Lightweight volcanic ash soil modified material as well as use method and application thereof

Abstract

The invention discloses a light volcanic ash soil modified material as well as a use method and application thereof, and relates to the technical field of soil improvement. The light volcanic ash soil modified material comprises the following raw materials: a potato-glutinous rice mixed solution, a graphene-polyaluminum chloride composite solution, a tannic acid aqueous solution and a chitosan modified nano carbon powder reagent. The modified light volcanic ash soil obtained in the invention can effectively reduce the content of nitrate ions and sulfate ions in soil and effectively improve the problem of soil salinization.

Description

Technical Field

[0001] The present invention relates to the technical field of soil improvement, and particularly relates to a lightweight volcanic ash soil modification material, a usage method thereof, and an application thereof. Background Art

[0002] Soil salinization is a process in which soluble salts accumulate in the soil, leading to the deterioration of the basic properties of the soil and the decline in quality. Its formation is affected by various factors such as climate, nutrients, geology, and hydrology, and human activities are one of the important reasons for accelerating land salinization.

[0003] Recently, when the applicant was conducting geotechnical engineering surveys, it was found that there was a lightweight volcanic ash soil layer with a thickness of about 10 - 50 m starting at about 10 m underground. The on-site core was judged to be mainly in a soft plastic state, locally plastic. The drilling could obtain columnar cores, but its texture was similar to foam or cotton wool, the soil was extremely light, and some cores were in the shape of thin cakes. The results of conventional geotechnical tests showed that the average void ratio e = 4.024, the average liquidity index I L = 2.03, the average compression modulus E s0.1-0.2 = 2.01 MPa, the average compression coefficient α 0.1-0.2 = 2.65 MPa-1, which was a flowing plastic high compressibility soil. The standard value of the direct quick shear cohesion C k = 27.3 kPa, and the standard value of the internal friction angle Φ k = 8.3 degrees. It can be seen that it has characteristics such as extremely high water content, extremely high compressibility, extremely light soil, large void ratio, medium - high sensitivity, and under - consolidation. When conducting in - hole shear wave tests on site, the shear wave velocity value reached 170 - 295 m / s, and it was found that the reserves of volcanic ash soil were rich.

[0004] Currently, the methods for solving soil salinization are divided into physical measures, biological measures, and chemical measures. Among them, physical measures are mainly divided into fresh water flushing for salt leaching, well drainage and well irrigation, plastic film mulching, and deep plowing of the soil, etc., which require a large amount of manual labor and have low economic benefits; biological measures are mainly to restore vegetation, plant trees and grass, plant salt - tolerant and drought - tolerant crops, etc., but the input cost is high; chemical measures are mainly to use chemical modifiers such as gypsum and calcium phosphate to neutralize the salts in the soil, but a large amount of water flushing is required, the cost is high, and it is difficult to apply in the case of water resource shortage. Therefore, the present application proposes to use a modification material to modify lightweight volcanic ash soil and apply it to the treatment of soil salinization. Summary of the Invention

[0005] Aiming at the above - mentioned defects of the prior art, the present invention proposes a lightweight volcanic ash soil modification material, a usage method thereof, and an application thereof to solve the problems raised in the above - mentioned background art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A lightweight volcanic ash soil modification material, comprising the following raw materials by weight: 50-60 parts of potato-rice mixed liquid, 30-50 parts of graphene-polyaluminum chloride composite solution, 25-40 parts of tannic acid aqueous solution, and 10-20 parts of chitosan-modified nano-carbon powder reagent.

[0008] Preferably, the volume fraction of the tannic acid aqueous solution is 5%, CAS number: 1401-55-4;

[0009] Preferably, the preparation method of the potato-rice mixed liquid comprises the following steps: mixing potato, rice and water in a mass ratio of (5-12):(10-20):(160-300), breaking the wall and filtering, and the filtrate is the potato-rice mixed liquid.

[0010] Preferably, the preparation method of the graphene-polyaluminum chloride composite solution comprises the following steps:

[0011] S1. Adding sodium hydroxide solution to polyaluminum chloride and stirring, then adding cyclodextrin, stirring and reacting sufficiently, and then standing for 20-30 min to obtain a cyclodextrin-polyaluminum chloride composite agent; wherein the cyclodextrin is purchased from Shanghai Aoji Chemical Co., Ltd., CAS number: 12619-70-4;

[0012] S2. Adding ferric sulfate solution to the cyclodextrin-polyaluminum chloride composite agent obtained in step S1, stirring at a speed of 600-800 r / min for 40-60 min, then adding graphene, and continuing to stir for 20-35 min to obtain a graphene-polyaluminum chloride composite solution; the mesh number of the graphene is 2000 mesh.

[0013] Preferably, the concentration of the sodium hydroxide solution in step S1 is 3-7 mol / L, and the mass ratio of polyaluminum chloride, sodium hydroxide solution and cyclodextrin is (1-3):(5-10):(0.3-0.8).

[0014] Preferably, the concentration of the ferric sulfate solution in step S2 is 0.01-0.05 mol / L, and the mass ratio of cyclodextrin-polyaluminum chloride composite agent, ferric sulfate solution and graphene is (3-5):(6-10):(1-3).

[0015] Preferably, the preparation method of the chitosan-modified nano-carbon powder reagent comprises the following steps:

[0016] Step 1: Feeding the nano-carbon powder into a reaction at 100-200 °C for 40-60 min, then cooling to 20-25 °C, adding deionized water, and preparing a 30-40% nano-carbon powder dispersion;

[0017] Step 2: Add chitosan and hydrochloric acid with a mass fraction of 1-5% to the nano-carbon powder dispersion obtained in Step 1, and stir and react at 50-60 °C for 3-6 h to obtain a chitosan-modified nano-carbon powder reagent.

