Method for in-situ ecological restoration of heavy metal contaminated soil

Abstract

The present invention provides a method for ecologically restoring heavy metal contaminated soil in-situ. 【Solution means】This method includes the following steps: S1, pretreatment: The area to be repaired is shallow plowed, plowed, rotary plowed, and then naturally air-dried. S2, fermentation treatment: The soil is piled up into a conical soil pile, mixed with fermentation bacteria, coarse sand, and charcoal powder, and naturally fermented for 10 to 20 days. S3, plant concentration treatment: Herbaceous plants, trees, and leguminous crops are sequentially planted in the soil to concentrate and purify heavy metals in the soil. S4, fungal concentration treatment: Fungi are planted in the soil to concentrate and purify heavy metals in the soil. S5, disinfection and sterilization treatment. S6, pH adjustment treatment. The restoration method of the present invention can reduce the transfer of heavy metal substances and protect the environment and ecosystem to the greatest extent.

Description

Technical Field

[0001] The present invention relates to the technical field of soil pollution remediation, and specifically to a method for in-situ ecological remediation of heavy metal contaminated soil. to repair.

Background Art

[0002] In the methods for repairing soil heavy metal pollution, commonly used methods such as the topsoil replacement method, application of lime or chelating agents, and chemical leaching method play a certain role in the improvement or repair of contaminated soil, but actually often have some limitations. For example, the process is complex, time-consuming and laborious, costly, the soil structure and fertility are easily damaged, and in the case of low-concentration, wide-range soil heavy metal pollution, the above methods are not suitable for treatment. Soil in-situ remediation is an environmentally friendly and effective soil purification technology that can reduce the risk of secondary pollution and transportation costs without excavating and moving the soil, and directly purifies and remediates the soil at the pollution site. Soil in-situ remediation is important for environmental protection, resource conservation, improvement of purification efficiency, and promotion of sustainable development. Therefore, the present invention provides a method for in-situ ecological remediation of heavy metal contaminated soil.

