A method for improving soil by combining nutrient soil and bacterial solution

Abstract

The present invention relates to the technical field of soil improvement, and in particular to a method for achieving soil improvement by combining nutrient soil and bacterial solution. The method comprises S1, preparing a nutrient soil main material, S2, preparing a first mixture, S3, preparing a bentonite composite, and S4, preparing a soil remediation agent. The method of the present invention repairs and improves the soil to be improved by preparing the soil remediation agent, thereby exerting an effective PGPR coordination effect. The nutrient soil main material can fully assist in exerting the effect of the bacterial community. The microbial community can decompose and utilize various organic macromolecules in the soil that are difficult to be utilized by plants, and convert them into small molecules that can be absorbed and utilized by plants. The decomposition effect of the microorganisms can achieve a slow-acting effect on soil fertility, thereby avoiding the phenomenon of seedling burning caused by excessive fertilization. The bentonite composite obtained by mixing sodium bentonite and chitosan acetic acid solution, and the aluminum bentonite in the second mixture can repair the heavy metal-contaminated soil to be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of soil improvement, and in particular to a method for improving soil by combining nutrient soil and bacterial solution. Background Art

[0002] Many parts of my country have been plagued by years of predatory farming practices, resulting in soil erosion, excessive fertilizer use, soil degradation, impoverishment, and insect pests. While fertilizers may generate high incomes in the short term, long-term use leads to soil compaction, pesticide residues (chemical elements, toxic substances), and other environmental problems. This is inconsistent with sustainable development and the concept of green agriculture. The widespread global use of pesticides in recent decades has exacerbated this problem. Furthermore, subjectively, people increasingly feel that fruits and vegetables have lost their original flavor or are inferior to their former self.

[0003] Therefore, how to effectively improve poor-quality soil and make full use of limited land resources is a major issue that needs to be urgently addressed in agricultural production, ecological construction and environmental protection.

[0004] Currently, domestic soil improvement efforts focus on minerals, natural materials, synthetic polymers, and the use of beneficial microbial agents. Despite these numerous approaches, their effectiveness has been limited. These products are limited in their functionality, overly focusing on soil fertility and failing to significantly prevent pests and diseases. Effective PGPR coordination between soil and microbial communities is ineffective, lacking comprehensive, multi-faceted regulation. Summary of the Invention

[0005] The present invention addresses the deficiencies in the prior art and provides a method for improving soil by combining nutrient soil and bacterial solution.

[0006] The technical solution of the present invention is: a method for improving soil by combining nutrient soil and bacterial solution, comprising:

[0007] S1. By mass percentage, 15-20% of decomposed organic fertilizer, 30-35% of straw ash and the remainder of soil are put into a mixer for mixing, and after mixing evenly, a nutrient soil main material is obtained;

[0008] S2. Adding composite microorganisms accounting for 25-30% of the weight of the nutrient soil main material to the nutrient soil main material to obtain a first mixed material; the composite microorganisms are one or more of Bacillus amyloliquefaciens at a concentration of 2-4 billion cfu / g, Bacillus gelatinosa at a concentration of 150-300 million cfu / g, Trichoderma harzianum at a concentration of 30-100 million cfu / g, Paecilomyces lilacinus at a concentration of 100-50 million cfu / g, and Streptomyces griseus at a concentration of 100-50 million cfu / g, mixed with an organic carrier accounting for 75-85% of the total mass of the composite microorganisms;

[0009] S3. Select 3-5% of any one of Na2CO3, NaNO3 or NACl3, 1-3% of modified attapulgite powder, and the balance of water, and stir them thoroughly to obtain a sodium-forming agent solution; add the sodium-forming agent solution to the calcium-based soil and mix them in a sodium-forming mixture ratio of 1:4-6; sodium-forming the mixture at a temperature of 60-80°C for 30-50 minutes to obtain sodium-based bentonite; mix the sodium-based bentonite with chitosan acetic acid solution in a ratio of 1:2-3 to obtain a bentonite composite;

[0010] S4. Mix 40-60% of a bentonite compound, 20-25% of an aluminum-based bentonite, 4-6% of a modified sepiolite, and the remainder of urea and hydrogen peroxide, by mass percentage, and stir at a speed of 1000-1500 r / min for 25-35 minutes to obtain a second mixture; mix the first mixture and the second mixture in a ratio of 1-2:5-7 to obtain a soil remediation agent.

[0011] Furthermore, the preparation method of the straw ash in step S1 is: stacking and burning wheat straw or corn straw by mass percentage to obtain ash; adding the ash to a magnesium ion solution, stirring for 0.5 to 1 hour, and then adding an iron ion solution, stirring for 20 to 30 minutes, and then standing and settling for 0.5 to 1 hour, and removing the precipitated ash to obtain modified straw ash.

[0012] Description: By adding magnesium ion solution and iron ion solution to the ash in sequence to precipitate the ash, modified straw ash is synthesized. The use of biochar can increase the effective nitrogen content in the soil, increase the nitrogen source available for plant absorption, further promote soil remediation, and benefit crop growth.

