A graphene-based soil conditioner made from tortoise shell medicinal residue and its preparation method

Abstract

This invention relates to the field of soil conditioner technology, specifically to a tortoise shell medicinal residue graphene composite soil conditioner and its preparation method. The raw materials include tortoise shell medicinal residue powder, graphene, fermentation mixture, and nano-silver, in a mass ratio of (5-10):(7-15):(15-35):(1-2). The tortoise shell medicinal residue powder has a particle size of 800-1000 mesh, the graphene is obtained from the tortoise shell medicinal residue, and the fermentation mixture includes wood ash, straw, manure, granulating agent, humic acid, and fermentation inoculant. In preparation, the tortoise shell medicinal residue is powdered, and graphene is obtained through oxidation-reduction of the tortoise shell medicinal residue. The resulting mixture is then combined with the tortoise shell medicinal residue powder, graphene, fermentation mixture, and nano-silver. This tortoise shell medicinal residue graphene composite soil conditioner improves soil permeability, water retention, and fertilizer retention capacity. It provides inorganic and organic nutrients to the soil and absorbs harmful components, resulting in excellent soil improvement and maximizing the utilization of the tortoise shell medicinal residue.

Description

Technical Field

[0001] This invention relates to the field of soil conditioner technology, specifically to a tortoise shell residue graphene composite soil conditioner and its preparation method. Background Technology

[0002] Tortoise shell is a traditional Chinese medicinal material with a history of thousands of years. According to the "Compendium of Materia Medica," it is one of the five most precious medicinal materials in China. Studies have shown that tortoise shell residue is rich in various beneficial components, such as protein, calcium carbonate, collagen, chondroitin sulfate, amino acids, calcium, phosphorus, and magnesium. The protein content is approximately 30%, and the calcium carbonate content is around 50%. Tortoise shell is used extensively, and even the residue after decoction or preliminary processing still has high medicinal value. However, current treatment of tortoise shell residue mainly involves low-value applications and extensive processing. Most of it is not utilized as a resource but is instead landfilled or incinerated, resulting in resource waste and serious environmental pollution. Therefore, its transformation and efficient utilization are particularly important.

[0003] Existing patent literature discloses a granular bio-organic fertilizer and its production process, in which tortoise shell residue is used as aggregate, and its volume ratio with other components in the fertilizer is only 1:(25-30). This makes it impossible to consume a large amount of tortoise shell residue. The particle size used is 20-30 mesh. The main purpose is to utilize its structure in combination with other raw materials to promote the fertilizer's fertility and enhance its compressive strength, but it does not fully utilize the fertility of the tortoise shell residue itself for plants. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the prior art, such as low utilization of tortoise shell residue and failure to fully utilize the fertility of tortoise shell residue for plants, thereby providing a tortoise shell residue graphene composite soil conditioner and its preparation method.

[0005] Therefore, the present invention provides the following technical solution:

[0006] This invention provides a tortoise shell medicinal residue graphene composite soil conditioner, the raw materials of which include tortoise shell medicinal residue powder, graphene, fermentation mixture and nano silver; the mass ratio of the tortoise shell medicinal residue powder, the graphene, the fermentation mixture and the nano silver is (5-10):(7-15):(15-35):(1-2); the particle size of the tortoise shell medicinal residue powder is 800-1000 mesh; the graphene is prepared from tortoise shell medicinal residue; the raw materials of the fermentation mixture include wood ash, straw, manure, granulating agent, humic acid and fermentation agent.

[0007] Preferably, the mass ratio of the wood ash, the straw, the manure, the granulating agent, the humic acid, and the fermentation agent is (4-8):(2-4):(2-3):(1-2):(1-2):(2-3).

[0008] Preferably, the fermentation agent includes any one or more of the following: yeast agent, Bacillus licheniformis agent, photosynthetic bacteria agent, Trichoderma harzianum agent, Bacillus subtilis agent, and Lactobacillus agent.

[0009] Preferably, the granulating agent includes any one or a mixture of two of bentonite and attapulgite.

[0010] This invention also provides a method for preparing the above-mentioned tortoise shell residue graphene composite soil conditioner, comprising the following steps:

[0011] S1: Clean the tortoise shell residue, dry it, and grind it into powder to 800-1000 mesh to obtain the tortoise shell residue powder;

[0012] S2: Carbonize, oxidize and reduce the tortoise shell residue to obtain the graphene;

[0013] S3: Mix the tortoise shell residue powder and the graphene, add a dispersant, and disperse evenly to obtain mixture A;

[0014] S4: Mix the wood ash, straw, manure, granulating agent, and humic acid to obtain mixture B;

[0015] S5: Mix the mixture B with the fermentation agent, seal and ferment to obtain the fermentation mixture;

[0016] S6: Mix the mixture A, the fermentation mixture, and the nano-silver, granulate them, and obtain the tortoise shell residue graphene composite soil conditioner.

[0017] In this invention, the sources of tortoise shell residue include pharmaceutical companies and TCM hospitals or other TCM clinics with decoction-making functions. The collected tortoise shell residue is manually screened and stored in a cool, dry and ventilated place for later use, thus realizing the large-scale recycling and utilization of tortoise shell residue.

