Biomass charcoal adsorption material, preparation method and application of biomass charcoal adsorption material in pesticide degradation

Abstract

The invention provides a biomass charcoal adsorption material and a preparation method thereof, and belongs to the field of pesticide degradation. The preparation method comprises the following steps: preparing biochar, preparing modified biochar and compounding. The compounding method comprises the following steps: adding modified biochar, bacillus subtilis, pseudomonas FH2, bacillus licheniformis and phanerochaete chrysosporium into deionized water, stirring, filtering, adding a filter cake into a chitosan solution, then adding Tween 60, stirring for 2-3 hours at the speed of 500-600r / min, slowly dropwise adding a glutaraldehyde solution, continuously stirring for 8-10 hours after dropwise adding, finally centrifuging at the speed of 7000-8000r / min, and drying to obtain the biochar composite material. Collecting solids, and drying to obtain a biomass charcoal adsorption material; the biomass charcoal adsorption material disclosed by the invention has broad spectrum on pesticide degradation, the degradation rate on trichlorfon reaches 87 to 89 percent, the degradation rate on acetamiprid reaches 89 to 93 percent, the degradation rate on deltamethrin reaches 93 to 96 percent, and the degradation rate on DDT reaches 65 to 70 percent.

Description

Technical Field

[0001] This invention belongs to the field of pesticide degradation technology, specifically relating to a biochar adsorbent material, its preparation method, and its application and process in pesticide degradation. Background Technology

[0002] Pesticides have made a significant contribution to increasing and stabilizing crop yields. Currently, common pesticide types include organophosphates, pyrethroids, carbamates, neonicotinoids, and herbicides. However, some pesticide varieties have long residual periods and are not easily degraded in the soil, which can seriously pollute the soil ecological environment and even accumulate through the food chain, causing great harm to humans, animals, and plants. For example, organophosphate (chlorpyrifos) residues can hinder rice growth and are highly toxic to beneficial organisms such as bees and earthworms, leading to bee deaths, decreased soil fertility, and convulsions and death of birds after accidental ingestion.

[0003] Biochar has a large specific surface area and porous structure, which gives it a strong adsorption capacity for pesticides and other substances in the soil. However, its adsorption capacity is limited, and once it is saturated, it is difficult to separate from the soil and is prone to desorption, causing secondary pollution. At the same time, it has a poor degradation effect on pesticides.

[0004] Patent CN119639465A discloses an iron-based soil conditioner for rapid degradation of pesticides in farmland and its application method. This technical solution utilizes the synergistic effect of nitrogen- and sulfur-doped biochar and industrial micronized iron powder. The biochar adsorbs pesticides, while the nitrogen and sulfur elements enhance the reactivity of zero-valent iron, thus achieving rapid pesticide degradation. However, S1, after the conditioner is applied to the soil, irrigation and mulching are required to retain moisture and isolate oxygen, increasing water consumption. The mulching and uncovering steps also increase labor costs, and in windy and rainy areas, the mulch is easily damaged, potentially affecting the maintenance effect. S2, if this conditioner is applied to the same plot for several consecutive years, the total iron content in the soil may gradually increase, potentially inhibiting the absorption of other trace elements (such as zinc and manganese) by crop roots, leading to reduced crop yield. Furthermore, nitrogen and sulfur are released over a long period (especially in acidic soils, where nitrogen readily releases as NH4+). + Sulfur is released in the form of SO4. 2- (In some forms, NH4+ is released), which may lead to excessive nitrogen and sulfur in the soil, thereby altering the nutrient dependence of the microbial community, such as the release of NH4+ into the soil. + Excessive SO4 can promote the proliferation of nitrifying bacteria, which consume oxygen and carbon sources in the soil and inhibit other beneficial bacteria. In anaerobic soils (such as paddy fields), excessive SO4 can further exacerbate the problem. 2- It will be reduced to H2S (a toxic gas) by sulfate-reducing bacteria, which will inhibit the respiration of most microorganisms, leading to a sharp drop in the activity of the microbial community.

