Efficient carbon-fixing fertilizing carbon-based material for treating soil degradation and preparation method thereof

Abstract

The application discloses a kind of high-efficiency carbon fixation and fertilization carbon-based material for treating soil degradation and preparation method thereof, and relates to the technical field of carbon-based material.The high-efficiency carbon fixation and fertilization carbon-based material for treating soil degradation includes the following raw materials by weight fraction: corn straw biochar 40-60 parts, ammonium magnesium phosphate 10-20 parts, humic acid potassium 3-8 parts, modified synergist 20-30 parts, binder 2-5 parts.The application generates intermediate 1 by reacting 1,3,6,8-tetraaminopyrene with oleic acid, intermediate 1 reacts with glutathione under the action of photoinitiator to generate intermediate 2, and intermediate 2 reacts with N-(4-chlorobutyl)-3-hydroxy-4-[(β-D-glucopyranosyl)oxy]benzamide to prepare modified synergist.The high-efficiency carbon fixation and fertilization carbon-based material for treating soil degradation prepared by the application has excellent carbon fixation capacity and can effectively improve soil fertility.

Description

Technical Field

[0001] This invention relates to the field of carbon-based materials technology, specifically to a highly efficient carbon-based material for soil degradation control and its preparation method. Background Technology

[0002] With the emergence of soil degradation problems, such as declining soil organic matter, compaction, salinization, and nutrient imbalance, the development of efficient soil remediation and improvement materials has become increasingly important. Carbon-based materials, especially biochar prepared from agricultural waste (such as straw), are widely considered one of the most promising materials for remediating soil degradation due to their rich porous structure, chemical stability, and environmental friendliness. Biochar's high chemical and microbial stability allows it to sequester carbon in the soil for extended periods, achieving carbon sequestration and emission reduction; simultaneously, its excellent adsorption properties help retain water and fertilizer, thereby improving soil health. However, in practical applications, traditional biochar materials have been found to have limitations in carbon sequestration and fertilization effects.

[0003] Chinese invention patent CN103351217A discloses a method for preparing multifunctional biochar potassium fertilizer, including the following steps: A. crushing raw materials; B. mixing biomass raw materials with potassium hydroxide; C. preparing biochar potassium fertilizer. This invention is a one-step method for preparing multifunctional biochar potassium fertilizer via biomass pyrolysis. During the preparation process, potassium hydroxide reacts with carbon dioxide and organic acids produced by pyrolysis, reducing carbon dioxide emissions and capturing carbon elements in the biomass, achieving the purpose of carbon fixation and emission reduction. The prepared multifunctional biochar potassium fertilizer, when applied to the field, adsorbs pollutants in the soil, improves the soil environment, and can provide a long-term potassium source, realizing green agriculture. However, its fertilization effect is still insufficient. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a highly efficient carbon-based material for soil degradation control and its preparation method.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A highly efficient carbon-based material for soil degradation control includes the following raw materials in parts by weight: 40-60 parts corn straw biochar, 10-20 parts magnesium ammonium phosphate, 3-8 parts potassium humate, 20-30 parts modifier and synergist, and 2-5 parts binder. The modified synergist is prepared by the following method: S1: 1,3,6,8-Tetraaminopyrene reacts with oleic acid to form intermediate 1, and the reaction equation is shown below:

[0006] S2: Intermediate 1 reacts with glutathione under the action of a photoinitiator to generate intermediate 2. The reaction equation is shown below:

[0007] S3: Intermediate 2 reacts with N-(4-chlorobutyl)-3-hydroxy-4-[(β-D-glucopyranosyl)oxy]benzamide to generate a modified synergist, and the reaction equation is shown below:

[0008] In step S1, the molar ratio of 1,3,6,8-tetraaminopyrene to oleic acid is 1:(4.1-4.3).

[0009] In step S2, the molar ratio of intermediate 1 to glutathione is 1:(4.05-4.1).

[0010] In step S3, the molar ratio of intermediate 2 to N-(4-chlorobutyl)-3-hydroxy-4-[(β-D-glucopyranosyl)oxy]benzamide is 1:(4.1-4.2).

[0011] The reaction time for step S1 is 7-9 hours, and the reaction temperature is 25-30℃.

[0012] In step S2, the photoinitiator is 2,2-dimethoxy-2-phenylacetophenone.

