Composite bactericidal resin material, preparation method and application thereof

Abstract

The application discloses a kind of composite bactericidal resin materials and preparation method and application thereof, belong to ion exchange resin material technical field.The application provides a kind of composite bactericidal resin materials, including carrier, photocatalytic material and quaternary ammonium salt;The carrier is macroporous polystyrene type ion exchange resin;The photocatalytic material is low-dimensional nanostructure polymeric carbonitride;The carbon chain length of long-chain alkyl of the quaternary ammonium salt is C12~C16;Wherein, the low-dimensional nanostructure polymeric carbonitride is loaded on the carrier;The quaternary ammonium salt is loaded on the carrier containing photocatalytic material;Composite bactericidal resin material provided by the application has high removal efficiency for drug-resistant bacteria, is removed more thoroughly, has good stability and is not easy to fall off, has higher safety, and can be regenerated and used multiple times.

Description

Technical Field

[0001] This invention belongs to the field of ion exchange resin material technology, and more specifically, relates to a composite bactericidal resin material, its preparation method and application. Background Technology

[0002] With economic and social development and continuous technological progress, antibiotics are playing an increasingly important role in various fields of production and daily life. However, the widespread use of antibiotics has also brought about a series of environmental problems. Antibiotic abuse has led to pollution problems in the water environment caused by antibiotic-resistant bacteria (ARBs) and antibiotic-resistant genes (ARGs). Antibiotics and resistance genes are continuously released into the environment through medical wastewater, pharmaceutical wastewater, and aquaculture excrement, and traditional wastewater treatment processes are ineffective in removing them, resulting in long-term high concentrations of antibiotic residues in the environment, forming a continuous source of pollution. In the water cycle, antibiotic-resistant bacteria (ARBs) and antibiotic-resistant genes (ARGs) are widespread. ARBs and ARGs in water can enter the human body through drinking water ingestion or skin contact, causing conventional antibiotic treatment to fail and significantly increasing the difficulty of treating clinical infections and mortality rates.

[0003] ARBs and ARGs possess unique biological characteristics and environmental adaptation mechanisms, making them difficult to remove effectively from aquatic environments. ARBs actively expel antibiotic molecules from bacterial cells, directly preventing intracellular antibiotic concentrations from reaching effective bactericidal or bacteriostatic levels, thus allowing bacterial survival (efflux pump mechanism). ARGs exhibit strong stability, widely present in the chromosomes, plasmids, transposons, integrons, and other genetic elements of environmental microorganisms. They are not easily altered by external environmental influences and can persist persistently in the environment. Furthermore, ARGs can be vertically transferred through bacterial reproduction and horizontally transferred between different bacteria via mobile genetic elements such as plasmids and transposons, accelerating the spread of antibiotic resistance genes. Even after killing host bacteria, free ARG fragments can still be captured by other bacteria. The synergistic effect of efflux pumps, human gene transfer (HGT), and other resistance mechanisms (such as enzyme modification, target mutation, and reduced cell membrane permeability) makes the removal of ARBs and ARGs from aquatic environments increasingly difficult.

[0004] Currently, the removal of ARBs and ARGs from water bodies mainly relies on traditional disinfection processes and advanced oxidation technologies, but these technologies have significant limitations. Among traditional disinfection processes, chlorination is the most widely used, but studies have found that it may lead to an increase in ARG abundance, especially the enrichment of multidrug resistance genes. While ultraviolet (UV) disinfection can effectively inactivate bacteria, its effect on ARBs encapsulated in suspended particles is limited, and it may induce horizontal transfer of ARGs. Ozone disinfection has a certain removal effect on some ARGs (such as bacitracin resistance genes), but it significantly increases the proportion of multidrug resistance genes and may produce toxic byproducts. Advanced oxidation processes (AOPs), such as UV / H2O2 and UV / PS, remove ARGs by generating... OH, SO4 2- Active free radicals can destroy ARGs, and the removal rate of sulfonamide resistance gene 1 (sul1) and tetracycline resistance gene W (tetW) can reach 40% to 90%. However, it is significantly affected by factors such as water quality conditions and oxidant dosage, and may cause secondary pollution.

[0005] Quaternary ammonium salt resins are a class of resins containing quaternary ammonium groups (-N). + R3 ion exchange resin, as a novel water treatment material, exhibits unique advantages in ARB removal. It works through surface quaternary ammonium groups (N... + The electrostatic attraction of quaternary ammonium salts adsorbs near negatively charged bacteria, creating a barrier effect that inhibits bacterial growth. Then, the lipophilic alkyl chains on the quaternary ammonium salt diffuse through the cell wall, disrupting the stability of the intercellular matrix, altering cell membrane permeability, and subsequently causing cytolysis, thus destroying cell structure. Ultimately, this leads to the inhibition or inactivation of bacterial growth. However, quaternary ammonium salt resins still have significant drawbacks in the removal of ARBs and ARGs. First, when used alone, their removal effect on ARGs is limited, making it difficult to effectively prevent the spread of antibiotic resistance genes. Second, quaternary ammonium salt resins do not completely remove ARBs, resulting in a high reactivation index of resistant bacteria. Furthermore, existing quaternary ammonium salt resins suffer from problems such as easy shedding of the quaternary ammonium salt, high short-term leakage, difficulty in maintaining long-term effectiveness, and significant susceptibility of bactericidal effects to environmental interference.

[0006] In summary, existing technologies still have many shortcomings in effectively controlling the concentration and spread of ARBs and ARGs in water bodies. There is an urgent need to develop new, efficient, safe and reliable composite bactericidal resin materials to address the increasingly serious challenge of antibiotic resistance. Summary of the Invention

[0007] 1. The problem to be solved In order to overcome the problems of low efficiency and incomplete removal of ARBs and ARGs in the existing technologies, the present invention provides a composite bactericidal resin material, its preparation method and its application.

[0008] 2. Technical Solution To solve the above problems, the technical solution adopted in this application is as follows: The first aspect of this invention provides a composite bactericidal resin material, comprising: The carrier is a macroporous polystyrene-based ion exchange resin; Photocatalytic materials, wherein the photocatalytic materials are low-dimensional nanostructured polymeric carbonitrides; Quaternary ammonium salt, wherein the carbon chain length of the long-chain alkyl group of the quaternary ammonium salt is C12~C16; The photocatalytic material is loaded on a support, and the mass ratio of the photocatalytic material to the support is (3~7):100; The quaternary ammonium salt is loaded onto a support containing photocatalytic material, and the mass ratio of the quaternary ammonium salt to the support is (1~3):100.

[0009] It should be noted that in the context of polymeric carbonitrides with low-dimensional nanostructures, "low-dimensional" refers to zero-dimensional (0D), one-dimensional (1D), and two-dimensional (2D). Typical zero-dimensional structures include quantum dots, one-dimensional structures include nanorods, nanowires, and nanotubes, and two-dimensional structures include nanosheets.

[0010] The carrier (ion exchange resin) has a certain water content during normal use. The "mass of the carrier" mentioned here refers to the dry weight of the carrier. "Dry weight" means the state in which the water has been removed.

[0011] As a preferred embodiment of any technical solution in the first aspect of the present invention, the carbon chain length of the long-chain alkyl group of the quaternary ammonium salt is C13~C16.

[0012] More preferably, the carbon chain length of the long-chain alkyl group of the quaternary ammonium salt is C14~C16.

[0013] Further preferably, the carbon chain length of the long-chain alkyl group of the quaternary ammonium salt is C15~C16.

[0014] As a preferred embodiment of any technical solution of the first aspect of the present invention, the mass ratio of the quaternary ammonium salt to the support is (1.5~2.5):100.

[0015] As a preferred embodiment of any technical solution in the first aspect of the present invention, the composite bactericidal resin material further includes a slow-release shell layer located on the outermost layer; The sustained-release shell layer comprises several alternating layers of anionic polyelectrolyte and cationic polyelectrolyte.

[0016] More preferably, the slow-release shell layer is attached to the outer layer of the composite bactericidal resin material in a layer-by-layer self-assembly (LbL) manner.

[0017] Further preferably, the sustained-release shell layer comprises 1 to 4 alternating layers of anionic polyelectrolyte and cationic polyelectrolyte.

