A treatment agent for marine microplastic degradation and a preparation method thereof

Abstract

This invention relates to the field of marine environmental protection technology and discloses a treatment agent for the degradation of marine microplastics and its preparation method. The treatment agent is composed of 8-12 parts by weight of quaternary ammonium salt-modified SBA-15 and 4-5 parts by weight of S-nZVI@ATP material. The quaternary ammonium salt-modified SBA-15 is prepared by a tertiary amine-modified coupling agent, synthesized by a bis-quaternary ammonium salt-modified silane, acidified SBA-15, and grafted with silane. The S-nZVI@ATP material is prepared by loading sulfide nano-zero-valent iron onto attapulgite clay. Finally, the two components are mixed to obtain the final product. This treatment agent exhibits strong synergistic properties and excellent stability in high-salinity marine environments. It can efficiently degrade various types of marine microplastics, solving the problems of incomplete degradation, poor environmental adaptability, and easy secondary pollution associated with existing technologies. It produces no secondary pollution and is suitable for complex marine environments, providing an efficient and feasible solution for marine microplastic management, applicable to the field of marine environmental protection.

Description

Technical Field

[0001] This invention relates to the field of marine environmental protection technology, specifically to a treatment agent for the degradation of marine microplastics and its preparation method. Background Technology

[0002] Microplastics, referring to plastic fragments, particles, or fibers with a diameter of less than 5 millimeters, have become a global marine environmental crisis. Microplastics in the ocean originate from various sources, including the physical breaking down and chemical decomposition of plastic waste, as well as the release of microbeads from synthetic fiber clothing washing and cosmetics. They can persist in the marine environment for extended periods, forming complex pollution by adsorbing toxic organic and inorganic pollutants in the water. These pollutants are then ingested by marine life and passed down the food chain, ultimately threatening human health and ecosystem stability.

[0003] Currently, marine microplastic remediation technologies are mainly divided into three categories: physical separation, biological treatment, and advanced oxidation. Physical separation technologies (such as membrane filtration and flocculation sedimentation) can only achieve phase transfer of microplastics, but cannot completely degrade them. They also have limitations such as high energy consumption, difficulty in recycling, and easy secondary pollution, especially in treating high-density microplastics deposited in dark, oxygen-deficient areas on the seabed. Biological treatment technologies rely on the catalytic action of microorganisms or enzymes, but the degradation rate of natural microorganisms is extremely slow, enzyme preparations are prone to aggregation and inactivation, and leakage. Furthermore, they are limited by environmental conditions such as ocean temperature and salinity, making it difficult to achieve engineering applications. Traditional advanced oxidation technologies (such as single photocatalysis and Fenton oxidation) have problems such as narrow light response range, low reactive oxygen generation efficiency, and incomplete degradation. For example, pure titanium dioxide photocatalysts can only respond to ultraviolet light, have low solar energy utilization, and the easy recombination of photogenerated electron-hole pairs restricts degradation efficiency.

[0004] While some researchers have developed composite catalytic degradation systems in existing technologies, most suffer from drawbacks such as poor component compatibility, insufficient stability in high-salinity marine environments, and inability to adapt to complex marine environments, making it difficult to achieve efficient degradation of various marine microplastics. Therefore, developing a microplastic degradation agent with strong component synergy, good environmental adaptability, no secondary pollution, and compatibility with marine environments has become a key issue that urgently needs to be addressed in the field of marine environmental protection. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a treatment agent for the degradation of marine microplastics and its preparation method, so as to achieve efficient adsorption and degradation of marine microplastics and solve the problems of low degradation efficiency, poor environmental adaptability and easy ecological harm of microplastics in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A treatment agent for the degradation of marine microplastics comprises the following components by weight: 8-12 parts by weight of quaternary ammonium salt modified SBA-15 and 4-5 parts by weight of S-nZVI@ATP material;

[0008] The preparation method of the quaternary ammonium salt modified SBA-15 is as follows:

[0009] S1. A silane coupling agent containing a tertiary amine group was prepared by reacting 3-isocyanate-propyltrimethoxysilane with 3-dimethylamino-1-propane.

