49 results about "Crosslinked chitosan" patented technology

The invention relates to the technical field of functional materials, in particular to a chitosan nanocapsule as well as a preparation method and application thereof. The preparation method of the chitosan nanocapsule comprises the following steps: (a) mixing and emulsifying a chitosan solution, an oil-in-water emulsifier and essential oil to form an oil-in-water emulsion, adding an aqueous solution of sodium tripolyphosphate into the oil-in-water emulsion, and stirring to obtain a first mixture; (b) adding the first mixture into an oil phase solvent containing a water-in-oil emulsifier, and stirring to obtain a multiple emulsion; and (c) adding an aqueous solution of a dialdehyde cross-linking agent into the multiple emulsion, carrying out a cross-linking reaction, collecting a solid-phase substance, and drying. The physical / chemical double-crosslinking chitosan nanocapsule is obtained by utilizing physical crosslinking between the chitosan and the sodium tripolyphosphate and chemical crosslinking between the chitosan and the binary aldehyde crosslinking agent, so that the encapsulation efficiency and the encapsulation efficiency of the nanocapsule are remarkably improved; meanwhile, the nanocapsule also has pH responsiveness and has a slow release effect after pH response.

The present invention describes capsule compositions consisting of crosslinked chitosan, beta-glucan or alginate, and encapsulates an environmentally compatible insecticide, especially larvicidal agents such as essential oils or essential oil components or other ingestible larvicides such as Bacillus thuringiensis which are lethal to the larvae and adults of pest insects, especially mosquito larvae.

The invention provides a chitosan composite material and a compound feed additive, and relates to the technical field of feed additives. The chitosan composite material comprises cross-linked chitosan and a porous carrier, the cross-linked chitosan is coated on the surface of the porous carrier; the porous carrier comprises a first porous carrier and a second porous carrier, the average particle size of the first porous carrier is 80-150 [mu] m, and the average particle size of the second porous carrier is 10-30 [mu] m. The chitosan composite material disclosed by the invention has relatively good heavy metal ion adsorption performance and can be used as a feed additive.

This invention relates to a lint free absorbent wound dressing, comprising a plasticized blend of a natural biopolymer and poly vinyl alcohol mixed in an acidic solvent which is neutralized and crosslinked using green crosslinking buffer system, finding application in exudating and bleeding wounds.

The application provides a long-acting, non-embolism filling monodisperse chitosan microsphere, the base material of the microsphere is cross-linked chitosan, the cross-linked chitosan is formed by cross-linking reaction of component A and a cross-linking agent, or formed by cross-linking reaction of component A, component B and the cross-linking agent; the component A is at least one of chitosan and modified chitosan, and the component B is at least one of hyaluronic acid, collagen and gelatin; the particle size of the microsphere is 20-120 mu m, and the variation coefficient of the microsphere particle size is not more than 5%. The application also provides a preparation method of the microsphere. The monodispersity of the microsphere is excellent, the degradation time is relatively longer, the water absorption performance is good, the embolism risk can be reduced, the filling effect maintaining time can be prolonged, and the effect of improving wrinkles can be increased, and the problems of short filling effect maintaining time and easy to cause blood vessel embolism of the filling hyaluronic acid product used in the existing medical and beauty field can be solved.

The present invention describes capsule compositions consisting of crosslinked chitosan, beta-glucan or alginate, and encapsulates an environmentally compatible ingestible larvicide, especially larvicidal agents such as essential oils or other ingestible larvicides such as Bacillus thuringiensis which are lethal to the larvae of pest insects, especially mosquito larvae.

The invention discloses a preparation method of a super-hydrophilic-underwater super-oleophobic oil-water separation material. The preparation method comprises the following steps: dissolving polyacrylonitrile and cellulose powder in an organic solvent, and mixing and stirring to obtain a spinning solution; standing the spinning solution, defoaming, carrying out electrostatic spinning on the defoamed spinning solution, and drying after spinning to obtain a polyacrylonitrile cellulose nano composite membrane; the preparation method comprises the following steps: preparing a chitosan cross-linking solution, dipping the polyacrylonitrile cellulose nano-composite membrane in the chitosan cross-linking solution, coating chitosan, cleaning and drying after dipping, and finally obtaining a super-hydrophilic-underwater super-oleophobic oil-water separation material, namely the polyacrylonitrile cellulose cross-linked chitosan composite membrane. The super-hydrophilic-underwater super-oleophobic oil-water separation material prepared by the invention has the advantages of long-acting stability, high flux, high separation efficiency, emulsified oil adaptability and simple and convenient process, and has relatively high flux and separation efficiency of 99% or above for various oil-water emulsions and oil-water emulsions with different concentrations.