[0013] Furthermore, the preparation method of the magnesium ion solution is as follows: 1-1.5% of metallic magnesium accounting for the total mass of the magnesium ion solution is mixed with 20-25% of water, the remaining amount of hydrochloric acid is slowly added, and after complete dissolution, the solution is heated to boiling, and then cooled to room temperature to obtain a first original solution; then, water accounting for 10-15 times the first original solution is slowly added to dilute it to obtain a magnesium ion solution.

[0014] Note: Dissolve metallic magnesium in hydrochloric acid and heat until the solution boils to quickly prepare a magnesium ion solution.

[0015] Furthermore, the preparation method of the iron ion solution is: select 4-6% of the total mass of the iron ion solution and 1-2% of sulfuric acid, add the rest of water and mix, then add 2-3% of the total mass of the iron ion solution disodium ethylenediaminetetraacetic acid dihydrate, and then slowly add water with a proportion of 10-15 times that of the first original solution to dilute it to obtain the iron ion solution.

[0016] Description: The trivalent iron ions in ammonium ferric sulfate are easily hydrolyzed. The use of disodium ethylenediaminetetraacetic acid dihydrate can quickly complex the metal ions and quickly prepare the iron ion solution.

[0017] Furthermore, the preparation method of the modified attapulgite powder in step S3 is as follows: selecting a attapulgite raw material and placing it in a muffle furnace, heating it to 350-550°C at a heating rate of 3-6°C / min and calcining it for 1-2 hours, then placing the calcined attapulgite raw material into deionized water 20-25 times its mass, letting it stand for 25-30 minutes under an ultrasonic environment, and then stirring it for 20-30 minutes to obtain a attapulgite solution; adding a surfactant with a mass ratio of 1:1 to the attapulgite solution, letting it stand for 25-35 minutes under an ultrasonic environment, and then stirring it for 20-30 minutes; then adding 400-600% FeCl3·6H2O and 150-250% anhydrous ethanol, which account for 400-600% of the mass percentage of the attapulgite raw material, letting it stand for 25-35 minutes under an ultrasonic environment, and then stirring it for 20-30 minutes to obtain a composite solution; the composite solution is dropwise added and mixed with an aqueous solution of sodium borohydride, and then sieved to obtain a modified attapulgite powder after drying.

[0018] Description: Attapulgite is a crystalline hydrated magnesium aluminum silicate mineral with a unique layered chain structure. It has a large specific surface area, good chemical stability, strong adsorption capacity, and does not cause secondary pollution. The modified attapulgite powder is prepared by this method, and the carbonates and structural water therein are removed by calcination to form pores, thereby achieving the advantages of high dispersibility and good biocompatibility of the attapulgite powder. The modification cost is low, and the modified attapulgite powder has a fast removal rate for heavy metals and a high removal rate effect.

[0019] Furthermore, the dropwise addition and drying method is as follows: nitrogen is introduced, the composite solution and the sodium borohydride aqueous solution are dropwise added and mixed, the mixing mass ratio is 2:0.5-1, the dropwise addition time is 25-35 minutes, and the mixture is rinsed 2-4 times with a mixed solution of ethanol and deionized water respectively. After centrifugation, the mixture is vacuumed and dried at a temperature of 45°C for 24-28 hours.

[0020] Description: By adding sodium borohydride aqueous solution to the composite solution, the active aldehyde and ketone carbonyl groups in the composite solution can be reduced, and the modified attapulgite powder can be quickly obtained by rinsing and drying.

[0021] Furthermore, the surfactant is an anionic surfactant SDS with a concentration of 1 to 4 wt%; and the concentration of the sodium borohydride aqueous solution is 1 to 3 wt%.

[0022] Note: The use of anionic surfactant SDS can enhance the adsorption performance of the surface of attapulgite raw materials.

[0023] Furthermore, the preparation method of the modified sepiolite in step S4 is: placing the sepiolite in a muffle furnace for roasting at a temperature of 350-450° C. for 1.5-2.5 hours to obtain the modified sepiolite.

[0024] Description: Place sepiolite in a muffle furnace for roasting, so that the organic matter or other minerals in the sepiolite ore decompose or undergo phase change at high temperature. At the same time, the roasting process will release the adsorbed water, zeolite water, crystal water and structural water in the sepiolite structure, so that the sepiolite fibers are dispersed and the specific surface area is increased. The adsorption performance of the modified sepiolite can reach the best effect. When roasted at a temperature of 350-450℃, the specific surface area can reach 141.36m 2 / g, showing that sepiolite has the best adsorption performance.

[0025] Furthermore, the preparation method of the decomposed organic fertilizer is: using decomposed rotten fruits and vegetables or animal feces, collecting them and drying them, adding water accounting for 60-75% of the total mass, and then sealing the bag to decompose for 2-4 days to obtain decomposed organic fertilizer; the soil is leaf mold, compost soil, vegetable garden soil or mountain mud.

