Soil remediation agent containing traditional Chinese medicine residue leavening and preparation method of soil remediation agent

Abstract

The invention relates to the technical field of soil remediation, in particular to a soil remediation agent containing traditional Chinese medicine residue leavening and a preparation method of the soil remediation agent. By adding rice bran, peanut meal, dried orange peel residue powder, cortex phellodendri residue powder, radix isatidis residue powder and eugenol residue powder, a bacterial liquid culture solution is prepared. And inoculating the microbial bacterial liquid into the culture solution, and culturing and fermenting to obtain the traditional Chinese medicine residue fermented product. Straw powder, urea, the fermented traditional Chinese medicine residue, the magnetic composite material, a magnetic loading material and a forming aid are mixed and stirred, granulation and drying are performed after uniform stirring, and the soil remediation agent containing the fermented traditional Chinese medicine residue is obtained. The soil remediation agent prepared by the invention has excellent bacteriostasis and sterilization performance and heavy metal passivation effect, so that the soil remediation agent has a wide application prospect in the technical field of soil remediation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soil remediation, in particular to a soil remediation agent containing traditional Chinese medicine residue fermentation and a preparation method thereof. BACKGROUND

[0002] In modern society, soil remediation agents are playing an important role that cannot be ignored, and their value is reflected in multiple key areas such as ecology, agriculture, and economy. In the ecological aspect, soil remediation agents can significantly improve soil quality. With the advancement of industrialization and urbanization, soil pollution problems are becoming increasingly serious, and heavy metals, organic matter and other pollutants have seriously damaged the ecological balance of the soil. The effective components in soil remediation agents can remove pollutants through adsorption, degradation and other ways, and restore the ecological function of the soil. At the same time, it can also promote the growth and reproduction of soil microorganisms, and enhance the self-purification ability of the soil, laying a foundation for the stability of the ecological system and the protection of biodiversity. In the agricultural aspect, soil remediation agents are the key to ensuring food security and the quality of agricultural products. Polluted soil can affect the growth and development of crops, leading to reduced yield and quality; by using soil remediation agents, the physical, chemical and biological properties of the soil can be improved, and the fertility of the soil can be increased to provide a good growing environment for crops.

[0003] However, harmful bacteria still exist in the soil, which can cause root rot, wilt and other diseases of crops. This situation can easily lead to hindered growth of crops, reduced yield, and even absolute loss in severe cases. Therefore, it is necessary to improve the bacteriostatic and bactericidal performance of soil remediation agents to effectively inhibit the breeding and reproduction of harmful bacteria, create a healthy growing environment for crops, improve the survival rate and yield of crops, and ensure the stable supply of agricultural products. In addition, with the intensification of industrial pollution and agricultural non-point source pollution, heavy metals, pesticide residues and other pollutants in the soil are increasing. These pollutants can be absorbed by crops and enter the food chain, endangering human health. The passivation effect of soil remediation agents can convert pollutants into low-activity and low-toxicity forms, reduce their mobility and bioavailability in the soil, and reduce the absorption of pollutants by crops, thereby improving the quality and safety of agricultural products.

[0004] In order to overcome the defects of the prior art, the present application provides a soil remediation agent containing traditional Chinese medicine residue fermentation and a preparation method thereof. SUMMARY

[0005] The purpose of the present application is to provide a soil remediation agent containing traditional Chinese medicine residue fermentation and a preparation method thereof to solve the problems in the prior art.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions: A preparation method of a soil remediation agent containing traditional Chinese medicine residue fermentation, comprising the following steps: Step one: mix the rice bran, peanut meal, pericarpium citri reticulatae residue powder, phellodendri chinensis residue powder, radix isatidis residue powder, and eugenol residue powder, crush and sterilize to obtain a mixture; add the mixture to distilled water, stir until uniform, and then prepare a culture solution; Step two: inoculate the microbial liquid into the culture solution, and obtain a traditional Chinese medicine residue fermentation product after cultivation; mix the straw powder, urea, traditional Chinese medicine residue fermentation product, magnetic composite material, magnetic loaded material, and molding aid, stir until uniform, and then granulate and dry to obtain a finished product.

[0007] More preferably, in step one, the content of each component of the mixture is as follows: 300-400 parts of rice bran, 200-300 parts of peanut meal, 150-200 parts of pericarpium citri reticulatae residue powder, 100-150 parts of phellodendri chinensis residue powder, 100-150 parts of radix isatidis residue powder, and 80-100 parts of eugenol residue powder; the pH of the culture solution is 6.5-7.0, and the water content is 50-60%.

[0008] More preferably, in step two, the concentration of bacillus thuringiensis in the microbial liquid is 20-25 g / L, the concentration of bacillus subtilis is 10-15 g / L, and the concentration of trichoderma is 20-25 g / L; the process of liquid culture is as follows: cultivate and ferment at 30-35℃ for 8-10 days; the content of each component of the finished product is as follows: 40-50 parts of straw powder, 15-20 parts of urea, 20-30 parts of traditional Chinese medicine residue fermentation product, 10-15 parts of magnetic composite material, 5-10 parts of magnetic loaded material, and 3-5 parts of molding aid; the molding aid is specifically sodium carboxymethyl cellulose.

[0009] More preferably, the preparation process of the magnetic composite material is as follows: Step S1: wash, dry, and grind the traditional Chinese medicine residue to obtain a traditional Chinese medicine residue powder; pyrolyze the traditional Chinese medicine residue powder in an oxygen-free environment at 300-400℃ for 3.0-3.5h, and then grind and sieve to obtain a traditional Chinese medicine biochar; add ferric chloride hexahydrate and ferrous sulfate heptahydrate to ultrapure water, stir until uniform, add the traditional Chinese medicine biochar, slowly add sodium hydroxide solution, adjust the pH to 10.0-10.5, and then stand overnight; after standing, wash with water and alcohol, dry, grind, and sieve to obtain a magnetic biochar; Step S2: in a nitrogen environment, add ferric chloride hexahydrate and ferrous sulfate heptahydrate to ultrapure water, stir until uniform, add sepiolite, stir at 55-60℃ for 20-25min, slowly add concentrated ammonia water, adjust the pH to 10.0-10.5, and then stand overnight; after standing, wash with water and alcohol, dry, grind, and sieve to obtain a magnetic sepiolite; Step S3: add butyl titanate into anhydrous ethanol, continuously stir the reaction for 40-60 min to obtain a titanium dioxide precursor; disperse the magnetic biochar and magnetic sepiolite into anhydrous ethanol, after adding 30-33 wt% ammonia water, ultrasonic dispersion for 25-30 min, then stir at 30-35℃ for 70-90 min, after stirring, drop the titanium dioxide precursor, continue to stir for 8-9 h after dropping, after the reaction, wash with water, alcohol, vacuum drying, grinding, and sieving to obtain the magnetic composite material.

[0010] More preferably, in step S1, the traditional Chinese medicine residues include pericarpium citri reticulatae residue powder, cortex phellodendri residue powder, radix isatidis residue powder, and eugenol residue powder, and the mixing ratio is 15:10:10:(7-9); the reaction mass ratio of ferric chloride hexahydrate, ferrous sulfate heptahydrate, and traditional Chinese medicine biochar is (1.8-2.0):1:2.5; in step S2, the reaction mass ratio of ferric chloride hexahydrate, ferrous sulfate heptahydrate, and sepiolite is (1.8-2.0):1:3.5.