[0018] In the preparation method of the tortoise shell medicinal residue graphene composite soil conditioner provided by this invention, grinding the tortoise shell medicinal residue to 800-1000 mesh is a conventional method in the field. Typically, and not specifically, the specific operation is as follows: grinding is carried out using an aerodynamic method. The supersonic airflow pulverizer has the following parameters: voltage: 380 (220) V, power: 238.5 kW, capacity: 180 kg, weight: 1000 kg, external dimensions: 500 × 860 × 1070 cm, maximum feed particle size ≤ 30 mm, and output 1-2 t / h. The cleaned and dried tortoise shell medicinal residue is placed into a supersonic airflow pulverization and classification system. This system typically consists of an air source, a feeding system, a supersonic nozzle, a pulverization chamber, a classification chamber, a cyclone collector, and a bag collector. Purified and dried compressed air is introduced into the Laval nozzle to form a supersonic airflow, which enters the pulverization chamber through six opposing nozzles. The tortoise shell residue is fed into the pulverizing chamber by a hopper, where it is accelerated by the airflow from various nozzles and pulverized by impacts at the intersection of the jets. It then passes through a high-speed vortex classifier, where it is classified under centrifugal force and pulverized again. A gourd-shaped Laval nozzle is used at the nozzle, with the airflow inlet on the left side of the nozzle throat (the narrowest part of the tube). The material, after sufficient collision, is accelerated from subsonic speed to Mach 1 at the throat. After passing through the throat, the nozzle opening widens, and the airflow, already at sonic speed, is quickly accelerated to supersonic speeds of Mach 7-8. Under this supersonic collision, the material can be pulverized to the micron or even nanometer scale.

[0019] Preferably, in step S1, the tortoise shell residue is cleaned with a white vinegar aqueous solution, wherein the volume ratio of water to white vinegar in the white vinegar aqueous solution is (900-1000):1. Typically, and not specifically, the specific operation for cleaning the tortoise shell residue is as follows: The collected tortoise shell residue is placed in a self-made cleaning container, which is a cylindrical container 1.5m high and 1m in diameter, equipped with a rubber stirring device. Sufficient water is added to completely submerge the residue. White vinegar is added in proportion. The stirring device is set to a speed of 200-400 r / min, and the residue is gently stirred and cleaned for 15 minutes. After cleaning, the water is drained. The above operation is repeated once. The cleanliness of the tortoise shell residue is checked. For any residue that is not cleaned properly, it can be gently rubbed with rubber gloves to remove impurities and residue.

[0020] Preferably, in step S1, the drying temperature for the tortoise shell residue is 90–100°C, and the drying time is 8–14 hours. Typically, and not specifically, the specific operation for drying the tortoise shell residue is as follows: the cleaned tortoise shell residue is placed in a professional dryer with a cylinder diameter of Ф2200mm, a cylinder length of 24m, and a cylinder volume of 91.23m³. 3Maximum inlet air temperature: 800℃, outlet exhaust gas temperature: 80~120℃, cylinder rotation speed: 3.45~0.17r / min, machine body inclination: 5%, set drying temperature to 90~100℃, time to 8~14h.

[0021] Preferably, in step S2, the carbonization temperature is 500–700°C and the carbonization time is 4–6 hours.

[0022] Preferably, in step S2, the oxidant is hydrogen peroxide, the mass ratio of carbonization product to hydrogen peroxide is (3-6):(2-5), the oxidation temperature is 100-130℃, and the oxidation time is 4-6h.

[0023] Preferably, before oxidation treatment, the carbonized product is pulverized to a particle size of <10μm.

[0024] In the preparation method of the tortoise shell residue graphene composite soil conditioner provided by this invention, pulverizing graphite particles to <10μm is a conventional method in the field. Typically, and non-limitingly, the specific operation involves using an intelligent pulverizing system, which consists of a feeder, a continuous feed ball mill, an ultrasonic screen (1500 mesh), a weighing module, a recycling system, and a central control unit. The feeder transfers graphite particles into the ball mill, transferring 5-10 kg at a time. The ball mill speed is set to a variable speed grinding speed of 10000 rpm to 20000 rpm. An ultrasonic screen is installed at the ball mill outlet to screen out particles smaller than 10μm, which are weighed in real time by the weighing module. Based on the weight of the produced graphite powder, the central control unit controls the feeder to add the corresponding weight of graphite particles. Simultaneously, the recycling system recovers the large particles screened out by the screen to the ball mill inlet for repeated pulverization. The entire screen system employs a closed-loop quality control system to ensure stable particle weight inside the ball mill, enabling continuous feeding and discharging, and is suitable for large-scale, high-quality grinding of graphite particles.

[0025] Preferably, in step S2, the reduction treatment includes the following steps: placing the oxidation product in a protective gas environment, injecting hydrogen gas, wherein the mass ratio of the oxidation product to the hydrogen gas is (9-12):(1-3), the reduction temperature is 100-130°C, and the reduction time is 10-15 h; the protective gas includes at least one of nitrogen, helium, neon, argon, krypton, xenon, and radon.