Summary of the Invention

[0003] The technical solution of the present invention is as follows: A method for in-situ ecological remediation of heavy metal contaminated soil includes the following steps: S1. Pretreatment: First, the heavy metal contaminated soil is shallowly plowed, and the shallow plowing depth is 1.5 - 2.0 m, then plowed up, and the plowing depth is 0.5 - 0.8 m, and the total plowing is carried out 2 - 5 times, then rotary plowing is carried out 2 - 3 times, and finally naturally air-dried for 15 - 30 days to obtain pretreated soil, and the heavy metal is lead, zinc or cadmium. ​​​​Yes, Here, reduced tillage, plowing, and rotary tillage are soil tillage methods commonly used in agricultural production. Reduced tillage means loosening the soil mechanically or manually to improve soil structure and aeration. Plowing means using a plow or other farming tools to scoop up, loosen, and turn over the soil. It is a method of soil tillage, and rotary tillage is a land preparation method using a rotary tiller. The depth of rotary tillage is usually shallow, at 12 - 15 cm. S2. Fermentation treatment: Mix fermenting bacteria, coarse sand, and charcoal powder into the topsoil of the pretreated soil, and stack the topsoil into a conical soil pile. During the process of stacking the conical soil pile, lay a layer of rice straw powder with a thickness of 3 - 5 cm every 20 - 30 cm along the vertical direction of the conical soil pile. Let it ferment naturally for 10 - 20 days to obtain the soil after fermentation treatment. Here, the thickness of the topsoil is 0.5 - 0.8 m, the mixing amount of fermenting bacteria is 10 - 20 g / Kg, the mixing amount of coarse sand is 15 - 30 kg / t, the particle diameter of the coarse sand is 0.5 - 2 mm, the mixing amount of charcoal powder is 5 - 10 kg / t, the bottom diameter of the conical soil pile is 1.5 - 2.0 m, and the height is 0.8 - 1.5 m. S3. Plant concentration treatment: Till the soil after fermentation treatment, with a tillage depth of 0.5 - 0.8 m. Then plant herbaceous plants, and the spacing between the herbaceous plants is 0.1 - 0.5 m. After the herbaceous plants have grown for 2 years, pull out their roots and remove them. Then till the soil again, with a tillage depth of 0.5 - 0.8 m, replant trees, and the spacing between the trees is 1 - 3 m. During the growth period of the trees, simultaneously plant leguminous crops between the trees. The spacing between the leguminous crops is 0.2 - 0.4 m. After the trees have grown for 4 - 6 years, pull out their roots and remove them to obtain the soil after plant concentration treatment. ​ S4, fungal enrichment treatment: The soil after the plant enrichment treatment was tilled to a tillage depth of 0.5 to 0.8 m, and then the fungus was planted. After three years, the plants were uprooted and soil was obtained after fungal enrichment treatment. S5, Disinfection and sterilization: 1~2kg / m 2 After fungal concentration treatment, the soil was sprayed with 95% alcohol solution. Pour the liquid into the container and let the alcohol burn. The alcohol itself has a sterilizing and disinfecting effect, and the alcohol burns. The soil is disinfected and sterilized at a high temperature by using a method according to the present invention to obtain disinfected and sterilized soil. S6, pH adjustment treatment: 1~2kg / m 2 Add wood ash to the soil after disinfection and sterilization at the dosage of The soil is then plowed to a depth of 0.5 to 0.8 m, and the wood ash and soil are thoroughly mixed. Complete the ecological restoration of soil. In one embodiment of the present invention, in S1, the soil is tilled every 2 to 3 days during the natural air drying period. The tillage depth is 0.5 to 0.8 m. In one embodiment of the present invention, in S2, a hole diameter of 2 to 3 cm and a hole depth of 0. A 2m vertical ventilation hole was opened, and water was supplied to the cone-shaped soil pile by mist sprinkling. The soil moisture content of the top 10-20 cm of the conical soil pile is maintained at 60-65 wt% at night. During this period, the cone-shaped soil pile is covered with an insulating plastic film. In one embodiment of the present invention, in S2, the fermentation bacteria is Bacillus coagulans, Bacillus subtilis, Bacteria, Bacillus clausii, Bacillus indigotica, Bacillus licheniformis Enterococcus faecalis, or Clostridium butyricum. It is selected. In one embodiment of the present invention, in S3, the herbaceous plant is a first herbaceous plant, a second herbaceous plant, a third herbaceous plant, including 3 herbaceous plants, and the plant ratio of the first herbaceous plant, the second herbaceous plant, and the third herbaceous plant is 1:1: 1, and the first herbaceous plant, the second herbaceous plant, and the third herbaceous plant are evenly mixed and planted, the first herbaceous plant is selected from any one of Teffrosia candida, Small-flowered Anemone, Bidens maximowicziana, Oxalis corniculata, Vetiver, Green Wild Amaranthus, Bidens maximowicziana, Oxalis corniculata, Purple Knotweed, Ayer's Wife, Conical Mustard, Red Scaly Knotweed, and is selected from any one of them, the second herbaceous plant is selected from any one of Indian Mustard, Rue, Turnip, Southern Sassafras, and Birakomisohagi and is selected from any one of them, the third herbaceous plant is selected from any one of Poinsettia cordifolia, Lesser Flowered Lobelia, Fritillaria, Merchantrand, Lobelia, Bulbous Nasturtium, Purple Jasmine, Crocus, and Bidens pilosa. Here, the first herbaceous plant is mainly used to concentrate lead, the second herbaceous plant is mainly used to concentrate zinc, and the third herbaceous plant is mainly used to concentrate cadmium. As one aspect of the present invention, in S3, the tree is selected from any one or more of poplar trees, pear trees, Longjing tea trees, or acacia trees, and the leguminous crops are selected from any one or more of white lupin, chickpeas, black beans, peanuts, and red kidney beans. As one aspect of the present invention, in S4, the fungus includes the first fungus, the second fungus, and the third fungus, and the soil after tillage in S4 is divided into three equal-sized areas according to the area, and they are respectively marked as the first area, the second area, and the third area, first, plant the first fungus in the first area, plant the second fungus in the second area, and plant the third fungus in the third area. Plant the fungi, and after one year, extract the roots completely. Next, replant the second fungus in the first area, replant the third fungus in the second area, and replant the first fungus in the third area. After one year, extract the roots completely. Next, replant the third fungus in the first area, replant the first fungus in the second area, and replant the second fungus in the third area. After one year, extract the roots completely. The first fungus is selected from any one of *Pleurotus pulmonarius*, *Agaricus bisporus*, *Agaricus blazei*, and *Amanita phalloides*. The second fungus is selected from any one of *Auricularia auricula*, *Lentinus edodes*, *Agaricus campestris*, and *Dictyophora indusiata*. The third fungus is selected from any one of *Flammulina velutipes*, *Collybia radicata*, *Bryophyllum pinnatum*, *Tricholoma giganteum*, and *Macrolepiota procera*. Here, the first fungus is mainly used to concentrate lead, the second fungus is mainly used to concentrate zinc, and the third fungus is mainly used to concentrate cadmium.

Advantages of the Invention

[0004] Compared with the prior art, the present invention has the following beneficial effects. 1. The ecological restoration method of the present invention has environmental sustainability. Through the restoration of this restoration method, the movement and discharge of substances can be reduced, the integrity of the environment and the ecosystem can be maximally protected, and sustainable environmental restoration can be realized. 2. The ecological restoration method of the present invention is low-cost and high-efficiency. Compared with traditional off-site soil restoration methods, this restoration method utilizes the restoration ability of the natural ecosystem, does not require large-scale soil excavation and replacement, and reduces the consumption of human, material and financial resources. 3. The ecological restoration method of the present invention can better protect the soil structure, reduce the damage to the soil structure, and improve the ecological environment of the soil, thereby improving the soil microorganisms. ​​​It can promote growth and activity, improve the self - repair ability of the soil, and contribute to the maintenance of soil fertility and sustainable use. 4. The ecological restoration method of the present invention has multiple functions. It can not only repair the heavy metal pollution problem of the soil but also provide other additional ecological services. For example, by planting plants and trees, it can improve the water - holding capacity and wind - erosion resistance of the soil, and reduce the occurrence of soil erosion and sandstorms . 5. The ecological restoration method of the present invention is characterized by high feasibility. The restoration method is relatively simple, the implementation process can be widely applied, and it is possible to simultaneously repair many types of heavy metal pollution such as lead, zinc, and cadmium.

