Efficient preparation method of micro-nano biochar conditioner

Abstract

The invention relates to the technical field of soil conditioners, in particular to an efficient preparation method of a micro-nano biochar conditioner, which comprises the following steps: crushing and compressing raw materials, and heating under a nitrogen filling condition to obtain a biochar matrix; the preparation method comprises the following steps: ball-milling a biochar matrix, mixing the ball-milled biochar matrix with deionized water, sequentially carrying out stirring, ultrasonic oscillation and filter membrane filtration at room temperature, and then carrying out freezing and freeze-drying; when it is judged that the preparation of the micro-nano biological particles does not meet the preset standard according to the particle evaluation value, secondary judgment is conducted, or the reason for the preparation of the micro-nano biological particles does not meet the preset standard is determined; mixing the micro-nano biological particles meeting the preset standard with the bacterial suspension, and oscillating by using a shaking table according to a preset shaking table rotating speed, so as to obtain the micro-nano biological carbon conditioner; when it is judged that the preparation of the micro-nano biochar conditioner does not meet the preset standard according to the adsorption characterization value, the rotating speed of a shaking table is increased, or the centrifugal rotating speed is increased, and the product quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of soil conditioners, and in particular to a method for efficiently preparing a micro-nano biochar conditioner. Background Art

[0002] Biochar, a common soil amendment material, has been extensively studied and has demonstrated positive effects in increasing soil fertility, improving water retention, and enhancing soil microbial activity. While its porous structure can be used as a biocarrier for environmental purification, it suffers from drawbacks such as high dosage, complex composition, and difficulty in biological utilization. This lack of sustainability also makes it more susceptible to impacts on native organisms.

[0003] Micro-nano biochar is a microscopic particle made of carbonaceous material, typically ranging in diameter from nanometers to micrometers. Combining it with beneficial bacteria can more effectively optimize the soil microecological environment. Furthermore, the morphology of micro-nano biochar particles plays a significant role in soil ecological restoration.

[0004] Chinese Patent Publication No. CN108129200A discloses a novel activated agricultural and forestry biochar micro-nano composite soil conditioner and its preparation method, belonging to the fields of soil conditioner technology and compound fertilizer technology. The novel activated agricultural and forestry biochar micro-nano composite soil conditioner is composed of the following components by weight: 40-60% micro-nano activated agricultural and forestry biochar and 40-60% other auxiliary materials; the other auxiliary materials are composed of the following components by weight: 25-35% agricultural and forestry biomass waste, 15-35% non-metallic oxyacid minerals, 15-30% natural macromolecular organic matter, and 15-30% traditional Chinese medicine.

[0005] It can be seen that the above technical solution does not consider the effect of the morphology of micro-nano biochar particles on bacterial adsorption and does not consider the effect of the pore structure of the particles on the bacterial loading effect, which leads to the problem of poor product quality. Summary of the Invention

[0006] To this end, the present invention provides an efficient preparation method of a micro-nano biochar conditioner to overcome the problem in the prior art that the influence of the morphology of micro-nano biochar particles on bacterial adsorption and the influence of the pore structure of the particles on the bacterial loading effect are not considered, thereby leading to poor product quality.

[0007] To achieve the above objectives, the present invention provides a method for efficiently preparing a micro-nano biochar conditioner, comprising:

[0008] The raw materials are crushed and compressed, and heated to a preset temperature at a preset heating rate and maintained for a preset time in a muffle furnace under nitrogen filling conditions to obtain raw granular biochar;

[0009] The original biochar particles are crushed, ball-milled and sieved to obtain a biochar matrix;

[0010] The biochar matrix was ball-milled and mixed with deionized water, and then stirred, ultrasonically vibrated, and filtered through a membrane at room temperature, followed by freezing and freeze-drying to obtain micro-nano biochar particles. The average aspect ratio and weight of the micro-nano biochar particles were measured to obtain a particle evaluation value.

