KR20180079227A - Method for purifying heavy metal contaminated soil - Google Patents

Abstract

The present invention relates to a method for purifying soil contaminated with heavy metals. According to the present invention, the method comprises the following steps: (A) introducing into soil contaminated with heavy metals: autotrophic microorganisms, a microorganism culture medium composed of livestock manure, lime, and minerals; a mineral fertilizer selected from the group consisting of kaolinite, montmorillonite, vermiculite, chlorite, Ge-lite, illite, zeolite, micas, barley stone, germanium, and Bashim; and a highly absorbent polymer; (B) tilling to a depth of 30-40 cm; (C) supplying moisture for 3-5 months, wherein initially, 4-6 mm of moisture is supplied 1-2 times per day, and after 4-5 weeks, the amount of moisture supplied is reduced to 30-50% of the initial amount; and (D) d1) planting stevia; d2) cultivating the stevia; and d3) harvesting the overground part of stevia once the heavy metals in the soil are absorbed and moved to the overground part of stevia.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying heavy metal contaminated soil,

The present invention relates to a method of purifying soil contaminated with heavy metals, and more particularly, to a method of purifying soil which can be cultivated but which is contaminated with heavy metals and can not be utilized as agricultural land by a biological method.

Recently, the problem of contamination of soil and groundwater by heavy metals has become serious. Heavy metals are wastewater from wastewater and waste incineration such as leather factory, dyeing factory and plating factory that processes products by using heavy metals, mine water and exhaust gas, mine tailings, exhaust gas, etc. generated during mining, beneficiation and refining of metal mine The heavy metals accumulated in the soil may be transferred to the crops and contaminate the agricultural products.

Heavy metals are relatively heavy metals with a specific gravity of 4 to 5 or more. Among them, heavy metals such as cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni) Is toxic when stored in the human body. Representative pollution diseases caused by heavy metal contamination are "Minamata disease" caused by mercury and "Itaitai disease" caused by cadmium. Among them, "Minamata disease" is known to be caused by algae foods contaminated with organic methylmercury, and "Itaitai disease" is a result of long-term intake of cadmium-contaminated rice.

Methods for the purification of contaminated soil can be divided into physical, chemical and biological methods. Physical methods include clay, clay, and silt. Chemical methods include insolubilization, adsorption, leaching of harmful substances, and separate washing of contaminated soil. Biological methods include bioremediation and phytoremediation techniques.

For example, Korean Patent Laid-Open Publication No. 2013-0094520 entitled " Physical and Chemical Complex Purification Process for Purifying Heavy Metal Contaminated Soil and Its Apparatus "includes (1) a step of inputting contaminated soil into a hopper; (2) a first particle size selection step of starting the physical selection process by dividing the soil containing heavy metals of gravel size or larger and the heavy metal less than gravel size by particle size; (3) adding and stirring a dispersant to start the chemical extraction process by adding the dispersant solution to the heavy metal contaminated soil and stirring the mixture; (4) a magnetic force selection step of dividing the heavy-metal-containing soil by magnetic force into heavy metal-containing magnetic waste and magnetic waste-free soil; (5) a second particle size selection step of dividing the separated soil having a granulometric size or more and the non-crystallizable fine granular soil (refractory granular soil) and the heavy metal particles smaller than the granular size by the particle size; (6) a washing step of washing the separated soil with water to prepare a purified soil; And (7) a waste treatment step of discarding the non-crystallizing fine particles (hardly-diffusible fine granular soil) and heavy metal particles, and a physico-chemical complex purification process for purifying heavy metal contaminated soil .

Such physical and chemical methods may be suitable for the purification of a narrow range of contaminated soils, but they are not suitable for a wide range of contaminated soils such as cropland. These physical and chemical methods require huge amounts of money and labor, deteriorate nature, and cause secondary pollution. Further, when the contaminated soil is washed separately, other beneficial components required for agriculture may be removed, which is not suitable as a method for purifying agricultural land.

On the other hand, microbial restoration and plant restoration technology using microorganisms, which are biological methods, are clean technology operated by solar energy, minimize environmental disturbance, are highly applicable to the field, do not produce secondary pollutants, It has an advantage in that it gives aesthetic stability and is economical.