[0005] Studies have shown that the more aromatic components on the surface of biochar, the more π-π interactions the benzene rings in the aromatic components can form with the N heterocycles in pesticides, thus resulting in better adsorption of pesticides. The more oxygen-containing functional groups on the surface of biochar, the more electrons the oxygen-containing functional groups can transfer to dissolved oxygen to form superoxide radicals, which in turn form hydroxyl radicals, thus resulting in better oxidative degradation of pesticides.

[0006] However, in the process of biochar preparation, a lower preparation temperature results in more oxygen-containing functional groups and fewer aromatic components; a higher preparation temperature results in fewer oxygen-containing functional groups and more aromatic components. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a biochar adsorbent material, a preparation method, and its application and process in pesticide degradation, achieving the following objectives: it can effectively adsorb and decompose different pesticide residues, and the decomposition effect is long-lasting.

[0008] To solve the above technical problems, the technical solution adopted by the present invention is as follows: A biochar adsorbent material and its preparation method include: preparing biochar, preparing modified biochar, and combining them; 1. Preparation of biochar S1, Primary pyrolysis Clean the pine wood and dry it at 60-95℃ for 12-24 hours. After crushing, pass it through a 40-100 mesh sieve to obtain a uniform powder. Then, add it to the reaction vessel along with deionized water, stir evenly, seal the reaction vessel, and place the reaction vessel in a muffle furnace. Heat the mixture to 260-300℃ at a rate of 5-10℃ / min and hold it at that temperature for 16-20 hours. During this period, maintain the pressure inside the reaction vessel at 4-8MPa. After the reaction is completed, allow the reaction vessel to cool naturally to room temperature, filter it, and wash the solid product repeatedly with deionized water until the filtrate is neutral. Dry it in an oven at 60-80℃ to constant weight to obtain primary pyrolytic biochar. The mass ratio of the powdered raw material to deionized water is 0.8–1.2:20–30.

[0009] S2, secondary pyrolysis The pyrolysis biochar was added to hydrochloric acid solution and soaked for 20-40 minutes. After filtration, the filter cake and pretreated chicken manure were mixed evenly. Then, under N2 atmosphere, the temperature was raised to 500-700℃ at 4-6℃ / min and kept at that temperature for 1.5-2.5 hours. After natural cooling, the biochar was obtained. The hydrochloric acid solution has a mass fraction of 10-20%. The mass ratio of the filter cake to the pretreated chicken manure is 1-3:2-4; The method for preparing the pretreated chicken manure is as follows: rinse the chicken manure with clean water 1 to 3 times, air dry it naturally until the moisture content is 30 to 40%, then place it in an oven at 60 to 80°C to dry for 12 to 18 hours, then crush it with a pulverizer and pass it through a 20 to 40 mesh sieve to obtain the pretreated chicken manure.

[0010] 2. Preparation of modified biochar Biochar, glucose, arabinose, and xylose were added to deionized water, ultrasonically dispersed for 10–15 min, allowed to stand for 6–8 h, filtered, and the filter cake was dried at 60–70 °C for 1–3 h. The temperature was then increased to 160–200 °C at a rate of 1–3 °C / min, kept at that temperature for 3–5 h, and allowed to cool naturally to obtain modified biochar. The mass ratio of biochar, glucose, arabinose, xylose, and deionized water is 10–15:4–6:0.8–1.2:2.5–3.5:25–35.

