CN110420995A - A kind of method of cadmium pollution soil repair - Google Patents

Abstract

The invention discloses a method for repairing cadmium-contaminated soil, and belongs to the technical field of repairing soil heavy metal pollution. The method for repairing cadmium-contaminated soil includes the following steps: step 1: sow the cadmium seeds in the cadmium-contaminated soil, and perform routine management; step 2: in the fifth month after sowing the cadmium seeds, inject Evenly spread ammonium chloride and citric acid, and at the same time inject Bacillus megaterium bacterium liquid into the rhizosphere soil of each plant of Pleurotus chinensis; Step 3: Harvest the roots, stems and leaves of Pleurotus chinensis in the 6th month after sowing the seeds , to get the repaired soil. In the present invention, green twigs are used as cadmium hyperaccumulation plants, ammonium chloride is used to improve the cadmium enrichment of green twigs, citric acid is used to improve the efficiency of repairing green tweezers, and bacillus megaterium bacterium liquid is used as an inoculant. The synergistic effect of Cedarwort, ammonium chloride, citric acid and Bacillus megaterium greatly improved the remediation efficiency of Cedarium to cadmium-contaminated farmland soil.

Description

A method for remediating cadmium-contaminated soil

technical field

The invention relates to a method for repairing cadmium-contaminated soil, and belongs to the technical field of repairing soil heavy metal pollution.

Background technique

Cadmium (Cd) is one of the most prevalent pollutants in soil. According to the "National Soil Pollution Survey Bulletin" released in 2014, the excessive rate of soil cadmium sites in my country is the highest among all heavy metal pollutants. Compared with other heavy metal elements, cadmium has higher mobility and bioavailability, and is easy to threaten human health through the food chain, so this element is also considered to be one of the most harmful pollutants in soil. In the "Soil Pollution Prevention and Control Action Plan" (Soil Ten Articles) issued by the State Council on May 28, 2016, cadmium is also included as a key prevention and control target. It can be seen that the control and remediation of soil cadmium pollution has become a major strategic demand in my country.

Phytoremediation has the advantages of cost-effectiveness, environmental friendliness, and easy operation, and is considered to be one of the most potential methods for remediating heavy metal-contaminated soils. As the core carrier of phytoremediation, the related research on hyperaccumulative plants has become a research hotspot at home and abroad for more than 20 years. Plant strengthening measures in the prior art include: (1) changing the traits of plants fundamentally through transgenic technology; (2) increasing the availability of heavy metals in the soil by adding activators to the soil; (3) increasing the biomass of plants through agronomic measures . These methods have certain limitations, such as the legality of transgenic technology and the risk of heavy metal leaching increased by activators. In addition, most of the cadmium-enriched plants found so far have weak reproductive ability, slow growth, and small aboveground biomass, which are limited in practical application; in addition, most of the heavy metals in the soil are bound to solid phases and are difficult to be absorbed and utilized by restoration plants. state, resulting in low repair efficiency and longer repair time.

Plant-microbe combined remediation technology, as an emerging phytoremediation enhancement measure in recent years, has the advantages of good effect, low cost, and no secondary pollution, and has become a research hotspot at home and abroad. However, the inoculation of strains may not necessarily improve the heavy metal accumulation capacity of all plants, and the strengthening methods and specific conditions will also affect each other, which will have a huge impact on the final strengthening effect. In addition, the current research on the effect of microorganisms on phytoremediation is mostly pot experiments in the laboratory, and the experimental results are often quite different from the results of field remediation, which is difficult to guide the practice of field remediation.

In view of this, it is necessary to study a new method for remediating cadmium-contaminated farmland soil to solve the deficiencies of existing technologies.

Contents of the invention

The purpose of the invention is to overcome the deficiencies of the prior art and provide a method for remediating cadmium-contaminated soil. In the method for repairing cadmium-contaminated soil of the present invention, the method for repairing cadmium-contaminated soil uses Pseudomonas as cadmium super-accumulating plants, uses ammonium chloride to improve the enrichment of cadmium by Pseudomonas, uses citric acid to improve the efficiency of Pseudomonas remediation, and uses Bacillus megaterium bacterium liquid as inoculation agent, through the Bacillus megaterium to promote the growth of scorpion, improve its ability to absorb cadmium in the soil. The synergistic effect of Cedarwort, ammonium chloride, citric acid and Bacillus megaterium greatly improved the remediation efficiency of Cedarium to cadmium-contaminated farmland soil.