[0018] It should be noted that in the sustained-release shell, the anionic polyelectrolyte layer is the inner layer, in contact with the quaternary ammonium salt; the cationic polyelectrolyte layer is the outer layer. On the one hand, the sustained-release shell forms a dense film layer that acts as a physical barrier to prevent the quaternary ammonium salt from being released too quickly. On the other hand, the anionic polyelectrolyte layer is negatively charged and has an electrostatic interaction with the positively charged quaternary ammonium salt, further preventing the quaternary ammonium salt from being released too quickly, thereby achieving a sustained-release effect.

[0019] As a preferred embodiment of any technical solution in the first aspect of the present invention, the anionic polyelectrolyte includes one or more of sodium polystyrene sulfonate (PSS), polyacrylic acid (PAA), sodium alginate (SA), and carboxymethyl cellulose (CMC).

[0020] As a preferred embodiment of any technical solution in the first aspect of the present invention, the cationic polyelectrolyte includes one or more of polydiallyldimethylammonium chloride (PDADMAC), polylysine (PLL), and polyamidoamine dendritic molecules (PAMAM).

[0021] As a preferred embodiment of any technical solution in the first aspect of the present invention, the macroporous polystyrene-based ion exchange resin is a strongly basic anion exchange resin, satisfying one or more of the following conditions (I) to (IV): (I) Specific surface area is 10~50 m² 2 ·g -1 ; (II) Total pore volume is 0.2~0.7 cm³ 3 ·g -1 ; (III) Exchange capacity (Cl) - Type) ≥1.0 eq·L -1 ; (Ⅳ) Particle size is 0.3~0.7 mm.

[0022] The same resin has different exchange capacities for different ionic forms. Exchange capacity (Cl...) - The term "type" refers to the maximum amount of anions that a unit mass or unit volume of resin can exchange under chloride ion conditions.

[0023] As a preferred embodiment of any technical solution in the first aspect of the present invention, the macroporous polystyrene-based ion exchange resin includes one or more of the following: D201 macroporous strong basic styrene-based anion exchange resin (abbreviated as D201), Purolite A500 macroporous strong basic styrene-based anion exchange resin (abbreviated as Purolite A500), Purolite A520 macroporous strong basic styrene-based anion exchange resin (abbreviated as Purolite A520), Amberlite IRA-900 macroporous strong basic styrene-based anion exchange resin (abbreviated as Amberlite IRA-900), Amberlite IRA-958 macroporous strong basic styrene-based anion exchange resin (abbreviated as Amberlite IRA-958), and Lanxess Lewatit M500 macroporous strong basic styrene-based anion exchange resin (abbreviated as Lewatit M500).

[0024] Further preferably, the macroporous polystyrene-based ion exchange resin is D201.

[0025] As a preferred embodiment of any technical solution in the first aspect of the present invention, the polymeric carbonitride with the low-dimensional nanostructure satisfies one or more of the following conditions (a) to (d): (a) Lateral size is 50–1000 nm; (b) Thickness is 0.6~10 nm; (c) The optical bandgap is 2.0~3.2 eV; preferably 2.4~2.9 eV; (d) The low-dimensional nanostructured polymeric carbon nitrides include one or more of graphitic carbon nitride quantum dots (g-C3N4QDs), carbon-doped carbon nitride quantum dots (C-doped CN QDs), carbon nitride nanotubes (CN-NT), graphitic carbon nitride nanosheets (g-C3N4 nanosheets), nitrided graphene nanosheets (C2N nanosheets), and C3N5 nanosheets.

[0026] As a preferred embodiment of any technical solution in the first aspect of the present invention, the low-dimensional nanostructured polymeric carbonitride includes one or more of g-C3N4 nanosheets, C2N nanosheets, and C3N5 nanosheets.

[0027] As a preferred embodiment of any technical solution in the first aspect of the present invention, the quaternary ammonium salt includes hexadecyltrimethylammonium chloride (CTAC), hexadecyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium chloride (DTAC), dialcyldimethylammonium chloride (DDAC), hexadecylpyridinium chloride (CPC), and benzalkonium chloride (BAC). 12 -C 16 One or more of the following.

[0028] A second aspect of the present invention provides a method for preparing a composite bactericidal resin material, comprising the following steps: A. Cleaning and wetting the carrier; B. The carrier treated in step A is immersed in a solution containing adhesive and treated at 20~30℃ for 4~8 h, and then washed until the supernatant is colorless; C. The carrier treated in step B is immersed in a solution containing a crosslinking agent and treated at 20-30°C for 20-60 min, then washed; it is then immersed in a solution containing a modifier and crosslinked at 20-30°C for 30-60 min, then washed to obtain an amino-modified carrier. D. Prepare an activated dispersion of the photocatalytic material, such that the concentration of the photocatalytic material in the activated dispersion is 0.5~2.0 g·L⁻¹. -1 ; The content of active groups on the surface of the photocatalytic material is 0.2~2.5 mmol·g. -1 ; The content of active groups on the surface of the photocatalytic material refers to the number of reactive groups on the surface of the photocatalytic material after activation treatment, expressed as the number of moles of active groups per unit of photocatalytic material.

[0029] E. The amino-modified support obtained in step C is mixed with the activated dispersion of photocatalytic material prepared in step D, and reacted at pH 7.2-7.4 and temperature 20-30℃ for 2-4 h. After washing and drying, the support containing photocatalytic material is obtained. F. The carrier containing photocatalytic material obtained in step E is immersed in a quaternary ammonium salt solution for 60-100 min, filtered, rinsed, and allowed to stand and drip dry for 10-30 min; In step E, the mass ratio of the carrier to the photocatalytic material in the mixture is 1:(0.03~0.07).

[0030] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step A, the carrier is a macroporous polystyrene-based ion exchange resin.

[0031] As a preferred embodiment of any technical solution in the second aspect of the present invention, the macroporous polystyrene-based ion exchange resin is a strongly basic anion exchange resin, satisfying one or more of the following conditions (I) to (IV): (I) Specific surface area is 10~50 m² 2 ·g -1 ; (II) Total pore volume is 0.2~0.7 cm³ 3 ·g -1 ; (III) Exchange capacity (Cl) - Type) ≥1.0 eq·L -1 ; (Ⅳ) Particle size is 0.3~0.7 mm.

[0032] As a preferred embodiment of any technical solution in the second aspect of the present invention, the macroporous polystyrene-based ion exchange resin includes one or more of the following: D201 macroporous strong basic styrene-based anion exchange resin (abbreviated as D201), Purolite A500 macroporous strong basic styrene-based anion exchange resin (abbreviated as Purolite A500), Purolite A520 macroporous strong basic styrene-based anion exchange resin (abbreviated as Purolite A520), Amberlite IRA-900 macroporous strong basic styrene-based anion exchange resin (abbreviated as Amberlite IRA-900), Amberlite IRA-958 macroporous strong basic styrene-based anion exchange resin (abbreviated as Amberlite IRA-958), and Lanxess Lewatit M500 macroporous strong basic styrene-based anion exchange resin (abbreviated as Lewatit M500).

[0033] Further preferably, the macroporous polystyrene-based ion exchange resin is D201.

[0034] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step A, the cleaning and wetting are performed by sequentially treating with ethanol solution, hydrochloric acid solution, and sodium chloride solution for 15-30 minutes each, followed by rinsing with deionized water until the pH of the supernatant is approximately 7.

[0035] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step B, the adhesive includes one or more of polydopamine (PDA), polytannic acid, polyproanthocyanidins, and polyvinylcatechol.

[0036] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step B, the concentration of the adhesive in the adhesive-containing solution is 1.5~2.5 g·L. -1 The pH of the solution containing the adhesive is 8.0~9.0.

[0037] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step C, the crosslinking agent includes one or more of glutaraldehyde (GA), paraformaldehyde (PFA), terephthalaldehyde (TPA), glyoxal (GO), and malondialdehyde (MDA).

[0038] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step C, the concentration of the crosslinking agent in the solution containing the crosslinking agent is 4.0~8.0 mmol / L, and the pH of the solution containing the crosslinking agent is 6.8~7.6.

[0039] More preferably, in step C, the concentration of the crosslinking agent in the solution containing the crosslinking agent is 4.0~8.0 mmol / L, and the pH is 7.2~7.4.

[0040] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step C, the modifier includes one or more of polyethyleneimine (PEI), polyamide amine dendritic molecules, protonated chitosan, and ethylenediamine modified polymers (such as EDA-PEG).

[0041] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step C, the concentration of the modifier in the solution containing the modifier is 0.08~0.20 wt%, and the pH is 8.0~9.0.

