CN112522147A

CN112522147A - Method for repairing iron tailing sandy soil by using microbial agent and waste rocks

Info

Publication number: CN112522147A
Application number: CN202011427788.6A
Authority: CN
Inventors: 许灏; 赵虹; 陈晓寒; 郝忠庆; 崔兆杰; 何竟宇
Original assignee: Ansteel Mining Co Ltd
Current assignee: Ansteel Mining Co Ltd
Priority date: 2020-12-09
Filing date: 2020-12-09
Publication date: 2021-03-19

Abstract

The invention relates to a method for repairing iron tailing sandy soil by using a microbial agent and waste rocks, which comprises the steps of adding 10-30 wt% of waste rocks with the particle size of 0.5-1.5 cm into tailing sandy soil with the depth of 25-40 cm, turning, uniformly mixing, and covering with 1-3 cm of additional soil; applying 0.1-0.5 kg/m²10-20 g/m of organic fertilizer²And (4) using a microbial agent, then turning over 10-30 cm, and planting herbaceous plants. The iron tailing sandy soil after being repaired for 3 months has the water content of 15.66-17.44%, the porosity of 48.23-65.42%, the soil organic matter of 6.93-7.49%, the plant POD of 30.08-47.04 and the plant SOD of 374.45-452.97. The method for restoring the iron tailing sandy soil by using the microbial agent and the waste rocks solves the problems of low porosity and easy loss of the tailing sandy soil, and enables the ecological restoration of the mining area to be long-acting and stable and the environment to be continuously improved.

Description

Method for repairing iron tailing sandy soil by using microbial agent and waste rocks

Technical Field

The invention relates to the technical field of iron tailing sandy soil restoration, in particular to a method for restoring iron tailing sandy soil by using a microbial agent and waste rocks.

Background

According to the 2009 development report of the Chinese resource comprehensive utilization association, the total production of tailings in China in 2012 reaches 11.92 hundred million tons, which accounts for more than 45% of industrial solid wastes in China, and the comprehensive utilization rate is only 13.3%, and 100 hundred million tons of tailings are accumulated and stockpiled at present. Because the utilization rate of iron tailings in China is low, a large amount of tailings are piled up in a tailing pond, which not only wastes mineral resources greatly, but also consumes a large amount of funds for discharging and storing the tailings.

The tailings sandy soil is properly improved and utilized in the form of soil, so that the problem that the tailings are piled up to occupy a large amount of land can be solved, the tailings are beneficial to the construction of green mines, and the problem that the increasingly serious cultivated land shortage is met in China can be relieved.

At present, the method for improving iron tailing sandy soil is mainly mine ecological restoration, and includes vegetation restoration, mining area reclamation, tailing utilization technology, and application technologies of various additives, microbial agents, water retention agents and the like in soil improvement are reported in many cases, for example:

CN201611072217 discloses a method for preparing reclaimed soil from iron tailings, comprising: respectively collecting iron tailings, fourth series secondary loess and organic materials for later use; uniformly mixing the iron tailings, the fourth-series secondary loess and the organic material according to the mass ratio of 45-55: 40-50: 5 to obtain reclaimed soil; the organic material is decomposed livestock and poultry breeding waste or decomposed sludge discharged by urban domestic sewage treatment plants. The method for preparing the reclamation soil by using the iron tailings takes the iron tailings, the sludge and the livestock and poultry breeding wastes as raw materials to prepare the reclamation soil, so that the mine is greened, the wastes such as the iron tailings, the sludge and the like are comprehensively utilized, the occupation of land resources is relieved, and the environment is protected.

CN202010194028.9 discloses a preparation method of composite improved planting soil for vegetation restoration of mine side slopes, which comprises the following steps: (1) grinding and sieving vinasse, bagasse, diatomite and fly ash to obtain a prefabricated material a; (2) concentrating and dehydrating the municipal sludge, drying, crushing, adding iron tailing sand, uniformly mixing, adjusting the water content, then adding a binder, granulating, then sending into a rotary kiln, carbonizing at the temperature of 500 ℃ and 600 ℃ for 20-30min, cooling, adding activated carbon and decomposed organic fertilizer, and uniformly mixing to obtain a prefabricated material b; (3) uniformly mixing the prefabricated material a and the prefabricated material b, adding zymophyte liquid into the mixture for decomposition at the temperature of 40-50 ℃ for 20-40 days, keeping the water content of the mixture at 16-20 wt% in the decomposition process, drying, adding polymaleic anhydride and polyvinyl alcohol, uniformly mixing, and granulating to obtain the composite improved planting soil for repairing vegetation on the mine slope.

