Soil remediation complex microbial inoculant composition and preparation method thereof

Abstract

The invention relates to a soil remediation complex microbial inoculant composition and a preparation method thereof, and belongs to the technical field of soil remediation. Comprising the following raw materials: 10-15 parts of a microbial complex inoculant, 40-50 parts of a porous carrier, 20-25 parts of an organic matter and 3-5 parts of a surface protective agent, wherein the porous carrier is obtained by treating diatomite with phytic acid and polylysine. Paenibacillus polymyxa, trichoderma harzianum, bacillus subtilis and azotobacter chroococcum are taken as a microbial compound inoculant, modified diatomite is taken as a porous carrier, and the microbial compound inoculant is mixed with organic matters under the action of a protective agent, so that the soil remediation compound inoculant composition which can effectively improve soil and is excellent in strain activity is obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of soil pollution remediation, and relates to a soil remediation composite microbial agent composition and a preparation method thereof. Background Art

[0002] With the development of traditional industrial planting and industry, soil problems have become increasingly serious, including soil compaction, soil salinization and alkalization, and soil heavy metal pollution, which have had a profound impact on agricultural production and the ecological environment, resulting in serious degradation of soil quality.

[0003] At present, a large amount of financial and energy resources have been invested in the remediation of soil compaction degradation and soil pollution. Traditional fertilizers are generally inorganic fertilizers or organic-inorganic compound fertilizers. The main problems are the lack of living biological substances, the lack of microorganisms in the soil, slow conversion of material energy, slow improvement and restoration of the physical properties, biological properties, etc. of the soil ecosystem, long reclamation cycles, and problems such as soil compaction, weakening of soil fertility, eutrophication of water bodies, and reduction of agricultural product quality when overused; while microbial fertilizers are a kind of safe, efficient and environmentally friendly microbial live products, which can effectively increase the content of elements such as nitrogen, phosphorus, and potassium in the soil, but the existing microbial fertilizers have an insignificant improvement effect on the reclaimed soil in mining areas.

[0004] Therefore, it is necessary to develop a composite microbial agent with wide adaptability, good soil improvement effect, and still able to maintain good effective bacteria activity after long-term storage to prevent corruption and deterioration to overcome the problems existing in the prior art. Summary of the Invention

[0005] The purpose of the present invention is to provide a soil remediation composite microbial agent composition and a preparation method thereof. The prepared soil remediation composite microbial agent composition can effectively improve soil problems and effectively maintain the activity of bacteria.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A soil remediation composite microbial agent composition, calculated by weight, comprises the following raw materials: 10 - 15 parts of a microbial composite microbial agent, 40 - 50 parts of a porous carrier, 20 - 25 parts of organic matter, and 3 - 5 parts of a surface protective agent, wherein the porous carrier is obtained by treating diatomaceous earth with phytic acid and polylysine;

[0008] Wherein the microbial agent protective agent comprises the following raw materials in parts by weight: 1 - 3 parts of superphosphate, 0.5 - 1.5 parts of ammonium sulfate, 1 - 3 parts of chitosan, 0.5 - 1.5 parts of trehalose, 0.5 - 1.5 parts of PBS buffer solution, and 30 - 40 parts of deionized water;

[0009] The organic matter comprises the following raw materials in parts by weight: 20 to 30 parts of modified biomass activated carbon and 15 to 25 parts of humic acid, wherein the modified biomass activated carbon is obtained by treating with calcium peroxide and rhamnolipid;

[0010] The microbial composite bacterial agent comprises the following raw materials in parts by weight: 10 to 15 parts of Bacillus polymyxa, 8 to 15 parts of Trichoderma harzianum, 50 to 65 parts of Bacillus subtilis, and 5 to 8 parts of Nitrogen-fixing Bacteria.