[0011] Perform a secondary determination when the preparation of the micro-nano bioparticles is determined not to meet the preset standards based on the particle evaluation value, or determine the reasons for not meeting the preset standards;

[0012] The micro-nano bioparticles meeting the preset standards are mixed with the bacterial suspension, and the mixture is shaken on a shaker at a preset shaker speed to obtain a micro-nano biochar conditioner;

[0013] Obtain the bacterial coverage rate on the surface of each micro-nano biological particle in the micro-nano biochar conditioner, calculate the adsorption characterization value, and increase the shaker speed or the centrifuge speed when judging that the preparation of the micro-nano biochar conditioner does not meet the preset standard based on the adsorption characterization value.

[0014] Furthermore, the process of preparing the bacterial suspension includes:

[0015] The bacteria isolated by single cell cloning were inoculated into LB liquid medium and cultured at 37°C to 38°C with shaking for 12 to 18 hours to obtain bacterial culture solution;

[0016] Place the bacterial culture solution in a centrifuge and run it at the preset centrifugal speed for 5 to 10 minutes to collect the bacterial precipitate;

[0017] Sterile deionized water was added to the bacterial precipitate, and the mixture was mixed to obtain a bacterial suspension.

[0018] Furthermore, the process of determining whether the preparation of the micro-nano bioparticles does not meet the preset standards based on the particle evaluation value includes:

[0019] The particle evaluation value is compared with the first preset particle threshold and the second preset particle threshold respectively.

[0020] If the particle evaluation value is greater than or equal to the first preset particle threshold and less than the second preset particle threshold, it is determined that the preparation of the micro-nano bioparticles does not meet the preset standard, and a second determination is made based on the shape uniformity characterization value whether the preparation of the micro-nano bioparticles meets the preset standard;

[0021] If the particle evaluation value is greater than or equal to the second preset particle threshold, it is determined that the preparation of the micro-nano bioparticles does not meet the preset standard, and the reason why the preparation of the micro-nano bioparticles does not meet the preset standard is determined based on the porosity.

[0022] Furthermore, the particle evaluation value is determined by the average aspect ratio of the micro-nano bioparticles and the weight of the micro-nano bioparticles, wherein the aspect ratio of each micro-nano bioparticle is the ratio of the longest axis to the shortest axis of each micro-nano bioparticle.

[0023] Furthermore, the process of secondarily determining whether the preparation of the micro-nano bioparticles meets the preset standards based on the shape uniformity characterization value includes:

[0024] Compare the shape uniformity characterization value with the preset shape uniformity characterization value,

[0025] If the shape uniformity characterization value is less than the preset shape uniformity characterization value, it is determined that the preparation of the micro-nano bioparticles meets the preset standard;

[0026] If the shape uniformity characterization value is greater than or equal to the preset shape uniformity characterization value, it is determined that the preparation of the micro-nano bioparticles does not meet the preset standard, and the ball milling time is increased according to the difference between the shape uniformity characterization value and the preset shape uniformity characterization value;

[0027] The shape uniformity characteristic value is the variance of the aspect ratio of the micro-nano bioparticles.

[0028] Furthermore, several time adjustment methods are provided for increasing the ball milling time, and each time adjustment method increases the ball milling time by a different amount.

[0029] Furthermore, the reasons why the preparation of micro-nano bioparticles does not meet the preset standards are determined based on the total porosity, including:

[0030] The total pore volume of the micro-nano bioparticles and the total volume of the micro-nano bioparticles were collected to calculate the total porosity;

[0031] comparing the total porosity with the preset porosity;

[0032] If the total porosity is less than the preset porosity, it is determined that the reason why the preparation does not meet the preset standard is that the heating rate of the muffle furnace does not meet the standard, and the heating rate is reduced according to the difference between the preset porosity and the total porosity;

[0033] If the total porosity is greater than or equal to the preset porosity, it is determined that the reason why the preparation does not meet the preset standard is that the freeze-drying time does not meet the standard, and the freeze-drying time is increased according to the ratio of the total porosity to the preset porosity.

