Preparation method and application of photocatalytic microorganism-nanomaterial hybrid

Abstract

The present invention provides a preparation method and application of a photocatalytic microorganism-nanomaterial hybrid. Shewanella oneidensis MR‑1 and nanomaterials CN with photoelectric effect x Composite formation, using CN under natural light conditions x The photogenerated electrons and holes generated by the excitation accelerate the degradation of antibiotics like tetracycline, alleviating their inhibitory effects on microbial activity and improving microbial metabolic efficiency. This rapidly induces the formation of magnesium ammonium phosphate crystals from nitrogen and phosphorus in the wastewater, achieving simultaneous antibiotic degradation and nitrogen and phosphorus resource recovery. This method is simple to operate, environmentally friendly, and boasts high phosphorus recovery efficiency. The resulting magnesium ammonium phosphate crystals have a controllable particle size and excellent quality, making it suitable for resource recovery of antibiotic-containing organic pollutants such as aquaculture wastewater, and has promising prospects for widespread application.

Description

Technical Field

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

[0002] Among the many phosphorus recovery methods, magnesium ammonium phosphate (struvite) is widely used in agricultural fertilizers and wastewater resource utilization due to its excellent slow-release properties and high phosphorus content. Traditional magnesium ammonium phosphate precipitation methods rely primarily on chemical pH manipulation (such as the addition of NaOH or MgCl2). While this method offers high recovery rates, it is associated with high costs, cumbersome procedures, and secondary pollution. Microbial methods utilize bacterial metabolic activity to promote the formation of magnesium ammonium phosphate through alkali production and conversion of phosphorus and nitrogen sources. These methods offer advantages such as environmental friendliness and low cost, and have become a research hotspot in recent years.

[0003] Shewanella oneidensis MR-1 is a widely studied electroactive bacterium with strong extracellular electron transfer capabilities. It can carry out metabolic activities through a complex electron transport chain in anaerobic or hypoxic environments, and has shown 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 microbial growth and affects its ability to induce the mineralization of magnesium ammonium phosphate. Tetracycline can bind to the 30S ribosomal subunit, inhibiting protein synthesis. Furthermore, its molecular structure contains multiple complexing groups that easily compete with extracellular metal ions, hindering the mineral nucleation process.

[0004] In recent years, photocatalytic technology has attracted attention because it can generate reactive oxygen species (ROS) by stimulating photosensitive materials under mild conditions and be used to degrade organic pollutants. x ) is a metal-free, photostable, and excellent photocatalytic nanosemiconductor material commonly used for visible-light-driven pollutant degradation and resource conversion. Previous studies have shown that creating hybrid systems with nanomaterials and microorganisms not only enhances microbial electron transfer activity but also improves pollutant degradation and resource recovery efficiency through synergistic effects.

[0005] However, there is still little research on the application of photocatalytic nanomaterials and microorganisms in the recovery of magnesium ammonium phosphate and degradation of antibiotics in aquaculture wastewater, and related technologies still have bottlenecks such as low stability, bacterial inactivation, 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 cooperates with nanomaterials to produce reactive oxygen species, so as to improve phosphorus recovery efficiency and solve the technical difficulties in resource treatment of aquaculture wastewater. Summary of the Invention

[0007] The main purpose of the present invention is to overcome the bottleneck problems existing in the above-mentioned background technology and provide a method for preparing a microorganism-nanomaterial hybrid, a photocatalytic microorganism-nanomaterial hybrid and its application in nitrogen and phosphorus recovery and antibiotic degradation in antibiotic-contaminated aquaculture wastewater.

[0008] A method for preparing a photocatalytic microorganism-nanomaterial hybrid comprises the following steps:

[0009] (1) Polymerize carbon nitride CN x The nanomaterials are synthesized by thermal polymerization and activated;

[0010] (2) Bacteria Shewanella oneidensis MR-1 was cultured in modified LB medium to the logarithmic growth phase;

[0011] (3) The bacteria are mixed with CN x The nanomaterials are mixed under anaerobic conditions to form bio-nano hybrids.

[0012] Furthermore, in step (1), the activation treatment includes: x The nanomaterial was modified to obtain g-C3N4 material modified with potassium thiocyanate (KSCN).

