Disclosure of Invention
In order to solve the technical problems mentioned in the background technology, the invention provides a bio-based fiber soil and a preparation method thereof.
The purpose of the invention can be realized by the following technical scheme:
the bio-based fiber soil comprises the following raw materials in parts by weight: 50-55 parts of humus, 15-20 parts of perlite, 10-15 parts of straw, 4-8 parts of sawdust, 16-21 parts of peanut shell, 8-12 parts of coconut husk, 16-18 parts of pig manure, 0.2-0.4 part of cellulase, 5-8 parts of water-retention antibacterial component and 0.3-0.5 part of fermentation strain;
the bio-based fiber soil is prepared by the following steps:
firstly, crushing straw, sawdust, peanut shell and coconut coir to a diameter of less than 3mm, transferring the crushed material into a fermentation tank, adding cellulase and fermentation strain, controlling the temperature to be 40-45 ℃, the pH value to be 6-8, the water content to be 50-60%, fermenting for 36-48h, then carrying out solid-liquid separation, washing and drying solid, sterilizing at 120-125 ℃ for 15-20min, and crushing to obtain a fermented fertilizer;
and secondly, adding the fermented fertilizer, humus, perlite, pig manure and water-retention antibacterial components into a stirring tank, and stirring and mixing for 1-2 hours to obtain the bio-based fiber soil.
Further, the water-retention antibacterial component is prepared by the following steps:
mixing polyvinyl alcohol, urea and ammonium polyphosphate, stirring and reacting for 3 hours at 60 ℃ to obtain a first component, adding a straw cellulose derivative into a reaction kettle, controlling the reaction temperature to be 60 ℃, adding ammonium persulfate and potassium sulfate, stirring and reacting for 20-25min, adding acrylic acid and N, N' -methylene bisacrylamide, heating to 80 ℃, uniformly stirring, adding the first component, continuously stirring and reacting for 3-5 hours, and after the reaction is finished, carrying out vacuum freeze drying at-40 ℃ to obtain a water-retaining antibacterial component, wherein the mass ratio of the polyvinyl alcohol to the urea to the sodium polyphosphate is 5:2:5, the mass ratio of the straw cellulose derivative to the ammonium persulfate to the potassium sulfate to the acrylic acid to the N, N' -methylene-bisacrylamide is 1:0.1:0.1:6:0.1-0.2:2.5.
the method comprises the steps of firstly, carrying out esterification reaction on polyvinyl alcohol and ammonium polyphosphate to form a copolymer to obtain a first component, then carrying out polymerization reaction on straw cellulose derivatives, acrylic acid and N, N' -methylene bisacrylamide to form an interpenetrating network structure with the first component, and penetrating polymers containing nitrogen phosphate fertilizer effect factors into cellulose-based polymer resin to obtain a water-retention antibacterial component.
Further, the straw cellulose derivative is prepared by the following steps:
step A1, cleaning and drying corn straws, crushing the corn straws, putting the crushed corn straws into a reaction kettle, adding a hydrogen peroxide solution with the mass fraction of 2%, uniformly mixing the mixture, adjusting the pH value to 12.5 by using a sodium hydroxide solution, reacting the mixture at the temperature of 60-65 ℃ for 5-6 hours under stirring, filtering the mixture while the mixture is hot, washing a filter cake by using deionized water until a washing solution is neutral, and drying the washing solution to obtain straw cellulose; the mass ratio of the crushed straw powder to the hydrogen peroxide solution is 1:20;
step A2, adding straw cellulose, betaine hydrochloride, itaconic acid, arginine, phosphotungstic acid and deionized water into a ball milling tank, carrying out ball milling for 2-2.5 hours, transferring the ball milled materials into a reaction kettle, stirring and reacting for 4-6 hours at 80-100 ℃, carrying out suction filtration, washing a filter cake with ethanol, and carrying out freeze drying to obtain a straw cellulose graft, wherein the mass ratio of the straw cellulose, the betaine hydrochloride, the itaconic acid, the arginine, the phosphotungstic acid and the deionized water is 1:0.3-0.5:0.2-0.3:0.2-0.3:0.03-0.05:40-60 parts;
and A3, ultrasonically dispersing nano-selenium in a water solution to obtain a dispersion liquid with the concentration of 0.5-0.8mg/mL, adding a straw cellulose graft, stirring, standing for 4-6h, carrying out suction filtration, and freeze-drying a filter cake to obtain a straw cellulose derivative, wherein the mass ratio of the straw cellulose graft to the dispersion liquid is 1.