[0013] The reaction time for step S3 is 6-8 hours, and the reaction temperature is 50-55℃.

[0014] The reaction solvent in step S1 is anhydrous DMF; the reaction solvent in step S2 is a mixed solution of deionized water and DMF; the reaction solvent in step S3 is a mixed solution of deionized water and DMF.

[0015] The adhesive is a sodium alginate solution with a concentration of 2-5% w / v.

[0016] A method for preparing a highly efficient carbon-based material for soil degradation control includes the following steps: (1) Weigh out the following by weight: 40-60 parts of corn straw biochar, 10-20 parts of magnesium ammonium phosphate, 3-8 parts of potassium humate, 20-30 parts of modifier and synergist, and 2-5 parts of binder; (2) Add corn straw biochar, magnesium ammonium phosphate, potassium humate and modifier to a mixer, mix evenly, add binder and stir to obtain a mixture; place the mixture in a disc granulator for granulation, let stand at room temperature, dry, cool naturally to room temperature, and sieve to obtain a high-efficiency carbon-based material for soil degradation control.

[0017] Due to the adoption of the above technical solutions, the beneficial effects of the present invention include: The high-efficiency carbon-based material for soil degradation control prepared by this invention can increase the total organic carbon content of the soil, has a high soil cation exchange capacity, exhibits excellent carbon fixation ability, and can effectively improve soil fertility. Among them, the added modifier enhances the carbon fixation ability of the carbon-based material through the synergistic effect of polycyclic aromatic hydrocarbons, carboxyl groups, and hydroxyl groups; and enhances the fertilization ability of the carbon-based material through the hydrophobic effect of long-chain alkyl groups, the electrostatic effect of carboxyl groups, and the coordination effect of hydroxyl groups. Detailed Implementation

[0018] The following description, in conjunction with specific embodiments, provides further details, but the present invention is not limited to these embodiments.

[0019] Example 1: Preparation of N-(4-chlorobutyl)-3-hydroxy-4-[(β-D-glucopyranosyl)oxy]benzamide: Under nitrogen protection and in an ice bath, 300 ml of anhydrous DMF, 0.1 mol of protocatechuic acid 4-O-BETA-glucoside, 22.9 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 13.8 g of N-hydroxysuccinimide were mixed and stirred for 45 min to obtain an activated protocatechuic acid 4-O-BETA-glucoside DMF solution. 0.11 mol of 4-chloro-1-butylamine was added to 50 ml of anhydrous DMF and stirred until well mixed. The activated protocatechuic acid 4-O-BETA-glucoside DMF solution was slowly added dropwise over 60 min, and the reaction was carried out at 25 °C for 9 h (using 0.1 M... (The pH of the solution was maintained between 5.5 and 6 using HCl / NaOH solution). The mixture was slowly poured into 800 ml of cold n-hexane and stirred to precipitate. The mixture was filtered, and the filter cake was washed with 3 × 200 ml of cold n-hexane and dried under vacuum at 65 °C for 3 h to obtain N-(4-chlorobutyl)-3-hydroxy-4-[(β-D-glucopyranosyl)oxy]benzamide. The reaction equation is shown below:

[0020] Its 1H NMR data are as follows: 1 H NMR (300 MHz, DMSO- d 6) δ 8.30 (d, J = 0.5 Hz, 1H), 7.99 (s, 1H), 7.63 (dd, J = 7.5, 2.0 Hz, 1H), 7.25 (d, J = 2.0 Hz, 1H), 7.03 (d, J = 7.5 Hz, 1H), 5.02 (s, 1H), 4.71 (d, J = 5.0 Hz, 1H), 4.54 (d, J= 5.0 Hz, 1H), 4.40 (d, J = 5.0 Hz, 1H), 4.03 (t, J = 5.5 Hz, 1H), 3.86-3.60(m, 2H), 3.54-3.40 (m, 6H), 3.28 (dd, J = 1.5, 0.5 Hz, 2H), 1.94-1.77 (m,2H), 1.69 (d, J = 1.1 Hz, 2H).