[0010] S2. The tertiary amine-modified coupling agent is reacted with 1,4-dibromobutane and converted into a bisquaternary ammonium salt-modified silane through a quaternization reaction;

[0011] S3. SBA-15 is acidified with dilute hydrochloric acid to activate the hydroxyl groups on its surface;

[0012] S4. In the tetrahydrofuran system, bisquaternary ammonium salt modified silane is grafted onto the acidified surface of SBA-15 to finally obtain quaternary ammonium salt modified SBA-15.

[0013] Quaternary ammonium salt modified SBA-15: As an adsorption carrier, the mesoporous structure of SBA-15 provides physical adsorption sites; at the same time, through the grafted quaternary ammonium salt groups, electrostatic interaction is formed with microplastics to achieve the capture and enrichment of microplastics.

[0014] S-nZVI@ATP (sulfide nano-zero valent iron supported on attapulgite): As a catalytic degradation unit, S-nZVI (sulfide nano-zero valent iron) is the core active component, which can generate ·OH and SO4 through electron transfer reactions. - • Strong oxidizing free radicals disrupt the CC backbone of microplastics; ATP (attapulgite) acts as a carrier to disperse S-nZVI particles through a layered structure (avoiding aggregation and inactivation).

[0015] Furthermore, the preparation method of the quaternary ammonium salt modified SBA-15 is as follows:

[0016] S1. Add 3-isocyanate-propyltrimethoxysilane and 3-dimethylamino-1-propylamine to tetrahydrofuran, heat and reflux at 75-80℃ for 20-24h, rotary evaporate after the end, add n-hexane, sonicate to dissolve and disperse, and recrystallize to obtain tertiary amine modified coupling agent.

[0017] S2. Add a tertiary amine-modifying coupling agent and 1,4-dibromobutane to a reactor containing N,N-dimethylformamide solvent, stir and mix, and react at 100-110℃ for 5-6 hours. After the reaction is completed, distill under reduced pressure and dry under vacuum to obtain a bis-quaternary ammonium salt-modified silane. The tertiary amine group of the tertiary amine-modifying coupling agent undergoes a quaternization reaction with the bromine atom of 1,4-dibromobutane to generate a bis-quaternary ammonium salt structure. The bis-quaternary ammonium salt can provide stronger positive charge and enhance the electrostatic interaction with microplastics.

[0018] S3. Add 2 mol / L dilute hydrochloric acid to the reactor containing SBA-15 and stir at room temperature for 2-3 hours to obtain acidified SBA-15;

[0019] S4. Add acidified SBA-15 to anhydrous tetrahydrofuran, disperse by ultrasonication at room temperature, then add bisquaternary ammonium salt modified silane, stir under nitrogen atmosphere for 25-30 min, heat under reflux at 75-80℃ for 16-24 h, filter the product after the reaction is completed, and wash with toluene to obtain quaternary ammonium salt modified SBA-15.

[0020] Further, in S1, the ratio of 3-isocyanate-propyltrimethoxysilane, 3-dimethylamino-1-propylamine, and tetrahydrofuran is 2-3 mmol: 2-3 mmol: 50-60 mL.

[0021] Furthermore, in S2, the ratio of N,N-dimethylformamide, tertiary amine modifying coupling agent, and 1,4-dibromobutane is 45-55 mL: 1-1.5 mmol: 0.5-0.75 mmol.

[0022] Furthermore, in S3, the ratio of SBA-15 to dilute hydrochloric acid is 0.8-1g:62-68mL.

[0023] Furthermore, in S4, the ratio of acidified SBA-15, anhydrous tetrahydrofuran, and bisquaternary ammonium salt modified silane is 0.1-0.2g: 15-20mL: 0.05-0.1g.

[0024] Furthermore, in S4, the room temperature ultrasonic dispersion time is 25-30 min.

[0025] Furthermore, the preparation method of the treatment agent for marine microplastic degradation is as follows: add quaternary ammonium salt modified SBA-15 and S-nZVI@ATP materials into a stirrer and stir for 8-10 min to obtain the treatment agent for marine microplastic degradation.