[0042] It should be noted that step C, the crosslinking reaction, includes the crosslinking of the crosslinking agent and the modifier into a network, as well as the crosslinking of the modifier with the adhesive deposited on the carrier surface into a network, forming Schiff base bonds (C=N) to achieve covalent crosslinking, thus enabling the modifier to exist stably on the carrier surface. Simultaneously, the modifier provides a large number of -NH2 sites, which is beneficial for subsequent coupling reactions.

[0043] Alternatively, a reducing agent can be used to further solidify the C=N into a more stable CN.

[0044] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step D, the photocatalytic material is a low-dimensional nanostructured polymeric carbonitride, satisfying one or more of the following conditions (a) to (d): (a) Lateral scale is 50–1000 nm; (b) Thickness is 0.6~10 nm; (c) The optical bandgap is 2.0~3.2 eV; preferably 2.4~2.9 eV; (d) The low-dimensional nanostructured polymeric carbon nitrides include one or more of graphitic carbon nitride quantum dots (g-C3N4QDs), carbon-doped carbon nitride quantum dots (C-doped CN QDs), carbon nitride nanotubes (CN-NT), graphitic carbon nitride nanosheets (g-C3N4 nanosheets), nitrided graphene nanosheets (C2N nanosheets), and C3N5 nanosheets.

[0045] Further preferably, in step D, the low-dimensional nanostructured polymeric carbonitride includes one or more of g-C3N4 nanosheets, C2N nanosheets, and C3N5 nanosheets.

[0046] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step D, the surface-active group includes one or more of carboxyl, epoxy, aldehyde, and hydroxyl groups.

[0047] It should be noted that the surface-active group is a group that can undergo a coupling reaction with -NH2. The essence of step D is to introduce a group on the surface of the photocatalytic material that can undergo a coupling reaction with the amino-modified support in step C, so that the photocatalytic material is covalently coupled to the support, rather than a simple physical adsorption or electrostatic adsorption. The bond is stronger, which is beneficial to improving the stability of the composite bactericidal resin material and making it less likely to fall off.

[0048] The content of the surface active groups can be determined by appropriate methods for the specific introduced groups. For example, the content of carboxyl groups can be determined by Boehm titration and verified by XPS on the peak area of ​​O–C=O.

[0049] As a preferred embodiment of any technical solution in the second aspect of the present invention, step D, in preparing the photocatalytic material activation dispersion, includes: The photocatalytic material is oxidized to introduce carboxyl or hydroxyl groups; Alternatively, glutaraldehyde treatment can be used to introduce aldehyde groups; Alternatively, ethylene glycol diglycidyl ether (EGDGE) treatment can be used to introduce epoxy groups.

[0050] As a preferred embodiment of any technical solution in the second aspect of the present invention, the photocatalytic material activation dispersion prepared in step D is... The photocatalytic material is oxidized to introduce carboxyl groups. Specific steps include: S1: Oxidation treatment of photocatalytic materials; S2: Disperse the oxidized photocatalytic material in a weakly acidic buffer solution; S3: Add 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl) and N-hydroxysuccinimide (NHS) to the dispersion in S2, and activate it for 15-40 min in the dark at pH 5.0-6.0 and temperature 20-30℃ to obtain the activated dispersion of photocatalytic material.

[0051] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step S1, the oxidation treatment is as follows: The photocatalytic material was treated with hydrogen peroxide solution, 0.1-0.5 M dilute nitric acid solution, 1-50 mM persulfate solution, ozone, or plasma at 25-50°C for 0.5-2 h, filtered, washed with water until neutral, and dried at 50-70°C. As a preferred embodiment of any technical solution in the second aspect of the present invention, in step S2, the pH of the weakly acidic buffer solution is 5.0 to 6.0.

[0052] It should be noted that a pH range of 5.0 to 6.0 is the optimal range before carboxyl group activation, which is used to ensure that EDC·HCl / NHS is not prematurely hydrolyzed. The weakly acidic buffer solution used can be any buffer solution that meets this pH requirement.

[0053] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step E, after the coupling reaction is completed, the sample can be immersed in an EGDGE solution with a concentration of 0.3~0.5 wt% and a pH of 8.5 for 30~45 minutes, and then washed and dried.

[0054] EGDGE relies on the "bidirectional nucleophilic ring-opening reaction" of its diepoxy groups to covalently anchor the amino group and the hydroxyl group of the carboxyl-containing substance, forming a stable cured product, which further increases and improves the stability of the composite bactericidal resin material.

[0055] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step F, the concentration of the quaternary ammonium salt solution is 1~15 g·L. -1 .

[0056] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step F, the carbon chain length of the long-chain alkyl group of the quaternary ammonium salt is C12~C16.

[0057] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step F, the carbon chain length of the long-chain alkyl group of the quaternary ammonium salt is C13~C16.

[0058] Further preferably, in step F, the carbon chain length of the long-chain alkyl group of the quaternary ammonium salt is C14~C16.

[0059] In a further preferred embodiment, in step F, the carbon chain length of the long-chain alkyl group of the quaternary ammonium salt is C15~C16.

[0060] Further preferably, in step F, the quaternary ammonium salt includes hexadecyltrimethylammonium chloride (CTAC), hexadecyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium chloride (DTAC), dialcyldimethylammonium chloride (DDAC), hexadecylpyridinium chloride (CPC), and benzalkonium chloride (BAC). 12 -C 16 One or more of the following.

[0061] As a preferred embodiment of any technical solution in the second aspect of the present invention, step G is further included: Several layers of anionic polyelectrolyte and cationic polyelectrolyte are alternately deposited on the surface of the product obtained in step F to form a slow-release shell.

[0062] The slow-release shell is formed through layer-by-layer self-assembly (LbL).

[0063] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step G, the method for depositing the anionic polyelectrolyte layer is to immerse the product obtained in step F in an anionic polyelectrolyte solution with a concentration of 0.05~0.5 wt% and a pH of 6.8~7.0 for 10~60 min, and then rinse with deionized water.

[0064] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step G, the method for depositing the cationic polyelectrolyte layer is to immerse the product with the deposited sodium polystyrene sulfonate (PSS) film in a cationic polyelectrolyte solution with a concentration of 0.05~0.5wt% and a pH of 6.0~7.5 for 10~60 min, and then rinse with deionized water.

[0065] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step G, the anionic polyelectrolyte layer and the cationic polyelectrolyte layer can be deposited repeatedly.

[0066] As a preferred embodiment of any technical solution in the second aspect of the present invention, in step G, the sustained-release shell layer comprises 1 to 4 alternating layers of anionic polyelectrolyte and cationic polyelectrolyte.

[0067] The third aspect of the present invention provides an application of the composite bactericidal resin material described in any of the technical solutions of the first aspect of the present invention or the composite bactericidal resin material prepared by the preparation method described in any of the technical solutions of the second aspect of the present invention in water treatment sterilization.

[0068] As a preferred embodiment of any of the technical solutions in the third aspect of the present invention, the application includes the removal of antibiotic-resistant bacteria (ARBs) and antibiotic resistance genes (ARGs).

[0069] 3. Beneficial effects Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The composite bactericidal resin material provided by the present invention contains both photocatalytic materials and quaternary ammonium salts. Through the synergistic effect of photocatalysis and quaternary ammonium salt contact bactericidal action, it has a high removal efficiency for drug-resistant bacteria and removes them more thoroughly; and it also has a high concentration of SO4 2- / HCO3 - / Cl - In a competitive environment, it still exhibits good bactericidal performance, stronger anti-interference ability, and is suitable for more complex real-world environments; Furthermore, this invention uses low-dimensional nanostructured polymeric carbonitrides as photocatalytic materials, which have a higher specific surface area, more active sites, and can generate more reactive oxygen species, thus improving sterilization efficiency. Moreover, they are not easily blocked by the pores of the carrier, and the pressure drop during use is not significant.

[0070] (2) The composite bactericidal resin material provided by the present invention is loaded with long-chain quaternary ammonium salt (alkyl chain length is C12~C16). Under the same loading amount or even lower loading amount, compared with short-chain quaternary ammonium salt (alkyl chain length is C8~C11), it not only has higher bactericidal efficiency, but is also less likely to fall off, which increases the stability of the composite bactericidal resin material and improves the safety of the effluent.