Further, the nano-selenium is prepared by the following steps:
dissolving polyvinylpyrrolidone in deionized water, adding a sodium selenite solution with the concentration of 0.1mol/L and a glutathione solution with the concentration of 0.2mol/L, uniformly stirring by magnetic force, dropwise adding a sodium hydroxide solution with the concentration of 1mol/L, stirring for 20-30min after dropwise adding is finished, performing centrifugal separation, washing precipitates with deionized water for multiple times, and drying at 100 ℃ to constant weight to obtain nano selenium, wherein the dosage ratio of the polyvinylpyrrolidone, the deionized water, the sodium selenite solution, the glutathione solution and the sodium hydroxide solution is 150mg:10-15mL:4mL of: 8mL of: 2.0-2.8mL, and reducing sodium selenite by glutathione to obtain nano-selenium.
Further, the fermentation strain is one of bacillus cereus and geotrichum candidum.
The invention has the beneficial effects that:
in order to improve the utilization rate of the straws, firstly, crushed corn straws are pretreated in a hydrogen peroxide solution and a sodium hydroxide solution to dissolve hemicellulose and lignin in the straws to obtain straw cellulose, then, phosphotungstic acid is used as a catalyst to enable the straw cellulose to be subjected to an esterification reaction with betaine hydrochloride, itaconic acid and arginine to obtain a straw cellulose graft (containing carboxyl, hydroxyl, amino, unsaturated double bonds and other groups), finally, the characteristic that the hydroxyl, the amino and the carboxyl in the straw cellulose graft molecules are easy to combine with nano selenium is utilized to enable the nano selenium to be stably dispersed in the straw cellulose to obtain a straw cellulose derivative, and then, the straw cellulose derivative is used as a base material to be matched with a polymerization monomer such as acrylic acid to prepare a water-retention antibacterial component which not only has excellent absorption and retention characteristics, but also has a slow-release nitrogen-phosphorus fertilizer characteristic and more importantly can resist bacteria.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
A straw cellulose derivative is prepared by the following steps:
step A1, cleaning 10g of corn straws, drying at 70 ℃, crushing, sieving with a 40-mesh sieve, taking crushed straw powder, placing the crushed straw powder into a reaction kettle, adding 200g of a hydrogen peroxide solution with the mass fraction of 2%, uniformly mixing, adjusting the pH value to 12.5 by using a sodium hydroxide solution with the mass fraction of 20%, stirring and reacting at the temperature of 60 ℃ for 5 hours, filtering while hot, washing a filter cake with deionized water until a washing solution is neutral, and drying to obtain straw cellulose;
step A2, adding 10g of straw cellulose, 3g of betaine hydrochloride, 2g of itaconic acid, 2g of arginine, 0.3g of phosphotungstic acid and 40mL of deionized water into a ball milling tank, carrying out ball milling at the rotating speed of 600r/min for 2h, transferring the ball milled mixture into a reaction kettle, stirring and reacting at 80 ℃ for 6h, carrying out suction filtration, washing a filter cake with ethanol for multiple times, and carrying out freeze drying to obtain a straw cellulose graft;
and A3, ultrasonically dispersing nano-selenium in a water solution to obtain a dispersion liquid with the concentration of 0.5mg/mL, adding a straw cellulose graft, stirring for 30min, standing for 4h, performing suction filtration, and freeze-drying a filter cake to obtain a straw cellulose derivative, wherein the mass ratio of the straw cellulose graft to the dispersion liquid is 1.
