A composite degradation preparation for degrading microplastics in wastewater and a method of application thereof

Abstract

The application discloses a composite degradation preparation for degrading microplastics in wastewater and an application method thereof, and relates to the technical field of wastewater purification. The preparation is prepared by three steps of preparing a rare earth doped titanium-based porous framework, preparing an enzyme-containing bacteria coated precursor solution, and in-situ cross-linking and co-fixing. The framework realizes visible light response and magnetic separation characteristics. The co-fixing of enzyme and bacteria is completed by microcapsule embedding and carrier adsorption cross-linking. The preparation integrates the functions of photocatalysis, enzymatic degradation and microbial degradation. In application, the wastewater is pretreated to SS≤60mg / L, and then the preparation is added to a degradation tank. Under the conditions of 395-450nm light, 25-40 DEG C, and pH 6.0-8.0, the wastewater is degraded by stage light irradiation. Finally, the preparation is recycled by magnetic separation. The preparation solves the problem of free radical damage in the light-biological synergy, and has strong impact resistance, high microplastic removal rate, and recyclable preparation. The preparation is suitable for continuous treatment of wastewater, greatly reduces the operation cost, and is suitable for purification treatment of various wastewater containing microplastics.

Description

Technical Field

[0001] This application relates to the field of wastewater purification technology, and in particular to a composite degradation agent for the degradation of microplastics in wastewater and its application method. Background Technology

[0002] With the widespread use of plastic products in industrial production, daily life, and agriculture, large amounts of plastic waste enter aquatic environments through various pathways. Microplastic pollution (plastic particles / fragments with a diameter of less than 5 mm) in wastewater has become a global environmental problem. Industrial wastewater, domestic sewage, and aquaculture wastewater are the core pathways for microplastics to enter the natural environment. The microplastics in these wastewaters are not only diverse, encompassing various mainstream plastic types such as PET, PE, PP, and PS, but they also readily adsorb toxic and harmful substances such as heavy metals and persistent organic pollutants. Through bioaccumulation in the food chain, they pose a serious potential threat to the stability of aquatic ecosystems and human health. Therefore, developing efficient, environmentally friendly microplastic degradation technologies adapted to the complex conditions of wastewater is a crucial issue that urgently needs to be addressed in the field of water environment management.

[0003] Currently, wastewater microplastic treatment technologies are mainly divided into three categories: physical methods, chemical methods, and biodegradation methods. Physical methods, including screen filtration, membrane separation, and magnetic adsorption, can only achieve phase transfer separation of microplastics and cannot fundamentally degrade the plastics, easily causing secondary pollution. Chemical methods, based on advanced oxidation and photocatalytic oxidation, can break plastic molecular chains through free radical action, but their reaction conditions are harsh, energy consumption is high, they easily generate toxic intermediate products, have poor adaptability to complex wastewater qualities, and cannot achieve stable engineering operation.

[0004] Biodegradation, with its advantages of being environmentally friendly, having mild conditions, and producing no secondary pollution, has become a research hotspot in microplastic remediation technologies. It mainly includes two pathways: enzymatic degradation and microbial degradation. However, existing biodegradation technologies still face several insurmountable technical bottlenecks: First, single enzyme preparations or microbial strains can only target and degrade specific types of plastics, making it difficult to address complex pollution systems where multiple microplastics coexist in wastewater. Second, free enzymes and microorganisms are easily lost with the water flow in wastewater systems, and are greatly affected by fluctuations in wastewater pH, temperature changes, and interference from toxic impurities, resulting in rapid activity decay and making long-term continuous operation impossible. Third, in the synergistic application of photocatalysis and biodegradation, the strong oxidizing hydroxyl radicals generated by photocatalysis indiscriminately attack the active sites of enzymes and the cell structure of microorganisms, directly leading to enzyme inactivation and microbial death.

[0005] To address the aforementioned issues, existing related technologies have been explored. For example, Chinese patent CN121020930B discloses a method for degrading microplastics in aquaculture wastewater, which uses mesoporous magnetic materials to immobilize composite enzymes and combines them with composite thermostable bacteria to degrade microplastics in stages. However, this scheme does not introduce a photocatalytic synergistic mechanism, resulting in limited degradation efficiency for highly crystalline microplastics. Furthermore, the use of a staged process of enzymatic hydrolysis and microbial degradation does not achieve co-immobilization and synergistic degradation of enzymes and bacteria, leaving considerable room for improvement in degradation efficiency and operational stability. Summary of the Invention

[0006] The purpose of this application is to provide a composite degradation agent for the degradation of microplastics in wastewater and its application method, so as to solve at least one of the above-mentioned technical problems.

[0007] To achieve the above-mentioned technical objectives, this application provides a composite degradation agent for the degradation of microplastics in wastewater and its application method. In a first aspect, this application provides a composite degradation agent for the degradation of microplastics in wastewater, the composite degradation agent being prepared by the following method: S1. Preparation of rare earth-doped titanium-based porous framework: Add titanium source, rare earth dopant source, magnetic precursor and soft template agent to solvent in proportion, stir evenly to obtain a homogeneous precursor solution, transfer the precursor solution to high pressure reactor, react at 140-180℃ for 6-12h, separate, wash and dry after cooling to obtain framework precursor, place framework precursor in inert atmosphere, calcine at 500-650℃ for 3-5h, cool and acid wash, wash to neutral, dry to obtain the rare earth-doped titanium-based porous framework. S2. Add the compound enzyme preparation and compound functional microbial agent to the chitosan-sodium alginate mixture in proportion, then add calcium-based diatomaceous earth, stir evenly at constant temperature to obtain the encapsulation precursor solution containing enzyme bacteria. S3. The enzyme-containing bacteria coating precursor solution is mixed with the rare earth-doped titanium-based porous photocatalytic framework, and calcium chloride crosslinking solution is added dropwise to complete the in-situ crosslinking. Simultaneously, the enzyme bacteria are microcapsule-encapsulated and the carrier is adsorbed and crosslinked to achieve co-fixation. After magnetic separation and low-temperature drying, the composite degradation preparation is obtained.

[0008] Preferably, in step S1, the rare earth-doped titanium-based porous framework is prepared by the following mass fractions: 80-120 parts of titanium source, 3-10 parts of rare earth doping source, 5-15 parts of magnetic precursor, 10-20 parts of soft template agent, and 800-1200 parts of solvent.