[0026] Preferably, in step S3, the mass ratio of the tortoise shell residue powder and the graphene mixture to the dispersant is (50-60):(100-130).

[0027] Preferably, in step S3, the dispersant includes any one of an ethanol solution and a tetrahydrofuran solution of polymethyl methacrylate.

[0028] Preferably, in step S3, the mass fraction of the dispersant is 5% to 15%.

[0029] Preferably, in step S3, uniform dispersion is achieved by ultrasonic oscillation for 6–8 hours.

[0030] Preferably, in step S5, the fermentation temperature is 45-55℃, the mixture is stirred once every 12-15 hours during the fermentation process, and the fermentation time is 2-3 days.

[0031] Preferably, step S6 further includes a drying step before granulation, wherein the drying temperature is 50-60°C and the drying time is 8-10 hours.

[0032] In the preparation method of the tortoise shell residue graphene composite soil conditioner provided by the present invention, a high-speed mixer can be used to mix wood ash, straw, manure, granulating agent and humic acid, with a mixing speed of 1100-1500 r / min and a mixing time of 45-60 min; a high-speed mixer can also be used to mix mixture A, fermentation mixture and nano silver, with a mixing speed of 1000-1500 r / min and a mixing time of 2-4 h.

[0033] The technical solution of this invention has the following advantages:

[0034] The raw materials of the tortoise shell medicinal residue graphene composite soil conditioner provided by this invention include tortoise shell medicinal residue powder, graphene, fermentation mixture, and nano-silver; the mass ratio of tortoise shell medicinal residue powder, graphene, fermentation mixture, and nano-silver is (5-10):(7-15):(15-35):(1-2); the particle size of the tortoise shell medicinal residue powder is 800-1000 mesh; the raw material for preparing graphene includes the tortoise shell medicinal residue powder; the fermentation mixture includes wood ash, straw, manure, granulating agent, humic acid, and fermentation inoculant. This invention achieves the recycling and utilization of tortoise shell medicinal residue and fully utilizes its own fertility through the coordination of the components, adjustment of dosage, and limitation of particle size. Specifically, tortoise shell residue contains various beneficial components, such as protein, nitrogen, phosphorus, potassium, and calcium, which can improve soil nutrition, provide corresponding nutrients for crop growth, and promote plant production. Controlling the particle size of the tortoise shell residue to 800-1000 mesh increases the specific surface area of ​​the powder, improving the proportion of tortoise shell residue powder absorbed by plants. It also effectively transports the protein and elements such as nitrogen, phosphorus, and potassium from the tortoise shell residue into the soil, improving soil fertility and creating a favorable soil environment for crops. Furthermore, the ultrafine powder structure allows it to remove heavy metals. Humic acid is a natural organic substance with weak acidity, water absorption, colloidal properties, adsorption, ion exchange, complexing properties, redox properties, and physiological activity. It helps retain soil nutrients and form soil structure, promotes mineral decomposition and nutrient release, increases the activity of aminotransferase in crops, reduces cell membrane permeability and abscisic acid content, thereby enhancing crop resistance. Nano-silver can release a large number of silver ions. Appropriate amounts of nano-silver, combined with tortoise shell residue powder and fermentation mixes, can promote plant growth and nutrient absorption. Nano-silver also helps reduce the emission of greenhouse gases (CO2, CH4, and N2O) from the soil, thus improving soil quality. Graphene has an extremely high specific surface area and adsorption capacity, and can be used to adsorb organic matter, heavy metals, and other harmful substances in the soil, achieving soil purification, reducing environmental pollution, and maintaining a healthy agricultural ecosystem. Using tortoise shell residue to produce graphene solves multiple needs with a single raw material, maximizing resource utilization. Tortoise shell residue-graphene composite soil conditioner can improve soil permeability, water retention, and fertilizer retention. Utilizing the effective components of tortoise shell residue and the properties of graphene, it simultaneously provides inorganic and organic nutrients to the soil and can absorb harmful components, resulting in excellent soil improvement effects.

[0035] The preparation method of the tortoise shell medicinal residue graphene composite soil conditioner provided by this invention includes the following steps: washing the tortoise shell medicinal residue, drying it, and pulverizing it to 800-1000 mesh to obtain tortoise shell medicinal residue powder; taking the tortoise shell medicinal residue powder, carbonizing it to obtain graphite particles, pulverizing the graphite particles, oxidizing them, and then reducing them to obtain graphene; mixing the tortoise shell medicinal residue powder and graphene, adding a dispersant, and dispersing them evenly to obtain mixture A; mixing wood ash, straw, manure, granulating agent, humic acid, and fermentation agent to obtain fermented mixture; mixing mixture A, fermented mixture, and nano-silver, granulating them, and obtaining the tortoise shell medicinal residue graphene composite soil conditioner. Tortoise shell medicinal residue contains 70% carbon, which can be grapheneized. The obtained graphene particle size is typically between several hundred nanometers and several micrometers, and can be adjusted within a wide range depending on the application scenario. Furthermore, the above processing methods can effectively transform tortoise shell residue into high-value-added graphite products. Since soil conditioners have relatively low requirements for graphene purity (90% is sufficient), a low-cost, high-efficiency preparation method can be used to achieve large-scale production, reducing the negative environmental impact of waste and realizing resource recycling. By simply pulverizing the tortoise shell residue to 800-1000 mesh before mixing it with other raw materials for granulation, the key effective components of the tortoise shell residue are preserved as much as possible, improving its utilization rate. After mixing the tortoise shell residue powder and graphene, a dispersant is used to help ensure more uniform mixing, allowing each component to exert its full effect. Detailed Implementation

