Titanium-loaded microbial solidified particle water treatment agent and preparation method thereof

Abstract

The application discloses a kind of titanium-carrying microbial solidified granular water treatment agent and preparation method thereof, it is related to water treatment technical field;The titanium-carrying microbial solidified granular water treatment agent is by citric acid and double modification adsorbent of titanium dioxide, magnetic stripping bentonite-based aerogel material, bacillus subtilis and lock throw yeast composition;The active bacteria of bacillus subtilis and lock throw yeast are loaded on citric acid and double modification adsorbent of titanium dioxide, then form mechanical interlocking with magnetic stripping bentonite-based aerogel material, rich in pore structure, increase adsorption site, not only strengthen the adsorption capacity of water treatment agent to heavy metal ions, organic pollutants, also improve the solidification of microorganism, reduce the adverse effects of acid-base environment on microorganism, with microbial combination functional material, give full play to adsorption, decomposition, reduce various pollutants in water body.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, specifically referring to a titanium-loaded microbial solidified particle water treatment agent and its preparation method. Background Technology

[0002] With the acceleration of urbanization, the expansion of industrial activities, and the impact of climate change, the discharge of domestic sewage and industrial wastewater continues to increase, which is rich in heavy metals (such as Pb). 2+ Cd 2+ Harmful substances such as phosphates and organic pollutants (such as antibiotics) pose a serious threat to the quality of the water environment, damaging not only the ecological environment but also human health. At the same time, the problem of water scarcity is becoming increasingly prominent, prompting people to pay more attention to the resource utilization and sustainable development of wastewater. Against this backdrop, the wastewater treatment industry is undergoing a transformation from traditional end-of-pipe treatment to intelligent, resource-based, and low-carbon development.

[0003] Water pollution treatment methods include physical, chemical, and biological methods. Among them, biological methods use the metabolic functions of microorganisms to decompose, absorb, or adsorb pollutants to purify water. These methods are characterized by low cost, safety, and no pollution, and are the main method of wastewater treatment today.

[0004] The existing technology currently suffers from the following main problems:

[0005] The activity of microorganisms is easily affected by adverse aquatic environments, which limits the adsorption and degradation of pollutants by the microorganisms. Furthermore, due to the limited number of surface sites of microorganisms, their adsorption performance is weak, thus failing to achieve effective water purification. Summary of the Invention

[0006] In view of the above situation and to overcome the defects of the prior art, the present invention proposes a titanium-loaded microbial solidified particle water treatment agent, comprising the following components in parts by weight: 50-60 parts of citric acid and titanium dioxide dual-modified adsorbent, 20-30 parts of magnetically exfoliated bentonite-based aerogel precursor material, 1-2 parts of Bacillus subtilis, and 1-2 parts of storax yeast.

[0007] The citric acid and titanium dioxide dual-modified adsorbent comprises the following components in parts by weight: 30-40 parts of sea urchin-like magnetic composite nanoparticles, 10-20 parts of citric acid, and 6-10 parts of nano-titanium dioxide.

[0008] The magnetically exfoliated bentonite-based aerogel precursor material comprises the following components in parts by weight: 5-8 parts magnetically exfoliated bentonite, 8-10 parts carboxylated cellulose nanofibers, and 1-3 parts polyethyleneimine.

[0009] The preparation method of the dual-modified adsorbent of citric acid and titanium dioxide specifically includes the following steps:

[0010] (1) Dissolve 3.5g of ferric chloride hexahydrate in 40mL of ethylene glycol, add 3.7g of anhydrous sodium acetate at a stirring speed of 1000-2000rpm until completely dissolved, then transfer to a 50mL polytetrafluoroethylene liner, seal and place in a reaction vessel, keep warm at 180-200℃ for 10-12h, collect the precipitate by magnetic separation, wash with deionized water and anhydrous ethanol, and then vacuum dry at 60℃. The magnetic Fe3O4 microspheres obtained by hydrothermal synthesis are rich in active sites on their surface, which can adsorb heavy metal ions and pollutants through electrostatic interaction or coordination bonds, generate hydroxyl radicals through chemical catalysis, degrade antibiotic-like organic compounds that are difficult to decompose, and reduce highly toxic pollutants to low-toxicity forms, which are convenient for subsequent degradation treatment, and obtain Fe3O4 microspheres;

[0011] (2) Disperse the Fe3O4 microspheres described in step (1) in a mixed solution of 30 mL anhydrous ethanol and 3 mL water, sonicate for 3-5 min, then add 1 mL ammonia, 10 mL anhydrous ethanol and 0.3-0.5 mL tetraethyl orthosilicate in sequence, sonicate at 20-30 °C for 2-3 h, collect the precipitate by magnetic separation, wash with deionized water and anhydrous ethanol, and then vacuum dry at 60 °C. Silica is coated on the surface of Fe3O4 microspheres. The introduction of silanol groups enhances the adsorption capacity for heavy metal ions and organic pollutants. The silica coating layer can not only prevent the aggregation between Fe3O4 microspheres, but also expose more active sites and improve adsorption efficiency. It can also broaden the pH range of use. Even in acidic environments, it can prevent the oxidation or dissolution of Fe3O4, improve the stability and recyclability of the material, and obtain modified Fe3O4 microspheres.

[0012] (3) Add sodium aluminate powder to 30 mL of water and stir until dissolved. Add 0.3-0.5 g of urea and stir for 0.5-1 h. Then add the modified Fe3O4 microspheres described in step (2), sonicate for 1-2 h, and then transfer to a reaction vessel. React at 160-180 °C for 5-6 h. Collect the product by magnetic separation, wash with deionized water 3-5 times, and then vacuum dry at 50 °C. The addition of urea will increase the amount of hydroxide in the solution, thereby increasing the OH content. - The concentration of OH in the solution promotes the formation of layered or fibrous crystals. - and AL 3+When supersaturated, boehmite forms densely distributed on the surface of the modified Fe3O4 microspheres, exhibiting a layered, urchin-like core-shell structure. Its porous network facilitates the adsorption of heavy metals and organic pollutants in the water, as well as the immobilization of microorganisms. Specifically, boehmite provides attachment sites for microorganisms, creating a local microenvironment that reduces the impact of acids and alkalis on them. Surface hydroxyl groups form hydrogen bonds or coordination bonds with the extracellular polymers of microorganisms, enhancing the immobilization effect. Simultaneously, boehmite can encapsulate microbial cells, forming an isolation layer that hinders the absorption of hydrogen ions (H2O). + and OH - The penetration of the microorganisms reduces the damage to microorganisms caused by acidic or alkaline environments, enhances the colonization density and activity of microorganisms, and yields sea urchin-shaped magnetic composite nanoparticles.

[0013] (4) Dissolve 1.0-2.0g of citric acid in 100mL of water to form a citric acid solution for later use. Disperse the sea urchin-like magnetic composite nanoparticles described in step (3) in 40mL of dimethyl sulfoxide and stir at 100-200rpm for 12h. Then add 6mL of tetraethyl orthosilicate and continue stirring for 3-5h. Add 0.6-1.0g of nano-titanium dioxide and stir for 8-12h. Centrifuge and wash the precipitate twice with distilled water. After vacuum drying, immerse it in the citric acid solution and stir at 100-200rpm for 24h under a nitrogen atmosphere. Then vacuum dry to achieve chelation of citric acid. The effect is to partially dissolve the amorphous regions of boehmite, and to form a richer mesoporous structure by combining with nano-titanium dioxide. After nano-titanium dioxide doping and citric acid acidification, not only is the porosity and adsorption sites of the sea urchin-like magnetic composite nanoparticles increased, thereby improving the adsorption capacity for heavy metal ions and organic pollutants, but also the physical encapsulation efficiency of microorganisms is improved, which is beneficial to the loading stability of microorganisms. Citric acid can promote the uniform dispersion of nano-titanium dioxide, and the high hardness of nano-titanium dioxide enhances the mechanical strength of the composite material and reduces structural collapse during recycling, thus obtaining a dual-modified adsorbent of citric acid and titanium dioxide.

[0014] Preferably, in step (3), the amount of sodium aluminate added is 0.1-0.2g. Sodium aluminate dissolves in water and releases aluminate ions, which serve as the key aluminum source for boehmite synthesis. The alkaline environment of sodium aluminate can reduce the formation of amorphous aluminum hydroxide or gibbsite, thereby selectively guiding the formation of boehmite.

[0015] Preferably, in step (4), the nano-titanium dioxide is of the rutile type with a particle size of 100-300nm, exhibiting low photocatalytic activity, avoiding the generation of harmful intermediate products, and also having good chemical stability, remaining stable in strong acids and strong bases.

[0016] This invention also provides a method for preparing titanium-loaded microbial solidified granular water treatment agent, specifically including the following steps:

[0017] S1. Add 10.0g of bentonite to a mixed solution of 500mL ultrapure water and anhydrous ethanol (volume ratio of ultrapure water to anhydrous ethanol: 1:2.5), stir well, microwave the solution at 600-800W and 60℃ for 1-2 hours, then ultrasonically disperse it at 600-700W for 1-2 hours, and then vacuum dry it at 60℃ for 12 hours to obtain exfoliated bentonite sheets for later use. Add 1.0-1.8g of ferric chloride and 0.6g of ferric chloride to 100mL of water, and pre-react it at 500-600W and 60℃ for 3-5 minutes. Add 10.5 mL of ammonia water and continue stirring in a microwave at 500-600 W and 60 °C for 0.5-1 h. Then add the exfoliated bentonite sheets and stir thoroughly for 1-2 h. After cooling to room temperature, collect the product by magnetic separation and wash it several times with anhydrous ethanol and ultrapure water until the pH reaches 7.0. Finally, vacuum dry and grind. The exfoliated bentonite has a large specific surface area and its layered structure exposes more active sites, which can adsorb and accommodate more pollutants. At the same time, combined with the catalytic effect of the magnetic component Fe3O4, it further promotes the decomposition of pollutants, thus obtaining magnetically exfoliated bentonite.