[0071] (3) The composite bactericidal resin material provided by the present invention uses macroporous polystyrene-based ion exchange resin as a carrier, which has a high specific surface area and total pore volume, and can provide sufficient loading space for photocatalytic materials and quaternary ammonium salts. Moreover, thanks to the pore structure characteristics of macroporous polystyrene-based ion exchange resin, the composite bactericidal resin material provided by the present invention still has stable electro-adsorption properties under high ion strength conditions and strong resistance to environmental interference.

[0072] (4) The preparation method of the composite bactericidal resin material provided by the present invention performs surface functionalization treatment on both the carrier surface and the photocatalytic material surface, so that the two are connected by covalent bonds rather than simple physical adsorption or electrostatic adsorption. Therefore, the composite bactericidal resin material prepared has better erosion resistance. At the same time, the LbL method is used to form a slow-release shell to prevent excessive early release of quaternary ammonium salt and extend the service life of the composite bactericidal resin material. Based on this, the composite bactericidal resin material prepared by the method of the present invention has a longer single sterilization time, and due to its better material stability, it still has a good photocatalytic synergistic effect after multiple regenerations, which further improves the service life of the composite bactericidal resin material and has high practicality and good economic value. Attached Figure Description

[0073] Figure 1 This is a schematic diagram of the structure of D201@CTAC@g-C3N4 in Example 1; Figure 2 The FTIR spectrum of D201 resin is shown below. Figure 3 The FTIR spectrum of D201@CTAC@g-C3N4 in Example 1; Figure 4 This is a schematic diagram of the experimental setup; Figure 5 This is a schematic diagram of the sterilization mechanism of D201@CTAC@g-C3N4 in Example 1. Detailed Implementation

[0074] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0075] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0076] Concentration, amount, and other numerical data may be presented in range format herein. It should be understood that such range format is used solely for convenience and brevity and should be flexibly interpreted to include not only the values ​​explicitly stated as the limits of the range, but also all individual values ​​or subranges encompassed within the range, as if each value and subrange were explicitly stated. For example, a range of values ​​from about 1 to about 4.5 should be interpreted to include not only the explicitly stated limits of 1 to 4.5, but also individual numbers (such as 2, 3, 4) and subranges (such as 1 to 3, 2 to 4, etc.). The same principle applies to ranges that describe only a single value, such as "less than about 4.5," which should be interpreted to include all the values ​​and ranges described above. Furthermore, this interpretation should apply regardless of the breadth of the range or characteristic described.

[0077] The present invention will be further described below with reference to specific embodiments.

[0078] Information on raw materials and reagents used in the embodiments of this invention Styrene-divinylbenzene strong base anion exchange resin (D201): macroporous, particle size 0.5 mm, water content approximately 52 wt%, specific surface area 25~40 m². 2 ·g -1 Total pore volume is 0.35~0.55 cm³. 3 ·g -1 ; Exchange capacity Cl - Type) 1.10eq·L -1 Lumo Chemical Co., Ltd., model number D201; Quaternary ammonium pyridine type strong basic anion exchange resin (Ac-81): Shandong Kaisen New Material Co., Ltd., model Ac-81; High-efficiency antibacterial anion exchange resin preloaded with long-chain quaternary ammonium groups (AER6-1): Shandong Kaisen New Material Co., Ltd., model AER6-1; g-C3N4 nanosheets: sheet diameter (lateral scale) 50~700nm, sheet thickness 0.6~3 nm, optical bandgap 2.7eV; The following raw materials were all purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. or Sigma-Aldrich (Shanghai) Trading Co., Ltd.: Bulk g-C3N4 nanoparticles: particle size 3~8 μm, specific surface area <15 m² 2 ·g -1 ; Polydopamine (PDA): Purity ≥ 98%; Glutaraldehyde (GA) aqueous solution: 25 wt% (2.6M); Polyethyleneimine (PEI): Branched type, number average molecular weight approximately 10 kDa; Sodium polystyrene sulfonate (PSS): Molecular weight 200 kDa; Polydiallyl dimethylammonium chloride (PDADMAC): 100~300 kDa; 2-(N-morpholine)ethanesulfonic acid buffer (MES buffer): 50 mM, pH 5.5; Phosphate-buffered saline (PBS): 10 mM, pH 7.4; 4-(2-Hydroxyethyl)-1-piperazine ethanesulfonic acid buffer (HEPES buffer): 20 mM, pH 8.2; Tris buffer (Tris buffer): 10 mM, pH 8.5; Hydrogen peroxide (H2O2, 30%), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl), N-hydroxysuccinimide (NHS), sodium borohydride (NaBH3CN), ethylene glycol diglycidyl ether (EGDGE), octyltrimethylammonium chloride (C8-ATAC or OTAC), undecyltrimethylammonium chloride (C11-ATAC or UTAC), and hexadecyltrimethylammonium chloride (C16-ATAC or CTAC) were all of analytical grade.

[0079] Solution preparation 2.0 g·L -1 Polydopamine solution (pH=8.5): Weigh out polydopamine (PDA) and dissolve it in 10 mM Tris buffer at pH 8.5 to prepare a polydopamine concentration of 2.0 g·L⁻¹. -1 The solution.

[0080] Example 1 Preparation of composite bactericidal resin material (D201@CTAC@g-C3N4) A. Vector (D201) pretreatment Take 100g (dry basis) of D201 resin and place it in a 2 L beaker. Add 1 L of a mixture of ethanol and water (V 乙醇 V 水 =1:1), sonicated for 10 min, and treated on a shaker at 150 rpm for 30 min to fully wet D201. Then, D201 was sequentially cleaned with deionized water, hydrochloric acid solution, and sodium chloride solution, specifically: ① Add 1 L of deionized water, shake on a shaker for 15 min, and then discard the supernatant; ② Add 1 L of 0.5 M HCl solution, shake on a shaker for 30 min, and then discard the supernatant; ③ Add 1 L of 1.0 M NaCl solution, shake on a shaker for 30 min, and then discard the supernatant; B. Deposited adhesive layer (adhesive is polydopamine) Place the D201 processed in step A into 2L of 2.0 g·L⁻¹ solution. -1 In a polydopamine solution (brown in color), the mixture was treated at room temperature (25°C) and under aerobic conditions (air atmosphere) on a shaker at 150 rpm for 6 hours. After the treatment, the mixture was filtered and washed with deionized water until the supernatant was nearly colorless, thus obtaining a resin (denoted as PDA@D201) with polydopamine deposited on its inner and outer surfaces.

[0081] D201 is a porous resin, and the inner surface is the surface inside the pores.

[0082] C. In-situ crosslinking of glutaraldehyde / polyethyleneimine (GA / PEI) (glutaraldehyde is the crosslinking agent, and polyethyleneimine is the modifier) Dilute glutaraldehyde aqueous solution (25 wt%) with PBS at pH 7.4 to a molar concentration of glutaraldehyde of 6.6 mmol / L. Take 1 L of glutaraldehyde dilution (6.6 mmol / L) and soak the PDA@D201 obtained in step B at 25℃ for 45 min. Then discard the supernatant and wash the solid twice with PBS. Then, soak the sample in 1L of 0.10 wt% polyethyleneimine solution (pH=8.5) at 25°C for 45 minutes. After that, discard the supernatant and rinse with deionized water until there is no obvious foaming.

[0083] At this point, the GA and PEI adsorbed on the inner and outer surfaces of PDA@D201 undergo a cross-linking reaction. The PDA on the surface of PDA@D201 can also cross-link with PEI to form a network, so that PEI can exist stably on the inner and outer surfaces of PDA@D201 and provide -NH2 sites (the surface zeta potential (pH 7) of the material is ≥10 mV by the flow potential method, which proves that the surface has amino modification). The product at this time is an amino-modified support, denoted as PDA-GA / PEI@D201.

[0084] D. Preparation of activated dispersion of photocatalytic material (g-C3N4 nanosheets) S1: Weigh 5.0 g of g-C3N4 nanosheets and add them to 1 L of hydrogen peroxide solution (V 30% H2O2 V 水 = 1:10) was stirred at 150 rpm at 50 ℃ for 1.5 h for oxidation treatment; after the treatment, it was filtered and washed with deionized water until neutral (KI-starch paper did not show color), and dried at 60 ℃.

[0085] S2: Disperse the g-C3N4 nanosheets treated in step S1 in MES buffer (pH=5.5), sonicate for 10 min, and prepare a g-C3N4 dispersion with a concentration of 1.0 g·L⁻¹. -1 .