CN201911344547.2 provides a soda saline-alkali soil improver containing microorganisms and an improving method. The soda saline-alkali soil modifier consists of azospirillum brasilense, iron tailings and organic fertilizer, wherein the proportion of the three components is 1800-2000 mL: 4000 g-4500 g: 1200-1500 g, and the concentration of the azospirillum brasilense bacterial liquid is 1-9 multiplied by 107 CFU/mL. Through the compound application of the azospirillum brasilense and the iron tailings, the salinity of the soil can be further reduced, the pH value of the soil is balanced, the growth of crops is promoted, and the long-acting improvement of the saline-alkali soil is realized.

CN201911220687.9 provides greening soil prepared from iron tailings, and the raw materials of the greening soil comprise the following components in parts by mass: 7.4-9.6 parts of iron tailings, 0.3-2.1 parts of edible fungus residues and 0.1-1.6 parts of rice hulls; the application also provides a preparation method of the greening soil prepared from the iron tailings; the greening soil provided by the invention takes the iron tailings as the main material and the edible fungus residues and the rice hulls as the auxiliary materials, so that the resource recycling of the industrial waste iron tailings is realized, the resource recycling of the agricultural waste edible fungus residues and the rice hulls is realized, and the resource and environment pressure is relieved; the greening soil is rich in nutrition, and no additional fertilizer is needed, so that the continuous nutrition requirement of greening plants can be met, and the later maintenance cost can be reduced; most materials of the greening soil can be obtained from local materials, the operation method is simple, the raw material sources are wide, the cost can be reduced, and the greening soil has remarkable economic benefit and ecological benefit.

In the existing tailings repairing technology, a single repairing technology is mostly adopted, and the physicochemical properties of soil are improved by combining compound fertilizers, nutrient additives and the like, so that the content of organic nutrients is increased. The compound fertilizer and the nutrient additive can play the roles of the compound fertilizer and the nutrient additive in a short term as an external chemical additive, and may have certain negative effects in the long term.

In order to solve the problems of fine particle size and easy loss of tailings in the process of sandy utilization of the tailings, a method for long-acting restoration of the sandy soil of the iron tailings is found. The inventor explores a method for repairing iron tailing sandy soil by using a microbial agent, waste rocks and cultivated plants, wherein the tailing sandy soil and the waste rocks are mixed, and the microbial agent is added to increase the air permeability of the soil and improve the soil environment.

Disclosure of Invention

The invention aims to provide a method for repairing iron tailing sandy soil by using a microbial agent and waste rocks.

The purpose of the invention is realized by the following technical scheme:

the method for repairing the iron tailing sand by using the microbial agent and the waste rocks is characterized by comprising the following steps of:

(1) adding 10-30 wt% of waste rock with the particle size of 0.5-1.5 cm into tailing sandy soil with the depth of 25-40 cm, turning, uniformly mixing, and covering with 1-3 cm of additional soil;

(2) applying 0.1 to 0.5kg/m²10-20 g/m of organic fertilizer²Turning over 10-30 cm after the microbial agent is added;

(3) planting herbaceous plants, and performing field management;

wherein the microbial agent is respectively activated, propagated and diluted into effective bacteria with the number concentration as follows: 1X 10⁷～9×10⁷CFU/mL, and according to the volume ratio: 6-8: 2-4, and the bacterial liquid of the Paecilomyces lilacinus with the preservation number of CGMCC No.60794, the Pseudomonas aeruginosa with the preservation number of ATCC14358 and the Pseudomonas aeruginosa with the preservation number of ATCC 9027; the soil dressing is natural soil or farmland planting soil; the organic fertilizer is one or more of fermented bean sauce, straw, chicken manure and cattle and sheep manure.