[0034] Furthermore, the increase in the freeze-drying time is positively correlated with the porosity deviation value, wherein the porosity deviation value is the ratio of the total porosity to the preset porosity.

[0035] Furthermore, the process of determining whether the preparation of the micro-nano biochar conditioning agent does not meet the preset standard based on the adsorption characterization value includes:

[0036] The adsorption characterization value is compared with the first preset adsorption threshold and the second preset adsorption threshold respectively,

[0037] If the adsorption characteristic value is greater than or equal to the first preset adsorption threshold and less than the second preset adsorption threshold, it is determined that the preparation of the micro-nano biochar conditioner does not meet the preset standard, and the shaking table speed is increased according to the difference between the adsorption characteristic value and the first preset adsorption threshold;

[0038] If the adsorption characterization value is greater than or equal to the second preset adsorption threshold, it is determined that the preparation of the micro-nano biochar conditioner does not meet the preset standard, and the centrifugal speed of the centrifuge is increased according to the difference between the adsorption characterization value and the second preset adsorption threshold.

[0039] Furthermore, the adsorption characterization value is the difference between the maximum and minimum bacterial coverage rates on the surfaces of all micro-nano bioparticles.

[0040] Compared with the existing technology, the beneficial effects of the present invention are that the present invention realizes the efficient preparation of micro-nano biochar particles through the mutual cooperation of carbonization, ball milling, ultrasonic oscillation and membrane filtration; the preparation of nano-bioparticles is tested by particle evaluation value and shape uniformity characterization value, thereby improving the preparation efficiency; and the shaker speed and centrifuge speed are regulated by total porosity classification to achieve uniform bacterial load, thereby improving product quality.

[0041] Furthermore, the present invention determines whether the preparation of micro-nano biochar particles does not meet preset standards based on the particle evaluation value, combines the average aspect ratio and average weight to characterize the morphology and weight deviation of the micro-nano biochar particles, and makes dynamic adjustments based on the judgment results, thereby improving production stability.

[0042] Furthermore, the present invention converts the fuzzy quality qualification into a calculable numerical index by setting the particle evaluation value, and quantitatively evaluates it, thereby improving the reliability of the evaluation result.

[0043] Furthermore, the present invention determines whether the preparation of micro-nano bioparticles meets the preset standards by setting a shape uniformity characterization value. The shape uniformity characterization value is the variance of the aspect ratio of the particles. By quantifying the discrete degree of the particle shape and dynamically adjusting the process parameters according to the comparison results, the uniformity of the bacterial load is improved.

[0044] Furthermore, the present invention provides several time adjustment methods for increasing the ball milling time, and each time adjustment method increases the ball milling time by a different amount, thereby achieving precise control of the ball milling time.

[0045] Furthermore, the present invention determines the reason why the preparation of micro-nano bioparticles does not meet preset standards based on the total porosity, and quickly distinguishes the cause of the problem, including defects in the pore structure or defects in the bacterial mixing process, thereby achieving precise control of the preparation process.

[0046] Furthermore, the present invention determines the preparation of the micro-nano biochar conditioner through the adsorption characterization value. The adsorption characterization value is the difference between the maximum and minimum values ​​of the bacterial coverage rate. The discrete degree of bacterial distribution on the particle surface is quantified, compared with the preset threshold and the corresponding control strategy is adopted to improve the adsorption efficiency, thereby improving the biological activity. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a flow chart of an efficient preparation method of a micro-nano biochar conditioner according to an embodiment of the present invention;

[0048] Figure 2 This is a flow chart of an embodiment of the present invention for determining whether the preparation of micro-nano bioparticles meets preset standards based on the particle evaluation value;

[0049] Figure 3 This is a flow chart of determining the reason why the preparation of micro-nano bioparticles does not meet the preset standard based on the total porosity according to an embodiment of the present invention;

[0050] Figure 4 This is a flow chart of determining whether the preparation of a micro-nano biochar conditioning agent meets preset standards based on adsorption characterization values ​​according to an embodiment of the present invention;

[0051] Figure 5 This is a scanning electron microscope image of the original granular biochar according to an embodiment of the present invention;