[0021] Example 2: Preparation of the modified synergist: S1: Under nitrogen protection and in an ice bath, 1000 ml of anhydrous DMF, 0.41 mol of oleic acid, 94.0 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 56.6 g of N-hydroxysuccinimide were mixed and stirred for 45 min to obtain an activated oleic acid DMF solution. 0.1 mol of 1,3,6,8-tetraaminopyrene was added to 200 ml of anhydrous DMF and stirred until homogeneous. The activated oleic acid DMF solution was then slowly added dropwise over 3 h. The reaction was carried out at 25 °C for 9 h (the pH of the solution was maintained between 5.5 and 6 during the reaction using 0.1 M HCl / NaOH solution). The mixture was slowly poured into 2000 ml of ice water and stirred to precipitate. The precipitate was filtered, and the filter cake was washed with deionized water (3 × 500 ml) and dried under vacuum at 65 °C for 3 h to obtain intermediate 1. Its 1H NMR data are as follows: 1 H NMR (400 MHz, Chloroform- d )δ 9.48 (s, 4H), 8.10-7.66 (m, 4H), 7.58 (d, J = 0.5 Hz, 2H), 5.35 (s, 8H), 2.38 (s, 8H), 2.02 (s, 16H), 1.63 (s, 8H), 1.37-1.26 (m, 80H), 0.90 (s, 12H); S2: 1000 ml anhydrous DMF, 0.1 mol intermediate 1, 0.405 mol glutathione, and 0.3 g 2,2-dimethoxy-2-phenylacetophenone were added to a reaction vessel and stirred until homogeneous. The mixture was irradiated at 100 W 365 nm UV light for 30 min at room temperature, followed by vacuum distillation at 60 °C for 3 h. 800 ml n-hexane was added and stirred to precipitate the precipitate. The precipitate was filtered and dried under vacuum at 60 °C for 12 h to obtain intermediate 2. Its 1H NMR spectrum is as follows: 1 H NMR (400 MHz, Chloroform- d ) δ 11.53 (s, 4H), 11.34 (s,4H), 9.48 (s, 4H), 8.03 (d, J = 0.6 Hz, 2H), 7.97 (d, J = 0.5 Hz, 4H), 7.70(s, 2H), 7.60-7.55 (m, 6H), 4.44 (d, J = 0.5 Hz, 4H), 3.94-3.81 (m, 8H), 3.63(d, J = 0.6 Hz, 4H), 3.16-3.01 (m, 8H), 2.92 (d, J = 0.5 Hz, 4H), 2.78 (s,4H), 2.72 (d, J = 0.5 Hz, 4H), 2.41-2.23 (m, 16H), 2.08-1.90 (m, 8H), 1.63 (s, 8H), 1.55-1.42 (m, 16H), 1.39-1.26 (m, 88H), 0.90 (s, 12H); S3: Mix 1600 ml DMF, 400 ml deionized water, 0.1 mol intermediate 2, and 0.41 mol N-(4-chlorobutyl)-3-hydroxy-4-[(β-D-glucopyranosyl)oxy]benzamide, add 0.5 mol N,N-diisopropylethylamine, react at 50 °C for 8 h, cool to room temperature, wash three times with saturated brine (600 ml each time), dry with 50 g anhydrous magnesium sulfate for 2 h, filter, concentrate under reduced pressure at 60 °C for 2 h to obtain an oily crude product, purify by silica gel column chromatography (eluent: dichloromethane / methanol V / V = 5:1), and rotary evaporate at 40 °C for 5 h to obtain the modified synergist; its 1H NMR data are as follows: 1 H NMR (400 MHz, Chloroform- d) δ 11.54 (s, 4H), 11.34 (s, 4H), 9.48 (s, 4H), 8.03 (d, J = 0.5 Hz, 2H), 7.99-7.92 (m, 8H), 7.70 (s, 2H), 7.64 (dd, J = 7.5, 2.0 Hz, 4H), 7.58 (d, J =2.3 Hz, 6H), 7.28 (d, J = 2.0 Hz, 4H), 7.03 (d, J = 7.5 Hz, 4H), 5.46 (s,4H), 5.14-5.06 (m, 8H), 4.54 (d, J = 5.0 Hz, 4H), 4.44 (dd, J = 3.6, 0.5 Hz, 8H), 3.94-3.65 (m, 24H), 3.62-3.49 (m, 12H), 3.38 (d, J = 5.0 Hz, 4H), 3.30 (dd, J = 2.2, 0.5 Hz, 8H), 3.16-3.00 (m, 8H), 2.91-2.69 (m, 16H), 2.42-2.26(m, 16H), 1.94-1.74 (m, 8H), 1.65-1.42 (m, 40H), 1.41-1.26 (m, 88H), 0.90 (s,12H).

