Search

CN-121991697-A - Cultivated land soil restoration modifier based on waste biomass and preparation method thereof

CN121991697ACN 121991697 ACN121991697 ACN 121991697ACN-121991697-A

Abstract

The invention relates to the technical field of soil remediation, in particular to a cultivated land soil remediation modifier based on waste biomass and a preparation method thereof, wherein the cultivated land soil remediation modifier comprises, by mass, 5-10% of modified biomass, 1-5% of microbial agents, 1-5% of gel materials, 10-20% of bentonite and the balance of organic fertilizers, the preparation method comprises the following steps of S1, preparing a rigid matrix, S2, preparing flexible slurry, S3, preparing the cultivated land soil remediation modifier, the cultivated land soil remediation modifier provided by the invention uses the modified biomass and the bentonite as the rigid matrix, uses the gel materials, the microbial agents and the organic fertilizers as the flexible slurry, the rigid matrix is favorable for breaking hardening, increasing pores, and the flexible slurry can promote the water retention capacity, so that particles can be prevented from loosening and collapsing in soil when encountering water, and the action time of the cultivated land soil remediation modifier is prolonged.

Inventors

  • ZHAO WENJUAN
  • TIAN JIA
  • XU SHENGYUN
  • QIN TAO
  • CHEN WEIFENG

Assignees

  • 陕西省生物农业研究所
  • 陕西省微生物研究所

Dates

Publication Date
20260508
Application Date
20260112

Claims (9)