[0009] Preferably, the titanium source includes one of tetrabutyl titanate and isopropyl titanate; the rare earth doping source includes one of cerium nitrate and praseodymium nitrate; the magnetic precursor is a mixture of ferric chloride hexahydrate and ferrous chloride tetrahydrate in a molar ratio of 2:1; the soft template agent includes hexadecyltrimethylammonium bromide; and the solvent includes a mixture of anhydrous ethanol and deionized water in a volume ratio of 4:1.

[0010] Preferably, the composite functional microbial agent comprises *Pichia pastoris*, *Pseudomonas putida*, *Bacillus thermophilus*, and *Bacillus sicca* in a ratio of (25-35):(20-30):(15-25):(15-25); the loading amount of the composite functional microbial agent in the carrier is (2-8)×10⁻⁶. 9 CFU / g carrier.

[0011] Preferably, the Latin name of the *Pichia pastoris* is... Pichia kudriavzevii The accession number is CGMCC 2.124; the Latin name of the *Pseudomonas putida* is... Pseudomonas putida The accession number is CGMCC 1.1003; the Latin name of the heat-resistant Bacillus is... Bacillus thermotolerans The accession number is CGMCC1.2764; the Latin name of the *Bacillus sicca* is... Bacillus siamensis The accession number is 1.9076.

[0012] Preferably, the compound enzyme preparation comprises 2-4 parts of PET hydrolase, 2-3 parts of keratinase, 1-2 parts of PE degrading enzyme, 1-2 parts of PP degrading enzyme, and 0.5-1 parts of laccase, and the total enzyme activity of the compound enzyme preparation is 800-1200 U / g carrier.

[0013] Secondly, this application provides an application method based on any of the above-described composite degradation agents, the application method comprising the following steps: A1. Wastewater pretreatment: The wastewater to be treated is filtered through a bar screen and treated by coagulation and sedimentation to remove large particulate suspended solids and control the effluent SS ≤ 60 mg / L. A2. Introduce the pretreated wastewater into the degradation reaction tank, add the composite degradation agent, turn on the light module with a wavelength of 395-450nm, and carry out a continuous degradation reaction under the conditions of 25-40℃ and pH 6.0-8.0. A3. The effluent after the degradation reaction is magnetically separated to recover the photo-co-enzyme-bacteria composite degradation material. After regeneration treatment, it is recycled and reused. The separated effluent is discharged after deep sedimentation to meet the standards.

[0014] Preferably, in step A2, the dosage of the composite degradation agent is 0.5-3 g / L, and the light intensity of the light module is 50-200 mW / cm². 2.

[0015] Preferably, in step A2, the hydraulic retention time of the degradation reaction tank is 4-8 hours, and intermittent aeration is performed at 30-minute intervals during the reaction, with an air-to-water ratio of 5:1-10:1.

[0016] Preferably, in step A2, a phased illumination mode is adopted: first at 150-200mW / cm². 2 Irradiate with light intensity for 1-2 hours, then switch to 50-100 mW / cm². 2 The light intensity is continuous.

[0017] Compared with the prior art, this application includes at least the following technical effects: This solution constructs a protective isolation layer by encapsulating microcapsules to isolate the attack of photocatalytic free radicals on enzymes and bacteria, thus solving the core contradiction of the combined use of photocatalysis and biodegradation. It achieves spatial confinement integration and synergistic effect of the three functional units of photocatalysis, enzymatic hydrolysis and microbial degradation.

[0018] In this scheme, the rare earth-doped titanium-based porous framework extends the photoresponse from the ultraviolet region to the 395-450nm visible light region, and photocatalysis can be achieved using ordinary LED light sources, which greatly reduces the energy consumption of the photocatalytic process and avoids the high cost problem of deep ultraviolet light sources.

[0019] In this solution, the compound enzyme preparation covers target enzyme species for mainstream microplastics such as PET, PE, and PP. The compound microbial community achieves complementary degradation spectrum and metabolic synergy, which can cope with the complex pollution scenario of multiple microplastics coexisting in wastewater and break through the bottleneck of narrow degradation spectrum of single enzymes / bacteria.

[0020] In this solution, the enzymes and bacteria are encapsulated in microcapsules and cross-linked with the carrier for adsorption, which prevents them from being lost with the water during continuous treatment. At the same time, it improves the resistance to interference from fluctuations in wastewater pH and temperature and toxic impurities, resulting in high enzyme activity retention and adaptability to complex wastewater conditions.

[0021] The framework of this solution introduces a magnetic precursor, which imparts superparamagnetic properties to the formulation. It can be quickly and efficiently recovered through magnetic separation and recycled after simple regeneration, significantly reducing the dosage of the formulation and lowering the material and operating costs for engineering applications. Detailed Implementation

[0022] To make the objectives, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention are described in detail below with reference to examples. Several embodiments of the present invention are given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present invention will be more thorough and complete: This application provides a composite degradation agent for the degradation of microplastics in wastewater and its application method. In a first aspect, this application provides a composite degradation agent for the degradation of microplastics in wastewater, which is prepared by the following method: S1. Preparation of rare earth-doped titanium-based porous framework: Add titanium source, rare earth dopant source, magnetic precursor and soft template agent to solvent in proportion, stir evenly to obtain a homogeneous precursor solution, transfer the precursor solution to high pressure reactor, react at 140-180℃ for 6-12h, separate, wash and dry after cooling to obtain framework precursor, place framework precursor in inert atmosphere, calcine at 500-650℃ for 3-5h, cool and acid wash, wash to neutral, dry to obtain the rare earth-doped titanium-based porous framework. S2. Add the compound enzyme preparation and compound functional microbial agent to the chitosan-sodium alginate mixture in proportion, then add calcium-based diatomaceous earth, stir evenly at constant temperature to obtain the encapsulation precursor solution containing enzyme bacteria. S3. The enzyme-containing bacteria coating precursor solution is mixed with the rare earth-doped titanium-based porous photocatalytic framework, and calcium chloride crosslinking solution is added dropwise to complete the in-situ crosslinking. Simultaneously, the enzyme bacteria are microcapsule-encapsulated and the carrier is adsorbed and crosslinked to achieve co-fixation. After magnetic separation and low-temperature drying, the composite degradation preparation is obtained.