[0086] S3: Add solid EDC·HCl and NHS to the g-C3N4 dispersion in step S2 to make the concentration of EDC·HCl 0.2 g·L⁻¹. -1 The NHS concentration was 0.3 g·L⁻¹. -1 After mixing thoroughly, the mixture was left to stand at room temperature in the dark for 30 minutes to obtain an activated dispersion of g-C3N4 (forming -COOH-g-C3N4), wherein the concentration of g-C3N4 was 1.0 g·L⁻¹. -1 The active group is a carboxyl group, and the carboxyl content was determined to be 2.5 mmol·g using the Boehm titration method. -1 (That is, each gram of photocatalytic material contains 2.5 mg / mmol of carboxyl groups).

[0087] E Coupling reaction The g-C3N4 activated dispersion obtained in step D was mixed with the PDA-GA / PEI@D201 obtained in step C (the mass ratio of D201 (dry basis) to g-C3N4 nanosheets in the mixture was 1:0.05), and the pH was adjusted to 7.3±0.1 with PBS. The mixture was reacted at room temperature (25℃) and stirred at 150 rpm for 4 h. Then it was washed twice with PBS, rinsed three times with deionized water, and dried at 60℃ for 2 h to obtain activated g-C3N4@D201 (-COOH-g-C3N4 and -NH2 on PDA-GA / PEI@D201 form -CONH- through a coupling reaction).

[0088] In the obtained activated g-C3N4@D201, the mass ratio of g-C3N4 nanosheets to D201 was 5:100.

[0089] Use 200 mL·min -1 After rinsing with water at a constant flow rate for 10 minutes, the turbidity of the effluent was measured to be 1 NTU, indicating that the activated g-C3N4@D201 has good anti-erosion performance. This verifies that g-C3N4 and D201 in the activated g-C3N4@D201 are connected by covalent bonds, rather than by simple physical adsorption.

[0090] F Supported quaternary ammonium salt (CTAC, long-chain alkyl with a carbon chain length of C16) The activated D201@g-C3N4 obtained in step E was placed in 2 L of a solution with a concentration of 1.0 g·L⁻¹. -1 The solution was treated in CTAC solution at 150 rpm for 60 min on a shaker; then filtered, the surface free liquid was rinsed with 0.5 L of deionized water, the supernatant was discarded, and the solution was allowed to stand and drip dry for 10 min.

[0091] The mass ratio of CTAC to D201 (dry basis) in the product is 1.9:100.

[0092] G-layer-by-layer (LbL) sustained-release shell PSS (anionic polyelectrolyte) and PDADMAC (cationic polyelectrolyte) were paired for depositing a slow-release LbL shell.

[0093] First, place the product from step F in a 1L mixture of PSS and NaCl at pH 7.0 (where the PSS concentration is 0.10 wt% and the NaCl concentration is 10 mM), soak for 30 min, discard the supernatant, and rinse with 0.5L of deionized water. The sample was then soaked in a 1L solution of PDADMAC and NaCl (pH=7.0, 0.10 wt% PDADMAC and 10 mM NaCl) for 30 min. The supernatant was discarded, and the sample was rinsed with 0.5L of deionized water to obtain a final product with a PSS / PDADMAC shell, denoted as D201@CTAC@g-C3N4. The structural diagram is shown below. Figure 1 As shown.

[0094] To further verify the composition of D201@CTAC@g-C3N4, Fourier transform infrared spectroscopy (FTIR) was performed on D201@CTAC@g-C3N4, and the results are as follows. Figure 3 As shown: As shown in the figure, compared to the FTIR spectrum of D201 ( Figure 2 D201@CTAC@g-C3N4 at ~810cm -1 It exhibits a characteristic absorption band at 1200-1600 cm⁻¹, and at 1200-1600 cm⁻¹. -1 The presence of multiple peaks in the region, which are consistent with the typical vibrational characteristics of the heptaazine ring skeleton in g-C3N4, indicates that a nitrogen-containing structure has been successfully introduced.

[0095] Example 2 The only difference between this embodiment and Example 1 is step E. In this embodiment, after the coupling reaction (reacting for 2-4 hours under stirring at 150 rpm, followed by washing twice with PBS) and before rinsing three times with deionized water in step E of Example 1, a solidification step is added: that is, the product washed twice with PBS at this time is soaked in 0.5 wt% EGDGE solution for 30 minutes.

[0096] Example 3 The only difference between this embodiment and Embodiment 1 is the absence of step G, i.e., this comparative example does not construct an LbL sustained-release shell based on the product obtained in step F.

[0097] Comparative Example 1 The only difference between this comparative example and Example 1 is the difference in steps D and E. Steps D and E in this comparative example are as follows: D. Weigh 5.0 g of C3N4 nanosheets and disperse them in an aqueous ethanol solution (V... 水 V 乙醇 =7:3), ultrasonic treatment for 10 min, the concentration of the prepared g-C3N4 dispersion was 1.0 g·L⁻¹. -1 .

[0098] E. The g-C3N4 dispersion obtained in step D of this comparative example was mixed with the PDA-GA / PEI@D201 obtained in step C (the mass ratio of D201 (dry basis) to g-C3N4 nanosheets in the mixture was 1:0.05), and the pH was adjusted to 7.3±0.1 with PBS. The mixture was reacted at room temperature (25℃) and stirred at 150 rpm for 6 h. The mixture was then washed twice with PBS, followed by reaction with a concentration of 0.8 g·L⁻¹. -1 The PDA solution (pH 8.5) was soaked for 1 h, rinsed 3 times with deionized water, and dried at 60℃ for 2 h to obtain the blend g-C3N4@D201.

[0099] This step, which involves treating the nanosheets with PDA solution, can increase the adhesion between the g-C3N4 nanosheets and PDA-GA / PEI@D201 to a certain extent.

[0100] Comparative Example 2 The only difference between this comparative example and Example 1 is that the mass ratio of CTAC to D201 is different in step F. In this comparative example, step F involves placing the activated D201@g-C3N4 obtained in step E into 2 L of a solution with a concentration of 5.0 g·L⁻¹. -1 The final product was obtained in a CTAC solution with a CTAC to D201 mass ratio of 7.9:100.

[0101] Comparative Example 3 The only difference between this comparative example and Example 1 is in step F: ① The types of quaternary ammonium salts used are different. In this comparative example, C8-ATAC (OTAC) is used instead of CTAC. ②The mass ratio of quaternary ammonium salt to D201 is slightly different. In the final product obtained in this comparative example, the mass ratio of OTC to D201 is 2:100.

[0102] Comparative Example 4 The only difference between this comparative example and Example 1 is in step F: ① The types of quaternary ammonium salts used are different. In this comparative example, C8-ATAC (OTAC) is used instead of CTAC. ②The mass ratio of quaternary ammonium salt to D201 is different. In the final product obtained in this comparative example, the mass ratio of OTAC to D201 is 6:100.

[0103] Comparative Example 5 The only difference between this comparative example and Example 1 is in step F: ① The types of quaternary ammonium salts used are different. In this comparative example, C11-ATAC (UTAC) is used instead of CTAC. ②The mass ratio of quaternary ammonium salt to D201 is slightly different. In the final product obtained in this comparative example, the mass ratio of UTAC to D201 is 2:100.

[0104] Comparative Example 6 The only difference between this comparative example and Example 1 is in step F: ① The types of quaternary ammonium salts used are different. In this comparative example, C11-ATAC (UTAC) is used instead of CTAC. ②The mass ratio of quaternary ammonium salt to D201 is different. In the final product obtained in this comparative example, the mass ratio of UTAC to D201 is 3.5:100.

[0105] Comparative Example 7 The only difference between this comparative example and Example 1 is that steps D to E are omitted. That is, in this comparative example, step F directly involves placing the product PDA-GA / PEI@D201 obtained in step C into a 2 L container with a concentration of 1.0 g·L⁻¹. -1 In the CTAC solution, g-C3N4 nanosheets are not introduced.

[0106] Comparative Example 8 The only difference between this comparative example and Example 1 is the photocatalytic material used. In this comparative example, bulk g-C3N4 nanoparticles are used instead of g-C3N4 nanosheets in Example 1.