  1. 1. The farmland soil restoration improver based on the waste biomass is characterized by comprising the following components in percentage by mass: 5-10% of modified biomass; 1-5% of microbial agent; 1-5% of gel material; 10-20% of bentonite; organic fertilizer with the balance; The preparation method of the modified biomass comprises the following steps: Grinding and drying the waste biomass to obtain powder with the particle size of 0.1-0.2 mm, and then carrying out microwave irradiation modification on the powder, wherein the power of microwave irradiation is 500-600W, and the time is 30-40 min, so as to obtain modified powder; Mixing the modified powder with 45-55% phosphoric acid solution in a solid-liquid ratio of 1 g:50-80 mL, carrying out reflux extraction at 85-90 ℃ for 1-2 h, and filtering after the reflux extraction is completed to obtain an extracting solution; Firstly adding 1-2% of hexadecyl trimethyl ammonium bromide aqueous solution into the extracting solution in a volume ratio of 10-15:1, firstly mixing for 15-20 min under 0.5-1 MPa to obtain a first mixed solution, then adjusting the pH of the first mixed solution to 7-9, adding humic acid accounting for 5-10wt% of modified powder into the first mixed solution after the pH adjustment is completed, adjusting the pressure to 0.1-0.2 MPa, and continuously mixing for 30-40 min to obtain a second mixed solution; And heating the second mixed solution to 600-650 ℃ at 5-10 ℃ per min under inert gas, and preserving heat for 2-3 hours to obtain the modified biomass.
  2. 2. The waste biomass-based farmland soil restoration improver as set forth in claim 1, wherein said waste biomass is one or more of corn stover, apple tree branches and prickly ash tree branches.
  3. 3. The waste biomass-based farmland soil restoration improver according to claim 1, wherein the gel material is a modified fiber composite aerogel material, and the preparation method of the modified fiber composite aerogel material is as follows: Performing surface alkalization treatment on the mulberry fibers to obtain alkalized mulberry fibers, dissolving polyglutamic acid and tetraethylenepentamine in HEPES buffer solution according to a solid-to-liquid ratio of 1g to 100ml to 15-20 ml, regulating the pH value to 8-9 to obtain modified solution, soaking the alkalized mulberry fibers in the modified solution according to a solid-to-liquid ratio of 1g to 20-30 ml for 5-7 h to obtain pre-modified mulberry fibers, and washing and drying the pre-modified mulberry fibers; Immersing the pre-modified mulberry fiber in a hydrolysate of a silane coupling agent with the volume fraction of 20-25% for 1-2 hours according to the solid-to-liquid ratio of 1 g:15-20 ml to obtain the modified mulberry fiber, taking out and washing the modified mulberry fiber, and performing heat treatment for 30-40 min at 105-115 ℃ to obtain the heat-treated mulberry fiber; Dispersing iron oxide nano particles with the particle size of 20-30 nm in ethanol solution with the mass fraction of 50-55% according to the solid-to-liquid ratio of 1 g:80-90 ml to obtain dispersion liquid of organic magnetized particles, mixing heat treated mulberry fibers, ethylene oxide and the dispersion liquid of the organic magnetized particles according to the solid-to-liquid ratio of 1g:10 ml:60-80 ml for 60-90 min, and filtering and drying the product to obtain a composite material; And (3) vacuum impregnating the composite material in silica sol with the pH value of 6-7 at the solid-liquid ratio of 1 g:40-50 ml, wherein the temperature is 25-35 ℃, the vacuum degree is 0.08-0.09 MPa, the impregnation time is 30-40 min, an impregnated product is obtained, fumed silica is introduced into the impregnated product at the rate of 0.5-0.8L/min, the reaction is carried out for 2-4 h at the temperature of 50-60 ℃, and the modified fiber composite aerogel material is obtained through supercritical drying.
  4. 4. The waste biomass-based farmland soil restoration improver according to claim 3, wherein the supercritical drying pressure is 10-15 mpa, the temperature is 30-50 ℃, the drying time is 10-12 h, and the pressure is released at a speed of 150-200 kpa/min after the drying is completed.
  5. 5. The waste biomass-based farmland soil restoration improver is characterized in that the surface alkalization treatment method of the mulberry fibers comprises the steps of reacting the mulberry fibers with 10-20% NaOH solution in a solid-to-liquid ratio of 1 g:50-60 ml, wherein the reaction temperature is 80-100 ℃, and the reaction time is 2-4 hours.
  6. 6. The waste biomass-based tilling soil remediation improver of claim 1, wherein the gel material is one or more of a cellulose hydrogel, a polyacrylic acid-based hydrogel, and a carboxymethyl chitosan gel.
  7. 7. The waste biomass-based farmland soil remediation improver disclosed in claim 1, wherein the microbial agent has a strain concentration of 1×10 8 ~1×10 10 CFU/mL, and comprises bacillus fermentation liquor, azotobacter fermentation liquor and phosphate-solubilizing bacteria fermentation liquor in a volume ratio of 1:1:0.8-1, and the bacillus fermentation liquor, azotobacter fermentation liquor and phosphate-solubilizing bacteria fermentation liquor have the same strain concentration.
  8. 8. The waste biomass-based farmland soil restoration improver as set forth in claim 1, wherein said organic fertilizer is one or more of manure, okara, and pericarp.
  9. 9. The method for preparing the waste biomass-based farmland soil restoration improver according to any one of claims 1 to 8, which is characterized by comprising the following steps: S1, preparing a rigid matrix Mixing the modified biomass with bentonite for 30-40 min to obtain a mixture, and extruding and granulating the mixture to obtain a rigid matrix with the particle size of 3-5 mm; S2, preparing flexible slurry Adding a microbial agent into an organic fertilizer, and stirring and mixing for 15-20 min at 100-200 rpm to obtain a premix; Adding a gel material into the premix, and continuously stirring and mixing for 20-30 min at 200-300 rpm to obtain flexible slurry; s3, preparing soil restoration modifier for cultivated land In a vacuum environment of-0.06 to-0.09 MPa, compounding the flexible slurry prepared in the step S2 with the rigid matrix prepared in the step S1 by a low-pressure pouring method, wherein the pressure of low-pressure pouring is 0.1-0.3 MPa, and obtaining a composite matrix; And drying the composite matrix at 30-35 ℃ until the water content is less than 15%, thereby obtaining the farmland soil restoration modifier.