[0011] As a preferred technical solution of the present invention, the specific preparation process of the porous carrier is as follows:

[0012] The diatomaceous earth is dispersed in a phytic acid aqueous solution with a mass fraction of 1 to 3%, and the mixture is stirred at a speed of 400 r / min for 30 to 45 minutes. After filtering, the mixture is dried at 75°C for 10 hours, and then subjected to plasma treatment to obtain solid A. Solid A is further dispersed in a phytic acid aqueous solution with a mass fraction of 10 to 15%, and the mixture is stirred at a speed of 400 r / min for 30 to 45 minutes. Solid B is obtained after filtering and drying in a vacuum drying oven at 80 to 110°C for 10 to 12 hours. 4 to 6 parts of solid B are added to 30 to 35 parts of a polylysine aqueous solution with a concentration of 0.1 to 0.2 g / mL, and the mixture is stirred at a speed of 400 r / min for 30 to 45 minutes. The porous carrier is obtained after filtering and drying in a vacuum drying oven at 90°C for 15 hours.

[0013] As a preferred technical solution of the present invention, the preparation process of the microbial composite agent is as follows:

[0014] 10-15 parts of Paenibacillus polymyxa, 8-15 parts of Trichoderma harzianum, 50-65 parts of Bacillus subtilis and 5-8 parts of Azotobacter nitrofuga are inoculated into LB liquid culture medium at a 10% inoculation rate, and cultured under shaking at 25° C. for 24 hours to obtain the microbial composite agent.

[0015] As a preferred technical solution of the present invention, the preparation process of the modified biomass activated carbon is as follows:

[0016] Calcium chloride was dissolved in deionized water, and the pH value was adjusted to 9.5-10 by ammonia water to obtain a mixed solution A, and a 30% by mass fraction hydrogen peroxide aqueous solution was added to the mixed solution A, and the mixture was stirred at a speed of 500 r / min for 30-60 min, and the pH of the solution was adjusted to 11 by sodium hydroxide to obtain a mixed solution B, wherein the amount ratio of calcium chloride, deionized water and hydrogen peroxide aqueous solution was 2g: (20-30mL): 10mL; the mixed solution B with a mass ratio of 3:1 was mixed with biomass activated carbon, and the mixture was stirred at a speed of 500 r / min for 30-60 min, filtered and dried at 80°C for 10h to obtain a solid A;

[0017] Mix rhamnolipid with water to obtain a rhamnolipid solution. Ultrasonically treat the solid A with a mass ratio of 1:5 to the rhamnolipid solution at a power of 100 - 200 W for 20 - 35 min. After the ultrasonic treatment, vacuum dry the obtained solid at 90 - 100 °C for 10 - 15 h to obtain the modified biomass activated carbon.

[0018] As a preferred technical solution of the present invention, the solid-liquid ratio of the diatomite to the phytic acid aqueous solution is 1 g:20 mL.

[0019] As a preferred technical solution of the present invention, the treatment power of the plasma treatment is 220 - 240 W, the treatment atmosphere is nitrogen, the time is 5 - 10 min, and the nitrogen gas flow rate is 70 - 100 mL / min.

[0020] As a preferred technical solution of the present invention, the solid-liquid ratio of the solid A to the phytic acid aqueous solution is 1 g:20 mL.

[0021] As a preferred technical solution of the present invention, the concentration of the microbial complex bactericide is 3ⅹ10 8 cfu / mL.

[0022] As a preferred technical solution of the present invention, the mass fraction of the rhamnolipid solution is 10 - 20%.

[0023] A preparation method of a soil remediation complex bactericide composition, comprising the following steps:

[0024] S1. By weight, mix the microbial complex bactericide and the surface protectant, then add sterilized pure water, and after mixing evenly, form a muddy mixture, and keep it warm and static in a sealed environment at 35 - 40 °C for 8 - 12 h;

[0025] S2. Naturally cool to room temperature, then continue to add the porous carrier, and stir at a speed of 500 r / min for 40 - 55 min;

[0026] S3. Continue to add the organic matter, keep the rotation speed and continue to stir for 35 - 60 min, then add sterilized pure water to form a suspension, dehydrate, dry, and granulate to obtain the soil remediation complex bactericide composition.