[0023] Specifically, in one embodiment, the preparation steps of the rare earth-doped titanium-based porous framework are as follows: adding a titanium source, a rare earth dopant source, a magnetic precursor, and a soft template agent to a solvent, and heating at 20-25°C and 400-600 r / min. Stir for 30-40 min to obtain a homogeneous and transparent precursor solution. Transfer the precursor solution to a high-pressure reactor lined with polytetrafluoroethylene, seal it, and heat it to 140-180℃. React at this temperature for 6-12 h. After the reaction, allow it to cool naturally to room temperature. Collect the solid product by magnetic separation, wash it three times with anhydrous ethanol and deionized water respectively, and dry it under vacuum at 60-80℃ for 6-8 h to obtain the framework precursor. Further, spread the framework precursor in a corundum boat, place it in a tubular atmosphere furnace, and introduce high-purity nitrogen as an inert protective gas. Heat it to 500-650℃ at a heating rate of 2-5℃ / min and calcine it at this temperature for 3-5 h. After calcination, allow it to cool naturally to room temperature, add the product to 0.5-1 mol / L dilute nitric acid, stir and acid wash for 30 min, collect the product by magnetic separation, wash it with deionized water until the washing solution is neutral, and dry it under vacuum at 60-80℃ for 4 h to obtain the rare earth-doped titanium-based porous framework.

[0024] Understandably, the framework preparation in this scheme employs a one-step hydrothermal method, where the soft template agent decomposes to form a through-porous structure, rare earth ions enter the titanium dioxide lattice to complete doping, and titanium dioxide forms a mixed crystal structure dominated by highly active anatase. Furthermore, it is understood that the hydrothermal method is a relatively conventional synthesis process, and its detailed process principle will not be further elaborated in this embodiment.

[0025] In this scheme, the rare-earth-doped titanium-based porous framework prepared in step S1 broadens the photoresponse range of pure titanium dioxide through rare-earth doping, extending the photoresponse from the ultraviolet region to the 395-450nm visible light region, significantly reducing photocatalytic energy consumption, while suppressing photogenerated carrier recombination and improving the generation efficiency of hydroxyl radicals. The introduction of magnetic precursors endows the framework with superparamagnetic properties, laying the foundation for subsequent magnetic separation and recycling. The hierarchical porous structure constructed by the soft template agent provides an ultra-large specific surface area, providing sufficient sites for enzyme and bacteria immobilization, while enhancing the mass transfer efficiency between wastewater and active sites. Step S2 constructs a biocompatible microcapsule wall material using a chitosan-sodium alginate mixture, and combines it with calcium-based diatomaceous earth to enhance the mechanical strength of the wall material. This achieves uniform dispersion of the complex enzyme and complex bacteria, avoiding aggregation and inactivation, and also constructs a preliminary protective barrier for the enzyme and bacteria. At the same time, it can enrich microplastics and degradation intermediates, increase the local reaction concentration, and enhance the degradation efficiency. The in-situ crosslinking and co-immobilization process in step S3 achieves two key benefits. First, the microcapsule shell forms a precise "protective isolation layer," isolating the enzymes and bacteria from photocatalytic free radical attacks and resolving the core contradiction of photo-biological synergy. Second, it enables the spatially confined integration of the three functional units—photocatalysis, enzymatic hydrolysis, and microbial degradation—on the same carrier. Simultaneously, the co-immobilized structure firmly anchors the enzymes and bacteria to the carrier, preventing loss with water during continuous treatment. This significantly improves the formulation's resistance to shock loads and operational stability. Combined with magnetic separation and recovery characteristics, the formulation can be recycled, greatly reducing engineering application costs and making it well-suited for the needs of large-scale continuous wastewater treatment.

[0026] In one embodiment, in step S1, the rare earth-doped titanium-based porous framework is prepared by the following mass fractions: 80-120 parts of titanium source, 3-10 parts of rare earth doping source, 5-15 parts of magnetic precursor, 10-20 parts of soft template agent, and 800-1200 parts of solvent. It is understood that the titanium source is the main crystallizing material of the framework. Insufficient titanium source will lead to poor formability and loose structure of the framework, which cannot withstand the hydraulic scouring during wastewater treatment and is prone to structural breakage. Excessive titanium source will lead to over-crystallization, a significant decrease in porosity, and a reduction in specific surface area. This will not only reduce the active sites for enzyme fixation but also block the photocatalytic active sites, reducing photon utilization efficiency. The dosage range of 80-120 parts can better balance the mechanical strength and porosity of the framework. Insufficient rare earth ion doping prevents the formation of effective impurity energy levels within the titanium dioxide bandgap, resulting in limited broadening of the photoresponse range and ineffective suppression of photogenerated carrier recombination, leading to minimal improvement in photocatalytic activity. Excessive rare earth ions form aggregates on the titanium dioxide surface, becoming recombination centers for photogenerated carriers and significantly reducing photocatalytic efficiency. They also clog porous channels, disrupting the hierarchical porous structure of the framework. In this solution, 3-10 parts of rare earth dopant source achieve a better balance. Insufficient magnetic components fail to impart adequate magnetic responsiveness to the framework, resulting in low subsequent recovery rates and higher costs. Excessive magnetic components coat the titanium dioxide surface, obscuring photocatalytic active sites and significantly reducing photon absorption efficiency. They also affect the titanium dioxide crystallization process, disrupting the formation of the porous framework. Insufficient soft template agent fails to form a uniform, interconnected hierarchical porous structure, resulting in insufficient framework specific surface area and limited enzyme fixation sites. Excessive agent can lead to framework collapse after calcination, a sharp drop in mechanical strength, and easy breakage and failure during wastewater treatment. If the precursor concentration is too high, local agglomeration is likely to occur, resulting in uneven distribution of the prepared framework components and strong performance fluctuations; if the precursor concentration is too low, the hydrothermal reaction nucleation efficiency is insufficient, and a complete porous framework structure cannot be formed.