[0011] More preferably, in step S3, the reaction volume ratio of butyl titanate and anhydrous ethanol is 1:10; the mass-volume ratio of magnetic biochar, magnetic sepiolite, anhydrous ethanol, ammonia water, and titanium dioxide precursor is 0.03 g:0.03 g:5 mL:0.05 mL:(1.0-1.2) mL.

[0012] More preferably, the preparation process of the magnetic loading material is as follows: Step S1: add p-toluenesulfonyl chloride into acetonitrile, stir uniformly to obtain a p-toluenesulfonyl chloride solution; add β-cyclodextrin into distilled water, stir uniformly, then drop 8.0-8.2 mol / L sodium hydroxide solution, after dropping, drop the p-toluenesulfonyl chloride solution at 0-2℃, continue to react at 0-2℃ for 2.5-3.0 h, after the reaction, filter, adjust pH, stand overnight, recrystallize, and vacuum dry to obtain modified β-cyclodextrin; Step S2: add the modified β-cyclodextrin into N,N-dimethylformamide to obtain a modified liquid; add chitosan into an ice acetic acid aqueous solution, stir uniformly, then add the modified liquid, vacuumize, pass nitrogen, reflux at 100-105℃ for 12-14 h, after the reaction, wash, vacuum dry, extract, and dry again to obtain a chitosan-cyclodextrin material; Step S3: add anhydrous ferric chloride and sodium citrate dihydrate into ethylene glycol, ultrasonic stir uniformly, then add anhydrous sodium acetate, continue to ultrasonic stir until a homogeneous solution is formed; react the homogeneous solution at 200-220℃ for 9-10 h, after the reaction, cool, wash, and vacuum dry to obtain Fe3O4 nanoparticles; Step S4: Dissolve the chitosan-cyclodextrin material in a 10-12 wt% acetic acid solution, adjust the pH of the solution to 3.5-5.0, and slowly add sodium tripolyphosphate solution under stirring to obtain a chitosan-cyclodextrin solution; add Fe3O4 nanoparticles to the sodium tripolyphosphate solution, stir evenly, and then slowly add the chitosan-cyclodextrin solution dropwise. After the addition is complete, continue stirring and reacting for 45-50 hours. After the reaction is complete, dialyze to obtain the magnetically loaded material.

[0013] In a more optimized manner, in step S1, the mass-to-volume ratio of p-toluenesulfonyl chloride, β-cyclodextrin, and sodium hydroxide solution is 5 g: 30 g: (12-14) mL; in step S2, the mass-to-volume ratio of modified β-cyclodextrin, N,N-dimethylformamide, chitosan, and glacial acetic acid aqueous solution is (1.0-1.2) g: 40 mL: (1.0-1.2) g: 80 mL; and the volume fraction of glacial acetic acid aqueous solution is 1.2-1.5%.

[0014] In a more optimized manner, in step S3, the mass-to-volume ratio of anhydrous ferric chloride, sodium citrate dihydrate, anhydrous sodium acetate, and ethylene glycol is (4.8-5.0) g: 2 g: 7.5 g: 120 mL; in step S4, the concentration of sodium tripolyphosphate solution is 0.0013-0.0015 g / mol, and the reaction mass ratio of chitosan-cyclodextrin material and Fe3O4 nanoparticles is 2: (1.0-1.2).

[0015] The beneficial effects of this invention are: The invention is characterized by preparing a bacterial culture medium by adding rice bran, peanut meal, dried tangerine peel residue powder, cork tree bark residue powder, isatis root residue powder, and eugenol residue powder. The microbial culture medium is then inoculated into the culture medium, and fermentation yields a fermented product of traditional Chinese medicine residues. The rice bran and peanut meal in the bacterial culture medium serve as nutrients, providing ample carbon and nitrogen sources for microbial fermentation, promoting the proliferation of beneficial microorganisms, forming a dominant microbial community, and inhibiting the growth of harmful bacteria. Dried tangerine peel residue powder contains volatile oils and flavonoids, which can inhibit root rot pathogens in the soil and reduce plant root diseases. Berberine in cork tree bark residue powder has broad-spectrum antibacterial properties, inhibiting nucleic acid synthesis in common soil-borne Escherichia coli and acting on the cell membrane of Staphylococcus aureus, disrupting bacterial biological structures. Indigo and indirubin in isatis root residue powder can interfere with the energy metabolism of harmful bacteria and inhibit Ralstonia solanacearum in the soil. Eugenol in eugenol residue powder has strong antibacterial properties, inhibiting Fusarium and Staphylococcus aureus in the soil. The microbial inoculum in the solution can decompose substances such as cellulose in the residue, providing nutrients for the continued growth of beneficial bacteria.

[0016] Therefore, this fermented Chinese medicinal residue, through the synergistic effect of the antibacterial components of the raw materials and the fermentation process, has a significant inhibitory and killing effect on a variety of harmful soil bacteria such as Staphylococcus aureus, root rot fungi, bacterial wilt fungi, and Fusarium.

[0017] The invention is characterized by the following steps: First, after pyrolysis of treated Chinese herbal medicine residue, a Chinese herbal medicine biochar is obtained. Then, ferric chloride hexahydrate, ferrous sulfate heptahydrate, and sodium hydroxide solution are added to prepare magnetic biochar. Next, sepiolite, ferric chloride hexahydrate, ferrous sulfate heptahydrate, and sodium hydroxide solution are added to prepare magnetic sepiolite. Finally, magnetic biochar, magnetic sepiolite, titanium dioxide precursor, and ammonia are mixed to prepare a magnetic composite material. The Chinese herbal medicine residue itself contains various organic components, and the pyrolysis process gives the Chinese herbal medicine biochar a rich porous structure and a large specific surface area. This structural characteristic provides numerous adsorption sites for heavy metal ions, enabling the physical adsorption of heavy metal ions from the soil onto the pores and surface of the biochar. Sepiolite has a fibrous, porous crystal structure with a large specific surface area and abundant pores. This structure gives sepiolite a strong adsorption capacity, enabling the physical adsorption of heavy metal ions from the soil. Its pores can accommodate heavy metal ions, fixing them internally and reducing their migration in the soil.

[0018] Furthermore, during the preparation of magnetic biochar and magnetic sepiolite, ferric chloride hexahydrate and ferrous sulfate heptahydrate undergo a co-precipitation reaction under alkaline conditions to generate magnetite (Fe3O4) magnetic particles. These magnetic particles are uniformly distributed on the surface of the biochar and sepiolite, endowing the composite material with magnetism. This allows the composite material to be separated and aggregated in the soil by an external magnetic field. In soil contaminated with heavy metals, the magnetic composite material can bind to heavy metal ions and then separate them from the soil by applying a magnetic field, thereby reducing the heavy metal content in the soil. Simultaneously, the presence of magnetic particles also helps the composite material disperse and aggregate in the soil, increasing the contact opportunities with heavy metal ions and improving the passivation effect. Furthermore, titanium dioxide, when combined with magnetic biochar and magnetic sepiolite, forms a synergistic system. Titanium dioxide can adhere to the surface of magnetic biochar and magnetic sepiolite, increasing the specific surface area and adsorption sites of the composite material. Simultaneously, its photocatalytic properties promote the oxidation and precipitation of heavy metals, further improving the passivation effect of the composite material on heavy metals in the soil. In summary, this magnetic composite material exhibits excellent soil heavy metal passivation effects due to the characteristics of its reactants and the synergistic reaction mechanism formed during the preparation process.