[0027] In the composite bacterial composition prepared by the present invention, polymyxa paenibacillus, trichoderma harzianum, bacillus subtilis, and azotobacter chroococcum are used as microbial composite bactericides. The extracellular polysaccharides and other viscous substances produced by the reproduction of microorganisms in the soil improve the soil structure, increase the air permeability, water permeability, and water retention of the soil; the nitrogen fixation of azotobacter chroococcum and the decomposition of organic substances in the soil by bacillus increase the soil fertility; polymyxa paenibacillus and trichoderma harzianum inhibit soil-borne diseases; the addition of this microbial composite bactericide can increase the diversity and quantity of microorganisms in the soil. Different microorganisms cooperate and promote each other, forming a stable microbial community, enhancing the activity and function of soil microorganisms, and improving the stability and self-repair ability of the soil ecosystem.

[0028] Mix the microbial composite bactericide with a protectant. The protectant synergistically improves the survival rate and activity of the microbial composite bactericide through multiple mechanisms such as nutrient supply by superphosphate and ammonium sulfate, physical protection by chitosan and trehalose, and environmental buffering by PBS, and realizes efficient degradation of pollutants, stabilization of heavy metals, and restoration of ecological functions in soil remediation.

[0029] In the present invention, the porous carrier is based on diatomite. Its natural pores are further optimized after being treated with phytic acid and plasma, providing a high specific surface area and a microporous structure, which can provide an ideal attachment and growth environment for microorganisms and protect them from external environmental stresses.

[0030] The introduction of phytic acid and polylysine enhances the affinity between the diatomite carrier and microorganisms. The negative charge of phytic acid and the positive charge of polylysine form a multi-layer structure through electrostatic interaction, improving the microbial immobilization efficiency. At the same time, it can provide C, N, and P sources, and inhibit pathogenic bacteria by using the antibacterial property of polylysine, indirectly protecting beneficial bacterial groups. Polylysine can form a network structure in the soil through intermolecular interactions, and this structure can agglomerate soil particles together, increasing the stability of soil aggregates.

[0031] During the preparation process, after the first phytic acid treatment, plasma treatment is carried out to increase the surface roughness and chemical activity, promote the uniform loading of the subsequent phytic acid layer, enhance the structural stability of the carrier, and extend its service life in the soil. Through the synergistic adsorption of diatomite treated twice and phytic acid, diatomite adsorbs organic pollutants and phytic acid chelates heavy metal ions, playing a dual role in purifying the soil environment and creating favorable conditions for microbial remediation.

[0032] Moreover, the pH sensitivity of phytic acid and polylysine may enable the on-demand release of microorganisms. For example, in acidic soil, the dissociation of phytic acid accelerates the degradation of the carrier and releases the bactericide.

[0033] The biomass activated carbon is modified by calcium peroxide and rhamnolipid. During the preparation process, calcium peroxide can be stably combined with the activated carbon. And through the treatment with rhamnolipid, the poor pore connectivity caused by the pores formed by the decomposition of calcium peroxide to generate oxygen during use is avoided, and the diffusion and adsorption efficiency of pollutant molecules in the pores of the activated carbon are improved. Rhamnolipid can be used as a biosurfactant to reduce the surface tension of the liquid, enabling the solution to better penetrate into the pores of the activated carbon, which helps to open up some originally unsmooth pores and optimize the pore connectivity, thereby overcoming the problem that the pore structure may not be ideal when only modified with calcium peroxide, and improving the adsorption rate and adsorption capacity of the activated carbon for pollutants. At the same time, the calcium ions generated by the decomposition of calcium peroxide can change the surface charge distribution and increase the surface basic sites, which is beneficial to the adsorption of acidic pollutants. And rhamnolipid makes the surface of the activated carbon carry more hydrophilic functional groups, improving the adsorption ability of the activated carbon for polar pollutants, and also enhancing the dispersibility and stability of the activated carbon in the soil environment.

[0034] The modified activated carbon and humic acid are mixed as organic matter, which can provide a habitat and nutrients for soil microorganisms.

[0035] The beneficial effects of the present invention:

[0036] In the present invention, Paenibacillus polymyxa, Trichoderma harzianum, Bacillus subtilis, and Azotobacter chroococcum are used as a microbial complex bactericide, and modified diatomite is used as a porous carrier. Under the action of a protective agent, it is mixed with organic matter to obtain a soil remediation composite bactericide composition that can effectively improve the soil and has excellent bacterial activity. Specific embodiments

[0037] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following, in combination with embodiments, details the specific embodiments, structures, features, and their effects according to the present invention.