Korean Patent No. 0830703 entitled " Microbes of the genus Methylobacterium, the method of producing organic acids using the same, the method of purifying heavy metals contaminated soil and the method of promoting plant growth " A new microorganism Methylobacterium sp. A method for producing organic acids by using this microorganism by separating SY-NiR1 from dormancy, mountain hoe foreskin, chicken wool or whitewashed rhizospheric soil, and a method for purifying soil contaminated with heavy metals by improving the removal efficiency of heavy metals of plants " .

Korean Patent Publication No. 2010-0028311 entitled " Method for recovering heavy metal contaminated soil using cucurbit plants "includes " restoring soil by accumulating heavy metals in the soil by cultivating cucumbers in soil contaminated with heavy metals such as arsenic And Korean Patent Laid-Open Publication No. 2009-0081892 entitled " Method for promoting the growth of daphnia using a seed extract, and method for purifying heavy metal contaminated soil using this method " The method of promoting the growth of germination, stalks and roots by injection, and the method of applying the method to the soil contaminated with heavy metals to promote heavy metal migration by phytoextraction, and unlike conventional physical or chemical restoration methods, A method of purifying soil polluted with heavy metals, in which tea contamination is not accompanied " have.

According to the recent statistics of the Ministry of Environment Protection and Ministry of Land and Resources (2014), 16.1% of the land surveyed by China was contaminated with heavy metals such as cadmium, arsenic, lead and mercury. In addition, 19.4% of cultivated farmland exceeded safety standards, which means that 333,000 농 (33,300㎢) of cultivated land, which is more than one-third of the total area of Korea, is actually not cultivated. Soil contamination by heavy metals is especially severe in central and southwestern China.

The agricultural products cultivated in such polluted soil and the livestock products raised by these agricultural products can be a serious problem for us because they can be exported to Korea and climbed to the table of our country. The possibility of exposure to Chinese food products, which have a high concern for heavy metal contamination due to the Korea-China FTA, has increased, and a countermeasure must be prepared.

The present inventors have studied a method for efficiently purifying agricultural land contaminated with heavy metals and using the byproducts. By applying the above-mentioned bioremediation and phytoremediation techniques, the agricultural land contaminated with heavy metals The present invention has been completed.

It is an object of the present invention to provide a method of purifying soil contaminated with heavy metals by a biological method.

Another object of the present invention is to provide a method for producing feed or fertilizer using stevia harvested in the course of the purification method.

To achieve the above object, according to the present invention, there is provided a pharmaceutical composition comprising (A) an autotrophic microorganism; A microbial medium consisting of livestock feces, lime and minerals; Mineral fertilizers selected from the group consisting of kaolinite, montmorillonite, vermiculite, chlorite, gelite, ilite, zeolite, mica, elvan, germanium and bases; And introducing the superabsorbent polymer into a heavy metal contaminated soil; (B) Rotating to a depth of 30 to 40 cm; (C) supplying moisture in an amount of 4 to 6 mm per one or two times a day for 3 to 5 months, initially reducing the amount of 30 to 50% after 4 to 5 weeks; And (D) d1) planting stevia; d2) growing stevia; And d3) harvesting the ground portion of the stevia when the heavy metals in the soil are absorbed and moved to the ground portion of stevia.

 In this case, the metallothionein enzyme capable of adsorbing heavy metals together with the abovementioned autotrophic microorganisms is preferably added to the soil.

In step (A), the autotrophic microorganism is preferably an anabaena genus, a Nostoc genus, a Microcoleus genus, an Oscillatoria genus, a Calothrix genus, a Pharmidium genus or a mixture thereof. More preferably, at least one bacterium selected from the group consisting of Aspergillus genus Aspergillus oryzae, Aspergillus niger and Rhizopus nigricans with a fungus fungus is mixed with the cyanobacteria.

An organic fertilizer may be used in place of or in place of the shaft fraction. At this time, organic fertilizer rich in nitrogen and phosphoric acid components can be used, and its shape can be used as a granule type, a fine powder of 100 nm or less or liquefied.

The mineral fertilizer can be used by foaming to improve air permeability, water retention and bobbility, and granular type, 100 nm or less, or liquefied.