[0052] Figure 6 This is a scanning electron microscope image of the biochar matrix according to an embodiment of the present invention;

[0053] Figure 7 This is a transmission electron microscope image of the micro-nano biochar conditioner according to an embodiment of the present invention;

[0054] Figure 8 This is a bar graph showing the effects of the micro-nano biochar conditioning agent on the body length of nematodes according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0056] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0057] It should be pointed out that the data in this embodiment are all obtained by comprehensive analysis and evaluation of the historical test data of the present invention in the three months before this test and the corresponding historical test results. Those skilled in the art can understand that the method of determining the above-mentioned single parameter of the method of the present invention can be to select the value with the highest proportion as the preset standard parameter according to the data distribution, use weighted summation to use the obtained value as the preset standard parameter, substitute each historical data into a specific formula and use the value obtained by the formula as the preset standard parameter or other selection methods, as long as the method of the present invention can clearly define the different specific situations in the single determination process through the obtained value.

[0058] See also Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 as well as Figure 8 As shown, they are respectively a flow chart of an efficient preparation method of a micro-nano biochar conditioner according to an embodiment of the present invention; a flow chart of determining whether the preparation of micro-nano biological particles meets the preset standards according to the particle evaluation value according to an embodiment of the present invention; a flow chart of determining the reason why the preparation of micro-nano biological particles does not meet the preset standards according to the total porosity according to an embodiment of the present invention; a flow chart of determining whether the preparation of a micro-nano biochar conditioner meets the preset standards according to the adsorption characterization value according to an embodiment of the present invention; a scanning electron microscope image of the original granular biochar according to an embodiment of the present invention; a scanning electron microscope image of the biochar matrix according to an embodiment of the present invention; a transmission electron microscope image of the micro-nano biochar conditioner according to an embodiment of the present invention; and a bar chart of the effect of the micro-nano biochar conditioner on the body length of nematodes according to an embodiment of the present invention.

[0059] The embodiment of the present invention provides an efficient preparation method of a micro-nano biochar conditioner, comprising:

[0060] Step S1, crushing and compressing the corn straw, and heating the temperature to a preset temperature of 700° C. at a preset heating rate of 10° C. / min in a muffle furnace filled with nitrogen and maintaining the temperature for a preset time of 2 h to obtain raw granular corn straw biochar;

[0061] Step S2: crushing the obtained raw corn straw biochar particles with a grinder for 1 minute, grinding them with a planetary ball mill, and then passing them through a 0.15 mm pore size sieve to obtain a biochar matrix, wherein the ball-to-powder ratio of the planetary ball mill is 20:1, the rotation speed of the planetary ball mill is 350 rpm, and the planetary ball mill is used for grinding for 12 hours;

[0062] Step S3: 50 g of the biochar matrix was mixed with 1 L of deionized water. The mixture was stirred at 150 rpm for 24 hours using a mechanical stirring device at room temperature, and then subjected to ultrasonic oscillation at an ultrasonic power of 100 W for 2 hours. The ultrasonically treated suspension was filtered through a polymer filter membrane with a pore size of 0.65 μm to 0.80 μm, and the filtrate was collected. The filtrate was frozen at an ultra-low temperature of -80°C and then transferred to a freeze dryer for freeze drying to obtain micro-nano biochar particles with a particle size of 0.1 μm to 0.3 μm. The aspect ratio and average weight of each micro-nano biochar particle were collected to obtain a particle evaluation value.

[0063] Step S4, performing a secondary determination when it is determined based on the particle evaluation value that the preparation of the micro-nano bioparticles does not meet the preset standard, or determining the reason for not meeting the preset standard;

[0064] Step S5, dissolving the micro-nano bioparticles meeting the preset standards in deionized water to obtain a 1000 mg / L micro-nano biochar solution, mixing the 1000 mg / L micro-nano biochar solution with an equal volume of the bacterial suspension, and shaking the mixture at 180 rpm for 24 hours in a shaker to obtain a micro-nano biochar conditioner;

[0065] Step S6, obtaining the bacterial coverage rate on the surface of each micro-nano biological particle in the micro-nano biochar conditioner, obtaining the adsorption characterization value, and increasing the shaking table speed or the centrifuge speed when it is determined that the preparation of the micro-nano biochar conditioner does not meet the preset standard based on the adsorption characterization value.