[0038] The biomass activated carbon is prepared from corn straw.

[0039] Example 1

[0040] The microbial bactericide protective agent includes the following raw materials in parts by weight: 1 part of calcium superphosphate, 0.5 part of ammonium sulfate, 1 part of chitosan, 0.5 part of trehalose, 0.5 part of PBS buffer solution, and 30 parts of deionized water;

[0041] The organic matter includes the following raw materials in parts by weight: 20 parts of modified biomass activated carbon and 15 parts of humic acid;

[0042] The microbial complex bactericide includes the following raw materials in parts by weight: 10 parts of Paenibacillus polymyxa, 8 parts of Trichoderma harzianum, 50 parts of Bacillus subtilis, and 5 parts of Azotobacter chroococcum.

[0043] Preparation of porous carrier:

[0044] Disperse diatomite in an aqueous solution of phytic acid with a mass fraction of 1%. The solid-liquid ratio of diatomite to the aqueous solution of phytic acid is 1 g: 20 mL. Stir well at a speed of 400 r / min for 30 min. After filtration, dry at 75 °C for 10 h and then perform plasma treatment to obtain solid A. The treatment power of the plasma treatment is 220 W, the treatment atmosphere is nitrogen, the time is 5 min, and the nitrogen gas flow rate is 70 mL / min. Continue to redisperse solid A in an aqueous solution of phytic acid with a mass fraction of 10%. The solid-liquid ratio of solid A to the aqueous solution of phytic acid is 1 g: 20 mL. Continue to stir at a speed of 400 r / min for 30 min. After filtration and drying in a vacuum drying oven at 80 °C for 10 h, solid B is obtained. Add 4 parts of solid B to 30 parts of an aqueous solution of polylysine with a concentration of 0.1 g / mL. Stir at a speed of 400 r / min for 30 min. After filtration and drying in a vacuum drying oven at 90 °C for 15 h, the porous carrier is obtained.

[0045] Preparation of microbial complex bactericide:

[0046] Inoculate 10 Paenibacillus polymyxa, 8 parts of Trichoderma harzianum, 50 parts of Bacillus subtilis, and 5 parts of Azotobacter chroococcum into LB liquid medium at an inoculation amount of 10% respectively. Shake culture at 25 °C for 24 h to obtain the microbial complex bactericide, and the concentration of the microbial complex bactericide is 3×10 8 cfu / mL.

[0047] The preparation process of modified biomass activated carbon is as follows:

[0048] Dissolve calcium chloride in deionized water, adjust the pH value to 9.5 - 10 with ammonia water to obtain mixed solution A. Add an aqueous solution of hydrogen peroxide with a mass fraction of 30% to mixed solution A, stir at a speed of 500 r / min for 30 min, and then adjust the pH of the solution to 11 with sodium hydroxide to obtain mixed solution B, where the dosage ratio of calcium chloride, deionized water, and the aqueous solution of hydrogen peroxide is 2 g: 20 mL: 10 mL; Mix mixed solution B and biomass activated carbon with a mass ratio of 3:1, stir at a speed of 500 r / min for 30 min, filter and dry at 80 °C for 10 h to obtain solid A;

[0049] Mix rhamnolipid with water to obtain a rhamnolipid solution with a mass fraction of 10%. Ultrasonically treat solid A with a mass ratio of 1:5 to the rhamnolipid solution at a power of 100 W for 20 min. After the ultrasonic treatment, dry the obtained solid in a vacuum at 90 °C for 10 h to obtain the modified biomass activated carbon.

[0050] Preparation of soil remediation complex bactericide composition:

[0051] S1. Mix 10 parts of microbial composite agent and 3 parts of surface protective agent by weight, add sterilized purified water, mix well to form a muddy mixture, and keep it in a sealed environment at 35°C for 8 hours;

[0052] S2, naturally cool to room temperature, continue to add 40 parts of porous carrier, and stir at a speed of 500r / min for 40min;

[0053] S3, continue to add 20 parts of organic matter, maintain the speed and continue stirring for 35 minutes, then add sterile purified water to form a suspension, dehydrate, dry and granulate to obtain the soil remediation composite bacterial agent composition.