In the step (C), the water supply is preferably performed through the drop hose. The superabsorbent polymer is made of a material capable of expanding at 100 to 200 times its magnetic volume and capable of repeated expansion and contraction, and is preferably a polymer having an age of 5 to 10 years.

It is preferable that the above-mentioned independent nutrient microorganisms are used in a range of 1 to 10 g based on 20% dry microorganism, 1 to 2 kg of the medium, 0.1 to 1 kg of the mineral fertilizer and 120 to 150 g of the superabsorbent polymer based on the soil 3.3 m 2 Do.

It is preferable that the stevia ground portion is harvested for 2 to 3 years in the step (D), although it may vary depending on the degree of heavy metal contamination. The heavy metals are characterized by being arsenic, cadmium, copper and lead.

According to another aspect of the present invention, there is provided a method for preparing a stevia feed or fertilizer by combined fermentation of the harvested stevia.

According to the present invention, soil contaminated with heavy metals can be efficiently purified, so that safe cultivation of crops becomes possible, and stevia harvested in the purification process can be used as an excellent fertilizer or feed.

1 to 4 are photographs showing growth of stevia planted according to the method for purifying contaminated soil according to the present invention.

Hereinafter, the present invention will be described more specifically.

The present invention relates to a method for purifying soil contaminated with heavy metals by biological methods using an autotrophic microorganism and cultivating stevia. It is an object of the present invention to provide a method for purifying soil contaminated with heavy metals Of the polymer is added together to help the microorganisms settle in the soil stably, and the stevia is cultivated to absorb and remove the heavy metals in the soil.

Stevia (Stevia) is a perennial silkworm that grows around rivers and wetlands. The roots are not evident in the development of the root roots, and there are many side root and root roots. In the latter stages of development, thick roots develop and storage functions are developed. A new branch grows from a hidden eye near its roots and forms a new stem every year. The stem is straight and the function of the stem is lost during the winter. Leaves hang on the stem node and branches grow on the axil. Leaves are opposite and basal, 4 ~ 10cm long and 2.5cm wide. There are fine sawtooth and curves and three leaf veins. There is no petiole, and there is fine hairs all over the abdomen. Flower is bloomed with one to five or six ornamental flowers, and has the property of self-incompatibility. Because it is a single plant, flowers bloom quickly under single conditions. The seeds have a low fertility rate and are very small. At the end of the seed, there is a tortoise-like tubular shape. Paraguay, South America, Argentina, Brazil and the country's origin is the border. Paraguay has used stevia leaves as a sweetener for a long time, but recently it became more noticeable when the harmfulness of saccharin, a synthetic sweetener, became a problem. The leaf contains stevioside, which is about 6 ~ 7% of the weight, and its content varies depending on the individual. The sweetness component is 300 times as much as sugar, and it is used as a sweetener for refreshing drinks by making tea or substituting gum. It has also been introduced in Korea in 1973 to cultivate new varieties. Breeding is done with seeds or bunches. Harvesting can be done once or twice a year, with early and mid-September being the fewest. Stevia contains inorganic salts and nutrients such as potassium, sodium, beta carotene, vitamin A, vitamin B2, vitamin B6 and vitamin E. It has powerful antioxidant, bactericidal and detoxifying effects. It is known that dioxins can be used for the purpose of restoring soil contaminated with dioxins.

According to one embodiment of the present invention, there is provided a pharmaceutical composition comprising (A) an autotrophic microorganism; A microbial medium consisting of livestock feces, lime and minerals; Mineral fertilizers selected from the group consisting of kaolinite, montmorillonite, vermiculite, chlorite, gelite, ilite, zeolite, mica, elvan, germanium and bases; And introducing the superabsorbent polymer into a heavy metal contaminated soil; (B) Rotating to a depth of 30 to 40 cm; (C) supplying moisture in an amount of 4 to 6 mm per one or two times a day for 3 to 5 months, initially reducing the amount of 30 to 50% after 4 to 5 weeks; And (D) d1) planting stevia; d2) growing stevia; And d3) harvesting the ground portion of the stevia when the heavy metals in the soil are absorbed and moved to the ground portion of stevia.

