Conditioner for soil heavy metal pollution remediation and preparation method thereof

Abstract

The invention provides a conditioner for soil heavy metal pollution remediation and a preparation method thereof, and belongs to the technical field of soil conditioning. The conditioner for soil heavy metal pollution remediation provided by the invention is prepared from the following components in parts by mass: 12 to 25 parts of biochar, 5 to 7 parts of potassium feldspar, 1 to 5 parts of inorganic nano material and 40 to 70 parts of water, the fertilizer is prepared from 40-50 parts of humic acid, 15-25 parts of amino acid, 5-12 parts of citric acid, 4-8 parts of bagasse and 25-40 parts of vinasse. 0.5 to 1 part of aspergillus niger and 0.1 to 1 part of clostridium capsulatum. By utilizing the adsorption of inorganic components on heavy metal elements, the improvement of organic components on saline-alkali soil and the continuous remediation effect of microbial components on the soil, through the synergistic effect of the multiple components, the soil is treated at the same time from multiple aspects of soil fertilization, plant growth, soil loosening, salinity and alkalinity reduction and the like; the soil salinity and alkalinity are reduced, and heavy metals are adsorbed and absorbed.

Description

Technical Field

[0001] The present invention relates to the technical field of soil conditioning, and in particular to a conditioning agent for repairing soil heavy metal pollution and a preparation method thereof. Background Art

[0002] Saline-alkali land is a type of salt accumulation, which means that the salt contained in the soil affects the normal growth of crops. According to incomplete statistics from UNESCO and FAO, the area of ​​saline-alkali land in the world is 954.38 million hectares. The formation of alkaline soil and alkaline soil is mostly related to the accumulation of carbonates in the soil, so the alkalinity is generally high. Plants can hardly survive in areas with severe saline-alkali soil. The physical and chemical properties of saline-alkali land are poor, with high salt content and high alkalinity, which causes the leaching of soil humus and the destruction of soil structure. It is sticky when wet and hard when dry. There is often white salt accumulation on the soil surface, poor ventilation and water permeability, and severe cases will cause plant wilt, poisoning and root rot, which is extremely toxic to plants. Land salinization not only harms the soil conditions on which crops depend for survival, but also affects the growth of crops, causing crop seedlings or death, thereby hindering the development of agricultural production. Soil salinization is an important limiting factor in the development of local agricultural economy.

[0003] At the same time, with the development of industry, heavy metal pollution in soil has become more and more serious. For example, industrial wastewater irrigation, excessive use of pesticides and unreasonable mining have led to the continuous accumulation of heavy metal elements such as mercury, cadmium, lead, copper, chromium, arsenic, nickel, iron, manganese and zinc in the soil. However, heavy metal pollution in soil is hidden and lagging. It cannot be overcome by cutting off the pollution source and using its self-purification effect like air pollution and water pollution. Heavy metal pollution is often difficult to detect and deal with in time. At the same time, heavy metal pollution in soil is irreversible. It is difficult to reduce the content of heavy metals over time. Not only is it difficult to control and has a long period of time, but it also brings a series of ecological problems, food problems, and groundwater pollution problems, which have a serious impact on human health and ecological balance. Therefore, it is urgent to solve the problem of heavy metal pollution in soil.

[0004] At present, soil remediation technologies are mainly divided into three categories: physical, chemical and biological remediation. Physical remediation has obvious effects on soil remediation of heavily polluted and small areas, but it is easy to cause soil structure damage and fertility decline, which is not suitable for farmland soil remediation, and the cost is high, and the fertility of cultivated land is affected. Biological remediation has a long cycle, limited remediation capacity, and is restricted by climate and geographical factors. Chemical passivation remediation has relatively low cost, is easy to operate, has fast results, and can be repaired while producing. It is currently the most commonly used method for large-scale farmland soil remediation, but there is a problem of soil compaction caused by the addition of a large number of chemical components. In addition, the soil conditioners currently available on the market can only be targeted at a certain type of soil problem, and the treatment effect on other soil problems is poor, which is difficult to meet the current market requirements.