[0054] Example 2

[0055] The microbial agent protective agent includes the following raw materials in parts by weight: 2 parts of superphosphate, 1 part of ammonium sulfate, 2 parts of chitosan, 1 part of trehalose, 1 part of PBS buffer, and 35 parts of deionized water;

[0056] The organic matter includes the following raw materials in parts by weight: 25 parts of modified biomass activated carbon, 20 parts of humic acid;

[0057] The microbial composite bacterial agent comprises the following raw materials in parts by weight: 12 parts of Bacillus polymyxa, 10 parts of Trichoderma harzianum, 53 parts of Bacillus subtilis, and 6 parts of Nitrogen-fixing Bacteria.

[0058] Preparation of porous carrier:

[0059] The diatomite is dispersed in a phytic acid aqueous solution with a mass fraction of 2%, and the solid-liquid ratio of the diatomite to the phytic acid aqueous solution is 1g:20mL. The mixture is fully stirred at a speed of 400r / min for 35min. After filtering, the mixture is dried at 75°C for 10h, and then plasma treated to obtain solid A. The processing power of the plasma treatment is 230W, the processing atmosphere is nitrogen, the time is 8min, and the nitrogen gas flow rate is 80mL / min. Solid A is further dispersed in a phytic acid aqueous solution with a mass fraction of 13%, and the solid-liquid ratio of the solid A to the phytic acid aqueous solution is 1g:20mL. The mixture is further stirred at a speed of 400r / min for 35min. Solid B is obtained after filtering and drying in a vacuum drying oven at 90°C for 11h. Five parts of solid B are added to 33 parts of a polylysine aqueous solution with a concentration of 0.15g / mL, and stirred at a speed of 400r / min for 35min. The porous carrier is obtained after filtering and drying in a vacuum drying oven at 90°C for 15h.

[0060] Preparation of microbial composite agents:

[0061] 13 parts of Paenibacillus polymyxa, 11 parts of Trichoderma harzianum, 56 parts of Bacillus subtilis, and 6 parts of Azotobacter chroococcum were respectively inoculated into LB liquid medium at an inoculation amount of 10%, and cultured with shaking at 25 °C for 24 h to obtain the microbial composite bactericide, and the concentration of the microbial composite bactericide was 3×10 8 cfu / mL.

[0062] The preparation process of the modified biomass activated carbon is as follows:

[0063] Calcium chloride was dissolved in deionized water, and the pH value was adjusted to 9.5 - 10 with ammonia water to obtain a mixed solution A. An aqueous hydrogen peroxide solution with a mass fraction of 30% was added to the mixed solution A, and it was stirred at a speed of 500 r / min for 40 min, and then the pH of the solution was adjusted to 11 with sodium hydroxide to obtain a mixed solution B, where the dosage ratio of calcium chloride, deionized water, and aqueous hydrogen peroxide solution was 2 g:25 mL:10 mL; the mixed solution B and biomass activated carbon with a mass ratio of 3:1 were mixed and stirred at a speed of 500 r / min for 40 min, and after filtration, it was dried at 80 °C for 10 h to obtain solid A;

[0064] Rhamnolipid was mixed with water to obtain a rhamnolipid solution with a mass fraction of 15%. Solid A and the rhamnolipid solution with a mass ratio of 1:5 were ultrasonically treated at a power of 150 W for 25 min. After the ultrasonic treatment, the obtained solid was vacuum dried at 95 °C for 12 h to obtain the modified biomass activated carbon.

[0065] Preparation of the soil remediation composite bactericide composition:

[0066] S1. By weight, 13 parts of the microbial composite bactericide and 4 parts of the surface protective agent were mixed and then added with sterilized pure water. After mixing evenly, a mud-like mixture was formed, and it was kept warm and static at 37 °C in a sealed environment for 8 - 12 h;

[0067] S2. Naturally cooled to room temperature, and 45 parts of the porous carrier were continuously added, and it was stirred at a speed of 500 r / min for 45 min;

[0068] S3. 23 parts of organic matter were continuously added, and the stirring was continued at the same speed for 40 min, and then sterilized pure water was added to form a suspension. After dehydration, drying, and granulation, the soil remediation composite bactericide composition was obtained.