The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a method for remediating cadmium-contaminated soil comprises the steps:

Step 1: in cadmium-contaminated soil, sow the seeds of the sage, carry out routine management, and thin the seedlings when the sage grows to 6cm-7cm;

Step 2: In the 5th month of step 1 sowing the seeds of Paleopsis japonica, evenly sprinkle ammonium chloride and citric acid in the cadmium-contaminated soil of step 1, so that the concentration of ammonium chloride in the cadmium-contaminated soil is 180mg/kg-200mg /kg, the concentration of citric acid is 4mmol/kg-6mmol/kg, injects the Bacillus megaterium bacterium liquid of 15mL-25mL to the rhizosphere soil of every plant green jasmine simultaneously;

Step 3: Harvest the roots, stems and leaves of Lily chinensis in the 6th month after sowing the seeds of Lily chinensis in step 1, and obtain the repaired soil.

Principle of the present invention:

Lemongrass is an annual herbaceous plant of the family Amaranthaceae. It has the characteristics of high seed production, sun-loving and drought-tolerant, and easy artificial planting. It is a hyper-accumulator of heavy metals manganese and cadmium.

Bacillus megaterium (Bacillus megaterium) belongs to the genus Bacillus (Bacillus), is a Gram-positive bacterium, can form spores, and its spores have strong radiation resistance, can grow on glucose and ammonium salt medium, and are aerobic. widely distributed. Studies in recent years have shown that Bacillus megaterium is an excellent strain with multiple functions, safety, high efficiency, no residue, and no side effects. It has been widely used in the production of bio-organic fertilizers, the production of phosphorus bacterial fertilizers, pesticide degradation, antibiotic synthesis and Enzyme industry, etc. However, there is no report on the combination of Bacillus megaterium, ammonium chloride, citric acid, and celery for remediation of cadmium pollution.

Ammonium chloride is a kind of physiologically acidic ammonium nitrogen fertilizer, which can effectively increase the biomass of fennel, without reducing the cadmium content in licorice, and then increase the enrichment of cadmium in licorice.

Citric acid is a natural chelating agent, which can change the form of cadmium and promote its release, thereby improving the absorption and enrichment of cadmium in the soil. In the present invention, the addition of citric acid can effectively improve the efficiency of remediation of cadmium-contaminated soil.

In the method for repairing cadmium-contaminated soil of the present invention, the method for repairing cadmium-contaminated soil uses Pseudomonas as cadmium super-accumulating plants, uses ammonium chloride to improve the enrichment of cadmium by Pseudomonas, uses citric acid to improve the efficiency of Pseudomonas remediation, and uses Bacillus megaterium bacterium liquid as inoculation agent, through the Bacillus megaterium to promote the growth of scorpion, improve its ability to absorb cadmium in the soil. The synergistic effect of Cedarwort, ammonium chloride, citric acid and Bacillus megaterium greatly improved the remediation efficiency of Cedarium to cadmium-contaminated farmland soil. Moreover, the inventors of the present application have found through many experiments that in the fifth month after sowing the seeds of the cadmium in step 1, that is, in the first month before the harvest of the licorice in the step 3, intensive measures are carried out to restore the effect of cadmium-contaminated soil is better.

In step 2, to make the concentration of ammonium chloride in the cadmium-contaminated soil be 180mg/kg-200mg/kg, the specific calculation method is: first calculate the volume of the plow layer cadmium-contaminated soil to be treated, then multiply by the soil density, Get the soil quality. Multiply the concentration of ammonium chloride by the soil mass to obtain the amount of ammonium chloride that needs to be spread. Similarly, the amount of citric acid that needs to be sprinkled is also calculated by the above method.

Compared with the strengthening means such as chemical methods and agronomic measures in the prior art, the method for remediating cadmium-contaminated soil of the present invention has obvious cadmium remediation effect, stable, continuous and long-term remediation cycle, no secondary pollution, small amount of manual labor, Low cost and other advantages, has broad application prospects and market space.

In the prior art, pot experiments or hydroponic experiments are used to study the absorption of heavy metals by plants. The cycle is generally 2-3 months, the time is short, and the experimental effect needs to be studied. And the present invention is different with it, has passed the verification of the field experiment of up to 6 months, has practical application value more.