[0005] Therefore, providing a conditioner that can simultaneously solve the problems of soil salinization and heavy metal pollution has become a technical problem that needs to be urgently solved in the field. Summary of the invention

[0006] The purpose of the present invention is to provide a conditioner for soil heavy metal pollution remediation and a preparation method thereof. The conditioner provided by the present invention can improve soil fertility, reduce soil salinization, solidify and adsorb heavy metal elements, and can be used to solve the problems of soil salinization and heavy metal pollution at the same time.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides a conditioning agent for repairing soil heavy metal pollution, which comprises the following components by weight:

[0009] Inorganic components: 12-25 parts of biochar, 5-7 parts of potassium feldspar, 1-5 parts of inorganic nanomaterials and 40-70 parts of water;

[0010] Organic components: 40-50 parts of humic acid, 15-25 parts of amino acids, 5-12 parts of citric acid, 4-8 parts of bagasse and 25-40 parts of distiller's grains;

[0011] Microbial components: 0.5-1 part of Aspergillus niger and 0.1-1 part of Clostridium capsulatum.

[0012] Preferably, the conditioning agent for soil heavy metal pollution remediation comprises the following components by weight:

[0013] Inorganic components: 15-22 parts of biochar, 5-6 parts of potassium feldspar, 2-4 parts of inorganic nanomaterials and 45-65 parts of water;

[0014] Organic components: 42-45 parts of humic acid, 18-22 parts of amino acids, 7-11 parts of citric acid, 5-7 parts of bagasse and 30-35 parts of distiller's grains;

[0015] Microbial components: 0.5-0.9 parts of Aspergillus niger and 0.2-0.8 parts of Clostridium capsulatum.

[0016] Preferably, the conditioning agent for soil heavy metal pollution remediation comprises the following components by weight:

[0017] Inorganic components: 18-20 parts of biochar, 6 parts of potassium feldspar, 3 parts of inorganic nanomaterials and 50-60 parts of water;

[0018] Organic components: 45 parts of humic acid, 20 parts of amino acids, 10 parts of citric acid, 6 parts of bagasse and 30-35 parts of distiller's grains;

[0019] Microbial components: 0.5-0.7 parts of Aspergillus niger and 0.5-0.8 parts of Clostridium capsulatum.

[0020] Preferably, the biochar is wheat straw biochar; the particle size of the biochar is 0.01 to 5 mm.

[0021] Preferably, the particle size of the potassium feldspar is 20-300 meshes.

[0022] Preferably, the inorganic nanomaterial is nano-silicon dioxide.

[0023] Preferably, the particle size of the inorganic nanomaterial is 50 to 1000 nm.

[0024] Preferably, the amino acid is aspartic acid, lysine or threonine.

[0025] The present invention provides a method for preparing a conditioning agent for soil heavy metal pollution remediation according to the above technical solution, comprising the following steps:

[0026] (1) mixing biochar, potassium feldspar and inorganic nanomaterials to obtain a mixture;

[0027] (2) mixing humic acid, amino acid, citric acid, bagasse, vinasse and water to obtain a mixed slurry;

[0028] (3) mixing the mixture obtained in step (1) and the mixed slurry obtained in step (2), and then adding Aspergillus niger and Clostridium capsulatum to obtain a conditioner for soil heavy metal pollution remediation;

[0029] The preparation of step (1) and step (2) is not in any particular order.

[0030] The present invention provides the use of the conditioning agent for soil heavy metal pollution remediation described in the above technical solution or the conditioning agent prepared by the preparation method described in the above technical solution in soil treatment.

[0031] The invention provides a conditioner for repairing soil heavy metal pollution, which comprises the following components by weight: an inorganic component: 12 to 25 parts of biochar, 5 to 7 parts of potassium feldspar, 1 to 5 parts of inorganic nanomaterials and 40 to 70 parts of water; an organic component: 40 to 50 parts of humic acid, 15 to 25 parts of amino acids, 5 to 12 parts of citric acid, 4 to 8 parts of bagasse and 25 to 40 parts of vinasse; and a microbial component: 0.5 to 1 part of Aspergillus niger and 0.1 to 1 part of Clostridium capsulatum.