[0026] Note: Leaf mold or compost soil is preferred. This type of soil has a loose texture and is rich in fertility, which is more conducive to improving the soil to be repaired.

[0027] Furthermore, the preparation method of the decomposed organic fertilizer is as follows: using decomposed rotten fruits and vegetables, putting them into a sealed barrel, adding water, taking 3 parts of decomposed rotten fruits and vegetables by mass, putting them into the sealed barrel, adding 2 parts of water, and then adding 1 part of brown sugar or microbial fungus cap, sealing the barrel with a lid for 2 to 3 months until it is completely decomposed, and adding a total of 1 to 2 parts of any one or more of animal offal, rice washing water, and egg shells to obtain decomposed organic fertilizer.

[0028] Note: Use fertilizer fermented from rotten fruits and vegetables, which contains more nitrogen and is more conducive to crop growth; adding animal offal, rice washing water, and eggshells can supplement the phosphorus and potassium elements of decomposed organic fertilizer.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The method of the present invention repairs and improves the soil to be improved by preparing a soil repair agent. The soil improvement method has the functions of preventing and controlling insect pests, restoring soil capacity, forming a small habitat, and playing an effective PGPR coordination role. By adding composite microorganisms to the main material of nutrient soil, the microbial flora and the main material of nutrient soil rich in minerals and having strong water and fertilizer retention capacity are mixed, so that the flora and soil form a good coordination effect, and the main material of nutrient soil can fully assist the flora in playing its role. The microbial flora can decompose and utilize various organic macromolecules in the soil that are difficult for plants to utilize, and convert them into small molecules that can be absorbed and utilized by plants. The decomposition of microorganisms can play a slow-acting role in soil fertility, avoid the phenomenon of seedling burning caused by excessive fertilization, and at the same time, the soil material can also ensure that the number of microorganisms is in a relatively stable state.

[0031] (2) The method of the present invention sodiumizes calcium-based soil through a sodiumizing agent solution to improve the quality of sodium-based bentonite, and the sodium-based bentonite is mixed with a chitosan acetic acid solution to obtain a bentonite composite. The aluminum-based bentonite in the second mixture can repair the heavy metal-contaminated soil to be improved; the modified attapulgite powder is added, and the crystalline hydrated magnesium aluminum silicate mineral with a unique layered chain structure of the attapulgite has the advantages of large specific surface area, good chemical stability, strong adsorption capacity, and no secondary pollution, which can enhance the adsorption effect of the soil remediation agent; the use of urea hydrogen peroxide can degrade antibiotics in the soil and enhance the repair effect of the soil to be improved. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below in conjunction with specific implementation methods to better demonstrate the advantages of the present invention.

[0033] Example 1

[0034] A method for improving soil by combining nutrient soil and bacterial solution, comprising:

[0035] S1. Put 17.5% of decomposed organic fertilizer, 32.5% of straw ash, and the remainder of soil into a mixer, and mix them evenly to obtain a nutrient soil main material; the straw ash is prepared by: piling and burning wheat straw, by mass percentage, to obtain ash; adding the ash to a magnesium ion solution, stirring for 0.75 h, and then adding an iron ion solution; stirring for 25 min, and then standing and settling for 0.75 h, and removing the settled ash to obtain modified straw ash;

[0036] The magnesium ion solution is prepared by: selecting 1.25% of metallic magnesium and 22.5% of water to mix, slowly adding the remaining amount of hydrochloric acid, heating the solution until it is completely dissolved, and then cooling it to room temperature to obtain a first stock solution; then slowly adding water with a proportion of 12.5 times that of the first stock solution to dilute it, to obtain a magnesium ion solution;

[0037] The iron ion solution is prepared by: selecting 5% of the total mass of the iron ion solution and 1.5% of sulfuric acid, adding the balance of water and mixing, then adding 2.5% of the total mass of the iron ion solution and disodium ethylenediaminetetraacetic acid dihydrate, and then slowly adding water with a proportion of 12.5 times that of the first original solution to dilute the solution, to obtain the iron ion solution;

[0038] The main material of the nutrient soil has an organic matter content of 17.5%, a total nitrogen content of 0.75%, a fast-acting nitrogen content of 80 mg / kg, a fast-acting phosphorus content of 125 mg / kg, a fast-acting potassium content of 100 mg / kg, and a pH value of 6.25;

[0039] The method for preparing the decomposed organic fertilizer comprises: collecting animal feces, drying them in the sun, adding 70% of the total mass of water, and then sealing the bag to decompose for 3 days to obtain the decomposed organic fertilizer; the soil is leaf mold;

[0040] S2. Adding 27.5% of the weight of the composite microorganisms to the main material of the nutrient soil to obtain a first mixture; the composite microorganisms are Bacillus amyloliquefaciens at a concentration of 3 billion cfu / g, Bacillus gelatinosa at a concentration of 225 million cfu / g, Trichoderma harzianum at a concentration of 65 million cfu / g, Paecilomyces lilacinus at a concentration of 30 million cfu / g, and Streptomyces griseus at a concentration of 30 million cfu / g, mixed with an organic carrier accounting for 80% of the total mass of the composite microorganisms;