[0026] Compared with the prior art, the present invention has the following beneficial technical effects:

[0027] The quaternary ammonium salt modified SBA-15 of this invention retains the ordered mesoporous structure of SBA-15, with a large specific surface area and good pore connectivity, providing ample adsorption sites for microplastic particles. The grafted bisquaternary ammonium salt groups are positively charged and can tightly bind to negatively charged microplastic particles in the ocean through electrostatic interactions. At the same time, the hydrophobic chains of the quaternary ammonium salts can generate hydrophobic interactions with the microplastics, achieving rapid and efficient capture of microplastics through this dual action. In the S-nZVI@ATP material, sulfide nano-zero-valent iron (S-nZVI) serves as the core catalytic component, releasing electrons to generate ·OH and SO4. - • Active oxygen free radicals, which have strong oxidizing power, can break the high molecular carbon chain of microplastics, thus achieving chain-breaking degradation; ATP (attapulgite) as a carrier can not only disperse S-nZVI particles and prevent them from agglomerating and becoming inactive, but also bind to microplastics through surface hydroxyl groups, thereby increasing the local concentration at degradation sites; sulfur modification further improves the antioxidant and reactivity of nZVI in the high-salt and hypoxic marine environment, solving the problems of easy passivation and low degradation efficiency of traditional zero-valent iron.

[0028] The quaternary ammonium salt modified SBA-15 has a highly efficient trapping effect on microplastics, which can enrich microplastic particles on the surface and in the pores of the treatment agent, so that the active free radicals generated by S-nZVI@ATP material can act precisely on microplastics, achieving a synergistic effect of adsorption and degradation. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Preparation of SBA-15 (Reference: Wei Zhibo, Bai Rui, Zhang Faai. Solution polymerization of methyl methacrylate in the channels of modified mesoporous molecular sieve SBA-15, Acta Polymerica Sinica, 2013, (7): 849-855): 80 mL of deionized water and 15 mL of hydrochloric acid were added to a 250 mL round-bottom flask and mixed thoroughly. 2.5 g of P123 (polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer) preheated at 60 °C was added dropwise to the above hydrochloric acid solution. The solution was heated in a water bath at 35 °C and stirred for 2 h until completely dissolved. Then, 5.5 g of tetraethyl orthosilicate was slowly added dropwise and stirred at 35 °C for 24 h. After the reaction was completed, the mixture was transferred to a hydrothermal reactor and placed in an oven at 100°C for 24 hours to crystallize. Finally, the obtained product was filtered, washed until the pH reached 4-5 and dried. The resulting white powder was calcined in a high-temperature furnace at 550°C for 5 hours (heating rate 1 K / min) to obtain SBA-15.

[0031] Preparation of S-nZVI@ATP material (Reference: Zhang Lili et al., "Study on the Performance and Mechanism of Attapulgite-Supported Sulfated Nano-Zero-Variant Iron-Activated Persulfate Aging Degradation Microplastics", Plastics Industry, 2013, Vol. 41 (No. 5)): In the experiment, an appropriate amount of FeSO4·7H2O was first added to a three-necked flask containing 100mL of distilled water, and a certain amount of ATP was added according to an iron-to-calcium mass ratio of 2:1. Then, the mixture was stirred for 2 hours under N2 protection to ensure thorough mixing. Next, 100mL of anhydrous ethanol was added, and stirring continued for 30 minutes. Then, 150mL of freshly prepared 1mol / L NaBH4 solution was added, and the S / Fe ratio was adjusted accordingly. 2+ A certain amount of Na₂S·9H₂O was dissolved in a solution at a molar ratio of 0.75 and stirred thoroughly. This solution was then added dropwise to the mixture in a three-necked flask while continuously stirring for 15 minutes. All reactions were carried out under a nitrogen atmosphere. The mixture was then centrifuged and washed three times each with pure water and ethanol to obtain the prepared material. The material was then placed in a vacuum drying oven and dried at 40°C. Finally, it was filtered through a 200-mesh sieve to obtain the S-nZVI@ATP composite material.