[0018] S2. Add 0.8-1.0g of carboxylated cellulose nanofibers to 100mL of ultrapure water and stir magnetically to form a carboxylated cellulose nanofiber suspension. Then add a 50% (w / w) polyethyleneimine solution and the magnetically exfoliated bentonite described in step S1. Stir at 60-70℃ for 3-4 hours at a stirring speed of 200-300rpm. This process forms a uniform network porous structure with slight wrinkles, which can increase the adsorption performance of heavy metal ions and organic pollutants. The network structure effectively protects the stability of the magnetic component Fe3O4, so it can be used as a stable and reusable adsorbent material in the field of water treatment, thus obtaining a magnetically exfoliated bentonite-based aerogel precursor material.

[0019] S3. Inoculate 1.0-2.0g of Bacillus subtilis and 1.0-2.0g of Cytomegalovirus into MSM basal salt medium, adding 1% glucose and 0.5% glycerol during inoculation, while maintaining the pH at 6.5-7.0. Incubate at 28-30℃ and 150-200rpm until the viable cell concentration reaches 10⁻⁶. 8The bacterial culture was obtained by centrifugation, discarding the supernatant, and collecting the active bacterial cells. Then, the dual-modified adsorbent of citric acid and titanium dioxide was soaked in MSM basic salt medium for 6-8 hours. After removal, it was mixed with the active bacterial cells and freeze-dried. Using the dual-modified adsorbent of citric acid and titanium dioxide as a carrier, the active bacterial cells formed through biofilm or were directly adsorbed onto the carrier, which enhanced the stability of the bacterial cells in water, reduced the adverse effects of acid and alkaline environment on bacterial activity, and ensured high bacterial activity. This is conducive to exerting the purification effect of Bacillus subtilis and Saccharomyces cerevisiae on water, and titanium-loaded microbial solidified particles were obtained.

[0020] S4. Add the titanium-loaded microbial solidified particles described in step S3 to the magnetically exfoliated bentonite-based aerogel precursor material described in step S2, and then perform ultrasonic dispersion treatment for 0.5-1 h, followed by freeze drying. The titanium-loaded microbial solidified particles form a mechanical interlock with the network structure of the magnetically exfoliated bentonite-based aerogel precursor material in a sea urchin-like shape, which increases the stability of the structure, reduces the risk of aerogel collapse, broadens the pH range of the aerogel material, and is beneficial to the stability of recycling. The magnetic porous network enhances the adsorption stability of microorganisms and further protects the activity of microorganisms. At the same time, the magnetic function enhances the adsorption performance of the composite material for pollutants. Combined with the decomposition effect of microorganisms, a highly efficient water purification effect is achieved, resulting in a titanium-loaded microbial solidified particle water treatment agent.

[0021] Preferably, in step S2, the carboxylated cellulose nanofibers have a diameter of 4-10 nm and a length of 1-3 μm. Carboxylated cellulose nanofibers with suitable diameter have higher adsorption capacity, and micron-sized fibers are more likely to form interwoven porous networks, improving mechanical strength and elasticity, and are suitable for dynamic adsorption in water.

[0022] Preferably, in step S2, the amount of polyethyleneimine solution added is 0.1-0.3 g. Polyethyleneimine is rich in amino groups and can react with substances such as Pb. 2+ Cd 2+ Hg 2+ Heavy metal ions can also adsorb organic pollutants such as phenols and antibiotics through coordination, electrostatic attraction, or ion exchange. They can also act as cross-linking agents, increasing the specific surface area and porosity of aerogels, improving adsorption capacity, enhancing mechanical strength, and increasing structural stability of aerogels in water.

[0023] The beneficial effects achieved by this invention are as follows:

[0024] This invention loads active cells of Bacillus subtilis and Cyclosporium tumefaciens onto a dual-modified adsorbent of citric acid and titanium dioxide, forming titanium-loaded microbial solidified particles. These particles are then mechanically interlocked with a magnetically exfoliated bentonite-based aerogel precursor material, further enriching the pore structure and increasing adsorption sites. This not only enhances the water treatment agent's adsorption capacity for heavy metal ions and organic pollutants but also improves the solidification of microorganisms, reducing the adverse effects of acidic and alkaline environments on microorganisms. By combining microorganisms with functional materials, the adsorption and decomposition effects are fully utilized to reduce various pollutants in water. Furthermore, the high strength and magnetic properties endow the water treatment agent with good stability for repeated use, maintaining its properties even after multiple applications. Excellent water treatment effect; in the citric acid and titanium dioxide dual-modified adsorbent, boehmite is first densely grown on the surface of modified Fe3O4 microspheres, presenting a layered sea urchin-like core-shell structure. Its porous structure is beneficial for adsorbing heavy metals and organic pollutants in water, as well as solidifying microbial loads. Silica and boehmite improve the uniform dispersion of Fe3O4 microspheres, reduce the oxidation of Fe3O4 microspheres, and broaden the pH range of application. They also have a positive effect on the stability of microorganisms and the microsphere structure. Furthermore, the sea urchin-like magnetic composite nanoparticles are doped and acidified with nano-titanium dioxide and citric acid, increasing the adsorption sites and chemical stability, thereby improving the adsorption of heavy metal ions and organic pollutants. The adsorption capacity is enhanced, improving the loading capacity and stability of microorganisms and reducing damage to microorganisms from acidic and alkaline environments. Citric acid promotes the uniform dispersion of nano-titanium dioxide, thus better exerting its protective effect. Nano-titanium dioxide also enhances mechanical strength, reducing the risk of collapse after adsorbent recycling. In the magnetically exfoliated bentonite-based aerogel precursor material, the exfoliated bentonite sheet structure crosslinks with carboxylated cellulose nanofibers and polyethyleneimine to form a uniform three-dimensional network structure with slight wrinkles, increasing the adsorption capacity for heavy metal ions and organic pollutants. The network structure effectively protects the stability of the magnetic component Fe3O4. The exfoliated bentonite exists as a single layer or a few layers of nano-... The flakes are dispersed in the aerogel matrix through physical cross-linking or chemical bonding, enhancing interfacial bonding, effectively dispersing stress, and improving the compressive and tensile strength of the aerogel, thus contributing to the structural stability of the aerogel material. Loading titanium-loaded microbial solidified particles into magnetically exfoliated bentonite-based aerogel precursor materials can reduce the aggregation of titanium-loaded microbial solidified particles due to their sea urchin-like shape, reduce the risk of aerogel collapse, broaden the pH range of the aerogel material, further protect the activity of microorganisms and the structural stability of the water treatment agent, and facilitate multiple recycling. At the same time, the dual magnetic material increases the adsorption performance of pollutants, and combined with the decomposition of microorganisms, achieves a highly efficient water purification effect.This invention utilizes a dual-modified adsorbent of citric acid and titanium dioxide, a magnetically exfoliated bentonite-based aerogel precursor material, Bacillus subtilis, and Saccharomyces cerevisiae to create a titanium-loaded microbial solidified granular water treatment agent. This agent protects the activity of microorganisms, enhances the adsorption performance for heavy metal ions and organic pollutants, and exhibits highly efficient purification effects. Attached Figure Description

[0025] Figure 1 This is a scanning electron microscope image of the titanium-loaded microbial solidified particle water treatment agent prepared in Example 1 of the present invention;

[0026] Figure 2 The graph shows the cell survival rate results of Examples 1-4 and Comparative Examples 1-3 of this invention;

[0027] Figure 3 The graphs show the pollutant adsorption results for Examples 1-4 and Comparative Examples 1-3 of this invention.

[0028] Figure 4 The graph shows the adsorption retention rate results of Examples 1-4 and Comparative Examples 1-3 of the present invention. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to this invention. The preferred embodiments and materials described herein are for illustrative purposes only and do not limit the scope of this application.

[0031] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; unless otherwise specified, the experimental materials used in the following embodiments are all purchased from commercial channels.

[0032] The reagents used in the examples were sourced from the following sources:

[0033] Bacillus subtilis brand Tanmo quality inspection, product number BHCC100903;

[0034] Lock-on yeast brand Tanmo quality inspection, product number BHCC104355.

[0035] Example 1

[0036] This embodiment proposes a titanium-loaded microbial solidified particle water treatment agent, comprising the following components in parts by weight: 60 parts of citric acid and titanium dioxide dual-modified adsorbent, 30 parts of magnetically exfoliated bentonite-based aerogel precursor material, 2 parts of Bacillus subtilis, and 2 parts of *Saccharomyces cerevisiae*.

[0037] The adsorbent, modified with citric acid and titanium dioxide, comprises the following components in parts by weight: 40 parts sea urchin-shaped magnetic composite nanoparticles, 20 parts citric acid, and 10 parts nano titanium dioxide.

[0038] The magnetically exfoliated bentonite-based aerogel precursor material comprises the following components in parts by weight: 8 parts magnetically exfoliated bentonite, 10 parts carboxylated cellulose nanofibers, and 3 parts polyethyleneimine.

[0039] The preparation method of the adsorbent modified by citric acid and titanium dioxide specifically includes the following steps:

[0040] (1) Dissolve 3.5g of ferric chloride hexahydrate in 40mL of ethylene glycol, add 3.7g of anhydrous sodium acetate at a stirring speed of 2000rpm until completely dissolved, then transfer to a 50mL polytetrafluoroethylene liner, seal and place in a reaction vessel, keep warm at 200℃ for 12h, collect the precipitate by magnetic separation, wash with deionized water and anhydrous ethanol, and then vacuum dry at 60℃. The magnetic Fe3O4 microspheres obtained by hydrothermal synthesis have a surface rich in active sites, which can adsorb heavy metal ions and pollutants through electrostatic interaction or coordination bonds, generate hydroxyl radicals through chemical catalysis, degrade antibiotic-like organic compounds that are difficult to decompose, and reduce highly toxic pollutants to low-toxicity forms, which are convenient for subsequent degradation treatment, and obtain Fe3O4 microspheres;

[0041] (2) Disperse the Fe3O4 microspheres described in step (1) in a mixed solution of 30 mL anhydrous ethanol and 3 mL water, sonicate for 5 min, then add 1 mL ammonia, 10 mL anhydrous ethanol and 0.5 mL tetraethyl orthosilicate in sequence, sonicate at 30 °C for 3 h, collect the precipitate by magnetic separation, wash with deionized water and anhydrous ethanol, and then vacuum dry at 60 °C. Silica is coated on the surface of Fe3O4 microspheres. The introduction of silanol groups enhances the adsorption capacity for heavy metal ions and organic pollutants. The silica coating layer can not only prevent the aggregation between Fe3O4 microspheres, but also expose more active sites and improve adsorption efficiency. It can also broaden the pH range of use. Even in acidic environments, it can prevent the oxidation or dissolution of Fe3O4, improve the stability and recyclability of the material, and obtain modified Fe3O4 microspheres.