[0011] 3. Composite Modified biochar, Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, and Phanerochaete chrysosporium were added to deionized water and stirred at 15–25 r / min for 4–6 h. After filtration, the filter cake was added to a chitosan solution, followed by the addition of Tween 60. The mixture was stirred at 500–600 r / min for 2–3 h, and then glutaraldehyde solution was slowly added dropwise at a rate of 1–3 ml / min. After the addition was complete, stirring was continued for 8–10 h. Finally, the mixture was centrifuged at 7000–8000 r / min, the solid was collected, and dried at 30–50 °C for 10–15 min to obtain the biochar adsorbent material. The mass ratio of the modified biochar, Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, Phanerochaete chrysosporium, and deionized water is 8–12:3–4:1–2:2–3:0.6–0.8:20–25. The mass ratio of the filter cake, chitosan solution, Tween 60, and glutaraldehyde solution is 4–6:20–30:0.15–0.25:10–15. The chitosan solution has a mass fraction of 2-5%; The glutaraldehyde solution has a mass fraction of 6-8%.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: The biochar prepared by this invention is first obtained by hydrothermal method at low temperature to obtain primary pyrolysis biochar with abundant oxygen-containing functional groups and carbon-rich skeleton on its surface. Then, it is mixed with pretreated chicken manure and subjected to secondary pyrolysis. During the pyrolysis process, the pretreated chicken manure is rich in protein, which undergoes dehydration, deammoniation and decarboxylation reactions. Subsequently, peptide bonds are broken, amino acids are degraded, and nitrogen-containing compounds such as amides, nitriles, pyrroles, and indoles are formed. Finally, these compounds undergo cross-linking, condensation and aromatization reactions with the oxygen-containing functional groups and carbon-rich skeleton on the surface of the primary pyrolysis biochar to obtain biochar rich in aromatic components.

[0013] During the preparation of modified biochar, after the biochar adsorbs glucose, arabinose and xylose, it undergoes pyrolysis, cross-linking and polymerization at 160-200℃, ultimately forming a large number of oxygen-containing functional groups on the biochar.

[0014] After modified biochar is adsorbed with Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, and Phanerochaete chrysosporium, chitosan is formed on the surface of the biochar to form a thin film. This can effectively reduce the impact of the environment on Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, and Phanerochaete chrysosporium, and improve the survival rate of microorganisms.

[0015] The biochar adsorbent material of this invention is rich in aromatic components and contains a large number of oxygen-containing functional groups. The benzene ring in the aromatic components can form π-π interactions with the N heterocycle in pesticides, which can effectively adsorb pesticide residues. The oxygen-containing functional groups on the surface can transfer electrons and have a high ability to generate reactive oxygen species. They can transfer electrons to dissolved oxygen to form superoxide radicals, which in turn form hydroxyl radicals, thereby promoting the degradation of pesticides. It is loaded with Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, and Proteobacterium chrysosporium, which can further degrade pesticides or even completely decompose them.

[0016] The biochar adsorbent material of this invention exhibits broad-spectrum degradation effects on various types of pesticides, achieving degradation rates of 87-89% for trichlorfon, 89-93% for acetamiprid, 93-96% for deltamethrin, and 65-70% for DDT. It also demonstrates persistent pesticide degradation, remaining effective even after secondary applications, with degradation rates of 80-84% for trichlorfon, 87-90% for acetamiprid, 90-95% for deltamethrin, and 65-68% for DDT. Detailed Implementation

[0017] Example 1 A biochar adsorbent material and its preparation method, comprising: 1. Preparation of biochar S1, Primary pyrolysis Clean the pine wood, dry it at 80℃ for 18 hours, pulverize it and pass it through a 60-mesh sieve to obtain a uniform powder. Then, add it to the reactor along with deionized water, stir it evenly, seal the reactor, place the reactor in a muffle furnace, heat it to 280℃ at a rate of 7℃ / min, and hold it at that temperature for 18 hours. During this period, maintain the pressure inside the reactor at 6MPa. After the reaction is completed, allow the reactor to cool naturally to room temperature, filter it, and wash the solid product repeatedly with deionized water until the filtrate is neutral. Dry it in a 70℃ oven to constant weight to obtain primary pyrolytic biochar. The mass ratio of the powdered raw material to deionized water is 1:25.

[0018] S2, secondary pyrolysis The biochar from the first pyrolysis was added to hydrochloric acid solution and soaked for 30 minutes. After filtration, the filter cake and pretreated chicken manure were mixed evenly. Then, under N2 atmosphere, the temperature was raised to 600℃ at 5℃ / min and kept at that temperature for 2 hours. After natural cooling, the biochar was obtained. The hydrochloric acid solution has a mass fraction of 15%. The mass ratio of the filter cake to the pretreated chicken manure is 2:3; The method for preparing the pretreated chicken manure is as follows: rinse the chicken manure twice with clean water, air dry it naturally until the moisture content is 35%, then dry it in a 70℃ oven for 15 hours, then crush it with a pulverizer and pass it through a 30-mesh sieve to obtain the pretreated chicken manure.