[0069] Example 3

[0070] The microbial bactericide protective agent includes the following raw materials in parts by weight: 3 parts of calcium superphosphate, 1.5 parts of ammonium sulfate, 3 parts of chitosan, 1.5 parts of trehalose, 1.5 parts of PBS buffer solution, and 40 parts of deionized water;

[0071] The organic matter includes the following raw materials in parts by weight: 30 parts of modified biomass activated carbon and 25 parts of humic acid;

[0072] The microbial composite bactericide comprises the following raw materials in parts by weight: 15 parts of Paenibacillus polymyxa, 15 parts of Trichoderma harzianum, 65 parts of Bacillus subtilis, and 8 parts of Azotobacter chroococcum.

[0073] Preparation of the porous carrier:

[0074] Diatomite is dispersed in an aqueous solution of phytic acid with a mass fraction of 3%, and the solid-liquid ratio of diatomite to the aqueous solution of phytic acid is 1 g: 20 mL. It is sufficiently stirred at a speed of 400 r / min for 45 min, filtered, dried at 75 °C for 10 h, and then treated with plasma to obtain solid A. The treatment power of the plasma treatment is 240 W, the treatment atmosphere is nitrogen, the time is 10 min, and the nitrogen gas flow rate is 100 mL / min. Solid A is further dispersed in an aqueous solution of phytic acid with a mass fraction of 15%, and the solid-liquid ratio of solid A to the aqueous solution of phytic acid is 1 g: 20 mL. It is continuously stirred at a speed of 400 r / min for 45 min, filtered, and dried in a vacuum drying oven at 110 °C for 12 h to obtain solid B. 6 parts of solid B are added to 35 parts of an aqueous solution of polylysine with a concentration of 0.2 g / mL, stirred at a speed of 400 r / min for 45 min, filtered, and dried in a vacuum drying oven at 90 °C for 15 h to obtain the porous carrier.

[0075] Preparation of the microbial composite bactericide:

[0076] 15 parts of Paenibacillus polymyxa, 15 parts of Trichoderma harzianum, 65 parts of Bacillus subtilis, and 8 parts of Azotobacter chroococcum are respectively inoculated into LB liquid medium at an inoculation amount of 10%, and cultured by shaking at 25 °C for 24 h to obtain the microbial composite bactericide, and the concentration of the microbial composite bactericide is 3×10 8 cfu / mL.

[0077] The preparation process of the modified biomass activated carbon is as follows:

[0078] Calcium chloride is dissolved in deionized water, and the pH value is adjusted to 9.5 - 10 with ammonia water to obtain a mixed solution A. An aqueous solution of hydrogen peroxide with a mass fraction of 30% is added to the mixed solution A, stirred at a speed of 500 r / min for 60 min, and then the pH of the solution is adjusted to 11 with sodium hydroxide to obtain a mixed solution B, where the dosage ratio of calcium chloride, deionized water, and the aqueous solution of hydrogen peroxide is 2 g: 30 mL: 10 mL; the mixed solution B and biomass activated carbon with a mass ratio of 3:1 are mixed, stirred at a speed of 500 r / min for 60 min, filtered, and dried at 80 °C for 10 h to obtain solid A;

[0079] Mix rhamnolipid with water to obtain a rhamnolipid solution with a mass fraction of 20%. Ultrasonically treat the solid A with a mass ratio of 1:5 to the rhamnolipid solution at a power of 200 W for 35 min. After the ultrasonic treatment, dry the obtained solid in a vacuum at 100 °C for 15 h to obtain the modified biomass activated carbon.

[0080] Preparation of the soil remediation composite microbial agent composition:

[0081] S1. By weight, mix 15 parts of the microbial composite agent and 5 parts of the surface protective agent, then add sterilized pure water. After mixing evenly, form a paste-like mixture and keep it in a sealed environment at 40 °C for 12 h.

[0082] S2. Naturally cool to room temperature, then continue to add 50 parts of the porous carrier and stir at a speed of 500 r / min for 55 min.

[0083] S3. Continue to add 25 parts of the organic matter, keep the rotation speed and continue to stir for 60 min. Then add sterilized pure water to form a suspension. After dehydration, drying, and granulation, obtain the soil remediation composite microbial agent composition.