[0036] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0037] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0038] Example 1

[0039] This embodiment provides a method for preparing a graphene composite soil conditioner made from tortoise shell residue, comprising the following steps:

[0040] (1) Use a white vinegar solution with a volume ratio of 1000:1 (water and white vinegar) to wash the tortoise shell residue. Put the washed tortoise shell residue into a dryer, set the temperature to 90℃, and dry for 8 hours. Use a supersonic airflow pulverizer to grind it into powder with a particle size of 800-850 mesh to obtain tortoise shell residue powder.

[0041] (2) Take a portion of the tortoise shell residue powder obtained in (1) and put it into a carbonization furnace. Heat it to 500℃ and keep it at that temperature for 4 hours to obtain graphite particles with impurities. Use an intelligent pulverizing system to pulverize the graphite particles to <10μm to obtain graphite powder. Mix the graphite powder with hydrogen peroxide at a mass ratio of 3:2 and stir it. Then put it into an oxidation furnace, heat it to 100℃ and keep it at that temperature for 4 hours to obtain graphene oxide. Spray the graphene oxide into a reduction furnace and inject hydrogen under nitrogen protection. The mass ratio of graphene oxide to hydrogen is 9:1. Control the temperature at 100℃ and keep it at that temperature for 12 hours to obtain graphene.

[0042] (3) Take 1.5 kg of tortoise shell residue powder obtained in (1) and 2.5 kg of graphene obtained in (2) and mix them. Add 10% ethanol solution. The total mass ratio of tortoise shell residue powder and graphene to ethanol solution is 60:110. Perform ultrasonic oscillation treatment for 8 hours to obtain mixture A1.

[0043] (4) The wood ash, straw, animal manure, bentonite and humic acid in a mass ratio of 4:2:2:1:1 were fed into a high-speed mixer and stirred at a speed of 1100 r / min for 45 min to obtain mixture B1.

[0044] (5) Put mixture B1 into a fermentation tank, add yeast inoculum, the mass ratio of yeast inoculum to wood ash is 2:4, maintain the internal temperature of the fermentation material between 45 and 55°C, stir once every 12 hours, seal and ferment for 2 days to obtain fermented mixture.

[0045] (6) Add all mixture A1, 10kg of fermentation mixture and 0.2kg of nano silver to a high-speed mixer, with a speed of 1000r / min and a stirring time of 4h. Then send the mixture to a dryer and dry it at 50℃. Then send it to a granulator to granulate to obtain the tortoise shell residue graphene composite soil conditioner.

[0046] Example 2

[0047] This embodiment provides a method for preparing a graphene composite soil conditioner made from tortoise shell residue, comprising the following steps:

[0048] (1) Use a white vinegar solution with a water-to-white vinegar volume ratio of 900:1 to wash the tortoise shell residue. Put the washed tortoise shell residue into a dryer, set the temperature to 95℃, and dry for 10 hours. Use a supersonic airflow pulverizer to grind it into powder with a particle size of 900-950 mesh to obtain tortoise shell residue powder.

[0049] (2) Take a portion of the tortoise shell residue powder obtained in (1) and put it into a carbonization furnace. Heat it to 600℃ and keep it at that temperature for 5 hours to obtain graphite particles with impurities. Use an intelligent pulverizing system to pulverize the graphite particles to <10μm to obtain graphite powder. Mix the graphite powder with hydrogen peroxide at a mass ratio of 3:2 and stir it. Then put it into an oxidation furnace, heat it to 120℃ and keep it at that temperature for 5 hours to obtain graphene oxide. Spray the graphene oxide into a reduction furnace and inject hydrogen under nitrogen protection. The mass ratio of graphene oxide to hydrogen is 12:3. Control the temperature at 110℃ and keep it at that temperature for 10 hours to obtain graphene.

[0050] (3) Take 1.5 kg of tortoise shell residue powder obtained in (1) and 2.0 kg of graphene obtained in (2) and mix them. Add 9% ethanol solution. The total mass ratio of tortoise shell residue powder and graphene to ethanol solution is 70:120. Perform ultrasonic oscillation treatment for 8 hours to obtain mixture A2.

[0051] (4) The wood ash, straw, animal manure, bentonite and humic acid in a mass ratio of 6:3:2.5:1.5:1.5 were fed into a high-speed mixer and stirred at a speed of 1100 r / min for 45 min to obtain mixture B2.