[0042] (3) Add sodium aluminate powder to 30 mL of water and stir until dissolved. The amount of sodium aluminate added is 0.2 g. Sodium aluminate releases aluminate ions when dissolved in water, which serve as the key aluminum source for boehmite synthesis. The alkaline environment of sodium aluminate can reduce the formation of amorphous aluminum hydroxide or gibbsite, thereby selectively guiding the formation of boehmite. Add 0.5 g of urea and stir for 1 h. Then add the modified Fe3O4 microspheres described in step (2), sonicate for 2 h, and then transfer to a reaction vessel. React at 180 °C for 6 h. Collect the product by magnetic separation, wash with deionized water 5 times, and then vacuum dry at 50 °C. The addition of urea will increase the amount of hydroxide in the solution, thereby increasing the OH group. - The concentration of OH in the solution promotes the formation of layered or fibrous crystals. - and AL 3+ When supersaturated, boehmite forms densely distributed on the surface of the modified Fe3O4 microspheres, exhibiting a layered, urchin-like core-shell structure. Its porous network facilitates the adsorption of heavy metals and organic pollutants in the water, as well as the immobilization of microorganisms. Specifically, boehmite provides attachment sites for microorganisms, creating a local microenvironment that reduces the impact of acids and alkalis on them. Surface hydroxyl groups form hydrogen bonds or coordination bonds with the extracellular polymers of microorganisms, enhancing the immobilization effect. Simultaneously, boehmite can encapsulate microbial cells, forming an isolation layer that hinders the absorption of hydrogen ions (H2O). + and OH - The penetration of the microorganisms reduces the damage to microorganisms caused by acidic or alkaline environments, enhances the colonization density and activity of microorganisms, and yields sea urchin-shaped magnetic composite nanoparticles.

[0043] (4) Dissolve 2.0g of citric acid in 100mL of water to form a citric acid solution for later use. Disperse the sea urchin-shaped magnetic composite nanoparticles described in step (3) in 40mL of dimethyl sulfoxide and stir at 200rpm for 12h. Then add 6mL of tetraethyl orthosilicate and continue stirring for 5h. Then add 1.0g of nano titanium dioxide. The nano titanium dioxide is rutile with a particle size of 300nm. It exhibits low photocatalytic activity, avoids the generation of harmful intermediate products, and has good chemical stability. It remains stable in strong acids and strong bases. Stir for 12h, centrifuge, wash the precipitate twice with distilled water, vacuum dry it, and then immerse it in the citric acid solution. Stir in a nitrogen atmosphere at 200rpm for 12h. Stirred at 00 rpm for 24 hours, then vacuum dried. The chelating effect of citric acid can partially dissolve the amorphous regions of boehmite, forming a richer mesoporous structure with nano-titanium dioxide. After nano-titanium dioxide doping and citric acid acidification, not only is the porosity and adsorption sites of the sea urchin-like magnetic composite nanoparticles increased, thereby improving the adsorption capacity for heavy metal ions and organic pollutants, but also the physical encapsulation efficiency of microorganisms is improved, which is beneficial to the loading stability of microorganisms. Citric acid can promote the uniform dispersion of nano-titanium dioxide, and the high hardness of nano-titanium dioxide enhances the mechanical strength of the composite material and reduces structural collapse during recycling, resulting in a dual-modified adsorbent of citric acid and titanium dioxide.

[0044] This embodiment provides a method for preparing titanium-loaded microbial solidified granular water treatment agent, specifically including the following steps:

[0045] S1. Add 10.0g of bentonite to a mixed solution of 500mL ultrapure water and anhydrous ethanol (volume ratio of ultrapure water to anhydrous ethanol: 1:2.5), stir well, microwave the solution at 800W and 60℃ for 2 hours, then ultrasonically disperse it at 700W for 2 hours, and then vacuum dry it at 60℃ for 12 hours to obtain exfoliated bentonite sheets for later use. Add 1.8g of ferric chloride and 0.6g of ferric chloride to 100mL of water, pre-react at 600W and 60℃ for 5 minutes, then add 10.5g of... mL of ammonia water was added and stirred in a microwave at 600W and 60℃ for 1 hour. Then, the exfoliated bentonite sheets were added and stirred thoroughly for 2 hours. After cooling to room temperature, the product was collected by magnetic separation and washed multiple times with anhydrous ethanol and ultrapure water until the pH reached 7.0. Finally, it was vacuum dried and ground. The exfoliated bentonite has a large specific surface area and its layered structure exposes more active sites, which can adsorb and accommodate more pollutants. At the same time, combined with the catalytic effect of the magnetic component Fe3O4, the decomposition of pollutants is further promoted, thus obtaining magnetically exfoliated bentonite.

[0046] S2. Add 1.0g of carboxylated cellulose nanofibers to 100mL of ultrapure water and magnetically stir to form a carboxylated cellulose nanofiber suspension. The carboxylated cellulose nanofibers have a diameter of 10nm and a length of 3μm. Carboxylated cellulose nanofibers with a suitable diameter have a higher adsorption capacity, and the micron-sized fibers are more likely to form an interwoven porous network, improving mechanical strength and elasticity, making them suitable for dynamic adsorption in water. Then, add a 50% (w / w) polyethyleneimine solution and the magnetically exfoliated bentonite described in step S1. The amount of polyethyleneimine solution added is 0.3g. Polyethyleneimine is rich in amino groups and can react with substances such as Pb. 2+ Cd 2+ Hg 2+ Heavy metal ions can also adsorb organic pollutants such as phenols and antibiotics through coordination, electrostatic attraction, or ion exchange. They can also act as cross-linking agents, increasing the specific surface area and porosity of the aerogel, improving its adsorption capacity, mechanical strength, and structural stability in water. By stirring at 70℃ for 4 hours at 300 rpm, a uniform network porous structure with slight wrinkles was formed, which can increase the adsorption performance of heavy metal ions and organic pollutants. The network structure effectively protects the stability of the magnetic component Fe3O4, thus it can be used as a stable and reusable adsorbent material in the field of water treatment, resulting in a magnetically exfoliated bentonite-based aerogel precursor material.

[0047] S3. Inoculate 2.0 g of Bacillus subtilis and 2.0 g of Cytomegalovirus into MSM basal salt medium, adding 1% glucose and 0.5% glycerol during inoculation, while maintaining the pH at 7.0. Incubate at 30℃ and 200 rpm until the viable cell concentration reaches 10⁻⁶. 8 The bacterial culture was obtained by centrifugation, discarding the supernatant, and collecting the active bacterial cells. Then, the dual-modified adsorbent of citric acid and titanium dioxide was soaked in MSM basic salt medium for 8 hours. After removal, it was mixed with the active bacterial cells and freeze-dried. Using the dual-modified adsorbent of citric acid and titanium dioxide as a carrier, the active bacterial cells formed through biofilm or were directly adsorbed onto the carrier, which enhanced the stability of the bacterial cells in water, reduced the adverse effects of acid and alkaline environment on bacterial activity, and ensured high bacterial activity. This is conducive to exerting the purification effect of Bacillus subtilis and Saccharomyces cerevisiae on water, and titanium-loaded microbial solidified particles were obtained.

[0048] S4. Add the titanium-loaded microbial solidified particles described in step S3 to the magnetically exfoliated bentonite-based aerogel precursor material described in step S2, and then perform ultrasonic dispersion treatment for 1 hour, followed by freeze drying. The titanium-loaded microbial solidified particles, in a sea urchin-like shape, form a mechanical interlock with the network structure of the magnetically exfoliated bentonite-based aerogel precursor material, increasing the stability of the structure, reducing the risk of aerogel collapse, broadening the pH range of the aerogel material, and facilitating the stability of recycling. The magnetic porous network enhances the adsorption stability of microorganisms, further protecting the activity of microorganisms. At the same time, the magnetic function enhances the adsorption performance of the composite material for pollutants. Combined with the decomposition effect of microorganisms, a highly efficient water purification effect is achieved, resulting in a titanium-loaded microbial solidified particle water treatment agent.

[0049] In this embodiment, the microstructure of the prepared titanium-loaded microbial solidified particle water treatment agent was observed using scanning electron microscopy. Figure 1 This is a 100x magnified SEM image of the titanium-loaded microbial solidified particle water treatment agent prepared in Example 1, as shown below. Figure 1 The titanium-loaded microbial solidified particle water treatment agent prepared in this embodiment exhibits a tightly bound, stable, and abundant porous structure.

[0050] Example 2

[0051] This embodiment proposes a titanium-loaded microbial solidified particle water treatment agent, comprising the following components in parts by weight: 50 parts of citric acid and titanium dioxide dual-modified adsorbent, 20 parts of magnetically exfoliated bentonite-based aerogel precursor material, 1 part of Bacillus subtilis, and 1 part of *Saccharomyces cerevisiae*.

[0052] The adsorbent, modified with citric acid and titanium dioxide, comprises the following components in parts by weight: 30 parts sea urchin-shaped magnetic composite nanoparticles, 10 parts citric acid, and 6 parts nano titanium dioxide.

[0053] The magnetically exfoliated bentonite-based aerogel precursor material comprises the following components in parts by weight: 5 parts magnetically exfoliated bentonite, 8 parts carboxylated cellulose nanofibers, and 1 part polyethyleneimine.