[0013] Furthermore, in step (1), melamine is heated at high temperature in an air atmosphere to obtain an intermediate product, which is then ground and mixed evenly with thiocyanate after cooling, and then subjected to two-step heat treatment under a protective atmosphere, and then washed to remove impurities after cooling, and finally freeze-dried to obtain polymeric carbon nitrogen CN x Nanomaterials.

[0014] Furthermore, in step (3), the composite ratio of the bacteria and the nanomaterial is configured as the bacterial OD 600 The value is 2.0-3.0, CN x The added mass concentration is 0.5-1.0g / L.

[0015] Furthermore, in step (3), the bacteria are mixed with CN x The nanomaterials were cultured at 28-32°C with shaking at 140-180 rpm for 24 h.

[0016] Furthermore, the polymeric carbon nitride CN x The preparation of nanomaterials includes: heating melamine in air atmosphere at high temperature to obtain an intermediate product, grinding it after cooling and mixing it evenly with thiocyanate, then performing two-step heat treatment under protective atmosphere, washing it after cooling to remove impurities, and finally freeze-drying it to obtain polymeric nitrogen carbonide CN. x Nanomaterials.

[0017] A photocatalytic microorganism-nanomaterial hybrid composed of polymerized carbon nitride (CN) x Nanomaterials and bacteria Shewanella oneidensis MR-1 is formed by combination, which has the synergistic effect of photogenerated electron transfer and biocatalysis.

[0018] 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.

[0019] Furthermore, the hybrid degrades organic pollutants through photocatalysis and induces phosphorus recovery without the need for the addition of an external base or an oxidant.

[0020] Furthermore, the initial tetracycline concentration of the treated wastewater was 5–20 mg / L.

[0021] The beneficial effects of the present invention are:

[0022] The present invention proposes a photocatalytic microorganism-nanomaterial hybrid system, which synergistically achieves antibiotic removal and rapid mineralization of magnesium ammonium phosphate, thereby improving the nitrogen and phosphorus recovery efficiency in aquaculture wastewater. Shewanella oneidensis MR-1 and CN x Materials build complexes, using CN x The generated photogenerated holes form reactive oxygen species to eliminate the inhibitory effect of tetracycline. At the same time, its photogenerated electrons are captured by the bacterial outer membrane, increasing metabolic flux, promoting pH increase and precipitation of magnesium ammonium phosphate.

[0023] The present invention provides a method for preparing a photocatalytic microorganism-nanomaterial hybrid and its application in aquaculture wastewater treatment, innovatively constructing a hybrid with both photocatalytic function and biological electron transfer ability. Shewanella oneidensis MR-1-CN x The hybrid system successfully solved the technical bottlenecks of the traditional chemical method, such as low efficiency of magnesium ammonium phosphate precipitation under the interference of antibiotics, complex operation, and poor stability of the microbial method.

[0024] The main advantage of the present invention is that the constructed hybrid can achieve efficient degradation of broad-spectrum antibiotics such as tetracycline under natural light conditions, while promoting the extracellular electron transfer process, inducing the local alkalinization environment to form magnesium ammonium phosphate crystals, and achieving the coordinated degradation of antibiotics and phosphorus recovery. The system does not rely on the addition of alkali or oxidants, has mild reaction conditions, is easy to operate, and has strong adaptability. In addition, the hybrid material prepared by the present invention has a wide range of sources, good biocompatibility, a 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, and has significant environmental benefits and industrial application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the SEM result of the microorganism-nanomaterial hybrid in the embodiment of the present invention;

[0026] Figure 2 This is the SEM result of the magnesium ammonium phosphate crystal recovery product in the embodiment of the present invention;

[0027] Figure 3 This is the XRD result of the magnesium ammonium phosphate crystal recovery product in the embodiment of the present invention;

[0028] Figure 4 It is the FTIR result of the magnesium ammonium phosphate crystallization recovery product in the embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to make the invention purpose, technical solution and technical effect of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described in this specification are only for explaining the present invention and are not intended to limit the present invention.

[0030] Unless otherwise specified, the experimental materials and reagents used are consumables and reagents that can be obtained from conventional commercial channels.

[0031] In some embodiments, a method for preparing a photocatalytic microorganism-nanomaterial hybrid comprises the following steps:

[0032] Step (1) polymerizing carbon nitride CN x The nanomaterials are synthesized by thermal polymerization and activated;

[0033] Step (2) Bacteria Shewanella oneidensis MR-1 was cultured in modified LB medium to the logarithmic growth phase;

[0034] Step (3) the bacteria are mixed with CN x The nanomaterials are mixed under anaerobic conditions to form bio-nano hybrids.