[0019] The key feature of this invention is that modified β-cyclodextrin is obtained by adding p-toluenesulfonyl chloride and β-cyclodextrin. Chitosan-cyclodextrin material is obtained by adding modified β-cyclodextrin, chitosan, and an aqueous solution of glacial acetic acid. The prepared Fe3O4 nanoparticles are then mixed with the chitosan-cyclodextrin material, acetic acid solution, and sodium tripolyphosphate solution to prepare a magnetically loaded material. Sodium tripolyphosphate dissociates into negatively charged tripolyphosphate ions in aqueous solution. Therefore, mixing the sodium tripolyphosphate solution containing Fe3O4 nanoparticles with the protonated chitosan-cyclodextrin solution allows for ionic cross-linking via electrostatic interactions. The Fe3O4 nanoparticles are encapsulated and fixed within the polymer network structure as the tripolyphosphate ions cross-link with the chitosan.

[0020] β-Cyclodextrin possesses a unique hydrophobic interior and hydrophilic exterior structure, enabling it to encapsulate hydrophobic molecules. For some organic-heavy metal complexes in soil, β-cyclodextrin can immobilize them through encapsulation, reducing the migration of heavy metals. Chitosan is a natural high-molecular-weight polysaccharide containing numerous amino and hydroxyl groups. Amino groups have strong coordinating abilities, forming stable coordinate bonds with heavy metal ions and adsorbing them onto the material surface through complexation. Fe3O4 nanoparticles exhibit excellent magnetic properties, allowing the magnetically loaded material to be separated and enriched under the influence of an external magnetic field. In soil remediation, after the material adsorbs heavy metal ions, applying a magnetic field can separate them from the soil for centralized treatment, thereby reducing the heavy metal content in the soil. Therefore, this magnetically loaded material exhibits excellent soil heavy metal passivation effects due to the characteristics of its reactants and the synergistic reaction mechanism formed during preparation.

[0021] Finally, straw powder, urea, fermented Chinese medicinal herb residue, magnetic composite material, magnetic loading material, and molding aid were mixed and stirred until homogeneous. After granulation and drying, a soil remediation agent containing fermented Chinese medicinal herb residue was obtained. In summary, this soil remediation agent containing fermented Chinese medicinal herb residue, due to the unique functions of each component and their synergistic effect, possesses excellent antibacterial and bactericidal properties and soil heavy metal passivation effects. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Raw material source: The medicinal herb residue powders (dried tangerine peel residue powder, phellodendron bark residue powder, isatis root residue powder, and eugenol residue powder) used in this application are all derived from pharmaceutical factory waste; rice bran was provided by Rongze Agriculture (Shijiazhuang) Co., Ltd., with a particle size of 150μm; peanut meal was provided by Jining Tongsheng Biotechnology Development Co., Ltd., with an effective ingredient content of 47%; straw powder, specifically corn straw powder, with a size of 1mm; sepiolite was provided by Hebei Huihao Environmental Protection Technology Co., Ltd., with a particle size of 45μm; chitosan was provided by Jinan Haidebei Bioengineering Co., Ltd., and was de-ethylenediamined. Acrylamide content is 90%; sodium carboxymethyl cellulose, provided by Hebei Chaoyan New Material Technology Co., Ltd., has a particle size of 100μm; Bacillus thuringiensis, provided by Hubei Xingdongcheng Chemical Co., Ltd., has an active ingredient content of 99% and a pH of 4.0-7.5; Bacillus subtilis, provided by Shandong Quansheng Chemical Technology Co., Ltd., has an active ingredient content of 99% and a model number of 01; Trichoderma, provided by Shandong Huafeng Chemical Technology Co., Ltd., has an active ingredient content of 99% and a fineness of 80 mesh; by mass, one part is 1g.

[0024] Example 1: Step 1: Mix 300g rice bran, 200g peanut meal, 150g dried tangerine peel residue powder, 100g phellodendron bark residue powder, 100g isatis root residue powder, and 80g eugenol residue powder. After pulverizing and sterilizing, a mixture is obtained. The mixture is added to distilled water and stirred evenly to prepare a culture medium. The pH of the culture medium is 7.0 and the water content is 60%. Step 2: The preparation process of the magnetic composite material is as follows: Step S1: Wash, dry, and grind the Chinese herbal medicine residue to obtain Chinese herbal medicine residue powder; place the Chinese herbal medicine residue powder in an oxygen-deficient environment at 400℃ for 3.5 hours for pyrolysis; after pyrolysis, grind and sieve to obtain Chinese herbal medicine biochar; add ferric chloride hexahydrate and ferrous sulfate heptahydrate to ultrapure water, stir evenly, add Chinese herbal medicine biochar, and then slowly add sodium hydroxide solution to adjust the pH to 10.5 and let stand overnight. After standing, wash with water, wash with alcohol, dry, grind, and sieve to obtain magnetic biochar; the Chinese herbal medicine residue includes tangerine peel residue powder, phellodendron bark residue powder, isatis root residue powder, and eugenol residue powder, with a mixing ratio of 15:10:10:8; the reaction mass ratio of ferric chloride hexahydrate, ferrous sulfate heptahydrate, and Chinese herbal medicine biochar is 1.9:1:2.5; Step S2: Under nitrogen atmosphere, ferric chloride hexahydrate and ferrous sulfate heptahydrate were added to ultrapure water and stirred until homogeneous. Then sepiolite was added and stirred at 60°C for 25 minutes. After stirring, concentrated ammonia was slowly added dropwise to adjust the pH to 10.5. The mixture was then allowed to stand overnight. After standing, the mixture was washed with water, washed with alcohol, dried, ground, and sieved to obtain magnetic sepiolite. The mass ratio of ferric chloride hexahydrate, ferrous sulfate heptahydrate, and sepiolite was 1.9:1:3.5. Step S3: Add tetrabutyl titanate to anhydrous ethanol and stir continuously for 60 min to obtain titanium dioxide precursor; disperse magnetic biochar and magnetic sepiolite in anhydrous ethanol, add 33wt% ammonia water and ultrasonically disperse for 30 min, then stir at 35℃ for 90 min. After stirring, add titanium dioxide precursor dropwise. After the dropwise addition is completed, continue stirring for 9 h. After the reaction is completed, wash with water, wash with alcohol, vacuum dry, grind and sieve to obtain magnetic composite material; the reaction volume ratio of tetrabutyl titanate to anhydrous ethanol is 1:10; the mass-volume ratio of magnetic biochar, magnetic sepiolite, anhydrous ethanol, ammonia water and titanium dioxide precursor is 0.03g:0.03g:5mL:0.05mL:1.1mL. Step 3: The preparation process of the magnetic load material is as follows: Step S1: Add p-toluenesulfonyl chloride to acetonitrile and stir until homogeneous to obtain a p-toluenesulfonyl chloride solution; add β-cyclodextrin to distilled water and stir until homogeneous, then add 8.2 mol / L sodium hydroxide solution dropwise. After the addition is complete, add p-toluenesulfonyl chloride solution dropwise at 2℃. After the addition is complete, continue the reaction at 2℃ for 3.0 h. After the reaction is complete, filter, adjust pH, let stand overnight, recrystallize, and vacuum dry to obtain modified β-cyclodextrin; the mass-volume ratio of p-toluenesulfonyl chloride, β-cyclodextrin, and sodium hydroxide solution is 5 g: 30 g: 13 mL. Step S2: Modified β-cyclodextrin was added to N,N-dimethylformamide to obtain a modified solution; chitosan was added to an aqueous solution of glacial acetic acid, stirred evenly, and then the modified solution was added. The mixture was refluxed at 105°C for 14 hours under vacuum and nitrogen purging. After the reaction, the mixture was washed, vacuum dried, extracted, and dried again to obtain the chitosan-cyclodextrin material. The mass-volume ratio of modified β-cyclodextrin, N,N-dimethylformamide, chitosan, and aqueous solution of glacial acetic acid was 1.1 g: 40 mL: 1.1 g: 80 mL; the volume fraction of the aqueous solution of glacial acetic acid was 1.4%. Step S3: Anhydrous ferric chloride and sodium citrate dihydrate were added to ethylene glycol and ultrasonically stirred until homogeneous. Then, anhydrous sodium acetate was added and ultrasonically stirred again until a homogeneous solution was formed. The homogeneous solution was reacted at 220℃ for 10 h. After the reaction was completed, the solution was cooled, washed, and vacuum dried to obtain Fe3O4 nanoparticles. The mass-volume ratio of anhydrous ferric chloride, sodium citrate dihydrate, anhydrous sodium acetate, and ethylene glycol was 4.9 g: 2 g: 7.5 g: 120 mL. Step S4: Dissolve the chitosan-cyclodextrin material in a 12wt% acetic acid solution, adjust the pH of the solution to 5.0, and then slowly add sodium tripolyphosphate solution under stirring to obtain a chitosan-cyclodextrin solution. Add Fe3O4 nanoparticles to the sodium tripolyphosphate solution, stir evenly, and then slowly add the chitosan-cyclodextrin solution dropwise. After the addition is complete, continue stirring and react for 50 hours. After the reaction is complete, dialyze to obtain the magnetically loaded material. The concentration of sodium tripolyphosphate solution is 0.0014 g / mol, and the reaction mass ratio of chitosan-cyclodextrin material to Fe3O4 nanoparticles is 2:1.1. Step 4: Inoculate the microbial inoculum into the culture medium and ferment at 35℃ for 10 days. After the fermentation is completed, the fermented Chinese medicine residue is obtained. The concentration of Bacillus thuringiensis in the microbial inoculum is 25g / L, the concentration of Bacillus subtilis is 15g / L, and the concentration of Trichoderma is 25g / L. 40g of straw powder, 15g of urea, 20g of fermented Chinese medicinal residue, 10g of magnetic composite material, 5g of magnetic load material, and 3g of sodium carboxymethyl cellulose were mixed and stirred. After stirring evenly, the mixture was granulated and dried to obtain the finished product.