The invention belongs to the field of photoelectric materials, and particularly relates to a silver nanowire composite citric acid cross-linked chitosan transparent conductive film and a preparation method thereof. The preparation method comprises the following steps: sequentially adding chitosan, citric acid and deionized water into a beaker, uniformly stirring, sequentially adding acetic acid and glycerol, continuously stirring, and reacting under a high-temperature condition to obtain a citric acid cross-linked chitosan solution; pET is cleaned and dried, then the silver nanowire suspension liquid is evenly sprayed on the surface of PET, and a silver nanowire / PET conductive film is obtained; and coating the citric acid cross-linked chitosan solution on the surface of the silver nanowire / PET conductive thin film, drying, and then stripping the thin film from PET. The silver nanowires on the conductive film have a grid structure, citric acid cross-linked chitosan is used as the substrate of the conductive film, the obtained conductive film has excellent heat resistance, light transmission and conductivity, and the preparation method is simple and easy to implement, free of toxic and side raw materials, safe and environmentally friendly.

The application discloses a finishing method of chitosan fiber and chitosan fiber prepared by the method, and comprises the following steps: preparing an acid aqueous solution of an anionic polyelectrolyte, adding a crosslinking agent and stirring uniformly, pre-crosslinking, and obtaining a pre-crosslinked chitosan fiber finishing solution; immersing formed chitosan fiber into the pre-crosslinked chitosan fiber finishing solution for soaking, drying and heat-crosslinking, and immersing into ethanol, and obtaining finished chitosan fiber. The application utilizes the property that chitosan fiber is activated into a cationic electrolyte under an acid condition, and an anionic polyelectrolyte is strongly adsorbed on the surface of the chitosan fiber through electrostatic interaction, effectively solves the problem that the interaction force between a sizing agent and other finishing agents and the chitosan fiber is weak, and effectively avoids the problem that the mechanical property of the chitosan fiber is poor due to the falling-off of the finishing agents and the sizing agent during use.

The invention discloses a bi-crosslinked chitosan derivative antioxidant hydrogel as well as a preparation method and application thereof. The structure of the hydrogel comprises chitosan modified by 2, 3-dihydroxybenzoic acid and phosphate, and the chitosan modified by 2, 3-dihydroxybenzoic acid and the phosphate are combined through electrostatic interaction; and in the hydrogel, a crystalline region exists in at least partial region of the 2, 3-dihydroxybenzoic acid modified chitosan. The hydrogel provided by the invention is excellent in biocompatibility, high in antioxidant stability and remarkable in blood coagulation activity, has multiple free radical scavenging ability, can inhibit macrophage M1 type polarization activity, promote angiogenesis and regulate granulation tissue regeneration, and finally realizes the effect of promoting chronic wound healing. The composition is applied to the field of chronic wound treatment, and can promote regeneration of granulation tissues of chronic wounds and angiogenesis by removing ROS (reactive oxygen species) on the wounds and regulating and controlling the oxidative stress level of the wounds, so that the healing process of the chronic wounds is accelerated.

The invention belongs to the technical field of biology, and particularly relates to a bacteriostatic agent and a preparation method and application thereof. Comprising the following steps that antibacterial peptide modified silver nanoparticles are prepared, specifically, antibacterial peptide and silver nitrate grow in situ under the action of a reducing agent, and the antibacterial peptide modified silver nanoparticles are obtained; preparing a bacteriostatic agent: dissolving the antibacterial peptide modified silver nanoparticles by using a cross-linked substance of chitosan and dextran sulfate to obtain the bacteriostatic agent; the charge of the cross-linked substance of the chitosan and the dextran sulfate is 0. Through mutual attraction of positive charges of the antibacterial peptide and negative charges of the silver nanoparticles, the silver nanoparticles wrapped by the antibacterial peptide are formed, the self-assembly or irregular agglomeration behavior of the antibacterial peptide is effectively controlled, a nanometer network formed by crosslinking chitosan with dextran sulfate can stabilize the nanometer form of the silver nanoparticles, and the antibacterial activity of the antibacterial peptide is improved. The core-shell structure formed by the silver nanoparticles wrapped by the antibacterial peptide can be stabilized, the silver nanoparticles wrapped by the antibacterial peptide can also be dispersed, and mutual agglomeration of the core-shell structure is prevented.