In order to biologically purify the soil, it is necessary to improve it into a soil in which microorganisms can act vigorously. Since there is almost no indigenous microorganism in the barren soil, the microorganism should be supplied from the outside. At this time, it is necessary to supply an autotrophic microorganism which can survive only by replenishing light and moisture in an unfavorable soil with a low organic matter.

Cyanobacteria (cyanobacteria, blue-green algae) are nucleated and chloroplast-free algae, also known as blue-green algae. In addition to chlorophyll-a, β-carotene, micalcoxanthin, and c-ficocyanin and picobillin, and c-picoerythrin. Make a cyanophycean starch or glycogen with an anabolic product.

It lives in the surface layer of the ground, fresh water, and seawater. However, very dry condition and high temperature (80 ℃) are also found. Cyanobacteria also produce a large amount of secretion during their growth, forming a mucous envelope or mucilage sheath outside the cell. This is known as polysaccharides. Its role is to protect itself by containing water, to protect against other organisms, to store essential nutrients, and so on. According to studies by soil botanists, these secretions act as soil particles and chelator, which plays a major role in the formation of water-resistant habitats in the soil, which is known to contribute greatly to improving the water holding capacity and conservation of soil. It forms an elongated fibrous shape and sticks between soil or sand to form an independent structure. In this structure, a variety of lichens, mosses, and fungi are gathered, and these independent structures gather to form a large cake-like sponge body. These sponge bodies prevent the loss of soil from various erosions and absorb and retain moisture .

Cyanobacteria also have a protein content of over 65%, and the protein contains all the essential amino acids necessary for plant growth, thus helping to improve the soil activity even when the cyanobacteria are killed. Due to the enzymatic action resulting from the active metabolism of these microorganisms, soil uptake of sand proceeds rapidly.

In the present invention, it is preferable to use microorganisms such as Anabaena genus, Nostoc genus, Microcoleus genus, Oscillatoria genus, Calothrix genus, Phormidium genus genus, or a mixture thereof.

At this time, it is preferable to mix Rhizopus nigricans and Aspergillus bacteria involved in the fermentation of the soil together with the cyanobacteria. Cyanobacterium is a very good nutrition source. However, the skin is thick and the plant absorbs 30 ~ 35% of its efficiency. When Aspergillus oryzae, Aspergillus niger or Rhizopus nigricans are used together with the cyanobacterium, the Aspergillus and Rhizopus nigricans form their own soil There is also a function to activate, but it disassembles the carcass of the cyanobacterium and transforms it into a form that the plant absorbs. In this case, absorption efficiency increases to 90 ~ 95%.

According to one embodiment of the present invention, there is provided a method for producing a microorganism, which comprises culturing in a culture tank a culture medium comprising kaolinite, Montmorillonite, Vermiculite, Chlorite, gelite, ilite, zeolite, mica, elvanite, germanium, And at least one bacterium selected from the group consisting of Aspergillus genus Aspergillus oryzae, Aspergillus niger and Rhizopus nigricans with a fungus fungus are mixed together, And cultured.

More specifically, during the cultivation of cyanobacteria, fine-purified minerals rich in trace elements (kaolinite, montmorillonite, vermiculite, chlorite, gelite, ilite, zeolite, , Germanium, basim, etc.) were added to the culture tank to periodically rotate the cultivator during the cultivation of the cyanobacteria. The precipitated minerals (Kaolinite, Montmorillonite, Vermiculite, Chlorite, Colloidal particles and cyanobacteria of fine minerals are cultivated vigorously, and the resulting polysaccharide is mixed with a point substance, and the mixture is accumulated in a culture tank. The same process is repeated and a very basic step of 'Stromatolite' is formed.

The sediment precipitated and the cyanobacteria cultivated in the upper layer were classified in a culture tank to have a water content of 80 to 90%, and then mixed with 1/2 of the separated cyanobacteria separated from the suspended matter (initial stage of stromatolite) formed below Aspergillus oryzae, Aspergillus niger and Rhizopus nigricans, which were cultured separately and cultured separately, were uniformly mixed at a ratio of 1/1000 to the suspension of stromatolite in the early stage and mixed with cyanobacteria, The fermentation is carried out at a fermentation facility at 27 ℃ where the light is shaded.