[0019] 2. Preparation of modified biochar Biochar, glucose, arabinose, and xylose were added to deionized water, ultrasonically dispersed for 12 minutes, allowed to stand for 7 hours, filtered, and the filter cake was dried at 65℃ for 2 hours. The temperature was then increased to 180℃ at 2℃ / min and kept at that temperature for 4 hours. After natural cooling, modified biochar was obtained. The mass ratio of biochar, glucose, arabinose, xylose, and deionized water is 13:5:1:3:30.

[0020] 3. Composite Modified biochar, Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, and Phanerochaete chrysosporium were added to deionized water and stirred at 20 r / min for 5 h. After filtration, the filter cake was added to a chitosan solution, followed by the addition of Tween 60. After stirring at 550 r / min for 2.5 h, glutaraldehyde solution was slowly added dropwise at a rate of 2 ml / min. After the addition was complete, stirring was continued for 9 h. Finally, the mixture was centrifuged at 7500 r / min, the solid was collected, and dried at 40 °C for 12 min to obtain the biochar adsorbent material. The mass ratio of the modified biochar, Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, Phanerochaete chrysosporium, and deionized water is 10:3.5:1.5:2.4:0.7:23. The mass ratio of the filter cake, chitosan solution, Tween 60, and glutaraldehyde solution is 5:25:0.2:13. The chitosan solution has a mass fraction of 4%; The glutaraldehyde solution has a mass fraction of 7%.

[0021] Example 2 A biochar adsorbent material and its preparation method, comprising: 1. Preparation of biochar S1, Primary pyrolysis Clean the pine wood, dry it at 60℃ for 12 hours, pulverize it and pass it through a 40-mesh sieve to obtain a uniform powder. Then, add it to the reaction vessel along with deionized water, stir it evenly, seal the reaction vessel, place the reaction vessel in a muffle furnace, heat it to 260℃ at a rate of 5℃ / min, and hold it at that temperature for 16 hours. During this period, maintain the pressure inside the reaction vessel at 4MPa. After the reaction is completed, allow the reaction vessel to cool naturally to room temperature, filter it, and wash the solid product repeatedly with deionized water until the filtrate is neutral. Dry it in a 60℃ oven to constant weight to obtain primary pyrolytic biochar. The mass ratio of the powdered raw material to deionized water is 0.8:20.

[0022] S2, secondary pyrolysis The pyrolysis biochar was added to hydrochloric acid solution and soaked for 20 minutes. After filtration, the filter cake and pretreated chicken manure were mixed evenly. Then, under N2 atmosphere, the temperature was increased to 500℃ at 4℃ / min and kept at 1.5h. After natural cooling, the biochar was obtained. The hydrochloric acid solution has a mass fraction of 10%. The mass ratio of the filter cake to the pretreated chicken manure is 1-3:2-4; The method for preparing the pretreated chicken manure is as follows: rinse the chicken manure once with clean water, air dry it naturally until the moisture content is 30%, then dry it in a 60℃ oven for 12 hours, then crush it with a pulverizer and pass it through a 20-mesh sieve to obtain the pretreated chicken manure.

[0023] 2. Preparation of modified biochar Biochar, glucose, arabinose, and xylose were added to deionized water, ultrasonically dispersed for 10 min, allowed to stand for 6 h, filtered, and the filter cake was dried at 60℃ for 1 h. The temperature was then increased to 160℃ at 1℃ / min, kept at that temperature for 3 h, and naturally cooled to obtain modified biochar. The mass ratio of biochar, glucose, arabinose, xylose, and deionized water is 10:4:0.8:2.5:25.