On the basis of the above technical solutions, the present invention can also be improved as follows.

Further, in step 1, the total cadmium content in the cadmium-contaminated soil is 3.5 mg/kg-4 mg/kg.

Further, in step 1, the sage seeds are first sterilized with 70wt% ethanol for 1 min, then the sterilized sage seeds and sand are mixed in a mass ratio of 1:1, the sowing method is drill, the row spacing is 30cm, and the plant spacing is 30cm -50cm, sow in ditches, and then cover with soil 0.5cm-1cm.

Furthermore, the seeds of C. chinensis were collected from Shangdengyuan Village, Dabu Township, Yanshan District, Guilin City, Guangxi.

Further, in step 2, the Bacillus megaterium bacterium liquid is to take Bacillus megaterium, the inoculum size is 2%, inoculated in potato glucose liquid medium, at 25°C-30°C, the speed is 150r/min-200r/min It is obtained by shaking and culturing for 36h-60h under the condition of 1 min, and the effective number of viable bacteria of the Bacillus megaterium is ≥10 ⁸ cfu/mL.

The further beneficial effect of adopting the above is that after the Bacillus megaterium strain is activated and expanded, the fermented liquid is obtained, and then added to the cadmium-contaminated soil, which is more conducive to the degradation of the cadmium pollutant by the strain.

Furthermore, the Bacillus megaterium was purchased from the China Center for Type Culture Collection, its strain preservation number is CCTCC AB 207465, and its preservation date is June 15, 2007.

Furthermore, the potato dextrose liquid medium is obtained by taking 200g of potatoes, 20g of glucose and 1000mL of distilled water, and sterilizing at 121°C and 2.4×10 ⁵ Pa for 20 minutes.

Further, in step 2, the ammonium chloride is purchased from Xilong Science Co., Ltd., analytically pure, 500g/bottle, and the mass percentage of ammonium chloride is ≥99.5%.

Further, in step 2, the citric acid is purchased from Xilong Science Co., Ltd., analytically pure, 500g/bottle, and the mass percentage of citric acid is ≥99.5%.

Further, in step 3, the total cadmium content in the repaired soil is 3.0 mg/kg-3.3 mg/kg.

Beneficial effects of the present invention:

(1) The method for remediating cadmium-contaminated soil of the present invention uses Pseudomonas cadmium as a cadmium hyperaccumulation plant, improves the enrichment of Pseudomonas cadmium with ammonium chloride, improves the efficiency of Pseudomonas remediation with citric acid, and uses Bacillus megaterium bacterium The liquid is used as an inoculant to promote the growth of Pseudomonas spp. through Bacillus megaterium and improve its ability to absorb cadmium in the soil. The synergistic effect of Cedarwort, ammonium chloride, citric acid and Bacillus megaterium greatly improved the remediation efficiency of Cedarium to cadmium-contaminated farmland soil.

(2) Compared with the strengthening means such as chemical methods and agronomic measures of the prior art, the method for remediating cadmium-contaminated soil of the present invention has obvious cadmium remediation effect, stable remediation cycle, continuous, long-term, no secondary pollution, and artificial labor It has the advantages of small quantity and low cost, and has broad application prospects and market space.

Detailed ways

The principles and features of the present invention will be described below in conjunction with specific embodiments, and the examples given are only used to explain the present invention, and are not intended to limit the scope of the present invention.

Example 1

The method for repairing cadmium-contaminated soil of the present embodiment may further comprise the steps:

Step 1: sow the seeds of Lily chinensis in the cadmium-contaminated soil with a total cadmium content of 3.52 mg/kg. The seeds of Cedarweed were collected in Shangdengyuan Village, Dabu Township, Yanshan District, Guilin City, Guangxi. First, sterilize the seeds with 70wt% ethanol for 1 min, then mix the sterilized seeds and sand at a mass ratio of 1:1, sow in drill, with a row spacing of 30 cm and a plant spacing of 30 cm, sow in ditches, and then cover with soil 0.5 cm. cm. Routine management is carried out, and the seedlings are thinned out when the green squid grows to 6 cm.