[0066] In this embodiment, the mechanical stirring device can be an electric stirrer or a magnetic stirrer, and is not specifically limited thereto, as long as it meets the stirring requirements.

[0067] The polymer filter membrane can be a polytetrafluoroethylene filter membrane or a polyvinylidene fluoride filter membrane, and there is no specific limitation, as long as it meets the filtering requirements.

[0068] Specifically, the process of preparing bacterial suspension includes:

[0069] The bacteria isolated by single cell cloning were inoculated into LB liquid medium and cultured at 37°C to 38°C with shaking for 12 to 18 hours to obtain bacterial culture solution;

[0070] Place the bacterial culture solution in a centrifuge and run it at the preset centrifugal speed for 5 to 10 minutes to collect the bacterial precipitate;

[0071] Sterile deionized water was added to the bacterial precipitate, and the mixture was mixed to obtain a bacterial suspension.

[0072] In this embodiment, the bacteria selected are Escherichia coli. Escherichia coli is cloned by single cell cloning and added to liquid LB culture medium. After shaking and culturing at 37.5°C at 180 rpm overnight, the culture medium is centrifuged at 2000 rpm to remove the upper layer of culture medium, and deionized sterile water is added to obtain a bacterial suspension.

[0073] Specifically, the process of determining whether the preparation of micro-nano bioparticles meets the preset standards based on the particle evaluation value includes:

[0074] The particle evaluation value is compared with the first preset particle threshold of 1.08 and the second preset particle threshold of 1.23.

[0075] If the particle evaluation value is less than the first preset particle threshold, it is determined that the preparation of the micro-nano bioparticles meets the preset standard;

[0076] If the particle evaluation value is greater than or equal to the first preset particle threshold and less than the second preset particle threshold, it is determined that the preparation of the micro-nano bioparticles does not meet the preset standard, and a second determination is made based on the shape uniformity characterization value whether the preparation of the micro-nano bioparticles meets the preset standard;

[0077] If the particle evaluation value is greater than or equal to the second preset particle threshold, it is determined that the preparation of the micro-nano bioparticles does not meet the preset standard, and the reason why the preparation of the micro-nano bioparticles does not meet the preset standard is determined based on the porosity.

[0078] In practice, the first preset particle threshold is generally selected from the range of [0.90, 1.15], and the second preset particle threshold is generally selected from the range of [1.20, 1.30]. Preferably, the first preset particle threshold is selected as 1.08, and the second preset particle threshold is selected as 1.23.

[0079] Specifically, the particle evaluation value is determined by the average aspect ratio of the micro-nano bioparticles and the average weight of the micro-nano bioparticles, wherein the aspect ratio of each micro-nano bioparticle is the ratio of the longest axis to the shortest axis of each micro-nano bioparticle.

[0080] The particle evaluation value is calculated using the following formula:

[0081]

[0082] Where P represents the particle evaluation value; α represents the aspect ratio weight, and α is set to 0.6; represents the average aspect ratio of micro-nano bioparticles; L0 represents the preset aspect ratio of a single micro-nano bioparticle, and L0 is set to 1.3; represents the average weight of micro-nano bioparticles; W0 represents the preset weight of a single micro-nano bioparticle, set W0 = 3fg; β represents the weight, set β = 0.4;

[0083] Specifically, the process of secondary determining whether the preparation of micro-nano bioparticles meets the preset standards based on the shape uniformity characterization value includes:

[0084] Compare the shape uniformity characterization value with the preset shape uniformity characterization value 0.15,

[0085] If the shape uniformity characterization value is less than the preset shape uniformity characterization value, it is determined that the preparation of the micro-nano bioparticles meets the preset standard;

[0086] If the shape uniformity characterization value is greater than or equal to the preset shape uniformity characterization value, it is determined that the preparation of the micro-nano bioparticles does not meet the preset standard, and the ball milling time is increased according to the difference between the shape uniformity characterization value and the preset shape uniformity characterization value;

[0087] The shape uniformity characteristic value is the variance of the aspect ratio of the micro-nano bioparticles.

