CN-118458739-B - Modified biochar and preparation method thereof

Abstract

The invention discloses modified biochar and a preparation method thereof, and relates to the technical field of biochar materials. The invention carries out modification treatment on pine nut shells, and on the basis, a soda saline-alkali soil conditioner is obtained, and is prepared by mixing modified biochar, biochar-based fermented products, phosphogypsum, oxalic acid and plant ash as raw materials.

Inventors

• XU CHENXI
• SHI JIA
• SONG LIANCHENG
• Bian Lisheng

Assignees

• 黑龙江八一农垦大学

Dates

Publication Date

20260505

Application Date

20240430

Claims (7)

1. 1. The soda saline-alkali soil conditioner is characterized by comprising the following raw material components in parts by mass: 25-35 parts of modified biochar, 45-55 parts of biochar-based fermented product, 6-8 parts of phosphogypsum, 15-20 parts of oxalic acid and 10-12 parts of plant ash; The preparation method of the modified biochar comprises the following steps: The pine nut shells subjected to heat treatment at 120-150 ℃ are subjected to first soaking in sodium hydroxide solution, then subjected to pyrolysis treatment at 450-500 ℃ in protective atmosphere, cooled, placed in a mixed aqueous solution of citric acid and a water extract of spina date seeds, subjected to second soaking, and dried to obtain the modified biochar; The preparation method of the charcoal-based fermentation product comprises the following steps: Mixing biochar, fungus dreg and beet leaf according to the mass ratio of 3-5:4-5:5-8, adding paenibacillus polymyxa, and fermenting at 37+/-2 ℃ to obtain the biochar-based fermentation product.
2. 2. The soda saline-alkali soil conditioner according to claim 1, wherein the heat treatment time is 0.5-1h, and the pyrolysis treatment time is 1.5-2h.
3. 3. The soda saline-alkali soil conditioner according to claim 1, wherein the concentration of the sodium hydroxide solution is 1-2mol/L, the concentration of the citric acid in the mixed aqueous solution of the citric acid and the semen zizyphi spinosae aqueous extract is 2-3wt%, and the concentration of the semen zizyphi spinosae aqueous extract is 1-2wt%.
4. 4. The soda saline-alkali soil conditioner of claim 1, wherein the first soaking time is 15-20min and the second soaking time is 15-20min.
5. 5. The soda saline-alkali soil conditioner according to claim 1, wherein the biochar is obtained by pyrolysis of semen ziziphi spinosae, and the pyrolysis temperature is 450-500 ℃ and the pyrolysis time is 2-3h.
6. 6. The soda saline-alkali soil conditioner of claim 1, wherein the fermentation time is 3-4d.
7. 7. Use of a soda saline-alkali soil conditioner according to any one of claims 1-6 in the improvement of soda saline-alkali paddy field, wherein after spring transplanting, the conditioner is applied in paddy field according to an application amount of 90-100kg/hm 2 .

Description

Modified biochar and preparation method thereof Technical Field The invention relates to the technical field of biochar materials, in particular to modified biochar and a preparation method thereof. Background Soda saline-alkali soil is one of the most difficult land types to treat in saline-alkali soil, and the pH value of severe soda saline-alkali soil is even higher than 10, and the soil has high sodium ion content, small infiltration coefficient, poor soil air permeability, low organic matter content and extremely poor nutrient condition. The soda saline-alkali soil mainly inhibits the growth of crops by means of osmotic stress, ionic toxicity and the like. Saline-alkali stress can influence the growth of plant root systems, restrict the absorption of plants to nutrients and water, and therefore influence the growth and development of plants, and planting rice is an important way for utilizing soda saline-alkali soil, mainly because a flooding mode can ensure the growth requirement of rice and also realize the leaching of salt, thereby reducing the adverse effect of saline-alkali on crops. However, with the increasing serious salinization and barren phenomena of the soil in the soda saline-alkali area and the obvious problems of the shortage of water resources, the growth of rice in the soda saline-alkali rice field is seriously threatened, and the development of agriculture in the soda saline-alkali area is restricted. Therefore, how to increase the yield of rice planting in soda saline-alkali areas has become a urgent problem to be solved in soda saline-alkali areas. Biochar is a carbon-rich solid substance produced by high-temperature pyrolysis of biomass materials under oxygen-limited or anaerobic conditions, has abundant raw material sources, abundant porous structures and special physicochemical properties, and has wide application in various fields, but with rapid development of science, technology and economy, the inherent characteristics of the biochar are difficult to meet the performance requirements of various fields. The aim of regulating and improving the performance of the biomass material can be achieved by modifying the biochar material, so that the application field of the biochar material is expanded, and the biochar material becomes a current technical research hot spot. The modified biochar material with different purposes can be obtained by modifying the biochar material in different modes, so that the application range of the biomass material is greatly expanded. At present, the modified biochar material is directly applied to soda saline-alkali soil to realize limited improvement effect, and meanwhile, the modified biochar material is insufficient in application research in soda saline-alkali rice fields, and if the modified biochar material can realize soil improvement on the basis of proper modification treatment of the biochar, the improvement of the rice planting yield in soda saline-alkali areas is improved, and the modified biochar material has important practical significance for promoting the agricultural development in soda saline-alkali areas. Disclosure of Invention The invention aims to provide modified biochar and a preparation method thereof, which are used for solving the problems in the prior art and realizing soil improvement in soda saline-alkali areas. In order to achieve the above object, the present invention provides the following solutions: the invention provides a modified biochar, and the preparation method comprises the following steps: And (3) carrying out first soaking on pine nut shells subjected to heat treatment at 120-150 ℃ in a sodium hydroxide solution, then carrying out pyrolysis treatment at 450-500 ℃ in a protective atmosphere, cooling, placing in a mixed aqueous solution of citric acid and a spine date seed aqueous extract, carrying out second soaking, and drying to obtain the modified biochar. The protective atmosphere in the present invention is more preferably an argon atmosphere. As a further preferable aspect of the present invention, the time of the heat treatment is 0.5 to 1 hour, and the time of the pyrolysis treatment is 1.5 to 2 hours. As a further preferred aspect of the present invention, the concentration of the sodium hydroxide solution is 1-2mol/L, and the concentration of the citric acid in the mixed aqueous solution of the citric acid and the aqueous extract of the spina date seed is 2-3wt%, and the concentration of the aqueous extract of the spina date seed is 1-2wt%. As a further preferred aspect of the present invention, the first soaking time is 15-20min, and the second soaking time is 15-20min. The preparation method comprises the following steps of decocting the semen ziziziphi spinosae powder in water, concentrating the decoction, and freeze-drying to obtain the semen ziziphi spinosae water extract. The second technical scheme of the invention is to provide the application of the modified biochar in preparing a soda sa