[0032] The present invention adds biochar as a soil improvement material. The biochar has a porous structure, a large specific surface area, and a strong adsorption capacity. It can adsorb heavy metal elements in the soil, thereby reducing the harm of heavy metals to the soil. It also has the function of solidifying soil fertility and moisture, and can promote plant growth. Potassium feldspar is added, which is rich in silicon. Silicon is the main heavy metal passivating substance. At the same time, potassium feldspar has a microporous structure and a large specific surface area, which can passivate and adsorb heavy metals in the soil. Adding inorganic nanomaterials can significantly improve the stress resistance of plants, thereby alleviating the damage of heavy metal-contaminated soil to plants. It can reduce the toxic effects on plants and promote plant growth, thereby improving the degree of heavy metal pollution in the soil; humic acid can be dissolved in alkaline solutions, and through a series of reactions such as adsorption, complexation, and ion exchange, it can transform the heavy metal elements in the soil into a stabilized form, thereby reducing the mobility of heavy metal elements and improving their bioavailability. In this way, plants can absorb heavy metals in the soil through humic acid, and then recover heavy metals by burning plants, thereby realizing the recovery of heavy metals; at the same time, humic acid can also supplement soil organic matter, improve soil aggregate structure, alleviate the compaction of soil by lime, and reduce soil salinity. Improve soil fertility; by adding amino acids to the conditioner, the soil can be improved, the soil performance can be increased, and the necessary components can be provided for the growth of bacteria and plants, thereby promoting the reproduction of bacteria and promoting plant growth; citric acid is an organic acid, which can improve salinized soil and reduce its salinity on the one hand, and repair the soil and improve soil fertility on the other hand, thereby promoting plant growth; by adding sugarcane bagasse, it is used to improve the fertility of the soil and provide sufficient nutrients for the growth of bacteria and plants; by adding distiller's grains, the fertility of the soil can be improved and sufficient nutrients can be provided for the growth of bacteria and plants. At the same time, the lees contain certain strains that can accelerate the decomposition of organic matter; Aspergillus niger can decompose components such as starch and sugar, and has a certain decomposition ability for proteins, tannins, cellulose, pectin, etc., and will produce acidic substances in the decomposition process, thereby reducing the salinity of the soil. At the same time, the decomposed components will become nutrients for plant growth and accelerate plant growth; Clostridium capsulatum can ferment organic matter and produce acidic substances and gas components. The acidic substances are mainly acetic acid and butyric acid, which can reduce the salinity of the soil, and the gas will form pores in the soil during the escape process, thereby loosening the soil to a small extent.

[0033] The present invention simultaneously adds inorganic components, organic components and microbial components, utilizes the adsorption of heavy metal elements by inorganic components, the improvement of saline-alkali soil by organic components, and the continuous repair effect of microbial components on soil, and through the synergistic effect of multiple components, simultaneously treats the soil from multiple aspects such as soil fertilization, plant growth, soil loosening, and reduction of salinity, thereby ensuring the reduction of soil salinity, the adsorption and absorption of heavy metal elements, and the normal growth of the vegetation layer. The results of the embodiment show that the pH value of the soil can be reduced to about 7 in 10 hours by using the conditioner provided by the present invention to improve the soil, and at the same time, the mortality rate of vegetation after 6 months of growth is low, and the degree of heavy metal solidification and adsorption is high. DETAILED DESCRIPTION

[0034] The present invention provides a conditioning agent for repairing soil heavy metal pollution, which comprises the following components by weight:

[0035] Inorganic components: 12-25 parts of biochar, 5-7 parts of potassium feldspar, 1-5 parts of inorganic nanomaterials and 40-70 parts of water;

[0036] Organic components: 40-50 parts of humic acid, 15-25 parts of amino acids, 5-12 parts of citric acid, 4-8 parts of bagasse and 25-40 parts of distiller's grains;

[0037] Microbial components: 0.5-1 part of Aspergillus niger and 0.1-1 part of Clostridium capsulatum.

[0038] In the present invention, unless otherwise specified, the raw materials used are commercially available products well known to those skilled in the art or are prepared by preparation methods well known to those skilled in the art.

[0039] The conditioning agent for soil heavy metal pollution restoration provided by the present invention comprises inorganic components.

[0040] In terms of mass fraction, the inorganic component in the conditioner provided by the present invention includes 12 to 25 parts of biochar, preferably 15 to 22 parts, and more preferably 18 to 20 parts. The present invention adds biochar as a soil improvement material. Biochar has a porous structure, a large specific surface area, and a strong adsorption capacity. It can adsorb heavy metal elements in the soil, thereby reducing the harm of heavy metals to the soil. It also has the effect of solidifying soil fertility and moisture, and can promote plant growth.

[0041] In the present invention, the biochar is preferably wheat straw biochar; the particle size of the biochar is preferably 0.01 to 5 mm, more preferably 0.05 to 2 mm, and further preferably 0.1 to 1 mm. The present invention has no particular limitation on the preparation method of the biochar, and wheat straw can be prepared into biochar using methods well known to those skilled in the art. The present invention uses wheat straw to prepare biochar, which can achieve resource recycling of wheat straw, improve the practical value of wheat straw, and reduce pollution caused by straw burning.

