Carbon-based coenzyme polypeptide-containing soil remediation agent and preparation process thereof

Abstract

The invention discloses a carbon-based coenzyme polypeptide-containing soil remediation agent and a preparation process thereof, and belongs to the technical field of soil remediation. The soil remediation agent is prepared from the following components: modified charcoal, immobilized coenzyme, sepiolite / polypeptide amino acid, microbial agent microcapsules and fucose oligosaccharide intercalated magnesium-aluminum hydrotalcite. The prepared soil remediation agent containing the carbon-based coenzyme polypeptide can efficiently remedy polluted soil, has slow-release performance, can play a long-acting remediation role, and solves the problems that an existing soil remediation agent is limited in remediation effect on complex pollutants and short in effectiveness maintenance time; and the components of the remediation agent can improve the soil structure, improve the air permeability, water retention and granular structure of the soil, solve the problems of soil hardening and fertility decline of the polluted soil, and meanwhile, can greatly improve the crop yield, optimize the crop quality and improve the stress resistance of the crops.

Description

Technical Field

[0001] This invention relates to a carbon-based coenzyme polypeptide soil remediation agent and its preparation process, belonging to the field of soil remediation technology. Background Technology

[0002] In modern agriculture and forestry production, soil fertility and nutrient balance directly affect crop yield and quality. However, with rapid industrialization and urbanization, soil pollution has become increasingly serious, posing a significant threat to human health and the ecological environment. Therefore, soil remediation has become crucial for addressing environmental challenges.

[0003] Soil remediation agents are materials primarily used to improve the physical, chemical, and biological properties of soil, making it more suitable for plant growth. They can enhance soil fertility and promote plant growth by altering soil structure and chemical properties; they can also reduce the concentration and toxicity of heavy metals in the soil through mechanisms such as adsorption, passivation, and reduction, thus mitigating the negative impact of soil on the ecological environment. However, soil remediation agents have limited effectiveness in remediating complex pollutants, particularly heavy metals. Their application is also affected by factors such as season, temperature, and precipitation, limiting their use under different environmental conditions. Furthermore, their effectiveness is short-lived, and excessive use can have adverse effects on the soil.

[0004] Therefore, a high-efficiency, long-lasting soil remediation agent that can effectively improve soil structure is crucial for soil restoration and environmental improvement. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a carbon-based coenzyme peptide soil remediation agent and its preparation process. The resulting soil remediation agent can effectively improve soil structure, has slow-release properties, and a long-lasting effect.

[0006] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows: A carbon-based coenzyme polypeptide soil remediation agent comprises the following components: modified biochar, immobilized coenzyme, sepiolite / polypeptide amino acids, microcapsules of microbial agents, and magnesium aluminum hydrotalcite intercalated with fucoidan oligosaccharides.

[0007] Furthermore, the immobilized coenzyme is prepared as follows: the coenzyme and chitin are added to Tris-HCl buffer, gently shaken at 4°C for 36-72 hours, the supernatant is removed by centrifugation, and the mixture is washed three times with Tris-HCl buffer to obtain the immobilized coenzyme. Immobilizing the coenzyme with chitin avoids its easy inactivation in soil, improves its stability and durability, and enhances its promoting effect on microbial metabolism and organic matter degradation.

[0008] Furthermore, the mass ratio of the coenzyme to chitin is 1:(100-150); the coenzyme includes amylase, chitosanase, catalase, and protease; the ratio of chitin to Tris-HCl buffer is 1g:(10-20)mL; the concentration of Tris-HCl buffer is 50mmol / L, and the pH is 8.0. The coenzyme can promote the metabolic activities and growth and reproduction of microorganisms, accelerate the degradation of organic matter and the transformation of nutrients, reduce organic pollution in the soil, thereby improving soil structure and fertility, and promoting plant growth.

[0009] Furthermore, the method for preparing the modified biochar is as follows: (1) Crush the straw, place it in an electric resistance furnace, and pyrolyze it at 550-600℃ for 6-7 hours under a nitrogen atmosphere to obtain biochar; (2) Mix biochar, FeSO4, FeCl3 with deionized water, adjust the pH value to 9.5-10.5, sonicate for 8-12 min, vacuum filter, and pyrolyze at 400-600℃ for 1-2 h under nitrogen atmosphere to obtain iron-nitrogen biochar. (3) Add the iron-nitrogen biochar and porphyrin composite material to ethanol, ultrasonically disperse for 10-15 min, vacuum filter, wash, and dry at 100-110℃ to obtain modified biochar.

[0010] Iron-nitrogen biochar possesses a porous structure, which improves soil aeration and water retention. It is rich in organic matter and minerals, enhancing soil fertility. Furthermore, it exhibits strong adsorption capacity, forming stable complexes with heavy metal ions to effectively adsorb organic pollutants in the soil. This reduces the bioavailability of heavy metals and the biotoxicity of pesticides, promoting soil environmental remediation and improvement. Modification with porphyrin composite materials enables photocatalytic degradation of adsorbed organic pollutants, increasing the pollutant removal rate and extending the biochar's effectiveness.