The application discloses a high-transparency PET film resistant to steaming and cooking and a preparation method thereof, and belongs to the technical field of PET films. The preparation method comprises the following steps: preparing a filler, preparing a high-barrier additive, preparing a coating liquid, processing, coating and vacuum evaporation. The preparation of the filler comprises the following steps: coating cross-linked chitosan and adsorbing sodium carboxymethyl cellulose. The preparation of the high-barrier additive comprises the following steps: adsorbing magnesium citrate, adsorbing polyvinyl alcohol and adsorbing magnesium ions. The PET film prepared by the application has excellent resistance to steaming and cooking, high transparency, high barrier property and high flatness, does not need to use organic solvents in the preparation, and the coating in the PET film has strong bonding force and no defects on the surface.

The present invention discloses an adsorbent for removing excess hepcidin and a preparation method thereof. The adsorbent for removing excess hepcidin is made by using EDTA as a cross-linking agent to form cross-linked chitosan microspheres embedded with zirconium phosphate and / or zirconium oxide, and L-glutathione is bonded to the surface of the cross-linked chitosan microspheres. The adsorbent for removing excess hepcidin of the present invention uses chitosan microspheres as a carrier, and while the microspheres are cross-linked, further bonding ligands are introduced, eliminating the need for additional cross-linking agents and ligands. The reaction conditions are mild, the preparation method is simple, and the cross-linked microspheres have suspended carboxyl groups, which can be further coupled with peptides and amino acids to achieve functional modification. The microspheres can withstand high-temperature steam sterilization and effectively remove excess hepcidin and urea nitrogen from the blood.

The invention discloses a herba leonuri exosome-loaded hydrogel drug delivery system and a preparation method and application thereof, and relates to the technical field of medical materials, the drug delivery system comprises hydrogel and herba leonuri exosomes; cefotaxime is wrapped in the motherwort exosome; the hydrogel is prepared by crosslinking chitosan and sodium beta-glycerophosphate. The invention further discloses a preparation method of the drug delivery system and application of the drug delivery system in preparation of drugs for treating endometritis. Through double-layer entrapment slow release of the exosome and the temperature-sensitive hydrogel, the retention time of the cefotaxime in vivo is prolonged, the problem that the half-life period of the cefotaxime is short is solved, synergistic interaction is achieved through the anti-inflammatory effect of the motherwort exosome and the cefotaxime, the antibacterial effect is enhanced, and the temperature-sensitive hydrogel has high application value in treatment of endometritis.

The invention belongs to the field of functional materials and water treatment, and provides a preparation method of organic phosphonic acid functionalized super-crosslinked chitosan hydrogel, which comprises the following steps: dissolving chitosan in an alkali solution to obtain a chitosan suspension; adding benzaldehyde into the chitosan suspension, and carrying out condensation reaction to obtain a modified chitosan suspension; reacting the modified chitosan suspension with a quinary organic phosphonic acid solution to obtain an organic phosphonic acid functionalized chitosan solution; adding a potassium tripolyphosphate solution into the organic phosphonic acid functionalized chitosan solution, carrying out a cross-linking reaction, carrying out alcohol precipitation after the reaction is completed, carrying out solid-liquid separation, and collecting a precipitate; dispersing the precipitate in water to obtain a suspension; and uniformly mixing the suspension with a sodium alginate solution and a calcium salt solution, and carrying out a cross-linking reaction to obtain the quinary organic phosphonic acid functionalized super-crosslinked chitosan hydrogel. An organic phosphonic acid group and a C-P covalent bond are successfully introduced into a chitosan molecular chain, the morphology structure of original chitosan powder is greatly improved, adsorption sites on the chitosan molecular chain are enriched, and efficient application of chitosan in uranium-containing wastewater is remarkably improved.