[0018] Preferably, the volume-mass ratio of the nano-carbon powder dispersion, chitosan and hydrochloric acid in Step 2 is (2-8) mL: 1 g: (0.2-0.7) mL.

[0019] Preferably, the method for using the light volcanic ash soil modifier includes the following steps:

[0020] (1) Grind the dry light volcanic ash soil, and perform a roasting treatment at a temperature of 750-850 °C to obtain pyrolyzed volcanic ash soil;

[0021] (2) Add a potato-rice mixture to the pyrolyzed volcanic ash soil and soak for 10-20 h. After soaking, filter to obtain pretreated volcanic ash soil;

[0022] (3) Add tannic acid aqueous solution and chitosan-modified nano-carbon powder reagent to the pretreated volcanic ash soil, stir and let stand for 30-50 min, then remove the supernatant, add graphene-polyaluminum chloride composite solution, react for 1-3 h, separate the solid product and dry it to obtain the modified light volcanic ash soil.

[0023] Preferably, the mass-volume ratio of the pyrolyzed volcanic ash soil and the potato-rice mixture in Step (2) is 1 g: (2-4) mL.

[0024] Preferably, the application of the modified light volcanic ash soil obtained in this application in improving soil salinization and increasing crop germination rate.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] (1) This application first proposes to modify volcanic ash soil to prepare a soil conditioner, which effectively improves the soil salinization condition, significantly reduces the salt content in the soil, is beneficial to crop growth, and can make full use of volcanic ash soil, providing a new idea for improving soil salinization problems and opening up a new application direction for volcanic ash soil.

[0027] (2) The raw material preparation method of the light volcanic ash soil modifier in this application is relatively simple, the usage method is very simple, the production cost is low, it is suitable for industrial large-scale production, and the performance of the prepared soil conditioner is stable and uniform, and will not cause additional harm to the soil. Specific Embodiments

[0028] The technical solutions of the present invention will be further described in detail below in conjunction with specific embodiments.

[0029] Example 1

[0030] A lightweight volcanic ash soil modification material, comprising the following raw materials by weight: 50 parts of potato - glutinous rice mixed solution, 30 parts of graphene - polyaluminum chloride composite solution, 25 parts of tannic acid aqueous solution, and 10 parts of chitosan - modified nano - carbon powder reagent.

[0031] The preparation method of the potato - glutinous rice mixed solution comprises the following steps: Mix potato, glutinous rice, and water in a mass ratio of 5:10:160, break the wall and grind, and then filter. The filtrate is the potato - glutinous rice mixed solution.

[0032] The preparation method of the graphene - polyaluminum chloride composite solution comprises the following steps:

[0033] S1. Add a sodium hydroxide solution with a concentration of 3 mol / L to polyaluminum chloride and stir, then add cyclodextrin. After sufficient stirring and reaction, let it stand for 20 min to obtain a cyclodextrin - polyaluminum chloride composite agent; the mass ratio of polyaluminum chloride, sodium hydroxide solution, and cyclodextrin is 1:5:0.3;

[0034] S2. Add a ferric sulfate solution with a concentration of 0.01 mol / L to the cyclodextrin - polyaluminum chloride composite agent obtained in step S1. First, stir at a speed of 600 r / min for 40 min, then add graphene and continue to stir for 20 min to obtain a graphene - polyaluminum chloride composite solution; the mass ratio of cyclodextrin - polyaluminum chloride composite agent, ferric sulfate solution, and graphene is 3:6:1.

[0035] The preparation method of the chitosan - modified nano - carbon powder reagent comprises the following steps:

[0036] Step 1: Feed the nano - carbon powder into a reaction at 100 °C for 40 min, then cool to 20 °C, add deionized water, and prepare a 30% nano - carbon powder dispersion;

[0037] Step 2: Add chitosan and 1% hydrochloric acid by mass fraction to the nano - carbon powder dispersion obtained in step 1, stir and react at 50 °C for 3 h to obtain a chitosan - modified nano - carbon powder reagent; the volume - mass ratio of nano - carbon powder dispersion, chitosan, and hydrochloric acid is 2 mL:1 g:0.2 mL.

[0038] The usage method of the lightweight volcanic ash soil modification material comprises the following steps:

[0039] (1) Grind the dry lightweight volcanic ash soil, and perform roasting treatment at a temperature of 750 °C to obtain pyrolyzed volcanic ash soil;

[0040] (2) Add the potato - sticky rice mixture to the pyrolyzed volcanic ash soil and soak for 10 h. After soaking, filter to obtain the pretreated volcanic ash soil. The mass - volume ratio of the pyrolyzed volcanic ash soil to the potato - sticky rice mixture is 1 g:2 mL;

[0041] (3) Add tannic acid aqueous solution and chitosan - modified nano - carbon powder reagent to the pretreated volcanic ash soil, stir and let stand for 30 min, then remove the supernatant. Then add the graphene - polyaluminum chloride composite solution and react for 1 h. After separating the solid product, dry it to obtain the modified lightweight volcanic ash soil.

[0042] Example 2

[0043] A lightweight volcanic ash soil modification material, comprising the following raw materials by weight: 60 parts of potato - sticky rice mixture, 50 parts of graphene - polyaluminum chloride composite solution, 40 parts of tannic acid aqueous solution, and 20 parts of chitosan - modified nano - carbon powder reagent.

[0044] The preparation method of the potato - sticky rice mixture comprises the following steps: Mix potato, sticky rice, and water in a mass ratio of 12:20:300, break the wall and filter, and the filtrate is the potato - sticky rice mixture.