[0032] Example 1

[0033] A treatment agent for the degradation of marine microplastics comprises the following components by weight: 8 parts by weight of quaternary ammonium salt modified SBA-15 and 4 parts by weight of S-nZVI@ATP material.

[0034] The preparation method of quaternary ammonium salt modified SBA-15 is as follows:

[0035] S1. Add 2 mmol of 3-isocyanate-propyltrimethoxysilane and 2 mmol of 3-dimethylamino-1-propylamine to 50 mL of tetrahydrofuran, heat under reflux at 75 °C for 20 h, rotary evaporate after the reaction, add n-hexane, sonicate to dissolve and disperse, and recrystallize to obtain the tertiary amine modified coupling agent.

[0036] S2. Add 1 mmol of tertiary amine modifying coupling agent and 0.5 mmol of 1,4-dibromobutane to a reactor containing 45 mL of N,N-dimethylformamide solvent, stir and mix, react at 100 °C for 5 h, and after the reaction is completed, distill under reduced pressure and dry under vacuum to obtain bisquaternary ammonium salt modified silane.

[0037] S3. Add 62 mL of 2 mol / L dilute hydrochloric acid to a reactor containing 0.8 g of SBA-15 and stir at room temperature for 2 h to obtain acidified SBA-15;

[0038] S4. Add 0.1 g of acidified SBA-15 to 15 mL of anhydrous tetrahydrofuran, sonicate at room temperature for 25 min, then add 0.05 g of bisquaternary ammonium salt modified silane, stir under nitrogen atmosphere for 25 min, heat at 75 °C under reflux for 16 h, after the reaction is completed, filter the product and wash with toluene to obtain quaternary ammonium salt modified SBA-15.

[0039] The preparation method is as follows: add the quaternary ammonium salt modified SBA-15 and S-nZVI@ATP materials into a stirrer and stir for 8 minutes to obtain a treatment agent for the degradation of marine microplastics.

[0040] Example 2

[0041] A treatment agent for the degradation of marine microplastics comprises the following components by weight: 12 parts by weight of quaternary ammonium salt modified SBA-15 and 5 parts by weight of S-nZVI@ATP material.

[0042] The preparation method of quaternary ammonium salt modified SBA-15 is as follows:

[0043] S1. Add 3 mmol of 3-isocyanate-propyltrimethoxysilane and 3 mmol of 3-dimethylamino-1-propylamine to 60 mL of tetrahydrofuran, heat under reflux at 80 °C for 24 h, rotary evaporate after the reaction, add n-hexane, sonicate to dissolve and disperse, and recrystallize to obtain the tertiary amine modified coupling agent.

[0044] S2. Add 1.5 mmol of tertiary amine modifying coupling agent and 0.75 mmol of 1,4-dibromobutane to a reactor containing 55 mL of N,N-dimethylformamide solvent, stir and mix, react at 110 °C for 6 h, and after the reaction is completed, distill under reduced pressure and dry under vacuum to obtain bisquaternary ammonium salt modified silane.

[0045] S3. Add 68 mL of 2 mol / L dilute hydrochloric acid to a reactor containing 1 g of SBA-15 and stir at room temperature for 3 h to obtain acidified SBA-15;

[0046] S4. Add 0.2 g of acidified SBA-15 to 20 mL of anhydrous tetrahydrofuran, sonicate at room temperature for 30 min, then add 0.1 g of bisquaternary ammonium salt modified silane, stir under nitrogen atmosphere for 30 min, heat at 80 °C and reflux for 24 h, after the reaction is completed, filter the product and wash with toluene to obtain quaternary ammonium salt modified SBA-15.

[0047] The preparation method is as follows: add the quaternary ammonium salt modified SBA-15 and S-nZVI@ATP materials into a stirrer and stir for 10 min to obtain a treatment agent for the degradation of marine microplastics.

[0048] Example 3

[0049] A treatment agent for the degradation of marine microplastics comprises the following components by weight: 10 parts by weight of quaternary ammonium salt modified SBA-15 and 4.5 parts by weight of S-nZVI@ATP material.

