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CN-121991699-A - Acidified biochar composite modifier for saline-alkali soil improvement and preparation method thereof

CN121991699ACN 121991699 ACN121991699 ACN 121991699ACN-121991699-A

Abstract

An acidified biochar composite modifier for improving saline-alkali soil and a preparation method thereof belong to the technical field of soil improvement. The invention provides an acidified biochar composite modifier for improving saline-alkali soil, which aims at solving the problems that a traditional single improvement material for saline-alkali soil or a simple compounding technology can only aim at a single pain point and the effect is difficult to be durable and stable in the prior art, wherein the acidified biochar composite modifier takes humic acid grafted and modified acidified biochar as a core salt-reducing and base-reducing material, vinasse as a fertilizer carrier, a DNA-calcium phosphate composite gel precursor is introduced, a granular product is prepared by matching natural zeolite and a composite salt-tolerant microbial inoculum through a gel granulation process, and a synergistic mechanism of 'targeted adsorption-chemical neutralization-biological synergism-mineralization retention' is constructed, so that the acidified biochar composite modifier has the advantages of high salt-reducing and base-reducing efficiency, long-acting stability, environmental friendliness and simplicity and convenience in preparation.

Inventors

  • DAI YINGJIE
  • ZHOU CONGHUI
  • WANG HONGWAI
  • YAN LILONG
  • LI ZHIXIN
  • NIU LU
  • WANG XINYAO
  • Qu Kongliang
  • MA MEILI
  • ZHAO YUN

Assignees

  • 东北农业大学

Dates

Publication Date
20260508
Application Date
20260120

Claims (10)