[0011] Furthermore, in step (2), the mass ratio of biochar, FeSO4, FeCl3, urea, and deionized water is 1:(0.1-0.2):(0.15-0.25):(0.2-0.4):(5-7). The introduction of iron and nitrogen elements can change the internal structure of biochar, increase its specific surface area and pore volume, improve its adsorption capacity for pollutants, and increase active sites, which can catalyze the degradation of organic waste and the oxidation-reduction of pollutants.

[0012] Furthermore, in step (3), the mass ratio of the porphyrin composite material to the iron-nitrogen biochar is 1:(10-20); the ratio of the carbon-nitrogen biochar to ethanol is 1g:(10-15)mL.

[0013] Furthermore, the preparation method of the porphyrin composite material is as follows: Alkali-treated nano-titanium dioxide is ultrasonically dispersed in ethanol, then porphyrin is added, and the mixture is reacted at a speed of 800-1000 r / min and a temperature of 60-80℃ for 10-20 min. After centrifugation, drying, washing, and grinding into powder, the porphyrin composite material is obtained. The ratio of porphyrin, alkali-treated nano-titanium dioxide, and ethanol is 1 g:(0.3-0.5) g:(40-100) mL. Porphyrin is a biological growth regulator that can promote crop development and improve plant stress resistance. It also has a strong light-capturing ability. When combined with nano-titanium dioxide, it forms an organic-inorganic complex. The two work synergistically to improve photocatalytic activity and oxidize and decompose organic pollutants such as pesticides.

[0014] Furthermore, the alkali-treated nano-titanium dioxide is prepared by soaking the nano-titanium dioxide in a NaOH solution with a concentration of 0.1-0.5 mol / L for 0.5-2 hours.

[0015] Furthermore, the preparation method of the sepiolite / polypeptide amino acid is as follows: sepiolite and anhydrous ethanol are added to deionized water and stirred evenly. Then, a polypeptide amino acid solution is added and stirred for 20-30 minutes. The mixture is filtered, placed in an oven and dried at a temperature of 70-80℃, and ground into powder to obtain sepiolite / polypeptide amino acid.

[0016] Furthermore, the ratio of sepiolite, anhydrous ethanol, deionized water, and polypeptide amino acid solution is 1g:(0.3-0.7)mL:(2-4)mL:(0.4-0.6)mL; the concentration of the polypeptide amino acid solution is 50-80mg / mL. Since polypeptide amino acids are hygroscopic, water will reduce their stability, while sepiolite has a high specific surface area and excellent adsorption performance, capable of adsorbing large amounts of water. Grafting polypeptide amino acids onto sepiolite ensures the stability of the polypeptide amino acids due to sepiolite's strong water absorption. Polypeptide amino acids can increase the organic matter content in the soil, optimize soil structure, promote plant growth, and enhance plant resistance. Moreover, sepiolite can adsorb and fix nutrients in the soil, reducing nutrient loss, improving soil aeration and water retention, and also has a large adsorption capacity and ion exchange capacity, enabling it to fix pollutants in the soil or treat toxic pollutants into non-toxic or low-toxic substances.

[0017] Furthermore, the method for preparing the immobilized microbial agent microcapsules is as follows: (1) Add β-cyclodextrin and porous starch to dimethyl sulfoxide, stir for 20-40 min, adjust pH to 7-10, add epichlorohydrin, heat to 55-70℃ and react for 4-6 h, filter, wash and dry to obtain porous starch / cyclodextrin. (2) Porous starch / cyclodextrin and microbial agent are dissolved in deionized water to prepare porous starch / cyclodextrin solution and microbial agent solution, respectively. Then, the porous starch / cyclodextrin solution and microbial agent solution are mixed, shaken at 200r / min for 20-30min, and dried to obtain porous starch / cyclodextrin with immobilized microbial agent. (3) Add the porous starch / cyclodextrin and sodium alginate of the immobilized microbial agent to deionized water and stir until dissolved. Then add it dropwise at a uniform rate to a mixed solution of chitosan and calcium chloride. Stir magnetically for 10-15 minutes, separate by centrifugation, wash and dry to obtain microcapsules of microbial agent.

[0018] Further, in step (1), the mass ratio of starch to β-cyclodextrin is (10-20):1; the ratio of the total amount of β-cyclodextrin and porous starch to dimethyl sulfoxide is 1g:(25-40)mL; and the amount of epichlorohydrin added is 0.5-3% of the total mass of β-cyclodextrin and porous starch. Porous starch and β-cyclodextrin are polysaccharides that can form aggregates with soil particles, improving soil structure. They contain a large number of hydrophilic groups such as hydroxyl and carboxyl groups, which can form hydrogen bonds with water molecules, improving soil water retention capacity. They can also provide energy for microbial agents and microorganisms in the soil, promoting the growth and reproduction of microorganisms. Moreover, porous starch / cyclodextrin can undergo complexation reactions with heavy metal ions, reducing the bioavailability of metals, thereby mitigating the toxic effects of heavy metals on plants.