[0084] Comparative Example 1

[0085] The difference between Comparative Example 1 and Example 1 is that the protective agent was not added in Comparative Example 1, and the rest of the operations were the same.

[0086] Comparative Example 2

[0087] The difference between Comparative Example 2 and Example 1 is that polylysine was not added during the preparation of the porous carrier in Comparative Example 2, and the rest of the operations were the same.

[0088] Comparative Example 3

[0089] The difference between Comparative Example 3 and Example 1 is that the porous carrier in Comparative Example 3 was diatomite and was not subjected to any modification treatment, and the rest of the operations were the same.

[0090] Comparative Example 4

[0091] The difference between Comparative Example 4 and Example 1 is that rhamnolipid was not added during the preparation of the modified biomass activated carbon in Comparative Example 4, and the rest of the operations were the same.

[0092] Comparative Example 5

[0093] The difference between Comparative Example 5 and Example 1 is that the biomass activated carbon in Comparative Example 5 was not subjected to any modification treatment, and the rest of the operations were the same.

[0094] Performance test:

[0095] 1. The soil remediation composite microbial agent compositions prepared in Examples 1 - 3 and Comparative Examples 1 - 5 were packed into sealed bags. At 1 day and 30 days respectively, the effective viable count of bacteria was measured. The measurement of the effective viable count of bacteria was carried out according to the method for measuring the effective viable count specified in the Inspection Code for Microbial Fertilizer Products NY / T 2321 - 2013. The test results are shown in Table 1:

[0096] Table 1

[0097]

[0098]

[0099] According to the above data, it can be seen that the soil remediation composite microbial agent composition prepared in the example has a high effective viable count and good storage property.

[0100] 2. Treatment application for saline - alkali land around the reservoir:

[0101] Test plot soil sample conditions: soil pH value is 8.51, salt content is 15.87 mg / g, organic matter is 0.88%, nitrogen is 660 ppm, potassium is 2.37%, and phosphorus is 1058.5 ppm;

[0102] The tested crop variety is Xinong 17 wheat;

[0103] A total of 9 test plots were set up in this test, including 3 experimental groups of examples, 5 experimental groups of comparative examples, and a blank control group. Each test plot is 1 mu. The plots are randomly arranged and repeated three times respectively, and the average value is taken. Among them, 3 experimental groups of examples and 5 experimental groups of comparative examples use 20 kg of the soil remediation composite microbial agent composition, while the blank control plot only uses 20 kg of clear water.

[0104] On the 28th day after sowing, the growth and development of wheat are shown in Table 2:

[0105] Table 2

[0106]

[0107]

[0108] Moreover, yellow tips and wilting phenomena occurred in the wheat of the comparative example group and the blank control group, while such phenomena did not occur in the wheat of the experimental plots of the examples.

[0109] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments of equivalent changes within the scope of the technical solution of the present invention by using the above-disclosed technical content. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A soil remediation composite bacterial agent composition, characterized in that: The raw materials include, by weight: 10 to 15 parts of a microbial composite agent, 40 to 50 parts of a porous carrier, 20 to 25 parts of organic matter, and 3 to 5 parts of a surface protective agent, wherein the porous carrier is obtained by treating diatomaceous earth with phytic acid and polylysine; The microbial agent protective agent comprises the following raw materials in parts by weight: 1 to 3 parts of superphosphate, 0.5 to 1.5 parts of ammonium sulfate, 1 to 3 parts of chitosan, 0.5 to 1.5 parts of trehalose, 0.5 to 1.5 parts of PBS buffer, and 30 to 40 parts of deionized water; The organic matter comprises the following raw materials in parts by weight: 20 to 30 parts of modified biomass activated carbon and 15 to 25 parts of humic acid, wherein the modified biomass activated carbon is obtained by treating with calcium peroxide and rhamnolipid; The microbial composite bacterial agent comprises the following raw materials in parts by weight: 10 to 15 parts of Bacillus polymyxa, 8 to 15 parts of Trichoderma harzianum, 50 to 65 parts of Bacillus subtilis, and 5 to 8 parts of Nitrogen-fixing Bacteria.