[0088] In this embodiment, the preset shape uniformity characterization value has a value range of (0.1, 0.3). Preferably, the preset shape uniformity characterization value has a value of 0.15.

[0089] Specifically, there are several time adjustment methods for increasing the ball milling time, among which:

[0090] If the shape uniformity difference is less than the first preset shape uniformity difference of 0.07, the first adjustment coefficient of 1.02 is used to increase the ball milling time to a corresponding value;

[0091] If the shape uniformity difference is greater than or equal to the first preset shape uniformity difference and less than the second preset shape uniformity difference of 0.11, the second adjustment coefficient of 1.04 is used to increase the ball milling time to the corresponding value;

[0092] If the shape uniformity difference is greater than or equal to the second preset shape uniformity difference, the ball milling time is increased to a corresponding value using a third adjustment coefficient of 1.06;

[0093] The shape uniformity characterization difference is the difference between the shape uniformity characterization value and the preset shape uniformity characterization value.

[0094] Specifically, the reasons why the preparation of micro-nano bioparticles does not meet the preset standards based on total porosity include:

[0095] The total pore volume of the micro-nano bioparticles and the total volume of the micro-nano bioparticles were collected, and the ratio between the total pore volume and the total volume was recorded as the total porosity;

[0096] Compare the total porosity with the preset porosity of 75%;

[0097] If the total porosity is less than the preset porosity, it is determined that the reason why the preparation does not meet the preset standard is that the heating rate of the muffle furnace does not meet the standard, and the heating rate is reduced according to the difference between the preset porosity and the total porosity;

[0098] If the total porosity is greater than or equal to the preset porosity, it is determined that the reason why the preparation does not meet the preset standard is that the freeze-drying time does not meet the standard, and the freeze-drying time is increased according to the ratio of the total porosity to the preset porosity.

[0099] Specifically, the preset porosity ranges from (65%, 85%). In this embodiment, the preset porosity is selected as 75%, but the above value is not limited thereto. Those skilled in the art may also adjust the value according to actual needs.

[0100] In this embodiment, the total pore volume of the micro-nano bioparticles is measured by a particle porosimeter, and a scanning electron microscope captures an image of the particles, which is then analyzed to calculate the total volume of the micro-nano bioparticles. The software used for image analysis is not specifically limited and only needs to meet the total volume calculation requirements.

[0101] Specifically, the increase in the freeze-drying time is positively correlated with the pore deviation value. The positive correlation is, for example, a linear positive correlation or a nonlinear positive correlation. The linear slope of the linear positive correlation is not specifically limited. It can be understood that the greater the pore deviation value, the greater the increase in the freeze-drying time; the pore deviation value is the ratio of the total porosity to the preset porosity.

[0102] Specifically, the process of determining whether the preparation of the micro-nano biochar conditioner meets the preset standards based on the adsorption characterization value includes:

[0103] The adsorption characterization value is compared with the first preset adsorption threshold of 8% and the second preset adsorption threshold of 19%.

[0104] If the adsorption characteristic value is less than the first preset adsorption threshold, it is determined that the preparation of the micro-nano biochar conditioner meets the preset standard;

[0105] If the adsorption characteristic value is greater than or equal to the first preset adsorption threshold and less than the second preset adsorption threshold, it is determined that the preparation of the micro-nano biochar conditioner does not meet the preset standard, and the shaking table speed is increased according to the difference between the adsorption characteristic value and the first preset adsorption threshold;

[0106] If the adsorption characterization value is greater than or equal to the second preset adsorption threshold, it is determined that the preparation of the micro-nano biochar conditioner does not meet the preset standard, and the centrifugal speed of the centrifuge is increased according to the difference between the adsorption characterization value and the second preset adsorption threshold.