[0045] The preparation method of the graphene - polyaluminum chloride composite solution comprises the following steps:

[0046] S1. Add sodium hydroxide solution with a concentration of 7 mol / L to polyaluminum chloride and stir, then add cyclodextrin. After stirring and reacting sufficiently, let stand for 30 min to obtain the cyclodextrin - polyaluminum chloride complex. The mass ratio of polyaluminum chloride, sodium hydroxide solution, and cyclodextrin is 3:10:0.8;

[0047] S2. Add ferric sulfate solution with a concentration of 0.05 mol / L to the cyclodextrin - polyaluminum chloride complex obtained in step S1. First, stir at a speed of 800 r / min for 60 min, then add graphene and continue to stir for 35 min to obtain the graphene - polyaluminum chloride composite solution. The mass ratio of the cyclodextrin - polyaluminum chloride complex, ferric sulfate solution, and graphene is 5:10:3.

[0048] The preparation method of the chitosan - modified nano - carbon powder reagent comprises the following steps:

[0049] Step 1: Feed the nano - carbon powder into a reaction at 200 °C for 60 min, then cool to 25 °C, add deionized water, and prepare a 40% nano - carbon powder dispersion;

[0050] Step 2: Add chitosan and 5% hydrochloric acid by mass to the nano-carbon powder dispersion obtained in Step 1, and stir and react at 60 °C for 6 h to obtain a chitosan-modified nano-carbon powder reagent; the volume-mass ratio of the nano-carbon powder dispersion, chitosan, and hydrochloric acid is 8 mL: 1 g: 0.7 mL.

[0051] The usage method of the light volcanic ash soil modification material includes the following steps:

[0052] (1) Grind the dry light volcanic ash soil, and perform a calcination treatment at a temperature of 850 °C to obtain pyrolyzed volcanic ash soil;

[0053] (2) Add a potato-rice mixture to the pyrolyzed volcanic ash soil and soak for 20 h. After soaking, filter to obtain pretreated volcanic ash soil; the mass-volume ratio of the pyrolyzed volcanic ash soil and the potato-rice mixture is 1 g: 4 mL;

[0054] (3) Add tannic acid aqueous solution and chitosan-modified nano-carbon powder reagent to the pretreated volcanic ash soil, stir and let stand for 50 min, then remove the supernatant, add graphene-polyaluminum chloride composite solution, react for 3 h, separate the solid product and dry it to obtain the modified light volcanic ash soil.

[0055] Example 3

[0056] A light volcanic ash soil modification material, comprising the following raw materials by weight: 55 parts of potato-rice mixture, 40 parts of graphene-polyaluminum chloride composite solution, 30 parts of tannic acid aqueous solution, and 15 parts of chitosan-modified nano-carbon powder reagent.

[0057] The preparation method of the potato-rice mixture includes the following steps: Mix potato, rice, and water in a mass ratio of 10:15:200, break the wall and filter, and the filtrate is the potato-rice mixture.

[0058] The preparation method of the graphene-polyaluminum chloride composite solution includes the following steps:

[0059] S1. Add a 5 mol / L sodium hydroxide solution to polyaluminum chloride and stir, then add cyclodextrin, stir and react fully, and let stand for 25 min to obtain a cyclodextrin-polyaluminum chloride composite agent; the mass ratio of polyaluminum chloride, sodium hydroxide solution, and cyclodextrin is 2:7:0.5;

[0060] S2. Add an iron sulfate solution with a concentration of 0.04 mol / L to the cyclodextrin-polyaluminum chloride composite agent obtained in step S1. First, stir at a speed of 700 r / min for 50 min, then add graphene and continue stirring for 30 min to obtain a graphene-polyaluminum chloride composite solution. The mass ratio of the cyclodextrin-polyaluminum chloride composite agent, the iron sulfate solution, and graphene is 4:9:2.

[0061] The preparation method of the chitosan-modified nano-carbon powder reagent includes the following steps:

[0062] Step 1: Feed the nano-carbon powder into a reaction at 150 °C for 50 min, then cool to 24 °C, add deionized water, and prepare a 35% nano-carbon powder dispersion.

[0063] Step 2: Add chitosan and 3% hydrochloric acid by mass fraction to the nano-carbon powder dispersion obtained in step 1, and stir and react at 55 °C for 5 h to obtain a chitosan-modified nano-carbon powder reagent. The volume-mass ratio of the nano-carbon powder dispersion, chitosan, and hydrochloric acid is 7 mL:1 g:0.5 mL.

[0064] The usage method of the light volcanic ash soil modification material includes the following steps:

[0065] (1) Grind the dry light volcanic ash soil and conduct a roasting treatment at a temperature of 800 °C to obtain pyrolyzed volcanic ash soil.

[0066] (2) Add a potato-rice mixture to the pyrolyzed volcanic ash soil and soak for 15 h. After soaking, filter to obtain pretreated volcanic ash soil. The mass-volume ratio of the pyrolyzed volcanic ash soil and the potato-rice mixture is 1 g:3 mL.

[0067] (3) Add a tannic acid aqueous solution and a chitosan-modified nano-carbon powder reagent to the pretreated volcanic ash soil, stir and let stand for 40 min, then remove the supernatant, add the graphene-polyaluminum chloride composite solution, react for 2 h, separate the solid product, and dry to obtain the modified light volcanic ash soil.

[0068] Comparative Example 1

[0069] The difference between this comparative example and Example 3 is that the potato-rice mixture is replaced with glutinous rice slurry, and the other components and steps remain unchanged.

[0070] A light volcanic ash soil modification material, comprising the following raw materials by weight: 55 parts of glutinous rice slurry, 40 parts of graphene-polyaluminum chloride composite solution, 30 parts of tannic acid aqueous solution, and 15 parts of chitosan-modified nano-carbon powder reagent.

[0071] The preparation method of the glutinous rice slurry comprises the following steps: Mix glutinous rice and water in a mass ratio of 25:200, break the mixture through wall-breaking and then filter it. The filtrate is the glutinous rice slurry.