[0052] (5) Put mixture B2 into a fermentation tank, add yeast inoculant and Bacillus licheniformis inoculant in a mass ratio of 1:1, the mass ratio of yeast inoculant plus Bacillus licheniformis inoculant to wood ash is 2.5:6, maintain the internal temperature of the fermentation material between 45 and 55°C, stir once every 12 hours, seal and ferment for 2 days to obtain fermented mixture.

[0053] (6) Add all mixture A2, 8kg of fermentation mixture and 0.3kg of nano silver to a high-speed mixer, with a speed of 1000r / min and a stirring time of 4h. Then send the mixture to a dryer and dry it at 50℃. Then send it to a granulator to granulate it to obtain the tortoise shell residue graphene composite soil conditioner.

[0054] Example 3

[0055] This embodiment provides a method for preparing a graphene composite soil conditioner made from tortoise shell residue, comprising the following steps:

[0056] (1) Use a white vinegar solution with a volume ratio of 1000:1 (water and white vinegar) to wash the tortoise shell residue. Put the washed tortoise shell residue into a dryer, set the temperature to 100℃, and dry for 12 hours. Use a supersonic airflow pulverizer to grind it into powder with a particle size of 950-1000 mesh to obtain tortoise shell residue powder.

[0057] (2) Take a portion of the tortoise shell residue powder obtained in (1) and put it into a carbonization furnace. Heat it to 700℃ and keep it at that temperature for 6 hours to obtain graphite particles with impurities. Use an intelligent pulverizing system to pulverize the graphite particles to <10μm to obtain graphite powder. Mix the graphite powder with hydrogen peroxide at a mass ratio of 5.5:2.5 and stir it. Then put it into an oxidation furnace, heat it to 130℃ and keep it at that temperature for 6 hours to obtain graphene oxide. Spray the graphene oxide into a reduction furnace and inject hydrogen under nitrogen protection. The mass ratio of graphene oxide to hydrogen is 11:2. Control the temperature at 130℃ and keep it at that temperature for 15 hours to obtain graphene.

[0058] (3) Take 2.0 kg of tortoise shell residue powder obtained in (1) and 3.1 kg of graphene obtained in (2) and mix them. Add 10% ethanol solution. The total mass ratio of tortoise shell residue powder and graphene to ethanol solution is 50:95. Perform ultrasonic oscillation treatment for 8 hours to obtain mixture A3.

[0059] (4) The wood ash, straw, animal manure, bentonite and humic acid in a mass ratio of 7:4:3:2:2 were fed into a high-speed mixer and stirred at a speed of 1100 r / min for 45 min to obtain mixture B3.

[0060] (5) Put mixture B3 into the fermentation tank, add photosynthetic bacteria inoculant, the mass ratio of photosynthetic bacteria inoculant to wood ash is 3:7, maintain the internal temperature of the fermentation material between 45 and 55°C, stir once every 12 hours, seal and ferment for 3 days to obtain fermented mixture.

[0061] (6) Add all mixture A3, 6kg of fermentation mixture and 0.4kg of nano silver to a high-speed mixer, with a speed of 1000r / min and a stirring time of 4h. Then send the mixture to a dryer and dry it at 50℃. Then send it to a granulator to granulate to obtain the tortoise shell medicine residue graphene composite soil conditioner.

[0062] Example 4

[0063] This embodiment provides a method for preparing a graphene composite soil conditioner made from tortoise shell residue, comprising the following steps:

[0064] (1) Wash 6 kg of tortoise shell residue with a white vinegar solution with a volume ratio of 1000:1 (water and white vinegar). Put the washed tortoise shell residue into a dryer, set the temperature to 100℃, and dry for 12 hours. Use a supersonic airflow pulverizer to grind it into powder with a particle size of 950-1000 mesh to obtain tortoise shell residue powder.

[0065] (2) Take a portion of the tortoise shell residue powder obtained in (1) and put it into a carbonization furnace. Heat it to 700℃ and keep it at that temperature for 6 hours to obtain graphite particles with impurities. Use an intelligent pulverizing system to pulverize the graphite particles to <10μm to obtain graphite powder. Mix the graphite powder with hydrogen peroxide at a mass ratio of 4:2 and stir it. Then put it into an oxidation furnace, heat it to 100℃ and keep it at that temperature for 6 hours to obtain graphene oxide. Spray the graphene oxide into a reduction furnace and inject hydrogen under nitrogen protection. The mass ratio of graphene oxide to hydrogen is 12:2. Control the temperature at 100℃ and keep it at that temperature for 15 hours to obtain graphene.

[0066] (3) Take 3.0 kg of tortoise shell residue powder obtained in (1) and 2.1 kg of graphene obtained in (2) and mix them. Add 9% ethanol solution. The total mass ratio of tortoise shell residue powder and graphene to ethanol solution is 50:110. Perform ultrasonic oscillation treatment for 8 hours to obtain mixture A4.

[0067] (4) The wood ash, straw, animal manure, bentonite and humic acid in a mass ratio of 8:4:3:2:2 were fed into a high-speed mixer and stirred at a speed of 1100 r / min for 45 min to obtain mixture B4.