[0027] Specifically, in one embodiment, the titanium source includes one of tetrabutyl titanate and isopropyl titanate; the rare earth dopant source includes one of cerium nitrate and praseodymium nitrate; the magnetic precursors are a mixture of ferric chloride hexahydrate and ferrous chloride tetrahydrate in a molar ratio of 2:1; the soft template agent includes hexadecyltrimethylammonium bromide; and the solvent includes a mixture of anhydrous ethanol and deionized water in a volume ratio of 4:1. It is understood that the titanium source is selected from tetrabutyl titanate or isopropyl titanate, both of which are titanium alkoxides. These alkoxides possess excellent solubility and a controllable hydrolysis rate in the ethanol-water mixed solvent, enabling slow and uniform crystallization nucleation during the hydrothermal reaction. This avoids agglomeration of titanium dioxide particles caused by excessively rapid hydrolysis, ensuring that rare earth ions and magnetic components can be uniformly doped into the titanium dioxide lattice or dispersed in the framework. The rare earth dopant source is selected from cerium nitrate or praseodymium nitrate, as the ionic radii of cerium and praseodymium ions are highly similar to those of titanium ions, allowing them to smoothly enter the titanium dioxide lattice to form substitutional doping. The magnetic precursor is a 2:1 molar ratio of ferric chloride hexahydrate and ferrous chloride tetrahydrate, which can generate superparamagnetic iron oxide nanoparticles in situ during the hydrothermal reaction. This eliminates the need for additional magnetic particle preparation and loading steps, achieving uniform dispersion of the magnetic component within the titanium-based framework in one step. This avoids the problems of active site shielding and particle detachment caused by subsequent loading. Furthermore, the prepared iron oxide has no remanence and does not aggregate after magnetic separation, facilitating regeneration and reuse. The soft template agent is hexadecyltrimethylammonium bromide (CTAB), a cationic surfactant that forms an ordered micelle structure in the hydrothermal system. This serves as a soft template to guide the directional growth and ordered stacking of titanium dioxide nanoparticles, resulting in a uniformly interconnected hierarchical porous structure after calcination.

[0028] Specifically, in one embodiment, the composite functional microbial agent comprises *Pichia pastoris*, *Pseudomonas putida*, *Bacillus thermophilus*, and *Bacillus sicca* in a ratio of (25-35):(20-30):(15-25):(15-25); the loading amount of the composite functional microbial agent in the carrier is (2-8)×10⁻⁶. 9CFU / g carrier; understandably, this scheme precisely defines the strain composition, quantity ratio, and carrier loading of the composite functional microbial agent, constructing a stable microbial community system with complementary degradation spectra, synergistic metabolism, and strong environmental resistance. This solves the problems of narrow degradation spectra, poor community synergy, and rapid activity decay in complex wastewater environments associated with existing microbial degradation technologies using single strains. *Pichia pastoris* possesses excellent hydrophobic surface binding capabilities, efficiently adsorbing and attaching to microplastic surfaces via extracellular polymers. It also secretes multiple enzyme systems such as esterases and lipases, efficiently degrading oligomers and monomers after the depolymerization of PET and PE. Furthermore, it exhibits good acid and alkali resistance, maintaining stable activity in complex wastewater conditions. This strain also demonstrated good high-temperature resistance during testing, coping with some extreme sudden temperature changes, demonstrating strong environmental adaptability. *Pseudomonas putida* is a dominant strain for organic pollutant degradation, secreting multiple hydrolytic and oxidoreductase enzymes. It can also enhance the colonization ability of the strain on the carrier by forming a biofilm, reducing loss with water. Thermoresistant Bacillus and Bacillus sicca exhibit excellent environmental resistance, maintaining stable metabolic activity under fluctuating wastewater temperature and pH conditions. Their secreted keratinase and lipase can directly attack microplastic molecular chains, enhancing degradation efficiency. Furthermore, this scheme involved extensive experimentation with various strain ratios. Under these ratios, the bacterial community exhibited no vicious nutrient competition, forming a stable symbiotic system. The bacterial loading rate was also determined through extensive experimentation. Insufficient strain numbers prevented rapid and deep mineralization of degradation products, resulting in insufficient microplastic mineralization. Conversely, excessive strain numbers not only failed to significantly improve performance but also led to excessive strain aggregation, preventing internal strains from obtaining nutrients and oxygen, resulting in mass mortality and activity decline. Simultaneously, it clogged the porous channels of the carrier, reducing mass transfer efficiency and exacerbating nutrient competition within the bacterial community, ultimately leading to a decrease in overall degradation performance.

[0029] Specifically, in one embodiment, the Latin name of *Pichia kudriezweig* is... Pichia Kudriavzevii The accession number is CGMCC 2.124; the Latin name of *Pseudomonas putida* is... Pseudomonas Putida The accession number is CGMCC 1.1003; the Latin name of the thermostable Bacillus is... Bacillus Thermotolerans The accession number is CGMCC1.2764; the Latin name of Bacillus sicca is... Bacillus Siamensis The accession number is 1.9076.

[0030] Understandably, the above-mentioned strains are all from the China General Microbiological Culture Collection Center, and can be easily obtained by those skilled in the art.

[0031] Specifically, in one embodiment, the composite enzyme preparation comprises 2-4 parts of PET hydrolase, 2-3 parts of keratinase, 1-2 parts of PE degrading enzyme, 1-2 parts of PP degrading enzyme, and 0.5-1 parts of laccase. The total enzyme activity of the composite enzyme preparation is 800-1200 U / g carrier. It is understood that this composite enzyme preparation covers the most common mainstream microplastics in wastewater, such as PET, PE, and PP, and introduces laccase as an auxiliary degradation agent, forming a comprehensive enzymatic hydrolysis system of "directed main chain cleavage + auxiliary oxidation modification + product inhibition and elimination." PET hydrolase can specifically hydrolyze the ester bonds in PET plastics, breaking the long PET chain into terephthalic acid and ethylene glycol monomers, making it the core enzyme for PET microplastic degradation. Keratinase has a broad-spectrum ester bond hydrolysis ability, which not only assists PET hydrolase in enhancing the degradation of polyester plastics but also attacks the amorphous regions of polyolefin plastics such as PE and PP, introducing polar groups such as hydroxyl and carboxyl groups onto the plastic surface, thus disrupting the density of the plastic. The structure provides attack sites for other degrading enzymes and can also degrade oligomers generated by plastic depolymerization; PE degrading enzymes and PP degrading enzymes are specific degrading enzymes for polyolefin plastics, which can specifically break the long carbon-carbon chains of PE and PP plastics, degrading the high-crystallinity polyolefin long chains into low-molecular-weight alkanes, fatty acids and other small molecule products, breaking through the industry bottleneck of the difficulty in biodegrading polyolefin microplastics; Laccase, as an oxidoreductase, can generate free radicals through single-electron oxidation reactions, which can not only oxidize and break plastic molecular chains, but also degrade toxic intermediates such as phenols and aromatics generated during enzymatic hydrolysis, eliminating product inhibition effects, and can also modify enzyme molecules to improve enzyme stability and prolong the activity retention time. PET hydrolase and keratinase, as core hydrolases, constitute a relatively high proportion, covering the degradation needs of most polyester microplastics, while also providing a pretreatment effect for the degradation of polyolefin microplastics. The ratio of PE degrading enzymes and PP degrading enzymes is matched to the degradation difficulty of polyolefin microplastics, specifically addressing the problem of difficult degradation of polyolefins. Laccase, as an auxiliary enzyme, can eliminate product inhibition and enhance degradation efficiency with low-dose addition, avoiding cost increases and enzyme activity waste caused by excessive addition. This scheme further limits the total enzyme activity of the compound enzyme preparation, and this range is well matched with the carrier's loading capacity, microplastic degradation needs, and microbial metabolic capacity.

