CN-121494680-B - Environment-friendly soil improvement restoration agent and preparation method thereof

CN121494680BCN 121494680 BCN121494680 BCN 121494680BCN-121494680-B

Abstract

The invention relates to the technical field of soil remediation and discloses an environment-friendly soil improvement restoration agent and a preparation method thereof, wherein the restoration agent comprises, by weight, 30-50 parts of biochar, 15-25 parts of humic acid, 2-3 parts of modified attapulgite, 1-1.5 parts of citric acid grafted ramie fibers, 5-10 parts of composite microbial agents, 8-15 parts of organic slow release fertilizers, 5-10 parts of zeolite powder, 3-8 parts of plant source chelating agents and 2-5 parts of pH regulators. The preparation process comprises the steps of raw material pretreatment, primary mixing, compound mixing, granulating, drying and the like, and ensures stable product performance by precisely controlling the crushing granularity, the mixing rotating speed, the drying temperature and the like. The repairing agent integrates the functions of heavy metal passivation, saline-alkali neutralization, soil loosening and nutrient supplement, has the advantages of green and pollution-free preparation process, lasting repairing effect and no secondary pollution, and can effectively improve the physicochemical property of soil, promote the fertility of the soil, aid the sustainable development of agriculture and improve the ecological environment.

Inventors

WANG XIAO
XU DANYANG
SHEN WANYU
WU JI
HU JIANKUN
HUI XIAOLI
ZHANG YANFENG
LI WENFENG
XIA QIANG
XUE LIHUI

Assignees

安徽省农业科学院土壤肥料研究所

Dates

Publication Date: 20260508
Application Date: 20260113

Claims (5)

1. The environment-friendly soil improvement restoration agent is characterized by comprising, by weight, 30-50 parts of biochar, 15-25 parts of humic acid, 2-3 parts of modified attapulgite, 1-1.5 parts of citric acid grafted ramie fiber, 5-10 parts of composite microbial agent, 8-15 parts of organic slow release fertilizer, 5-10 parts of zeolite powder, 3-8 parts of plant source chelating agent and 2-5 parts of pH regulator; The preparation method of the modified attapulgite comprises the steps of crushing 4-5g of attapulgite to 100-200 meshes, adding deionized water with the mass of 5-8 times of that of the attapulgite, stirring and dispersing to form a suspension, adding aluminum sulfate with the mass of 3-6% of that of the attapulgite and polyacrylamide with the mass of 2-5% into the suspension, stirring and reacting for 1-2 hours at 50-70 ℃, filtering and washing until the filtrate is neutral after the reaction is finished, and drying for 3-5 hours at 105-115 ℃; The organic slow release fertilizer is prepared by mixing thoroughly decomposed livestock manure, bean pulp, bone meal and modified chitosan according to a mass ratio of 5:3:1:1, wherein the organic matter content is more than or equal to 40%, and the total content of nitrogen, phosphorus and potassium is more than or equal to 8%; Preparing modified chitosan, namely weighing epsilon-caprolactone and a catalyst Sn (OCt) 2 , adding the epsilon-caprolactone and the catalyst Sn (OCt) 2 into a chitosan/[ BMIM ] Ac solution, continuously stirring and reacting under the N 2 atmosphere, cooling the solution to room temperature after the reaction is finished, adding 3-5 times of ethanol, precipitating a graft copolymer, repeatedly washing with the ethanol, collecting the precipitate, extracting a product by using toluene as an extracting agent by using a Soxhlet extractor until caprolactone homopolymer is completely removed, and drying the obtained graft copolymer in a vacuum drying oven at 80 ℃ for 24 hours; The preparation method of the citric acid grafted ramie fiber comprises the steps of putting 1g of dried ramie fiber into 100mL of 18% sodium hydroxide aqueous solution, treating for 3 hours at room temperature, washing to be neutral by water, drying at 60 ℃ for 12 hours for standby, mixing the pretreated ramie fiber with 100mL of 20mmol of citric acid solution, adding 0.4g of sodium hypophosphite, stirring for 30 minutes at normal temperature, drying at 60 ℃ for 24 hours, removing water, heating to 120 ℃ for esterification reaction for 90 minutes, washing to be neutral after cooling to room temperature, and drying at 60 ℃ to obtain the citric acid grafted ramie fiber.
2. The environment-friendly soil improvement restoration agent according to claim 1, wherein the biochar is prepared by high-temperature anaerobic carbonization of crop straws, forestry waste or livestock manure, the carbonization temperature is 450-650 ℃, the carbonization time is 2-4h, the specific surface area is 150-300m2/g, the pore diameter is 2-10nm, the crop straws comprise one or more of corn straws, wheat straws and rice straws, and the forestry waste comprises one or more of dried branches, fallen leaves and wood dust.
3. The environment-friendly soil improvement restoration agent according to claim 1, wherein the plant source chelating agent is one or more of citric acid, malic acid or tea saponin, the purity is more than or equal to 95%, the pH regulator is one or more of plant ash, dolomite powder or gypsum powder, and the particle size is 100-200 meshes.
4. The method for preparing the environment-friendly soil improvement restoration agent according to claim 1, which is characterized in that the method for preparing the environment-friendly soil improvement restoration agent comprises the following steps: (1) Raw material pretreatment, namely respectively crushing biochar, humic acid and zeolite powder to 100-200 meshes, sieving, crushing the organic slow release fertilizer to 80-120 meshes, and sieving for later use; (2) Primary mixing, namely adding pretreated biochar, humic acid, zeolite powder, modified attapulgite, citric acid grafted ramie fibers and organic slow release fertilizer into a double-screw mixer, and mixing for 20-30min at the rotating speed of 150-200r/min to obtain a primary mixed material; (3) Mixing, namely adding a plant source chelating agent and a pH regulator into the primary mixed material, continuously mixing for 15-25min at the rotating speed of 180-220r/min, then adding a compound microbial agent, and mixing for 5-10min at the low speed of 80-120r/min to obtain a mixed material; (4) Granulating and drying, namely feeding the mixed material into a disc granulator, spraying deionized water to regulate the humidity of the material, granulating to form particles with the particle size of 2-5mm, and feeding the particles into a low-temperature dryer, and drying at 40-50 ℃ until the moisture content is less than or equal to 8%, thus obtaining the environment-friendly soil improvement restoration agent.
5. The method for preparing an environment-friendly soil improvement restoration agent as claimed in claim 4, wherein the humidity of the material in the step (4) is adjusted to 20-30%.