[0019] Furthermore, in step (2), the mass ratio of porous starch / cyclodextrin to microbial agent is 1:(0.1-0.5); the ratio of porous starch / cyclodextrin to deionized water is 1g:(20-30)mL; and the volume ratio of porous starch / cyclodextrin solution to microbial agent solution is (2-3):1. Porous starch / cyclodextrin has a well-developed pore structure and abundant surface functional groups, which allows it to create a relatively independent microenvironment for microorganisms, maintaining their survival and vitality in environments with excessive pollutants.

[0020] Furthermore, in step (2), the microbial agent is Bacillus subtilis, Bacillus megaterium, Bacillus mucilaginosus, or Bacillus amyloliquefaciens. The addition of microbial agents can decompose organic matter in the soil, produce humus, improve soil aeration, permeability, and water retention, and can also effectively remove heavy metals and pesticides and other organic pollutants in the soil through mechanisms such as biodegradation, biotransformation, and redox, significantly reducing pollutants in the soil and improving soil structure.

[0021] Furthermore, in step (3), the ratio of porous starch / cyclodextrin, sodium alginate, and deionized water in the immobilized microbial agent is (0.1-0.3) g : (1-2) g : (50-70) mL. The microbial agent is encapsulated in microcapsules to prevent it from being affected by light, heat, oxygen, etc., thus extending its shelf life and activity retention time, ensuring high activity during use. After being added to the soil, the microcapsule wall material slowly ruptures, achieving a slow and long-lasting release of the microbial agent, improving its survival rate and activity in harsh environments, and enhancing its ability to continuously degrade pollutants.

[0022] Further, in step (3), the preparation method of the chitosan and calcium chloride mixed solution is as follows: add 1 wt.% glacial acetic acid to 100 mL of chitosan solution with a concentration of 0.4-1.2 wt.% to dissolve the chitosan, then add anhydrous CaCl2 and stir until dissolved to obtain the chitosan and calcium chloride mixed solution; the concentration of CaCl2 in the mixed solution is 0.1-0.5 mol / L.

[0023] Furthermore, the preparation method of the fucoidan-intercalated magnesium aluminum hydrotalcite is as follows: magnesium nitrate and aluminum nitrate are added to deionized water and stirred evenly. Urea is added and stirred until completely dissolved. Then, fucoidan is added to the solution and stirred and reacted in a water bath at a temperature of 90-100℃ for 1-2 hours. The mixture is then filtered, washed, and dried to obtain fucoidan-intercalated magnesium aluminum hydrotalcite.

[0024] Magnesium aluminum hydrotalcite can neutralize soil pH, passivate heavy metals, and disrupt pollution chains. Through slow-release action, it reduces nitrogen and phosphorus loss, improves fertilizer utilization, and locks in nutrients and moisture, enhancing soil vitality. After hydrotalcite adsorbs heavy metals and organic pollutants, soil microorganisms can degrade them. The fucoidan in the interlayer promotes the reproduction of beneficial microorganisms in the soil. Fucoidan can also induce crops to produce stress-resistance substances, enhancing their resistance to adverse conditions, increasing intracellular hormone levels, and promoting plant growth and development.

[0025] Furthermore, the mass ratio of magnesium nitrate, aluminum nitrate, urea, fucoidan, and deionized water is (3-5):(4-6):(8-10):(0.2-0.5):(20-30).

[0026] The preparation process of a carbon-based coenzyme peptide soil remediation agent is as follows: 30-35 parts by weight of modified biochar, 15-20 parts by weight of immobilized coenzyme, 12-20 parts by weight of sepiolite / peptide amino acids, 5-10 parts by weight of microbial inoculants, and 8-12 parts by weight of fucoidan-intercalated magnesium aluminum hydrotalcite are mixed evenly to obtain the carbon-based coenzyme peptide soil remediation agent.

[0027] The principle of this invention is: Existing soil remediation agents mostly rely on single components (such as simple biochar or microbial agents) or a few combinations, which have weak synergistic treatment capabilities for complex pollutants (heavy metals + organic pollutants), and each component is easily deactivated by environmental factors. This invention innovatively designs an integrated synergistic remediation system of "adsorption-catalysis-degradation-slow release-growth promotion", which achieves efficient removal of soil pollutants (heavy metals, organic pollutants, etc.), systematic improvement of soil structure, and long-term promotion of plant growth.

[0028] (1) The porous structure formed by iron and nitrogen modification of biochar provides a large specific surface area and abundant active sites, which can capture heavy metals and organic pollutants through complexation and physical adsorption. The introduction of porphyrin composite material can also enhance the adsorption specificity of specific organic pollutants (such as pesticides) through molecular recognition. Sepiolite / polypeptide amino acids supplement the adsorption of heavy metal ions not captured by biochar through the high specific surface area and ion exchange capacity of sepiolite, and at the same time adsorb free water in the soil to avoid the instability of polypeptide amino acids due to hygroscopicity. Its layered structure can also lock in some volatile organic pollutants to prevent secondary diffusion. Fucoidosaccharide-intercalated magnesium aluminum hydrotalcite adsorbs heavy metals through ion exchange through the layered structure of magnesium aluminum hydrotalcite, while passivating the activity of heavy metals and blocking their migration to plants. The adsorption of nutrients such as nitrogen and phosphorus in the soil can reduce nutrient loss and reserve resources for subsequent growth promotion. The adsorption of the three components achieves comprehensive capture of complex pollutants and avoids the diffusion of pollutants, which leads to a decrease in remediation efficiency.