[0041] S3. Select 4% Na2CO3, 2% modified attapulgite powder, and the remainder water by mass percentage, and stir them thoroughly to obtain a sodium agent solution; add the sodium agent solution to the calcium-based soil and mix them in a sodium-based mixture ratio of 1:5; sodium-based bentonite is obtained at a temperature of 70°C for 40 minutes; and the sodium-based bentonite and chitosan acetate solution are mixed in a ratio of 1:2.5 to obtain a bentonite composite;

[0042] The preparation method of the modified attapulgite powder is as follows: selecting an attapulgite raw material and placing it in a muffle furnace, heating it to 450°C at a heating rate of 4.5°C / min and calcining it for 1.5 hours, then placing the calcined attapulgite raw material into deionized water with a mass 22.5 times that of the attapulgite raw material, standing it for 27.5 minutes under an ultrasonic environment, and then stirring it for 25 minutes to obtain a attapulgite solution; adding a surfactant with a mass ratio of 1:1 to the attapulgite solution, standing it for 30 minutes under an ultrasonic environment, and then stirring it for 25 minutes; then adding 500% FeCl3·6H2O and 200% anhydrous ethanol, which account for 500% by mass of the attapulgite raw material, and standing it for 30 minutes under an ultrasonic environment, and then stirring it for 25 minutes to obtain a composite solution; the composite solution and a sodium borohydride aqueous solution are dropwise added and mixed, and the modified attapulgite powder is obtained by sieving after drying;

[0043] The dropwise addition and drying method comprises the following steps: introducing nitrogen, dropwise mixing the composite solution and a sodium borohydride aqueous solution at a mass ratio of 2:0.75, and adding for 30 minutes; rinsing with a mixed solution of ethanol and deionized water three times, centrifuging, and drying in a vacuum environment at 45° C. for 26 hours;

[0044] The surfactant is an anionic surfactant SDS with a concentration of 3 wt%; the concentration of the sodium borohydride aqueous solution is 2 wt%;

[0045] S4. Mix 50% of a bentonite composite, 22.5% of an aluminum-based bentonite, 5% of a modified sepiolite, and the remainder of urea and hydrogen peroxide, by mass percentage, and stir at 1250 rpm for 30 min to obtain a second mixture; mix the first mixture and the second mixture in a ratio of 1.5:6 to obtain a soil remediation agent;

[0046] The modified sepiolite is prepared by placing the sepiolite in a muffle furnace for calcination at 400° C. for 2 h to obtain the modified sepiolite.

[0047] Sprinkle the soil remediation agent evenly on the cultivated soil to be improved to complete the soil improvement.

[0048] Example 2

[0049] The difference between this embodiment and embodiment 1 is that in step S1: 15% of decomposed organic fertilizer, 30% of straw ash and the rest of soil are put into a mixer for mixing, and after mixing evenly, the main material of nutrient soil is obtained.

[0050] Example 3

[0051] The difference between this embodiment and embodiment 1 is that in step S1: 20% of decomposed organic fertilizer, 35% of straw ash and the rest of soil are put into a mixer for mixing, and after mixing evenly, the main material of nutrient soil is obtained.

[0052] Example 4

[0053] This embodiment differs from embodiment 1 in that the straw ash is prepared by: piling and burning wheat straw to obtain ash material by mass percentage; adding the ash material to a magnesium ion solution, stirring for 0.5 h, then adding an iron ion solution, stirring for 20 min, and then allowing to settle for 0.5 h; and removing the settled ash material to obtain modified straw ash;

[0054] The magnesium ion solution is prepared by: selecting 1% of metallic magnesium and 20% of water to mix, slowly adding the remaining amount of hydrochloric acid, heating the solution until it is completely dissolved, and then cooling it to room temperature to obtain a first stock solution; then slowly adding water with a proportion of 10 times that of the first stock solution to dilute it, to obtain a magnesium ion solution;

[0055] The preparation method of the iron ion solution is as follows: 4% of the total mass of the iron ion solution is selected, 1% of sulfuric acid is added to the balance of water and mixed, then 2% of the total mass of the iron ion solution is added with disodium ethylenediaminetetraacetic acid dihydrate, and then water with a proportion of 10 times that of the first original solution is slowly added to dilute the solution to obtain the iron ion solution.