  1. 1. The acidified biochar composite modifier for improving the saline-alkali soil is characterized by comprising, by weight, 12-18 parts of humic acid grafted and modified acidified biochar, 10-16 parts of vinasse, 0.4-0.7 part of DNA-calcium phosphate composite gel precursor, 2-4 parts of zeolite and 0.1-0.2 part of composite salt-tolerant microbial inoculum.
  2. 2. The acidified biochar composite modifier according to claim 1, wherein the acidified biochar composite modifier comprises 15 parts by weight of humic acid grafted modified acidified biochar, 14 parts by weight of vinasse, 0.6 part by weight of a DNA-calcium phosphate composite gel precursor, 3 parts by weight of zeolite and 0.15 part by weight of a composite salt-tolerant microbial agent.
  3. 3. The preparation method of the acidified biochar composite modifier is characterized by comprising the steps of adding the acidified biochar into a humic acid solution with the mass fraction of 8% according to the solid-to-liquid ratio of 1:15, reacting for 6h under the constant-temperature oscillation condition of 60 ℃ and 120 r/min, carrying out suction filtration after the reaction is finished, and drying at 80 ℃ to constant weight to obtain the humic acid grafted and modified acidified biochar.
  4. 4. The acidified biochar composite modifier according to claim 3, wherein the preparation method of the acidified biochar comprises the steps of crushing corn stalk biochar, sieving with a 100-mesh sieve, adding the crushed corn stalk biochar into 30% by mass of industrial phosphoric acid according to a solid-to-liquid ratio of 1:20, maintaining the temperature at 25 ℃ in a magnetic stirrer, fully stirring for 12 h, fully reacting the biochar with the industrial phosphoric acid, performing suction filtration, separating the phosphoric acid from the biochar, washing the mixture with deionized water for a plurality of times to neutrality, and drying the mixture in an oven until the weight is unchanged, thereby obtaining the acidified biochar.
  5. 5. The acidified biochar composite modifier of claim 1, wherein the method of preparing the distillers 'grains comprises the steps of placing fresh distillers' grains in a 60 ℃ oven for drying 12h, crushing, sieving with a 100 mesh sieve, and sealing for later use.
  6. 6. The acidified biochar complex modifier of claim 1 wherein the method of preparing a DNA-calcium phosphate complex gel precursor comprises the steps of: Dissolving salmon sperm DNA powder in deionized water under magnetic stirring at 37 deg.C and 100 r/min for 30 min to form 0.8% concentration DNA water solution, adding calcium phosphate nanometer particles into the DNA water solution in the weight ratio of 3:1, stirring while maintaining stirring speed for 150 r/min to obtain mixed solution, regulating pH value of the mixed solution to 7.0-7.5 with 0.1 mol/L hydrochloric acid or sodium hydroxide solution, and standing for 2 h at 25 deg.C to obtain DNA-calcium phosphate composite gel precursor.
  7. 7. The acidified biochar composite modifier according to claim 1, wherein the zeolite preparation method comprises the steps of crushing zeolite, sieving with a 100-mesh sieve, and sealing for later use.
  8. 8. The acidified biochar composite modifier of claim 1, wherein the method of preparing the composite salt tolerant microbial agent comprises the steps of: S1, strain activation and pure culture: inoculating Azotobacter bailii into a Leptoradix Abdominae Bei Modan liquid culture medium, and culturing under shaking at 30deg.C and 180: 180 rpm for 24-36: 36 h until the concentration of bacterial liquid is not less than 5×10: 10 9 CFU/mL; Inoculating bacillus megatherium into LB liquid culture medium, and shake culturing at 30 deg.C and 180 rpm for 18-24 h until bacterial liquid concentration is not less than 8×10 9 CFU/mL; inoculating the salt-tolerant actinomycetes into a liquid culture medium with improved high salt GauseI, and culturing in an oscillating way under the conditions of 30 ℃ and 180 rpm for 48-60 h until the concentration of bacterial liquid is more than or equal to 3 multiplied by 10 9 CFU/mL; S2, expanding culture: Mixing the activated bacteria liquid of the Azotobacter bailii, the bacillus megatherium and the salt-tolerant actinomycetes obtained in the step S1 according to the ratio of the number of the active bacteria of 2:2:1 to obtain mixed bacteria, inoculating the mixed bacteria into a cooled fermentation culture medium according to the inoculum size of 5% (v/v), fermenting and culturing 48: 48 h under the conditions of 30 ℃ and 200 rpm and the aeration rate of 1:0.8 (v/v.min), carrying out pH detection every 6: 6 h, and regulating the pH value to 7.0-7.5 by using sterile acid/alkali liquor, wherein the total concentration of the fermentation end bacteria liquid is more than or equal to 1.0x10 10 CFU/mL; s3, carrier adsorption and drying molding: Selecting diatomite, crushing, sieving with a 200-mesh sieve, carrying out wet heat sterilization at 121 ℃ for 2 h ℃, drying until the water content is less than or equal to 5%, obtaining pretreated diatomite carrier, adding 5% (w/v) of pretreated diatomite carrier into fermentation end-point bacteria liquid in S2, stirring and adsorbing for 30min under the conditions of 25 ℃ and 100 rpm, drying by adopting a spray drying tower, controlling the inlet temperature at 120+/-5 ℃, controlling the outlet temperature at 40+/-2 ℃ and the feeding rate at 10 mL/min, and obtaining the powdery compound salt-tolerant bacteria, wherein the total number of effective viable bacteria of the compound salt-tolerant bacteria is more than or equal to 2.0x10 9 CFU/g, the water content is less than or equal to 8%, the pH value is 7.0-7.5, and sealing and storing at a shade and dry place.
  9. 9. The acidified biochar composite modifier according to claim 8, wherein the Abenta Bei Modan liquid medium consists of glucose 10 g, KH 2 PO 4 0.2 g、MgSO 4 7H 2 O 0.2 g、NaCl 0.2 g、CaCO 3 g, distilled water 1000 ml, ph=7.2; the LB liquid medium comprises tryptone 10g, yeast extract 5 g, naCl 10g, distilled water 1000 mL, and pH=7.2; The improved high-salt GauseI liquid culture medium comprises soluble starch 20 g and KNO 3 1 g、K 2 HPO 4 3H 2 O 0.5 g、MgSO 4 7H 2 O 0.5 g、NaCl 100 g、FeSO 4 7H 2 O0.01 g, 1000 ml of distilled water, ph=7.4; The fermentation medium comprises glucose 20g, peptone 10 g,NaCl 15 g,KH 2 PO 4 3 g,MgSO 4 ·7H 2 O 1 g,CaCO 3 , g, yeast extract 3g, distilled water 1000 mL and pH=7.2.
  10. 10. A process for the preparation of an acidified biochar complex modifier according to any one of claims 1 to 9, characterised in that the process comprises the steps of: The preparation method comprises the steps of weighing humic acid grafted modified acidified biochar, vinasse, zeolite and a composite salt-tolerant microbial inoculum according to parts by weight, placing the materials in a magnetic stirrer, stirring the materials for 30min at a rotating speed of 200 r/min to obtain a mixture powder, adding a DNA-calcium phosphate composite gel precursor into the mixture powder, stirring the materials for 20 min at a rotating speed of 150 r/min at a feeding interval of 5 min each time to finally form a pasty slurry which is sticky, uniform, non-caking and strong in plasticity, making the pasty slurry into small particles with a diameter of 2 mm, spreading the small particles on a tray, placing the small particles in a 37 ℃ constant-temperature constant-humidity box, standing the small particles for 40 min, placing the solidified particles in a 50 ℃ air-blast oven, drying the particles for 8h, cooling the particles to room temperature, and screening to remove the crushed particles to obtain the acidified biochar composite modifier.

