CN110862827A - Attapulgite soil remediation agent for mine remediation and preparation method thereof - Google Patents

Abstract

The invention discloses the technical field of soil repairing agents, in particular to an attapulgite soil repairing agent for mine repairing and a preparation method thereof, the raw materials of the attapulgite soil repairing agent comprise attapulgite, biochar and fulvic acid, the surface aperture of the attapulgite expands under high temperature conditions, most of the biochar can be inserted into surface pores of the attapulgite, so as to increase the total adsorption area of a mixture, the biochar has rich oxygen-containing functional groups, porous structures, cation exchange capacity, aromatic structures and the like, so that the biochar has good fixing effect on heavy metals, the fulvic acid can be complexed with metal ions, the adsorption effect of the attapulgite soil repairing agent on the metal ions is further increased, the increase of the fulvic acid enables carbon in soil to be accumulated after long-term application, the organic matter content can be effectively increased, the organic matter is decomposed by microorganisms, the pH value of the soil can be effectively reduced and the formation of granular structures in the soil can be promoted, the physicochemical properties of the soil are improved.

Description

Attapulgite soil remediation agent for mine remediation and preparation method thereof

Technical Field

The invention relates to the technical field of soil restoration agents, in particular to an attapulgite soil restoration agent for mine restoration and a preparation method thereof.

Background

In recent years, with the rapid development of industry and agriculture, more and more heavy metal pollutants enter soil, according to the national soil pollution condition survey bulletin issued by the ministry of environmental protection and the national resources, the heavy metal pollution is the main pollutant of the soil, especially the exceeding rate of the cadmium point of the heavy metal reaches 7.0 percent, so far, a great deal of research aiming at the soil heavy metal pollution remediation technology is carried out at home and abroad, the in-situ chemical immobilization technology is widely researched and applied due to the advantages of simplicity and convenience in implementation, high efficiency, low investment, environmental friendliness and the like, the key point of the in-situ chemical immobilization repair technology is to select a proper passivating agent, the currently commonly used passivating agent mainly comprises an alkaline material, clay minerals, organic materials and the like, and the natural clay minerals are more and more concerned due to the advantages of rich varieties, large reserves, easiness in obtaining, low price, environmental friendliness and the like. Attapulgite clay is a water-containing magnesium-rich aluminosilicate mineral with a layer chain structure, has strong ion exchange and adsorption capacity due to large specific surface area and high porosity, and is widely used for heavy metal pollution treatment of water and soil, but the selectivity of adsorbing pollutants and the product stability of natural attapulgite are not strong enough, and many modification researches are carried out at home and abroad aiming at overcoming the defects of the natural attapulgite, for example, silane coupling agent and polyacrylamide are adopted for modification, groups are grafted on the attapulgite to form complex precipitates with heavy metal ions, although the modified attapulgite is increased, modified materials have the danger of secondary pollution to the repaired soil, so that the safe attapulgite soil remediation agent for mines and the preparation method thereof are provided.

Disclosure of Invention

The invention aims to provide an attapulgite soil remediation agent for mine remediation and a preparation method thereof, and aims to solve the problems in the background art.

In order to achieve the purpose, the invention provides the following technical scheme: the attapulgite soil remediation agent for mine remediation comprises the following raw materials in parts by weight: 15-50 parts of attapulgite, 3-10 parts of biochar and 3-10 parts of fulvic acid.

Preferably, the attapulgite soil remediation agent for mine remediation comprises the following raw materials in parts by weight: 20-40 parts of attapulgite, 5-8 parts of biochar and 5-8 parts of fulvic acid.

Preferably, the attapulgite soil remediation agent for mine remediation comprises the following raw materials in parts by weight: 30 parts of attapulgite, 7 parts of charcoal and 7 parts of fulvic acid.

Preferably, the biochar is formed by pyrolyzing animal wastes.

Preferably, the preparation method of the attapulgite soil remediation agent for mine remediation comprises the following steps:

step 1:

crushing attapulgite with the particle size of 50-80 meshes;

step 2:

placing the animal wastes outdoors for air drying treatment, after 24 hours, placing the animal wastes in a pyrolysis furnace at 120-150 ℃ for anoxic pyrolysis, wherein the pyrolysis time is 5 hours, and then crushing the pyrolysis products to obtain crushed particles with the particle size of 150-300 meshes;

and step 3:

dissolving fulvic acid in water, uniformly stirring the fulvic acid in the water to form a fulvic acid solution, and then slowly stirring the attapulgite, the biochar and the fulvic acid aqueous solution which are crushed in the steps 1 and 2 at the temperature of 70-90 ℃ for 3 hours.

The invention has the beneficial effects that: the attapulgite soil repairing agent for repairing mines and the preparation method thereof, the surface aperture of the attapulgite is expanded under the high temperature condition, because the grain diameter of the prepared biochar is smaller than that of the attapulgite, most biochar can be inserted into the surface pores of the attapulgite, so as to increase the total adsorption area of the mixture, the biochar has rich oxygen-containing functional groups, porous structures, cation exchange capacity, aromatic structures and the like, so that the biochar has good fixing effect on heavy metals, and the fulvic acid can be complexed with metal ions, so as to further increase the adsorption effect of the attapulgite soil repairing agent on the metal ions, the increase of the fulvic acid can accumulate carbon in soil after long-term application, effectively increase the content of organic matters, the organic matters can be decomposed by microorganisms to generate organic acid and organic colloid, so that the PH value of the soil can be effectively reduced, and the formation of granular structures in the soil can be promoted, the physicochemical properties of the soil are improved.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

step 1:

pulverizing attapulgite into 50 mesh powder;

step 2:

placing the animal wastes outdoors for air drying treatment, after 24 hours, placing the animal wastes in a 120 ℃ pyrolysis furnace for anoxic pyrolysis, wherein the pyrolysis time is 5 hours, and then crushing the pyrolysis products to obtain 150-mesh crushed particles;

and step 3:

dissolving 3 parts of fulvic acid in 10 volumes of water, uniformly stirring the fulvic acid in the water to form a fulvic acid solution, and then slowly stirring the crushed attapulgite 15 parts and the crushed charcoal 3 parts in the steps 1 and 2 and the fulvic acid aqueous solution at the temperature of 70 ℃ for 3 hours.