In this process, the sediments fed by the strain and the excreta of the cyanobacteria are nanoized and replaced with high quality nutrients that the plants can grow.

This fermentation process is performed by fermenting until the fungus strain covers the surface whiten. After cultivation, 1/2 of the cyanobacteria left before incubation is dried in a low temperature drier and mixed evenly. It may be used in liquid form or in powder or pellet form if necessary.

The amount of microorganisms to be added depends on the condition of the soil, but it is 1 ~ 10g per 3.3 ㎡ based on 20% moisture and dry microorganism, and 100ml ~ 1,000ml for culture.

In addition to soil microorganisms, soil microorganisms require nutrients that can be bought first. Organic materials, such as shale-based organic matter, limestone, which is subjected to a rapid reaction process, and various minerals are put together.

Straw counts, poultry, and cows can be used, and it is preferable to use counts. At this time, various types of organic fertilizers rich in nitrogen and phosphoric acid components may be used together with or instead of the above-mentioned shaft fractions. The shape also includes a granule type, a case where high concentration is required in consideration of a distribution cost and a labor cost, and a case where the particle size is not more than 100 nanometers in size to increase the water absorbency, or liquefied. Examples of the minerals include magnesium, iron, boron, manganese, zinc, copper, molybdenum and cobalt. The amount of the above-mentioned medium may vary depending on the condition of the soil, but 1 to 2 kg per 3.3 m 2 may be used.

Since the nutrients can not be accumulated in the case of a barren soil, the present invention replaces the soil by injecting a certain amount of a functional mineral fertilizer having a cation substitution function. The soil with strong cation exchange function is a clay mineral. Mineral fertilizers include kaolinite, montmorillonite, gelite (natural pozzolan), ilite, vermiculite, chlorite, Zeolite, mica, elvan, germanium, basement, etc., can emit abundant far-infrared rays, maintain water permeability, and function as a cation substitute. The larger the cation exchange capacity, the greater the proportion of the nutrients used as fertilizers to the crop. In other words, the more fertile the soil, the greater the cation exchange capacity. The mineral fertilizer can be used by foaming to improve air permeability, water retention and bobbility, and granular type, 100 nm or less, or liquefied. The input amount of the mineral fertilizer may vary depending on the state of the soil, but 0.1 to 1 kg per 3.3 m 2 may be used.

In order for microorganisms to settle in the soil, a constant supply of water is required. It is important that the moisture content is always kept in the soil because the atmospheric moisture is evaporated in the area where the barren soil is located. According to one embodiment of the present invention, water is supplied about 4 to 6 mm each time by a drip hose every 30 minutes for one to two days on the first day. However, a highly water-absorbing polymer serving as a water tank for continuously supplying water required for growth of microorganisms Put them together in the soil. In addition, in the present invention, stevia cultivated to absorb heavy metals in the soil grows well in wetlands, so it is important to supply sufficient moisture to the soil.

The superabsorbent polymer is made of a material capable of expanding to 100 to 200 times its magnetic volume and capable of repeated expansion and contraction, and it is preferable to use a material having a life of 5 to 10 years. When a water absorbing polymer absorbs moisture, it changes into a gel-like structure. The absorbing power (affinity of the polymer and the water, penetration of water) which intends to confine water in the gel is absorbed in the gel absorbing the water. And a force to suppress the absorption action (rubber elastic force caused by the three-dimensional mesh of the polymer). At the point where the sum of the affinity and the penetration is parallel to the elastic force, the absorption of water and the expansion of the molecular chain are stopped, and the stable state of moisture saturation is attained and the moisture can be kept continuously. When the high absorption polymer is mixed with the soil, the absorption gel serves as a water tank, and as a source of water for microorganism settlement, the water content in the soil can be kept constant. According to one embodiment of the present invention, a commercially available K-SM acrylamide-based super absorbent polymer resin or a soil improving agent (WCS) containing polyacrylic acid as a main component may be used.