[0072] The preparation method of the graphene-polyaluminum chloride composite solution comprises the following steps:

[0073] S1. Add a sodium hydroxide solution with a concentration of 5 mol / L to polyaluminum chloride and stir, then add cyclodextrin. After stirring and reacting sufficiently, let it stand for 25 min to obtain a cyclodextrin-polyaluminum chloride composite agent. The mass ratio of polyaluminum chloride, sodium hydroxide solution and cyclodextrin is 2:7:0.5.

[0074] S2. Add a ferric sulfate solution with a concentration of 0.04 mol / L to the cyclodextrin-polyaluminum chloride composite agent obtained in step S1. First, stir at a speed of 700 r / min for 50 min, then add graphene and continue to stir for 30 min to obtain a graphene-polyaluminum chloride composite solution. The mass ratio of cyclodextrin-polyaluminum chloride composite agent, ferric sulfate solution and graphene is 4:9:2.

[0075] The preparation method of the chitosan-modified nano-carbon powder reagent comprises the following steps:

[0076] Step 1: Feed nano-carbon powder into a reaction at 150 °C for 50 min, then cool it to 24 °C, add deionized water, and prepare a 35% nano-carbon powder dispersion.

[0077] Step 2: Add chitosan and 3% hydrochloric acid by mass fraction to the nano-carbon powder dispersion obtained in step 1, stir and react at 55 °C for 5 h to obtain a chitosan-modified nano-carbon powder reagent. The volume-mass ratio of nano-carbon powder dispersion, chitosan and hydrochloric acid is 7 mL:1 g:0.5 mL.

[0078] The usage method of the light volcanic ash soil modification material comprises the following steps:

[0079] (1) Grind dry light volcanic ash soil, and conduct a roasting treatment at a temperature of 800 °C to obtain pyrolyzed volcanic ash soil.

[0080] (2) Add glutinous rice slurry to the pyrolyzed volcanic ash soil and soak for 15 h. After soaking, filter it to obtain pretreated volcanic ash soil. The mass-volume ratio of pyrolyzed volcanic ash soil and glutinous rice slurry is 1 g:3 mL.

[0081] (3) Add tannic acid aqueous solution and chitosan-modified nano-carbon powder reagent to the pretreated volcanic ash soil, stir and let it stand for 40 min, then remove the supernatant, add graphene-polyaluminum chloride composite solution, react for 2 h, separate the solid product and dry it to obtain the modified light volcanic ash soil.

[0082] Comparative Example 2

[0083] The difference between this comparative example and Example 3 is that the potato - sticky rice mixture is not added, and the remaining components and steps remain unchanged.

[0084] A lightweight volcanic ash soil modification material, comprising the following raw materials by weight: 40 parts of graphene - polyaluminum chloride composite solution, 30 parts of tannic acid aqueous solution, and 15 parts of chitosan - modified nano - carbon powder reagent.

[0085] The preparation method of the graphene - polyaluminum chloride composite solution comprises the following steps:

[0086] S1. Add a sodium hydroxide solution with a concentration of 5 mol / L to polyaluminum chloride and stir, then add cyclodextrin, and after sufficient stirring reaction, let it stand to obtain a cyclodextrin - polyaluminum chloride complex; the mass ratio of polyaluminum chloride, sodium hydroxide solution, and cyclodextrin is 2:7:0.5;

[0087] S2. Add a ferric sulfate solution with a concentration of 0.04 mol / L to the cyclodextrin - polyaluminum chloride complex obtained in step S1, first stir at a speed of 700 r / min for 50 min, then add graphene and continue to stir for 30 min to obtain a graphene - polyaluminum chloride composite solution; the mass ratio of cyclodextrin - polyaluminum chloride complex, ferric sulfate solution, and graphene is 4:9:2.

[0088] The preparation method of the chitosan - modified nano - carbon powder reagent comprises the following steps:

[0089] Step 1: Feed the nano - carbon powder into a reaction at 150 °C for 50 min, then cool to 24 °C, add deionized water, and prepare a 35% nano - carbon powder dispersion;

[0090] Step 2: Add chitosan and 3% hydrochloric acid by mass fraction to the nano - carbon powder dispersion obtained in step 1, and stir - react at 55 °C for 5 h to obtain a chitosan - modified nano - carbon powder reagent; the volume - mass ratio of nano - carbon powder dispersion, chitosan, and hydrochloric acid is 7 mL:1 g:0.5 mL.

[0091] The usage method of the described lightweight volcanic ash soil modification material comprises the following steps:

[0092] (1) Grind the dry lightweight volcanic ash soil, and conduct a roasting treatment at a temperature of 800 °C to obtain pyrolyzed volcanic ash soil;

[0093] (2) Add tannic acid aqueous solution and chitosan-modified nano-carbon powder reagent to 19 parts by weight of pyrolyzed volcanic ash soil, stir and let stand for 40 min, then remove the supernatant, add graphene-polyaluminum chloride composite solution, react for 2 h, separate the solid product and dry it to obtain the modified light volcanic ash soil.

[0094] Comparative Example 3

[0095] The difference between this comparative example and Example 3 is that the graphene-polyaluminum chloride composite solution is replaced with a cyclodextrin-polyaluminum chloride composite agent, and the other components and steps remain unchanged.

[0096] A light volcanic ash soil modification material, comprising the following raw materials in parts by weight: 55 parts of potato-rice mixed solution, 40 parts of cyclodextrin-polyaluminum chloride composite agent, 30 parts of tannic acid aqueous solution, and 15 parts of chitosan-modified nano-carbon powder reagent.

[0097] The preparation method of the potato-rice mixed solution comprises the following steps: Mix potato, rice and water in a mass ratio of 10:15:200, break the wall and filter, and the filtrate is the potato-rice mixed solution.

[0098] The preparation method of the cyclodextrin-polyaluminum chloride composite agent comprises the following steps: Add sodium hydroxide solution with a concentration of 5 mol / L to polyaluminum chloride and stir, then add cyclodextrin, stir and react fully and let stand for 25 min to obtain the cyclodextrin-polyaluminum chloride composite agent; the mass ratio of polyaluminum chloride, sodium hydroxide solution and cyclodextrin is 2:7:0.5.