[0056] Example 5

[0057] This embodiment differs from embodiment 1 in that the straw ash is prepared by: stacking and burning corn straw to obtain ash material by mass percentage; adding the ash material to a magnesium ion solution, stirring for 1 hour, and then adding an iron ion solution; stirring for 30 minutes, and then allowing to settle for 1 hour; and removing the settled ash material to obtain modified straw ash;

[0058] The magnesium ion solution is prepared by: selecting 1.5% of metallic magnesium and 25% of water to mix, slowly adding the remaining amount of hydrochloric acid, heating the solution until it is completely dissolved, and then cooling it to room temperature to obtain a first stock solution; then slowly adding water with a proportion of 15 times that of the first stock solution to dilute it, to obtain a magnesium ion solution;

[0059] The preparation method of the iron ion solution is as follows: 6% of the total mass of the iron ion solution is selected, 2% of sulfuric acid is added to the balance of water and mixed, then 3% of the total mass of the iron ion solution is added with disodium ethylenediaminetetraacetic acid dihydrate, and then 15 times the mass of the first original solution is slowly added to dilute it to obtain the iron ion solution.

[0060] Example 6

[0061] The difference between this embodiment and embodiment 1 is that the method for preparing the decomposed organic fertilizer is: using animal feces, collecting them and drying them in the sun, adding water accounting for 60% of the total mass, and then sealing the bag and decomposing them for 2 days to obtain decomposed organic fertilizer.

[0062] Example 7

[0063] This embodiment differs from embodiment 1 in that the method for preparing the decomposed organic fertilizer is as follows: animal feces are collected and dried, water accounting for 75% of the total mass is added, and then the bag is sealed and decomposed for 4 days to obtain decomposed organic fertilizer.

[0064] Example 8

[0065] This embodiment differs from Example 1 in that the method for preparing the decomposed organic fertilizer is as follows: decomposed rotten fruits and vegetables are placed in a sealed barrel, filled with water, 3 parts of decomposed rotten fruits and vegetables are taken by mass, placed in a sealed barrel, 2 parts of water are added, 1 part of brown sugar or microbial fungi are added, the barrel is sealed with a lid for 2 months until it is fully decomposed, and a total of 1 part of animal offal is added to obtain decomposed organic fertilizer.

[0066] Example 9

[0067] This embodiment is different from Example 1 in that the preparation method of the decomposed organic fertilizer is as follows: decomposed rotten fruits and vegetables are used, which are placed in a sealed barrel, filled with water, 3 parts of decomposed rotten fruits and vegetables are taken by mass, which are placed in a sealed barrel, 2 parts of water are added, 1 part of brown sugar or microbial fungi are added, and the lid is sealed for 3 months until the barrel is fully decomposed, and a total of 2 parts of rice washing water are added to obtain decomposed organic fertilizer.

[0068] Example 10

[0069] This embodiment differs from Example 1 in that the method for preparing the decomposed organic fertilizer is as follows: decomposed rotten fruits and vegetables are placed in a sealed barrel, filled with water, 3 parts by mass of brown sugar are added, the barrel is covered with a lid and sealed for 2.5 months until fully decomposed, and a total of 1.5 parts of egg shells are added to obtain decomposed organic fertilizer.

[0070] Example 11

[0071] The difference between this embodiment and embodiment 1 is that, in step S2, composite microorganisms accounting for 25% of the weight of the nutrient soil main material are added to the nutrient soil main material to obtain a first mixed material.

[0072] Example 12

[0073] The difference between this embodiment and embodiment 1 is that, in step S2, composite microorganisms accounting for 30% of the weight of the nutrient soil main material are added to the nutrient soil main material to obtain a first mixed material.

[0074] Example 13

[0075] This embodiment differs from embodiment 1 in that the composite microorganisms are mixed with an organic carrier accounting for 75% of the total mass of the composite microorganisms, including Bacillus amyloliquefaciens at a concentration of 2 billion cfu / g, Bacillus gelatinosa at a concentration of 150 million cfu / g, Trichoderma harzianum at a concentration of 30 million cfu / g, Paecilomyces lilacinus at a concentration of 100 million cfu / g, and Streptomyces griseus at a concentration of 100 million cfu / g.

[0076] Example 14

[0077] This embodiment differs from embodiment 1 in that the composite microorganisms are mixed with an organic carrier accounting for 85% of the total mass of the composite microorganisms, comprising Bacillus amyloliquefaciens at a concentration of 4 billion cfu / g, Bacillus gelatinosa at a concentration of 300 million cfu / g, Trichoderma harzianum at a concentration of 100 million cfu / g, Paecilomyces lilacinus at a concentration of 50 million cfu / g, and Streptomyces griseus at a concentration of 50 million cfu / g.

[0078] Example 15

[0079] The difference between this embodiment and Example 1 is that 3% Na2CO3, 1% modified attapulgite powder, and the remainder water are selected and stirred thoroughly to obtain a sodium agent solution; the sodium agent solution is added to the calcium-based soil and mixed to sodiumize, and the mixing mass ratio is 1:4; sodiumization is carried out at a temperature of 60°C for 30 minutes to obtain sodium bentonite; and the sodium bentonite and chitosan acetate solution are mixed in a ratio of 1:2 to obtain a bentonite composite.