[0054] The preparation method of the adsorbent modified by citric acid and titanium dioxide specifically includes the following steps:

[0055] (1) Dissolve 3.5g of ferric chloride hexahydrate in 40mL of ethylene glycol, add 3.7g of anhydrous sodium acetate while stirring at 1000rpm until completely dissolved, then transfer to a 50mL polytetrafluoroethylene liner, seal and place in a reaction vessel, keep warm at 180℃ for 10h, collect the precipitate by magnetic separation, wash with deionized water and anhydrous ethanol, and then vacuum dry at 60℃. The magnetic Fe3O4 microspheres obtained by hydrothermal synthesis are rich in active sites on their surface, which can adsorb heavy metal ions and pollutants through electrostatic interaction or coordination bonds, generate hydroxyl radicals through chemical catalysis, degrade antibiotic-like organic compounds that are difficult to decompose, and reduce highly toxic pollutants to low-toxicity forms, which are convenient for subsequent degradation treatment, and obtain Fe3O4 microspheres;

[0056] (2) The Fe3O4 microspheres described in step (1) are dispersed in a mixed solution of 30 mL anhydrous ethanol and 3 mL water, sonicated for 3 min, and then 1 mL ammonia, 10 mL anhydrous ethanol and 0.3 mL tetraethyl orthosilicate are added in sequence. The mixture is sonicated at 20 °C for 2 h. The precipitate is collected by magnetic separation, washed with deionized water and anhydrous ethanol, and then vacuum dried at 60 °C. Silica is coated on the surface of Fe3O4 microspheres. The introduction of silanol groups enhances the adsorption capacity for heavy metal ions and organic pollutants. The silica coating layer can not only prevent the aggregation between Fe3O4 microspheres and expose more active sites to improve adsorption efficiency, but also broaden the pH range. Even in acidic environments, it can prevent the oxidation or dissolution of Fe3O4, improve the stability and recyclability of the material, and obtain modified Fe3O4 microspheres.

[0057] (3) Add sodium aluminate powder to 30 mL of water and stir until dissolved. The amount of sodium aluminate added is 0.1 g. Sodium aluminate releases aluminate ions when dissolved in water, which serve as the key aluminum source for boehmite synthesis. The alkaline environment of sodium aluminate can reduce the formation of amorphous aluminum hydroxide or gibbsite, thereby selectively guiding the formation of boehmite. Add 0.3 g of urea and stir for 0.5 h. Then add the modified Fe3O4 microspheres described in step (2), sonicate for 1 h, and then transfer to a reaction vessel. React at 160 °C for 5 h. Collect the product by magnetic separation, wash three times with deionized water, and then vacuum dry at 50 °C. The addition of urea will increase the amount of hydroxide in the solution, thereby increasing the OH group. - The concentration of OH in the solution promotes the formation of layered or fibrous crystals. - and AL 3+When supersaturated, boehmite forms densely distributed on the surface of the modified Fe3O4 microspheres, exhibiting a layered, urchin-like core-shell structure. Its porous network facilitates the adsorption of heavy metals and organic pollutants in the water, as well as the immobilization of microorganisms. Specifically, boehmite provides attachment sites for microorganisms, creating a local microenvironment that reduces the impact of acids and alkalis on them. Surface hydroxyl groups form hydrogen bonds or coordination bonds with the extracellular polymers of microorganisms, enhancing the immobilization effect. Simultaneously, boehmite can encapsulate microbial cells, forming an isolation layer that hinders the absorption of hydrogen ions (H2O). + and OH - The penetration of the microorganisms reduces the damage to microorganisms caused by acidic or alkaline environments, enhances the colonization density and activity of microorganisms, and yields sea urchin-shaped magnetic composite nanoparticles.

[0058] (4) Dissolve 1.0g of citric acid in 100mL of water to form a citric acid solution for later use. Disperse the urchin-shaped magnetic composite nanoparticles described in step (3) in 40mL of dimethyl sulfoxide and stir at 100rpm for 12h. Then add 6mL of tetraethyl orthosilicate and continue stirring for 3h. Then add 0.6g of nano titanium dioxide. The nano titanium dioxide is rutile with a particle size of 100nm. It exhibits low photocatalytic activity, avoids the generation of harmful intermediate products, and has good chemical stability. It remains stable in strong acids and strong bases. Stir for 8h, centrifuge, wash the precipitate twice with distilled water, vacuum dry it, and then immerse it in the citric acid solution. Stir in a nitrogen atmosphere at 100rpm. Stirred at 0 rpm for 24 hours, then vacuum dried. The chelating effect of citric acid can partially dissolve the amorphous regions of boehmite, forming a richer mesoporous structure with nano-titanium dioxide. After nano-titanium dioxide doping and citric acid acidification, not only is the porosity and adsorption sites of the sea urchin-like magnetic composite nanoparticles increased, thereby improving the adsorption capacity for heavy metal ions and organic pollutants, but also the physical encapsulation efficiency of microorganisms is improved, which is beneficial to the loading stability of microorganisms. Citric acid can promote the uniform dispersion of nano-titanium dioxide, and the high hardness of nano-titanium dioxide enhances the mechanical strength of the composite material and reduces structural collapse during recycling, resulting in a dual-modified adsorbent of citric acid and titanium dioxide.

[0059] This embodiment provides a method for preparing titanium-loaded microbial solidified granular water treatment agent, specifically including the following steps:

[0060] S1. Add 10.0g of bentonite to a mixed solution of 500mL ultrapure water and anhydrous ethanol (volume ratio of ultrapure water to anhydrous ethanol: 1:2.5), stir well, microwave the solution at 600W and 60℃ for 1 hour, then ultrasonically disperse it at 600W for 1 hour, and then vacuum dry it at 60℃ for 12 hours to obtain exfoliated bentonite sheets for later use. Add 1.0g of ferric chloride and 0.6g of ferric chloride to 100mL of water, pre-react at 500W and 60℃ for 3 minutes, then add 10.5mg of... L of ammonia water was stirred in a microwave at 500W and 60℃ for 0.5h. Then, the exfoliated bentonite sheets were added and stirred thoroughly for 1h. After cooling to room temperature, the product was collected by magnetic separation and washed multiple times with anhydrous ethanol and ultrapure water until the pH reached 7.0. Finally, it was vacuum dried and ground. The exfoliated bentonite has a large specific surface area and its layered structure exposes more active sites, which can adsorb and accommodate more pollutants. At the same time, combined with the catalytic effect of the magnetic component Fe3O4, the decomposition of pollutants is further promoted, thus obtaining magnetically exfoliated bentonite.

[0061] S2. Add 0.8g of carboxylated cellulose nanofibers to 100mL of ultrapure water and magnetically stir to form a carboxylated cellulose nanofiber suspension. The carboxylated cellulose nanofibers have a diameter of 4nm and a length of 1μm. Carboxylated cellulose nanofibers with a suitable diameter have a higher adsorption capacity, and the micron-sized fibers are more likely to form an interwoven porous network, improving mechanical strength and elasticity, making them suitable for dynamic adsorption in water. Then, add a 50% (w / w) polyethyleneimine solution and the magnetically exfoliated bentonite described in step S1. The amount of polyethyleneimine solution added is 0.1g. Polyethyleneimine is rich in amino groups and can react with substances such as Pb. 2+ Cd 2+ Hg 2+ Heavy metal ions can also adsorb organic pollutants such as phenols and antibiotics through coordination, electrostatic attraction, or ion exchange. They can also act as cross-linking agents, increasing the specific surface area and porosity of the aerogel, improving its adsorption capacity, mechanical strength, and structural stability in water. By stirring at 60℃ for 3 hours at a stirring speed of 200 rpm, a uniform network porous structure with slight wrinkles was formed, which can increase the adsorption performance of heavy metal ions and organic pollutants. The network structure effectively protects the stability of the magnetic component Fe3O4, thus it can be used as a stable and reusable adsorbent material in the field of water treatment, resulting in a magnetically exfoliated bentonite-based aerogel precursor material.

[0062] S3. Inoculate 1.0 g of Bacillus subtilis and 1.0 g of Cytomegalovirus into MSM basal salt medium, adding 1% glucose and 0.5% glycerol during inoculation, while maintaining the pH at 6.5. Incubate at 28℃ and 150 rpm until the viable cell concentration reaches 10⁻⁶. 8 The bacterial culture was obtained by centrifugation, discarding the supernatant, and collecting the active bacterial cells. Then, the dual-modified adsorbent of citric acid and titanium dioxide was soaked in MSM basic salt medium for 6 hours. After removal, it was mixed with the active bacterial cells and freeze-dried. Using the dual-modified adsorbent of citric acid and titanium dioxide as a carrier, the active bacterial cells formed through biofilm or were directly adsorbed onto the carrier, which enhanced the stability of the bacterial cells in water, reduced the adverse effects of acid and alkaline environment on bacterial activity, and ensured high bacterial activity. This is conducive to exerting the purification effect of Bacillus subtilis and Saccharomyces cerevisiae on water, and titanium-loaded microbial solidified particles were obtained.

[0063] S4. The titanium-loaded microbial solidified particles described in step S3 are added to the magnetically exfoliated bentonite-based aerogel precursor material described in step S2, and then ultrasonically dispersed for 0.5 hours, followed by freeze-drying. The titanium-loaded microbial solidified particles, in a sea urchin-like shape, form a mechanical interlock with the network structure of the magnetically exfoliated bentonite-based aerogel precursor material, increasing structural stability, reducing the risk of aerogel collapse, broadening the pH range of the aerogel material, and improving the stability of recycling. The magnetic porous network enhances the adsorption stability of microorganisms, further protecting their activity. At the same time, the magnetic function enhances the adsorption performance of the composite material for pollutants. Combined with the decomposition effect of microorganisms, a highly efficient water purification effect is achieved, resulting in a titanium-loaded microbial solidified particle water treatment agent.

[0064] Example 3

[0065] This embodiment proposes a titanium-loaded microbial solidified particle water treatment agent, comprising the following components in parts by weight: 55 parts of citric acid and titanium dioxide dual-modified adsorbent, 25 parts of magnetically exfoliated bentonite-based aerogel precursor material, 1.5 parts of Bacillus subtilis, and 1.5 parts of *Saccharomyces cerevisiae*.