[0032] This embodiment also provides an application method based on any of the above-described composite degradation agents, which includes the following steps: A1. Wastewater pretreatment: The wastewater to be treated is filtered through a bar screen and treated by coagulation and sedimentation to remove large particulate suspended solids and control the effluent SS ≤ 60 mg / L. A2. Introduce the pretreated wastewater into the degradation reaction tank, add the composite degradation agent, turn on the light module with a wavelength of 395-450nm, and carry out a continuous degradation reaction under the conditions of 25-40℃ and pH 6.0-8.0. A3. The effluent after the degradation reaction is magnetically separated to recover the photo-co-enzyme-bacteria composite degradation material. After regeneration treatment, it is recycled and reused. The separated effluent is discharged after deep sedimentation to meet the standards. Understandably, the wastewater pretreatment in step A1, through bar filtration and coagulation sedimentation to remove large suspended solids and control the effluent SS to ≤60mg / L, removes obstacles for the subsequent degradation reaction. Large suspended solids in the wastewater can block light, affecting the photon absorption efficiency of the photocatalytic unit. They can also clog the porous channels of the composite degradation agent, blocking the active sites of the enzymes, and can aggregate with microplastic particles, hindering sufficient contact between the degradation agent and the microplastics. Pretreatment to control SS below 60mg / L significantly reduces the interference of suspended solids on the degradation reaction, ensuring sufficient light penetration to the photocatalytic unit and adequate contact between the degradation agent and microplastic particles. This provides a good water quality foundation for efficient degradation, reduces physical wear on the agent from large particles, and extends the agent's lifespan. The core degradation reaction in step A2 involves introducing pretreated wastewater into a degradation reaction tank, adding a composite degradation agent, and activating a 395-450nm wavelength light module. Continuous degradation occurs at 25-40℃ and pH 6.0-8.0. These process parameters perfectly match the performance characteristics of the composite degradation agent: the 395-450nm light wavelength precisely matches the photoresponse range of the rare-earth-doped titanium-based porous framework, fully stimulating photocatalytic activity and generating a large number of hydroxyl radicals. This achieves highly efficient pretreatment for the destruction of highly crystalline microplastics. Furthermore, this wavelength range can be achieved using ordinary LED light sources, significantly reducing costs. The photocatalytic process avoids the high cost and energy consumption issues associated with deep ultraviolet light sources. The reaction temperature of 25-40℃ and the reaction conditions of pH 6.0-8.0 perfectly match the optimal enzyme activity range of the composite enzyme preparation and the optimal growth and metabolic conditions of the composite microorganisms, ensuring high enzyme activity and vigorous microbial metabolism. This avoids enzyme inactivation and microbial activity decline caused by deviations in reaction conditions. Furthermore, this temperature and pH range highly matches the discharge water quality characteristics of most industrial wastewater, domestic sewage, and aquaculture wastewater, eliminating the need for large-scale temperature and pH adjustments, significantly reducing operating costs and complexity. The magnetic separation and deep treatment in step A3 fully utilizes the magnetic response characteristics of the composite degradation agent, enabling rapid and efficient separation of the agent from the effluent. This avoids secondary pollution caused by agent loss with the effluent and significantly reduces agent addition costs during continuous operation. The recovered agent can regain its degradation activity through simple regeneration treatment, achieving recycling and further reducing operating costs.

[0033] Specifically, in one embodiment, in step A2, the dosage of the composite degradation agent is 0.5-3 g / L, and the light intensity of the light module is 50-200 mW / cm².2 Understandably, the dosage of the composite degradation agent is limited to 0.5-3 g / L. This range is highly compatible with the conventional concentration of microplastics in the wastewater, the hydraulic retention time in the degradation reaction tank, and the photon utilization efficiency of the photocatalytic unit. When the dosage is too low, the number of photocatalytic active sites, enzymatic active sites, and microorganisms in the system is insufficient, making it impossible to fully degrade microplastics in the wastewater. Even if the light intensity is increased, the insufficient number of photocatalytic carriers will result in insufficient photon utilization, leading to wasted light energy, and the degradation rate and mineralization of microplastics will not meet the treatment requirements. When the dosage is too high, excessive composite degradation agents will form aggregates in the reaction system, leading to an increase in turbidity and blocking light, preventing light from penetrating the water. When the light reaches various areas of the reaction tank, the formulation inside cannot be excited by light, and the photocatalytic activity cannot be exerted, resulting in waste of the formulation. At the same time, excessive formulation will aggravate the consumption of oxygen and nutrients in the system, leading to a decrease in the metabolic activity of microorganisms. This will prevent the overall degradation efficiency from improving linearly and will also significantly increase the processing cost. When the light intensity is too low, the generation efficiency of photogenerated charge carriers is low, and the number of hydroxyl radicals generated is insufficient to effectively destroy the dense molecular structure of highly crystalline microplastics. The photocatalytic pretreatment effect is insufficient, resulting in a significant decrease in the efficiency of subsequent enzymatic hydrolysis and microbial degradation. When the light intensity is too high, it will not only fail to achieve a linear improvement in performance, but will also increase energy consumption, causing unnecessary energy waste and increasing the cost of engineering operation.

[0034] Specifically, in one embodiment, the hydraulic retention time of the degradation reaction tank is 4-8 hours, and intermittent aeration is performed at 30-minute intervals during the reaction process, with an air-to-water ratio of 5:1-10:1.