[0029] (2) Immobilized coenzymes maintain high activity in the soil, catalyzing the hydrolysis of organic pollutants into small molecules, and simultaneously catalyzing the decomposition of hydrogen peroxide in the soil, reducing the damage of oxidative stress to microorganisms and providing a suitable environment for microbial metabolism; the porphyrin-nano titanium dioxide composite material in the modified biochar has strong photocatalytic activity, and the light-trapping ability of porphyrin can enhance the utilization rate of visible light by nano titanium dioxide, catalyzing the decomposition of recalcitrant organic pollutants adsorbed by biochar and converting them into small molecule organic matter that is easily utilized by microorganisms. Enzyme catalysis and photocatalysis complement each other, decomposing recalcitrant pollutants and significantly improving the efficiency of subsequent microbial degradation.

[0030] (3) The microcapsules of microbial agents release Bacillus subtilis, Bacillus megaterium, etc., through biodegradation, redox and other mechanisms to decompose small molecule pollutants generated in the catalytic process, while simultaneously degrading heavy metals and organic pollutants adsorbed by biochar, sepiolite, and magnesium aluminum hydrotalcite; immobilized coenzymes promote the metabolic activity and growth and reproduction of microorganisms, improve the degradation rate of pollutants by microorganisms, and activate beneficial native microorganisms in the soil to form a synergistic degradation network of exogenous bacteria and native bacteria; magnesium aluminum hydrotalcite intercalated with fucoidan can provide carbon source and energy for microorganisms through fucoidan, promote the reproduction of beneficial microorganisms, strengthen the number and activity of degradation bacteria, and adsorb pollutants through magnesium aluminum hydrotalcite, slowly releasing them to provide microorganisms with continuous degradation substrates and avoid the degradation bacteria from becoming inactive due to insufficient substrates; sepiolite in sepiolite / polypeptide amino acids improves soil aeration and water retention, providing a suitable living environment for microorganisms; small molecule peptides and amino acids produced by the decomposition of polypeptide amino acids supplement the nutrients required for microbial metabolism and further enhance degradation activity. All components work together to degrade pollutants, achieving efficient removal of pollutants.

[0031] (4) The microbial agent microcapsules slowly degrade in the soil, controlling the release rate of the microbial agent and enabling it to continuously exert its degradation and improvement effects throughout the entire crop growth period. The porous starch / cyclodextrin in the inner layer provides a microenvironment for the microorganisms, further extending their active period. The magnesium aluminum hydrotalcite intercalated with fucoidan can slowly release the adsorbed nitrogen and phosphorus nutrients and fucoidan, avoiding rapid nutrient loss. At the same time, the slow release of fucoidan continuously promotes microbial reproduction, ensuring the long-term effectiveness of the degradation effect. The water and polypeptide amino acids adsorbed by sepiolite in the sepiolite / polypeptide amino acid mixture are slowly released, ensuring the stability of the polypeptide amino acids and providing a continuous supply of organic matter for the plants. The ion exchange characteristics of sepiolite can slowly release the adsorbed micronutrients, supplementing soil fertility. The chitin carrier immobilized with coenzyme slowly degrades in the soil, gradually releasing the coenzyme, avoiding the coenzyme from being degraded or inactivated by soil enzymes due to rapid release, and ensuring the continuous effect of enzyme catalysis. The slow release of the four components achieves long-term remediation, solving the pain points of existing remediation agents that have short efficacy and require frequent reapplication.

[0032] (5) Polypeptides and amino acids can optimize soil structure, increase organic matter content, promote plant root development and nutrient absorption, and enhance plant stress resistance; Fucoidooligosaccharides can induce crops to produce stress-resistant substances (such as phytoalexins), reduce the toxicity of heavy metals and pollutants to plants; increase the hormone content in plant cells and promote growth and development; the porous structure of modified biochar improves soil aeration and water retention, and the rich organic matter and mineral elements supplement soil fertility. After the pollutants adsorbed by it are degraded, the released nutrients further enhance soil fertility; microbial agents can decompose organic matter to produce humus and improve soil aggregate structure; fix nitrogen in the air and dissolve insoluble phosphorus and potassium in the soil to provide direct nutrition for plants; inhibit the reproduction of harmful bacteria and reduce plant diseases; sepiolite improves soil aeration and water retention, and together with biochar and microbial agents, further optimizes soil physical properties and creates suitable conditions for plant growth. The components added in this invention improve soil structure and fertility, enhance plant stress resistance, and synergistically achieve the dual benefits of soil remediation and high-quality, high-yield crops, forming a closed loop of soil improvement → plant growth promotion → further soil optimization.

[0033] Compared with the prior art, the beneficial effects of the present invention are: (1) The carbon-based coenzyme peptide soil remediation agent prepared by the present invention can efficiently remediate contaminated soil and has slow-release properties, thus having a long-lasting remediation effect. It improves the problem that existing soil remediation agents have limited remediation effects on complex pollutants and have a short duration of effectiveness. Moreover, the raw materials in this soil remediation agent all contribute to soil remediation.