[0025] Example 2: Step 1: Mix 300g rice bran, 200g peanut meal, 150g dried tangerine peel residue powder, 100g phellodendron bark residue powder, 100g isatis root residue powder, and 80g eugenol residue powder. After pulverizing and sterilizing, a mixture is obtained. The mixture is added to distilled water and stirred evenly to prepare a culture medium. The pH of the culture medium is 6.7 and the water content is 55%. Step 2: The preparation process of the magnetic composite material is as follows: Step S1: Wash, dry, and grind the Chinese herbal medicine residue to obtain Chinese herbal medicine residue powder; place the Chinese herbal medicine residue powder in an oxygen-deficient environment at 350℃ for 3.3 hours for pyrolysis; after pyrolysis, grind and sieve to obtain Chinese herbal medicine biochar; add ferric chloride hexahydrate and ferrous sulfate heptahydrate to ultrapure water, stir evenly, add Chinese herbal medicine biochar, and then slowly add sodium hydroxide solution to adjust the pH to 10.2 and let stand overnight. After standing, wash with water, wash with alcohol, dry, grind, and sieve to obtain magnetic biochar; the Chinese herbal medicine residue includes tangerine peel residue powder, phellodendron bark residue powder, isatis root residue powder, and eugenol residue powder, with a mixing ratio of 15:10:10:8; the reaction mass ratio of ferric chloride hexahydrate, ferrous sulfate heptahydrate, and Chinese herbal medicine biochar is 1.9:1:2.5; Step S2: Under nitrogen atmosphere, ferric chloride hexahydrate and ferrous sulfate heptahydrate were added to ultrapure water and stirred until homogeneous. Then sepiolite was added and stirred at 57°C for 23 minutes. After stirring, concentrated ammonia was slowly added dropwise to adjust the pH to 10.3. The mixture was then allowed to stand overnight. After standing, the mixture was washed with water, washed with alcohol, dried, ground, and sieved to obtain magnetic sepiolite. The mass ratio of ferric chloride hexahydrate, ferrous sulfate heptahydrate, and sepiolite was 1.9:1:3.5. Step S3: Add tetrabutyl titanate to anhydrous ethanol and stir continuously for 50 min to obtain titanium dioxide precursor; disperse magnetic biochar and magnetic sepiolite in anhydrous ethanol, add 33wt% ammonia and ultrasonically disperse for 27 min, then stir at 33℃ for 80 min. After stirring, add titanium dioxide precursor dropwise, and continue stirring for 8.5 h. After the reaction, wash with water, wash with alcohol, vacuum dry, grind and sieve to obtain magnetic composite material; the reaction volume ratio of tetrabutyl titanate to anhydrous ethanol is 1:10; the mass-volume ratio of magnetic biochar, magnetic sepiolite, anhydrous ethanol, ammonia and titanium dioxide precursor is 0.03g:0.03g:5mL:0.05mL:1.1mL. Step 3: The preparation process of the magnetic load material is as follows: Step S1: Add p-toluenesulfonyl chloride to acetonitrile and stir until homogeneous to obtain a p-toluenesulfonyl chloride solution; add β-cyclodextrin to distilled water and stir until homogeneous, then add 8.2 mol / L sodium hydroxide solution dropwise. After the addition is complete, add p-toluenesulfonyl chloride solution dropwise at 1℃. After the addition is complete, continue the reaction at 1℃ for 2.7 h. After the reaction is complete, filter, adjust pH, let stand overnight, recrystallize, and vacuum dry to obtain modified β-cyclodextrin; the mass-volume ratio of p-toluenesulfonyl chloride, β-cyclodextrin, and sodium hydroxide solution is 5 g: 30 g: 13 mL. Step S2: Modified β-cyclodextrin was added to N,N-dimethylformamide to obtain a modified solution; chitosan was added to an aqueous solution of glacial acetic acid, stirred evenly, and then the modified solution was added. The mixture was refluxed at 103°C for 13 hours under vacuum and nitrogen purging. After the reaction, the mixture was washed, vacuum dried, extracted, and then dried again to obtain the chitosan-cyclodextrin material. The mass-volume ratio of modified β-cyclodextrin, N,N-dimethylformamide, chitosan, and aqueous solution of glacial acetic acid was 1.1 g: 40 mL: 1.1 g: 80 mL; the volume fraction of the aqueous solution of glacial acetic acid was 1.4%. Step S3: Anhydrous ferric chloride and sodium citrate dihydrate were added to ethylene glycol and ultrasonically stirred until homogeneous. Then, anhydrous sodium acetate was added and ultrasonically stirred again until a homogeneous solution was formed. The homogeneous solution was reacted at 210℃ for 9.5 h. After the reaction was completed, the solution was cooled, washed, and vacuum dried to obtain Fe3O4 nanoparticles. The mass-volume ratio of anhydrous ferric chloride, sodium citrate dihydrate, anhydrous sodium acetate, and ethylene glycol was 4.9 g: 2 g: 7.5 g: 120 mL. Step S4: Dissolve the chitosan-cyclodextrin material in a 12wt% acetic acid solution, adjust the pH of the solution to 4.2, and then slowly add sodium tripolyphosphate solution under stirring to obtain a chitosan-cyclodextrin solution. Add Fe3O4 nanoparticles to the sodium tripolyphosphate solution, stir evenly, and then slowly add the chitosan-cyclodextrin solution dropwise. After the addition is complete, continue stirring and react for 47 hours. After the reaction is complete, dialyze to obtain the magnetically loaded material. The concentration of sodium tripolyphosphate solution is 0.0014 g / mol, and the reaction mass ratio of chitosan-cyclodextrin material to Fe3O4 nanoparticles is 2:1.1. Step 4: Inoculate the microbial inoculum into the culture medium and ferment at 33℃ for 9 days. After the fermentation is completed, the fermented Chinese medicine residue is obtained. The concentration of Bacillus thuringiensis in the microbial inoculum is 25g / L, the concentration of Bacillus subtilis is 15g / L, and the concentration of Trichoderma is 25g / L. 40g of straw powder, 15g of urea, 20g of fermented Chinese medicinal residue, 10g of magnetic composite material, 5g of magnetic load material, and 3g of sodium carboxymethyl cellulose were mixed and stirred. After stirring evenly, the mixture was granulated and dried to obtain the finished product.