The application belongs to the technical field of pharmaceutical preparations, and particularly relates to a diclofenac sodium enteric-coated tablet and a preparation method thereof. The diclofenac sodium enteric-coated tablet comprises a quick-release layer, a slow-release layer and an enteric-coated layer; the quick-release layer comprises the following components in parts by weight: 20-40 parts of diclofenac sodium, 5-15 parts of a disintegrating agent, 20-50 parts of a filling agent, 1-3 parts of a lubricant and 1-5 parts of a binder; the slow-release layer comprises the following components in parts by weight: 50-80 parts of diclofenac sodium, 5-15 parts of crosslinked chitosan, 1-3 parts of a lubricant and 1-5 parts of a binder; and the enteric-coated layer comprises the following components in parts by weight: 20-45 parts of an enteric material and 5-15 parts of N-acetylneuraminic acid derivative. The diclofenac sodium enteric-coated tablet has excellent in-vitro cumulative release degree, and has low hygroscopicity, high stability and high friability.

The invention discloses a high-elasticity polyester-cotton blended fabric and a preparation process thereof, and belongs to the technical field of blended fabrics. The fabric comprises cross-linked cotton fibers and aminated polyester fibers; the cross-linked cotton fibers are oxidized cotton fibers jointly cross-linked by chitosan quaternary ammonium salt and sulfhydrylated polyethylene glycol; the aminated polyester fibers are aminated polyester fibers carrying disulfide bonds; the cotton fibers and the polyester fibers are modified respectively to obtain the cross-linked cotton fibers and the aminated polyester fibers, and in the heat setting process, disulfide bonds in the aminated polyester fibers and sulfydryl in the cross-linked cotton fibers can be subjected to dynamic exchange reaction, so that the cross-linked cotton fibers and the aminated polyester fibers are subjected to heat setting; amino groups on the surfaces of the aminated polyester fibers can be combined with groups such as hydroxyl groups in the cross-linked cotton fibers through hydrogen-bond interaction, so that the cotton fibers and the polyester fibers form a network structure in a three-dimensional space, the mechanical property and elasticity of the fabric are improved, and the air permeability and hygroscopicity of the fabric are not degraded.

The present application relates to the field of environmental microorganism and wastewater treatment technology, and specifically discloses a kind of fermentation microbial inoculum for sewage treatment and application.The fermentation microbial inoculum is made by immobilizing multifunctional composite microbial inoculum on chitosan magnetic microspheres;The multifunctional composite microbial inoculum is compounded by the fermentation broth of Pseudomonas koreensis, Lactobacillus acidophilus, Brevibacillus brevis, Timumasidium and Bacillus licheniformis according to a specific viable count ratio.The chitosan magnetic microspheres have Fe3O4 as magnetic core and are coated with crosslinked chitosan layer.The present application successfully constructs a microbial repair system with functional complementation and easy recovery by combining specific flora compounding with magnetic immobilization technology.The microbial inoculum can efficiently and synchronously remove nitrate, tetrabromobisphenol A and heavy metal multi-component pollutants in groundwater or contaminated water bodies, and can be quickly recovered and reused by external magnetic field, with the advantages of high treatment efficiency, environmental friendliness and low cost.

The subject matter described herein relates to crosslinked chitosan hydrogels having desirable properties and methods of making and using the same.

The invention discloses a cooking-resistant high-transparency PET (polyethylene terephthalate) film and a preparation method thereof, and belongs to the technical field of PET films, the preparation method comprises the following steps: preparing a filler, preparing a high-barrier additive, preparing a coating liquid, treating, coating and carrying out vacuum evaporation; the preparation of the filler comprises the following steps: coating cross-linked chitosan, and adsorbing sodium carboxymethyl cellulose; the step of preparing the high-barrier-property additive comprises the steps of adsorbing magnesium citrate, adsorbing polyvinyl alcohol and adsorbing magnesium ions. The prepared PET film not only has excellent boiling resistance and high transparency, but also has high barrier property and high flatness, an organic solvent does not need to be used in the preparation process, the binding force of a coating in the PET film is strong, and the surface of the PET film does not have defects.

The invention relates to the technical field of concrete, and particularly discloses a long-acting water retention type semi-flexible pavement grouting material and a preparation method thereof. The long-acting water retention type semi-flexible pavement grouting material provided by the invention has excellent high strength and long-acting water retention performance, the citric acid cross-linked chitosan can realize long-acting latching and slow release of water, the activated metakaolin can cooperate with the cementing material to improve the strength, the ettringite type expanding agent can counteract hydration shrinkage, and the long-acting water retention type semi-flexible pavement grouting material has excellent water retention performance. The problems that in the prior art, a semi-flexible pavement grouting material is low in strength and short in water retention time efficiency, cracks are easily generated due to drying shrinkage, and pavement water seepage or interface stripping is caused are effectively solved, and the use requirements of heavy traffic scenes such as expressways, urban main roads or large freight stations are met.