[0042] Based on the mass fraction of biochar being 12 to 25 parts, the inorganic component in the conditioning agent provided by the present invention includes 5 to 7 parts of potassium feldspar, preferably 6 parts. In the present invention, the particle size of the potassium feldspar is preferably 20 to 300 meshes, more preferably 50 to 150 meshes. The present invention adds potassium feldspar, which is rich in silicon, and silicon is the main heavy metal passivating substance. At the same time, potassium feldspar has a microporous structure and a large specific surface area, which can passivate and adsorb heavy metals in the soil.

[0043] Based on the mass fraction of biochar being 12 to 25 parts, the inorganic component in the conditioning agent provided by the present invention includes 1 to 5 parts of inorganic nanomaterials, preferably 2 to 4 parts, and more preferably 3 parts. In the present invention, the inorganic nanomaterial is preferably nano-silicon dioxide; the particle size of the inorganic nanomaterial is preferably 50 to 1000 nm, and more preferably 200 to 500 nm. By adding inorganic nanomaterials, the present invention can significantly improve the stress resistance of plants, thereby alleviating the toxic effects of heavy metal contaminated soil on plants, promoting plant growth, and thus improving the degree of heavy metal pollution in the soil.

[0044] Based on the mass fraction of biochar being 12 to 25 parts, the inorganic component in the conditioning agent provided by the present invention includes 40 to 70 parts of water, preferably 45 to 65 parts, more preferably 50 to 60 parts, and further preferably 55 parts. In the present invention, the water is preferably tap water or treated domestic sewage. In the present invention, water is used as a solvent to prepare the conditioning agent.

[0045] Based on the mass fraction of biochar being 12 to 25 parts, the organic component in the conditioner provided by the present invention includes 40 to 50 parts of humic acid, preferably 42 to 48 parts, and more preferably 45 parts. In the present invention, humic acid can be dissolved in an alkaline solution, and through a series of reactions such as adsorption, complexation, and ion exchange, the heavy metal elements in the soil are transformed into a stabilized form, thereby reducing the mobility of the heavy metal elements and improving their bioavailability. In this way, plants can absorb the heavy metals in the soil through humic acid, and then recover the heavy metals by burning plants, thereby realizing the recovery of heavy metals; at the same time, humic acid can also supplement soil organic matter, improve soil aggregate structure, alleviate the compaction of soil by lime, reduce soil salinity, and improve soil fertility.

[0046] Based on the mass fraction of biochar being 12 to 25 parts, the organic component in the conditioner provided by the present invention includes 15 to 25 parts of amino acids, preferably 20 parts; the amino acid is preferably aspartic acid, lysine or threonine. By adding amino acids to the conditioner, the present invention can improve the soil, increase soil properties, provide necessary components for the growth of bacteria and plants, thereby promoting the reproduction of bacteria and promoting plant growth.

[0047] Based on the mass fraction of biochar being 12 to 25 parts, the organic component in the conditioner provided by the present invention includes 5 to 12 parts of citric acid, preferably 7 to 11 parts, and more preferably 8 to 10 parts. In the present invention, citric acid is an organic acid, which can improve salinized soil and reduce its salinity on the one hand, and repair the soil and improve soil fertility, thereby promoting plant growth on the other hand.

[0048] Based on the mass fraction of biochar being 12 to 25 parts, the organic component in the conditioner provided by the present invention includes 4 to 8 parts of bagasse, preferably 5 to 7 parts, and more preferably 6 parts. The present invention improves soil fertility by adding bagasse, thereby providing sufficient nutrients for the growth of bacteria and plants.

[0049] Based on the mass fraction of biochar being 12 to 25 parts, the organic component in the conditioner provided by the present invention includes 25 to 40 parts of vinasse, preferably 30 to 35 parts. By adding vinasse, the present invention can improve the fertility of the soil and provide sufficient nutrients for the growth of bacteria and plants. At the same time, the vinasse contains certain bacteria, which can accelerate the decomposition of organic matter.

[0050] Based on the mass fraction of biochar being 12 to 25 parts, the microbial component in the conditioning agent provided by the present invention includes 0.5 to 1 part of Aspergillus niger, preferably 0.6, 0.7, 0.8 or 0.9 parts. In the present invention, Aspergillus niger can decompose components such as starch and sugars, and has a certain decomposition ability for proteins, tannins, cellulose, pectin, etc., and will produce acidic substances during the decomposition process, thereby reducing the salinity of the soil. At the same time, the decomposed components will become nutrients for plant growth, accelerating plant growth.

[0051] Based on the mass fraction of biochar being 12 to 25 parts, the microbial component in the conditioner provided by the present invention includes 0.1 to 1 part of Clostridium capsulatum, preferably 0.2 to 0.8 parts, and more preferably 0.5 to 0.8 parts. In the present invention, Clostridium capsulatum can ferment glucose, maltose, lactose and sucrose, and produce acidic substances and gas components. The acidic substances are mainly acetic acid and butyric acid, which can reduce the salinity of the soil, and the gas will form pores in the soil during the escape process, thereby playing a role in loosening the soil to a small extent.