[0107] Specifically, the adsorption characteristic value is the difference between the maximum and minimum bacterial coverage on the surface of all micro-nanoparticles.

[0108] In this embodiment, a field emission scanning electron microscope was used to capture images, and the images were imported into ImageJ software to obtain the bacterial coverage area ratio on the surface of a single micro-nano bioparticle, which was recorded as the bacterial coverage rate on the surface of a single micro-nano bioparticle;

[0109] Select the maximum and minimum values ​​of bacterial coverage on the surface of all micro-nano bioparticles;

[0110] The adsorption characteristic value is the difference between the maximum and minimum bacterial coverage on the surface of all micro-nanoparticles.

[0111] Experiment 1: Verification of the concentration effect of micro-nano biochar conditioner on the growth of Caenorhabditis elegans.

[0112] The synchronized L1-stage Caenorhabditis elegans were exposed to culture medium containing different concentrations of micro-nano-biochar conditioners and cultured in a constant temperature incubator at 20°C for 48 hours until they reached the juvenile adult stage.

[0113] The average body length of young adults was measured to evaluate the effects of different concentrations of micro-nano biochar conditioners on the growth of C. elegans, e.g. Figure 8 As shown, the average body length of young adults in the 500 mg / L treatment group increased significantly to 1064.34±14.04 μm, while the body length of young adults in the 1000 mg / L treatment group decreased to 900.67±16.61 μm.

[0114] The L1 stage of Caenorhabditis elegans is the first stage of the larval stage of Caenorhabditis elegans.

[0115] It can be seen that the effect of micro-nano biochar conditioner on the growth of Caenorhabditis elegans is not a single direction, but shows different effects with changes in concentration.

[0116] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

[0117] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An efficient preparation method of micro-nano biochar conditioner, characterized in that: include: The raw materials are crushed and compressed, and heated to a preset temperature at a preset heating rate and maintained for a preset time in a muffle furnace under nitrogen filling conditions to obtain raw granular biochar; The original biochar particles are crushed, ball-milled and sieved to obtain a biochar matrix; The biochar matrix was ball-milled and mixed with deionized water, and then stirred, ultrasonically vibrated, and filtered through a membrane at room temperature, followed by freezing and freeze-drying to obtain micro-nano biochar particles. The average aspect ratio and weight of the micro-nano biochar particles were measured to obtain a particle evaluation value. Perform a secondary determination when the preparation of the micro-nano bioparticles is determined not to meet the preset standards based on the particle evaluation value, or determine the reasons for not meeting the preset standards; The micro-nano bioparticles meeting the preset standards are mixed with the bacterial suspension, and the mixture is shaken on a shaker at a preset shaker speed to obtain a micro-nano biochar conditioner; Obtain the bacterial coverage rate on the surface of each micro-nano biological particle in the micro-nano biochar conditioner, calculate the adsorption characterization value, and increase the shaker speed or the centrifuge speed when judging that the preparation of the micro-nano biochar conditioner does not meet the preset standard based on the adsorption characterization value.

2. The efficient preparation method of the micro-nano biochar conditioner according to claim 1, characterized in that: The process of preparing the bacterial suspension comprises: The bacteria isolated by single cell cloning were inoculated into LB liquid medium and cultured at 37°C to 38°C with shaking for 12 to 18 hours to obtain bacterial culture solution; Place the bacterial culture solution in a centrifuge and run it at the preset centrifugal speed for 5 to 10 minutes to collect the bacterial precipitate; Sterile deionized water was added to the bacterial precipitate, and the mixture was mixed to obtain a bacterial suspension.