Description

Cultivated land soil restoration modifier based on waste biomass and preparation method thereof Technical Field The invention relates to the technical field of soil remediation, in particular to a farmland soil remediation modifier based on waste biomass and a preparation method thereof. Background Cultivated land soil is a basic resource for agricultural production, and the health state of the cultivated land soil is directly related to grain safety and ecological sustainability. However, with the rapid development of industry and agriculture, cultivated lands face multiple risk problems such as soil acidification, salinization, organic matter reduction, heavy metal pollution and the like. For example, the problem of acidification of the soil in the south farmland is prominent (pH value is lower than 5.5), which results in the enhancement of heavy metal activity and the increase of crop absorption risk, and meanwhile, excessive use of chemical fertilizer and pesticide causes soil hardening and microbial community degradation, so that the ecological function of the cultivated land is degraded. Although the current common repair technology (such as chemical passivation, soil replacement and the like) can take effect in a short period, the current common repair technology has the bottlenecks of high cost (thousands of yuan per mu investment), high secondary pollution risk, unsustainable effect and the like. In addition, it is difficult for a single technology to cope with the complex pollution, and part of mineral improvers (such as lime) can destroy the soil aggregate structure after long-term use, further aggravating the soil productivity. The waste biomass (such as straw, rice husk, garden trimming waste and the like) is used as a repairing raw material, has the unique advantages of green, low cost and recycling, and is a win-win path for solving the environmental pollution and soil repairing requirements. For example, ash of biomass power plants is rich in silicate, calcium, potassium and other elements, and can be made into passivating agent, and the content of cadmium in rice is reduced by 69-93% and the yield is increased by 24-79% through ion exchange adsorption of heavy metals. And the waste biomass can be converted into biochar through a carbonization technology, the porous structure of the biomass can improve the water and fertilizer retaining capacity of soil and fix pollutants, and the organic fertilizer produced by fermentation can also supplement soil organic matters and reconstruct microbial communities. The data show that after the Liaoning Xiuyan county is improved by the straw carbon base fertilizer, the organic matters in the soil are improved, and the yield of crops is increased by more than 20%. Compared with the traditional modifier, the biomass material is natural in origin, degradable and free of residues, and accords with the concept of 'natural-based repair'. Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a waste biomass-based conditioner for restoring farmland soil and a method for preparing the same. Disclosure of Invention In order to solve the problems, the invention provides a farmland soil restoration improver based on waste biomass and a preparation method thereof. The farmland soil restoration modifier based on the waste biomass comprises the following components in percentage by mass: 5-10% of modified biomass; 1-5% of microbial agent; 1-5% of gel material; 10-20% of bentonite; organic fertilizer with the balance; The preparation method of the modified biomass comprises the following steps: Grinding and drying the waste biomass to obtain powder with the particle size of 0.1-0.2 mm, and then carrying out microwave irradiation modification on the powder, wherein the power of microwave irradiation is 500-600W, and the time is 30-40 min, so as to obtain modified powder; Mixing the modified powder with 45-55% phosphoric acid solution in a solid-liquid ratio of 1 g:50-80 mL, carrying out reflux extraction at 85-90 ℃ for 1-2 h, and filtering after the reflux extraction is completed to obtain an extracting solution; Firstly adding 1-2% of hexadecyl trimethyl ammonium bromide aqueous solution into the extracting solution in a volume ratio of 10-15:1, firstly mixing for 15-20 min under 0.5-1 MPa to obtain a first mixed solution, then adjusting the pH of the first mixed solution to 7-9, adding humic acid accounting for 5-10wt% of modified powder into the first mixed solution after the pH adjustment is completed, adjusting the pressure to 0.1-0.2 MPa, and continuously mixing for 30-40 min to obtain a second mixed solution; And heating the second mixed solution to 600-650 ℃ at 5-10 ℃ per min under inert gas, and preserving heat for 2-3 hours to obtain the modified biomass. Further, the waste biomass is one or more of corn straw, apple branches and pricklyash branches. Th