nm. 600 ), when OD 600 The value stabilized at 3.0, indicating that the bacterial concentration reached the late logarithmic growth phase and could be used for subsequent experimental operations.

[0047] Step S3: Obtained CN x The nanomaterials were placed in a sterile EP tube, ultrapure water was added to prepare a 1 mg / mL suspension, and ultrasonic treatment was performed for 30 minutes to promote its full dispersion. x The suspension was sterilized by high pressure steam at 121°C for 20 minutes and cooled to room temperature for later use. 600 ≈3.0 S.oneidensis The MR-1 bacterial solution was centrifuged under sterile conditions (8000 rpm, 5 min), washed twice with sterile phosphate buffered saline (PBS) to remove residual culture medium components, and then resuspended in an equal volume of fresh sterile PBS. x The nanomaterial suspension was mixed in a 1:1 volume ratio, placed in simulated wastewater, and co-cultured at 30°C and 160rpm for 24 hours in the dark to promote the surface adsorption, spontaneous binding and electron transfer interface establishment of bacteria and nanomaterials. After the co-culture, the resulting mixture was centrifuged and washed with PBS to remove the unbound part, and the resulting mixture was obtained. S.oneidensis MR-1 and modified CN x Stable hybrid constructed by nanomaterials ( Figure 1 ).

[0048] The present invention provides a photocatalytic microorganism-nanomaterial hybrid and its application in synergistically degrading pollutants and recovering nitrogen and phosphorus resources in antibiotic-polluted aquaculture wastewater, with the following remarkable advantages: The constructed Shewanella oneidensis hybrid system of MR-1 and modified CN x nanomaterials has both the dual functions of photogenerated electron transfer and biocatalysis, and can achieve efficient degradation of antibiotics such as tetracycline under natural light conditions, while accelerating the crystallization and mineralization process of magnesium ammonium phosphate. This system can induce the formation of magnesium ammonium phosphate crystals without relying on additional oxidants or external alkaline regulation, showing advantages such as mild reaction conditions, stable cell activity, and high resource conversion efficiency. Compared with traditional chemical methods, the method of the present invention is green and environmentally friendly, easy to operate, applicable to the synchronous treatment of nitrogen and phosphorus recovery and antibiotic removal in complex actual wastewater, and has good practical popularization value and application prospects. Example 1

[0049] Weigh 20 mg of modified polymeric carbon nitride (CN x ) nanomaterials, add them to 200 mL of simulated aquaculture wastewater, and inoculate S.oneidensis MR-1 bacterial solution to make the OD 600 be 3.0. The system is oscillated and cultured at 30 °C and 160 rpm for 120 hours under the conditions of a wavelength of 400–800 nm and a light intensity of 7.5 mW / cm 2 .

[0050] The results show that tetracycline is basically degraded within the first 12 hours, and the degradation rate reaches 98.8% after 48 hours. Crystal precipitation forms earlier, and the precipitation of magnesium ammonium phosphate can be observed about 8 hours after the reaction, and the precipitation grows rapidly. After measurement, the precipitation amount at 24 hours is about 200 mg / L, increases to 265 mg / L at 48 hours, and approaches saturation at 72 hours, being 270 mg / L. This result indicates that under low antibiotic loads, the microorganism-nanomaterial hybrid system exhibits higher phosphorus recovery efficiency and faster mineralization reaction kinetics.

[0051] Figure 2 are the SEM results of the recovered product of magnesium ammonium phosphate crystallization in the example of the present invention. Figure 3 are the XRD results of the recovered product of magnesium ammonium phosphate crystallization in the example of the present invention. Figure 4 are the FTIR results of the recovered product of magnesium ammonium phosphate crystallization in the example of the present invention. Example 2

[0052] Under the same experimental conditions as in Example 1, the initial concentration of tetracycline is adjusted to 10 mg / L, and the other parameters remain unchanged, including the dosage of CN x nanomaterials (20 mg), light intensity (7.5 mW / cm2 ), cell concentration (OD 600 = 3.0), and oscillating reaction conditions (30 °C, 160 rpm, 120 h).

[0053] The experimental results showed that the tetracycline degradation rate was slightly lower than that of Example 1, and the degradation rate was 91.4% after 48 hours. Crystal precipitation in the system started at about 15 hours, and white magnesium ammonium phosphate crystals were initially formed. The precipitation amount gradually increased with the reaction time: the concentration was about 180 mg / L at 24 hours of reaction, 260 mg / L at 48 hours, and stabilized at 72 hours, with a maximum precipitation amount of 270 mg / L. This indicates that under the influence of medium-concentration antibiotics, the system still has good synergistic catalysis and resource conversion performance. Example 3

[0054] In the same system as Example 1, the initial concentration of tetracycline was increased to 20 mg / L, and the rest of the experimental conditions remained the same.