[0035] Specifically, in one embodiment, in step A2, a phased illumination mode is adopted: first at 150-200 mW / cm². 2 Irradiate with light intensity for 1-2 hours, then switch to 50-100 mW / cm². 2 Continuous illumination with high light intensity is appropriate. Understandably, the biodegradation of microplastics involves a rate-limiting step: the dense molecular structure and strong hydrophobicity of highly crystalline microplastics make it difficult for enzymes and microorganisms to attach and attack them, thus constituting the rate-limiting stage of the entire degradation process. A staged illumination mode precisely matches the degradation kinetics of microplastics, effectively overcoming this rate-limiting bottleneck. The first stage of this scheme uses 150-200 mW / cm² light. 2High-intensity light irradiation for 1-2 hours constitutes the photocatalytic pretreatment stage for microplastics. This stage rapidly stimulates the photocatalytic activity of the rare-earth-doped titanium-based porous framework, generating a large number of hydroxyl radicals in a short time. These highly oxidizing free radicals quickly attack the surface and molecular chains of the microplastics, introducing polar groups such as hydroxyl and carboxyl groups onto the surface. This disrupts the dense crystalline structure of the microplastics, significantly reducing their crystallinity and hydrophobicity, thus overcoming the rate-limiting bottleneck of microplastic biodegradation. This provides numerous attackable sites and suitable interfacial conditions for the subsequent targeted hydrolysis of compound enzymes and the attachment and metabolism of microorganisms. Simultaneously, the short-duration high-intensity light irradiation rapidly oxidizes and decomposes toxic and harmful pollutants in wastewater, preventing these pollutants from inhibiting the toxicity of enzymes and microorganisms, and providing a favorable reaction environment for subsequent enzymatic hydrolysis and microbial degradation. More importantly, this stage lasts only 1-2 hours. This short period of high-intensity light irradiation will not negatively affect the enzymes and bacteria encapsulated in the microcapsules. The shell structure of the microcapsules can completely isolate the excessive hydroxyl radicals generated under high light intensity, protecting the enzyme's active sites and the microbial cell structure from attack, effectively avoiding the problem of enzyme inactivation caused by high light intensity. The second stage switches to 50-100 mW / cm². 2 The low-intensity continuous irradiation is the photo-assisted enzymatic-microbial deep degradation stage. During this stage, the low light intensity maintains the photocatalytic framework's continuous generation of low-concentration hydroxyl radicals. On one hand, this allows for continued slow oxidation of the pretreated microplastics, assisting the enzymatic hydrolysis process in further breaking down the plastic molecular chains. On the other hand, it sustainably oxidizes and decomposes toxic intermediates generated during enzymatic hydrolysis and microbial metabolism, eliminating product inhibition effects and ensuring the continuous and efficient progress of enzymatic hydrolysis and microbial metabolism. Simultaneously, the low light intensity does not generate excessive amounts of strong oxidizing free radicals, maintaining high enzyme activity and vigorous microbial metabolism for a long period, achieving continuous deep degradation and complete mineralization of microplastics. Furthermore, continuous low-intensity irradiation significantly reduces the operating energy consumption of the irradiation module. Compared to continuous high-intensity irradiation, this effectively reduces light energy consumption and significantly lowers the operating costs of the process. Example 1

[0036] This embodiment provides a composite degradation agent for the degradation of microplastics in wastewater, which is prepared by the following method: S1. Preparation of rare earth-doped titanium-based porous framework: Add titanium source, rare earth dopant source, magnetic precursor and soft template agent to solvent in proportion, stir evenly to obtain a homogeneous precursor solution, transfer the precursor solution to high pressure reactor, react at 160℃ for 9h, cool, separate, wash and dry to obtain framework precursor, place framework precursor in inert atmosphere, calcine at 680℃ for 4h, cool, acid wash, wash until neutral, dry to obtain the rare earth-doped titanium-based porous framework. S2. Add the compound enzyme preparation and compound functional microbial agent to the chitosan-sodium alginate mixture in proportion, then add calcium-based diatomaceous earth, stir evenly at constant temperature to obtain the encapsulation precursor solution containing enzyme bacteria. S3. Mix the enzyme-containing bacteria coating precursor solution with the rare earth-doped titanium-based porous photocatalytic framework, add calcium chloride crosslinking solution dropwise to complete in-situ crosslinking, and simultaneously achieve microcapsule embedding of enzyme bacteria and carrier adsorption crosslinking co-fixation. After magnetic separation and low-temperature drying, the composite degradation preparation is obtained. The composition includes 100 parts titanium source, 6 parts rare earth doped source, 10 parts magnetic precursor, 15 parts soft template agent, and 1000 parts solvent. The titanium source is tetrabutyl titanate; the rare earth doping source is cerium nitrate; the magnetic precursor is a mixture of ferric chloride hexahydrate and ferrous chloride tetrahydrate in a molar ratio of 2:1; the soft template agent includes hexadecyltrimethylammonium bromide; the solvent includes a mixture of anhydrous ethanol and deionized water in a volume ratio of 4:1. The compound functional microbial agent contains *Pichia pastoris*, *Pseudomonas putida*, *Bacillus thermosus*, and *Bacillus sicca* in a ratio of 6:5:4:4; the loading of the compound functional microbial agent in the carrier is 5 × 10⁻⁶. 9 CFU / g carrier; The compound enzyme preparation contains 3 parts PET hydrolase, 2 parts keratinase, 1 part PE degrading enzyme, 1 part PP degrading enzyme, and 0.5 parts laccase. The total enzyme activity of the compound enzyme preparation is 1000 U / g carrier. Example 2

[0037] This embodiment provides a composite degradation agent for the degradation of microplastics in wastewater, which is prepared by the following method: S1. Preparation of rare earth-doped titanium-based porous framework: Add titanium source, rare earth dopant source, magnetic precursor and soft template agent to solvent in proportion, stir evenly to obtain a homogeneous precursor solution, transfer the precursor solution to high pressure reactor, react at 140℃ for 12h, cool, separate, wash and dry to obtain framework precursor, place framework precursor in inert atmosphere, calcine at 500℃ for 5h, cool, acid wash, wash until neutral, dry to obtain the rare earth-doped titanium-based porous framework. S2. Add the compound enzyme preparation and compound functional microbial agent to the chitosan-sodium alginate mixture in proportion, then add calcium-based diatomaceous earth, stir evenly at constant temperature to obtain the encapsulation precursor solution containing enzyme bacteria. S3. Mix the enzyme-containing bacteria coating precursor solution with the rare earth-doped titanium-based porous photocatalytic framework, add calcium chloride crosslinking solution dropwise to complete in-situ crosslinking, and simultaneously achieve microcapsule embedding of enzyme bacteria and carrier adsorption crosslinking co-fixation. After magnetic separation and low-temperature drying, the composite degradation preparation is obtained. The composition includes 80 parts of titanium source, 3 parts of rare earth doped source, 5 parts of magnetic precursor, 20 parts of soft template agent, and 800 parts of solvent. The titanium source is isopropyl titanate; the rare earth doping source is cerium nitrate; the magnetic precursor is a mixture of ferric chloride hexahydrate and ferrous chloride tetrahydrate in a molar ratio of 2:1; the soft template agent includes hexadecyltrimethylammonium bromide; the solvent includes a mixture of anhydrous ethanol and deionized water in a volume ratio of 4:1. The compound functional microbial agent contains *Pichia pastoris*, *Pseudomonas putida*, *Bacillus thermosus*, and *Bacillus sicca* in a ratio of 5:6:3:5; the loading of the compound functional microbial agent in the carrier is 3 × 10⁻⁶. 9 CFU / g carrier; The compound enzyme preparation contains 4 parts of PET hydrolase, 3 parts of keratinase, 2 parts of PE degrading enzyme, 2 parts of PP degrading enzyme, and 1 part of laccase. The total enzyme activity of the compound enzyme preparation is 1200 U / g carrier. Example 3