Step 2: In the 5th month of step 1 sowing the quince seeds, evenly spread ammonium chloride and citric acid in the cadmium-contaminated soil of step 1, so that the concentration of ammonium chloride in the cadmium-contaminated soil is 180mg/kg, lemon The concentration of the acid was 4mmol/kg, and at the same time, 15mL of Bacillus megaterium bacterium liquid was injected into the rhizosphere soil of each Phalaenopsis japonica. The Bacillus megaterium bacteria liquid is obtained by inoculating Bacillus megaterium in a potato dextrose liquid medium at an inoculum size of 2%, and vibrating for 60 hours at 25°C with a rotational speed of 150r/min. The effective viable count of the Bacillus megaterium is 10 ⁸ cfu/mL. Bacillus megaterium was purchased from China Center for Type Culture Collection, its strain preservation number is CCTCC AB 207465, and its preservation date is June 15, 2007. The potato dextrose liquid culture medium is obtained by taking 200g of potatoes, 20g of glucose and 1000mL of distilled water, and sterilizing at 121°C and 2.4×10 ⁵ Pa for 20 minutes. The ammonium chloride is purchased from Xilong Science Co., Ltd., analytically pure, 500g/bottle, and the mass percentage of ammonium chloride is ≥99.5%. The citric acid is purchased from Xilong Science Co., Ltd., analytically pure, 500g/bottle, and the mass percentage of citric acid is ≥99.5%.

Step 3: In the 6th month after sowing the seeds of C. chinensis in step 1, harvest the roots, stems and leaves of C. chinensis, and obtain the repaired soil with a total cadmium content of 3.05 mg/kg, and the removal rate of cadmium in the soil is 13.35%.

Example 2

The method for repairing cadmium-contaminated soil of the present embodiment may further comprise the steps:

Step 1: Sow the seeds of Lily chinensis in the cadmium-contaminated soil with a total cadmium content of 3.68 mg/kg. The seeds of Cedarweed were collected in Shangdengyuan Village, Dabu Township, Yanshan District, Guilin City, Guangxi. First, sterilize the seeds with 70wt% ethanol for 1min, and then mix the sterilized seeds and sand at a mass ratio of 1:1. cm. Routine management is carried out, and the seedlings are thinned out when the green squid grows to 6.5 cm.

Step 2: in the 5th month of step 1 sowing the quince seeds, evenly spread ammonium chloride and citric acid in the cadmium-contaminated soil of step 1, so that the concentration of ammonium chloride in the cadmium-contaminated soil is 190mg/kg, lemon The concentration of the acid was 5 mmol/kg, and at the same time, 20 mL of Bacillus megaterium bacterium liquid was injected into the rhizosphere soil of each Phalaenopsis japonica. The Bacillus megaterium bacteria liquid is obtained by inoculating Bacillus megaterium in a potato dextrose liquid medium at an inoculum size of 2%, and vibrating for 48 hours at 28°C with a rotational speed of 170r/min. The effective viable count of the Bacillus megaterium is 10 ⁹ cfu/mL. Bacillus megaterium was purchased from China Center for Type Culture Collection, its strain preservation number is CCTCC AB 207465, and its preservation date is June 15, 2007. The potato dextrose liquid culture medium is obtained by taking 200g of potatoes, 20g of glucose and 1000mL of distilled water, and sterilizing at 121°C and 2.4×10 ⁵ Pa for 20 minutes. The ammonium chloride is purchased from Xilong Science Co., Ltd., analytically pure, 500g/bottle, and the mass percentage of ammonium chloride is ≥99.5%. The citric acid is purchased from Xilong Science Co., Ltd., analytically pure, 500g/bottle, and the mass percentage of citric acid is ≥99.5%.

Step 3: In the 6th month after sowing the seeds of C. chinensis in step 1, the roots, stems and leaves of C. chinensis were harvested, and the repaired soil with a total cadmium content of 3.18 mg/kg was obtained, and the soil cadmium removal rate was 13.59%.

Example 3

The method for repairing cadmium-contaminated soil of the present embodiment may further comprise the steps:

Step 1: Sow the seeds of Lily chinensis in the cadmium-contaminated soil with a total cadmium content of 3.72 mg/kg. The seeds of Cedarweed were collected in Shangdengyuan Village, Dabu Township, Yanshan District, Guilin City, Guangxi. First, sterilize the seeds with 70wt% ethanol for 1 min, then mix the sterilized seeds and sand at a mass ratio of 1:1, sow in drill, with a row spacing of 30cm and a plant spacing of 50cm, sow in ditches, and then cover with soil 1cm . Routine management is carried out, and the seedlings are thinned out when the green squid grows to 7 cm.