[0050] The preparation method of quaternary ammonium salt modified SBA-15 is as follows:

[0051] S1. 2.5 mmol of 3-isocyanate-propyltrimethoxysilane and 2.5 mmol of 3-dimethylamino-1-propylamine were added to 55 mL of tetrahydrofuran and heated under reflux at 78 °C for 22 h. After the reaction was completed, the mixture was rotary evaporated, and hexane was added to dissolve and disperse the mixture by ultrasonication. The mixture was then recrystallized to obtain the tertiary amine modified coupling agent.

[0052] S2. Add 1.25 mmol of tertiary amine modifying coupling agent and 0.65 mmol of 1,4-dibromobutane to a reactor containing 50 mL of N,N-dimethylformamide solvent, stir and mix, and react at 105 °C for 5.5 h. After the reaction is completed, distill under reduced pressure and dry under vacuum to obtain bisquaternary ammonium salt modified silane.

[0053] S3. Add 65 mL of 2 mol / L dilute hydrochloric acid to a reactor containing 0.9 g of SBA-15 and stir at room temperature for 3 h to obtain acidified SBA-15;

[0054] S4. Add 0.15 g of acidified SBA-15 to 18 mL of anhydrous tetrahydrofuran, sonicate at room temperature for 28 min, then add 0.075 g of bisquaternary ammonium salt modified silane, stir under nitrogen atmosphere for 26 min, heat at 77 °C and reflux for 20 h, after the reaction is completed, filter the product and wash with toluene to obtain quaternary ammonium salt modified SBA-15.

[0055] The preparation method is as follows: add the quaternary ammonium salt modified SBA-15 and S-nZVI@ATP materials into a stirrer and stir for 9 min to obtain a treatment agent for the degradation of marine microplastics.

[0056] Example 4

[0057] A treatment agent for the degradation of marine microplastics comprises the following components by weight: 12 parts by weight of quaternary ammonium salt modified SBA-15 and 5 parts by weight of S-nZVI@ATP material.

[0058] The preparation method of quaternary ammonium salt modified SBA-15 is as follows:

[0059] S1. Add 3 mmol of 3-isocyanate-propyltrimethoxysilane and 3 mmol of 3-dimethylamino-1-propylamine to 60 mL of tetrahydrofuran, heat under reflux at 80 °C for 24 h, rotary evaporate after the reaction, add n-hexane, sonicate to dissolve and disperse, and recrystallize to obtain the tertiary amine modified coupling agent.

[0060] S2. Add 1.5 mmol of tertiary amine modifying coupling agent and 0.75 mmol of 1,4-dibromobutane to a reactor containing 55 mL of N,N-dimethylformamide solvent, stir and mix, react at 110 °C for 6 h, and after the reaction is completed, distill under reduced pressure and dry under vacuum to obtain bisquaternary ammonium salt modified silane.

[0061] S3. Add 62 mL of 2 mol / L dilute hydrochloric acid to a reactor containing 0.8 g of SBA-15 and stir at room temperature for 2 h to obtain acidified SBA-15;

[0062] S4. Add 0.1 g of acidified SBA-15 to 15 mL of anhydrous tetrahydrofuran, sonicate at room temperature for 25 min, then add 0.05 g of bisquaternary ammonium salt modified silane, stir under nitrogen atmosphere for 25 min, heat at 75 °C under reflux for 16 h, after the reaction is completed, filter the product and wash with toluene to obtain quaternary ammonium salt modified SBA-15.

[0063] The preparation method is as follows: add the quaternary ammonium salt modified SBA-15 and S-nZVI@ATP materials into a stirrer and stir for 9 min to obtain a treatment agent for the degradation of marine microplastics.

[0064] Comparative Example 1

[0065] The main difference between this comparative example and Example 4 is that acidified SBA-15 is used instead of quaternary ammonium salt to modify SBA-15.

[0066] Comparative Example 2

[0067] The main difference between this comparative example and Example 4 is that nano-zero valent iron (nZVI) is used instead of S-nZVI@ATP material.