[0035] In some embodiments, in step (1), the activation treatment includes x The nanomaterial was modified to obtain g-C3N4 material modified with potassium thiocyanate (KSCN).

[0036] In some embodiments, in step (1), melamine is heated at high temperature in an air atmosphere to obtain an intermediate product, which is then ground and mixed evenly with thiocyanate after cooling, and then subjected to two-step heat treatment under a protective atmosphere, and then washed to remove impurities after cooling, and finally freeze-dried to obtain polymeric nitrogen carbonide CN x Nanomaterials.

[0037] In some embodiments, in step (3), the compound ratio of the bacteria and the nanomaterial is configured as the bacterial OD 600 The value is 2.0-3.0, CN x The added mass concentration is 0.5-1.0 g / L.

[0038] In some embodiments, in step (3), the bacteria are mixed with CN x The nanomaterials were cultured at 28-32°C with shaking at 140-180 rpm for 24 h.

[0039] In some embodiments, a photocatalytic microorganism-nanomaterial hybrid is composed of polymerized carbon nitride (CN). x Nanomaterials and bacteria Shewanella oneidensis MR-1 is formed by combination, which has the synergistic effect of photogenerated electron transfer and biocatalysis.

[0040] 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 and the rapid mineralization of magnesium ammonium phosphate in the wastewater under natural light conditions.

[0041] In some embodiments, the hybrid photocatalytically degrades organic pollutants and induces phosphorus recovery without the need for added base or oxidant.

[0042] In some embodiments, the initial tetracycline concentration of the treated wastewater is 5-20 mg / L.

[0043] In one embodiment, the preparation method of the photocatalytic microorganism-nanomaterial hybrid comprises a liquid LB medium containing 10 g tryptone, 5 g yeast extract, and 10 g sodium chloride per liter of liquid LB medium, with a pH of 7.0. The preparation method comprises mixing the above ingredients, adding 1000 mL of distilled water, dissolving thoroughly, and sterilizing at 121°C before use.

[0044] In one experimental example, the simulated wastewater used contained the following components per liter: 10g tryptone, 5g yeast extract, 10g sodium chloride, 0.399g magnesium chloride, and 0.408g potassium dihydrogen phosphate (pH 7.0). The preparation method involved mixing the above components, adding 1000mL of distilled water, and dissolving thoroughly. After sterilization at 121°C, tetracycline was added through a 0.22μm sterile filter to a concentration of 8mM before use.

[0045] The present invention addresses the shortcomings of existing chemical and microbial methods for recovering phosphorus from aquaculture wastewater and provides a method for preparing a microorganism-nanomaterial hybrid and its application in antibiotic degradation and phosphorus recovery. The hybrid can simultaneously degrade antibiotics and recover phosphorus from aquaculture wastewater under light.

[0046] The present invention provides a method for preparing a microorganism-nanomaterial hybrid, comprising the following steps:

[0047] Step S1: Melamine is placed in a crucible and heated at high temperature in air atmosphere to obtain an intermediate product. After cooling, the intermediate product is ground and mixed with thiocyanate. Then, two steps of heat treatment are performed under protective atmosphere. After cooling, the intermediate product is washed with water several times to remove impurities and finally freeze-dried to obtain modified polynitrogen carbide (CN x ) nanomaterials.

[0048] Step S2: The strain is inoculated into a liquid culture medium and cultured under suitable temperature and shaking conditions until the bacterial concentration reaches the late logarithmic growth phase for use in subsequent experiments.

[0049] Step S3: CN x The nanomaterials were dispersed in sterile water, ultrasonically treated to make them uniformly dispersed, and then sterilized for use. The active bacterial solution was washed by centrifugation and resuspended in buffer solution. x After mixing with the nanomaterials, the cells are incubated in a dark, temperature-controlled environment for a specified period of time. After incubation, the microorganism-nanomaterial hybrid system is obtained by centrifugation and washing.