[0026] Example 3: Step 1: Mix 300g rice bran, 200g peanut meal, 150g dried tangerine peel residue powder, 100g phellodendron bark residue powder, 100g isatis root residue powder, and 80g eugenol residue powder. After pulverizing and sterilizing, a mixture is obtained. The mixture is added to distilled water and stirred evenly to prepare a culture medium. The pH of the culture medium is 6.5 and the water content is 50%. Step 2: The preparation process of the magnetic composite material is as follows: Step S1: Wash, dry, and grind the Chinese herbal medicine residue to obtain Chinese herbal medicine residue powder; place the Chinese herbal medicine residue powder in an oxygen-deficient environment at 300℃ for 3.0h for pyrolysis; after pyrolysis, grind and sieve to obtain Chinese herbal medicine biochar; add ferric chloride hexahydrate and ferrous sulfate heptahydrate to ultrapure water, stir evenly, add Chinese herbal medicine biochar, and then slowly add sodium hydroxide solution to adjust the pH to 10.0 and let stand overnight. After standing, wash with water, wash with alcohol, dry, grind, and sieve to obtain magnetic biochar; the Chinese herbal medicine residue includes tangerine peel residue powder, phellodendron bark residue powder, isatis root residue powder, and eugenol residue powder, with a mixing ratio of 15:10:10:8; the reaction mass ratio of ferric chloride hexahydrate, ferrous sulfate heptahydrate, and Chinese herbal medicine biochar is 1.9:1:2.5; Step S2: Under nitrogen atmosphere, ferric chloride hexahydrate and ferrous sulfate heptahydrate were added to ultrapure water and stirred until homogeneous. Then sepiolite was added and stirred at 55°C for 20 minutes. After stirring, concentrated ammonia was slowly added dropwise to adjust the pH to 10.0. The mixture was then allowed to stand overnight. After standing, the mixture was washed with water, washed with alcohol, dried, ground, and sieved to obtain magnetic sepiolite. The mass ratio of ferric chloride hexahydrate, ferrous sulfate heptahydrate, and sepiolite was 1.9:1:3.5. Step S3: Add tetrabutyl titanate to anhydrous ethanol and stir continuously for 40 min to obtain titanium dioxide precursor; disperse magnetic biochar and magnetic sepiolite in anhydrous ethanol, add 33wt% ammonia water and ultrasonically disperse for 25 min, then stir at 30℃ for 70 min. After stirring, add titanium dioxide precursor dropwise. After the dropwise addition is complete, continue stirring for 8 h. After the reaction is complete, wash with water, wash with alcohol, vacuum dry, grind and sieve to obtain magnetic composite material; the reaction volume ratio of tetrabutyl titanate to anhydrous ethanol is 1:10; the mass-volume ratio of magnetic biochar, magnetic sepiolite, anhydrous ethanol, ammonia water and titanium dioxide precursor is 0.03g:0.03g:5mL:0.05mL:1.1mL. Step 3: The preparation process of the magnetic load material is as follows: Step S1: Add p-toluenesulfonyl chloride to acetonitrile and stir until homogeneous to obtain a p-toluenesulfonyl chloride solution; add β-cyclodextrin to distilled water and stir until homogeneous, then add 8.2 mol / L sodium hydroxide solution dropwise. After the addition is complete, add p-toluenesulfonyl chloride solution dropwise at 0℃. After the addition is complete, continue the reaction at 0℃ for 2.5 h. After the reaction is complete, filter, adjust pH, let stand overnight, recrystallize, and vacuum dry to obtain modified β-cyclodextrin; the mass-volume ratio of p-toluenesulfonyl chloride, β-cyclodextrin, and sodium hydroxide solution is 5 g: 30 g: 13 mL. Step S2: Modified β-cyclodextrin was added to N,N-dimethylformamide to obtain a modified solution; chitosan was added to an aqueous solution of glacial acetic acid, stirred evenly, and then the modified solution was added. The mixture was then refluxed at 100°C for 12 hours under vacuum and nitrogen purging. After the reaction, the mixture was washed, vacuum dried, extracted, and then dried again to obtain the chitosan-cyclodextrin material. The mass-to-volume ratio of modified β-cyclodextrin, N,N-dimethylformamide, chitosan, and aqueous solution of glacial acetic acid was 1.1 g: 40 mL: 1.1 g: 80 mL; the volume fraction of the aqueous solution of glacial acetic acid was 1.4%. Step S3: Anhydrous ferric chloride and sodium citrate dihydrate were added to ethylene glycol and ultrasonically stirred until homogeneous. Then, anhydrous sodium acetate was added and ultrasonically stirred again until a homogeneous solution was formed. The homogeneous solution was reacted at 200℃ for 9 hours. After the reaction was completed, the solution was cooled, washed, and vacuum dried to obtain Fe3O4 nanoparticles. The mass-volume ratio of anhydrous ferric chloride, sodium citrate dihydrate, anhydrous sodium acetate, and ethylene glycol was 4.9 g: 2 g: 7.5 g: 120 mL. Step S4: Dissolve the chitosan-cyclodextrin material in a 12wt% acetic acid solution, adjust the pH of the solution to 3.5, and then slowly add sodium tripolyphosphate solution under stirring to obtain a chitosan-cyclodextrin solution. Add Fe3O4 nanoparticles to the sodium tripolyphosphate solution, stir evenly, and then slowly add the chitosan-cyclodextrin solution dropwise. After the addition is complete, continue stirring and react for 45 hours. After the reaction is complete, dialyze to obtain the magnetically loaded material. The concentration of sodium tripolyphosphate solution is 0.0014 g / mol, and the reaction mass ratio of chitosan-cyclodextrin material to Fe3O4 nanoparticles is 2:1.1. Step 4: Inoculate the microbial inoculum into the culture medium and ferment at 30℃ for 8 days. After the fermentation is completed, the fermented Chinese medicine residue is obtained. The concentration of Bacillus thuringiensis in the microbial inoculum is 25g / L, the concentration of Bacillus subtilis is 15g / L, and the concentration of Trichoderma is 25g / L. 40g of straw powder, 15g of urea, 20g of fermented Chinese medicinal residue, 10g of magnetic composite material, 5g of magnetic load material, and 3g of sodium carboxymethyl cellulose were mixed and stirred. After stirring evenly, the mixture was granulated and dried to obtain the finished product.