[0068] Comparative Example 3

[0069] The main difference between this comparative example and Example 4 is that S-nZVI@ATP material is used instead of quaternary ammonium salt to modify SBA-15; its composition is 12 parts by weight of S-nZVI@ATP material and 5 parts by weight of S-nZVI@ATP material.

[0070] For the samples from Examples 1-4 and Comparative Examples 1-2, a microplastic degradation test was designed under a simulated marine environment. The specific method is as follows:

[0071] (a) Preparation of test samples

[0072] Typical polyethylene (PE), polypropylene (PP), and polystyrene (PS) microplastics (particle size 100-500 μm) from the marine environment were selected as target degradation products. The treatment agents of each example and comparative example were prepared into suspensions with a concentration of 1 g / L for later use.

[0073] (II) Construction of Ocean Simulation System

[0074] Artificial seawater (salinity 35‰, pH=8.1±0.2, simulating a high-salt nearshore environment) was prepared. 200mL of artificial seawater was added to a 500mL stoppered conical flask, along with 0.5g of the target microplastic and 10mL of treatment agent suspension. Three parallel experiments were conducted for each experimental group.

[0075] (III) Reaction conditions

[0076] The conical flask was placed in a constant temperature shaker at 25°C (oceanic ambient temperature) and 150 r / min for 7 days in the dark (simulating the static degradation environment of the ocean, eliminating light interference, and verifying the catalytic degradation ability of the treatment agent separately).

[0077] (iv) Detection indicators and methods

[0078] Microplastic degradation rate: After the reaction, residual microplastics were separated by vacuum filtration, dried to constant weight, and the degradation rate was calculated as follows: Degradation rate = (Initial microplastic mass - Residual microplastic mass) / Initial microplastic mass × 100%;

[0079] Stability of the treatment agent: After the reaction is completed, the amount of iron ions dissolved in the system is detected (atomic absorption spectrophotometry) to characterize the passivation resistance of S-nZVI. The lower the amount of dissolution, the better the stability.

[0080] Table 1 Performance Tests (Salinity‰)

[0081]

[0082] As shown in Table 1, in Comparative Example 1, replacing the quaternary ammonium salt-modified SBA-15 with acidified SBA-15 resulted in a sharp drop in degradation rate to 52.4%. This demonstrates that the SBA-15 grafted with the quaternary ammonium salt achieves efficient enrichment of microplastics through physical adsorption and electrostatic interaction, providing a basis for catalytic degradation and improving degradation efficiency. In Comparative Example 2, replacing S-nZVI@ATP with pure nZVI resulted in a degradation rate of only 45.7%, with an iron ion dissolution rate as high as 0.54 mg / L. This indicates that the loading effect of attapulgite (ATP) effectively prevented nZVI aggregation, and the sulfurization modification significantly improved the passivation and oxidation resistance of nZVI, enabling it to maintain high catalytic activity in the marine environment.

[0083] Table 2 High salt test (salinity 50‰)

[0084]

[0085] As shown in Table 2, the microplastic enrichment capacity of Comparative Example 1 decreased due to the absence of quaternary ammonium salt modified SBA-15; the dual advantages of sulfur modification and attapulgite loading were lost in Comparative Example 2 due to the use of pure nZVI to replace S-nZVI@ATP, and nZVI was rapidly passivated in the high-salt environment with a degradation rate of only 38.5%; the iron ion dissolution of the examples was lower than that of Comparative Example 2 (0.62 mg / L), proving that S-nZVI@ATP has excellent stability in the ultra-salt environment. As shown in Tables 1-2, Comparative Example 3 lacks the adsorption and enrichment effect of the quaternary ammonium salt modified SBA-15. The microplastics are highly dispersed in seawater, and the contact probability between the catalytic active sites of S-nZVI@ATP and the microplastics is greatly reduced, limiting the mass transfer efficiency and leading to a significant decrease in catalytic degradation efficiency. Without the fixation and dispersion effect of the SBA-15 carrier, the S-nZVI@ATP particles are prone to aggregation and passivation, accelerating the release of iron ions. The insufficient contact between the microplastics and the catalytic sites reduces the activation efficiency of persulfate, and more free radicals are consumed in side reactions, further aggravating the corrosion and dissolution of the material.