[0052] The present invention adds biochar as a soil improvement material. The biochar has a porous structure, a large specific surface area, and a strong adsorption capacity. It can adsorb heavy metal elements in the soil, thereby reducing the harm of heavy metals to the soil. It also has the function of solidifying soil fertility and moisture, and can promote plant growth. Potassium feldspar is added, which is rich in silicon. Silicon is the main heavy metal passivating substance. At the same time, potassium feldspar has a microporous structure and a large specific surface area, which can passivate and adsorb heavy metals in the soil. Adding inorganic nanomaterials can significantly improve the stress resistance of plants, thereby alleviating the damage of heavy metal-contaminated soil to plants. It can reduce the toxic effects on plants and promote plant growth, thereby improving the degree of heavy metal pollution in the soil; humic acid can be dissolved in alkaline solutions, and through a series of reactions such as adsorption, complexation, and ion exchange, it can transform the heavy metal elements in the soil into a stabilized form, thereby reducing the mobility of heavy metal elements and improving their bioavailability. In this way, plants can absorb heavy metals in the soil through humic acid, and then recover heavy metals by burning plants, thereby realizing the recovery of heavy metals; at the same time, humic acid can also supplement soil organic matter, improve soil aggregate structure, alleviate the compaction of soil by lime, and reduce soil salinity. Improve soil fertility; by adding amino acids to the conditioner, the soil can be improved, the soil performance can be increased, and the necessary components can be provided for the growth of bacteria and plants, thereby promoting the reproduction of bacteria and promoting plant growth; citric acid is an organic acid, which can improve salinized soil and reduce its salinity on the one hand, and repair the soil and improve soil fertility on the other hand, thereby promoting plant growth; by adding sugarcane bagasse, it is used to improve the fertility of the soil and provide sufficient nutrients for the growth of bacteria and plants; by adding distiller's grains, the fertility of the soil can be improved and sufficient nutrients can be provided for the growth of bacteria and plants. At the same time, the lees contain certain strains that can accelerate the decomposition of organic matter; Aspergillus niger can decompose components such as starch and sugar, and has a certain decomposition ability for proteins, tannins, cellulose, pectin, etc., and will produce acidic substances in the decomposition process, thereby reducing the salinity of the soil. At the same time, the decomposed components will become nutrients for plant growth and accelerate plant growth; Clostridium capsulatum can ferment organic matter and produce acidic substances and gas components. The acidic substances are mainly acetic acid and butyric acid, which can reduce the salinity of the soil, and the gas will form pores in the soil during the escape process, thereby loosening the soil to a small extent.

[0053] The present invention simultaneously adds inorganic components, organic components and microbial components, utilizes the adsorption of heavy metal elements by inorganic components, the improvement of saline-alkali soil by organic components, and the continuous repair effect of soil by microbial components, and through the synergistic effect of multiple components, simultaneously treats the soil from multiple aspects such as soil fertilization, plant growth, soil loosening, and reduction of salinity, thereby ensuring the reduction of soil salinity, the adsorption and absorption of heavy metal elements, and the normal growth of the vegetation layer.

[0054] The present invention provides a method for preparing a conditioning agent for soil heavy metal pollution remediation according to the above technical solution, comprising the following steps:

[0055] (1) mixing biochar, potassium feldspar and inorganic nanomaterials to obtain a mixture;

[0056] (2) mixing humic acid, amino acid, citric acid, bagasse, vinasse and water to obtain a mixed slurry;

[0057] (3) mixing the mixture obtained in step (1) and the mixed slurry obtained in step (2), and then adding Aspergillus niger and Clostridium capsulatum to obtain a conditioner for soil heavy metal pollution remediation;

[0058] The preparation of step (1) and step (2) is not in any particular order.

[0059] The present invention mixes biochar, potassium feldspar and inorganic nanomaterials to obtain a mixture. The present invention has no particular limitation on the specific manner of the mixing, as long as the components can be mixed evenly. In one embodiment of the present invention, the mixing manner may be ball milling.

[0060] The invention mixes humic acid, amino acid, citric acid, bagasse, vinasse and water to obtain mixed slurry.