[0080] Example 16

[0081] The difference between this embodiment and Example 1 is that 5% Na2CO3, 3% modified attapulgite powder, and the remainder water are selected and fully stirred to obtain a sodium agent solution; the sodium agent solution is added to the calcium-based soil and mixed for sodiumization, and the mixing mass ratio is 1:6; sodiumization is carried out at a temperature of 80°C for 50 minutes to obtain sodium bentonite; and the sodium bentonite and chitosan acetic acid solution are mixed in a ratio of 1:3 to obtain a bentonite composite.

[0082] Example 17

[0083] The difference between this embodiment and Example 1 is that the preparation method of the modified attapulgite powder is as follows: selecting a attapulgite raw material and placing it in a muffle furnace, heating it to 350°C at a heating rate of 3°C / min and calcining it for 1 hour, then placing the calcined attapulgite raw material into deionized water 20 times its mass, letting it stand for 25 minutes under an ultrasonic environment and then stirring it for 20 minutes to obtain a attapulgite solution; adding a surfactant with a mass ratio of 1:1 to the attapulgite solution, letting it stand for 25 minutes under an ultrasonic environment and then stirring it for 20 minutes; then adding 400% FeCl3·6H2O and 150% anhydrous ethanol, which account for 400% by mass of the attapulgite raw material, letting it stand for 25 minutes under an ultrasonic environment and then stirring it for 20 minutes to obtain a composite solution; the composite solution is dropwise added and mixed with an aqueous solution of sodium borohydride, and then sieved to obtain a modified attapulgite powder after drying.

[0084] Example 18

[0085] The difference between this embodiment and Example 1 is that the preparation method of the modified attapulgite powder is as follows: selecting a attapulgite raw material and placing it in a muffle furnace, heating it to 550°C at a heating rate of 6°C / min and calcining it for 2 hours, then placing the calcined attapulgite raw material into deionized water 25 times its mass, letting it stand for 30 minutes under an ultrasonic environment, and then stirring it for 30 minutes to obtain a attapulgite solution; adding a surfactant with a mass ratio of 1:1 to the attapulgite solution, letting it stand for 35 minutes under an ultrasonic environment, and then stirring it for 30 minutes; then adding 600% FeCl3·6H2O and 250% anhydrous ethanol, which account for 600% of the mass percentage of the attapulgite raw material, letting it stand for 35 minutes under an ultrasonic environment, and then stirring it for 30 minutes to obtain a composite solution; the composite solution is dropwise added and mixed with an aqueous solution of sodium borohydride, and then sieved to obtain a modified attapulgite powder after drying.

[0086] Example 19

[0087] This embodiment differs from embodiment 1 in that the dropping and drying method is as follows: nitrogen is introduced, the composite solution and the sodium borohydride aqueous solution are dropwise mixed in a mixing mass ratio of 2:0.5, the dropping time is 25 minutes, and the mixture is rinsed twice with a mixed solution of ethanol and deionized water, and then dried in a vacuum environment at 45°C for 24 hours after centrifugation.

[0088] Example 20

[0089] The difference between this embodiment and embodiment 1 is that the dropping and drying method is as follows: nitrogen is introduced, the composite solution and the sodium borohydride aqueous solution are dropwise mixed at a mixing mass ratio of 2:1, the dropping time is 35 minutes, and the mixture is rinsed 4 times with a mixed solution of ethanol and deionized water, and then dried at 45°C for 28 hours in a vacuum environment after centrifugation.

[0090] Example 21

[0091] The difference between this embodiment and embodiment 1 is that the surfactant is an anionic surfactant SDS with a concentration of 1 wt %; and the concentration of the sodium borohydride aqueous solution is 1 wt %.

[0092] Example 22

[0093] The difference between this embodiment and embodiment 1 is that the surfactant is an anionic surfactant SDS with a concentration of 4 wt %; and the concentration of the sodium borohydride aqueous solution is 3 wt %.

[0094] Example 23

[0095] This embodiment differs from Example 1 in that 40% of a bentonite compound, 20% of an aluminum-based bentonite, 4% of a modified sepiolite, and the remainder of urea and hydrogen peroxide are mixed and stirred at a speed of 1000 r / min for 25 minutes to obtain a second mixture; and the first mixture and the second mixture are mixed in a ratio of 1:5 to obtain a soil remediation agent.

[0096] Example 24

[0097] This embodiment differs from Example 1 in that 60% of a bentonite compound, 25% of an aluminum-based bentonite, 6% of a modified sepiolite, and the remainder of urea and hydrogen peroxide are mixed and stirred at a speed of 1500 r / min for 35 minutes to obtain a second mixture; and the first mixture and the second mixture are mixed in a ratio of 2:7 to obtain a soil remediation agent.

[0098] Example 25

[0099] The difference between this embodiment and embodiment 1 is that the preparation method of the modified sepiolite is as follows: the sepiolite is placed in a muffle furnace for roasting at a temperature of 350° C. for 1.5 hours to obtain the modified sepiolite.