Embodiments for Carrying out the Invention

[0005] Example 1: A method for in - situ ecological restoration of heavy - metal - contaminated soil includes the following steps : S1. Pretreatment: First, the soil co - contaminated with lead, zinc, and cadmium is shallow - plowed, and the shallow - plowing depth is 1.8 m. Then it is plowed, and the plowing depth is 0.6 m. After plowing three times, it is rotary - plowed three times. Finally, it is air - dried naturally for 25 days. During the natural air - drying period, the soil is plowed every three days, and the plowing depth is 0.6 m. Thus, the pretreated soil is obtained. S2. Fermentation treatment: Fermentation bacteria, coarse sand, and charcoal powder are mixed into the surface soil of the pretreated soil. The fermentation bacteria are commercially available Bacillus coagulans, and the charcoal powder is a commercial product. The surface soil is piled up into a conical soil pile. During the process of piling up the conical soil pile, a layer of straw powder with a thickness of 4 cm is laid every 25 cm along the vertical direction of the conical soil pile, and it is fermented naturally for 15 days to obtain the soil after fermentation treatment. Vertical ventilation holes with a pore diameter of 3 cm and a pore depth of 0.2 m are opened on the conical soil pile, and the mist spraying method is used to supply moisture to the conical soil pile, and the water content of the soil in the surface layer of 15 cm of the conical soil pile is maintained at 62 wt%, and during the night period, the conical soil pile is covered with a plastic film for heat preservation Here, the thickness of the surface soil is 0.6 m, the mixing amount of fermenting bacteria is 15 g / Kg, and the mixing amount of coarse sand is 25 kg / t, the particle diameter of the coarse sand is 1 mm, the mixing amount of charcoal powder is 8 kg / t, the bottom diameter of the conical soil pile is 1.8 m, and the height is 1.2 m Here, S3. Plant concentration treatment: The soil after fermentation treatment is plowed, and the plowing depth is 0.6 m. Then, herbaceous plants are planted, and the interval between the herbaceous plants is 0.3 m. After the herbaceous plants have grown for 2 years, they are uprooted. Here, the herbaceous plants include the first herbaceous plant, the second herbaceous plant, and the third herbaceous plant. The plant ratio of the first herbaceous plant, the second herbaceous plant, and the third herbaceous plant is 1:1:1. The first herbaceous plant, the second herbaceous plant and the third herbaceous plant are evenly mixed and planted. The first herbaceous plant is Teffrosia candida, the second herbaceous plant is Indian mustard and the third herbaceous plant is Poinsettia cordifolia. Then, the soil is plowed again, and the plowing depth is 0.6 m. Poplar trees are replanted, and the interval between the poplar trees is 2 m. During the growth period of the poplar trees, white lupins are planted between the poplar trees at the same time. The interval between the white lupins is 0.3 m. After the poplar trees have grown for 5 years, they are uprooted to obtain the soil after plant concentration treatment. S4. Fungal concentration treatment: The soil after plant concentration treatment is plowed, and the plowing depth is 0.6 m. The plowed soil is according to the area S4. Fungal concentration treatment: The area was divided into three equal areas of 3m x 3m, designated as Area 1, Area 2, and Area 3. Inscribed in the area, First, plant pork belly mushrooms in the first area, wood ear mushrooms in the second area, and shiitake mushrooms in the third area. I planted it, and after a year I uprooted it. Next, replant Kuritake mushrooms in the first area, Naganetake mushrooms in the second area, and Agari mushrooms in the third area. The Cus bisporus was replanted and then uprooted a year later. Next, replant Umbrella mushroom in the first area, Agaricus blazei in the second area, and Agaricus blazei in the third area. The bamboo fungus was replanted inside the plant, and after a year it was uprooted. S5, Disinfection and sterilization: 1.5kg / m 2 After fungal concentration treatment, the soil was sprayed with 95% alcohol solution. Pour the liquid into the container and burn the alcohol. The alcohol itself has a sterilizing and disinfecting effect, and the alcohol combustion is what kills the bacteria. The soil is disinfected and sterilized at a high temperature to obtain disinfected and sterilized soil. S6, pH adjustment treatment: 1.3kg / m 2 Wood ash was added to the soil after disinfection and sterilization at the dosage of The plowing depth was 0.6m, and the wood ash and soil were thoroughly mixed. Complete the revenge. Since 2013, the area of ​​one area of ​​the city has been reduced by 1.7 km2. 2 Heavy metal remediation tests carried out on contaminated land in Before remediation, the contents of lead, zinc and cadmium in the soil of the area were measured, and the results are shown in the table below. 1 Shown in: Table 1. Initial contents of lead, zinc, and cadmium in local soils TIFF0007687556000001.tif27153 After 10 years of remediation, the heavy metal content of the soil in the area was measured and the results are shown in Table 2 below: Table 2. Contents of lead, zinc, and cadmium in soils in the area after remediation TIFF0007687556000002.tif26152 As can be seen from the results in Table 2, after the heavy metal contaminated soil was ecologically repaired in-situ using the method of Example 1 of the present invention, the contents of lead, zinc, and cadmium in the soil of the area decreased significantly. The lead content was 7 mg / kg on average, the zinc content was 13 mg / kg on average, the cadmium content was 0.6 mg / kg on average, and the heavy metal content returned to the normal level of agricultural land. The in-situ ecological restoration method had a lead removal rate reaching 99.27%, a zinc removal rate reaching 98.08%, and a cadmium removal rate reaching 99.45%. Example 2: This example is different from Example 1 in the following points. In S1, the tillage depth was 1.5 m, the plowing depth was 0.5 m, and it was plowed twice and rotary plowed twice. Example 3: This example is different from Example 