The amount of the superabsorbent polymer to be injected may vary depending on the condition of the soil, but 120 to 150 g per 3.3 m 2 may be used. In this case, when the mineral fertilizer, the organic fertilizer and the microorganism are liquefied, the superabsorbent polymer absorbs the liquid phase first or uses the mineral fertilizer organic fertilizer and the superabsorbent polymer absorbing the liquid phase of the microorganism by re- It is also possible to use it in the form of a pellet or a type.

In the case of fine particles, the diffusivity and absorbability of the effect are increased but it is difficult to guarantee the continuity of the effect. Especially in the case of unfavorable soil, there is little water conservancy and bibbing power at the beginning, so there is a great concern about the loss of the soil when spraying on the soil surface. Therefore, it is possible to make the liquid mineral fertilizer, organic fertilizer and microorganism absorb through the super absorbent polymer and dry it to reduce the weight and volume so that it can be easily moved and used. Once the microorganism and various nutrients Once filled, it dries to reduce volume and weight, making it easy to use in logistics and use. When the water and temperature conditions are met at the time of field use, the microorganisms are activated immediately, and the nutrients and moisture suitable for them can be discharged gradually over time The soil has the advantage of maintaining a sustained effect up to the time when the soil has its own excellent water retention and bracing ability.

After the above ingredients are added to the soil, they are rotary kneaded to a depth of 30 to 40 cm and mixed with the soil. Then, water is supplied to the soil so that microorganisms can settle. Depending on the condition of the soil, it will provide moisture for 3 to 5 months. Initially, water is supplied in an amount of 4 to 6 mm per one or two times per day (the depth of the water that is not absorbed by the soil), and after 4 to 5 weeks, water is supplied by reducing the amount to 30 to 50%. Dot hoses can be used.

As a result of improving the soil in this way, it was improved to a soil suitable for growing Stevia.

 It is more efficient to add metallothionein enzyme having heavy metal adsorbing ability together with the abovementioned autotrophic microorganisms together into the soil. Metallothionein is a low molecular weight metal binding protein with a molecular mass of 6,000-8,000 and has a cysteine content of 30%. Therefore, the redox reaction easily occurs. According to this reactivity, the metal is reacted with a metal, (reactive electrophile), active oxygen and nitrogen species (ROS / RNS). The 20 cysteine residues that constitute metallothionein are arranged in alpha and beta type thiolate clusters with metal binding capacity. These thiol groups can bind heavy metals such as mercury and cadmium. Therefore, it is known to be involved in detoxification and neutralization of heavy metals. When the metallothionein enzyme is added to the soil together with microorganisms and fertilizers, the heavy metals in the soil can be decrypted and neutralized by itself.

Subsequently, Stevia is planted and cultivated in the soil to remove residual heavy metals. Stevia plants seeds through seeds or bunches. As the stevia grows, the heavy metals absorbed through the roots migrate to the ground. At this time, it is possible to harvest stevia with roots, but since stevia is a perennial plant, it can be harvested for many years if it only prevents the roots from verbing in winter. Depending on the degree of contamination of heavy metals in the soil, heavy metals in the soil can be removed to a high level by harvesting the ground part for 2 ~ 3 years.

The reason for planting stevia in contaminated soil is that it requires a large amount of fertilizer to grow dabbi, and the crop is a crop whose yield is greatly increased as the fertilizer is added to a certain limit. Plants have the ability to absorb soil nutrients and other pollutants from the roots intensively to neutralize the contaminated soil, and have the ability to purify dioxin and heavy metal soils when processing stevia and spreading them on the field. Korean Patent Laid-Open No. 10-2009-0002551 "Vegetable (Stevia) Dioxin Release and Preparation Method for Food Additive" also discloses an experimental result that Stevia extract decomposes dioxins in soil. Soil contaminated with heavy metals could be efficiently purified by this method.

Stevia harvested in the soil remediation process can be used as fertilizer for growing crops or animal feed. Since it can not be used as fertilizer or feed in the state containing heavy metals, it is necessary to be detoxified through a complex fermentation process. According to one embodiment of the present invention, microorganisms of the genus Bacillus, Lactobacillus, and Pichia are added to the harvested Stevia and fermented. Preferably, two or more of the above microorganisms are mixed and used in fermentation. Two or more microorganisms may be used simultaneously or sequentially to be fermented to detoxify. At this time, when the microorganism is added for the efficient removal of the heavy metal, it is preferable to add the metallothionein enzyme together. The fermented product thus produced is added with the usual fertilizer or a component added to the feed to prepare a fertilizer or feed.