The nano selenium is prepared by the following steps:
dissolving 150mg of polyvinylpyrrolidone in 10mL of deionized water, adding 4mL of 0.1mol/L sodium selenite solution with concentration and 8mL of 0.2mol/L glutathione solution with concentration, stirring uniformly by magnetic force, dropwise adding 2.0mL of 1mol/L sodium hydroxide solution with concentration, stirring for 20min, performing centrifugal separation, washing precipitates with deionized water for multiple times, and drying at 100 ℃ to constant weight to obtain the nano-selenium.
Example 2
A straw cellulose derivative is prepared by the following steps:
step A1, cleaning 10g of corn straws, drying at 70 ℃, crushing, sieving with a 40-mesh sieve, taking crushed straw powder, placing the crushed straw powder into a reaction kettle, adding 200g of a hydrogen peroxide solution with the mass fraction of 2%, uniformly mixing, adjusting the pH value to 12.5 by using a sodium hydroxide solution with the mass fraction of 20%, stirring and reacting for 6 hours at the temperature of 65 ℃, filtering while hot, washing a filter cake with deionized water until a washing solution is neutral, and drying to obtain straw cellulose;
step A2, adding 10g of straw cellulose, 5g of betaine hydrochloride, 3g of itaconic acid, 3g of arginine, 0.5g of phosphotungstic acid and 60mL of deionized water into a ball milling tank, carrying out ball milling at the rotating speed of 600r/min for 2.5h, transferring the ball milled mixture into a reaction kettle, stirring and reacting at 100 ℃ for 6h, carrying out suction filtration, washing a filter cake with ethanol for multiple times, and carrying out freeze drying to obtain a straw cellulose graft;
and A3, ultrasonically dispersing nano-selenium in a water solution to obtain a dispersion liquid with the concentration of 0.8mg/mL, adding a straw cellulose graft, stirring for 50min, standing for 6h, performing suction filtration, and freeze-drying a filter cake to obtain a straw cellulose derivative, wherein the mass ratio of the straw cellulose graft to the dispersion liquid is 1.
The nano selenium is prepared by the following steps:
dissolving 150mg of polyvinylpyrrolidone in 15mL of deionized water, adding 4mL of 0.1mol/L sodium selenite solution with concentration and 8mL of 0.2mol/L glutathione solution with concentration, stirring uniformly by magnetic force, dropwise adding 2.8mL of 1mol/L sodium hydroxide solution with concentration, stirring for 30min, performing centrifugal separation, washing precipitates with deionized water for multiple times, and drying at 100 ℃ to constant weight to obtain the nano-selenium.
Comparative example 1
This comparative example is the material obtained in step A2 of example 1.
Comparative example 2
The betaine hydrochloride in step A2 of example 2 was removed and the remaining starting materials and preparation were the same as in example 2.
Example 3
A water-retaining antibacterial component is prepared by the following steps:
mixing polyvinyl alcohol, urea and ammonium polyphosphate, stirring and reacting for 3 hours at 60 ℃ to obtain a first component, adding the straw cellulose derivative obtained in example 1 into a reaction kettle, controlling the reaction temperature to be 60 ℃, adding ammonium persulfate and potassium sulfate, stirring and reacting for 20 minutes, adding acrylic acid and N, N' -methylene bisacrylamide, heating to 80 ℃, stirring uniformly, adding the first component, continuing stirring and reacting for 5 hours, after the reaction is finished, performing vacuum freeze drying at-40 ℃ to obtain a water-retaining antibacterial component, wherein the mass ratio of the polyvinyl alcohol to the urea to the sodium polyphosphate is 5:2:5, the mass ratio of the straw cellulose derivative to the ammonium persulfate to the potassium sulfate to the acrylic acid to the N, N' -methylene-bisacrylamide is 1:0.1:0.1:6:0.1:2.5, the degree of neutralization of acrylic acid is 75%.