The invention discloses a production process of a water-soluble thiophanate-methyl preparation, and belongs to the technical field of pesticide preparations, the production process comprises the following steps: preparing porous drug-loaded microspheres by a spray drying method, crosslinking chitosan and methoxypolyethylene glycol under the action of a crosslinking agent to form polyethylene glycol modified chitosan, and coating thiophanate-methyl by using the polyethylene glycol modified chitosan as a loading material to prepare the water-soluble thiophanate-methyl preparation. Under the synergistic effect of the pore-forming agent, the granulation and pore-forming of the microspheres can be realized in one step. The thiophanate-methyl preparation prepared by taking the porous drug-loaded microspheres as the raw material not only has excellent water solubility and wettability, but also has the functions of slow release and pyrolysis resistance due to the combination of coating and micropores, the utilization rate of thiophanate-methyl is increased, and the raw material components have excellent biocompatibility and environmental friendliness, so that the thiophanate-methyl preparation has good application prospects. The sustainable development of agriculture is facilitated.

The present invention discloses a PPR pipe with copper resistance and a preparation method thereof, relating to the technical field of building water supply PPR pipes. An anti-copper masterbatch comprises the following components: modified activated carbon; random copolymer polypropylene resin; antioxidant and copper inhibitor 1024; the modified activated carbon comprises activated carbon and amino / amine-modified crosslinked chitosan nanospheres loaded on the activated carbon. A PPR pipe with copper resistance comprises a PPR outer layer and an anti-copper functional inner layer, and the anti-copper functional inner layer comprises PPR resin and the anti-copper masterbatch. By the synergistic effect of adding activated carbon loaded with amino / amine-modified crosslinked chitosan nanospheres and antioxidant and copper inhibitor 1024 to the inner layer of the PPR pipe, the present invention is beneficial to improving the ability to adsorb and complex copper ions and has long-term effectiveness, thus effectively solving the "copper harm" problem of PPR pipes, and the formed PPR pipes meet the sanitary performance requirements for transporting drinking water.

The application provides a hollow mesoporous silica (BTA@HMSNs-CS) material for metal material targeted corrosion inhibition and Pickering emulsion stabilization in an oil production well, a preparation method and an application. The material selects hollow mesoporous silica (HMSNs) as a nano container for loading corrosion inhibitors, cross-linked chitosan (CS) as a pH response valve for controlling corrosion inhibitor release and reducing interfacial tension to form a Pickering emulsion. The BTA@HMSNs-CS is assembled from an acid response cross-linked CS network and a large cavity HMSNs, the preparation method is simple and easy to implement, has good acid response and emulsion stabilization performance, and has great reference value and application prospect in the field of downhole metal corrosion prevention and emulsion stabilization.

The application belongs to the technical field of rare earth recovery, and particularly relates to a modified chitosan adsorbent for recovering scandium and a preparation method thereof, which comprises the following steps: (1) preparing a chitosan-acetic acid mixed solution, dropping the mixed solution into a NaOH solution, filtering off the alkali solution after soaking and solidifying, and cleaning the solid with deionized water until the filtrate is neutral to obtain a spherical gel; (2) adding a pre-crosslinking agent to the spherical gel, oscillating or stirring, filtering off the liquid, and washing the solid multiple times to obtain pre-crosslinked chitosan; (3) adding deionized water to the pre-crosslinked chitosan, mixing uniformly, then dropping in a crosslinking agent, oscillating until sufficient crosslinking is achieved, filtering off the liquid, and washing the solid to obtain the solid; (4) adding an ethanol solution and an amination reagent to the solid, oscillating or stirring, filtering off the liquid, and washing the solid to obtain polyaminated chitosan; and (5) uniformly mixing a solvent, the polyaminated chitosan, a phosphinic acid and an inorganic acid, heating, adding a formaldehyde solution, constant-temperature reaction, extraction, and removing the solvent to obtain the modified chitosan adsorbent.

This invention belongs to the field of clarifier technology, specifically relating to an environmentally friendly swimming pool water clarifier based on modified chitosan. It is formed by grafting and crosslinking chitosan with 2-acrylamido-2-methylpropanesulfonic acid and vinylimidazole using an initiator and a crosslinking agent. This invention uses AMPS and VIM to double-graft modify chitosan, giving the product excellent flocculation and turbidity removal, flocculation and algae removal, chlorine resistance, and wide pH adaptability. At a dosage of 5 mg / L, the turbidity removal rate reaches 96.2%, and the algae cell removal rate reaches 93.5%, demonstrating comprehensive performance superior to existing products such as unmodified chitosan, polyaluminum chloride, and cationic polyacrylamide.