Further, the microbial agent: the paecilomyces lilacinus has a preservation number of CGMCC No.60794, the Pseudomonas aeruginosa has a preservation number of ATCC14358 and the Pseudomonas aeruginosa has a preservation number of ATCC9027 in volume ratio: 7-8: 3-4.

The method for repairing the iron tailing sandy soil by using the microbial agent and the waste rocks is characterized in that the herbaceous plants are one or more of black nightshade, cosmos and festuca arundinacea, and the planting density is 20-25 plants/m²。

The method for restoring the iron tailing sandy soil by using the microbial agent and the waste rocks is characterized in that the alien soil is farmland planting soil and covers 2.0-3.0 cm; the organic fertilizer is chicken manure, and the application amount is as follows: 0.25 to 0.4kg/m²。

The method for repairing the iron tailing sand soil by using the microbial agent and the waste rocks is characterized in that the preparation method of the bacterial liquid of the paecilomyces lilacinus, the pseudomonas aeruginosa and the pseudomonas aeruginosa in the microbial agent comprises the following steps:

(1) under aseptic conditions, activated culture is adoptedInoculating the first-class seed of the strain at 23-27 deg.C for 180-230 r.min^-1Culturing for 7-10 days on a shaking table to obtain second-stage seeds of the strains;

(2) the activated strain is cultured by adopting an expansion culture medium at the temperature of 30-32 ℃ and the temperature of 180-230 r.min^-1Culturing for 5-8 days on a shaking table, and performing propagation;

(3) diluting the activated and propagated strains with sterile water to 1 × 10 respectively⁷～9×10⁷CFU/mL bacterial liquid is obtained;

wherein the components of the activation and propagation culture medium are as follows: nitrogen source: 1.0-3.0 g/L, carbon source: 1.0-3.0 g/L, yeast extract: 1.0-3.0 g/L, peptone: 2.0-5.0 g/L, dipotassium hydrogen phosphate: 0.5-1.0 g/L, magnesium sulfate: 0.03-0.05 g/L, pH is 6.0-7.0.

The method for repairing the iron tailing sand by using the microbial agent and the waste rocks has the following additive effects:

the main additive of the invention is the waste rock which is obtained from tailing ore of fine crushed products of a separation plant after magnetic separation by a magnetic pulley through screening. The invention prepares novel soil by compounding the waste rock, the iron tailing sandy soil and the natural soil, can increase the air permeability of a compound system and improve the performance of the iron tailing sandy soil.

The other additive of the invention is the microbial agent which consists of paecilomyces lilacinus, pseudomonas aeruginosa and pseudomonas aeruginosa. The paecilomyces lilacinus secretion can bond soil, increase the porosity of the soil, can produce a product similar to indoleacetic acid, has the most obvious physiological effects of promoting the growth of plant roots and plant nutritive organs, has a promoting effect on the germination and growth of seeds, can generate a mycorrhizal symbiosis system with plants, and strengthens the capability of fixing and absorbing nutrients of the plant roots, so that the organic matter is nutritionally and circularly utilized. The pseudomonas oxydans can repair pollutants in soil, mainly degrade organic matters, adsorb heavy metals and weaken the effective form content of the heavy metals. The pseudomonas aeruginosa can also repair heavy metal organic matters in soil on one hand, and mainly can produce a biosurfactant rhamnolipid on the other hand, the rhamnolipid can generate a stimulation effect on the growth of crops, vegetables and fruits, assist in absorbing nutrition, increase the effect of pesticides and fertilizers and the like, has no toxic or side effect on human and animals, and can improve alkaline soil. The three microbial inocula are a combination with a good screening effect after being researched by different treatment combinations among various microbial inocula. As each of the three bactericides has different effects, the combined application of the three bactericides shows that the soil environment can be improved, the soil pollution can be repaired, the plant growth can be promoted and the synergistic effect can be exerted.