[0034] (2) The components of this invention can improve soil structure, improve soil aeration, water retention and aggregate structure, solve the problems of soil compaction and fertility decline caused by pollution, and at the same time can significantly increase crop yield, optimize crop quality and improve crop stress resistance.

[0035] (3) All components of this invention are prepared using low-toxicity and easily degradable raw materials, with no harmful chemical reagent residues, and the process conditions are mild, energy consumption is low, and there is no harmful gas or waste liquid emission, thus avoiding secondary pollution during the remediation process and meeting environmental protection requirements. Detailed Implementation

[0036] The polypeptide amino acids of this invention are: agricultural-grade enzymatically hydrolyzed polypeptides, Shijiazhuang Xuermei Biotechnology; the protease is papain, Chengdu Wanxiang Hongrun Biotechnology.

[0037] Example 1 (1) Preparation of modified biochar: The straw was crushed and placed in an electric resistance furnace and pyrolyzed at 550℃ for 7h under a nitrogen atmosphere to obtain biochar; the biochar, FeSO4, FeCl3 and deionized water were mixed in a mass ratio of 1:0.2:0.2:0.4:7, the pH value was adjusted to 10, ultrasonicated for 10min, vacuum filtered, and pyrolyzed at 600℃ for 1h under a nitrogen atmosphere to obtain iron-nitrogen biochar; the iron-nitrogen biochar and porphyrin composite material were added to ethanol in a mass ratio of 15:1, and the ratio of carbon-nitrogen biochar to ethanol was 1g. 15 mL, ultrasonically dispersed for 15 min, vacuum filtered, washed, and dried at 105℃ to obtain modified biochar; wherein, the preparation method of porphyrin composite material is as follows: the preparation method of porphyrin composite material is as follows: the alkali-treated nano-titanium dioxide is ultrasonically dispersed in ethanol, and then porphyrin is added. The ratio of porphyrin, alkali-treated titanium dioxide and ethanol is 1 g: 0.4 g: 70 mL. The reaction is carried out at 1000 r / min and 70℃ for 15 min. After centrifugation, drying and washing, it is ground into powder to obtain porphyrin composite material; (2) Preparation of sepiolite / polypeptide amino acids: 10 parts sepiolite and 5 parts anhydrous ethanol were added to 30 parts deionized water and stirred evenly. Then 5 parts of polypeptide amino acid solution were added and stirred for 20-30 minutes. After filtration, the mixture was placed in an oven and dried at 70-80℃. It was then ground into powder to obtain sepiolite / polypeptide amino acids. (3) Preparation of microbial agent microcapsules: β-cyclodextrin and porous starch were added to dimethyl sulfoxide at a mass ratio of 1:10, stirred for 30 min, pH adjusted to 8, and then 1.5% (m / m) epichlorohydrin was added. The mixture was heated to 60℃ and reacted for 5 h. After filtration, washing and drying, porous starch / cyclodextrin was obtained. Porous starch / cyclodextrin and microbial agent were dissolved in deionized water to prepare porous starch / cyclodextrin solution and microbial agent solution, respectively. The porous starch / cyclodextrin solution and microbial agent solution were then mixed and shaken at 200 r / min for 25 min. After drying, porous starch / cyclodextrin immobilized with microbial agent was obtained. 0.1 g of porous starch / cyclodextrin immobilized with microbial agent and 1 g of sodium alginate were added to 50 mL of deionized water and stirred until dissolved. Then, the mixture was added dropwise to a mixed solution of chitosan and calcium chloride at a uniform rate. The mixture was magnetically stirred for 10 min, centrifuged, washed and dried to obtain microcapsules of immobilized microbial agent. (4) The preparation method of fucoidan-intercalated magnesium aluminum hydrotalcite is as follows: magnesium nitrate and aluminum nitrate are added to deionized water and stirred evenly. Urea is added and stirred until completely dissolved. Then fucoidan is added to the solution and stirred in a water bath at a temperature of 90-100℃ for 1-2 hours. The mixture is filtered, washed, and dried to obtain fucoidan-intercalated magnesium aluminum hydrotalcite. The mass ratio of magnesium nitrate, aluminum nitrate, urea, fucoidan, and water is 3:6:8:0.3:30. (5) Add coenzyme and chitin to 50mM Tris-HCl buffer (pH=8.0) at a mass ratio of 1:150, gently shake at 4℃ for 72h, centrifuge to remove supernatant, and wash three times with Tris-HCl buffer (pH=8.0) to obtain immobilized coenzyme. (6) Preparation of carbon-based coenzyme polypeptide soil remediation agent: 35 parts by weight of modified biochar, 15 parts by weight of immobilized coenzyme, 12 parts by weight of sepiolite / polypeptide amino acid, 5 parts by weight of microbial agent microcapsules, and 12 parts by weight of fucoidan-intercalated magnesium aluminum hydrotalcite are mixed evenly to obtain carbon-based coenzyme polypeptide soil remediation agent.