[0050] The present invention proposes a method for preparing a photocatalytic microorganism-nanomaterial hybrid and its application in aquaculture wastewater treatment. S.oneidensis MR-1 and nanomaterial CN with photoelectric effect x Composite formation, using CN under natural light conditions x The photogenerated electrons and holes generated by the excitation accelerate the degradation of antibiotics like tetracycline, alleviating their inhibitory effects on microbial activity and improving microbial metabolic efficiency. This rapidly induces the formation of magnesium ammonium phosphate crystals from nitrogen and phosphorus in the wastewater, achieving simultaneous antibiotic degradation and nitrogen and phosphorus resource recovery. This method is simple to operate, environmentally friendly, and boasts high phosphorus recovery efficiency. The resulting magnesium ammonium phosphate crystals have a controllable particle size and excellent quality, making it suitable for resource recovery of antibiotic-containing organic pollutants such as aquaculture wastewater, and has promising prospects for widespread application.

[0051] Specific embodiments of the present invention are further described below.

[0052] In some embodiments, the microorganism-nanomaterial hybrid is a microorganism with extracellular electronic capabilities. Shewanella and biocompatible nanomaterials CN x The preparation method comprises the following steps:

[0053] Step S1: Weigh 4–6 g of melamine into a crucible and heat at 500–600°C in air for 3–5 hours to generate a yellow precursor. After cooling and grinding, mix with 1–3 g of KSCN and heat at 380–420°C for 0.5–1 hour and 480–520°C for 20–40 minutes under argon. After cooling and grinding, resuspend in ultrapure water and centrifuge at 7000–9000 rpm for 8–12 minutes. Discard the supernatant and repeat washing 3–6 times to remove KSCN. Finally, freeze-dry for 20–30 hours to obtain modified CN. x Nanomaterials.

[0054] Step S2: Shewanella Inoculate into LB liquid medium and culture at 28–32°C, 140–180 rpm with shaking until OD 600 When the value reaches 2.0–3.0, it indicates that the cells are in the late logarithmic growth phase and are suitable for subsequent experiments.

[0055] Step S3: CN x The nanomaterials were prepared into a 0.5–2 mg / mL suspension, then ultrasonicated for 20–40 minutes to fully disperse them, sterilized by autoclaving at 121°C for 15–25 minutes, and cooled for later use. 600 The bacterial solution was diluted to 2.0–3.0, centrifuged at 8000–9000 rpm for 4–6 minutes, washed 1–3 times with sterile PBS and resuspended. x The suspensions were mixed at a volume ratio of 1:1–3:1, placed in a simulated wastewater system, and co-cultured at 28–32°C, 140–180 rpm in the dark for 18–30 hours. After centrifugation and washing, stable bacteria-material hybrids were obtained.

[0056] In some embodiments, the microorganism-nanomaterial hybrid described above is used by adding the prepared hybrid to simulated wastewater, irradiating the simulated wastewater under a light source, and incubating the mixture under shaking conditions at 30°C and 160 rpm. The hybrid is introduced into the water via the photoelectric effect to generate free radicals, which, through the active free radicals, enable efficient removal of antibiotics and recovery of phosphorus under the action of the microorganisms. The light source has a wavelength of 400-800 nm and an intensity of 5-10 mW / cm2.

[0057] Step S1: First, 5g of melamine (C3H6N6) was placed in a crucible and heated at 550°C in an air atmosphere for 4 hours to obtain a yellow block precursor. After it was cooled naturally, it was thoroughly ground in a mortar and mixed evenly with 2g 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 under an argon atmosphere. After cooling to room temperature, the product was thoroughly ground, added with ultrapure water, 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 carbon nitride (CN x ) nanomaterials, namely, g-C3N4 (CN x ) nanomaterials.

[0058] Step S2: S.oneidensis The MR-1 strain was inoculated into LB liquid medium. The inoculated culture was placed in a constant temperature shaking incubator at 30°C and 160 rpm to ensure sufficient dissolved oxygen and uniform growth. During the incubation process, the optical density (OD) of the culture was regularly monitored at a wavelength of 600 nm using a spectrophotometer. 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.

[0059] Step S3: Obtained CN x The nanomaterials were placed in a sterile EP tube, and ultrapure water was added to prepare a 1 mg / mL suspension, which was then ultrasonically treated 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 MR-1 bacterial suspension 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 and placed in simulated wastewater. Co-culture was carried out at 30°C and 160 rpm in the dark for 24 hours to promote the surface adsorption, spontaneous binding and electron transfer interface between bacteria and nanomaterials. After the co-culture, the resulting mixture was centrifuged and washed with PBS to remove the unbound part. S.oneidensis MR-1 and modified CN x Stable hybrid constructed by nanomaterials ( Figure 1 ).