[0061] In the present invention, the humic acid, amino acid, citric acid, bagasse, vinasse and water are preferably mixed in the following manner: amino acid and citric acid are first added to water and mixed evenly, then humic acid is added and mixed evenly, and finally bagasse and vinasse are added to obtain a mixed slurry. In the present invention, the mixing is preferably carried out under stirring conditions. The present invention has no particular limitation on the stirring rate, which can be determined according to the technical common sense of those skilled in the art. The present invention can ensure that the components are mixed evenly by mixing in the above manner.

[0062] After obtaining the mixture and the mixed slurry, the present invention mixes the mixture and the mixed slurry, and then adds Aspergillus niger and Clostridium capsulatum to obtain a conditioner for repairing soil heavy metal pollution.

[0063] In the present invention, the mixing is preferably carried out under stirring conditions. The present invention has no particular limitation on the stirring rate, which can be determined according to the technical common sense of those skilled in the art.

[0064] The preparation method provided by the invention is simple, has few processes, is easy to prepare under any environment, and is conducive to large-scale industrial promotion.

[0065] The present invention also provides the use of the conditioning agent for soil heavy metal pollution remediation described in the above technical solution or the conditioning agent prepared by the preparation method described in the above technical solution in soil treatment.

[0066] In the present invention, the application method is preferably: digging out the surface soil to be repaired, then mixing the soil to be repaired with a conditioner and backfilling, and finally planting vegetation in the backfilled surface soil.

[0067] In the present invention, the thickness of the excavated soil is preferably 15 to 25 cm. By controlling the thickness of the excavated soil, the present invention can ensure that the soil with severe surface salinization and heavy metal pollution can be fully mixed with the conditioner.

[0068] In the present invention, the mass ratio of the soil to be repaired and the conditioner is preferably 300:(1-5), more preferably 300:(2-4).

[0069] The present invention has no particular limitation on the specific type of the vegetation, and the plants with strong vitality and easy survival in saline-alkali land and heavy metal-contaminated soil can be selected according to the technical common sense of those skilled in the art. In one embodiment of the present invention, the vegetation is preferably shrubs.

[0070] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0071] Example 1

[0072] A conditioning agent for soil heavy metal pollution remediation, comprising the following components by weight:

[0073] Inorganic components: 20 parts of biochar, 6 parts of potassium feldspar, 3 parts of inorganic nanomaterials and 55 parts of water; the biochar is wheat straw biochar, and the particle size of the biochar is 0.01-5 mm; the particle size of the potassium feldspar is 50-150 mesh; the inorganic nanomaterial is nano-silicon dioxide, and the particle size of the inorganic nanomaterial is 200-500 nm; the water is tap water;

[0074] Organic components: 45 parts of humic acid, 20 parts of amino acids, 10 parts of citric acid, 6 parts of bagasse and 35 parts of distiller's grains; the amino acid is aspartic acid;

[0075] Microbial components: 0.5 parts of Aspergillus niger and 0.8 parts of Clostridium capsulatum.

[0076] The preparation method of the conditioning agent for soil heavy metal pollution remediation comprises the following steps:

[0077] (1) mixing biochar, potassium feldspar and inorganic nanomaterials to obtain a mixture;

[0078] (2) firstly adding amino acid and citric acid into water and mixing them evenly, then adding humic acid and mixing them evenly, and finally adding bagasse and distiller's grains to obtain a mixed slurry;

[0079] (3) The mixture obtained in step (1) and the mixed slurry obtained in step (2) are mixed, and then Aspergillus niger and Clostridium capsulatum are added to obtain a conditioner for soil heavy metal pollution remediation.

[0080] Example 2

[0081] The mass fraction of biochar is 15 parts, and other conditions are the same as those in Example 1.

[0082] Example 3

[0083] The mass fraction of biochar is 25 parts, and other conditions are the same as those in Example 1.

[0084] Example 4

[0085] The mass fraction of the inorganic nanomaterial is 1 part, and other conditions are the same as those in Example 1.

[0086] Example 5

[0087] The mass fraction of the inorganic nanomaterial is 5 parts, and other conditions are the same as those in Example 1.

[0088] Example 6

[0089] The mass fraction of citric acid is 5 parts, and other conditions are the same as those in Example 1.

[0090] Example 7

[0091] The mass fraction of Aspergillus niger is 1 part, and other conditions are the same as those in Example 1.

[0092] Example 8

[0093] The mass fraction of Clostridium capsulatum was 0.1 parts, and other conditions were the same as those in Example 1.

[0094] Example 9

[0095] The mass fraction of Clostridium capsulatum was 0.5 parts, and other conditions were the same as those in Example 1.

[0096] Comparative Example 1

[0097] Biochar was omitted, and other conditions were the same as in Example 1.