[0027] Comparative Example 1: The fermented herbal medicine residue was removed, and the rest was the same as in Example 1. The specific steps are as follows: Step 1: The preparation process of the magnetic composite material is as follows: Step S1: Wash, dry, and grind the Chinese herbal medicine residue to obtain Chinese herbal medicine residue powder; place the Chinese herbal medicine residue powder in an oxygen-deficient environment at 400℃ for 3.5 hours for pyrolysis; after pyrolysis, grind and sieve to obtain Chinese herbal medicine biochar; add ferric chloride hexahydrate and ferrous sulfate heptahydrate to ultrapure water, stir evenly, add Chinese herbal medicine biochar, and then slowly add sodium hydroxide solution to adjust the pH to 10.5 and let stand overnight. After standing, wash with water, wash with alcohol, dry, grind, and sieve to obtain magnetic biochar; the Chinese herbal medicine residue includes tangerine peel residue powder, phellodendron bark residue powder, isatis root residue powder, and eugenol residue powder, with a mixing ratio of 15:10:10:8; the reaction mass ratio of ferric chloride hexahydrate, ferrous sulfate heptahydrate, and Chinese herbal medicine biochar is 1.9:1:2.5; Step S2: Under nitrogen atmosphere, ferric chloride hexahydrate and ferrous sulfate heptahydrate were added to ultrapure water and stirred until homogeneous. Then sepiolite was added and stirred at 60°C for 25 minutes. After stirring, concentrated ammonia was slowly added dropwise to adjust the pH to 10.5. The mixture was then allowed to stand overnight. After standing, the mixture was washed with water, washed with alcohol, dried, ground, and sieved to obtain magnetic sepiolite. The mass ratio of ferric chloride hexahydrate, ferrous sulfate heptahydrate, and sepiolite was 1.9:1:3.5. Step S3: Add tetrabutyl titanate to anhydrous ethanol and stir continuously for 60 min to obtain titanium dioxide precursor; disperse magnetic biochar and magnetic sepiolite in anhydrous ethanol, add 33wt% ammonia water and ultrasonically disperse for 30 min, then stir at 35℃ for 90 min. After stirring, add titanium dioxide precursor dropwise. After the dropwise addition is completed, continue stirring for 9 h. After the reaction is completed, wash with water, wash with alcohol, vacuum dry, grind and sieve to obtain magnetic composite material; the reaction volume ratio of tetrabutyl titanate to anhydrous ethanol is 1:10; the mass-volume ratio of magnetic biochar, magnetic sepiolite, anhydrous ethanol, ammonia water and titanium dioxide precursor is 0.03g:0.03g:5mL:0.05mL:1.1mL. Step 2: The preparation process of the magnetic support material is as follows: Step S1: Add p-toluenesulfonyl chloride to acetonitrile and stir until homogeneous to obtain a p-toluenesulfonyl chloride solution; add β-cyclodextrin to distilled water and stir until homogeneous, then add 8.2 mol / L sodium hydroxide solution dropwise. After the addition is complete, add p-toluenesulfonyl chloride solution dropwise at 2℃. After the addition is complete, continue the reaction at 2℃ for 3.0 h. After the reaction is complete, filter, adjust pH, let stand overnight, recrystallize, and vacuum dry to obtain modified β-cyclodextrin; the mass-volume ratio of p-toluenesulfonyl chloride, β-cyclodextrin, and sodium hydroxide solution is 5 g: 30 g: 13 mL. Step S2: Modified β-cyclodextrin was added to N,N-dimethylformamide to obtain a modified solution; chitosan was added to an aqueous solution of glacial acetic acid, stirred evenly, and then the modified solution was added. The mixture was refluxed at 105°C for 14 hours under vacuum and nitrogen purging. After the reaction, the mixture was washed, vacuum dried, extracted, and dried again to obtain the chitosan-cyclodextrin material. The mass-volume ratio of modified β-cyclodextrin, N,N-dimethylformamide, chitosan, and aqueous solution of glacial acetic acid was 1.1 g: 40 mL: 1.1 g: 80 mL; the volume fraction of the aqueous solution of glacial acetic acid was 1.4%. Step S3: Anhydrous ferric chloride and sodium citrate dihydrate were added to ethylene glycol and ultrasonically stirred until homogeneous. Then, anhydrous sodium acetate was added and ultrasonically stirred again until a homogeneous solution was formed. The homogeneous solution was reacted at 220℃ for 10 h. After the reaction was completed, the solution was cooled, washed, and vacuum dried to obtain Fe3O4 nanoparticles. The mass-volume ratio of anhydrous ferric chloride, sodium citrate dihydrate, anhydrous sodium acetate, and ethylene glycol was 4.9 g: 2 g: 7.5 g: 120 mL. Step S4: Dissolve the chitosan-cyclodextrin material in a 12wt% acetic acid solution, adjust the pH of the solution to 5.0, and then slowly add sodium tripolyphosphate solution under stirring to obtain a chitosan-cyclodextrin solution. Add Fe3O4 nanoparticles to the sodium tripolyphosphate solution, stir evenly, and then slowly add the chitosan-cyclodextrin solution dropwise. After the addition is complete, continue stirring and react for 50 hours. After the reaction is complete, dialyze to obtain the magnetically loaded material. The concentration of sodium tripolyphosphate solution is 0.0014 g / mol, and the reaction mass ratio of chitosan-cyclodextrin material to Fe3O4 nanoparticles is 2:1.1. Step 3: Mix 40g of straw powder, 15g of urea, 10g of magnetic composite material, 5g of magnetic load material, and 3g of sodium carboxymethyl cellulose. After mixing evenly, granulate and dry to obtain the finished product.