Description

Environment-friendly soil improvement restoration agent and preparation method thereof Technical Field The invention relates to the technical field of soil remediation, in particular to an environment-friendly soil improvement remediation agent and a preparation method thereof. Background With the acceleration of industrialization process, excessive use of chemical fertilizers and pesticides in agricultural production and unreasonable exploitation of mineral resources, the problem of soil pollution is increasingly prominent, and the problems are mainly manifested by soil acidification degradation, excessive heavy metals, aggravation of salinization, soil hardening, reduction of organic matter content, unbalanced nutrients and the like, which seriously affect the growth development and yield quality of crops, even harm to human health through food chains, and restrict sustainable development of agriculture and improvement of ecological environment. At present, the soil improvement and restoration technology mainly comprises three major categories of physical restoration, chemical restoration and biological restoration. The physical restoration method has the defects of large engineering quantity, high cost, easy secondary pollution and the like, the chemical restoration method reduces the activity of pollutants in the soil by adding chemical chelating agents, modifying agents and the like, but most of common chemical agents are artificial synthetic substances, are easy to remain in the soil, destroy the microbial community structure of the soil and influence the ecological balance of the soil, and the biological restoration method has better environmental protection, long restoration period and low efficiency, and is difficult to meet the requirement of quickly restoring the large-area polluted soil. Therefore, development of an environment-friendly soil improvement restoration agent which is environment-friendly and renewable in raw materials, has multiple restoration functions, has lasting restoration effect and does not have secondary pollution is needed. Disclosure of Invention (One) solving the technical problems Aiming at the defects of the prior art, the invention provides an environment-friendly soil improvement restoration agent and a preparation method thereof, which have multiple functions of heavy metal passivation, saline-alkali neutralization, soil loosening and nutrient supplement, and the preparation process is environment-friendly. (II) technical scheme The environment-friendly soil improvement restoration agent comprises, by weight, 30-50 parts of biochar, 15-25 parts of humic acid, 2-3 parts of modified attapulgite, 1-1.5 parts of citric acid grafted ramie fibers, 5-10 parts of composite microbial agents, 8-15 parts of organic slow release fertilizers, 5-10 parts of zeolite powder, 3-8 parts of plant source chelating agents and 2-5 parts of pH regulators. Further, the biochar is prepared by high-temperature anaerobic carbonization of crop straws, forestry waste or livestock and poultry manure, the carbonization temperature is 450-650 ℃, the carbonization time is 2-4h, the specific surface area is 150-300m < 2 >/g, the aperture is 2-10nm, the crop straws comprise one or more of corn straws, wheat straws and rice straws, and the forestry waste comprises one or more of dried branches, fallen leaves and wood dust. The preparation method of the modified attapulgite comprises the steps of crushing 4-5g of attapulgite to 100-200 meshes, adding deionized water with the mass of 5-8 times of that of the crushed attapulgite, stirring and dispersing to form a suspension, adding aluminum sulfate with the mass of 3-6% of that of the attapulgite and polyacrylamide with the mass of 2-5% into the suspension, stirring and reacting for 1-2 hours at 50-70 ℃, filtering and washing until filtrate is neutral after the reaction is finished, and drying for 3-5 hours at 105-115 ℃. Further, the compound microbial agent is prepared by mixing bacillus subtilis, phosphate-dissolving bacteria, potassium-dissolving bacteria, azotobacter and saccharomyces cerevisiae according to a mass ratio of 3:2:2:2:1, wherein the effective viable count is more than or equal to 2.0X10 9 cfu/g. Further, the organic slow release fertilizer is prepared by mixing thoroughly decomposed livestock manure, bean pulp, bone meal and modified chitosan according to a mass ratio of 5:3:1:1, wherein the organic matter content is more than or equal to 40%, and the total content of nitrogen, phosphorus and potassium is more than or equal to 8%. Further, the plant source chelating agent is one or more of citric acid, malic acid or tea saponin, the purity is more than or equal to 95%, the pH regulator is one or more of plant ash, dolomite powder or gypsum powder, and the particle size is 100-200 meshes. Further, the preparation method of the environment-friendly soil improvement restoration agent comprises the following steps: (1) Raw material pretreatm