[0038] This embodiment provides a composite degradation agent for the degradation of microplastics in wastewater, which is prepared by the following method: S1. Preparation of rare earth-doped titanium-based porous framework: Add titanium source, rare earth dopant source, magnetic precursor and soft template agent to solvent in proportion, stir evenly to obtain a homogeneous precursor solution, transfer the precursor solution to high pressure reactor, react at 180℃ for 6h, cool, separate, wash and dry to obtain framework precursor, place framework precursor in inert atmosphere, calcine at 650℃ for 3h, cool, acid wash, wash until neutral, dry to obtain the rare earth-doped titanium-based porous framework. S2. Add the compound enzyme preparation and compound functional microbial agent to the chitosan-sodium alginate mixture in proportion, then add calcium-based diatomaceous earth, stir evenly at constant temperature to obtain the encapsulation precursor solution containing enzyme bacteria. S3. Mix the enzyme-containing bacteria coating precursor solution with the rare earth-doped titanium-based porous photocatalytic framework, add calcium chloride crosslinking solution dropwise to complete in-situ crosslinking, and simultaneously achieve microcapsule embedding of enzyme bacteria and carrier adsorption crosslinking co-fixation. After magnetic separation and low-temperature drying, the composite degradation preparation is obtained. The composition includes 120 parts of titanium source, 10 parts of rare earth doped source, 15 parts of magnetic precursor, 10 parts of soft template agent, and 1200 parts of solvent. The titanium source is tetrabutyl titanate; the rare earth doping source is cerium nitrate; the magnetic precursor is a mixture of ferric chloride hexahydrate and ferrous chloride tetrahydrate in a molar ratio of 2:1; the soft template agent includes hexadecyltrimethylammonium bromide; the solvent includes a mixture of anhydrous ethanol and deionized water in a volume ratio of 4:1. The compound functional microbial agent contains *Pichia pastoris*, *Pseudomonas putida*, *Bacillus thermosus*, and *Bacillus sicca* in a ratio of 7:4:5:3; the loading of the compound functional microbial agent in the carrier is 7 × 10⁻⁶. 9 CFU / g carrier; The compound enzyme preparation contains 2 parts of PET hydrolase, 2 parts of keratinase, 1 part of PE degrading enzyme, 1 part of PP degrading enzyme, and 0.5 parts of laccase. The total enzyme activity of the compound enzyme preparation is 800 U / g carrier. Comparative Example 1

[0039] This comparative example provides a composite degradation agent for the degradation of microplastics in wastewater. This comparative example is basically the same as Example 1, except that Pichia kudricazwieldii is not added in this comparative example. Comparative Example 2

[0040] This comparative example provides a composite degradation agent for the degradation of microplastics in wastewater. This comparative example is basically the same as Example 1, except that Bacillus sicca is not added in this comparative example. Comparative Example 3

[0041] This comparative example provides a composite degradation agent for the degradation of microplastics in wastewater. This comparative example is basically the same as Example 1, except that laccase is not added in this comparative example. Example 4

[0042] This embodiment applies the composite degradation agent prepared in Comparative Example 1. The application method includes the following steps: A1. Wastewater pretreatment: The wastewater to be treated is filtered through a bar screen and treated by coagulation and sedimentation to remove large particulate suspended solids and control the effluent SS ≤ 60 mg / L. A2. The pretreated wastewater is introduced into the degradation reaction tank, the composite degradation agent is added, and the 420nm wavelength light module is turned on. A continuous degradation reaction is carried out at 32℃ and pH 6.8. The hydraulic retention time in the degradation reaction tank is 6 hours. Intermittent aeration is performed at 30-minute intervals during the reaction, with an air-to-water ratio of 8:1. A staged illumination mode is adopted: initially at 175mW / cm². 2 The light intensity was irradiated for 1.5 hours, then switched to 75mW / cm². 2 Continuous illumination with high light intensity; A3. The effluent after the degradation reaction is magnetically separated to recover the photo-co-enzyme-bacteria composite degradation material. After regeneration treatment, it is recycled and reused. The separated effluent is discharged after deep sedimentation to meet the standards. Example 5

[0043] This embodiment is basically the same as that of embodiment 4, except that the application method provided in this embodiment is based on the composite degradation agent prepared in embodiment 2. Example 6

[0044] This embodiment is basically the same as Example 4, except that the application method provided in this embodiment is based on the composite degradation agent prepared in Example 3. Comparative Example 4

[0045] This comparative example is basically the same as Example 4, except that the application method provided in this comparative example is based on the composite degradation agent prepared in Comparative Example 1. Comparative Example 5

[0046] This comparative example is basically the same as Example 4, except that the application method provided in this comparative example is based on the composite degradation agent prepared in Comparative Example 2. Comparative Example 6

[0047] This comparative example is basically the same as Example 4, except that the application method provided in this comparative example is based on the composite degradation agent prepared in Comparative Example 3. Comparative Example 7

[0048] This comparative example is basically the same as Example 4, except that in step A2 of this comparative example, a light module with a wavelength of 365nm is used. Comparative Example 8

[0049] This comparative example is basically the same as Example 4, except that the aeration process is not added in step A2 of this comparative example. Comparative Example 9

[0050] This comparative example is basically the same as Example 4, except that in step A2 of this comparative example, continuous illumination of 175mW / cm² is used. 2 Light intensity and illumination.

[0051] The water bodies in Examples 4-6 and Comparative Examples 4-9 were tested, and the specific results are as follows: (1) Microplastic removal rate: Test standard: GB / T39304-2020 Determination of microplastics in water by micro-counting method.