1 in the following points. In S1, the tillage depth was 2.0 m, the plowing depth was 0.8 m, and it was plowed five times and rotary plowed three times. Example 4: This example is different from Example 1 in the following points. In S1, it was naturally air-dried for 15 days. During the natural air-drying period, the soil was plowed every two days, the plowing depth was 0.8 m, and the pretreated soil was obtained. Example 5: This example is different from Example 1 in the following points. In S1, it was naturally air-dried for 30 days. During the natural air-drying period, the soil was plowed for three days, the plowing depth was 0.5 m, and the pretreated soil was obtained. In order to verify the effects of different pretreatment methods on the in-situ ecological restoration of heavy metal contaminated soil, in the heavy metal restoration test of contaminated land, a large number of contaminated lands with the same lead, zinc, and cadmium contents were set up for the control test. The area of each contaminated land was 1 km Example 2: This example is different from Example 1 in the following points. In S1, the tillage depth was 1.5 m, the plowing depth was 0.5 m, and it was plowed twice and rotary plowed twice. Example 3: This example is different from Example 1 in the following points. In S1, the tillage depth was 2.0 m, the plowing depth was 0.8 m, and it was plowed five times and rotary plowed three times. Example 4: This example is different from Example 1 in the following points. In S1, it was naturally air-dried for 15 days. During the natural air-drying period, the soil was plowed every two days, the plowing depth was 0.8 m, and the pretreated soil was obtained. Example 5: This example is different from Example 1 in the following points. In S1, it was naturally air-dried for 30 days. During the natural air-drying period, the soil was plowed for three days, the plowing depth was 0.5 m, and the pretreated soil was obtained. Example 4: This example is different from Example 1 in the following points. In S1, it was naturally air-dried for 15 days. During the natural air-drying period, the soil was plowed every two days, the plowing depth was 0.8 m, and the pretreated soil was obtained. Example 5: This example is different from Example 1 in the following points. In S1, it was naturally air-dried for 30 days. During the natural air-drying period, the soil was plowed for three days, the plowing depth was 0.5 m, and the pretreated soil was obtained. Example 5: This example is different from Example 1 in the following points. In S1, it was naturally air-dried for 30 days. During the natural air-drying period, the soil was plowed for three days, the plowing depth was 0.5 m, and the pretreated soil was obtained. Example 5: This example is different from Example 1 in the following points. In S1, it was naturally air-dried for 30 days. During the natural air-drying period, the soil was plowed for three days, the plowing depth was 0.5 m, and the pretreated soil was obtained. . In order to verify the effects of different pretreatment methods on the in-situ ecological restoration of heavy metal contaminated soil, in the heavy metal restoration test of contaminated land, a large number of contaminated lands with the same lead, zinc, and cadmium contents were set up for the control test. The area of each contaminated land was 1 km Example 4: This example is different from Example 1 in the following points. In S1, it was naturally air-dried for 15 days. During the natural air-drying period, the soil was plowed every two days, the plowing depth was 0.8 m, and the pretreated soil was obtained. Example 5: This example is different from Example 1 in the following points. In S1, it was naturally air-dried for 30 days. During the natural air-drying period, the soil was plowed for three days, the plowing depth was 0.5 m, and the pretreated soil was obtained. 2 Example 4: This example is different from Example 1 in the following points. In S1, it was naturally air-dried for 15 days. During the natural air-drying period, the soil was plowed every two days, the plowing depth was 0.8 m, and the pretreated soil was obtained. Adjust the content of mu, and maintain the lead, zinc, and cadmium contents at 965 ± 5 mg / kg (lead), 678 ± 5 mg / kg (zinc), and 113 ± 5 mg / kg (cadmium). After 10 years of restoration, measure the heavy metal content of the soil in this area, and the results are shown in Table 3 below: Table 3 Content Table of Lead, Zinc, and Cadmium in the Soil of the Restored Area As can be seen from the results in Table 3, different pretreatment methods have a certain impact on the in-situ ecological restoration effect of heavy metal contaminated soil. Here, the treatment effects of Example 3 and Example 4 are almost the same as that of Example 1 TIFF0007687556000003.tif49154 Also, as can be seen from the results in Table 3, different pretreatment methods have a certain impact on the in-situ ecological restoration effect of heavy metal contaminated soil. Here, the treatment effects of Example 3 and Example 4 are almost the same as that of Example 1 However, for Example 2 and Example 5, the removal rates of lead, zinc, and cadmium are significantly lower than that of Example 1 Therefore, reducing the depth and frequency of reduced tillage, ploughing, and rotary ploughing and increasing the interval time between ploughing will reduce the pretreatment effect Therefore, the treatment effects of Example 3, Example 4, and Example 1 are good. However, considering that Example 3 has more treatment labor for reduced tillage, ploughing, and rotary ploughing, and Example 4 has more treatment labor for ploughing the overall effect of Example 1 is relatively excellent Example 6: This example is different from Example 1 in the following points. In S2, lay a layer of rice straw powder with a thickness of 3 cm every 20 cm along the vertical direction of the conical soil pile Example 7: This example is different from Example 1 in the following points. In S2, lay a layer of rice straw powder with a thickness of 5 cm every 30 cm along the vertical direction of the conical soil pile Example 8: This example is different from Example 1 in the following points. In S2, the natural fermentation