[0098] Comparative Example 2

[0099] Potash feldspar was omitted, and other conditions were the same as those in Example 1.

[0100] Comparative Example 3

[0101] The inorganic nanomaterials were omitted, and other conditions were the same as those in Example 1.

[0102] Comparative Example 4

[0103] Humic acid was omitted, and other conditions were the same as in Example 1.

[0104] Comparative Example 5

[0105] Amino acids were omitted, and other conditions were the same as in Example 1.

[0106] Comparative Example 6

[0107] Citric acid was omitted, and other conditions were the same as in Example 1.

[0108] Comparative Example 7

[0109] Bagasse was omitted, and other conditions were the same as in Example 1.

[0110] Comparative Example 8

[0111] The lees were omitted and other conditions were the same as those in Example 1.

[0112] Comparative Example 9

[0113] Aspergillus niger was omitted, and other conditions were the same as in Example 1.

[0114] Comparative Example 10

[0115] Omit Clostridium capsulatum, and other conditions are the same as in Example 1.

[0116] The conditioning agents provided in Examples 1 to 9 and Comparative Examples 1 to 10 are respectively used for soil treatment, and the specific method is: digging out the surface soil to be repaired, then mixing the soil to be repaired and the conditioning agent and backfilling, and finally planting vegetation in the backfilled surface soil;

[0117] The thickness of the excavated soil is 20 cm; the mass ratio of the soil to be repaired and the conditioner is 300:2; and the vegetation is Salix psammophila.

[0118] The pH values ​​of the backfilled soils of Examples 1 to 19 and the blank control group were tested at different times, and the results are shown in Table 1:

[0119] Table 1 pH values ​​of the backfilled soils of Examples 1 to 9 and Comparative Examples 1 to 10 and the blank control group at different times

[0120]

[0121]

[0122] By comparing Examples 1 to 5 and Comparative Examples 1 to 3 in Table 1, it can be seen that the changes in the content of biochar, inorganic nanomaterials and potassium feldspar have a small impact on the pH value of the soil within 12 hours; by comparing Examples 1 and 6 and Comparative Examples 4 to 6, it can be seen that humic acid and citric acid have a greater impact on the pH value of the soil, indicating that humic acid and citric acid can reduce the alkalinity of the soil. By comparing Examples 1, 7 to 9 and Comparative Examples 7 to 10, it can be seen that bagasse, vinasse, black Aspergillus and capsular Clostridium have a small impact on the pH value of the soil within 12 hours. This is because the bacteria have just begun to reproduce and release less acid, so they have a small impact on the pH value of the soil. It can be seen from Application Examples 1 to 19 that the conditioner provided by the present invention can reduce the pH value of saline-alkali land with a pH value of 8.3 to a pH value of about 6.7, effectively reducing the salinity of the soil, making it more suitable for plant growth.

[0123] The same amount of water was applied to the vegetation on the soil improved by the conditioners of Examples 1 to 9 and Comparative Examples 1 to 10 under the same conditions, and the growth was observed after 6 months. It was found that the Salix psammophila of Examples 1 to 9 grew very well with an extremely low mortality rate, the Salix psammophila of Comparative Examples 1 to 3 grew better, and the mortality rate was 1.5 to 2% higher than that of Examples 1 to 9, while the Salix psammophila of Comparative Examples 4, 5, 7 and 8 grew generally and were on the low side, indicating that the omission of organic components resulted in poor soil fertility and slow plant growth; the Salix psammophila of Application Example 6 grew slightly worse, presumably because of the slightly higher soil salinity; the Salix psammophila of Application Examples 9 and 10 were slightly better than those of Application Examples 7 and 8, but slightly worse than those of Examples 1 to 9. Analysis showed that the reason may be that the omission of microorganisms resulted in slower decomposition of bagasse and distiller's grains, resulting in insufficient nutrition.

[0124] The cadmium content of the soils improved by the conditioners of Examples 1 to 9 and Comparative Examples 1 to 10 and the blank control group at different times was tested, and the results are shown in Table 2:

[0125] Table 2 Cadmium content in the soils of backfill improved by the conditioners of Examples 1 to 9 and Comparative Examples 1 to 10 and the blank control group at different times