[0028] Comparative Example 2: The magnetic composite material was removed, and the rest was the same as in Example 1. The specific steps are as follows: Step 1: 300g rice bran, 200g peanut meal, 150g dried tangerine peel residue powder, 100g phellodendron bark residue powder, 100g isatis root residue powder, and 80g eugenol residue powder were mixed, pulverized, and sterilized to obtain a mixture; the mixture was added to distilled water and stirred evenly to prepare a culture medium; the pH of the culture medium was 7.0 and the water content was 60%. Step 2: The preparation process of the magnetic support material is as follows: Step S1: Add p-toluenesulfonyl chloride to acetonitrile and stir until homogeneous to obtain a p-toluenesulfonyl chloride solution; add β-cyclodextrin to distilled water and stir until homogeneous, then add 8.2 mol / L sodium hydroxide solution dropwise. After the addition is complete, add p-toluenesulfonyl chloride solution dropwise at 2℃. After the addition is complete, continue the reaction at 2℃ for 3.0 h. After the reaction is complete, filter, adjust pH, let stand overnight, recrystallize, and vacuum dry to obtain modified β-cyclodextrin; the mass-volume ratio of p-toluenesulfonyl chloride, β-cyclodextrin, and sodium hydroxide solution is 5 g: 30 g: 13 mL. Step S2: Modified β-cyclodextrin was added to N,N-dimethylformamide to obtain a modified solution; chitosan was added to an aqueous solution of glacial acetic acid, stirred evenly, and then the modified solution was added. The mixture was refluxed at 105°C for 14 hours under vacuum and nitrogen purging. After the reaction, the mixture was washed, vacuum dried, extracted, and dried again to obtain the chitosan-cyclodextrin material. The mass-volume ratio of modified β-cyclodextrin, N,N-dimethylformamide, chitosan, and aqueous solution of glacial acetic acid was 1.1 g: 40 mL: 1.1 g: 80 mL; the volume fraction of the aqueous solution of glacial acetic acid was 1.4%. Step S3: Anhydrous ferric chloride and sodium citrate dihydrate were added to ethylene glycol and ultrasonically stirred until homogeneous. Then, anhydrous sodium acetate was added and ultrasonically stirred again until a homogeneous solution was formed. The homogeneous solution was reacted at 220℃ for 10 h. After the reaction was completed, the solution was cooled, washed, and vacuum dried to obtain Fe3O4 nanoparticles. The mass-volume ratio of anhydrous ferric chloride, sodium citrate dihydrate, anhydrous sodium acetate, and ethylene glycol was 4.9 g: 2 g: 7.5 g: 120 mL. Step S4: Dissolve the chitosan-cyclodextrin material in a 12wt% acetic acid solution, adjust the pH of the solution to 5.0, and then slowly add sodium tripolyphosphate solution under stirring to obtain a chitosan-cyclodextrin solution. Add Fe3O4 nanoparticles to the sodium tripolyphosphate solution, stir evenly, and then slowly add the chitosan-cyclodextrin solution dropwise. After the addition is complete, continue stirring and react for 50 hours. After the reaction is complete, dialyze to obtain the magnetically loaded material. The concentration of sodium tripolyphosphate solution is 0.0014 g / mol, and the reaction mass ratio of chitosan-cyclodextrin material to Fe3O4 nanoparticles is 2:1.1. Step 3: Inoculate the microbial inoculum into the culture medium and ferment at 35℃ for 10 days. After the fermentation is completed, the fermented Chinese medicine residue is obtained. The concentration of Bacillus thuringiensis in the microbial inoculum is 25g / L, the concentration of Bacillus subtilis is 15g / L, and the concentration of Trichoderma is 25g / L. 40g of straw powder, 15g of urea, 20g of fermented Chinese medicinal residue, 5g of magnetic loading material, and 3g of sodium carboxymethyl cellulose were mixed and stirred. After stirring evenly, the mixture was granulated and dried to obtain the finished product.

[0029] Comparative Example 3: The magnetic composite material and magnetic load material were removed, and the rest was the same as in Example 1. The specific steps are as follows: Step 1: 300g rice bran, 200g peanut meal, 150g dried tangerine peel residue powder, 100g phellodendron bark residue powder, 100g isatis root residue powder, and 80g eugenol residue powder were mixed, pulverized, and sterilized to obtain a mixture; the mixture was added to distilled water and stirred evenly to prepare a culture medium; the pH of the culture medium was 7.0 and the water content was 60%; Step 2: Inoculate the microbial inoculum into the culture medium and ferment at 35℃ for 10 days. After the fermentation is completed, the fermented Chinese medicine residue is obtained. The concentration of Bacillus thuringiensis in the microbial inoculum is 25g / L, the concentration of Bacillus subtilis is 15g / L, and the concentration of Trichoderma is 25g / L. 40g of straw powder, 15g of urea, 20g of fermented Chinese medicinal herb residue, and 3g of sodium carboxymethyl cellulose were mixed and stirred until uniform. The mixture was then granulated and dried to obtain the finished product.

[0030] Six maize experimental plots contaminated with heavy metals were selected, each plot measuring 10m × 10m. The average copper ion content in each plot was 340 mg / kg, and the average chromium ion content was 530 mg / kg. Six plots were treated with the six groups of soil remediation agents prepared in Examples 1-3, with 15g of the agent sprayed per square meter of soil. Using a controlled variable method, and maintaining consistent planting conditions, maize was planted in the plots. After the planting period, the average copper ion content, average chromium ion content, and yield of the experimental plots were measured. The results are shown in the table below:

[0031] Conclusion: In Examples 1-3, the dosage remained unchanged, with only some reaction parameters modified. Experimental data show that the various properties of the samples did not exhibit significant fluctuations.

[0032] Comparative Example 1: The fermented Chinese medicine residue was removed, and the rest was the same as in Example 1. The experimental data showed that, compared with Example 1, pests and diseases appeared in the corn experimental field, and the yield decreased to 74 kg. The reason for this was that the fermented Chinese medicine residue contained a variety of antibacterial components, and the dominant bacterial group formed during the fermentation process also inhibited the growth of harmful bacteria. Therefore, after removing the fermented Chinese medicine residue, pests and diseases appeared in the corn crop during its growth, and the yield decreased.

[0033] Comparative Example 2: The magnetic composite material was removed, while the rest remained the same as in Example 1. Experimental data showed that, compared to Example 1, the average copper ion content increased to 67.4 mg / kg, the average chromium ion content increased to 128.6 mg / kg, and the yield decreased to 108 kg. The reason for this is that the magnetic composite material contains various materials capable of adsorbing heavy metal ions, and the presence of magnetic particles allows the composite material to be effectively separated in the soil by an external magnetic field. Therefore, removing the magnetic composite material resulted in an increase in the average copper ion content, an increase in the average chromium ion content, and a decrease in corn crop yield compared to Example 1.

[0034] Comparative Example 3: The magnetic composite material and magnetic load material were removed. The experimental data showed that, compared with Example 1, the average copper ion content increased to 113.9 mg / kg, the average chromium ion content increased to 205.7 mg / kg, and the yield decreased to 93 kg. The reason for this is that, based on Comparative Example 2, the magnetic load material was further removed, which further reduced the adsorption effect of heavy metal ions. Therefore, compared with Example 1, the average copper ion content increased further, the average chromium ion content increased further, and the corn crop yield decreased further.

[0035] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process method article or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process method article or apparatus.

[0036] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a soil remediation agent containing traditional Chinese medicine residue ferment, characterized in that: The method comprises the following steps: ​ Step one: mix rice bran, peanut meal, dried tangerine or orange peel residue powder, cortex phellodendri residue powder, radix isatidis residue powder, and eugenol residue powder, and then crush and sterilize the mixture to obtain a mixed material; add the mixed material to distilled water, stir until uniform, and then prepare a culture solution; Step two: inoculate the microbial liquid into the culture solution, and obtain a traditional Chinese medicine residue fermentation product after cultivation; mix straw powder, urea, the traditional Chinese medicine residue fermentation product, a magnetic composite material, a magnetic loaded material, and a molding aid, stir until uniform, and then granulate, dry, and obtain a finished product.

2. The preparation method of the soil remediation agent containing traditional Chinese medicine residue ferment according to claim 1, characterized in that: In step one, the content of each component in the mixed material is as follows: 300-400 parts of rice bran, 200-300 parts of peanut meal, 150-200 parts of dried tangerine or orange peel residue powder, 100-150 parts of cortex phellodendri residue powder, 100-150 parts of radix isatidis residue powder, and 80-100 parts of eugenol residue powder; the pH of the culture solution is 6.5-7.0, and the water content is 50-60%.