[0060] The present invention provides a photocatalytic microorganism-nanomaterial hybrid and its application in synergistically degrading pollutants and recovering nitrogen and phosphorus resources in antibiotic-contaminated aquaculture wastewater, which has the following significant advantages: Shewanella oneidensis MR-1 and modified CN x This hybrid nanomaterial system combines the dual functions of photogenerated electron transfer and biocatalysis, enabling efficient degradation of antibiotics such as tetracycline under natural light conditions while simultaneously accelerating the crystallization and mineralization of magnesium ammonium phosphate. This system, which does not rely on additional oxidants or alkaline regulation to induce the formation of magnesium ammonium phosphate crystals, exhibits advantages such as mild reaction conditions, stable bacterial activity, and high resource conversion efficiency. Compared with traditional chemical methods, the present method is environmentally friendly, simple to operate, and suitable for the simultaneous recovery of nitrogen and phosphorus and removal of antibiotics from complex wastewater, possessing excellent practical application value and promising prospects. Example 1

[0061] Weigh 20 mg of modified polymeric carbon nitride (CN x ) nanomaterials, added to 200 mL of simulated aquaculture wastewater, and inoculated S.oneidensis MR-1 bacterial suspension, make OD 600 The system is at a wavelength of 400–800 nm and a light intensity of 7.5 mW / cm 2 Under the same conditions, the cells were cultured at 30°C and 160 rpm with shaking for 120 h.

[0062] Results showed that tetracycline was largely degraded within the first 12 hours, reaching a degradation rate of 98.8% after 48 hours. Crystals formed early, with magnesium ammonium phosphate precipitation observed approximately 8 hours into the reaction, and the precipitate grew rapidly. The precipitate volume was approximately 200 mg / L after 24 hours, increasing to 265 mg / L after 48 hours and reaching near saturation at 270 mg / L after 72 hours. These results demonstrate that, at low antibiotic loadings, the microbial-nanomaterial hybrid system exhibits higher phosphorus recovery efficiency and faster mineralization kinetics.

[0063] 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 crystallization recovery product in the embodiment of the present invention. Example 2

[0064] Under the same experimental conditions as in Example 1, the initial concentration of tetracycline was adjusted to 10 mg / L, and the other parameters remained unchanged, including CN x Nanomaterial dosage (20 mg), light intensity (7.5 mW / cm2 ), bacterial concentration (OD 600 = 3.0) and shaking reaction conditions (30 °C, 160 rpm, 120 h).

[0065] The experimental results showed that the tetracycline degradation rate was slightly lower than that of Example 1, reaching a degradation rate of 91.4% after 48 hours. Crystal precipitation in the system began at approximately 15 hours, initially forming white magnesium ammonium phosphate crystals. The amount of precipitation gradually increased with reaction time: the concentration was approximately 180 mg / L after 24 hours, 260 mg / L after 48 hours, and stabilized after 72 hours, with a maximum precipitation amount of 270 mg / L. This demonstrates that the system still exhibits good synergistic catalytic and resource conversion performance under the influence of moderate antibiotic concentrations. Example 3

[0066] In the same system as Example 1, the initial concentration of tetracycline was increased to 20 mg / L, and the other experimental conditions remained the same.

[0067] Experimental results showed that high tetracycline concentrations strongly inhibited microbial metabolic activity, slowing tetracycline degradation to 86.2% after 48 hours. Crystal precipitation did not begin until approximately 24 hours into the reaction, significantly delaying the onset of phosphorus recovery. Precipitation increased slowly: from 90 mg / L at 24 hours, it increased to 180 mg / L at 48 hours, 210 mg / L at 72 hours, and 260 mg / L at 96 hours. These results suggest that the hybrid system maintains some adaptability under high antibiotic loadings, but overall reaction efficiency and mineralization capacity are reduced.