[0107] Comparative Example 9 The only difference between this comparative example and Comparative Example 7 is the different carriers used and the different pretreatment methods for the carriers. This comparative example uses Ac-81 instead of D201 in Comparative Example 7, and follows the manufacturer's instructions to first wash with deionized water, then soak in 1.0 M NaCl solution for 30 min, and finally wash with deionized water until pH≈7.

[0108] Comparative Example 10 The only difference between this comparative example and Comparative Example 7 is the different carriers used and the different pretreatment methods for the carriers. In this comparative example, AER6-1 was used to replace D201 in Comparative Example 7. In accordance with the manufacturer's instructions, the carriers were first washed with deionized water, then soaked in 1.0 M NaCl solution for 30 min, and finally washed with deionized water until pH≈7.

[0109] Test Example 1 Use such as Figure 4 The apparatus shown was used to test the surface zeta potential and material stability of the bactericidal resin materials prepared in Example 1 and Comparative Examples 1-8. The sample to be tested was filled into... Figure 4In the continuous column of the device shown (with an inner diameter of 2 cm and a bed height of 20 cm), pressure sensors (accuracy ±1 mbar) are installed at the inlet and outlet of the continuous column to monitor the pressure. Different conditions were set to test the zeta potential of the sample, the turbidity of the effluent from the high-flow scouring, the mass loss after 72 hours of operation, the steady-state CTAC leakage concentration, and the pressure drop (ΔP).

[0110] (1) ζ potential test After the sample to be tested was packed into a continuous column, the zeta potential was measured using the flowing potential method under the conditions of 1 mM KCl solution, pH 7.0, and 25 ℃ (the test method was performed in accordance with ISO 13100:2024 "Methods for zeta potential determination — Streaming potential and streaming current methods for porous materials" and GB / Z42353-2023 "Guideline for the determination of zeta potential"). The test results are shown in Table 1.

[0111] (2) Material stability test 2-1) Turbidity of effluent from strong current flushing: After filling the continuous column with the test sample, the flow rate was 200 mL / min. -1 After flushing with strong current for 10 minutes, the turbidity of the effluent is tested. If the turbidity of the effluent is <2 NTU, it meets the requirements of water treatment materials and has good erosion resistance.

[0112] 2-2) Mass loss after 72 hours of operation: After the sample to be tested is filled into the continuous column, it is loaded at an apparent linear velocity of 8 m·h. -1 Water was introduced, with an empty bed contact time (EBCT) of approximately 3 min, an excitation wavelength of 420–450 nm, and an optical power density of 8 mW·cm⁻¹. -2 Under the condition of running for 72 hours, calculate the sample mass loss (sample mass loss = initial sample mass - sample mass after running for 72 hours).

[0113] 2-3) Steady-state CTAC leakage concentration: After filling the continuous column with the sample to be tested, the flow rate was 8 m·h. -1The sample was rinsed at an apparent linear velocity for 60 min; the effluent was collected, and an absorbance-CTAC concentration working curve was established using the methylene blue active material (MBAS) colorimetric method (652 nm). The concentration of CTAC (or expressed as CTAC) in the effluent was monitored to assess the leakage of quaternary ammonium salts from the sample, and to evaluate the stability of the material releasing quaternary ammonium salts. For safety reasons, the effluent CTAC concentration was ≤0.05 mg·L⁻¹. -1 It is considered qualified.

[0114] 2-4) Pressure Drop Test During the "2-2) 72h mass loss" test of the sample to be tested, the pressure difference between the inlet and outlet was recorded at 0, 24, 48 and 72 h. ΔP is the relative initial change (%). The calculation formula is ΔP=(P-P0) / P0, where P is the pressure difference between the inlet and outlet at different time points and P0 is the initial pressure difference between the inlet and outlet.

[0115] The results of the stability tests on the above materials are shown in Table 1: Table 1. Test results of zeta potential and material stability

[0116] Comparing Example 1 and Comparative Example 1, it can be seen that the composite bactericidal resin material in Example 1 exhibits better material stability, with lower turbidity in the strong-flow effluent, smaller mass loss after 72 hours of operation, and lower steady-state CTAC leakage concentration. This indicates that step D, which activates the g-C3N4 nanosheets, gives the final product the advantages of "anti-detachment" and "low leakage." This is because the activated g-C3N4 nanosheets contain active groups on their surface, which undergo a coupling reaction with the -NH2 on the PDA-GA / PEI@D201 obtained in step C, forming amide bonds. The carrier and photocatalytic material are then covalently bonded, resulting in a stronger bond. Furthermore, the formation of the slow-release shell effectively prevents the initial large-scale release of CTAC from D201@CTAC@g-C3N4, keeping the steady-state quaternary ammonium salt concentration at 0.05 mg·L⁻¹. -1 The following steps achieve a sustained-release effect.

[0117] Comparing Example 1 and Comparative Example 2, it can be seen that the excessively high CTAC content in Comparative Example 2 (CTAC:D201 mass ratio = 7.9:100) will cause its steady-state CTAC leakage concentration to consistently exceed the limit of 0.05 mg·L⁻¹. -1 Furthermore, the initial appearance of obvious foaming does not meet the requirements for water treatment and sterilization, posing a certain safety hazard, indicating that the load of CTAC is not necessarily better the higher it is.

[0118] Comparing Example 1 with Comparative Examples 3-6, it can be seen that under the same quaternary ammonium salt loading, the bactericidal resin prepared using short-chain quaternary ammonium salts (Comparative Examples 3 and 5) has a lower zeta potential, indicating that its bactericidal ability is also relatively lower. Furthermore, compared to the bactericidal resin prepared using long-chain quaternary ammonium salts (Example 1), the turbidity of the effluent from the strong current flushing, the mass loss after 72 hours of operation, and the steady-state CTAC leakage concentration are higher, indicating that the material stability of the bactericidal resin prepared using short-chain quaternary ammonium salts is also poor. When the loading of short-chain quaternary ammonium salts is increased (Comparative Examples 4 and 6), the zeta potential of the obtained bactericidal resin material increases, but it exhibits even worse material stability.

[0119] Comparing Example 1 and Comparative Example 7, it can be seen that the bactericidal resin material (Comparative Example 7) prepared by loading CTAC directly onto PDA-GA / PEI@D201 obtained in step C without introducing g-C3N4 nanosheets has slightly worse zeta potential and material stability than that of Example 1, but is better than that of Comparative Example 3 and Comparative Example 5 using short-chain quaternary ammonium salts.

[0120] Comparing Example 1 and Comparative Example 8, it can be seen that the selection of photocatalytic material has a slight impact on the final bactericidal resin material in terms of zeta potential, turbidity of strong flow effluent, mass loss after 72 hours of operation, and steady-state CTAC leakage concentration. The main impacts are a significant increase in pressure drop and a significant decrease in bactericidal effect (see Table 2).

[0121] Test Example 2 use Figure 4 The device was tested for sterilization performance using the following method: (1) Pack the sample to be tested into the continuous column (φ2 cm, bed height 20 cm), and spray at 8 m·h -1 The wastewater containing bacteria was introduced at an apparent linear velocity and operated for 60 minutes under the condition that the empty bed contact time (EBCT) was approximately 3 minutes.

[0122] For the first 30 minutes, the photocatalytic lamp was not turned on, resulting in dark contact. Subsequently, the photocatalytic lamp was turned on, and a trace amount of hydrogen peroxide was added to the influent (controlling the H2O2 concentration in the influent to 1 mM) to stimulate ROS generation. This was done under visible light (wavelength 420-450 nm, optical power density 5-10 mW·cm²). -2 Continue running under irradiation for 30 minutes, that is, the 30-60 minute running period is the light-assisted sterilization period.

[0123] (2) Collect effluent at 10, 30, and 60 min of operation, and dilute it in a gradient (10 -1 ~10 -6The colonies were inoculated onto R2A plates at 25°C and incubated for 48 hours. The colony count was determined by counting and recorded as Nt. The logarithmic reduction (LR) for different time periods was calculated using the formula LR=lg(N0 / Nt), where N0 is the initial colony count before treatment, i.e., the colony count of the wastewater containing bacteria, and Nt is the residual colony count after treatment.

[0124] (3) Take 10 mL of water from 30 min and 60 min, and inoculate it into R2A (1 / 10) medium at a water-to-medium volume ratio of 1:10. Let it stand at 25℃ for 24 h; count the colonies and record them as N. 24h Calculate the Resurrection Index (RI), RI = N 24h / N0, the larger the RI value, the stronger the possibility of resurrection or regrowth.