[0100] Example 26

[0101] The difference between this embodiment and embodiment 1 is that the preparation method of the modified sepiolite is as follows: the sepiolite is placed in a muffle furnace for roasting at a temperature of 450° C. for 2.5 hours to obtain the modified sepiolite.

[0102] Application examples:

[0103] The performance of the soil remediation agent was tested using the methods of Examples 1 to 5, 11 to 14, 17, 18, 25, and 26 and Comparative Examples 1 and 2. Taking potted cabbage in a greenhouse as an example, cabbage seeds were planted in equal amounts in the soil of Comparative Examples 1 and 2 and in the soil sprayed with the remediation agent prepared in the examples. The experimental results were averaged, and the comparative data are shown in the following table. The results are shown in Table 1 below:

[0104] Table 1: Planting performance test table of soil remediation agent samples of Examples 1 to 5, 11 to 14, 17, 18, 25, 26 and Comparative Examples 1 and 2

[0105]

[0106]

[0107] The difference from Example 1 is that there are no steps S3 and S4 in which the second mixture is used as a soil remediation agent to obtain soil remediation agents with different components. This method is Comparative Example 1, and its performance data are shown in Table 1.

[0108] Different from Example 1, unmodified commercially available attapulgite powder was used as Comparative Example 2 in step S3 to obtain soil remediation agents with different compositions, and their performance data are shown in Table 1.

[0109] 1. Explore the influence of the ratio of main ingredients of nutrient soil on the performance of soil remediation agent:

[0110] It can be seen from the data in Table 1 that, compared with Comparative Example 1, the plant height and fresh weight of cabbage cultivated in the soil repaired by Comparative Example 1 are lower than those in Example 1. Overall, the repair performance of Example 1 is better than that of Comparative Example 1. Compared with Examples 2 and 3, Example 1 is the best.

[0111] 2. Investigate the influence of process parameters for preparing straw ash on the performance of soil remediation agent:

[0112] It can be seen from the data in Table 1 that, compared with Examples 1, 4, and 5, the cabbage plant height and fresh weight cultivated in the soil repaired in Example 5 are the best, and the plant height of Example 1 is the highest. Overall, Example 5 has the best repair performance.

[0113] 3. Explore the influence of the first mixture ratio on the performance of soil remediation agent:

[0114] It can be seen from the data in Table 1 that, compared with Examples 1, 11, and 12, the cabbage plant height and fresh weight cultivated in the soil repaired by Example 1 are the best. Overall, Example 1 has the best repair performance.

[0115] 4. Investigate the effect of the ratio of composite microbial components on the performance of soil remediation agents:

[0116] It can be seen from the data in Table 1 that, compared with Examples 1, 13, and 14, the cabbage plant height and fresh weight cultivated in the soil repaired by Example 1 are the best. Overall, Example 1 has the best repair performance.

[0117] 5. Investigate the effects of process parameters for preparing modified attapulgite powder on the performance of soil remediation agents:

[0118] It can be seen from the data in Table 1 that, compared with Examples 1, 17, 18 and Comparative Example 2, the cabbage plant height and fresh weight cultivated in the soil repaired by Example 18 are the best, and Comparative Example 2 is the lowest. Overall, Example 18 has the best repair performance.

[0119] 6. Investigate the influence of the process parameters of sepiolite preparation on the performance of soil remediation agent:

[0120] It can be seen from the data in Table 1 that, compared with Examples 1, 25, and 26, the cabbage plant height and fresh weight cultivated in the soil repaired by Example 1 are the best. Overall, Example 1 has the best repair performance.

Claims

1. A method for improving soil by combining nutrient soil and bacterial solution, characterized in that: include: S1. By mass percentage, 15-20% of decomposed organic fertilizer, 30-35% of straw ash and the remainder of soil are put into a mixer for mixing, and after mixing evenly, a nutrient soil main material is obtained; S2. Adding composite microorganisms accounting for 25-30% by weight of the main material of the nutrient soil to the main material of the nutrient soil to obtain a first mixed material; the composite microorganisms are a mixture of one or more of Bacillus amyloliquefaciens at a concentration of 2-4 billion cfu / g, Bacillus gelatinosa at a concentration of 150-300 million cfu / g, Trichoderma harzianum at a concentration of 30-100 million cfu / g, Paecilomyces lilacinus at a concentration of 100-50 million cfu / g, and Streptomyces griseus at a concentration of 100-50 million cfu / g, and an organic carrier accounting for 75-85% of the total mass of the composite microorganisms; S3. Select 3-5% of any one of Na2CO3, NaNO3 or NACl3, 1-3% of modified attapulgite powder, and the balance of water, and stir them thoroughly to obtain a sodium agent solution; add the sodium agent solution to the calcium-based soil for sodium treatment, and the mixing ratio of the two is 1:4-6; sodium treatment is carried out at a temperature of 60-80°C for 30-50 minutes to obtain sodium bentonite; the sodium bentonite and chitosan acetic acid solution are mixed in a mass ratio of 1:2-3 to obtain a bentonite composite; The preparation method of the modified attapulgite powder is as follows: selecting an attapulgite raw material and placing it in a muffle furnace, heating it to 350-550° C. at a heating rate of 3-6° C. / min and calcining it for 1-2 hours, then placing the calcined attapulgite raw material into deionized water 20-25 times its mass, standing it for 25-30 minutes under an ultrasonic environment, and then stirring it for 20-30 minutes to obtain a attapulgite solution; adding a surfactant with a mass ratio of 1:1 to the attapulgite solution, standing it for 25-35 minutes under an ultrasonic environment, and then stirring it for 20-30 minutes; then adding 400-600% of FeCl3·6H2O and 150-250% of anhydrous ethanol, which accounts for 400-600% of the mass percentage of the attapulgite raw material, standing it for 25-35 minutes under an ultrasonic environment, and then stirring it for 20-30 minutes to obtain a composite solution; dropping the composite solution and a sodium borohydride aqueous solution and mixing them, drying them, and sieving them to obtain the modified attapulgite powder; S4. Mix 40-60% of a bentonite compound, 20-25% of an aluminum-based bentonite, 4-6% of a modified sepiolite, and the remainder of urea and hydrogen peroxide, by mass percentage, and stir at a speed of 1000-1500 r / min for 25-35 minutes to obtain a second mixture; mix the first mixture and the second mixture in a ratio of 1-2:5-7 to obtain a soil remediation agent.