[0022] Example 3: Preparation of the modified synergist: S1: Under nitrogen protection and in an ice bath, 1000 ml of anhydrous DMF, 0.42 mol of oleic acid, 94.0 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 56.6 g of N-hydroxysuccinimide were mixed and stirred for 45 min to obtain an activated oleic acid DMF solution; 0.1 mol of 1,3,6,8-tetraaminopyrene was added to 200 ml of anhydrous DMF and stirred to mix well, and the activated oleic acid DMF solution was slowly added dropwise over 3 h. The reaction was carried out at 25 °C for 8 h (the pH of the solution was maintained between 5.5 and 6 during the reaction using 0.1 M HCl / NaOH solution); the mixture was slowly poured into 2000 ml of ice water and stirred to precipitate, filtered, and the filter cake was washed with deionized water (3 × 500 ml) and dried under vacuum at 65 °C for 3 h to obtain intermediate 1; S2: 1000 ml of anhydrous DMF, 0.1 mol of intermediate 1, 0.408 mol of glutathione, and 0.3 g of 2,2-dimethoxy-2-phenylacetophenone were added to a reaction vessel and stirred until homogeneous. The mixture was then irradiated with 100 W of 365 nm ultraviolet light at room temperature for 30 min, followed by vacuum distillation at 60 °C for 3 h. 800 ml of n-hexane was added and stirred to precipitate the precipitate. The precipitate was filtered and dried under vacuum at 60 °C for 12 h to obtain intermediate 2. S3: Mix 1600ml DMF, 400ml deionized water, 0.1mol intermediate 2, and 0.415mol N-(4-chlorobutyl)-3-hydroxy-4-[(β-D-glucopyranosyl)oxy]benzamide, add 0.5mol N,N-diisopropylethylamine, react at 50℃ for 7h, cool to room temperature, wash three times with saturated brine (600ml each time), dry with 50g anhydrous magnesium sulfate for 2h, filter, concentrate under reduced pressure at 60℃ for 2h to obtain an oily crude product, purify by silica gel column chromatography (eluent: dichloromethane / methanol V / V=5:1), and rotary evaporate at 40℃ for 5h to obtain the modified synergist.

[0023] Example 4: Preparation of the modified synergist: S1: Under nitrogen protection and in an ice bath, 1000 ml of anhydrous DMF, 0.43 mol of oleic acid, 94.0 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 56.6 g of N-hydroxysuccinimide were mixed and stirred for 45 min to obtain an activated oleic acid DMF solution; 0.1 mol of 1,3,6,8-tetraaminopyrene was added to 200 ml of anhydrous DMF and stirred to mix well, and the activated oleic acid DMF solution was slowly added dropwise over 3 h. The reaction was carried out at 30 °C for 7 h (the pH of the solution was maintained between 5.5 and 6 during the reaction using 0.1 M HCl / NaOH solution); the mixture was slowly poured into 2000 ml of ice water and stirred to precipitate, filtered, and the filter cake was washed with deionized water (3 × 500 ml) and dried under vacuum at 65 °C for 3 h to obtain intermediate 1; S2: Add 1000ml of anhydrous DMF, 0.1mol of intermediate 1, 0.41mol of glutathione, and 0.3g of 2,2-dimethoxy-2-phenylacetophenone to a reaction vessel, stir and mix well, irradiate under 100W 365nm ultraviolet light at room temperature for 30min, distill under reduced pressure at 60℃ for 3h, add 800ml of n-hexane and stir to precipitate, filter, and dry under vacuum at 60℃ for 12h to obtain intermediate 2; S3: Mix 1600ml DMF, 400ml deionized water, 0.1mol intermediate 2, and 0.42mol N-(4-chlorobutyl)-3-hydroxy-4-[(β-D-glucopyranosyl)oxy]benzamide, add 0.5mol N,N-diisopropylethylamine, react at 55℃ for 6h, cool to room temperature, wash three times with saturated brine (600ml each time), dry with 50g anhydrous magnesium sulfate for 2h, filter, concentrate under reduced pressure at 60℃ for 2h to obtain an oily crude product, purify by silica gel column chromatography (eluent: dichloromethane / methanol V / V=5:1), and rotary evaporate at 40℃ for 5h to obtain the modified synergist.