The method for repairing the tailing sandy soil is to plant plants. The planted solanum nigrum and festuca arundinacea are heavy metal super-accumulation plants, have good adsorption effect on heavy metals in soil, and can restore soil environment to the maximum extent under the condition of ensuring self growth. The root system function of the planted black nightshade, cosmos and festuca arundinacea can obviously improve the cohesive force of soil, the secretion of the root system can increase the nutrients in the soil and improve the water content of the soil, and the plant root system interpenetrates the soil to cause the soil porosity to be increased, so that the soil ecological environment can be improved.

The method for repairing the iron tailing sandy soil by using the microbial agent and the waste rocks has the following characteristics:

1. the method adopts a plant and microorganism combined restoration technology, realizes the long-acting restoration of the iron tailings, solves the problem of large-scale accumulation of mine sandy soil and waste rocks, relieves the atmospheric dust and soil pollution around a mining area, and reduces the risks of dam collapse, ecological landslide and the like of a tailing pond.

2. The iron tailing sandy soil and the waste rock are subjected to soil utilization, so that the problems of low porosity and easy loss of the tailing sandy soil are solved, and the long-acting stability of the ecological restoration of a mining area and the continuous improvement of the environment are realized.

3. The invention adopts the microbial agent, the waste rocks and the organic fertilizer to restore the physicochemical properties of the tailings and the sandy soil, improves the biomass and the survivability of the planted plants, and has simple method and convenient use.

Detailed Description

The following examples are provided for illustrative purposes only and are not intended to limit the scope of the claims, and other alternatives that may occur to those skilled in the art from consideration of the specification are intended to be within the scope of the claims.

The test site is a flat open space located on the southeast side of the large solitary mountain tailing pond. The terrain is high, the illumination is sufficient, the terrain is flat, and the device has no other use in recent years, is suitable for a tailing pond to carry out a simulated ecological restoration test, and has the following performance index numerical conditions in a tailing sand background area:

index (I)	Detection value
		Volume weight (g/cm)³)	1.57
Total porosity (%)	44.68
		Water content (%)	11.88
pH value	8.75
		Organic matter content (g/kg)	1.15
Cu(mg/kg)	12.5
		Mn(mg/kg)	1070
Cd(mg/kg)	0.69

Microbial agents described in examples and comparative examples: the method for preparing the bacterial liquid by the paecilomyces lilacinus preservation number CGMCC No.60794, the pseudomonas oxydans preservation number ATCC14358 and the pseudomonas aeruginosa preservation number ATCC9027 comprises the following steps:

(1) inoculating the first-stage seed of the strain with an activated culture medium under aseptic conditions at 30 deg.C for 220r min^-1Culturing for 8 days on a shaking table to obtain second-stage seeds of the strains;

(2) the activated strain is cultured in a propagation culture medium at 30 deg.C and 220r min^-1Culturing on a shaking table for 8 days, and performing propagation;

(3) diluting the activated and propagated strains with sterile water to 5 × 10 respectively⁶～1.1×10⁸CFU/mL bacterial liquid is obtained;

wherein the components of the activation and propagation culture medium are as follows: 2.0g/L, carbon source: 2.0g/L, yeast extract: 2.0g/L, peptone: 3.0g/L, dipotassium hydrogen phosphate: 1.0g/L, magnesium sulfate: 0.03g/L, pH is 6.5.

Example 1

The method for restoring the sandy soil of the iron tailings comprises the following steps:

(1) adding 20 wt% of waste stones with the particle size of 0.5-1.5 cm into tailing sandy soil with the depth of 25-40 cm, turning, uniformly mixing, and covering 2.5cm of foreign soil on the waste stones; further according to 0.3kg/m²Applying a commercially available fermented chicken manure organic fertilizer to the standard;

(2) according to 15g/m²Is applied in a quantitative concentration of 4.5X 10⁷A microbial agent prepared by mixing CFU/mL paecilomyces lilacinus, pseudomonas aeruginosa and pseudomonas aeruginosa according to the volume ratio of 7:3: 3;

(3) ploughing the soil into 30cm depth; after one week of agingSowing plant seeds, selecting seeds one day before sowing the solanum nigrum seeds and soaking the seeds overnight, wherein the plant seeds are 20 plants/m²The standard of (2) sowing in the next morning, performing the three repeated tests, and performing field management;

the numerical conditions of the performance indexes of the tailings sandy soil after one week of curing are as follows:

index (I)	Detection value
		Volume weight (g/cm)³)	1.2～1.5
Total porosity (%)	50％～65％
		Water content (%)	15％～20％
pH value	6～8
		Organic matter content (g/kg)	5～15

The performance index value of the tailings sandy soil is as follows: the volume weight, the total porosity, the water content, the pH value and the organic matter content reach the range suitable for planting the plant soil.