[0125] (4) Take 200 mL of water at 30 min and 60 min, filter it with a 0.22 μm filter membrane, extract DNA with a water sample DNA kit (such as Power Water) and elute to 50 μL, and determine the content of ARGs (expressed as eDNA / ARG) by real-time quantitative polymerase chain reaction (qPCR). The change before and after the reaction is recorded as Δ(eDNA / ARG), (Δ(eDNA / ARG) = initial (eDNA / ARG) - termination (eDNA / ARG)).

[0126] Preparation of wastewater containing bacteria: Gram-negative bacteria dominant groups from domestic wastewater reclaimed water were selected. Screening revealed that at least 30% of these bacteria were integron-positive, containing genes for disinfectant resistance (qacEΔ1), sulfonamide resistance (sul1), or integrase (intI1). The mixed population included representative strains such as *Escherichia coli*, *Klebsiella pneumoniae*, and *Pseudomonas aeruginosa*, with an initial colony concentration of 8 × 10⁻⁶. 6 CFU·mL -1 Dissolved organic carbon (DOC) ≈ 3 mg·L -1 .

[0127] Using this ARB mixture as the bacterial wastewater, the bactericidal performance of the bactericidal resin materials obtained in Example 1 and Comparative Examples 3-8 was tested, and the results are shown in Table 2: Table 2 Results of bactericidal performance test

[0128] In the table, LR-30min represents the LR after running for 30 minutes, and the range in the table represents the floating range after multiple tests.

[0129] The results of Examples 1 and Comparative Examples 3-8 in Table 2 show that, under ARB conditions, the log reduction in bactericidal activity of short-chain quaternary ammonium salts (Comparative Examples 3 and 5) with the same quaternary ammonium salt loading (quaternary ammonium salt to carrier ratio) is significantly lower than that of long-chain quaternary ammonium salts (corresponding to Example 1). Even if the loading of short-chain quaternary ammonium salts is increased (e.g., Comparative Examples 4 and 6), it is difficult to achieve the same log reduction in bactericidal activity as long-chain quaternary ammonium salts. Furthermore, the reactivation index RI of short-chain quaternary ammonium salts (Comparative Examples 3-6) is significantly lower. At 30 min, the reactivation index (RI) was 0.6-1.1, significantly higher than the 0.3-0.5 of the long-chain quaternary ammonium salt (Example 1). At 60 min, the reactivation index (RI) of the short-chain quaternary ammonium salt (Comparative Examples 3-6) was 0.4-0.8, also higher than the 0.2-0.4 of the long-chain quaternary ammonium salt (Example 1). The composite bactericidal resin material prepared by the present invention using long-chain quaternary ammonium salt exhibits the advantages of better bactericidal effect and less reactivation of ARB. Combined with the results in Table 1, the composite bactericidal resin material prepared by the present invention using long-chain quaternary ammonium salt also has the advantages of "anti-shedding" and "low leakage", and has better material stability.

[0130] The results of Comparative Example 7 in Table 2 show that the logarithmic reduction of bactericide and the reactivation index RI of the effluent did not change significantly with time and whether there was light assistance at 60 min (visible light synergy) and 30 min (dark contact). This indicates that the bactericidal resin material in Comparative Example 7 does not have photocatalytic activity, that is, it lacks g-C3N4 and therefore does not have photocatalytic activity.

[0131] Comparative results of Example 1 and Comparative Example 7 show that although the absence of g-C3N4 (Comparative Example 7) does not affect its certain dark-state antibacterial effect (LR-30min), its reactivation index RI (including RI at 30min and 60min) is significantly higher than that of the composite bactericidal resin material containing g-C3N4 (Example 1), and its ability to remove eDNA / ARG is insufficient, failing to achieve the goal of "reducing the risk of ARG transmission", and making it difficult to completely remove drug-resistant bacteria.

[0132] The data in Table 2 also show that when g-C3N4 is in block form (Comparative Example 8), the bactericidal logarithmic reduction is lower compared to when g-C3N4 is in nanosheet form (Example 1), and the removal of eDNA / ARG is also poor. This is because the contact area between block g-C3N4 and the carrier pore wall is small, making it difficult to form a multi-point covalent +π-π attachment network. Furthermore, the block form exhibits rapid carrier recombination, severe self-shading, and low ROS yield, thus limiting the oxidative degradation ability of eDNA / ARG and weakening its ability to inhibit eDNA / ARG reactivation and propagation. Combined with the results in Table 1, the pressure drop increases rapidly in actual use, reflecting its poor hydraulic stability. Therefore, the selection of g-C3N4 nanosheets is one of the important features for achieving the purpose of this invention.

[0133] Test Example 3 To verify that the bactericidal resin provided by this invention has good resistance to environmental interference, this test example uses two different environments containing bacteria-laden wastewater to test its bactericidal performance: One is consistent with that in Test Example 2, with a conductivity of ≈250 μS·cm. -1 (NaCl concentration approximately 0.15 g / L), pH 7.5 ± 0.2, ionic strength I ≈ 2.56 mM; Debye length κ -1 ≈ 6.0 nm (weak electrical shielding), referred to as a single environment (C1).

[0134] The second method involves adding Na₂SO₄, NaHCO₃, and NaCl, so that SO₄²⁻ is present in the solution. 2- The concentration was 2.08 mmol / L, HCO3 - The concentration was 3.0 mmol / L, Cl - At a concentration of 4.23 mmol / L and a pH of 7.5 ± 0.2, its ionic strength I ≈ 13.5 mM; Debye length κ -1 ≈2.6 nm (strong electrical shielding, significantly weakened long-range electroattraction), due to the high concentration of SO4. 2- HCO3 - Cl - This is called the competitive environment (C2).

[0135] The bactericidal performance of the products from Examples 1, 7, and 9-10 were tested under these two environments, and the pressure drop (ΔP) was tested under C2 conditions according to method 2-4). The results are shown in Table 3. Table 3. Test results of sterilization performance in different environments

[0136] As shown in Table 3, the bactericidal performance of existing bactericidal resins, Ac-81 (Comparative Example 9) and AER6-1 (Comparative Example 10), significantly decreased in a competitive environment (C2) compared to a single environment (C1). However, the D201 resin used in this invention (Example 1, Comparative Example 7) maintained good bactericidal performance in the competitive environment (C2), indicating that the D201 resin used in this invention has superior antibacterial stability. Analysis suggests that this difference mainly stems from the electroadsorption stability and pore structure differences of different resins under high ionic strength and complex ionic competitive environments. The D201 resin possesses a well-developed pore structure and stable quaternary ammonium functional groups, maintaining good adsorption and contact bactericidal capabilities even in complex aquatic environments, demonstrating good electroadsorption stability under high ionic strength conditions.

[0137] Test Example 4 To verify the photocatalytic synergistic bactericidal mechanism of the composite material under light irradiation, the reactive oxygen species (ROS) in the reaction systems corresponding to different bactericidal resin materials under the two environments described in Test Example 3 were detected, including hydroxyl radicals (·OH) and superoxide radicals (O2). - ·), singlet oxygen ( 1 O2) and total ROS.

[0138] All detections were performed under visible light illumination of 420–450 nm, with a light power density of 8 mW·cm⁻¹. -2 The temperature was maintained at 25 ℃ during the test, and the results are shown in Table 4: Table 4. Test results of reactive oxygen species in different reaction systems

[0139] Test results show that, under a single environment, compared to bactericidal resins containing g-C3N4 (Example 1, Comparative Example 8), bactericidal resins without g-C3N4 (Comparative Examples 7, 9-10) produce fewer reactive oxygen species, indicating that the reactive oxygen species are mainly generated by photocatalysis. Comparing the data from C1-Example 1 and C1-Comparative Example 8, it can be seen that the photocatalytic production of reactive oxygen species by g-C3N4 nanosheets (Example 1) is superior to that of bulk g-C3N4 (Comparative Example 8).

[0140] Based on the results in Table 2, it can be seen that the composite bactericidal resin material in Example 1 works synergistically with quaternary ammonium salt contact sterilization and ROS-generating sterilization by photocatalytic materials. The mechanism of action is as follows: Figure 5As shown: CTAC in D201@CTAC@g-C3N4 carries a positive charge, which adsorbs bacteria through electrostatic attraction and kills bacteria by destroying the cell membrane; g-C3N4 generates reactive oxygen species under visible light, which destroys the DNA and RNA of bacteria, completely kills drug-resistant bacteria, and blocks the spread of antibiotic resistance genes.