[0099] The preparation method of the chitosan-modified nano-carbon powder reagent comprises the following steps:

[0100] Step 1: Feed the nano-carbon powder into a reaction at 150 °C for 50 min, then cool to 24 °C, add deionized water, and prepare a 35% nano-carbon powder dispersion;

[0101] Step 2: Add chitosan and 3% hydrochloric acid by mass fraction to the nano-carbon powder dispersion obtained in Step 1, stir and react at 55 °C for 5 h to obtain the chitosan-modified nano-carbon powder reagent; the volume-mass ratio of the nano-carbon powder dispersion, chitosan and hydrochloric acid is 7 mL:1 g:0.5 mL.

[0102] The usage method of the light volcanic ash soil modification material comprises the following steps:

[0103] (1) Grind the dry light volcanic ash soil, and carry out roasting treatment at a temperature of 800 °C to obtain pyrolyzed volcanic ash soil;

[0104] (2) Add the potato - sticky rice mixture to the pyrolyzed volcanic ash soil and soak for 15 h. After soaking, filter to obtain the pretreated volcanic ash soil. The mass - volume ratio of the pyrolyzed volcanic ash soil to the potato - sticky rice mixture is 1 g:3 mL;

[0105] (3) Add tannic acid aqueous solution and chitosan - modified nano - carbon powder reagent to the pretreated volcanic ash soil, stir and let stand for 40 min, then remove the supernatant. Then add the cyclodextrin - polyaluminum chloride composite agent and react for 2 h. After separating the solid product, dry it to obtain the modified lightweight volcanic ash soil.

[0106] Comparative Example 4

[0107] The difference between this comparative example and Example 3 is that the raw material does not add the graphene - polyaluminum chloride composite solution, and the other components and steps remain unchanged.

[0108] A lightweight volcanic ash soil modification material, comprising the following raw materials by weight: 55 parts of potato - sticky rice mixture, 30 parts of tannic acid aqueous solution, and 15 parts of chitosan - modified nano - carbon powder reagent.

[0109] The preparation method of the potato - sticky rice mixture includes the following steps: Mix potato, sticky rice, and water in a mass ratio of 10:15:200, break the wall and grind, and then filter. The filtrate is the potato - sticky rice mixture.

[0110] The preparation method of the chitosan - modified nano - carbon powder reagent includes the following steps:

[0111] Step 1: Feed the nano - carbon powder into a reaction at 150 °C for 50 min, then cool to 24 °C, add deionized water, and prepare a 35% nano - carbon powder dispersion;

[0112] Step 2: Add chitosan and 3% hydrochloric acid by mass fraction to the nano - carbon powder dispersion obtained in Step 1, stir and react at 55 °C for 5 h to obtain the chitosan - modified nano - carbon powder reagent. The volume - mass ratio of the nano - carbon powder dispersion, chitosan, and hydrochloric acid is 7 mL:1 g:0.5 mL.

[0113] The usage method of the described lightweight volcanic ash soil modification material includes the following steps:

[0114] (1) Grind the dry lightweight volcanic ash soil and perform a roasting treatment at 800 °C to obtain the pyrolyzed volcanic ash soil;

[0115] (2) Add the potato - sticky rice mixture to the pyrolyzed volcanic ash soil and soak for 15 h. After soaking, filter to obtain the pretreated volcanic ash soil. The mass - volume ratio of the pyrolyzed volcanic ash soil to the potato - sticky rice mixture is 1 g:3 mL;

[0116] (3) Add an aqueous tannic acid solution and a chitosan-modified nano-carbon powder reagent to the pretreated volcanic ash soil, stir and let stand for 40 min, then remove the supernatant. After separating the solid product, dry it to obtain the modified lightweight volcanic ash soil.

[0117] Comparative Example 5

[0118] The difference between this comparative example and Example 3 is that the aqueous tannic acid solution is replaced with hydrochloric acid with a mass fraction of 3%, and the other components and steps remain unchanged.

[0119] A lightweight volcanic ash soil modification material, comprising the following raw materials by weight: 55 parts of potato-rice mixture, 40 parts of graphene-polyaluminum chloride composite solution, 30 parts of hydrochloric acid, and 15 parts of chitosan-modified nano-carbon powder reagent.

[0120] The preparation method of the potato-rice mixture comprises the following steps: Mix potato, rice, and water in a mass ratio of 10:15:200, break the wall and filter, and the filtrate is the potato-rice mixture.

[0121] The preparation method of the graphene-polyaluminum chloride composite solution comprises the following steps:

[0122] S1. Add a sodium hydroxide solution with a concentration of 5 mol / L to polyaluminum chloride and stir, then add cyclodextrin, stir and react sufficiently, and let stand for 25 min to obtain a cyclodextrin-polyaluminum chloride complex; the mass ratio of polyaluminum chloride, sodium hydroxide solution, and cyclodextrin is 2:7:0.5;

[0123] S2. Add a ferric sulfate solution with a concentration of 0.04 mol / L to the cyclodextrin-polyaluminum chloride complex obtained in step S1, stir at a speed of 700 r / min for 50 min, then add graphene and continue to stir for 30 min to obtain a graphene-polyaluminum chloride composite solution; the mass ratio of cyclodextrin-polyaluminum chloride complex, ferric sulfate solution, and graphene is 4:9:2.

[0124] The preparation method of the chitosan-modified nano-carbon powder reagent comprises the following steps:

[0125] Step 1: Feed the nano-carbon powder into a reaction at 150 °C for 50 min, then cool to 24 °C, add deionized water, and prepare a 35% nano-carbon powder dispersion;

[0126] Step 2: Add chitosan and hydrochloric acid with a mass fraction of 3% to the nano-carbon powder dispersion obtained in step 1, stir and react at 55 °C for 5 h to obtain a chitosan-modified nano-carbon powder reagent; the volume-mass ratio of nano-carbon powder dispersion, chitosan, and hydrochloric acid is 7 mL:1 g:0.5 mL.