When it is desired to produce the liquid fertilizer, it is preferable that the stevia is fermented after being squeezed.

[Example]

Hereinafter, the present invention will be described in more detail with reference to the following examples. It should be understood, however, that these embodiments are merely examples for the purpose of easily describing the scope and scope of the technical idea of the present invention, and thus the technical scope of the present invention is not limited or changed. It will be apparent to those of ordinary skill in the art that various changes and modifications can be made within the scope of the technical idea of the present invention based on these examples.

Example 1: Purification of contaminated soil

From February to October 2017, soil contamination tests were conducted. The test site was ginseng field in Ujang-dong, Yeoju-si, Gyeonggi-do. The ginseng was cultivated for 5 years and the chemical fertilizers, various fungicides, insecticides and herbicides were sprayed continuously for 5 years to kill the beneficial bacteria and microorganisms in the soil. The test was carried out in a field which was contained in large quantities in the soil and which turned into soil which was hardened below 10 cm of the soil and could not reach the root of the plant. For the actual experiment, I dig soil below 10cm from the field, but when I tried to hate the whole body in the shovel, it hardened like a concrete floor made of cement, and the shovel did not enter anymore.

The microorganism, the medium and the fertilizer were put into the cured field of the test subject for the size of 30m ² to start the purification work.

As an independent nutrient microorganism, Anabaena chlorella and Rhizopus nigricans were used. Zeolite, mica, and a superabsorbent polymer were added to the contaminated soil as the autotrophic microorganism, microorganism medium, and mineral fertilizer. At this time, the independent nutrient microorganisms were 5 g based on 20% dry microorganism, 1.5 kg for the medium, 1 kg for the mineral fertilizer, and 120 to 150 g for the superabsorbent polymer.

After tilling at a depth of 30 ~ 40cm, a test group of group A was made for cultivation test. On the same day, in comparison with the experiment of heavy metal contaminant soil remediation method in the size of 30m ² of the same area, the general manure was sprayed with 5kg per 3.3m ² (pork and rice husks, The test group of group B for the cultivation test was made.

Moisture was supplied for 3 months. During the first 4 weeks, the water was supplied in a quantity of 4-6 mm per one or two times per day, and the amount of water was reduced by 50% after 4 weeks.

On May 3, 2017, stevia plants were planted in the test camps of group A and group B, respectively, and water was supplied at the same time on the same day. Rainy irrigation method, remove the cloudy day, from May 2017 to June was drenched with water of 3.3m ² 10L per once every three days until the end, every three days from July 1, 2017 until October 5 20 liters of water per one 3.3 m ² was used. The fields under cultivation test were characterized by hardening of the land and easy burning of the drought, so more water had to be supplied than ordinary fields. Stevia plants are water-loving plants. They are easy to dry on weak drought, and have a lot of water evaporation due to strong sunlight in summer.

Stevia was planted in two rows at intervals of 30 cm × 25 cm with the seedlings produced by the primary seedling process being 70 cm in height, 10 cm in height, and 30 cm in width. Prevention of insect pests, separate nutrient spraying, and laughing horses were carried out once every three days through water hose without uniform fertilization and spraying.

FIG. 1 shows a photograph of the specimen after 2 months (Jul. 3, 2017).

In the photograph of FIG. 1, group A is a photograph planted in the soil to which the biologically polluted soil purification method of the present invention is applied, and plant B is planted by a general planting method. Stevia in group A, which provided a medium for biological contamination soil purification, is showing rapid growth.

FIG. 2 shows a photograph of the specimen after three months (Aug. 3, 2017).

Stevia in Group A grew rapidly during one month, but Stevia in Group B did not show much difference after one month.