[0024] 3. Composite Modified biochar, Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, and Phanerochaete chrysosporium were added to deionized water and stirred at 15 r / min for 4 h. After filtration, the filter cake was added to a chitosan solution, and then Tween 60 was added. After stirring at 500 r / min for 2 h, glutaraldehyde solution was slowly added dropwise at a rate of 1 ml / min. After the addition was completed, stirring was continued for 8 h. Finally, the mixture was centrifuged at 7000 r / min, the solid was collected, and dried at 30 °C for 10 min to obtain the biochar adsorbent material. The mass ratio of the modified biochar, Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, Phanerochaete chrysosporium, and deionized water is 8:3:1:2:0.6:20. The mass ratio of the filter cake, chitosan solution, Tween 60, and glutaraldehyde solution is 4:20:0.15:10. The chitosan solution has a mass fraction of 2%; The glutaraldehyde solution has a mass fraction of 6%.

[0025] Example 3 A biochar adsorbent material and its preparation method, comprising: 1. Preparation of biochar S1, Primary pyrolysis Clean the pine wood, dry it at 95℃ for 24 hours, pulverize it and pass it through a 100-mesh sieve to obtain a uniform powder. Then, add it to the reaction vessel along with deionized water, stir it evenly, seal the reaction vessel, place the reaction vessel in a muffle furnace, heat it to 300℃ at a rate of 10℃ / min, and hold it at that temperature for 20 hours. During this period, maintain the pressure inside the reaction vessel at 8MPa. After the reaction is completed, allow the reaction vessel to cool naturally to room temperature, filter it, and wash the solid product repeatedly with deionized water until the filtrate is neutral. Dry it in an oven at 80℃ to constant weight to obtain primary pyrolytic biochar. The mass ratio of the powdered raw material to deionized water is 1.2:30.

[0026] S2, secondary pyrolysis The pyrolysis biochar was added to hydrochloric acid solution and soaked for 40 minutes. After filtration, the filter cake and pretreated chicken manure were mixed evenly. Then, under N2 atmosphere, the temperature was increased to 700℃ at 6℃ / min and kept at that temperature for 2.5 hours. After natural cooling, the biochar was obtained. The hydrochloric acid solution has a mass fraction of 20%. The mass ratio of the filter cake to the pretreated chicken manure is 3:4. The method for preparing the pretreated chicken manure is as follows: the chicken manure is rinsed with clean water three times, naturally dried until the moisture content is 40%, then placed in an 80℃ oven for 18 hours, pulverized with a pulverizer, and passed through a 40-mesh sieve to obtain the pretreated chicken manure.

[0027] 2. Preparation of modified biochar Biochar, glucose, arabinose, and xylose were added to deionized water, ultrasonically dispersed for 15 minutes, allowed to stand for 8 hours, filtered, and the filter cake was dried at 70℃ for 3 hours. The temperature was then increased to 200℃ at 3℃ / min and kept at that temperature for 5 hours. After natural cooling, modified biochar was obtained. The mass ratio of biochar, glucose, arabinose, xylose, and deionized water is 15:6:1.2:3.5:35.

[0028] 3. Composite Modified biochar, Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, and Phanerochaete chrysosporium were added to deionized water and stirred at 25 r / min for 6 h. After filtration, the filter cake was added to a chitosan solution, followed by the addition of Tween 60. After stirring at 600 r / min for 3 h, glutaraldehyde solution was slowly added dropwise at a rate of 3 ml / min. After the addition was complete, stirring was continued for 10 h. Finally, the mixture was centrifuged at 8000 r / min, the solid was collected, and dried at 50 °C for 15 min to obtain the biochar adsorbent material. The mass ratio of the modified biochar, Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, Phanerochaete chrysosporium, and deionized water is 12:4:2:3:0.8:25. The mass ratio of the filter cake, chitosan solution, Tween 60, and glutaraldehyde solution is 6:30:0.25:15. The chitosan solution has a mass fraction of 5%; The glutaraldehyde solution has a mass fraction of 8%.