[0055] The experimental results showed that high-concentration tetracycline had a strong inhibitory effect on the microbial metabolic activity, delaying the tetracycline degradation process, and the degradation rate was 86.2% after 48 hours. Crystal precipitation was delayed until about 24 hours of reaction, and the phosphorus recovery process started significantly later. The precipitation increased slowly: the precipitation amount was 90 mg / L at 24 hours, increased to 180 mg / L at 48 hours, rose to 210 mg / L at 72 hours, and reached 260 mg / L at 96 hours. The results indicate that the hybrid system still has a certain adaptability under high antibiotic loads, but the overall reaction efficiency and mineralization ability have decreased.

[0056] The photocatalytic microorganism-nanomaterial hybrid system constructed in the present invention has dual functions of synergistic catalysis and resource conversion. The system is composed of electroactive bacteria S.oneidensis MR-1 and modified polymeric carbon nitride (CN x ). The nanomaterial has good light response characteristics and electron transfer ability, and can generate reactive oxygen species under visible light irradiation, effectively promoting the degradation of antibiotics in aquaculture wastewater and alleviating its inhibitory effect on microbial metabolism. Microorganisms further enhance the extracellular electron transfer flux with the assistance of photocatalysis, regulate the pH of the system, and achieve rapid mineralization precipitation of magnesium ammonium phosphate.

[0057] The hybrid system constructed by the present invention has mild operating conditions, and no additional oxidants or alkaline regulators need to be introduced during the reaction process. It has the advantages of being environmentally friendly, pollution-free, simple to construct, and the materials can be reused, and is suitable for the co-treatment of antibiotics and nitrogen and phosphorus pollutants in complex aquaculture wastewater. This system not only improves the sewage treatment efficiency, but also realizes the harmless degradation of antibiotics and the resource utilization of nitrogen and phosphorus, providing a new technical path for the efficient treatment of antibiotic-polluted wastewater and making up for the deficiencies of traditional chemical methods and single microbial methods in terms of treatment efficiency and resource recovery.

[0058] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention pertains, without departing from the concept of the present invention, several alternatives or modifications can be made to these described embodiments, and these alternative or modified forms should all be regarded as belonging to the protection scope of the present invention. In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. Without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the scope of protection of the patent application.

Claims

1. A preparation method of a photocatalytic microorganism-nanomaterial hybrid, characterized in that, Comprising the following steps: (1) Synthesize polymeric carbon nitride CN x nanomaterials through a thermal polymerization process and perform activation treatment; (2) The bacteria Shewanella oneidensis MR-1 was cultured in improved LB medium until the logarithmic growth phase; (3) Mix the bacterium with CN x nanomaterials under anaerobic conditions to form a bio-nano hybrid.

2. The preparation method according to claim 1, wherein In step (1), the activation treatment includes treating the CN x nanomaterials to obtain a g-C3N4 material modified with potassium thiocyanate (KSCN).

3. The preparation method according to claim 1, wherein, In step (1), melamine is heated at high temperature in an air atmosphere to obtain an intermediate product. After cooling, it is ground and mixed evenly with thiocyanate, and then two-step heat treatment is carried out in a protective atmosphere. After cooling, impurities are removed by washing, and finally freeze-dried to obtain polymeric carbon nitride CN x nanomaterials.

4. The preparation method according to claim 1 or 2, characterized in that In step (3), the compounding ratio of the bacteria to the nanomaterial is configured such that the OD 600 value is 2.0 - 3.0, and the mass concentration of CN x added is 0.5 - 1.0 g / L.

5. The preparation method according to claim 1, characterized in that, In step (3), the bacteria and CN x nanomaterials are cultured for 24 hours under the oscillation conditions of 28 - 32 °C and 140 - 180 rpm.

6. A photocatalytic microorganism-nanomaterial hybrid, characterized in that, Formed by the combination of polymeric carbon nitride CN x nanomaterials and bacteria Shewanella oneidensis MR-1, with the synergistic effect of photogenerated electron transfer and biocatalysis.

7. Application of the photocatalytic microorganism-nanomaterial hybrid as claimed in claim 6 in the treatment of antibiotic wastewater, which can simultaneously achieve the degradation of tetracycline antibiotics in the wastewater and the rapid mineralization of struvite under natural light conditions.

8. The application according to claim 7, wherein The hybrid degrades organic pollutants through photocatalysis and induces phosphorus recovery without the need for additional alkali or oxidant.

9. The application according to claim 7 or 8, characterized in that, The initial tetracycline concentration of the wastewater to be treated is 5–20 mg / L.

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