(4) After sowing, samples were taken and analyzed 1 month, 2 months and 3 months later, and the water content, porosity, organic matter, superoxide dismutase (POD) and superoxide dismutase (SOD) of the soil were measured.

The results of the test of each physical and chemical index of the soil within 3 months are shown in table 1.

Example 2

(1) selecting waste rocks with the particle size of 0.5-1.5 cm, mixing the waste rocks with the iron tailing sand soil according to the mass percentage of 10%, and carrying out the rest steps in the same way as the example 1.

The results of the test of each physical and chemical index of the soil within 3 months are shown in table 2.

Example 3

(1) selecting waste rocks with the particle size of 0.5-1.5 cm, mixing the waste rocks with the iron tailing sand soil according to the mass percentage of 30 percent, and carrying out the rest steps in the same way as the example 1.

The results of the test of each physical and chemical index of the soil within 3 months are shown in table 3.

Example 4

wherein (2) is in the range of 10g/m²Applying a microbial agent;

the rest of the procedure was the same as in example 1.

The results of the tests on the physical and chemical indexes of the soil within 3 months are shown in table 4.

Example 5

wherein (2) is in the range of 20g/m²Applying a microbial agent;

the rest of the procedure was the same as in example 1.

The results of the test of each physical and chemical index of the soil within 3 months are shown in table 5.

Example 6

wherein (2) is in the range of 15g/m²Applied in a quantity concentration of 1X 10⁷CFU/mL microbial agent prepared by mixing paecilomyces lilacinus, pseudomonas oxydans and pseudomonas aeruginosa according to volume ratio of 7:3:3；

The rest of the procedure was the same as in example 1.

The results of the tests on the physical and chemical indexes of the soil within 3 months are shown in table 6.

Example 7

wherein (2) is in the range of 15g/m²Applied in a quantity concentration of 9X 10⁷CFU/mL is a microbial agent prepared by mixing paecilomyces lilacinus, pseudomonas aeruginosa and pseudomonas aeruginosa according to the volume ratio of 7:3: 3;

the rest of the procedure was the same as in example 1.

The results of the tests on the physical and chemical indexes of the soil within 3 months are shown in table 7.

Example 8

wherein (3) adopting the cosmos seeds for planting;

the rest of the procedure was the same as in example 1.

The results of the tests on the physical and chemical indexes of the soil within 3 months are shown in table 8.

Example 9

wherein (3) tall fescue seeds are adopted for planting;

the rest of the procedure was the same as in example 1.

The results of the tests on the physical and chemical indexes of the soil within 3 months are shown in table 9.

TABLE 1

TABLE 2

TABLE 3

TABLE 4

TABLE 5

TABLE 6

TABLE 7

TABLE 8

TABLE 9

Comparative example 1

applied in a quantitative concentration of 4.5X 10⁷The CFU/mL of a paecilomyces lilacinus bacterial solution and the rest of the method and the steps are the same as the example 1, and the results are shown in the following table:

comparative example 2

applied in a quantitative concentration of 4.5X 10⁷CFU/mL of a bacterial solution of Pseudoarthrobacter oxydans, the rest of the procedure and procedure were the same as in example 1, and the results are shown in the following table:

comparative example 3

applied in a quantitative concentration of 4.5X 10⁷CFU/mL of a bacterial solution of Pseudomonas aeruginosa, the other methods and procedures were the same as in example 1, and the results are shown in the following table:

comparative example 4

applied in a quantitative concentration of 4.5X 10⁷The procedure of example 1 was followed to prepare a microbial preparation containing CFU/mL of a mixture of Paecilomyces lilacinus and Pseudomonas aeruginosa in a volume ratio of 7:3, and the results are shown in the following table:

comparative example 5

applying effective microbial inoculum with the number concentration of 4.5 multiplied by 10⁷A microbial agent prepared by mixing CFU/mL paecilomyces lilacinus and pseudomonas oxydans according to the volume ratio of 7: 3; the procedure and procedure were the same as in example 1, and the results are shown in the following table:

comparative example 6

applying effective microbial inoculum with the number concentration of 4.5 multiplied by 10⁷A microbial agent prepared by mixing CFU/mL pseudomonas aeruginosa and pseudomonas aeruginosa according to the volume ratio of 3: 3; the procedure and procedure were the same as in example 1, and the results are shown in the following table:

comparative example 7

adding waste rocks with the particle size of 0.5-1.5 cm into iron tailing sand soil according to the weight percentage of 5%, and performing the same steps as the example 1 by the rest method, wherein the results are shown in the following table:

comparative example 8

adding waste rocks with the particle size of 0.5-1.5 cm into iron tailing sand soil according to the weight percentage of 40%, and performing the same steps as the example 1 by the rest method, wherein the results are shown in the following table:

comparative example 9

according to 2g/m²The microbial inoculum was applied and the procedure was the same as in example 1, with the results shown in the following table:

comparative example 10

according to 30g/m²The microbial inoculum was applied and the procedure was the same as in example 1, with the results shown in the following table:

comparative example 11

the number concentration is 5 × 10⁶The other method and the steps are the same as the example 1, and the results are shown in the following table:

comparative example 12

the number concentration of the effective microbial inoculum is 1.1 multiplied by 10⁸CFU/mL microbial inoculum prepared by mixing Paecilomyces lilacinus, Arthrobacter oxydans and Pseudomonas aeruginosa in a volume ratio of 7:3:3, and the rest of the method and procedure are the same as in example 1, and the results are shown in the following table:

comparative example 13

the planting of nightshade is changed into the planting of hot pepper, and the rest of the method and the steps are the same as the example 1, and the results are shown in the following table:

and (3) assigning a standard according to soil physicochemical properties, wherein when the water content reaches 15-20%, the soil porosity is 50-65%, and when the soil organic matter is 5-15 g/kg, the soil ecological environment is suitable for the growth of plants and organisms.

The test data results of the examples 1 to 9 show that the iron tailing sandy soil after 3 months of restoration has the water content of 15.66 to 17.44%, the porosity of 48.23 to 65.42%, the organic matter of the soil of 6.93 to 7.49%, the POD of the plant of 30.08 to 47.04 and the SOD of the plant of 374.45 to 452.97. The physical and chemical properties of the soil are better, the pH is reduced, the porosity and the water content are in a range suitable for the growth of plants, and the organic matter content is higher; meanwhile, the stress resistance of the plant is improved and the growth condition of the plant is better. However, the soil of the comparative examples 1 to 13 has poor physicochemical properties, poor nutrients, poor stress resistance of plants, and poor plant height, emergence rate and plant growth vigor.

The results of the example 1 and the comparative examples 1 to 6 show that the improvement effect of the mixture of the three bactericides on the soil is obviously better than the improvement effect of one or two bactericides. The common application of the paecilomyces lilacinus, the pseudomonas aeruginosa and the pseudomonas aeruginosa enables the three bactericides to jointly exert a synergistic effect.

The data results of examples 1-3 and comparative examples 7 and 8 show that the optimal proportion of the waste rocks is 10% -30%, when the addition amount of the waste rocks is less than 10%, the tailings are small in particle size, large in density, poor in air permeability of a system, and the soil is cohesive, so that the soil is not beneficial to plant rooting soil. When the content of the waste rocks is more than 30 percent, the particle size of the waste rocks is large, so that more water is lost, the soil texture is loose, and the plants are unstable in rooting.

As shown by the data of examples 1, 4 and 5 and comparative examples 9 and 10, the optimal range of spreading the microbial inoculum is 10-20 g/m²In comparative example 9, the amount of the microbial inoculum applied was only 2g/m²The content is too low, and the effect is difficult to exert; in comparative example 10, the amount of the microbial inoculum applied was 30g/m²If the content is too high, the microorganisms compete with the plants for nutrients, so that antagonism is generated and the growth of the plants is influenced.