[0068] The photocatalytic microorganism-nanomaterial hybrid system constructed by the present invention has the dual functions of synergistic catalysis and resource conversion. S.oneidensis MR-1 and modified polymeric carbon nitride (CN x ) nanomaterials, which exhibit excellent photoresponsiveness and electron transfer capabilities. Under visible light, they generate reactive oxygen free radicals, effectively promoting the degradation of antibiotics in aquaculture wastewater and alleviating their inhibitory effects on microbial metabolism. Photocatalytically assisted microorganisms further enhance extracellular electron transfer flux, regulate the system pH, and achieve rapid mineralization and precipitation of magnesium ammonium phosphate.

[0069] The hybrid system constructed in this invention features mild operating conditions and requires no additional oxidants or alkaline regulators during the reaction process. It is environmentally friendly and free of secondary pollution. Furthermore, it is simple to construct and uses reusable materials, making it suitable for the synergistic treatment of antibiotics and nitrogen and phosphorus pollutants in complex aquaculture wastewater. This system not only improves wastewater treatment efficiency but also achieves the harmless degradation of antibiotics and the resourceful utilization of nitrogen and phosphorus. This provides a new technical approach for the efficient treatment of antibiotic-contaminated wastewater, addressing the shortcomings of traditional chemical and single-microbial methods in terms of treatment efficiency and resource recovery.

[0070] The above description further details the present invention in conjunction with specific / preferred embodiments, and the specific implementation of the present invention should not be construed as being limited to these descriptions. Persons skilled in the art will appreciate that, without departing from the spirit of the present invention, they may make various substitutions or modifications to the described embodiments, and these substitutions or modifications should be considered to fall within the scope of protection of the present invention. Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "preferred embodiments," "examples," "specific examples," or "some examples" indicates that the specific features, structures, materials, or characteristics described in conjunction with such embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Persons skilled in the art may combine and assemble the different embodiments or examples described in this specification, as well as features of different embodiments or examples, without conflicting opinions. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications may be made herein without departing from the scope of protection of the patent application.

Claims

1. Application of a photocatalytic microorganism-nanomaterial hybrid in the treatment of antibiotic wastewater, characterized in that: The preparation method of the photocatalytic microorganism-nanomaterial hybrid comprises the following steps: Step S1: Melamine is heated at high temperature in air atmosphere to obtain an intermediate product, which is then ground and mixed evenly with potassium thiocyanate (KSCN) after cooling; then subjected to two-step heat treatment under protective atmosphere, cooled, washed with water several times to remove impurities, and finally freeze-dried to obtain modified polymeric carbon nitrogen (CN x ) Nanomaterials; Step S2: Bacteria Shewanella oneidensis MR-1 was inoculated into liquid culture medium and cultured under suitable temperature and shaking conditions until the bacterial concentration reached the late logarithmic growth phase; Step S3: Modified polymeric carbon nitrogen (CN x ) nanomaterials were dispersed in sterile water, ultrasonically treated to make them uniformly dispersed and then sterilized for use; the active bacterial solution obtained in step S2 was washed by centrifugation and resuspended in a buffer solution, and then mixed with the modified polymeric nitrogen carbonate (CN x ) After the nanomaterials are mixed, they are co-cultured under light-proof and suitable temperature conditions; after the cultivation is completed, the photocatalytic microorganism-nanomaterial hybrid is obtained by centrifugation and washing; The photocatalytic microorganism-nanomaterial hybrid realizes the simultaneous degradation of tetracycline antibiotics in wastewater and the mineralization of nitrogen and phosphorus in the wastewater to form magnesium ammonium phosphate crystals under natural light conditions.

2. The use according to claim 1, characterized in that In step S3, bacteria are reacted with modified polymeric carbon nitride (CN x ) The composite ratio of nanomaterials is configured as bacterial OD 600 The value is 2.0-3.0, modified polymeric carbon nitrogen (CN x ) The mass concentration of nanomaterial added is 0.5-1.0g / L.

3. The use according to claim 1, characterized in that In step S3, bacteria are mixed with modified polymeric carbon nitride (CN x ) The nanomaterials were cultured at 28-32°C and 140-180 rpm shaking for 24 h.

4. The use according to any one of claims 1 to 3, characterized in that The hybrid degrades organic pollutants through photocatalysis and induces nitrogen and phosphorus recovery without the need for adding an external base or an oxidant.

5. The use according to any one of claims 1 to 3, characterized in that The initial tetracycline concentration in the treated wastewater was 5–20 mg / L.

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