[0141] Test Example 5 To verify that the bactericidal resin provided by this invention has good regeneration performance, the composite bactericidal resin material in Example 1 was used for sterilization until its dark-state sterilization effect was close to 0 (LR-30min≈0) as tested according to the method in Test Example 2. Then, backwashing, NaCl replacement, and cleaning with ethanol were performed to remove contaminants. CTAC was then loaded again according to step F in Example 1 to obtain the regenerated composite bactericidal resin material. Subsequently, the performance of the regenerated composite bactericidal resin material was evaluated again according to the methods and conditions of Test 1 and Test Example 2, and the process of consumption until ineffectiveness, regeneration, and performance retesting was repeated three times. The performance of the regenerated composite bactericidal resin material is shown in Tables 5 and 6. Table 5. Material stability results before and after regeneration cycle

[0142] Table 6. Sterilization performance results before and after regeneration cycle

[0143] Table 5 shows that after three regenerations, the effluent turbidity was still <2 NTU and the steady-state leakage of CTAC was still ≤0.05 mg·L⁻¹. -1 The pressure drop increase remains controllable. Table 6 shows that after three regenerations, the logarithmic decrease at 60 min sterilization remains between 1.7 and 2.4 log, the RI remains low, and Δ(eDNA / ARG) still shows a significant decrease. Tables 5 and 6 demonstrate that after multiple regenerations, the properties of the composite bactericidal resin material provided by this invention do not show significant degradation, fully illustrating the structural stability of the composite bactericidal resin material prepared by this invention, allowing for multiple regenerations and reuse.

[0144] The above description provides an illustrative overview of the present invention and its embodiments. This description is not restrictive, and the embodiments shown are merely one example of the invention's implementation. Actual implementations are not limited to these examples. Therefore, if those skilled in the art are inspired by this description and design similar implementations and examples without departing from the spirit of the invention, such designs should fall within the scope of protection of the present invention.

Claims

1. A composite bactericidal resin material, characterized in that, include: The carrier is a macroporous polystyrene-based ion exchange resin; Photocatalytic materials, wherein the photocatalytic materials are low-dimensional nanostructured polymeric carbonitrides; Quaternary ammonium salt, wherein the carbon chain length of the long-chain alkyl group of the quaternary ammonium salt is C12~C16; The photocatalytic material is loaded on a support, and the mass ratio of the photocatalytic material to the support is (3~7):100; The quaternary ammonium salt is loaded onto a support containing photocatalytic material, and the mass ratio of the quaternary ammonium salt to the support is (1~3):

100.

2. The composite bactericidal resin material according to claim 1, characterized in that, The composite bactericidal resin material also includes a slow-release shell layer located on the outermost layer; The sustained-release shell layer comprises several alternating layers of anionic polyelectrolyte and cationic polyelectrolyte.

3. The composite bactericidal resin material according to claim 2, characterized in that, The macroporous polystyrene-based ion exchange resin is a strongly basic anion exchange resin, satisfying one or more of the following conditions (I) to (IV): (I) Specific surface area is 10~50 m² 2 ·g -1 ; (II) Total pore volume is 0.2~0.7 cm³ 3 ·g -1 ; (III) Exchange capacity (Cl) - Type) ≥1.0 eq·L -1 ; (Ⅳ) Particle size is 0.3~0.7 mm.

4. The composite bactericidal resin material according to claim 1 or 3, characterized in that, The polymeric carbonitrides with the low-dimensional nanostructures satisfy one or more of the following conditions (a) to (d): (a) Lateral scale is 50–1000 nm; (b) Thickness is 0.6~10 nm; (c) The optical bandgap is 2.0~3.2 eV; (d) The low-dimensional nanostructured polymeric carbon nitrides include one or more of graphitic carbon nitride quantum dots, carbon-doped carbon nitride quantum dots, carbon nitride nanotubes, graphitic carbon nitride nanosheets, nitrided graphene nanosheets, and C3N5 nanosheets.

5. The composite bactericidal resin material according to claim 1 or 4, characterized in that, The quaternary ammonium salt includes one or more of hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, dialcyldimethylammonium chloride, hexadecylpyridineammonium chloride, and benzalkonium chloride.

6. A method for preparing a composite bactericidal resin material, characterized in that, Includes the following steps: A. Cleaning and wetting the carrier; B. The carrier treated in step A is immersed in a solution containing adhesive and treated at 20~30℃ for 4~8 h, and then washed until the supernatant is colorless; C. The carrier treated in step B is immersed in a solution containing a crosslinking agent and treated at 20-30°C for 20-60 min, then washed; it is then immersed in a solution containing a modifier and crosslinked at 20-30°C for 30-60 min, then washed to obtain an amino-modified carrier. D. Prepare an activated dispersion of the photocatalytic material, such that the concentration of the photocatalytic material in the activated dispersion is 0.5~2.0 g·L⁻¹. -1 ; The content of active groups on the surface of the photocatalytic material is 0.2~2.5 mmol·g. -1 ; E. The amino-modified support obtained in step C is mixed with the activated dispersion of photocatalytic material prepared in step D, and reacted at pH 7.2-7.4 and temperature 20-30℃ for 2-4 h. After washing and drying, the support containing photocatalytic material is obtained. F. The carrier containing photocatalytic material obtained in step E is immersed in a quaternary ammonium salt solution for 60-100 min, filtered, rinsed, and allowed to stand and drip dry for 10-30 min; In step E, the mass ratio of the carrier to the photocatalytic material in the mixture is 1:(0.03~0.07).

7. The method for preparing the composite bactericidal resin material according to claim 6, characterized in that, In step A, the macroporous polystyrene-based ion exchange resin is a strongly basic anion exchange resin, satisfying one or more of the following conditions (I) to (IV): (I) Specific surface area is 10~50 m² 2 ·g -1 ; (II) Total pore volume is 0.2~0.7 cm³ 3 ·g -1 ; (III) Exchange capacity (Cl) - Type) ≥1.0 eq·L -1 ; (Ⅳ) Particle size is 0.3~0.7 mm; In step B, the adhesive comprises one or more of polydopamine, polytannic acid, polyproanthocyanidins, and polyvinylcatechol; the concentration of the adhesive in the solution containing the adhesive is 1.5~2.5 g·L. -1 The pH value is 8.0~9.0; In step C, the crosslinking agent includes one or more of glutaraldehyde, paraformaldehyde, terephthalaldehyde, glyoxal, and malondialdehyde; the concentration of the crosslinking agent in the solution containing the crosslinking agent is 4.0~8.0 mmol / L, and the pH of the solution containing the crosslinking agent is 6.8~7.6; The modifier includes one or more of polyethyleneimine, polyamide amine dendritic molecules, protonated chitosan, and ethylenediamine modified polymers; the concentration of the modifier in the solution containing the modifier is 0.08~0.20 wt%, and the pH of the solution containing the modifier is 8.0~9.0; In step D, the photocatalytic material is a low-dimensional nanostructured polymeric carbonitride that satisfies one or more of the following conditions (a) to (d): (a) Lateral scale is 50–1000 nm; (b) Thickness is 0.6~10 nm; (c) The optical bandgap is 2.0~3.2 eV; (d) The low-dimensional nanostructured polymeric carbon nitrides include one or more of graphitic carbon nitride quantum dots, carbon-doped carbon nitride quantum dots, carbon nitride nanotubes, graphitic carbon nitride nanosheets, nitrided graphene nanosheets, and C3N5 nanosheets.

8. The method for preparing the composite bactericidal resin material according to claim 7, characterized in that, In step F, the carbon chain length of the long-chain alkyl group of the quaternary ammonium salt is C12~C16; The quaternary ammonium salt includes one or more of hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, dialcyldimethylammonium chloride, hexadecylpyridineammonium chloride, and benzalkonium chloride; The concentration of the quaternary ammonium salt solution is 1~15 g·L. -1 .

9. The method for preparing the composite bactericidal resin material according to claim 8, characterized in that, It also includes step G: Several layers of anionic polyelectrolyte and cationic polyelectrolyte are alternately deposited on the surface of the product obtained in step F to form a slow-release shell.

10. The application of the composite bactericidal resin material according to any one of claims 1 to 5 or the composite bactericidal resin material prepared by any one of claims 6 to 9 in water treatment sterilization.

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