Step 2: In the 5th month of step 1 sowing the quince seeds, evenly sprinkle ammonium chloride and citric acid in the cadmium-contaminated soil of step 1, so that the concentration of ammonium chloride in the cadmium-contaminated soil is 200mg/kg, lemon The concentration of the acid was 6mmol/kg, and at the same time, 25mL of Bacillus megaterium bacterium liquid was injected into the rhizosphere soil of each Phalaenopsis japonica. The Bacillus megaterium bacteria solution is obtained by inoculating Bacillus megaterium in a potato dextrose liquid medium at an inoculum size of 2%, and vibrating for 36 hours at 30°C with a rotational speed of 200r/min. The effective viable count of the Bacillus megaterium is 10 ¹⁰ cfu/mL. Bacillus megaterium was purchased from China Center for Type Culture Collection, its strain preservation number is CCTCC AB 207465, and its preservation date is June 15, 2007. The potato dextrose liquid culture medium is obtained by taking 200g of potatoes, 20g of glucose and 1000mL of distilled water, and sterilizing at 121°C and 2.4×10 ⁵ Pa for 20 minutes. The ammonium chloride is purchased from Xilong Science Co., Ltd., analytically pure, 500g/bottle, and the mass percentage of ammonium chloride is ≥99.5%. The citric acid is purchased from Xilong Science Co., Ltd., analytically pure, 500g/bottle, and the mass percentage of citric acid is ≥99.5%.

Step 3: In the 6th month after sowing the seeds of C. chinensis in step 1, harvest the roots, stems and leaves of C. chinensis, and obtain the repaired soil with a total cadmium content of 3.25 mg/kg, and the removal rate of cadmium in the soil is 12.63%.

Experimental example

The experimental farmland is located in Sidi Village, Yangshuo County, Guilin City, 110°13′-110°40′ east longitude, 24°38′-25°04′ north latitude, where cadmium pollution is caused by the mining of lead-zinc mines in the upper reaches of the area. The physical and chemical properties of the soil in the test farmland are: pH 6.00, organic matter content 0.7%, ammonium nitrogen content 15.2 mg kg ^-1 , available phosphorus content 51.4 mg kg ^-1 , available potassium content 225.8 mg kg ^-1 , total The cadmium content is 3.58 mgkg ^-1 .

In the experimental farmland, 15 experimental plots were separated, each with an area of 2m×4m, and the interval between the plots was 0.5m. Among them, 3 plots were the control group of "Qingli" and 3 plots were "Qingli plus Bacillus megaterium". "Test group; 3 plots are the test group of "green squid plus ammonium chloride"; 3 plots are the test group of "green squid plus citric acid"; Acid" test group.

In the cadmium-contaminated soil, sow the seeds of the sage, carry out routine management, and thin the seedlings when the sage grows to 6cm-7cm;

In the 5th month of sowing the seeds of C. chinensis, inject 20 mL of deionized water into the rhizosphere soil of each plant of C. spp. Inject 20mL of Bacillus megaterium bacterium liquid into the rhizosphere soil of Pseudomonas chinensis; in the test group of "Pseudomonas plus ammonium chloride", add ammonium chloride to the soil so that the concentration of ammonium chloride in the soil is 200mg/kg, and at the same time Inject 20mL of Bacillus megaterium bacterium liquid into the rhizosphere soil of each plant of Pseudomonas chinensis; in the "Pseudomonas plus citric acid" test group, add citric acid to the soil so that the concentration of citric acid in the soil is 5mmol/kg, and at the same time add citric acid to the soil Inject 20mL of Bacillus megaterium bacterium liquid into the rhizosphere soil of each plant of Pleurotus spp.; in the test group of "Pseudomonas plus Bacillus megaterium plus ammonium chloride plus citric acid", add ammonium chloride and citric acid to the soil to make the soil The concentration of ammonium chloride is 200mg/kg, and the concentration of citric acid is 5mmol/kg, simultaneously injects 20mL of Bacillus megaterium bacterium liquid to the rhizosphere soil of each plant of Paleopsis chinensis;

In the 6th month after sowing the seeds of Pleurotus chinensis, the roots, stems and leaves of 15 test plots were harvested, rinsed with deionized water 3-5 times, then killed at 105°C for 30min, dried at 65°C to constant weight, and measured dry weight. The dried samples were ground and passed through a 5mm sieve, digested with HNO ₃ -HClO ₄ , and the cadmium content was determined with an atomic absorption spectrometer (PE-AA700). At the same time, the soil of 15 test plots was taken to measure the cadmium content.