Example 2:

step 1:

pulverizing attapulgite to obtain powder with particle size of 60 meshes;

step 2:

placing the animal wastes outdoors for air drying treatment, after 24 hours, placing the animal wastes in a pyrolysis furnace at 125 ℃ for anoxic pyrolysis, wherein the pyrolysis time is 5 hours, and then crushing the pyrolysis products to obtain crushed particles with the particle size of 190 meshes;

and step 3:

dissolving 5 parts of fulvic acid in 10 volumes of water, uniformly stirring the fulvic acid in the water to form a fulvic acid solution, and then slowly stirring 20 parts of attapulgite and 5 parts of biochar which are crushed in the steps 1 and 2 and the fulvic acid aqueous solution at the temperature of 75 ℃ for 3 hours.

Example 3:

step 1:

pulverizing attapulgite into powder with particle size of 70 mesh;

step 2:

placing the animal wastes outdoors for air drying treatment, after 24 hours, placing the animal wastes in a pyrolysis furnace at 130 ℃ for anoxic pyrolysis, wherein the pyrolysis time is 5 hours, and then crushing the pyrolysis products to obtain 230 meshes of crushed particles;

and step 3:

dissolving 7 parts of fulvic acid in 10 volumes of water, uniformly stirring the fulvic acid in the water to form a fulvic acid solution, and then slowly stirring 30 parts of attapulgite and 7 parts of biochar which are crushed in the steps 1 and 2 and the fulvic acid aqueous solution at the temperature of 80 ℃ for 3 hours.

Example 4:

step 1:

pulverizing attapulgite into 80 mesh powder;

step 2:

placing the animal wastes outdoors for air drying treatment, after 24 hours, placing the animal wastes in a pyrolysis furnace at 140 ℃ for anoxic pyrolysis, wherein the pyrolysis time is 5 hours, and then crushing the pyrolysis products to 270 meshes;

and step 3:

dissolving 8 parts of fulvic acid in 10 volumes of water, uniformly stirring the fulvic acid in the water to form a fulvic acid solution, and then slowly stirring 40 parts of attapulgite and 8 parts of biochar crushed in the steps 1 and 2 and the fulvic acid aqueous solution at the temperature of 85 ℃ for 3 hours.

Example 5:

step 1:

pulverizing attapulgite into 80 mesh powder;

step 2:

placing the animal wastes outdoors for air drying treatment, after 24 hours, placing the animal wastes in a pyrolysis furnace at 150 ℃ for anoxic pyrolysis, wherein the pyrolysis time is 5 hours, and then crushing the pyrolysis products to obtain the crushed particles with the particle size of 300 meshes;

and step 3:

dissolving 10 parts of fulvic acid in 10 volumes of water, uniformly stirring the fulvic acid in the water to form a fulvic acid solution, and then slowly stirring 50 parts of attapulgite and 10 parts of biochar which are crushed in the steps 1 and 2 and the fulvic acid aqueous solution at the temperature of 90 ℃ for 3 hours.

The attapulgite soil remediation agent prepared in the examples 1-5 and the existing attapulgite (comparative example) are respectively mixed with the same test soil (lower layer), the physicochemical properties of the soil are detected after 7 days, the detection results are shown in table 2, and the detection results of the initial physicochemical properties of the test soil are shown in table 1.

Table 1:

table 2:

note: the chromium metal content in tables 1 and 2 is the chromium metal content in the upper soil.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (5)

1. The attapulgite soil remediation agent for mine remediation is characterized by comprising the following components in parts by weight: the raw materials and corresponding parts by weight are as follows: 15-50 parts of attapulgite, 3-10 parts of biochar and 3-10 parts of fulvic acid.

2. The attapulgite soil remediation agent for mine remediation of claim 1, wherein: the raw materials and corresponding parts by weight are as follows: 20-40 parts of attapulgite, 5-8 parts of biochar and 5-8 parts of fulvic acid.

3. The attapulgite soil remediation agent for mine remediation of claim 1, wherein: the raw materials and corresponding parts by weight are as follows: 30 parts of attapulgite, 7 parts of charcoal and 7 parts of fulvic acid.

4. The attapulgite soil remediation agent for mine remediation of claim 1, wherein: the biochar is prepared by pyrolyzing animal wastes.

5. The preparation method of the attapulgite soil remediation agent for mine remediation is characterized by comprising the following steps: the method comprises the following steps:

step 1:

crushing attapulgite with the particle size of 50-80 meshes;

step 2:

placing the animal wastes outdoors for air drying treatment, after 24 hours, placing the animal wastes in a pyrolysis furnace at 120-150 ℃ for anoxic pyrolysis, wherein the pyrolysis time is 5 hours, and then crushing the pyrolysis products to obtain crushed particles with the particle size of 150-300 meshes;

and step 3:

dissolving fulvic acid in water, uniformly stirring the fulvic acid in the water to form a fulvic acid solution, and then slowly stirring the attapulgite, the biochar and the fulvic acid aqueous solution which are crushed in the steps 1 and 2 at the temperature of 70-90 ℃ for 3 hours.