[0024] Example 5: Preparation of high-efficiency carbon-based materials for soil degradation control and fertilization: (1) Weigh the following by weight: 40g of corn stalk biochar, 10g of magnesium ammonium phosphate, 3g of potassium humate, 20g of modifier (prepared in Example 2), and 2g of binder (2% w / v sodium alginate solution); (2) Add corn straw biochar, magnesium ammonium phosphate, potassium humate and modifier to a mixer, stir at 500 rpm for 30 min, mix evenly, add binder, stir at 500 rpm for 1 h to obtain a mixture; place the mixture in a disc granulator for granulation (30 rpm, 45° tilt angle) to obtain 2-5 mm particles, let stand at room temperature for 2 h, place in a vacuum drying oven, dry at 50℃ for 2 h, raise the temperature to 60℃ for 6 h, cool naturally to room temperature, pass through a 4 mesh sieve to obtain a high-efficiency carbon-based material for soil degradation control.

[0025] Example 6: Preparation of high-efficiency carbon-based materials for soil degradation control and fertilization: (1) Weigh the following by weight: 50g of corn stalk biochar, 15g of magnesium ammonium phosphate, 6g of potassium humate, 25g of modifier (prepared in Example 3), and 3.5g of binder (4% w / v sodium alginate solution); (2) Add corn straw biochar, magnesium ammonium phosphate, potassium humate and modifier to a mixer, stir at 500 rpm for 30 min, mix evenly, add binder, stir at 500 rpm for 1 h to obtain a mixture; place the mixture in a disc granulator for granulation (30 rpm, 45° tilt angle) to obtain 2-5 mm particles, let stand at room temperature for 2 h, place in a vacuum drying oven, dry at 50℃ for 2 h, heat to 65℃ for 5 h, cool naturally to room temperature, pass through a 4 mesh sieve to obtain a high-efficiency carbon-based material for soil degradation control.

[0026] Example 7: Preparation of high-efficiency carbon-based materials for soil degradation control and fertilization: (1) Weigh the following by weight: 60g of corn stalk biochar, 20g of magnesium ammonium phosphate, 8g of potassium humate, 30g of modifier (prepared in Example 4), and 5g of binder (5% w / v sodium alginate solution); (2) Add corn straw biochar, magnesium ammonium phosphate, potassium humate and modifier to a mixer, stir at 500 rpm for 30 min, mix evenly, add binder, stir at 500 rpm for 1 h to obtain a mixture; place the mixture in a disc granulator for granulation (30 rpm, 45° tilt angle) to obtain 2-5 mm particles, let stand at room temperature for 2 h, place in a vacuum drying oven, dry at 50℃ for 2 h, heat to 70℃ for 4 h, cool naturally to room temperature, pass through a 4 mesh sieve to obtain a high-efficiency carbon-based material for soil degradation control.

[0027] Comparative Example 1 The raw material composition and preparation method of the high-efficiency carbon-based material for soil degradation remediation are basically the same as those in Example 6, except that the modifier is replaced with an equal weight of the modifier prepared by the following method: The preparation method of the modified synergist is basically the same as that in Example 3, except that 1,3,6,8-tetraaminopyrene in step S1 is replaced with an equimolar amount of 1,3,5,7-tetraaminonaphthalene (CAS No.: 98331-98-7).

[0028] Comparative Example 2 The raw material composition and preparation method of the high-efficiency carbon-based material for soil degradation remediation are basically the same as those in Example 6, except that the modifier is replaced with an equal weight of the modifier prepared by the following method: The preparation method of the modified synergist is basically the same as that in Example 3, except that the oleic acid in step S1 is replaced with an equimolar amount of (E)-4-heptenoic acid.

[0029] Comparative Example 3 The raw material composition and preparation method of the high-efficiency carbon-based material for soil degradation remediation are basically the same as those in Example 6, except that the modifier is replaced with an equal weight of the modifier prepared by the following method: The preparation method of the modified synergist is basically the same as that in Example 3, except that the glutathione in step S2 is replaced with an equimolar amount of L-cysteine.