[0127] The method for using the light volcanic ash soil modifying material includes the following steps:

[0128] (1) Grind the dry light volcanic ash soil and conduct roasting treatment at a temperature of 800 °C to obtain pyrolyzed volcanic ash soil;

[0129] (2) Add the potato - glutinous rice mixed solution to the pyrolyzed volcanic ash soil and soak for 15 h. After soaking, filter to obtain pretreated volcanic ash soil; the mass - volume ratio of the pyrolyzed volcanic ash soil to the potato - glutinous rice mixed solution is 1 g:3 mL;

[0130] (3) Add hydrochloric acid and chitosan - modified nano - carbon powder reagent to the pretreated volcanic ash soil, stir and let stand for 40 min, then remove the supernatant. Then add graphene - polyaluminum chloride composite solution, react for 2 h, separate the solid product and dry it to obtain the modified light volcanic ash soil.

[0131] Comparative Example 6

[0132] The difference between this comparative example and Example 3 is that the chitosan - modified nano - carbon powder reagent is replaced with nano - carbon powder, and the other components and steps remain unchanged.

[0133] A light volcanic ash soil modifying material, comprising the following raw materials by weight: 55 parts of potato - glutinous rice mixed solution, 40 parts of graphene - polyaluminum chloride composite solution, 30 parts of tannic acid aqueous solution, and 15 parts of nano - carbon powder.

[0134] The preparation method of the potato - glutinous rice mixed solution includes the following steps: Mix potato, glutinous rice and water in a mass ratio of 10:15:200, break the wall and grind, and then filter. The filtrate is the potato - glutinous rice mixed solution.

[0135] The preparation method of the graphene - polyaluminum chloride composite solution includes the following steps:

[0136] S1. Add sodium hydroxide solution with a concentration of 5 mol / L to polyaluminum chloride and stir, then add cyclodextrin, stir and react fully and then let stand for 25 min to obtain cyclodextrin - polyaluminum chloride complex; the mass ratio of polyaluminum chloride, sodium hydroxide solution and cyclodextrin is 2:7:0.5;

[0137] S2. Add ferric sulfate solution with a concentration of 0.04 mol / L to the cyclodextrin - polyaluminum chloride complex obtained in step S1, first stir at a speed of 700 r / min for 50 min, then add graphene and continue to stir for 30 min to obtain graphene - polyaluminum chloride composite solution; the mass ratio of cyclodextrin - polyaluminum chloride complex, ferric sulfate solution and graphene is 4:9:2.

[0138] The usage method of the light volcanic ash soil modification material includes the following steps:

[0139] (1) Grind the dry light volcanic ash soil, and perform roasting treatment at a temperature of 800 °C to obtain pyrolyzed volcanic ash soil;

[0140] (2) Add potato - glutinous rice mixed solution to the pyrolyzed volcanic ash soil and soak for 15 h. After soaking, filter to obtain pretreated volcanic ash soil; the mass - volume ratio of the pyrolyzed volcanic ash soil to the potato - glutinous rice mixed solution is 1 g:3 mL;

[0141] (3) Add tannic acid aqueous solution and nano - carbon powder to the pretreated volcanic ash soil, stir and let stand for 40 min, then remove the supernatant, add graphene - polyaluminum chloride composite solution, react for 2 h, separate the solid product and dry it to obtain the modified light volcanic ash soil.

[0142] Comparative Example 7

[0143] The difference between this comparative example and Example 3 is that the chitosan - modified nano - carbon powder reagent is replaced with a dextran - modified nano - carbon powder reagent, and the other components and steps remain unchanged.

[0144] A light volcanic ash soil modification material, comprising the following raw materials by weight: 55 parts of potato - glutinous rice mixed solution, 40 parts of graphene - polyaluminum chloride composite solution, 30 parts of tannic acid aqueous solution, and 15 parts of dextran - modified nano - carbon powder reagent.

[0145] The preparation method of the potato - glutinous rice mixed solution includes the following steps: Mix potato, glutinous rice and water in a mass ratio of 10:15:200, break the wall and filter, and the filtrate is the potato - glutinous rice mixed solution.

[0146] The preparation method of the graphene - polyaluminum chloride composite solution includes the following steps:

[0147] S1. Add sodium hydroxide solution with a concentration of 5 mol / L to polyaluminum chloride and stir, then add cyclodextrin, stir and react fully, and let stand for 25 min to obtain cyclodextrin - polyaluminum chloride complex; the mass ratio of polyaluminum chloride, sodium hydroxide solution and cyclodextrin is 2:7:0.5;

[0148] S2. Add ferric sulfate solution with a concentration of 0.04 mol / L to the cyclodextrin - polyaluminum chloride complex obtained in step S1, stir at a speed of 700 r / min for 50 min, then add graphene and continue to stir for 30 min to obtain graphene - polyaluminum chloride composite solution; the mass ratio of cyclodextrin - polyaluminum chloride complex, ferric sulfate solution and graphene is 4:9:2.

[0149] The preparation method of the dextran-modified nano-carbon powder reagent comprises the following steps:

[0150] Step 1: Feed the nano-carbon powder into a reaction at 150 °C for 50 min, then cool it to 24 °C, add deionized water, and prepare a 35% nano-carbon powder dispersion;

[0151] Step 2: Add dextran and 3% hydrochloric acid by mass fraction to the nano-carbon powder dispersion obtained in Step 1, stir and react at 55 °C for 5 h to obtain the dextran-modified nano-carbon powder reagent; the volume-mass ratio of the nano-carbon powder dispersion, dextran, and hydrochloric acid is 7 mL: 1 g: 0.5 mL.