[0038] Example 2 Steps (1)-(5) are the same as in Example 1; (6) Preparation of carbon-based coenzyme polypeptide soil remediation agent: 30 parts by weight of modified biochar, 15 parts by weight of immobilized coenzyme, 20 parts by weight of sepiolite / polypeptide amino acid, 10 parts by weight of microbial agent microcapsules, and 8 parts by weight of fucoidan-intercalated magnesium aluminum hydrotalcite are mixed evenly to obtain carbon-based coenzyme polypeptide soil remediation agent.

[0039] Example 3 Steps (1)-(5) are the same as in Example 1; (6) Preparation of carbon-based coenzyme polypeptide soil remediation agent: 30 parts by weight of modified biochar, 20 parts by weight of immobilized coenzyme, 15 parts by weight of sepiolite / polypeptide amino acid, 8 parts by weight of microbial agent microcapsules, and 10 parts by weight of fucoidan-intercalated magnesium aluminum hydrotalcite are mixed evenly to obtain carbon-based coenzyme polypeptide soil remediation agent.

[0040] Comparative Example 1 The difference from Example 1 is that no modified biochar is added.

[0041] Comparative Example 2 The difference from Example 1 is that no modified biochar is added, but biochar from step (1) is added.

[0042] Comparative Example 3 The difference from Example 1 is that no modified biochar is added, but iron-nitrogen biochar from step (1) is added.

[0043] Comparative Example 4 The difference from Example 1 is that no modified biochar is added, but a biochar and porphyrin composite material from step (1) is added.

[0044] Comparative Example 5 The difference from Example 1 is that sepiolite / peptide amino acids are not added.

[0045] Comparative Example 6 The difference from Example 1 is that sepiolite / peptide amino acids are not added, but peptide amino acids from step (2) are added.

[0046] Comparative Example 7 The difference from Example 1 is that no microbial inoculant microcapsules are added.

[0047] Comparative Example 8 The difference from Example 1 is that no microbial inoculant microcapsules are added, but the microbial inoculant from step (3) is added.

[0048] Comparative Example 9 The difference from Example 1 is that microbial agent microcapsules are not added, but porous starch / cyclodextrin immobilized in step (3) is added.

[0049] Comparative Example 10 The difference from Example 1 is that no magnesium aluminum hydrotalcite with fucoidan intercalation is added.

[0050] Comparative Example 11 The difference from Example 1 is that the magnesium aluminum hydrotalcite intercalated with fucoidan is not added, but the magnesium aluminum hydrotalcite in step (4) is added.

[0051] Comparative Example 12 The difference from Example 1 is that the magnesium aluminum hydrotalcite intercalated with fucoidan is not added, but the magnesium aluminum hydrotalcite and fucoidan in step (4) are added.

[0052] Comparative Example 13 The difference from Example 1 is that no immobilized coenzyme is added.

[0053] Comparative Example 14 The difference from Example 1 is that no immobilized coenzyme is added, but the coenzyme from step (5) is added.

[0054] Experimental Example 1 (1) Take 300 kg of contaminated soil from a certain location and randomly divide it into 6 portions. Apply the carbon-based coenzyme peptide soil remediation agent obtained in Examples 1-3 to each portion of soil at a mass ratio of 0.5%. Spray water to make the soil moisture content 35%. Cultivate the soil for 30 days while maintaining this moisture content. Use a heavy metal detector (BZ-LD-ZSE, Shanghai Biaozhuo Scientific Instruments Co., Ltd.) to determine the heavy metal content in the soil before and after remediation. No soil remediation agent was applied as a control group.

[0055] (2) This experiment was conducted in a plastic greenhouse (30m×70m). The soil remediation agents containing carbon-based coenzyme peptides from Examples 1-3 were applied as experimental groups, while the control group received no soil remediation agent. The experiment was repeated four times, with a total of 16 plots, each 45m². 2The experiment employed a completely randomized block design. To minimize marginal effects, a 1.2m buffer zone was maintained between plots. Uniformly grown cucumber seedlings, cultured for 15 days, were transplanted into each plot at a density of 45,000 plants per acre. During the cucumber growing season, furrow irrigation was used to maintain field water capacity at 70-80%. Cucumber yield was then measured.

[0056] The measurement results are listed in Table 1.

[0057] Table 1. Verification of the effectiveness of soil remediation agents The measurements showed that the heavy metal content in the soil before remediation was as follows: lead 235.7 mg / kg, mercury 94.9 mg / kg, arsenic 86.2 mg / kg, and copper 368.4 mg / kg. After the application of the soil remediation agent, the heavy metal content was significantly reduced, indicating that the carbon-based coenzyme peptide soil remediation agent can effectively adsorb heavy metals in the soil and improve soil structure.

[0058] As shown in Table 1, compared with the control group, the cucumber yield was significantly increased and the nitrate content in cucumbers was significantly reduced after treatment with the carbon-based coenzyme peptide soil remediation agent of Examples 1-3. This indicates that the carbon-based coenzyme peptide soil remediation agent of the present invention can improve soil structure, promote plant growth, and improve plant yield and quality.

[0059] Experimental Example 2 The effectiveness of soil remediation in Example 1 and Comparative Examples 1-14 was determined, with commercially available soil remediation agents used as a control group. The method was the same as in Example 1. The results are listed in Table 2.