[0068] (5) Put mixture B4 into a fermentation tank, add Bacillus subtilis inoculant and Lactobacillus inoculant in a mass ratio of 1:1, the mass ratio of Bacillus subtilis inoculant plus Lactobacillus inoculant to wood ash is 3:8, maintain the internal temperature of the fermentation material between 45 and 55°C, stir once every 12 hours, seal and ferment for 3 days to obtain fermentation mixture.

[0069] (6) Add all the mixture A4, 18kg of fermentation mixture and 1.2kg of nano silver to a high-speed mixer, with a speed of 1000r / min and a stirring time of 4h. Then send the mixture to a dryer and dry it at 50℃. Then send it to a granulator to granulate to obtain the tortoise shell medicine residue graphene composite soil conditioner.

[0070] Example 5

[0071] This embodiment provides a method for preparing a graphene composite soil conditioner made from tortoise shell residue, comprising the following steps:

[0072] (1) Use a white vinegar solution with a water-to-white vinegar volume ratio of 1000:1 to wash the tortoise shell residue. Put the washed tortoise shell residue into a dryer, set the temperature to 100℃, and dry for 12 hours. Use a supersonic airflow pulverizer to grind it into powder with a particle size of 800-850 mesh to obtain tortoise shell residue powder.

[0073] (2) Take a portion of the tortoise shell residue powder obtained in (1) and put it into a carbonization furnace. Heat it to 500℃ and keep it at that temperature for 6 hours to obtain graphite particles with impurities. Use an intelligent pulverizing system to pulverize the graphite particles to <10μm to obtain graphite powder. Mix the graphite powder and hydrogen peroxide in a mass ratio of 5.5:2.5 and put them into an oxidation furnace. Heat it to 120℃ and keep it at that temperature for 6 hours to obtain graphene oxide. Spray the graphene oxide into a reduction furnace and inject hydrogen under nitrogen protection. The mass ratio of graphene oxide to hydrogen is 10:3. Control the temperature at 120℃ and keep it at that temperature for 15 hours to obtain graphene.

[0074] (3) Take 2.0 kg of tortoise shell residue powder obtained in (1) and 3.1 kg of graphene obtained in (2) and mix them. Add 9% ethanol solution. The total mass ratio of tortoise shell residue powder and graphene to ethanol solution is 50:110. Perform ultrasonic oscillation treatment for 8 hours to obtain mixture A5.

[0075] (4) The wood ash, straw, animal manure, bentonite and humic acid in a mass ratio of 6:3:2:2:2 are fed into a high-speed mixer and stirred at a speed of 1100 r / min for 45 min to obtain mixture B5.

[0076] (5) Put mixture B5 into a fermentation tank, add Trichoderma harzianum inoculant, the mass ratio of Trichoderma harzianum inoculant to wood ash is 3:6, maintain the internal temperature of the fermentation material between 45 and 55°C, stir once every 12 hours, seal and ferment for 3 days to obtain fermented mixture.

[0077] (6) Add all the mixture A5, 4kg of fermentation mixture and 0.5kg of nano silver to a high-speed mixer, with a speed of 1000r / min and a stirring time of 4h. Then send the mixture to a dryer and dry it at 50℃. Then send it to a granulator to granulate it to obtain the tortoise shell residue graphene composite soil conditioner.

[0078] Example 6

[0079] This embodiment provides a method for preparing a graphene composite soil conditioner made from tortoise shell residue, comprising the following steps:

[0080] (1) Use a white vinegar solution with a volume ratio of 900:1 (water and white vinegar) to wash the tortoise shell residue. Put the washed tortoise shell residue into a dryer, set the temperature to 100℃, and dry for 12 hours. Use a supersonic airflow pulverizer to grind it into powder with a particle size of 950-1000 mesh to obtain tortoise shell residue powder.

[0081] (2) Take a portion of the tortoise shell residue powder obtained in (1) and put it into a carbonization furnace. Heat it to 700℃ and keep it at that temperature for 6 hours to obtain graphite particles with impurities. Use an intelligent pulverizing system to pulverize the graphite particles to <10μm to obtain graphite powder. Mix the graphite powder with hydrogen peroxide at a mass ratio of 3:2 and stir it. Then put it into an oxidation furnace, heat it to 110℃ and keep it at that temperature for 6 hours to obtain graphene oxide. Spray the graphene oxide into a reduction furnace and inject hydrogen under nitrogen protection. The mass ratio of graphene oxide to hydrogen is 9:2. Control the temperature at 110℃ and keep it at that temperature for 10 hours to obtain graphene.

[0082] (3) Take 1.5 kg of tortoise shell residue powder obtained in (1) and 2.5 kg of graphene obtained in (2), add 9% ethanol solution, the total mass ratio of tortoise shell residue powder and graphene to ethanol solution is 60:110, perform ultrasonic oscillation treatment for 8 hours, and obtain mixture A6.