The invention discloses an antibacterial material, an antibacterial polyethylene material, an antibacterial polyethylene film as well as a preparation method and application thereof, belongs to the technical field of antibacterial polyethylene, and overcomes the defects that chitosan is directly adopted as an antibacterial material in the prior art, and the antibacterial performance of polyethylene is limited and is not durable. The antibacterial material comprises an inner core and a coating layer, the inner core is talcum powder, and the coating layer comprises crosslinked ultra-high molecular weight polyethylene and crosslinked chitosan. According to the antibacterial material, the antibacterial performance of the antibacterial polyethylene film can be improved, and the antibacterial durability is greatly improved.

The invention belongs to the technical field of essence preparation, and discloses a green preparation method of safe and non-irritating essence for children products, which comprises the following steps: a) extracting aromatic plant raw materials by using a natural deep eutectic solvent (NADES) at 30-45 DEG C, the NADES being selected from lactic acid, glycerol and water in a ratio of 1: 2: 1 or choline chloride and glycerol in a molar ratio of 1: 2 and containing 10-20% of water; b) selectively removing aldehydes and peroxide / epoxidation by-products from the extracting solution obtained in the step a) through an adsorption microbead layer which is formed by crosslinking chitosan through genipin and has the primary amine density of 0.8-2.0 mmol / g at the temperature of 20-30 DEG C; and c) forming an inclusion compound from the aroma component treated in the step b) and beta and / or gamma-cyclodextrin according to a mass ratio of 1: (6-12), thereby obtaining the water-dispersible essence. According to the method, NADES low-temperature extraction and glycosaminoglycan selective aldehyde removal are connected in series, then cyclodextrin immobilization and controlled release are carried out, the aldehyde removal contact and mass transfer efficiency is improved, aldehyde is directionally removed, stimulation is reduced, the microbeads can be recycled, and a green closed loop is formed.

This invention provides a toothpaste for strengthening teeth and gums, belonging to the field of oral hygiene technology. It comprises the following components in parts by weight: 40-80 parts gallic acid extract, 1-5 parts antibacterial agent, 3-6 parts xanthate-crosslinked chitosan resin, 330-400 parts abrasive, and humectants, surfactants, and binders in a weight ratio of (100-300):(5-50):(5-40), with water added to bring the total to 1000 parts. The toothpaste for strengthening teeth and gums provided by this application contains gallic acid extract rich in active substances. Its various biological activities, including anti-inflammatory, antioxidant, antibacterial, and antiviral properties, can strengthen teeth and gums, kill bacteria, and relieve pain, showing significant efficacy in preventing and treating oral diseases such as periodontitis and oral mucosal ulcers. It also contains xanthate-crosslinked chitosan resin, which can better exert the efficacy of chitosan, improve the oral environment through adsorption, reduce damage to teeth from excessive friction, and help improve the anti-sensitivity and anti-inflammatory effects of the toothpaste.

The invention relates to the technical field of environmental microorganisms and wastewater treatment, and particularly discloses a fermentation inoculant for sewage treatment and application. The fermentation inoculant is prepared by immobilizing a multifunctional composite inoculant on chitosan magnetic microspheres, the multifunctional complex microbial inoculant is prepared by compounding fermentation broth of pseudomonas koreensis, lactobacillus acidophilus, bacillus brevis, massinia pemophila and bacillus licheniformis according to a specific viable count ratio, wherein the fermentation broth of the pseudomonas koreensis, the lactobacillus acidophilus, the bacillus brevis, the massinia pemophila and the bacillus licheniformis are used as raw materials. Fe3O4 is used as a magnetic core of the chitosan magnetic microsphere, and a cross-linked chitosan layer is coated outside the magnetic core. Through combination of specific flora compounding and a magnetic immobilization technology, a microbial remediation system which has complementary functions and is easy to recover is successfully constructed. The microbial agent can efficiently and synchronously remove nitrate, tetrabromobisphenol A and heavy metal multi-component composite pollutants in underground water or polluted water, can be quickly recycled and reused through an external magnetic field, and has the advantages of high treatment efficiency, environment friendliness and low cost.