[0060] Table 2. Verification of the effectiveness of soil remediation agents As shown in Table 2, compared with commercially available soil remediation agents, Comparative Examples 1-4 can all reduce the heavy metal content in the soil, increase cucumber yield, and reduce the nitrate content in cucumbers. However, their effects are all lower than those of Example 1. This indicates that the present invention modifies biochar with iron and nitrogen and introduces porphyrin composite materials, which can have a strong adsorption capacity for heavy metals and pollutants in the soil and degrade them, improve soil structure, increase soil fertility, and promote plant growth and development. Moreover, the degradation can improve the pollutant removal rate of biochar and prolong the effectiveness of biochar.

[0061] Comparative Examples 5 and 6 showed superior performance to commercially available soil remediation agents, effectively reducing heavy metal content in the soil and increasing crop yield. This demonstrates that the introduction of sepiolite and polypeptide amino acids in this invention is beneficial for improving soil structure and enhancing plant growth and stress resistance. However, the performance was inferior to Example 1, indicating that the preparation of sepiolite / polypeptide amino acids in this invention improves the stability of both components. Compared with the soil remediation agent of Comparative Example 7, the soil remediation agents of Comparative Examples 8-9 can all reduce the heavy metal content in the soil and increase crop yield, and have a soil remediation effect. However, the effect is worse than that of the soil remediation agent of Example 1. This shows that the present invention achieves slow and long-term release of microbial agents by immobilizing microbial agents in porous starch / cyclodextrin and then preparing them into microcapsules. This can not only improve soil structure, but also provide nutrients for plants after degradation.

[0062] The soil remediation agents prepared by Comparative Example 10 (magnesium aluminum hydrotalcite without fucoidan intercalation), Comparative Example 11 (magnesium aluminum hydrotalcite with only fucoidan), and Comparative Example 12 (magnesium aluminum hydrotalcite with fucoidan) were all inferior to those prepared in Example 1. This indicates that the magnesium aluminum hydrotalcite with fucoidan intercalation of the present invention helps to improve soil structure, and fucoidan can promote microbial reproduction and provide nutrients for crops.

[0063] The soil remediation agents prepared by Comparative Example 13 without immobilized coenzyme and Comparative Example 14 with coenzyme both had worse remediation effects than those of Example 1. This is because directly adding coenzyme would affect its stability. Therefore, in this invention, the coenzyme is immobilized to ensure its stability.

[0064] Experimental Example 3 Three equal soil samples were taken from a contaminated area. Commercially available soil remediation agents and the carbon-based coenzyme peptide soil remediation agent of this invention were added to each sample, respectively. The changes in the degradation rate of organic pollutants during the remediation process were measured. The main organic pollutants in the contaminated soil were petroleum hydrocarbons and polychlorinated biphenyls (PCBs). Soil without the added soil remediation agent served as a control group. The results are listed in Table 3.

[0065] Table 3. Degradation rates of organic pollutants Table 3 shows that the degradation rate of organic pollutants in soil without added soil remediation agent was low and the degradation rate was slow. Compared with the control group, the degradation rate of organic pollutants in the soil increased and the degradation rate accelerated after adding commercially available soil remediation agent. Furthermore, the addition of the carbon-based coenzyme peptide soil remediation agent of this invention significantly increased the degradation rate of organic pollutants and significantly accelerated the degradation rate. This indicates that the carbon-based coenzyme peptide soil remediation agent of this invention can effectively degrade organic pollutants.

[0066] Experiment Example 4 The test crop was wheat, specifically the variety Yannong 15.

[0067] Sow seeds after applying basal fertilizer. The seedbed width is 1.45m, and the seeding rate is 6.5kg / mu.

[0068] Application method: Base fertilizer was evenly spread and then tilled throughout the experimental area. Topdressing was applied by furrow application, followed by irrigation. Field management and agronomic measures were consistent across all groups throughout the experiment.

[0069] Treatment Group 1: Base fertilizer: organic-inorganic compound fertilizer (nutrient content N+P2O5+K2O≥40%, 16-16-8, organic matter≥15%) + 25kg of carbon-based coenzyme peptide soil remediation agent from Example 1, topdressing was 15kg of carbon-based coenzyme peptide soil remediation agent from Example 1. Control group 1: Base fertilizer: organic-inorganic compound fertilizer (nutrient content N+P2O5+K2O≥40%, 16-16-8, organic matter≥15%) + 25kg commercially available soil remediation agent, topdressing was 15kg commercially available soil remediation agent; the commercially available soil remediation agent was purchased from Henan Shenyu Biotechnology Co., Ltd. Blank control group: Base fertilizer: organic-inorganic compound fertilizer (nutrient content N+P2O5+K2O≥40%, 16-16-8, organic matter≥15%), topdressing was 15kg Shuangbao organic-inorganic compound fertilizer.

[0070] The quality of the wheat was determined after harvest. The results are shown in Table 4.