[0126] Example Cadmium content in 3 months (mg / kg) Cadmium content at 6 months (mg / kg) Example 1 2.315 2.078 Example 2 2.342 2.043 Example 3 2.328 2.105 Example 4 2.409 2.061 Example 5 2.369 2.037 Example 6 2.327 2.027 Example 7 2.351 2.058 Example 8 2.347 2.041 Example 9 2.369 2.116 Comparative Example 1 2.412 2.265 Comparative Example 2 2.394 2.202 Comparative Example 3 2.408 2.274 Comparative Example 4 2.389 2.319 Comparative Example 5 2.368 2.185 Comparative Example 6 2.354 2.171 Comparative Example 7 2.411 2.232 Comparative Example 8 2.436 2.248 Comparative Example 9 2.347 2.263 Comparative Example 10 2.374 2.143 Blank control group 2.476 2.468

[0127] From the analysis of Table 2, it can be seen that the conditioning agents provided by Examples 1 to 9 of the present invention have significantly higher solidification and adsorption effects on heavy metal elements in the soil than those of Comparative Examples 1 to 10, wherein the solidification and adsorption effects of heavy metals are affected by many aspects, on the one hand, by the solidification and adsorption of adsorption materials such as biochar, and on the other hand, by being absorbed by plants and affected by aspects such as plant growth. It can be seen that in the present invention, the synergistic effect of inorganic components, organic components, and microbial components is used to regulate soil salinity, solidification and adsorption of heavy metal elements, adjustment of soil fertility, and reproduction of microorganisms, thereby achieving the goal of simultaneously solving the problems of soil salinity and heavy metal pollution.

[0128] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A conditioning agent for soil heavy metal pollution remediation, comprising the following components by weight: Inorganic components: 12-25 parts of biochar, 5-7 parts of potassium feldspar, 1-5 parts of inorganic nanomaterials and 40-70 parts of water; Organic components: 40-50 parts of humic acid, 15-25 parts of amino acids, 5-12 parts of citric acid, 4-8 parts of bagasse and 25-40 parts of distiller's grains; Microbial components: 0.5-1 part of Aspergillus niger and 0.1-1 part of Clostridium capsulatum.

2. The conditioning agent for soil heavy metal pollution remediation according to claim 1, characterized in that: By mass, it includes the following components: Inorganic components: 15-22 parts of biochar, 5-6 parts of potassium feldspar, 2-4 parts of inorganic nanomaterials and 45-65 parts of water; Organic components: 42-45 parts of humic acid, 18-22 parts of amino acids, 7-11 parts of citric acid, 5-7 parts of bagasse and 30-35 parts of distiller's grains; Microbial components: 0.5-0.9 parts of Aspergillus niger and 0.2-0.8 parts of Clostridium capsulatum.

3. The conditioning agent for soil heavy metal pollution remediation according to claim 2, characterized in that: By mass, it includes the following components: Inorganic components: 18-20 parts of biochar, 6 parts of potassium feldspar, 3 parts of inorganic nanomaterials and 50-60 parts of water; Organic components: 45 parts of humic acid, 20 parts of amino acids, 10 parts of citric acid, 6 parts of bagasse and 30-35 parts of distiller's grains; Microbial components: 0.5-0.7 parts of Aspergillus niger and 0.5-0.8 parts of Clostridium capsulatum.

4. The conditioning agent for soil heavy metal pollution remediation according to any one of claims 1 to 3, characterized in that: The biochar is wheat straw biochar; the particle size of the biochar is 0.01-5 mm.

5. The conditioning agent for soil heavy metal pollution remediation according to any one of claims 1 to 3, characterized in that: The particle size of the potassium feldspar is 20 to 300 meshes.

6. The conditioning agent for soil heavy metal pollution remediation according to any one of claims 1 to 3, characterized in that: The inorganic nano material is nano silicon dioxide.

7. The conditioning agent for soil heavy metal pollution remediation according to claim 6, characterized in that: The particle size of the inorganic nano material is 50 to 1000 nm.

8. The conditioning agent for soil heavy metal pollution remediation according to any one of claims 1 to 3, characterized in that: The amino acid is aspartic acid, lysine or threonine.

9. The method for preparing the conditioner for soil heavy metal pollution remediation according to any one of claims 1 to 8, comprising the following steps: (1) mixing biochar, potassium feldspar and inorganic nanomaterials to obtain a mixture; (2) mixing humic acid, amino acid, citric acid, bagasse, vinasse and water to obtain a mixed slurry; (3) mixing the mixture obtained in step (1) and the mixed slurry obtained in step (2), and then adding Aspergillus niger and Clostridium capsulatum to obtain a conditioner for soil heavy metal pollution remediation; The preparation of step (1) and step (2) is not in any particular order.

10. Use of the conditioning agent for soil heavy metal pollution remediation according to any one of claims 1 to 8 or the conditioning agent prepared by the preparation method according to claim 9 in soil treatment.

Images