time is 1 0 days Example 9: This example is different from Example 1 in the following points. In S2, the natural fermentation time is 2 0 days Example 8: This example is different from Example 1 in the following points. In S2, the natural fermentation time is 1 0 days Example 9: This example is different from Example 1 in the following points. In S2, the natural fermentation time is 2 0 days Example 9: This example is different from Example 1 in the following points. In S2, the natural fermentation time is 2 Example 10: This example is different from Example 1 in the following aspects. The thickness of the topsoil is 0.5 m, the mixing amount of fermenting bacteria is 10 g / Kg, the mixing amount of coarse sand is 15 kg / t, the particle size of the coarse sand is 0.5 mm, the mixing amount of charcoal powder is 5 kg / t, and the bottom diameter of the conical soil pile is 1.5 m and the height is 0.8 m. Example 11: This example is different from Example 1 in the following aspects. The thickness of the topsoil is 0.8 m, the mixing amount of fermenting bacteria is 20 g / Kg, the mixing amount of coarse sand is 30 kg / t, the particle size of the coarse sand is 2 mm, the mixing amount of charcoal powder is 10 kg / t, and the bottom diameter of the conical soil pile is 2.0 m and the height is 1.5 m. Example 12: This example is different from Example 1 in the following aspects. Ventilation holes with a pore diameter of 2 cm and a hole depth of 0.2 m are vertically opened on the conical soil pile, and water is supplied to the conical soil pile by the mist spraying method, and the moisture content of the soil in the top 10 cm of the surface layer of the conical soil pile is maintained at 60 wt%. Example 13: This example is different from Example 1 in the following aspects. Ventilation holes with a pore diameter of 3 cm and a hole depth of 0.2 m are vertically opened on the conical soil pile, and water is supplied to the conical soil pile by the mist spraying method, and the moisture content of the soil in the top 20 cm of the surface layer of the conical soil pile is maintained at 65 wt%. Example 14: This example is different from Example 1 in the following aspect. The fermenting bacteria is Bacillus subtilis. Example 15: This example is different from Example 1 in the following aspect. The fermenting bacteria is Bacillus licheniformis Loomis. To verify the effects of different fermentation treatment methods on the in-situ ecological restoration of heavy metal contaminated soil, during the heavy metal restoration test of contaminated land, a number of contaminated soils with the same lead, zinc, and cadmium contents are set up for the control test. The area of each contaminated land is 1 km and the contents of lead, zinc, and cadmium 2 are Adjust the amount and maintain the lead, zinc, and cadmium contents at 965 ± 5 mg / kg (lead), 678 ± 5 mg / kg (zinc), and 113 ± 5 mg / kg (cadmium). After 10 years of restoration, measure the heavy metal content of the soil in this area, and the results are shown in Table 4 below: Table 4 Lead, Zinc, and Cadmium Content Table of the Restored Regional Soil TIFF0007687556000004.tif72124 As can be seen from the results in Table 4, different fermentation treatment methods have a certain impact on the in-situ ecological restoration of heavy metal-contaminated soil. Here, the treatment effects of Example 7, Example 9, Example 11, Example 12, and Example 13 are almost the same as those of Example 1. The treatment effects of Example 6, Example 8, Example 10, Example 14, and Example 15 show that compared with Example 1, the removal rates of lead, zinc, and cadmium are significantly reduced . From this, it can be seen that in examples such as reducing the amount of rice straw powder used, shortening the fermentation time, reducing the mixing amount of fermentation bacteria, etc., the fermentation treatment effect will decrease . Therefore, the treatment effects of Example 7, Example 9, Example 11, Example 12, and Example 1 are better. However, considering that Example 7 has a large amount of rice straw powder used, Example 9 has a long fermentation time, high environmental temperature requirements, Example 12 has a large amount of hole-making work, and a long mist spraying time , the overall effect of Example 1 is relatively excellent . Example 16: This example is different from Example 1 in the following points. After the fermentation treatment, the soil is plowed, and the plowing depth is 0.5 m. Then, herbaceous plants are planted, and the interval between the herbaceous plants is 0.5 m. After the herbaceous plants have grown for 2 years, they are completely uprooted . Example 17: This example is different from Example 1 in the following points. After the fermentation treatment, the soil is plowed, and the plowing depth is 0.5 m . ​​The starting depth is 0.8 m. Then, herbaceous plants are planted with a spacing of 0.1 m between the herbaceous plants. After the herbaceous plants have grown for two years, they are completely uprooted. Example 18: This example is different from Example 1 in the following points. The first herbaceous plant is *Lysimachia christinae* Hance, the second herbaceous plant is *Ruta graveolens* L., and the third herbaceous plant is *Lobelia erinus* Thunb. . Example 19: This example is different from Example 1 in the following points. The first herbaceous plant is *Sedum makinoi* Maxim., the second herbaceous plant is *Camellia japonica* L., and the third herbaceous plant is *Bidens pilosa* L. . Example 20: This example is different from Example 1 in the following points. The soil is re-plowed with a plowing depth of 0 .5 m. The *Camellia sinensis* trees are replanted with a spacing of 3 m between the *Camellia sinensis* trees. After the *Camellia sinensis* trees have grown for four years, they are completely uprooted. Example 21: This example is different from Example 1 in the following points. The soil is re-plowed with a plowing depth of 0 .8 m. The poplar trees are replanted with a spacing of 1 m between the poplar trees. After the poplar trees have grown for six years, they are completely uprooted. Example 22: This example is different from Example 1 in the following points. The tree planted in S3 is