[0029] Comparative Example 1 Based on Example 1, the step of preparing modified biochar is omitted, specifically: 1. Preparation of biochar S1, Primary pyrolysis Clean the pine wood, dry it at 80℃ for 18 hours, pulverize it and pass it through a 60-mesh sieve to obtain a uniform powder. Then, add it to the reactor along with deionized water, stir it evenly, seal the reactor, place the reactor in a muffle furnace, heat it to 280℃ at a rate of 7℃ / min, and hold it at that temperature for 18 hours. During this period, maintain the pressure inside the reactor at 6MPa. After the reaction is completed, allow the reactor to cool naturally to room temperature, filter it, and wash the solid product repeatedly with deionized water until the filtrate is neutral. Dry it in a 70℃ oven to constant weight to obtain primary pyrolytic biochar. The mass ratio of the powdered raw material to deionized water is 1:25.

[0030] S2, secondary pyrolysis The biochar from the first pyrolysis was added to hydrochloric acid solution and soaked for 30 minutes. After filtration, the filter cake and pretreated chicken manure were mixed evenly. Then, under N2 atmosphere, the temperature was raised to 600℃ at 5℃ / min and kept at that temperature for 2 hours. After natural cooling, the biochar was obtained. The hydrochloric acid solution has a mass fraction of 15%. The mass ratio of the filter cake to the pretreated chicken manure is 2:3; The method for preparing the pretreated chicken manure is as follows: rinse the chicken manure twice with clean water, air dry it naturally until the moisture content is 35%, then dry it in a 70℃ oven for 15 hours, then crush it with a pulverizer and pass it through a 30-mesh sieve to obtain the pretreated chicken manure.

[0031] 2. Composite Biochar, Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, and Phanerochaete chrysosporium were added to deionized water and stirred at 20 r / min for 5 h. After filtration, the filter cake was added to a chitosan solution, followed by the addition of Tween 60. After stirring at 550 r / min for 2.5 h, glutaraldehyde solution was slowly added dropwise at a rate of 2 ml / min. After the addition was complete, stirring was continued for 9 h. Finally, the mixture was centrifuged at 7500 r / min, the solid was collected, and dried at 40 °C for 12 min to obtain the biochar adsorbent material. The mass ratio of biochar, Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, Phanerochaete chrysosporium, and deionized water is 10:3.5:1.5:2.4:0.7:23. The mass ratio of the filter cake, chitosan solution, Tween 60, and glutaraldehyde solution is 5:25:0.2:13. The chitosan solution has a mass fraction of 4%; The glutaraldehyde solution has a mass fraction of 7%.

[0032] Comparative Example 2 Based on Example 1, the steps are modified as follows: Modified biochar, Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, and Phanerochaete chrysosporium were added to deionized water and stirred at 20 r / min for 5 h. After filtration, the filter cake was dried at 40 °C for 12 min to obtain biochar adsorbent material. The mass ratio of the modified biochar, Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, Phanerochaete chrysosporium, and deionized water is 10:3.5:1.5:2.4:0.7:23.

[0033] Experimental Example 1 The degradation rates of different pesticides were tested on the biochar adsorbents prepared in Examples 1-3 and Comparative Examples 1-2. The test results are shown in Table 1. Table 1

[0034] Test method: Add 30g / kg of biochar adsorbent to 0.2mg / kg of pesticide-containing soil to be treated, then till the soil to a depth of 15cm. After one week, test the pesticide residues in the soil and calculate the pesticide degradation rate.

[0035] Second spraying After completing the tests using the methods described above, 0.2 mg / kg of the aforementioned pesticide was added to the soil, and the soil was then tilled to a depth of 15 cm. One week later, pesticide residues in the soil were tested, and the pesticide degradation rate was calculated. The results are shown in Table 2. Table 2

[0036] The results above show that Comparative Example 1 did not modify the biochar, resulting in a reduction in the number of oxygen-containing functional groups and thus a decrease in the degradation effect on pesticides. In Comparative Example 2, after the modified biochar adsorbed Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, and Protozoa chrysophyllariae, no chitosan was added. Without the protection of the chitosan film, the microorganisms were more susceptible to external influences, resulting in a decrease in the persistence of pesticide degradation.