[0066] The adsorbent, modified with citric acid and titanium dioxide, comprises the following components in parts by weight: 35 parts sea urchin-shaped magnetic composite nanoparticles, 15 parts citric acid, and 8 parts nano titanium dioxide.

[0067] The magnetically exfoliated bentonite-based aerogel precursor material comprises the following components in parts by weight: 6.5 parts magnetically exfoliated bentonite, 9 parts carboxylated cellulose nanofibers, and 2 parts polyethyleneimine.

[0068] The preparation method of the adsorbent modified by citric acid and titanium dioxide specifically includes the following steps:

[0069] (1) Dissolve 3.5g of ferric chloride hexahydrate in 40mL of ethylene glycol, add 3.7g of anhydrous sodium acetate while stirring at 1500rpm until completely dissolved, then transfer to a 50mL polytetrafluoroethylene liner, seal and place in a reaction vessel, keep at 190℃ for 11h, collect the precipitate by magnetic separation, wash with deionized water and anhydrous ethanol, and then vacuum dry at 60℃. The magnetic Fe3O4 microspheres obtained by hydrothermal synthesis have a surface rich in active sites, which can adsorb heavy metal ions and pollutants through electrostatic interaction or coordination bonds, generate hydroxyl radicals through chemical catalysis, degrade antibiotic-like organic compounds that are difficult to decompose, and reduce highly toxic pollutants to low-toxicity forms, which are convenient for subsequent degradation treatment, and obtain Fe3O4 microspheres;

[0070] (2) The Fe3O4 microspheres described in step (1) were dispersed in a mixed solution of 30 mL anhydrous ethanol and 3 mL water, and sonicated for 4 min. Then, 1 mL ammonia, 10 mL anhydrous ethanol and 0.4 mL tetraethyl orthosilicate were added in sequence, and the mixture was sonicated at 25 °C for 2.5 h. The precipitate was collected by magnetic separation, washed with deionized water and anhydrous ethanol, and then vacuum dried at 60 °C. Silica was coated on the surface of the Fe3O4 microspheres. The introduction of silanol groups enhanced the adsorption capacity for heavy metal ions and organic pollutants. The silica coating layer not only prevented the aggregation between Fe3O4 microspheres and exposed more active sites to improve adsorption efficiency, but also broadened the pH range. Even in acidic environments, it prevented the oxidation or dissolution of Fe3O4, improved the stability and recyclability of the material, and obtained modified Fe3O4 microspheres.

[0071] (3) Add sodium aluminate powder to 30 mL of water and stir until dissolved. The amount of sodium aluminate added is 0.15 g. Sodium aluminate releases aluminate ions when dissolved in water, which serve as the key aluminum source for boehmite synthesis. The alkaline environment of sodium aluminate can reduce the formation of amorphous aluminum hydroxide or gibbsite, thereby selectively guiding the formation of boehmite. Add 0.4 g of urea and stir for 0.75 h. Then add the modified Fe3O4 microspheres described in step (2), sonicate for 1.5 h, and then transfer to a reaction vessel. React at 170 °C for 5.5 h. Collect the product by magnetic separation, wash with deionized water 4 times, and then vacuum dry at 50 °C. The addition of urea will increase the amount of hydroxide in the solution, thereby increasing the OH group. - The concentration of OH in the solution promotes the formation of layered or fibrous crystals. - and AL 3+When supersaturated, boehmite forms densely distributed on the surface of the modified Fe3O4 microspheres, exhibiting a layered, urchin-like core-shell structure. Its porous network facilitates the adsorption of heavy metals and organic pollutants in the water, as well as the immobilization of microorganisms. Specifically, boehmite provides attachment sites for microorganisms, creating a local microenvironment that reduces the impact of acids and alkalis on them. Surface hydroxyl groups form hydrogen bonds or coordination bonds with the extracellular polymers of microorganisms, enhancing the immobilization effect. Simultaneously, boehmite can encapsulate microbial cells, forming an isolation layer that hinders the absorption of hydrogen ions (H2O). + and OH - The penetration of the microorganisms reduces the damage to microorganisms caused by acidic or alkaline environments, enhances the colonization density and activity of microorganisms, and yields sea urchin-shaped magnetic composite nanoparticles.

[0072] (4) Dissolve 1.5g of citric acid in 100mL of water to form a citric acid solution for later use. Disperse the urchin-shaped magnetic composite nanoparticles described in step (3) in 40mL of dimethyl sulfoxide and stir at 150rpm for 12h. Then add 6mL of tetraethyl orthosilicate and continue stirring for 4h. Then add 0.8g of nano titanium dioxide. The nano titanium dioxide is rutile with a particle size of 200nm. It exhibits low photocatalytic activity, avoids the generation of harmful intermediate products, and has good chemical stability. It remains stable in strong acids and strong bases. Stir for 10h, centrifuge, wash the precipitate twice with distilled water, vacuum dry it, and then immerse it in the citric acid solution. Stir in a nitrogen atmosphere at 1 The mixture was stirred at 50 rpm for 24 hours and then vacuum dried. The chelating effect of citric acid can partially dissolve the amorphous regions of boehmite, forming a richer mesoporous structure with nano-titanium dioxide. After doping with nano-titanium dioxide and acidifying with citric acid, not only is the porosity and adsorption sites of the sea urchin-like magnetic composite nanoparticles increased, thereby improving the adsorption capacity for heavy metal ions and organic pollutants, but also the physical encapsulation efficiency of microorganisms is improved, which is beneficial to the loading stability of microorganisms. Citric acid can promote the uniform dispersion of nano-titanium dioxide, and the high hardness of nano-titanium dioxide enhances the mechanical strength of the composite material and reduces structural collapse during recycling, resulting in a dual-modified adsorbent of citric acid and titanium dioxide.

[0073] This embodiment provides a method for preparing titanium-loaded microbial solidified granular water treatment agent, specifically including the following steps:

[0074] S1. Add 10.0g of bentonite to a mixed solution of 500mL ultrapure water and anhydrous ethanol (volume ratio of ultrapure water to anhydrous ethanol: 1:2.5), stir well, microwave the solution at 700W and 60℃ for 1.5h, then ultrasonically disperse it at 650W for 1.5h, and then vacuum dry it at 60℃ for 12h to obtain exfoliated bentonite sheets for later use. Add 1.4g of ferric chloride and 0.6g of ferric chloride to 100mL of water, pre-react at 550W and 60℃ for 4min, then add 10.5g of bentonite. mL of ammonia water was added and stirred in a microwave at 550W and 60℃ for 0.75h. Then, the exfoliated bentonite sheets were added and stirred thoroughly for 1.5h. After cooling to room temperature, the product was collected by magnetic separation and washed multiple times with anhydrous ethanol and ultrapure water until the pH reached 7.0. Finally, it was vacuum dried and ground. The exfoliated bentonite has a large specific surface area and its layered structure exposes more active sites, which can adsorb and accommodate more pollutants. At the same time, combined with the catalytic effect of the magnetic component Fe3O4, the decomposition of pollutants is further promoted, thus obtaining magnetically exfoliated bentonite.

[0075] S2. Add 0.9g of carboxylated cellulose nanofibers to 100mL of ultrapure water and magnetically stir to form a carboxylated cellulose nanofiber suspension. The carboxylated cellulose nanofibers have a diameter of 7nm and a length of 2μm. Carboxylated cellulose nanofibers with a suitable diameter have a higher adsorption capacity, and the micron-sized fibers are more likely to form an interwoven porous network, improving mechanical strength and elasticity, making them suitable for dynamic adsorption in water. Then, add a 50% (w / w) polyethyleneimine solution and the magnetically exfoliated bentonite described in step S1. The amount of polyethyleneimine solution added is 0.2g. Polyethyleneimine is rich in amino groups and can react with substances such as Pb. 2+ Cd 2+ Hg 2+ Heavy metal ions can also adsorb organic pollutants such as phenols and antibiotics through coordination, electrostatic attraction, or ion exchange. They can also act as cross-linking agents, increasing the specific surface area and porosity of the aerogel, improving its adsorption capacity, mechanical strength, and structural stability in water. By stirring at 65℃ for 3.5h at a stirring speed of 250rpm, a uniform network porous structure with slight wrinkles was formed, which can increase the adsorption performance of heavy metal ions and organic pollutants. The network structure effectively protects the stability of the magnetic component Fe3O4, thus it can be used as a stable and reusable adsorbent material in the field of water treatment, resulting in a magnetically exfoliated bentonite-based aerogel precursor material.

[0076] S3. Inoculate 1.5g of Bacillus subtilis and 1.5g of Cytomegalovirus into MSM basal salt medium, adding 1% glucose and 0.5% glycerol during inoculation, while maintaining the pH at 6.8. Incubate at 28℃ and 175rpm until the viable cell concentration reaches 10⁻⁶. 8 The bacterial culture was obtained by centrifugation, centrifugation, and discarding the supernatant. Active bacterial cells were collected and then soaked in MSM basic salt medium for 7 hours with a dual-modified adsorbent of citric acid and titanium dioxide. After removal, the adsorbent was mixed with the active bacterial cells and freeze-dried. Using the dual-modified adsorbent of citric acid and titanium dioxide as a carrier, the active bacterial cells formed through biofilm or were directly adsorbed onto the carrier, which enhanced the stability of the bacterial cells in water, reduced the adverse effects of acid and alkaline environments on bacterial activity, and ensured high bacterial activity. This is beneficial for Bacillus subtilis and Saccharomyces cerevisiae to exert their combined purification effect on water, resulting in titanium-loaded microbial solidified particles.

[0077] S4. The titanium-loaded microbial solidified particles described in step S3 are added to the magnetically exfoliated bentonite-based aerogel precursor material described in step S2, and then ultrasonically dispersed for 0.75 hours, followed by freeze-drying. The titanium-loaded microbial solidified particles, in a sea urchin-like shape, form a mechanical interlock with the network structure of the magnetically exfoliated bentonite-based aerogel precursor material, increasing structural stability, reducing the risk of aerogel collapse, broadening the pH range of the aerogel material, and improving the stability for recycling. The magnetic porous network enhances the adsorption stability of microorganisms, further protecting their activity. At the same time, the magnetic function enhances the adsorption performance of the composite material for pollutants. Combined with the decomposition effect of microorganisms, a highly efficient water purification effect is achieved, resulting in a titanium-loaded microbial solidified particle water treatment agent.