a pear tree. Example 23: This example is different from Example 1 in the following points. The tree planted in S3 is an acacia tree. Example 24: This example is different from Example 1 in the following points. The leguminous crop planted in S3 is a broad bean. Example 25: This example is different from Example 1 in the following points. The leguminous crop planted in S3 is a red radish bean. To verify the effects of in-situ ecological restoration of heavy metal contaminated soil by different plant concentration treatment methods, during the heavy metal restoration test of the contaminated land, for the control test, the lead, zinc, and cadmium contents are the same. Multiple contaminated lands are set, and the area of each contaminated land is 1 km 2 and the contents of lead, zinc, and cadmium are adjusted, and the contents of lead, zinc, and cadmium are maintained at 965 ± 5 mg / kg (lead), 678 ± 5 mg / kg (zinc), and 113 ± 5 mg / kg (cadmium). After 10 years of restoration , the heavy metal content of the soil in the area is measured, and the results are shown in Table 5 below: Table 5 Contents of lead, zinc, and cadmium in the soil of the area after restoration As can be seen from the results in Table 5 of TIFF0007687556000005.tif55130, different plant concentration treatment methods have a certain impact on the in-situ ecological restoration effect of heavy metal contaminated soil, and the analysis is as follows: 1) After reducing the tillage depth, widening the interval between herbaceous plants, or increasing the tillage depth and narrowing the interval between herbaceous plants, the contents of lead, zinc, and cadmium in the soil of the restored area increase to a certain extent compared with those in Example 1. This is considered to be due to the fact that the herbaceous plants are too dense and affect the growth of the herbaceous plants, or the herbaceous plants are too sparse and affect the effect of the herbaceous plants. 2) Under different combinations of the first, second, and third herbaceous plants, the contents of lead, zinc and cadmium in the soil of the restored area increase to a certain extent compared with those in Example 1. From this, it can be seen that the combination of the first, second, and third herbaceous plants in Example 1 has a relatively optimal use effect. 3) After increasing or decreasing the interval between trees, the contents of lead, zinc, and cadmium in the soil of the restored area increase to a certain extent compared with those in Example 1. This is considered to be due to the fact that the trees are too dense and affect the growth of the trees, or the trees are too sparse and affect the effect of the trees. 4) When planting with different combinations of trees, the contents of lead, zinc, and cadmium in the soil of the restored area increase to a certain extent compared with those in Example 1. From this, it can be seen that the combination of trees in Example 1 is 5) When planting with different combinations of trees, the contents of lead, zinc, and cadmium in the soil of the restored area increase to a certain extent compared with those in Example 1. From this, it can be seen that the combination of trees in Example 1 has a relatively optimal use effect. The usage effect is relatively optimal, 5) When planting with different combinations of leguminous crops, the lead, zinc, and cadmium contents in the soil of the restored area increase to a certain extent compared with Example 1. From this, it can be seen that the combination of trees in Example 1 has a relatively optimal usage effect. Example 26: This example is different from Example 1 in the following points. After the soil is subjected to plant concentration treatment, it is plowed, and the plowing depth is 0.5 m. Then, fungi are planted. After 3 years, they are completely uprooted to obtain the soil after fungal concentration treatment. Example 27: This example is different from Example 1 in the following points. After the soil is subjected to plant concentration treatment, it is plowed, and the plowing depth is 0.8 m. Then, fungi are planted. After 3 years, they are completely uprooted to obtain the soil after fungal concentration treatment. Example 28: This example is different from Example 1 in the following points. First, Agaricus bisporus is planted in the first area, Pleurotus eryngii is planted in the second area, and Grifola elongata is planted in the third area. After 1 year, they are completely uprooted, Next, Dictyophora indusiata is replanted in the first area, Bryophyllum pinnatum is replanted in the second area, and Agaricus blazei is replanted in the third area. After 1 year, they are completely uprooted, Next, Tricholoma giganteum is replanted in the first area, Amanita phalloides is replanted in the second area, and Pleurotus eryngii is replanted in the third area. After 1 year, they are completely uprooted. Example 29: This example is different from Example 1 in the following points. First, Amanita phalloides is planted in the first area, Mushroom is planted in the second area, and Bryophyllum pinnatum is planted in the third area. After 1 year, they are completely uprooted, Next, Dictyophora indusiata is replanted in the first area, Shiitake mushroom is replanted in the second area, and Amanita phalloides is replanted in the third area. After 1 year, they are completely uprooted, Next, Shiitake mushroom is replanted in the first area, Hohenbuehelia serotina is replanted in the second area, and Lactarius deliciosus is replanted in the third area. After 1 year, they are completely uprooted, Next, Shiitake mushroom is replanted in the first area, Hohenbuehelia serotina is replanted in the second area, and Lactarius deliciosus is replanted in the third area.