[0071] Table 4. Wheat Quality Table 4 shows that, compared with the blank control group, the application of commercially available soil remediation agent to control group 1 improved wheat quality and yield; compared with control group 1, the application of the carbon-based coenzyme peptide soil remediation agent of this invention significantly improved wheat quality and yield. This indicates that the carbon-based coenzyme peptide soil remediation agent of this invention significantly increases wheat yield by improving soil structure, enhancing fertility, and promoting wheat growth.

Claims

1. A carbon-based coenzyme peptide soil remediation agent, characterized in that: It contains the following components: modified biochar, immobilized coenzyme, sepiolite / peptide amino acids, microcapsules of microbial agents, and magnesium aluminum hydrotalcite intercalated with fucoidan oligosaccharides.

2. The carbon-based coenzyme peptide soil remediation agent according to claim 1, characterized in that: The method for preparing the immobilized coenzyme is as follows: add the coenzyme and chitin to Tris-HCl buffer, gently shake at 4°C for 36-72 hours, centrifuge to remove the supernatant, and wash three times with Tris-HCl buffer to obtain the immobilized coenzyme.

3. The carbon-based coenzyme peptide soil remediation agent according to claim 1, characterized in that: The method for preparing the modified biochar is as follows: (1) Crush the straw, place it in an electric resistance furnace, and pyrolyze it at 550-600℃ for 6-7 hours under a nitrogen atmosphere to obtain biochar; (2) Mix biochar, FeSO4, FeCl3 with deionized water, adjust the pH value to 9.5-10.5, sonicate for 8-12 min, vacuum filter, and pyrolyze at 400-600℃ for 1-2 h under nitrogen atmosphere to obtain iron-nitrogen biochar. (3) Add the iron-nitrogen biochar and porphyrin composite material to ethanol, ultrasonically disperse for 10-15 min, vacuum filter, wash, and dry at 100-110℃ to obtain modified biochar.

4. The carbon-based coenzyme peptide soil remediation agent according to claim 3, characterized in that: In step (3), the preparation method of the porphyrin composite material is as follows: the nano-titanium dioxide treated with alkali is ultrasonically dispersed in ethanol, then porphyrin is added, and after reaction, it is centrifuged, dried, washed, and ground into powder to obtain the porphyrin composite material.

5. The carbon-based coenzyme peptide soil remediation agent according to claim 1, characterized in that: The preparation method of the sepiolite / polypeptide amino acid is as follows: sepiolite and anhydrous ethanol are added to deionized water and stirred evenly. Then, a polypeptide amino acid solution is added and stirred for 20-30 minutes. The mixture is filtered, placed in an oven and dried at a temperature of 70-80℃, and ground into powder to obtain sepiolite / polypeptide amino acid.

6. The carbon-based coenzyme peptide soil remediation agent according to claim 1, characterized in that: The preparation method of the microbial agent microcapsules is as follows: (1) Add β-cyclodextrin and porous starch to dimethyl sulfoxide, stir for 20-40 min, adjust pH to 7-10, add epichlorohydrin, heat to 55-70℃ and react for 4-6 h, filter, wash and dry to obtain porous starch / cyclodextrin. (2) Porous starch / cyclodextrin and microbial agent are dissolved in deionized water to prepare porous starch / cyclodextrin solution and microbial agent solution, respectively. Then, the porous starch / cyclodextrin solution and microbial agent solution are mixed, shaken at 200r / min for 20-30min, and dried to obtain porous starch / cyclodextrin with immobilized microbial agent. (3) Add the porous starch / cyclodextrin and sodium alginate of the immobilized microbial agent to deionized water and stir until dissolved. Then add it dropwise at a uniform rate to a mixed solution of chitosan and calcium chloride. Stir magnetically for 10-15 minutes, separate by centrifugation, wash and dry to obtain microcapsules of microbial agent.

7. The carbon-based coenzyme peptide soil remediation agent according to claim 6, characterized in that: In step (2), the mass ratio of the porous starch / cyclodextrin to the microbial agent is 1: (0.1-0.5).

8. The carbon-based coenzyme peptide soil remediation agent according to claim 1, characterized in that: The preparation method of the fucoidan-intercalated magnesium aluminum hydrotalcite is as follows: magnesium nitrate and aluminum nitrate are added to deionized water and stirred evenly. Urea is added and stirred until completely dissolved. Then, fucoidan is added to the solution and stirred and reacted in a water bath at a temperature of 90-100℃ for 1-2 hours. The mixture is then filtered, washed, and dried to obtain fucoidan-intercalated magnesium aluminum hydrotalcite.

9. The carbon-based coenzyme peptide soil remediation agent according to claim 8, characterized in that: The mass ratio of magnesium nitrate, aluminum nitrate, urea, fucoidan, and water is (3-5):(4-6):(8-10):(0.2-0.5):(20-30).

10. A preparation process for the carbon-based coenzyme peptide soil remediation agent according to claim 1, characterized in that: Mix 30-35 parts by weight of modified biochar, 15-20 parts by weight of coenzyme, 12-20 parts by weight of sepiolite / peptide amino acids, 5-10 parts by weight of microbial inoculant microcapsules, and 8-12 parts by weight of fucoidan-intercalated magnesium aluminum hydrotalcite evenly to obtain a carbon-based coenzyme peptide soil remediation agent.

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