Example 4
A water-retaining antibacterial component is prepared by the following steps:
mixing polyvinyl alcohol, urea and ammonium polyphosphate, stirring and reacting for 3 hours at 60 ℃ to obtain a first component, adding the straw cellulose derivative obtained in the embodiment 2 into a reaction kettle, controlling the reaction temperature to be 60 ℃, adding ammonium persulfate and potassium sulfate, stirring and reacting for 25 minutes, adding acrylic acid and N, N' -methylene bisacrylamide, heating to 80 ℃, uniformly stirring, adding the first component, continuously stirring and reacting for 5 hours, after the reaction is finished, carrying out vacuum freeze drying at-40 ℃ to obtain a water-retaining antibacterial component, wherein the mass ratio of the polyvinyl alcohol to the urea to the sodium polyphosphate is 5:2:5, the mass ratio of the straw cellulose derivative to the ammonium persulfate to the potassium sulfate to the acrylic acid to the N, N' -methylene-bisacrylamide is 1:0.1:0.1:6:0.2:2.5, the degree of neutralization of acrylic acid is 75%.
Comparative example 3
The straw cellulose derivative in the example 3 is replaced by the substance in the comparative example 1, and the rest raw materials and the preparation process are the same as the example 4.
Comparative example 4
The straw cellulose derivative in the example 3 is replaced by the substance in the comparative example 2, and the rest raw materials and the preparation process are the same as the example 4.
Testing the substances prepared in the embodiments 3-4 and the comparative examples 3-4, (1) testing the absorption performance, namely weighing 0.3g of each group of samples by adopting an immersion method, placing the samples into a nylon mesh bag with 100 meshes, then putting the nylon mesh bag into a beaker filled with 500mL of water, standing the nylon mesh bag for 24 hours, taking out the mesh bag, draining the mesh bag in a natural state until no water drop is generated, and then bearing the weight of the mesh bag, wherein the liquid absorption rate is calculated by Q = (M1-M2)/M1, M1 is the mass of a dried sample, and M2 is the mass of a sample after saturated absorption; (2) Measuring water retention performance, namely weighing a dry sample, placing the dry sample in a beaker filled with water, removing the dry sample and bearing the load after the water absorption is saturated, calculating the weight M3 after 12 hours at 25 ℃, calculating the water retention rate by R = (M2-M3)/(M2-M1) multiplied by 100 percent, and (3) testing the antibacterial performance, namely, measuring escherichia coli and golden yellow grapeCulturing the cocci to logarithmic phase, diluting to 10% with culture medium 5 CFU/mL, the diluted bacterial solution was spread evenly on the solid medium using a spreader. Vertically placing an oxford cup on the surface of the culture medium, adding a sample to be detected into the oxford cup, culturing for 16 hours at 37 ℃ after the oxford cup is filled, measuring the diameter of a bacteriostatic circle by using a vernier caliper, and measuring the test result as shown in table 1:
TABLE 1
As can be seen from Table 1, the water-retaining antibacterial components prepared in examples 3 to 4 have higher water-absorbing and water-retaining properties and superior antibacterial properties as compared with those of comparative examples 3 to 4.
Example 5
The bio-based fiber soil comprises the following raw materials in parts by weight: 50 parts of humus, 15 parts of perlite, 1 part of straw, 4 parts of sawdust, 16 parts of peanut shell, 8 parts of coconut husk, 16 parts of pig manure, 0.2 part of cellulase, 5 parts of water-retention antibacterial component in example 3 and 0.3 part of fermentation strain;
the bio-based fiber soil is prepared by the following steps:
crushing straw, sawdust, peanut shells and coconut coir to a diameter of less than 3mm, transferring the crushed materials into a fermentation tank, adding cellulase and fermentation strains, controlling the temperature to be 40 ℃, the pH value to be 6, the water content to be 50%, fermenting for 36 hours, then carrying out solid-liquid separation, washing and drying solid, sterilizing at 120 ℃ for 15min, and crushing to obtain a fermented fertilizer;
and secondly, adding the fermented fertilizer, humus, perlite, pig manure and water-retention antibacterial components into a stirring tank, and stirring and mixing for 1h to obtain the bio-based fiber soil.