2. The method for improving soil by combining nutrient soil and bacterial solution according to claim 1, characterized in that: The preparation method of the straw ash in step S1 is as follows: wheat straw or corn straw is piled and burned by mass percentage to obtain ash; the ash is added to a magnesium ion solution with a volume ratio of 300% of the ash, stirred for 0.5 to 1 hour, and then an iron ion solution is added; after stirring for 20 to 30 minutes, the ash is allowed to settle for 0.5 to 1 hour, and the settled ash is removed to obtain modified straw ash.

3. The method for improving soil by combining nutrient soil and bacterial solution according to claim 2, characterized in that: The magnesium ion solution is prepared by: selecting 1-1.5% of metallic magnesium accounting for the total mass of the magnesium ion solution and mixing it with 20-25% of water, slowly adding the remaining amount of hydrochloric acid, heating the solution until it is completely dissolved, and then cooling it to room temperature to obtain a first stock solution; then slowly adding water 10-15 times the volume of the first stock solution to dilute it to obtain the magnesium ion solution.

4. The method for improving soil by combining nutrient soil and bacterial solution according to claim 2, characterized in that: The preparation method of the iron ion solution comprises: selecting 4-6% of ferric ammonium sulfate and 1-2% of sulfuric acid accounting for the total mass of the iron ion solution, adding the balance of water and mixing, then adding 2-3% of disodium ethylenediaminetetraacetic acid dihydrate accounting for the total mass of the iron ion solution, and then slowly adding 10-15 times the volume of water relative to the first original solution for dilution to obtain the iron ion solution.

5. The method for improving soil by combining nutrient soil and bacterial solution according to claim 1, characterized in that: The dropwise addition and drying method comprises the following steps: introducing nitrogen, dropwise adding and mixing the composite solution and the sodium borohydride aqueous solution in a mixing mass ratio of 2:0.5-1, adding for 25-35 minutes, rinsing with a mixed solution of ethanol and deionized water for 2-4 times, centrifuging, and drying in a vacuum environment at 45° C. for 24-28 hours.

6. The method for improving soil by combining nutrient soil and bacterial solution according to claim 1, characterized in that: The surfactant is an anionic surfactant SDS with a concentration of 1 to 4 wt%; The concentration of the sodium borohydride aqueous solution is 1 to 3 wt%.

7. The method for improving soil by combining nutrient soil and bacterial solution according to claim 1, characterized in that: The preparation method of the modified sepiolite in step S4 is: placing the sepiolite in a muffle furnace for roasting at a temperature of 350-450° C. for 1.5-2.5 hours to obtain the modified sepiolite.

8. The method for improving soil by combining nutrient soil and bacterial solution according to claim 1, characterized in that: The method for preparing the decomposed organic fertilizer comprises the following steps: using decomposed rotten fruits and vegetables or animal feces, collecting them and drying them in the sun, adding 60-75% of water by weight, and then sealing the bag to decompose for 2-4 days to obtain the decomposed organic fertilizer; the soil is leaf mold, compost soil, garden soil or mountain mud.

9. The method for improving soil by combining nutrient soil and bacterial solution according to claim 1, characterized in that: The preparation method of the decomposed organic fertilizer comprises the following steps: taking 3 parts of decomposed fruits and vegetables by weight, putting them into a sealed barrel, adding 2 parts of water, and then adding 1 part of brown sugar or microbial caps, sealing the barrel with a lid, and performing the process for 2 to 3 months until the barrel is fully decomposed; and adding 1 to 2 parts of any one or more of animal offal, rice washing water, and egg shells to obtain the decomposed organic fertilizer.

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