[0083] (4) The wood ash, straw, animal manure, bentonite and humic acid in a mass ratio of 5:4:2:2:2 were fed into a high-speed mixer and stirred at a speed of 1100 r / min for 45 min to obtain mixture B6.

[0084] (5) Put mixture B6 into a fermentation tank, add yeast inoculum, the mass ratio of yeast inoculum to wood ash is 2:5, maintain the internal temperature of the fermentation material between 45 and 55°C, stir once every 12 hours, seal and ferment for 3 days to obtain fermented mixture.

[0085] (6) Add all the mixture A6, 3kg of fermentation mixture and 0.6kg of nano silver to a high-speed mixer, with a speed of 1000r / min and a stirring time of 4h. Then send the mixture to a dryer and dry it at 50℃. Then send it to a granulator to granulate it to obtain the tortoise shell residue graphene composite soil conditioner.

[0086] Comparative Example 1

[0087] This comparative example provides a method for preparing a tortoise shell residue graphene composite soil conditioner. Compared with Example 1, the only difference is the mass ratio of tortoise shell residue powder, graphene, fermentation mixture, and nano silver. The amounts used in this comparative example are: 4 kg tortoise shell residue powder, 20 kg graphene, 5 kg fermentation mixture, and 4 kg nano silver.

[0088] Comparative Example 2

[0089] This comparative example provides a method for preparing a graphene composite soil conditioner made from tortoise shell residue. The only difference from Example 1 is that the particle size of the tortoise shell residue powder is 20-30 mesh.

[0090] Comparative Example 3

[0091] This comparative example provides a method for preparing a soil conditioner using tortoise shell residue. The only difference from Example 1 is that an equal mass of tortoise shell residue powder is used instead of graphene.

[0092] Comparative Example 4

[0093] This comparative example provides a method for preparing a graphene composite soil conditioner based on tortoise shell residue. The only difference from Example 1 is that the fermentation mixture does not include humic acid.

[0094] Comparative Example 5

[0095] This comparative example provides a method for preparing a graphene composite soil conditioner made from tortoise shell residue. The only difference from Example 1 is that it does not include nano-silver.

[0096] The soil conditioners obtained from the various examples and comparative examples were applied to 11 1m × 1m wheat fields at the same location, with 150g applied to each field. These fields were labeled as Experimental Groups 1 to 6 and Control Groups 1 to 5, respectively. The wheat variety planted in the fields was durum spring wheat. At the time of application, the wheat was in its growth stage, during which it continued to grow and develop leaves, gradually increasing in height and forming stems, leaves, and roots. Two more 1m × 1m plots were selected at the same location without any soil conditioner applied, labeled as Control Group 1 and Control Group 2, respectively. Ten wheat plants were randomly selected from each plot, avoiding marginal plants. Their growth height was measured over one month, specifically the absolute plant height of the selected wheat plants measured with a measuring tape at the beginning and one month later. The resulting growth heights are recorded in Table 1. The content of metal ions of arsenic, lead, cadmium, chromium, mercury, nickel, iron, aluminum, zinc, manganese and copper in soil samples was measured using a soil heavy metal detector and the results were added together to record the heavy metal content. The soil moisture content was measured one month later using a soil moisture detector and recorded in Table 1.

[0097] Table 1. Data on wheat growth height, soil heavy metal content, and soil moisture after one month in the experimental group, control group, and blank group.

[0098]

[0099]

[0100] As shown in Table 1, in experimental groups 1 to 6, where the tortoise shell residue graphene composite soil conditioner produced by the method of this invention was applied, the wheat growth height was more than 30 cm taller than in control groups 1 and 2, with the highest wheat growth height reaching 87.2 cm. In contrast, in control groups 1 to 5, where the soil conditioner produced by the methods of comparative examples 1 to 5 was applied, the wheat growth height was only slightly more than 10 cm taller than in control groups 1 and 2, with the highest wheat growth height being only 68.0 cm. The tortoise shell residue graphene composite soil conditioner produced by the method of this invention fully utilizes the inherent fertility of the tortoise shell residue, providing inorganic and organic nutrients to the soil, thus greatly improving crop quality.

[0101] As shown in Table 1, the experimental groups 1 to 6, which used the tortoise shell residue graphene composite soil conditioner manufactured by the method of this invention, exhibited a reduction of over 75% in heavy metal content in the soil compared to control groups 1 and 2. In contrast, the control groups 1 to 5, which used the soil conditioner manufactured by the method in the comparative example, only showed a reduction of over 7.1% in heavy metal content compared to control groups 1 and 2, with a maximum reduction of 45%. The tortoise shell residue graphene composite soil conditioner manufactured by the method of this invention effectively utilizes the heavy metal adsorption function of graphene, reducing environmental pollution and improving soil quality.

[0102] Table 1 data also shows that, compared to control groups 1 and 2, the soil moisture in experimental groups 1 to 6, which used the tortoise shell residue graphene composite soil conditioner manufactured by the method of this invention, increased by more than 60%, with the highest reaching 86%. In contrast, in control groups 1 to 5, which used the soil conditioner manufactured by the method in the comparative example, although some samples showed an increase in soil moisture as high as 73% compared to control groups 1 and 2, most samples only saw an increase of 12% to 30%. The tortoise shell residue graphene composite soil conditioner manufactured by the method of this invention effectively improves the soil's water retention capacity and exhibits excellent soil improvement effects.