​ Replant the ge, and after one year, extract it by the roots. To verify the effect of in-situ ecological restoration of heavy metal contaminated soil by different fungal concentration treatment methods During the heavy metal restoration test of contaminated land, for the control test, the lead, zinc, and cadmium contents are the same Set a large number of contaminated lands, and the area of each contaminated land is 1 km 2 And adjust the lead, zinc, and cadmium contents, and maintain the lead, zinc, and cadmium contents at 965 ± 5 mg / kg (lead), 678 ± 5 mg / kg (zinc), 113 ± 5 mg / kg (cadmium). After 10 years of restoration Measure the heavy metal content of the soil in the area, and the results are shown in Table 6 below: Table 6 Lead, zinc, and cadmium content table of the soil in the area after restoration As can be seen from the results of TIFF0007687556000006.tif33138 Table 6, different fungal concentration treatment methods have a certain impact on the effect of in-situ ecological restoration of heavy metal contaminated soil. Here, the treatment effect of Example 27 is almost the same as that of Example 1 And the removal rates of lead, zinc, and cadmium in Examples 26, 28, and 29 are significantly lower than those in Example 1. From this, it can be seen that when the tillage depth is reduced and the fungal composition is changed, the fungal concentration effect will decrease Therefore, the treatment effects of Example 27 and Example 1 are good, but considering that the depth during deep tillage in Example 27 is deep and the workload is large, the overall effect of Example 1 is relatively excellent Example 30: This example is different from Example 1 in the following points. Pour an alcohol solution with a volume concentration of 95% into the soil after fungal concentration treatment at a watering rate of 1 kg / m 2 Example 31: This example is different from Example 1 in the following points. Pour an alcohol solution with a volume concentration of 95% into the soil after fungal concentration treatment at a watering rate of 2 kg / m 2 ​​​​​​​​​ To verify the effects of in-situ ecological restoration of heavy metal contaminated soil by different disinfection and sterilization treatment methods During the heavy metal restoration test of contaminated land, for the control test, the lead, zinc, and cadmium contents are the same A number of contaminated lands are set, and the area of each contaminated land is 1 km 2 and the lead, zinc, and cadmium contents are adjusted to maintain the lead, zinc, and cadmium contents at 965 ± 5 mg / kg (lead), 678 ± 5 mg / kg (zinc), and 113 ± 5 mg / kg (cadmium). After 10 years of restoration the heavy metal content of the soil in the area is measured, and the results are shown in Table 7 below: Table 7 Lead, zinc, and cadmium content table of the soil in the area after restoration TIFF0007687556000007.tif25144 As can be seen from the results in Table 7, different disinfection and sterilization treatment methods have a certain impact on the effect of in-situ ecological restoration of heavy metal contaminated soil Here, the treatment effect of Example 31 is almost the same as that of Example 1 and for Example 30, compared with Example 1, the removal rates of lead, zinc, and cadmium decrease. From this it can be seen that after reducing the water spraying amount of the alcohol solution, the disinfection and sterilization effect decreases Therefore, the treatment effects of Example 31 and Example 1 are good, but considering that the alcohol solution usage amount in Example 31 is large, the overall effect of Example 1 is relatively excellent . Example 32: This example is different from Example 1 in the following points. After disinfection and sterilization treatment with an addition amount of 1 kg / m 2 wood ash is added to the soil, and the soil is plowed 5 times with a plowing depth of 0.5 m . Example 33: This example is different from Example 1 in the following points. After disinfection and sterilization treatment with an addition amount of 2 kg / m 2 wood ash is added to the soil, and the soil is plowed 8 times with a plowing depth of 0.8 m . To verify the effect of in-situ ecological restoration of heavy metal contaminated soil by different pH adjustment treatments, during the heavy metal restoration test of contaminated land, a number of contaminated lands with the same lead, zinc, and cadmium contents were set up for the control test. The area of each contaminated land was 1 km and the lead, zinc, and cadmium contents were adjusted to maintain the lead, zinc, and cadmium contents at 965 ± 5 mg / kg (lead), 678 ± 5 m g / kg (zinc), and 113 ± 5 mg / kg (cadmium). After 10 years of restoration, the heavy metal content of the soil in this area was measured, and the results are shown in Table 8 below: 2 Table 8 Heavy metal content table of the regional soil after restoration As can be seen from the results of Table 8 TIFF0007687556000008.tif25143, different pH adjustment treatments have a certain impact on the effect of in-situ ecological restoration of heavy metal contaminated soil. Here, the treatment effect of Example 33 is almost the same as that of Example 1. Compared with Example 1, in Example 32, the removal rates of lead, zinc, and cadmium decreased. From this, it can be seen that after reducing the usage amount of plant ash, the pH adjustment effect decreases. Therefore, although the treatment effects of Example 33 and Example 1 are good, considering the large usage amount of plant ash in Example 33, the overall effect of Example 1 is relatively excellent. Table 8 Heavy metal content table of the regional soil after restoration As can be seen from the results of Table 8, different pH adjustment treatments have a certain impact on the effect of in-situ ecological restoration of heavy metal contaminated soil. Here, the treatment effect of Example 33 is almost the same as that of Example 1. Compared with Example 1, in Example 32, the removal rates of lead, zinc, and cadmium decreased. From this, it can be seen that after reducing the usage amount of plant ash, the pH adjustment effect decreases. Therefore, although the treatment effects of Example 33 and Example 1 are good, considering the large usage amount of plant ash in Example 33, the overall effect of Example 1 is relatively excellent. After reducing the usage amount of plant ash, the pH adjustment effect decreases. Therefore, although the treatment effects of Example 33 and Example 1 are good, considering the large usage amount of plant ash in Example 33, the overall effect of Example 1 is relatively excellent. Considering the large usage amount of plant ash in Example 33, the overall effect of Example 1 is relatively excellent.