[0078] Example 4

[0079] This embodiment proposes a titanium-loaded microbial solidified particle water treatment agent, comprising the following components in parts by weight: 60 parts of dual-modified adsorption by citric acid and titanium dioxide, 20 parts of magnetically exfoliated bentonite-based aerogel precursor material, 2 parts of Bacillus subtilis, and 1 part of *Saccharomyces cerevisiae*.

[0080] The adsorbent, modified with citric acid and titanium dioxide, comprises the following components in parts by weight: 40 parts sea urchin-shaped magnetic composite nanoparticles, 10 parts citric acid, and 10 parts nano titanium dioxide.

[0081] The magnetically exfoliated bentonite-based aerogel precursor material comprises the following components in parts by weight: 8 parts magnetically exfoliated bentonite, 10 parts carboxylated cellulose nanofibers, and 1 part polyethyleneimine.

[0082] The preparation method of the adsorbent modified by citric acid and titanium dioxide specifically includes the following steps:

[0083] (1) Dissolve 3.5g of ferric chloride hexahydrate in 40mL of ethylene glycol, add 3.7g of anhydrous sodium acetate at a stirring speed of 2000rpm until completely dissolved, then transfer to a 50mL polytetrafluoroethylene liner, seal and place in a reaction vessel, keep warm at 200℃ for 10h, collect the precipitate by magnetic separation, wash with deionized water and anhydrous ethanol, and then vacuum dry at 60℃. The magnetic Fe3O4 microspheres obtained by hydrothermal synthesis have a surface rich in active sites, which can adsorb heavy metal ions and pollutants through electrostatic interaction or coordination bonds, generate hydroxyl radicals through chemical catalysis, degrade antibiotic-like organic compounds that are difficult to decompose, and reduce highly toxic pollutants to low-toxicity forms, which are convenient for subsequent degradation treatment, and obtain Fe3O4 microspheres;

[0084] (2) Disperse the Fe3O4 microspheres described in step (1) in a mixed solution of 30 mL anhydrous ethanol and 3 mL water, sonicate for 3 min, then add 1 mL ammonia, 10 mL anhydrous ethanol and 0.5 mL tetraethyl orthosilicate in sequence, sonicate at 30 °C for 2 h, collect the precipitate by magnetic separation, wash with deionized water and anhydrous ethanol, and then vacuum dry at 60 °C. Silica is coated on the surface of Fe3O4 microspheres. The introduction of silanol groups enhances the adsorption capacity for heavy metal ions and organic pollutants. The silica coating layer can not only prevent the aggregation between Fe3O4 microspheres, but also expose more active sites and improve the adsorption efficiency. It can also broaden the pH range of use. Even in acidic environments, it can prevent the oxidation or dissolution of Fe3O4, improve the stability and recyclability of the material, and obtain modified Fe3O4 microspheres.

[0085] (3) Add sodium aluminate powder to 30 mL of water and stir until dissolved. The amount of sodium aluminate added is 0.2 g. Sodium aluminate releases aluminate ions when dissolved in water, which serve as the key aluminum source for boehmite synthesis. The alkaline environment of sodium aluminate can reduce the formation of amorphous aluminum hydroxide or gibbsite, thereby selectively guiding the formation of boehmite. Add 0.3 g of urea and stir for 0.5 h. Then add the modified Fe3O4 microspheres described in step (2), sonicate for 1 h, and then transfer to a reaction vessel. React at 180 °C for 5 h. Collect the product by magnetic separation, wash with deionized water 5 times, and then vacuum dry at 50 °C. The addition of urea will increase the amount of hydroxide in the solution, thereby increasing the OH group. - The concentration of OH in the solution promotes the formation of layered or fibrous crystals. - and AL 3+When supersaturated, boehmite forms densely distributed on the surface of the modified Fe3O4 microspheres, exhibiting a layered, urchin-like core-shell structure. Its porous network facilitates the adsorption of heavy metals and organic pollutants in the water, as well as the immobilization of microorganisms. Specifically, boehmite provides attachment sites for microorganisms, creating a local microenvironment that reduces the impact of acids and alkalis on them. Surface hydroxyl groups form hydrogen bonds or coordination bonds with the extracellular polymers of microorganisms, enhancing the immobilization effect. Simultaneously, boehmite can encapsulate microbial cells, forming an isolation layer that hinders the absorption of hydrogen ions (H2O). + and OH - The penetration of the microorganisms reduces the damage to microorganisms caused by acidic or alkaline environments, enhances the colonization density and activity of microorganisms, and yields sea urchin-shaped magnetic composite nanoparticles.

[0086] (4) Dissolve 1.0g of citric acid in 100mL of water to form a citric acid solution for later use. Disperse the urchin-shaped magnetic composite nanoparticles described in step (3) in 40mL of dimethyl sulfoxide and stir at 200rpm for 12h. Then add 6mL of tetraethyl orthosilicate and continue stirring for 3h. Then add 1.0g of nano titanium dioxide. The nano titanium dioxide is of rutile type with a particle size of 300nm. It exhibits low photocatalytic activity, avoids the generation of harmful intermediate products, and also has good chemical stability. It remains stable in strong acids and strong bases. Stir for 8h, centrifuge, wash the precipitate twice with distilled water, vacuum dry it, and then immerse it in the citric acid solution. Stir in a nitrogen atmosphere at 200rpm. Stirred at 0 rpm for 24 hours, then vacuum dried. The chelating effect of citric acid can partially dissolve the amorphous regions of boehmite, forming a richer mesoporous structure with nano-titanium dioxide. After nano-titanium dioxide doping and citric acid acidification, not only is the porosity and adsorption sites of the sea urchin-like magnetic composite nanoparticles increased, thereby improving the adsorption capacity for heavy metal ions and organic pollutants, but also the physical encapsulation efficiency of microorganisms is improved, which is beneficial to the loading stability of microorganisms. Citric acid can promote the uniform dispersion of nano-titanium dioxide, and the high hardness of nano-titanium dioxide enhances the mechanical strength of the composite material and reduces structural collapse during recycling, resulting in a dual-modified adsorbent of citric acid and titanium dioxide.

[0087] This embodiment provides a method for preparing titanium-loaded microbial solidified granular water treatment agent, specifically including the following steps:

[0088] S1. Add 10.0g of bentonite to a mixed solution of 500mL ultrapure water and anhydrous ethanol (volume ratio of ultrapure water to anhydrous ethanol: 1:2.5), stir well, microwave the solution at 800W and 60℃ for 1 hour, then ultrasonically disperse it at 700W for 1 hour, and then vacuum dry it at 60℃ for 12 hours to obtain exfoliated bentonite sheets for later use. Add 1.8g of ferric chloride and 0.6g of ferric chloride to 100mL of water, pre-react at 600W and 60℃ for 3 minutes, then add 10.5mg of... L of ammonia water was stirred in a microwave at 600W and 60℃ for 0.5h. Then, the exfoliated bentonite sheets were added and stirred thoroughly for 1h. After cooling to room temperature, the product was collected by magnetic separation and washed multiple times with anhydrous ethanol and ultrapure water until the pH reached 7.0. Finally, it was vacuum dried and ground. The exfoliated bentonite has a large specific surface area and its layered structure exposes more active sites, which can adsorb and accommodate more pollutants. At the same time, combined with the catalytic effect of the magnetic component Fe3O4, the decomposition of pollutants is further promoted, thus obtaining magnetically exfoliated bentonite.

[0089] S2. Add 1.0g of carboxylated cellulose nanofibers to 100mL of ultrapure water and magnetically stir to form a carboxylated cellulose nanofiber suspension. The carboxylated cellulose nanofibers have a diameter of 10nm and a length of 1μm. Carboxylated cellulose nanofibers with a suitable diameter have a higher adsorption capacity, and the micron-sized fibers are more likely to form an interwoven porous network, improving mechanical strength and elasticity, making them suitable for dynamic adsorption in water. Then, add a 50% (w / w) polyethyleneimine solution and the magnetically exfoliated bentonite described in step S1. The amount of polyethyleneimine solution added is 0.1g. Polyethyleneimine is rich in amino groups and can react with substances such as Pb. 2+ Cd 2+ Hg 2+ Heavy metal ions can also adsorb organic pollutants such as phenols and antibiotics through coordination, electrostatic attraction, or ion exchange. They can also act as cross-linking agents, increasing the specific surface area and porosity of the aerogel, improving its adsorption capacity, mechanical strength, and structural stability in water. By stirring at 70℃ for 3 hours at 300 rpm, a uniform network porous structure with slight wrinkles was formed, which can increase the adsorption performance of heavy metal ions and organic pollutants. The network structure effectively protects the stability of the magnetic component Fe3O4, thus it can be used as a stable and reusable adsorbent material in the field of water treatment, resulting in a magnetically exfoliated bentonite-based aerogel precursor material.

[0090] S3. Inoculate 2.0 g of Bacillus subtilis and 1.0 g of *Saccharomyces cerevisiae* into MSM basal salt medium, adding 1% glucose and 0.5% glycerol while maintaining the pH at 7.0. Incubate at 30°C and 200 rpm until the viable cell concentration reaches 10⁻⁶. 8 The bacterial culture was obtained by centrifugation, discarding the supernatant, and collecting the active bacterial cells. Then, the dual-modified adsorbent of citric acid and titanium dioxide was soaked in MSM basic salt medium for 6 hours. After removal, it was mixed with the active bacterial cells and freeze-dried. Using the dual-modified adsorbent of citric acid and titanium dioxide as a carrier, the active bacterial cells formed through biofilm or were directly adsorbed onto the carrier, which enhanced the stability of the bacterial cells in water, reduced the adverse effects of acid and alkaline environment on bacterial activity, and ensured high bacterial activity. This is conducive to exerting the purification effect of Bacillus subtilis and Saccharomyces cerevisiae on water, and titanium-loaded microbial solidified particles were obtained.