Wherein the fermentation strain is geotrichum candidum.
Example 6
The bio-based fiber soil comprises the following raw materials in parts by weight: 52 parts of humus, 18 parts of perlite, 13 parts of straw, 6 parts of sawdust, 18 parts of peanut shell, 10 parts of coconut husk, 17 parts of pig manure, 0.3 part of cellulase, 7 parts of water-retention antibacterial component in example 3 and 0.4 part of fermentation strain;
the bio-based fiber soil is prepared by the following steps:
firstly, crushing straws, sawdust, peanut shells and coconut coir to the diameter of less than 3mm, transferring the crushed materials into a fermentation tank, adding cellulase and fermentation strains, controlling the temperature at 42 ℃, the pH value at 7 and the water content at 55%, fermenting for 42 hours, then carrying out solid-liquid separation, washing and drying solid, sterilizing at 123 ℃ for 18min, and crushing to obtain a fermented fertilizer;
and secondly, adding the fermented fertilizer, humus soil, perlite, pig manure and water-retention antibacterial components into a stirring tank, and stirring and mixing for 1.5 hours to obtain the bio-based fiber soil.
Wherein the fermentation strain is geotrichum candidum.
Example 7
The bio-based fiber soil comprises the following raw materials in parts by weight: 55 parts of humus, 20 parts of perlite, 15 parts of straw, 8 parts of sawdust, 21 parts of peanut shell, 12 parts of coconut husk, 18 parts of pig manure, 0.4 part of cellulase, 8 parts of water-retention antibacterial component in example 4 and 0.5 part of fermentation strain;
the bio-based fiber soil is prepared by the following steps:
firstly, crushing straws, sawdust, peanut shells and coconut chaff to the diameter of less than 3mm, transferring the crushed materials into a fermentation tank, adding cellulase and fermentation strains, controlling the temperature at 45 ℃, the pH value at 8 and the water content at 60%, fermenting for 48 hours, then carrying out solid-liquid separation, washing and drying solid, sterilizing at 125 ℃ for 20min, and crushing to obtain a fermented fertilizer;
and secondly, adding the fermented fertilizer, humus soil, perlite, pig manure and water-retention antibacterial components into a stirring tank, and stirring and mixing for 2 hours to obtain the bio-based fiber soil.
Wherein the fermentation strain is bacillus cereus.
Comparative example 5
The water-retaining antibacterial component in example 5 was replaced with the substance in comparative example 3, and the rest of the raw materials and the preparation process were the same as in example 5.
Comparative example 6
The water-retaining antibacterial component in example 6 was replaced with the substance in comparative example 4, and the remaining raw materials and preparation process were the same as in example 6.
The bio-based fiber soils prepared in examples 5 to 7 and comparative examples 5 to 6 were respectively bagged, 30 in each group, then sprayed with the same amount of water, transplanted impatiens balsamina seedlings of the same size, one in each bag, cultured under the same illumination and humidity conditions, 60 days after cultivation, the number of surviving and dead plants of each group of impatiens balsamina seedlings was counted, the survival rate thereof was calculated, and the appearance state thereof was observed, and the plant height growth rate was recorded, with the results shown in table 2:
TABLE 2
Item
|
Survival rate (%)
|
Plant height growth rate (%)
|
Example 5
|
100
|
49.6
|
Example 6
|
99.7
|
52.1
|
Example 7
|
100
|
53.4
|
Comparative example 5
|
90
|
41.2
|
Comparative example 6
|
93
|
45.5 |
As can be seen from Table 2, the bio-based fiber soils prepared in examples 5-7 are superior in performance and can improve plant survival and plant growth compared to comparative examples 5-6.
In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The foregoing is illustrative and explanatory only, and it will be appreciated by those skilled in the art that various modifications, additions and substitutions can be made to the embodiments described without departing from the scope of the invention as defined in the appended claims.