3. The efficient preparation method of the micro-nano biochar conditioner according to claim 2, characterized in that: The process of determining whether the preparation of micro-nano bioparticles does not meet the preset standards based on the particle evaluation value includes: The particle evaluation value is compared with the first preset particle threshold and the second preset particle threshold respectively. If the particle evaluation value is greater than or equal to the first preset particle threshold and less than the second preset particle threshold, it is determined that the preparation of the micro-nano bioparticles does not meet the preset standard, and a second determination is made based on the shape uniformity characterization value whether the preparation of the micro-nano bioparticles meets the preset standard; If the particle evaluation value is greater than or equal to the second preset particle threshold, it is determined that the preparation of the micro-nano bioparticles does not meet the preset standard, and the reason why the preparation of the micro-nano bioparticles does not meet the preset standard is determined based on the porosity.

4. The efficient preparation method of the micro-nano biochar conditioner according to claim 3, characterized in that: The particle evaluation value is determined by the average aspect ratio of the micro-nano bioparticles and the weight of the micro-nano bioparticles, wherein the aspect ratio of each micro-nano bioparticle is the ratio of the longest axis to the shortest axis of each micro-nano bioparticle.

5. The efficient preparation method of the micro-nano biochar conditioner according to claim 4, characterized in that: The process of secondary judging whether the preparation of micro-nano bioparticles meets the preset standards based on the shape uniformity characterization value includes: Compare the shape uniformity characterization value with the preset shape uniformity characterization value, If the shape uniformity characterization value is less than the preset shape uniformity characterization value, it is determined that the preparation of the micro-nano bioparticles meets the preset standard; If the shape uniformity characterization value is greater than or equal to the preset shape uniformity characterization value, it is determined that the preparation of the micro-nano bioparticles does not meet the preset standard, and the ball milling time is increased according to the difference between the shape uniformity characterization value and the preset shape uniformity characterization value; The shape uniformity characteristic value is the variance of the aspect ratio of the micro-nano bioparticles.

6. The efficient preparation method of the micro-nano biochar conditioner according to claim 5, characterized in that: Several time adjustment methods are provided for increasing the ball milling time, and each time adjustment method increases the ball milling time by a different amount.

7. The efficient preparation method of the micro-nano biochar conditioner according to claim 6, characterized in that: The reasons why the preparation of micro-nano bioparticles does not meet the preset standards based on total porosity include: The total pore volume of the micro-nano bioparticles and the total volume of the micro-nano bioparticles were collected to calculate the total porosity; comparing the total porosity with the preset porosity; If the total porosity is less than the preset porosity, it is determined that the reason why the preparation does not meet the preset standard is that the heating rate of the muffle furnace does not meet the standard, and the heating rate is reduced according to the difference between the preset porosity and the total porosity; If the total porosity is greater than or equal to the preset porosity, it is determined that the reason why the preparation does not meet the preset standard is that the freeze-drying time does not meet the standard, and the freeze-drying time is increased according to the ratio of the total porosity to the preset porosity.

8. The efficient preparation method of the micro-nano biochar conditioner according to claim 7, characterized in that: The increase in freeze-drying time is positively correlated with the porosity deviation value, where the porosity deviation value is the ratio of the total porosity to the preset porosity.

9. The efficient preparation method of the micro-nano biochar conditioner according to claim 8, characterized in that: The process of determining whether the preparation of the micro-nano biochar conditioner does not meet the preset standards based on the adsorption characterization value includes: The adsorption characterization value is compared with the first preset adsorption threshold and the second preset adsorption threshold respectively, If the adsorption characteristic value is greater than or equal to the first preset adsorption threshold and less than the second preset adsorption threshold, it is determined that the preparation of the micro-nano biochar conditioner does not meet the preset standard, and the shaking table speed is increased according to the difference between the adsorption characteristic value and the first preset adsorption threshold; If the adsorption characterization value is greater than or equal to the second preset adsorption threshold, it is determined that the preparation of the micro-nano biochar conditioner does not meet the preset standard, and the centrifugal speed of the centrifuge is increased according to the difference between the adsorption characterization value and the second preset adsorption threshold.

10. The efficient preparation method of the micro-nano biochar conditioner according to claim 9, characterized in that: The adsorption characteristic value is the difference between the maximum and minimum bacterial coverage on the surface of all micro-nanoparticles.

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