[0091] S4. The titanium-loaded microbial solidified particles described in step S3 are added to the magnetically exfoliated bentonite-based aerogel precursor material described in step S2, and then ultrasonically dispersed for 0.5 hours, followed by freeze-drying. The titanium-loaded microbial solidified particles, in a sea urchin-like shape, form a mechanical interlock with the network structure of the magnetically exfoliated bentonite-based aerogel precursor material, increasing structural stability, reducing the risk of aerogel collapse, broadening the pH range of the aerogel material, and improving the stability of recycling. The magnetic porous network enhances the adsorption stability of microorganisms, further protecting their activity. At the same time, the magnetic function enhances the adsorption performance of the composite material for pollutants. Combined with the decomposition effect of microorganisms, a highly efficient water purification effect is achieved, resulting in a titanium-loaded microbial solidified particle water treatment agent.

[0092] Comparative Example 1

[0093] This comparative example provides a titanium-loaded microbial solidified particle water treatment agent, which differs from Example 1 in that the citric acid and titanium dioxide dual-modified adsorbent does not contain boehmite; the preparation method of the citric acid and titanium dioxide dual-modified adsorbent does not include step (3); the preparation method of the titanium-loaded microbial solidified particle water treatment agent is the same as that of Example 1.

[0094] Comparative Example 2

[0095] This comparative example provides a titanium-loaded microbial solidified particle water treatment agent, which differs from Example 1 in that the dual-modified adsorbent of citric acid and titanium dioxide does not contain citric acid or nano-titanium dioxide; the preparation method of the dual-modified adsorbent of citric acid and titanium dioxide does not include step (4); the preparation method of the titanium-loaded microbial solidified particle water treatment agent is the same as that of Example 1.

[0096] Comparative Example 3

[0097] This comparative example provides a titanium-loaded microbial solidified particle water treatment agent, which differs from Example 1 in that the magnetically exfoliated bentonite-based aerogel precursor material does not contain magnetically exfoliated bentonite; the preparation method of the dual-modified adsorbent of citric acid and titanium dioxide is the same as that of Example 1; and the preparation method of the titanium-loaded microbial solidified particle water treatment agent does not include step S1.

[0098] Experimental Example 1

[0099] Bacterial cell activity test

[0100] Test samples: Titanium-loaded microbial solidified granular water treatment agents prepared in Examples 1-4 and Comparative Examples 1-3.

[0101] Test method: Weigh 0.5g of test sample to determine the viable bacterial count. Take 50mL of sample from the polluted water body (pH 4.0). Add the test sample to 50mL of polluted water and incubate at 37℃ and 120rpm for 3h with shaking. Take 0.5mL of the sample solution and perform serial dilution with PBS buffer to determine the viable bacterial count. Calculate the bacterial survival rate. The higher the bacterial survival rate, the stronger the bacterial activity. The formula for calculating the bacterial survival rate is as follows:

[0102] Bacterial cell survival rate (%) = (Number of viable bacteria after test / Number of viable bacteria before test) × 100%

[0103] Figure 2 The figures show the cell survival rates of Examples 1-4 and Comparative Examples 1-3. As shown, the cell survival rate of Examples 1-4 was 90.5-93.2%, indicating strong cell activity; the cell survival rate of Comparative Examples 1-3 was 78.4-83.3%, indicating weaker cell activity. The citric acid and titanium dioxide dual-modified adsorbent in Comparative Example 1 did not contain boehmite, thus failing to form a sea urchin-like structure. This was neither conducive to microbial attachment and solidification stability nor to encapsulating microbial cells, hindering the effectiveness of the isolation layer against H2O. + and OH - The penetration and obstruction of the acid and alkaline environment increased the damage to microorganisms, resulting in weak cell activity. The dual-modified adsorbent of citric acid and titanium dioxide in Comparative Example 2 did not contain citric acid or nano-titanium dioxide, and could not increase adsorption sites and chemical stability through doping and acidification modification, which reduced the number and stability of microbial loads and was not conducive to reducing the damage to microorganisms in the acid and alkaline environment, resulting in weak cell activity. The magnetically exfoliated bentonite-based aerogel precursor material in Comparative Example 3 did not contain magnetically exfoliated bentonite, which was not conducive to the formation of a slightly wrinkled magnetic porous network, which was not conducive to the loading of titanium-loaded microbial solidification particles, weakened the protection of microbial activity, and resulted in weak cell activity.

[0104] Experiment Example 2

[0105] Adsorption experiment

[0106] Test samples: Titanium-loaded microbial solidified granular water treatment agents prepared in Examples 1-4 and Comparative Examples 1-3.

[0107] Test method: Simulated polluted water with an antibiotic concentration of 100 mg / L and a heavy metal concentration of 100 mg / L was prepared, and the pH of the water was 4.0-4.5. Tetracycline, a common organic pollutant, was selected for this experiment, along with Pb. 2+ Adsorption experiments were conducted on heavy metal pollutants. 1.0 g of the test sample was weighed and added to 1000 mL of simulated polluted water. The mixture was placed in a constant-temperature shaker (303 K, 120 rpm) for 24 h. Afterward, the solution was filtered through a 0.45 μm organic filter membrane. The absorbance of tetracycline in the filtrate was measured at 355 nm using UV. The standard curve fitting equation based on the concentration-absorbance of tetracycline solutions at different mass concentrations was y = 5.5728x - 0.0186 (R²). 2 =0.99834), the tetracycline mass concentration corresponding to the absorbance of the measured solution was obtained, and Pb was measured at 520 nm using ultraviolet spectrophotometry. 2+ The absorbance was measured, and the adsorption capacity (mg / g) for tetracycline and Pb²⁺ was calculated using the following formula:

[0108] Adsorption capacity (mg / g) = (C0 - C) e )×V / m

[0109] Where C0 is the initial pollutant mass concentration in mg / L, C e V represents the mass concentration of the pollutant after adsorption (mg / L), V is the solution volume (L), and m is the amount of test sample added (g).

[0110] Figure 3 Figure 1 shows the pollutant adsorption results for Examples 1-4 and Comparative Examples 1-3; as shown, tetracycline and Pb in Examples 1-4... 2+ The adsorption capacities were 80-89 mg / g and 71-76 mg / g, respectively, indicating good adsorption properties; compared to tetracycline and Pb in comparative examples 1-3... 2+The adsorption capacities were 58-71 mg / g and 46-60 mg / g, indicating poor adsorption performance. Comparative Example 1, with its dual-modified adsorbent of citric acid and titanium dioxide, lacked boehmite, preventing the formation of layered urchin-like structures on the modified Fe3O4 microspheres. This hindered the increase of adsorption sites for heavy metals and organic pollutants in the water, resulting in poor adsorption performance. Comparative Example 2, also with its dual-modified adsorbent of citric acid and titanium dioxide, lacked both citric acid and nano-titanium dioxide, preventing the increase of adsorption sites and chemical stability of the microspheres through doping and acidification. This reduced the adsorption capacity for heavy metal ions and organic pollutants, leading to poor adsorption performance. Comparative Example 3, with its magnetically exfoliated bentonite-based aerogel precursor material, lacked magnetically exfoliated bentonite, preventing the formation of a three-dimensional magnetic network structure through layered cross-linking. This reduced the adsorption capacity and efficiency for heavy metal ions and organic pollutants, resulting in poor adsorption performance.

[0111] Experimental Example 3

[0112] Cyclic stability experiment

[0113] Test samples: Titanium-loaded microbial solidified granular water treatment agents prepared in Examples 1-4 and Comparative Examples 1-3.

[0114] Test method: Prepare simulated polluted water with an antibiotic concentration of 100 mg / L and a heavy metal concentration of 100 mg / L, and set the pH of the water to 4.0-4.5. In this experiment, Pb was selected as the target pollutant. 2+ Cyclic stability experiments were conducted on heavy metal pollutants. 1.0 g of the test sample was weighed and added to 1000 mL of simulated polluted water. The sample was placed in a constant-temperature shaker (303 K, 120 rpm) and reacted for 24 h. Then, it was filtered through a 0.45 μm organic filter membrane. The sample was removed, vacuum dried at 60 °C for 2 h, and then placed in freshly replaced 1000 mL of simulated polluted water. This adsorption-removal-drying experiment was repeated 20 times. The Pb content of the filtrate was measured at 520 nm using ultraviolet spectrophotometry. 2+ The absorbance was obtained from the formula in Experiment 2 to determine Pb. 2+ Adsorption capacity Q 20 (mg / g), and then compared with the adsorption amount Q1 after one treatment in Experiment 2, the adsorption retention rate (%) was calculated according to the following formula:

[0115] Adsorption retention rate (%) = Q 20 / Q1×100%

[0116] Figure 4The graph shows the adsorption retention rates of Examples 1-4 and Comparative Examples 1-3. As shown, the adsorption retention rate of Examples 1-4 was 88-93%, indicating good cycling stability; the adsorption retention rate of Comparative Examples 1-3 was 58-75%, indicating poor cycling stability. The citric acid and titanium dioxide dual-modified adsorbent in Comparative Example 1 did not contain boehmite, making it impossible to mechanically interlock the titanium microbial solidified particles with the magnetically exfoliated bentonite-based aerogel precursor material in a sea urchin-like shape. This reduced structural stability and hindered the expansion of the aerogel material's pH range, resulting in poor cycling stability. The citric acid and titanium dioxide in Comparative Example 2... The dual-modified adsorbent does not contain citric acid or nano-titanium dioxide, so it cannot increase the chemical stability of the adsorbent through the coating of citric acid and nano-titanium dioxide, nor is it conducive to enhancing the mechanical strength of the adsorbent. This increases the risk of collapse after repeated use, resulting in poor cycle stability. The magnetically exfoliated bentonite-based aerogel precursor material in Comparative Example 3 does not contain magnetically exfoliated bentonite, so it cannot be dispersed in the aerogel matrix as a single layer or a few layers of nanosheets through physical cross-linking or chemical bonding. This is not conducive to enhancing interfacial bonding, cannot effectively disperse stress, and reduces the compressive and tensile strength and structural stability of the aerogel, resulting in poor cycle stability.