Claims

1. A biochar adsorbent material and its preparation method, characterized in that: The preparation method includes preparing biochar, preparing modified biochar, and compounding; The method for preparing biochar includes primary pyrolysis and secondary pyrolysis; The method of primary pyrolysis is as follows: clean the pine wood, dry it at 60-95℃ for 12-24 hours, pulverize it and pass it through a 40-100 mesh sieve to obtain a uniform powdered raw material, then add it to the reaction vessel together with deionized water, stir it evenly and seal the reaction vessel, put the reaction vessel into a muffle furnace, heat it to 260-300℃ at a rate of 5-10℃ / min, and hold it at that temperature for 16-20 hours, during which the pressure inside the reaction vessel is maintained at 4-8MPa. After the reaction is completed, cool it to room temperature, filter it, wash it and dry it to obtain primary pyrolysis biochar. The secondary pyrolysis method is as follows: add the biochar from the primary pyrolysis to a hydrochloric acid solution, soak for 20-40 minutes, filter, mix the filter cake and pretreated chicken manure evenly, and then heat to 500-700℃ at 4-6℃ / min under N2 atmosphere, keep at the temperature for 1.5-2.5 hours, and cool naturally to obtain biochar.

2. The biochar adsorbent material and its preparation method according to claim 1, characterized in that: In the method for preparing biochar, the mass ratio of powdered raw material to deionized water is 0.8–1.2:20–30; The mass fraction of the hydrochloric acid solution is 10-20%. The mass ratio of filter cake to pretreated chicken manure is 1-3:2-4.

3. The biochar adsorbent material and its preparation method according to claim 1, characterized in that: In the method for preparing biochar, the method for preparing pretreated chicken manure is as follows: the chicken manure is rinsed with clean water 1 to 3 times, naturally dried until the moisture content is 30 to 40%, then placed in an oven at 60 to 80°C for 12 to 18 hours, pulverized with a pulverizer, and passed through a 20 to 40 mesh sieve to obtain pretreated chicken manure.

4. The biochar adsorbent material and its preparation method according to claim 1, characterized in that: The method for preparing modified biochar is as follows: biochar, glucose, arabinose, and xylose are added to deionized water, ultrasonically dispersed for 10-15 minutes, allowed to stand for 6-8 hours, filtered, and the filter cake is dried at 60-70℃ for 1-3 hours. Then, the temperature is increased to 160-200℃ at a rate of 1-3℃ / min, kept at that temperature for 3-5 hours, and naturally cooled to obtain modified biochar.

5. The biochar adsorbent material and its preparation method according to claim 4, characterized in that: In the method for preparing modified biochar, the mass ratio of biochar, glucose, arabinose, xylose, and deionized water is 10–15:4–6:0.8–1.2:2.5–3.5:25–35.

6. The biochar adsorbent material and its preparation method according to claim 1, characterized in that: The composite method involves adding modified biochar, Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, and Phanerochaete chrysosporium to deionized water, stirring at a rate of 15–25 r / min for 4–6 h, filtering, adding the filter cake to a chitosan solution, then adding Tween 60, stirring at a rate of 500–600 r / min for 2–3 h, slowly adding glutaraldehyde solution at a rate of 1–3 ml / min, continuing stirring for 8–10 h after the addition is complete, and finally centrifuging at 7000–8000 r / min to collect the solid, drying at 30–50 °C for 10–15 min to obtain the biochar adsorbent material.

7. The biochar adsorbent material and its preparation method according to claim 6, characterized in that: In the aforementioned composite method, the mass ratio of modified biochar, Bacillus subtilis, Pseudomonas FH2, Bacillus licheniformis, Phanerochaete chrysosporium, and deionized water is 8–12:3–4:1–2:2–3:0.6–0.8:20–25. The mass ratio of filter cake, chitosan solution, Tween 60, and glutaraldehyde solution is 4–6:20–30:0.15–0.25:10–15. The mass fraction of the chitosan solution is 2-5%; The mass fraction of glutaraldehyde solution is 6-8%.

8. A biochar adsorbent material prepared by the preparation method according to any one of claims 1-7.

Images