[0030] Comparative Example 4 The raw material composition and preparation method of the high-efficiency carbon-based material for soil degradation remediation are basically the same as those in Example 6, except that the modifier is replaced with an equal weight of the modifier prepared by the following method: The preparation method of the modified synergist is basically the same as that in Example 3, except that N-(4-chlorobutyl)-3-hydroxy-4-[(β-D-glucopyranosyl)oxy]benzamide in step S3 is replaced with an equimolar amount of N-(4-chlorobutyl)-3-hydroxybenzamide. The preparation method of N-(4-chlorobutyl)-3-hydroxybenzamide is as follows: Under nitrogen protection and in an ice bath, 300 ml of anhydrous DMF, 0.1 mol of m-hydroxybenzoic acid, 22.9 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 13.8 g of N-hydroxysuccinimide were mixed and stirred for 45 min to obtain an activated m-hydroxybenzoic acid DMF solution. 0.11 mol of 4-chloro-1-butylamine was added to 50 ml of anhydrous DMF and stirred to mix. The activated m-hydroxybenzoic acid DMF solution was slowly added dropwise over 60 min, and the reaction was carried out at 25 °C for 9 h (the pH of the solution was maintained between 5.5 and 6 during the reaction using 0.1 M HCl / NaOH solution). The mixture was slowly poured into 800 ml of cold n-hexane and stirred to precipitate. The mixture was filtered, and the filter cake was washed with cold n-hexane (3 × 200 ml) and dried under vacuum at 65 °C for 3 h to obtain N-(4-chlorobutyl)-3-hydroxybenzamide.

[0031] The sodium alginate molecules used in the embodiments and comparative examples of this application have a viscosity of 200 mPa·s and a number-average molecular weight of 10000 Da; the physicochemical properties of the corn straw biochar are as follows: pH 7.89, total nitrogen content 1.11 g / kg, total phosphorus content 1.83 g / kg, total potassium content 14.46 g / kg, and organic carbon content 518.11 g / kg; the potassium humate is a powder type I, produced by Shandong Huayuan Humic Acid Ecological Agriculture Technology Co., Ltd.

[0032] The carbon-based materials for carbon fixation and fertilization prepared in Examples 5-7 and Comparative Examples 1-4 were used in a wheat pot experiment. After the wheat was harvested, the soil from the pots was collected. The soil samples were air-dried indoors and then passed through a 10-mesh sieve for testing of total organic carbon content and cation exchange capacity. The test results are shown in Table 1.

[0033] Total organic carbon content test: Different fertilizers were applied to the soil in the wheat pot experiment. The experimental group (T1) was treated with carbon-based materials for carbon fixation and fertilization prepared in Examples 5-7 and Comparative Examples 1-4, respectively. The control group 1 was not treated with any fertilizer, and the control group 2 was treated with the same amount of original corn straw biochar as T1.

[0034] Total organic carbon in soil was determined using the externally heated potassium dichromate oxidation method: 10.00 mL of 0.4 mol / L K₂Cr₂O₇-H₂SO₄ solution was accurately transferred and mixed with 0.5 g of soil. The mixture was heated in an oil bath at 170℃ for 5 min to induce a redox reaction. Excess K₂Cr₂O₇ was back-titrated with FeSO₄ standard solution. The calculated organic carbon content was multiplied by 1.724 to obtain the soil organic matter content. The calculation formula is as follows: W = [c × (V₀ - V) × 0.003 × 1.724 × 1.10] / m (W—soil organic matter content, g / kg; c—concentration of FeSO₄ standard solution, mol / L; V₀—volume of FeSO₄ standard solution consumed in the blank test, mL; V—volume of FeSO₄ standard solution consumed in the soil determination, mL; 0.003—millimolecular mass of 1 / 4 C atom, g; 1.724—organic carbon to organic matter dilution; 1.10—oxidation correction coefficient; m—soil mass, g).