[0152] The usage method of the light volcanic ash soil modification material comprises the following steps:

[0153] (1) Grind the dry light volcanic ash soil, and perform a roasting treatment at a temperature of 800 °C to obtain pyrolyzed volcanic ash soil;

[0154] (2) Add a potato-rice mixture to the pyrolyzed volcanic ash soil and soak for 15 h, then filter after soaking to obtain pretreated volcanic ash soil; the mass-volume ratio of the pyrolyzed volcanic ash soil and the potato-rice mixture is 1 g: 3 mL;

[0155] (3) Add an aqueous tannic acid solution and the dextran-modified nano-carbon powder reagent to the pretreated volcanic ash soil, stir and let stand for 40 min, then remove the supernatant, add a graphene-polyaluminum chloride composite solution, react for 2 h, separate the solid product and dry it to obtain the modified light volcanic ash soil.

[0156] Comparative Example 8

[0157] The difference between this comparative example and Example 3 is that the chitosan-modified nano-carbon powder reagent is not added to the raw materials, and the other components and steps remain unchanged.

[0158] A light volcanic ash soil modification material, comprising the following raw materials by weight: 55 parts of a potato-rice mixture, 40 parts of a graphene-polyaluminum chloride composite solution, and 30 parts of an aqueous tannic acid solution.

[0159] The preparation method of the potato-rice mixture comprises the following steps: Mix potato, rice, and water in a mass ratio of 10: 15: 200, break the wall and filter, and the filtrate is the potato-rice mixture.

[0160] The preparation method of the graphene-polyaluminum chloride composite solution comprises the following steps:

[0161] S1. Add a sodium hydroxide solution with a concentration of 5 mol / L to polyaluminum chloride and stir. Then add cyclodextrin. After sufficient stirring and reaction, let it stand for 25 min to obtain a cyclodextrin-polyaluminum chloride composite agent. The mass ratio of polyaluminum chloride, sodium hydroxide solution, and cyclodextrin is 2:7:0.5.

[0162] S2. Add a ferric sulfate solution with a concentration of 0.04 mol / L to the cyclodextrin-polyaluminum chloride composite agent obtained in step S1. First, stir at a speed of 700 r / min for 50 min, then add graphene and continue to stir for 30 min to obtain a graphene-polyaluminum chloride composite solution. The mass ratio of cyclodextrin-polyaluminum chloride composite agent, ferric sulfate solution, and graphene is 4:9:2.

[0163] The usage method of the light volcanic ash soil modification material includes the following steps:

[0164] (1) Grind the dry light volcanic ash soil and conduct a roasting treatment at a temperature of 800 °C to obtain pyrolyzed volcanic ash soil.

[0165] (2) Add a potato-rice mixture to the pyrolyzed volcanic ash soil and soak for 15 h. After soaking, filter to obtain pretreated volcanic ash soil. The mass-volume ratio of pyrolyzed volcanic ash soil to potato-rice mixture is 1 g:3 mL.

[0166] (3) Add an aqueous tannic acid solution to the pretreated volcanic ash soil, stir and let it stand for 40 min, then remove the supernatant. Then add the graphene-polyaluminum chloride composite solution and react for 2 h. After separating the solid product, dry it to obtain the modified light volcanic ash soil.

[0167] Test Example 1 Performance Detection Test for Improving Soil Salinization

[0168] 1.1 Test Method

[0169] Select soil with soil salinization. Use the original salinized soil as the detection object for the control group, and use the salinized soil after applying the modified light volcanic ash soil in Examples 1 - 3 and Comparative Examples 1 - 8 as the detection objects for the test group. That is, the modified light volcanic ash soil and the original salinized soil are plowed and fully mixed with the land, and the contents of NO 3- and SO4 2- are detected respectively. The specific detection steps and detection standards refer to "Methods of Soil Agricultural Chemistry Analysis" written by Lu Rukun (Lu Rukun, 2000).

[0170] 1.2 Test Results

[0171] The results are shown in Table 1:

[0172] Table 1 Performance Detection Results for Improving Soil Salinization

[0173] Group <![CDATA[NO 3- (mg / kg)]]> <![CDATA[SO4 2- (mg / kg)]]> Original salinized soil 496.40 360.15 Example 1 45.3 34.8 Example 2 44.6 32.1 Example 3 41.7 30.3 Comparative example 1 71.5 56.4 Comparative example 2 84.9 70.4 Comparative example 3 73.8 61.2 Comparative example 4 86.4 74.6 Comparative example 5 60.9 45.1 Comparative example 6 80.1 65.3 Comparative example 7 63.5 48.7 Comparative example 8 91.6 81.3

[0174] As can be seen from Table 1, after applying the modified light volcanic ash soil to the original saline-alkali soil, it is found that the salinization phenomenon has been significantly improved. The NO 3- content in Examples 1 to 3 is only 41.7 - 45.3 mg / kg, which is reduced by 90.87 - 91.60% compared with the original saline-alkali soil. The SO4 2- content is only 30.3 - 34.8 mg / kg, which is reduced by 90.34 - 91.59% compared with the original saline-alkali soil. By comparing Example 3 with Comparative Examples 1 to 8, it can be seen that the raw materials used in this application, namely the potato-rice mixed solution, graphene-polyaluminum chloride composite solution, tannic acid aqueous solution, and chitosan-modified nanocarbon powder reagent, are all essential components for reducing soil salinity. Potato-rice is rich in starch, and starch is a polysaccharide. After biodegradation, organic acids can be produced, and these organic acids can react with the salts in the soil, thereby reducing the soil salinity; graphene has excellent adsorption performance and can effectively adsorb and fix the salts in the soil, reducing the soil salinity. After being combined with polyaluminum chloride, the adsorption effect is more significant; the amino and hydroxyl groups on the chitosan molecular chain can adsorb salt ions such as Na+ in the soil through electrostatic interaction, reducing their free concentration. The high specific surface area of the nanocarbon powder further enhances the adsorption efficiency. The modified nanocarbon powder combines with chitosan to form porous aerogel microspheres, which can increase the soil permeability. After forming a composite structure after modification, the salts can be fixed more stably. It can be seen that the modified light volcanic ash soil prepared in this application can significantly improve the salinization phenomenon of the soil, reduce salt accumulation, improve the salt ion composition, optimize the nutrient balance, and is beneficial to crop growth.