[0052] Detection method: Take wastewater samples before and after treatment, and enrich microplastics by negative pressure filtration through a 0.45μm filter membrane; place the filter membrane under a microscope, identify and count the number of PET, PE and PP microplastics according to their morphology (particulate, fibrous, etc.); calculate the removal rate of each type and the total removal rate according to "(number before treatment - number after treatment) / number before treatment × 100%".

[0053] (2) Enzyme activity retention rate: Detection standard: GB / T23195-2008 "Determination of amylase value in honey by ultraviolet spectrophotometry" Detection method: Take a sample of mesoporous magnetic immobilized material, add the corresponding substrate (PET powder, PP emulsion, etc.), and react for 1 h at 38℃ and pH 7.0; centrifuge and collect the supernatant, and use a UV spectrophotometer to detect the absorbance of the product (such as terephthalic acid, short-chain fatty acid) at the characteristic wavelength (240-280nm); calculate the enzyme activity by referring to the enzyme activity standard curve, and express it as "U / g carrier".

[0054] (3) Effluent COD: Detection standard: HJ828-2017 Determination of Chemical Oxygen Demand in Water by dichromate method; Detection method: Take the supernatant after precipitation treatment, add potassium dichromate digestion solution, and digest at 165℃ for 2h; after cooling, titrate with ferrous ammonium sulfate standard solution, calculate the COD value based on the volume consumed, and express the degree of organic pollution in the effluent as "mg / L".

[0055] The test results are shown below: It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0056] The above description is merely a preferred embodiment of this application and is not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application shall fall within the scope of the technical solution of this application.

Claims

1. A composite degradation agent for the degradation of microplastics in wastewater, characterized in that: The composite degradation agent is prepared by the following method: S1. Preparation of rare earth-doped titanium-based porous framework: Add titanium source, rare earth dopant source, magnetic precursor and soft template agent to solvent in proportion, stir evenly to obtain a homogeneous precursor solution, transfer the precursor solution to high pressure reactor, react at 140-180℃ for 6-12h, separate, wash and dry after cooling to obtain framework precursor, place framework precursor in inert atmosphere, calcine at 500-650℃ for 3-5h, cool and acid wash, wash to neutral, dry to obtain the rare earth-doped titanium-based porous framework. S2. Add the compound enzyme preparation and compound functional microbial agent to the chitosan-sodium alginate mixture in proportion, then add calcium-based diatomaceous earth, stir evenly at constant temperature to obtain the encapsulation precursor solution containing enzyme bacteria. S3. The enzyme-containing bacteria coating precursor solution is mixed with the rare earth-doped titanium-based porous photocatalytic framework, and calcium chloride crosslinking solution is added dropwise to complete the in-situ crosslinking. Simultaneously, the enzyme bacteria are microcapsule-encapsulated and the carrier is adsorbed and crosslinked to achieve co-fixation. After magnetic separation and low-temperature drying, the composite degradation preparation is obtained.

2. The composite degradation agent according to claim 1, characterized in that: In step S1, the rare earth-doped titanium-based porous framework is prepared by the following mass fractions: 80-120 parts of titanium source, 3-10 parts of rare earth doping source, 5-15 parts of magnetic precursor, 10-20 parts of soft template agent, and 800-1200 parts of solvent.

3. The composite degradation agent according to claim 2, characterized in that: The titanium source includes one of tetrabutyl titanate and isopropyl titanate; the rare earth doping source includes one of cerium nitrate and praseodymium nitrate; the magnetic precursor is a mixture of ferric chloride hexahydrate and ferrous chloride tetrahydrate in a molar ratio of 2:1; the soft template agent includes hexadecyltrimethylammonium bromide; and the solvent includes a mixture of anhydrous ethanol and deionized water in a volume ratio of 4:

1.

4. The composite degradation agent according to claim 1, characterized in that: The composite functional microbial agent contains *Pichia pastoris*, *Pseudomonas putida*, *Bacillus thermophilus*, and *Bacillus sicca*, in a ratio of (25-35):(20-30):(15-25):(15-25); the loading amount of the composite functional microbial agent in the carrier is (2-8)×10⁻⁶. 9 CFU / g carrier.

5. The composite degradation agent according to claim 4, characterized in that: The Latin name of the aforementioned Pichia kudriezweig is Pichia kudriavzevii The accession number is CGMCC 2.124; the Latin name of the *Pseudomonas putida* is... Pseudomonas putida The accession number is CGMCC 1.1003; the Latin name of the heat-resistant Bacillus is... Bacillus thermotolerans The accession number is CGMCC1.2764; the Latin name of the *Bacillus sicca* is... Bacillus siamensis The accession number is 1.9076.

6. The composite degradation agent according to claim 1, characterized in that: The compound enzyme preparation contains 2-4 parts of PET hydrolase, 2-3 parts of keratinase, 1-2 parts of PE degrading enzyme, 1-2 parts of PP degrading enzyme, and 0.5-1 parts of laccase. The total enzyme activity of the compound enzyme preparation is 800-1200 U / g carrier.

7. A method for applying the composite degradation agent according to any one of claims 1-6, characterized in that: The application method includes the following steps: A1. Wastewater pretreatment: The wastewater to be treated is filtered through a bar screen and treated by coagulation and sedimentation to remove large particulate suspended solids and control the effluent SS ≤ 60 mg / L. A2. Introduce the pretreated wastewater into the degradation reaction tank, add the composite degradation agent, turn on the light module with a wavelength of 395-450nm, and carry out a continuous degradation reaction under the conditions of 25-40℃ and pH 6.0-8.

0. A3. The effluent after the degradation reaction is magnetically separated to recover the photo-co-enzyme-bacteria composite degradation material. After regeneration treatment, it is recycled and reused. The separated effluent is discharged after deep sedimentation to meet the standards.

8. The application method according to claim 7, characterized in that: In step A2, the dosage of the composite degradation agent is 0.5-3 g / L, and the light intensity of the light module is 50-200 mW / cm². 2 .

9. The application method according to claim 7, characterized in that: In step A2, the hydraulic retention time in the degradation reaction tank is 4-8 hours, and intermittent aeration is performed at 30-minute intervals during the reaction process, with an air-to-water ratio of 5:1-10:

1.

10. The application method according to claim 7, characterized in that: In step A2, a phased illumination mode is adopted: first at 150-200mW / cm². 2 Irradiate with light intensity for 1-2 hours, then switch to 50-100 mW / cm². 2 The light intensity is continuous.