3. The method according to claim 1, wherein the soil remediation agent is prepared by the following steps: (1) mixing the Chinese medicine residue with the fermentation material to obtain a mixture; (2) fermenting the mixture to obtain the soil remediation agent. In step two, the concentration of bacillus thuringiensis in the microbial liquid is 20-25 g / L, the concentration of bacillus subtilis is 10-15 g / L, and the concentration of trichoderma is 20-25 g / L; the culture process of the microbial liquid is as follows: cultivate and ferment at 30-35℃ for 8-10 days; the content of each component in the finished product is as follows: 40-50 parts of straw powder, 15-20 parts of urea, 20-30 parts of the traditional Chinese medicine residue fermentation product, 10-15 parts of the magnetic composite material, 5-10 parts of the magnetic loaded material, and 3-5 parts of the molding aid; the molding aid is specifically sodium carboxymethyl cellulose.

4. The method of claim 1, wherein the soil remediation agent comprises Chinese medicine residue fermented product. The preparation process of the magnetic composite material is as follows: ​ Step S1: wash, dry, and grind the traditional Chinese medicine residue to obtain a traditional Chinese medicine residue powder; pyrolyze the traditional Chinese medicine residue powder in an oxygen-free environment at 300-400℃ for 3.0-3.5 hours, and then grind and sieve the pyrolyzed product to obtain a traditional Chinese medicine biochar; add ferric chloride hexahydrate and ferrous sulfate heptahydrate to ultrapure water, stir until uniform, add the traditional Chinese medicine biochar, slowly add sodium hydroxide solution, adjust the pH to 10.0-10.5, and then stand overnight; after standing, wash with water and alcohol, dry, grind, and sieve to obtain a magnetic biochar; Step S2: in a nitrogen environment, add ferric chloride hexahydrate and ferrous sulfate heptahydrate to ultrapure water, stir until uniform, add sepiolite, stir at 55-60℃ for 20-25 min, slowly add concentrated ammonia water, adjust the pH to 10.0-10.5, and then stand overnight; after standing, wash with water and alcohol, dry, grind, and sieve to obtain a magnetic sepiolite; Step S3: add tetrabutyl titanate to anhydrous ethanol, continuously stir for 40-60 min to obtain a titanium dioxide precursor; disperse the magnetic biochar and the magnetic sepiolite in anhydrous ethanol, add 30-33 wt% ammonia water, ultrasonic disperse for 25-30 min, stir at 30-35℃ for 70-90 min, add the titanium dioxide precursor dropwise, continue to stir for 8-9 h after the addition is completed, and then wash with water and alcohol, vacuum dry, grind, and sieve to obtain a magnetic composite material.

5. The method of claim 4, wherein the soil remediation agent is prepared by the following steps: (1) mixing the Chinese medicine residue and the fermentation material; (2) fermenting the mixture; (3) drying the fermented mixture; and (4) grinding the dried fermented mixture. In step S1, the Chinese herbal medicine residue includes tangerine peel residue powder, phellodendron bark residue powder, isatis root residue powder, and eugenol residue powder, with a mixing ratio of 15:10:10:(7-9); the reaction mass ratio of ferric chloride hexahydrate, ferrous sulfate heptahydrate, and Chinese herbal biochar is (1.8-2.0):1:2.5; in step S2, the reaction mass ratio of ferric chloride hexahydrate, ferrous sulfate heptahydrate, and sepiolite is (1.8-2.0):1:3.

5.

6. The method of claim 4, wherein the soil remediation agent is prepared by the following steps: (1) mixing the Chinese medicine residue and the fermentation material; (2) fermenting the mixture; (3) drying the fermented mixture; and (4) grinding the dried fermented mixture. In step S3, the reaction volume ratio of tetrabutyl titanate and anhydrous ethanol is 1:10; the mass-volume ratio of magnetic biochar, magnetic sepiolite, anhydrous ethanol, ammonia, and titanium dioxide precursor is 0.03g:0.03g:5mL:0.05mL:(1.0-1.2)mL.

7. The method according to claim 1, wherein the soil remediation agent is prepared by the following steps: (1) mixing the Chinese medicine residue with the fermentation material; (2) fermenting the mixture; (3) drying the fermented mixture; and (4) grinding the dried fermented mixture to obtain the soil remediation agent. The preparation process of the magnetic load material is as follows: Step S1: Add p-toluenesulfonyl chloride to acetonitrile and stir until homogeneous to obtain a p-toluenesulfonyl chloride solution; add β-cyclodextrin to distilled water and stir until homogeneous, then add 8.0-8.2 mol / L sodium hydroxide solution dropwise. After the addition is complete, add p-toluenesulfonyl chloride solution dropwise at 0-2℃. After the addition is complete, continue the reaction at 0-2℃ for 2.5-3.0 h. After the reaction is complete, filter, adjust pH, let stand overnight, recrystallize, and vacuum dry to obtain modified β-cyclodextrin. Step S2: Add modified β-cyclodextrin to N,N-dimethylformamide to obtain a modified solution; add chitosan to glacial acetic acid aqueous solution, stir evenly, add the modified solution, and reflux at 100-105℃ for 12-14 hours under vacuum and nitrogen. After the reaction is completed, wash, vacuum dry, extract, and dry again to obtain chitosan-cyclodextrin material. Step S3: Add anhydrous ferric chloride and sodium citrate dihydrate to ethylene glycol, stir ultrasonically until homogeneous, then add anhydrous sodium acetate and continue ultrasonic stirring until a homogeneous solution is formed; react the homogeneous solution at 200-220℃ for 9-10 hours, and after the reaction is completed, cool, wash and vacuum dry to obtain Fe3O4 nanoparticles; Step S4: Dissolve the chitosan-cyclodextrin material in a 10-12 wt% acetic acid solution, adjust the pH of the solution to 3.5-5.0, and slowly add sodium tripolyphosphate solution under stirring to obtain a chitosan-cyclodextrin solution; add Fe3O4 nanoparticles to the sodium tripolyphosphate solution, stir evenly, and then slowly add the chitosan-cyclodextrin solution dropwise. After the addition is complete, continue stirring and reacting for 45-50 hours. After the reaction is complete, dialyze to obtain the magnetically loaded material.

8. The method according to claim 7, wherein the soil remediation agent is prepared by the following steps: (1) mixing the Chinese medicine residue with the fermentation material; (2) fermenting the mixture; (3) drying the fermented mixture; and (4) grinding the dried fermented mixture to obtain the soil remediation agent. In step S1, the mass-to-volume ratio of p-toluenesulfonyl chloride, β-cyclodextrin, and sodium hydroxide solution is 5 g: 30 g: (12-14) mL; in step S2, the mass-to-volume ratio of modified β-cyclodextrin, N,N-dimethylformamide, chitosan, and glacial acetic acid aqueous solution is (1.0-1.2) g: 40 mL: (1.0-1.2) g: 80 mL; the volume fraction of glacial acetic acid aqueous solution is 1.2-1.5%.

9. The method according to claim 7, wherein the soil remediation agent is prepared by the following steps: (1) mixing the Chinese medicine residue with the fermentation material; (2) fermenting the mixture; (3) drying the fermented mixture; and (4) grinding the dried fermented mixture to obtain the soil remediation agent. In step S3, the mass-volume ratio of anhydrous ferric chloride, sodium citrate dihydrate, anhydrous sodium acetate, and ethylene glycol is (4.8-5.0) g:2 g:7.5 g:120 mL; in step S4, the concentration of the sodium tripolyphosphate solution is 0.0013-0.0015 g / mol, and the reaction mass ratio of the chitosan-cyclodextrin material and the Fe3O4 nanoparticles is 2:(1.0-1.2).

10. A soil remediation agent containing a Chinese medicine residue ferment, characterized in that, Prepared according to the preparation method of any one of claims 1-9.

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