2. The soil remediation composite bacterial agent composition according to claim 1, characterized in that: The specific preparation process of the porous carrier is as follows: The diatomaceous earth is dispersed in a phytic acid aqueous solution with a mass fraction of 1 to 3%, and the mixture is stirred at a speed of 400 r / min for 30 to 45 minutes. After filtering, the mixture is dried at 75°C for 10 hours, and then subjected to plasma treatment to obtain solid A. Solid A is further dispersed in a phytic acid aqueous solution with a mass fraction of 10 to 15%, and the mixture is stirred at a speed of 400 r / min for 30 to 45 minutes. Solid B is obtained after filtering and drying in a vacuum drying oven at 80 to 110°C for 10 to 12 hours. 4 to 6 parts of solid B are added to 30 to 35 parts of a polylysine aqueous solution with a concentration of 0.1 to 0.2 g / mL, and the mixture is stirred at a speed of 400 r / min for 30 to 45 minutes. The porous carrier is obtained after filtering and drying in a vacuum drying oven at 90°C for 15 hours.

3. The soil remediation composite bacterial agent composition according to claim 1, characterized in that: The preparation process of the microbial composite agent is as follows: 10-15 parts of Paenibacillus polymyxa, 8-15 parts of Trichoderma harzianum, 50-65 parts of Bacillus subtilis and 5-8 parts of Azotobacter nitrofuga are inoculated into LB liquid culture medium at a 10% inoculation rate, and cultured under shaking at 25° C. for 24 hours to obtain the microbial composite agent.

4. The soil remediation composite bacterial agent composition according to claim 1, characterized in that: The preparation process of the modified biomass activated carbon is as follows: Calcium chloride was dissolved in deionized water, and the pH value was adjusted to 9.5-10 by ammonia water to obtain a mixed solution A, and a 30% by mass fraction hydrogen peroxide aqueous solution was added to the mixed solution A, and the mixture was stirred at a speed of 500 r / min for 30-60 min, and the pH of the solution was adjusted to 11 by sodium hydroxide to obtain a mixed solution B, wherein the amount ratio of calcium chloride, deionized water and hydrogen peroxide aqueous solution was 2g: (20-30mL): 10mL; the mixed solution B with a mass ratio of 3:1 was mixed with biomass activated carbon, and the mixture was stirred at a speed of 500 r / min for 30-60 min, filtered and dried at 80°C for 10h to obtain a solid A; Rhamnolipid and water are mixed to obtain a rhamnolipid solution, solid A and the rhamnolipid solution are ultrasonically treated at a mass ratio of 1:5 at a power of 100 to 200 W for 20 to 35 minutes, and after the ultrasonic treatment, the obtained solid is vacuum dried at 90 to 100° C. for 10 to 15 hours to obtain the modified biomass activated carbon.

5. The soil remediation composite bacterial agent composition according to claim 2, characterized in that: The solid-to-liquid ratio of the diatomaceous earth to the phytic acid aqueous solution is 1 g:20 mL.

6. The soil remediation composite bacterial agent composition according to claim 2, characterized in that: The plasma treatment has a processing power of 220-240 W, a processing atmosphere of nitrogen, a processing time of 5-10 min, and a nitrogen gas flow rate of 70-100 mL / min.

7. The soil remediation composite bacterial agent composition according to claim 2, characterized in that: The solid-to-liquid ratio of the solid A to the phytic acid aqueous solution is 1 g:20 mL.

8. The soil remediation composite bacterial agent composition according to claim 3, characterized in that: The concentration of the microbial composite agent is 3×10 8 cfu / mL.

9. The soil remediation composite bacterial agent composition according to claim 4, characterized in that: The mass fraction of the rhamnolipid solution is 10-20%.

10. A method for preparing the soil remediation composite bacterial agent composition according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Mix the microbial composite agent and the surface protective agent by weight, add sterilized purified water, mix evenly to form a muddy mixture, and keep it in a sealed environment at 35-40°C for 8-12 hours; S2, naturally cool to room temperature, continue to add porous carrier, and stir at a speed of 500r / min for 40-55min; S3, continue to add organic matter, maintain the speed and continue stirring for 35 to 60 minutes, then add sterile purified water to form a suspension, dehydrate, dry and granulate to obtain the soil remediation composite bacterial agent composition.

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