[0117] The above experimental results show that the bacterial cell activity, adsorption capacity, and cycle stability of Examples 1-4 of the present invention are significantly better than those of Comparative Examples 1-3. Among them, Example 1, which uses drug-loaded nanoparticles with both magnetic and reactive oxygen species responsiveness and modified carbon nanotube hydrogel carrier, exhibits stronger bacterial cell activity, better adsorption capacity, and better cycle stability. Loading titanium-loaded microbial solidification particles into a magnetically exfoliated bentonite-based aerogel precursor material can reduce the aggregation of titanium-loaded microbial solidification particles due to their sea urchin-like shape, reduce the risk of aerogel collapse, broaden the pH range of the aerogel material, further protect the activity of microorganisms and the structural stability of the water treatment agent, and facilitate multiple cycles of use. At the same time, the dual magnetic material increases the adsorption performance of pollutants, and combined with the decomposition effect of microorganisms, achieves a highly efficient water purification effect.

[0118] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

[0119] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention. The actual application is not limited to this. In conclusion, if those skilled in the art are inspired by this description and design similar methods and embodiments without departing from the spirit of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A titanium-loaded microbial solidified particle water treatment agent, characterized in that: The titanium-loaded microbial solidified particle water treatment agent comprises the following components in parts by weight: 50-60 parts of citric acid and titanium dioxide dual-modified adsorbent, 20-30 parts of magnetically exfoliated bentonite-based aerogel precursor material, 1-2 parts of Bacillus subtilis, and 1-2 parts of *Saccharomyces cerevisiae*; the citric acid and titanium dioxide dual-modified adsorbent comprises the following components in parts by weight: 30-40 parts of sea urchin-like magnetic composite nanoparticles, 10-20 parts of citric acid, and 6-10 parts of nano-titanium dioxide; the magnetically exfoliated bentonite-based aerogel precursor material comprises the following components in parts by weight: 5-8 parts of magnetically exfoliated bentonite, 8-10 parts of carboxylated cellulose nanofibers, and 1-3 parts of polyethyleneimine. The preparation method of the dual-modified adsorbent of citric acid and titanium dioxide specifically includes the following steps: (1) Dissolve 3.5g of ferric chloride hexahydrate in 40mL of ethylene glycol, add 3.7g of anhydrous sodium acetate while stirring at 1000-2000rpm until completely dissolved, then transfer to a 50mL polytetrafluoroethylene liner, seal and place in a reaction vessel, keep warm at 180-200℃ for 10-12h, collect the precipitate by magnetic separation, wash with deionized water and anhydrous ethanol, and then vacuum dry at 60℃ to obtain Fe3O4 microspheres; (2) Disperse the Fe3O4 microspheres described in step (1) in a mixed solution of 30 mL anhydrous ethanol and 3 mL water, sonicate for 3-5 min, then add 1 mL ammonia, 10 mL anhydrous ethanol and 0.3-0.5 mL tetraethyl orthosilicate in sequence, sonicate at 20-30 °C for 2-3 h, collect the precipitate by magnetic separation, wash with deionized water and anhydrous ethanol, and then vacuum dry at 60 °C to obtain modified Fe3O4 microspheres; (3) Add sodium aluminate powder to 30 mL of water and stir until dissolved. Add 0.3-0.5 g of urea and stir for 0.5-1 h. Then add the modified Fe3O4 microspheres described in step (2), sonicate for 1-2 h, and then transfer to a reaction vessel. React at 160-180 °C for 5-6 h. Collect the product by magnetic separation, wash with deionized water 3-5 times, and then vacuum dry at 50 °C to obtain sea urchin-shaped magnetic composite nanoparticles. (4) Dissolve 1.0-2.0g of citric acid in 100mL of water and set aside the citric acid solution. Disperse the sea urchin-shaped magnetic composite nanoparticles described in step (3) in 40mL of dimethyl sulfoxide and stir at 100-200rpm for 12h. Then add 6mL of tetraethyl orthosilicate and continue stirring for 3-5h. Then add 0.6-1.0g of nano titanium dioxide and stir for 8-12h. Centrifuge and wash the precipitate twice with distilled water. After vacuum drying, immerse it in the citric acid solution and stir at 100-200rpm for 24h in a nitrogen atmosphere. Then vacuum dry to obtain a dual-modified adsorbent of citric acid and titanium dioxide. The preparation method of the titanium-loaded microbial solidified granular water treatment agent specifically includes the following steps: S1. Add 10.0g of bentonite to a mixed solution of 500mL ultrapure water and anhydrous ethanol (volume ratio of ultrapure water to anhydrous ethanol: 1:2.5), stir well, microwave the solution at 600-800W and 60℃ for 1-2 hours, then ultrasonically disperse it at 600-700W for 1-2 hours, and finally vacuum dry it at 60℃ for 12 hours to obtain exfoliated bentonite sheets for later use. Add 1.0-1.8g of ferric chloride and 0.6g of ferrous chloride... Add 100 mL of water and pre-react under microwave conditions of 500-600 W and 60 °C for 3-5 min. Then add 10.5 mL of ammonia water and continue stirring under microwave conditions of 500-600 W and 60 °C for 0.5-1 h. Then add the exfoliated bentonite sheets and stir thoroughly for 1-2 h. After cooling to room temperature, collect the product by magnetic separation and wash it several times with anhydrous ethanol and ultrapure water until the pH reaches 7.

0. Finally, vacuum dry and grind to obtain magnetically exfoliated bentonite. S2. Add 0.8-1.0g of carboxylated cellulose nanofibers to 100mL of ultrapure water and stir magnetically to form a carboxylated cellulose nanofiber suspension. Then add a 50% (w / w) polyethyleneimine solution and the magnetically exfoliated bentonite described in step S1. Stir at 60-70℃ for 3-4h at a stirring speed of 200-300rpm to obtain a magnetically exfoliated bentonite-based aerogel precursor material. S3. Inoculate 1.0-2.0g of Bacillus subtilis and 1.0-2.0g of Cytomegalovirus into MSM basal salt medium, adding 1% glucose and 0.5% glycerol during inoculation, while maintaining the pH at 6.5-7.

0. Incubate at 28-30℃ and 150-200rpm until the viable cell concentration reaches 10⁻⁶. 8 The bacterial culture was obtained by centrifugation, discarding the supernatant and collecting the active bacterial cells. Then, the dual-modified adsorbent of citric acid and titanium dioxide was soaked in MSM basic salt medium for 6-8 hours. After being taken out, it was mixed with the active bacterial cells and freeze-dried to obtain titanium-loaded microbial solidified particles. S4. Add the titanium-loaded microbial solidified particles described in step S3 to the magnetically exfoliated bentonite-based aerogel precursor material described in step S2, then perform ultrasonic dispersion treatment for 0.5-1 h, and then freeze-dry to obtain the titanium-loaded microbial solidified particle water treatment agent.

2. A method for preparing the titanium-loaded microbial solidified particle water treatment agent according to claim 1, characterized in that: Specifically, the following steps are included: S1. Add 10.0g of bentonite to a mixed solution of 500mL ultrapure water and anhydrous ethanol (volume ratio of ultrapure water to anhydrous ethanol: 1:2.5), stir well, microwave the solution at 600-800W and 60℃ for 1-2 hours, then ultrasonically disperse it at 600-700W for 1-2 hours, and finally vacuum dry it at 60℃ for 12 hours to obtain exfoliated bentonite sheets for later use. Add 1.0-1.8g of ferric chloride and 0.6g of ferrous chloride... Add 100 mL of water and pre-react under microwave conditions of 500-600 W and 60 °C for 3-5 min. Then add 10.5 mL of ammonia water and continue stirring under microwave conditions of 500-600 W and 60 °C for 0.5-1 h. Then add the exfoliated bentonite sheets and stir thoroughly for 1-2 h. After cooling to room temperature, collect the product by magnetic separation and wash it several times with anhydrous ethanol and ultrapure water until the pH reaches 7.

0. Finally, vacuum dry and grind to obtain magnetically exfoliated bentonite. S2. Add 0.8-1.0g of carboxylated cellulose nanofibers to 100mL of ultrapure water and stir magnetically to form a carboxylated cellulose nanofiber suspension. Then add a 50% (w / w) polyethyleneimine solution and the magnetically exfoliated bentonite described in step S1. Stir at 60-70℃ for 3-4h at a stirring speed of 200-300rpm to obtain a magnetically exfoliated bentonite-based aerogel precursor material. S3. Inoculate 1.0-2.0g of Bacillus subtilis and 1.0-2.0g of Cytomegalovirus into MSM basal salt medium, adding 1% glucose and 0.5% glycerol during inoculation, while maintaining the pH at 6.5-7.

0. Incubate at 28-30℃ and 150-200rpm until the viable cell concentration reaches 10⁻⁶. 8 The bacterial culture was obtained by centrifugation, discarding the supernatant and collecting the active bacterial cells. Then, the dual-modified adsorbent of citric acid and titanium dioxide was soaked in MSM basic salt medium for 6-8 hours. After being taken out, it was mixed with the active bacterial cells and freeze-dried to obtain titanium-loaded microbial solidified particles. S4. Add the titanium-loaded microbial solidified particles described in step S3 to the magnetically exfoliated bentonite-based aerogel precursor material described in step S2, then perform ultrasonic dispersion treatment for 0.5-1 h, and then freeze-dry to obtain the titanium-loaded microbial solidified particle water treatment agent.

3. The preparation method of the titanium-loaded microbial solidified particle water treatment agent according to claim 2, characterized in that: In step S2, the carboxylated cellulose nanofibers have a diameter of 4-10 nm and a length of 1-3 μm; the amount of polyethyleneimine solution added is 0.1-0.3 g.

4. The preparation method of the titanium-loaded microbial solidified particle water treatment agent according to claim 3, characterized in that: In step (3), the amount of sodium aluminate added is 0.1-0.2g.

5. The preparation method of the titanium-loaded microbial solidified particle water treatment agent according to claim 4, characterized in that: In step (4), the nano-titanium dioxide is of the rutile type and has a particle size of 100-300 nm.

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