[0103] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A graphene-based composite soil conditioner made from tortoise shell residue, characterized in that, The raw materials include tortoise shell residue powder, graphene, fermentation mixture, and nano silver; The mass ratio of the tortoise shell residue powder, the graphene, the fermentation mixture, and the nano silver is (5~10):(7~15):(15~35):(1~2). The particle size of the tortoise shell residue powder is 800~1000 mesh; The graphene was prepared from tortoise shell residue; The raw materials for the fermentation mixture include wood ash, straw, manure, granulating agent, humic acid, and fermentation agent; The preparation method of the tortoise shell residue graphene composite soil conditioner includes the following steps: S1: Clean the tortoise shell residue, dry it, and grind it into powder to 800~1000 mesh to obtain the tortoise shell residue powder; S2: Carbonize, oxidize and reduce the tortoise shell residue to obtain the graphene; S3: Mix the tortoise shell residue powder and the graphene, add a dispersant, and disperse evenly to obtain mixture A; S4: Mix the wood ash, straw, manure, granulating agent, and humic acid to obtain mixture B; S5: Mix the mixture B with the fermentation agent, seal and ferment to obtain the fermentation mixture; S6: Mix the mixture A, the fermentation mixture, and the nano-silver, granulate them, and obtain the tortoise shell residue graphene composite soil conditioner; In step S2, the carbonization temperature is 500~700℃ and the carbonization time is 4~6 h.

2. The tortoise shell residue graphene composite soil conditioner according to claim 1, characterized in that, The mass ratio of the plant ash, the straw, the manure, the granulating agent, the humic acid, and the fermentation agent is (4~8):(2~4):(2~3):(1~2):(1~2):(2~3).

3. A tortoise shell residue graphene composite soil conditioner according to claim 1 or 2, characterized in that, The fermentation agent includes any one or more of the following: yeast agent, Bacillus licheniformis agent, photosynthetic bacteria agent, Trichoderma harzianum agent, Bacillus subtilis agent, and Lactobacillus agent.

4. A tortoise shell residue graphene composite soil conditioner according to claim 1 or 2, characterized in that, The granulating agent includes any one or a mixture of two of bentonite and attapulgite.

5. The tortoise shell residue graphene composite soil conditioner according to claim 1, characterized in that, In step S1, the tortoise shell residue is cleaned with a white vinegar aqueous solution, wherein the volume ratio of water to white vinegar in the white vinegar aqueous solution is (900~1000):

1.

6. The tortoise shell residue graphene composite soil conditioner according to claim 1, characterized in that, In step S1, when drying the tortoise shell residue, the drying temperature is 90~100℃ and the time is 8~14 h.

7. The tortoise shell residue graphene composite soil conditioner according to claim 1, characterized in that, In step S2, the oxidant in the oxidation treatment is hydrogen peroxide, the mass ratio of carbonization product to hydrogen peroxide is (3~6):(2~5), the oxidation temperature is 100~130℃, and the oxidation time is 4~6 h.

8. The tortoise shell residue graphene composite soil conditioner according to claim 1, characterized in that, Before oxidation treatment, the carbonized products are pulverized to a particle size of <10 μm.

9. The tortoise shell residue graphene composite soil conditioner according to claim 1, characterized in that, In step S2, the reduction treatment includes the following steps: placing the oxidation product in a protective gas environment, injecting hydrogen gas, wherein the mass ratio of the oxidation product to the hydrogen gas is (9~12):(1~3), the reduction temperature is 100~130℃, and the reduction time is 10~15 h; The protective gas includes at least one of nitrogen, helium, neon, argon, krypton, xenon, and radon.

10. The tortoise shell residue graphene composite soil conditioner according to claim 1, characterized in that, In step S3, the mass ratio of the tortoise shell residue powder and graphene mixture to the dispersant is (50~60):(100~130).

11. The tortoise shell residue graphene composite soil conditioner according to claim 1, characterized in that, In step S3, the dispersant includes any one of an ethanol solution or a tetrahydrofuran solution of polymethyl methacrylate.

12. The tortoise shell residue graphene composite soil conditioner according to claim 1, characterized in that, In step S3, the mass concentration of the dispersant is 5% to 15%.

13. The tortoise shell residue graphene composite soil conditioner according to claim 1, characterized in that, In step S3, uniform dispersion is achieved by ultrasonic oscillation for 6-8 hours.

14. A tortoise shell residue graphene composite soil conditioner according to any one of claims 5 to 13, characterized in that, In step S5, the fermentation temperature is 45~55℃, and the mixture is stirred once every 12~15 hours during the fermentation process. The fermentation time is 2~3 days.

15. A tortoise shell residue graphene composite soil conditioner according to any one of claims 5 to 13, characterized in that, In step S6, a drying step is also included before granulation. The drying temperature is 50~60℃ and the drying time is 8~10 h.

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