Description

Acidified biochar composite modifier for saline-alkali soil improvement and preparation method thereof Technical Field The invention belongs to the technical field of soil improvement, and particularly relates to an acidified biochar composite modifier for improving saline-alkali soil and a preparation method thereof. Background Saline-alkali soil is a soil that is subject to saline pollution leading to soil degradation and is widely distributed worldwide. Saline-alkali soil is usually accompanied with problems of lack of humus fertilizer sources, low cation exchange capacity and the like, so that soil aggregates are hardened, air and water permeability is poor, nutrient loss and lack are caused, and the yield and quality of crops are further reduced. The traditional improvement technology mainly comprises a first water conservancy improvement measure, such as irrigation salt washing, and leaching soluble salt in surface soil from top to bottom. However, this requires the construction of a large drainage and irrigation system, which requires a lot of manpower and material resources and is costly. Second, biological improvement measures, by planting plants. However, coastal wetlands have a high salt content, plants which can grow on the coastal wetlands are very limited, and most of the coastal wetlands are non-commercial crops, so that the resource recycling cannot be realized after the plants die. Third, chemical modification measures. By applying gypsum and other chemical modifiers, free alkali and exchangeable sodium are eliminated, the alkalinity is reduced, and the physical properties are improved to increase the yield of crops. However, although the chemical method takes effect quickly, secondary pollution is easily caused. In addition, the traditional single improved material or simple compounding technology can only aim at a certain pain point, and long-acting and systematic repair is difficult to realize. For example, the acidified biochar can adsorb part of sodium ions and adjust pH, but has insufficient construction capability on soil aggregation structure and continuous nutrient supply, and the organic wastes such as vinasse and the like can supplement carbon sources and excite microbial activity, but has loose structure and easy decomposition, and can not perform functions stably for a long time under high saline-alkali stress. Therefore, the development of a multifunctional composite system capable of deeply integrating physical structure reconstruction, chemical ion balance and biological function activation is a key for breaking through the technical bottleneck of the improvement of the current saline-alkali soil. Disclosure of Invention The invention provides an acidified biochar composite modifier for improving saline-alkali soil and a preparation method thereof, which are used for solving the problems that a traditional single improvement material for saline-alkali soil or a simple compounding technology in the prior art can only aim at a single pain point and the effect is difficult to be durable and stable. The invention aims to provide an acidified biochar composite modifier for improving saline-alkali soil, which consists of, by weight, 12-18 parts of humic acid grafted and modified acidified biochar, 10-16 parts of vinasse, 0.4-0.7 part of DNA-calcium phosphate composite gel precursor, 2-4 parts of zeolite and 0.1-0.2 part of composite salt-tolerant microbial inoculum. In a preferred embodiment of the invention, the acidified biochar composite modifier consists of 15 parts by weight of humic acid grafted modified acidified biochar, 14 parts by weight of vinasse, 0.6 part by weight of DNA-calcium phosphate composite gel precursor, 3 parts by weight of zeolite and 0.15 part by weight of composite salt-tolerant microbial inoculum. In a preferred embodiment of the invention, the preparation method of the humic acid grafted modified acidified biochar comprises the following steps of adding the acidified biochar into a humic acid solution with the mass fraction of 8% according to the solid-to-liquid ratio of 1:15, reacting for 6h under the constant-temperature oscillation condition of 60 ℃ and 120 r/min, filtering after the reaction is finished, and drying at 80 ℃ to constant weight to obtain the humic acid grafted modified acidified biochar. In a preferred embodiment of the invention, the preparation method of the acidified biochar comprises the following steps of crushing corn stalk biochar, sieving the crushed corn stalk biochar with a 100-mesh sieve, adding the crushed corn stalk biochar into 30% by mass of industrial phosphoric acid according to a solid-to-liquid ratio of 1:20, maintaining the temperature at 25 ℃ in a magnetic stirrer, fully stirring the crushed corn stalk biochar with the industrial phosphoric acid for 12 h, fully reacting the biochar with the industrial phosphoric acid, performing suction filtration, separating the phosphoric acid from the biochar, washing the crush