[0086] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0087] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A treatment agent for the degradation of marine microplastics, characterized in that, Includes the following components by weight: 8-12 parts by weight of quaternary ammonium salt modified SBA-15, and 4-5 parts by weight of S-nZVI@ATP material; The preparation method of the quaternary ammonium salt modified SBA-15 is as follows: S1. A silane coupling agent containing a tertiary amine group was prepared by reacting 3-isocyanate-propyltrimethoxysilane with 3-dimethylamino-1-propane. S2. The tertiary amine-modified coupling agent is reacted with 1,4-dibromobutane and converted into a bisquaternary ammonium salt-modified silane through a quaternization reaction; S3. SBA-15 is acidified with dilute hydrochloric acid to activate the hydroxyl groups on its surface; S4. In the tetrahydrofuran system, bisquaternary ammonium salt modified silane is grafted onto the acidified surface of SBA-15 to finally obtain quaternary ammonium salt modified SBA-15.

2. The treatment agent for the degradation of marine microplastics according to claim 1, characterized in that, The preparation method of the quaternary ammonium salt modified SBA-15 is as follows: S1. Add 3-isocyanate-propyltrimethoxysilane and 3-dimethylamino-1-propylamine to tetrahydrofuran, heat and reflux at 75-80℃ for 20-24h, rotary evaporate after the end, add n-hexane, sonicate to dissolve and disperse, and recrystallize to obtain tertiary amine modified coupling agent. S2. Add tertiary amine modifying coupling agent and 1,4-dibromobutane to a reactor containing N,N-dimethylformamide solvent, stir and mix, react at 100-110℃ for 5-6 h, distill under reduced pressure after the reaction is completed, and dry under vacuum to obtain bisquaternary ammonium salt modified silane. S3. Add 2 mol / L dilute hydrochloric acid to the reactor containing SBA-15 and stir at room temperature for 2-3 hours to obtain acidified SBA-15; S4. Add acidified SBA-15 to anhydrous tetrahydrofuran, disperse by ultrasonication at room temperature, then add bisquaternary ammonium salt modified silane, stir under nitrogen atmosphere for 25-30 min, heat under reflux at 75-80℃ for 16-24 h, filter the product after the reaction is completed, and wash with toluene to obtain quaternary ammonium salt modified SBA-15.

3. The treatment agent for the degradation of marine microplastics according to claim 2, characterized in that, In S1, the ratio of 3-isocyanate-propyltrimethoxysilane, 3-dimethylamino-1-propylamine, and tetrahydrofuran is 2-3 mmol: 2-3 mmol: 50-60 mL.

4. The treatment agent for the degradation of marine microplastics according to claim 2, characterized in that, In S2, the ratio of N,N-dimethylformamide, tertiary amine modifying coupling agent, and 1,4-dibromobutane is 45-55 mL: 1-1.5 mmol: 0.5-0.75 mmol.

5. The treatment agent for the degradation of marine microplastics according to claim 2, characterized in that, In S3, the ratio of SBA-15 to dilute hydrochloric acid is 0.8-1g: 62-68mL.

6. The treatment agent for the degradation of marine microplastics according to claim 2, characterized in that, In S4, the ratio of acidified SBA-15, anhydrous tetrahydrofuran, and bisquaternary ammonium salt modified silane is 0.1-0.2g: 15-20mL: 0.05-0.1g.

7. The treatment agent for the degradation of marine microplastics according to claim 2, characterized in that, In S4, the ultrasonic dispersion time at room temperature is 25-30 min.

8. A method for preparing a treatment agent for the degradation of marine microplastics as described in any one of claims 1-7, characterized in that, The preparation method of the treatment agent for marine microplastic degradation is as follows: add quaternary ammonium salt modified SBA-15 and S-nZVI@ATP materials into a stirrer and stir for 8-10 min to obtain the treatment agent for marine microplastic degradation.

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