It was confirmed that the contaminated soil was greatly improved in the contaminated soil purification test through the stevia cultivation conducted according to the method of the present invention. 3 and 4 show photographs of root cross sections after 5 months of stevia cultivation (October 5, 2017). Stevia cultivated by the general cultivation method of group B did not have roots in average less than 13cm and thick roots existed in 13cm above. However, in the cultivated area of the group A treated according to the method of the present invention, the stevia roots were uniformly lowered to an average of 25 cm. Also, when the soil condition was checked, the soil up to 25cm from which the roots grew up became soft and the soil changed into the soil that the plants grew. Furthermore, it was confirmed that the amount of heavy metals contained in the soil of A group was greatly decreased.

Stevia was harvested and dried. Cultivation test A comparison of the amounts of A and B groups was made. Was 3.3m per cow ² emissions of the group B through a common cultivation cultivation is 2.8kg, is 3.3m per cow ² emissions of the group A after the cultivation process according to the method of the present invention than 1.1kg to 3.9kg cultivation of group B , Respectively.

Claims (15)

(A) an autotrophic microorganism; A microbial medium consisting of livestock feces, lime and minerals; Mineral fertilizers selected from the group consisting of kaolinite, montmorillonite, vermiculite, chlorite, gelite, ilite, zeolite, mica, elvan, germanium and bases; And introducing the superabsorbent polymer into a heavy metal contaminated soil;
(B) Rotating to a depth of 30 to 40 cm;
(C) supplying moisture in an amount of 4 to 6 mm per one or two times a day for 3 to 5 months, initially reducing the amount of 30 to 50% after 4 to 5 weeks; And
(D) d1) planting stevia; d2) growing stevia; And d3) harvesting the ground portion of the stevia when the heavy metals in the soil are absorbed and moved to the ground portion of the stevia. The method for purifying heavy metals contaminated soil according to claim 1, wherein the metallothionein enzyme capable of adsorbing heavy metals together with the autotrophic microorganisms is added to the soil. The method for purifying heavy metal contaminated soil according to claim 1, wherein an organic fertilizer rich in nitrogen and phosphoric acid components is used together with or instead of the shaft fraction. The method according to claim 1, wherein, in step (C), the water supply is performed through a drip hose. The mineral fertilizer and the organic fertilizer according to claim 1 or 3, wherein the mineral fertilizer and the organic fertilizer are used by foaming to enhance the breathability, water retention and bobbility, or granular type, How to clean. The method according to claim 1, wherein the autotrophic microorganism is an organism of Anabaena genus, Nostoc genus, Microcoleus genus, Oscillatoria genus, Calothrix genus, Phormidium genus or a mixture thereof. [Claim 6] The method according to claim 6, wherein at least one bacterium selected from the group consisting of Aspergillus genus Aspergillus oryzae, Aspergillus niger and Rhizopus nigricans belonging to the genus Aspergillus is mixed with the cyanobacteria Methods for the purification of heavy metal contaminated soil. The method according to claim 7, wherein the culture tank is selected from the group consisting of kaolinite, montmorillonite, vermiculite, chlorite, gelite, ilite, zeolite, mica, elvanite, germanium, At least one bacterium selected from the group consisting of Aspergillus genus Aspergillus oryzae, Aspergillus niger and Rhizopus nigricans with fungus fungi is mixed and cultured together Wherein the soil is contaminated with heavy metals. [6] The method of claim 1, wherein the superabsorbent polymer is a polymer capable of expanding at 100 to 200 times its magnetic volume and capable of repeated expansion and contraction, and having a content life of 5 to 10 years Methods for the purification of heavy metal contaminated soil. The method according to claim 1, wherein the autotrophic microorganism has a moisture content of 1 to 10 g, a medium of 1 to 2 kg, a mineral fertilizer of 0.1 to 1 kg, Wherein the soil is contaminated with heavy metals. The method of claim 1, wherein the heavy metals are arsenic, cadmium, copper, and lead. (A) adding a metallothionein enzyme to stevia harvested in claim 1; And
(B) fermenting the microorganism by adding at least two microorganisms selected from the group consisting of Bacillus, Lactobacillus, and Pichia. (A) squeezing the stevia harvested in claim 1;
(B) adding a stearic acid solution and a metallothionein enzyme to the residue; And
(C) fermenting two or more microorganisms selected from the group consisting of Bacillus genus, Lactobacillus genus, and Pichia genus. 13. The stevia plant produced according to claim 12. The stevia fertilizer produced according to claim 13.

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