[0035] Soil cation exchange capacity test: Accurately weigh 2g of soil sample into a centrifuge tube, add 25ml of 1mol / L ammonium acetate solution, stir to completely wet the sample, centrifuge at 4000rpm, discard the supernatant, and repeat this step 3 times; add 25ml of 95wt% ethanol, stir, centrifuge at 3000rpm, discard the supernatant, and repeat this step until Nessler's reagent shows no yellow color in the supernatant (i.e., no NH4+). + Continue distilling until the sample is cleaned. Transfer the cleaned sample to a Kjeldahl nitrogen analyzer for distillation. Add 1g of solid magnesium oxide to the distillation flask and immediately connect the apparatus. Insert the distillate delivery tube into an Erlenmeyer flask containing 25mL of 2wt% boric acid solution and 1 drop of methyl red-bromocresol green mixed indicator (below the liquid level). Distill until the distillate reaches 200ml. Titrate the boric acid absorption solution with 0.01mol / L hydrochloric acid standard solution. The endpoint is when the color changes from blue to slightly red. Record the volume of hydrochloric acid consumed, V. Calculate the soil cation exchange capacity using the following formula: CEC=(c×V×100) / m (CEC—soil cation exchange capacity, cmol / kg; c—concentration of hydrochloric acid standard solution, mol / L; V—volume of hydrochloric acid standard solution consumed in sample titration, mL; m—mass of soil sample, g).

[0036] Table 1

[0037] As can be seen from the data in Table 1, the high-efficiency carbon-fixing and fertilization carbon-based materials for soil degradation control prepared in Examples 5-7 of this application can increase the total organic carbon content of the soil, have a high soil cation exchange capacity, demonstrate excellent carbon fixation capacity, and effectively improve soil fertility.

[0038] The high-efficiency carbon-based material for soil degradation control prepared in this application has excellent carbon fixation capacity and high soil cation exchange capacity, which can effectively improve soil fertility. This is mainly due to the addition of modifiers containing polycyclic aromatic hydrocarbons, carboxyl groups, hydroxyl groups, and long-chain alkyl structures. Among these features, the polycyclic aromatic hydrocarbon (PAH) structure can tightly bind with the aromatic domains on the surface of biochar through π-π stacking, forming a biochar-synergist composite adsorption interface, expanding the physical adsorption capacity for greenhouse gases such as CO2 and methane, and achieving enhanced physical carbon fixation efficiency. Carboxyl groups can fix some soluble organic carbon in the soil through hydrogen bonds, while hydroxyl groups can stabilize active carbon in soil organic matter through hydrogen bonds, slowing its decomposition rate and achieving long-term sequestration of organic carbon. Furthermore, the presence of carboxyl groups and a large number of hydroxyl groups can effectively increase the soil cation exchange capacity through electrostatic interactions, efficiently capturing nutrients such as nitrogen, phosphorus, and potassium in the soil through electrostatic attraction and coordination bonds, reducing leaching loss, and maintaining nutrient supply capacity for a longer period. The presence of long-chain alkyl structures improves the hydrophobic properties of biochar, preventing water molecules from penetrating into the fertilizer core, thereby slowing nutrient release and improving soil fertility. The modified synergist used in Comparative Example 2 has poorer hydrophobic properties than the example, resulting in a less effective slowing of nutrient release and a weakened fertilization capacity of the carbon-based material. The reduction in hydroxyl structures in the modified synergist used in Comparative Example 4 resulted in a decrease in the ability to stabilize active carbon in soil organic matter, leading to a decline in the carbon fixation capacity of the carbon-based material.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. However, any modifications, alterations, and variations made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A highly efficient carbon-based material for soil degradation control and fertilization, characterized in that, The raw materials include the following parts by weight: 40-60 parts corn stalk biochar, 10-20 parts magnesium ammonium phosphate, 3-8 parts potassium humate, 20-30 parts modifier and synergist, and 2-5 parts binder. The structural formula of the modified synergist is as follows: 。 2. The high-efficiency carbon-based material for soil degradation remediation according to claim 1, characterized in that, The adhesive is a sodium alginate solution with a concentration of 2-5% w / v.

3. A method for preparing a high-efficiency carbon-based material for soil degradation remediation as described in any one of claims 1-2, characterized in that, Includes the following steps: (1) Weigh out the following by weight: 40-60 parts of corn straw biochar, 10-20 parts of magnesium ammonium phosphate, 3-8 parts of potassium humate, 20-30 parts of modifier and synergist, and 2-5 parts of binder; (2) Add corn straw biochar, magnesium ammonium phosphate, potassium humate and modifier to a mixer, mix evenly, add binder and stir to obtain a mixture; place the mixture in a disc granulator for granulation, let stand at room temperature, dry, cool naturally to room temperature, and sieve to obtain a high-efficiency carbon-based material for soil degradation control.

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