Data processing and analysis: The experimental data is represented by the arithmetic mean ± standard deviation (SD) of three repeated samples. Statistical analysis was performed by one-way analysis of variance (ANOVA) in SPSS19.0, and the least significant difference method (LSD) was used for significance test (p<0.05).

In each treatment group, the biomass of S. chinensis is shown in Table 1.

In each treatment group of table 1, the biomass of green squid

In the table, a, b, and c respectively represent the data of the same group are significantly different at the 0.05 level. In each treatment group, the cadmium enrichment of C. chinensis is shown in Table 2.

Table 2 In each treatment, the cadmium enrichment situation of Qinglong

In the table, a, b, and c respectively represent the data of the same group are significantly different at the 0.05 level.

In each treatment group, the cadmium content in the soil before and after remediation is shown in Table 3.

In each treatment of table 3, the cadmium content situation in the soil

In the table, a, b, and c respectively represent the data of the same group are significantly different at the 0.05 level.

Thus it can be seen that the present invention is cadmium hyperaccumulation plant with Pseudomonas chinensis, improves the enrichment of cadmium by ammonium chloride, improves the efficiency of Pseudomonas remediation with citric acid, takes Bacillus megaterium bacterial agent as inoculant, through huge Bacillus can promote the growth of Pseudomonas and improve its ability to absorb cadmium in the soil. The synergistic effect of Cedarwort, ammonium chloride, citric acid and Bacillus megaterium greatly improved the remediation efficiency of Cedarium to cadmium-contaminated farmland soil.

The above descriptions are only 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 of the present invention. within range.

Claims (6)

1. a method for remediating cadmium-contaminated soil, is characterized in that, comprises the steps: Step 1: in cadmium-contaminated soil, sow the seeds of the sage, carry out routine management, and thin the seedlings when the sage grows to 6cm-7cm; Step 2: In the 5th month of step 1 sowing the seeds of Paleopsis japonica, evenly sprinkle ammonium chloride and citric acid in the cadmium-contaminated soil of step 1, so that the concentration of ammonium chloride in the cadmium-contaminated soil is 180mg/kg-200mg /kg, the concentration of citric acid is 4mmol/kg-6mmol/kg, injects the Bacillus megaterium bacterium liquid of 15mL-25mL to the rhizosphere soil of every plant green jasmine simultaneously; Step 3: Harvest the roots, stems and leaves of Lily chinensis in the 6th month after sowing the seeds of Lily chinensis in step 1, and obtain the repaired soil. 2. The method for remediating cadmium-contaminated soil according to claim 1, characterized in that, in step 1, the total cadmium content in the cadmium-contaminated soil is 3.5 mg/kg-4 mg/kg. 3. the method for remediating cadmium-contaminated soil according to claim 1, is characterized in that, in step 1, described fennel seeds are sterilized with 70wt% ethanol for 1min, and then the sterilized kelp seeds and sand are mass-ratio 1:1 mixing, the sowing method is drill sowing, the row spacing is 30cm, the plant spacing is 30cm-50cm, sow in ditches, and then cover with soil 0.5cm-1cm. 4. the method for remediating cadmium-contaminated soil according to claim 1, is characterized in that, in step 2, described Bacillus megaterium bacterium liquid is to get Bacillus megaterium, is 2% by inoculum size, is inoculated in potato glucose liquid culture culture medium at 25°C-30°C with a rotating speed of 150r/min-200r/min for 36h-60h, and the effective viable count of the Bacillus megaterium is ≥10 ⁸ cfu/mL. 5. The method for remediating cadmium-contaminated soil according to claim 4, wherein the potato glucose liquid medium is sterilized at 121° C. and 2.4×10 ⁵ Pa with 200 g of potatoes, 20 g of glucose and 1000 mL of distilled water. obtained after 20 minutes. 6. The method for repairing cadmium-contaminated soil according to claim 1, characterized in that in step 3, the total cadmium content in the repaired soil is 3.0 mg/kg-3.3 mg/kg.