Claims

1. It includes the following steps: S1, Pretreatment: First, the heavy metal contaminated soil is gently tilled to a depth of 1.5 to 2.0 m. Then, the soil is plowed and tilled. The soil is cultivated to a depth of 0.5 to 0.8 m. The soil is ploughed a total of 2 to 5 times, then rotatably cultivated 2 to 3 times, and finally The soil was then naturally air-dried for 15 to 30 days to obtain pretreated soil, and the heavy metals were determined to be lead, zinc and cadmium. Including, S2, fermentation treatment: The surface layer of the pretreated soil is mixed with fermentation bacteria, coarse sand, and charcoal powder, and the surface layer of the pretreated soil is then cut into a cone shape. During the process of stacking the conical soil pile, A layer of straw powder 3-5 cm thick was laid every 20-30 cm along the vertical direction of the tube, and the tube was then cooled for 10 min. After natural fermentation for 20 days, the fermented soil is obtained. Here, the thickness of the surface soil is 0.5 to 0.8 m, and the amount of fermentation bacteria mixed is 10 to 20 g. / kg, the amount of coarse sand mixed is 15-30 kg / t, and the particle size of the coarse sand is 0.5- 2 mm, the amount of charcoal powder mixed is 5-10 kg / t, and the bottom of the cone-shaped soil pile The diameter of the section is 1.5 to 2.0 m, and the height is 0.8 to 1.5 m. S3, Plant enrichment treatment: The soil after the fermentation treatment is tilled to a tilling depth of 0.5 to 0.8 m, and then herbaceous plants are planted. The spacing between herbaceous plants is 0.1-0.5m. After the herbaceous plants have grown for two years, they are uprooted. Remove it, The soil was then re-cultivated to a depth of 0.5-0.8m, and trees were replanted with a spacing of 1. During the growth period of the trees, legume crops are planted between the trees. The spacing between the trees is 0.2 to 0.4 m. After the trees have grown for 4 to 6 years, they are uprooted and replanted. Obtain soil after enrichment treatment; S4. Fungal concentration treatment: The soil after the plant enrichment treatment was tilled to a tillage depth of 0.5 to 0.8 m, and then the fungus was planted. After three years, the plants were uprooted and soil was obtained after fungal enrichment treatment. S5. Disinfection and sterilization treatment: 1-2kg / m ２ After fungal concentration treatment, the soil was treated with 95% alcohol solution at a watering rate of Pour the liquid into the container and burn the alcohol. The alcohol itself has a sterilizing and disinfecting effect, and the alcohol combustion is what kills the bacteria. The soil is disinfected and sterilized at a high temperature to obtain disinfected and sterilized soil. S6, pH adjustment treatment: 1-2kg / m ２ Mix wood ash with the soil after disinfection and sterilization at the dosage of 100 mg / kg, and till the soil 5 to 8 times. The soil is tilled to a depth of 0.5 to 0.8 m, and the wood ash and soil are thoroughly mixed to remove heavy metal contamination. Complete soil ecological restoration; 1. A method for in situ ecological remediation of heavy metal contaminated soil, comprising:

2. In S1, the soil is plowed every 2 to 3 days during the natural air drying period, and the plow depth is 0.5 to 0.

2. The method of claim 1, wherein the distance is 0.05 to 0.8 m.

3. In S2, a ventilation hole with a diameter of 2-3 cm and a depth of 0.2 m was opened vertically in the cone-shaped soil pile. Then, water is supplied to the cone-shaped soil pile by mist sprinkling method, and the surface layer 10 of the cone-shaped soil pile is The moisture content of the soil at ~20 cm is maintained at 60-65 wt% and the cone-shaped soil pile is placed in the soil during the nighttime period.

2. The method according to claim 1, further comprising covering the container with a plastic film for heat retention.

4. In S2, The fermentation bacteria include Bacillus coagulans, Bacillus subtilis, Bacillus clausii, Bacillus indigotica, Bacillus licheniformis, Enterococcus faecalis, Chlorophyll 2. The method according to claim 1, characterized in that the microbial organism is selected from any one of the following: The method described.

5. In S3, the herbaceous plants include a first herbaceous plant, a second herbaceous plant, and a third herbaceous plant, The plant ratio of the first herbaceous plant, the second herbaceous plant, and the third herbaceous plant is 1:1:1, The main plant, the secondary herbaceous plant, and the tertiary herbaceous plant are planted in a uniform mixture. The first herbaceous plant is selected from the group consisting of Tephrosia candida, Lamium purpureum, Bidens maximowiczii. Witchia, Vitis vinifera, Vetiver, Green Wild Amaranth, Bidens maximo Vitchiana, Tradescantia, Alewife, Conical Southern Mustard, Red and selected from any one of the following: The second herbaceous plant is Indian mustard, rue, turnip, camellia sasanqua, or mallow. is selected from one of The third herbaceous plant is Poinsettia cordifolia, Lesser Flower Lobelia, Friuliella arvensis, Chilaria, Merchantland, Lobelia, Bulbous Nasturtium, Purple Jasmine, , Bidens pilosa, or any one of the following:

2. The method according to claim 1.

6. In S3, the tree is any one of a poplar tree, a pear tree, a Longjing tea tree, and an acacia tree. The legume crop is selected from one or more of white lupin, chickpea, black bean, peanut, etc.

2. The method according to claim 1, further comprising the step of: The method according to

7. In S4, the fungus includes a first fungus, a second fungus and a third fungus, The soil after the experiment was divided into three equal-sized regions according to the area, and the first region, the second region, and the third region were Region 1, Region 3, First, a first fungus is planted in a first region, a second fungus is planted in a second region, and a third fungus is planted in a third region. The fungus is planted, and after a year, it is uprooted. A second fungus is then replanted in the first region, a third fungus is replanted in the second region, and a first fungus is replanted in the third region. The fungus was replanted, and after a year it was uprooted. A third fungus is then replanted in the first region, the first fungus in the second region, and the second fungus in the third region. The fungus was replanted, and after a year it was uprooted. The first fungus is selected from the group consisting of Agaricus bisporus, Agaricus blazei, and Agaricus blazei. Choose from one of the umbrellas, The second fungus is selected from any one of a wood ear fungus, a shiitake mushroom, a mushroom, and a bamboo fungus. R, The third fungus is any one of Shiitake mushroom, Naganetake mushroom, Phoenix mushroom, Tricholoma giganteum, and Umbrella mushroom.

2. The method of claim 1, wherein the first and second electrodes are selected from the group consisting of:

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