[0175] Test Example 2 Germination Rate

[0176] 2.1 Test Method

[0177] Set up a blank group, a control group, and an experimental group. Sow intact rice seeds into the blank group, the control group, and the experimental group respectively. Among them, the blank group is applied with normal non-saline-alkali soil and irrigated with clear water, the control group is applied with the original saline-alkali soil and irrigated with clear water, and the experimental group is applied with the modified light volcanic ash soil prepared in Example 3 and the original saline-alkali soil. Test the germination rate of the above rice seeds. Germination rate = (number of germinated seeds / number of seeds for detection) × 100%.

[0178] 2.2 Germination Rate

[0179] The results are shown in Table 2:

[0180] Table 2 Germination Rate

[0181]

[0182] As can be seen from Table 2, the modified light volcanic ash soil prepared in Example 3 can significantly reduce the stress of the salts contained in the original saline soil on rice seeds, which is beneficial to the germination of rice seeds. After adding the modified light volcanic ash soil, the germination rate of rice seeds in the original saline soil is similar to that in the normal non-saline soil. At the same time, it is also found that applying the modified light volcanic ash soil does not inhibit the germination of rice seeds or have other toxic effects, indicating that the modified light volcanic ash soil of the present application is safe for crop planting, suitable for large-scale promotion, and provides a new improvement direction for solving the problem that saline soil inhibits crop growth.

[0183] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A lightweight volcanic ash soil modification material, characterized in that, The invention comprises the following raw materials in parts by weight: 50 to 60 parts of potato-glutinous rice mixed solution, 30 to 50 parts of graphene-polyaluminium chloride composite solution, 25 to 40 parts of tannic acid aqueous solution and 10 to 20 parts of chitosan modified nano carbon powder reagent.

2. The lightweight volcanic ash soil modified material according to claim 1, characterized in that The preparation method of the potato-glutinous rice mixed liquid comprises the following steps: mixing potatoes, glutinous rice and water in a mass ratio of (5-12):(10-20):(160-300), breaking the walls and filtering, and obtaining a filtrate which is the potato-glutinous rice mixed liquid.

3. The lightweight volcanic ash soil modification material according to claim 1, characterized in that, The preparation method of the graphene-polyaluminium chloride composite solution comprises the following steps: S1, adding sodium hydroxide solution to polyaluminium chloride and stirring, then adding cyclodextrin, stirring and reacting fully and then standing for 20 to 30 minutes to obtain a cyclodextrin-polyaluminium chloride composite; S2. Add ferric sulfate solution to the cyclodextrin-polyaluminium chloride composite agent obtained in step S1, stir at a speed of 600-800 r / min for 40-60 min, then add graphene, and continue stirring for 20-35 min to obtain a graphene-polyaluminium chloride composite solution.

4. The light volcanic ash soil modified material according to claim 3, characterized in that, The concentration of the sodium hydroxide solution in step S1 is 3-7 mol / L, and the mass ratio of polyaluminium chloride, sodium hydroxide solution and cyclodextrin is (1-3):(5-10):(0.3-0.8).

5. The light volcanic ash soil modified material according to claim 3, characterized in that The concentration of the ferric sulfate solution in step S2 is 0.01-0.05 mol / L, and the mass ratio of the cyclodextrin-polyaluminium chloride complex, the ferric sulfate solution and the graphene is (3-5):(6-10):(1-3).

6. The lightweight volcanic ash soil modifying material according to claim 1, characterized in that, The preparation method of the chitosan modified nano carbon powder reagent comprises the following steps: Step 1: Send the nano-carbon powder to 100-200°C for reaction for 40-60 minutes, then cool to 20-25°C, add deionized water, and prepare a 30-40% nano-carbon powder dispersion; Step 2: Add chitosan and 1-5% by mass of hydrochloric acid to the nano-carbon powder dispersion obtained in step 1, and stir the mixture at 50-60° C. for 3-6 hours to obtain a chitosan-modified nano-carbon powder reagent.

7. The lightweight volcanic ash soil modification material according to claim 3, characterized in that, In step 2, the volume mass ratio of the nano-carbon powder dispersion, chitosan and hydrochloric acid is (2-8) mL: 1 g: (0.2-0.7) mL.

8. The method for using the light volcanic ash soil modified material according to claim 1, characterized in that, The steps include: (1) grinding the dried light volcanic ash soil and calcining it at a temperature of 750 to 850° C. to obtain pyrolyzed volcanic ash soil; (2) adding a potato-glutinous rice mixture to the pyrolyzed volcanic ash soil and soaking it for 10 to 20 hours, filtering it after the soaking is completed, and obtaining the pretreated volcanic ash soil; (3) Add tannic acid aqueous solution and chitosan modified nano-carbon powder reagent to the pretreated volcanic ash soil, stir and let stand for 30 to 50 minutes, then remove the supernatant, add graphene-polyaluminum chloride composite solution, react for 1 to 3 hours, separate the solid product and dry it to obtain the modified light volcanic ash soil.

9. The method for using the lightweight volcanic ash soil modified material according to claim 8, characterized in that, The mass volume ratio of the pyrolyzed volcanic ash soil and the potato-glutinous rice mixed solution in step (2) is 1g:(2-4)mL.

10. Application of the modified light volcanic ash soil obtained by the method for using the light volcanic ash soil modifier according to claim 8 or claim 9 in improving soil salinization problems and increasing the germination rate of crops.

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