Examples 1,6. 7 and comparative examples 11 and 12, it can be seen that the optimal range of microbial agents is 1X 10⁷～9×10⁷CFU/mL. The content of the microbial inoculum in comparative example 11 is only 5X 10⁶CFU/mL, the content is too low, which is not beneficial to the exertion of the effect of the microbial inoculum. In contrast, in comparative example 12, the microbial agent content was 1.1X 10⁸CFU/mL, the content is higher, which may lead to the situation that the concentration of the microbial inoculum is saturated, and the improvement effect on the soil is not obviously increased, and on the other hand, the higher concentration of the microbial inoculum also increases the cost, and the cost of the soil improvement is increased.

It can be seen from examples 1, 8 and 9 that mycorrhiza infection rates of three plants are within 28.14% -37.54%, which indicates that a symbiotic relationship is established between microorganisms and plants, and the plant-mycorrhiza synergistic effect can be seen through physicochemical property index data of soil and plants, so that physicochemical properties of iron tailing sandy soil can be better improved. In contrast, in the comparative example 13, when the planted nightshade, boswellia rosea and festuca arundinacea are changed into hot pepper, the mycorrhiza infection rate is very low and is only 1.37% -2.98%, and the physicochemical properties of soil and plants are poorer than those of examples 1, 8 and 9, which shows that the microorganisms used in the invention are difficult to establish symbiotic relationship with other plants, so that the microorganisms cannot play a role in synergy.

In addition, the method has obvious effect within three months, and can effectively shorten the treatment period of the tailings sand.

Claims

1. A method for repairing iron tailing sand by using a microbial agent and waste rocks is characterized by comprising the following steps:

(3) planting herbaceous plants, and performing field management;

wherein the microbial agents are respectivelyThe number concentration of the effective bacteria after activation, propagation and dilution is as follows: 1X 10⁷～9×10⁷CFU/mL, and according to the volume ratio: mixing bacterial liquids of the paecilomyces lilacinus with the preservation number of CGMCC No.60794, the pseudomonas aeruginosa with the preservation number of ATCC14358 and the pseudomonas aeruginosa with the preservation number of ATCC9027 in a ratio of 6-8: 2-4; the soil dressing is natural soil or farmland planting soil; the organic fertilizer is one or more of fermented bean sauce, straw, chicken manure and cattle and sheep manure.

2. The method for repairing iron tailing sand soil by using the microbial agent and the waste rocks as claimed in claim 1, wherein the microbial agent: the paecilomyces lilacinus has a preservation number of CGMCC No.60794, the pseudomonas aeruginosa has a preservation number of ATCC14358 and the pseudomonas aeruginosa has a preservation number of ATCC9027, and the mixture is mixed according to the volume ratio of 7-8: 3-4.

3. The method for repairing iron tailing sand soil by using microbial agent and waste stone as claimed in claim 1, wherein the herbaceous plant is one or more of black nightshade herb, cosmos and festuca arundinacea, and the planting density is 20-25 plants/m²。

4. The method for repairing the iron tailing sandy soil by using the microbial agent and the waste rocks as claimed in claim 1, wherein the alien soil is farmland planting soil covering 2.0-3.0 cm; the organic fertilizer is chicken manure, and the application amount is as follows: 0.25 to 0.4kg/m²。

5. The method for repairing iron tailing sand soil by utilizing the microbial agent and the waste stones as claimed in claim 1, wherein the preparation method of the bacterial solution of the paecilomyces lilacinus, the pseudomonas aeruginosa and the pseudomonas aeruginosa in the microbial agent comprises the following steps:

(1) under the aseptic condition, inoculating the first-stage seeds of the strain by adopting an activated culture medium, and inoculating the first-stage seeds of the strain at the temperature of 23-27 ℃ for 180-230 r.min^-1Culturing for 7-10 days on a shaking table to obtain second-stage seeds of the strains;

(2) will aliveThe strain after transformation adopts an expansion culture medium at the temperature of 30-32 ℃ and the temperature of 180-230 r.min^-1Culturing for 5-8 days on a shaking table, and performing propagation;